Automatic injection pen with double-cavity structure

Abstract

The invention discloses an automatic injection pen with a double-cavity structure, and belongs to the technical field of medical instruments. Comprising a shell, a refill frame, a double-cavity clamping type bottle, a push rod, a base, an unlocking piece, a releasing piece, an injection spring and a button, the push rod is provided with a first hook hole, the base is provided with a first clamping hook matched with the first hook hole, the base is further provided with a second hook hole, and the unlocking piece is provided with a second clamping hook matched with the second hook hole; the unlocking piece is used for keeping or releasing matching of the first hook hole and the first clamping hook; and the release piece is used for keeping or releasing matching of the second hook hole and the second clamping hook, so that before the release piece releases the second hook hole and the second clamping hook, the button cannot be pressed down, and the unlocking piece cannot slide by pressing the button. The release piece and the unlocking piece ensure that double-cavity liquid medicine cannot be triggered before being mixed, operation is easy, stability is high, and a patient can conveniently and safely conduct injection.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a dual-chamber automatic injection pen for drug injection. Background Technology

[0002] Automated injectors have reduced the difficulty of injection therapy and decreased patient pain, making them popular with many healthcare professionals and patients. However, most automated injectors on the market are currently single-chamber injectors. For some treatment regimens requiring combination therapy, such as mixing powders, lyophilized solutions, and diluents, single-chamber injectors are insufficient, necessitating dual-chamber storage. While some dual-chamber injectors can hold two medications, such as the drug delivery device disclosed in Chinese invention patent CN113164694B, which includes: a housing with proximal and distal ends; a multi-chamber container arranged within the housing; and a power unit with stored energy... The device is arranged within a housing and configured to act on a multi-chamber container for obtaining and delivering a mixed compound within the container. A manually operable component extends from the distal end of the housing and is connected to a power assembly, wherein when the manually operable component is manually moved, the power assembly is forced to move proximally, thereby pressurizing the multi-chamber container. The drug delivery device also includes a needle sheath slidably arranged within the housing, configured to interact with the power assembly to release stored energy after the power assembly moves proximally. This approach also involves manually rotating the mixed drug solution, but lacks a safety mechanism to prevent triggering before complete mixing, resulting in a lack of precision in drug mixing and overall pen safety. Furthermore, the structure is complex and lacks a post-injection sound mechanism.

[0003] In addition, Chinese utility model patent CN222195644U discloses a dual-chamber syringe assembly and an automatic injection pen. The dual-chamber syringe assembly includes an injection syringe, a middle plug, and a rear plug. One end of the injection syringe is open, and the other end has an injection needle communicating with its interior. The periphery of the middle plug is in movable contact with the inner wall of the injection needle. A front cavity exists between the middle plug and the injection needle. The inner wall of the injection syringe has an injection channel communicating with the injection needle. The length of the injection channel is greater than the length of the middle plug. The periphery of the rear plug is in movable contact with the inner wall of the injection needle. A rear cavity exists between the rear plug and the middle plug. By providing an injection channel in the inner wall of the injection syringe, which is connected to the rear cavity, a second drug solution in the rear cavity is injected together until the end faces of the rear plug and the middle plug abut against each other. Two incompatible drugs can be administered in a single injection. However, this method makes it difficult to precisely control the dosage of each drug during injection, which can easily lead to overdose or underdose. Furthermore, the method does not include a safety mechanism to prevent triggering or a sound-emitting mechanism after injection. Summary of the Invention

[0004] To address the problems mentioned in the background, this solution provides a dual-chamber automatic injection pen that is simple to operate, compact in structure, highly stable, and features a structure to prevent accidental triggering and provide a sound signal upon injection completion, making it convenient for patients to use.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: a dual-chamber automatic injection pen, including a shell, a cartridge holder, a dual-chamber cartridge bottle, a push rod, a base, an unlocking component, a release component, an injection spring, and a button. The dual-chamber cartridge bottle has an upper stopper and a lower stopper. The cartridge holder has an inner cavity for installing the dual-chamber cartridge bottle. The cartridge holder has an external thread, and the shell has an internal thread that matches the external thread. The cartridge holder is rotatably connected to the shell. During the upward rotation of the cartridge holder relative to the shell, the push rod presses against the upper stopper of the dual-chamber cartridge bottle, mixing the two drugs in the dual-chamber cartridge bottle. The push rod has a first hook hole, and the base has a hook hole that connects to the first hook hole. The base has a first hook that mates with the hole, and a second hook hole is also provided on the base. The unlocking component has a second hook that mates with the second hook hole. The unlocking component is slidably sleeved on the outside of the base to hold or release the first hook hole and the first hook. After the first hook hole and the first hook are released, the push rod is released, and the injection spring pushes the push rod downward to inject the mixed drug. The release component is sleeved on the outside of the unlocking component to hold or release the second hook hole and the second hook. Before the second hook hole and the second hook are released, the button is in a locked state, and the unlocking component cannot slide by pressing the button, thereby preventing the push rod from being released.

[0006] Furthermore, the pen refill holder is provided with a first anti-reverse buckle, a second anti-reverse buckle, and a third anti-reverse buckle. The first anti-reverse buckle, the second anti-reverse buckle, and the third anti-reverse buckle are arranged sequentially from top to bottom at different heights on the outer wall of the pen refill holder. The outer shell is provided with anti-reverse grooves that cooperate with the first anti-reverse buckle, the second anti-reverse buckle, and the third anti-reverse buckle. When the pen refill holder rotates upward relative to the outer shell, the first anti-reverse buckle, the second anti-reverse buckle, and the third anti-reverse buckle are sequentially engaged into the anti-reverse grooves.

[0007] Furthermore, when the first anti-reverse buckle is engaged in the anti-reverse slot, the push rod abuts against the upper stopper of the dual-chamber cartridge bottle, and the first hook hole and the first hook remain engaged, as do the second hook hole and the second hook.

[0008] Furthermore, when the second anti-reverse latch is engaged in the anti-reverse slot, the upper plug and the lower plug abut against each other.

[0009] Furthermore, when the third anti-reverse buckle is engaged in the anti-reverse slot, the release member has already been lifted a certain distance by the pen refill holder, and the release member releases the second hook hole and the second hook.

[0010] Furthermore, when the release member releases the second hook hole and the second latch, the second latch of the unlocking member is still subjected to the force of the release member and the force of the second hook hole, thereby remaining stationary in the axial direction.

[0011] Furthermore, the pen refill holder is also equipped with letter markings, and the outer casing is equipped with a window that matches the letter markings. When the pen refill holder is rotated to a certain stage, the corresponding letter will be displayed on the window, giving a direct visual experience to remind the user of the status of the pen refill holder.

[0012] Furthermore, it also includes a hidden needle sleeve and a hidden needle cap. The hidden needle sleeve is installed at the lower end of the pen refill holder, and the hidden needle cap is fitted at the lower end of the hidden needle sleeve and is movably connected to the hidden needle sleeve. A hidden needle spring is also installed inside the hidden needle sleeve, and the hidden needle spring abuts against the hidden needle cap. The hidden needle cap can cover the needle tip and reduce the patient's discomfort during injection.

[0013] Furthermore, it also includes a pen cap, which is fitted onto the concealed needle sleeve and is detachably connected to the concealed needle sleeve.

[0014] Furthermore, the button has a protrusion at its lower end, and the unlocking component has an unlocking column structure that cooperates with the protrusion. When the button is pressed, the protrusion presses against the unlocking column structure, causing the unlocking component to slide downward.

[0015] Furthermore, it also includes a pressure cover, on which the button is provided with a button wedge-shaped hook, and the pressure cover is provided with an upper pressure cover groove and a lower pressure cover groove that cooperate with the button wedge-shaped hook. Before the button is pressed, the button wedge-shaped hook is engaged in the upper pressure cover groove, and after the button is pressed, the button wedge-shaped hook is engaged in the lower pressure cover groove, so that the button can no longer return to the position before it was pressed.

[0016] Furthermore, it also includes a sound-generating element and a sound-generating spring. The push rod has a first columnar structure with an upper radial slope at the bottom. The base has a base groove and a collision protrusion. The sound-generating element has a second columnar structure that cooperates with the first columnar structure, with a lower radial slope at the top. The sound-generating element is movably sleeved on the base, and the sound-generating spring presses upward against the sound-generating element. In the initial stage of downward injection by the push rod, the first and second columnar structures push downward within the base groove. In the final stage of injection, the second columnar structure disengages from the base groove, while the first columnar structure remains within it. Due to the slope of the first and second columnar structures, the sound-generating element rotates radially. After the first and second columnar structures are completely separated, the sound-generating spring presses against the sound-generating element to collide with the collision protrusion, thus emitting a sound to indicate that the injection is complete.

[0017] The beneficial effects of this invention are: the injection pen of this solution is small in size, the components are compact and easy to operate, and after the injection is completed, there is a sound-generating component separated by an inclined plane, which is more fluid. The structure is simpler, saving costs and easy to implement. Multiple safety protection devices effectively avoid accidental injuries and enhance safety. Attached Figure Description

[0018] Figure 1 This is a front view of the injection pen provided by the present invention; Figure 2 An exploded view of the structure of the injection pen provided by this invention; Figure 3a A perspective view of the button provided by the present invention; Figure 3b A cross-sectional view of the button provided by the present invention; Figure 4a A perspective view of the cap provided for this invention; Figure 4b A cross-sectional view of the pressure cap provided by the present invention; Figure 5 This is a front view of the injection spring support of the present invention; Figure 6 This is a perspective view of the injection spring of the present invention; Figure 7aThis is a front view of the push rod of the present invention; Figure 7b This is a cross-sectional view of the push rod of the present invention; Figure 8a A front view of the base provided by the present invention; Figure 8b A cross-sectional view of the base provided by the present invention; Figure 9 A perspective view of the sound-generating component provided by the present invention; Figure 10 A perspective view of the sound-generating spring provided by the present invention; Figure 11 A perspective view of the hidden needle spring provided by the present invention; Figure 12a A perspective view of the unlocking component provided by the present invention; Figure 12b A cross-sectional view of the unlocking component provided by the present invention; Figure 13a A perspective view of the release element provided by the present invention; Figure 13b A perspective view of the release element provided by the present invention; Figure 14a A half-sectional view of the outer casing provided for this invention; Figure 14b A cross-sectional view of the outer casing provided for this invention; Figure 15a A perspective view of the pen refill holder provided by the present invention; Figure 15b A cross-sectional view of the pen refill holder provided by the present invention; Figure 16 A cross-sectional view of the hidden needle sleeve provided by the present invention; Figure 17 A perspective view of the concealed needle cap provided by the present invention; Figure 18 A cross-sectional view of the pen cap provided by the present invention; Figure 19 A cross-sectional view of the dual-chamber cartridge bottle provided by the present invention; Figure 20 A front view of the fastener provided by the present invention; Figure 21 A perspective view of the release spring provided by the present invention; Figure 22 This is a schematic diagram of the initial state structure of the present invention; Figure 23 This is a schematic diagram of the mixed state structure of the present invention; Figure 24 This is a schematic diagram of the exhaust state structure of the present invention; Figure 25 This is a schematic diagram of the injection state structure of the present invention; In the figure: 1. Button; 101. First annular outer surface; 102. First annular inner cavity; 103. First circular planar structure; 104. Bottom structure; 105. Protruding ring; 106. Protruding post; 106a. First structure; 107. Button wedge hook; 107a. First upper inclined plane; 107b. Lower inclined plane structure; 2. Cap; 201. First outer surface; 202. First inner cavity surface; 203. First annular plane; 204. First step; 205. Second annular plane; 206. First inner cavity; 206a. Bottom surface of the first inner cavity; 207. Countersunk hole; 208. Cap guide post; 209. Cap guide groove; 210. Cap buckle; 211. First through groove; 212. Second inner cavity; 212a. Bottom surface of the second inner cavity; 215. Opening; 216. Intermediate partition; 216a. Second upper inclined plane; 216b. Lower inclined plane; 3. Injection spring support; 301. Second circular planar structure; 302. Circular structure; 303. Rod; 4. Injection spring; 401. Spring top end; 402. Spring bottom end; 5. Push rod; 501. Outer surface of push rod; 502. Spring cavity; 502a. Bottom surface of spring cavity; 503. First annular planar structure; 504. Third circular planar structure; 505. First columnar structure; 506. Upper radial inclined surface; 507. First hook hole; 6. Base; 601. Upper outer surface; 602. Upper inner cavity surface; 603. Lower outer surface; 604. Lower inner cavity surface; 605. Upper annular planar structure; 606. Second step; 607. Lower annular planar structure; 608. Bottom surface of upper inner cavity; 609. Base mounting buckle; 610. Base sliding groove; 611. Collision protrusion; 612. First hook; 613. Second hook hole; 614. Second through groove; 615. Base guide post; 7. Sound-generating component; 701. First annular outer surface structure; 702. First annular inner cavity structure; 703. Upper circular planar structure; 704. First lower annular planar structure; 705. Second columnar structure; 706. Lower radial inclined surface; 707. First groove; 708. Second groove; 8. Sound-producing spring; 801. Upper structure of the sound-producing spring; 802. Lower structure of the sound-producing spring; 9. Unlocking component; 901. Second annular outer surface; 902. Second annular inner cavity; 903. First upper annular planar structure; 904. Second lower annular planar structure; 905. Unlocking protrusion; 905a. Termination planar structure; 906. Head columnar structure; 906a. Columnar structure plane; 907. Unlocking opening; 908. Second hook; 909. Inner cavity structure; 909a. First stepped surface; 910. Wedge-shaped step; 910a. Upper stepped surface; 910b. Side stepped surface; 10. Release element; 1001. Second annular outer surface structure; 1002. Second annular inner cavity structure; 1003. Second annular planar structure; 1004. Third annular planar structure; 1005. Protruding ring structure; 1005a. Upper end face; 1006. Release element guide post; 1008. Release element snap-fit ​​structure; 1008a. End plane; 1009. Protrusion structure; 1009a. Plane; 1009b. Second structure; 1010. Release columnar structure; 1010a. Inclined columnar structure; 11. Outer shell; 1101. Circular outer surface of the outer shell; 1102. Circular inner cavity of the outer shell; 1103. Second upper circular annular planar structure; 1104. Third lower circular annular planar structure; 1105. Mounting hole; 1106. Slide groove; 1107. Internal thread; 1108. Anti-reverse groove; 1109. Viewing window; 1110. Anti-slip protrusion; 12. Pen refill holder; 1201. Circular outer surface of the pen refill holder; 1202. Inner cavity of the pen refill holder; 1203. Third upper circular annular planar structure; 1204. Fourth lower circular annular planar structure; 1205. Circular stepped surface; 1205a. Upper circular annular plane; 1205b. Lower circular annular plane; 1206. External thread; 1207a. First anti-reverse latch; 1207b. Second anti-reverse latch; 1207c. Third anti-reverse latch; 1208. Pen cap latch; 1209. Medicine bottle latch; 1210. First columnar structure; 1211. Circular stepped surface; 1212. Circular groove; 1213. Wedge-shaped locking block; 13. Double-chamber cartridge bottle; 1301. Third inner chamber; 1302. Upper stopper; 1303. Lower stopper; 1304. Channel; 14. Needle assembly; 15. Hidden needle sleeve; 1501. Circular outer surface of the hidden needle sleeve; 1502. Circular inner cavity of the hidden needle sleeve; 1503. Upper circular planar structure of the hidden needle sleeve; 1504. Lower circular planar structure of the hidden needle sleeve; 1505. Circular step; 1505a. Circular inclined plane; 1505b. Third circular plane; 1506. Second columnar structure; 1507. Hidden needle mounting groove; 1508. Second step surface; 16. Hidden needle spring; 1601. Spring top structure; 1602. Spring bottom structure; 17. Hidden needle cap; 1701. Circular outer surface of the hidden needle cap; 1702. Circular inner cavity of the hidden needle cap; 1703. Fifth circular planar structure; 1704. Fourth circular planar structure; 1705. Mounting slider; 18. Pen cap; 1801. Circular outer surface of pen cap; 1802. Circular inner cavity of pen cap; 1803. Fourth circular planar structure; 1804. Circular groove; 19. Release spring; 1901. Upper structure of release spring; 1902. Lower structure of release spring; 20. Fixing element; 2001. Second outer surface; 2002. Second inner cavity surface; 2003. Fourth annular plane; 2004. Annular platform; 2005. Fifth annular plane; 2006. Guide post; 2007. Columnar groove; 2008. Third structure. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. In this application, when the terms "upper end" or "up" are used, it refers to the button direction; correspondingly, when "lower end" or "lower" is used, it refers to the direction towards the needle tip. It is worth noting that these specific embodiments are merely representative specific embodiments of the present invention, and the specific methods, devices, conditions, materials, etc., exemplified are not intended to limit the present invention or the corresponding specific embodiments.

[0020] Dual-chamber automated injection pen, such as Figures 1-25 As shown, the device includes a housing 11, an injection assembly, a refill holder 12, a dual-chamber cartridge bottle 13, a hidden needle assembly, and a pen cap 18. The injection assembly is formed by assembling a button 1, a pressure cap 2, a fixing member 20, an injection spring bracket 3, an injection spring 4, a push rod 5, a base 6, a sound-emitting member 7, a sound-emitting spring 8, an unlocking member 9, a release member 10, and a release spring 19. The hidden needle assembly is formed by assembling a hidden needle sleeve 15, a hidden needle spring 16, and a hidden needle cap 17. The injection assembly is installed inside the housing 11. The dual-chamber cartridge bottle 13 is provided with an upper stopper 1302 and a lower stopper 1303. The refill holder 12 has an inner cavity for installing the dual-chamber cartridge bottle 13. The dual-chamber cartridge bottle 13 is installed inside the refill holder 12. The lower end of the dual-chamber cartridge bottle 13 is provided with a needle assembly 14. The pen refill holder 12 is rotatably connected to the outer shell 11 via an internal thread. When the pen refill holder 12 rotates upward, the injection assembly can abut against the dual-chamber cartridge bottle 13, causing the liquid medicine and powder medicine between the upper stopper 1302 and the lower stopper 1303 inside the dual-chamber cartridge bottle 13 to mix.

[0021] like Figure 3a and Figure 3bAs shown, in some embodiments, the button 1 is a hollow cylindrical structure with one open end. The button 1 has a first annular outer surface 101 and a first annular inner cavity 102. The upper end of the button 1 is a first circular planar structure 103, which facilitates pressing to release, unlock, or inject. The lower end of the button 1 is open, forming an annular plane, which also serves as the stop position after pressing. The convex ring 105 is an annular structure attached to the outer surface, with the starting plane at the lower end and extending a certain distance to the upper end to form an annular fastener, which cooperates with the pressure cap 2 to fix the button 1 and prevent the button 1 from falling off under no force. The lower end of the button 1 extends with two symmetrical protrusions 106 of a certain length. The protrusions 106 are crescent-shaped, and the first structure 106a is the terminating plane of the protrusions 106. The two sides of the protrusions 106 are planar, and the width needs to be less than one-quarter of the arc of the body so as to be inserted into the pressure cover 2 and make linear movement. A rectangular through groove is also provided on the outer surface of the protrusions 106, which is a certain distance away from the terminating plane. The bottom surface of the rectangle is used as the starting surface to approach the terminating plane and extends a certain length towards the bottom structure 104 of the button 1, forming a button wedge hook 107. The button wedge hook 107 is symmetrically distributed on the two protrusions 106. The button wedge hook 107 is provided with a first upper inclined plane 107a and a lower inclined plane structure 107b.

[0022] like Figure 4a and Figure 4bAs shown, in some embodiments, the gland 2 is a cylindrical structure with hollow ends, a middle layer, and steps. One end is a large cylinder, and the other end is a small cylinder. The first step 204 is the dividing plane between the large cylinder and the small cylinder. The small cylinder has a first outer surface 201 and a first inner cavity surface 202. The upper end of the gland 2 is a first circular plane 203, and the lower end is a second circular plane 205. The large cylinder has a first inner cavity 206 and forms a first inner cavity bottom surface 206a. The counterbore 207 is an annular structure that starts from the circular plane at the upper end of the gland 2 with a diameter larger than that of the first inner cavity 206 and extends downward for a certain length, thus forming a circular step with the first inner cavity 206. Its function is to cooperate with the convex ring 105. During movement, the convex ring 105 can also perform a linear up-and-down sliding movement in the first inner cavity 206. The gland guide post 208 is a columnar body that starts from the first step 204, terminates at the bottom second circular plane 205, and is attached to the first outer surface 201, and is symmetrically distributed on both sides; its outer shape is preferably an isosceles trapezoid. The gland guide groove 209 is an isosceles trapezoidal columnar groove that is concave inward from the surface of the first inner cavity surface 202 towards the gland guide post 208, has a certain depth, and is also symmetrically distributed. The gland buckle 210 is a columnar buckle with a certain width attached to the surface of the first outer surface 201, which cooperates with the housing 11 to fix and install the gland 2 on the housing 11. On both sides of the gland buckle 210, there is a rectangular first through groove 211 respectively, which is used to fix the base 6. With the first step 204 as the bottom surface, a cylinder with an outer diameter smaller than the first inner cavity surface 202 extends downward. The cylinder is hollow inside and forms a second inner cavity 212 and a second inner cavity bottom surface 212a. The gland 2 is provided with an opening 215 that cooperates with the convex column 106. Starting from the bottom surface of the opening 215, a pair of symmetrically distributed "convex"-shaped grooves extend downward. The size of the grooves is slightly larger than the outer dimension of the convex column 106, which is convenient for the insertion of the convex column 106. A middle layer 216 is formed in the middle position of the grooves. The upper and lower sides of the middle layer 216 form a second upper inclined plane 216a and a lower inclined plane 216b. The second upper inclined plane 216a and the lower inclined plane 216b constitute an upper gland groove and a lower gland groove that cooperate with the button wedge hook 107.

[0023] As Figure 5 shown, in some embodiments, the injection spring bracket 3 is a cylindrical structure. The upper end of the injection spring bracket 3 is a mushroom-shaped second circular plane structure 301, and the lower end is a circular structure 302. The diameter of the rod body 303 is smaller than the inner diameter of the injection spring 4, which is convenient for the installation and energy storage of the injection spring 4. The circular structure 302 abuts against the upper end of the injection spring 4, and the second circular plane structure 301 abuts against the second inner cavity bottom surface 212a to maintain relative static.

[0024] As Figure 6As shown, in some embodiments, the injection spring 4 is a compression spring structure with a certain length, having a spring tip 401 and a spring bottom 402. The inner diameter of the injection spring 4 needs to be larger than the diameter of the rod 303, and the outer diameter of the injection spring 4 needs to be smaller than the diameter of the spring cavity 502. The spring tip 401 abuts against the bottom surface 212a of the second inner cavity, and the spring bottom 402 abuts against the bottom surface 502a of the spring cavity. The two sides interact with each other for storing and releasing the force of the injection spring 4.

[0025] like Figure 7a and Figure 7b As shown, in some embodiments, the push rod 5 is a hollow cylindrical structure with one open end. The outer surface 501 of the push rod is an annular outer surface of the push rod 5, and the spring cavity 502 is an annular inner cavity of the push rod 5 with a certain depth, forming a bottom surface 502a of the spring cavity. The upper end of the push rod 5 is a first annular planar structure 503, and the lower end is a third circular planar structure 504, which contacts the upper stopper 1302 of the double-cavity cartridge bottle 13. Under force, it pushes the stopper downward, thereby performing injection. The upper end of the push rod 5 is provided with a first columnar structure 505 with an upper radial inclined surface 506. The middle part of the push rod 5 is provided with a first hook hole 507, which is a rectangular straight slot hole that penetrates the outer surface of the push rod 5 and is located below the first columnar structure 505, for fixing to the base 6.

[0026] like Figure 8a and Figure 8bAs shown, in some embodiments, the base 6 is a cylindrical structure with hollow ends, a partition in the middle, and a step. One end is a large cylinder, and the other end is a small cylinder. The second step 606 is the dividing plane between the large and small cylinders. The large cylinder has an upper outer surface 601, an upper inner cavity surface 602, and an upper inner cavity bottom surface 608. The small cylinder has a lower outer surface 603 and a lower inner cavity surface 604. The upper and lower ends of the base 6 are an upper annular planar structure 605 and a lower annular planar structure 607, respectively. Base mounting buckles 609 are distributed on the upper outer surface 601. The upper surface of the base mounting buckles 609 is a sloping columnar body that can be fastened into the first through groove 211, thereby fixing the base 6. The base 6 is provided with a vertically oriented base groove 610. The upper end of the base groove 610 starts from the bottom surface 608 of the upper inner cavity and extends to a certain depth at the lower end, but the bottom surface has a certain slope to cooperate with the first columnar structure 505 to make linear vertical movements during movement. On both sides of the base groove 610, there are collision protrusions 611. The collision protrusions 611 start from the second step 606 and extend to a certain depth at the lower end, and the ends of the collision protrusions 611 have toothed structures. Below the base groove 610, there is a flexible first hook 612. The first hook 612 is a certain distance from the lower end of the base 6 and can cooperate with the first hook hole 507. In this embodiment, the first hooks 612 are symmetrically distributed circumferentially. Between the first hook 612 and the lower end of the base 6, there is also a rectangular through-hole 613 for fixing the unlocking component 9. A base guide post 615 is also provided in the vertical direction of the base slide groove 610. The base guide post 615 starts from the upper end of the base 6 and ends at the second step 606, and is attached to the upper outer surface 601, and is symmetrically distributed on both sides. The base guide post 615 is in the shape of an isosceles trapezoid and can be inserted into the outer shell 11. The base 6 is also provided with a second through groove 614 corresponding to the position of the opening 215. The second through groove 614 is crescent-shaped to facilitate the connection between the protrusion 106 and the unlocking member 9.

[0027] like Figure 9As shown, in some embodiments, the sound-generating element 7 is a cylindrical structure hollow at both ends. The sound-generating element 7 has a first annular outer surface structure 701 and a first annular inner cavity structure 702. The upper and lower ends of the sound-generating element 7 are an upper circular planar structure 703 and a first lower annular planar structure 704, respectively. The sound-generating element 7 is provided with a second columnar structure 705 with a lower radial inclined surface 706 that cooperates with the first columnar structure 505. The second columnar structure 705 starts from the first lower annular planar structure 704 and extends upward, exceeding the height of the upper circular planar structure 703 by a certain distance. The second columnar structures 705 are symmetrically distributed. On the left side of the second columnar structure 705, there is a crescent-shaped first groove 707 with a certain depth, which serves to reduce the weight of the component; on the right side of the second columnar structure 705, there is also a crescent-shaped second groove 708 with a certain depth, and the bottom surface is a sloped shape that matches the first columnar structure 505. When the first columnar structure 505 and the second columnar structure 705 are separated, the first columnar structure 505 will fall into the second groove 708.

[0028] like Figure 10As shown, in some embodiments, the sound-generating spring 8 is a compression spring structure of a certain length, having an upper sound-generating spring structure 801 and a lower sound-generating spring structure 802. The inner diameter of the spring needs to be larger than the diameter of the lower outer surface 603, and the outer diameter of the spring needs to be smaller than the inner diameter of the unlocking member 9. It is installed in the inner cavity of the unlocking member 9. In the initial state, the upper sound-generating spring structure 801 abuts against the first lower annular planar structure 704; the lower sound-generating spring structure 802 abuts against the unlocking member 9. The two sides interact with each other for the storage and release of the sound-generating spring 8. During the downward injection process of the push rod 5, the first columnar structure 505 and the second columnar structure 705 are simultaneously pushed downward within the base groove 610. Due to the inclined surface of the first columnar structure 505 and the second columnar structure 705, the axial force of the first columnar structure 505 and the second columnar structure 705, respectively, is decomposed into a radial force by the inclined surface. This causes the sound-producing element 7 to rotate radially, i.e., the inclined surface of the second columnar structure 705 slides relative to the inclined surface of the first columnar structure 505. However, in the initial stage of injection, since both the first columnar structure 505 and the second columnar structure 705 are within the base groove 610, the radial force cannot cause the second columnar structure 705 to rotate. 705 rotates; at the end of the injection, the second columnar structure 705 will disengage from the constraint of the base slide groove 610. At this time, the second columnar structure 705 begins to rotate, and the first columnar structure 505 continues to move downward. The inclined surfaces of the first columnar structure 505 and the second columnar structure 705 will cause them to separate. After they separate, the sound-producing spring 8 slides upward against the sound-producing element 7, and the inclined surface of the second columnar structure 705 collides with the collision protrusion 611 to produce a sound. When the first columnar structure 505 and the second columnar structure 705 separate, the injection is about to be completed. The first columnar structure 505 will stop immediately or will only move downward a short distance, thus ensuring that the inclined surface of the second columnar structure 705 will collide with the collision protrusion 611 only after the injection is completed.

[0029] like Figure 12a and Figure 12bAs shown, in some embodiments, the unlocking member 9 is a cylindrical structure with hollow ends. The unlocking member 9 has a second annular outer surface 901 and a second annular inner cavity 902. The upper and lower ends of the unlocking member 9 are respectively a first upper annular planar structure 903 and a second lower annular planar structure 904. The unlocking member 9 is movably sleeved on the base 6. The second annular inner cavity 902 is provided with an unlocking limiting part that restricts the first hook 612 from engaging with the first hook hole 507, which is usually the inner wall of the second annular inner cavity 902. The upper end of the unlocking member 9 extends with two symmetrical unlocking columnar structures of a certain length. The unlocking columnar structure includes an unlocking protrusion 905 and a head columnar structure 906. The unlocking protrusion 905 is crescent-shaped and has a terminating planar structure 905a at its upper end. The two sides of the unlocking protrusion 905 are planar, and the width must be less than one-quarter of the arc of the body. A head columnar structure 906, with a width smaller than the unlocking protrusion 905 and a thickness greater than the outer surface of the second annular ring 901, extends outward from the plane of the terminating plane 905a and terminates on the plane 906a. The head columnar structure 906 matches the shape and size of the second through groove 614. A rectangular unlocking opening 907 is provided in the middle of the unlocking member 9 to disengage the first hook 612 from the first hook hole 507. The unlocking opening 907 is perpendicular to the unlocking protrusion 905. A flexible second hook 908 is provided at the lower part of the unlocking member 9, located below the unlocking opening 907, for engaging with the second hook hole 613 to fix the base 6. A new inner cavity structure 909 extends from the lower end of the unlocking member 9, forming a first stepped surface 909a. The lower end of the unlocking component 9 is provided with two discontinuous wedge-shaped steps 910 that rotate around the outer surface 901 of the second annular ring at a certain angle. The wedge-shaped steps 910 are provided with an upper step surface 910a, a lower step surface and a side step surface 910b.

[0030] like Figure 13a and Figure 13bAs shown, in some embodiments, the release member 10 is a cylindrical structure with hollow ends. The release member 10 has a second annular outer surface structure 1001 and a second annular inner cavity structure 1002. The release member 10 is movably sleeved outside the unlocking member 9, and the inner wall of the second annular inner cavity structure 1002 allows the second hook 908 to engage with the second hook hole 613. The upper and lower ends of the release member 10 are a second annular planar structure 1003 and a third annular planar structure 1004, respectively. The lower outer wall of the release member 10 is provided with a convex ring structure 1005, and the upper end of the convex ring structure 1005 is provided with an upper end face 1005a, which cooperates with the lower end face of the release spring. The upper end of the release member 10 extends with two symmetrical release columnar structures 1010 of a certain length. The upper surface of each release columnar structure has a sloping columnar structure 1010a. The shape of the release columnar structure 1010 is crescent-shaped, with planar sides and a width less than one-quarter the arc of the body, cooperating with the columnar groove 2007. The release member 10 also has release member guide posts 1006, attached to the second annular outer surface structure 1001. The release member guide posts 1006 are symmetrically distributed on both sides and terminate at the sloping columnar structure 1010a. The release member 10 has a cuboid groove penetrating the second annular outer surface structure 1001. A release member latching structure 1008 is provided within the cuboid groove. The end of the release member latching structure 1008 is bent inwards, forming an end plane 1008a, which cooperates with the unlocking member 9 to prevent the release member 10 from moving downwards. In the initial state, it is stopped by the upper stepped surface 910a and will not move downwards. The surface of the second annular inner cavity structure 1002 is also provided with an "L"-shaped protrusion structure 1009. The protrusion structure 1009 has a plane 1009a and a second structure 1009b, which can contact and cooperate with the wedge-shaped step 910. The release member 10 is rotated. When rotated to a certain angle, the upper step surface 910a abuts against the second structure 1009b, which limits the release member. At the same time, the release member guide post 1006 is precisely inserted into the third structure 2008, which limits the left and right rotation of the release member.

[0031] like Figure 14a and Figure 14bAs shown, in some embodiments, the outer shell 11 is a cylindrical structure with hollow ends. The outer shell 11 has an annular outer surface 1101 and an annular inner cavity 1102. The upper and lower ends of the outer shell 11 are respectively provided with a second upper annular planar structure 1103 and a third lower annular planar structure 1104. The upper end of the outer shell 11 is provided with a rectangular straight groove mounting hole 1105 for cooperating with the pressure cap buckle 210 to install and fix the pressure cap 2. The upper end of the annular inner cavity 1102 of the outer shell is provided with a sliding groove 1106 for cooperating with the pressure cap guide post 208 and the fixing guide post 2006, which facilitates the installation of the base 6. The lower end of the annular inner cavity 1102 of the outer shell is provided with a circumferential internal thread 1107, and an anti-reverse groove 1108 is also provided at the internal thread 1107 for cooperating with the pen refill holder 12. A rectangular window 1109 is provided on the surface of the outer shell 11. When the pen refill holder 12 is rotated to a certain stage, the corresponding letter mark will be displayed on the window 1109, giving people an intuitive visual experience. On both sides of the window 1109, there is a non-slip protrusion 1110 with a certain length and thickness, which serves to prevent the injection pen from slipping on the table.

[0032] like Figure 15a and Figure 15bAs shown, in some embodiments, the pen refill holder 12 is a cylindrical structure with hollow ends. The pen refill holder 12 has an annular outer surface 1201 and an inner cavity 1202. The inner cavity 1202 is polygonal and has the same shape as the fixing block at the head of the dual-cavity cartridge bottle 13. The upper and lower ends of the pen refill holder 12 are a third upper annular planar structure 1203 and a fourth lower annular planar structure 1204, respectively. The lower part of the annular outer surface 1201 of the pen refill holder is provided with an annular stepped surface 1205, on which an upper annular plane 1205a and a lower annular plane 1205b are provided. The annular outer surface 1201 of the pen refill holder is provided with an external thread 1206 between the upper annular plane 1205a and the third upper annular planar structure 1203, and the external thread 1206 is used to engage with the internal thread 1107. The pen refill holder 12 is further provided with a first anti-reverse latch 1207a, a second anti-reverse latch 1207b, and a third anti-reverse latch 1207c at different heights from top to bottom on the external thread 1206. These latches function to produce sound and prevent reversal at different stages during the upward rotation of the pen refill holder 12. They are the same size and shape. The pen refill holder 12 is also marked with multiple letter marks at the positions corresponding to the first anti-reverse latch 1207a, the second anti-reverse latch 1207b, and the third anti-reverse latch 1207c. Below the lower annular plane 1205b, there is also a pen cap holder 1208. The pen cap holder 1208 has a certain width, is circumferentially distributed, and has at least two pieces, used to fix the pen cap. The lower part of the pen refill holder 12 is also provided with an inwardly inclined medicine bottle buckle 1209. The medicine bottle buckle 1209 is symmetrically distributed around the circumference and can cooperate with the fixing block of the head of the double-cavity cartridge bottle 13 to fix the double-cavity cartridge bottle 13, so that the double-cavity cartridge bottle 13 cannot move up and down within the pen refill holder 12. The lower end of the pen refill holder 12 is also provided with an annular stepped surface 1211 to stop the bottom surface of the fixing block of the head of the double-cavity cartridge bottle 13. The lower end of the inner cavity 1202 of the pen refill holder is also provided with several first column structures 1210 for cooperating to fix the double-cavity cartridge bottle 13. The lower end of the pen refill holder is also provided with an annular groove 1212 and a wedge-shaped locking block 1213 for cooperating with the hidden needle sleeve 15.

[0033] like Figure 16As shown, in some embodiments, the concealed needle sleeve 15 is a cylindrical structure with hollow ends. The concealed needle sleeve 15 has an annular outer surface 1501 and an annular inner cavity 1502. The upper and lower ends of the concealed needle sleeve 15 are respectively an upper annular planar structure 1503 and a lower annular planar structure 1504. The annular inner cavity 1502 of the concealed needle sleeve is provided with an annular step 1505, the upper end surface of the annular step 1505 is an annular inclined plane 1505a, and the lower end surface is a third annular plane 1505b. The annular inner cavity 1502 of the concealed needle sleeve also has a crescent-shaped second column structure 1506. The second column structure 1506 starts from the upper end of the concealed needle sleeve 15 and extends a certain distance to the lower end, but cannot contact the annular step 1505. The second column structure 1506 can rotate within the annular groove 1212 and forms a stop with the wedge-shaped locking block 1213 after rotating to a certain position. Several concealed needle mounting grooves 1507 are also provided between the third annular plane 1505b and the lower annular plane structure 1504 of the concealed needle sleeve. A second step surface 1508 is provided at the bottom of each concealed needle mounting groove 1507. The concealed needle mounting groove 1507 is used to install the concealed needle cap 17. A certain number of serrated column structures are also provided on the annular outer surface 1501 of the concealed needle sleeve at positions corresponding to the concealed needle mounting grooves 1507, which can facilitate the screwing and installation of the concealed needle sleeve 15.

[0034] like Figure 11 As shown, in some embodiments, the concealed needle spring 16 has a compression spring structure of a certain length, with a spring top structure 1601 and a spring bottom structure 1602. The inner diameter of the concealed needle spring 16 needs to be larger than the diameter of the concealed needle cap 17, and the outer diameter of the concealed needle spring 16 needs to be smaller than the diameter of the annular inner cavity 1502 of the concealed needle sleeve. It is installed in the inner cavity of the concealed needle sleeve 15. In the initial state, the spring top structure 1601 abuts against the third annular plane 1505b; the spring bottom structure 1602 abuts against the concealed needle cap 17. The two sides interact with each other for the storage and release of the concealed needle spring 16.

[0035] like Figure 17As shown, in some embodiments, the hidden needle cap 17 is a cylindrical structure with hollow ends. The hidden needle cap 17 has an annular outer surface 1701 and an annular inner cavity 1702. The upper and lower ends of the hidden needle cap 17 are respectively a fifth annular planar structure 1703 and a fourth annular planar structure 1704. The upper end of the annular outer surface 1701 of the hidden needle cap is provided with several mounting sliders 1705 that engage with the hidden needle mounting groove 1507. The mounting sliders 1705 are circumferentially distributed and their number matches that of the hidden needle mounting groove 1507. The lower end of the annular outer surface 1701 of the hidden needle cap is provided with a protruding ring portion that engages with the bottom end structure 1602 of a spring. The fourth annular planar structure 1704 is also provided with several spaced protrusions to increase the contact area between the planar structure and the skin, thus better securing the injection pen.

[0036] like Figure 18 As shown, in some embodiments, the pen cap 18 is a hollow cylindrical structure with one open end. The pen cap 18 has a pen cap annular outer surface 1801 and a pen cap annular inner cavity 1802. The upper end of the pen cap 18 is a fourth circular planar structure 1803, and the pen cap 18 is provided with an annular groove 1804 that matches the pen cap fastener 1208.

[0037] like Figure 19 As shown, in some embodiments, the dual-chamber cartridge bottle 13 includes a third inner cavity 1301, an upper stopper 1302, a lower stopper 1303, and a channel 1304. The channel 1304 is located in the lower part of the cartridge bottle and is lower than the bottom surface of the lower stopper 1303 to prevent the liquid medicine from mixing with the powder medicine prematurely. The liquid medicine is stored between the upper stopper 1302 and the lower stopper 1303, while the powder medicine or other substances are stored in the lower stopper 1303 and the bottom of the cartridge bottle. During movement, the upper stopper 1302 is pushed downwards by the force, which simultaneously pushes the lower stopper 1303 to move, so that the top of the lower stopper 1303 is lower than the top of the channel 1304, thereby allowing the liquid medicine to flow from the channel into the bottom of the cartridge bottle and mix with the powder medicine.

[0038] like Figure 20As shown, in some embodiments, the fixing member 20 is a cylindrical structure with hollow ends, a partition in the middle, and steps. One end is a large cylinder, and the other end is a small cylinder. The annular platform 2004 is the dividing plane between the large cylinder and the small cylinder. The fixing member includes a second outer surface 2001 and a second inner cavity surface 2002. The upper and lower ends of the fixing member are respectively a fourth annular plane 2003 and a fifth annular plane 2005. The guide post 2006 starts from the fourth annular plane 2003 and ends at the annular platform 2004, and is attached to the outer surface of the large cylinder. It is symmetrically distributed on both sides and has an isosceles trapezoidal shape. It is used for guiding and fixing the fixing member when it is installed inside the shell. The columnar groove 2007 is a crescent shape that starts from the fourth annular plane 2003 and has a certain depth. It is symmetrically distributed and used for the left and right limit and radial linear movement of the unlocking protrusion 905. The third structure 2008 originates from the fifth annular plane 2005 and is attached to the surface of the columnar groove 2007, extending upwards a certain distance as a columnar structure. Simultaneously, a central groove is formed at a certain distance in the middle to fix the release guide post 1006 and prevent lateral swaying. The upper surface of the third structure 2008 is an inclined plane, used to cooperate with the inclined columnar structure 1010a to provide downward limiting.

[0039] like Figure 21 As shown, in some embodiments, the release spring 19 is a compression spring structure of a certain length, having an upper release spring structure 1901 and a lower release spring structure 1902. The inner diameter of the release spring 19 needs to be larger than the diameter of the second outer surface 2001, and the outer diameter of the release spring 19 needs to be smaller than the diameter of the annular inner cavity 1102 of the outer shell. It is installed on the outer surface of the fixing member 20. In the initial state, the upper release spring structure 1901 abuts against the annular platform 2004; the lower release spring structure 1902 abuts against the upper end surface 1005a. The two sides interact with each other to release the force stored in the release spring 19 and release it. Another function is to control the release member to move arbitrarily in a free state, forming a relatively fixed state.

[0040] The actual usage of this solution can be divided into the following states: 1. Initial state: such as Figure 22As shown, the pen refill holder 12 is screwed into the pen body shell 11 to a certain depth. At this time, the window 1109 will display the letter A, indicating that the initial installation has been completed. Before any other operation, the parts of the injection pen are relatively stationary. If button 1 is pressed, there should be no action. In this state, the first hook 612 remains engaged in the first hook hole 507, the second hook 908 remains engaged in the second hook hole 613, the button wedge hook 107 is engaged in the cap groove, the bottom end of the protrusion 106 abuts against the top end of the head columnar structure 906 of the unlocking member 9, the release spring 19 abuts against the release member 10, and the bottom end of the push rod 5 abuts against the dual-chamber cartridge bottle 13.

[0041] 2. Mixed state: such as Figure 23 As shown, the user holds the pen body shell 11 with one hand and the pen refill holder 12 with the other, rotating it upwards. The pen refill holder 12 will move upwards, and correspondingly, the push rod 5 will move downwards against the upper stopper 1302 of the dual-chamber cartridge 13 until the window 1109 displays the letter B. At this point, a "click" sound will be heard, indicating that the second anti-reverse latch 1207b of stage B has engaged with the anti-reverse latch 1108, and that the liquid and powder between the upper stopper 1302 and the lower stopper 1303 have been mixed. To ensure that the liquid and powder are fully mixed, the pen can be held with both hands and shaken left and right several times.

[0042] 3. Exhaust status: such as Figure 24 As shown, the user continues to rotate the pen refill holder 12 upwards. At this time, the third upper annular plane structure 1203 at the upper end of the pen refill holder 12 will contact the third annular plane structure 1004 at the lower end of the release member 10. Continue to rotate upwards, thereby pushing the release member 10 upwards along the slide groove 1106. Until the window 1109 displays the letter C, a "click" sound will be heard. This is the third anti-reverse latch 1207c of stage C engaging with the anti-reverse latch 1108. At this time, the upper annular plane 1205a at the top of the pen refill holder 12 is exactly against the third lower annular plane structure 1104 at the lower end of the outer shell 11, so that a small amount of liquid will be discharged from the needle. The release member 10 is pushed up by the pen refill holder 12 by one end, and the release member 10 releases the engagement of the second hook 908 and the second hook hole 613. At this time, the inner wall of the release member 10 is still partially against the second hook 908 and is subjected to the squeezing force (friction) of the inner wall of the release member 10. The second hook 908 is also still retained in the second hook hole 613 and is subjected to the force of the hook hole, so that the unlocking member 9 remains stationary in the axial direction. However, the force of the release member 10 and the force of the second hook hole 613 can be overcome by the force of pressing the button 1, so that the unlocking member 9 can slide by pressing the button 1.

[0043] 4. Injection status: such as Figure 25As shown, the user aligns the center of the hidden needle cap 17 at the tip of the injection pen with the injection site, making radial contact with the skin, while simultaneously holding the injection pen and pressing downwards. The hidden needle cap 17, subjected to downward pressure and resistance from the skin surface, contracts in the opposite direction, exposing the needle tip for insertion into the body. At this time, the user presses down on button 1. The first annular outer surface 101 of button 1 moves linearly downwards within the first inner cavity 206 of the pressure cap 2. The button wedge-shaped latch 107 disengages from the pressure cap groove, causing the bottom end of the protrusion 106 to push downwards towards the unlocking member 9. When button 1 can no longer be pressed, it indicates that the bottom structure 104 of button 1 has fully contacted the bottom surface 206a of the first inner cavity of the pressure cover 2. At this time, the first upper inclined plane 107a will be blocked by the lower inclined plane 216b (i.e., the button wedge-shaped hook 107 is engaged in the groove of the lower pressure cover). This further indicates that the protrusion 106 has pushed the unlocking member 9 to its maximum movable position. At this time, the unlocking opening 907 is directly opposite the first hook 612, and the first hook 612 will not be subjected to the inward pushing force of the unlocking limiting part. Under the greater thrust of the spring 4, the first hook 612 disengages from the first hook hole 507 and is locked into the unlocking opening 907 due to the elastic force. The constraint between the base 6 and the push rod 5 is released, the push rod 5 separates from the base 6, and the injection spring 4 changes from a compressed energy storage state to an unfolded working state. The injection spring 4 pushes the push rod 5 downward, thereby squeezing the upper stopper 1302 and the lower stopper 1303 of the dual-chamber cartridge bottle 13 to move downward synchronously for injection. The first columnar structure 505 at the top of the push rod 5 is combined with the second columnar structure 705 of the sound-emitting element 7 and is locked in the base groove 610. During the downward injection process of the push rod 5, the first columnar structure 505 and the second columnar structure 705 are attached together due to the inclined surface. Due to the restriction of the base groove 610, they can only make linear downward movement. At the end of the injection, the sound-emitting element has moved down a certain distance and is freed from the restriction of the base groove 610. At this time, it is in a critical state. The push rod 5 continues to push the sound-emitting element 7. Due to the inclined surface of the first columnar structure 505 and the second columnar structure 705, the sound-emitting element 7 rotates in the radial direction. When the injection is about to be completed, the first columnar structure 505 and the second columnar structure 705 are misaligned. When the sound-emitting element 7 is freed from the downward push of the push rod 5, the sound-emitting element 7 is pushed upward by the sound-emitting spring 8, so that the sound-emitting element 7 and the collision protrusion 611 of the base 6 collide with each other to make a "click" sound, indicating that the injection is completed. After the first columnar structure 505 and the second columnar structure 705 are offset, the first columnar structure 505 will immediately stop or only move downwards a very short distance, thus ensuring that the inclined surface of the second columnar structure 705 will collide with the collision protrusion 611 only after the injection is completely completed. The pen refill holder 12 in this design is preferably made of transparent material, allowing the user to visually inspect whether the rubber stopper in the dual-chamber cartridge 13 has been pushed to the bottom to further assess the injection status. The button 1, once pressed, will be locked and cannot return to its initial state.

[0044] The injection pen in this solution is small and convenient for patients to carry, allowing for injections anytime. Its operation is simple, and the automatic injection function reduces the burden on patients, making it especially suitable for those with limited self-care abilities. The pen features multiple safety protection designs: the push rod 5 and base 6 are locked together by the first latch 612, and the unlocking component 9 and base 6 are locked together by the second latch 908. Injection can only proceed after unlocking using the release component 10 and the unlocking component 9, preventing accidental activation and effectively avoiding accidental injuries. Furthermore, this solution includes a sound function after injection, enhancing its functionality. The sound-emitting structure is disengaged via two sliding inclined surfaces, resulting in smoother operation.

[0045] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the description of the invention shall still fall within the scope of the patent of the present invention.

Claims

1. A dual-chamber automatic injection pen, comprising a housing (11), a cartridge holder (12), a dual-chamber cartridge (13), a push rod (5), a base (6), an unlocking component (9), a release component (10), an injection spring (4), and a button (1). The dual-chamber cartridge (13) is provided with an upper stopper (1302) and a lower stopper (1303). The cartridge holder (12) is provided with a cartridge holder cavity (1202) for mounting the dual-chamber cartridge (13). The cartridge holder (12) is provided with external threads. (1206) The outer shell (11) is provided with an internal thread (1107) that matches the external thread (1206). The pen refill holder (12) is rotatably connected to the outer shell (11). During the upward rotation of the pen refill holder (12) relative to the outer shell (11), the push rod (5) presses against the upper stopper (1302) of the double-chamber cartridge bottle (13) to mix the two drugs in the double-chamber cartridge bottle (13). The push rod (5) is provided with a first hook hole (507). The base (6) is provided with a first hook (612) that cooperates with the first hook hole (507), and the base (6) is also provided with a second hook hole (613). The unlocking member (9) is provided with a second hook (908) that cooperates with the second hook hole (613). The unlocking member (9) is slidably sleeved on the outside of the base (6) to keep or release the first hook hole (507) and the first hook (612). After the first hook hole (507) and the first hook (612) are released, the push rod (5) is released. The injection spring (4) pushes the push rod (5) downward to inject the mixed drug. The release member (10) is slidably sleeved on the outside of the unlocking member (9) to keep or release the second hook hole (613) and the second hook (908). Before the second hook hole (613) and the second hook (908) are released, the button (1) is in a locked state to prevent the push rod (5) from being released.

2. The dual-cavity automatic injection pen according to claim 1, characterized in that, The pen refill holder (12) is provided with a first anti-reverse buckle (1207a), a second anti-reverse buckle (1207b) and a third anti-reverse buckle (1207c). The first anti-reverse buckle (1207a), the second anti-reverse buckle (1207b) and the third anti-reverse buckle (1207c) are arranged at different heights on the outer wall of the pen refill holder (12) from top to bottom. The outer shell (11) is provided with an anti-reverse groove (1108) that cooperates with the first anti-reverse buckle (1207a), the second anti-reverse buckle (1207b) and the third anti-reverse buckle (1207c). When the pen refill holder (12) rotates upward relative to the outer shell (11), the first anti-reverse buckle (1207a), the second anti-reverse buckle (1207b) and the third anti-reverse buckle (1207c) are sequentially engaged in the anti-reverse groove (1108).

3. The dual-cavity automatic injection pen according to claim 2, characterized in that, When the first anti-reverse buckle (1207a) is engaged in the anti-reverse slot (1108), the push rod (5) abuts against the upper plug (1302) of the dual-chamber cartridge bottle (13), the first hook hole (507) and the first hook (612) remain engaged, and the second hook hole (613) and the second hook (908) remain engaged.

4. The dual-cavity automatic injection pen according to claim 2, characterized in that, When the second anti-reverse buckle (1207b) is engaged in the anti-reverse slot (1108), the upper plug (1302) and the lower plug (1303) abut against each other.

5. The dual-cavity automatic injection pen according to claim 2, characterized in that, When the third anti-reverse buckle (1207c) is engaged in the anti-reverse slot (1108), the release member (10) is lifted by the pen refill holder (12), and the release member (10) releases the second hook hole (613) and the second hook (908).

6. The dual-cavity automatic injection pen according to claim 5, characterized in that, After the release member (10) releases the second hook hole (613) and the second latch (908), the second latch (908) of the unlocking member (9) is still subjected to the force of the release member (10) and the force of the second hook hole (613), and remains stationary in the axial direction.

7. The dual-cavity automatic injection pen according to any one of claims 1 to 6, characterized in that, The pen refill holder (12) is also provided with letter markings, and the outer shell (11) is provided with a window (1109) that matches the letter markings.

8. The dual-cavity automatic injection pen according to claim 2, characterized in that, It also includes a hidden needle sleeve (15) and a hidden needle cap (17). The hidden needle sleeve (15) is installed at the lower end of the pen refill holder (12). The hidden needle cap (17) is fitted onto the lower end of the hidden needle sleeve (15) and is movably connected to the hidden needle sleeve (15). A hidden needle spring (16) is also installed inside the hidden needle sleeve (15). The hidden needle spring (16) abuts against the hidden needle cap (17).

9. The dual-cavity automatic injection pen according to claim 8, characterized in that, It also includes a pen cap (18), which is fitted onto the hidden needle sleeve (15) and is detachably connected to the hidden needle sleeve (15).

10. The dual-cavity automatic injection pen according to claim 1, wherein the lower end of the button (1) is provided with a protrusion (106), and the unlocking member (9) is provided with an unlocking column structure that cooperates with the protrusion (106). When the button (1) is pressed, the protrusion (106) presses against the unlocking column structure, causing the unlocking member (9) to slide downward.

11. The dual-cavity automatic injection pen according to claim 1, characterized in that, It also includes a pressure cover (2), on which a button wedge hook (107) is provided. The pressure cover (2) is provided with an upper pressure cover groove and a lower pressure cover groove that cooperate with the button wedge hook (107). Before the button (1) is pressed, the button wedge hook (107) is engaged in the upper pressure cover groove. After the button (1) is pressed, the button wedge hook (107) is engaged in the lower pressure cover groove.

12. The dual-cavity automatic injection pen according to claim 1, characterized in that, It also includes a sound-generating element (7) and a sound-generating spring (8). The push rod (5) is provided with a first columnar structure (505), and the bottom of the first columnar structure (505) is provided with an upper radial slope (506). The base (6) is provided with a base groove (610) and a collision protrusion (611). The sound-generating element (7) is provided with a second columnar structure (705) that cooperates with the first columnar structure (505). The top of the second columnar structure (705) is provided with a lower radial slope (706). The sound-generating element (7) is movably sleeved on the base (6). The sound-generating spring (8) presses the sound-generating element (7) upward. In the initial stage of downward injection of the push rod (5), the first columnar spring... The first columnar structure (505) and the second columnar structure (705) are pushed downward in the base groove (610). At the end of the injection, the second columnar structure (705) is released from the constraint of the base groove (610), while the first columnar structure (505) remains in the base groove (610). Due to the inclined surface of the first columnar structure (505) and the second columnar structure (705), the sound-emitting element (7) rotates in the radial direction. After the first columnar structure (505) and the second columnar structure (705) are completely separated, the sound-emitting spring presses against the sound-emitting element (7) to collide with the collision protrusion (611) to emit a sound to indicate that the injection is complete.

Images