A multi-dose injection drive structure and injection device

Abstract

The utility model relates to pen formula injection device technical field especially, a kind of multiple dose injection drive structure and injection device;Including shell, limit ring, clutch, drive rod, injection button and push rod, the limit ring is fixedly connected in the shell interior, the clutch is sleeved in the limit ring, the drive rod is arranged in the shell interior, the drive rod one end is set out of the shell, the end of the drive rod that sets out of the shell is connected with the injection button, the push rod is set through the limit ring and the clutch, the push rod one end is set into the drive rod interior;The drive rod and the clutch exist meshing state and separation state, when the drive rod and the clutch are in meshing state, rotate the injection button to realize the injection operation of the push rod, when the drive rod and the clutch are in separation state, the push rod does not inject;Convenient for user to use, improve the stability of injection.

Description

Technical Field

[0001] This utility model relates to the field of pen-type injection device technology, and in particular to a multi-dose injection driving structure and injection device. Background Technology

[0002] Currently, there are single-use mechanical injection devices on the market, mainly used for administering medications with single-dose (small doses) and regular intervals (e.g., weekly). There are also multiple-use mechanical injection devices, mainly used for administering medications with multiple doses and higher frequency (e.g., daily). Compared to single-use devices, multiple-use mechanical injection devices have lower operating costs, more flexible single-dose adjustment, and can be discarded after a cycle or a certain number of injections. Therefore, multiple-use mechanical injection devices better meet user needs.

[0003] Currently available multi-shot mechanical injection devices allow the injection screw to rotate either clockwise or counterclockwise during drug administration. The direction of rotation is arbitrary and requires manual control to administer the drug. However, this method can be inconvenient for users and affect the stability of the injection.

[0004] Therefore, there is an urgent need to provide a multi-dose injection drive structure and injection device that, compared with existing technologies, is more convenient for users and improves injection stability. Utility Model Content

[0005] This invention addresses the technical problems existing in the prior art by providing a multi-dose injection drive structure and injection device.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A multi-dose injection drive structure includes a housing, a limiting ring, a clutch, a drive rod, an injection button, and a push rod. The limiting ring is fixedly connected inside the housing, and the clutch is sleeved inside the limiting ring. The drive rod is disposed inside the housing, with one end extending out of the housing and connected to the injection button. The push rod passes through the limiting ring and the clutch, with one end extending into the drive rod. The drive rod and the clutch are in an engaged state and a disengaged state. When the drive rod and the clutch are engaged, the drive rod rotates to perform the injection operation of the push rod. When the drive rod and the clutch are disengaged, the push rod does not perform injection.

[0008] Furthermore, the outer wall of the clutch is provided with a plurality of first meshing ribs, and the inner wall of the drive rod is provided with a plurality of second meshing ribs. The second meshing ribs are located close to the clutch. When the second meshing ribs mesh with the first meshing ribs, the drive rod and the clutch are in a meshing state.

[0009] Furthermore, the outer wall of the clutch is provided with multiple ratchet gears, and the inner wall of the limiting ring is provided with multiple second meshing teeth. The ratchet gears mesh with the second meshing teeth, and the ratchet gears move in only one direction relative to the second meshing teeth.

[0010] Furthermore, the ratchet is elastic.

[0011] Furthermore, the extension direction of the plurality of ratchet gears is opposite to the rotation direction of the clutch.

[0012] Furthermore, the sides of the second meshing teeth are inclined, and all the sides of the second meshing teeth are inclined in the same direction.

[0013] Furthermore, the outer wall of the push rod is provided with threaded teeth, and the inner wall of the limiting ring is provided with meshing threads, and the threaded teeth are engaged with the meshing threads.

[0014] Furthermore, the outer wall of the push rod is provided with a guide groove, and the inner wall of the clutch is provided with a push rod engagement rib, which extends into the guide groove.

[0015] Furthermore, the inner wall of the clutch is provided with a first engagement tooth, and the end of the push rod near the injection button is provided with a termination engagement tooth. When the termination engagement tooth contacts the first engagement tooth, the injection stops.

[0016] An injection device includes a self-injection drive assembly and a pen cap, the pen cap being attached to the end of the housing remote from the injection button.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] (1) In the entire injection process, the present invention ensures that the push rod can only move in the direction of injection by limiting the relationship between the ratchet and the second meshing tooth and the threaded tooth and the meshing threaded tooth. The push rod will not move in the opposite direction, which ensures the injection accuracy, makes it more convenient to use, and has higher stability.

[0019] (2) In the injection process, the ratchet gear and the second meshing tooth have an interference fit, a transition fit, or a small clearance fit. When the clutch rotates, the ratchet gear and the second meshing tooth touch each other and make a "clicking" sound, which serves as a reminder to the user and is more convenient for the user. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the overall structure of Embodiment 1 of this utility model.

[0021] Figure 2 This is a schematic diagram of the drive rod in Embodiment 1 of this utility model.

[0022] Figure 3 This is a schematic diagram of the clutch structure in Embodiment 1 of this utility model.

[0023] Figure 4 This is a schematic diagram of the limiting ring in Embodiment 1 of this utility model.

[0024] Figure 5 This is a schematic diagram of the engagement of the limiting ring, push rod, and clutch in Embodiment 1 of this utility model.

[0025] Figure 6 This is a structural schematic diagram of Embodiment 2 of this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Pen cap;

[0028] 2. Outer shell;

[0029] 3. Injection button;

[0030] 4. Push rod; 41. Termination engagement tooth; 42. Threaded tooth; 43. Guide groove;

[0031] 5. Clutch; 51. Ratchet tooth; 52. First meshing tooth; 53. First meshing rib; 54. First connecting cylinder; 55. Second connecting cylinder; 56. Push rod meshing rib;

[0032] 6. Drive rod; 61. First connecting part; 62. Second connecting part; 63. Second meshing rib;

[0033] 7. Limiting ring; 71. Second meshing tooth; 72. Meshing thread; 73. Inner ring; 74. Outer ring;

[0034] 8. Torsion spring;

[0035] 9. Metering setting loop. Detailed Implementation

[0036] The technical solution of this utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of this utility model. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description. They 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 this utility model.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a multi-dose injection drive structure, comprising a housing 2, an injection button 3, a push rod 4, a clutch 5, a drive rod 6, a limiting ring 7, a torsion spring 8, and a metering setting ring 9. The limiting ring 7 is fixedly connected to the inner wall of the housing 2. The drive rod 6 is disposed inside the housing 2, with one end extending out of the housing 2 and connected to the injection button 3. The clutch 5 is disposed within the limiting ring 7. After the drive rod 6 moves into the housing 2, it engages with the clutch 5. Rotating the drive rod 6 will cause the clutch 5 to rotate synchronously. The push rod 4 passes through the limiting ring 7, the clutch 5, and the drive rod 6, and is threadedly engaged with the limiting ring 7. The metering setting ring 9 is fitted on the end of the housing 2 near the injection button 3 and is fitted on the outside of the drive rod 6. One end of the torsion spring 8 is fixedly connected to the end of the drive rod 6 near the clutch 5, and the other end is fixedly connected to the inner wall of the housing.

[0039] like Figure 1 and Figure 2 As shown, the push rod includes a first connecting part 61 and a second connecting part 62. The first connecting part 61 and the second connecting part 62 are integrally connected. The outer diameter of the second connecting part 62 is larger than the outer diameter of the first connecting part 61. The second connecting part 62 is provided with a plurality of second meshing ribs 63. Each second meshing rib 63 extends along the axial direction of the second connecting part 62. The plurality of second meshing ribs 63 are spaced apart along the circumferential direction of the second connecting part 62. Each second meshing rib 63 has guide cut surfaces at both ends.

[0040] like Figure 3As shown, the clutch 5 includes a first connecting cylinder 54 and a second connecting cylinder 55. The first connecting cylinder 54 and the second connecting cylinder 55 are integrally connected. The outer diameter of the first connecting cylinder 54 is larger than the outer diameter of the second connecting cylinder 55. The inner diameter of the first connecting cylinder 54 is the same as the inner diameter of the second connecting cylinder 55. The outer wall of the first connecting cylinder 54 is provided with two ratchet teeth 51. The ratchet teeth are elastic, and the extension direction of the two ratchet teeth is opposite to the rotation direction of the clutch 5.

[0041] The inner wall of the second connecting cylinder 55 is provided with a plurality of first meshing teeth 52, preferably two, and the two first meshing teeth 52 are arranged at intervals along the circumference of the second connecting cylinder 55. The inner wall of the second connecting cylinder 55 is also provided with a plurality of push rod 4 meshing ribs, preferably two, each push rod 4 meshing rib is arranged close to one of the first meshing teeth 52, and the two push rod 4 meshing ribs are arranged at intervals along the circumference of the second connecting cylinder 55.

[0042] The outer wall of the second connecting cylinder 55 is provided with a plurality of first meshing ribs 53, each of which extends along the axial direction of the second connecting cylinder 55 and the plurality of first meshing ribs 53 are spaced apart along the circumference of the second connecting cylinder 55. When the drive rod 6 and the clutch 5 rotate synchronously, the second meshing rib 63 extends into the first meshing rib 53 and the second meshing rib 63 meshes with the first meshing rib 53, thereby causing the drive rod 6 to rotate and drive the clutch 5 to rotate synchronously.

[0043] like Figure 4 As shown, the limiting ring 7 is located on the inner wall of the outer casing 2 at the end away from the injection button 3. The limiting ring 7 includes an outer ring 74 and an inner ring 73. The inner ring 73 is integrally connected to the inside of the outer ring 74 and is coaxially arranged with the outer ring 74. The inner ring 73 extends into the first connecting cylinder 54. The outer ring 74 is fixedly connected to the inner wall of the outer casing 2. The inner wall of the outer ring 74 is provided with a plurality of second meshing teeth 71. The side of each second meshing tooth 71 is inclined, and the inclination direction of the side of each second meshing tooth 71 is the same. Each second meshing tooth 71 extends along the axis of the outer ring 74. The plurality of second meshing teeth 71 are spaced apart circumferentially along the outer ring 74. The second meshing teeth 71 interact with the ratchet. The ratchet teeth 51 are meshed together, and there is an interference fit, a transition fit, or a small clearance fit between the ratchet teeth 51 and the second meshing teeth 71. During the rotation of the clutch 5, due to the meshing fit between the ratchet teeth 51 and the second meshing teeth 71, the clutch 5 can only rotate in one direction. In this embodiment, the clutch 5 can only rotate counterclockwise. At the same time, due to the interference fit between the ratchet and the second meshing teeth 71, during the rotation of the clutch 5, the ratchet will make a "click" sound every time it moves from one second meshing tooth 71 to an adjacent second meshing tooth 71, to indicate to the user that an injection is in progress; the inner ring 73 has meshing threads 72 on its inner wall.

[0044] like Figure 5As shown, the outer wall of the push rod 4 is provided with threaded teeth 42, which are engaged with the meshing threads 72. The end of the push rod 4 near the injection button 3 is integrally connected with multiple terminating meshing teeth 41, preferably two, which are spaced apart along the circumference of the push rod 4. When the push rod 4 moves to the point where the terminating meshing teeth 41 and the first meshing teeth 52 are engaged, the injection stops. The outer wall of the push rod 4 is also provided with multiple guide grooves 43, preferably two, which are spaced apart along the circumference of the push rod 4. The push rod meshing ribs 56 extend into the guide grooves 43. During the rotation of the clutch 5, the push rod 4 rotates synchronously with the clutch 5.

[0045] The working principle of the multi-dose injection drive structure provided in this embodiment is as follows: During the metering setting, the drive rod 6 engages with the metering setting ring 9, rotating the metering setting ring 9 to perform the metering setting. During the metering setting process, the lower end of the torsion spring 8 rotates with the drive rod 6, while the upper end of the torsion spring 8 does not rotate, thus storing force in the torsion spring 8. When injection is required, the injection button 3 is pressed towards the direction of the outer shell 2. The injection button 3 drives the drive rod 6 to move towards the inside of the outer shell 2, disengaging the drive rod 6 from the metering setting ring 9. The second engagement rib 63 inside the drive rod 6 extends into the first engagement rib 53 provided on the outer wall of the clutch 5, realizing the engagement of the drive rod 6 with the clutch 5. At this time, Under the action of the return force of the torsion spring 8, the drive rod 6 rotates, causing the clutch 5 to rotate synchronously as well. Due to the engagement relationship between the ratchet tooth 51 of the clutch 5 and the second meshing tooth 71 of the limiting ring 7, the clutch 5 can only rotate counterclockwise relative to the limiting ring 7, that is, it can only make the push rod 4 move in the direction of injection, and cannot move in the opposite direction. The push rod 4 and the clutch 5 rotate synchronously. At the same time, the engagement relationship between the threaded teeth 42 on the outside of the push rod 4 and the meshing threads 72 provided inside the limiting ring 7 also restricts the direction of movement of the push rod 4. When the terminating surface of the terminating meshing tooth 41 at the end of the push rod 4 is in contact with the side of the first meshing tooth 52 provided inside the clutch 5, the injection stops, and the injection button 3 cannot be rotated at this time.

[0046] The structure provided in this embodiment ensures that, throughout the injection process, the push rod 4 can only move in the direction of injection through the limiting relationship between the ratchet and the second meshing tooth 71, and the limiting relationship between the threaded tooth 42 and the meshing thread 72. The push rod 4 will not move in the opposite direction, which not only ensures injection accuracy but also makes it more convenient to use and has higher stability.

[0047] In this embodiment, during the injection process, the interference fit between the ratchet and the second meshing tooth 71 will produce a "clicking" sound as the clutch 5 rotates, which serves as a reminder to the user and makes the process more convenient for the user.

[0048] Example 2

[0049] like Figure 6 As shown, this embodiment provides an injection device, including the autonomous injection drive assembly and pen cap 1 provided in embodiment 1. The pen cap 1 is connected to the housing 2 in the autonomous injection drive assembly, and the pen cap 1 is disposed at the end of the housing 2 away from the injection button 3.

[0050] Finally, it should be noted that the above content is only used to illustrate the technical solution of this utility model, and is not intended to limit the scope of protection of this utility model. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model do not depart from the essence and scope of the technical solution of this utility model.

Claims

1. A multi-dose injection driving structure, characterized in that, The device includes a housing, a limiting ring, a clutch, a drive rod, an injection button, and a push rod. The limiting ring is fixedly connected inside the housing, and the clutch is sleeved inside the limiting ring. The drive rod is disposed inside the housing, with one end extending out of the housing and connected to the injection button. The push rod passes through the limiting ring and the clutch, with one end extending into the drive rod. The drive rod and the clutch are in an engaged and disengaged state. When the drive rod and the clutch are engaged, the drive rod rotates to perform the injection operation using the push rod. When the drive rod and the clutch are disengaged, the push rod does not perform injection.

2. The multi-dose injection driving structure according to claim 1, characterized in that, The outer wall of the clutch is provided with a plurality of first meshing ribs, and the inner wall of the drive rod is provided with a plurality of second meshing ribs. The second meshing ribs are located close to the clutch. When the second meshing ribs mesh with the first meshing ribs, the drive rod and the clutch are in a meshing state.

3. The multiple-dose injection driving structure according to claim 1, characterized in that, The outer wall of the clutch is provided with multiple ratchet gears, and the inner wall of the limiting ring is provided with multiple second meshing teeth. The ratchet gears mesh with the second meshing teeth, and the ratchet gears move in only one direction relative to the second meshing teeth.

4. The multiple-dose injection driving structure according to claim 3, characterized in that, The ratchet is elastic.

5. The multiple-dose injection driving structure according to claim 3, characterized in that, The extension direction of the plurality of ratchet gears is opposite to the rotation direction of the clutch.

6. The multiple-dose injection driving structure according to claim 4, characterized in that, The sides of the second meshing teeth are inclined, and all the sides of the second meshing teeth are inclined in the same direction.

7. The multiple-dose injection driving structure according to claim 1, characterized in that, The outer wall of the push rod is provided with threaded teeth, and the inner wall of the limiting ring is provided with meshing threads, and the threaded teeth are engaged with the meshing threads.

8. The multiple-dose injection driving structure according to claim 1, characterized in that, The outer wall of the push rod is provided with a guide groove, and the inner wall of the clutch is provided with a push rod engagement rib, which extends into the guide groove.

9. The multiple-dose injection driving structure according to claim 1, characterized in that, The inner wall of the clutch is provided with a first engagement tooth, and the end of the push rod near the injection button is provided with a termination engagement tooth. When the termination engagement tooth contacts the first engagement tooth, the injection stops.

10. An injection device, characterized in that, The invention includes a multi-dose injection drive structure and a pen cap as described in any one of claims 1-9, the pen cap being connected to the end of the housing away from the injection button.

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