Anti-misoperation mechanism of emergency injection pen

Abstract

The utility model relates to medical instrument manufacturing technical field especially first-aid injection pen anti -misoperation mechanism, it includes safety bolt, upper casing and outer main body. Safety bolt includes bolt body, radial rebound locking body and spacing post. Radial rebound locking body and spacing post all are extended from bolt body, and the radial rebound locking body is formed with locking hook, and its number is 2, and the axial symmetry distribution. Upper casing is formed with locking gap and spacing hole. Outer main body is set in the upper casing. In the different stage of outer main body execution axial displacement movement process, the locking state of excitation lever is different. In the initial state, locking hook buckle is in locking gap, spacing post passes through spacing hole and directly abuts against outer main body, before pre -execution excitation operation, the radial rebound locking body of opposite because of the extrusion force action simultaneously and the opposite retreat, until locking hook is taken out from locking gap, after safety bolt is pulled out, and outer main body restores axial displacement freedom degree.

Description

Technical Field

[0001] This utility model relates to the field of medical device manufacturing technology, and in particular to a mechanism for preventing misoperation of an emergency injection pen. Background Technology

[0002] As a critical device in emergency medical scenarios, the reliability of the anti-misoperation design of the emergency injection pen is directly related to the patient's life safety.

[0003] Currently, most anti-accidental activation mechanisms in the industry employ a unidirectional locking design, requiring only resistance in one dimension to unlock. This results in a high risk of accidental activation during everyday carrying or unintended operation of emergency injection pens. For example, axial locking structures (such as spring clips) restrict the movement of the outer body through axial resistance but lack radial restraint. For instance, one adrenaline injection pen uses an axial spring clip design; when the pen is radially compressed in a pocket, the spring may become misaligned due to uneven force, causing the clip to accidentally disengage and trigger injection. Furthermore, another adrenaline injection pen uses a rotational unlocking mechanism (such as unlocking by rotating the outer shell 90°), which provides some protection against accidental activation, but only requires overcoming circumferential rotational resistance to unlock. Children or those prone to accidental operation may trigger the unlock by repeatedly trying random rotation angles, especially when the device lacks clear operational markings, significantly increasing the risk of misoperation. For example, a certain adrenaline injection pen unlocks via a single button press, but in emergencies (such as friction from clothing or impact from objects), the button is easily triggered accidentally due to unidirectional force, releasing the activation lever. Therefore, technical personnel urgently need to address these issues. Utility Model Content

[0004] To address the shortcomings of existing technologies where unidirectional locking is susceptible to single-dimensional external force, this invention proposes an anti-misoperation mechanism for emergency injection pens. This mechanism is based on the synergistic effect of dual radial rebound locking bodies to achieve the design goal of multi-dimensional resistance constraint and synchronous unlocking.

[0005] This utility model relates to a mechanism for preventing misoperation of an emergency injection pen, which includes:

[0006] The safety pin includes a pin body, a radial spring-loaded locking element, and a limiting post. Both the radial spring-loaded locking element and the limiting post extend from the pin body.

[0007] The radial spring-loaded locking body has two locking hooks formed on it, and they are symmetrically distributed along the central axis of the pin body.

[0008] The upper outer shell has a locking notch adapted to the locking hook and a limiting hole for the limiting pin to pass through;

[0009] The outer body is fitted inside the upper shell and has axial displacement freedom; and the locking state of the excitation rod is different at different stages of the outer body's axial displacement motion.

[0010] In the initial state, the locking hook is engaged in the locking notch, the limiting pin passes through the limiting hole and directly abuts against the outer body, and the axial displacement freedom of the outer body is restricted;

[0011] Before the emergency injection pen is activated, the opposing radial spring-loaded locking bodies retract towards each other due to the simultaneous pressure, until the locking hook is dislodged from the locking notch; after the safety pin is pulled out from the upper shell, the axial displacement freedom of the outer body is restored.

[0012] As a further improvement to the technical solution disclosed in this utility model, the number of limiting posts is 2, and they are symmetrically distributed along the central axis of the pin body.

[0013] As a further improvement to the technical solution disclosed in this utility model, the elastic modulus of the radial rebound locking body is 1.8 to 2.5 GPa, and the yield strength is ≥35 MPa.

[0014] As a further improvement to the technical solution disclosed in this utility model, multiple linear arrays of friction-increasing grooves are formed on the outer side wall of the radial rebound locking body.

[0015] As a further improvement to the technical solution disclosed in this utility model, the cross-sectional shape of the friction-enhancing groove is preferably V-shaped or U-shaped, and its depth is 0.3-0.5mm and its width is 0.5-1.0mm.

[0016] As a further improvement to the technical solution disclosed in this utility model, the free end of the locking hook is formed with a guide slope. Furthermore, a guide angle of 15–30° is formed between the guide slope and the inner wall of the locking notch.

[0017] As a further improvement to the technical solution disclosed in this utility model, both the safety pin and the upper shell are integral injection molded parts, and their materials are any one of nylon, polypropylene, glass fiber reinforced polypropylene, polyoxymethylene, polyamide 6 and polyphenylene ether.

[0018] In practical applications, the working principle of the anti-misoperation mechanism of the emergency injection pen is as follows:

[0019] In the initial state, the two opposing locking hooks engage with their corresponding locking notches, and the limiting post abuts against the outer body, thus restricting the axial displacement freedom of the outer body and keeping the trigger rod locked.

[0020] During unlocking, the two symmetrically distributed radially rebounding locking bodies must be pinched together simultaneously with the thumb and forefinger, causing them to overcome elastic resistance and retract towards the center until the locking hook disengages from the locking notch, releasing the radial constraint. Subsequently, the safety pin is pulled out axially, the limiting post releases its axial resistance to the outer body, and the outer body regains its axial displacement freedom, allowing the trigger rod to be pushed up to complete the injection.

[0021] By adopting the above technical solution, on the one hand, the two radial spring-loaded locking bodies are arranged opposite each other, and the locking hooks must disengage from their corresponding locking notches simultaneously to unlock. When a foreign object squeezes a single radial spring-loaded locking body in one direction, the other radial spring-loaded locking body cannot be triggered to unlock because it is not under force. When actually performing the unlocking operation, opposing squeezing forces must be applied simultaneously, which can effectively prevent the occurrence of accidental triggering due to single-sided accidental contact, collision, or other single-dimensional external force design. On the other hand, the locking hook and locking notch adopt a deep engagement design (embedding depth ≥ 1.5mm). When asymmetrical external forces are applied, the two radial spring-loaded locking bodies cannot retract synchronously, and the accidental contact path is effectively blocked. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional schematic diagram of the emergency injection pen disclosed in this utility model.

[0024] Figure 2 yes Figure 1 Side view.

[0025] Figure 3 yes Figure 2 AA sectional view.

[0026] Figure 4 yes Figure 1 Top view.

[0027] Figure 5 yes Figure 4 BB cross-sectional view.

[0028] Figure 6 This is a schematic diagram of the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model (i.e. Figure 3 (Enlarged view of part of I).

[0029] Figure 7 This is also a schematic diagram of the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model (i.e.) Figure 5 (Partial enlarged view of section II).

[0030] Figure 8 This is a three-dimensional schematic diagram of the safety pin in the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model.

[0031] Figure 9 This is a three-dimensional schematic diagram of the safety pin in the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model from another perspective.

[0032] Figure 10 This is a three-dimensional schematic diagram of the upper outer shell of the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model.

[0033] 1-Safety pin; 11-Pin body; 12-Radial spring-loaded locking body; 121-Locking hook; 1211-Guide slope; 122-Friction-increasing groove; 13-Limiting post; 2-Upper outer shell; 21-Locking notch; 22-Limiting hole; 3-Outer body. Detailed Implementation

[0034] In the description of this utility model, it should be understood that the terms "left", "right", "front", "rear", "upper", "lower", etc., indicate the position or positional relationship based on the position or positional relationship shown in the drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, or be constructed and operated in a specific position, and therefore should not be construed as a limitation of this utility model.

[0035] An emergency injection pen is a portable automated injection device designed for emergency medical situations, used to quickly and accurately administer emergency medications (such as adrenaline and insulin) to patients. Its core function is to complete puncture and medication delivery in a short time. Anti-misoperation mechanisms are crucial in the design of emergency injection pens, their value lying in preventing fatal misoperations and ensuring patient safety.

[0036] The following detailed description, with reference to specific embodiments, further illustrates the anti-misoperation mechanism of the emergency injection pen disclosed in this utility model. Figures 1-7 As shown, it mainly consists of a safety pin 1, an upper outer shell 2, and an outer body 3. The outer body 3 is fitted inside the upper outer shell 2, and the safety pin 1 and the upper outer shell 2 work together to restrict the axial displacement freedom of the outer body 3. At different stages of the axial displacement movement of the outer body 3, the locking state of the excitation rod, which serves as the power source for drug injection, varies.

[0037] like Figure 8 , Figure 9As shown, the safety pin 1 is a one-piece injection molded part, mainly composed of a pin body 11, a radial spring-loaded locking body 12, and a limiting post 13. Both the radial spring-loaded locking body 12 and the limiting post 13 extend from the pin body 11, and there are two of each, symmetrically distributed along the central axis of the pin body 11. A locking hook 121 is also formed on the radial spring-loaded locking body 12.

[0038] like Figure 10 As shown, the upper outer shell 2 is also preferably an integral injection molded part, on which a locking notch 21 adapted to the locking hook 121 and a limiting hole 22 for the limiting post 13 to pass through are formed.

[0039] As Figure 6 , Figure 7 As shown, in the initial state, the locking hook 121 is snapped into the locking notch 21, and the limiting post 13 passes through the limiting hole 22 and directly abuts against the outer body 3, thereby restricting the axial displacement freedom of the outer body 3.

[0040] During unlocking, the user must simultaneously pinch the two symmetrically distributed radially rebounding locking bodies 12 with their thumb and forefinger to overcome elastic resistance and retract towards the center until the locking hook 121 disengages from the locking notch 21, releasing the radial constraint. Then, the safety pin 1 is pulled out axially. At this point, the limiting post 13 releases its axial contact with the outer body 3, allowing the outer body 3 to regain its axial displacement freedom, and thus the trigger rod can be pushed to complete the subsequent injection operation.

[0041] By adopting the above technical solution, on the one hand, the two radial spring-loaded locking bodies 12 are arranged opposite each other, and the locking hook 121 must disengage from the corresponding locking notch 21 at the same time to unlock. When a foreign object squeezes a single radial spring-loaded locking body 12 in one direction, the other radial spring-loaded locking body 12 cannot be triggered to unlock because it is not under force. When the unlocking operation is actually performed, opposing squeezing forces must be applied at the same time, which can effectively prevent the occurrence of accidental triggering due to single-sided accidental contact, collision and other single-dimensional external force design. On the other hand, the locking hook 121 and the locking notch 21 adopt a deep engagement design (embedding depth ≥ 1.5mm). When asymmetrical external force is applied, the two radial spring-loaded locking bodies 12 cannot be retracted synchronously, and the accidental contact path is effectively blocked.

[0042] To ensure that the unlocking force remains stable at the design value, preventing children from accidentally unlocking the device and facilitating one-handed operation in emergencies, as a further optimization of the above technical solution, the elastic modulus of the radial rebound locking body 12 is also controlled between 1.8 and 2.5 GPa, and the yield strength is ≥35 MPa.

[0043] like Figure 8 , Figure 9As shown, the outer wall of the radially spring-loaded locking body 12 has multiple linearly arrayed friction-enhancing grooves 122. The cross-sectional shape of the friction-enhancing grooves 122 is preferably U-shaped, with a depth of 0.3–0.5 mm and a width of 0.5–1.0 mm. Thus, on the one hand, thanks to the friction-enhancing grooves 122, it is easier for fingers to apply insertion and extraction force to the radially spring-loaded locking body 12, avoiding slippage during unlocking and ensuring smooth completion of the unlocking operation; on the other hand, the linearly arrayed friction-enhancing grooves 122 are suitable for direct molding using injection molds, eliminating the need for additional post-processing steps and reducing production costs.

[0044] Furthermore, such as Figure 6 , Figure 8 , Figure 9 As shown, the free end of the locking hook 121 is formed with a guide slope 1211. Furthermore, a guide angle of 15–30° is formed between the guide slope 1211 and the inner wall of the locking notch 21. Thus, on the one hand, the guide slope 1211 forms a gradually changing guide structure, allowing the locking hook 121 to slide smoothly along the inner wall of the upper housing 2 when the safety pin 1 is inserted into the upper housing 2, avoiding jamming caused by rigid impact; on the other hand, thanks to the 15–30° guide angle design, the locking stability of the locking hook 121 can be effectively enhanced by the reaction force, and it can be ensured that the locking hook 121 can only disengage from the locking notch 21 when the radially rebounding locking body 12 is deliberately pinched.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A misoperation prevention mechanism for an emergency injection pen, characterized by comprising: include: A safety pin includes a pin body, a radially spring-loaded locking body, and a limiting post; both the radially spring-loaded locking body and the limiting post are extensions of the pin body. The radial spring-loaded locking body is formed with two locking hooks, which are symmetrically distributed along the central axis of the pin body. The upper outer shell has a locking notch adapted to the locking hook and a limiting hole for the limiting post to pass through; The outer body is fitted inside the upper shell and has axial displacement freedom; and the locking state of the excitation rod is different at different stages of the axial displacement movement of the outer body. In the initial state, the locking hook is engaged in the locking notch, the limiting post passes through the limiting hole and directly abuts against the outer body, and the axial displacement freedom of the outer body is restricted; Before the emergency injection pen activation operation is performed, the opposing radial rebound locking bodies are simultaneously subjected to compressive force and retract towards each other until the locking hook is dislodged from the locking notch; After the safety pin is pulled out from the upper housing, the axial displacement degree of freedom of the outer body is restored.

2. The mechanism for preventing the misuse of the injection pen according to claim 1, wherein The number of limiting posts is 2, and they are symmetrically distributed along the central axis of the pin body.

3. The mechanism for preventing the misuse of the injection pen according to claim 2, wherein The elastic modulus of the radial rebound locking body is 1.8 to 2.5 GPa, and the yield strength is ≥35 MPa.

4. The mechanism for preventing the misuse of the injection pen according to claim 2, wherein The outer wall of the radial spring-loaded locking body is formed with multiple linear arrays of friction-increasing grooves.

5. The mechanism for preventing the misuse of the injection pen according to claim 4, wherein The friction-enhancing groove has a V-shaped or U-shaped cross-section, with a depth of 0.3–0.5 mm and a width of 0.5–1.0 mm.

6. The mechanism for preventing the misuse of the injection pen according to claim 1, wherein The free end of the locking hook is formed with a guide slope; and the guide slope forms an inlet angle of 15 to 30° with the inner wall of the locking notch.

7. A mechanism for preventing an accidental operation of a pen-type injection device according to any one of claims 1 to 6, characterized in that Both the safety pin and the upper housing are integral injection molded parts, and their materials are any one of nylon, polypropylene, glass fiber reinforced polypropylene, polyoxymethylene, polyamide 6 and polyphenylene ether.

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