A pen-type injection device with drive

Abstract

This utility model relates to the field of pen-type injection device technology, specifically a driven pen-type injection device, including a vial holder, a shell, a dosage setting ring, a trigger mechanism, and a self-driven injection assembly. The vial holder houses a vial; the shell is connected to the vial holder; the dosage setting ring is rotatably connected to the shell; the dosage setting ring is configured to set the dosage by rotating it in the forward direction relative to the shell, and to correct the dosage by rotating it in the reverse direction relative to the shell; the self-driven injection assembly includes a drive assembly and an injection assembly. During dosage setting, the drive assembly stores driving force; during dosage correction, the drive assembly releases driving force; when the trigger mechanism is triggered, the drive assembly drives the injection assembly to move towards the vial to achieve injection. This utility model can perform functions such as dosage setting, dosage correction, self-driven injection of liquid medication triggered by an injection button, and locking after all liquid medication in the device has been injected and emptied.

Description

Technical Field

[0001] This utility model relates to the technical field of pen-type injection devices, specifically a pen-type injection device with a drive. More specifically, this utility model relates to a multi-disposable mechanical injection pen with a built-in torsion spring drive that can autonomously propel the liquid medicine by setting the dosage, adjusting the dosage, triggering the injection button, and injecting all the liquid medicine in the device before discarding it. Background Technology

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

[0003] Currently, there are different types of products on the market. In terms of dosage setting, the dosage setting ring of a typical multi-shot mechanical injection pen rotates and extends out of the pen as the dosage is set, requiring active injection after setting, as it does not have an autonomous injection structure. Other injection pens with an autonomous injection structure can keep the setting ring in place when setting the dosage, but they often do not have a dosage correction function. This means that when the user sets the dosage incorrectly, it cannot be corrected, resulting in inaccurate dosage injection.

[0004] In addition, existing mechanical injection pens can still perform operations such as dose setting, dose correction or injection after injection, resulting in low reliability and safety of the device.

[0005] Therefore, this utility model provides a pen-type injection device with drive. Utility Model Content

[0006] In order to solve at least one of the above-mentioned technical problems existing in the prior art, the present invention provides a pen-type injection device with drive.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] This utility model provides a pen-type injection device with drive, comprising:

[0009] A medicine bottle holder, wherein the medicine bottle holder contains medicine bottles;

[0010] The outer casing is connected to the medicine bottle holder;

[0011] The feature is that: a dose setting ring is rotatably connected to the housing; the dose setting ring is configured to set the dose by rotating the dose setting ring in the forward direction relative to the housing, and to correct the dose by rotating the dose setting ring in the reverse direction relative to the housing;

[0012] A triggering mechanism is disposed at one end of the housing;

[0013] An autonomously driven injection assembly includes a driving component and an injection component. When the dosage is set, the driving component stores driving force; when the dosage is corrected, the driving component releases the driving force.

[0014] When the triggering mechanism is activated, the drive component can drive the injection component to move toward the vial to achieve injection.

[0015] Furthermore, it also includes a post-injection locking and residual monitoring component, which is a termination ring disposed between the drive rod and the push rod;

[0016] The post-injection locking and residual monitoring component is configured such that after all the medication has been injected, the post-injection locking and residual monitoring component can lock the injection component, thereby preventing further injection.

[0017] Furthermore, during the final dose setting, if the set dose is greater than the remaining dose, the post-injection locking and remaining dose monitoring components can lock the injection component, thereby allowing only the remaining dose to be set.

[0018] Furthermore, a dose setting ratchet is provided inside the dose setting ring, a drive arm is provided on the inner wall of the dose setting ring, a drive protrusion is provided on the outer wall of the dose setting ratchet, and the front end of the drive arm abuts against the side wall of the drive protrusion. During the dose setting process, the drive arm pushes the drive protrusion to rotate.

[0019] The dosage setting ratchet has multiple curved arms on its outer wall, and bidirectional ratchet teeth are provided on the curved arms. A bidirectional ratchet meshing groove is provided on the inner wall of one end of the housing, and the bidirectional ratchet meshing groove and the bidirectional ratchet teeth mesh together.

[0020] Furthermore, the dosage setting ratchet has two drive protrusions and two curved arms on its outer wall, with the two drive protrusions and two curved arms arranged alternately.

[0021] Furthermore, a bidirectional ratchet meshing groove is provided on the inner wall of one end of the outer casing, and a plurality of curved arms are provided on the dose setting ring, the curved arms extending in the opposite direction to the dose setting rotation direction;

[0022] The curved arm is provided with bidirectional ratchet teeth, and the bidirectional ratchet meshing groove and the bidirectional ratchet teeth mesh.

[0023] Furthermore, the two sides of the bidirectional ratchet meshing groove are inclined surfaces, wherein the angle between the inclined surface facing the dose setting rotation direction and the tangential direction is smaller than the angle between the inclined surface away from the dose setting rotation direction and the tangential direction.

[0024] Furthermore, the drive assembly includes a drive rod, the drive rod includes a drive rod sleeve and a drive rod cylinder, the drive rod sleeve is sleeved outside the drive rod cylinder and the drive rod sleeve and the drive rod cylinder are connected; a torsion spring is provided between the drive rod sleeve and the drive rod cylinder;

[0025] One end of the drive rod is provided with a torsion spring retaining ring, and the torsion spring retaining ring is fixed inside the outer casing;

[0026] One end of the torsion spring is fixed to the torsion spring fixing ring, and the other end of the torsion spring is fixed to the drive rod. The torsion direction of the torsion spring is set to rotate along the dosage setting direction as the driving force.

[0027] When the triggering mechanism is triggered, the torsion spring drives the drive rod to reverse, thereby driving the injection assembly to move toward the medicine bottle, thus realizing injection.

[0028] Furthermore, the injection assembly includes a limiting ring, a clutch, and a push rod, with the push rod disposed inside the drive rod; the limiting ring is disposed on the inner wall of the connection between the outer shell and the vial holder, and the inner wall of the limiting ring engages with the helical teeth on the outer wall of the push rod; the clutch is disposed on one side of the limiting ring, the inner wall of the clutch is provided with a push rod engagement rib, and the outer wall of the push rod is provided with an engagement rib groove, with the push rod engagement rib embedded in the engagement rib groove;

[0029] The inner wall of the limiting ring is provided with one-way meshing teeth, and the outer wall of the clutch is provided with one-way ratchet teeth, the one-way meshing teeth and the one-way ratchet teeth meshing;

[0030] The outer wall of the clutch is provided with drive rod meshing teeth, and the inner wall of the drive rod near the medicine bottle holder is provided with clutch meshing teeth; when the triggering mechanism is triggered, the drive rod meshing teeth can mesh with the clutch meshing teeth.

[0031] Furthermore, a limiting plate is provided on one side of the clutch, and a limiting plate buckle is provided at one end of the limiting ring. The limiting plate buckle restricts the clutch and the limiting plate within the limiting ring.

[0032] Furthermore, a dose setting ring engagement tooth is provided on the outer wall of one end of the drive rod cylinder, and a drive rod engagement tooth is provided on the inner wall of the dose setting ring, wherein the dose setting ring engagement tooth and the drive rod engagement tooth mesh.

[0033] Furthermore, a dose setting ring meshing tooth is provided on the outer wall of one end of the drive rod cylinder, and a drive rod meshing tooth is provided on the inner wall of the dose setting ratchet, wherein the dose setting ring meshing tooth and the drive rod meshing tooth mesh.

[0034] Furthermore, the triggering mechanism is an injection button, which is located at the top of the drive rod.

[0035] Furthermore, a buckle is provided on the inner side of the injection button, and a retaining strip is provided on the inner wall of the top of the drive rod, with the buckle engaging with the inner side of the retaining strip.

[0036] Furthermore, a terminating ring limiting groove is provided on the inner wall of the drive rod, and an engaging rib is provided on the outer wall of the terminating ring, with the engaging rib embedded in the terminating ring limiting groove; thus, when the drive rod rotates, it can drive the terminating ring to rotate synchronously.

[0037] The outer wall of the push rod is provided with helical teeth, and the inner wall of the termination ring is provided with helical grooves that mesh with the helical teeth; thus, when the dosage is set, the termination ring rotates in the forward direction and moves towards the end of the push rod; when the injection is performed, the termination ring rotates in the reverse direction and moves towards the injection direction.

[0038] The push rod is provided with a termination ring engagement surface at one end near the dose setting ring, and a push rod termination surface at one end of the termination ring. When the push rod pushes the medicine bottle to complete the injection of all the medicine, the push rod termination surface abuts against the termination ring engagement surface.

[0039] During the final dose setting, if the dose setting amount is greater than the remaining dose, the push rod termination surface abuts against the termination ring engagement surface when the dose setting ring rotates within the range of the remaining dose, thus preventing further dose setting.

[0040] Furthermore, a scale is provided between the housing and the drive rod, the inner wall of the housing is provided with a scale engagement thread, and the outer wall of the scale is provided with a housing engagement thread groove; the scale engagement thread is embedded in the housing engagement thread groove.

[0041] The inner wall of the scale is provided with a drive rod engagement rib, and the outer wall of the drive rod is provided with a scale engagement rib groove, and the drive rod engagement rib is embedded in the scale engagement rib groove;

[0042] The outer casing is provided with a customer observation window, and the outer wall of the scale is provided with graduations.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] This utility model provides a pen-type injection device with a drive mechanism. The inner wall of the outer shell is provided with a bidirectional ratchet meshing groove, and the dosage setting ring is provided with a curved arm. The curved arm is provided with bidirectional ratchet teeth. When setting the dosage, the dosage is set by the deformation and meshing of the curved arm. When correcting the dosage, the correction can also be achieved by the deformation and meshing of the curved arm. Therefore, it can correct the dosage setting error, improve the injection accuracy, and improve the user-friendliness of the injection pen.

[0045] This invention incorporates a torsion spring within the drive rod. During the dosage setting process, the torsion spring stores energy to provide driving force for subsequent autonomous injection, thereby achieving a single-quantity self-driven injection.

[0046] This invention, through the meshing linkage of the termination ring and the push rod, and the one-way ratchet teeth of the clutch, can achieve a dosage setting that cannot exceed the actual remaining dosage, meaning the injection pen can judge and indicate the final remaining dosage.

[0047] The engagement and linkage between the termination ring and the push rod in this invention ensures that after the entire dose has been injected, the termination ring locks the push rod, and the dose setting ring is constrained and cannot rotate, thus preventing injection and making the injection pen safer, more reliable and intelligent.

[0048] In addition, during the injection process, the engagement structure between the limiting ring and the clutch can produce a "tap tap tap" prompt sound. During the dosage setting and dosage correction process, the engagement structure between the dosage setting ring and the outer shell can produce a "tap tap tap" prompt sound, making the present invention have an excellent interactive and user-friendly design. Attached Figure Description

[0049] Figure 1 This is an isometric view of the present invention;

[0050] Figure 2 This is an exploded axial view of Embodiment 1 of this utility model;

[0051] Figure 3 This is an isometric view of the injection button described in this utility model;

[0052] Figure 4 This is a front view of the dose setting ring described in Example 1;

[0053] Figure 5 This is a bottom view of the dosage setting ring described in Example 1;

[0054] Figure 6 This is an isometric view of the internal structure of the dose setting ring described in Example 1;

[0055] Figure 7 This is a schematic diagram of the dosage setting ratchet described in Example 1;

[0056] Figure 8 This is an isometric view of the torsion spring retaining ring described in Embodiment 1;

[0057] Figure 9 This is an isometric view of the drive rod described in Example 1;

[0058] Figure 10 This is a diagram showing the internal structure of the drive rod described in Embodiment 1;

[0059] Figure 11 This is an isometric view of the push rod described in this utility model;

[0060] Figure 12 This is an axonometric drawing of the scale described in Example 1;

[0061] Figure 13 This is an isometric view of the clutch described in Example 1;

[0062] Figure 14 This is an isometric view of the limiting ring described in this utility model;

[0063] Figure 15 This is an isometric view of the outer casing described in this utility model;

[0064] Figure 16 This is a schematic diagram of the internal structure of the outer shell described in this utility model;

[0065] Figure 17 This is a top view of the outer casing described in this utility model;

[0066] Figure 18 This is an isometric view of the termination ring described in this utility model;

[0067] Figure 19 This is a schematic diagram of the internal structure of the present invention in its initial state;

[0068] Figure 20 This is a schematic diagram of the internal structure of the present invention after dosage setting;

[0069] Figure 21 This is a schematic diagram of the internal structure of the present invention after the injection button is pressed;

[0070] Figure 22 This is a schematic diagram of the internal structure of the present invention after injection.

[0071] Figure 23 This is an axial exploded view of Embodiment 2 of this utility model;

[0072] Figure 24 This is a front view of the dose setting ring described in Example 2;

[0073] Figure 25This is a top view of the dose setting ring described in Example 2;

[0074] Figure 26 This is a bottom view of the dosage setting ring described in Example 2;

[0075] Figure 27 This is a schematic diagram of the internal structure of the dose setting ring described in Example 2;

[0076] Figure 28 This is an isometric view of the internal structure of the dose setting ring described in Example 2;

[0077] Figure 29 This is an isometric view of the torsion spring retaining ring described in Embodiment 2;

[0078] Figure 30 This is an isometric view of the drive rod described in Embodiment 2;

[0079] Figure 31 This is a diagram showing the internal structure of the drive rod described in Embodiment 2;

[0080] Figure 32 This is an axonometric drawing of the scale described in Example 2;

[0081] Figure 33 This is an isometric view of the clutch described in Example 2;

[0082] Figure 34 This is a schematic diagram of the internal structure in the initial state of Example 2;

[0083] Figure 35 This is a schematic diagram of the internal structure after the dosage was set in Example 2;

[0084] Figure 36 This is a schematic diagram of the internal structure after the injection button is pressed in Example 2;

[0085] Figure 37 This is a schematic diagram of the internal structure after injection in Example 2.

[0086] Figure label:

[0087] 1. Injection button, 101. Clip; 2. Compression spring;

[0088] 3. Dosage setting ring, 301. Bending arm, 302. Bidirectional ratchet teeth, 303. Drive rod meshing teeth, 304. Injection button termination surface, 305. Housing limiting groove;

[0089] 4. Torsion spring retaining ring, 401. Torsion spring limiting groove, 402. Scale termination limiting surface, 403. Housing limiting rib;

[0090] 5. Drive rod, 501. Dosage setting ring meshing teeth, 502. Locking bar, 503. Termination ring limiting groove, 504. Clutch meshing teeth, 505. Scale meshing rib groove, 506. Torsion spring lower limiting groove.

[0091] 6. Push rod, 601. Helical tooth, 602. Meshing groove, 603. Termination ring meshing surface;

[0092] 7. Torsion spring;

[0093] 8. Scale, 801. Outer shell engagement thread groove, 802. Drive rod engagement rib, 803. Termination surface, 804. Scale zero limit surface;

[0094] 9. Limiting plate;

[0095] 10. Clutch; 1001. Push rod engagement rib; 1002. One-way ratchet tooth; 1003. Drive rod engagement tooth;

[0096] 11. Limiting ring; 1101. One-way meshing teeth; 1102. Limiting plate buckle; 1103. Scale termination surface; 1104. Push rod meshing trapezoidal thread.

[0097] 12. Push rod top plate; 13. Medicine bottle holder;

[0098] 14. Outer shell; 1401. Bidirectional ratchet meshing tooth groove; 1402. Scale meshing thread; 1403. Observation window; 1404. Annular rib; 1405. Torsion spring retaining ring snap hole; 1406. Medicine bottle holder retaining groove.

[0099] 15. Medicine bottle; 16. Pen cap;

[0100] 17. Termination ring; 1701. Engaging rib; 1702. Spiral groove; 1703. Push rod termination surface;

[0101] 18. Dosage setting ratchet, 1801. Drive protrusion, 19. Drive arm. Detailed Implementation

[0102] 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.

[0103] It should be noted that, unless otherwise specifically stated, the relative arrangement and numerical expressions of the components and steps described in these embodiments should not be construed as limiting the scope of this utility model.

[0104] The following description of exemplary embodiments is merely illustrative and is not intended to limit the present invention or its application or use in any way. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail herein, but where applicable, such techniques, methods, and apparatus should be considered part of this specification.

[0105] Example 1

[0106] This embodiment provides a driven pen-type injection device, including a trigger mechanism, a compression spring 2, a dose setting ring 3, a dose setting ratchet 18, a torsion spring retaining ring 4, a drive rod 5, a push rod 6, a torsion spring 7, a scale 8, a limiting plate 9, a clutch 10, a limiting ring 11, a push rod top plate 12, a medicine bottle holder 13, a housing 14, a medicine bottle 15, a pen cap 16, and a termination ring 17. In this embodiment, the trigger mechanism is an injection button 1. Figure 1 and Figure 2 As shown, a medicine bottle holder 13 is provided inside the pen cap 16, and the medicine bottle holder 13 contains a medicine bottle 15; the outer shell 14 is connected to the medicine bottle holder 13; the dosage setting ring 3 is disposed on the outer shell 14 and can rotate relative to the outer shell 14.

[0107] The dose setting ring 3 is configured to set the dose by rotating the dose setting ring 3 in the forward direction relative to the housing 14, and to correct the dose by rotating the dose setting ring 3 in the reverse direction relative to the housing 14.

[0108] A dose setting ratchet 18 is provided inside the dose setting ring 3. A drive arm 19 is provided on the inner wall of the dose setting ring 3. A drive protrusion 1801 is provided on the outer wall of the dose setting ratchet 18. The front end of the drive arm 19 abuts against the side wall of the drive protrusion 1801. During the dose setting process, the drive arm 19 pushes the drive protrusion 1801 to rotate.

[0109] The dosage setting ratchet 18 has multiple curved arms 301 on its outer wall, and bidirectional ratchet teeth 302 are provided on the curved arms 301. The inner wall of one end of the housing 14 has a bidirectional ratchet meshing groove 1401, and the bidirectional ratchet meshing groove 1401 and the bidirectional ratchet teeth 302 mesh.

[0110] A drive rod 5 is provided inside the outer casing 14, and the push rod 6 is provided inside the drive rod 5. The drive rod 5 is connected to the dose setting ratchet 18. When the dose setting ring 3 rotates, the drive rod 5 is driven to rotate through the dose setting ratchet 18. An injection button 1 is provided at one end of the outer casing 14. When the injection button 1 is triggered (pressed), the drive rod 5 reverses and drives the push rod 6 to move toward the medicine bottle 15, thereby realizing injection.

[0111] like Figure 3 The diagram shows the structure of the injection button 1. Two latches 101 are provided on the inner side of the injection button 1, with a gap between them to facilitate deformation and engagement. The injection button 1 is engaged with the drive rod 5 via the latches 101. Additionally, a circular protrusion is provided on the outer surface of the injection button 1 to increase friction when pressed, preventing slippage.

[0112] like Figures 4 to 6 The diagram shows the structure of the dose setting ring 3. The dose setting ring 3 has two layers: an inner cylinder and an outer cylinder. The outer cylinder is fitted over the inner cylinder and the two are connected by a connecting plate in the middle. The outer cylinder is connected to the outer shell. The specific connection structure is as follows: a shell limiting groove 305 is provided on the lower inner wall of the outer cylinder, and a corresponding annular rib 1404 is provided on the outer shell 14. The annular rib 1404 is embedded in the shell limiting groove 305 to realize the connection between the outer shell 14 and the dose setting ring 3.

[0113] Within the space between the outer cylinder and the inner cylinder, a drive arm 19 is provided below the connecting plate, with the clockwise direction as the forward direction for dose setting. The front end of the drive arm 19 abuts against the drive protrusion 1801 of the dose setting ratchet 18.

[0114] When the outer casing 14 is connected to the dose setting ring 3, the upper end of the outer casing 14 is inserted into the space between the outer cylinder and the inner cylinder of the dose setting ring 3.

[0115] In addition, the upper end of the inner cylinder of the dosage setting ring 3 is the injection button termination surface 304, which limits the injection button 1 when it is pressed.

[0116] The outer surface of the dose setting ring 3 is also provided with an axial groove to increase the friction when rotating the dose setting ring.

[0117] Figure 7 The dosage setting ratchet 18 is shown in the structural diagram. The inner wall of the dosage setting ratchet 18 is provided with drive rod meshing teeth 303 for driving the drive rod 5 to rotate. The outer wall of the dosage setting ratchet 18 is provided with a curved arm 301. The curved arm 301 has a structure in which one end is fixed and the other end is free, so it is deformable. The curved arm 301 extends in the opposite direction to the dosage setting rotation direction.

[0118] The curved arm 301 is provided with a bidirectional ratchet tooth 302 on its exterior. In this embodiment, two curved arms 301 are provided, and each curved arm 301 is provided with a bidirectional ratchet tooth 302. A bidirectional ratchet meshing groove 1401 is provided on the inner wall of one end of the housing 14, and the bidirectional ratchet meshing groove 1401 and the bidirectional ratchet tooth 302 mesh.

[0119] The outer wall of the dose setting ratchet 18 is also provided with two drive protrusions 1801, and the two drive protrusions 1801 and two curved arms 301 are arranged alternately. In addition, when setting the dose, the front end of the drive arm 19 drives the drive protrusions 1801 to rotate, which in turn drives the dose setting ratchet 18 to rotate. The curved arm 301 of the dose setting ratchet 18 is blocked by the bidirectional ratchet meshing groove 1401. The deformation of the curved arm 301 causes the bidirectional ratchet teeth 302 to mesh with the next bidirectional ratchet meshing groove 1401. During the deformation and meshing process, a "click-click-click" sound is produced, which enhances the user experience.

[0120] like Figure 8 The diagram shows the structure of the torsion spring retaining ring 4. The torsion spring retaining ring 4 is located inside the upper end of the outer shell 14 and is sleeved on the upper end of the drive rod 5. The upper surface of the torsion spring retaining ring 4 is provided with a torsion spring limiting groove 401. Part of the torsion spring limiting groove 401 is a through hole structure, which is used for one end of the torsion spring 7 to be engaged in the torsion spring limiting groove 401. The lower surface of the torsion spring retaining ring 4 is provided with a scale termination limiting surface 402 to limit the scale 8; the outer surface of the torsion spring retaining ring 4 is provided with a housing limiting rib 403, which is a toothed structure that meshes with the bidirectional ratchet meshing groove 1401. By embedding the housing limiting rib 403 into the bidirectional ratchet meshing groove 1401, the torsion spring retaining ring 4 is limited within the housing 14. In addition, the outer wall of the torsion spring retaining ring 4 is also provided with a buckle, which is snapped into the torsion spring retaining ring buckle hole 1405 on the inner wall of the housing 14 to fix the torsion spring retaining ring 4 to the housing 14.

[0121] like Figure 9 and Figure 10 The diagram shows the structure of the drive rod 5. The drive rod 5 includes a drive rod sleeve and a drive rod cylinder. The drive rod sleeve is fitted outside the drive rod cylinder, and the lower end of the drive rod sleeve is fixedly connected to the drive rod cylinder. In this embodiment, the drive rod sleeve and the drive rod cylinder are detachably connected. Specifically, a buckle is provided at the lower end of the drive rod sleeve, and a retaining strip is provided on the outer wall of the drive rod cylinder. The buckle and the retaining strip engage to connect the drive rod sleeve and the drive rod cylinder.

[0122] A torsion spring 7 is provided between the drive rod sleeve and the drive rod cylinder; a lower limit groove (not shown) for the torsion spring is provided at the connection between the drive rod sleeve and the drive rod cylinder, the lower end of the torsion spring 7 is engaged in the lower limit groove of the torsion spring, and the torsion direction of the torsion spring 7 is set to rotate along the dose setting direction as the driving force.

[0123] A dose setting ring engagement tooth 501 is provided on the top outer wall of the drive rod 5, and the dose setting ring engagement tooth 501 engages with the drive rod engagement tooth 303.

[0124] Multiple scale engagement grooves 505 extending axially are provided on the outer wall of the drive rod 5, and drive rod engagement ribs 802 are provided on the inner wall of the scale 8. The drive rod engagement ribs 802 are embedded in the scale engagement grooves 505, so that the scale 8 can rotate synchronously with the drive rod 5 when the drive rod 5 rotates.

[0125] Clutch engagement teeth 504 are provided on the inner wall of the lower end of the drive rod 5, and drive rod engagement teeth 1003 are provided on the outer wall of the clutch 10. When the injection button 1 is pressed, the drive rod 5 moves axially, and the drive rod engagement teeth 1003 can engage with the clutch engagement teeth 504.

[0126] like Figure 10 As shown, a retaining strip 502 is provided on the inner wall of the upper end of the drive rod 5 for engaging with the injection button 1.

[0127] The inner wall of the lower end of the drive rod 5 is also provided with a stop ring limiting groove 503, and the outer wall of the stop ring 17 is provided with a meshing rib 1701. The meshing rib 1701 is embedded in the stop ring limiting groove 503, so that the stop ring 17 can only move along the axial direction of the drive rod 5, and cannot rotate relative to the drive rod 5.

[0128] like Figure 11 The diagram shows the structure of push rod 6. Push rod 6 is located inside drive rod 5. Helical teeth 601 are provided on the outer wall of push rod 6. Helical teeth 601 mesh with stop ring 17 and limit ring 11. Stop ring limit surface 603 is provided at the upper end of push rod 6. By using stop ring limit surface 603, stop ring 17 can lock push rod 6, thereby limiting the movement of push rod 6.

[0129] Two meshing rib grooves 602 are also provided on the outer wall of the push rod 6, and push rod meshing ribs 1001 are provided on the inner wall of the clutch 10, and the push rod meshing ribs 1001 are embedded in the meshing rib grooves 602.

[0130] In addition, the lower end of the push rod 6 has a ball head, which engages with the spherical groove on the push rod top plate 12. Using the ball head, the push rod 6 pushes the push rod top plate 12 to move, and the push rod top plate 12 pushes the rubber stopper inside the medicine bottle 15 to move, thereby realizing injection.

[0131] like Figure 12 The diagram shows the structure of the scale 8. The outer wall of the scale 8 is provided with a shell engagement thread groove 801, and the inner wall of the shell 14 is provided with a scale engagement thread 1402. The scale engagement thread 1402 is embedded in the shell engagement thread groove 801. Thus, the radial rotational motion of the scale 8 can be transformed into a combination of axial movement and radial rotation.

[0132] The scale 8 can be set with graduations on its outer wall, and the scale 8 can display the set dose when the dose is set. The upper end of the scale 8 is provided with a termination surface 803, which contacts the scale termination limiting surface 402 of the torsion spring retaining ring 4, limiting the upper end of the scale 8; the lower end of the scale 8 is provided with a scale zero limiting surface 804, which is used to limit the lower end of the scale 8.

[0133] The inner wall of the scale 8 is provided with a drive rod engagement rib 802 extending axially, which matches the scale engagement rib groove 505 on the outer wall of the drive rod 5.

[0134] like Figure 13 The diagram shows the structure of the clutch 10. The outer wall of the clutch 10 is provided with drive rod meshing teeth 1003 and one-way ratchet teeth 1002. The inner wall of the limiting ring 11 is provided with one-way meshing teeth 1101, and the one-way meshing teeth 1101 and the one-way ratchet teeth 1002 mesh. The inner wall of the lower end of the drive rod 5 is provided with clutch meshing teeth 504, and the drive rod meshing teeth 1003 and the clutch meshing teeth 504 can mesh.

[0135] A push rod engagement rib 1001 is provided on the inner wall of the clutch 10, and the push rod engagement rib 1001 is embedded in the engagement rib groove 602 of the push rod 6.

[0136] like Figure 14 The diagram shows the structure of the limiting ring 11. The clutch 10 is located inside the limiting ring 11 and is covered by the limiting plate 9. The limiting ring 11 is provided with a limiting plate buckle 1102, which engages with the outer surface of the limiting plate 9, thereby fixing the clutch 10 inside the limiting ring 11.

[0137] The limiting ring 11 includes a disc and a cylinder. The inner wall of the disc is provided with push rod engaging trapezoidal threads 1104, which mesh with the helical teeth 601 on the outer wall of the push rod 6. The inner wall of the cylinder is provided with one-way engaging teeth 1101, which mesh with one-way ratchet teeth 1002 on the clutch 10, ensuring that the clutch 10 can only rotate in one direction relative to the limiting ring 11 and cannot rotate in the opposite direction. Furthermore, the one-way engaging teeth 1101 and the one-way ratchet teeth 1002 produce a "click-click-click" sound during relative rotation. This sound continues throughout the injection process, representing a very user-friendly design for injection interaction.

[0138] In this embodiment, the rotation direction of the dose setting ring 3 is clockwise, so the clutch 10 can only rotate counterclockwise and cannot rotate clockwise.

[0139] The upper end face of the limiting ring 11 is also provided with a scale termination surface 1103. When the scale 8 moves axially toward the limiting ring 11, the scale zero limiting surface 804 contacts the scale termination surface 1103, limiting the lower end of the scale 8.

[0140] like Figures 15 to 17 The diagram shows the structure of the outer casing. The inner wall of the upper end of the outer casing 14 is provided with a bidirectional ratchet meshing groove 1401, which meshes with the bidirectional ratchet teeth 302 on the dose setting ring 3. During the dose setting and dose correction process, the bidirectional ratchet teeth 302 and the bidirectional ratchet meshing groove 1401 will also produce a "click-click-click" sound due to the deformation and meshing of the bending arm 301. This sound will continue to occur during the dose setting process, which is a very user-friendly design for dose setting interaction.

[0141] An annular rib 1404 is provided on the upper outer wall of the outer shell 14. A torsion spring retaining ring buckle hole 1405 is provided on the outer wall of the outer shell 14 below the annular rib 1404. An observation window 1403 is provided on the outer shell below the torsion spring retaining ring buckle hole 1405, which allows the scale ruler 8 to be observed, and thus the dose setting size can be observed.

[0142] The inner wall of the outer casing 14 is provided with a scale engagement thread 1402, the inner wall of the lower end of the outer casing 14 is provided with a medicine bottle holder fixing groove 1406, and the outer wall of the medicine bottle holder 13 is provided with a buckle. The buckle is engaged in the medicine bottle holder fixing groove 1406 to realize the connection between the outer casing 14 and the medicine bottle holder 13.

[0143] like Figure 17 The diagram shows a top view of the housing 14. Both sides of the bidirectional ratchet meshing groove 1401 are inclined planes relative to the radial direction of the housing 14. The angle between the inclined plane facing the dose setting rotation direction and the tangent is smaller than the angle between the inclined plane away from the dose setting rotation direction and the tangent.

[0144] like Figure 18 The diagram shows the structure of the termination ring 17. The upper surface of the termination ring 17 is provided with a push rod termination surface 1703. When the termination ring 17 moves relative to the push rod 6 to the upper end of the push rod, the push rod termination surface 1703 abuts against the termination ring meshing surface 603. The outer wall of the termination ring 17 is provided with a meshing rib 1701, and the inner wall of the termination ring 17 is provided with a spiral groove 1702. The termination ring 17 meshes with the helical teeth of the push rod 6 through the engagement of the spiral groove 1702.

[0145] like Figure 19The diagram shows the initial state of the pen-type injection device provided in this embodiment. The lower half is the drug reservoir structure, and the upper half includes a dosage setting and correction component, an autonomous injection component, a post-injection locking and residual volume monitoring component, and a trigger mechanism. A vial holder 13 is provided on the inner wall of the pen cap 16, and the pen cap 16 is snapped into the vial holder 13, allowing the pen cap 16 to be smoothly removed from or reinstalled on the vial holder 13. A vial 15 is provided inside the vial holder 13, and an injection needle can be installed at the lower end of the vial 15. The upper end of the vial 15 is sealed with a rubber stopper, and a push rod top plate 12 is provided on the rubber stopper, which contacts and engages with the push rod 6.

[0146] The upper end of the medicine bottle holder 13 is snapped into the outer shell 14. The upper end of the outer shell 14 is connected to the dosage setting ring 3. A scale 8 is set inside the outer shell 14. A drive rod 5 is set inside the scale 8. A push rod 6 is set inside the drive rod 5. A stop ring 17 is set between the lower end of the drive rod 5 and the push rod 6. A clutch 10 is set below the stop ring 17. A limit ring 11 is set below the clutch 10. The upper end of the limit ring 11 is limited by the outer shell 14, and the lower end is limited by the medicine bottle holder 13.

[0147] A torsion spring 7 is installed in the side wall space of the drive rod 5, and a torsion spring retaining ring 4 is installed on the upper outer side of the drive rod 5. A dose setting ratchet 18 is installed above the torsion spring retaining ring 4, and the dose setting ratchet 18 is engaged with the dose setting ring 3. The outer wall of the drive rod 5 meshes with the dose setting ratchet 18. An injection button 1 is installed on the upper side of the drive rod 5, and a compression spring 2 is installed between the injection button 1 and the dose setting ring 3.

[0148] In the initial state, the zero-position limiting surface 804 of the scale 8 abuts against the end surface 1103 of the scale.

[0149] Figure 20 The figure shows the state after the dose is set in this embodiment. The dose is set by rotating the dose setting ring 3 clockwise. After rotating the dose setting ring 3, the dose setting ring 3 drives the drive rod 5 to rotate through the dose setting ratchet 18 by engaging the drive rod meshing teeth 303 and the dose setting ring meshing teeth 501. The upper end of the torsion spring 7 is locked on the torsion spring fixing ring 4. The torsion spring fixing ring 4 is fixed by the outer shell 14 and cannot rotate. Therefore, the lower end of the torsion spring 7 rotates with the drive rod 5 to complete the storage of the torsion spring 7.

[0150] Simultaneously, the bidirectional ratchet teeth 302 and the bidirectional ratchet meshing groove 1401 mesh, and the dosage is set through the deformation of the bending arm 301 and the cycle of meshing. In addition, since the angles of the inclined surfaces on both sides of the bidirectional ratchet meshing groove 1401 are different, with a smaller angle in the positive direction and a larger angle in the negative direction, combined with the deformation of the bending arm 301, square dosage setting and negative direction dosage correction are achieved.

[0151] At the same time, after rotating the dose setting ring 3, the drive rod 5 rotates, which in turn drives the scale 8 to rotate. Since the scale 8 is engaged with the scale engagement thread 1402 of the outer casing 14, the scale 8 moves axially and rotates radially. After the dose is set, the scale 8 moves a certain displacement in the direction of the torsion spring fixing ring 4. The scale on the scale 8, i.e. the dose setting amount, can be observed through the observation window 1403.

[0152] Furthermore, the engagement rib 1701 of the termination ring 17 is embedded in the clutch engagement tooth 504 of the drive rod 5. When the drive rod 5 rotates, the termination ring 17 rotates accordingly, but the inner wall of the termination ring 17 is still engaged with the push rod 6. Therefore, when the termination ring 17 rotates radially, it also moves axially, specifically, the termination ring 17 rotates upward. That is, during the dosage setting action, the rotation of the drive rod 5 drives the termination ring 17 to move away from the clutch 10. During the injection action, it moves towards the clutch 10 with the rotation of the drive rod 5. In the initial state, before the dosage setting, the termination ring 17 and the clutch 10 are in contact. After the injection, it returns to this position. It can be understood that after each dosage setting and injection action, the termination ring 17 completes a back-and-forth reciprocating motion.

[0153] Simultaneously, it can be understood that, assuming each dose is set to 10 units, when the last dose is less than 10 units, the push rod 6 moves to a position closer to the stop ring 17. At this time, assuming there are only 5 units of medicine, the rotational displacement of the stop ring 17 relative to the stop ring engagement surface 603 is only 5 units. It can be understood that the stop ring 17 also has a last dose setting counting function, which can interact with the user to set the last dose. Exceeding the set dose will not be allowed.

[0154] Specifically, the engagement of the one-way ratchet tooth 1002 on the clutch 10 and the one-way meshing tooth 1101 on the limiting ring 11 allows the clutch 10 to rotate only counterclockwise (injection rotation direction) and not clockwise (dosage setting direction). Simultaneously, the engagement rib 1001 of the clutch 10 and the engagement rib groove 602 of the push rod 6 engage, thus limiting the rotation of the clutch 10 to control the rotation direction of the push rod 6. This can be understood as follows: during the dosage setting operation, clockwise rotation of the push rod 6 is restricted. After the termination ring 17 contacts the termination ring engagement surface 603 at the end of the push rod, the push rod 6 cannot rotate clockwise. The termination ring 17 is restricted, thus restricting the drive rod 5, which in turn restricts the dosage setting ring 3, preventing it from continuing to rotate clockwise for dosage setting.

[0155] like Figure 21As shown, after the injection button 1 is pressed, the injection button 1 drives the drive rod 5 to move downward. At this time, the drive rod engagement tooth 303 and the dose setting ring engagement tooth 501 are separated, the rotation of the drive rod 5 is unrestrained, the torsion spring 7 is released, and the drive rod 5 rotates counterclockwise.

[0156] Simultaneously, the clutch engagement teeth 504 and the drive rod engagement teeth 1003 change from a disengaged state to an engaged state. The drive rod 5 drives the clutch 10 to rotate counterclockwise, and the clutch 10 drives the push rod 6 to rotate counterclockwise. The helical teeth 601 of the push rod 6 and the push rod engagement trapezoidal threads 1104 of the limit ring 11 engage, so that while the push rod 6 rotates, it moves axially and towards the rubber stopper of the medicine bottle 15. The push rod top plate 12 pushes the rubber stopper, thereby injecting the medicine.

[0157] After injection, injection button 1 is released, and the pen-type injection device will return to normal. Figure 19 In the initial state shown, after each injection, the push rod 6 will move relative to the stopper of the medicine bottle until all the medicine in the medicine bottle 15 has been injected. Then, the push rod 6 moves to the farthest position relative to the drive rod 5. At this time, the engagement surface 603 of the stop ring and the end surface 1703 of the push rod abut. Since the drive rod 5 is locked due to the locking of the stop ring 17, the dosage setting ring 3 can be understood as being unable to set the dosage. This is very user-friendly and intelligent.

[0158] like Figure 22 As shown, after the injection is completed, the injection button 1 has not yet been released, but the torsion spring 7 has been released, and the push rod 6 has completed pushing the rubber stopper to move. At this time, the scale 8 is reset, and the termination ring 17 is reset. Figure 22 The state shown is the state where all the drug solution has been injected. At this time, the push rod 6 and the termination ring 17 are engaged, and the dose setting ring 3 is constrained and cannot rotate.

[0159] Example 2

[0160] This embodiment provides a driven pen-type injection device, including a trigger mechanism, a compression spring 2, a dosage setting ring 3, a torsion spring fixing ring 4, a drive rod 5, a push rod 6, a torsion spring 7, a scale 8, a limiting plate 9, a clutch 10, a limiting ring 11, a push rod top plate 12, a medicine bottle holder 13, a housing 14, a medicine bottle 15, a pen cap 16, and a termination ring 17. In this embodiment, the trigger mechanism is an injection button 1. Figure 23 As shown, a medicine bottle holder 13 is provided inside the pen cap 16, and the medicine bottle holder 13 contains a medicine bottle 15; the outer shell 14 is connected to the medicine bottle holder 13; the dosage setting ring 3 is disposed on the outer shell 14 and can rotate relative to the outer shell 14.

[0161] A drive rod 5 is provided inside the outer casing 14, and the push rod 6 is provided inside the drive rod 5; the drive rod 5 is connected to the dose setting ring 3, and when the dose setting ring 3 rotates, it drives the drive rod 5 to rotate; an injection button 1 is provided at one end of the outer casing 14, and when the injection button 1 is triggered (pressed), the drive rod 5 reverses and drives the push rod 6 to move toward the medicine bottle 15, thereby realizing injection.

[0162] The structure of injection button 1 is the same as that of injection button 1 in Embodiment 1, and will not be described again here.

[0163] like Figures 24 to 28 The diagram shows the structure of the dose setting ring 3. The dose setting ring 3 has two layers: an inner cylinder and an outer cylinder. The outer cylinder is fitted over the inner cylinder and the two are connected by a connecting plate in the middle. The inner wall of the inner cylinder is provided with a drive rod meshing tooth 303 for driving the drive rod 5 to rotate. The outer cylinder is connected to the outer shell. The specific connection structure is as follows: the lower inner wall of the outer cylinder is provided with an outer shell limiting groove 305, and the outer shell 14 is provided with a corresponding annular rib 1404. The annular rib 1404 is embedded in the outer shell limiting groove 305 to realize the connection between the outer shell 14 and the dose setting ring 3.

[0164] Within the space between the outer cylinder and the inner cylinder, a curved arm 301 is provided below the connecting plate. The curved arm 301 is connected to the outer wall of the inner cylinder. The curved arm 301 has a structure in which one end is fixed and the other end is free, so it is deformable. The curved arm 301 extends in the opposite direction to the dose setting rotation direction.

[0165] The curved arm 301 is provided with a bidirectional ratchet tooth 302 on its exterior. In this embodiment, multiple curved arms 301 are arranged in a cylindrical circumference array along the inner side, and each curved arm 301 is provided with a bidirectional ratchet tooth 302. A bidirectional ratchet meshing groove 1401 is provided on the inner wall of one end of the outer shell 14, and the bidirectional ratchet meshing groove 1401 and the bidirectional ratchet tooth 302 mesh.

[0166] When the housing 14 is connected to the dose setting ring 3, the upper end of the housing 14 is inserted into the space between the outer cylinder and the curved arm of the dose setting ring 3.

[0167] In addition, the upper end of the inner cylinder of the dosage setting ring 3 is the injection button termination surface 304, which limits the injection button 1 when it is pressed.

[0168] The outer surface of the dose setting ring 3 is also provided with axial protrusions to increase the friction when rotating the dose setting ring.

[0169] like Figure 29The diagram shows the structure of the torsion spring retaining ring 4. The torsion spring retaining ring 4 is located inside the upper end of the outer shell 14 and is sleeved on the upper end of the drive rod 5. A torsion spring limiting groove 401 is provided on the upper surface of the torsion spring retaining ring 4. A portion of the torsion spring limiting groove 401 is a through-hole structure, used to engage one end of the torsion spring 7 within the torsion spring limiting groove 401. A scale termination limiting surface 402 is provided on the lower surface of the torsion spring retaining ring 4 to limit the scale 8. An outer shell limiting rib 403 is provided on the outer surface of the torsion spring retaining ring 4. A limiting groove matching the outer shell limiting rib 403 is provided inside the outer shell 14. By inserting the outer shell limiting rib 403 into the limiting groove inside the outer shell 14, the torsion spring retaining ring 4 is confined within the outer shell 14. Additionally, a buckle is provided on the outer wall of the torsion spring retaining ring 4, which engages with the torsion spring retaining ring buckle hole 1405 on the inner wall of the outer shell 14 to fix the torsion spring retaining ring 4 to the outer shell 14.

[0170] like Figure 30 and Figure 31 The diagram shows the structure of the drive rod 5. The drive rod 5 includes a drive rod sleeve and a drive rod cylinder. The drive rod sleeve is fitted outside the drive rod cylinder, and the lower end of the drive rod sleeve is fixedly connected to the drive rod cylinder. A torsion spring 7 is provided between the drive rod sleeve and the drive rod cylinder.

[0171] A torsion spring lower limiting groove 506 is provided at the connection between the drive rod sleeve and the drive rod cylinder. The lower end of the torsion spring 7 is engaged in the torsion spring lower limiting groove 506, and the torsion direction of the torsion spring 7 is set to rotate along the dosage setting direction as the driving force.

[0172] A dose setting ring engagement tooth 501 is provided on the top outer wall of the drive rod 5, and the dose setting ring engagement tooth 501 engages with the drive rod engagement tooth 303.

[0173] Multiple scale engagement grooves 505 extending axially are provided on the outer wall of the drive rod 5, and drive rod engagement ribs 802 are provided on the inner wall of the scale 8. The drive rod engagement ribs 802 are embedded in the scale engagement grooves 505, so that the scale 8 can rotate synchronously with the drive rod 5 when the drive rod 5 rotates.

[0174] Clutch engagement teeth 504 are provided on the inner wall of the lower end of the drive rod 5, and drive rod engagement teeth 1003 are provided on the outer wall of the clutch 10. When the injection button 1 is pressed, the drive rod 5 moves axially, and the drive rod engagement teeth 1003 can engage with the clutch engagement teeth 504.

[0175] like Figure 31 As shown, a retaining strip 502 is provided on the inner wall of the upper end of the drive rod 5 for engaging with the injection button 1.

[0176] The inner wall of the lower end of the drive rod 5 is also provided with a stop ring limiting groove 503, and the outer wall of the stop ring 17 is provided with a meshing rib 1701. The meshing rib 1701 is embedded in the stop ring limiting groove 503, so that the stop ring 17 can only move along the axial direction of the drive rod 5, and cannot rotate relative to the drive rod 5.

[0177] The structure of push rod 6 is the same as that of push rod 6 in Embodiment 1, and will not be described again here.

[0178] like Figure 32 The diagram shows the structure of the scale 8. The outer wall of the scale 8 is provided with a shell engagement thread groove 801, and the inner wall of the shell 14 is provided with a scale engagement thread 1402. The scale engagement thread 1402 is embedded in the shell engagement thread groove 801. Thus, the radial rotational motion of the scale 8 can be transformed into a combination of axial movement and radial rotation.

[0179] The scale 8 can be set with graduations on its outer wall, and the scale 8 can display the set dose when the dose is set. The upper end of the scale 8 is provided with a termination surface 803, which contacts the scale termination limiting surface 402 of the torsion spring retaining ring 4, limiting the upper end of the scale 8; the lower end of the scale 8 is provided with a scale zero limiting surface 804, which is used to limit the lower end of the scale 8.

[0180] The inner wall of the scale 8 is provided with a drive rod engagement rib 802 extending axially, which matches the scale engagement rib groove 505 on the outer wall of the drive rod 5.

[0181] like Figure 33 The diagram shows the structure of the clutch 10. The outer wall of the clutch 10 is provided with drive rod meshing teeth 1003 and one-way ratchet teeth 1002. The inner wall of the limiting ring 11 is provided with one-way meshing teeth 1101, and the one-way meshing teeth 1101 and the one-way ratchet teeth 1002 mesh. The inner wall of the lower end of the drive rod 5 is provided with clutch meshing teeth 504, and the drive rod meshing teeth 1003 and the clutch meshing teeth 504 can mesh.

[0182] A push rod engagement rib 1001 is provided on the inner wall of the clutch 10, and the push rod engagement rib 1001 is embedded in the engagement rib groove 602 of the push rod 6.

[0183] The structure of the limiting ring 11 is the same as that of the limiting ring 11 in Embodiment 1, and will not be described again here.

[0184] In this embodiment, the rotation direction of the dose setting ring 3 is clockwise, so the clutch 10 can only rotate counterclockwise and cannot rotate clockwise.

[0185] The structure of the outer shell is the same as that of the outer shell 14 in Embodiment 1, and will not be described again here.

[0186] The structure of the termination ring 17 is the same as that in Embodiment 1, and will not be described again here.

[0187] like Figure 34 The diagram shows the initial state of the pen-type injection device provided in this embodiment. The lower half is the drug reservoir structure, and the upper half is the drive and dosage setting structure. A drug bottle holder 13 is provided on the inner wall of the pen cap 16, and the pen cap 16 is snapped into the drug bottle holder 13, allowing the pen cap 16 to be smoothly removed from or reinstalled on the drug bottle holder 13. A drug bottle 15 is provided inside the drug bottle holder 13, and an injection needle can be installed at the lower end of the drug bottle 15. The upper end of the drug bottle 15 is sealed with a rubber stopper, and a push rod top plate 12 is provided on the rubber stopper, which contacts and engages with the push rod 6.

[0188] The upper end of the medicine bottle holder 13 is snapped into the outer shell 14. The upper end of the outer shell 14 is connected to the dosage setting ring 3. A scale 8 is set inside the outer shell 14. A drive rod 5 is set inside the scale 8. A push rod 6 is set inside the drive rod 5. A stop ring 17 is set between the lower end of the drive rod 5 and the push rod 6. A clutch 10 is set below the stop ring 17. A limit ring 11 is set below the clutch 10. The upper end of the limit ring 11 is limited by the outer shell 14, and the lower end is limited by the medicine bottle holder 13.

[0189] A torsion spring 7 is installed in the side wall space of the drive rod 5, and a torsion spring retaining ring 4 is installed on the upper outer side of the drive rod 5. The outer wall of the drive rod 5 above the torsion spring retaining ring 4 meshes with the dose setting ring 3. An injection button 1 is installed above the drive rod 5, and a compression spring 2 is installed between the injection button 1 and the dose setting ring 3.

[0190] In the initial state, the end surface 803 of the scale 8 abuts against the end limiting surface 402 of the scale.

[0191] Figure 35 The figure shows the state after the dose is set in this embodiment. The dose is set by rotating the dose setting ring 3 clockwise. After rotating the dose setting ring 3, the dose setting ring 3 drives the drive rod 5 to rotate through the engagement of the drive rod meshing teeth 303 and the dose setting ring meshing teeth 501. The upper end of the torsion spring 7 is locked on the torsion spring fixing ring 4. The torsion spring fixing ring 4 is fixed by the outer shell 14 and cannot rotate. Therefore, the lower end of the torsion spring 7 rotates with the drive rod 5 to complete the storage of the torsion spring 7.

[0192] Simultaneously, the bidirectional ratchet teeth 302 and the bidirectional ratchet meshing groove 1401 mesh, and the dosage is set through the deformation of the bending arm 301 and the cycle of meshing. In addition, since the angles of the inclined surfaces on both sides of the bidirectional ratchet meshing groove 1401 are different, with a smaller angle in the positive direction and a larger angle in the negative direction, combined with the deformation of the bending arm 301, square dosage setting and negative direction dosage correction are achieved.

[0193] At the same time, after rotating the dose setting ring 3, the drive rod 5 rotates, which in turn drives the scale 8 to rotate. Since the scale 8 is engaged with the scale engagement thread 1402 of the outer casing 14, the scale 8 moves axially and rotates radially. After the dose is set, the scale 8 moves a certain displacement towards the pen cap 16. The scale on the scale 8, i.e. the dose setting amount, can be observed through the observation window 1403.

[0194] Furthermore, the engagement rib 1701 of the termination ring 17 is embedded in the clutch engagement tooth 504 of the drive rod 5. When the drive rod 5 rotates, the termination ring 17 rotates accordingly, but the inner wall of the termination ring 17 is still engaged with the push rod 6. Therefore, when the termination ring 17 rotates radially, it also moves axially, specifically, the termination ring 17 rotates upward. That is, during the dosage setting action, the rotation of the drive rod 5 drives the termination ring 17 to move away from the clutch 10. During the injection action, it moves towards the clutch 10 with the rotation of the drive rod 5. In the initial state, before the dosage setting, the termination ring 17 and the clutch 10 are in contact. After the injection, it returns to this position. It can be understood that after each dosage setting and injection action, the termination ring 17 completes a back-and-forth reciprocating motion.

[0195] Simultaneously, it can be understood that, assuming each dose is set to 10 units, when the last dose is less than 10 units, the push rod 6 moves to a position closer to the stop ring 17. At this time, assuming there are only 5 units of medicine, the rotational displacement of the stop ring 17 relative to the stop ring engagement surface 603 is only 5 units. It can be understood that the stop ring 17 also has a last dose setting counting function, which can interact with the user to set the last dose. Exceeding the set dose will not be allowed.

[0196] Specifically, the engagement of the one-way ratchet tooth 1002 on the clutch 10 and the one-way meshing tooth 1101 on the limiting ring 11 allows the clutch 10 to rotate only counterclockwise (injection rotation direction) and not clockwise (dosage setting direction). Simultaneously, the engagement rib 1001 of the clutch 10 and the engagement rib groove 602 of the push rod 6 engage, thus limiting the rotation of the clutch 10 to control the rotation direction of the push rod 6. This can be understood as follows: during the dosage setting operation, clockwise rotation of the push rod 6 is restricted. After the termination ring 17 contacts the termination ring engagement surface 603 at the end of the push rod, the push rod 6 cannot rotate clockwise. The termination ring 17 is restricted, thus restricting the drive rod 5, which in turn restricts the dosage setting ring 3, preventing it from continuing to rotate clockwise for dosage setting.

[0197] like Figure 36 As shown, after the injection button 1 is pressed, the injection button 1 drives the drive rod 5 to move downward. At this time, the drive rod engagement tooth 303 and the dose setting ring engagement tooth 501 are separated, the rotation of the drive rod 5 is unrestrained, the torsion spring 7 is released, and the drive rod 5 rotates counterclockwise.

[0198] Simultaneously, the clutch engagement teeth 504 and the drive rod engagement teeth 1003 change from a disengaged state to an engaged state. The drive rod 5 drives the clutch 10 to rotate counterclockwise, and the clutch 10 drives the push rod 6 to rotate counterclockwise. The helical teeth 601 of the push rod 6 and the push rod engagement trapezoidal threads 1104 of the limit ring 11 engage, so that while the push rod 6 rotates, it moves axially and towards the rubber stopper of the medicine bottle 15. The push rod top plate 12 pushes the rubber stopper, thereby injecting the medicine.

[0199] After injection, injection button 1 is released, and the pen-type injection device will return to normal. Figure 34 In the initial state shown, after each injection, the push rod 6 will move relative to the stopper of the medicine bottle until all the medicine in the medicine bottle 15 has been injected. Then, the push rod 6 moves to the farthest position relative to the drive rod 5. At this time, the engagement surface 603 of the stop ring and the end surface 1703 of the push rod abut. Since the drive rod 5 is locked due to the locking of the stop ring 17, the dosage setting ring 3 can be understood as being unable to set the dosage. This is very user-friendly and intelligent.

[0200] like Figure 37 As shown, after the injection is completed, the injection button 1 has not yet been released, but the torsion spring 7 has been released, and the push rod 6 has completed pushing the rubber stopper to move. At this time, the scale 8 is reset, and the termination ring 17 is reset. Figure 37 The state shown is the state where all the drug solution has been injected. At this time, the push rod 6 and the termination ring 17 are engaged, and the dose setting ring 3 is constrained and cannot rotate.

[0201] The above specific embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A pen-type injection device with a drive, comprising: A medicine bottle holder, wherein the medicine bottle holder contains medicine bottles; The outer casing is connected to the medicine bottle holder; Its characteristic is that it further includes: A dose setting ring is rotatably connected to the housing; the dose setting ring is configured to set the dose by forward rotation of the dose setting ring relative to the housing, and to correct the dose by reverse rotation of the dose setting ring relative to the housing. A triggering mechanism is disposed at one end of the housing; An autonomously driven injection assembly includes a driving component and an injection component. When the dosage is set, the driving component stores driving force; when the dosage is corrected, the driving component releases the driving force. When the triggering mechanism is activated, the drive component can drive the injection component to move toward the vial to achieve injection.

2. The pen-type injection device with drive according to claim 1, characterized in that, It also includes a post-injection locking and residual monitoring component, wherein the post-injection locking and residual monitoring component is a termination ring, and the termination ring is disposed between the drive rod and the push rod; The post-injection locking and residual monitoring component is configured such that after all the medication has been injected, the post-injection locking and residual monitoring component can lock the injection component, thereby preventing further injection. Furthermore, during the final dose setting, if the set dose is greater than the remaining dose, the post-injection locking and remaining dose monitoring components can lock the injection component, thereby allowing only the remaining dose to be set.

3. The pen-type injection device with drive according to claim 1, characterized in that, A dose setting ratchet is provided inside the dose setting ring, a drive arm is provided on the inner wall of the dose setting ring, and a drive protrusion is provided on the outer wall of the dose setting ratchet. The front end of the drive arm abuts against the side wall of the drive protrusion. During the dose setting process, the drive arm pushes the drive protrusion to rotate. The dosage setting ratchet has multiple curved arms on its outer wall, and bidirectional ratchet teeth are provided on the curved arms. A bidirectional ratchet meshing groove is provided on the inner wall of one end of the housing, and the bidirectional ratchet meshing groove and the bidirectional ratchet teeth mesh together.

4. The pen-type injection device with drive according to claim 1, characterized in that, The inner wall of one end of the outer casing is provided with a bidirectional ratchet meshing groove, and the dose setting ring is provided with a plurality of curved arms, which extend in the opposite direction to the dose setting rotation direction. The curved arm is provided with bidirectional ratchet teeth, and the bidirectional ratchet meshing groove and the bidirectional ratchet teeth mesh.

5. The driven pen-type injection device according to claim 3 or 4, characterized in that, The two sides of the bidirectional ratchet meshing groove are inclined surfaces, wherein the angle between the inclined surface facing the dose setting rotation direction and the tangential direction is smaller than the angle between the inclined surface away from the dose setting rotation direction and the tangential direction.

6. The pen-type injection device with drive according to claim 2, characterized in that, The drive assembly includes a drive rod, the drive rod includes a drive rod sleeve and a drive rod cylinder, the drive rod sleeve is sleeved outside the drive rod cylinder and the drive rod sleeve and the drive rod cylinder are connected; a torsion spring is provided between the drive rod sleeve and the drive rod cylinder; One end of the drive rod is provided with a torsion spring retaining ring, and the torsion spring retaining ring is fixed inside the outer casing; One end of the torsion spring is fixed to the torsion spring fixing ring, and the other end of the torsion spring is fixed to the drive rod. The torsion direction of the torsion spring is set to rotate along the dosage setting direction as the driving force. When the triggering mechanism is triggered, the torsion spring drives the drive rod to reverse, thereby driving the injection assembly to move toward the medicine bottle, thus realizing injection.

7. The pen-type injection device with drive according to claim 6, characterized in that, The injection assembly includes a limiting ring, a clutch, and a push rod, with the push rod disposed inside the drive rod. The limiting ring is disposed on the inner wall of the connection between the outer shell and the vial holder, and the inner wall of the limiting ring engages with the helical teeth on the outer wall of the push rod. The clutch is disposed on one side of the limiting ring, and the inner wall of the clutch is provided with a push rod engagement rib. The outer wall of the push rod is provided with an engagement rib groove, and the push rod engagement rib is embedded in the engagement rib groove. The inner wall of the limiting ring is provided with one-way meshing teeth, and the outer wall of the clutch is provided with one-way ratchet teeth, the one-way meshing teeth and the one-way ratchet teeth meshing; The outer wall of the clutch is provided with drive rod meshing teeth, and the inner wall of the drive rod near the medicine bottle holder is provided with clutch meshing teeth; when the triggering mechanism is triggered, the drive rod meshing teeth can mesh with the clutch meshing teeth.

8. The pen-type injection device with drive according to claim 7, characterized in that, The outer wall of one end of the drive rod cylinder is provided with a dose setting ring meshing tooth, and the inner wall of the dose setting ring is provided with a drive rod meshing tooth, and the dose setting ring meshing tooth and the drive rod meshing tooth mesh.

9. The pen-type injection device with drive according to claim 7, characterized in that, The outer wall of one end of the drive rod cylinder is provided with a dose setting ring meshing tooth, and the inner wall of the dose setting ratchet is provided with a drive rod meshing tooth. The dose setting ring meshing tooth and the drive rod meshing tooth mesh.

10. The driven pen-type injection device according to claim 8 or 9, characterized in that, The inner wall of the drive rod is provided with a stop ring limiting groove, and the outer wall of the stop ring is provided with a meshing rib. The meshing rib is embedded in the stop ring limiting groove; thus, when the drive rod rotates, it can drive the stop ring to rotate synchronously. The outer wall of the push rod is provided with helical teeth, and the inner wall of the termination ring is provided with helical grooves that mesh with the helical teeth; thus, when the dosage is set, the termination ring rotates in the forward direction and moves towards the end of the push rod; when the injection is performed, the termination ring rotates in the reverse direction and moves towards the injection direction. The push rod is provided with a termination ring engagement surface at one end near the dose setting ring, and a push rod termination surface at one end of the termination ring. When the push rod pushes the medicine bottle to complete the injection of all the medicine, the push rod termination surface abuts against the termination ring engagement surface. During the final dose setting, if the dose setting amount is greater than the remaining dose, the push rod termination surface abuts against the termination ring engagement surface when the dose setting ring rotates within the range of the remaining dose, thus preventing further dose setting.

11. The driven pen-type injection device according to claim 6, characterized in that, A scale is provided between the outer casing and the drive rod; a scale engagement thread is provided on the inner wall of the outer casing; and an outer casing engagement thread groove is provided on the outer wall of the scale; the scale engagement thread is embedded in the outer casing engagement thread groove. The inner wall of the scale is provided with a drive rod engagement rib, and the outer wall of the drive rod is provided with a scale engagement rib groove, and the drive rod engagement rib is embedded in the scale engagement rib groove; The outer casing is provided with a customer observation window, and the outer wall of the scale is provided with graduations.

Images