RU2229901C1 - Apparatus for positioning of needle holder of hypodermic safety syringe - Google Patents

Abstract

FIELD: medicine, in particular, equipment for keeping needle holder in required position. SUBSTANCE: apparatus has syringe cylinder-liquid vessel having front part of small inner diameter, rear part with larger inner diameter, edge coupled between front and rear parts, and inner flange arranged in rear part in the vicinity of edge. Needle holder is positioned in syringe cylinder and is composed of base with tubular central portion and coupling coaxially arranged and made integral with base peripheral part. Base with tubular central part has holding portion arranged at its rear part. Coupling has front engagement part tightly inserted into front part with smaller inner diameter of liquid vessel of syringe cylinder, and rear resilient extendable part with front edge corresponding to rear side of syringe cylinder edge and rear edge arranged near front side of inner flange. Rear extendable part form in conjunction with base peripheral part annular connecting chamber extendable in rear direction, and fixing ring positioned in syringe cylinder and engaged with needle holder. Outer surface of fixing ring wall is in contact with inner surface of liquid vessel rear wall. Inner surface of wall is in contact with base peripheral part. Front part of outer surface of fixing ring wall defines neck portion, which is inserted in engaged state into rear extendable part of needle holder coupling. Outer diameter of neck portion is at least equal to inner diameter of extendable part of needle holder coupling. EFFECT: increased safety of syringe by providing arrangement of needle holder in predetermined position and, accordingly, preventing needle holder from casual getting into syringe cylinder. 8 cl, 7 dwg

Description

The invention relates to medical equipment, in particular to devices for installing a needle holder in a predetermined position, designed for safe hypodermic syringes.

Already there are some devices for positioning the needle holder of safe hypodermic syringes, which are quite simple in design and can be manufactured in large quantities, having a low cost; however, they do not ensure accuracy and therefore medical personnel find them generally unacceptable.

A device for positioning the needle holder of a safe hypodermic syringe is already known, including a syringe barrel — a fluid container, a front part, a back part, a collar connected between said front part and a back part, and an internal flange device located in the back part next to said bead; a needle holder installed in said syringe barrel and consisting of a base with a tubular center and a sleeve coaxially and integrally with the periphery of the base with a tubular center and a retaining ring (see US Pat. No. 5,232,458, published 03.04.1993).

A disadvantage of the known device is the complexity of manufacturing, which leads to a large percentage of marriage.

The objective of the invention is to provide a safe hypodermic syringe with a device to set the needle holder in a predetermined position, preventing accidental dropping of the needle holder into the syringe barrel, and to provide a safe hypodermic syringe with such a device to set the needle holder in a predetermined position, which has a simple design and does not cost much in the manufacture.

The objective of the claimed invention is achieved due to the fact that the positioning device of the needle holder of a safe syringe for hypodermic injection includes a syringe barrel - a liquid container having a front part with a small inner diameter, a back part with a large inner diameter, a shoulder connected between the front part with a small inner diameter and said rear end with a large inner diameter, and an inner flange arrangement located in said back end with a large inner with a diameter next to said shoulder, a needle holder installed in the said syringe barrel and consisting of a base with a tubular center and a sleeve coaxially and integrally with the periphery of the base with the tubular center, said base with a tubular center has a holding part with its back side, said clutch has a front mating part, inserted with a tight fit inside the front part with a small inner diameter of the liquid container of the above cylinder tsa, and a rear elastic stretch portion, said rear stretch portion having a leading edge corresponding to the rear side of said shoulder of said syringe barrel, and a trailing edge located at the front side of the inner flange fixture of said syringe barrel, and said rear stretching portion along with the periphery of said the base with a tubular center forms a rearwardly extending annular connecting chamber, and a retaining ring mounted inside said of said syringe barrel and concatenated with said needle holder, wherein the outer wall surface of the retaining ring contacts the inner wall surface of the rear portion of said liquid container with a large internal diameter of the syringe barrel, which makes it possible to move the retaining ring axially in the syringe barrel; the inner surface of the wall is in contact with the periphery of the base with the tubular center of the needle holder, which makes it possible to move said retaining ring axially relative to the needle holder; the front part of the outer surface of the wall of the retaining ring forms a neck that engages with the aforementioned rear stretching part of the needle holder clutch, and the outer diameter of this neck is not less than the inner diameter of the stretching part of the needle holder clutch, which ensures stretching of the rear stretching part of the sleeve to stop the rear edge of the rear stretching part at the front side of the inner flange fixture of the syringe barrel, the first holding portion forms a unit with the front astyu inner wall surface of the retaining ring and engages with the holding portion of the base to the tubular center of the needle hub; and the second holding part forms a unit with the rear part of the inner surface of the wall of the retaining ring.

The inner flange fixture of the syringe barrel may be an inwardly protruding inner annular flange.

The inner flange fixture of the syringe barrel may have a wedge-shaped cross-sectional shape.

The back stretch part of the needle holder may be a thin annular wall having elastic properties.

The back stretch part of the needle holder may consist of at least two elastic strips.

At least two elastic strips of the rear stretch part of the needle holder can be located symmetrically.

The back stretch part of the needle holder can be made of elastic plastic.

The holding portion of the needle holder may be an outer annular flange surrounding the periphery of the base with a tubular center.

Figure 1 presents a three-dimensional image of a preferred embodiment of the present invention.

Figure 2 presents a slice of a preferred embodiment of the present invention before attaching the retaining ring to the needle holder.

FIG. 3 is a sectional view of a prefabricated structure of a preferred embodiment of the present invention, showing a retaining ring attached to a needle holder.

Figure 4 presents a slice showing the effect of a preferred embodiment of the present invention (I).

5 is a slice showing the effect of a preferred embodiment of the present invention (II).

6 is a slice showing the effect of a preferred embodiment of the present invention (III).

Figure 7 presents a vertical projection of an alternative form of the needle holder corresponding to this invention.

As shown in FIG. 1, a safe hypodermic syringe consists of a syringe barrel (1), a needle holder (2), a retaining ring (3) and a piston (4). As shown in figure 2, the cylinder of the syringe (1) is a hollow cylindrical part - a container for liquid (10). The liquid tank (10) has a front part with a small inner diameter (11); the back with a large inner diameter (12); a shoulder (13) connected between the front part with a small inner diameter (11) and the rear part with a large inner diameter (12); an inner flange (14) located at the rear with a large inner diameter (12) near the shoulder (13). As shown in figures 1 and 2, the design of the needle holder (2) provides retention of the needle cannula (not shown) from the front of the cylinder of the syringe (1); the needle holder consists of a base with a tubular center (21) and a sleeve (22) located coaxially and forming a single unit with the periphery of the base with a tubular center (21); the sleeve (22) has a front mating portion (221) and a rear stretching portion (222). The front mating part (221) of the coupling (22) is inserted with a tight fit inside the front of the fluid container (11) of the syringe barrel (1) with a small inner diameter on the rear side. The rear stretch portion (222) has a leading edge (223) corresponding to the rear side of the shoulder (13) of the syringe barrel (1), and a trailing edge (224) located at the front side of the inner flange (14) of the syringe barrel (1). The rear stretch portion (222), together with the periphery (210) of the base with the tubular center (21), forms a rearwardly extending annular connecting chamber.

As shown in FIG. 3 and FIGS. 1 and 2, the retaining ring (3) has an outer wall surface (31) and an inner wall surface (32). The outer wall surface of the retaining ring wall (31) is in contact with the inner wall surface of the rear part (12) of the syringe barrel (1) with a large inner diameter; this makes it possible to move the locking ring (3) in the barrel of the syringe (1) along its axis. The inner surface of the wall (32) is in contact with the periphery (210) of the base with the tubular center (21) of the needle holder (2), which makes it possible to move the locking ring (3) along the axis relative to the needle holder (2). The front of the outer surface of the wall (31) forms a neck (311). The outer diameter of the neck (311) is slightly larger than the inner diameter of the stretched part (222) of the needle holder sleeve (22) (2). The retaining ring (3) further consists of a first holding part (321), forming a single unit with the front part of the inner surface of the wall (32), and a second holding part (322), forming a single unit with the back of the inner surface of the wall (32). The first holding portion (321) is adapted to engage with the holding portion (211) at the rear end of the periphery (210) of the base with the tubular center (21) of the needle holder (2). The second holding portion (322) is adapted to engage the swept front holding tip (41) of the piston (4). In accordance with this embodiment of the invention, the retaining part (211) of the needle holder (2) is an outer annular flange surrounding the periphery (210) of the base with a tubular center (21). The first holding portion (321) is an annular flange surrounding the inner surface of the wall (32) of the retaining ring (3). The cross section of the holding part (211) has the shape of a wedge, and the first holding part (321) has the shape of an opposed wedge. Thus, the first holding portion (321) is easily engaged with the holding portion (211) and is difficult to separate from it.

The assembly process in accordance with this invention is presented below (see figure 3). The needle holder (2) and the retaining ring (3) are inserted in the correct order into the fluid container (10) of the syringe barrel (1) from the rear side, after which the piston (4) is inserted into the fluid reservoir (10) of the syringe barrel (1) and push the locking ring (3) and the needle holder (2) forward. When pushing the locking ring (3) and the needle holder (2) forward into the fluid container (10) of the syringe barrel (1), the front mating part (221) of the sleeve (22) engages with the front portion (11) of the syringe barrel (1) with a small inner diameter, and the neck (311) of the retaining ring (3) engages with the rearwardly extending annular connecting chamber (225) of the needle holder (2). When the locking ring (3) is inserted into the neck (311) with the clutch into the rearwardly extending annular connecting chamber (225) of the needle holder (2), the rear stretch part (222) is pulled out, leading to the rear edge (224) being engaged with the front side of the inner the flange (14) of the syringe barrel (1), which prevents the needle holder 2 from moving backward in the barrel of the syringe 1.

As shown in FIG. 3, the neck (311) of the retaining ring (3) has a beveled front surface (312) guiding the neck (311) of the retaining ring (3) into the rearwardly elongated annular connecting chamber (225) of the needle holder (2). The inner flange (14) of the syringe barrel (1) is an inwardly projecting annular flange having a beveled rear surface (141) guiding the needle holder (2) into its position. Alternatively, the inner flange (14) may be formed of separate protruding blocks, wedge-shaped blocks, or blocks having a triangular or arched cross section located at equal angles to each other around the inner surface of the back with a large inner diameter (12) of the syringe barrel ( 1). As shown in FIG. 4, after pushing the piston (4) to the frontal position (injection completion position), the piston (4) is further pushed forward to engage the swept front holding tip (41) of the piston (4) with the second holding part (322 ) of the fixing ring (3). As shown in FIG. 5, after engagement of the swept front holding tip (41) of the piston (4) with the second holding part (322) of the locking ring (3), the piston (4) together with the second holding part (322) of the locking ring (3) moves relative to the needle holder 2, thereby leading to the engagement of the first holding part (321) of the retaining ring (3) with the holding part (211) of the base with the tubular center (21) of the needle holder (2), so that the needle holder (2) can be moved together with locking ring (3) and piston (4) n Azad. At this time, the neck (311) of the retaining ring (3) is separated from the stretching part (222) of the needle holder (2), and the stretching part (222) restores its former shape and is disconnected from the inner flange (14) of the syringe barrel (1). As shown in FIG. 6, when the piston is continuously pulled back after the first holding part (321) of the retaining ring (3) engages with the retaining part (211) of the base with the tubular center (21) of the needle holder (2), the needle holder (2) moves with the fixing ring (3) back into the syringe barrel (1). In accordance with the present preferred embodiment, the stretch portion (222) of the needle holder (2) is a thin annular wall having elastic properties. 7 shows an alternative embodiment of the present invention. In accordance with this alternative, the back stretch portion of the needle holder sleeve (2 ’) consists of four elastic strips (226) located at equal angles to each other. Preference should be given to molded plastic (e.g. polypropylene) elastic strips (226). Alternatively, spring steel or any other of a variety of elastic materials can be used to make elastic strips (226) or the aforementioned rear stretch portion (222).

In accordance with this invention, the requirements for dimensional accuracy of manufactured needle holders and syringe cylinders are mitigated; In this regard, in order to reduce production costs and increase production output, the needle holder and the syringe barrel can be manufactured by injection molding.

A prototype of a device for installing a needle holder in a predetermined position for safe hypodermic syringes was created, the parameters of which are illustrated in figures 1-7. A safe hypodermic syringe works smoothly, providing all of the features described above.

Although one specific embodiment has been described in detail in order to illustrate the invention, various modifications can be made and various performance enhancements applied without departing from the spirit and scope of the invention. Thus, this invention should not have any restrictions, with the exception of those defined in the attached claims.

The technical essence of the invention lies in the fact that in the device for installing the needle holder in a predetermined position for safe hypodermic syringes, which includes a syringe barrel, a needle holder with a sleeve and a retaining ring, a needle holder sleeve, or a sleeve, has a front mating part mounted with a tight fit inside the front of the syringe barrel with a small inner diameter, and the rear elastic stretch part; the back elastic stretch part is stretched and installed between the shoulder and the inner flange in the syringe barrel when the piston inserted into the syringe barrel pushes the locking ring forward and displaces the front neck of the locking ring into the rear elongated annular connecting chamber in the needle holder sleeve.

Claims (8)

1. The positioning device of the needle holder of a safe hypodermic syringe, comprising a syringe barrel - a liquid container having a front part with a small inner diameter, a back part with a large inner diameter, a flange connected between said front part with a small inner diameter and said back part with a large inner diameter, and an inner flange device located in said rear part with a large inner diameter next to said shoulder; a needle holder installed in said syringe barrel and consisting of a base with a tubular center and a sleeve coaxially and integrally with the periphery of said base with a tubular center, characterized in that said base with a tubular center has a holding part on its back side, said sleeve has a front mating part inserted with a tight fit inside the front part with a small inner diameter of the liquid container of the said syringe barrel, and the rear elastic stretching a retractable portion, said rear stretch portion having a leading edge corresponding to the rear side of said shoulder of said syringe barrel, and a trailing edge located at the front side of the inner flange fixture of said syringe barrel, and this trailing back portion together with the periphery of said base with a tubular center forms rearwardly extending annular connecting chamber and a retaining ring mounted inside said syringe barrel and fief with said needle holder, wherein the outer wall surface of the retaining ring contacts the inner wall surface of the rear portion of said liquid container with a large internal diameter of the syringe barrel, which makes it possible to move the retaining ring axially in the syringe barrel; the inner surface of the wall is in contact with the periphery of the base with the tubular center of the needle holder, which makes it possible to move said retaining ring axially relative to the needle holder; the front part of the outer surface of the wall of the retaining ring forms a neck that engages with the aforementioned rear stretching part of the needle holder clutch, and the outer diameter of this neck is not less than the inner diameter of the stretching part of the needle holder clutch, which ensures stretching of the rear stretching part of the sleeve to stop the rear edge of the rear stretching part at the front of the inner flange fixture of the syringe barrel; the first holding part forms a whole with the front part of the inner surface of the wall of the retaining ring and engages with the holding part of the base with the tubular center of the needle holder and the second holding part forms a whole with the back of the inner surface of the wall of the retaining ring. 2. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the inner flange device of the syringe barrel is an inner ring-shaped flange protruding inward. 3. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the inner flange device of the syringe barrel has a wedge-shaped cross-sectional shape. 4. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the back stretching part of the needle holder is a thin annular wall having elastic properties. 5. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the back stretching part of the needle holder consists of at least two elastic strips. 6. The positioning device of the needle holder of a safe hypodermic syringe according to claim 5, characterized in that at least two elastic strips of the rear stretch part of the needle holder are located symmetrically. 7. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the back stretchable part of the needle holder is made of elastic plastic. 8. The positioning device of the needle holder of a safe hypodermic syringe according to claim 1, characterized in that the holding part of the needle holder is an outer ring-shaped flange surrounding the periphery of the base with a tubular center.

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