WO2026014989A1 - Automatic drug injection device - Google Patents

Abstract

An embodiment relates to an automatic drug injection device and, more specifically, to an automatic drug injection device having a malfunction prevention structure. An embodiment provides the automatic drug injection device comprising: a tubular housing for forming the exterior thereof; a drug container which is fixed to the tubular housing, and which has a drug storage part for storing a drug and a syringe needle that penetrates the skin so that the drug stored in the drug storage part can be injected; an activation member which is provided to be slidable along the tubular housing, and which has a proximal end portion protruding to the outside of the housing at an initial position; a first elastic member for pressing the activation member toward the base thereof; a plunger which slides into the drug container and presses the drug and which has a trigger arm at the distal end portion thereof; a trigger housing in which the trigger arm of the plunger is locked when the activation member is in the initial position; a second elastic member for pressing the plunger toward the base thereof; a safety pin, which is inserted into the distal end portion of the plunger so as to press the trigger arm outward in the radial direction, thereby maintaining a state in which the trigger arm is locked in the trigger housing; and a locking pin which moves by means of the pressure of the activation member and removes the safety pin from the plunger so as to release locking and activate the plunger.

Description

automatic drug injection device

The present invention relates to an automatic drug injection device. More particularly, it relates to an automatic drug injection device having a malfunction prevention structure.

In cases of chronic diseases requiring continuous management, such as diabetes, or acute attacks requiring immediate response, such as anaphylactic shock in allergy patients, autoinjectors that allow users to inject themselves without visiting a hospital are widely used.

An auto injector in the form of a pen needle has been developed and is widely used. It can be carried around and inserted into an injection site that suits the conditions, automatically inserting the needle into the muscle and automatically injecting the injection liquid by a device such as a spring.

Figure 1 is an exploded view showing an automatic drug injection device according to the prior art.

An automatic drug injection device according to an embodiment comprises a tubular housing (10) forming an exterior, an activating member (20) slidably installed axially on the proximal end side of the tubular housing (10), and a first elastic member (30) for pressing the activating member (20) in a proximal direction. The proximal end (21) of the activating member (20) is exposed outside the proximal end of the tubular housing (10) before drug injection.

Additionally, a trigger housing (50) is installed on the distal end side of the tubular housing (10). A plunger (40) is slidably installed inside the trigger housing (50).

A second elastic member (60) is installed between the trigger housing (50) and the plunger (40), and the second elastic member (60) is installed in a compressed state so as to press the plunger (40) in the base direction.

The plunger (40) is locked with the trigger housing (50) so that it does not move in the proximal direction even when the pressure of the second elastic member (60) is applied until the activation member (20) slides in the distal direction to activate the automatic drug injection device.

The trigger housing (50) has a guide element (51) that extends axially and a locking element (52) that extends circumferentially on one side from the guide element (51). The plunger (40) has a tubular body (41) and a locking projection (42) that is formed on the outer surface of the body (41) and penetrates the trigger housing (50). The locking projection (42) is inserted into the locking element (52) at an initial position and is locked, so that the plunger (40) does not move despite the pressing force of the second elastic member (60).

The activation member (20) has a proximal end (21) in a cap shape and a contact surface at the end of the proximal end (21) that contacts the user's skin. The activation member (20) further includes an activation arm (22) extending distally from the proximal end (21). An activation protrusion (22a) is formed on the activation arm (220) to be inserted into the guide element (51) and move along the guide element (51). When in the initial position, the activation protrusion (22a) maintains a position that can block the locking protrusion (42) of the plunger (40) from moving from the locking element (52) to the guide element (51). That is, when in the initial position, the activation protrusion (22a) maintains a position adjacent to the locking element (52) within the guide element (51).

A drug container (70) having a drug storage section (71) for storing a drug and an injection needle (72) for injecting the drug stored in the tubular housing (10) is installed. At this time, the drug container (70) is fixedly installed to the tubular housing (10) by a drug container holder (73), and its position is maintained fixed to the tubular housing (10) by the drug container holder (73) regardless of movement of the activating member (20) or the plunger (40).

At this time, when the second elastic member (60) presses the plunger (40), the plunger (40) moves in the proximal direction within the drug storage unit (71), and the drug is injected into the user's body through the injection needle (72).

A proximal cap (12) is installed at the proximal end of the tubular housing (10), and if the proximal cap (12) is not removed, the activating member (20) does not operate. Meanwhile, a distal cap (14) is installed at the distal end of the tubular housing (10), and prevents foreign substances from entering the tubular housing (10).

However, in the case of the conventional technology, if the automatic drug injection device is dropped or receives a strong impact from the outside, there was a concern that the locking of the trigger housing (50) and the locking protrusion (42) may be released unintentionally without the activation member (20) sliding, resulting in a drug leak.

The invention aims to provide an automatic drug injection device having a malfunction-preventing structure in which a trigger is not released even when dropped or subjected to external impact.

In addition, the embodiment aims to provide an automatic drug injection device having a structure that prevents a needle of the automatic drug injection device from being re-exposed after use.

An embodiment provides an automatic drug injection device comprising: a tubular housing forming an exterior; a drug storage unit storing a drug, and a drug container fixed to the tubular housing, the drug container having a drug storage unit that stores a drug and an injection needle that can inject the drug stored in the drug storage unit by piercing the skin; an activating member that is slidably installed along the tubular housing and has a proximal end protruding outside the housing in an initial position; a first elastic member that urges the activating member in a proximal direction; a plunger that slides into the drug container and urges the drug, the plunger having a trigger arm at a distal end; a trigger housing in which the trigger arm of the plunger is locked when the activating member is in the initial position; a second elastic member that urges the plunger in a proximal direction; a safety pin inserted into the distal end of the plunger and urges the trigger arm radially outward to maintain a locked state with the trigger housing; and a locking pin that is moved by the urging force of the activating member to remove the safety pin from the plunger to unlock and activate the plunger.

In another aspect of the embodiment, an automatic drug injection device is provided, characterized in that the distal end of the activating member and the proximal end of the locking pin are spaced apart from each other in the initial position, so that even if the activating member moves in the distal direction by a distance, the locking pin remains stationary.

As another aspect of the embodiment, an automatic drug injection device is provided, characterized in that a distance between a distal end of an activating member and a proximal end of a locking pin is 7 mm or more.

In another aspect of the embodiment, an automatic drug injection device is provided, characterized in that a distance between a distal end of an activating member and a proximal end of a locking pin is longer than a distance between a proximal end of the activating member and a proximal end of an injection needle.

As another aspect of the embodiment, an automatic drug injection device is provided, further comprising a distal cap that is inserted and installed into a distal end of a housing and has a distal-disengagement hole; wherein the locking pin has a flexible element, the locking pin moves in a distal direction, and the flexible element of the locking pin is inserted and fixed within the distal-disengagement hole of the distal cap.

In another aspect of the present invention, an automatic drug injection device is provided, wherein the distal cap has a distal surface for closing a distal end of the housing, a mating surface for engaging an inner surface of the housing, and a pair of anti-separation arms extending proximally from the mating surface, and an anti-separation hole is formed in each of the anti-separation arms.

In another aspect of the invention, an automatic drug injection device is provided, characterized in that the locking pin includes a tubular body coupled to an outer surface of a trigger housing, an arm extending distally from the body and pushing the safety pin when moved distally, and a flexible element extending from the body.

In another aspect of the present invention, an automatic drug injection device is provided, characterized in that the safety pin has a tubular body, a bridge crossing a distal end of the body, a pin portion extending from the bridge in a proximal direction, and a pair of anti-disengagement arms extending from the body in a proximal direction.

In another aspect of the present invention, an automatic drug injection device is provided, wherein the locking pin has a re-locking arm extending from the body in a proximal direction, the activating member has a re-locking jaw that engages with the extended re-locking arm when returning to an initial position, the re-locking arm is retracted by the activating member in the initial position, and when the locking pin moves distally and then the activating member moves to the initial position, the re-locking arm of the locking pin spreads radially outward to restrict movement of the activating member, thereby preventing re-exposure of the needle.

In another aspect of the present invention, an automatic drug injection device is provided, characterized in that the activation member has a tubular proximal end exposed outside the proximal end of the housing, and an activation arm extending distally from the proximal end, and a re-locking jaw is formed on the distal side of the activation arm.

As another aspect of the embodiment, an automatic drug injection device is provided, characterized in that the re-locking jaw is a part of a hole formed in an activation arm, and an end of the re-locking arm is received in the hole.

In another aspect of the present invention, an automatic drug injection device is provided, wherein the re-locking jaw is a distal end of an activation arm.

The drug injection device provided by the embodiment has the advantage of preventing the trigger from being unintentionally released even when dropped or subjected to external impact.

Additionally, the drug injection device provided by the embodiment can prevent the needle from being exposed by restricting the movement of the activation device of the automatic drug injection device when use is complete.

Figure 1 is an exploded view showing an automatic drug injection device according to the prior art;

Figure 2 is a cross-sectional view of an automatic drug injection device according to the first embodiment;

Figure 3 is a drawing showing the appearance before and after operation of the automatic drug injection device according to the first embodiment.

Figure 4 is a drawing showing an activation member provided in an automatic drug injection device according to the first embodiment;

Figure 5 is a drawing showing a distal cap provided in an automatic drug injection device according to the first embodiment;

Figure 6 is a drawing showing a locking pin provided in an automatic drug injection device according to the first embodiment;

Figure 7 is a drawing showing a safety pin provided in an automatic drug injection device according to the first embodiment;

FIG. 8 is a drawing showing a locking pin detachment prevention structure of an automatic drug injection device according to the first embodiment;

Fig. 9 is a cross-sectional view showing a locking pin detachment prevention structure of an automatic drug injection device according to the first embodiment.

FIG. 10 is a drawing showing the state in which the locking pin detachment prevention structure of the automatic drug injection device according to the first embodiment is released.

Fig. 11 is a cross-sectional view of an automatic drug injection device according to a second embodiment;

Fig. 12 is a drawing showing a trigger housing provided in an automatic drug injection device according to a second embodiment;

Figure 13 is a drawing showing a safety pin provided in an automatic drug injection device according to the second embodiment;

Fig. 14 is a drawing showing a locking pin provided in an automatic drug injection device according to the second embodiment.

Fig. 15 is a drawing showing the initial state of the automatic drug injection device according to the second embodiment;

Fig. 16 is a drawing showing the trigger of the automatic drug injection device according to the second embodiment released.

Hereinafter, embodiments will be described in more detail with reference to the drawings. However, the concept of the present invention may be implemented in many different forms and should not be limited to the embodiments disclosed herein. Rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete and sufficiently convey the scope of the concept of the present invention to those skilled in the art.

As used herein, the term "proximal end" refers to that end of a drug delivery device from which drug release can be provided. Thus, it is that end of the drug delivery device that is pointed toward an injection or release site. This definition also extends to any internal or external component of the drug delivery device, i.e., the proximal end of any component is the end closest to the proximal end of the drug delivery device. The "distal end" is the end opposite the proximal end.

"Proximal direction" means the direction from the distal end to the proximal end along the central axis of the drug delivery device. "Distal direction" means the direction opposite to "proximal direction."

Figure 2 is a cross-sectional view of an automatic drug injection device according to the first embodiment.

According to the first embodiment, an automatic drug injection device includes a drug storage unit (710) for storing a drug in a tubular housing (100) forming an exterior, and a drug container having an injection needle (720) capable of injecting the drug stored in the drug storage unit (710) by piercing the skin, and is fixed by a drug holder (730). An activation member (200) and a first elastic member (300) for pressing the activation member (200) in a proximal direction are installed on the proximal side of the drug container within the tubular housing (100). The proximal end (210) of the activation member (200) is exposed outside the proximal end of the tubular housing (100) before drug injection, and is utilized as a structure for preventing exposure of the needle. If necessary, a proximal cap (not shown) is coupled to the proximal end (210) of the activating member (200), and the distal end of the proximal cap (not shown) and the proximal end of the housing (100) come into contact to prevent the activating member (200) from being pressed. A distal cap (120) is installed at the distal end of the housing (100) to close the distal end of the housing (100) after assembling the components within the housing (100).

On the distal side of the drug container, a plunger (400) for pressurizing the drug and a trigger module (420, 500, 800, 850) for deactivating the plunger (400) and then activating it by movement of an activating member (200) are installed. In the initial state, the plunger (400) is locked and deactivated by the trigger module (420, 500, 800, 850), and when the trigger of the trigger module (420, 500, 800, 850) is released by movement of the activating member (200), the plunger (400) is activated and slides within the drug storage unit (710) to pressurize the drug.

The plunger (400) is composed of a plunger rod (410) and a trigger arm (420) extending distally from the plunger (410), and the trigger arm (420) forms part of a trigger module (420, 500, 800, 850). If necessary, a trigger protrusion may be provided at the end of the trigger arm (420) to ensure more secure locking.

The trigger module (420, 500, 800, 850) is composed of a trigger housing (500), a trigger arm (420), a safety pin (800) that keeps the trigger arm (420) engaged with the trigger housing (500), and a locking pin (850) that prevents the safety pin (800) from coming off.

The proximal end of the second elastic member (600) is supported by the plunger (400), the distal end is supported by the trigger housing (500), and the second elastic member (600) is installed in a compressed state so as to pressurize the plunger (400) in the proximal direction. When the trigger of the trigger module (420, 500, 800, 850) is released, the second elastic member (600) presses the plunger (400) in the proximal direction. At this time, a plunger tube (430) that wraps the second elastic member (600) may be further provided between the second elastic member (600) and the trigger housing (500). The proximal end of the plunger tube (430) is coupled with the plunger rod (410) and moves together with the plunger rod (410). The plunger tube (430) can prevent a buckling phenomenon that may occur during compression and extension of the second elastic member (600).

The trigger housing (500) according to the first embodiment surrounds the plunger (400) and engages with the plunger arm (420) to limit the movement of the plunger (400).

The plunger (400) is locked by the trigger module (420, 500, 800, 850) so that it does not move in the proximal direction even when the pressure of the second elastic member (600) is applied until the activation member (200) slides in the distal direction to release the trigger of the trigger module.

The proximal end (210) of the activating member (200) is tubular and has a contact surface at the end of the proximal end (210) that comes into contact with the user's skin. A hole is provided in the center of the contact surface so that when the activating member (200) is retracted, the injection needle (720) is exposed through the hole.

The activation member (200) further includes an activation arm (220) extending distally from the proximal end (210). When the activation arm (220) moves distally, the activation arm (220) pushes the locking pin (850) distally, and the locking pin (850) pushes the safety pin module (800) distally. When the safety pin module (800) moves distally, the locking of the trigger modules (420, 500, 800, 850) is released, and the plunger (400) is activated. The plunger (400) is forced in the proximal direction by the second elastic member (600) to move within the drug storage unit (710), and the drug stored within the drug storage unit (710) is injected into the body through the injection needle (720).

Figure 3 is a drawing showing the appearance before and after operation of the automatic drug injection device according to the first embodiment.

In the embodiment, a free space is provided so that the locking pin (850) does not move even when the activation arm moves, so that the trigger is not released due to a recoil generated by an impact such as a drop before use of the product.

That is, in the first embodiment, a gap is set between the locking pin installation position and the distal end of the activation arm so that contact with the locking pin is not made even if the activation member moves 7.5 mm. Furthermore, when the activation arm and the locking pin make contact and move an additional 6 mm, the safety pin is removed from the trigger housing, releasing the trigger and activating the plunger.

At this time, the gap to prevent malfunction, i.e., the distance between the distal end of the activating member and the proximal end of the locking pin in the initial position, is preferably longer than the distance between the proximal end of the activating member and the proximal end of the injection needle. In this case, the injection needle can be prevented from being exposed to the outside when the activating member moves within the gap to prevent malfunction.

FIG. 4 is a drawing illustrating an activation member provided in an automatic drug injection device according to the first embodiment.

As described above, the activating member (200) has a proximal end (210) exposed outside the proximal end of the tubular housing (100; see FIG. 2) before drug injection, and is utilized as a structure to prevent exposure of the needle. It has a pair of activating arms (220) extending distally from the proximal end (210), and the activating arms (220) move to push the locking pin (850; see FIG. 2) and the safety pin (800; see FIG. 2) distally, thereby releasing the trigger.

In each activation arm (220), a re-locking hole (230) is formed to lock the activation member (200) by the plunger (400) moving in the direction of the base and then expanding and engaging with the re-locking arm (520) of the trigger housing (500).

FIG. 5 is a drawing illustrating a distal cap provided in an automatic drug injection device according to the first embodiment.

The distal cap (120) is coupled to the distal end of the housing (100) as described above to close the distal end of the housing (100). The distal cap (120) has a distal surface (121) that closes the distal end of the housing (100), a coupling surface (122) that engages with the inner surface of the housing (100), a pair of anti-separation arms (123) that extend proximally from the coupling surface (122), and a separation prevention hole (124) formed on each of the anti-separation arms (123) and capable of accommodating a hook of a locking pin (850; see FIG. 2) to be described later to prevent the safety pin (800; see FIG. 2) from being detached.

Fig. 6 is a drawing showing a locking pin provided in an automatic drug injection device according to the first embodiment.

The locking pin (850) has a tubular body (851) that is coupled to the outer surface of the trigger housing (500; see Fig. 2). It has an arm (852) that extends distally from the body (851), and when the locking pin (850) moves distally, the arm (852) pushes the safety pin (800; see Fig. 2) distally, thereby releasing the locking pin (850) and the trigger arm (420).

At this time, the locking pin (850) is provided with a flexible element (854) that can be bent radially outward on the proximal side. If necessary, a hook that protrudes inward may be provided at the proximal end of the flexible element (854).

Fig. 7 is a drawing showing a safety pin provided in an automatic drug injection device according to the first embodiment.

The safety pin (800) has a tubular body (802) and a bridge (803) crossing the distal end of the body (802). A pin portion (801; see FIG. 2) extends proximally from the bridge (803). When the pin portion (801) is inserted into the inside of the trigger arm (420), the trigger arm (420) is pressed radially outward, thereby maintaining the trigger arm (420) and the trigger housing in a locked state. When the pin portion (801) is moved distally by the locking pin (850) and comes out of the trigger arm (420), the locking of the trigger arm (420) and the trigger housing (500) is released, and the plunger (400) is activated.

The safety pin (800) has a pair of anti-separation arms (804) extending from the body (802) in the direction of the base.

FIG. 8 is a perspective view illustrating a locking pin detachment prevention structure of an automatic drug injection device according to the first embodiment, and FIG. 9 is a cross-sectional view illustrating a locking pin detachment prevention structure of an automatic drug injection device according to the first embodiment.

As the locking pin (850) moves distally to release the trigger, the flexible element (854) of the locking pin (850) spreads outward and is inserted into the anti-separation hole (124) of the distal cap (120). Therefore, the locking pin (850) is fixed and does not come out from the position where it is engaged with the distal cap (120) due to simple shaking or external impact. Therefore, the position of the locking pin (850) is fixed after the activating member (200) pushes out the locking pin (850), and the locking pin (850) pushes out the safety pin (800).

Fig. 10 is a drawing showing the locking pin detachment prevention structure of the automatic drug injection device according to the first embodiment released.

As the activation arm (220) moves distally, the locking pin (850) and the safety pin (800) are pushed distally, and the flexible element (854) of the locking pin (850) moves distally while coming out of the anti-separation hole (124) of the distal cap (120). When the engagement of the trigger arm (420) of the plunger (400) and the safety pin (800) is released, the trigger is released and the plunger (400) is moved proximally by the second elastic member (600).

Meanwhile, the re-locking arm (520) of the trigger housing (500) is initially in a retracted state by the locking pin (850), but as the locking pin (850) moves distally, the re-locking arm (520) is spread out radially. When the activating member (200) moves again in the proximal direction, that is, when it returns to the initial position, the re-locking arm (520) is inserted into the re-locking hole (230) of the activating member (200) to restrict the movement of the activating member (200). Therefore, the activating member (200) is locked, so that the needle of the automatic drug injection device, which has completed drug injection, can be prevented from being re-exposed.

Fig. 11 is a cross-sectional view of an automatic drug injection device according to a second embodiment.

According to a second embodiment, an automatic drug injection device comprises a drug storage unit (710a) for storing a drug in a tubular housing (100a) forming an exterior, and a drug container having an injection needle (720a) capable of injecting the drug stored in the drug storage unit (710a) by piercing the skin, and the drug container is fixed by a drug holder (730a). An activation member (200a) and a first elastic member (300a) for pressing the activation member (200a) in a proximal direction are installed on the proximal side of the drug container within the tubular housing (100a). The proximal end (210a) of the activation member (200a) is exposed outside the proximal end of the tubular housing (100a) before drug injection, and is utilized as a structure for preventing exposure of the needle. If necessary, a proximal cap (not shown) is coupled to the proximal end (210a) of the activating member (200a), and the distal end of the proximal cap (not shown) and the proximal end of the housing (100a) come into contact to prevent the activating member (200a) from being pressed. A distal cap (120a) is installed at the distal end of the housing (100a) to close the distal end of the housing (100a) after assembling the components within the housing (100a).

On the distal side of the drug container, a plunger (400a) for pressurizing the drug and a trigger module (420a, 500a, 800a, 850a) for deactivating the plunger (400a) and then activating it by movement of an activating member (200a) are installed. In the initial state, the plunger (400a) is locked and deactivated by the trigger module (420a, 500a, 800a, 850a), and when the trigger of the trigger module (420a, 500a, 800a, 850a) is released by movement of the activating member (200a), the plunger (400a) is activated and slides within the drug storage unit (710a) to pressurize the drug.

The plunger (400a) is composed of a plunger rod (410a) and a trigger arm (420a) extending distally from the plunger (410a), and the trigger arm (420a) forms part of a trigger module (420, 500, 800, 850a). If necessary, a trigger protrusion may be provided at the end of the trigger arm (420a) to ensure more secure locking.

The trigger module (420a, 500a, 800a, 850a) is composed of a trigger housing (500a), a trigger arm (420a), a safety pin (800a) that keeps the trigger housing (500a) and the trigger arm (420a) locked to the trigger housing (500a), and a locking pin (850a) that prevents the safety pin (800a) from coming off.

The proximal end of the second elastic member (600a) is supported by the plunger (400a), the distal end is supported by the trigger housing (500a), and the second elastic member (600a) is installed in a compressed state so as to pressurize the plunger (400a) in the proximal direction. When the trigger of the trigger module (420a, 500a, 800a, 850a) is released, the second elastic member (600a) presses the plunger (400a) in the proximal direction. At this time, a plunger tube (430a) that surrounds the second elastic member (600a) may be further provided between the second elastic member (600a) and the trigger housing (500a). The proximal end of the plunger tube (430a) is coupled with the plunger rod (410a) and moves together with the plunger rod (410a). The plunger tube (430a) can prevent a buckling phenomenon that may occur when the second elastic member (600a) is compressed and extended.

The trigger housing (500a) according to the second embodiment surrounds the plunger (400a) and engages with the plunger arm (420a) to limit the movement of the plunger (400a).

The plunger (400a) is locked by the trigger module (420a, 500a, 800a, 850a) so that it does not move in the proximal direction even when the pressure of the second elastic member (600a) is applied until the activation member (200a) slides in the distal direction to release the trigger of the trigger module.

The proximal end (210a) of the activating member (200a) is tubular and has a contact surface at the end of the proximal end (210a) that comes into contact with the user's skin. A hole is provided in the center of the contact surface, so that when the activating member (200a) is retracted, the injection needle (720a) is exposed through the hole.

The activation member (200a) further includes an activation arm (220a) extending distally from the proximal end (210a). When the activation arm (220a) moves distally, the activation arm (220a) pushes the locking pin (850a) distally, and the locking pin (850a) pushes the safety pin module (800a) distally. When the safety pin module (800a) moves distally, the locking of the trigger modules (420a, 500a, 800a, 850a) is released, and the plunger (400a) is activated. The plunger (400a) is forced in the proximal direction by the second elastic member (600a) to move within the drug storage unit (710a), and the drug stored within the drug storage unit (710a) is injected into the body through the injection needle (720a).

Fig. 12 is a drawing showing a trigger housing provided in an automatic drug injection device according to a second embodiment.

The trigger housing (500a) of the automatic drug injection device according to the second embodiment has a tubular body (510a). At this time, in order to prevent the trigger from being unintentionally released due to the automatic drug injection device being dropped or an external force being applied to the safety pin (800a) coming off from the trigger module, the trigger housing (500a) has a fixing hole (512a) for fixing the safety pin (800a).

Fig. 13 is a drawing showing a safety pin provided in an automatic drug injection device according to a second embodiment.

The safety pin (500a) has a pin portion (810a) that is inserted into the trigger housing (500a) to lock the trigger arm (420a), and a body (820a) that is coupled to the distal end of the trigger housing (500a) to fix the pin portion (810a). The body (820a) is generally in the shape of a tube and is coupled to the outer periphery of the trigger housing (500a). Here, the safety pin (500a) has a fixing hook (830a) to prevent unintentional trigger release. The fixing hook (830a) has a flexible element extending proximally from the body (820a) and an inclined protrusion formed at the proximal end of the flexible element and protruding radially inward.

Fig. 14 is a drawing showing a locking pin provided in an automatic drug injection device according to the second embodiment.

In the second embodiment, the activating member (200a) does not directly push the safety pin (800a) distally, but the movement is mediated by the locking pin (850a). That is, the activating arm (220a) pushes the locking pin (850a) distally, and the locking pin (850a) pushes the safety pin (800a) distally.

The locking pin (850a) has a tubular body (852a) that is coupled to the outer periphery of the trigger housing (500a) and has a flange portion (854a) that extends radially outward from the body (852a). The flange portion (854a) contacts the distal end of the activation arm (220a) and receives force from the activation arm (220a).

Meanwhile, the locking pin (850a) has a re-locking arm (856a) extending from the body (852a) in the base direction. The re-locking arm (856a) is movable in and out in the radial direction and is of a form that can be opened radially outward.

At this time, the body (852a) of the locking pin (850a) has a release slope whose outer diameter decreases as it goes in the distal direction.

Fig. 15 is a drawing showing the initial state of the automatic drug injection device according to the second embodiment, and Fig. 16 is a drawing showing the state in which the trigger of the automatic drug injection device according to the second embodiment is released.

When the activation member (200a) moves distally, the locking pin (850a) also moves distally, and the release slope formed on the body (542a) of the locking pin (850a) causes the fixing hook (830a) of the safety pin (800a) to spread radially outward. When the release slope moves distally, the fixing hook (830a) spreads radially outward and comes out of the fixing hole (512a) of the trigger housing (500a).

Therefore, the safety pin (500a) does not come out of its original position by simple impact due to the combination of the fixing hole (512a) and the fixing hook (830a), and the trigger can be released only when the activating member (200a) moves in the distal direction.

Meanwhile, when the locking pin (850a) moves distally and then the activating member (200a) moves to the initial position, the re-locking arm (856a) of the locking pin (850a) spreads radially outward and is engaged with the re-locking hole (230a) of the activating arm (220a). The end of the re-locking hole (230a) is utilized as a re-locking jaw. If necessary, the end of the activating arm (220a) can be utilized as a re-locking jaw without the re-locking hole (230a). When the re-locking jaw and the re-locking arm (856a) are engaged, the movement of the activating device (200a) of the automatic drug injection device that has been used is restricted, and the needle can be prevented from being exposed.

Claims (12)

A tubular housing forming the exterior; A drug container having a drug storage compartment for storing a drug and an injection needle for injecting the drug stored in the drug storage compartment by penetrating the skin, and fixed to a tubular housing; An activating member slidably installed along a tubular housing, the proximal end of which protrudes outside the housing in the initial position; A first elastic member that presses the activation member in the direction of the base; A plunger that slides into a drug container to pressurize the drug, and has a trigger arm at its distal end; A trigger housing in which the trigger arm of the plunger is locked when the activating member is in the initial position; A second elastic member that presses the plunger in the base direction; A safety pin inserted into the distal end of the plunger to force the trigger arm radially outward to maintain engagement with the trigger housing; and An automatic drug injection device characterized by including a locking pin that is moved by the pressure of an activating member to remove the safety pin from the plunger to unlock and activate the plunger. In the first paragraph, An automatic drug injection device characterized in that, in an initial position, the distal end of the activating member and the proximal end of the locking pin are spaced apart, so that even if the activating member moves in the distal direction by a distance, the locking pin remains stationary. In the second paragraph, An automatic drug injection device characterized in that the distance between the distal end of the activation member and the proximal end of the locking pin is 7 mm or more. In the second paragraph, An automatic drug injection device, characterized in that the distance between the distal end of the activating member and the proximal end of the locking pin is longer than the distance between the proximal end of the activating member and the proximal end of the injection needle. In the first paragraph, Further comprising a distal cap which is inserted and installed at the distal end of the housing and has a distal hole for preventing detachment; The locking pin has a flexible element, An automatic drug injection device characterized in that the locking pin moves distally and the flexible element of the locking pin is inserted and fixed within the anti-disengagement hole of the distal cap. In paragraph 5, The distal cap has a distal surface that closes the distal end of the housing, a mating surface that engages the inner surface of the housing, and a pair of anti-separation arms extending proximally from the mating surface. An automatic drug injection device characterized in that a disengagement prevention hole is formed in each disengagement prevention arm. In paragraph 5, The locking pin includes a tubular body that engages the outer surface of the trigger housing, and an arm that extends distally from the body and pushes the safety pin when moved distally. An automatic drug injection device characterized in that the flexible element extends from the body. In paragraph 5, An automatic drug injection device characterized in that the safety pin has a tubular body, a bridge crossing the distal end of the body, a pin portion extending from the bridge in a proximal direction, and a pair of anti-disengagement arms extending from the body in a proximal direction. In the first paragraph, The locking pin has a re-locking arm extending from the body in the direction of the base, The activating member has a relocking jaw that engages with the extended relocking arm when returning to the initial position, An automatic drug injection device characterized in that the re-locking arm is retracted by the activating member in the initial position, the locking pin moves distally, and then when the activating member moves to the initial position, the re-locking arm of the locking pin opens radially outward to restrict movement of the activating member and prevent re-exposure of the needle. In paragraph 9, The activating member has a tubular proximal end exposed outside the proximal end of the housing, and an activating arm extending distally from the proximal end, An automatic drug injection device characterized in that the re-locking jaw is formed on the distal side of the activation arm. In Article 10, The relocking jaw is part of the hole formed in the activation arm. An automatic drug injection device characterized in that the end of the re-locking arm is received in a hole. In Article 10, An automatic drug injection device characterized in that the re-locking jaw is the distal end of the activation arm.