An automatic injector

Abstract

This application discloses an autoinjector, including an injection assembly. The injection assembly includes a sound-generating base, and a sound-generating component and a release component are movably sleeved on the outer periphery of the sound-generating base. A limiting block and a boss located on one side of the limiting block are provided on the outer periphery of the sound-generating base. A boss inclined surface is provided on the side of the boss facing the limiting block. A limiting groove is provided between the boss inclined surface and the limiting block. The release component has a first protrusion that can be engaged in the limiting groove. The first protrusion has a first end face that mates with the boss inclined surface, a second end face that mates with the limiting groove, and a third end face that mates with the limiting block. This autoinjector is reliable and practical, effectively preventing accidental triggering in case of drops or other unexpected situations. It significantly improves the impact resistance and stability of the product structure after injection, avoids the problem of limiting failure caused by accidental force, and effectively prevents premature displacement of the push rod linkage, thus improving the stability of the autoinjector's sound-generating function after injection.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to an automatic injector. Background Technology

[0002] In the field of medical device technology, autoinjectors have become an important tool widely used in drug therapy due to their ability to significantly reduce the difficulty of injection operations and minimize patient pain during injection, and have been welcomed by many medical professionals and patients. However, existing autoinjectors still have the following problems:

[0003] 1. During actual use and transportation, autoinjectors may experience unexpected displacement of their internal structure due to accidental drops or external impacts. In particular, the release mechanism may be accidentally triggered by vibration or impact, leading to unintended activation of the autoinjector, resulting in drug waste or potential safety risks. Although existing technologies include some structural designs to prevent accidental triggering, their protective effect is still insufficient against high-intensity impacts or drops at specific angles. In particular, the locking structure between the release mechanism and adjacent components is prone to displacement under stress, making it difficult to completely prevent accidental injection.

[0004] 2. Common automatic injectors typically include a drive mechanism for performing the injection and an audible alert mechanism to indicate completion. After injection, the release mechanism and the audible alert mechanism are usually locked together by a latching structure, preventing the release mechanism from moving downwards and thus locking it in place to prevent secondary injections. This also prevents the protective sleeve covering the needle tip from shifting and exposing the needle tip, effectively preventing secondary injury to the user. However, existing latching structures between the release and audible alert mechanisms are prone to failure under external impact or improper force, leading to a breakdown in the fit between the release and audible alert mechanisms, resulting in loosening of the product structure or malfunction, ultimately affecting the reliability and safety of the injector.

[0005] 3. The push rod linkage in existing automatic injectors does not move smoothly enough during injection. This unstable movement may cause the push rod linkage to trigger the sound mechanism prematurely, resulting in false early sounding. This not only interferes with the user's correct judgment of the injection process, but may also affect the reliability of the injection action. Summary of the Invention

[0006] To address the aforementioned issues, this application provides an auto-injector that is reliable and practical, effectively preventing accidental triggering in the event of drops or other unexpected situations. Furthermore, its release mechanism firmly abuts against the sound-generating component, ensuring reliable positioning and significantly improving the impact resistance and stability of the product structure after injection. This avoids limit failure caused by accidental force, thus ensuring the safety and reliability of the auto-injector after use. In addition, its push rod linkage moves more smoothly during injection, effectively preventing premature displacement of the push rod linkage and premature sound generation, improving the stability of the auto-injector's sound generation function after injection. It also ensures that the push rod linkage will not shift due to shaking during installation and transportation, guaranteeing the stability of the auto-injector.

[0007] Specifically, the following technical solutions are included:

[0008] This application provides an automatic injector, including an injection assembly, the injection assembly including a sound-generating base, and a sound-generating element and a release element are movably sleeved on the outer periphery of the sound-generating base;

[0009] The outer periphery of the sound-generating base is provided with a limiting block and a boss located on one side of the limiting block. The side of the boss facing the limiting block is provided with a boss slope. A limiting groove is provided between the boss slope and the limiting block. The release member is provided with a first protrusion that can be engaged in the limiting groove. The first protrusion is provided with a first end face that cooperates with the boss slope, a second end face that cooperates with the limiting groove, and a third end face that cooperates with the limiting block.

[0010] The release member has a first spring arm on the side facing the sound-generating member. The end of the first spring arm has a limiting platform and a second protrusion located on one side of the limiting platform. The sound-generating member has a stop on the side facing the release member. When the first spring arm retracts inward, the second protrusion and the limiting platform can be embedded into the inner wall of the sound-generating member. When the first spring arm expands outward, the second protrusion can abut against the stop.

[0011] The sound-generating base is equipped with a movable push rod linkage component. The push rod linkage component is provided with a mounting groove and a spring piece located in the mounting groove. The end of the spring piece facing the bottom of the sound-generating base is connected to the push rod linkage component. The outer wall of the end of the spring piece facing the top of the sound-generating base is provided with an elastic locking block. The sound-generating base is provided with a locking hole that cooperates with the elastic locking block.

[0012] In one embodiment of this application, an embedding groove is provided between the second protrusion and the limiting platform, a first abutting surface is provided on the side of the blocking platform, a second abutting surface is provided on the top of the blocking platform, a first limiting surface that cooperates with the second abutting surface is provided on the side of the second protrusion facing the embedding groove, and a second limiting surface that cooperates with the first abutting surface is provided on the side of the limiting platform facing the embedding groove.

[0013] In one embodiment of this application, the push rod linkage is provided with third protrusions on both sides, and the sound-generating base is provided with a slot that mates with the third protrusions.

[0014] In one embodiment of this application, the first protrusion is disposed on the inner wall of the release member; the third end face is located at the top of the first protrusion, the second end face is located on the side of the first protrusion, the first end face is located at the bottom side of the first protrusion and is inclined, and the first end face, the second end face and the third end face are connected in sequence.

[0015] In one embodiment of this application, the outer periphery of the sound-generating base is provided with a first shaft portion, a second shaft portion, a third shaft portion, and a fourth shaft portion with increasing outer diameters. The release member is movably sleeved on the outer periphery of a portion of the first shaft portion and a portion of the second shaft portion. The sound-generating member is movably sleeved on the outer periphery of a portion of the second shaft portion and a portion of the third shaft portion. A release spring is provided between the release member and the sound-generating member, and the two ends of the release spring respectively abut against and connect the release member and the sound-generating member.

[0016] In one embodiment of this application, a pressure cap is installed at the bottom of the sound-generating base. The pressure cap is sleeved on the outer periphery of the fourth shaft portion and seals the bottom end of the sound-generating base. A push rod is installed inside the sound-generating base. An injection spring bracket is provided inside the push rod. An injection spring is sleeved on the outer periphery of the injection spring bracket. One end of the injection spring abuts against the bottom end of the injection spring bracket, and the other end abuts against the top end of the inner wall of the push rod. The bottom end of the injection spring bracket abuts against the pressure cap.

[0017] In one embodiment of this application, the first limiting surface and the second blocking surface are inclined surfaces; the outer side of the second protrusion is an inclined surface, and the two first elastic arms are symmetrically arranged on both sides of the release member in a figure-eight shape.

[0018] In one embodiment of this application, the end of the spring sheet facing the top of the sound-generating base does not contact the end face of the mounting groove; the outer peripheral surface of the elastic block is an arc surface, and the cross-sectional area of ​​the third protrusion increases from the end facing the top of the sound-generating base to the end facing the bottom of the sound-generating base.

[0019] In one embodiment of this application, the device further includes a pen body, a needle tip protective sleeve installed at one end of the pen body, a refill holder installed at the other end of the pen body, and a syringe installed in the pen body. The injection assembly is installed in the pen body, the tip of the needle tip protective sleeve extends out of the pen body, a pen cap is fitted onto the tip of the needle tip protective sleeve, the pen cap is snapped onto the tip of the needle tip protective sleeve, the needle tip protective sleeve triggers the injection assembly, and the injection assembly squeezes the syringe to complete the injection operation.

[0020] In one embodiment of this application, the needle tip protective sleeve is provided with needle tip protective sleeve slots on both sides and a sliding groove above the needle tip protective sleeve slots. The pen refill holder is provided with second spring arms on both sides. A pen refill holder buckle is provided on the outer wall of one end of the second spring arm. The pen refill holder buckle can cooperate with the needle tip protective sleeve slot to be locked in the needle tip protective sleeve slot. The pen refill holder buckle can cooperate with the sliding groove to be slidably connected in the sliding groove.

[0021] The beneficial effects of this application are:

[0022] 1. The auto-injector provided in this application has a boss and a limiting block on the top of the sound-generating base, and a limiting groove is formed between the boss and the limiting block. When the first protrusion of the release member moves to the limiting groove, the first protrusion can be snapped into the limiting groove. At this time, the inclined surface of the boss cooperates with the first end face, limiting the first end face through the inclined surface of the boss; the limiting groove cooperates with the second end face, limiting the second end face through the limiting groove; the limiting block cooperates with the third end face, limiting the third end face through the lower end face of the limiting block. Thus, through the limiting effect of the above three surfaces, the first protrusion can be tightly locked in the limiting groove, thereby locking the release member on the outer periphery of the sound-generating base, preventing the release member from displacing after being subjected to force, thus effectively preventing automatic injection caused by the displacement of the release member when the product is dropped. It can effectively prevent the auto-injector from being accidentally triggered in the event of a drop or other accident, and is reliable and practical.

[0023] 2. The auto-injector provided in this application has a limiting platform and a second protrusion at the bottom of the first spring arm of the release member, and a stop platform at the top of the sound-generating member. When the auto-injector is in an unused state, the first spring arm retracts inward, and its second protrusion and limiting platform are embedded in the inner wall of the sound-generating member. When the auto-injector is in the state of injection completion and sound generation, the release member separates from the sound-generating member. At this time, the elastic force of the first spring arm drives the first spring arm to expand outward for reset. The first spring arms on both sides of the release member will deform outward in a "V" shape and support the sound-generating member. The stop platform at the bottom of the release member can prevent the first spring arm from deforming excessively outward, thereby allowing the release member to tightly abut against the sound-generating member. Specifically, the first limiting surface of the second protrusion cooperates with the second abutting surface of the stop, limiting the release member against the sound-generating member by means of the first limiting surface and the second abutting surface; simultaneously, the second limiting surface of the limiting platform cooperates with the first abutting surface of the stop, limiting the first elastic arm against the first abutting surface by means of the second limiting surface, preventing the first elastic arm from expanding excessively outward and detaching from the sound-generating member. At this point, the release member and the sound-generating member can no longer move relative to each other. Even under strong external force, the first elastic arm of the release member can still firmly abut against the sound-generating member, ensuring reliable limiting. The release member is jammed, preventing secondary injection and protecting the syringe needle tip from secondary injury to the user. This structure significantly improves the impact resistance and stability of the product structure after injection, avoiding the problem of limiting failure caused by accidental force, thereby ensuring the safety and reliability of the automatic injector after use.

[0024] 3. The automatic injector provided in this application has an arc-shaped outer surface for the elastic locking block, and a locking hole for engaging the elastic locking block is provided on the sound-generating base. When the injection spring pushes the push rod and the push rod linkage to move upward synchronously, the elastic locking block can disengage from the locking hole under force. The engagement between the elastic locking block and the locking hole is used to position and fix the connection between the push rod linkage and the sound-generating base, ensuring that the push rod linkage will not be displaced due to shaking during installation and transportation. When subjected to a sufficiently large driving force from the injection spring, the engagement between the elastic locking block and the locking hole will fail, allowing the push rod and the push rod linkage to move upward synchronously. Thus, the engagement between the elastic locking block and the locking hole ensures that the sliding parts will not rotate and cause misalignment, ensuring the stability of the mechanism. Furthermore, compared to the design where the spring extends downwards and the elastic block is located at the lower part of the spring, the design of the push rod linkage provided in this application, where the spring extends upwards and the elastic block is located at the upper part of the spring, makes the push rod linkage move more smoothly during injection, effectively preventing premature displacement of the push rod linkage and premature sound emission, thus improving the stability of the automatic injector's sound emission function after injection. Attached Figure Description

[0025] Figure 1 This is a front view of the autoinjector of this application.

[0026] Figure 2 This is a cross-sectional view of the autoinjector of this application in its unused state.

[0027] Figure 3 This is a perspective view of the injection component of this application.

[0028] Figure 4 for Figure 3 A magnified view of A in the middle.

[0029] Figure 5 This is a cross-sectional view of the injection component of this application.

[0030] Figure 6 for Figure 5 A magnified view of B in the middle.

[0031] Figure 7 for Figure 5 A magnified view of C.

[0032] Figure 8 This is a cross-sectional view of the automatic injector of this application after injection is completed and sound is emitted.

[0033] Figure 9 for Figure 8 A magnified view of D.

[0034] Figure 10 This is a perspective view of the release document of this application.

[0035] Figure 11 This is the main view of the release document in this application.

[0036] Figure 12 This is a perspective view of the sound-generating base, push rod, and push rod linkage of this application.

[0037] Figure 13 This is a perspective view of the push rod linkage component of this application.

[0038] Figure 14 This is a front view of the sound-generating base, push rod, and push rod linkage of this application.

[0039] Figure 15 This is a side view of the sound-generating base, push rod, and push rod linkage of this application.

[0040] Figure 16 This is a cross-sectional view of the sound-generating base, push rod, and push rod linkage of this application.

[0041] Figure 17 This is a perspective view of the pen refill holder of this application.

[0042] Figure 18 This is a perspective view of the needle tip protective sleeve of this application.

[0043] In the diagram: 1. Sound-generating base; 11. First shaft; 12. Second shaft; 13. Third shaft; 14. Fourth shaft; 15. Limiting block; 16. Boss; 161. Boss inclined surface; 17. Limiting groove; 18. Locking hole; 19. Locking slot; 2. Sound-generating component; 21. Baffle; 22. First abutting surface; 23. Second abutting surface; 3. Release component; 31. First protrusion; 311. First end face; 312. Second end face; 313. Third end face; 32. Second protrusion; 321. First limiting surface; 33. Embedded groove; 34. Limiting platform 341. Second limiting surface; 35. Rib; 36. First spring arm; 4. Push rod; 5. Pressure cap; 6. Release spring; 7. Injection spring; 8. Injection spring bracket; 9. Push rod linkage; 91. Spring piece; 92. Elastic block; 93. Mounting groove; 94. Third protrusion; 100. Injection assembly; 101. Pen body; 102. Pen cap; 103. Needle tip protective sleeve; 1031. Needle tip protective sleeve slot; 1032. Slide groove; 104. Pen refill holder; 1041. Second spring arm; 1042. Pen refill holder buckle; 105. Syringe. Detailed Implementation

[0044] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0046] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0047] like Figures 1 to 18 As shown, this application provides an automatic injector, including a pen body 101, a needle tip protective sleeve 103 installed at one end inside the pen body 101, a pen refill holder 104 installed at the other end inside the pen body 101, and an injection assembly 100 and a syringe 105 installed inside the pen body 101. The needle tip protective sleeve 103 triggers the injection assembly 100, which squeezes the syringe 105 to complete the injection operation. The injection assembly 100 is designed to be rotatable. In its initial state, the injection assembly 100 is not rotated and cannot trigger automatic injection. When the injection assembly 100 rotates a certain angle, it becomes a triggerable automatic injection form. After the triggerable automatic injection form of the injection assembly 100 is installed in the pen body 101, the needle tip protective sleeve 103 triggers the injection assembly 100 to squeeze the syringe 105 to complete the injection operation.

[0048] In some embodiments, the injection assembly 100 includes a sound-generating base 1, a sound-generating element 2 and a release element 3 are movably sleeved on the outer periphery of the sound-generating base 1, a limiting block 15 and a boss 16 located on one side of the limiting block 15 are provided on the outer periphery of the sound-generating base 1, a boss inclined surface 161 is provided on the side of the boss 16 facing the limiting block 15, a limiting groove 17 is provided between the boss inclined surface 161 and the limiting block 15, and the release element 3 is provided with a first protrusion 31 that can be engaged in the limiting groove 17, the first protrusion 31 is provided with a first end face 311 that cooperates with the boss inclined surface 161, a second end face 312 that cooperates with the limiting groove 17, and a third end face 313 that cooperates with the limiting block 15.

[0049] Optionally, the first protrusion 31 is disposed on the inner wall of the release member 3; the third end face 313 is located on the top of the first protrusion 31, the second end face 312 is located on the side of the first protrusion 31, and the first end face 311 is located on the side bottom of the first protrusion 31 and is inclined; the first end face 311, the second end face 312, and the third end face 313 are connected in sequence.

[0050] Optionally, the outer periphery of the sound-generating base 1 is provided with a first shaft portion 11, a second shaft portion 12, a third shaft portion 13, and a fourth shaft portion 14 with increasing outer diameters. The release member 3 is movably sleeved on the outer periphery of a portion of the first shaft portion 11 and a portion of the second shaft portion 12. The sound-generating member 2 is movably sleeved on the outer periphery of a portion of the second shaft portion 12 and a portion of the third shaft portion 13. A release spring 6 is provided between the release member 3 and the sound-generating member 2, and the two ends of the release spring 6 respectively abut against and connect the release member 3 and the sound-generating member 2.

[0051] Optionally, a pressure cap 5 is installed at the bottom of the sound-generating base 1. The pressure cap 5 is sleeved on the outer periphery of the fourth shaft portion 14 and seals the bottom end of the sound-generating base 1. A push rod 4 is installed inside the sound-generating base 1. An injection spring bracket 8 is provided inside the push rod 4. An injection spring 7 is sleeved on the outer periphery of the injection spring bracket 8. One end of the injection spring 7 abuts against the bottom end of the injection spring bracket 8, and the other end abuts against the top end of the inner wall of the push rod 4. The bottom end of the injection spring bracket 8 abuts against the pressure cap 5.

[0052] In this embodiment, the elastic force of the injection spring 7 can drive the push rod 4 to move, and the push rod 4 squeezes the syringe 105 to complete the injection operation.

[0053] Optionally, the sound-generating component 2 and the sound-generating base 1 are provided with a mutually cooperating axial limiting groove and axial limiting strip, so that the sound-generating component 2 and the sound-generating base 1 can rotate synchronously.

[0054] The injection assembly 100 provided in this embodiment of the application has a boss 16 and a limiting block 15 on the top of the sound-generating base 1, and a limiting groove 17 is formed between the boss 16 and the limiting block 15. When the first protrusion 31 of the release member 3 moves to the limiting groove 17, the first protrusion 31 can be snapped into the limiting groove 17. At this time, the boss inclined surface 161 cooperates with the first end face 311, limiting the first end face 311 through the boss inclined surface 161; the limiting groove 17 cooperates with the second end face 312, limiting the second end face 312 through the limiting groove 17; the limiting block 15 cooperates with the third end face 313, limiting the third end face 313 through the lower end face of the limiting block 15; thus, through the limiting effect of the above three surfaces, the first protrusion 31 can be tightly locked in the limiting groove 17, thereby locking the release member 3 on the outer periphery of the sound-generating base 1, preventing the release member 3 from displacing after being subjected to force, thus effectively preventing automatic injection caused by the displacement of the release member 3 when the product falls, and effectively preventing the automatic injector from being accidentally triggered in the event of a fall or other accidents, which is reliable and practical.

[0055] In some embodiments, the release member 3 is provided with a first spring arm 36 on the side facing the sound-generating member 2. The end of the first spring arm 36 is provided with a limiting platform 34 and a second protrusion 32 located on one side of the limiting platform 34. The sound-generating member 2 is provided with a baffle 21 on the side facing the release member 3. When the first spring arm 36 retracts inward, the second protrusion 32 and the limiting platform 34 can be embedded into the inner wall of the sound-generating member 2. When the first spring arm 36 expands outward, the second protrusion 32 can abut against the baffle 21. An embedding groove 33 is provided between the second protrusion 32 and the limiting platform 34. The side of the baffle 21 is provided with a first abutting surface 22, and the top of the baffle 21 is provided with a second abutting surface 23. The side of the second protrusion 32 facing the embedding groove 33 is provided with a first limiting surface 321 that cooperates with the second abutting surface 23. The side of the limiting platform 34 facing the embedding groove 33 is provided with a second limiting surface 341 that cooperates with the first abutting surface 22.

[0056] Optionally, the first limiting surface 321 and the second blocking surface 23 are inclined surfaces; the outer side of the second protrusion 32 is an inclined surface, and the two first spring arms 36 are symmetrically arranged on both sides of the release member 3 in a figure-eight shape.

[0057] Optionally, the release member 3 is provided with ribs 35 on both sides, and the ribs 35 are arranged longitudinally on the outer side of the first spring arm 36 and the second protrusion 32. In this embodiment, the ribs 35 are provided to improve the strength of the first spring arm 36 and the second protrusion 32, so as to ensure the contact strength between the sound-emitting member 2 and the release member 3 when the second protrusion 32 abuts against the stop 21, and to avoid product structure loosening or functional abnormality.

[0058] The injection assembly 100 provided in this embodiment of the application includes a limiting platform 34 and a second protrusion 32 at the bottom of the first spring arm 36 of the release member 3, and a baffle 21 at the top of the sound-generating member 2. When the auto-injector is in an unused state, the first spring arm 36 retracts inward, and its second protrusion 32 and limiting platform 34 are embedded in the inner wall of the sound-generating member 2. When the auto-injector is in the state of injection completion and sound generation, the release member 3 separates from the sound-generating member 2. At this time, the elastic force of the first spring arm 36 drives the first spring arm 36 to expand outward for reset. The first spring arms 36 on both sides of the release member 3 will deform outward in a "V" shape and support the sound-generating member 2. The baffle 21 at the bottom of the release member 3 can prevent the first spring arm 36 from deforming excessively outward, so that the release member 3 can be tightly abutted against the sound-generating member 2. Specifically, the first limiting surface 321 of the second protrusion 32 cooperates with the second abutting surface 23 of the stop 21, limiting the second abutting surface 23 by the first limiting surface 321, causing the release member 3 to abut against the sound-generating member 2. Simultaneously, the second limiting surface 341 of the limiting platform 34 cooperates with the first abutting surface 22 of the stop 21, limiting the first abutting surface 22 by the second limiting surface 341, preventing the first spring arm 36 from excessively expanding outward and detaching from the sound-generating member 2. At this point, the release member 3 and the sound-generating member 2 can no longer move relative to each other. Even under strong external force, the first spring arm 36 of the release member 3 can firmly abut against the sound-generating member 2, ensuring reliable limiting. The release member 3 is locked, preventing secondary injection and protecting the syringe needle tip, preventing secondary injury to the user. This structure significantly improves the impact resistance and stability of the product structure after injection, avoiding limiting failure caused by accidental force, thereby ensuring the safety and reliability of the automatic injector after use.

[0059] In some embodiments, the injection assembly 100 further includes a movable push rod linkage 9 installed in the sound-generating base 1. The push rod linkage 9 is provided with a mounting groove 93 and a spring piece 91 located in the mounting groove 93. One end of the spring piece 91 facing the bottom of the sound-generating base 1 is connected to the push rod linkage 9. An elastic block 92 is provided on the outer wall of the end of the spring piece 91 facing the top of the sound-generating base 1. The sound-generating base 1 is provided with a locking hole 18 that cooperates with the elastic block 92. Third protrusions 94 are provided on both sides of the push rod linkage 9. The sound-generating base 1 is provided with a locking groove 19 that cooperates with the third protrusions 94.

[0060] Optionally, the end of the spring 91 facing the top of the sound-generating base 1 does not contact the end face of the mounting groove 93; the outer peripheral surface of the elastic block 92 is an arc surface, and the cross-sectional area of ​​the third protrusion 94 increases from the end facing the top of the sound-generating base 1 to the end facing the bottom of the sound-generating base 1.

[0061] In this embodiment, the cross-sectional area of ​​the third protrusion 94 increases progressively from top to bottom, facilitating the installation of the push rod linkage 9 from the bottom of the sound-generating base 1 into the sound-generating base 1. Furthermore, after installation, the bottom surface of the third protrusion 94 of the push rod linkage 9 can abut against the slot 19, thereby restricting the displacement of the push rod linkage 9 after it is installed into the sound-generating base 1, thus preventing the installed push rod linkage 9 from detaching from the sound-generating base 1.

[0062] The injection assembly 100 provided in this embodiment of the application has an outer peripheral surface of the elastic locking block 92 as an arc surface. The sound-generating base 1 is provided with a locking hole 18 that engages with the elastic locking block 92. When the injection spring 7 pushes the push rod 4 and the push rod linkage 9 to move upward synchronously, the elastic locking block 92 can disengage from the locking hole 18 under force. The engagement between the elastic locking block 92 and the locking hole 18 is used to position and fix the connection between the push rod linkage 9 and the sound-generating base 1, ensuring that the push rod linkage 9 will not be displaced due to shaking during installation and transportation. When subjected to a sufficiently large driving force from the injection spring 7, the engagement between the elastic locking block 92 and the locking hole 18 will fail, allowing the push rod 4 and the push rod linkage 9 to move upward synchronously. Thus, through the engagement between the elastic locking block 92 and the locking hole 18, it is ensured that the sliding parts will not rotate and cause misalignment, ensuring the stability of the mechanism. Furthermore, compared to the configuration where the spring 91 extends downwards and the elastic block 92 is located at the lower part of the spring 91, the configuration where the spring 91 of the push rod linkage 9 provided in this application extends upwards and the elastic block 92 is located at the upper part of the spring 91 makes the push rod linkage 9 move more smoothly during injection, effectively preventing the push rod linkage 9 from shifting prematurely and causing premature sound emission, thus improving the stability of the sound emission function after injection of the automatic injector.

[0063] In some embodiments, the needle tip protective sleeve 103 is provided with needle tip protective sleeve slots 1031 on both sides and a sliding groove 1032 located above the needle tip protective sleeve slots 1031. The pen refill holder 104 is provided with second spring arms 1041 on both sides. A pen refill holder buckle 1042 is provided on the outer wall of one end of the second spring arm 1041. The pen refill holder buckle 1042 can cooperate with the needle tip protective sleeve slots 1031 to be locked in the needle tip protective sleeve slots 1031. The pen refill holder buckle 1042 can cooperate with the sliding groove 1032 to be slidably connected in the sliding groove 1032.

[0064] In this embodiment, the pen tip holder 1042 is engaged with the needle tip protective sleeve groove 1031 to lock into the needle tip protective sleeve groove 1031, thereby achieving positioning between the needle tip protective sleeve 103 and the pen tip holder 104. When the needle tip protective sleeve 103 moves down, if there is no sliding groove 1032 above the needle tip protective sleeve groove 1031, the pen tip holder 1042 on both sides of the pen tip holder 104 will always interfere with the inner wall of the needle tip protective sleeve 103, which will affect the injection resistance and the needle shielding function after injection. However, with the addition of the sliding groove 1032 provided in this application, there will only be resistance between the pen tip holder 1042 on both sides of the second spring arm 1041 of the pen tip holder 104 and the needle tip protective sleeve 103 at the moment of injection initiation. When the pen tip holder 1042 enters the sliding groove 1032, it can move in the sliding groove 1032, and the resistance will disappear. Therefore, the design of the pen refill holder buckle 1042 of this application, which can cooperate with the slide groove 1032 to slide in the slide groove 1032, can avoid the pen refill holder buckles 1042 on both sides of the pen refill holder 104 from interfering with the inner wall of the needle tip protective sleeve 103, and significantly reduce injection resistance.

[0065] Optionally, the tip of the needle tip protective sleeve 103 extends out of the pen body 101, and the tip of the pen body 101 is fitted with a pen cap 102. The pen cap 102 covers the tip of the needle tip protective sleeve 103, and the pen cap 102 is engaged with the pen body 101.

[0066] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An automatic injector, characterized in that, The injection assembly (100) includes a sound-generating base (1), and a sound-generating element (2) and a release element (3) are movably sleeved on the outer periphery of the sound-generating base (1). The outer periphery of the sound-generating base (1) is provided with a limiting block (15) and a boss (16) located on one side of the limiting block (15). The boss (16) is provided with a boss slope (161) on the side facing the limiting block (15). A limiting groove (17) is provided between the boss slope (161) and the limiting block (15). The release member (3) is provided with a first protrusion (31) that can be engaged in the limiting groove (17). The first protrusion (31) is provided with a first end face (311) that cooperates with the boss slope (161), a second end face (312) that cooperates with the limiting groove (17), and a third end face (313) that cooperates with the limiting block (15). The release member (3) is provided with a first spring arm (36) on the side facing the sound-generating member (2). The end of the first spring arm (36) is provided with a limiting platform (34) and a second protrusion (32) located on the side of the limiting platform (34). The sound-generating member (2) is provided with a baffle (21) on the side facing the release member (3). When the first spring arm (36) retracts inward, the second protrusion (32) and the limiting platform (34) can be embedded into the inner wall of the sound-generating member (2). When the first spring arm (36) expands outward, the second protrusion (32) can abut against the baffle (21). The sound-generating base (1) is equipped with a movable push rod linkage (9). The push rod linkage (9) is provided with a mounting groove (93) and a spring piece (91) located in the mounting groove (93). The end of the spring piece (91) facing the bottom of the sound-generating base (1) is connected to the push rod linkage (9). The outer wall of the end of the spring piece (91) facing the top of the sound-generating base (1) is provided with an elastic locking block (92). The sound-generating base (1) is provided with a locking hole (18) that cooperates with the elastic locking block (92). An embedding groove (33) is provided between the second protrusion (32) and the limiting platform (34). A first abutting surface (22) is provided on the side of the blocking platform (21), and a second abutting surface (23) is provided on the top of the blocking platform (21). A first limiting surface (321) that cooperates with the second abutting surface (23) is provided on the side of the second protrusion (32) facing the embedding groove (33). A second limiting surface (341) that cooperates with the first abutting surface (22) is provided on the side of the limiting platform (34) facing the embedding groove (33). The first protrusion (31) is disposed on the inner wall of the release member (3); the third end face (313) is located on the top of the first protrusion (31), the second end face (312) is located on the side of the first protrusion (31), the first end face (311) is located on the bottom side of the first protrusion (31) and is inclined, and the first end face (311), the second end face (312) and the third end face (313) are connected in sequence; The first limiting surface (321) and the second blocking surface (23) are inclined surfaces; the outer side of the second protrusion (32) is an inclined surface, and the two first elastic arms (36) are symmetrically arranged on both sides of the release member (3) and are in the shape of an "eight".

2. The auto-injector according to claim 1, characterized in that, The push rod linkage (9) has a third protrusion (94) on both sides, and the sound-generating base (1) has a slot (19) that cooperates with the third protrusion (94).

3. The automatic injector according to claim 1, characterized in that, The outer periphery of the sound-generating base (1) is provided with a first shaft portion (11), a second shaft portion (12), a third shaft portion (13), and a fourth shaft portion (14) with increasing outer diameters. The release member (3) is movably sleeved on the outer periphery of a portion of the first shaft portion (11) and a portion of the second shaft portion (12). The sound-generating member (2) is movably sleeved on the outer periphery of a portion of the second shaft portion (12) and a portion of the third shaft portion (13). A release spring (6) is provided between the release member (3) and the sound-generating member (2). The two ends of the release spring (6) respectively abut against and connect the release member (3) and the sound-generating member (2).

4. The automatic injector according to claim 3, characterized in that, The bottom of the sound-generating base (1) is fitted with a pressure cap (5). The pressure cap (5) is sleeved on the outer periphery of the fourth shaft part (14) and seals the bottom end of the sound-generating base (1). A push rod (4) is installed inside the sound-generating base (1). An injection spring bracket (8) is provided inside the push rod (4). An injection spring (7) is sleeved on the outer periphery of the injection spring bracket (8). One end of the injection spring (7) abuts against the bottom end of the injection spring bracket (8), and the other end abuts against the top end of the inner wall of the push rod (4). The bottom end of the injection spring bracket (8) abuts against the pressure cap (5).

5. The auto-injector according to claim 2, characterized in that, The end of the spring piece (91) facing the top of the sound-generating base (1) does not contact the end face of the mounting groove (93); the outer peripheral surface of the elastic block (92) is an arc surface, and the cross-sectional area of ​​the third protrusion (94) increases from the end facing the top of the sound-generating base (1) to the end facing the bottom of the sound-generating base (1).

6. The auto-injector according to claim 1, characterized in that, It also includes a pen body (101), a needle tip protective sleeve (103) installed at one end inside the pen body (101), a pen refill holder (104) installed at the other end inside the pen body (101), and a syringe (105) installed inside the pen body (101). The injection assembly (100) is installed inside the pen body (101). The top end of the needle tip protective sleeve (103) extends out of the pen body (101). A pen cap (102) is fitted onto the top end of the pen body (101). The pen cap (102) covers the top end of the needle tip protective sleeve (103). The pen cap (102) is snapped into the pen body (101). The needle tip protective sleeve (103) triggers the injection assembly (100). The injection assembly (100) squeezes the syringe (105) to complete the injection operation.

7. The auto-injector according to claim 6, characterized in that, The needle tip protective sleeve (103) is provided with needle tip protective sleeve slots (1031) on both sides and a sliding groove (1032) located above the needle tip protective sleeve slots (1031). The pen refill holder (104) is provided with second spring arms (1041) on both sides. The outer wall of one end of the second spring arm (1041) is provided with a pen refill holder buckle (1042). The pen refill holder buckle (1042) can cooperate with the needle tip protective sleeve slots (1031) to be locked in the needle tip protective sleeve slots (1031). The pen refill holder buckle (1042) can cooperate with the sliding groove (1032) to be slidably connected in the sliding groove (1032).

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