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WO2025121395A1 - Seringue - Google Patents

Seringue Download PDF

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Publication number
WO2025121395A1
WO2025121395A1 PCT/JP2024/043139 JP2024043139W WO2025121395A1 WO 2025121395 A1 WO2025121395 A1 WO 2025121395A1 JP 2024043139 W JP2024043139 W JP 2024043139W WO 2025121395 A1 WO2025121395 A1 WO 2025121395A1
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WO
WIPO (PCT)
Prior art keywords
restricting
shaft portion
push
base end
shaft
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2024/043139
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English (en)
Japanese (ja)
Inventor
佑太郎 中久保
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Taisei Kako Co Ltd
Original Assignee
Taisei Kako Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Taisei Kako Co Ltd filed Critical Taisei Kako Co Ltd
Publication of WO2025121395A1 publication Critical patent/WO2025121395A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms

Definitions

  • the present invention relates to a syringe that can administer a medicinal liquid filled inside into the nostrils or oral cavity.
  • a syringe-type injector 901 that divides and dispenses a medicinal liquid or the like is known (Patent Document 1).
  • a syringe-type injector 901 includes a syringe 902 and a plunger 903 that is inserted into the syringe 902.
  • the plunger 903 has a first shaft member 903a and a second shaft member 903b that is held behind the first shaft member 903a.
  • the first shaft member 903a has a first elastic piece 931, a second elastic piece 932, and a third elastic piece 933, each of which is provided at a different axial position.
  • the first elastic piece 931, the second elastic piece 932, and the third elastic piece 933 have the same shape and are elastically deformable radially inward or outward.
  • the first elastic piece 931 extends from the base end 931a to the rear free end 931b, and has a locking protrusion 931d that can be locked to the rear end of the syringe 902.
  • the second elastic piece 932 is located further rearward than the first elastic piece 931.
  • the second elastic piece 932 is also provided at a different circumferential position from the first elastic piece 931.
  • the second elastic piece 932 extends from the base end 932a toward the rear free end 932b, and has a locking protrusion 932d that can be locked to the rear end of the syringe 902.
  • the third elastic piece 933 is located further rearward than the second elastic piece 932.
  • the third elastic piece 933 is also provided at the same circumferential position as the first elastic piece 931.
  • the third elastic piece 933 extends from the base end 933a toward the rear free end 933b, and has a locking protrusion 933d that can be locked to the rear end of the syringe 902.
  • the second shaft member 903b is held on the rear side of the first shaft member 903a.
  • the second shaft member 903b also includes a pressing shaft 941 disposed inside the cylindrical portion 936, and a pressing flange 942 provided on the rear of the pressing shaft 941.
  • the pressing shaft 941 has a first support portion 945a that supports the free end portion 931b from the radially inner side and engages the locking protrusion 931d with the rear end of the syringe 902 when the first elastic piece 931 enters the syringe 902.
  • the pressing shaft 941 also has a second support portion 945b that supports the free end portion 932b from the radially inner side when the second elastic piece 932 enters the syringe 902.
  • the pressing shaft 941 also has a third support portion 945c that supports the free end portion 933b from the radially inner side when the third elastic piece 933 enters the syringe 902.
  • the pressing shaft 941 has a first pressing portion 946a at its tip, which can axially press the free end 931b of the first elastic piece 931, whose engagement with the rear end of the syringe 902 by the engagement protrusion 931d has been released by the restoring force of the first elastic piece 931.
  • the pressing shaft 941 has a second pressing portion 946b that can axially press the free end 932b of the second elastic piece 932, and a third pressing portion 946c that can axially press the free end 933b of the third elastic piece 933.
  • the first pressing portion 946a is provided at the tip of the pressing shaft 941.
  • This syringe-type injector 901 can dispense the contents in the storage space in small portions at a predetermined rate by gradually pushing in the plunger 903.
  • the first elastic piece 931 enters the syringe 902.
  • a radially inward force is applied to the first elastic piece 931, and the free end 931b of the first elastic piece 931 is supported by the first support portion 945a, so that the area between the base end 931a and the free end 931b of the first elastic piece 931 elastically flexes and deforms radially inward.
  • the locking protrusion 931d of the first elastic piece 931 supported by the first support portion 945a is locked to the rear end of the syringe 902, so that the pushing of the plunger 903 is stopped and the first discharge is completed.
  • the second elastic piece 932 enters the syringe 902 while undergoing elastic deformation. Furthermore, the locking protrusion 932d of the second elastic piece 932 supported by the second support portion 945b engages with the rear end of the syringe 902, stopping the entry of the plunger 903 and ending the second ejection.
  • the pressure on the plunger 903 is released in this state, the restoring force of the second elastic piece 932 pushes and moves the second shaft member 903b rearward, resulting in the state shown in FIG. 37, making the third ejection possible.
  • the third elastic piece 933 enters the syringe 902 while undergoing elastic deformation, as shown in FIG. 37.
  • the locking protrusion 933d supported by the third support portion 945c locks onto the rear end of the syringe 902, stopping the entry of the plunger 903 and ending the third ejection.
  • the pressure on the plunger 903 is released in this state, the restoring force of the third elastic piece 933 pushes and moves the second shaft member 903b rearward, resulting in the state shown in FIG. 39, making the fourth ejection possible.
  • the plunger 903 is pushed into the syringe 902 from the state shown in FIG. 39 to the state shown in FIG. 40 to perform the fourth ejection.
  • the syringe-type injector 901 can eject the contents in the syringe 902 in four separate ejections.
  • the elastic forces of the first, second, and third elastic pieces 931, 932, and 933 are not sufficient to move the first, second, and third support portions 945a, 945b, and 945c completely backward, and the first, second, and third pressing portions 946a, 946b, and 946c may not reach the positions where they press the free ends, which may prevent the next ejection.
  • the objective of the present invention is to provide a syringe that can reliably eject multiple times.
  • the syringe of the present invention is a syringe for administering contents in portions, comprising: a barrel having a tip portion for discharging the contents and a base portion located on the axially opposite side of the tip portion; a plunger that can be pushed into the barrel from the base portion toward the tip portion, the plunger comprising a first shaft portion and a second shaft portion that is inserted into the first shaft portion and is movable in the axial direction relative to the first shaft portion; and a biasing member that biases the second shaft portion toward the base end side relative to the first shaft portion, the first shaft portion being a restricting and engaging portion for restricting the second shaft portion from moving relative to the first shaft portion due to the biasing force of the biasing member, the restricting and engaging portion being provided at intervals in the axial direction;
  • the second shaft portion includes a push-in locking portion that locks with the second shaft portion when the second shaft portion is pushed into the tube, and the second shaft portion includes a push-in locked portion that locks with
  • the restricting portion is configured to be rotatable around the starting end between a restricted retracted position where a free end on the base end side of the restricting portion is located on the radially inner side, and a restricted deployed position where the free end is located on the radially outer side.
  • the free end includes a restricted locked portion that locks with the restricting locking portion by the biasing force of the biasing member at the restricted deployed position, and a restricting release portion that moves the restricting portion from the restricted deployed position to the restricted retracted position at a position where the pushing for administering the one dose of content is completed, thereby releasing the lock of the restricted locked portion with the restricting locking portion.
  • the regulating portion may be moved to the regulating retracted position by the regulating release portion, and then moved to the regulating deployed position between a regulating locking portion that has been engaged for administering the one dose of contents among the plurality of regulating locking portions and a regulating locking portion adjacent to the regulating locking portion that has been engaged for administering the one dose of contents on the base end side in the axial direction.
  • the first shaft portion includes a first main shaft portion along the axial direction
  • the push-in locking portion includes a plurality of main shaft push-in locking portions provided on the first main shaft portion at intervals in the axial direction
  • the second shaft portion includes a second main shaft portion along the axial direction and a push-in portion provided on the second main shaft portion
  • the push-in portion includes a push-in portion configured to be rotatable around a starting end on the base end side of the push-in portion between a push-in retract position where a free end on the tip side of the push-in portion is located radially inward and a push-in deployed position where the free end is located radially outward
  • the push-in locked portion may include a main shaft push-in locked portion provided on the free end of the push-in portion, which locks with the main shaft push-in locking portion at the push-in deployed position during the push-in.
  • the syringe may also include a push-in guide portion between two axially adjacent spindle push-in locking portions that guides the push-in portion from the push-in deployment position to the push-in retract position, and the push-in guide portion may hold the push-in portion in the push-in retract position when the push-in portion moves axially from the spindle push-in locking portion on the tip side to the spindle push-in locking portion on the base side of the two spindle push-in locking portions, and release the hold of the push-in portion when the push-in portion is positioned on the base side relative to the spindle push-in locking portion on the base side.
  • FIG. 1A is a perspective view of a syringe according to an embodiment of the present invention in an initial state.
  • FIG. 1B is a left side view of a main part of the syringe in an initial state.
  • FIG. 1C is a cross-sectional view taken along line IC-IC in FIG. 1B.
  • FIG. 2A is an exploded perspective view of the syringe.
  • FIG. 2B is a front view of a second shaft portion of the plunger of the syringe.
  • FIG. 2C is a left perspective view of the second shaft portion.
  • FIG. 2D is a perspective view of the second shaft portion as viewed from the right side.
  • FIG. 2E is a left perspective view of the first shaft portion of the plunger.
  • FIG. 1A is a perspective view of a syringe according to an initial state.
  • FIG. 1B is a left side view of a main part of the syringe in an initial state.
  • FIG. 2F is a perspective view of the first shaft portion as viewed from the right side.
  • FIG. 3A is a left side view of the main parts of the syringe during the first discharge.
  • FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A.
  • FIG. 3C is a cross-sectional view taken along line IIIC-IIIC in FIG. 3A.
  • FIG. 4A is a left side view of the main part immediately before the second ejection from the syringe.
  • FIG. 4B is a cross-sectional view of a main part taken along line IVB-IVB in FIG. 4A.
  • FIG. 5A is a left side view of the main parts during the second ejection from the syringe.
  • FIG. 5A is a left side view of the main parts during the second ejection from the syringe.
  • FIG. 5B is a cross-sectional view taken along line VB-VB in FIG. 5A.
  • FIG. 5C is a cross-sectional view taken along line VC-VC in FIG. 5A.
  • FIG. 6A is a left side view of the main part immediately before the third ejection from the syringe.
  • FIG. 6B is a cross-sectional view taken along line VIB-VIB in FIG. 6A.
  • FIG. 7A is a left side view of the main parts during the third ejection from the syringe.
  • FIG. 7B is a cross-sectional view taken along line VIIB-VIIB of FIG. 7A.
  • FIG. 7C is a cross-sectional view taken along line VIIC-VIIC in FIG. 7A.
  • FIG. 8A is a left side view of the main parts immediately before the fourth discharge from the syringe.
  • FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB in FIG. 8A.
  • FIG. 9A is a left side view of the main parts during the fourth discharge from the syringe.
  • FIG. 9B is a cross-sectional view taken along line IXB-IXB in FIG. 9A.
  • FIG. 10 is a perspective view of a syringe according to a modified example in an initial state.
  • FIG. 11A is an exploded perspective view of the syringe.
  • FIG. 11B is a perspective view of the second shaft portion of the plunger of the syringe as viewed from the right side.
  • FIG. 11C is a perspective view of the first shaft portion of the plunger as viewed from the right side.
  • FIG. 12A is a left side view of a main part of the syringe in an initial state.
  • FIG. 12B is a cross-sectional view of a main portion taken along line XIIB-XIIB in FIG. 12A.
  • FIG. 13A is a left side view of the main parts during the first discharge from the syringe.
  • FIG. 13B is a cross-sectional view of a main portion taken along line XIIIB-XIIIB in FIG. 13A.
  • FIG. 13C is a cross-sectional view of a main portion taken along line XIIIC-XIIIC in FIG. 13A.
  • FIG. 14A is a left side view of the main parts immediately before the second ejection from the syringe.
  • FIG. 14B is a cross-sectional view of a main portion taken along line XIVB-XIVB in FIG. 14A.
  • FIG. 15A is a left side view of the main parts during the second ejection from the syringe.
  • FIG. 15B is a cross-sectional view of a main portion taken along line XVB-XVB in FIG. 15A.
  • FIG. 16 is a perspective view of a syringe according to another modified example in an initial state.
  • FIG. 17A is an exploded perspective view of the syringe.
  • FIG. 17B is a perspective view of the second shaft portion of the plunger of the syringe as viewed from the right side.
  • FIG. 17C is a perspective view of the first shaft portion of the plunger as viewed from the right side.
  • FIG. 18A is a left side view of a main part of the syringe in an initial state.
  • FIG. 18B is a cross-sectional view of a main portion taken along line XVIIIB-XVIIIB in FIG. 18A.
  • FIG. 18C is a cross-sectional view of a main portion taken along line XVIIIC-XVIIIC in FIG. 18A.
  • FIG. 19A is a left side view of the main parts during the first ejection from the syringe.
  • FIG. 19A is a left side view of the main parts during the first ejection from the syringe.
  • FIG. 19B is a cross-sectional view of a main portion taken along line XIXB-XIXB in FIG. 19A.
  • FIG. 19C is a cross-sectional view of a main portion taken along line XIXC-XIXC in FIG. 19A.
  • FIG. 20A is a left side view of the main parts immediately before the second ejection from the syringe.
  • FIG. 20B is a cross-sectional view of a main portion taken along line XXB-XXB in FIG. 20A.
  • FIG. 20C is a cross-sectional view of a main portion taken along line XXC-XXC in FIG. 20A.
  • FIG. 21A is a left side view of the main parts during the second ejection from the syringe.
  • FIG. 21B is a cross-sectional view of a main portion taken along line XXIB-XXIB in FIG. 21A.
  • FIG. 21C is a cross-sectional view of a main portion taken along line XXIC-XXIC in FIG. 21A.
  • FIG. 22A is a left side view of the main parts immediately before the third ejection from the syringe.
  • FIG. 22B is a cross-sectional view of a main portion taken along line XXIIB-XXIIB in FIG. 22A.
  • FIG. 22C is a cross-sectional view of a main portion taken along line XXIIC-XXIIC in FIG. 22A.
  • FIG. 23A is a left side view of the main parts during the third ejection from the syringe.
  • FIG. 23B is a cross-sectional view of a main portion taken along line XXIIIB-XXIIIB in FIG. 23A.
  • FIG. 23C is a cross-sectional view of a main portion taken along line XXIIIC-XXIIIC in FIG. 23A.
  • FIG. 24 is a perspective view of a syringe according to another modified example in an initial state.
  • FIG. 25A is an exploded perspective view of the syringe.
  • FIG. 25A is an exploded perspective view of the syringe.
  • FIG. 25B is a front view of the second shaft portion of the plunger of the syringe.
  • FIG. 25C is a left perspective view of the second shaft portion.
  • FIG. 25D is a left perspective view of the first shaft portion of the plunger.
  • FIG. 26A is a left side view of a main part of the syringe in an initial state.
  • FIG. 26B is a cross-sectional view of a main portion taken along line XXVIB-XXVIB in FIG. 26A.
  • FIG. 27A is a left side view of the main parts during the first discharge from the syringe.
  • FIG. 27B is a cross-sectional view of a main portion taken along line XXVIIB-XXVIIB in FIG. 27A.
  • FIG. 27C is a cross-sectional view of a main portion taken along line XXVIIC-XXVIIC in FIG. 27A.
  • FIG. 28A is a left side view of the main parts immediately before the second ejection from the syringe.
  • FIG. 28B is a cross-sectional view of a main portion taken along line XXVIIIB-XXVIIIB in FIG. 28A.
  • FIG. 29A is a left side view of the main parts during the second ejection from the syringe.
  • FIG. 29B is a cross-sectional view of a main portion taken along line XXIXB-XXIXB in FIG. 29A.
  • FIG. 30 is a cross-sectional view of a main portion of a syringe according to another modified example in an initial state.
  • FIG. 31 is an exploded perspective view of the syringe.
  • FIG. 32 is a front view of the second shaft portion of the plunger of the syringe.
  • FIG. 1 is a cross-sectional view of a conventional syringe-type injector in an initial state.
  • 1A and 1B are diagrams illustrating the first ejection of a conventional syringe-type injector.
  • FIG. 13 is a diagram showing a state in which the pressure applied to the conventional syringe-type injector is relaxed after the first ejection has been completed.
  • FIGS. 10A and 10B are diagrams illustrating the second ejection of a conventional syringe-type injector.
  • FIG. 13 is a diagram showing a state in which the pressure applied to the conventional syringe-type injector is relaxed after the second ejection has been completed.
  • 11A and 11B are diagrams illustrating the third ejection of a conventional syringe-type injector.
  • FIG. 13 is a diagram showing a state in which the conventional syringe-type injector has completed the third ejection and the pressure is relaxed.
  • 11A and 11B are diagrams illustrating a fourth ejection of a conventional syringe-type injector.
  • syringe 1 is a syringe for dividing and administering the contents.
  • syringe 1 is a nasal administration container that can divide and administer a mist of medicinal liquid into both nostrils.
  • This syringe 1 divides and administers the medicinal liquid into four doses, but the medicinal liquid may also be divided and administered into multiple doses of two or three or more doses.
  • the medicinal liquid is in liquid form, and is, for example, an influenza vaccine.
  • Syringe 1 is approximately cylindrical in shape.
  • the syringe 1 includes a barrel 2 having a tip portion 20 that ejects the contents and a base portion 21 that is located on the axially opposite side of the tip portion 20.
  • the syringe 1 also includes a plunger 3 and a biasing member 4.
  • the syringe 1 also includes a deregulation portion 5.
  • the syringe 1 also includes a push-in guide portion 6.
  • the syringe 1 also includes an ejection nozzle 9.
  • the side where the tip 20 of the barrel 2 is located (lower side in FIG. 1A) is the "tip side", and the side where the base end 21 of the barrel 2 is located (upper side in FIG. 1A) is the “base side”.
  • the "axial direction" of the syringe 1 is the cylindrical axis direction of the syringe 1.
  • the radial direction of the syringe 1 is also simply referred to as the "radial direction”.
  • the plunger 3 When using the syringe 1, from the initial state (Figs. 1A to 1C), the plunger 3 is pushed toward the tip to eject the first liquid medicine (Figs. 3A to 3C). Next, after passing through a state immediately before the second ejection of liquid medicine (Figs. 4A and 4B), the plunger 3 is pushed toward the tip to eject the second liquid medicine (Figs. 5A to 5C). After passing through a state immediately before the third ejection of liquid medicine (Figs. 6A and 6B), the plunger 3 is pushed toward the tip to eject the third liquid medicine (Figs. 7A to 7C). Furthermore, after passing through a state immediately before the fourth ejection of liquid medicine (Figs. 8A and 8B), the plunger 3 is pushed toward the tip to eject the fourth liquid medicine (Figs. 9A and 9B).
  • the barrel 2 is a member that contains a medicinal liquid inside (see FIG. 1A).
  • the barrel 2 includes a barrel body 22 and a finger grip 23 provided on the barrel body 22.
  • the barrel body 22 is a cylinder that contains the medicinal liquid.
  • the body tip portion 220 which is the tip portion of the barrel body 22, constitutes the tip portion 20 of the barrel 2
  • the body base portion 221 which is the base portion of the barrel body 22, constitutes the base portion 21 of the barrel 2 (see FIG. 2A).
  • the barrel body 22 includes a cylindrical body connection portion 222 that connects the body tip portion 220 and the body base portion 221.
  • the barrel body 22 also includes a flange portion 223 that extends outward (in the radially outward direction of the barrel body 22) from the entire outer periphery of one end of the body base portion 221 in the cylindrical axis direction.
  • the outer diameter of the main body tip portion 220 is smaller than the outer diameter of the main body connection portion 222.
  • the outer diameter of the main body connection portion 222 is substantially the same at any point in the axial direction.
  • the flange portion 223 is annular (e.g., circular) when viewed in the axial direction.
  • the barrel body 22 is formed, for example, from a transparent material that can withstand the internal pressure applied when administering the medicinal liquid.
  • the material of the barrel body 22 is a resin or glass that contains a cyclic olefin such as norbornene as a repeating unit.
  • the material of the barrel 2 is a transparent resin such as COP (cycloolefin polymer), which is a homopolymer of cyclic olefins, or COC (cycloolefin copolymer), which is a copolymer of cyclic olefins and ethylene, etc., or glass.
  • the finger grip 23 is a portion on which the user places their fingers when using the syringe 1. It is fitted onto the base end 221 and flange 223 of the barrel body 22.
  • the finger grip 23 includes a grip body 230 that covers the flange 223, and a pair of grip extensions 231 that extend radially outward from two opposing points on the grip body 230.
  • the grip body 230 is formed in a ring shape that surrounds the plunger 3.
  • the grip body 230 includes a body base end 232 that overlaps with the base end side of the flange 223 of the barrel body 22, and a body tip end 233 that overlaps with the tip end side of the flange 223.
  • the finger grip 23 has an ejection completion locking portion 24 that locks with the plunger 3 when the first, second, and third ejections of the syringe 1 are completed.
  • the surface of the finger grip 23 facing the base end specifically the base end surface 2320 that faces the base end of the main body base end 232, constitutes the ejection completion locking portion 24.
  • a pair of ejection completion locking portions 24 are provided at positions facing each other across the central axis of the finger grip 23. Specifically, the ejection completion locking portions 24 face each other at positions 180° apart in the circumferential direction of the finger grip 23.
  • the plunger 3 is a member that can be pushed into the barrel 2 from the base end 21 toward the tip end 20.
  • the plunger 3 also includes a first shaft portion 7 and a second shaft portion 8 that is inserted into the first shaft portion 7 and is movable in the axial direction relative to the first shaft portion 7.
  • the plunger 3 is provided with a piston 30.
  • a biasing member 4 is provided at the tip end of the second shaft portion 8, and a piston 30 is provided at the tip end of the first shaft portion 7.
  • the plunger 3 is inserted into the barrel 2 with the biasing member 4 located at the base end side and the piston 30 located at the tip end side.
  • the first shaft portion 7 is a shaft body that moves together with the second shaft portion 8 when the liquid medicine is discharged (see FIG. 1A).
  • the first shaft portion 7 is a member that surrounds the second shaft portion 8.
  • the first shaft portion 7 has a tubular shape, specifically, a substantially cylindrical shape.
  • the first shaft portion 7 also has an axially asymmetric shape.
  • the material of the first shaft portion 7 is a resin such as POM (polyacetal).
  • the first shaft portion 7 includes a first main shaft portion 70 along the axial direction, a first base end portion 71 provided at the base end portion of the first main shaft portion 70, and a first tip end portion 72 provided at the tip end portion of the first main shaft portion 70 (see FIG. 2A).
  • the first shaft portion 7 also includes a first-side convex portion 73 provided on one side, which is one position in the circumferential direction of the first main shaft portion 70, and a second-side convex portion 74 provided on the other side, which is another position in the circumferential direction of the first main shaft portion 70 (see FIG. 2E and FIG. 2F).
  • the first main shaft portion 70 is integrally molded with the first base end portion 71, the first tip end portion 72, and the convex portions 73 and 74.
  • the first main shaft portion 70 may be separate from at least one of the first base end portion 71, the first tip end portion 72, and the convex portions 73 and 74, or may be formed by combining separate members.
  • the first main shaft portion 70 is a portion that surrounds the second shaft portion 8.
  • the first main shaft portion 70 is substantially cylindrical with a uniform diameter at any portion in the axial direction.
  • a one-side slit 700 is formed on one side of the first main shaft portion 70, and an other-side slit 701 is formed on the other side of the first main shaft portion 70.
  • the slits 700, 701 are spaced apart in the circumferential direction, and in this embodiment, are located at opposing positions across the central axis of the first main shaft portion 70. Specifically, the slits 700, 701 are opposed to each other at positions 180° apart in the circumferential direction of the first main shaft portion 70.
  • the first main shaft portion 70 is formed with a number of ridges that each extend in the circumferential direction and are arranged side by side in the axial direction. Note that such irregularities do not have to be provided on the first main shaft portion 70.
  • the slits 700 and 701 each extend linearly along the axial direction. As shown in FIG. 3B, a portion of the second shaft portion 8 protrudes radially outward from the first main shaft portion 70 through the slits 700 and 701.
  • the first main shaft portion 70 has five pairs of one-side convex portions 73 spaced apart in the axial direction, sandwiching the one-side slit 700 (see FIG. 2E). Also, each pair of convex portions 731, 732, 733, 734, and 735 is provided, sandwiching the one-side slit 700.
  • the one-side convex portions 73 guide the portion of the second shaft portion 8 that protrudes radially outward from the one-side slit 700. Also, the pair of one-side convex portions 73 sandwiching the one-side slit 700 protrude from the first main shaft portion 70 in the circumferential direction by the same distance.
  • each one-side convex portion 73 guides the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4. Furthermore, the one-side convex portion 73 restricts the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • each convex portion 731, 732, 733, 734, 735 has guide surfaces 7310, 7320, 7330, 7340, 7350 facing the one-side slit 700 side that come into contact with a part of the second shaft portion 8, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the circumferential movement of the second shaft portion 8.
  • the guide surfaces 7310, 7320, 7330, 7340, and 7350 of the protrusion 73 are flat surfaces.
  • the protrusion 731 located at the base end and the protrusion 735 located at the tip end have a larger axial dimension than the protrusions 732, 733, and 734 located between them.
  • the protrusions 731, 732, 733, and 734 of the one-side protrusion 73, except for the protrusion 735 located at the most distal end in the axial direction, are provided with a restricting locking portion 76 that restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the distal end of each of the protrusions 731, 732, 733, and 734 constitutes the restricting locking portion 76.
  • the distal end faces 7311, 7321, 7331, and 7341 which are faces facing the distal ends of the protrusions 731, 732, 733, and 734, constitute the distal end face 760 of the restricting locking portion 76.
  • the restricting locking portion 76 restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force by the distal end face 760 of the restricting locking portion 76 coming into contact with a part of the second shaft portion 8.
  • the distal end face 760 of the restricting locking portion 76 is a flat surface.
  • the restricting and locking portions 76 are provided in a plurality of sets spaced apart in the axial direction, and in this embodiment, four sets are provided.
  • the restricting and locking portions 76 include a plurality of spindle restricting and locking portions 76 provided on the first spindle portion 70 so as to be spaced apart in the axial direction, and in this embodiment, the restricting and locking portions 76 are configured by four sets of spindle restricting and locking portions 76 lined up in the axial direction.
  • the first main shaft portion 70 is provided with four sets of other-side convex portions 74 spaced apart in the axial direction, sandwiching the other-side slit 701 (see FIG. 2F).
  • convex portions 741, 742, 743, and 744 are each provided in pairs, sandwiching the other-side slit 701.
  • the other-side convex portions 74 guide the portion of the second shaft portion 8 that protrudes radially outward from the other-side slit 701.
  • the pair of other-side convex portions 74 sandwiching the other-side slit 701 protrude from the first main shaft portion 70 in the circumferential direction by the same distance.
  • each other-side convex portion 74 guides the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the other-side convex portion 74 also restricts the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • the convex portions 741, 742, 743, and 744 have guide surfaces 7410, 7420, 7430, and 7440 facing the other-side slit 701 that come into contact with a part of the second shaft portion 8, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the circumferential movement of the second shaft portion 8.
  • the guide surfaces 7410, 7420, 7430, and 7440 of the convex portion 74 are flat surfaces.
  • the other-side convex portions 741, 742, and 743 excluding the convex portion 744 located at the most distal end, have a push-in locking portion 77 that locks the second shaft portion 8 when the plunger 3 is pushed into the barrel 2.
  • the base end of each of the convex portions 741, 742, and 743 constitutes the push-in locking portion 77.
  • the base end faces 7411, 7421, and 7431, which are the faces facing the base end side of the convex portions 741, 742, and 743, constitute the base end face 770 of the push-in locking portion 77.
  • the base end face 770 of the push-in locking portion 77 contacts a part of the second shaft portion 8, thereby restricting the movement of the second shaft portion 8 toward the axial tip side relative to the first shaft portion 7, and enabling the plunger 3 to be pushed into the barrel 2.
  • the base end face 770 of the push-in locking portion 77 is a flat surface.
  • the protrusion 741 located at the base end and the protrusion 744 located at the tip end have a larger axial dimension than the protrusions 742 and 743 located between them.
  • the push-in locking portions 77 are provided in a number of pairs spaced apart in the axial direction, and in this embodiment, three pairs are provided.
  • the push-in locking portions 77 also include a number of spindle push-in locking portions 77 provided on the first spindle portion 70 at intervals in the axial direction, and in this embodiment, the push-in locking portions 77 are configured by three pairs of spindle push-in locking portions 77 lined up in the axial direction.
  • the protrusions 741, 742, and 743 are provided with a push-in guide portion 6 that guides a portion of the second shaft portion 8 from a push-in deployment position to a push-in retract position between two axially adjacent main shaft push-in engagement portions 77.
  • the tip portions of the protrusions 741, 742, and 743 each constitute the push-in guide portion 6.
  • the tip surfaces 7412, 7422, and 7432, which are the surfaces facing the tip side of the protrusions 741, 742, and 743, constitute the tip surface 600 of the push-in guide portion 6.
  • the pushing guide section 6 guides a part of the second shaft section 8 from the pushing deployed position to the pushing retracted position by the tip surface 600 coming into contact with a part of the second shaft section 8. Furthermore, when the pushing section 85 moves axially from the tip side spindle pushing locking section 77 to the base side spindle pushing locking section 77 of the two spindle pushing locking sections 77, the pushing guide section 6 holds the pushing section 85 in the pushing retracted position. Furthermore, when the pushing section 85 is positioned on the base side relative to the base side spindle pushing locking section 77, the pushing guide section 6 releases the hold and allows the pushing section 85 to move to the pushing deployed position.
  • the push-in guide portions 6 are provided in a plurality of sets spaced apart in the axial direction, and in this embodiment, three sets are provided.
  • the push-in guide portions 6 include a plurality of spindle push-in guide portions 6 provided on the first spindle portion 70 so as to be spaced apart in the axial direction, and in this embodiment, the push-in guide portions 6 are composed of three sets of spindle push-in guide portions 6 lined up in the axial direction.
  • the first base end 71 is a portion that overlaps with the second base end 81 of the second shaft portion 8. In this embodiment, the first base end 71 extends radially outward from the entire outer periphery of the base end of the first main shaft portion 70.
  • the first base end 71 is annular (e.g., circular) when viewed from the axial direction. With this syringe 1, during the first ejection of medicinal liquid, the first base end 71 forms a push-in locking portion 77 that locks onto a portion of the second base end 81.
  • the first tip 72 is the portion to which the piston 30 is attached.
  • the first tip 72 is substantially cylindrical with a male thread on the outer circumferential surface.
  • the second shaft portion 8 is a shaft that is operated when ejecting the liquid medicine (see FIG. 2A).
  • the second shaft portion 8 is a member that is disposed within the first shaft portion 7.
  • the second shaft portion 8 is biased toward the base end by the biasing force of the biasing member 4.
  • the second shaft portion 8 has an axially asymmetric shape.
  • the material of the second shaft portion 8 is a resin such as POM (polyacetal). In this embodiment, the materials of the first shaft portion 7 and the second shaft portion 8 are the same, but may be different.
  • the second shaft portion 8 includes a second main shaft portion 80 along the axial direction and a second base end portion 81 provided at the base end portion of the second main shaft portion 80.
  • the second shaft portion 8 also includes a restricting portion 83 having a starting end 830 at the tip end side and a free end 831 at the base end side.
  • the restricting portion 83 is configured to be rotatable around the starting end 830 between a restricting retracted position where the free end 831 is located on the radial inside and a restricting deployed position where the free end 831 is located on the radial outside.
  • the second shaft portion 8 also includes a pushing portion 85 including a push-in interlocking portion 84 that engages with the push-in interlocking portion 77 of the first shaft portion 7 when the plunger 3 is pushed in.
  • the restricting portion 83 is provided on one circumferential side, and the pushing portion 85 is provided on the other circumferential side. Specifically, in this second shaft portion 8, the restricting portion 83 and the pushing portion 85 are provided at positions that face each other across the central axis. More specifically, the restricting portion 83 and the pushing portion 85 face each other at positions that are 180° apart in the circumferential direction of the second shaft portion 8.
  • the second shaft portion 8 also includes an ejection completion portion 87 that includes an ejection completion latched portion 86 that latches with the ejection completion latch portion 24 when ejection of the medicinal liquid is completed.
  • the second shaft portion 8 also includes a protrusion 88.
  • the protruding portion 88 is provided on one circumferential side, and the discharge completion portion 87 is provided on the other circumferential side.
  • the protruding portion 88 is aligned with the restricting portion 83 on the base end side in the axial direction.
  • the discharge completion portion 87 is aligned with the pushing portion 85 on the tip end side in the axial direction.
  • the second main shaft portion 80 is integrally molded with the second base end portion 81, the restricting portion 83, the pushing portion 85, the discharge completion portion 87, and the protruding portion 88. Note that it is separate from at least one of these, and may be formed by combining separate members.
  • the second main shaft portion 80 is a portion that fits within the first main shaft portion 70 (see FIG. 2A).
  • the second main shaft portion 80 is generally cylindrical and has a recess 90 that fits the regulating portion 83 when in the regulating retracted position (see FIG. 2B).
  • the second main shaft portion 80 is also provided with a recess 91 that fits the pushing portion 85 when in the pushing retracted position. The tip of the second main shaft portion 80 abuts against the biasing member 4.
  • the restricting portion 83 is a stopper for preventing the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the radially outer end surface 8321 of the restricting portion 83 is an inclined surface that is located radially inward toward the tip side and radially outward toward the base end side. This end surface 8321 is the surface that is pushed by the restriction release portion 5 at the position where one push is completed.
  • the restricting portion 83 is provided, at the free end 831 located on the base end side, with a restricting interlocking portion 82 that is interlocked with the restricting interlocking portion 76 of the first shaft portion 7 by the biasing force of the biasing member 4 in the restricting deployment position.
  • the restricting and locked portions 82 are provided in a pair with a gap therebetween in the circumferential direction of the second main shaft portion 80 (see FIG. 1B).
  • the surface facing the base end of the restricting portion 83 specifically the base end surface 820 of the restricting and locked portion 82, comes into contact with the tip surface 760 of the restricting and locked portion 76 of the first shaft portion 7, thereby restricting the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force (see FIG. 1C).
  • the base end surface 820 of the restricting and locked portion 82 is a flat surface.
  • the restricting portion 83 also includes a restricting guided portion 832 provided between the pair of restricting locked portions 82 (see FIG. 1B).
  • the restricting portion 83 also includes a restricting extension portion 833 that extends further toward the base end from the radially inner end of the restricting locked portion 82 (see FIG. 2B and FIG. 2C).
  • the restricted guided portion 832 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the restricted guided portion 832 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • the restricted guided portion 832 comes into contact with the one-side convex portions 732, 733, and 734 of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8320 of the restricted guided portion 832 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7320, 7330, and 7340 facing the one-side slit 700 side of the convex portions 732, 733, and 734, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8320 of the restricted guided portion 832 is a flat surface.
  • the radially outer end surface 8321 of the restricted guided portion 832 constitutes the radially outer end surface of the restricting portion 83.
  • the radially outer end surface 8321 of the restricted guided portion 832 is a flat inclined surface.
  • the restricting extension 833 is a stopper that prevents the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the restricting extension 833 is also located radially inward of a portion of the protrusion 88.
  • the restricting extension 833 is a rib that extends from the radially inner end of the restricting engaged portion 82 toward the base end along the axial direction.
  • the outer surface 8330 located radially outward of the restricting extension 833 is a flat surface.
  • the pushing portion 85 is provided on the second main shaft portion 80.
  • the base end of the pushing portion 85 is a starting end 850, and the tip end is a free end 851.
  • the pushing portion 85 is configured to be rotatable around the starting end 850 between a pushing retracted position where the free end 851 is located on the radially inner side, and a pushing deployed position where the free end 851 is located on the radially outer side.
  • the radially outer end face of the pushing portion 85 is an inclined surface that is located radially inward as it approaches the base end, and is located radially outward as it approaches the tip end.
  • the tip of the pushing portion 85 constitutes the push-in interlocking portion 84.
  • the push-in interlocking portion 84 is a main shaft push-in interlocking portion 84 provided at the free end 851 of the pushing portion 85, and is configured as a main shaft push-in interlocking portion 84 that interlocks with the main shaft push-in interlocking portion 77 of the first shaft portion 7 when pushed in the pushed-in deployed position.
  • the push-in interlocking portions 84 are provided in a pair with a gap in the circumferential direction of the second main shaft portion 80 (see FIG. 2D).
  • the surface facing the tip side of the pushing portion 85 specifically, the tip surface 840 of the push-in interlocking portion 84, hits the base end surface 770 of the push-in interlocking portion 77 of the first shaft portion 7, so that a force moving toward the tip side of the second shaft portion 8 is transmitted to the first shaft portion 7, and the first shaft portion 7 moves together with the second shaft portion 8 (see FIG. 5C).
  • the tip surface 840 of the push-in engaging portion 84 is a flat surface.
  • the base end surface 841 of the pushed-in interlocking portion 84 which faces the base end, is an inclined surface that is positioned radially inward as it approaches the base end (see FIG. 2B).
  • the base end surface 841 of the pushed-in interlocking portion 84 comes into contact with the tip end surfaces 7412, 7422, 7432, which are surfaces facing the tip end sides of the other-side convex portions 741, 742, 743 of the first shaft portion 7, and the pushed-in portion 85 moves from the pushed-in deployed position to the pushed-in retracted position (see FIGS. 3C, 5C, 7C).
  • the base end surface 841 of the pushed-in interlocking portion 84 is a flat inclined surface.
  • the pushing portion 85 includes a pushing guided portion 852 provided between a pair of pushing engaged portions 84 (see FIG. 2B).
  • the pushing portion 85 also includes a pushing extension portion 853 that extends from the radially inner end of the pushing engaged portions 84 toward the tip side.
  • the pushed-in guided portion 852 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the pushed-in guided portion 852 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • the pushed-in guided portion 852 comes into contact with the other-side convex portions 741, 742, and 743 of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8520 of the pushed-in guided portion 852 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7410, 7420, and 7430 facing the other-side slit 701 side of the convex portions 741, 742, and 743, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8520 of the pushed-in guided portion 852 is a flat surface.
  • the push-in extension 853 is a stopper that prevents the push-in portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side.
  • the push-in extension 853 is a rib that extends axially from the radially inner end of the push-in engaged portion 84 toward the tip side.
  • the push-in extension 853 is also located radially inward of a portion of the ejection completion portion 87.
  • a surface 8530 located radially outward of the push-in extension 853 is a flat surface.
  • the ejection completion portion 87 is a stopper that engages with the ejection completion locking portion 24 of the barrel 2 to restrict the plunger 3 that has moved a distance corresponding to one ejection (see Figures 2B to 2D). In this embodiment, the ejection completion portion 87 engages with the ejection completion locking portion 24 upon completion of the ejection of the medicinal liquid, excluding the final ejection.
  • the ejection completion portion 87 is also provided on the second main shaft portion 80.
  • the tip of the ejection completion portion 87 constitutes the ejection completion locked portion 86.
  • One ejection completion locked portion 86 is provided on the second main shaft portion 80. Furthermore, the surface of the ejection completion portion 87 facing the tip, specifically the tip surface 860 of the ejection completion locked portion 86, comes into contact with the base end surface 240 of the ejection completion locking portion 24 of the barrel 2, completing the movement of the second shaft portion 8 toward the tip side by the user of the syringe 1, i.e., completing one ejection of medicinal liquid.
  • the tip surface 860 of the ejection completion locked portion 86 is a flat surface.
  • the discharge completion portion 87 has a discharge guided portion 870, which is the radially outer end (see Figures 2B to 2C).
  • the discharge completion portion 87 has a discharge extension portion 871, which extends as the end on the base end side of the discharge guided portion 870 (see Figure 2B).
  • the discharge guided portion 870 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the discharge guided portion 870 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the discharge guided portion 870 comes into contact with the other-side convex portions 742, 743, and 744 of the first shaft portion 7, thereby guiding the movement along the axial direction of the second shaft portion 8 and restricting the movement in the circumferential direction of the second shaft portion 8.
  • the outer surface 8700 of the discharge guided portion 870 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7420, 7430, and 7440 facing the other-side slit 701 side of the convex portions 742, 743, and 744, thereby guiding the movement along the axial direction of the second shaft portion 8 and restricting the movement in the circumferential direction of the second shaft portion 8.
  • the outer surface 8700 of the discharge guided portion 870 is a flat surface.
  • the discharge extension portion 871 is a stopper pressing portion that presses the push-in extension portion 853 of the push-in portion 85 to prevent the push-in portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side.
  • the discharge extension portion 871 is also located radially outward of the push-in extension portion 853.
  • the discharge extension portion 871 is a rib that extends toward the base end along the axial direction as the end portion on the base end side of the discharge guided portion 870.
  • the inner surface 8710 on the radially inner side of the discharge extension portion 871 is a flat surface.
  • the inner surface 8710 of the discharge extension portion 871 abuts against the outer surface 8530 on the radially outer side of the push-in extension portion 853, thereby preventing the push-in portion 85 from opening radially outward (see Figures 3B, 5B, and 7B).
  • the protruding portion 88 is provided on the second main shaft portion 80.
  • the protruding portion 88 is provided closer to the base end than the restricting portion 83 (see FIG. 2B).
  • the protruding portion 88 has a protruding guided portion 880 which is the radially outer end.
  • the protruding portion 88 has a protruding extension portion 881 which extends as the end on the tip side of the protruding guided portion 880.
  • the protruding guided portion 880 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the protruding guided portion 880 is also a portion for restricting the circumferential movement of the second shaft portion 8 when the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the protruding guided portion 880 comes into contact with the convex portions 731, 732, and 733 of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8800 of the protruding guided portion 880 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7310, 7320, and 7330 facing the one-side slit 700 side of the convex portions 731, 732, and 733, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8800 is a flat surface.
  • the protruding extension 881 is a stopper pressing portion that presses the restricting extension 833 of the restricting portion 83 to prevent the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4 and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the protruding extension 881 is located radially outward of the restricting extension 833.
  • the protruding extension 881 is a rib that extends axially toward the tip side as an end portion on the tip side of the protruding guided portion 880.
  • the inner surface 8810 on the radial inner side of the protruding extension 881 is a flat surface.
  • the inner surface 8810 of the protruding extension 881 abuts against the outer surface 8330 on the radial outer side of the restricting extension 833, thereby preventing the restricting portion 83 from opening radially outward (see Figures 3B, 5B, and 7B).
  • the second base end 81 is a portion that overlaps with the first base end 71 of the first shaft portion 7. In this embodiment, the second base end 81 extends radially outward from the entire outer periphery of the base end of the second main shaft portion 80.
  • the second base end 81 is plate-shaped (e.g., disk-shaped) when viewed from the axial direction. With this syringe 1, during the first ejection of medicinal liquid, the second base end 81 forms a push-in interlocking portion 84 that interlocks with the first base end 71.
  • the biasing member 4 is an elastic member that is disposed inside the first shaft portion 7 together with the tip end of the second shaft portion 8. The biasing member 4 biases the second shaft portion 8 toward the base end side relative to the first shaft portion 7.
  • the biasing member 4 is, for example, a spring (specifically, a metal spring) (see FIG. 2A). Specifically, the biasing member 4 is a compression spring.
  • the biasing member 4 may be a member other than a metal spring, such as a resin spring.
  • a resin spring such as a resin spring.
  • the resin spring and the first shaft portion 7 may be integrally molded, or the resin spring and the second shaft portion 8 may be integrally molded.
  • the deregulation unit 5 moves the restricting portion 83 from the restricting deployed position to the restricting retracted position at the position where one push is completed, and releases the engagement of the restricting locked portion 82 with the restricting locking portion 76 (see Figs. 3B, 5B, and 7B).
  • the deregulation unit 5 is provided on the barrel 2, and specifically, is configured as a part of the finger grip 23. More specifically, the deregulation unit 5 is configured as the radially inner end 2321 of the grip body portion 230 of the finger grip 23, for example, the radially inner end 2321 of the body base end portion 232 of the grip body portion 230.
  • the deregulation unit 5 may be configured as a part of the barrel body 22.
  • the push-in guide portion 6 guides the push-in portion 85 of the second shaft portion 8 from the push-in deployment position to the push-in retract position between two axially adjacent main shaft push-in locking portions 77 of the first shaft portion 7.
  • the push-in guide portion 6 is provided on the first main shaft portion 70 of the first shaft portion 7, and specifically, is the tip portion of the convex portions 741, 742, and 743 of the first shaft portion 7 (see Figures 3C, 5C, and 7C).
  • the discharge nozzle 9 is the part that extracts the medicinal liquid (see FIG. 1A).
  • the discharge nozzle 9 is configured to discharge the medicinal liquid in a mist form.
  • the discharge nozzle 9 is attached to the tip 20 of the barrel body 22. Specifically, the discharge nozzle 9 is attached to the body tip 220 of the barrel body 22 by press-fitting.
  • the initial state is a state in which the syringe 1 has not yet ejected the medicinal liquid.
  • the second shaft portion 8 is biased toward the base end relative to the first shaft portion 7 by the biasing force of the biasing member 4, and the restricting portion 83 is in the restricted deployment position.
  • the restricting locked portion 82 of the restricting portion 83 is engaged with the restricting locking portion 76 of the fourth one-side protrusion 734 from the base end side of the first shaft portion 7 by the biasing force of the biasing member 4 (see FIG. 1C).
  • the base end surface 820 of the restricting locked portion 82 of the restricting portion 83 is engaged with the tip surface 7341 of the fourth one-side protrusion 734 from the base end side. This engagement restricts the movement of the second shaft portion 8 toward the base end side relative to the first shaft portion 7.
  • the second base end 81 of the second shaft portion 8 is disposed with a gap in the axial direction from the first base end 71 of the first shaft portion 7.
  • the first shaft 7 is pushed toward the tip together with the second shaft 8, as shown in Figures 3A to 3C, and the first ejection of medicinal liquid is performed.
  • the second base end 81 moves toward the tip until it abuts the first base end 71.
  • the tip surface 810 which is the surface of the second base end 81 facing the tip, abuts the base end surface 710, which is the surface of the first base end 71 facing the base end (see Figure 3A).
  • the first shaft 7 is pushed toward the tip end together with the second shaft 8 with the tip surface 810 of the second base end 81 pressed against the base end surface 710 of the first base end 71, and the first liquid medicine is discharged. That is, in the first liquid medicine discharge, the tip surface 810 of the second base end 81 is the locked surface of the push-in locked portion 84, and the base end surface 710 of the first base end 71 is the locking surface of the push-in locked portion 77. Note that from the initial state until immediately after the first discharge, the second shaft 8 is biased toward the base end by the biasing force of the biasing member 4 against the first shaft 7.
  • the first liquid medicine ejection is completed when the ejection completion locked portion 86 of the ejection completion portion 87 of the second shaft portion 8 is locked to the ejection completion locking portion 24 of the barrel 2 (see FIG. 3B). Specifically, the first liquid medicine ejection is completed when the tip surface 860 of the ejection completion locked portion 86 is locked to the base end surface 240 of the ejection completion locking portion 24.
  • the restricting portion 83 of the second shaft portion 8 is moved from the restricted deployment position to the retracted position by the restricting release portion 5. Specifically, the restricting portion 83 is deflected radially inward by the radially outer end surface 8321 of the restricting portion 83 hitting the restricting release portion 5 provided on the barrel 2, which in this embodiment is the radially inner end portion 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position.
  • the restricting interlocking portion 82 of the second shaft portion 8 also moves radially inward, and the locking of the restricting interlocking portion 82 to the restricting interlocking portion 76 of the first shaft portion 7 is released. Then, the second shaft portion 8 is moved toward the base end side relative to the first shaft portion 7 by the biasing force, and is in the state immediately before the second ejection shown in Figures 4A and 4B.
  • the restricting portion 83 is moved to the restricting retracted position by the restricting release portion 5, and then moves to the restricting deployed position between the restricting locking portion 76 that was previously locked for one dose of content administration and the (next) restricting locking portion 76 adjacent to this restricting locking portion 76 on the base end side in the axial direction (see FIG. 4B).
  • the restricting portion 83 moves to the restricting retracted position by the restricting release portion 5, it moves to the restricting deployed position between the restricting locking portion 76 of the fourth one-side protrusion 734 from the base end side of the first shaft portion 7 that was locked in the initial state, and the restricting locking portion 76 of the third one-side protrusion 733 from the base end side.
  • the pushing portion 85 of the second shaft portion 8 is located on the tip side of the other-side convex portion 743 located third from the base end side (see FIG. 3C).
  • the base end surface 841 of the pushing-in engaging portion 84 of the pushing portion 85 comes into contact with the tip surface 7432 of the other-side convex portion 743 third from the base end side of the first shaft portion 7 (see FIG. 4B).
  • the pushing portion 85 is pushed radially inward to the pushed-in retracted position, passes through the other-side convex portion 743 third from the base end side to the base end side, and moves between the other-side convex portion 742 second from the base end side and the other-side convex portion 743 third from the base end side.
  • the pushing portion 85 is moved to the pushing retracted position by the tip surface 7432 of the third other-side protrusion 743, and then moves to the pushing deployed position at a position closer to the base end than the third other-side protrusion 743 from the base end.
  • the pushing guide portion 6 releases the holding of the pushing portion 85 in the pushing retracted position.
  • the restricted guided portion 832 moves while being guided by the fourth one-side convex portion 734 from the base end side. Specifically, the restricted guided portion 832 is guided by the guide surface 7340 facing the one-side slit 700 of the one-side convex portion 734, and the second shaft 8 moves along the axial direction.
  • the pressed-in guided portion 852 moves while being guided by the third other-side convex portion 743 from the base end side. Specifically, the pressed-in guided portion 852 is guided by the guide surface 7430 facing the other-side slit 701 of the other-side convex portion 743, and the second shaft portion 8 moves along the axial direction.
  • the discharge guided portion 870 moves while being guided by the fourth other-side convex portion 744 from the base end side. Specifically, the discharge guided portion 870 is guided by the guide surface 7440 facing the other-side slit 701 of the other-side convex portion 744, and the second shaft portion 8 moves along the axial direction.
  • the protruding guided portion 880 moves while being guided by the third one-side convex portion 733 from the base end side. Specifically, the protruding guided portion 880 is guided by the guide surface 7330 facing the one-side slit 700 of the one-side convex portion 733, and the second shaft portion 8 moves along the axial direction.
  • the inner surface 8810 of the protruding extension portion 881 abuts against the radially outer surface 8330 of the restricting extension portion 833, thereby preventing the restricting portion 83 from opening radially outward (see FIG. 3B).
  • the inner surface 8710 of the ejection extension portion 871 abuts against the radially outer surface 8530 of the pushing extension portion 853, thereby preventing the pushing portion 85 from opening radially outward.
  • the restricting and locked portion 82 of the restricting portion 83 of the second shaft portion 8 is locked by the biasing force of the biasing member 4 to the restricting and locked portion 76 of the third one-side protrusion 733 from the base end side of the first shaft portion 7 (see FIG. 4B).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is locked to the tip end surface 7331 of the third one-side protrusion 733 from the base end side. This locking restricts the movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the second base end portion 81 of the second shaft portion 8 is disposed with a gap in the axial direction from the first base end portion 71 of the first shaft portion 7.
  • the tip surface 840 abuts the base end surface 7431 of the other-side protrusion 743 that is the third from the base end side.
  • the second shaft portion 8 is biased toward the base end side relative to the first shaft portion 7 by the biasing force of the biasing member 4.
  • the second liquid medicine ejection is completed when the tip surface 860 of the ejection completion locked portion 86 is locked to the base end surface 240 of the ejection completion locking portion 24 (see FIG. 5B).
  • the restricting portion 83 of the second shaft portion 8 is deflected radially inward as the radially outer end surface 8321 of the restricting portion 83 hits the radially inner end portion 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position.
  • the restricting locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricting locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released. Then, the second shaft portion 8 moves to the base end side relative to the first shaft portion 7 by the biasing force, and is in the state immediately before the third ejection shown in FIG. 6A and FIG. 6B.
  • the restricting portion 83 is moved to the restricted retracted position by the restricting release portion 5, and then moves to the restricted deployed position between the restricting locking portion 76 of the third one-side protrusion 733 from the base end of the first shaft portion 7, which was engaged immediately before the second discharge, and the restricting locking portion 76 of the second one-side protrusion 732 from the base end.
  • the base end surface 841 of the pushed-in locked portion 84 of the pushing portion 85 comes into contact with the tip surface 7422 of the second other-side convex portion 742 from the base end side of the first shaft portion 7, causing the pushing portion 85 to be pushed radially inward and into the pushed-in retracted position (see FIG. 6B).
  • the pushing portion 85 passes through the second other-side convex portion 742 from the base end side to the base end side, and moves between the other-side convex portion 741 located at the most base end side and the second other-side convex portion 742 from the base end side.
  • the restricted guided portion 832 is guided by the guide surface 7330 of the third one-side convex portion 734 from the base end side, and the second shaft portion 8 moves along the axial direction.
  • the pressed guided portion 852 is guided by the guide surface 7420 of the second other-side convex portion 742 from the base end side, and the second shaft portion 8 moves along the axial direction.
  • the discharge guided portion 870 is guided by the guide surface 7430 of the third other-side convex portion 743 from the base end side, and the second shaft portion 8 moves along the axial direction.
  • the protruding guided portion 880 is guided by the guide surface 7320 of the second one-side convex portion 732 from the base end side, and the second shaft portion 8 moves along the axial direction.
  • the inner surface 8810 of the protruding extension portion 881 abuts against the radially outer surface 8330 of the restricting extension portion 833, thereby preventing the restricting portion 83 from opening radially outward (see FIG. 5B).
  • the inner surface 8710 of the ejection extension portion 871 abuts against the radially outer surface 8530 of the pushing extension portion 853, thereby preventing the pushing portion 85 from opening radially outward.
  • the restricting and locked portion 82 of the restricting portion 83 of the second shaft portion 8 is locked to the restricting and locked portion 76 of the second one-side protrusion 732 from the base end side of the first shaft portion 7 by the biasing force of the biasing member 4 (see FIG. 6B).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is locked to the tip end surface 7321 of the second one-side protrusion 732 from the base end side. This locking restricts the movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the second base end portion 81 of the second shaft portion 8 is disposed with a gap in the axial direction from the first base end portion 71 of the first shaft portion 7.
  • the first shaft 7 is pushed toward the tip together with the second shaft 8, as shown in FIG. 7A to FIG. 7C, and the third ejection of the medicinal liquid is performed.
  • the first shaft 7 is pushed toward the tip together with the second shaft 8 with the tip surface 840 of the push-in engaging portion 84 abutting the base end surface 7421 of the second other-side protrusion 742 from the base end side (see FIG. 7C).
  • the second shaft 8 is biased toward the base end by the biasing force of the biasing member 4 against the first shaft 7.
  • the third liquid medicine discharge is completed when the tip surface 860 of the discharge completion locked portion 86 is locked to the base end surface 240 of the discharge completion locking portion 24 (see FIG. 7B).
  • the restricting portion 83 of the second shaft portion 8 is deflected radially inward as the radially outer end surface 8321 of the restricting portion 83 hits the radially inner end portion 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position.
  • the restricting locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricting locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released.
  • the second shaft portion 8 moves to the base end side relative to the first shaft portion 7 by the biasing force, and is in the state immediately before the fourth discharge shown in FIG. 8A and FIG. 8B.
  • the restricting portion 83 is moved to the restricted retracted position by the restricting release portion 5, and then moves to the restricted deployed position between the restricting locking portion 76 of the second one-side protrusion 732 from the base end of the first shaft portion 7 that was engaged immediately before the third discharge, and the restricting locking portion 76 of the one-side protrusion 731 located closest to the base end.
  • the base end surface 841 of the push-in interlocking portion 84 of the push-in portion 85 comes into contact with the tip surface 7412 of the other-side convex portion 741 located at the most proximal side of the first shaft portion 7, causing the push-in portion 85 to be pushed radially inward and into the push-in retracted position (see FIG. 8B).
  • the push-in portion 85 passes the other-side convex portion 741 located at the most proximal side to the base end side, and moves further to the base end side than the other-side convex portion 741 located at the most proximal side.
  • the restricted guided portion 832 is guided by the guide surface 7320 of the one-side convex portion 732 that is second from the base end side, and the second shaft 8 moves along the axial direction.
  • the pressed-in guided portion 852 is guided by the guide surface 7410 of the other-side convex portion 741 located at the most base end side, and the second shaft 8 moves along the axial direction.
  • the discharge guided portion 870 is guided by the guide surface 7420 of the other-side convex portion 742 that is second from the base end side, and the second shaft 8 moves along the axial direction.
  • the protruding guided portion 880 is guided by the guide surface 7310 of the one-side convex portion 731 located at the most base end side, and the second shaft 8 moves along the axial direction.
  • the inner surface 8810 of the protruding extension portion 881 abuts against the radially outer surface 8330 of the restricting extension portion 833, thereby preventing the restricting portion 83 from opening radially outward (see FIG. 7B).
  • the inner surface 8710 of the ejection extension portion 871 abuts against the radially outer surface 8530 of the pushing extension portion 853, thereby preventing the pushing portion 85 from opening radially outward.
  • the restricting and locked portion 82 of the restricting portion 83 of the second shaft portion 8 is locked by the biasing force of the biasing member 4 to the restricting and locked portion 76 of the one-side convex portion 731 located at the most proximal side of the first shaft portion 7 (see FIG. 8B).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is locked to the tip end surface 7311 of the one-side convex portion 731 located at the most proximal side.
  • This locking restricts the movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the second base end portion 81 of the second shaft portion 8 is disposed with a gap in the axial direction from the first base end portion 71 of the first shaft portion 7.
  • the second shaft 8 (specifically, the second base end 81) toward the tip from a state immediately before the fourth ejection (see FIG. 8 and FIG. 8B)
  • the first shaft 7 is pushed toward the tip together with the second shaft 8, as shown in FIG. 9A and FIG. 9B, and the second ejection of the drug solution is performed.
  • the first shaft 7 is pushed toward the tip together with the second shaft 8 with the tip surface 840 of the push-in engaging portion 84 abutting the base end surface 7411 of the other-side convex portion 741 located at the most base end (see FIG. 9B).
  • the second shaft 8 is biased toward the base end by the biasing force of the biasing member 4 against the first shaft 7.
  • the fourth liquid medicine ejection is completed when the piston 30 attached to the first tip 72 of the first shaft 7 hits the tip of the body connection part 222 of the barrel body 22.
  • the engagement between the restricting locking portion 76 and the restricting locked portion 82 restricts the movement of the second shaft portion 8 toward the base end relative to the first shaft portion 7 due to the force applied by the biasing member 4, while when the user presses the plunger 3 to perform the second, third, or fourth ejection, the engagement between the pushing locking portion 77 and the pushing locked portion 84 ensures that the entire plunger 3 can be pushed in to eject the liquid.
  • the restriction release section 5 releases the engagement between the restriction locking section 76 and the restriction locked section 82, so that the second shaft section 8 moves toward the base end side relative to the first shaft section 7 by the biasing force of the biasing member 4, and the restriction locked section 82 forms a next engagement (restriction) with the next restriction locking section 76 located on the base end side in the axial direction relative to the restriction locking section 76 that was engaged (previously engaged) for one dose of the contents, and the push-in locking section 77 and the push-in locked section 84 form the next engagement (pushing).
  • the syringe 1 is reliably switched to preparation for the next ejection, so multiple ejections can be reliably performed.
  • the pushing portion 85 of the second shaft portion 8 rotates between a pushing deployed position and a pushing retracted position, thereby switching between engagement and disengagement between the spindle pushing locking portion 77 of the first shaft portion 7 and the spindle pushing locked portion 84 of the second shaft portion 8. Therefore, after one discharge is completed, the spindle pushing locked portion 84 is securely locked to the next spindle pushing locking portion 77 located axially toward the base end side of the previously locked spindle pushing locking portion 77.
  • the pushing portion 85 switches to the pushing-in deployed position at a position on the axial base end side of the next spindle pushing-in locking portion 77, so that after one discharge is completed, the spindle pushing-in locked portion 84 is securely locked to the next spindle pushing-in locking portion 77.
  • the syringe of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
  • the configuration of one embodiment can be added to the configuration of another embodiment, and part of the configuration of one embodiment can be replaced with the configuration of another embodiment.
  • part of the configuration of one embodiment can be deleted.
  • each component of the syringe 1 may be different from that described above.
  • the first shaft portion 7 and the second shaft portion 8 of the plunger 3 were axially asymmetric, but they may be axially symmetric.
  • the finger grip 23 in addition to the grip body 230 and a pair of grip extensions 231, the finger grip 23 includes an annular grip base end extension 234 that extends from the radially inner end of the grip body 230 toward the base end and surrounds the plunger 3 (see Figures 10 and 11A).
  • the finger grip 23 also includes the grip base end extension 234 as an ejection completion locking portion 24 that engages with the plunger 3 when the first ejection of the syringe 1 is completed (see Figure 13B).
  • the base end surface 240 of the ejection completion locking portion 24 is composed of a base end surface 2340 that faces the base end side of the grip base end extension 234.
  • two points of the base end surface 2340 that face each other across the center line of the grip body 230 are the points where the plunger 3 is engaged.
  • the base end faces 240 of the discharge completion locking portions 24 face each other at positions 180° apart in the circumferential direction of the finger grip 23.
  • the first shaft portion 7 includes a first main shaft portion 70, a first base end portion 71, and a first tip end portion 72, as well as a plurality of convex portions 75 provided on one side and the other side of the first main shaft portion 70.
  • the first main shaft portion 70 is provided with two sets of convex portions 75 spaced apart in the axial direction, sandwiching slits 700, 701, respectively.
  • the protruding dimensions of the convex portions 75 relative to the slits 700, 701 are all the same.
  • the convex portion 751 provided on the base end side has a larger axial dimension than the convex portion 752 provided on the tip end side.
  • the convex portions 75 each guide the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the convex portions 75 also restrict the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • the guide surfaces 7510, 7520 of each of the convex portions 751, 752 facing the slits 700, 701 come into contact with a part of the second shaft portion 8, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the circumferential movement of the second shaft portion 8.
  • the guide surfaces 7510, 7520 of the convex portions 75 are flat surfaces.
  • the convex portions 751 and 752 are provided with a restricting locking portion 76 that restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the tip of each of the convex portions 751 and 752 constitutes the restricting locking portion 76.
  • the tip faces 7511 and 7521 that face the tip side of the convex portions 751 and 752 constitute the tip face 760 of the restricting locking portion 76.
  • the restricting locking portion 76 restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force by the tip face 760 of the restricting locking portion 76 coming into contact with a part of the second shaft portion 8.
  • the tip face 760 is a flat surface.
  • the restricting and locking portions 76 are provided in pairs, spaced apart in the axial direction, on either side of the central axis of the first shaft portion 7.
  • the restricting and locking portions 76 are composed of two pairs of spindle restricting and locking portions 76 arranged in the axial direction, on either side of the central axis of the first shaft portion 7.
  • the restricting and locking portions 76 face each other at positions spaced 180° apart in the circumferential direction of the first shaft portion 7.
  • the protruding portion 751 located on the base end side has a push-in locking portion 77 that locks with the second shaft portion 8 when the plunger 3 is pushed into the barrel 2.
  • a set of push-in locking portions 77 are provided in the axial direction.
  • the base end of the protruding portion 751 constitutes the push-in locking portion 77.
  • the base end surface 7512, which is the surface of the protruding portion 751 facing the base end side, constitutes the base end surface 770 of the push-in locking portion 77.
  • the base end surface 770 of the push-in locking portion 77 comes into contact with a part of the second shaft portion 8, thereby restricting the movement of the second shaft portion 8 toward the axial tip side relative to the first shaft portion 7, and enabling the plunger 3 to be pushed into the barrel 2.
  • the base end surface 770 of the push-in locking portion 77 is a flat surface.
  • the push-in locking portions 77 are provided in pairs on either side of the central axis of the first shaft portion 7. Specifically, the push-in locking portions 77 face each other at positions spaced 180° apart in the circumferential direction of the first shaft portion 7. In this embodiment, the push-in locking portions 77 are composed of a pair of main shaft push-in locking portions 77.
  • the protrusion 751 located on the base end side is provided with a push-in guide portion 6 that guides a portion of the second shaft portion 8 from a push-in deployment position to a push-in retract position.
  • the tip of the protrusion 751 constitutes the push-in guide portion 6.
  • the tip surface 7511, which is the surface facing the tip side of the protrusion 751, constitutes the tip surface 600 of the push-in guide portion 6.
  • the push-in guide portion 6 guides a portion of the second shaft portion 8 from the push-in deployment position to the push-in retract position by the tip surface 600 of the push-in guide portion 6 coming into contact with a portion of the second shaft portion 8.
  • the push-in guide parts 6 are provided in pairs on either side of the central axis of the first shaft part 7. Specifically, the push-in guide parts 6 face each other at positions 180° apart in the circumferential direction of the first shaft part 7.
  • the push-in guide parts 6 are composed of main shaft push-in guide parts 6 that are provided in pairs on either side of the central axis of the first shaft part 7.
  • the first base end 71 forms a push-in locking portion 77 that locks onto a part of the second base end 81 during the first ejection of the liquid medicine.
  • the second shaft portion 8 includes a second main shaft portion 80 and a second base end portion 81, as well as a restricting portion 83 having a starting end 830 at the tip end and a free end 831 at the base end.
  • the restricting portion 83 is configured to be rotatable around the starting end 830 between a restricting retracted position where the free end 831 is located on the radially inner side and a restricting deployed position where the free end 831 is located on the radially outer side.
  • the second shaft portion 8 also includes a pushing portion 85 including a pushing interlocking portion 84 that interlocks with the pushing interlocking portion 77 of the first shaft portion 7 when the plunger 3 is pushed in.
  • the second shaft portion 8 also includes a discharge completion portion 87 including a discharge completion interlocking portion 86 that interlocks with the discharge completion interlocking portion 24 when the discharge of the medicinal liquid is completed, and a protruding portion 89.
  • the regulating portions 83 are provided in pairs at positions facing each other across the central axis of the second main shaft portion 80 in the circumferential direction. Specifically, the regulating portions 83 face each other at positions 180° apart in the circumferential direction of the second main shaft portion 80.
  • the pushing portion 85, the discharge completion portion 87, and the protruding portions 88 and 89 are provided in pairs at positions facing each other across the central axis of the second main shaft portion 80 in the circumferential direction. Specifically, at least one of the pushing portion 85, the discharge completion portion 87, and the protruding portions 88 and 89, and in this embodiment, all of these, face each other at positions 180° apart in the circumferential direction of the second main shaft portion 80.
  • the protruding portion 89, the pushing portion 85, the discharge completion portion 87, and the regulating portion 83 are arranged in order from the base end side to the tip end side in the axial direction.
  • the second main shaft portion 80 includes a second main wall portion 800 having a substantially rectangular plate shape extending along the axial direction, and a second sub-wall portion 801 extending perpendicular to the second main wall portion 800 at the center of the width direction of the second main wall portion 800.
  • the second main wall portion 800 has a partially cut-out shape, and the remaining portion becomes the protrusion portion 89, the pushing portion 85, the discharge completion portion 87, and the regulating portion 83.
  • the second sub-wall portion 801 fits into the first shaft portion 7. This fitting restricts the circumferential movement of the second shaft portion 8 while restricting the movement of the second shaft portion 8 relative to the first shaft portion 7 due to the biasing force of the biasing member 4. This fitting also restricts the circumferential movement of the second shaft portion 8 when the plunger 3 is pushed in or when the second shaft portion 8 moves axially relative to the first shaft portion 7 due to the biasing force.
  • the restricting portion 83 has a restricting locked portion 82 at its free end 831 which is locked to the restricting locking portion 76 of the first shaft portion 7 by the biasing force of the biasing member 4 in the restricting deployed position.
  • the base end of the restricting portion 83 constitutes the restricting locked portion 82.
  • a set of restricting and locked portions 82 are provided on the restricting portion 83 (see FIG. 11B). Furthermore, the surface of the restricting portion 83 facing the base end, specifically, the base end surface 820 of the restricting and locked portion 82, comes into contact with the tip surface 760 of the restricting and locked portion 76 of the first shaft portion 7, thereby restricting the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force (see FIG. 12B and FIG. 14B).
  • the base end surface 820 of the restricting and locked portion 82 is a flat surface.
  • the restricting portion 83 includes a restricting guided portion 832 provided on the radially outer side of the pair of restricting and locked portions 82 (see FIG. 11B).
  • the restricting portion 83 also includes a restricting extension portion 833 that extends further toward the base end from the radially inner end of the restricting and locked portions 82.
  • the restricted guided portion 832 is a portion for guiding the movement of the second shaft portion 8 in the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the regulated guided portion 832 comes into contact with the convex portion 752 of the first shaft portion 7, thereby guiding the movement along the axial direction of the second shaft portion 8.
  • the outer surface 8320 of the regulated guided portion 832 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7520 of the convex portion 752 facing the slits 700, 701, thereby guiding the movement along the axial direction of the second shaft portion 8.
  • the outer surface 8320 of the regulated guided portion 832 is a flat surface.
  • the restricting extension 833 is a stopper that prevents the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the restricting extension 833 is also located radially inside a portion of the discharge completion portion 87.
  • the restricting extension 833 is a rib that extends from the radially inner end of the restricting engaged portion 82 toward the base end along the axial direction.
  • the outer surface 8330 located radially outward of the restricting extension 833 is a flat surface.
  • the pushing portion 85 has a starting end 850 at the base end and a free end 851 at the tip end, and is configured to be rotatable around the starting end 850 between a pushing retracted position where the free end 851 is located on the radially inner side and a pushing deployed position where the free end 851 is located on the radially outer side.
  • the tip of the pushing portion 85 constitutes the pushing engaged portion 84.
  • the pushing engaged portion 84 is a spindle pushing engaged portion 84 provided at the free end 851 of the pushing portion 85, and is configured as the spindle pushing engaged portion 84 that engages with the spindle pushing engaged portion 77 of the first shaft portion 7 when pushed in the pushing deployed position.
  • Each push-in portion 85 is provided with one push-in interlocking portion 84.
  • the surface of the push-in portion 85 facing the tip specifically the tip surface 840 of the push-in interlocking portion 84, comes into contact with the base end surface 770 of the push-in interlocking portion 77 of the first shaft portion 7, and a force moving toward the tip of the second shaft portion 8 is transmitted to the first shaft portion 7, causing the first shaft portion 7 to move together with the second shaft portion 8 (see FIG. 15B).
  • the tip surface 840 of the push-in interlocking portion 84 is a flat surface.
  • the base end face 841 of the pushed-in interlocking portion 84 which faces the base end, is an inclined surface that is positioned radially inward as it approaches the base end.
  • the base end face 841 of the pushed-in interlocking portion 84 comes into contact with the tip end face 7511, which faces the tip end of the convex portion 751 of the first shaft portion 7, and the pushed-in portion 85 moves from the pushed-in deployed position to the pushed-in retracted position (see FIG. 13C).
  • the base end face 841 of the pushed-in interlocking portion 84 is a flat surface.
  • the push-in portion 85 has a push-in extension portion 853 that extends further toward the tip side from the radially inner end of the push-in engaging portion 84 (see FIG. 11B).
  • the push-in extension 853 is a stopper that prevents the push-in portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side.
  • the push-in extension 853 is a rib that extends axially from the radially inner end of the push-in engaged portion 84 toward the tip side.
  • the push-in extension 853 is also located radially inward of a portion of the ejection completion portion 87.
  • the outer surface 8530 located radially outward of the push-in extension 853 is a flat surface.
  • the ejection completion portion 87 is a stopper that engages with the ejection completion locking portion 24 of the barrel 2 to restrict the plunger 3 from moving a distance corresponding to one ejection (see Figures 13A and 13B).
  • the tip of the ejection completion portion 87 constitutes the ejection completion locked portion 86.
  • the ejection completion locked portion 86 is provided in a set on the second main shaft portion 80.
  • the surface facing the tip of the ejection completion portion 87 comes into contact with the base end surface 240 of the ejection completion locking portion 24 of the barrel 2, completing the movement of the plunger 3 toward the tip side by the user of the syringe 1, i.e., completing the first ejection of the medicinal liquid (see Figure 13B).
  • the tip surface 860 of the ejection completion locked portion 86 is a flat surface.
  • the discharge completion portion 87 has a discharge guided portion 870, which is the radially outer end (see FIG. 11B).
  • the discharge completion portion 87 also has discharge extension portions 871, 872, which extend as the base end and tip end of the discharge guided portion 870, respectively.
  • the discharge guided portion 870 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the discharge guided portion 870 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the discharge guided portion 870 comes into contact with the convex portion 752 on the tip side of the first shaft portion 7, thereby guiding the movement along the axial direction of the second shaft portion 8 and restricting the movement in the circumferential direction of the second shaft portion 8.
  • the outer surface 8700 of the discharge guided portion 870 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7520 of the convex portion 752 facing the slits 700, 701, thereby guiding the movement along the axial direction of the second shaft portion 8 and restricting the movement in the circumferential direction of the second shaft portion 8.
  • the outer surface 8700 of the discharge guided portion 870 is a flat surface.
  • the discharge extension 871 is a stopper pressing portion that presses the push-in extension 853 of the push-in portion 85 to prevent the push-in portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side (see FIG. 11B).
  • the discharge extension 871 is located radially outward of the push-in extension 853.
  • the discharge extension 871 is a rib that extends toward the base end along the axial direction as the end portion on the base end side of the discharge guided portion 870.
  • the inner surface 8710 on the radially inner side of the discharge extension 871 is a flat surface. The inner surface 8710 of the discharge extension 871 abuts against the outer surface 8530 on the radially outer side of the push-in extension 853, thereby preventing the push-in portion 85 from opening radially outward.
  • the discharge extension 872 is a stopper pressing portion that presses the restricting extension 833 of the restricting portion 83 to prevent the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4 and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the discharge extension 872 is located radially outward of the restricting extension 833.
  • the discharge extension 872 is a rib that extends toward the tip side along the axial direction as the end portion on the tip side of the discharge guided portion 870.
  • the inner surface 8720 on the radial inner side of the discharge extension 872 is a flat surface. The inner surface 8720 of the discharge extension 872 abuts against the outer surface 8330 on the radial outer side of the restricting extension 833, thereby preventing the restricting portion 83 from opening radially outward.
  • the protruding portion 89 is provided on the second main shaft portion 80.
  • the protruding portion 89 also has a protruding guided portion 890, which is the radially outer end portion.
  • the protruding guided portion 890 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the protruding guided portion 890 is also a portion for restricting the circumferential movement of the second shaft portion 8 when the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the protruding guided portion 890 comes into contact with the convex portion 751 on the base end side of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8900 of the protruding guided portion 890 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7510 of the convex portion 751 facing the slits 700, 701, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8900 is a flat surface.
  • the deregulation unit 5 moves the regulating unit 83 from the regulating deployed position to the regulating retracted position, and releases the engagement of the regulating interlocked unit 82 with the regulating interlocking unit 76 (see FIG. 13B).
  • the deregulation unit 5 is formed by the radially inner end 2321 of the grip body 230 of the finger grip 23, for example, the radially inner end 2321 of the body base end 232 of the grip body 230.
  • the pushing guide portion 6 guides the pushing portion 85 of the second shaft portion 8 from the pushing deployed position to the pushing retracted position when the pushing portion 85 passes over the base end side protrusion 751 from the tip side to the base end side.
  • the pushing guide portion 6 is provided on the main shaft portion 70 of the first shaft portion 7, and specifically, is the tip surface 7511 of the protrusion 751 of the first shaft portion 7 (see FIG. 13C).
  • the initial state is a state in which the syringe 1 has not yet dispensed any medicinal liquid.
  • the restricting and locked portion 82 of the restricting portion 83 of the second shaft portion 8 is locked to the restricting and locked portion 76 of the protrusion 752 on the tip side of the first shaft portion 7 by the biasing force of the biasing member 4.
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is locked to the tip surface 7521 of the protrusion 752 on the tip side (see Figure 12B). This lock restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the first liquid medicine ejection is completed when the ejection completion latched portion 86 of the ejection completion portion 87 is latched to the ejection completion latching portion 24 of the barrel 2. Specifically, the first liquid medicine ejection is completed when the tip surface 860 of the ejection completion latched portion 86 is latched to the base end surface 240 of the ejection completion latching portion 24 (see FIG. 13B).
  • the restricting portion 83 of the second shaft portion 8 is moved from the restricted deployment position to the restricted retracted position by the restricting release portion 5. Specifically, the restricting portion 83 is deflected by the radially outer end face 8321 of the restricting portion 83 hitting the radially inner end 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position. As a result, the restricted locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricted locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released. Then, the second shaft portion 8 moves toward the base end side relative to the first shaft portion 7 by the biasing force of the biasing member 4, and is in the state immediately before the second discharge shown in Figures 14A and 14B.
  • the restricting portion 83 is moved to the restricting retracted position by the restricting release portion 5, and then moves to the restricting deployed position between the restricting locking portion 76 of the protrusion 752 on the tip side of the first shaft portion 7, which was locked in the initial state, and the restricting locking portion 76 of the protrusion 751 on the base side.
  • the pushing portion 85 of the second shaft portion 8 is located on the tip side of the base-side convex portion 751 (see FIG. 13C).
  • the base end surface 841 of the pushing-in interlocking portion 84 of the pushing portion 85 hits the tip surface 7511 of the base-side convex portion 751, so that the pushing portion 85 is pushed radially inward to the pushing-in retracted position, passes through the base-side convex portion 751 to the base end side, and moves to a position on the base side of the base-side convex portion 751 (see FIG. 15B).
  • the pushing portion 85 is moved to the pushing-in retracted position by the base-side convex portion 751, and then reaches the pushing-in deployed position at a position on the base side of the base-side convex portion 751.
  • the restricted guided portion 832 moves while being guided by the convex portion 752 on the tip side (see FIG. 14A).
  • the discharge guided portion 870 moves while being guided by the convex portion 752 on the tip side.
  • the protruding guided portion 890 moves while being guided by the convex portion 751 on the base end side.
  • the second shaft portion 8 is engaged by the biasing force of the biasing member 4 with the restricting and locked portion 82 of the restricting portion 83 against the restricting and locked portion 76 of the protruding portion 751 on the base end side of the first shaft portion 7 (see FIG. 14B).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is engaged with the tip end surface 7511 of the protruding portion 751 on the base end side. This engagement restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the second liquid medicine ejection is completed when the piston 30 attached to the first tip 72 of the first shaft 7 hits the inner tip surface of the body connection part 222 of the barrel body 22.
  • the finger grip 23 has a grip base end extension 234 as an ejection completion locking portion 24 that locks with the plunger 3 when the first and second ejections of the syringe 1 are completed.
  • the base end surface 240 of the ejection completion locking portion 24 is composed of a base end surface 2340 that faces the base end side of the grip base end extension 234.
  • the first shaft portion 7 includes a first main shaft portion 70, a first base end portion 71, and a first tip portion 72, as well as a plurality of convex portions 75 provided on one side and the other side of the first main shaft portion 70.
  • the first main shaft portion 70 is provided with five pairs of convex portions 75 spaced apart in the axial direction, sandwiching slits 700 and 701 between them.
  • the axial dimensions of the first and second convex portions 751 and 752 from the base end side among the convex portions 75 in the axial direction are smaller than the third, fourth, and fifth convex portions 753, 754, and 755 from the base end side.
  • the convex portions 75 guide the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the convex portions 75 also restrict the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • the guide surfaces 7510, 7520, 7530, 7540, 7550 of the convex portions 751, 752, 753, 754, 755 facing the slits 700, 701 come into contact with a part of the second shaft portion 8, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the guide surfaces 7510, 7520, 7530, 7540, 7550 of the convex portions 75 are flat surfaces.
  • the third, fourth, and fifth protrusions 753, 754, and 755 from the base end in the axial direction of the protrusions 75 are provided with a restricting locking portion 76 that restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the tip of each of the protrusions 753, 754, and 755 constitutes the restricting locking portion 76.
  • the tip faces 7531, 7541, and 7551 that face the tip side of the protrusions 753, 754, and 755 constitute the tip face 760 of the restricting locking portion 76 (see Figures 18C, 20C, and 22C).
  • the restricting locking portion 76 restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force by the tip face 760 of the restricting locking portion 76 coming into contact with a part of the second shaft portion 8.
  • the tip face 760 is a flat surface.
  • the restricting locking portions 76 are provided in a plurality of sets spaced apart in the axial direction, and in this embodiment, three sets are provided (see FIG. 17C). Specifically, the restricting locking portions 76 are composed of three sets of spindle restricting locking portions 76 lined up in the axial direction of the first spindle portion 70 so as to be spaced apart in the axial direction. In this embodiment, the restricting locking portions 76 are provided in three sets spaced apart in the axial direction at positions 180° apart in the circumferential direction of the first spindle portion 7.
  • the first and second protrusions 751 and 752 from the base end side have a push-in locking portion 77 that locks the second shaft portion 8 when the plunger 3 is pushed into the barrel 2.
  • Two sets of push-in locking portions 77 are provided in the axial direction.
  • the base end of each of the protrusions 751 and 752 constitutes the push-in locking portion 77.
  • the base end faces 7512 and 7522, which are the faces facing the base end side of the protrusions 751 and 752, constitute the base end face 770 of the push-in locking portion 77 ( Figures 21C and 23C).
  • the base end face 770 of the push-in locking portion 77 contacts a part of the second shaft portion 8, thereby restricting the movement of the second shaft portion 8 toward the axial tip side relative to the first shaft portion 7, and enabling the plunger 3 to be pushed into the barrel 2.
  • the base end face 770 of the push-in locking portion 77 is a flat surface.
  • the push-in locking portions 77 are provided in pairs, spaced apart in the axial direction, on both sides of the central axis of the first main shaft portion 70 (see FIG. 17C). Specifically, the push-in locking portions 77 are provided in pairs, spaced apart in the axial direction, at positions 180° apart in the circumferential direction of the first main shaft portion 70. In this embodiment, the push-in locking portions 77 are provided on both sides of the central axis of the first main shaft portion 70, and are composed of two pairs of main shaft push-in locking portions 77 lined up in the axial direction.
  • the first base end 71 forms a push-in locking portion 77 that locks onto a part of the second base end 81 during the first ejection of the liquid medicine.
  • the first and second protrusions 751, 752 from the base end are provided with a push-in guide portion 6.
  • the tip of each of the protrusions 751, 752 constitutes the push-in guide portion 6.
  • the tip surfaces 7511, 7521 facing the tip side of the protrusions 751, 752 constitute the tip surface 600 of the push-in guide portion 6 (see Figures 19C and 21C).
  • the tip surface 600 of the push-in guide portion 6 comes into contact with a part of the second shaft portion 8, and the push-in guide portion 6 guides the part of the second shaft portion 8 from the push-in deployment position to the push-in retract position.
  • the push-in guide portions 6 are provided in two sets spaced apart in the axial direction on both sides of the central axis of the first main shaft portion 70. Specifically, the push-in guide portions 6 are provided in two sets spaced apart in the axial direction at positions 180° apart in the circumferential direction of the first main shaft portion 70. In this embodiment, the push-in guide portions 6 are composed of two sets of main shaft push-in guide portions 6 arranged side by side and spaced apart in the axial direction on both sides of the central axis of the first main shaft portion 70.
  • the second shaft portion 8 includes a second main shaft portion 80 and a second base end portion 81, as well as a restricting portion 83 having a starting end 830 at the tip end and a free end 831 at the base end.
  • the restricting portion 83 is configured to be rotatable around the starting end 830 between a restricting retracted position where the free end 831 is located on the radially inner side and a restricting deployed position where the free end 831 is located on the radially outer side.
  • the second shaft portion 8 also includes a pushing portion 85 including a push-in interlocking portion 84 that interlocks with the push-in interlocking portion 77 of the first shaft portion 7 when the plunger 3 is pushed in.
  • the second shaft portion 8 also includes a discharge completion portion 87 including a discharge completion interlocking portion 86 that interlocks with the discharge completion interlocking portion 24 when the discharge of the medicinal liquid is completed, and protrusions 891 and 892.
  • the regulating portions 83 are provided in pairs at positions facing each other across the circumferential central axis of the second main shaft portion 80.
  • the pushing portion 85, the discharge completion portion 87, and the protruding portions 891 and 892 are provided in pairs at positions facing each other across the circumferential central axis of the second main shaft portion 80.
  • the protruding portion 891, the pushing portion 85, the protruding portion 892, the discharge completion portion 87, and the regulating portion 83 are arranged in order from the base end side to the tip end side in the axial direction.
  • the second main shaft portion 80 includes a second main wall portion 800 having a substantially rectangular plate shape extending along the axial direction, and a second sub-wall portion 801 extending perpendicular to the second main wall portion 800 at the center of the width direction of the second main wall portion 800.
  • the second main wall portion 800 has a shape in which the radially outer end is partially cut out, and the remaining portion becomes the protrusion portion 891, the pushing portion 85, the protrusion portion 892, the discharge completion portion 87, and the regulating portion 83.
  • the second sub-wall portion 801 fits into the first shaft portion 7.
  • This fitting restricts the circumferential movement of the second shaft portion 8 while restricting the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • This fitting also restricts the circumferential movement of the second shaft portion 8 when the plunger 3 is pushed in or when the second shaft portion 8 moves axially relative to the first shaft portion 7 due to the biasing force.
  • the restricting portion 83 has a restricting locked portion 82 at its free end 831 which is locked to the restricting locking portion 76 of the first shaft portion 7 by the biasing force of the biasing member 4 in the restricting deployed position.
  • the restricting portion 83 is also provided on the second main shaft portion 80.
  • the base end of the restricting portion 83 constitutes the restricting locked portion 82.
  • the restricting locked portion 82 is locked to the restricting locking portion 76 (see Figures 18C, 20C, and 22C).
  • the restricting locked portion 82 is not locked to the restricting locking portion 76.
  • the restricting and locked portions 82 are provided in a pair on either side of the central axis of the second main shaft portion 80 (see FIG. 17B).
  • the surface facing the base end of the restricting portion 83 specifically the base end surface 820 of the restricting and locked portion 82, comes into contact with the tip surface 760 of the restricting and locked portion 76 of the first shaft portion 7, thereby restricting the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force (see FIGS. 18C, 20C, and 22C).
  • the base end surface 820 of the restricting and locked portion 82 is a flat surface.
  • the restricting portion 83 includes a restricting guided portion 832 provided between a pair of restricting locked portions 82 (see FIG. 17B).
  • the restricting portion 83 also includes a restricting extension portion 833 that extends from the radially inner end of the restricting locked portion 82 toward the base end.
  • the restricted guided portion 832 is a portion for guiding the movement of the second shaft portion 8 in the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the regulated guided portion 832 comes into contact with the convex portions 754, 755 of the first shaft portion 7, thereby guiding the movement along the axial direction of the second shaft portion 8.
  • the outer surface 8320 of the regulated guided portion 832 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7540, 7550 of the convex portions 754, 755 facing the slits 700, 701, thereby guiding the movement along the axial direction of the second shaft portion 8.
  • the outer surface 8320 of the regulated guided portion 832 is a flat surface.
  • the restricting extension 833 is a stopper for preventing the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the restricting extension 833 is also located radially inside a portion of the discharge completion portion 87.
  • the restricting extension 833 is a rib that extends from the radially inner end of the restricting engaged portion 82 toward the base end along the axial direction.
  • the outer surface 8330 located radially outward of the restricting extension 833 is a flat surface (see Figures 19B and 21B).
  • the pushing portion 85 has a starting end 850 at the base end and a free end 851 at the tip end, and is configured to be rotatable around the starting end 850 between a pushing retracted position where the free end 851 is located on the radially inner side and a pushing deployed position where the free end 851 is located on the radially outer side (see FIG. 17B).
  • the tip of the pushing portion 85 constitutes the pushing engaged portion 84.
  • the pushing engaged portion 84 is a spindle pushing engaged portion 84 provided at the free end 851 of the pushing portion 85, and is configured as the spindle pushing engaged portion 84 that engages with the spindle pushing engaged portion 77 of the first shaft portion 7 when pushed in the pushing deployed position.
  • the push-in locked portions 84 are provided in pairs on both sides of the central axis of the second main shaft portion 80.
  • the surface facing the tip of the push-in portion 85 specifically the tip surface 840 of the push-in locked portions 84, comes into contact with the base end surface 770 of the push-in locked portion 77 of the first shaft portion 7, and a force moving toward the tip of the second shaft portion 8 is transmitted to the first shaft portion 7, causing the first shaft portion 7 to move together with the second shaft portion 8 (see Figures 21C and 23C).
  • the tip surface 840 of the push-in locked portions 84 is a flat surface.
  • the base end surface 841 of the pushed-in interlocking portion 84 facing the base end is an inclined surface that is positioned radially inward as it approaches the base end.
  • the base end surface 841 of the pushed-in interlocking portion 84 comes into contact with the tip surfaces 7511, 7521 that face the tip sides of the first and second protrusions 751, 752 from the base end side of the first shaft portion 7, causing the pushed-in portion 85 to move from the pushed-in deployed position to the pushed-in retracted position (see Figures 19C and 21C).
  • the base end surface 841 of the pushed-in interlocking portion 84 is a flat surface.
  • the push-in portion 85 has a push-in extension portion 853 that extends further toward the tip side from the radially inner end of the push-in engaging portion 84 (see FIG. 17B).
  • the push-in extension 853 is a stopper for preventing the push-in portion 85 from opening radially outward when the second shaft portion 8 is moved toward the tip by the user of the syringe 1 as the second shaft portion 8 is moved relative to the first shaft portion 7 by the biasing force of the biasing member 4.
  • the push-in extension 853 is a rib that extends axially from the radially inner end of the push-in engagement portion 84 toward the tip.
  • the push-in extension 853 is also located radially inside a portion of the discharge completion portion 87.
  • the outer surface 8530 located radially outward of the push-in extension 853 is a flat surface (see Figures 19B and 21B).
  • the ejection completion portion 87 is a stopper that engages with the ejection completion locking portion 24 of the barrel 2 to restrict the plunger 3 that has moved a distance corresponding to one ejection.
  • the ejection completion portion 87 engages with the ejection completion locking portion 24 upon completion of the first and second ejections of the medicinal liquid.
  • the ejection completion portion 87 is also provided on the second main shaft portion 80.
  • the tip of the ejection completion portion 87 constitutes the ejection completion locked portion 86.
  • the ejection completion locked portions 86 are provided in a pair on either side of the central axis of the second main shaft portion 80. Furthermore, when the tip surface 860 of the ejection completion locked portion 86 comes into contact with the base end surface 240 of the ejection completion lock portion 24 of the barrel 2, the movement of the second shaft portion 8 toward the tip side by the user of the syringe 1, i.e., one ejection of medicinal liquid, is completed.
  • the tip surface 860 of the ejection completion locked portion 86 is a flat surface.
  • the discharge completion portion 87 has a discharge guided portion 870, which is the radially outer end (see FIG. 17B).
  • the discharge completion portion 87 also has a discharge extension portion 871, which extends as the end on the tip side of the discharge guided portion 870.
  • the discharge guided portion 870 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the discharge guided portion 870 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the discharge guided portion 870 comes into contact with the convex portions 753 and 754 of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8700 of the discharge guided portion 870 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surfaces 7530 and 7540 of the convex portions 753 and 754 facing the slits 700 and 701, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8700 of the discharge guided portion 870 is a flat surface.
  • the discharge extension 871 is a stopper pressing portion that presses the restricting extension 833 of the restricting portion 83 to prevent the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4 and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the discharge extension 871 is located radially outward of the restricting extension 833.
  • the discharge extension 871 is a rib that extends axially toward the tip side as an end portion on the tip side of the discharge guided portion 870.
  • the inner surface 8710 on the radial inner side of the discharge extension 871 is a flat surface.
  • the inner surface 8710 of the discharge extension 871 abuts against the outer surface 8330 on the radial outer side of the restricting extension 833, thereby preventing the restricting portion 83 from opening radially outward (see Figures 19B and 21B).
  • the protruding portion 891 has a protruding guided portion 8910, which is the radially outer end (see FIG. 17B).
  • the protruding guided portion 8910 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the protruding guided portion 8910 is also a portion for restricting the circumferential movement of the second shaft portion 8 when the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the protruding guided portion 8910 comes into contact with the convex portion 751 located at the base end side of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8911 of the protruding guided portion 8910 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7510 of the convex portion 751 facing the slits 700, 701 side, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8911 of the protruding guided portion 8910 is a flat surface.
  • the protruding portion 892 has a protruding guided portion 8920, which is the radially outer end.
  • the protruding portion 892 also has a protruding extension portion 8921, which extends as the end on the tip side of the protruding guided portion 8920.
  • the protruding guided portion 8920 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the protruding guided portion 8920 is also a portion for restricting the circumferential movement of the second shaft portion 8 when the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the protruding guided portion 8920 abuts against the second and third convex portions 752 and 753 from the base end side of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8922 of the protruding guided portion 8920 facing the circumferential direction of the second shaft portion 8 abuts against the guide surfaces 7520 and 7530 facing the one-side slit 700 side of the convex portions 752 and 753, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8922 of the protruding guided portion 8920 is a flat surface.
  • the protruding extension 8921 is a stopper pressing portion that presses the push-in extension 853 of the pushing portion 85 to prevent the pushing portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side.
  • the protruding extension 8921 is located radially outward of the push-in extension 853.
  • the protruding extension 8921 is a rib that extends toward the base end along the axial direction as the end portion on the base end side of the protruding portion 892.
  • the inner surface 8923 on the radially inner side of the protruding extension 8921 is a flat surface.
  • the inner surface 8923 of the protruding extension 8921 abuts against the radially outer outer surface 8530 of the push-in extension 853, thereby preventing the pushing portion 85 from opening radially outward (see Figures 19B and 21B).
  • the second base end 81 of the second shaft 8 forms a push-in engaging portion 84 that engages with the first base end 71 of the first shaft 7.
  • the deregulation unit 5 moves the regulating unit 83 from the regulating deployed position to the regulating retracted position, and releases the engagement of the regulating interlocked unit 82 with the regulating interlocking unit 76.
  • the deregulation unit 5 is formed by the radially inner end 2321 of the main body base end 232 of the grip main body 230.
  • the syringe 1 has not yet dispensed any liquid medicine.
  • the second shaft 8 is biased toward the base end by the biasing force of the biasing member 4 relative to the first shaft 7, and the restricting portion 83 is in the restricted deployment position (see Fig. 18B).
  • the restricting interlocking portion 82 of the restricting portion 83 is interlocked with the restricting interlocking portion 76 of the fifth protrusion 755 from the base end side of the first shaft 7 by the biasing force of the biasing member 4 (see Fig. 18C).
  • the base end surface 820 of the restricting interlocking portion 82 of the restricting portion 83 is interlocked with the tip end surface 7551 of the fifth protrusion 755 from the base end side. This interlocking restricts the movement of the second shaft 8 relative to the first shaft 7.
  • the first liquid medicine ejection is completed when the ejection completion locked portion 86 of the ejection completion portion 87 is locked to the ejection completion locking portion 24 of the barrel 2. Specifically, the first liquid medicine ejection is completed when the tip surface 860 of the ejection completion locked portion 86 is locked to the base end surface 240 of the ejection completion locking portion 24 (see FIG. 19B).
  • the restricting portion 83 of the second shaft portion 8 is moved from the restricted deployment position to the restricted retracted position by the restricting release portion 5. Specifically, the restricting portion 83 is deflected by the radially outer end face 8321 of the restricting portion 83 hitting the radially inner end 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position. As a result, the restricted locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricted locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released. Then, the second shaft portion 8 moves toward the base end side relative to the first shaft portion 7 by the biasing force of the biasing member 4, and is in the state immediately before the second discharge shown in Figures 20A to 20C.
  • the restricting portion 83 is moved to the restricting retracted position by the restricting release portion 5, and then moves to the restricting deployed position between the restricting locking portion 76 of the fifth protrusion 735 from the base end of the first shaft portion 7, which was locked in the initial state, and the restricting locking portion 76 of the fourth protrusion 754 from the base end (see Figures 19C and 20C).
  • the pushing portion 85 of the second shaft portion 8 is located further towards the tip side than the convex portion 752 located second from the base end side (see FIG. 19C).
  • the base end surface 841 of the pushing-in interlocking portion 84 of the pushing portion 85 comes into contact with the tip end surface 7521 of the convex portion 752 located second from the base end side.
  • the pushing portion 85 is pushed radially inwards to the pushing-in retracted position, passes through the second convex portion 752 from the base end side to the base end side, and moves between the first convex portion 751 from the base end side and the second convex portion 752 from the base end side (see FIG. 20C).
  • the pushing portion 85 is moved to the pushing retracted position by the tip surface 7521 of the second protruding portion 752 from the base end, and then moves to the pushing deployed position at a position closer to the base end than the second protruding portion 752 from the base end.
  • the restricted guided portion 832 moves while being guided by the fifth convex portion 755 from the base end side.
  • the protruding guided portion 8920 moves while being guided by the third convex portion 753 from the base end side.
  • the second shaft portion 8 is engaged by the biasing force of the biasing member 4 with the restricting and locked portion 82 of the restricting portion 83 against the restricting and locked portion 76 of the fourth protrusion 754 from the base end side of the first shaft portion 7 (see FIG. 20C).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is engaged with the tip end surface 7541 of the fourth protrusion 754 from the base end side. This engagement restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the tip surface 840 of the push-in interlocking portion 84 comes into contact with the base end surface 770 of the push-in interlocking portion 77 of the first shaft portion 7, and the first shaft portion 7 is pushed toward the tip together with the second shaft portion 8, causing the second ejection of the medicinal liquid.
  • the tip surface 840 comes into contact with the base end surface 7522 of the second protrusion 752 from the base end side (see Fig. 21C).
  • the second liquid medicine discharge is completed when the tip surface 860 of the discharge completion locked portion 86 is locked to the base end surface 240 of the discharge completion locking portion 24 (see FIG. 21B).
  • the restricting portion 83 of the second shaft portion 8 is deflected by the radially outer end surface 8321 of the restricting portion 83 hitting the radially inner end portion 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position.
  • the restricting locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricting locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released.
  • the second shaft portion 8 moves to the base end side relative to the first shaft portion 7 by the biasing force of the biasing member 4, and is in the state immediately before the third discharge shown in FIG. 22A to FIG. 22C.
  • the restricting portion 83 is moved to the restricted retracted position by the restricting release portion 5, and then moves to the deployed position between the restricting locking portion 76 of the fourth protrusion 754 from the base end of the first shaft portion 7, which was engaged immediately before the second ejection, and the restricting locking portion 76 of the third protrusion 753 from the base end (see Figures 21C and 22C).
  • the base end surface 841 of the push-in interlocking portion 84 of the push-in portion 85 comes into contact with the tip surface 7511 of the protruding portion 751 located at the most proximal end of the first shaft portion 7.
  • the push-in portion 85 is pushed radially inward to the push-in retract position, passes through the protruding portion 751 at the base end, and moves to the base end side of the protruding portion 751 located at the most proximal end.
  • the restricted guided portion 832 is guided by the fourth convex portion 754 from the base end side, and the second shaft 8 moves along the axial direction (see Fig. 17B and Fig. 21A).
  • the discharge guided portion 870 is guided by the third convex portion 753 from the base end side, and the second shaft 8 moves along the axial direction.
  • the protruding guided portion 8910 is guided by the convex portion 751 located at the most base end side, and the second shaft 8 moves along the axial direction.
  • the protruding guided portion 8920 is guided by the second convex portion 752 from the base end side, and the second shaft 8 moves along the axial direction.
  • the second shaft portion 8 is engaged by the biasing force of the biasing member 4 with the restricting and locked portion 82 of the restricting portion 83 against the restricting and locked portion 76 of the third protrusion 753 from the base end side of the first shaft portion 7 (see FIG. 22C).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is engaged with the tip end surface 7531 of the third protrusion 753 from the base end side. This engagement restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the third liquid medicine ejection is completed when the piston 30 attached to the first tip 72 of the first shaft 7 hits the tip of the body connection part 222 of the barrel body 22.
  • the restricting portion 83 is provided on one circumferential side of the second shaft portion 8, and the pushing portion 85 is provided on the other circumferential side, but the restricting portion 83 and the pushing portion 85 may be provided on one circumferential side.
  • Figures 24 to 29B a configuration in which the first shaft portion 7 and the second shaft portion 8 have an axially asymmetric shape and the syringe 1 administers the medicinal liquid in two separate doses will be described.
  • the first shaft portion 7 includes a first main shaft portion 70, a first base end portion 71, and a first tip end portion 72, as well as a plurality of protrusions 75 provided on one side of the first main shaft portion 70.
  • the first main shaft portion 70 has two sets of protrusions 75 spaced apart in the axial direction.
  • the first main shaft portion 70 also has a pair of protrusions 75, sandwiching a slit 700 on one side.
  • the protrusions 75 all have the same protrusion dimension relative to the slit 700.
  • the protrusion 751 provided on the base end side has a larger axial dimension than the protrusion 752 provided on the tip end side.
  • the two sets of protrusions 75 each guide the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the two sets of protrusions 75 also restrict the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted by the biasing force of the biasing member 4.
  • Each of the protrusions 751, 752 has guide surfaces 7510, 7520 facing the slit 700 that come into contact with a part of the second shaft portion 8, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the circumferential movement of the second shaft portion 8.
  • the guide surfaces 7510, 7520 of the protrusions 751, 752 are flat surfaces.
  • the protrusions 751 and 752 are provided with a restricting locking portion 76 that restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the tip of each of the protrusions 751 and 752 constitutes the restricting locking portion 76.
  • the restricting locking portion 76 restricts the second shaft portion 8 from moving relative to the first shaft portion 7 due to the biasing force when the tip face 760 of the restricting locking portion 76 comes into contact with a part of the second shaft portion 8.
  • the tip face 760 is a flat surface.
  • Two sets of the restricting locking portions 76 are provided with an axial gap between them.
  • the protruding portion 751 located on the base end side has a push-in locking portion 77 that locks with the second shaft portion 8 when the plunger 3 is pushed into the barrel 2 (see FIG. 25D).
  • a set of push-in locking portions 77 is provided.
  • the base end of the protruding portion 751 constitutes the push-in locking portion 77.
  • the base end surface 7512, which is the surface of the protruding portion 751 facing the base end side, constitutes the base end surface 770 of the push-in locking portion 77.
  • the base end surface 770 of the push-in locking portion 77 contacts a part of the second shaft portion 8, thereby restricting the movement of the second shaft portion 8 toward the axial tip side relative to the first shaft portion 7, and enabling the plunger 3 to be pushed into the barrel 2.
  • the base end surface 770 of the push-in locking portion 77 is a flat surface.
  • a set of push-in locking portions 77 is provided.
  • the push-in locking portion 77 is composed of a set of main shaft push-in locking portions 77.
  • the protrusion 751 located on the base end side is provided with a push-in guide portion 6 that guides a portion of the second shaft portion 8 from a push-in deployment position to a push-in retract position.
  • the tip of the protrusion 751 constitutes the push-in guide portion 6.
  • the tip surface 7511 which is the surface of the protrusion 751 facing the tip side, constitutes the tip surface 600 of the push-in guide portion 6 (see FIG. 28B).
  • the push-in guide portion 6 guides a portion of the second shaft portion 8 from the push-in deployment position to the push-in retract position as the tip surface 600 of the push-in guide portion 6 comes into contact with a portion of the second shaft portion 8.
  • the push-in guide portion 6 is constituted by a set of main shaft push-in guide portions 6 provided on the first main shaft portion 70.
  • the first base end 71 forms a push-in locking portion 77 that locks onto a part of the second base end 81 during the first ejection of the liquid medicine.
  • the second shaft portion 8 includes a restricting portion 83 configured to be rotatable around a starting point end 830, and a pushing portion 85 including a pushing-in interlocking portion 84.
  • the second shaft portion 8 also includes a discharge completion portion 87 including a discharge completion interlocking portion 86, and a protruding portion 893.
  • the pushing portion 85, the protruding portion 893, and the restricting portion 83 are arranged in order from the base end side to the tip end side in the axial direction.
  • the discharge completion portion 87 is provided on the other side of the second main shaft portion 80.
  • the second main shaft portion 80 also includes a recess 90 into which the restricting portion 83 fits when in the pushing-in retracted position, and a recess 91 into which the pushing portion 85 fits when in the pushing-in retracted position.
  • the restricting portion 83 includes a pair of restricting and engaging portions 82 aligned in the circumferential direction, a restricting and guided portion 832, and a restricting extension portion 833.
  • the restricted guided portion 832 comes into contact with the convex portion 752 on the tip side of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8320 of the restricted guided portion 832 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7520 facing the one-side slit 700 side of the convex portion 752, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8320 of the restricted guided portion 832 is a flat surface.
  • the restricting extension 833 is a stopper that prevents the restricting portion 83 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the movement of the second shaft portion 8 relative to the first shaft portion 7 is restricted.
  • the restricting extension 833 is also located radially inward of a portion of the protrusion 893.
  • the restricting extension 833 is a rib that extends from the radially inner end of the restricting engaged portion 82 toward the base end along the axial direction.
  • the outer surface 8330 located radially outward of the restricting extension 833 is a flat surface.
  • the pushing portion 85 has a starting end 850 at the base end and a free end 851 at the tip end, and is configured to be rotatable around the starting end 850 between a pushing retracted position where the free end 851 is located on the radial inside and a pushing deployed position where the free end 851 is located on the radial outside.
  • the tip of the pushing portion 85 constitutes the push-in interlocking portion 84.
  • the push-in interlocking portion 84 is a spindle push-in interlocking portion 84 provided at the free end 851 of the pushing portion 85, and is configured as a spindle push-in interlocking portion 84 that interlocks with the spindle push-in interlocking portion 77 of the first shaft portion 7 when pushed in the pushed-in deployed position (see FIG. 29B).
  • One push-in interlocking portion 84 is provided on the pushing portion 85.
  • the surface facing the tip of the pushing portion 85 specifically the tip surface 840 of the push-in interlocking portion 84, hits the base end surface 770 of the push-in interlocking portion 77 of the first shaft portion 7, and a force moving toward the tip side of the second shaft portion 8 is transmitted to the first shaft portion 7, and the first shaft portion 7 moves together with the second shaft portion 8.
  • the tip surface 840 of the push-in engaging portion 84 is a flat surface.
  • the base end face 841 of the pushed-in interlocking portion 84 which faces the base end, is an inclined surface that is positioned radially inward as it approaches the base end (see FIG. 27C).
  • the base end face 841 of the pushed-in interlocking portion 84 comes into contact with the tip end face 7511, which is the surface facing the tip end of the protrusion 751 on the base end side of the first shaft portion 7, and the pushed-in portion 85 moves from the pushed-in deployed position to the pushed-in retracted position.
  • the base end face 841 of the pushed-in interlocking portion 84 is a flat surface.
  • the second base end 81 forms a push-in engaging portion 84 that engages with the first base end 71.
  • the push-in portion 85 has a push-in extension portion 853 that extends further toward the tip side from the radially inner end of the push-in engaging portion 84 (see Figures 25B and 25C).
  • the push-in extension 853 is a stopper that prevents the push-in portion 85 from opening radially outward when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4, and when the user of the syringe 1 moves the second shaft portion 8 toward the tip side.
  • the push-in extension 853 is a rib that extends axially from the radially inner end of the push-in engaged portion 84 toward the tip side.
  • the push-in extension 853 is also located radially inward of a portion of the protrusion 893.
  • the outer surface 8530 located radially outward of the push-in extension 853 is a flat surface.
  • the ejection completion portion 87 is a stopper that restricts the plunger 3 by engaging with the ejection completion locking portion 24 of the barrel 2 during the first ejection.
  • the distal end surface 860 of the ejection completion portion 87 abuts against the proximal end surface 240 of the ejection completion locking portion 24 of the barrel 2, completing the movement of the second shaft portion 8 toward the distal end by the user of the syringe 1, i.e., completing the first ejection of the medicinal liquid (see FIG. 27B).
  • the distal end surface 860 of the ejection completion locked portion 86 is a flat surface.
  • the ejection completion locking portion 24 is formed by the main body proximal end 232, and the proximal end surface 240 of the ejection completion locking portion 24 is formed by the proximal end surface 2320, which is the surface facing the proximal end of the main body proximal end 232.
  • the discharge completion portion 87 has a discharge guided portion 870, which is the radially outer end (see Figures 25B and 25C).
  • the discharge guided portion 870 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the discharge guided portion 870 is also a portion for restricting the circumferential movement of the second shaft portion 8 in a state in which the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the outer surface 8700 of the discharge guided portion 870 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 702 (see FIG. 25A) that defines the other side slit 701 of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the circumferential movement of the second shaft portion 8.
  • the protruding portion 893 includes a protruding guided portion 8930 (see FIG. 25C).
  • the protruding portion 893 also includes a base end protruding extension portion 8931 that extends as an end portion on the base end side of the protruding guided portion 8930, and a tip end protruding extension portion 8932 that extends as an end portion on the tip end side of the protruding guided portion 8930.
  • the protruding guided portion 8930 is a portion for guiding the movement of the second shaft portion 8 along the axial direction relative to the first shaft portion 7 when the second shaft portion 8 moves relative to the first shaft portion 7 due to the biasing force of the biasing member 4.
  • the protruding guided portion 8930 is also a portion for restricting the circumferential movement of the second shaft portion 8 when the movement of the second shaft portion 8 relative to the first shaft portion is restricted by the biasing force of the biasing member 4.
  • the protruding guided portion 8930 comes into contact with the convex portion 752 on the tip side of the first shaft portion 7, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8933 of the protruding guided portion 8930 facing the circumferential direction of the second shaft portion 8 comes into contact with the guide surface 7520 of the convex portion 752 facing the slit 700 side, thereby guiding the movement of the second shaft portion 8 along the axial direction and restricting the movement of the second shaft portion 8 in the circumferential direction.
  • the outer surface 8933 of the protruding guided portion 8930 is a flat surface.
  • the base end side protruding extension 8931 is a stopper pressing portion that presses the pushing extension 853 of the pushing portion 85 to prevent the pushing portion 85 from opening radially outward.
  • the base end side protruding extension 8931 is located radially outward of the pushing extension 853.
  • the base end side protruding extension 8931 is a rib that extends axially toward the base end as the base end side end of the protruding guided portion 8930.
  • the inner surface 8934 on the radially inner side of the base end side protruding extension 8931 is a flat surface.
  • the inner surface 8934 of the base end side protruding extension 8931 abuts against the outer surface 8530 on the radially outer side of the pushing extension 853, thereby preventing the pushing portion 85 from opening radially outward (see FIG. 27B).
  • the tip-side protruding extension 8932 is a stopper pressing portion that presses the restricting extension 833 of the restricting portion 83 to prevent the restricting portion 83 from opening radially outward.
  • the tip-side protruding extension 8932 is located radially outward of the restricting extension 833.
  • the tip-side protruding extension 8932 is a rib that extends toward the tip side along the axial direction as the tip-side end of the protruding guided portion 8930.
  • the inner surface 8935 on the radially inner side of the tip-side protruding extension 8932 is a flat surface. The inner surface 8935 of the tip-side protruding extension 8932 abuts against the outer surface 8330 on the radially outer side of the restricting extension 833, thereby preventing the restricting portion 83 from opening radially outward.
  • the deregulation portion 5 is formed by the radially inner end 2321 of the grip body portion 230 of the finger grip 23, for example, the radially inner end 2321 of the body base end portion 232 of the grip body portion 230.
  • the initial state is a state in which the syringe 1 has not yet dispensed the medicinal liquid.
  • the restricting and locked portion 82 of the restricting portion 83 of the second shaft portion 8 is locked to the restricting and locked portion 76 of the protrusion 752 on the tip side of the first shaft portion 7 by the biasing force of the biasing member 4.
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is locked to the tip surface 7521 of the protrusion 752 on the tip side (see Figure 26B). This lock restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the first liquid medicine ejection is completed when the ejection completion locked portion 86 of the ejection completion portion 87 is locked to the ejection completion locking portion 24 of the barrel 2 (see FIG. 27B). Specifically, the first liquid medicine ejection is completed when the tip surface 860 of the ejection completion locked portion 86 is locked to the base end surface 240 of the ejection completion locking portion 24.
  • the restricting portion 83 of the second shaft portion 8 is moved from the restricted deployment position to the restricted retracted position by the restricting release portion 5. Specifically, the restricting portion 83 is deflected by the radially outer end face 8321 of the restricting portion 83 hitting the radially inner end 2321 of the main body base end portion 232 of the finger grip 23, and is moved from the restricted deployment position to the restricted retracted position. As a result, the restricted locked portion 82 of the second shaft portion 8 also moves radially inward, and the lock of the restricted locked portion 82 to the restricting locking portion 76 of the first shaft portion 7 is released. Then, the second shaft portion 8 moves toward the base end side relative to the first shaft portion 7 by the biasing force of the biasing member 4, and reaches the state immediately before the second discharge shown in Figures 28A and 28B.
  • the restricting portion 83 is moved to the restricting retracted position by the restricting release portion 5, and then moves to the restricting deployed position between the restricting locking portion 76 of the protruding portion 752 on the tip side of the first shaft portion 7, which was initially locked, and the restricting locking portion 76 of the protruding portion 751 on the base side (see Figures 27C and 28B).
  • the pushing portion 85 of the second shaft portion 8 is located on the tip side of the base-side convex portion 751 (see FIG. 27C).
  • the base end surface 841 of the pushing-in interlocking portion 84 of the pushing portion 85 hits the tip surface 7511 of the base-side convex portion 751, so that the pushing portion 85 is pushed radially inward to the pushing-in retracted position, passes through the base-side convex portion 751 to the base end side, and moves to a position on the base side of the base-side convex portion 751 (see FIG. 28B).
  • the pushing portion 85 is moved to the pushing-in retracted position by the base-side convex portion 751, and then reaches the pushing-in deployed position at a position on the base side of the base-side convex portion 751.
  • the restricted guided portion 832 moves while being guided by the protruding portion 752 on the tip side.
  • the discharge guided portion 870 moves while being guided by the guide surface 702 that defines the other side slit 701 of the first main shaft 70.
  • the protruding guided portion 8930 moves while being guided by the protruding portion 751 on the tip side.
  • the restricting portion 83 is prevented from opening radially outward, and the pushing portion 85 is prevented from opening radially outward (see FIG. 27B).
  • the second shaft portion 8 is engaged by the biasing force of the biasing member 4 with the restricting and locked portion 82 of the restricting portion 83 against the restricting and locked portion 76 of the protruding portion 751 on the base end side of the first shaft portion 7 (see FIG. 28B).
  • the base end surface 820 of the restricting and locked portion 82 of the restricting portion 83 is engaged with the tip end surface 7511 of the protruding portion 751 on the base end side. This engagement restricts movement of the second shaft portion 8 relative to the first shaft portion 7.
  • the second liquid medicine ejection is completed when the piston 30 attached to the first tip 72 of the first shaft 7 hits the tip of the body connection part 222 of the barrel body 22.
  • the syringe 1 includes the barrel 2, plunger 3, biasing member 4, deregulation portion 5, push-in guide portion 6, and discharge nozzle 9, but it is sufficient if the syringe 1 includes at least the barrel 2, plunger 3, biasing member 4, and deregulation portion 5.
  • the syringe 1 does not need to include at least one of the push-in guide portion 6 and the discharge nozzle 9. If the syringe 1 does not include the discharge nozzle 9, it is conceivable that the contents (e.g., medicinal liquid) are discharged from the tip portion 20 of the barrel 2 in a line rather than in a mist.
  • the push-in locking portion 77 of the first shaft portion 7 includes a plurality of spindle push-in locking portions 77 provided on the first main shaft portion 70, but they may be provided at another location on the first shaft portion 7. Also, the push-in portion 85 of the second shaft portion 8 is provided on the second main shaft portion 80, but they may be provided at another location on the second shaft portion 8.
  • the first shaft portion 7 when the user pushes the second base end 81 toward the tip when discharging the medicinal liquid except for the first discharge, the first shaft portion 7 is pushed toward the tip together with the second shaft portion 8 with the tip surface 840 of the push-in interlocking portion 84 abutting the base surface 770 of the push-in interlocking portion 77 of the first shaft portion 7.
  • the first shaft portion 7 may be pushed toward the tip together with the second shaft portion 8 with the tip surface 840 of the push-in interlocking portion 84 abutting the base surface 770 of the push-in interlocking portion 77 of the first shaft portion 7 at all times when discharging the medicinal liquid.
  • the discharge completion locking portion 24 is provided on the finger grip 23, but it may be provided on a portion other than the finger grip 23.
  • the discharge completion locking portion 24 may be provided on the barrel body 22.
  • the discharge completion section 87 engages with the discharge completion locking section 24 when the discharge of the medicinal liquid is completed except for the final discharge, but it may also engage with the discharge completion locking section 24 at all times when the discharge of the medicinal liquid is completed.
  • the second shaft portion 8 has a first rib 92 and a second rib 93. Furthermore, in this second shaft portion 8, the outer surface 854 of the pushing portion 85 is aligned on the same line in the axial direction as the outer surface 873 of the discharge completion portion 87.
  • the first rib 92 is a rib that protrudes radially outward from the second main shaft portion 80, and in this embodiment, extends from the base end edge of the second main shaft portion 80 along the axial direction toward the tip side, up to just before the restricting portion 83. In other words, the first rib 92 is disposed on the base end side in the axial direction relative to the restricting portion 83. In this embodiment, the first rib 92 extends continuously between the second base end portion 81 and the protruding portion 88.
  • the protruding dimension of the first rib 92 i.e., the radial dimension of the first rib 92, is uniform.
  • the first rib 92 passes between adjacent one-side protrusions 73 in the one-side slit 700 of the first shaft portion 7 in the circumferential direction (see FIG. 30).
  • the first rib 92 also prevents the second shaft portion 8 from wobbling relative to the first shaft portion 7 by passing between adjacent one-side protrusions 73 in the one-side slit 700 of the first shaft portion 7 in the circumferential direction from the initial state through the first liquid medicine ejection, the second liquid medicine ejection, and until the liquid medicine ejection is completed.
  • the second rib 93 is a rib that protrudes radially outward from the second main shaft portion 80.
  • the second rib 93 extends from the base end edge of the second main shaft portion 80 along the axial direction to the tip side just before the pressed-in interlocking portion 84 and the discharge completion portion 87 (see FIG. 32).
  • the second rib 93 is disposed on the base end side in the axial direction relative to the pressed-in interlocking portion 84 and the discharge completion portion 87. That is, the second rib 93, the pressed-in interlocking portion 84, and the discharge completion portion 87 are arranged in order from the base end side to the tip side in the axial direction.
  • the second rib 93 is continuous with the second base end portion 81.
  • the protruding dimension of the second rib 93 i.e., the radial dimension of the second rib 93, is uniform.
  • the outer surface 930 of the second rib 93 is disposed on the same line in the axial direction as the outer surface 854 of the pressed-in portion 85 and the outer surface 873 of the discharge completion portion 87.
  • the second rib 93 has a tapered shape.
  • the tip surface 940 of the tip portion 94 of the second rib 93 is an inclined surface that extends at an angle so that the outer diameter of the tip surface is closer to the tip side.
  • the tip surface 940 also faces the base end surface 855 of the pushing portion 85 in the axial direction. In this embodiment, the tip surface 940 extends parallel to the base end surface 855 of the pushing portion 85.
  • the second rib 93 passes between the circumferentially adjacent other-side protrusions 74 in the other-side slit 701, i.e., between the circumferentially adjacent push-in guide portions 6.
  • the second rib 93 also passes between the circumferentially adjacent other-side protrusions 74 in the other-side slit 701 from the initial state through the first liquid medicine ejection, the second liquid medicine ejection, and until the liquid medicine ejection is completed, thereby preventing the second shaft portion 8 from wobbling relative to the first shaft portion 7.
  • the first rib 92 and the second rib 93 are provided at positions facing each other across the central axis of the second main shaft portion 80. Specifically, the first rib 92 and the second rib 93 face each other at positions spaced 180° apart in the circumferential direction of the second main shaft portion 80.
  • the present invention provides a syringe that can reliably eject multiple times.
  • the syringe of the present invention is a syringe for administering contents in portions, comprising: a barrel having a tip portion for discharging the contents and a base portion located on the axially opposite side of the tip portion; a plunger that can be pushed into the barrel from the base portion toward the tip portion, the plunger comprising a first shaft portion and a second shaft portion that is inserted into the first shaft portion and is movable in the axial direction relative to the first shaft portion; and a biasing member that biases the second shaft portion toward the base end side relative to the first shaft portion, the first shaft portion being a restricting engagement portion for restricting the second shaft portion from moving relative to the first shaft portion due to the biasing force of the biasing member, the restricting engagement portions being provided at intervals in the axial direction;
  • the second shaft portion includes a push-in locking portion that locks with the push-in locking portion when the second shaft portion is pushed into the container, and a restricting portion.
  • the restricting portion is configured to be rotatable around the starting end between a restrictive retracted position where a free end on the base end side of the restricting portion is located on the radially inner side and a restrictive deployed position where the free end is located on the radially outer side.
  • the restricting portion includes a restrictive locked portion at the free end that locks with the restrictive locking portion by the biasing force of the biasing member at the restrictive deployed position.
  • the restricting portion includes a restricting release portion that moves the restricting portion from the restrictive deployed position to the restrictive retracted position at a position where the pushing for administering the one dose of content is completed, thereby releasing the lock of the restrictive locked portion with the restrictive locking portion.
  • the restricting locking portion and the restricting locked portion engage to restrict the movement of the second shaft portion toward the base end relative to the first shaft portion due to the biasing force of the biasing member, and when the plunger is pushed in, the entire plunger can be reliably pushed in and discharged due to the engagement of the pushing locking portion and the pushing locked portion.
  • the restricting release portion releases the engagement between the restricting locking portion and the restricting locked portion, so that the second shaft portion moves toward the base end relative to the first shaft portion due to the biasing force of the biasing member, and the restricting locked portion forms a next engagement (restriction) with the next restricting locking portion located on the base end side in the axial direction relative to the previously engaged restricting locking portion, and the pushing locking portion and the pushing locked portion form a next engagement (pushing).
  • the syringe reliably switches to preparation for the next discharge, so multiple discharges can be reliably performed.
  • the regulating portion may be moved to the regulating retracted position by the regulating release portion, and then moved to the regulating deployed position between a regulating locking portion that has been engaged for administering the one dose of contents among the plurality of regulating locking portions and a regulating locking portion adjacent to the regulating locking portion that has been engaged for administering the one dose of contents on the base end side in the axial direction.
  • the restricting portion switches to the restricting deployed position at the tip side of the next restricting engaging portion, so that the restricting engaged portion is securely engaged with the next restricting engaging portion.
  • the first shaft portion includes a first main shaft portion along the axial direction
  • the push-in locking portion includes a plurality of main shaft push-in locking portions provided on the first main shaft portion at intervals in the axial direction
  • the second shaft portion includes a second main shaft portion along the axial direction and a push-in portion provided on the second main shaft portion
  • the push-in portion includes a push-in portion configured to be rotatable around a starting end on the base end side of the push-in portion between a push-in retract position where a free end on the tip side of the push-in portion is located radially inward and a push-in deployed position where the free end is located radially outward
  • the push-in locked portion may include a main shaft push-in locked portion provided on the free end of the push-in portion, which locks with the main shaft push-in locking portion at the push-in deployed position during the push-in.
  • the push-in portion rotates between the push-in deployed position and the push-in retracted position, switching between engagement and disengagement between the spindle push-in locking portion and the spindle push-in locked portion, so that the spindle push-in locked portion is securely locked to the next spindle push-in locking portion that is located axially toward the base end side of the previously locked spindle push-in locking portion.
  • the syringe may also include a push-in guide portion between two axially adjacent spindle push-in locking portions that guides the push-in portion from the push-in deployment position to the push-in retract position, and the push-in guide portion may hold the push-in portion in the push-in retract position when the push-in portion moves axially from the spindle push-in locking portion on the tip side to the spindle push-in locking portion on the base side of the two spindle push-in locking portions, and release the hold of the push-in portion when the push-in portion is positioned on the base side relative to the spindle push-in locking portion on the base side.
  • the push-in portion switches to the push-in deployment position at a position on the axial base end side of the next spindle push-in locking portion, so that the spindle push-in locked portion is securely locked to the next spindle push-in locking portion.
  • push-in locking portion spindle push-in locking portion
  • 80 second spindle portion, 81... second base end portion, 82... restricting locked portion, 83... restricting portion, 84... push-in locked portion (spindle push-in locked portion), 85... push-in portion, 86... discharge completion locked portion, 87... discharge completion portion, 88, 89... protruding portion, 90, 91... recessed portion, 92... first rib, 93... second rib, 94... tip portion, 220... main body tip portion, 221... main body base end portion, 222... main body connection portion, 2 23... flange portion, 230... grip main body portion, 231... grip extension portion, 232... main body base end portion, 233...
  • main body tip portion 234... grip base end side extension portion, 240... base end surface, 600... tip surface, 700... one side slit, 701... other side slit, 702... guide surface, 710... base end surface, 731, 732, 733, 734, 735... one side convex portion, 741, 742, 743, 744...

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  • Health & Medical Sciences (AREA)
  • Vascular Medicine (AREA)
  • Engineering & Computer Science (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)

Abstract

Une seringue (1) comprend : un cylindre (2) ; un piston (3) comprenant une première partie d'arbre (7) et une seconde partie d'arbre (8) ; et un élément de sollicitation (4), la première partie d'arbre comprenant une partie de verrouillage de régulation (76) et une partie de verrouillage de dépression (77), et la seconde partie d'arbre comprenant une partie verrouillée par dépression (84) et une partie de régulation (83), la partie de régulation étant conçue pour pouvoir tourner, autour d'une extrémité d'origine en tant qu'origine, entre une position rétractée de régulation au niveau de laquelle une extrémité libre sur le côté d'extrémité de base de la partie de régulation est située radialement vers l'intérieur et une position déployée de régulation au niveau de laquelle l'extrémité libre est située radialement vers l'extérieur. Sur l'extrémité libre, il est prévu une partie verrouillée de régulation (82) qui est verrouillée contre la partie de verrouillage de régulation par la force de sollicitation de l'élément de sollicitation au niveau de la position déployée de régulation. La seringue (1) comprend une partie de libération de régulation (5) pour déplacer la partie de régulation de la position déployée de régulation à la position rétractée de régulation, et libérer ainsi le verrouillage de la partie de verrouillage de régulation contre la partie de verrouillage de régulation, à une position où est achevée la dépression pour une administration du contenu de seringue.
PCT/JP2024/043139 2023-12-07 2024-12-06 Seringue Pending WO2025121395A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2023-206990 2023-12-07
JP2023206990 2023-12-07

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013145789A1 (fr) * 2012-03-30 2013-10-03 株式会社吉野工業所 Dispositif de pulvérisation de type seringue doseuse
WO2017072992A1 (fr) * 2015-10-29 2017-05-04 株式会社吉野工業所 Éjecteur du type seringue
JP2018108146A (ja) * 2016-12-28 2018-07-12 株式会社吉野工業所 シリンジ型噴出器

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JP2018108146A (ja) * 2016-12-28 2018-07-12 株式会社吉野工業所 シリンジ型噴出器

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