Hidden needle device for autoinjector and autoinjector

Abstract

This utility model provides a concealed needle device for an auto-injector and the same auto-injector, belonging to the technical field of medical devices. The concealed needle device includes: a pressing part, sleeved on the outside of the needle tip; a locking ring, with its front end abutting against the rear end of the pressing part and a first latch at its rear end; a stop ring, located at the rear end of the locking ring and having a first groove on its surface and a limiting platform with a protrusion facing the axis at its rear end; a latch, sleeved on the outside of a pushing device and located at the rear end of the locking ring, with a second latch on its surface, and the stop ring sleeved on the outside of the latch; before injection, the limiting platform is located at the rear end of the second latch and engages for locking; during injection, the pressing part pushes the locking ring backward, and the first latch pushes the second latch to open the stop ring and move it to the rear end of the limiting platform, releasing the injection from the pushing device; after injection, the first latch engages in the first groove, and the second latch abuts against the rear end of the stop ring to lock the pressing part. This concealed needle device prevents the pressing part from retracting after injection, protecting the needle and avoiding secondary use.

Description

Technical Field

[0001] This utility model belongs to the technical field of medical devices, and specifically relates to a hidden needle device for an autoinjector and the autoinjector thereof. Background Technology

[0002] Subcutaneous injection of medications via syringe is a common method of drug administration. For example, insulin injectors used by diabetic patients deliver a capsule containing a measured amount of artificial insulin subcutaneously through an internal delivery mechanism to regulate blood sugar.

[0003] Because the delivery mechanism is hidden inside the syringe, it needs to be pushed from the outside by a triggering mechanism on the outside of the syringe to push the drug capsule. The triggering mechanism needs to ensure that it can smoothly trigger the internal delivery mechanism to complete the delivery and injection of the drug capsule during injection, and also needs to protect and shield the needle after injection to prevent accidental needle exposure and secondary triggering.

[0004] Existing pre-filled syringes have the following drawbacks: after injection, the needle at the injection end is shielded by an external protective sleeve, but the trigger mechanism inside the syringe is not locked. If the external protective sleeve falls off, the exposed needle could cause accidental injury. Furthermore, the lack of a locking mechanism can lead to secondary triggering, which is detrimental to the syringe's single-use and recycling capabilities and poses a safety hazard.

[0005] In view of this, there is a need for a new type of hidden needle device for autoinjectors and an autoinjector thereof to solve all or part of the above problems. Utility Model Content

[0006] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of this utility model provide a concealed needle device for an autoinjector and the same device. Through the sliding engagement of the locking ring, stop ring, and latch of the concealed needle device, it ensures that during injection, the locking ring pushes and opens the latch to release the pusher for automatic injection. It also ensures that after injection, the concealed needle device will not retract upon resetting and being pressed again, thus protecting the needle tip and preventing accidental needle injury and secondary triggering of the autoinjector. The technical solution is as follows:

[0007] According to one aspect of the present invention, a concealed needle device for an autoinjector is provided. The concealed needle device includes:

[0008] The pressing part is a hollow cylinder that is fitted onto the outside of the needle of the auto-injector;

[0009] The locking ring has its front end abutting against the rear end of the pressing part, and its rear end is provided with a first buckle;

[0010] A stop ring is provided at the rear end of the locking ring. The surface of the stop ring is provided with a first groove, and the rear end of the stop ring is provided with a limiting platform facing the axis.

[0011] A locking buckle is fitted onto the outside of the pusher of the auto-injector and located at the rear end of the locking ring. A second buckle is provided on the surface of the locking buckle, and a stop ring is fitted onto the outside of the locking buckle.

[0012] Before injection, the limiting platform is located at the rear end of the second latch, and the two are locked together. During injection, pressing the pressing part pushes the locking ring backward, and the first latch pushes the second latch to open the stop ring and move to the rear end of the limiting platform. The pushing device is released from the latch to push the drug capsule to complete the injection. After injection, the first latch engages in the first slot, and the second latch abuts against the rear end of the stop ring and locks the pressing part.

[0013] In some embodiments, the concealed needle device further includes a compression spring sleeved on the outside of the concealed needle device.

[0014] In some embodiments, specifically, a first annular boss is provided on the outer side of the latch near the rear end, and the first annular boss is located at the rear end of the stop ring. A second annular boss is provided on the outer side of the locking ring near the front end, and the second annular boss is located at the front end of the first latch. One end of a compression spring abuts against the front end of the first annular boss, and the other end abuts against the rear end of the second annular boss. During injection, the locking ring moves rearward to compress the compression spring and store force. After injection, the compression spring releases the stored force, pushing the locking ring and the pressing part back to their original positions.

[0015] In some embodiments, preferably, a first positioning rib is also provided on the outer wall surface of the locking ring. When the autoinjector is assembled, the first positioning rib cooperates with the inner wall surface of the autoinjector housing to lock the locking ring in the circumferential position.

[0016] In some embodiments, specifically, the first latch includes at least two first latches, with each pair of the at least two first latches arranged symmetrically in pairs on the outer side of the locking ring wall. The first slot includes at least two first slots, with each pair of the at least two first slots corresponding to and matching each pair of the first latches on the wall of the stop ring.

[0017] In some embodiments, preferably, a second positioning rib is also provided on the outer wall surface of the latch, and during the assembly of the autoinjector, the second positioning rib cooperates with the inner wall surface of the autoinjector housing to lock the latch in the circumferential position.

[0018] In some embodiments, specifically, the front end of the latch is inserted into the interior of the rear end of the locking ring. During injection, pressing the pressing part pushes the locking ring to move to the rear end until the first latch pushes the second latch to move to the rear end of the stop ring.

[0019] In some embodiments, preferably, the first and second latches are resilient latches.

[0020] According to another aspect of the present invention, an automatic injector is provided, comprising a needle, a cartridge, and a delivery device sequentially connected in series from front to rear end inside a housing, and a concealed needle device sleeved on the outside of the needle, cartridge, and delivery device. The concealed needle device uses the concealed needle device described in the above aspects.

[0021] In some embodiments, specifically, the pushing device is located at the rear end of the drug reservoir, and the front end of the pushing device abuts against the drug capsule inside the drug reservoir. Before injection, the pushing device is fixed within the locking mechanism of the concealed needle device. During injection, pressing the pressing part of the concealed needle device pushes the locking ring backward, and the first latch at the rear end of the locking ring pushes the second latch at the front end of the locking ring to open the stop ring and move it to the rear end of the stop ring. The pushing device is then released from the locking mechanism to push the drug capsule to complete the injection. After injection, the first latch of the locking ring engages in the first slot of the stop ring, and the second latch of the locking mechanism abuts against the rear end of the stop ring, locking the pressing part so that it cannot retract.

[0022] The concealed needle device for an autoinjector and the autoinjector thereof provided by the embodiments of this utility model have at least one or a portion of the following advantages:

[0023] (1) By sliding and engaging the locking ring, stop ring and buckle of the hidden needle device, it is ensured that the locking ring of the hidden needle device pushes and opens the buckle to release the push device for automatic injection during injection, and that the hidden needle device will not retract after being reset and pressed again after injection, thereby wrapping and protecting the needle and avoiding accidental needle injury and secondary triggering of the automatic injector.

[0024] (2) The push before injection and the locking after injection are completed by the positional changes of the first buckle of the locking ring and the second buckle of the locking ring relative to the stop ring before and after injection. The assembly structure and processing technology are simple and the assembly stability is high.

[0025] (3) The second buckle of the lock moves to the rear end of the stop ring after injection and abuts against the stop ring, and the first buckle of the lock ring is engaged in the first slot of the stop ring, so that although the pressing part and the lock ring are reset after injection, the lock ring cannot be moved back when the pressing part is pressed again, thus avoiding the reuse of the automatic injector.

[0026] (4) The second buckle of the locking ring can be engaged with the limiting platform of the stop ring to lock the stop ring before injection to prevent the front end from accidentally touching the pressing part to start automatic injection;

[0027] (5) By fitting a compression spring on the outside of the hidden needle device and limiting the compression spring by the annular boss on the locking ring and the buckle, it is ensured that after the pressing part triggers the pushing device to push the drug capsule for automatic injection, the entire hidden needle device can smoothly and quickly retract and reset when the pressing part is released.

[0028] (6) By setting positioning ribs on the outer wall of the locking ring and the buckle, the limiting and positioning of each part of the hidden needle device of the automatic injector can be effectively guaranteed during the assembly process, avoiding the rotation of the locking ring and the buckle in the circumferential direction, and improving the assembly stability and use stability of the automatic injector. Attached Figure Description

[0029] These and / or other aspects and advantages of this invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 This is a cross-sectional structural schematic diagram of an automatic injector according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 The diagram shows an enlarged structural schematic of the hidden needle device of one embodiment of the autoinjector before injection.

[0032] Figure 3 for Figure 2 The diagram shows an enlarged structural schematic of the hidden needle device used in the autoinjector after injection.

[0033] Figure 4 for Figure 2 A schematic diagram of the locking ring of one embodiment of the concealed needle device is shown.

[0034] Figure 5 for Figure 2 A schematic diagram of the latch structure of one embodiment of the concealed needle device is shown;

[0035] Figure 6 for Figure 2 A schematic diagram of the stop ring structure of one embodiment of the hidden needle device shown. Detailed Implementation

[0036] The technical concept and technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of this utility model with reference to the accompanying drawings is intended to explain the overall concept of this utility model and should not be construed as a limitation thereof.

[0037] It should also be understood that although the terms "first," "second," "third," etc., may be used in the following embodiments of this utility model to describe a component comprising two or more of the same component, these components should not be limited to these terms, which are only used to distinguish each component from one another. Furthermore, descriptions indicating orientation such as "upper," "lower," "left," "right," "front," and "rear" are merely illustrative of the relative positions of components and should not be construed as a limitation of this utility model.

[0038] To address the problems of existing pre-filled syringes, such as accidental triggering before injection, inability to inject all medication during injection, lack of internal braking mechanism after injection, and inability to protect the needle externally, embodiments of this utility model provide a concealed needle device for an autoinjector and the autoinjector thereof. Through the sliding engagement of the locking ring, stop ring, and latch of the concealed needle device, it is ensured that during injection, the locking ring pushes and opens the latch to release the pusher for automatic injection, and that after injection, the concealed needle device will not retract when pressed again, thereby protecting the needle and preventing accidental needle injury and secondary triggering of the autoinjector.

[0039] According to one aspect of the present invention, a hidden needle device 100 for an autoinjector is provided.

[0040] See Figure 1 The diagram shows a cross-sectional structure of a concealed needle device 100 according to one embodiment, wherein the concealed needle device 100 is disposed at the injection end of an autoinjector 200 according to one embodiment. For example... Figure 1 The left side shown, where the needle 201 is located, is the front end of the autoinjector 200. Conversely, Figure 1 The right side shows the rear end of the autoinjector 200.

[0041] See Figure 2 This shows, as Figure 1 The diagram shows an enlarged view of the hidden needle device 100 in its unused state before injection by the autoinjector 200.

[0042] Combination Figure 1 and Figure 2As shown, the concealed needle device 100 includes four main parts connected sequentially from the front end to the rear end of the autoinjector 200: a pressing part 10, a locking ring 20, a stop ring 30, and a locking buckle 40. Specifically, the pressing part 10 is a hollow cylinder and is sleeved on the outside of the needle 201 of the autoinjector 200. The front end of the locking ring 20 abuts against the rear end of the pressing part 10, and a first buckle 21 is provided at its rear end. The stop ring 30 is located at the rear end of the locking ring 20, and a first groove 31 is provided on the surface of the stop ring 30. A limiting platform 32 facing the axis is provided at the rear end of the stop ring 30. The locking buckle 40 is sleeved on the outside of the pushing device 203 of the autoinjector 200 and is located at the rear end of the locking ring 20. A second buckle 42 is provided on the surface of the locking buckle 40, and the stop ring 30 is sleeved on the outside of the locking buckle 40.

[0043] See Figure 3 This shows, as Figure 1 An enlarged view of the structure of the hidden needle device 100 after injection by the autoinjector 200.

[0044] Combination Figures 1-3 As shown, before injection, the limiting platform 32 of the stop ring 30 is located at the rear end of the second latch 42 of the lock 40, and the two are locked together. During injection, pressing the pressing part 10 pushes the locking ring 20 backward, and the first latch 21 of the locking ring 20 pushes the second latch 42 of the lock to open the stop ring 30 and move it to the rear end of the limiting platform 32 of the stop ring 30. The pushing device 203 is released from the lock 40 to push the drug capsule 2021 in the drug chamber 202 to complete the injection. After injection, the first latch 21 of the locking ring 20 is engaged in the first slot 31 of the stop ring 30, and the second latch 42 of the lock 40 abuts against the rear end of the stop ring 30 and locks the pressing part 10.

[0045] Exemplarily, the sac 2021 may be a capsule pre-filled with a drug, and the capsule may be a shell structure made of a soluble material to contain the drug. The sac 2021 may also be a liquid drug or a solid drug (tablet, granule, etc.) directly pre-filled into the sac 202. These are merely illustrative examples and should not be construed as limiting the invention by those skilled in the art.

[0046] In one example, further, such as Figure 2 or Figure 3 As shown, the hidden needle device 100 also includes a compression spring 50, which is sleeved on the outside of the hidden needle device 100.

[0047] In one example, specifically, a second annular boss 22 is provided on the outer side of the locking ring 20 near the front end, and the second annular boss 22 is located at the front end of the first latch 21. A first annular boss 41 is provided on the outer side of the latch 40 near the rear end, and the first annular boss 41 is located at the rear end of the stop ring 30. One end of the compression spring 50 abuts against the front end of the first annular boss 41, and the other end abuts against the rear end of the second annular boss 22. During injection, the locking ring 20 moves rearward to compress the compression spring 50 to store force. After injection, the compression spring 50 releases the stored force, pushing the locking ring 20 and the pressing part 10 back to their original positions.

[0048] See Figure 4 , showing the use of Figure 1 The overall structure of the locking ring 20 in one embodiment of the hidden needle device 100.

[0049] In one example, preferably, a first positioning rib 23 is also provided on the outer wall surface of the locking ring 20. When the autoinjector 200 is assembled, the first positioning rib 23 cooperates with the inner wall surface of the housing 204 of the autoinjector 200 to lock the locking ring 20 in the circumferential position.

[0050] See Figure 5 , showing the use of Figure 1 The overall structure of the latch 40 in one embodiment of the hidden needle device 100.

[0051] In one example, preferably, a second positioning rib 43 is also provided on the outer wall surface of the latch 40. When the autoinjector 200 is assembled, the second positioning rib 43 cooperates with the inner wall surface of the housing 204 of the autoinjector 200 to lock the latch 40 in the circumferential position.

[0052] See Figure 6 , showing the use of Figure 1 The overall structure of the stop ring 30 in one embodiment of the hidden needle device 100.

[0053] In one example, specifically, combining Figure 4 and Figure 6 As shown, the first latch 21 of the locking ring 20 includes at least two first latches. Preferably, each pair of the at least two first latches is arranged symmetrically in pairs on the outer side of the rear wall of the locking ring 20. The first slot 31 of the stop ring 30 includes at least two first slots, and each pair of the at least two first slots is correspondingly matched with each pair of first latches and is formed on the wall of the stop ring 30.

[0054] In one example, alternatively, the locking ring 20 may have two first latches 21, which are symmetrically arranged around the circumference of the locking ring 20. Correspondingly, the stop ring 30 may have two first slots 31, which are configured to correspond one-to-one with the two first latches 21. The specific number of pairs of first latches 21 and first slots 31 can be designed according to the actual automatic injector. This is only an illustrative example and should not be construed as a limitation of the present invention by those skilled in the art.

[0055] In one example, further, combining Figures 4-6 As shown, the front end of the latch 40 is inserted into the interior of the rear end of the locking ring 20. During injection, pressing the pressing part 10 pushes the locking ring 20 to move rearward until the first latch 21 pushes the second latch 42 to move rearward to the rear end of the stop ring 30. Preferably, the first latch 21 and the second latch 42 are elastic latches, which facilitates easier elastic deformation when they come into contact, thus smoothly opening the latch 40 to release the internal pushing device 203. Figure 2 and Figure 3 As shown in the comparison before and after injection, it can be seen that the push rod 2031 of the pusher device 203 is fixed in the inner cavity of the latch 40 before injection. During the injection process, the latch 40 opens and moves backward, allowing the push rod 2031 to be released and move rapidly forward (towards the needle 201) under the pushing force of the rear push mechanism (such as a push spring), pushing the drug capsule 2021 in the drug chamber 202 to complete the automatic injection.

[0056] Combination Figure 2 and Figure 3 As shown, the concealed needle device 100 of the automatic injector 200 drives the locking ring 20 to move rearward along its axis by pressing the pressing part 10, and the locking ring 20 is provided with a first buckle 21. The surface of the stop ring 30 is provided with a first groove 31, and its rear end is provided with a limiting platform 32. The locking buckle 40 is provided with a second buckle 42 with elasticity.

[0057] In the initial state when the autoinjector 200 is not in use, the push rod 2031 of the internal pushing device 203 is fixed in the inner cavity of the latch 40, and the second latch 42 of the latch 40 is located at the front end of the limiting platform 32 of the stop ring 30. The two are locked together to prevent the stop ring 30 from shifting due to accidental contact with the front pressing part 10 before the autoinjector 200 is used, which would cause the autoinjector 200 to malfunction.

[0058] After the auto-injector 200 completes automatic injection, as the locking ring 20 moves axially towards the rear end, its first latch 21 engages with the first groove 31 on the surface of the stop ring 30. Simultaneously, the locking ring 20, along with the stop ring 30, moves towards the front end and returns to its initial position under the rebound force of the compression spring 50. However, at this point, because the second latch 42 of the locking buckle 40 has moved to the rear end of the stop ring 30 and abuts against it, preventing it from retracting, the entire concealed needle device 100 cannot retract when the pressing part 10 at the front end is pressed again. The needle 201 is encased inside the pressing part 10 and not exposed, and the auto-injector 200 cannot be triggered a second time.

[0059] According to another aspect of the present invention, an autoinjector 200 is provided, comprising a needle 201, a cartridge 202, and a delivery device 203 sequentially connected from front to rear end inside a housing 204, and a concealed needle device 100 sleeved on the outside of the needle 201, cartridge 202, and delivery device 203. The concealed needle device 100 is the same as described in the above aspects. The specific structure of the concealed needle device 100 can be found in the descriptions of the above embodiments, and will not be repeated here.

[0060] In one example, specifically, the pusher 203 is positioned at the rear end of the drug chamber 202, and the front end of the pusher 203 abuts against the drug capsule 2021 inside the drug chamber 202. Before injection, the pusher 203 is fixed within the latch 40 of the concealed needle device 100. During injection, pressing the pressing part 10 of the concealed needle device 100 pushes the locking ring 20 backward, and the first latch 21 at the rear end of the locking ring 20 pushes the second latch 42 at the front end of the latch 40 to open the stop ring 30 and move it to the rear end of the stop ring 30. The pusher 203 (specifically the push rod 2031) is released from the latch 40 to push the drug capsule 2021 to complete the injection. After injection, the first latch 21 of the locking ring 20 engages in the first slot 31 of the stop ring 30, and the second latch 42 of the latch 40 abuts against the rear end of the stop ring 30, locking the pressing part 10 so that it cannot retract.

[0061] The concealed needle device for an autoinjector and the autoinjector thereof provided by the embodiments of this utility model have at least one or a portion of the following advantages:

[0062] (1) By sliding and engaging the locking ring, stop ring and buckle of the hidden needle device, it is ensured that the locking ring of the hidden needle device pushes and opens the buckle to release the push device for automatic injection during injection, and that the hidden needle device will not retract after being reset and pressed again after injection, thereby wrapping and protecting the needle and avoiding accidental needle injury and secondary triggering of the automatic injector.

[0063] (2) The push before injection and the locking after injection are completed by the positional changes of the first buckle of the locking ring and the second buckle of the locking ring relative to the stop ring before and after injection. The assembly structure and processing technology are simple and the assembly stability is high.

[0064] (3) The second buckle of the lock moves to the rear end of the stop ring after injection and abuts against the stop ring, and the first buckle of the lock ring is engaged in the first slot of the stop ring, so that although the pressing part and the lock ring are reset after injection, the lock ring cannot be moved back when the pressing part is pressed again, thus avoiding the reuse of the automatic injector.

[0065] (4) The second buckle of the locking ring can be engaged with the limiting platform of the stop ring to lock the stop ring before injection to prevent the front end from accidentally touching the pressing part to start automatic injection;

[0066] (5) By fitting a compression spring on the outside of the hidden needle device and limiting the compression spring by the annular boss on the locking ring and the buckle, it is ensured that after the pressing part triggers the pushing device to push the drug capsule for automatic injection, the entire hidden needle device can smoothly and quickly retract and reset when the pressing part is released.

[0067] (6) By setting positioning ribs on the outer wall of the locking ring and the buckle, the limiting and positioning of each part of the hidden needle device of the automatic injector can be effectively guaranteed during the assembly process, avoiding the rotation of the locking ring and the buckle in the circumferential direction, and improving the assembly stability and use stability of the automatic injector.

[0068] While some embodiments of the general concept of this utility model have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept of this utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. A needle concealment device for an automatic injector, characterized in that The hidden needle device includes: The pressing part is a hollow cylinder and is sleeved on the outside of the needle of the auto-injector; A locking ring, the front end of which abuts against the rear end of the pressing part, and the rear end of the locking ring is provided with a first buckle; A stop ring is provided at the rear end of the locking ring. The surface of the stop ring is provided with a first groove, and the rear end of the stop ring is provided with a limiting platform facing the axis. A locking buckle is sleeved on the outside of the pusher of the auto-injector and located at the rear end of the locking ring. A second buckle is provided on the surface of the locking buckle, and a stop ring is sleeved on the outside of the locking buckle. Before injection, the limiting platform is located at the rear end of the second buckle and the two are locked together. During injection, pressing the pressing part pushes the locking ring backward, and the first buckle pushes the second buckle to open the stop ring and move it to the rear end of the limiting platform. The drug capsule is pushed out of the hidden needle device by the pushing device released inside the locking buckle. After injection, the first buckle engages in the first slot and the second buckle abuts against the locking and pressing part at the rear end of the stop ring.

2. The hidden needle device according to claim 1, characterized in that, The concealed needle device also includes a compression spring, which is sleeved on the outside of the concealed needle device.

3. The hidden needle device according to claim 2, characterized in that, A first annular protrusion is provided on the outer side of the latch near the rear end, and the first annular protrusion is located at the rear end of the stop ring; A second annular protrusion is provided on the outer side of the locking ring near the front end, and the second annular protrusion is located at the front end of the first buckle. One end of the compression spring abuts against the front end of the first annular boss, and the other end abuts against the rear end of the second annular boss; During injection, the locking ring moves to the rear end to compress the compression spring and store energy. After injection, the compression spring releases the stored energy and pushes the locking ring and the pressing part back to their original positions.

4. The hidden needle device according to claim 2, characterized in that, The outer wall of the locking ring is also provided with a first positioning rib. When the autoinjector is assembled, the first positioning rib cooperates with the inner wall of the autoinjector housing to lock the locking ring in the circumferential position.

5. The hidden needle device according to claim 4, characterized in that, The first latch includes at least two first latches, and each pair of the at least two first latches is arranged symmetrically in pairs on the outer side of the wall of the locking ring; The first slot includes at least two first slots, and each pair of the at least two first slots is correspondingly matched with each pair of first buckles and is formed on the wall surface of the stop ring.

6. The hidden needle device according to claim 5, characterized in that, A second positioning rib is also provided on the outer wall surface of the latch. During the assembly of the autoinjector, the second positioning rib cooperates with the inner wall surface of the autoinjector housing to lock the latch in the circumferential position.

7. The hidden needle device according to any one of claims 1-6, characterized in that, The front end of the latch is inserted into the interior of the rear end of the locking ring. During injection, pressing the pressing part pushes the locking ring to the rear end until the first buckle pushes the second buckle to the rear end of the stop ring.

8. The hidden needle device according to claim 7, characterized in that, The first and second buckles are elastic buckles.

9. An automatic injector comprising a needle, a cartridge and a pusher device which are sequentially connected in series inside a housing from a front end to a rear end, and a needle hiding device which is sleeved outside the needle, the cartridge and the pusher device, characterized in that, The hidden needle device is the hidden needle device according to any one of claims 1-8.

10. The automatic injector according to claim 9, characterized in that, The pushing device is located at the rear end of the medicine compartment and the front end of the pushing device abuts against the medicine sac inside the medicine compartment. Before injection, the pusher is fixed in the latch of the hidden needle device; During injection, pressing the pressing part of the hidden needle device pushes the locking ring backward, and the first buckle at the rear end of the locking ring pushes the second buckle at the front end of the locking buckle to open the stop ring and move to the rear end of the stop ring. The drug capsule is pushed out of the hidden needle device by the pushing device released inside the locking buckle. After injection, the first latch of the locking ring engages in the first slot of the stop ring, and the second latch of the locking ring abuts against the rear locking pressing part of the stop ring.

Images