Dose setting and correction structure and injection device

Abstract

This utility model relates to the technical field of pen-type injection devices, specifically a dosage setting and correction structure and injection device. The dosage setting and correction structure includes a housing, a dosage setting ring, and a dosage setting ratchet. The housing contains a bidirectional ratchet meshing groove, and the dosage setting ring includes a drive arm. The dosage setting ratchet has a curved arm and a drive protrusion on its exterior. The curved arm has bidirectional ratchet teeth that mesh with the bidirectional ratchet meshing groove. When the dosage setting ring rotates clockwise, the drive arm pushes the drive protrusion to rotate, forcing the bidirectional ratchet teeth to disengage from the current bidirectional ratchet meshing groove and engage with the next one, completing the dosage setting. When rotating counterclockwise, the drive arm rotates synchronously, pressing the curved arm, forcing the bidirectional ratchet teeth to disengage from the current bidirectional ratchet meshing groove and engage with the previous one, completing the dosage correction. This utility model can correct dosage setting errors, improve injection accuracy, and enhance the user-friendliness of the injection device.

Description

Technical Field

[0001] This utility model relates to the technical field of pen-type injection devices, specifically a dosage setting and correction structure and an injection device. 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] Therefore, this invention provides a dosage setting and correction structure and an injection device. Utility Model Content

[0005] In order to solve at least one of the above-mentioned technical problems existing in the prior art, the present invention provides a dosage setting and correction structure and an injection device.

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

[0007] In a first aspect, this utility model provides a dosage setting and correction structure, comprising:

[0008] Housing, dose setting ring, dose setting ratchet;

[0009] The inner wall of one end of the outer casing is provided with a bidirectional ratchet meshing tooth groove, and the inner wall of the dose setting ring is provided with a drive arm; the outer wall of the dose setting ratchet is provided with a curved arm and a drive protrusion, and the curved arm is provided with bidirectional ratchet teeth;

[0010] The dose setting ring is configured to rotate relative to the housing;

[0011] The dose setting ratchet is located inside the housing, and the drive arm is located between the curved arm and the drive protrusion;

[0012] The bidirectional ratchet teeth are configured to engage with the bidirectional ratchet meshing grooves;

[0013] When the dose setting ring is rotated clockwise by one unit, the drive arm rotates synchronously to abut against and push the drive protrusion to rotate, causing the bent arm to undergo elastic deformation, forcing the bidirectional ratchet teeth to disengage from the currently engaged bidirectional ratchet meshing slot and enter the next bidirectional ratchet meshing slot to mesh with it, thus completing the setting of one unit dose.

[0014] When the dose setting ring is rotated counterclockwise by one cell, the drive arm rotates synchronously to compress the bending arm, causing the bending arm to undergo elastic deformation. This forces the bidirectional ratchet teeth to disengage from the currently engaged bidirectional ratchet meshing slot and retract to the previous bidirectional ratchet meshing slot, thus completing the retraction and revision of the dose for one cell.

[0015] Furthermore, the dose setting ring includes a dose setting knob, and a drive arm is provided on the inner wall of the dose setting knob.

[0016] 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.

[0017] Furthermore, an annular rib is provided on the outer wall of the outer shell, and an outer shell limiting groove is provided on the inner wall of the dose setting ring. The annular rib is embedded in the outer shell limiting groove to achieve the snap-fit ​​between the outer shell and the dose setting ring.

[0018] Furthermore, multiple grooves are provided axially on the outer wall of the dose setting ring.

[0019] Furthermore, the dosage setting ring includes an outer cylinder and an inner cylinder, the outer cylinder is sleeved on the inner cylinder, and the outer cylinder and the inner cylinder are connected by a connecting plate;

[0020] The drive arm is provided on the outer wall of the inner cylinder, and the upper end of the outer shell is embedded between the outer cylinder and the inner cylinder.

[0021] 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.

[0022] Furthermore, the inner wall of the dose setting ratchet is provided with meshing teeth, which are used to mesh with the drive assembly to drive the drive assembly to complete the power storage for dose setting.

[0023] Furthermore, a drive assembly is provided inside the dose setting ratchet. The drive assembly includes a drive rod, and the dose setting ratchet meshes with the drive rod. Thus, when the dose setting ring rotates, it can drive the drive rod to rotate through the dose setting ratchet.

[0024] Furthermore, the drive rod includes a drive rod sleeve and a drive rod cylinder, the drive rod sleeve being fitted over the drive rod cylinder and the drive rod sleeve and the drive rod cylinder being 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 retaining 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] 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.

[0028] 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;

[0029] The outer casing is provided with a customer observation window, and the outer wall of the scale is provided with graduations.

[0030] Secondly, this utility model provides an injection device, including the above-mentioned dosage setting and correction structure.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a dosage setting and correction structure, wherein a bidirectional ratchet meshing groove is provided on the inner wall of the outer shell, a drive arm is provided on the dosage setting ring, a dosage setting ratchet is provided on the inner wall of the dosage setting ring, a drive protrusion and a curved arm are provided on the outer wall of the dosage setting ratchet, and a bidirectional ratchet tooth is provided on the curved arm.

[0033] When setting the dosage, the dosage setting ring is rotated, which in turn drives the dosage setting ratchet to rotate. The dosage is set by the deformation and engagement of the bending arm. When correcting the dosage, the deformation and engagement of the bending arm can also be used to correct the dosage. Therefore, it is possible to correct the dosage setting error, improve the injection accuracy, and improve the user-friendliness of the injection device.

[0034] In addition, the deformation of the curved arm in this invention is an active deformation. During dosage correction, the curved arm is first deformed by the drive arm squeezing it, and then the bidirectional ratchet teeth and the bidirectional ratchet meshing groove are re-engaged, which makes it less likely to damage the bidirectional ratchet teeth. It is especially suitable for setting and correcting large doses as well as setting and correcting frequently.

[0035] In addition, during the dosage setting and dosage correction process, the present invention can produce a "click-click-click" prompt sound through the meshing structure between the dosage setting ratchet and the outer shell, making the present invention have an excellent interactive and user-friendly design. Attached Figure Description

[0036] Figure 1 This is an isometric view of the present invention;

[0037] Figure 2 Front view of the dose setting ring;

[0038] Figure 3 A bottom view of the dosage setting ring;

[0039] Figure 4 Axonometric view of the internal structure of the dose setting ring;

[0040] Figure 5 A schematic diagram of the ratchet mechanism for setting the dosage;

[0041] Figure 6 This is an isometric view of the torsion spring retaining ring;

[0042] Figure 7 This is an isometric view of the drive rod;

[0043] Figure 8 This is a diagram of the internal structure of the drive rod;

[0044] Figure 9 This is an axonometric drawing of the scale.

[0045] Figure 10 This is an isometric view of the outer casing;

[0046] Figure 11 This is a schematic diagram of the internal structure of the outer shell;

[0047] Figure 12 This is a top view of the outer casing;

[0048] Figure 13 This is an isometric view of the injection button;

[0049] Figure 14 A cross-sectional view of the connection structure between the dose setting ring, the dose setting ratchet, and the housing;

[0050] Figure 15 A schematic diagram of the internal structure after dosage setting.

[0051] Figure label:

[0052] 1. Injection button, 101. Clip; 2. Compression spring;

[0053] 3. Dosage setting ring; 301. Drive arm; 302. Injection button termination surface; 303. Housing limiting groove;

[0054] 4. Torsion spring retaining ring, 401. Torsion spring limiting groove, 402. Scale termination limiting surface, 403. Housing limiting rib;

[0055] 5. Drive rod; 501. Dosage setting ring meshing teeth; 502. Locking strip; 503. Scale meshing rib groove; 504. Torsion spring lower limit groove.

[0056] 6. Push rod;

[0057] 7. Torsion spring;

[0058] 8. Scale, 801. Outer shell engagement thread groove, 802. Drive rod engagement rib, 803. Termination surface, 804. Scale zero limit surface;

[0059] 9. Outer shell; 901. Bidirectional ratchet meshing tooth groove; 902. Scale meshing thread; 903. Observation window; 904. Annular rib; 905. Torsion spring retaining ring snap hole; 906. Medicine bottle holder fixing groove.

[0060] 10. Dosage setting ratchet, 1001. Drive lug, 1002. Bidirectional ratchet teeth, 1003. Drive rod meshing teeth, 1004. Bending arm. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Example 1

[0065] This embodiment provides a dosage setting and correction structure, including an injection button 1, a pressure spring 2, a dosage setting ring 3, a dosage setting ratchet 10, a torsion spring retaining ring 4, a drive rod 5, a push rod 6, a torsion spring 7, a scale 8, and a housing 9. Figure 1 As shown, the outer casing 9 is disposed outside the body of the injection device, the dose setting ring 3 is disposed on the outer casing 9 and rotatably connected to the outer casing 9, and 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 outer casing 9, and to correct the dose by rotating the dose setting ring 3 in the reverse direction relative to the outer casing 9.

[0066] A drive rod 5 is installed inside the outer casing 9, and the push rod 6 is installed inside the drive rod 5. A dose setting ratchet 10 is installed inside the dose setting ring 3, and the dose setting ratchet 10 is sleeved on the upper part of the drive rod 5. The drive rod 5 is engaged with the dose setting ratchet 10. When the dose setting ring 3 rotates, the drive rod 5 is driven to rotate through the dose setting ratchet 10. An injection button 1 is installed at one end of the outer casing 9. When the injection button 1 is triggered (pressed), the drive rod 5 reverses and drives the push rod 6 to move towards the medicine bottle, thereby realizing injection.

[0067] like Figures 2 to 4 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 303 is provided on the lower inner wall of the outer cylinder, and a corresponding annular rib 904 is provided on the outer shell 9. The annular rib 904 is embedded in the shell limiting groove 303 to realize the connection between the outer shell 9 and the dose setting ring 3. The outer cylinder is the dose setting knob. Rotating the outer cylinder realizes the setting and correction of the dose.

[0068] Within the space between the outer cylinder and the inner cylinder, a drive arm 301 is provided below the connecting plate, with the clockwise direction as the forward direction for dose setting. The front end of the drive arm 301 abuts against the drive protrusion 1001 of the dose setting ratchet 10.

[0069] When the outer casing 9 is connected to the dose setting ring 3, the upper end of the outer casing 9 is inserted into the space between the outer cylinder and the inner cylinder of the dose setting ring 3.

[0070] In addition, the upper end of the inner cylinder of the dosage setting ring 3 is the injection button termination surface 302, which limits the injection button 1 when it is pressed.

[0071] 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.

[0072] Figure 5 The dosage setting ratchet 10 is shown in the structural diagram. The inner wall of the dosage setting ratchet 10 is provided with drive rod meshing teeth 1003 for driving the drive rod 5 to rotate. The outer wall of the dosage setting ratchet 10 is provided with a curved arm 1004. The curved arm 1004 has a structure in which one end is fixed and the other end is free, so it is deformable. The curved arm 1004 extends in the opposite direction to the dosage setting rotation direction.

[0073] The curved arm 1004 is provided with a bidirectional ratchet tooth 1002 on its exterior. In this embodiment, two curved arms 1004 are provided, and each curved arm 1004 is provided with a bidirectional ratchet tooth 1002. A bidirectional ratchet meshing groove 901 is provided on the inner wall of one end of the housing 9, and the bidirectional ratchet meshing groove 901 and the bidirectional ratchet tooth 1002 mesh.

[0074] The dosage setting ratchet 10 is also provided with two drive protrusions 1001 on its outer wall. The two drive protrusions 1001 and two curved arms 1004 are arranged alternately. In addition, when setting the dosage, the front end of the drive arm 301 drives the drive protrusions 1001 to rotate, which in turn drives the dosage setting ratchet 10 to rotate. The curved arms 1004 of the dosage setting ratchet 10 are blocked by the bidirectional ratchet meshing grooves 901. The curved arms 1004 deform so that the bidirectional ratchet teeth 1002 mesh with the next bidirectional ratchet meshing groove 901. During the deformation and meshing process, a "click-click-click" sound is produced to enhance the user experience.

[0075] like Figure 6 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 casing 9 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 casing limiting rib 403 is provided on the outer surface of the torsion spring retaining ring 4. The outer casing limiting rib 403 is a toothed structure that meshes with the bidirectional ratchet meshing groove 901. By embedding the outer casing limiting rib 403 into the bidirectional ratchet meshing groove 901, the torsion spring retaining ring 4 is confined within the outer casing 9. Additionally, a buckle is provided on the outer wall of the torsion spring retaining ring 4. The buckle engages with the torsion spring retaining ring buckle hole 905 on the inner wall of the outer casing 9, thus fixing the torsion spring retaining ring 4 to the outer casing 9.

[0076] like Figure 7 and Figure 8The 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.

[0077] A torsion spring 7 is provided between the drive rod sleeve and the drive rod cylinder; a torsion spring lower limiting groove 504 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 504, and the torsion direction of the torsion spring 7 is set to rotate along the dosage setting direction as the driving force.

[0078] 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 1003.

[0079] Multiple scale engagement grooves 503 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 503, so that the scale 8 can rotate synchronously with the drive rod 5 when the drive rod 5 rotates.

[0080] like Figure 8 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.

[0081] like Figure 9 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 9 is provided with a scale engagement thread 902. The scale engagement thread 902 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.

[0082] 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.

[0083] 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 503 on the outer wall of the drive rod 5.

[0084] like Figures 10 to 12The diagram shows the structure of the outer casing 9. The inner wall of the upper end of the outer casing 9 is provided with a bidirectional ratchet meshing groove 901, which meshes with the bidirectional ratchet teeth 1002 on the dose setting ratchet 10. During the dose setting and dose correction process, through the deformation and meshing of the bending arm 1004, a "click-click-click" sound is also generated between the bidirectional ratchet teeth 1002 and the bidirectional ratchet meshing groove 901. This sound occurs continuously during the dose setting process, which is a very user-friendly design for dose setting interaction.

[0085] An annular rib 904 is provided on the upper outer wall of the outer shell 9. A torsion spring fixing ring buckle hole 905 is provided on the outer wall of the outer shell 9 below the annular rib 904. An observation window 903 is provided on the outer shell below the torsion spring fixing ring buckle hole 905, which allows the scale 8 to be observed, and thus the dose setting size can be observed.

[0086] The inner wall of the outer casing 9 is provided with a scale engagement thread 902, the inner wall of the lower end of the outer casing 14 is provided with a medicine bottle holder fixing groove 906, and the outer wall of the medicine bottle holder is provided with a buckle that is engaged in the medicine bottle holder fixing groove 906 to realize the connection between the outer casing 9 and the medicine bottle holder.

[0087] like Figure 12 The diagram shows a top view of the outer casing 9. Both sides of the bidirectional ratchet meshing groove 901 are inclined planes relative to the radial direction of the outer casing 9. 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.

[0088] like Figure 13 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.

[0089] like Figure 1 The diagram shows the initial state of the dosage setting and correction structure provided in this embodiment. The upper end of the outer shell 9 is connected to the dosage setting ring 3. A scale 8 is provided inside the outer shell 9. A drive rod 5 is provided inside the scale 8. A push rod 6 is provided inside the drive rod 5. An autonomous drive component is provided at the lower end of the drive rod 5.

[0090] A torsion spring 7 is installed in the side wall space of the drive rod 5, a torsion spring retaining ring 4 is installed on the upper outer side of the drive rod 5, a dose setting ratchet 10 is installed above the torsion spring retaining ring 4, and the dose setting ratchet 10 is engaged with the dose setting ring 3; the outer wall of the drive rod 5 meshes with the dose setting ratchet 10, 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.

[0091] In the initial state, the scale zero limit surface 804 of the scale 8 is limited by the autonomous drive component below the drive rod.

[0092] like Figure 14 This is a schematic diagram of the connection structure of the dose setting ring 3, the outer casing 9, and the dose setting ratchet 10 in the initial state. The upper end of the outer casing is located between the dose setting knob (the outer cylinder) and the drive arm 301. The dose setting knob is rotatable relative to the outer casing 9.

[0093] The dosage setting ratchet 10 is located inside the upper end of the housing 9. The drive arm 301 is located between the bending arm 1004 and the drive protrusion 1001. One end of the drive arm 301 abuts against the drive protrusion 1001, and the other end abuts against the bending arm 1004. In the initial state, the bending arm 1004 is in a natural state and has no bending deformation.

[0094] When the dose setting knob is rotated clockwise by one unit, the drive arm 301 rotates synchronously to abut against and push the drive protrusion 1001 to rotate, causing the bent arm 1004 to undergo elastic deformation, forcing the bidirectional ratchet tooth 1002 to disengage from the currently engaged bidirectional ratchet engagement groove 901, enter the next bidirectional ratchet engagement groove 901 and engage with it, thus completing the setting of one unit dose.

[0095] When the dose setting knob is turned counterclockwise by one cell, the drive arm 301 rotates synchronously to press the bent arm 1004, causing the bent arm 1004 to undergo elastic deformation. This forces the bidirectional ratchet tooth 1002 to disengage from the currently engaged bidirectional ratchet engagement groove 901, retract to the previous bidirectional ratchet engagement groove 901, and engage with it, thus completing the retraction and revision of the dose for one cell.

[0096] The specific principle is as follows: When the dose setting knob is rotated clockwise, the front end of the drive arm 301 pushes the drive protrusion 1001 to rotate. The bent arm 1004 undergoes elastic deformation under the obstruction of the bidirectional ratchet meshing groove 901, causing the bidirectional ratchet teeth 1002 to disengage from the currently engaged bidirectional ratchet meshing groove 901 and enter the next bidirectional ratchet meshing groove 901 and mesh with it. In the continuous cycle of deformation and meshing, until the dose setting knob stops rotating, the bidirectional ratchet teeth 1002, after passing through multiple bidirectional ratchet meshing grooves 901, mesh with a new bidirectional ratchet meshing groove 901, thus completing the dose setting.

[0097] When the dosage setting knob is rotated counterclockwise, the rear end of the drive arm 301 presses against the bent arm 1004, causing the bent arm 1004 to deform actively. After the bent arm 1004 deforms, since dosage correction occurs after dosage setting, the torsion spring 7 has a certain reverse driving force. Under the driving force of the torsion spring 7, the bidirectional ratchet tooth 1002 disengages from the currently engaged bidirectional ratchet engagement groove 901, retracts to the previous bidirectional ratchet engagement groove 901, and engages with it. In the continuous cycle of deformation and engagement, until the dosage setting knob stops reversing, the bidirectional ratchet tooth 1002, after passing through multiple bidirectional ratchet engagement grooves 901, engages with a new bidirectional ratchet engagement groove 901, completing the dosage correction. During the correction process, the torsion spring 7 also releases the corresponding driving force, and the remaining driving force of the torsion spring 7 after correction completes the subsequent injection process.

[0098] Because the bending arm 1004 is deformed by the pressure of the drive arm 301, the dosage can be corrected with a small reverse force, which makes it less likely to damage the bidirectional ratchet teeth 1002. This is especially suitable for setting and correcting large doses and setting and correcting frequently, thus improving the reliability of the injection device.

[0099] Figure 15 The diagram shows the state after the dosage is set in this embodiment. The dosage is set by rotating the dosage setting ring 3 clockwise. After rotating the dosage setting ring 3, the drive arm 301 pushes the drive protrusion 1001 to rotate. Through the engagement of the drive rod meshing teeth 1003 and the dosage setting ring meshing teeth 501, the dosage setting ring 3 drives the drive rod 5 to rotate through the dosage setting ratchet 10. The upper end of the torsion spring 7 is engaged with the torsion spring fixing ring 4. The torsion spring fixing ring 4 is fixed by the outer shell 9 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.

[0100] Simultaneously, the bidirectional ratchet teeth 1002 and the bidirectional ratchet meshing groove 901 mesh, and the dosage is set through the deformation of the bending arm 1004 and the cycle of meshing. In addition, since the angles of the inclined surfaces on both sides of the bidirectional ratchet meshing groove 901 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 1004, square dosage setting and negative direction dosage correction are achieved.

[0101] 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 902 of the outer casing 9, 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 903.

[0102] Example 2

[0103] This embodiment provides an injection device, including the above-mentioned metering setting and correction structure and an autonomous driving component. The autonomous driving component is provided at the lower end of the drive rod 5. The autonomous driving component is used to drive the push rod to move towards the vial holder to realize injection.

[0104] 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 dosage setting and correction structure, characterized in that, include: Housing, dose setting ring, dose setting ratchet; The inner wall of one end of the outer casing is provided with a bidirectional ratchet meshing tooth groove, and the inner wall of the dose setting ring is provided with a drive arm; the outer wall of the dose setting ratchet is provided with a curved arm and a drive protrusion, and the curved arm is provided with bidirectional ratchet teeth; The dose setting ring is configured to rotate relative to the housing; The dose setting ratchet is located inside the housing, and the drive arm is located between the curved arm and the drive protrusion; The bidirectional ratchet teeth are configured to engage with the bidirectional ratchet meshing grooves; When the dose setting ring is rotated clockwise by one unit, the drive arm rotates synchronously to abut against and push the drive protrusion to rotate, causing the bent arm to undergo elastic deformation, forcing the bidirectional ratchet teeth to disengage from the currently engaged bidirectional ratchet meshing slot and enter the next bidirectional ratchet meshing slot to mesh with it, thus completing the setting of one unit dose. When the dose setting ring is rotated counterclockwise by one cell, the drive arm rotates synchronously to compress the bending arm, causing the bending arm to undergo elastic deformation. This forces the bidirectional ratchet teeth to disengage from the currently engaged bidirectional ratchet meshing slot and retract to the previous bidirectional ratchet meshing slot, thus completing the retraction and revision of the dose for one cell.

2. The dosage setting and correction structure according to claim 1, 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.

3. The dosage setting and correction structure according to claim 1, characterized in that, The outer wall of the outer shell is provided with an annular rib, and the inner wall of the dose setting ring is provided with an outer shell limiting groove. The annular rib is embedded in the outer shell limiting groove to achieve the snap-fit ​​between the outer shell and the dose setting ring.

4. The dosage setting and correction structure according to claim 1, characterized in that, Multiple grooves are provided along the axial direction on the outer wall of the dose setting ring.

5. The dosage setting and correction structure according to claim 1, characterized in that, The dosage setting ratchet has two drive protrusions and two curved arms on its outer wall, and the two drive protrusions and two curved arms are arranged alternately.

6. The dosage setting and correction structure according to claim 1, characterized in that, The inner wall of the dose setting ratchet is provided with meshing teeth, which are used to engage the drive assembly to drive the drive assembly to complete the power storage for dose setting.

7. The dosage setting and correction structure according to claim 6, characterized in that, The dose setting ratchet is equipped with a drive assembly, which includes a drive rod. The dose setting ratchet meshes with the drive rod, so that when the dose setting ring rotates, it can drive the drive rod to rotate through the dose setting ratchet.

8. The dosage setting and correction structure according to claim 7, characterized in that, 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 retaining 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.

9. The dosage setting and correction structure according to claim 8, 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.

10. An injection device, characterized in that, Includes the dosage setting and correction structure as described in any one of claims 1-9.

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