Injection spring locking excitation mechanism assembly for automatic injection pen

Abstract

The utility model relates to an injection spring locking excitation mechanism assembly for an automatic injection pen. The injection spring locking excitation mechanism assembly is formed by preassembling an injection spring sleeve, a safety unlocking sleeve, an injection spring and a push rod together. The injection spring has a compressed energy storage state and an unfolded working state; when the injection spring is in a compressed energy storage state, the injection spring sleeve is connected with the push rod; the safety unlocking sleeve is mounted outside the injection spring sleeve and can slide relative to the injection spring sleeve; when the safety unlocking sleeve slides to the maximum stroke relative to the injection spring sleeve, the injection spring sleeve is separated from the push rod, the injection spring is unlocked, the injection spring is converted into an unfolding working state from a compression energy storage state, the injection spring is unfolded and released from the compression state to generate thrust, and the injection spring pushes the push rod to move. According to the utility model, the injection spring can be reliably locked; and during unlocking, safe unlocking and unlocking of the injection spring can be completed at the same time, and release and work of the injection spring are achieved.

Description

Technical Field

[0001] The utility model relates to an injection spring locking and triggering mechanism assembly in an auto-injector pen, belonging to the field of medical syringes. Background Art

[0002] An auto-injector pen is a syringe product that is convenient for patients or the general public to operate. When manufacturers produce it, they first fill the liquid medicine into the syringe to form a prefilled syringe (PFS, also known as a drug-loaded syringe), as shown in Figure 1 、 Figure 2 ; then the PFS is loaded into the auto-injection device to form an auto-injector pen for transportation and sales. After obtaining the auto-injector pen, consumers use it as needed, remove the pen cap, then press it on the injection site of the patient to trigger the injection, and finally remove the injector pen to complete the automatic injection of the liquid medicine; compared with traditional syringes, it omits the processes of sucking medicine, pricking the needle, and pushing the medicine with a disposable syringe, the operation is more convenient, and the injection dose can be guaranteed, and there will be no deviation in the injection dose due to unskilled operation.

[0003] At present, there are many auto-injector pens for PFS with a one-time fully automatic injection function on the market, which is convenient for patients to use. However, due to regulatory requirements, the needle needs to be shielded before and after use to avoid needle injury, so generally two sets of spring systems are required inside to implement the functions of pushing the medicine and shielding respectively. Therefore, the structure of the auto-injector pen is generally more complex, which leads to the complexity of the assembly of the auto-injection device with the PFS.

[0004] However, after the pharmaceutical manufacturer completes the production of the medicine and fills it to form the PFS, when assembling the whole pen, it often hopes to simplify the assembly process as much as possible, that is, most of the structural parts of the auto-injection device are completed at the production manufacturer's end of the auto-injection device, which can reduce the facilities and equipment for loading the PFS and improve the assembly efficiency.

[0005] Therefore, in combination with the final assembly requirements of pharmaceutical manufacturers and the safety and convenient use requirements of the terminal for auto-injector pens, it is necessary to improve the structure of the auto-injector pen, especially to optimize the structure of the auto-injection device.

[0006] Moreover, among the whole auto-injector pen, one of the most important components is the injection spring locking and triggering mechanism assembly, that is, it is necessary to reliably store and maintain the energy of the injection spring and then quickly release it during use. Summary of the Utility Model

[0007] The purpose of the present utility model is to provide an injection spring locking and actuating mechanism assembly for an auto-injector pen, which can reliably and stably maintain the storage state of the injection spring during the production process of the auto-injector pen, thus facilitating the assembly, storage, and transportation of the injector pen; finally, during the use phase, it can be quickly and conveniently unlocked to stably and reliably release the injection spring.

[0008] To achieve the above-mentioned utility model purpose, the present utility model provides an injection spring locking and actuating mechanism assembly for an auto-injector pen, which is formed by pre-assembling an injection spring sleeve, a safety unlocking sleeve, an injection spring, and a push rod together;

[0009] The injection spring has a compressed energy storage state and a deployed working state;

[0010] When the injection spring is in the compressed energy storage state, the injection spring sleeve is connected to the push rod;

[0011] The safety unlocking sleeve is installed outside the injection spring sleeve, and the safety unlocking sleeve can slide relative to the injection spring sleeve;

[0012] When the safety unlocking sleeve slides relative to the injection spring sleeve to the maximum stroke, the injection spring sleeve is separated from the push rod, the injection spring is unlocked, the injection spring changes from the compressed energy storage state to the deployed working state, the injection spring expands and releases from the compressed state to generate a thrust force, and the injection spring pushes the push rod to move.

[0013] As a further improvement of the present utility model, the injection spring sleeve includes a locking piece, a connecting cylinder, and spring claws;

[0014] The locking piece is located at the top; a section of connecting cylinder is provided below the locking piece, and several spring claws are provided below the connecting cylinder;

[0015] The spring claws are elastic arms arranged downward, and the lower ends of the spring claws are free ends;

[0016] The lower part of the spring claw extends inward to form a locking hook;

[0017] A chamber for installing the top of the injection spring is formed inside the connecting cylinder;

[0018] The push rod includes a rod cylinder, a spring chamber, and a push head;

[0019] A spring chamber for storing the injection spring is provided inside the rod cylinder;

[0020] The bottom of the rod cylinder forms a push head that can contact the piston inside the syringe of the pre-filled syringe;

[0021] Several buckle grooves are provided at the top of the rod cylinder, and the buckle grooves are matched with the locking hooks;

[0022] The injection spring is located between the injection spring sleeve and the push rod;

[0023] The top of the injection spring is located within the connection cylinder of the injection spring sleeve;

[0024] The bottom of the injection spring is located at the bottom of the rod cylinder;

[0025] The locking hook of the spring claw of the injection spring sleeve can be inserted inward into the buckling groove at the top of the rod cylinder of the push rod, so that the injection spring sleeve is locked together with the push rod, and the injection spring is compressed and stores energy;

[0026] The spring claw of the injection spring sleeve can be deformed outward to disengage the locking hook from the buckling groove, so that the injection spring sleeve is separated from the push rod, and the injection spring is unlocked and expands to release elastic force.

[0027] Furthermore, below the locking hook, there is an unlocking inclined surface, and the unlocking inclined surface is an inclined surface that slopes downward from the inside to the outside;

[0028] The safety unlocking sleeve is provided with an unlocking cylinder, and the top of the unlocking cylinder is the unlocking part; the unlocking part is matched with the unlocking inclined surface;

[0029] The injection spring sleeve and the safety unlocking sleeve move relative to each other, so that the top of the unlocking cylinder of the safety unlocking sleeve presses the unlocking inclined surface below the locking hook, causing the spring claw of the injection spring sleeve to deform outward, and causing the locking hook to disengage from the buckling groove, and the injection spring is unlocked.

[0030] Furthermore, a spring guide post is provided in the middle of the injection spring sleeve, and the spring guide post is a slender rod.

[0031] Furthermore, there are 2 locking hooks at the lower part of the spring claw of the injection spring sleeve, and the 2 locking hooks are symmetrically arranged;

[0032] There are 2 buckling grooves at the top of the rod cylinder, and the 2 buckling grooves are symmetrically arranged.

[0033] Furthermore, the upper end of the spring claw of the injection spring sleeve is connected to the connection cylinder or the locking piece.

[0034] As a further improvement of the present utility model, the safety unlocking sleeve includes a sliding sleeve, a safety locking sleeve, and an unlocking cylinder;

[0035] The sliding sleeve is matched with the firing push piece at the upper part of the firing sleeve; the top of the firing push piece can abut against the bottom of the sliding sleeve and push the safety unlocking sleeve to move;

[0036] There is a safety locking sleeve above the sliding sleeve, and the safety locking sleeve is connected to the sliding sleeve;

[0037] The diameter of the safety lock sleeve is smaller than the sliding sleeve, and the inner diameter of the safety lock sleeve matches the outer diameter of the circle where the spring claw of the injection spring sleeve is located; the safety lock sleeve can move from the free end of the lower part of the spring claw to the fixed end of the upper part of the spring claw;

[0038] An unlocking cylinder is provided below the safety lock sleeve, and the unlocking cylinder is connected to the safety lock sleeve;

[0039] An unlocking cone is arranged on the top of the unlocking cylinder; the unlocking cone can open the free end of the spring claw of the injection spring sleeve outward.

[0040] Further, an injection connection sleeve is provided, including a receiving tube, a connecting elastic arm, a giving way groove, and a locking hook;

[0041] The accommodating tube is a thin-walled cylindrical tube, and the outer wall of the accommodating tube matches the inner wall of the sliding sleeve of the safety unlocking sleeve to form a sliding guide;

[0042] A plurality of connecting elastic arms are arranged above the accommodating tube, and clearance grooves are arranged between the connecting elastic arms, and the clearance grooves are used for the connecting arms to pass through;

[0043] The connecting elastic arm can accommodate a safety lock sleeve;

[0044] A locking hook is inwardly arranged at the top of the connecting elastic arm, and the size of the locking hook matches the size of the locking piece.

[0045] Furthermore, when the claw is in a natural state, the outer diameter of the bottom is larger than the inner diameter of the safety lock sleeve;

[0046] When the safety lock sleeve is in the locked state, there is friction between the safety lock sleeve and the spring claw.

[0047] The utility model provides an injection spring locking and triggering mechanism component for an automatic injection pen, which is in a locked state. At this time, the safety unlocking sleeve is located at a relatively lower position on the injection connecting sleeve, the connecting arm is limited by the bottom of the yielding groove, or the unlocking cylinder is limited by the needle-collecting unlocking piece. At this time, the unlocking cylinder and the unlocking cone are away from the unlocking inclined surface, and the safety locking sleeve is located outside the free end of the spring claw and close to the lock hook; at this time, the safety locking sleeve holds the spring claw tightly, so that the spring claw loses the space for outward deformation, so the lock hook is reliably clamped in the buckle groove, so that the injection spring is reliably compressed and locked.

[0048] The injection spring locking and actuating mechanism assembly for the automatic injection pen of the present utility model, during actuation, that is, during the process of the injection spring changing from the compressed energy storage state to the deployed working state, the safety unlocking sleeve can slide upward relative to the injection connection sleeve and the injection spring sleeve. At this time, the safety lock sleeve gradually moves away from the position of the locking hook, and the unlocking cylinder and the unlocking cone approach the unlocking inclined surface accordingly; as the safety unlocking sleeve slides upward, the safety lock sleeve moves away from the outside of the spring pawl and moves outside the connection cylinder. At this time, the bottom of the spring pawl, that is, the free end, is no longer restricted and regains the elastic deformation space outward. At the same time, the unlocking cone contacts the unlocking inclined surface and, during the upward movement, pushes the unlocking inclined surface and the spring pawl outward until the locking hook disengages from the buckle groove, making the push rod in a free state. The injection spring releases its elastic force and pushes the push rod downward.

[0049] The injection spring is unlocked and pushes the push rod downward. The push head of the push rod contacts the piston and, under the action of the injection spring, pushes the piston to move in the injection cylinder, injecting the medicament into the body through the needle.

[0050] The injection spring locking and actuating mechanism assembly for the automatic injection pen of the present utility model can reliably lock the injection spring; during unlocking, it can smoothly complete safety unlocking and unlocking of the injection spring, realizing the release and operation of the injection spring. Description of the Drawings

[0051] Figure 1 It is a schematic structural diagram of a prefilled syringe (PFS);

[0052] Figure 2 It is an internal cross-sectional view of a prefilled syringe (PFS);

[0053] In the figure, 1 - prefilled syringe (PFS); 11 - syringe (sliding sleeve), 12 - injection cylinder (container, containing the medicament inside), 13 - flange (also known as flange), 14 - injection needle, 15 - piston, 16 - protective cap (also known as protective sheath), 17 - shoulder;

[0054] Figure 3 It is a schematic diagram of the assembly preparation of the automatic injection pen of the present utility model;

[0055] Figure 4 It is a schematic diagram of the assembly process of the automatic injection pen of the present utility model;

[0056] Figure 5 It is a schematic diagram of the assembly preparation of the functional pre-component;

[0057] Figure 6 It is an internal cross-sectional view of the overall structure of the functional pre-component;

[0058] Figure 7 This is a schematic diagram of the overall structure of the injection spring sleeve of the present utility model;

[0059] Figure 8 This is a schematic diagram of the internal structure of the injection spring sleeve of the present utility model;

[0060] Figure 9 This is a schematic diagram of the overall structure of the safety unlocking sleeve of the present utility model;

[0061] Figure 10 This is a sectional view of the overall structure of the safety unlocking sleeve of the present utility model;

[0062] Figure 11 This is a schematic diagram of the internal structure of the safety unlocking sleeve of the present utility model;

[0063] Figure 12 This is a schematic diagram of the overall structure of the injection connection sleeve of the present utility model Figure 1 ;

[0064] Figure 13 This is a schematic diagram of the overall structure of the injection connection sleeve of the present utility model Figure 2 ;

[0065] Figure 14 This is a sectional view of the overall structure of the injection connection sleeve of the present utility model;

[0066] Figure 15 This is a schematic diagram of the internal structure of the injection connection sleeve of the present utility model;

[0067] Figure 16 This is a schematic diagram of the overall structure of the push rod of the present utility model;

[0068] Figure 17 This is a sectional view of the overall structure of the push rod of the present utility model;

[0069] Figure 18 This is a schematic diagram of the connection state of the injection spring sleeve, the push rod and the injection spring;

[0070] Figure 19 This is a schematic diagram of the overall structure of the injection spring locking and actuating mechanism (locking state);

[0071] Figure 20 This is a sectional view of the overall structure of the injection spring locking and actuating mechanism (locking state). Specific embodiments

[0072] The following further elaborates on the specific embodiments of the present utility model in conjunction with the accompanying drawings.

[0073] Such as Figure 3 、 Figure 4As shown, the automatic injection device mainly includes a medicine cartridge pre-assembly 2, a function pre-assembly 3, and a top cover 4, which are delivered to the pharmaceutical manufacturer in the state of three parts of components, and then assembled with the pre-filled syringe 1. First, the pre-filled syringe 1 is loaded into the medicine cartridge pre-assembly 2 and fixed to form the state as shown in Figure 4 . Then, the function pre-assembly 3 is loaded, and finally the top cover 4 is covered, thus forming the automatic injection pen of the present utility model.

[0074] Among them, the function pre-assembly 3, as shown in Figure 5 and Figure 6 , is mainly formed by pre-assembling an injection spring sleeve 31, a safety unlocking sleeve 32, an injection connection sleeve 33, a retracting needle spring 34, a retracting needle spring base 35, an injection spring 36, a push rod 37, and a retracting needle connection sleeve 38 together.

[0075] The injection spring sleeve 31, the safety unlocking sleeve 32, and the injection connection sleeve 33 are connected with the injection spring 36 and the push rod 37 to form an injection spring locking and actuating mechanism, which mainly compresses and locks the injection spring 36 and then unlocks and actuates it; while the retracting needle spring 34, the retracting needle spring base 35, and the retracting needle connection sleeve 38 are connected together to form a retracting needle spring locking and actuating mechanism, which mainly compresses and locks the retracting needle spring 34 and then unlocks and actuates it; the injection connection sleeve 33 and the retracting needle connection sleeve 38 are connected together to form a support sleeve.

[0076] The key improvement of the present utility model is the injection spring locking and actuating mechanism assembly.

[0077] For the specific structure of the injection spring sleeve 31, reference can be made to Figure 7 and Figure 8 , which includes a locking piece 311, a connecting cylinder 312, a spring claw 313, a locking hook 314, an unlocking inclined surface 315, and a spring guide post 316. The locking piece 311 is located at the top and is a large disc; a cylindrical connecting cylinder 312 is provided below the locking piece 311, and several spring claws 313 are provided below the connecting cylinder 312. The spring claws 313 are elastic arms arranged downward, the upper end of the spring claw 313 is connected to the connecting cylinder 312 or the locking piece 311, and the lower end of the spring claw 313 is a free end; the lower part of the spring claw 313 extends inward to form a locking hook 314, and below the locking hook 314, an unlocking inclined surface 315 is provided. The unlocking inclined surface 315 is an inclined surface that slopes downward from the inside to the outside; when an upward or outward force is applied to the unlocking inclined surface 315, the spring claw 313 will open outward together with the locking hook 314 and undergo elastic deformation; preferably, a spring guide post 316 is provided in the middle of the injection spring sleeve 31, and the spring guide post 316 is a slender cylindrical rod; an upper mounting seat for the injection spring 36 is formed inside the connecting cylinder 312, and the spring guide post 316 is inserted into the injection spring 36 to support the injection spring 36 to prevent it from being compressed and collapsed or misaligned and disordered, affecting the expansion and release of the elastic force.

[0078] For the specific structure of the safety unlocking sleeve 32, reference can be made to Figures 9 - 11 , which includes a sliding sleeve 321, a safety locking sleeve 322, and an unlocking cylinder 324; the sliding sleeve 321 is a thin-walled cylindrical tube with a diameter consistent with that of the cylinder formed by several firing push pieces. The top of the firing push piece can abut against the bottom of the sliding sleeve 321 to push the safety unlocking sleeve 32; above the sliding sleeve 321 is provided with a safety locking sleeve 322, and the safety locking sleeve 322 is connected to the sliding sleeve 321 through several connecting arms 323; the diameter of the safety locking sleeve 322 is smaller than that of the sliding sleeve 321, and the inner diameter of the safety locking sleeve 322 matches the outer diameter of the circle formed by several spring claws 313; below the safety locking sleeve 322 is provided with an unlocking cylinder 324, and the unlocking cylinder 324 is connected to the bottom of the safety locking sleeve 322 through several connecting strips 326; preferably, an unlocking cone 325 is provided at the top of the unlocking cylinder 324; the diameter of the unlocking cone 325 matches the diameter of the conical surface formed by several unlocking inclined surfaces 315.

[0079] For the specific structure of the injection connection sleeve 33, reference can be made to Figures 12 - 15 , which includes a receiving cylinder 331, connecting spring arms 332, a relief groove 333, a locking hook 334, a connecting sleeve 335, and a connecting groove 336; the receiving cylinder 331 is a thin-walled cylindrical tube, and the outer wall of the receiving cylinder 331 cooperates with the inner wall of the sliding sleeve 321 to form a sliding guide; above the receiving cylinder 331 are provided several connecting spring arms 332, and a relief groove 333 is provided between the connecting spring arms 332 for the connecting arm 323 to pass through; the safety locking sleeve 322 can be accommodated within the connecting spring arms 332; at the top of the connecting spring arms 332, a locking hook 334 is provided inward, and the size of the locking hook 334 matches the size of the locking piece 311; at the bottom of the receiving cylinder 331 is provided a connecting sleeve 335, and several connecting grooves 336 are formed on the connecting sleeve 335.

[0080] For the specific structure of the push rod 37, reference can be made to Figure 16 , Figure 17 , which includes a rod cylinder 371, a spring chamber 372, a push head 373, a buckle groove 374, and a needle retraction unlocking piece 375. The rod cylinder 371 is a thin-walled cylindrical tube, and a spring chamber 372 is provided inside for storing the injection spring 36; the bottom of the rod cylinder 371 is closed or semi-closed to form a push head 373, which is used to limit the injection spring 36 on the one hand and push the piston 15 on the other hand; several buckle grooves 374 are provided at the top of the rod cylinder 371, and the number and size of the buckle grooves 374 match those of the locking hooks 314; a protrusion is formed outward in the upper middle part of the rod cylinder 371 to form a needle retraction unlocking piece 375.

[0081] As Figure 18As shown, the injection spring sleeve 31 cooperates with the push rod 37. In particular, the spring claws 313 of the injection spring sleeve 31 wrap around the top of the push rod 37 from the outside, and the locking hook 314 snaps into the buckle groove 374, so that the injection spring sleeve 31 is connected to the push rod 37, compressing and locking the injection spring 36 located inside; at this time, a part of the unlocking slope 315 below the locking hook 314 is exposed outside the upper part of the rod barrel 371.

[0082] As Figure 19 , Figure 20 As shown, the injection spring sleeve 31, the safety unlocking sleeve 32, the injection connection sleeve 33 are connected to the injection spring 36 and the push rod 37 to form an injection spring locking and triggering mechanism; at this time, the injection spring sleeve 31 and the push rod 37 compress and lock the injection spring 36; the injection spring sleeve 31 is installed into the injection connection sleeve 33. During the installation process, the locking piece 311 of the injection spring sleeve 31 presses down on the locking hook 334, causing the connecting spring arm 332 to open outwards. Finally, the locking piece 311 passes over the locking hook 334, and the connecting spring arm 332 elastically deforms and resets, so that the locking hook 334 limits the top of the locking piece 311; the safety unlocking sleeve 32 is first inserted onto the injection connection sleeve 33, the sliding sleeve 321 is sleeved outside the receiving cylinder 331 and the connecting spring arm 332, and the safety locking sleeve 322 is located inside the connecting spring arm 332, and the safety locking sleeve 322 just fits outside the spring claws 313.

[0083] As Figure 19 , Figure 20 As shown, it is in the locked state. At this time, the safety unlocking sleeve 32 is located at a relatively lower position on the injection connection sleeve 33. The connecting arm 323 is limited by the bottom of the relief groove 333, or the unlocking cylinder 324 is limited by the needle retracting and unlocking piece 375. At this time, the unlocking cylinder 324 and the unlocking cone 325 are away from the unlocking slope 315, and the safety locking sleeve 322 is located outside the free end of the spring claws 313, close to the locking hook 314; at this time, the safety locking sleeve 322 holds the spring claws 313 tightly, so that the spring claws 313 lose the space to deform outwards. Therefore, the locking hook 314 is reliably snapped into the buckle groove 374, so that the injection spring 36 is reliably compressed and locked; preferably, in the natural state of the spring claws 313, the outer diameter of the bottom is slightly larger than the inner diameter of the safety locking sleeve 322. Therefore, when the safety locking sleeve 322 is in the locked state position, an inward pressure is applied to the spring claws 313, and a certain positive pressure is generated between the two, and then frictional force is generated, which can prevent the accidental sliding and unlocking of the safety locking sleeve 322 and the spring claws 313.

[0084] The safety unlocking sleeve 32 can slide upward relative to the injection connection sleeve 33 and the injection spring sleeve 31. At this time, the safety lock sleeve 322 gradually moves away from the position of the locking hook 314, and the unlocking cylinder 324 and the unlocking cone 325 approach the unlocking inclined surface 315 accordingly. As the safety unlocking sleeve 32 slides upward, the safety lock sleeve 322 leaves the outside of the spring pawl 313 and moves outside the connection cylinder 312. At this time, the bottom of the spring pawl 313, that is, the free end, is no longer restricted and regains the elastic deformation space outward. At the same time, the unlocking cone 325 contacts the unlocking inclined surface 315 and, during the rising process, pushes the unlocking inclined surface 315 and the spring pawl 313 outward until the locking hook 314 disengages from the buckle groove 374, enabling the push rod 37 to be in a free state. The injection spring 36 releases its elastic force and pushes the push rod 37 downward.

[0085] The injection spring 36 is unlocked and pushes the push rod 37 downward. The push head 373 of the push rod 37 contacts the piston 15 and, under the action of the injection spring 36, pushes the piston 15 to move within the injection cylinder 12, injecting the medicine into the body through the needle 14.

[0086] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An injection spring locking and triggering mechanism assembly for an automatic injection pen, characterized in that: It is formed by pre-assembling an injection spring sleeve, a safety unlocking sleeve, an injection spring, and a push rod; The injection spring has a compressed energy storage state and an expanded working state; When the injection spring is in a compressed energy storage state, the injection spring sleeve is connected to the push rod; The safety unlocking sleeve is installed outside the injection spring sleeve, and the safety unlocking sleeve can slide relative to the injection spring sleeve; When the safety unlocking sleeve slides to the maximum stroke relative to the injection spring sleeve, the injection spring sleeve separates from the push rod, the injection spring is unlocked, and the injection spring changes from a compressed energy storage state to an expanded working state. The injection spring is expanded from a compressed state to release and generate thrust, and the injection spring pushes the push rod to move.

2. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 1, characterized in that: The injection spring sleeve comprises a locking piece, a connecting tube and an elastic claw; The locking piece is located at the top; a connecting tube is provided below the locking piece, and a plurality of spring claws are provided below the connecting tube; The elastic claw is an elastic arm arranged downward, and the lower end of the elastic claw is a free end; The lower part of the spring claw extends inward to form a locking hook; A chamber is formed in the connecting cylinder for mounting the top of the injection spring; The push rod comprises a rod barrel, a spring chamber and a push head; A spring chamber for storing an injection spring is provided inside the rod barrel; The bottom of the rod barrel forms a push head that can contact the piston in the syringe of the prefilled syringe; The top of the rod tube is provided with a number of buckle grooves, which match the lock hooks; The injection spring is located between the injection spring sleeve and the push rod; The top of the injection spring is located in the connecting tube of the injection spring sleeve; The bottom of the injection spring is located at the bottom of the rod barrel; The locking hook of the spring claw of the injection spring sleeve can be inserted inwardly into the buckle groove at the top of the rod barrel of the push rod, so that the injection spring sleeve and the push rod are locked together, and the injection spring is compressed to store energy; The spring claw of the injection spring sleeve can be deformed outward to disengage the lock hook from the buckle groove, so that the injection spring sleeve is separated from the push rod, and the injection spring is unlocked and unfolded to release the elastic force.

3. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 2, characterized in that: An unlocking inclined plane is provided below the lock hook, and the unlocking inclined plane is an inclined plane extending downward from the inside to the outside; The safety unlocking sleeve is provided with an unlocking cylinder, and the top of the unlocking cylinder is an unlocking portion; the unlocking portion matches the unlocking inclined surface; The injection spring sleeve and the safety unlocking sleeve move relative to each other, so that the top of the unlocking cylinder of the safety unlocking sleeve squeezes the unlocking inclined surface below the lock hook, causing the spring claw of the injection spring sleeve to deform outward, and the lock hook to escape from the buckle groove, and the injection spring is unlocked.

4. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 2, characterized in that: A spring guide column is arranged in the middle of the injection spring sleeve, and the spring guide column is a slender rod.

5. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 2, characterized in that: The lower part of the spring claw of the injection spring sleeve is provided with two locking hooks, and the two locking hooks are symmetrically arranged; The top of the rod barrel is provided with two buckle grooves, and the two buckle grooves are symmetrically arranged.

6. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 2, characterized in that: The upper end of the spring claw of the injection spring sleeve is connected to the connecting cylinder or the locking piece.

7. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 2 or 3, characterized in that: The safety unlocking sleeve comprises a sliding sleeve, a safety locking sleeve and an unlocking cylinder; The sliding sleeve matches the excitation push piece on the upper part of the excitation sleeve; the top of the excitation push piece can abut against the bottom of the sliding sleeve and push the safety unlocking sleeve to move; A safety lock sleeve is provided above the sliding sleeve, and the safety lock sleeve is connected to the sliding sleeve; The diameter of the safety lock sleeve is smaller than that of the sliding sleeve, and the inner diameter of the safety lock sleeve matches the outer diameter of the circle where the spring claw of the injection spring sleeve is located; The safety lock sleeve can be moved from the free end of the lower part of the claw to the fixed end of the upper part of the claw; An unlocking cylinder is provided below the safety lock sleeve, and the unlocking cylinder is connected to the safety lock sleeve; An unlocking cone is arranged on the top of the unlocking cylinder; the unlocking cone can open the free end of the spring claw of the injection spring sleeve outward.

8. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 7, characterized in that: An injection connection sleeve is provided, comprising a receiving sleeve, a connecting elastic arm, a clearance groove, and a locking hook; The accommodating tube is a thin-walled cylindrical tube, and the outer wall of the accommodating tube matches the inner wall of the sliding sleeve of the safety unlocking sleeve to form a sliding guide; A plurality of connecting elastic arms are arranged above the accommodating tube, and clearance grooves are arranged between the connecting elastic arms, and the clearance grooves are used for the connecting arms to pass through; The connecting elastic arm can accommodate a safety lock sleeve; A locking hook is inwardly arranged at the top of the connecting elastic arm, and the size of the locking hook matches the size of the locking piece.

9. The injection spring locking and triggering mechanism assembly for an automatic injection pen according to claim 7, characterized in that: When the claw is in a natural state, the outer diameter of the bottom is larger than the inner diameter of the safety lock sleeve; When the safety lock sleeve is in the locked state, there is friction between the safety lock sleeve and the spring claw.

Images