Spring stabilizing structure for injection pen and injection pen

Abstract

The present application belongs to the field of hygiene technology, and particularly relates to a syringe, especially a spring stabilizing structure for an injection pen and the injection pen. The spring stabilizing structure for the injection pen comprises: a driving sleeve, an inner ring of which is provided with a positioning platform; a driving connecting rod, which is arranged in the driving sleeve and has one end provided with a limiting platform close to the positioning platform; a clutch rod, one end of which is fixed to the end of the driving sleeve; a reset spring, two ends of which are respectively in abutment with the positioning platform and the limiting platform; and at least two limiting plates, which are arranged at the end of the clutch rod close to the positioning platform. The clutch rod drives the driving sleeve to move axially to compress the reset spring, and the limiting plates move axially along the inner ring of the reset spring to limit the radial displacement of the reset spring. Through the cooperation of the limiting plates and the limiting platform, when the reset spring is compressed and deformed, each limiting plate can limit the reset spring from the inner ring to avoid the radial displacement of the reset spring.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hygiene, and particularly relates to a syringe, in particular to a spring stabilizing structure for an injection pen and the injection pen. BACKGROUND

[0002] As a convenient drug delivery tool, the core function of the injection pen is to achieve accurate dose adjustment and safe injection through internal precise structure. Such devices are widely used in the field of diabetes treatment, and the reliability of their design is directly related to the safety of medication and patient experience. The internal mechanism of the injection pen usually includes a dose adjustment mechanism, a drive system and a safety protection device, wherein the return spring as a key driving element is responsible for pushing the related components back to the initial position after injection, preparing for the next dose setting.

[0003] Patent No. CN107427643 provides a drug delivery device, which realizes the reset of the brake through the brake provided in the shell and the return spring, that is, the brake is in the initial position and is movable in the proximal direction when being actuated to act on the drug container for expelling a dose of drug, wherein after expelling a dose of drug, the actuator is released and moves distally back to the initial position. However, due to the fact that the return spring simultaneously experiences axial compression and circumferential rotation during the activation process, this combined motion causes relative rotation between the lower end (i.e. the end away from the injection button) of the spring coil and the drive link. Due to the friction between the spring coils, the slight changes in the elastic properties of the material, and the geometric constraints of the surrounding structure, this relative rotation is often not smooth, but occurs in a non-uniform and intermittent manner. This will cause the lower end of the return spring to experience radial displacement and axial superposition during compression deformation, which in turn causes coil compression overlap and energy loss. When the injection is completed, the return spring cannot fully recover its original shape and position due to this interference, so it cannot provide enough force or stroke to push the brake to fully reset.

[0004] Therefore, how to avoid the return spring from not recovering its original shape after compression deformation is a technical problem that needs to be solved in the field.

[0005] It should be noted that the above information disclosed in the background section is only used to understand the background of the present application, and therefore, the above description is not considered as information related to the prior art. SUMMARY

[0006] The present application provides at least a spring stabilizing structure for an injection pen and the injection pen.

[0007] In a first aspect, the present application provides a spring stabilizing structure for an injection pen, comprising: a drive sleeve, a positioning platform is arranged on the inner circle of the drive sleeve;

[0008] A driving link is arranged in the driving sleeve and a limiting table is arranged at one end of the positioning table;

[0009] A clutch link is arranged at one end of the driving sleeve;

[0010] A reset spring is arranged at the other end of the limiting table and the positioning table respectively;

[0011] At least two limiting plates are arranged at the end of the clutch link close to the positioning table;

[0012] The clutch link drives the driving sleeve to move axially to compress the reset spring, and the limiting plates move axially along the inner circle of the reset spring to limit the radial displacement of the reset spring.

[0013] In an optional embodiment, the end of the limiting table is provided with a plurality of positioning grooves matched with the limiting plates, and the limiting plates are adapted to be inserted into the positioning grooves.

[0014] In an optional embodiment, the limiting plates are in the shape of a circular arc, which are arranged inside the reset spring and extend axially along the clutch link.

[0015] In an optional embodiment, an outer protrusion is arranged at the lower end of the limiting plate, and an inclined surface is arranged on the outer wall of the outer protrusion.

[0016] In an optional embodiment, a limiting protrusion is arranged on the limiting table and abuts against the end wall of the reset spring to limit the rotation of the reset spring.

[0017] In an optional embodiment, the clutch link is arranged at one end of the driving sleeve;

[0018] At least two limiting plates are arranged at the end of the clutch link, which are arranged inside the reset spring and extend axially along the clutch link.

[0019] The limiting table is arranged on the outer wall of the driving link, and a limiting protrusion is arranged on the end wall of the limiting table, which is adapted to limit the circumferential rotation of the reset spring.

[0020] The reset spring is arranged on the outer wall of the driving link, and the two ends thereof abut against the outer protrusion and the inner end wall of the driving sleeve respectively.

[0021] The clutch link drives the driving sleeve to move axially to compress the reset spring, and the limiting plates move axially along the inner circle of the reset spring to limit the radial displacement of the reset spring.

[0022] In an optional embodiment, the end of the limiting table is provided with a plurality of positioning grooves matched with the limiting plates, and the limiting plates are adapted to be inserted into the positioning grooves.

[0023] In one optional embodiment, an outer protrusion is provided at the lower end of the limiting plate, and an inclined surface is provided on the outer wall of the outer protrusion.

[0024] Secondly, this disclosure also provides an injection pen, the injection pen comprising:

[0025] The drive sleeve is rotatably disposed inside the pen body;

[0026] The dosage knob is located at one end of the pen body;

[0027] A spring-loaded bracket is installed inside the pen body, and a spring is installed inside it;

[0028] During dosage adjustment, the dosage knob drives the clutch lever to rotate, and the clutch lever drives the drive sleeve to rotate synchronously to compress the coil spring.

[0029] In one optional embodiment, an inner core frame is rotatably disposed inside the coil spring bracket, and the inner end of the coil spring is fixed to the outer wall of the inner core frame.

[0030] The inner core frame has a convex strip axially arranged on its inner wall, and the clutch rod has a sliding groove axially arranged on its outer wall to match the convex strip.

[0031] When the clutch lever rotates, it pushes the inner core frame to rotate synchronously through the protrusion;

[0032] When activated, the clutch lever moves axially relative to the inner core frame, thereby driving the drive sleeve to move axially synchronously.

[0033] In one alternative embodiment, a button is retractably mounted on the end of the dosage knob, and the button is fixed to the end of the clutch lever.

[0034] The beneficial effects of the present invention are that it provides a spring stabilizing structure for an injection pen and an injection pen. Through the cooperation of the limiting plate and the limiting stage, when activated, the limiting plate moves axially along the inner ring of the reset spring. Each limiting plate can limit the reset spring from the inner ring, avoiding radial displacement and axial superposition of the reset spring when it is compressed and deformed.

[0035] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 A perspective view of the spring stabilizing structure for an injection pen provided in an embodiment of this disclosure;

[0039] Figure 2 A perspective view of the unfolded state of the drive sleeve, drive linkage, and return spring provided in an embodiment of this disclosure;

[0040] Figure 3 A perspective view of the clutch lever provided in an embodiment of this disclosure;

[0041] Figure 4 A perspective view of the limiting plate inserted into the positioning groove according to an embodiment of this disclosure;

[0042] Figure 5 A cross-sectional perspective view of the injection pen provided in an embodiment of this disclosure;

[0043] Figure 6 A cross-sectional perspective view of the coil spring bracket provided in an embodiment of this disclosure.

[0044] In the picture:

[0045] 1. Drive sleeve; 10. Positioning table;

[0046] 2. Drive linkage; 21. Limiting platform; 22. Positioning groove; 23. Limiting protrusion;

[0047] 3. Clutch lever; 30. Slide groove;

[0048] 4. Return spring;

[0049] 5. Limiting plate; 50. Outer protrusion; 51. Inclined surface;

[0050] 6. Pen body; 7. Dosage knob; 8. Spring support; 80. Spring; 81. Inner core frame; 82. Raised strip; 9. Button. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0053] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify an entire column of elements when following a column of elements. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0054] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise expressly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0055] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0056] Research has revealed that patent CN107427643 discloses a drug delivery device that uses a brake housed within the housing in conjunction with a return spring to reset the brake. Specifically, the brake is initially positioned and movable proximally when actuated to dispense a dose of drug onto the drug container. After dispensing the drug, the actuator is released and moves distally back to the initial position. However, because the return spring undergoes both axial compression and circumferential rotation during activation, this combined motion causes relative rotation between its lower end (the end furthest from the injection button) and the drive linkage. Due to friction between the spring coils, minute changes in the material's elastic properties, and geometric constraints of the surrounding structure, this relative rotation is often not smooth but occurs in a non-uniform, intermittent manner. This results in radial displacement and axial superposition at the lower end of the return spring during compression deformation, leading to coil compression overlap and energy loss. When injection ends, the return spring, due to this disturbance, cannot fully recover its original shape and position, thus failing to provide sufficient force or stroke to fully reset the brake.

[0057] Therefore, how to avoid radial displacement and axial superposition at the lower end of the return spring during compression deformation is a technical problem that urgently needs to be solved in this field.

[0058] The defects in the above solutions and the reasons for their occurrence are the results of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventors' contributions to this disclosure.

[0059] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0060] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0061] like Figure 1 and Figure 2As shown, at least one embodiment provides a spring stabilizing structure for an injection pen, comprising: a drive sleeve 1, which is a cylindrical structure with a radially inwardly protruding positioning platform 10 formed in the center of its inner ring; a drive linkage 2, coaxially disposed inside the drive sleeve 1, with a limiting platform 21 at one end near the positioning platform 10; the outer diameter of the limiting platform 21 is slightly smaller than the inner diameter of the drive sleeve 1 to ensure that the drive linkage 2 can move smoothly within the drive sleeve 1; a clutch rod 3, one end of which is fixed to the end of the drive sleeve 1; the clutch rod 3 is also fixed to the end of the drive sleeve 1 by a snap-fit, and the two move synchronously; a return spring 4 is sleeved on the outside of the drive linkage 2, with its two ends abutting against the end faces of the positioning platform 10 and the limiting platform 21, respectively; and at least two limiting plates 5, disposed at the end of the clutch rod 3 near the positioning platform 10; at least two limiting plates 5 are evenly disposed circumferentially at the end of the clutch rod 3 near the positioning platform 10. These limiting plates 5 are arc-shaped and extend axially along the clutch lever 3, their outer contours matching the inner ring of the return spring 4. The clutch lever 3 drives the drive sleeve 1 to move axially, compressing the return spring 4, and the limiting plates 5 move axially along the inner ring of the return spring 4 to limit its radial displacement. Through the cooperation of the limiting plates 5 and the limiting platform 21, during activation, the limiting plates 5 move axially along the inner ring of the return spring 4, and each limiting plate 5 can limit the return spring 4 from the inner ring, preventing the radial displacement and axial displacement of the return spring 4 from overlapping when it is compressed and deformed.

[0062] Reference Appendix Figure 4 The limiting platform 21 has several positioning grooves 22 at its end that are adapted to the limiting plate 5, and the limiting plate 5 is adapted to be inserted into the positioning grooves 22. The limiting plate 5 is arc-shaped, located inside the return spring 4, and extends axially along the clutch rod 3. When the clutch rod 3 moves to its limit position, the end of the limiting plate 5 can be precisely inserted into the corresponding positioning groove 22. This design not only provides axial limiting, but also further locks the entire structure radially, preventing end-effector wobbling.

[0063] Reference Appendix Figure 3 The lower end of the limiting plate 5 is provided with an outer protrusion 50, and the outer wall of the outer protrusion 50 is provided with an inclined surface 51. The design of the inclined surface 51 makes it easier for the limiting plate 5 to be inserted into the inner ring of the return spring 4 during initial assembly, and plays a guiding and initial limiting role for the inner ring of the spring.

[0064] like Figure 4 As shown, a limiting protrusion 23 is provided on the limiting platform 21. The limiting protrusion 23 abuts against the end of the reset spring 4 to limit the rotation of the reset spring 4. When the reset spring 4 needs to rotate circumferentially during dosage adjustment, the limiting protrusion 23 abuts against the end of the spring, effectively limiting excessive relative rotation between the reset spring 4 and the limiting platform 21, and avoiding the accumulation of torsion and potential deformation at the end of the spring.

[0065] Reference Appendix Figure 4 When injection is required, the clutch lever 3 is subjected to axial thrust, causing the drive sleeve 1 to move synchronously. The drive sleeve 1 drives the positioning table 10 to compress the return spring 4. During this process, the limiting plate 5 extends into the inner ring of the return spring 4 and moves axially. Because multiple limiting plates 5 support the return spring 4 from the inside, they effectively limit the radial displacement or torsion that may occur during compression, ensuring that the spring can only be compressed smoothly along the axial direction, avoiding misalignment, overlap, and energy loss of the spring coil.

[0066] At least one embodiment provides a spring stabilizing structure for an injection pen, comprising: a clutch rod 3, one end of which is disposed within a drive sleeve 1; at least two limiting plates 5, disposed at the end of the clutch rod 3, located inside a return spring 4, and extending axially along the clutch rod 3; a limiting platform 21, fitted onto the outer wall of the drive connecting rod 2, and having a limiting protrusion 23 on its end wall, the limiting protrusion 23 being adapted to limit the circumferential rotation of the return spring 4; and a return spring 4, fitted onto the outer wall of the drive connecting rod 2, with both ends abutting against the outer protrusion 50 and the inner end wall of the drive sleeve 1, respectively; wherein the clutch rod 3 drives the drive sleeve 1 to move axially to compress the return spring 4, and the limiting plates 5 move axially along the inner ring of the return spring 4 to limit the radial displacement of the return spring 4.

[0067] At least one embodiment provides an injection pen, comprising: a drive sleeve 1 rotatably disposed within a pen body 6; a dosage knob 7 rotatably disposed at one end of the pen body 6; and a spring support 8 disposed within the pen body 6, with a spring 80 internally disposed therein. During dosage adjustment, the dosage knob 7 drives a clutch lever 3 to rotate, which in turn drives the drive sleeve 1 to rotate synchronously, thereby compressing the spring 80. The dosage knob 7 drives the drive sleeve 1 to rotate synchronously via the clutch lever 3. During rotation, the clutch lever 3 can coil the spring 80, thereby storing the mechanical energy during injection. During this adjustment process, the return spring 4 may undergo a slight circumferential rotation due to the movement of the entire transmission chain; its rotation is limited by the limiting protrusion 23 on the limiting platform 21, preventing unnecessary torsion.

[0068] Reference Appendix Figure 6 An inner core frame 81 is rotatably disposed inside the coil spring bracket 8, and the inner end of the coil spring 80 is fixed to the outer wall of the inner core frame 81. A protrusion 82 is axially disposed on the inner wall of the inner core frame 81, and a sliding groove 30 adapted to the protrusion 82 is axially opened on the outer wall of the clutch rod 3. When the clutch rod 3 rotates, it pushes the inner core frame 81 to rotate synchronously through the protrusion 82. When activated, the clutch rod 3 moves axially relative to the inner core frame 81 to drive the drive sleeve 1 to move axially synchronously.

[0069] Reference Appendix Figure 5A button 9 is telescopically mounted on the end of the dosage knob 7, and the button 9 is fixed to the end of the clutch lever 3.

[0070] Reference Appendix Figure 5 and Figure 6 The working principle is as follows:

[0071] Once the dosage is set, the user presses button 9 to initiate the injection. Button 9 is fixed to the end of clutch lever 3. Pressing the button causes clutch lever 3, drive sleeve 1, and other components to move axially, compressing return spring 4 and releasing the energy stored in coil spring 80, thereby propelling the medication out. During this process, as described in the above embodiment, limiting plate 5 penetrates and moves into the inner ring of return spring 4, effectively preventing radial bending or twisting of return spring 4 under high pressure compression, ensuring linear and stable injection thrust, and guaranteeing the accuracy of the dosage. Clutch lever 3 rotates, driving inner core frame 81 to rotate synchronously through the cooperation of protrusion 82 and slide groove 30, thereby tightening coil spring 80. Clutch lever 3 is pressed and moves axially. At this time, protrusion 82 slides along slide groove 30, and clutch lever 3 can move axially without driving inner core frame 81 to rotate, thus achieving motion engagement and disengagement, ensuring that the axial thrust is fully used for injection.

[0072] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0073] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.

[0074] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A spring-stabilizing structure for an injection pen, characterized in that, include: A driving sleeve (1) has a positioning platform (10) on its inner ring. The drive link (2) is located inside the drive sleeve (1), and a limiting platform (21) is provided at one end near the positioning platform (10). The clutch lever (3) has one end fixed to the end of the drive sleeve (1); The return spring (4) has its two ends abutting against the positioning table (10) and the limiting table (21) respectively; At least two limiting plates (5) are provided at the end of the clutch lever (3) near the positioning table (10); The clutch lever (3) is adapted to drive the drive sleeve (1) to move axially to compress the reset spring (4), and the limiting plate (5) moves axially along the inner ring of the reset spring (4) to limit the radial displacement of the reset spring (4). The end of the limiting platform (21) is provided with several positioning grooves (22) that are adapted to the limiting plate (5), and the limiting plate (5) is adapted to be inserted into the positioning grooves (22); The limiting plate (5) is arc-shaped, located inside the reset spring (4), and extends axially along the clutch rod (3).

2. The spring-stabilizing structure for an injection pen as described in claim 1, characterized in that, The lower end of the limiting plate (5) is provided with an outer protrusion (50), and the outer wall of the outer protrusion (50) is provided with an inclined surface (51).

3. The spring-stabilizing structure for an injection pen as described in claim 1, characterized in that, A limiting protrusion (23) is provided on the limiting platform (21). The limiting protrusion (23) abuts against the end wall of the reset spring (4) to limit the rotation of the reset spring (4).

4. A spring-stabilizing structure for an injection pen, characterized in that, include: The clutch lever (3) has one end located inside the drive sleeve (1); At least two limiting plates (5) are provided at the end of the clutch rod (3) and located inside the return spring (4). The limiting plates (5) are arc-shaped and extend along the axial direction of the clutch rod (3). A limiting platform (21) is fitted on the outer wall of the drive connecting rod (2), and a limiting protrusion (23) is provided on its end wall. The limiting protrusion (23) is adapted to limit the circumferential rotation of the reset spring (4). The return spring (4) is sleeved on the outer wall of the drive connecting rod (2), and its two ends abut against the outer protrusion (50) and the inner end wall of the drive sleeve (1), respectively. The clutch lever (3) drives the drive sleeve (1) to move axially to compress the reset spring (4), and the limiting plate (5) moves axially along the inner ring of the reset spring (4) to limit the radial displacement of the reset spring (4).

5. The spring-stabilizing structure for an injection pen as described in claim 4, characterized in that, The end of the limiting platform (21) is provided with several positioning grooves (22) that are adapted to the limiting plate (5), and the limiting plate (5) is adapted to be inserted into the positioning grooves (22).

6. The spring-stabilizing structure for an injection pen as described in claim 5, characterized in that, The lower end of the limiting plate (5) is provided with an outer protrusion (50), and the outer wall of the outer protrusion (50) is provided with an inclined surface (51).

7. An injection pen, characterized in that, The injection pen employs a spring-stabilizing structure as described in any one of claims 1-6, wherein the injection pen comprises: The drive sleeve (1) is rotatably disposed inside the pen body (6); The dosage knob (7) is located at one end of the pen body (6); A spring support (8) is provided inside the pen body (6), and a spring (80) is provided inside it. During dose adjustment, the dose knob (7) is triggered to drive the clutch lever (3) to rotate, and the clutch lever (3) drives the drive sleeve (1) to rotate synchronously to pressurize the coil spring (80).

8. The injection pen as described in claim 7, characterized in that, An inner core frame (81) is rotatably disposed inside the coil spring bracket (8), and the inner end of the coil spring (80) is fixed to the outer wall of the inner core frame (81). The inner core frame (81) has a convex strip (82) axially arranged on its inner wall, and the clutch rod (3) has a sliding groove (30) axially arranged on its outer wall to match the convex strip (82). When the clutch lever (3) rotates, it pushes the inner core frame (81) to rotate synchronously through the protrusion (82); When activated, the clutch lever (3) moves axially relative to the inner core frame (81) to drive the drive sleeve (1) to move axially synchronously.

9. The injection pen as described in claim 8, characterized in that, A button (9) is telescopically mounted on the end of the dosage knob (7), and the button (9) is fixed to the end of the clutch lever (3).

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