Injection pen auxiliary assembly and injection pen

Abstract

The utility model is suitable for the technical field of injectors and provides an injection pen auxiliary assembly and an injection pen, the injection pen auxiliary assembly is used for being matched with a pre-filling and sealing clamping type bottle for use, and the pre-filling and sealing clamping type bottle comprises a medicine cylinder, a needle head arranged at the far end of the medicine cylinder, a needle cap arranged outside the needle head in a sleeving mode and a piston arranged in the near end of the medicine cylinder in a sliding mode; the injection pen auxiliary assembly comprises a shell, a first locking piece and a second locking piece, and the first locking piece and the pre-filling clamping type bottle are sequentially arranged in the shell in the direction from the near end of the shell to the far end of the shell; the second locking piece is used for pushing the piston to move from the near end of the medicine cylinder to the far end of the medicine cylinder so as to complete medicine injection in the medicine cylinder; when injection is completed, the second locking piece is contained in the shell, and the second locking piece and the first locking piece are locked. The piston is pushed through the second locking piece for injection, the second locking piece is contained in the shell after injection is completed, the first locking piece and the second locking piece are locked, and disposable use is achieved.

Description

Technical Field

[0001] This application belongs to the technical field of syringes, and more specifically, it relates to an injection pen auxiliary component and an injection pen. Background Art

[0002] In recent years, chronic non-communicable diseases such as psoriatic arthritis, Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis have gradually become major medical and health problems. For the above-mentioned chronic diseases, pre-filled syringes have emerged on the market. The pre-filled syringes are filled with drugs in advance through a filling and sealing device. In this way, when actually used, the syringe already contains drugs, which is convenient and fast to use, thus meeting the needs of chronic disease patients who need to self-inject medications. Currently, the most common pre-filled syringes on the market are usually disposable syringes. For example, the patent application with the application number 201610634700.5 discloses a safe pre-filled syringe, including a sleeve and a piston and a push rod slidably arranged inside the sleeve, and a protective cap is provided at the front end of the sleeve; in addition, pre-filled cartridge vials are also commonly used for disposable injections. For example, the patent with the application number CN111770770A discloses a housing for an injection system for receiving a syringe including a syringe received in a safety device. The housing and the safety device form a safety system for the syringe. The syringe system includes a safety system and a syringe. After injection, the syringe can be removed from the housing. The above-mentioned syringes are nominally disposable, but in the process of use, it cannot be guaranteed to be truly disposable. Since this type of pre-filled syringe is purchased by patients themselves for self-injection, after use, if the pre-filled syringe or pre-filled cartridge vial that has not been treated as standard medical waste is discarded, if not destroyed, by illegally collecting used disposable syringes, after simple treatment and packaging, it flows back into the medical market again, and there is often a possibility of being reused by some people seeking illegal interests, thus leaving great hidden dangers for virus cross-infection, disease transmission, etc. Summary of the Utility Model

[0003] The purpose of the embodiments of this application is to provide an injection pen auxiliary component and an injection pen, aiming to solve the technical problem that pre-filled syringes are easily illegally recycled and reused.

[0004] To achieve the above object, according to one aspect of the present application, there is provided an injection pen auxiliary assembly for use in conjunction with a prefilled cartridge. The prefilled cartridge includes a cartridge, a needle disposed at the distal end of the cartridge, a needle cap sleeved outside the needle, and a piston slidably disposed inside the proximal end of the cartridge. The injection pen auxiliary assembly includes a housing, a first locking member, and a second locking member. Along the direction from the proximal end to the distal end of the housing, the first locking member and the prefilled cartridge are sequentially disposed inside the housing; the second locking member is used to push the piston to move from the proximal end of the cartridge to the distal end of the cartridge to complete the injection of the drug inside the cartridge; when the injection is completed, the second locking member is received in the housing, and the second locking member is locked with the first locking member.

[0005] Optionally, a locking block is provided on the first locking member. The second locking member includes a first push rod and a second push rod. The distal end of the first push rod is used to connect with the piston. The proximal end of the first push rod is connected to the second push rod. The second push rod passes through the first locking member and is connected to the first locking member; a limiting groove and a sliding groove are circumferentially provided along the second push rod. The limiting groove and the sliding groove communicate with each other. A limiting protrusion protruding from the bottom of the sliding groove is provided at the proximal end of the sliding groove; in the initial state, the locking block is located in the limiting groove and abuts against the proximal end of the limiting groove. The locking block is used to block the second push rod from moving in the direction of the distal end of the housing; the second push rod can rotate around its own axis to move the locking block to the sliding groove; when the locking block is located in the sliding groove, the second push rod can move along the direction from the proximal end to the distal end of the sliding groove to enable the first push rod to push the piston to complete the injection; when the injection is completed, the locking block is clamped with the limiting protrusion to lock the first locking member and the second locking member inside the housing.

[0006] Optionally, the injection pen auxiliary assembly further includes a card seat. The card seat is fixedly installed inside the housing. The card seat is used to fix the prefilled cartridge. The card seat is located at the proximal end of the prefilled cartridge.

[0007] Optionally, the injection pen auxiliary assembly further includes a driving rod. The driving rod is used to support the first push rod and enable the first push rod to move along the direction from the proximal end to the distal end of the housing. A guiding groove extending along the axial direction of the card seat is provided on the outer side wall of the card seat. The proximal end of the driving rod is connected to the first push rod. The distal end of the driving rod is disposed in the guiding groove and can move along the guiding groove.

[0008] Optionally, the injection pen auxiliary assembly further includes a protective shell. The protective shell can move along its own axis. The housing is sleeved on the outer periphery of the protective shell. And the proximal end of the protective shell is sleeved on the outer periphery of the cartridge. A reset member is provided between the protective shell and the card seat. The two ends of the reset member respectively abut against the protective shell and the card seat; in the initial state, the distal end of the protective shell extends out of the housing to cover the needle; before injection, the protective shell moves towards the proximal end of the housing to compress the reset member, and then the protective shell is received in the housing, so that the needle can be inserted into the injection site for injection; when the injection is completed, the needle is pulled out, and the reset member resets to make the protective shell extend out of the housing to cover the needle.

[0009] Optionally, a first limiting portion is provided on the inner wall of the distal end of the outer shell; a first elastic member, a second elastic member and a second limiting portion are provided on the outer wall of the protective shell. The first elastic member and the second elastic member are arranged at intervals along the circumferential direction of the protective shell, and the second elastic member is located at the proximal end of the first elastic member. The first elastic member and the second elastic member can contract towards the outer wall of the protective shell when being squeezed; wherein, the first elastic member is arranged at an angle with the axis of the protective shell, the proximal end of the first elastic member is connected to the outer wall of the protective shell, and the distal end of the first elastic member protrudes from the outer wall of the protective shell; the second elastic member is arranged at an angle with the axis of the protective shell, the distal end of the second elastic member is connected to the outer wall of the protective shell, and the proximal end of the second elastic member protrudes from the outer wall of the protective shell; in the initial state, the first elastic member abuts against the first limiting portion to block the protective shell from moving towards the distal end of the outer shell, and the reset member abuts against the proximal end of the protective shell, so that the protective shell can move towards the proximal end of the outer shell only by overcoming the elastic force of the reset member under a certain external force; before injection, the first elastic member, the second elastic member and the second limiting portion are located between the first limiting portion and the card seat; when the injection is completed, the driving rod compresses the first elastic member, the needle is pulled out from the injection site, the protective shell extends out of the outer shell under the action of the elastic force of the reset member, and the first elastic member and the second elastic member respectively cross the first limiting portion, and the first limiting portion is clamped between the second elastic member and the second limiting portion to axially fix the protective shell.

[0010] Optionally, a first guide rail slidably connected to the driving rod and a second guide rail slidably connected to the second limiting portion are arranged on the inner wall of the outer shell along the axial extension direction of the outer shell. The first guide rail and the second guide rail are arranged along the circumferential direction of the outer shell. The first guide rail is arranged between the first locking member and the first limiting portion, and the second guide rail is arranged between the card seat and the first limiting portion.

[0011] Optionally, the injection pen auxiliary assembly further includes a pen cap, and the pen cap is sleeved on the outside of the needle cap; a third elastic member is arranged inside the pen cap, the number of the third elastic members is multiple, the multiple third elastic members are arranged along the circumferential direction of the needle cap, and the multiple third elastic members are used for clamping the needle cap. When the pen cap is pulled off, the pen cap can clamp the needle cap and move towards the distal end of the outer shell.

[0012] Optionally, the pen cap is provided with a stop block for blocking the needle cap from falling off from the distal end of the pen cap.

[0013] According to another aspect of the present application, an injection pen is provided, which includes a prefilled cartridge and an injection pen auxiliary assembly, and the injection pen auxiliary assembly is the above-mentioned injection pen auxiliary assembly.

[0014] The beneficial effects of the injection pen auxiliary component and the injection pen provided by this application are as follows: By installing the pre-filled cartridge vial in the outer shell, the second locking member pushes the piston of the pre-filled cartridge vial for injection, and after the injection is completed, the second locking member is received in the outer shell and locked by the first locking member and the second locking member to prevent it from being opened again, so that the used pre-filled cartridge vial cannot be removed from the outer shell, achieving single-use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 An exploded view of the injection pen auxiliary component provided by some embodiments of this application;

[0017] Figure 2 A structural diagram of the injection pen auxiliary component provided by some embodiments of this application;

[0018] Figure 3 A structural diagram of the pre-filled cartridge vial provided by some embodiments of this application;

[0019] Figure 4 A cross-sectional view of the pre-filled cartridge vial provided by some embodiments of this application;

[0020] Figure 5 A structural diagram of the outer shell provided by some embodiments of this application;

[0021] Figure 6 Provided by some embodiments of this application Figure 5 The schematic diagram of the E-E cross-section;

[0022] Figure 7 Provided by some embodiments of this application Figure 5 The schematic diagram of the F-F cross-section;

[0023] Figure 8 A structural diagram of the first locking member provided by some embodiments of this application;

[0024] Figure 9 A structural diagram of the first push rod provided by some embodiments of this application;

[0025] Figure 10 A structural diagram of the second push rod provided by some embodiments of this application;

[0026] Figure 11 Schematic structural diagram of the card seat provided in some embodiments of the present application;

[0027] Figure 12 Provided in some embodiments of the present application Figure 11 Schematic diagram of the G-G cross-section in;

[0028] Figure 13 Schematic structural diagram of the drive rod provided in some embodiments of the present application;

[0029] Figure 14 Schematic structural diagram of the protective shell provided in some embodiments of the present application;

[0030] Figure 15 Schematic structural diagram of the pen cap provided in some embodiments of the present application;

[0031] Figure 16 Schematic structural diagram of the pen cap from another angle provided in some embodiments of the present application;

[0032] Figure 17 Schematic diagram of the initial state of the injection pen auxiliary component provided in some embodiments of the present application;

[0033] Figure 18 Schematic diagram of the injection state of the injection pen auxiliary component provided in some embodiments of the present application;

[0034] Figure 19 Schematic diagram of the injection completion state of the injection pen auxiliary component provided in some embodiments of the present application;

[0035] Figure 20 Schematic diagram of the state where the protective shell is fixed after the injection pen auxiliary component is injected and completed provided in some embodiments of the present application.

[0036] The label details involved in the above drawings are as follows:

[0037] 1. Prefilled cartridge vial; 11. Cartridge; 12. Needle; 13. Needle cap; 14. Piston; 2. Outer shell;

[0038] 21. First limiting part; 211. Upper surface; 212. Lower surface; 22. First guide rail; 23. Second guide rail; 24. Second through hole; 25. First boss; 26. Positioning groove; 27. Third through hole; 28. Positioning boss; 29. Protrusion; 3. First locking part; 31. Locking block; 32. First clamping block; 33. Upper end face; 34. Lower end face; 35. Positioning strip; 4. Second locking part; 41. First push rod; 411. External thread; 412. Second boss; 413. Second clamping block; 42. Second push rod; 421. Limiting groove; 422. Sliding groove; 423. Limiting protrusion; 424. First hook; 425. Limiting boss; 426. Abutting rod; 5. Clamping seat; 51. First through hole; 52. Guide groove; 53. Third clamping block; 54. Second hook; 55. Second inner flange; 6. Driving rod; 61. Driving arm; 62. Connection end; 63. Driving end; 64. Connection arm; 65. Fourth through hole; 66. First inner flange; 7. Protective shell; 71. First elastic part; 711. First elastic sheet; 712. Third boss; 72. Second elastic part; 721. Second elastic sheet; 722. Fourth boss; 73. Second limiting part; 74. First end; 75. Second end; 76. Third inner flange; 8. Reset part; 9. Pen cap; 91. Third elastic part; 92. Groove; 93. Third elastic sheet; 94. Third hook; 95. Stopper. Detailed implementation mode

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the following further details this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0040] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. Without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will detail this application with reference to the accompanying drawings and in combination with the embodiments.

[0041] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0042] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more, unless otherwise specifically defined.

[0043] As described in the background art, currently, the most common pre-filled syringes on the market are usually disposable syringes. Although these syringes are nominally for single use, they can still be reused through simple processing during use, and cannot guarantee true single use. After the syringe is discarded after use, if not destroyed, there is often a possibility of being reused by some people seeking illegal benefits. These people specifically collect used and discarded disposable syringes, and after simple processing and packaging, they flow back into the medical market again, thus leaving great potential hazards for virus cross-infection, disease transmission, etc.

[0044] See Figures 1 to 2 As shown, to solve the above problems, according to one aspect of this application, some embodiments of this application provide an injection pen auxiliary assembly for use in conjunction with a pre-filled cartridge 1. The pre-filled cartridge 1 includes a cartridge 11, a needle 12 disposed at the distal end of the cartridge 11, a needle cap 13 sleeved outside the needle 12, and a piston 14 slidably disposed inside the proximal end of the cartridge 11. Since the pre-filled cartridge 1 is a prior art, its structure and principle will not be described in detail herein.

[0045] It should be noted that the injection pen in this application includes an injection pen auxiliary assembly and a pre-filled cartridge 1. The pre-filled cartridge 1 is assembled inside the injection pen auxiliary assembly and used in conjunction with the injection pen auxiliary assembly. Among them, the injection pen has an axis. The two axially opposite ends of the injection pen are respectively the proximal end and the distal end of the injection pen. The distal end is the end close to the injection site of the person to be injected, and the proximal end is the end far from the injection site of the person to be injected. Each component of the injection pen auxiliary assembly and the pre-filled cartridge 1 has a distal end and a proximal end. For example, the distal end and the proximal end of the outer shell 2 are respectively the end of the outer shell 2 close to the injection site of the person to be injected and the end of the outer shell 2 far from the injection site of the person to be injected; the distal end and the proximal end of the cartridge 11 are respectively the end of the cartridge 11 close to the injection site of the person to be injected and the end of the cartridge 11 far from the injection site of the person to be injected.

[0046] The injection pen auxiliary assembly includes a housing 2, a first locking member 3, and a second locking member 4. Along the direction from the proximal end to the distal end of the housing 2, the first locking member 3 and the prefilled cartridge 1 are sequentially arranged in the housing 2; the second locking member 4 is used to push the piston 14 from the proximal end of the cartridge 11 to the distal end of the cartridge 11 to complete the injection of the drug in the cartridge 11; when the injection is completed, the second locking member 4 is received in the housing 2, and the second locking member 4 is locked with the first locking member 3.

[0047] Applying the above technical solutions provided by the embodiments of the present application, by installing the prefilled cartridge 1 in the housing 2, the second locking member 4 is used to push the piston 14 of the prefilled cartridge 1 for injection. After the injection is completed, the second locking member 4 is received in the housing 2, and the first locking member 3 and the second locking member 4 are locked to prevent it from being opened again, so that the used prefilled cartridge 1 cannot be removed from the housing 2, realizing one-time use.

[0048] Specifically, as Figures 3 to 4 shown, the prefilled cartridge 1 includes a cartridge 11, a needle 12, a needle cap 13, and a piston 14. Among them, the needle 12 is arranged at the distal end of the cartridge 11, and the piston 14 is arranged in the proximal end of the cartridge 11. In the initial state, the cartridge 11 is pre-filled with a drug, and the piston 14 is located between the proximal end of the cartridge 11 and the drug; during the injection process, the piston 14 moves from the proximal end of the cartridge 11 to the distal end of the cartridge 11, so as to press the drug out of the needle 12; after the injection is completed, the piston 14 is at the distal end of the cartridge 11. As Figure 2 shown, the injection pen auxiliary assembly includes a housing 2, a first locking member 3, and a second locking member 4. As Figure 5 shown, the housing 2 is a hollow sleeve, and the prefilled cartridge 1 is fixedly installed in the housing 2. Among them, the cartridge 11 is arranged close to the proximal end of the housing 2, and the needle 12 is arranged close to the distal end of the housing 2; the first locking member 3 is arranged at the proximal end of the housing 2 and is spaced from the cartridge 11, and the second locking member 4 is slidably inserted through the housing 2 and is connected to the piston 14. The piston 14 is pushed towards the distal end of the cartridge 11 by the second locking member 4 to achieve injection. When the injection is completed, the first locking member 3 and the second locking member 4 are locked, and at this time, the proximal end of the second locking member 4 is located in the housing 2.

[0049] See Figure 8 、 Figure 9 and Figure 10As shown in the figure, a locking block 31 is provided on the first locking member 3 in some embodiments. The second locking member 4 includes a first push rod 41 and a second push rod 42. The distal end of the first push rod 41 is used to connect with the piston 14. The proximal end of the first push rod 41 is connected to the second push rod 42. The second push rod 42 passes through the first locking member 3 and is connected to the first locking member 3. A limiting groove 421 and a sliding groove 422 are provided along the circumferential direction of the second push rod 42. The limiting groove 421 and the sliding groove 422 are communicated. A limiting protrusion 423 protruding from the bottom of the sliding groove 422 is provided at the proximal end of the sliding groove 422. In the initial state, the locking block 31 is located in the limiting groove 421 and abuts against the proximal end of the limiting groove 421. The locking block 31 is used to block the second push rod 42 from moving towards the distal end direction of the housing 2. The second push rod 42 can rotate around its own axis to move the locking block 31 to the sliding groove 422. When the locking block 31 is located in the sliding groove 422, the second push rod 42 can move along the direction from the proximal end of the sliding groove 422 to the distal end of the sliding groove 422 to push the piston 14 by the first push rod 41 to complete the injection. When the injection is completed, the locking block 31 is clamped with the limiting protrusion 423 to lock the first locking member 3 and the second locking member 4 in the housing 2.

[0050] Specifically, as Figure 8 shown, the first locking member 3 is a hollow sleeve. The first locking member 3 is fixedly installed at the proximal end of the housing 2 and is spaced from the proximal end of the cartridge 11. The second push rod 42, the first push rod 41 and the piston 14 are connected in sequence. The second push rod 42 passes through the first locking member 3. A locking block 31 is provided on the inner side wall of the first locking member 3. The locking block 31 is a protrusion towards the inside of the first locking member 3. The sliding groove 422 is provided on the outer side wall of the second push rod 42. The length direction of the sliding groove 422 is the same as the length direction of the second push rod 42. The limiting groove 421 is arranged side by side with the sliding groove 422. The proximal end of the locking block 31 abuts against the proximal end of the limiting groove 421. In the axial direction, the surface where the limiting groove 421 abuts against the locking block 31 is spaced from the proximal end of the sliding groove 422 by a certain distance, and the certain distance is the distance spaced along the axial extension direction of the second push rod 42.

[0051] It should be noted here that for the convenience of assembly, as Figure 10 shown, the limiting groove 421 can be extended to the distal end of the second push rod 42. A limiting boss 425 is provided between the limiting groove 421 and the sliding groove 422 to ensure that the locking block 31 is positioned and installed in the limiting groove 421 during assembly.

[0052] Among them, in order to prevent the first push rod 41 from rotating when the second push rod 42 rotates, the second push rod 42 abuts against the first push rod 41. As Figure 10 shown, a contact rod 426 is provided inside the second push rod 42, and the contact rod 426 abuts against the proximal end of the first push rod 41.

[0053] Among them, an internal thread is provided inside the piston 14, and an external thread 411 is provided at one end of the first push rod 41 connected to the piston 14. The first push rod 41 and the piston 14 are connected through the external thread 411 and the internal thread, as Figure 9 shown.

[0054] In some embodiments, referring to Figures 5 to 7 shown, a second through hole 24 is provided on the side wall of the outer shell 2. The second through hole 24 is close to the proximal end of the outer shell 2. A first clamping block 32 is provided on the outer side wall of the first locking member 3 and is clamped in the second through hole 24, so that the first locking member 3 is fixed on the outer shell 2. Among them, the number of the second through holes 24 and the first clamping blocks 32 is multiple, and the multiple second through holes 24 and the multiple first clamping blocks 32 are arranged in one-to-one correspondence; a first boss 25 is provided on the inner side wall of the outer shell 2. The first boss 25 is located at the distal end of the second through hole 24. The first locking member 3 has an upper end surface 33 and a lower end surface 34 which are arranged at intervals. The upper end surface 33 is the proximal end of the first locking member 3, and the lower end surface 34 is the distal end of the first locking member 3. The lower end surface 34 is arranged on the first boss 25. The first boss 25 is used to support the first locking member 3 to prevent the first locking member 3 from moving towards the distal end of the outer shell 2 under the action of an external force.

[0055] Among them, the shapes of the second through hole 24 and the first clamping block 32 can be square, circular or other shapes, which are not limited herein.

[0056] In some alternative embodiments, referring to Figure 10As shown, a first hook 424 is provided on the outer sidewall of the second push rod 42. The first hook 424 is located at the distal end of the second push rod 42. The first hook 424 of the second push rod 42 is engaged with the lower end face 34 of the first locking member 3, and the limiting groove 421 of the second push rod 42 is engaged with the upper end face 33 of the first locking member 3. Thus, the second push rod 42 is axially fixed by the first hook 424 and the limiting groove 421. That is, when the locking block 31 is located in the limiting groove 421, it is in the locked state. In the locked state, the second push rod 42 cannot move along its own axis direction and can only rotate around its own axis to the sliding groove 422. When the locking block 31 is located in the sliding groove 422, it is in the unlocked state. In the unlocked state, the second push rod 42 can move along its own axis direction towards the distal end direction of the housing 2, and the locking block 31 moves along the sliding groove 422. When the injection is completed, the distal end of the locking block 31 is clamped on the proximal end of the limiting protrusion 423, that is, the locking block 31 is clamped between the limiting protrusion 423 and the proximal end of the second push rod 42, so that the locking block 31 and the limiting protrusion 423 are clamped at the proximal end of the second push rod 42 and the proximal end of the housing 2 to prevent the second push rod 42 from moving along the proximal end direction of the housing 2. In the cartridge 11, the piston 14 connected to the first push rod 41 abuts against the bottom of the cartridge 11, so that the second push rod 42, the first push rod 41 and the piston 14 are axially fixed. At the same time, since the second push rod 42 is received in the housing 2 and cannot move axially, it cannot be pulled out by an external force, such as Figure 20 。

[0057] In some other alternative embodiments, a plurality of locking blocks 31 are provided on the first locking member 3. The plurality of locking blocks 31 are arranged circumferentially along the inner sidewall of the first locking member 3. A plurality of limiting grooves 421 and a plurality of sliding grooves 422 are provided on the second push rod 42. The plurality of limiting grooves 421 and the plurality of sliding grooves 422 are respectively provided in one-to-one correspondence with the plurality of locking blocks 31, so that it is more difficult to pull out the second locking member 4, further strengthening the disposable function of the assembly.

[0058] In some other alternative embodiments, referring to Figure 6 and Figure 8 As shown, a positioning groove 26 is provided on the inner sidewall of the housing 2, and a positioning strip 35 is provided on the outer sidewall of the first locking member 3. The positioning strip 35 is inserted into the positioning groove 26. The positioning groove 26 and the positioning strip 35 are provided to facilitate the installation of the housing 2 and the first locking member 3. Among them, the number of the positioning groove 26 and the positioning strip 35 is multiple. The multiple positioning grooves 26 are arranged circumferentially along the housing 2, and the multiple positioning strips 35 are arranged circumferentially along the first locking member 3. The multiple positioning grooves 26 and the multiple positioning strips 35 are provided in one-to-one correspondence.

[0059] Referring to Figure 11 and Figure 12As shown, the injection pen assisting assembly in some embodiments further includes a card seat 5 fixedly installed inside the housing 2. The card seat 5 is used to fix the pre-filled cartridge vial, and the card seat 5 is located at the proximal end of the pre-filled cartridge vial.

[0060] In some embodiments, the card seat 5 is axially provided with a first through hole 51, and the cartridge 11 is installed in the first through hole 51. The card seat 5 and the first locking member 3 are spaced apart. A third clamping block 53 is provided on the outer side wall of the card seat 5, and a third through hole 27 is provided on the side wall of the housing 2. The third clamping block 53 is inserted into the third through hole 27, so that the card seat 5 is fixed on the housing 2. Among them, the third through hole 27 is provided near the distal end of the second through hole 24. A second hook 54 is provided on the outer side wall of the card seat 5, and the second hook 54 is used to clamp the proximal end of the cartridge 11, so that the cartridge 11 is fixedly installed on the card seat 5. Among them, the number of the second hooks 54 is multiple.

[0061] See Figure 13 As shown, the injection pen assisting assembly in some embodiments further includes a driving rod 6. The driving rod 6 is used to support the first push rod 41 and move the first push rod 41 from the proximal end of the housing 2 to the distal end of the housing 2. A guiding groove 52 extending along the axial direction of the card seat 5 is provided on the outer side wall of the card seat 5. The proximal end of the driving rod 6 is connected to the first push rod 41, and the distal end of the driving rod 6 is arranged in the guiding groove 52 and can move along the guiding groove 52.

[0062] Specifically, the driving rod 6 has a driving arm 61. The distal end of the driving arm 61 is slidably connected in the guiding groove 52 to ensure that the first push rod 41 moves axially. At the same time, the driving arm 61 can also support the first push rod 41 to prevent the first push rod 41 from shaking during movement. Among them, the driving arm 61 has a connecting end 62 connected to the first push rod 41 and a driving end 63 arranged in the guiding groove 52 away from the connecting end 62, that is, the connecting end 62 and the driving end 63 are respectively the proximal end and the distal end of the driving arm 61. The driving arm 61 and the guiding groove 52 cooperate with each other. During the movement process, the two driving arms 61 are driven to move axially along the guiding groove 52. For the convenience of description, it is described that the driving rod 6 has two driving arms 61. The driving rod 6 has two driving arms 61 and a connecting arm 64 connected between the two connecting ends 62. The two driving arms 61 are spaced apart. A fourth through hole 65 is provided on the connecting arm 64. A first inner flange 66 is provided along the circumferential direction of the inner side wall of the fourth through hole 65. A second boss 412 is provided at one end of the first push rod 41 connected to the driving arm 61. A second clamping block 413 is provided on the second boss 412. The second boss 412 is inserted into the fourth through hole 65, and the second clamping block 413 is clamped on the first inner flange 66.

[0063] The number of the driving arms 61 in the driving rod 6 can also be one, two, three, etc. Optionally, the number of the driving arms 61 in the driving rod 6 is two to make the structure stable.

[0064] In some alternative embodiments, the fourth through hole 65 is a circular through hole, and the second boss 412 is cylindrical, including two semi-cylindrical bosses arranged at intervals. Second locking blocks 413 are provided on the semi-cylindrical bosses. The second boss 412 is inserted into the fourth through hole 65. The two semi-cylindrical bosses are squeezed and deformed inward by the first inner flange 66, so as to smoothly pass through the fourth through hole 65, and the second locking blocks 413 are locked on the first inner flange 66.

[0065] See Figure 14 As shown, the injection pen auxiliary assembly in some embodiments further includes a protective shell 7. The protective shell 7 can move along its own axis. The outer shell 2 is sleeved on the outer periphery of the protective shell 7, and the proximal end of the protective shell 7 is sleeved on the outer periphery of the cartridge 11. A reset member 8 is provided between the protective shell 7 and the card seat 5. Two ends of the reset member 8 are respectively abutted against the protective shell 7 and the card seat 5; in the initial state, the distal end of the protective shell 7 extends out of the outer shell 2 to cover the needle 12; before injection, the protective shell 7 moves towards the proximal end direction of the outer shell 2 to compress the reset member 8, and further the protective shell 7 is received in the outer shell 2, so that the needle 12 is inserted into the injection site for injection; when the injection is completed, the needle 12 is pulled out, and the reset member 8 resets to make the protective shell 7 extend out of the outer shell 2 to cover the needle 12.

[0066] In some embodiments, the protective shell 7 is a hollow shell. The protective shell 7 is used to cover the needle 12 and plays a role in preventing needle stick after the injection is completed. The protective shell 7 has a first end 74 and a second end 75 connected to the first end 74. Among them, the first end 74 is the proximal end of the protective shell 7, and the second end 75 is the distal end of the protective shell 7. When injecting, the protective shell 7 is moved towards the card seat 5 to compress the reset member 8, and the protective shell 7 is received in the outer shell 2. At this time, the needle 12 is exposed. The needle 12 is inserted into the injection site, and the distal end of the outer shell 2 is abutted against the injection site, so that the protective shell 7 is maintained in the outer shell 2. The second push rod 42 is pressed for injection. After the injection is completed, under the action of the elastic force of the reset member 8, the protective shell 7 moves away from the card seat 5 to extend out of the outer shell 2 to cover the needle 12, so as to avoid being stabbed by the needle 12.

[0067] In some alternative embodiments, the outer shell 2 can be made of a transparent material so as to facilitate observing whether the injection is completed; a sound reminder device can also be provided, and a sound feedback is given after the injection is completed.

[0068] See Figure 1As shown, a first limiting portion 21 is provided on the inner wall of the distal end of the outer shell 2 in some embodiments; a first elastic member 71, a second elastic member 72 and a second limiting portion 73 are provided on the outer wall of the protective shell 7. The first elastic member 71 and the second elastic member 72 are arranged at intervals along the circumferential direction of the protective shell 7, and the second elastic member 72 is located at the proximal end of the first elastic member 71. The first elastic member 71 and the second elastic member 72 can contract towards the outer wall direction of the protective shell 7 when being squeezed; wherein, the first elastic member 71 is arranged at an angle with the axis of the protective shell 7. The proximal end of the first elastic member 71 is connected to the outer wall of the protective shell 7, and the distal end of the first elastic member 71 protrudes from the outer wall of the protective shell 7; the second elastic member 72 is arranged at an angle with the axis of the protective shell 7. The distal end of the second elastic member 72 is connected to the outer wall of the protective shell 7, and the proximal end of the second elastic member 72 protrudes from the outer wall of the protective shell 7; in the initial state, the first elastic member 71 abuts against the first limiting portion 21 to block the protective shell 7 from moving towards the distal end direction of the outer shell 2, and the reset member 8 abuts against the proximal end of the protective shell 7, so that the protective shell 7 can move towards the proximal end direction of the outer shell 2 only by overcoming the elastic force of the reset member 8 under a certain external force; before injection, the first elastic member 71, the second elastic member 72 and the second limiting portion 73 are located between the first limiting portion 21 and the card seat 5; when the injection is completed, the driving rod 6 compresses the first elastic member 71, the needle 12 is pulled out from the injection site, the protective shell 7 extends out of the outer shell 2 under the action of the elastic force of the reset member 8, and the first elastic member 71 and the second elastic member 72 cross over the first limiting portion 21, and the first limiting portion 21 is clamped between the second elastic member 72 and the second limiting portion 73, so that the protective shell 7 is axially fixed. Since when the injection is completed, the driving rod 6 compresses the first elastic member 71, causing the first elastic member 71 to contract towards the outer wall of the protective shell 7, so that the protective shell 7 moves towards the distal end of the outer shell 2 under the action of the elastic force of the reset member 8, and at the same time the first elastic member 71 moves to the distal end of the first limiting portion 21; when the second elastic member 72 moves towards the distal end of the outer shell 2, the second elastic member 72 will not be stuck at the proximal end of the first limiting portion 21, but is compressed inwards by the first limiting portion 21 and moves to the distal end of the first limiting portion 21, and the proximal end of the second elastic member 72 abuts against the distal end of the first limiting portion 21; on the one hand, due to the blocking effect of the first limiting portion 21 on the second limiting portion 73, the protective shell 7 cannot move towards the distal end direction, on the other hand, since the proximal end of the second elastic member 72 protrudes from the outer wall of the protective shell 7, the first limiting portion 21 also has a blocking effect on the second elastic member 72, making the protective shell 7 unable to move towards the proximal end direction. Therefore, the protective shell 7 is axially fixed, so that the protective shell 7 covers the needle 12 and cannot move again, thus achieving the purpose of preventing needle stick.

[0069] In some embodiments, the reset member 8 is a spring. A second inner flange 55 is provided on the inner sidewall of the first through hole 51 of the card holder 5, and a third inner flange 76 is provided on the inner sidewall of the protective shell 7, wherein the third inner flange 76 is located above the second elastic member 72. The spring is disposed between the second inner flange 55 and the third inner flange 76, and the spring is sleeved outside the cartridge 11. The first limiting portion 21 is a protrusion facing the inside of the housing 2. The first limiting portion 21 has an upper surface 211 facing the proximal end of the housing 2 and a lower surface 212 facing the distal end of the housing 2; the first elastic member 71 includes a first elastic sheet 711 and a third boss 712. The proximal end of the first elastic sheet 711 is connected to the outer sidewall of the housing 2, the distal end of the first elastic sheet 711 is connected to the third boss 712, and the third boss 712 protrudes from the outer sidewall of the housing 2; the second elastic member 72 includes a second elastic sheet 721 and a fourth boss 722. The distal end of the second elastic sheet 721 is connected to the outer sidewall of the housing 2, the proximal end of the second elastic sheet 721 is connected to the fourth boss 722, and the fourth boss 722 protrudes from the outer sidewall of the housing 2. The second limiting portion 73 is a strip-shaped block extending along the length direction of the protective shell 7. Along the direction from the proximal end to the distal end of the protective shell 7, the second limiting portion 73, the second elastic member 72, and the first elastic member 71 are sequentially disposed on the outer sidewall of the protective shell 7, and the second limiting portion 73, the second elastic member 72, and the first elastic member 71 are spaced apart from each other and are arranged in a staggered manner.

[0070] Among them, the number of the second limiting portions 73 is several. When there are multiple second limiting portions 73, the multiple second limiting portions 73 are circumferentially arranged along the outer sidewall of the protective shell 7. The number of the first elastic members 71 and the second elastic members 72 is several. Preferably, the number of the first elastic members 71 and the second elastic members 72 is two, and the two first elastic members 71 are centrosymmetric with each other, and the two second elastic members 72 are centrosymmetric with each other to maintain the stability of the protective shell 7 in the housing 2. It should be noted that the number of the driving arms 61 of the driving rod 6 is also equal to the number of the first elastic members 71, and the multiple driving arms 61 are arranged in one-to-one correspondence with the multiple first elastic members 71.

[0071] See Figure 6 As shown, on the inner sidewall of the housing 2 in some embodiments, a first guide rail 22 slidably connected to the driving arm 61 and a second guide rail 23 slidably connected to the second limiting portion 73 are provided along the axial extension direction of the housing 2. The first guide rail 22 and the second guide rail 23 are circumferentially arranged on the housing 2. The first guide rail 22 is disposed between the first locking member 3 and the first limiting portion 21, and the second guide rail 23 is disposed between the card holder 5 and the first limiting portion 21.

[0072] In some embodiments, a first guide rail 22 slidably connected to the driving arm 61 is provided on the inner sidewall of the housing 2 to ensure that the driving arm 61 moves along the direction of the first guide rail 22, wherein the first guide rail 22 is arranged along the axial extension direction of the housing 2.

[0073] Among them, the number of the first guide rails 22 can be set according to the number of the driving arms 61. The number of the first guide rails 22 can be one, two, three, etc. For example, two symmetric driving arms 61 are provided on the driving rod 6, and two first guide rails 22 respectively cooperating with the two driving arms 61 are provided on the inner side wall of the housing 2 to make the structure stable and the movement smooth.

[0074] In some embodiments, a second guide rail 23 slidably connected to the second limiting portion 73 is further provided on the housing 2. The second guide rail 23 is arranged along the axial extension direction of the housing 2 to ensure that the second limiting portion 73 moves axially. The second guide rail 23 is connected to the first limiting portion 21, and the second guide rail 23 is located on one side of the upper surface 211 of the first limiting portion 21. The first limiting portion 21 is used for limiting the second limiting portion 73 in the distal direction of the second guide rail 23. Among them, the first guide rail 22 and the second guide rail 23 are arranged side by side along the circumferential direction of the housing 2.

[0075] Among them, the number of the second guide rails 23 is set according to the number of the second limiting portions 73. For example, one or more, which is not limited herein.

[0076] See Figure 15 and Figure 16 As shown, the injection pen auxiliary assembly in some embodiments further includes a pen cap 9. The pen cap 9 is sleeved outside the needle cap 13. A plurality of third elastic members 91 are provided inside the pen cap 9. The plurality of third elastic members 91 are arranged along the circumferential direction of the needle cap 13. The plurality of third elastic members 91 are used for clamping the needle cap 13. When the pen cap 9 is pulled out, the pen cap 9 can clamp the needle cap 13 and move it in the distal direction of the housing 2.

[0077] In some embodiments, to prevent the needle cap 13 from easily falling off during transportation or handling, which may cause drug contamination, a pen cap 9 is provided outside the needle cap 13 to further protect the needle 12 and prevent the needle cap 13 from falling off. Specifically, the pen cap 9 is a hollow sleeve. The pen cap 9 is disposed at the distal end of the outer shell 2. A groove 92 is circumferentially provided on the inner sidewall of the pen cap 9. A positioning boss 28 and a protrusion 29 are provided on the outer sidewall of the outer shell 2. The protrusion 29 is disposed at the distal end of the positioning boss 28. The protrusion 29 is used to insert into the groove 92 to fixedly connect the pen cap 9 to the outer shell 2. The positioning boss 28 is used to position the pen cap 9 to facilitate the insertion of the protrusion 29 into the groove 92, realizing the quick assembly of the pen cap 9 to the outer shell 2. A plurality of third elastic members 91 are provided inside the pen cap 9. The plurality of third elastic members 91 are arranged circumferentially along the needle cap 13. In the initial state, the plurality of third elastic members 91 clamp the needle cap 13 by elastic force. When pulling out the pen cap 9, the needle cap 13 can be detached from the needle 12 while the pen cap 9 is detached from the outer shell 2 by the clamping of the plurality of third elastic members 91. Optionally, the number of the third elastic members 91 is two, and the two third elastic members 91 are symmetrically arranged.

[0078] In some alternative embodiments, the injection pen auxiliary assembly is provided with the above-mentioned protective shell 7. The third elastic members 91 are passed through the protective shell 7. During the assembly process, the plurality of third elastic members 91 extend into the protective shell 7. The needle cap 13 is inserted between the plurality of third elastic members 91. The plurality of third elastic members 91 clamp the needle cap 13 by elastic force. When the pen cap 9 is pulled out during use, the needle cap 13 will be taken out at the same time, exposing the needle 12, thus facilitating injection. The third elastic members 91 are arranged along the length direction of the pen cap 9. The third elastic member 91 includes a third elastic sheet 93 and a third hook 94. The distal end of the third elastic sheet 93 is fixedly connected to the needle cap 13. The proximal end of the third elastic sheet 93 is connected to the third hook 94. The third hook 94 is disposed close to the needle cap 13. When the pen cap 9 is sleeved outside the outer shell 2, the plurality of third elastic members 91 extend into the protective shell 7, and the needle cap 13 will be inserted between the plurality of third elastic members 91, causing the third elastic sheet 93 to deform and open outwards. When the assembly is in place, the third elastic member 91 restores the deformation, and the third hook 94 hooks the needle cap 13 to prevent the need to separately pull out / cover the pen cap 9 and pull out / cover the needle cap 13 during use, thereby reducing the risk of needle stick.

[0079] In some alternative embodiments, refer to Figure 16As shown, the pen cap 9 is provided with a stop block 95 for blocking the needle cap 13 from falling off from the distal end of the pen cap 9. Specifically, the pen cap 9 has a hollow structure, and the stop block 95 is arranged at the opening at the distal end of the pen cap 9 to block the opening, thereby preventing the needle cap 13 from falling off from the opening. Among them, the number of the stop blocks 95 can be multiple, and the multiple stop blocks 95 can be arranged circumferentially along the opening at the distal end of the pen cap 9. In addition, when the pen cap 9 is pulled out and the needle cap 13 is taken out, due to the limitation of the third hook 94, the needle cap 13 cannot be separated from the proximal end of the pen cap 9. Therefore, the needle cap 13 will be fixed in the pen cap 9 and will not fall off. Thus, after injection, the pen cap 9 can be installed on the injection pen together with the needle cap 13 and then discarded separately, further reducing the risk of needle stick and secondary infection.

[0080] The principle of the injection pen auxiliary assembly provided by the embodiment of the present application is as follows:

[0081] In the initial state, the piston 14 is in the position to be injected. The locking block 31 of the first locking member 3 is stuck in the limiting groove 421 of the second push rod 42. The syringe is in the locked state, and injection cannot be performed by pressing the second push rod 42; the protective shell 7 extends out of the distal end of the outer shell 2 and circumferentially wraps the needle 12, and the pen cap 9 is installed on the outer shell 2. Among them, the two ends of the spring are respectively abutted against the protective shell 7 and the card seat 5. The first elastic member 71 of the protective shell 7 is located above the upper surface 211 of the first limiting portion 21. Refer to Figure 17 shown.

[0082] In the unlocked state, rotate the second push rod 42 to move the locking block 31 from the limiting groove 421 to the sliding groove 422, that is, the unlocking is completed; then pull out the pen cap 9 and the needle cap 13, directly abut the protective shell 7 against the injection site, and press the protective shell 7 towards the proximal end of the outer shell 2 against the elastic force of the spring, so that the protective shell 7 is received into the outer shell 2 and the needle 12 penetrates into the injection site.

[0083] During injection, the protective shell 7 is located inside the outer shell 2, and the distal end of the protective shell 7 is flush with the distal end of the outer shell 2. Press the second push rod 42 to make the first push rod 41 push the piston 14 for injection. When moving in place, the first elastic member 71 on the protective shell 7 will be squeezed inwards by the driving arm 61 of the driving rod 6 moving towards the distal end of the outer shell 2. Refer to Figure 18 shown; after the injection is completed, the second push rod 42 is received in the outer shell 2, and the locking block 31 of the first locking member 3 is stuck in the limiting protrusion 423 of the second push rod 42, so that the second push rod 42 is fixed in the outer shell 2 and cannot be pulled out by an external force. Refer to Figure 19 shown.

[0084] When the patient pulls out the needle 12, since the first elastic member 71 is driven by the driving arm 61 to be squeezed inward, the first elastic member 71 will not block the movement of the protective shell 7 towards the distal end of the outer shell 2. Therefore, the protective shell 7 moves towards the distal end of the outer shell 2 under the elastic force of the spring. When the second elastic member 72 moves to the first limiting portion 21 of the outer shell 2, due to the extrusion of the second elastic member 72 by the first limiting portion 21, the second elastic member 72 contracts towards the outer side wall of the protective shell 7 and enables the second elastic member 72 to continue moving towards the distal end of the outer shell 2. When the second elastic member 72 reaches the lower surface 212 of the first limiting portion 21, the second limiting portion 73 abuts against the upper surface 211 of the first limiting portion 21, restricting the movement of the protective shell 7 towards the distal end direction of the outer shell 2. At the same time, the second elastic member 72 restores its deformation and abuts against the lower surface 212 of the first limiting portion 21, restricting the movement of the protective shell 7 towards the proximal end direction of the outer shell 2. At this time, the protective shell 7 is in a fixed state, covering the needle 12, performing the function of preventing needle stick. Refer to Figure 20 as shown.

[0085] According to another aspect of the present application, there is provided an injection pen, including a prefilled cartridge 1 and an injection pen auxiliary assembly, and the injection pen auxiliary assembly is the above-mentioned injection pen auxiliary assembly. The injection pen auxiliary assembly is used in cooperation with the prefilled cartridge 1. Since the injection pen provided in this embodiment has the same advantages as the above-mentioned injection pen auxiliary assembly, it will not be elaborated herein.

[0086] In summary, implementing the injection pen auxiliary assembly and the injection pen provided in this embodiment has at least the following beneficial technical effects: (1) By installing the prefilled cartridge 1 inside the outer shell 2, the second locking member 4 pushes the piston 14 of the prefilled cartridge 1 for injection, and after the injection is completed, the second locking member 4 is received inside the outer shell 2 and locked by the first locking member 3 and the second locking member 4, preventing it from being opened again. Thus, the used prefilled cartridge 1 cannot be removed from the outer shell 2, achieving single-use and avoiding secondary infection caused by recycling; (2) By providing the protective shell 7, after injection, the needle 12 is covered by the protective shell 7 and the protective shell 7 cannot be pushed again, thus achieving needle stick prevention; (3) By providing the needle cap 13, before injection, the needle cap 13 can be prevented from falling off and contacting the needle 12, with good safety; (4) Since the protective shell 7 does not rotate during use, it will not cause skin torsion, improving the comfort of use; (5) The components of the present utility model are simple, with a small number and low cost.

[0087] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An injection pen auxiliary component for use in conjunction with a pre-filled cartridge, the pre-filled cartridge comprising a cartridge, a needle disposed at a distal end of the cartridge, a needle cap sleeved outside the needle, and a piston slidably disposed within a proximal end of the cartridge, characterized in that, The injection pen auxiliary assembly includes a housing, a first locking member, and a second locking member. Along the direction from the proximal end of the housing to the distal end of the housing, the first locking member and the pre-filled cartridge are sequentially arranged in the housing; The second locking member is used to push the piston to move from the proximal end of the cartridge to the distal end of the cartridge to complete the injection of the drug in the cartridge; When the injection is completed, the second locking member is received in the housing, and the second locking member is locked with the first locking member; The injection pen auxiliary assembly further includes a pen cap, and the pen cap is sleeved on the outside of the needle cap; a third elastic member is arranged inside the pen cap, and the number of the third elastic members is multiple. The multiple third elastic members are arranged along the circumferential direction of the needle cap, and the multiple third elastic members are used to clamp the needle cap. When the pen cap is pulled off, the pen cap can clamp the needle cap and move it in the direction of the distal end of the housing. The pen cap is provided with a stop block, and the stop block is used to prevent the needle cap from falling off from the distal end of the pen cap; The first locking member is a hollow sleeve, and a locking block is arranged on the inner side wall of the first locking member. The locking block is a protrusion facing the inside of the first locking member. The second locking member includes a first push rod and a second push rod. The second push rod, the first push rod, and the piston are sequentially connected. The second push rod passes through the first locking member. A chute is arranged on the outer side wall of the second push rod. A limiting protrusion protruding from the bottom of the chute is arranged at the proximal end of the chute. During injection, the second push rod moves in the direction of the distal end of the housing along its own axis, and the locking block moves along the chute. After the injection is completed, the second push rod is received in the housing, and the distal end of the locking block is clamped on the proximal end of the limiting protrusion, so that the locking block and the limiting protrusion are clamped at the proximal end of the second push rod and the proximal end of the housing to prevent the second push rod from moving in the direction of the proximal end of the housing, and the piston abuts against the bottom of the cartridge, so that the second push rod, the first push rod, and the piston are axially fixed.

2. The injection pen auxiliary assembly according to claim 1, wherein The second push rod is connected to the first locking member; A limiting groove and the chute are arranged along the circumferential direction of the second push rod, the limiting groove and the chute are communicated, and a limiting protrusion protruding from the bottom of the chute is arranged at the proximal end of the chute; In the initial state, the locking block is located in the limiting groove and abuts against the proximal end of the limiting groove. The locking block is used to prevent the second push rod from moving in the direction of the distal end of the housing; the second push rod can rotate around its own axis to move the locking block to the chute; when the locking block is located in the chute, the second push rod can move in the direction from the proximal end of the chute to the distal end of the chute to enable the first push rod to push the piston to complete the injection; when the injection is completed, the locking block is clamped with the limiting protrusion to lock the first locking member and the second locking member in the housing.

3. The injection pen auxiliary assembly according to claim 2, wherein It further includes a card seat, and the card seat is fixedly installed inside the housing. The card seat is used to fix the pre-filled cartridge, and the card seat is located at the proximal end of the pre-filled cartridge.

4. The injection pen auxiliary assembly according to claim 3, wherein, It further includes a driving rod for supporting the first push rod and moving the first push rod in the direction from the proximal end to the distal end of the housing. A guiding groove extending along the axial direction of the card seat is provided on the outer side wall of the card seat. The proximal end of the driving rod is connected to the first push rod, and the distal end of the driving rod is arranged in the guiding groove and can move along the guiding groove.

5. The injection pen auxiliary assembly according to claim 4, wherein It further includes a protective shell capable of moving along its own axis. The housing is sleeved on the outer periphery of the protective shell, and the proximal end of the protective shell is sleeved on the outer periphery of the cartridge. A reset member is provided between the protective shell and the card seat, and both ends of the reset member are respectively abutted against the protective shell and the card seat. In the initial state, the distal end of the protective shell extends out of the housing to cover the needle. Before injection, the protective shell moves towards the proximal end of the housing to compress the reset member, so that the protective shell is received in the housing, enabling the needle to pierce into the injection site for injection. When the injection is completed, the needle is pulled out, and the reset member resets to make the protective shell extend out of the housing to cover the needle.

6. The injection pen auxiliary assembly according to claim 5, wherein, A first limiting portion is provided on the inner side wall at the distal end of the housing. A first elastic member, a second elastic member and a second limiting portion are provided on the outer side wall of the protective shell. The first elastic member and the second elastic member are arranged at intervals along the circumferential direction of the protective shell, and the second elastic member is located at the proximal end of the first elastic member. The first elastic member and the second elastic member can contract towards the outer side wall of the protective shell when being squeezed. Wherein, the first elastic member is arranged at an angle with the axis of the protective shell. The proximal end of the first elastic member is connected to the outer side wall of the protective shell, and the distal end of the first elastic member protrudes out of the outer side wall of the protective shell. The second elastic member is arranged at an angle with the axis of the protective shell. The distal end of the second elastic member is connected to the outer side wall of the protective shell, and the proximal end of the second elastic member protrudes out of the outer side wall of the protective shell. In the initial state, the first elastic member abuts against the first limiting portion to block the protective shell from moving towards the distal end of the housing, and the reset member abuts against the proximal end of the protective shell, so that the protective shell can move towards the proximal end of the housing only by overcoming the elastic force of the reset member under a certain external force. Before injection, the first elastic member, the second elastic member and the second limiting portion are located between the first limiting portion and the card seat. When the injection is completed, the driving rod compresses the first elastic member, the needle is pulled out from the injection site, and the protective shell extends out of the housing under the action of the elastic force of the reset member, and makes the first elastic member and the second elastic member respectively cross the first limiting portion. The first limiting portion is clamped between the second elastic member and the second limiting portion to axially fix the protective shell.

7. The injection pen auxiliary component according to claim 6, characterized in that, On the inner side wall of the outer shell, a first guide rail slidably connected to the driving rod and a second guide rail slidably connected to the second limiting portion are provided along the axial extension direction of the outer shell. The first guide rail and the second guide rail are arranged along the circumferential direction of the outer shell. The first guide rail is arranged between the first locking member and the first limiting portion, and the second guide rail is arranged between the card seat and the first limiting portion.

8. An injection pen, characterized in that, It includes a pre-filled and sealed cartridge vial and the injection pen auxiliary assembly according to any one of claims 1 to 7.

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