Clutch device for an injection pen and injection pen

Abstract

The application relates to a clutch device for an injection pen and the injection pen. The clutch device comprises a clutch, a moving piece and a screw rod. One of the clutch and the moving piece is rotationally connected with the screw rod, and the other is longitudinally guided with the screw rod and circumferentially locked relative to a shell part of the injection pen. The moving piece and the clutch can rotate relative to each other and drive the clutch to axially move, so that the clutch is switched between an engagement state and a separation state. In the engagement state, the clutch transmits driving torque to the screw rod, and force transmission is realized. In the separation state, the screw rod is allowed to rotate circumferentially. Through the separation design of the rotation connection and the longitudinal guidance, efficient power transmission is realized, the state switching of the clutch is ensured, repeated injection is realized, and the actual use requirements of users are met.

Description

Technical Field

[0001] This application relates primarily to the field of medical device technology, and more particularly to a clutch device for an injection pen and the injection pen itself. Background Technology

[0002] Traditional disposable injection pens cannot replace the cartridge assembly separately after the medication inside the cartridge is exhausted. The entire injection pen with the integrated cartridge needs to be disposed of in a harmless manner, resulting in high consumption of consumables and high usage costs.

[0003] Compared to traditional disposable injection pens, the existing internal rotation injection pen does not have the scale protruding from the shell assembly during dosage adjustment. The length of the pen does not change much during dosage adjustment and injection, resulting in a better grip and user experience. At the same time, the pen contains an energy storage component. When the stored energy is released during injection, it can reduce the continuous pressure of the finger, achieving a certain degree of automatic injection and less effort.

[0004] However, current internal rotation injection pens are all disposable, and their matching clutch devices are designed only for single-quantity injection conditions. Their structure and function have inherent limitations, making it difficult to adapt to reusable multiple-cycle injection conditions. This type of clutch device can only achieve simple transmission and cut-off of injection power. The clutch control accuracy is low, and it does not have the ability to automatically reset or repeat triggering after injection. It cannot achieve multiple-cycle injection, resulting in high costs and waste of resources, and it cannot meet the actual use needs of users who need repeated injections.

[0005] In addition, the clutch mechanism of existing internal rotation injection pens has structural defects in its layout design. The clutch action and the movement of the limiting structure interfere with each other, resulting in dose limiting failure, clutch control jamming, and problems such as injection dose deviation and drug leakage. Summary of the Invention

[0006] One objective of this application is to provide a clutch device and an injection pen for use in an injection pen, which solves the problems of inability to repeat injection and interference between dose limiting and clutch action in the prior art.

[0007] According to one aspect of this application, a clutch device for an injection pen is provided, the injection pen including a housing component and a drive device, both the drive device and the clutch device being disposed within a space enclosed by the housing component, the clutch device including: a clutch, a moving part and a screw; The screw is connected to the drive device in a transmission manner; One of the clutch and the moving part is rotatably connected to the screw, and the other is longitudinally guided to the screw and is circumferentially locked relative to the housing component; The movable component can rotate relative to the clutch and drive the clutch to move axially, so that the clutch switches between an engaged state and a disengaged state with respect to the drive device. In the engaged state, the clutch transmits the driving force of the drive device to the screw, thereby achieving force transmission; In the separated state, the screw moves axially relative to the moving part.

[0008] Optionally, the clutch device includes an elastic element, one end of which is used to abut against the housing fixing member of the injection pen, and the other end abuts against the end face of the moving member; When the drug container is installed on the housing component, the abutting force of the drug container drives the moving component to move the clutch to switch to the engaged state, and the elastic component deforms to store elastic potential energy. When the drug container is removed from the housing component, the elastic element releases elastic potential energy, which pushes the moving element to move the clutch, thereby switching to the disengaged state.

[0009] Optionally, the clutch is provided with an engagement structure for cooperating with the drive device; In the engaged state, the clutch engages with the drive device to receive the driving force released by the drive device; In the disengaged state, the clutch is disengaged from the drive device, and the screw moves axially relative to the moving part.

[0010] Optionally, the clutch device includes a dose limiting tooth, which is connected to the drive device and the screw. When the injection pen is adjusting the dosage, the driving device and the screw rotate relative to each other, causing the dosage limiting tooth to move toward the stop position. When the dosage limiting tooth moves to the stop position, the dosage is limited.

[0011] Optionally, the clutch device includes a conversion element, and the movable element is connected to the screw through the conversion element. The movable element moves axially to create a first engagement state and a second engagement state between the conversion element and the movable element. When in the first mating state, the moving part and the changing part are rotated and fixed so that the screw is circumferentially locked relative to the housing component; When in the second engagement state, the moving member and the switching member rotate relative to each other, so that the screw is allowed to rotate circumferentially.

[0012] Optionally, the outer periphery of the conversion member is provided with a spline, and the inner wall of the moving member is provided with a plug-in structure adapted to the spline; the plug-in structure includes at least one limiting protrusion, and in the first mating state, the limiting protrusion is inserted into the gap between adjacent splines of the conversion member to achieve locking; In the second mating state, the limiting protrusion disengages from the adjacent spline gap, and the screw can rotate relative to the moving member.

[0013] Optionally, the threads on the outer wall of the screw include a first thread and a second thread with opposite helical directions, the dose limiting tooth is engaged with the first thread, and one of the clutch and the moving part is engaged with the second thread; The dose limiting tooth is longitudinally guided to the drive device; in the separated state, the screw rotates circumferentially so that the screw moves away from the injection end relative to the moving member and resets, and the dose limiting tooth moves away from the stop position and resets.

[0014] Optionally, the housing component includes a container fixing member, and the movable member is connected to the container fixing member via a plug-in mating structure so that the movable member is circumferentially locked relative to the housing component and can only move axially.

[0015] Optionally, the plug-in mating structure includes a plurality of positioning grooves located on the container fixing member; The axial end of the moving part is provided with an insertion section that is adapted to the positioning groove. The insertion section is inserted into the corresponding positioning groove to achieve circumferential locking.

[0016] Optionally, the movable member engages with the peripheral arcuate structure of the clutch so that the movable member and the clutch are always engaged in the axial direction and can rotate relative to each other in the circumferential direction.

[0017] Optionally, the conversion component is provided with a longitudinal protrusion, which slidably engages with a longitudinal groove on the outer wall of the screw to transmit circumferential force.

[0018] Optionally, the outer wall of the dose limiting tooth is connected to the driving device through a first transmission thread, the second transmission thread on the outer wall of the screw is connected to the clutch, and the inner wall of the dose limiting tooth is axially slidingly connected to the screw, wherein the helical directions of the first transmission thread and the second transmission thread are opposite. In the separated state, the screw rotates circumferentially to move the screw relative to the clutch away from the injection end and reset the dose limiting teeth away from the stop position.

[0019] Optionally, a separable rotation-limiting structure is formed between the clutch and the container fixing member to limit the rotation of the clutch.

[0020] Optionally, the rotation limiting structure includes mutually cooperating protrusions and grooves, wherein: The protrusion is located at the lower end of the clutch or the upper end of the container fixing component; The groove is provided on the upper end of the corresponding container fixing component or the lower end of the clutch; When installing the drug container, the movable component drives the clutch to move upward so that the protrusion separates from the groove; When removing the drug container, the movable component drives the clutch to move downward so that the groove engages with the protrusion.

[0021] According to another aspect of this application, an injection pen is also provided, which is provided with the clutch device as described above.

[0022] Compared with the prior art, the clutch device for an injection pen provided in this application includes a housing component and a drive device. Both the drive device and the clutch device are disposed within the space enclosed by the housing component. The clutch device includes a clutch, a moving part, and a screw. The screw is drively connected to the drive device. One of the clutch and the moving part is rotatably connected to the screw, while the other is longitudinally guided and locked relative to the housing component. The moving part and the clutch are rotatable relative to each other, driving the clutch to move axially, thereby switching the clutch between an engaged and disengaged state with respect to the drive device. In the engaged state, the clutch transmits the driving force of the drive device to the screw, achieving force transmission. In the disengaged state, the screw moves axially relative to the moving part. Thus, through the design of rotational connection and longitudinal guidance, efficient power transmission is achieved, ensuring the switching between clutch engagement and disengagement, enabling repetitive injection, and meeting the actual needs of users. Attached Figure Description

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This diagram illustrates a clutch device structure according to one aspect of this application; Figure 2 This is a schematic cross-sectional view of the clutch device in one embodiment of the present application; Figure 3 This invention provides a schematic diagram of the clutch structure in one embodiment of the present application. Figure 4This is a cross-sectional schematic diagram of a clutch device with dose-limiting teeth in one embodiment of this application; Figure 5 This illustration shows an exploded view of the components in one embodiment of the present application; Figure 6 This is a schematic cross-sectional view of the clutch device in another embodiment of the present application; Figure 7 This diagram shows a structural schematic of the movable component in one embodiment of the present application; Figure 8 A cross-sectional schematic diagram of a movable component is shown in one embodiment of this application; Figure 9 This diagram shows a structural schematic of the conversion element in one embodiment of the present application; Figure 10 This illustration shows a schematic diagram of a screw double-thread structure in one embodiment of this application; Figure 11 This diagram illustrates the structure of a threaded configuration with a first cross-sectional angle in one embodiment of this application. Figure 12 This diagram illustrates the structure of a threaded configuration with a second cross-sectional angle in one embodiment of this application. Figure 13 This diagram shows a structural schematic of a container fastener according to one embodiment of the present application; Figure 14 A schematic diagram of an injection pen structure provided according to another aspect of this application is shown.

[0024] In the attached figures, the following labels are used: 1-Clutch device; 10-Clutch; 101-Arc-shaped structure; 102-Meshing structure; 20-Moving part; 201-First insertion section; 202-Second insertion section; 203-Plug-in structure; 30-Screw; 301-First thread; 302-Second thread; 40-Housing component; 50-Drive device; 60-Elastic element; 70-Ratchet sleeve; 80-Container fixing part; 801-Rotation limiting structure; 802-Protrusion; 803-Groove; 90-Plug-in mating structure; 901-Arc-shaped groove; 902-Inner ring positioning groove; 100-Conversion part; 110-Longitudinal protrusion; 200-Spline; 300-Dose limiting tooth; 400-Actuating lever; 401-Housing shell; 402-Knob.

[0025] The same or similar reference numerals in the accompanying drawings represent the same or similar parts. Detailed Implementation

[0026] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein, and therefore this application is not limited to the specific embodiments disclosed below.

[0028] In the description of this application, it should be noted that, 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 this invention based on the specific circumstances.

[0029] Furthermore, the terms “up,” “down,” “left,” “right,” “top,” “bottom,” “horizontal,” and “vertical” used in the following description should be understood as the orientations shown in the paragraph and related figures. This relative terminology is for illustrative purposes only and does not imply that the described device must be manufactured or operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0030] It is understood that although terms such as “first,” “second,” “third,” etc., may be used here to describe various pipes, channels, components, areas, layers, and / or parts, these components, areas, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different pipes, channels, components, areas, layers, and / or parts.

[0031] The injection pen includes a housing component and a drive mechanism. Both the drive mechanism and the clutch mechanism are located within the space enclosed by the housing component. In this embodiment, the clutch mechanism can switch between engaged and disengaged states, enabling repetitive injection from the pen. Figure 1 As shown, the clutch device 1 includes: a clutch 10, a moving part 20, and a screw 30; the screw 30 is drively connected to the drive device 50; one of the clutch 10 and the moving part 20 is rotatably connected to the screw 30, and the other is longitudinally guided and engaged with the screw 30, and the other is circumferentially locked relative to the housing component 40; the moving part 20 and the clutch 10 can rotate relative to each other, and drive the clutch 10 to move axially, so that the clutch 10 switches between an engaged state and a disengaged state with respect to the drive device 50; in the engaged state, the clutch 10 transmits the driving force of the drive device 50 to the screw 30, realizing force transmission; in the disengaged state, the screw 30 moves axially relative to the moving part 20.

[0032] The engagement between the clutch 10, the moving part 20, and the screw 30 can be configured in two ways: First, the clutch 10 can be rotatably connected to the screw 30. In this case, the moving part 20 and the screw 30 are longitudinally guided, and the moving part is fixed relative to the housing component 40 and does not rotate. Second, the moving part 20 is rotatably connected to the screw 30. In this case, the clutch 10 and the screw 30 are longitudinally guided, and the clutch 10 is circumferentially locked relative to the housing component 40, i.e., fixed and does not rotate. The longitudinally guided engagement refers to a relationship where the component (clutch or moving part) and the screw can have relative displacement along the axial direction of the screw 30 and synchronous circumferential rotation.

[0033] The clutch 10 has two states: a disengaged state and an engaged state with the drive unit 50 built into the injection pen. The drive unit 50 is a combination of all the components used for driving the pen located above the clutch mechanism, such as a lever, ratchet sleeve, and torsion spring. In either engagement state, the moving part 20 and the clutch 10 can rotate relative to each other, thereby driving the clutch 10 to move axially, realizing the disengaged and engaged states between the clutch 10 and the upper drive unit 50. In the engaged state, it cooperates with the drive unit 50 of the injection pen to transmit driving torque to the screw 30, realizing force transmission. In the disengaged state, the moving part 20 drives the clutch 10 to move downward, at which time the screw 30 is allowed to rotate circumferentially, and the screw 30 can move axially relative to the moving part 20, that is, the screw 30 can retract away from the injection end; thus, efficient power transmission is achieved, and the injection pen can be reused.

[0034] In one embodiment of this application, reference continues to be made to... Figure 1 as well as Figure 2 The clutch device includes an elastic element 60, one end of which abuts against the housing fixing member of the injection pen, and the other end abuts against the end face of the movable member 20. When the drug container is installed on the housing member 40, the abutting force of the drug container drives the movable member 20 to move and switch the clutch 10 to the engaged state, and the elastic element 60 deforms to store elastic potential energy; when the drug container is removed from the housing member 40, the elastic element 60 releases elastic potential energy, pushing the movable member 20 to move and switch the clutch 10 to the disengaged state.

[0035] The clutch 10 and the upper drive device 50 are switched between disengaged and engaged states via an elastic element 60. The elastic element 60 can be a clutch spring, one end of which is fixed to the housing and acts on the drive device 50 of the injection pen, while the other end acts on the end face of the moving part 20. When a drug container (such as a cartridge) is installed on the housing, the moving part 20 is pressed against the container, causing the clutch spring to deform elastically. At this time, the clutch 10 and the upper drive device 50 are engaged. When the drug container is removed, the clutch spring returns to its elastic deformation, releasing elastic potential energy. The moving part 20 is no longer constrained by the container and, after receiving the released elastic potential energy, drives the clutch 10 downwards, switching the drive device 50 and the clutch 10 to the disengaged state.

[0036] In one embodiment of this application, the clutch 10 is provided with an engagement structure 102 for cooperating with the drive device; in the engaged state, the clutch 10 engages with the drive device 50 to receive the driving force released by the drive device 50; in the disengaged state, the clutch 10 disengages from the drive device 50, and the screw 30 moves axially relative to the moving member.

[0037] like Figure 3 As shown, a meshing structure 102 may be provided on the clutch 10. The meshing structure 102 may be, for example, a tooth or a tooth groove that meshes with the tooth, so that it can engage or disengage with the drive device 50, thereby realizing the clutch engagement state. A ratchet sleeve 70 may be provided in the drive device 50 for releasing the driving force, so that the ratchet sleeve 70 engages or disengages from the meshing structure 102 of the clutch 10.

[0038] In a specific embodiment, the clutch engagement state is illustrated using a ratchet sleeve as an example. The ratchet sleeve 70 is a clutch engagement constraint component. After engaging with the clutch 10, it forms a motion restriction structure, thereby constraining the axial movement of the screw 30. Specifically: when installing the drug container, the end of the drug container pushes the moving part 20 upward axially, thereby causing the moving part 20 to drive the clutch 10 to move upward synchronously. The clutch 10 engages with the ratchet sleeve 70, switching to the engaged state and receiving the driving force released by the ratchet sleeve 70. The moving part 20 moves upward to compress the clutch spring, storing energy, thereby allowing the injection pen to enter a dose-adjustable and injectable working state.

[0039] While in the engaged state, the driving force is provided by the drive device 50 at the upper end of the clutch 10. After adjusting the injection dosage, the injection is performed by pressing. During the injection process, the screw 30 only moves downward to complete the dosage output. During this injection process, the moving part 20 has no vertical displacement and is fixed and does not rotate relative to the housing component, while the clutch 10 rotates relative to the housing component.

[0040] After the injection is completed, the drug container is removed. The pushing force of the drug container on the moving part 20 disappears, the clutch spring releases its elastic force, and pushes the moving part 20 downward. The moving part 20 drives the clutch 10 to move downward in sync, completely separating from the ratchet sleeve 70. Switching to the disengaged state, the screw 30 can rotate and move upward to achieve reset. After the reset is completed, the next cassette assembly can be performed.

[0041] In one embodiment of this application, as Figure 4 As shown, the clutch device includes a dose limiting tooth 300, which is connected to the drive device 50 and the screw 30. When the injection pen adjusts the dose, the drive device 50 and the screw 30 rotate relative to each other, causing the dose limiting tooth 300 to move towards the stop position. When the dose limiting tooth 300 moves to the stop position, the dose is limited.

[0042] To enable the injection pen to smoothly perform dosage adjustment, injection, and dosage limiting functions, a dosage limiting tooth 300 can be set in the clutch device, thereby cooperating with the screw 30 and the drive device 50 to achieve dosage adjustment and dosage limiting. When the clutch 10 is engaged, the user rotates the knob of the injection pen to adjust the dosage. Upon receiving external force, the drive device 50 rotates. The screw 30, constrained by the housing components, rotates relative to the drive device 50. The dosage limiting tooth 300 is connected to both the screw 30 and the drive device 50, and thus, under the coordinated transmission of the drive device 50 and the screw 30, moves towards a stop position. This stop position is when the dosage limiting tooth 300 moves to the upper end of the screw 30, i.e., the maximum preset dosage position, which matches the maximum capacity of the drug container. As the dosage is increased, the dosage limit tooth 300 continues to approach the stop position. When it reaches the stop position, the axial movement is blocked, the relative rotation of the drive device 50 and the screw 30 is synchronously restricted, the dosage adjustment action is terminated, the upper limit of dosage is constrained, and the injection dosage set by the injection pen is prevented from exceeding the remaining drug dosage in the drug container.

[0043] like Figure 5The exploded view shows that, through the cooperation between the components, during dose adjustment, the dose limiting tooth 300 moves up and down along the axial direction of the drive device 50. The rotation angle of the dose limiting tooth 300 relative to the screw 30 corresponds to the axial travel of the dose limiting tooth 300. That is, the displacement of the axial travel corresponds to the dose set by the user. The remaining travel between this displacement and the stop position corresponds to the remaining settable dose. For example, if the maximum capacity of the drug container is 10 units and the single injection volume is two units, then after the first injection adjustment, the dose limiting tooth 300 is in the first position, which corresponds to the axial displacement of the cumulative dose of two units. When the second injection adjustment is performed, the dose limiting tooth 300 continues to move from the first position towards the top of the screw 30 to the second position, which corresponds to the axial displacement of the cumulative dose of four units. And so on. When the fifth dose adjustment is performed, the remaining settable dose is exactly 2 units, and the dose limiting tooth 300 moves to the stop position (corresponding to 10 units). When the dose limit tooth 300 moves to the stop position with the dose adjustment action, it is rigidly blocked and cannot continue to move. The threaded drive is locked, which limits the screw 30 from continuing to adjust the dose and forms a mechanical hard limit, thereby avoiding exceeding the range.

[0044] In one embodiment of this application, reference continues to be made to... Figure 1 as well as Figure 6 The clutch device includes a conversion element 100, and the movable element 20 is connected to the screw 30 through the conversion element 100. The movable element 20 moves axially to create a first engagement state and a second engagement state between the conversion element 100 and the movable element 20. In the first engagement state, the movable element 20 and the conversion element 100 are rotatably fixed to lock the screw 30 circumferentially relative to the housing component 40. In the second engagement state, the movable element 20 and the conversion element 100 rotate relative to each other to allow the screw 30 to rotate circumferentially.

[0045] The movable component 20 is connected to the screw 30 via the conversion component 100. Axial movement of the movable component 20 allows for switchable engagement states between the two components, including a first engagement state and a second engagement state. In the first engagement state, the conversion component 100 and the movable component 20 are rotationally locked, thereby circumferentially locking the screw 30 connected to the conversion component 100 relative to the housing component 40. In this state, the screw 30 can only slide axially without deflection, ensuring injection accuracy. In the second engagement state, the conversion component 100 can rotate independently relative to the movable component 20, allowing the screw 30 to also rotate circumferentially. This means the screw 30 can rotate during retraction, achieving synchronous reset of the screw 30 and the dose limiting tooth 300. This eliminates the axial displacement error of traditional clutch devices and improves the accuracy of clutch control.

[0046] In one embodiment of this application, reference is made to Figure 8 The outer periphery of the conversion member 100 is provided with a spline 200, and the inner wall of the moving member 20 is provided with a plug-in structure 203 adapted to the spline 200. The plug-in structure 203 includes at least one limiting protrusion. In the first engagement state, the limiting protrusion is inserted into the adjacent spline gap of the conversion member 100 to achieve locking. In the second engagement state, the limiting protrusion is disengaged from the adjacent spline gap, and the screw 30 can rotate relative to the moving member 20.

[0047] The movable component 20 is fixed relative to the housing component 40 and does not rotate. It is engaged with the spline 200 through the insertion structure 203 provided on the inner wall, which drives the conversion component 100 to lock circumferentially and prevents it from rotating freely with the screw 30. When the drug container is removed, the insertion engagement between the movable component 20 and the conversion component 100 is released, and the movable component 20 no longer constrains the conversion component 100. As a result, the screw 30 connected to the conversion component 100 is no longer constrained by circumferential locking, and the screw 30 can rotate relative to the movable component 20, thereby enabling retraction.

[0048] Specifically, such as Figure 7 and Figure 8 As shown, the inner wall of the movable part 20 is provided with at least one limiting protrusion. When the movable part 20 and the conversion part 100 are in the first engagement state, the limiting protrusion is inserted into the adjacent spline gap of the conversion part 100 to lock it. When switching to the second engagement state, the limiting protrusion is disengaged from the adjacent spline gap, and the movable part 20 and the screw 30 can rotate relative to each other.

[0049] When the drug container is assembled, the clutch 10 is engaged. The moving part 20 is pushed upwards axially by the drug container, causing the limiting protrusion on the inner wall to move upwards synchronously and precisely insert into the adjacent spline gap of the conversion part 100. The moving part 20 and the conversion part 100 are in the first mating state. At this time, because the moving part 20 is inserted into the housing component, it is circumferentially locked relative to the housing component and cannot rotate. Therefore, when the limiting protrusion is engaged in the spline gap, it directly restricts the circumferential rotational freedom of the conversion part 100, making the conversion part 100 completely locked and unable to rotate. After the conversion part is locked, it indirectly restricts the reverse rotation of the screw 30, so that the screw 30 can only move downwards and extend.

[0050] After the drug container is removed, the clutch spring releases energy and pushes the moving part 20 to move axially downward, causing the inner wall limiting protrusion to move downward synchronously, so that it completely disengages from the spline gap of the conversion part and releases the circumferential limiting constraint on the conversion part 100.

[0051] After the limit protrusion exits the locking position, the conversion part 100 is no longer subject to circumferential rigid constraint and can rotate freely. At this time, relative rotation can occur between the moving part 20 and the screw 30, and the screw 30 can move upward to reset, preparing the structure for the next assembly injection, so that the injection pen can realize the function of repeated injection.

[0052] In one embodiment of this application, reference is made to Figure 1 as well as Figure 9 The conversion component 100 is provided with a longitudinal protrusion 110, which is slidably inserted into the longitudinal groove provided on the outer wall of the screw 30 to transmit circumferential force.

[0053] After the longitudinal protrusion 110 and the longitudinal groove are engaged, there is no relative rotational clearance in the circumferential direction, which allows the conversion element 100 and the screw 30 to be circumferentially fixed. This directly transmits the rotational torque of the clutch 10 to the screw 30, thereby completing the power transmission for dose adjustment injection drive. The longitudinal protrusion 110 and the groove are full-length axial longitudinal structures, which allows relative sliding displacement between the screw 30 and the conversion element 100 in the axial direction while maintaining circumferential torsion, without causing axial jamming or stroke limitation.

[0054] During dosage adjustment and injection, the clutch 10 and the drive device 50 are engaged. The moving part 20 moves upward, and the inner wall limiting protrusion is engaged in the spline gap of the conversion part 100. The conversion part 100 is circumferentially locked and fixed. At this time, the conversion part 100 restricts the screw 30 from rotating in the reverse direction through the engagement relationship between the longitudinal protrusion 110 and the groove of the screw 30, ensuring that the screw 30 can only move downward in one direction, thereby achieving stable dosage locking and downward injection.

[0055] The dosage limiting tooth 300 and the outer wall of the screw 30 can be connected in two ways, such as... Figure 10 and 11 As shown, in the first embodiment: the threads on the outer wall of the screw 30 include a first thread 301 and a second thread 302 with opposite helical directions; the dose limiting tooth 300 is engaged with the first thread 301; one of the clutch 10 and the moving member 20 is engaged with the second thread 302; the dose limiting tooth 300 is longitudinally guided to the drive device 50; in the disengaged state, the screw 30 rotates circumferentially to move the screw 30 relative to the moving member 20 away from the injection end and to reset the position, and the dose limiting tooth 300 moves away from the stop position.

[0056] The first thread 301 and the dose limiting tooth 300 form a threaded meshing relationship, thereby realizing the dose setting and stroke limit before injection; the helical direction of the second thread 302 is completely opposite to that of the first thread 301, which solves the problem of the contradiction between the movement direction of the clutch 10 or the moving part 20 and the dose limiting tooth 300, ensuring the effectiveness of dose limiting and improving the accuracy of injection dose.

[0057] During dosage adjustment, the clutch 10 remains engaged, and the clutch 10 is engaged with the drive device 50, placing the injection pen in an adjustable working condition. By rotating the knob on the injection pen, the screw 30 rotates relative to the drive device 50, and the dosage limiting teeth 300, which are threadedly connected to the screw 30, slide longitudinally relative to the drive device 50, completing the stroke limit of the set dosage.

[0058] The dose limiting tooth 300 moves to a stop position away from the injection end, corresponding to the size of the preset injection dose. The larger the displacement stroke, the larger the set injection dose, thereby achieving precise stepless dose adjustment. During the dose adjustment stage, the clutch 10 remains locked and stationary, with no relative rotation or axial displacement. The dose matching action is completed only by the screw 30 and the dose limiting tooth 300.

[0059] After dosage adjustment, the clutch 10 remains engaged during the injection process. During a single injection, after the injection drive is triggered, the clutch 10 rotates in the opposite direction relative to the screw 30. Due to the reverse helical transmission of the second thread 302 of the screw 30, the clutch 10 drives the screw 30 downwards as it rotates in the opposite direction. When there is still medication remaining in the cartridge, the knob is rotated to readjust the dosage for the next injection. During readjustment, the dosage limiting tooth 300 accumulates its travel and reaches a new position. After dosage adjustment, the injection process continues until the medication in the cartridge is exhausted. At this point, the dosage limiting tooth 300 moves to its stop position. It should be noted that in this embodiment, the stop position is at the end of the screw furthest from the injection end.

[0060] After the medication in the cartridge is depleted, the screw 30 extends into the medication container. The medication container is then removed, and the clutch 10 switches from engaged to disengaged, decoupling from the drive unit 50. The injection pen enters the mechanism reset state. The dose-limiting tooth 300 and the screw 30 begin to reset under manual pushing by the operator. The screw 30 rotates synchronously back under the constraint of the second thread. Because the two threads rotate in opposite directions, the screw 30 moves away from the injection end relative to the moving part 20. Simultaneously, the dose-limiting tooth 300 slides away from the stop position, i.e., moves towards the injection end, thus completing the reset. After reset, all moving parts return to their initial state, allowing for reassembly of the medication container, readjustment of the dosage, and injection, meeting the requirements for reusable injection pens.

[0061] In one embodiment of this application, the dose limiting scheme can also use a second scheme: the outer wall of the dose limiting tooth 300 is connected to the driving device 50 through a first transmission thread, the inner wall of the dose limiting tooth 300 is provided with a longitudinally extending guide engagement structure for engaging with the engagement structure corresponding to the screw 30, and the second transmission thread provided on the outer wall of the screw 30 is connected to the clutch 10, wherein the helical directions of the first transmission thread and the second transmission thread are opposite; in the disengaged state, the screw 30 rotates circumferentially, so that the screw 30 moves and resets relative to the clutch 10 in a direction away from the injection end, and the dose limiting tooth moves and resets in a direction away from the stop position.

[0062] like Figure 12 As shown, when the outer wall of the dose limiting tooth 300 is connected to the drive device 50, it can specifically be connected to the actuating rod 400 inside the drive device 50. The inner wall of the actuating rod 400 is connected to the outer wall of the dose limiting tooth through the first transmission thread. At the same time, only a single second transmission thread is provided on the outer wall of the screw 30, and no bidirectional thread is provided. The inner wall of the dose limiting tooth 300 covers the outer wall of the screw. The longitudinal guide fit structure on the inner wall is matched with the corresponding fit structure (such as the guide surface) of the screw 30, thereby realizing the longitudinal guide fit between the two. The second transmission thread is threaded with the clutch 10. The two transmission threads are connected to achieve circumferential transmission, while the dose limiting tooth can slide axially relative to the screw. The two transmission threads have opposite helical directions. Therefore, in the disengaged state, through the thread engagement of the second transmission thread, the screw 30 moves and resets relative to the clutch 10 and the dose limiting tooth 300 away from the injection end. At the same time, the drive device 50 drives the dose limiting tooth 300 to slide longitudinally along the engagement structure of the screw 30 through the first transmission thread, and moves and resets independently away from the stop position. This solves the problem of interference between the movement direction of the clutch 10 and the dose limiting tooth 300 in the disengaged state.

[0063] During dosage adjustment, the clutch 10 is engaged and locked, and the injection pen enters the dosage setting mode. By rotating the adjustment knob on the injection pen, the actuating lever 400 drives the dosage limiting tooth 300 to slide. Specifically, when adjusting the dosage, the actuating lever 400 rotates forward, so that the dosage limiting tooth 300 rises along the first transmission thread to reach the dosage setting position. By changing the dosage setting position to match different injection strokes, the precise setting of the injection dosage is achieved.

[0064] After the dosage is adjusted, the injection process begins. During the injection process, the injection pen relies on the locking structure to lock the posture of the mechanism. The dosage limiting tooth 300 serves as the positioning reference to limit and fix the effective injection stroke of the screw 30, and works with the drive device 50 and the clutch device to complete the injection operation.

[0065] It should be noted that the relative position of the dose limiting tooth 300 on the screw 30 changes. Each time an injection is given, the dose limiting tooth 300 moves a certain distance towards the distal end of the screw (i.e. towards the stop position). When the drug solution in the drug container is completely injected, the dose limiting tooth 300 moves to the stop position of the screw. At this time, the dose limiting can be achieved, that is, the injection pen cannot be set to exceed the dose of the remaining drug in the drug container.

[0066] Normally, after the medication in the drug container is consumed, the drug container is removed, and the clutch 10 switches from the engaged state to the disengaged state. Under the action of the clutch spring return force and the linkage reset mechanism of the injection pen, the user manually pushes the screw 30 back away from the injection end. The dose limit tooth 300 rotates back relative to the lever 400 through the thread engagement. That is, the dose limit tooth 300 follows the overall reset action of the mechanism. The screw 30 moves and resets relative to the clutch 10 away from the injection end, and the dose limit tooth 300 moves and resets away from the stop position, thereby realizing the retraction of the screw 30 and the reset of the dose limit tooth.

[0067] For example, during the retraction process, assuming that the screw 30 rotates clockwise with its own central axis as a reference to achieve retraction, that is, the screw 30 moves upward relative to the clutch 10; since the screw 30 and the dose limiting tooth 300 rotate in the same direction and rotate synchronously, and the second transmission thread that engages with the clutch 10 is opposite in direction to the first transmission thread on the inner wall of the lever 400, the clockwise rotation of the screw 30 and the dose limiting tooth 300 will move downward relative to the lever 400, thereby ultimately achieving the retraction and reset of the screw 30.

[0068] After reset, the dose limiting tooth 300 and the screw 30 return to their initial sliding fit, and the entire injection pen mechanism returns to standby mode. The drug container can be reassembled, the dose readjusted, and a second injection can be performed to meet the requirements of reusable injection pens.

[0069] In one embodiment of this application, as Figure 13 As shown, the housing component 40 includes a container fixing member 80, and the movable member 20 is connected to the container fixing member 80 through a plug-in mating structure 90, so that the movable member 20 is circumferentially locked relative to the housing component 40 and can only move axially.

[0070] The container holder 80 is detachably connected to the drug container used to store the liquid medicine. The container holder 80 can use a cartridge bottle holder. The engagement and disengagement of the drug container on the container holder 80 drives the clutch 10 to switch between engagement and disengagement states. The moving part 20 and the container holder 80 form a nested assembly relationship, thereby locking the circumferential degree of freedom of the moving part 20 relative to the housing part 40 and preventing rotational movement. When the moving part 20 is circumferentially fixed, it only retains the degree of freedom of vertical linear movement, thus ensuring precise engagement between the clutch 10 and the drive device 50 (specifically, a ratchet sleeve), accurately completing the transmission work of clutch engagement and disengagement state switching, and improving the stability of the repetitive movement of the screw 30.

[0071] Following the above embodiment, the plug-in mating structure 90 includes a plurality of positioning grooves located on the container fixing member 80; the axial end of the moving member is correspondingly provided with an insertion section adapted to the positioning groove, and the insertion section is inserted into the corresponding positioning groove to achieve circumferential locking.

[0072] Specifically, such as Figure 13 As shown, positioning grooves can be provided on the inner and outer sides of the container fixing member 80, such as multiple arc-shaped grooves 901 on the outer side and multiple inner ring positioning grooves 902 on the inner side; for example, Figure 7 and Figure 8 As shown, the axial end of the movable member 20 is provided with a first insertion section 201 that is adapted to the arc-shaped groove 901 and a second insertion section 202 that is adapted to the inner ring positioning groove 902. The first insertion section 201 and the second insertion section 202 are inserted into the corresponding grooves to achieve circumferential locking.

[0073] The plug-in mating structure uses an inner and outer double-layer combined plug-in structure, which is composed of a one-to-one corresponding and adapted groove structure of the container fixing part 80 and an insertion section structure of the moving part 20. Multiple sets of arc-shaped grooves 901 (e.g., ...) can be provided radially outward at the upper part of the container fixing part 80. Figure 13 The diagram shows three arc-shaped grooves. The grooves have an arc-shaped structure and match multiple first insertion segments 201 located on the outer side of the axial end of the moving part 20, thus providing outer guidance and limiting functions. Multiple sets of inner ring positioning grooves 902 (such as...) can be provided radially inward at the upper part of the container fixing part 80. Figure 13 The three positioning grooves shown are precision positioning groove structures that are adapted to the multiple second insertion segments 202 located on the inner side of the axial end of the moving part 20.

[0074] When assembling the drug container, the first insertion section 201 and the second insertion section 202 at the axial end of the movable part 20 correspond to the arc-shaped groove 901 on the outer side and the inner ring positioning groove 902 on the inner side of the container fixing part 80, respectively. Through the double-layered staggered insertion fit, the circumferential rotational freedom of the movable part 20 is completely restricted, thereby achieving the circumferential locking effect required for the entire injection pen. It should be noted that all grooves and insertion sections are axially continuous structures, providing rigid constraints only on circumferential rotation and not restricting axial displacement. This ensures that the movable part always maintains the ability to slide up and down along the axial direction of the screw 30, thus achieving the requirements of circumferential locking and axial movement only.

[0075] In one embodiment of this application, as Figure 3 As shown, the movable member 20 is engaged with the peripheral arc-shaped structure 101 of the clutch 10 so that the movable member 20 and the clutch 10 are always engaged in the axial direction and can rotate relative to each other in the circumferential direction.

[0076] The movable component 20 is snap-fitted onto the peripheral arc-shaped structure 101 of the clutch 10, specifically snapped onto the peripheral arc-shaped structure 101; thereby achieving synchronous axial displacement and completely synchronous up-and-down movement between the movable component 20 and the clutch 10, ensuring precise transmission of displacement for clutch engagement. The peripheral arc-shaped structure 101 allows for relative rotation between the two components in the circumferential direction, thus avoiding rotational interference between the clutch 10 and the movable component 20 during dosage adjustment and injection.

[0077] In one embodiment of this application, reference continues to be made to... Figure 2 A separable rotation limiting structure 801 is formed between the clutch 10 and the container fixing member 80 to limit the rotation of the clutch 10.

[0078] After removing the drug container, the clutch 10 moves downwards and connects with the container fixing part 80 of the injection pen. The rotation limiting structure 801 restricts the rotation of the clutch 10 when it is in the disengaged state. At this time, the clutch 10 cannot rotate, so when the screw 30 retracts, the conversion part 100 and the screw 30 rotate together and retract. When the screw 30 rotates, the dose limiting tooth 300 returns to its original position. At the same time, the clutch state switching is directly driven by the loading and unloading of the drug container, eliminating the manual unlocking step of the traditional clutch mechanism. The clutch device can be adapted to different drug containers, meeting the user's practical needs for quick and convenient replacement.

[0079] Specifically, the rotation limiting structure 801 includes a protrusion 802 and a groove 803 that cooperate with each other, wherein: the protrusion 802 is provided at the lower end of the clutch 10 or the upper end of the container fixing member 80; the groove 803 is provided at the corresponding upper end of the container fixing member 80 or the lower end of the clutch 10; when installing the drug container, the moving member 20 drives the clutch 10 to move upward so that the protrusion 802 and the groove 803 are separated; when removing the drug container, the moving member 20 drives the clutch 10 to move downward so that the groove 803 and the protrusion 802 are engaged.

[0080] The protrusion 802 can use a locking block, and the groove can use a locking slot. The clutch 10 and the container fixing member 80 are connected by a locking block and a locking slot structure to limit rotation. A locking block or a locking slot is provided at the lower end of the clutch 10, and a locking slot or locking block that mates with it is provided at the upper end of the container fixing member 80. The state switch is triggered by the installation or removal of the drug container. When the drug container is being replaced, when the drug container is removed, the moving part 20 drives the clutch 10 to move downward, so that the clutch 10 and the container fixing member 80 are connected by the locking block and the locking slot. After the drug container is installed, the moving part 20 moves upward under the pushing action of the drug container, so that the lower end face of the clutch 10 is disengaged from the upper end of the container fixing member 80.

[0081] Figure 14 This diagram illustrates a schematic representation of an injection pen structure according to another aspect of this application, with a cross-sectional view shown below. Figure 1 As shown, the injection pen includes a housing component 40, a drive device 50, and a clutch device 1 as described above. The housing component 40 includes a container fixing member 80. The drive device 50 and the clutch device 1 are both disposed inside the housing component 40, and the clutch device 1 is located below the drive device 50. The container fixing member 80 is assembled at the lower end of the housing component 40.

[0082] The injection pen can be a reusable, internally rotating pen-type injection pen. The housing component 40 includes an inner shell (not shown), an outer shell 401, a knob 402, etc. The injection pen is divided into a process of changing the drug container and a process of use. The process of use can be divided into a dosage adjustment process and an injection process. After the new container is installed, the injection dosage is adjusted and set, then the button is pressed to inject. The injection dosage is adjusted and set again and injected. After multiple dosage settings and injections, the drug solution in the drug container is exhausted. When it is exhausted, the drug container can be replaced.

[0083] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0084] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0085] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A clutch device for an injection pen, the injection pen comprising a housing component and a drive device, wherein both the drive device and the clutch device are disposed within a space enclosed by the housing component, characterized in that, The clutch device includes: a clutch, a moving part, and a screw; The screw is connected to the drive device in a transmission manner; The clutch is rotatably connected to the screw, the moving part is longitudinally guided to the screw and the moving part is circumferentially locked relative to the housing component, wherein the longitudinally guided engagement is a relationship in which the clutch and the screw can be relatively displaced along the screw axis and rotate synchronously in the circumferential direction; The movable component can rotate relative to the clutch and drive the clutch to move axially, so that the clutch switches between an engaged state and a disengaged state with respect to the drive device. In the engaged state, the clutch transmits the driving force of the drive device to the screw, thereby achieving force transmission; In the separated state, the screw moves axially relative to the moving part; The clutch device includes a conversion element, and the movable element is connected to the screw through the conversion element. The movable element moves axially to create a first engagement state and a second engagement state between the conversion element and the movable element. During dosage adjustment or injection, in the first engagement state, the moving part and the switching part are rotated and fixed so that the screw is circumferentially locked relative to the housing component; During the screw retraction process, in the second engagement state, the moving part and the changing part rotate relative to each other, so that the screw is allowed to rotate circumferentially.

2. The clutch device according to claim 1, characterized in that, The clutch device includes an elastic element, one end of which is used to abut against the housing fixing member of the injection pen, and the other end abuts against the end face of the moving member. When the drug container is installed on the housing component, the abutting force of the drug container drives the moving component to move the clutch to switch to the engaged state, and the elastic component deforms to store elastic potential energy. When the drug container is removed from the housing component, the elastic element releases elastic potential energy, which pushes the moving element to move the clutch, thereby switching to the disengaged state.

3. The clutch device according to claim 1, characterized in that, The clutch is provided with an engagement structure for cooperating with the drive device; In the engaged state, the clutch engages with the drive device to receive the driving force released by the drive device; In the disengaged state, the clutch is disengaged from the drive device, and the screw moves axially relative to the moving part.

4. The clutch device according to claim 1, characterized in that, The clutch device includes a dose limiting tooth, which is connected to the drive device and the screw. When the injection pen is adjusting the dosage, the driving device and the screw rotate relative to each other, causing the dosage limiting tooth to move toward the stop position. When the dosage limiting tooth moves to the stop position, the dosage is limited.

5. The clutch device according to claim 1, characterized in that, The outer periphery of the conversion component is provided with a spline, and the inner wall of the moving component is provided with a plug-in structure adapted to the spline; the plug-in structure includes at least one limiting protrusion, and in the first mating state, the limiting protrusion is inserted into the gap between adjacent splines of the conversion component to achieve locking; In the second mating state, the limiting protrusion disengages from the adjacent spline gap, and the screw can rotate relative to the moving member.

6. The clutch device according to claim 4, characterized in that, The threads on the outer wall of the screw include a first thread and a second thread with opposite helical directions. The dose limiting tooth is connected to the first thread, and the clutch is connected to the second thread. The dose limiting tooth is longitudinally guided to the drive device; in the separated state, the screw rotates circumferentially so that the screw moves away from the injection end relative to the moving member and resets, and the dose limiting tooth moves away from the stop position and resets.

7. The clutch device according to claim 1, characterized in that, The shell component includes a container fixing member, and the movable member is connected to the container fixing member through a plug-in mating structure so that the movable member is circumferentially locked relative to the shell component and can only move axially.

8. The clutch device according to claim 7, characterized in that, The plug-in mating structure includes multiple positioning grooves located on the container fixing member; The axial end of the moving part is provided with an insertion section that is adapted to the positioning groove. The insertion section is inserted into the corresponding positioning groove to achieve circumferential locking.

9. The clutch device according to claim 1, characterized in that, The movable component engages with the peripheral arc-shaped structure of the clutch, so that the movable component and the clutch are always engaged in the axial direction and can rotate relative to each other in the circumferential direction.

10. The clutch device according to claim 1, characterized in that, The conversion component has a longitudinal protrusion, which slides into and engages with a longitudinal groove on the outer wall of the screw to transmit circumferential force.

11. The clutch device according to claim 4, characterized in that, The outer wall of the dose limiting tooth is connected to the drive device through a first transmission thread, and the second transmission thread on the outer wall of the screw is connected to the clutch. The inner wall of the dose limiting tooth is axially slidingly connected to the screw, wherein the helical directions of the first transmission thread and the second transmission thread are opposite. In the separated state, the screw rotates circumferentially to move the screw relative to the clutch away from the injection end and reset the dose limiting teeth away from the stop position.

12. The clutch device according to claim 7, characterized in that, A separable rotation-limiting structure is formed between the clutch and the container fixing member to restrict the rotation of the clutch.

13. The clutch device according to claim 12, characterized in that, The rotation limiting structure includes mutually cooperating protrusions and grooves, wherein: The protrusion is located at the lower end of the clutch or the upper end of the container fixing component; The groove is provided on the upper end of the corresponding container fixing component or the lower end of the clutch; When installing the drug container, the movable component drives the clutch to move upward so that the protrusion separates from the groove; When removing the drug container, the movable component drives the clutch to move downward so that the groove engages with the protrusion.

14. An injection pen, characterized in that, The device is provided with a clutch as described in any one of claims 1 to 13.

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