WO2025025637A1 - Automatic injection pen - Google Patents

Abstract

The present application provides an automatic injection pen, comprising a pre-filled injector module. A guide groove is formed in a guide sleeve; a push rod is provided with fin-shaped structures corresponding to the guide groove; a trigger sleeve is provided with ribs at positions corresponding to the fin-shaped structures; during use of the injection pen, elastic pieces open and cause the trigger sleeve to move downwards; the ribs push the fin-shaped structures, so that the fin-shaped structures can slide in the guide groove; an injection spring pushes the push rod to perform injection; and a spring frame also moves downwards. Therefore, the assembly process is simplified, the assembly efficiency is improved, and the safety of the assembly process is improved.

Description

Automatic injection pen Technical Field

The present invention relates to the technical field of medical instruments, and more specifically, to an automatic injection pen.

Background Art

With the explosive population growth, the urban siphon effect, and the increasing shortage of medical resources, the management of chronic diseases will occupy a large amount of medical resources and cause huge economic costs. Society has put forward higher requirements for injection devices used by patients themselves. People hope that the operation of the injection devices is as simple as possible and does not require special training. Traditional injection devices usually require proficiency in the angle and depth of the needle and manual push injection, resulting in a certain difference in the effect of drug injection due to the user's proficiency. With the development of pharmaceutical technology, more and more chronic diseases are treated with periodic medication. The traditional injection method has a cumbersome and complicated injection process. Patients may forget the usage steps before each injection, resulting in the drug failing to exert its due effect.

The emergence of automatic injection devices provides an effective solution to this problem. People hope that the injection device is easy to operate, has high patient compliance, and has multi-dimensional feedback during the injection process, such as hearing, vision, and touch. Patients can control the entire injection process by obtaining feedback signals, reduce anxiety, and increase confidence; at the same time, the needle insertion depth is stable and consistent, and no adjustment is required by the patient, and the needle tip is exposed before and after the injection to avoid causing fear to the patient; the injection process does not require manual push injection and the injection time is reasonable; after the injection is completed, it should also have functions such as anti-accidental touch and/or anti-secondary use. At the same time, people pay more attention to personal privacy issues, and have higher requirements for the miniaturization, portability, and usability of products. How to achieve the above functions and performance to meet market demand is currently receiving the attention of more and more engineering and technical personnel. At present, such products on the market have the following disadvantages:

1. At present, in order to realize the automatic injection function, this type of product uses electric motors as the power source of the injection mechanism.

This method consumes energy, has high cost, and has a complex control system. The use of batteries will cause environmental pollution. Connecting with various transmission mechanisms will make the overall volume of the product large, and it is impossible to achieve the requirements of portability and ease of use.

2. In order to achieve multi-dimensional feedback, most of the related products on the market rely on electronic components to complete vision, Auditory feedback, the product still needs battery power. If the product is used in an environment with strong electromagnetic interference, it cannot achieve its intended function. Electronic components are easily affected by the environment and are prone to aging, so they are not suitable for long-term storage. It is difficult to ensure the stability and reliability of the entire device when used in a complex environment.

3. Currently, such products on the market have many operating steps, often requiring at least three steps. There is still a risk of patients forgetting when using them periodically, and patient compliance is poor.

4. After using the products on the market, users are often required to insert a limit pin or rotate the locking mechanism to achieve self-locking of the product, thereby preventing secondary use and mis-triggering. However, in certain specific cases, the limit parts may be lost or the patient may forget to operate, so that the product cannot ensure self-locking after use. Moreover, such a design violates ergonomics and does not conform to the design characteristics of such products.

5. In order to realize the automatic injection function, most existing products use buckle and other structural designs on the trigger mechanism, and use the elastic deformation of the parts to complete the triggering and locking processes. This design often requires the buckle and other structures to be in a compressed and deformed state. Since this type of product is used once, the parts are usually injection molded from polymer materials. The buckle structure of the parts is compressed, which is not conducive to transportation and long-term storage, and is greatly affected by the environment. Such structures are prone to plastic deformation.

Summary of the invention

The object of the present invention is to provide an automatic injection pen, comprising a prefilled syringe module 1, a guide groove 1002 is provided at the guide sleeve 10, a wing-shaped structure 801 corresponding to the guide groove 1002 is provided at the push rod 8, a spring piece 1101 is provided at the trigger sleeve 11, and a rib position 1102 is provided at the corresponding wing-shaped structure 801. When the injection pen is in use, the spring piece 1101 opens and causes the trigger sleeve 11 to move downward, and the trigger slope 11021 of the rib position 1102 pushes the wing-shaped structure 801 so that the wing-shaped structure 801 can slide in the guide groove 1002, the injection spring 9 pushes the push rod 8 to inject, and the spring frame also moves downward, thereby simplifying the number of parts, optimizing the assembly process, improving the assembly efficiency, and improving the safety of the assembly process.

An automatic injection pen, comprising a prefilled syringe module 1, wherein a push rod 8 is sleeved at the bottom of the prefilled syringe module 1, wherein the push rod 8 can slide in the prefilled syringe module 1, wherein an injection spring 9 is sleeved inside the push rod 8, wherein a needle protection sleeve 2 is sleeved outside the prefilled syringe module 1, wherein the injection spring 9 is penetrated by a spring frame 12, wherein the spring frame 12 comprises a spring guide rod structure 1202 arranged in the middle of the spring frame 12 and elastic arms arranged on both sides of the spring frame 12, wherein the elastic arms 1202 are provided at the bottom of the prefilled syringe module ... A hook 1201 is provided at the top of the arm, and the spring guide rod structure 1202 passes through the injection spring 9, so that one end of the injection spring 9 abuts against the push rod 8, and the other end abuts against the spring frame 12; the spring frame 12 is sleeved with a guide sleeve 10 on the outside, and a platform structure 1001 is provided on the upper part of the guide sleeve 10. Before the injection pen is used, the platform structure 1001 is engaged with the hook 1201, and a guide groove 1002 is also provided at the guide sleeve 10, and a wing-shaped structure 801 corresponding to the guide groove 1002 is provided at the push rod 8. A trigger sleeve 11 is provided on the outer sleeve of the guide sleeve 10, and the upper end of the trigger sleeve 11 abuts against the needle protection sleeve 2, and the lower end is provided with an end cover 14. The trigger sleeve 11 corresponds to the platform A spring piece 1101 is provided at the structure 1001, and a first protrusion 11012 is provided on the inner wall of the spring piece 1101 and abuts against the hook 1201. A rib position 1102 is provided at the trigger sleeve 11 corresponding to the wing-shaped structure 801, and a return spring 13 is provided on the outer sleeve of the trigger sleeve 11. When the injection pen is in use, the needle protection sleeve 2 pushes the trigger sleeve 11 downward, and the spring piece 1101 opens and moves the trigger sleeve 11 downward under the interaction between the first protrusion 11012 and the hook 1201. The rib position 1102 pushes the wing-shaped structure 801 so that the wing-shaped structure 801 can slide in the guide groove 1002, and the injection spring 9 pushes the push rod 8 to inject, and the spring frame 12 moves downward at the same time, and the injection ends.

Furthermore, the end close to the injector is the proximal end of the injection pen, and the end away from the injector is the distal end of the injection pen.

In some embodiments, a limiting straight surface 10021 is provided at the lower end of the guide groove 1002. Before the automatic injection pen is used, the upper surface of the wing-shaped structure 801 of the push rod 8 is pressed against the limiting straight surface 10021 at the lower end of the guide groove 1002; at this time, the injection spring 9 is compressed between the push rod 8 and the spring frame 12, and the injection spring 9 is in the shortest compressed position.

In some embodiments, the push rod 8 includes at least two wing-shaped structures 801 , and the wing-shaped structures 801 are centrally symmetrically distributed along the central axis of the push rod 8 .

Furthermore, the upper surface of the fin-shaped structure 801 is an inclined surface or an arc surface, which is convenient for contacting with the rib 1102 .

In some embodiments, the spring frame 12 is provided with at least two elongated elastic arms, and each of the at least two elastic arms is provided with a protruding hook 1201 .

Furthermore, the push rod 8 is located within the slender elastic arm of the spring frame 12 . Before the automatic injection pen is used, the deformation of the elastic arm of the spring frame 12 in the axial direction (inward) is limited by the push rod 8 .

Furthermore, the hook 1201 includes a hooking surface 12011 and an upper inclined surface 12012. The surface 12011 is an upwardly inclined surface, which facilitates the platform structure 1001 to be unhooked.

Furthermore, the upper inclined surface 12012 of the hook 1201 abuts against the lower inclined surface of the first protrusion 11012 of the trigger sleeve 11 .

In some embodiments, the second protrusions 11011 are symmetrically provided on both sides of the first protrusion 11012, and the upper surface and the lower surface of the second protrusion 11011 are both flat. When the automatic injection pen finishes injection, the second protrusion 11011 is located at the platform structure 1001 to prevent secondary false triggering.

Furthermore, the height of the first protrusion 11012 is "H", the wall thickness of the trigger sleeve 11 is "t", H＞t, and when in use, in order to allow the spring piece 1101 to move downward after opening, the second protrusion 11011 can avoid the platform structure 1001.

Furthermore, the rib 1102 is a "J"-shaped rib, and a trigger slope 11021 is provided at the bottom of the "J"-shaped rib. During the use of the syringe body, the trigger slope 11021 pushes the wing-shaped structure 801 to rotate and slide in the sliding guide groove 1002.

Furthermore, the upper end of the trigger sleeve 11 has a flange structure 1103 for limiting the return spring 13 .

Furthermore, the lower end of the return spring 13 abuts against the end cover 14, and the end cover 14 is clamped with the bottom end of the guide sleeve 10; the return spring 13 is confined between the trigger sleeve 11 and the end cover 14, and is in its longest position before the automatic injection pen is used.

In some embodiments, the needle protection sleeve 2 has an extended cantilever structure 201 . Before the injection pen is used (initial state), the lower surface of the cantilever structure 201 of the needle protection sleeve 2 abuts against the upper surface of the flange structure 1103 of the trigger sleeve 11 .

In some embodiments, before the injection pen is used (initial state), the prefilled syringe module 1 is pre-installed at the proximal end of the injection pen body, and a viewing window 3 is provided on the outside of the injection pen body, and the viewing window 3 is a transparent part, and a needle protection sleeve 2 is provided on the outer cover of the viewing window 3, and the needle protection sleeve 2 is provided on the outer cover of the outer shell 4, and the outer shell 4 has a window structure, and the drug solution and the piston can be seen through the window of the outer shell 4 and the viewing window 3.

Working principle:

When using, first, the patient needs to remove the pen cap, which will take off the needle cover and separate it from the needle. Then, hold the injection pen with your hand, align the upper end of the needle protection sleeve 2 with the injection position of the body, and press it towards the proximal end. The needle protection sleeve 2 pushes the trigger sleeve 11 to move towards the distal end. When the trigger sleeve 11 starts to move, its spring 1101 is Under the interaction of the lower inclined surface of the first protrusion 11012 on its inner wall and the upper inclined surface 12012 of the hook 1201 on the elastic wall of the spring frame 12, it opens outward, and continues to push hard, the needle will pierce the human body. When the trigger sleeve 11 is pushed to a certain position by the needle protection sleeve 2, the trigger inclined surface 11021 of the "J"-shaped rib position of the trigger sleeve 11 will contact the upper surface of the wing-shaped structure 801 of the push rod 8.

At this time, the patient continues to push hard, the trigger sleeve 11 will continue to move toward the distal end, the trigger slope 11021 of the "J" rib position of the trigger sleeve 11 will push the push rod 8 to rotate along its central axis X, and when the needle protection sleeve 2 moves to contact with the shell 4, the shell 4 limits the continued movement of the needle protection sleeve 2; the trigger slope 11021 of the "J" rib position of the trigger sleeve 11 pushes the push rod 8 to rotate to the maximum position, so that it is separated from the limiting straight surface 10021 of the guide groove 1002 of the guide sleeve 10; at this time, the return spring 13 is in the maximum compression position, and the push rod 8 is no longer limited by the guide sleeve 10. Under the elastic force of the injection spring 9, it will move toward the proximal end, thereby pushing the piston to cause the liquid medicine to be injected into the human body. During the injection process, the wing-shaped structure 801 of the push rod 8 will move from the distal end to the proximal end in the guide groove 1002 of the guide sleeve 10. When the injection is completed, the injection push rod 8 moves to the proximal end limit position. At this time, the lower end face of the push rod 8 just moves to the hook 1201 on the slender elastic arm of the injection spring 9 bracket, and the restriction on the deformation of the elastic arm in the axial direction (inward) is released. Because the engaging surface 12011 of the hook 1201 of the spring bracket is an inclined surface, under the push of the reverse elastic force of the injection spring 9, the slender elastic wall of the spring bracket is deformed in the axial direction, and the engaging surface 12011 of the hook 1201 is disengaged from the platform structure 1001 of the guide sleeve 10, and the injection spring 9 bracket is pushed toward the distal end by the reverse elastic force of the injection spring 9, and finally hits the end cover 14 to make a hitting sound, giving the user sound feedback that the injection is completed.

After use, when the injection is finished, the user pulls the injection pen out of the body. At this time, the trigger sleeve 11, under the elastic force of the return spring 13, pushes the needle protection sleeve 2 to move toward the proximal end, and finally retreats to the initial position. At this time, the needle is covered inside by the needle protection sleeve 2. The spring piece 1101 of the trigger sleeve 11 also recovers from the open state to the initial state under the internal stress of the part itself. At this time, if the needle protection sleeve 2 is pushed toward the distal end again, the needle protection sleeve 2 will contact the trigger sleeve 11. At this time, the lower planes of the second protrusions 11011 on both sides of the spring piece 1101 of the trigger sleeve 11 will contact the platform structure 1001 of the guide sleeve 10, thereby preventing the trigger sleeve 11 and the needle protection sleeve 2 from continuing to move toward the distal end, thereby preventing the needle from being exposed from the needle protection sleeve 2 again and causing harm to people.

The beneficial effects of the present invention are as follows: an automatic injection pen is provided, comprising a prefilled syringe module 1, a guide groove 1002 is provided at the guide sleeve 10, a wing-shaped structure 801 corresponding to the guide groove 1002 is provided at the push rod 8, a spring piece 1101 is provided at the trigger sleeve 11, and a rib position 1102 is provided at the position corresponding to the wing-shaped structure 801, when the injection pen is in use, the spring piece 1101 opens and causes the trigger sleeve 11 to move downward, the trigger slope 11021 of the rib position 1102 pushes the wing-shaped structure 801 so that the wing-shaped structure 801 can slide in the guide groove 1002, the injection spring 9 pushes the push rod 8 to inject, and the spring frame also moves downward, thereby simplifying the number of parts, optimizing the assembly process, improving the assembly efficiency, and improving the safety of the assembly process.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present application will be more fully described when read in conjunction with the following drawings. It will be understood that these drawings only depict several implementations of the present application and should not be considered as limiting the scope of the present application. By using the drawings, the present application will be more clearly and detailed.

FIG. 1 is an exploded view of the automatic injection pen of the present application.

FIG. 2 is a structural diagram of the guide sleeve of the automatic injection pen of the present application.

FIG. 3 is a structural diagram of a spring frame of the automatic injection pen of the present application.

FIG. 4 is a structural diagram of the trigger sleeve of the automatic injection pen of the present application.

FIG5 is a cross-sectional view 1 of the trigger sleeve of the automatic injection pen of the present application.

FIG. 6 is a structural diagram of the push rod of the automatic injection pen of the present application.

FIG. 7 is a structural diagram of the needle protection sleeve of the automatic injection pen of the present application.

FIG8 is a cross-sectional view of the automatic injection pen of the present application before use.

FIG. 9 is an enlarged view of the partial view A of FIG. 8 .

FIG. 10 is a structural diagram of the guide sleeve and the push rod of the automatic injection pen of the present application before use.

FIG. 11 is an enlarged view of the partial view B of FIG. 10 .

FIG. 12 is a cross-sectional view 2 of the trigger sleeve of the automatic injection pen of the present application.

FIG. 13 is an enlarged view of the partial view C of FIG. 12 .

FIG. 14 is a cross-sectional view of the starting movement of the automatic injection pen of the present application.

FIG. 15 is a partial structural diagram of the starting movement of the automatic injection pen of the present application.

FIG. 16 is a cross-sectional view of the continuous motion of the automatic injection pen of the present application.

FIG. 17 is a partial structural diagram of the continuous motion of the automatic injection pen of the present application.

FIG. 18 is a partial structural diagram of the automatic injection pen of the present application during the second movement.

FIG. 19 is a cross-sectional view of the automatic injection pen of the present application when the movement is stopped.

FIG. 20 is a cross-sectional view of an incorrectly triggered automatic injection pen of the present application.

FIG. 21 is a partial structural diagram of an incorrectly triggered automatic injection pen of the present application.

Description of main component symbols:

Prefilled syringe module 1, push rod 8, wing-shaped structure 801, injection spring 9, needle protection sleeve 2, cantilever structure 201, spring frame 12, spring guide rod structure 1202, hook 1201, hooking surface 12011, upper inclined surface 12012, guide sleeve 10, platform structure 1001, guide groove 1002, limit straight surface 10021, end cover 14, trigger sleeve 11, spring piece 1101, first protrusion 11012, second protrusion 11011, rib position 1102, trigger inclined surface 11021, flanging structure 1103, return spring 13, window 3, shell 4.

DETAILED DESCRIPTION

The following examples are described to assist the understanding of the present application, and the examples are not and should not be interpreted in any way as limiting the scope of protection of the present application.

In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as separate functional units (which may include subunits), but those skilled in the art will recognize that various components or portions thereof may be divided into separate components, or may be integrated together (including integration into a single system or component). The connections between components or systems are not intended to be limited to direct connections. Instead, the data between these components may be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections may be used. It should also be noted that the terms "connect", "connect", or "input" "fixed" should be understood to include direct connection, indirect connection or fixation through one or more intermediate media.

In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "side", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, or the positions or positional relationships when the product of the application is used or commonly known, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In addition, the terms "horizontal", "vertical" and "outside" are not intended to limit the present application. Terms such as "horizontal" and "vertical" do not mean that the structure must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

Embodiment 1:

As shown in Figure 1, the injection pen includes a pen cap, a needle protection sleeve 2, a window 3, a shell 4, and a prefilled syringe mold 1. The prefilled syringe mold 1 includes a needle cover, a syringe body, and a piston; an injection push rod 8, an injection spring 9, a guide sleeve 10, a trigger sleeve 11, an injection spring frame 12, a return spring 13, and an end cover 14.

An automatic injection pen comprises a prefilled syringe module 1, wherein a push rod 8 is sleeved at the bottom of the prefilled syringe module 1, wherein the push rod 8 can slide inside the prefilled syringe module 1, wherein an injection spring 9 is sleeved inside the push rod 8, wherein a needle protection sleeve 2 is sleeved outside the prefilled syringe module 1, wherein a spring frame 12 penetrates inside the injection spring 9.

The lower end of the return spring 13 abuts against the end cover 14, and the end cover 14 is clamped with the bottom end of the guide sleeve 10; the return spring 13 is confined between the trigger sleeve 11 and the end cover 14, and is in its longest position before the automatic injection pen is used.

Before the injection pen is used (initial state), the prefilled syringe module 1 is pre-installed on the proximal end of the injection pen body, and the injection pen body is provided with a viewing window 3, which is a transparent part, and the viewing window 3 is covered with a needle protection sleeve 2, and the needle protection sleeve 2 is covered with a shell 4, and the shell 4 has a window structure, and the drug solution and the piston can be seen through the window of the shell 4 and the viewing window 3.

As shown in Figures 2, 10 and 11, the spring frame 12 is externally sleeved with a guide sleeve 10, and a platform structure 1001 is provided on the upper portion of the guide sleeve 10. Before the injection pen is used, the platform structure 1001 is engaged with the hook 1201, and a guide groove 1002 is further provided on the guide sleeve 10; a limiting straight surface 10021 is provided at the lower end of the guide groove 1002, and before the automatic injection pen is used, the upper surface of the wing-shaped structure 801 of the push rod 8 is pressed against the limiting straight surface 10021 at the lower end of the guide groove 1002; at this time, the injection spring 9 is compressed between the push rod 8 and the spring frame 12, and the injection spring 9 is in the shortest compressed position.

As shown in FIG. 3 and FIG. 8 , the spring frame 12 includes a spring guide rod structure 1202 disposed in the middle of the spring frame 12 and elastic arms disposed on both sides of the spring frame 12, and a hook 1201 is disposed at the top of the elastic arm. The spring guide rod structure 1202 passes through the injection spring 9, so that one end of the injection spring 9 abuts against the push rod 8, and the other end abuts against the spring frame 12; the spring frame 12 is provided with at least two elongated elastic arms, and each of the at least two elastic arms is provided with a protruding hook 1201; the push rod 8 is located within the slender elastic arms of the spring frame 12, and before the automatic injection pen is used, the deformation of the elastic arms of the spring frame 12 in the axial direction (inward) is limited by the push rod 8.

The hook 1201 includes a hooking surface 12011 and an upper inclined surface 12012 . The hooking surface 12011 is an upward inclined surface, which facilitates the platform structure 1001 to be unhooked.

The upper inclined surface 12012 of the hook 1201 abuts against the lower inclined surface of the first protrusion 11012 of the trigger sleeve 11 .

As shown in Figure 6, the push rod 8 is provided with a wing-shaped structure 801 corresponding to the guide groove 1002. The push rod 8 contains at least two wing-shaped structures 801. The wing-shaped structures 801 are centrally symmetrically distributed along the central axis of the push rod 8. The upper surface of the wing-shaped structure 801 is an inclined surface or an arc surface, which is convenient for contact with the rib position 1102.

As shown in Figures 4, 5 and 9, the guide sleeve 10 is provided with a trigger sleeve 11 on its outer sleeve, the upper end of the trigger sleeve 11 abuts against the needle protection sleeve 2, and the lower end is provided with an end cover 14. The trigger sleeve 11 is provided with a spring piece 1101 at the corresponding platform structure 1001, and the inner wall of the spring piece 1101 is provided with a first protrusion 11012 and abuts against the hook 1201. The trigger sleeve 11 is provided with a rib position 1102 at the corresponding wing-shaped structure 801. The trigger sleeve 11 is provided with a cover. A return spring 13 is provided. When the injection pen is in use, the needle protection sleeve 2 pushes the trigger sleeve 11 downward, the spring piece 1101 opens under the interaction between the first protrusion 11012 and the hook 1201 and causes the trigger sleeve 11 to move downward, the rib 1102 pushes the wing-shaped structure 801 so that the wing-shaped structure 801 can slide in the guide groove 1002, the injection spring 9 pushes the push rod 8 to inject, and the spring frame 12 moves downward, and the injection ends.

The second protrusions 11011 are symmetrically arranged on both sides of the first protrusion 11012, and the upper surface and the lower surface of the second protrusion 11011 are both planes. When the injection of the automatic injection pen is completed, the second protrusion 11011 is located at the platform structure 1001 to prevent secondary false triggering. The height of the first protrusion 11012 is "H", and the wall thickness of the trigger sleeve 11 is "t", H＞t. When in use, in order to allow the spring 1101 to move downward after opening, the second protrusion 11011 can avoid the platform structure 1001.

The rib position 1102 is a "J"-shaped rib position, and a trigger slope 11021 is provided at the bottom of the "J"-shaped rib position. During the use of the syringe body, the trigger slope 11021 pushes the wing-shaped structure 801 to rotate and slide in the sliding guide groove 1002.

The upper end of the trigger sleeve 11 has a flange structure 1103 for limiting the return spring 13 .

As shown in Figures 7, 12 and 13, the needle protection sleeve 2 has an extended cantilever structure 201. Before the injection pen is used (initial state), the lower surface of the cantilever structure 201 of the needle protection sleeve 2 abuts against the upper surface of the flange structure 1103 of the trigger sleeve 11.

The end close to the injector is the proximal end of the injection pen, and the end away from the injector is the distal end of the injection pen.

Working principle:

When in use, first, the patient needs to remove the pen cap, which will bring down the needle cover and separate it from the needle. Then, hold the injection pen with your hand, align the upper end of the needle protection sleeve 2 with the injection position of the body, and press it toward the proximal end. The needle protection sleeve 2 pushes the trigger sleeve 11 to move toward the distal end. When the trigger sleeve 11 starts to move, its spring piece 1101 opens outwards under the interaction of the lower inclined surface of the first protrusion 11012 on its inner wall and the upper inclined surface 12012 of the hook 1201 on the elastic wall of the spring frame 12, as shown in Figure 14. Continue to push hard, and the needle will pierce the human body. When the trigger sleeve 11 is pushed to a certain position by the needle protection sleeve 2, as shown in Figure 15, the trigger inclined surface 11021 of the "J" rib position of the trigger sleeve 11 will contact the upper surface of the wing-shaped structure 801 of the push rod 8.

At this time, the patient continues to push hard, the trigger sleeve 11 will continue to move toward the distal end, and the trigger slope 11021 of the "J"-shaped rib position of the trigger sleeve 11 will push the push rod 8 to rotate along its central axis X, as shown in Figure 16. When the needle protection sleeve 2 moves to contact with the shell 4, the shell 4 limits the continued movement of the needle protection sleeve 2; as shown in Figure 17, the trigger slope 11021 of the "J"-shaped rib position of the trigger sleeve 11 pushes the push rod 8 to rotate to the maximum position, so that it is separated from the limiting straight surface 10021 of the guide groove 1002 of the guide sleeve 10, as shown in Figure 18; at this time, the return spring 13 is in the maximum compression position, and the push rod 8 is no longer restricted by the guide sleeve 10. Under the elastic force of the injection spring 9, it will move toward the proximal end, thereby pushing the piston to cause the liquid medicine to be injected into the human body. During the injection process, the wing-shaped structure 801 of the push rod 8 moves from the distal end to the proximal end in the guide groove 1002 of the guide sleeve 10. When the injection is completed, the injection push rod 8 moves to the proximal end limit position, as shown in FIG19. At this time, the lower end surface of the push rod 8 just moves to the hook 1201 on the slender elastic arm of the injection spring 9 bracket, and the restriction on the deformation of the elastic arm in the axial direction (inward) is released. Because the hook surface 12011 of the hook 1201 of the spring bracket is an inclined surface, the spring bracket is pushed by the reverse elastic force of the injection spring 9. The slender elastic wall is deformed toward the axial direction, and the engaging surface 12011 of the hook 1201 is disengaged from the platform structure 1001 of the guide sleeve 10. The injection spring 9 bracket is pushed toward the distal end by the reverse elastic force of the injection spring 9, and finally hits the end cover 14 to make a hitting sound, giving the user sound feedback that the injection is completed.

After use, when the injection is finished, the user pulls the injection pen out of the body. At this time, the trigger sleeve 11, under the elastic force of the return spring 13, pushes the needle protection sleeve 2 to move toward the proximal end, and finally retreats to the initial position. At this time, the needle is covered inside by the needle protection sleeve 2. The spring piece 1101 of the trigger sleeve 11 also recovers from the open state to the initial state under the internal stress of the part itself, as shown in Figure 20. At this time, if the needle protection sleeve 2 is pushed toward the distal end again, the needle protection sleeve 2 will contact the trigger sleeve 11. At this time, the lower planes of the second protrusions 11011 on both sides of the spring piece 1101 of the trigger sleeve 11 will contact the platform structure 1001 of the guide sleeve 10, as shown in Figure 21, thereby preventing the trigger sleeve 11 and the needle protection sleeve 2 from continuing to move toward the distal end, thereby preventing the needle from being exposed from the needle protection sleeve 2 again and causing harm to people.

The beneficial effects of the present invention are as follows: an automatic injection pen is provided, comprising a prefilled syringe module 1, a guide groove 1002 is provided at the guide sleeve 10, a wing-shaped structure 801 corresponding to the guide groove 1002 is provided at the push rod 8, a spring piece 1101 is provided at the trigger sleeve 11, and a rib position 1102 is provided at the position corresponding to the wing-shaped structure 801, when the injection pen is in use, the spring piece 1101 opens and causes the trigger sleeve 11 to move downward, the trigger slope 11021 of the rib position 1102 pushes the wing-shaped structure 801 so that the wing-shaped structure 801 can slide in the guide groove 1002, the injection spring 9 pushes the push rod 8 to inject, and the spring frame also moves downward, thereby simplifying the number of parts, optimizing the assembly process, improving the assembly efficiency, and improving the safety of the assembly process.

Although the present application has disclosed multiple aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art, and several modifications and improvements may be made without departing from the concept of the present application, all of which belong to the protection scope of the present application. The multiple aspects and embodiments disclosed in the present application are only for illustration and are not intended to limit the present application. The actual protection scope of the present application shall be subject to the claims.

Claims (10)

An automatic injection pen comprises a prefilled syringe module (1), wherein a push rod (8) is sleeved at the bottom of the prefilled syringe module (1), wherein the push rod (8) is capable of sliding inside the prefilled syringe module (1), wherein an injection spring (9) is sleeved inside the push rod (8), and wherein a needle protection sleeve (2) is sleeved outside the prefilled syringe module (1), wherein the injection spring (9) is penetrated by a spring frame (12), wherein the spring frame (12) comprises a spring guide rod structure (1202) arranged in the middle of the spring frame (12) and spring guide rods (1202) arranged on both sides of the spring frame (12). An elastic arm is provided at the top end of the elastic arm, and the spring guide rod structure (1202) passes through the interior of the injection spring (9), so that one end of the injection spring (9) abuts against the push rod (8), and the other end abuts against the spring frame (12); a guide sleeve (10) is sleeved on the outside of the spring frame (12), and a platform structure (1001) is provided on the upper part of the guide sleeve (10); before the injection pen is used, the platform structure (1001) is clamped with the hook (1201), and a guide groove (1002) is also provided on the guide sleeve (10), and the push rod (8) A wing-shaped structure (801) corresponding to the guide groove (1002) is provided at the guide sleeve (10), a trigger sleeve (11) is provided on the outer cover of the guide sleeve (10), the upper end of the trigger sleeve (11) is in contact with the needle protection sleeve (2), and the lower end is provided with an end cover (14), the trigger sleeve (11) is provided with a spring sheet (1101) at a position corresponding to the platform structure (1001), the inner wall of the spring sheet (1101) is provided with a first protrusion (11012) and is in contact with the hook (1201), the trigger sleeve (11) is provided with a rib position (1102) at a position corresponding to the wing-shaped structure (801), and the trigger sleeve (11) is provided with a rib position (1102) at a position corresponding to the wing-shaped structure (801), and the trigger sleeve (11) is provided with a rib position (1102) at a position corresponding to the wing-shaped structure (801). The sleeve (11) is provided with a return spring (13) on its outer sleeve. When the injection pen is in use, the needle protection sleeve (2) pushes the trigger sleeve (11) downward, the spring sheet (1101) opens under the interaction between the first protrusion (11012) and the hook (1201) and causes the trigger sleeve (11) to move downward, the rib (1102) pushes the wing-shaped structure (801) so that the wing-shaped structure (801) can slide in the guide groove (1002), the injection spring (9) pushes the push rod (8) to perform injection, and the spring frame (12) moves downward at the same time, and the injection ends. The automatic injection pen as described in claim 1 is characterized in that a limiting straight surface (10021) is provided at the lower end of the guide groove (1002), and before the automatic injection pen is used, the upper surface of the wing-shaped structure (801) of the push rod (8) is pressed against the limiting straight surface (10021) at the lower end of the guide groove (1002); at this time, the injection spring (9) is compressed between the push rod (8) and the spring frame (12), and the injection spring (9) is in the shortest compressed position. The automatic injection pen according to claim 1, characterized in that the push rod (8) comprises at least Two wing-shaped structures (801), wherein the wing-shaped structures (801) are centrally symmetrically distributed along the central axis of the push rod (8). The automatic injection pen as described in claim 1 is characterized in that the push rod (8) is located within the slender elastic arm of the spring frame (12), and before the automatic injection pen is used, the deformation of the elastic arm of the spring frame (12) in the axial direction (inward) is limited by the push rod (8). The automatic injection pen as described in claim 1 is characterized in that the hook (1201) includes a hooking surface (12011) and an upper inclined surface (12012), and the hooking surface (12011) is an upward inclined surface to facilitate the unhooking of the platform structure (1001). The automatic injection pen as described in claim 1 is characterized in that the upper inclined surface (12012) of the hook (1201) abuts against the lower inclined surface of the first protrusion (11012) of the trigger sleeve (11). The automatic injection pen as described in claim 1 is characterized in that second protrusions (11011) are symmetrically provided on both sides of the first protrusion (11012), and the upper surface and the lower surface of the second protrusion (11011) are both planes. When the automatic injection pen finishes injection, the second protrusion (11011) is located at the platform structure (1001) to prevent secondary false triggering. The automatic injection pen as described in claim 1 is characterized in that the rib position (1102) is a "J"-shaped rib position, and a trigger slope (11021) is provided at the bottom of the "J"-shaped rib position. During the use of the syringe body, the trigger slope (11021) pushes the wing-shaped structure (801) to rotate and slide in the sliding guide groove (1002). The automatic injection pen according to claim 1, characterized in that the upper end of the trigger sleeve (11) has a flange structure (1103) for limiting the return spring (13). The automatic injection pen as described in claim 1 is characterized in that the lower end of the return spring (13) abuts against the end cover (14), and the end cover (14) is clamped with the bottom end of the guide sleeve (10); the return spring (13) is confined between the trigger sleeve (11) and the end cover (14), and is in its longest position before the automatic injection pen is used.