Injection force activation mechanism and emergency injection pen comprising same
By combining a columnar spring and a limiting structure, the problems of unstable activation force and accidental triggering of the emergency injection pen are solved, achieving stability and safety in the injection process and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BAOJUHE (SUZHOU) MEDICAL TECHNOLOGY CO LTD
- Filing Date
- 2025-06-10
- Publication Date
- 2026-06-09
AI Technical Summary
The existing emergency injection pen's injection force activation mechanism has problems such as numerous parts, complex assembly, high production costs, high failure rate, and unstable activation force, which can easily lead to accidental triggering due to unexpected impact.
A columnar spring is used as the excitation power source. Through the synergistic effect of the radial extension limiting structure and the radial rebound blocking structure, a reliable locking mechanism is formed to ensure that the axial displacement freedom of the excitation rod is restricted. The columnar spring stores energy stably in the initial state and releases elastic potential energy instantaneously during excitation to drive the excitation rod to complete the injection operation.
It provides continuous and stable excitation force, ensuring the safety and accuracy of the injection process, reducing the risk of mis-injection, and simplifying the structure to reduce production costs.
Smart Images
Figure CN224331311U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of medical device manufacturing technology, and in particular to an injection force activating mechanism and an emergency injection pen including the same. Background Technology
[0002] In the field of emergency medical care, emergency injection pens have become important emergency medical devices due to their convenience and efficiency. Especially in emergency scenarios where rapid drug administration is required, such as anaphylactic shock or severe acute asthma attacks, their core injection force activation mechanism directly determines the reliability and safety of the injection operation.
[0003] Currently, most injection force activation mechanisms in the industry employ traditional mechanical structures. These structures not only have numerous parts and complex assembly processes, leading to high production costs, but also suffer from extremely high failure rates. Failures primarily manifest as insufficient activation force due to jamming in transmission components and abnormal activation action due to loose parts. Some injection force activation mechanisms rely on manual pressing, meaning the activation force depends entirely on the operator's hand strength and pressing speed, making precise control of the pressing force difficult. While some mechanisms utilize springs for driving, solving the problem of instability in manual activation, they generally lack effective locking mechanisms. For example, with the common single-clamp spring locking design, the spring is frequently accidentally triggered when the emergency injection pen is subjected to unexpected impact. Therefore, it is urgent for technicians to solve these problems. Utility Model Content
[0004] The present invention aims to provide an injection force activation mechanism that can provide a continuous and precise activation force through stable elastic potential energy, and can also ensure reliable locking of the activation rod in the untriggered state.
[0005] This utility model relates to an injection force actuation mechanism, comprising a columnar spring, an actuation rod, a spring storage component, and an inner body arranged sequentially from the inside out.
[0006] The excitation rod is formed with a receiving cavity, and a radially extended limiting structure is formed on it near its top.
[0007] Near its top, the inner main body is formed with a radial rebound blocking structure.
[0008] The columnar spring is housed in a spring housing and subjected to axial pressure, and is vertically inserted into the receiving cavity;
[0009] In the initial state, under the combined action of the radial extension limiting structure and the radial rebound blocking structure, the axial displacement degree of freedom of the excitation rod is restricted, while the column spring remains in a compressed state.
[0010] When the emergency injection pen is activated, and the radial rebound blocking structure and the radial extension limiting structure lose their blocking constraint relationship, the elastic potential energy stored in the columnar spring is released, and the activation rod can push the PFS component to complete the needle insertion and drug injection operation.
[0011] As a further improvement to the technical solution disclosed in this utility model, the spring storage component comprises a main body, a left elastic arm, a right elastic arm, and a central auxiliary positioning post. The left elastic arm, right elastic arm, and central auxiliary positioning post all extend downwards from the main body, and the left and right elastic arms are symmetrically distributed along the central axis of the central auxiliary positioning post. When the injection force actuation mechanism is assembled, the left and right elastic arms are encircled and constrained by the inner main body, and their axial movement is limited. The columnar spring is inserted into the central auxiliary positioning post, and the radial offset of its upper end is controlled within the design range.
[0012] As a further improvement to the technical solution disclosed in this utility model, a left-position limiting extension body is formed at the free end of the left elastic arm. A right-position limiting extension body is formed at the free end of the right elastic arm. At a predetermined distance from their top ends, a left-position stop extension body matching the left-position limiting extension body and a right-position stop extension body matching the right-position limiting extension body are simultaneously formed on the inner body.
[0013] As a further improvement to the technical solution disclosed in this utility model, the inner sidewall of the inner body undergoes a material removal process to form a left limiting groove adapted to the left elastic arm and a right limiting groove adapted to the right elastic arm.
[0014] As a further improvement to the technical solution disclosed in this utility model, the depth of the left limiting groove is 0.5 to 1.2 mm, and the groove width is 0.1 to 0.2 mm greater than the thickness of the left elastic arm.
[0015] As a further improvement to the technical solution disclosed in this utility model, multiple guide ribs are evenly distributed along the circumferential direction of the inner wall of the accommodating cavity. When it performs telescopic movement, a line contact is formed between the columnar spring and the excitation rod.
[0016] As a further improvement to the technical solution disclosed in this utility model, the radially extending limiting structure includes N built-in limiting protrusions. The built-in limiting protrusions extend radially from the circumferential outer wall of the excitation rod. The radially rebound blocking structure includes N radially rebound arms. The radially rebound arms are formed by cutting and removing material from the circumferential outer wall of the inner body, and an external limiting protrusion adapted to the built-in limiting protrusions is formed near its free end. N≥1.
[0017] Furthermore, this utility model also discloses an emergency injection pen, which includes the aforementioned injection force activation mechanism.
[0018] The working principle of the injection force activation mechanism disclosed in this utility model is roughly as follows:
[0019] In the initial state, the columnar spring is axially compressed by the spring housing and vertically inserted into the receiving cavity of the excitation rod, and is in a compressed state; the radial extension limiting structure and the radial rebound blocking structure cooperate with each other to limit the axial displacement of the excitation rod and ensure that the columnar spring can stably store energy.
[0020] When the emergency injection pen is activated, the radial extension limiting structure and the radial rebound blocking structure lose their blocking constraint relationship, and the elastic potential energy stored in the columnar spring is released instantly, pushing the activation rod to move axially, thereby driving the PFS component to complete the needle insertion and drug injection operation, achieving a stable and reliable injection process.
[0021] In practical applications, the injection force activation mechanism disclosed in this utility model can achieve at least the following beneficial technical effects, specifically:
[0022] 1) A columnar spring is used as the excitation power source. The elastic potential energy released after the columnar spring is compressed is used to drive the excitation rod, thereby effectively avoiding the problem of uneven pressure caused by traditional manual operation. It can provide a continuous, stable and precise excitation force to ensure the smooth implementation of subsequent needle insertion and drug injection.
[0023] 2) A reliable locking mechanism is formed through the synergistic effect of the radially extended limiting structure and the radially rebound blocking structure. In the initial state, the two work closely together to restrict the axial displacement freedom of the trigger rod, keeping the column spring stably in a compressed state. Even if the emergency injection pen is subjected to an unexpected impact, it can effectively prevent the column spring from being released prematurely or accidentally triggered, thereby ensuring the safety and stability of the injection force triggering mechanism, reducing the risk of accidental injection, and ensuring patient safety.
[0024] 3) The design structure is simpler, the number of parts is greatly reduced, the assembly process is optimized, and the manufacturing difficulty and production cost of the emergency injection pen are reduced. Attached Figure Description
[0025] 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.
[0026] Figure 1 This is a three-dimensional schematic diagram of the emergency injection pen disclosed in this utility model.
[0027] Figure 2 yes Figure 1 Side view.
[0028] Figure 3 yes Figure 2 AA sectional view.
[0029] Figure 4 This is a schematic diagram of the injection force activation mechanism disclosed in this utility model (i.e.) Figure 3 (Enlarged view of part of I).
[0030] Figure 5 yes Figure 4 A magnified view of part II.
[0031] Figure 6 yes Figure 1 The front view.
[0032] Figure 7 yes Figure 6 BB cross-sectional view.
[0033] Figure 8 This is also a schematic diagram of the injection force activation mechanism disclosed in this utility model (i.e.) Figure 7 (Partial enlarged view of section III).
[0034] Figure 9 This is a three-dimensional schematic diagram of the excitation rod in the injection force excitation mechanism disclosed in this utility model.
[0035] Figure 10 This is a three-dimensional schematic diagram of the spring storage component in the injection force activating mechanism disclosed in this utility model.
[0036] Figure 11 This is a three-dimensional schematic diagram of the inner body of the injection force activating mechanism disclosed in this utility model.
[0037] Figure 12 yes Figure 11 Side view.
[0038] Figure 13 yes Figure 12 CC section view.
[0039] 1-Columnar spring; 2-Actuating rod; 21-Accommodating cavity; 22-Radial extension limiting structure; 221-Built-in limiting protrusion; 3-Spring storage component; 31-Main body; 32-Left elastic arm; 321-Left limiting extension body; 33-Right elastic arm; 331-Right limiting extension body; 34-Center auxiliary positioning post; 4-Inner main body; 41-Radial rebound blocking structure; 411-Radial rebound arm; 4111-External limiting protrusion; 42-Left stop extension body; 43-Right stop extension body; 44-Left limiting groove; 45-Right limiting groove. Detailed Implementation
[0040] 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.
[0041] An emergency injection pen is a portable automatic injection device designed for emergency medical situations, used to quickly and accurately inject emergency medications (such as adrenaline and insulin) into patients. Its core function is to complete puncture and drug delivery in a short time. The injection force activation mechanism, as the power output core of the emergency injection pen, is used to precisely trigger the injection action.
[0042] The injection force activation mechanism disclosed in this utility model will be further described in detail below with reference to specific embodiments, such as... Figures 1-4 As shown in Figures 6-8, it mainly consists of several parts, including a columnar spring 1, an actuating rod 2, a spring housing 3, and an inner body 4, which are sequentially arranged from the inside out. The columnar spring 1 is housed in the spring housing 3 and subjected to axial pressure, and it is vertically inserted into the actuating rod 2. In practical applications, in the initial state, the injection force actuation mechanism stores energy through the axial compression of the columnar spring 1 in the spring housing 3, and the axial displacement of the actuating rod 2 is restricted. After the emergency injection pen is actuated, the displacement restriction applied to the actuating rod 2 is released, the elastic potential energy stored in the columnar spring 1 is released, and the actuating rod 2 can push the PFS assembly to complete the needle insertion and drug injection operation.
[0043] As one of the preferred design options, such as Figure 9 As shown, the excitation rod 2 has a receiving cavity 21 for inserting the columnar spring 1, and near its top end, a radially extending limiting structure 22 is also formed thereon. The radially extending limiting structure 22 consists of two axially symmetrical built-in limiting protrusions 221. The built-in limiting protrusions 221 extend radially from the circumferential outer wall of the excitation rod 2.
[0044] like Figures 11-13 As shown, near its top, the inner body 4 is formed with a radial spring-loaded blocking structure 41. The radial spring-loaded blocking structure 41 consists of two axially symmetrical radial spring-loaded arms 411. The radial spring-loaded arms 411 are formed by cutting and removing material from the circumferential outer wall of the inner body 4, and near its free end, an external limiting protrusion 4111 is formed to match the aforementioned built-in limiting protrusion 221.
[0045] In the initial state, the columnar spring 1 is axially compressed by the spring housing 3 and inserted into the excitation receiving cavity 21. At the same time, the radial rebound arm 411 is not allowed to tilt outward due to the circumferential binding force, and the internal limiting protrusion 221 can interlock with the external limiting protrusion 4111 (e.g., Figure 5 As shown in the diagram, the axial movement freedom of the activation rod 2 is restricted, and the spring 1 remains in a compressed, energy-storing state. When the emergency injection pen is activated, the circumferential restraint force applied to the radial rebound arm 411 is released, and the radial rebound arm 411 expands radially due to the radial component force from the built-in limiting protrusion 221. The built-in limiting protrusion 221 and the external limiting protrusion 4111 are then released from interlock. Subsequently, the spring 1 releases its elastic potential energy to push the activation rod 2 to perform axial displacement movement, thereby driving the PFS assembly to complete the needle insertion into the skin and the injection of medication. After the injection is completed, the radial rebound arm 411 cannot lock the activation rod 2 again, thus preventing the occurrence of repeated injections.
[0046] By adopting the above technical solution, on the one hand, the columnar spring 1 is used as the excitation power source. Its released elastic potential energy after compression is used to push the excitation rod 2, effectively avoiding the uneven pressure caused by traditional manual operation. This provides a continuous, stable, and precise excitation force, ensuring the smooth implementation of subsequent needle insertion and drug injection. On the other hand, the synergistic effect of the radially extended limiting structure 22 and the radially rebound blocking structure 41 forms a reliable locking mechanism. In the initial state, the built-in limiting protrusion 221 and the external limiting protrusion 4111 interlock to restrict the axial displacement freedom of the excitation rod 2, keeping the columnar spring 1 stably in a compressed state. Even if the emergency injection pen is subjected to unexpected impact, it can effectively prevent the columnar spring 1 from prematurely releasing or being accidentally triggered, thus ensuring the safety and stability of the injection force excitation mechanism, reducing the risk of accidental injection, and protecting patient safety.
[0047] It should also be noted that, compared with existing designs, the injection force activation mechanism disclosed in this embodiment has a simpler design structure, a significantly reduced number of parts, and an optimized assembly process, thereby greatly reducing the manufacturing difficulty and production cost of the emergency injection pen.
[0048] As a preferred design, such as Figure 10 As shown, the spring housing 3 consists of a body 31, a left elastic arm 32, a right elastic arm 33, and a central auxiliary positioning post 34. The left elastic arm 32, right elastic arm 33, and central auxiliary positioning post 34 all extend downwards from the body 31, and the three work together to achieve the constraint, positioning, and energy storage design of the columnar spring 1. Furthermore, the left elastic arm 32 and right elastic arm 33 are symmetrically distributed along the central axis of the central auxiliary positioning post 34.
[0049] like Figures 6-8 As shown, when the injection force activation mechanism is assembled, the left elastic arm 32 and the right elastic arm 33 are bound by the inner body 4, and their axial movement is limited to ensure that the columnar spring 1 can be compressed and store energy. The columnar spring 1 is inserted by the central auxiliary positioning post 34. Thus, on the one hand, thanks to the bounding design of the inner body 3, the left elastic arm 32 and the right elastic arm 33 can be subjected to force synchronously, ensuring that the columnar spring 1 is subjected to uniform force during compression, thereby providing a smooth axial thrust when released, ensuring the linearity of the activation rod 2 movement and the injection accuracy; on the other hand, through the cooperation between the cylindrical surface and the inner diameter of the columnar spring 1, the radial offset of the upper end of the columnar spring 1 can be controlled within a reasonable range, avoiding bending or radial swaying of the columnar spring 1 during compression, ensuring that the elastic potential energy is released axially.
[0050] like Figure 10 As shown, the free end of the left elastic arm 32 is formed with a left limiting extension body 321. The free end of the right elastic arm 33 is formed with a right limiting extension body 331. Figures 11-13 As shown, at a set distance from its top, the inner body 4 is simultaneously formed with a left-positioned blocking extension 42 that matches the left-positioned limiting extension 321 and a right-positioned blocking extension 43 that matches the right-positioned limiting extension 331.
[0051] It is known that, based on common design knowledge, various design structures can be adopted to achieve effective assembly of the spring storage component 3 relative to the inner body 4. However, a design structure that is easy to manufacture and implement, and has excellent installation stability is recommended here. Specifically, it is as follows: Figure 7 , Figure 8 , Figure 11 As shown, the inner wall of the inner body 4 undergoes a material removal process to form a left limiting groove 44 that matches the left elastic arm 32 and a right limiting groove 45 that matches the right elastic arm 33, thus forming an embedded constraint structure for the spring housing 3. The left limiting groove 44 and the right limiting groove 45 work together to form a radially encircling constraint on the spring housing 3. When the columnar spring 1 is compressed, the radial expansion forces of the left elastic arm 32 and the right elastic arm 33 are offset, preventing structural deformation caused by the outward expansion of the left elastic arm 32 and the right elastic arm 33.
[0052] As a further optimization of the above technical solution, the left limiting groove 44 and the right limiting groove 45 have the same design dimensions. Taking the left limiting groove 44 as an example, its depth is controlled between 0.5 and 1.2 mm, and the groove width is 0.1 to 0.2 mm larger than the thickness of the left elastic arm 32. In this way, when the columnar spring 1 is compressed, the left elastic arm 32 and the right elastic arm 33 can maintain precise axial positioning through the constraint of the inner body 4, and can also release sufficient elastic potential energy during excitation (such as after the radial rebound arm 411 is released from locking) to drive the excitation rod 2 to move smoothly.
[0053] It is known that the columnar spring 1 is prone to bending or eccentricity during compression / release due to uneven radial force. Furthermore, the frequent contact and friction between the columnar spring 1 and the inner wall of the accommodating cavity 2 not only accelerates surface wear and shortens its service life but also causes excessive frictional resistance, leading to excitation delay and even jamming. Therefore, as a further optimization of the above technical solution, multiple guide ribs (not shown in the figure) can be evenly distributed along the circumference of the inner wall of the accommodating cavity 21. When it performs its extension / retraction movement, a line contact is formed between the columnar spring 1 and the excitation rod 2. Thus, by changing the contact form between the columnar spring 1 and the excitation rod 2 from surface contact to line contact, the bending and eccentricity problem caused by uneven radial force on the columnar spring 1 is effectively solved, reducing frictional loss between them, avoiding wear, excitation delay, and jamming, and improving the motion accuracy and reliability of the injection force excitation mechanism.
[0054] 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. An injection force activation mechanism, characterized in that, It includes a columnar spring, an excitation rod, a spring storage component, and an inner body, which are sequentially arranged from the inside out. The excitation rod is formed with a receiving cavity, and a radially extending limiting structure is formed on it near its top. Near its top, the inner body is formed with a radially spring-back blocking structure; The columnar spring is housed in the spring receiving member and subjected to axial pressure, and is vertically inserted into the receiving cavity; In the initial state, under the combined action of the radially extended limiting structure and the radially rebound blocking structure, the axial displacement degree of freedom of the excitation rod is restricted, while the columnar spring remains in a compressed state. When the emergency injection pen is activated, and after the radial rebound blocking structure and the radial extension limiting structure lose their blocking constraint relationship, the elastic potential energy stored in the columnar spring is released, and the activation rod can push the PFS component to complete the needle insertion and drug injection operation.
2. The injection force activation mechanism according to claim 1, characterized in that, The spring housing consists of a main body, a left elastic arm, a right elastic arm, and a central auxiliary positioning post. The left elastic arm, right elastic arm, and central auxiliary positioning post all extend downwards from the main body, and the left and right elastic arms are symmetrically distributed along the central axis of the central auxiliary positioning post. When the injection force actuation mechanism is assembled, the left and right elastic arms are encircled and constrained by the inner main body, and their axial movement is limited. The columnar spring is inserted into the central auxiliary positioning post, and the radial offset of its upper end is controlled within the design range.
3. The injection force activation mechanism according to claim 2, characterized in that, A left-position limiting extension body is formed at the free end of the left elastic arm; a right-position limiting extension body is formed at the free end of the right elastic arm; at a set distance from its top end, a left-position blocking extension body matching the left-position limiting extension body and a right-position blocking extension body matching the right-position limiting extension body are simultaneously formed on the inner body.
4. The injection force activation mechanism according to claim 2, characterized in that, The inner wall of the inner body undergoes a material removal process to form a left limiting groove adapted to the left elastic arm and a right limiting groove adapted to the right elastic arm.
5. The injection force activation mechanism according to claim 4, characterized in that, The depth of the left limiting groove is 0.5 to 1.2 mm, and the groove width is 0.1 to 0.2 mm greater than the thickness of the left elastic arm.
6. The injection force activation mechanism according to claim 1, characterized in that, Multiple guide ribs are evenly distributed along the circumferential direction of the inner wall of the accommodating cavity; when it performs telescopic movement, the columnar spring and the excitation rod form line contact.
7. The injection force activation mechanism according to any one of claims 1-6, characterized in that, The radially extended limiting structure includes N built-in limiting protrusions; the built-in limiting protrusions are formed by radially extending from the circumferential outer wall of the excitation rod; the radially rebound blocking structure includes N radially rebound arms; the radially rebound arms are formed by cutting and removing material from the circumferential outer wall of the inner body, and an external limiting protrusion adapted to the built-in limiting protrusions is formed near its free end; N≥1.
8. An emergency injection pen, characterized in that, Includes the injection force activation mechanism as described in any one of claims 1-7.