Dose adjustment positive and negative rotation structure of drug delivery device

Abstract

The invention discloses a dose adjustment forward and reverse rotation structure of a medicine delivery device, and belongs to the technical field of medical instruments, the dose adjustment forward and reverse rotation structure comprises a knob, a ratchet seat, ratchet teeth, jumping teeth and an injection spring, the ratchet seat is connected with the ratchet teeth through a forward sound generating part, and the ratchet teeth and the jumping teeth are connected through a reverse sound generating part in a clutch mode; a first forward rotation cooperation part and a first reverse rotation cooperation part are arranged on the rotary knob, a second forward rotation cooperation part and a second reverse rotation cooperation part are arranged on the jumping teeth, and the injection spring is used for enabling the ratchet wheel teeth to be connected with the jumping teeth. The device is simple in structure, convenient to install and good in stability, the preset dosage can be adjusted through clockwise rotation, the force stored by the torsion spring can be clamped, the preset dosage can be reduced through anticlockwise rotation until the preset dosage returns to the zero position, forward rotation is converted into radial elastic tooth jumping meshing sound production, and reverse rotation is converted into axial tooth jumping meshing sound production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a dose adjustment positive and reverse rotation structure of a drug delivery device. BACKGROUND

[0002] Automatic injectors reduce the difficulty of injection treatment and reduce the pain of patients, so they are welcomed by many medical workers and patients. The existing automatic injectors are usually provided with a dose adjustment device. When adjusting the dose, the user rotates the dose adjustment member to store the applied force in the torsional spring for releasing during injection.

[0003] The Chinese patent with the authorized publication number CN103998077B discloses an up / down dial mechanism for an automatic retracting pen, which is used for a settable and adjustable dose size of a multiple injection liquid medicine, the injection device comprises a torsional spring which is tensioned when a dose is set by rotating a dose setting element in a first direction relative to a housing and is relaxed when the dose setting element is rotated in a second direction opposite to the first direction, the up / down dial mechanism comprises at least one ratchet arm arranged to follow the rotation of the dose setting element in the first direction when a dose is set, a toothed element which firmly fixes the at least one ratchet arm against the bias of the torsional spring such that the engagement of the at least one ratchet arm with the teeth of the toothed element prevents the torsional spring from unwinding, and wherein the rotation of the dose setting element in the first direction moves the ratchet arm from one tooth to a subsequent tooth of the toothed element, and the rotation of the dose setting element in the second direction of decreasing the set dose activates the at least one ratchet arm to disengage the teeth of the toothed element and thereby allow the torsional spring to move the ratchet arm in the second direction to a previous tooth such that the force accumulated in the torsional spring is cumulatively reduced, the at least one ratchet arm is arranged on a ratchet tube which is further engaged with the toothed element by a plurality of friction teeth to dampen the movement of the ratchet arm performed by the torsional spring when the at least one ratchet arm disengages the teeth of the toothed element. The above scheme realizes the dose setting by the ratchet arm and realizes the disengagement of the ratchet arm by a reset element to realize the reverse rotation. However, the above scheme has a large number of parts and is complex, the large number of parts is prone to cause functional failure, poor stability, and complicated installation process. SUMMARY

[0004] The dose adjusting positive and negative rotation structure of the drug delivery device has the advantages of simple structure, convenient installation and optimized dose adjusting hand feeling.

[0005] The technical scheme adopted by the present application to solve the technical problem is as follows: a dose adjusting positive and negative rotation structure of a drug delivery device, comprising a knob, a ratchet seat, a ratchet tooth, a jumping tooth and an injection spring, the ratchet seat is connected to or integrally formed with a pen body shell of a torsion spring pen, the ratchet seat is connected with the ratchet tooth through a positive rotation sound emitting part, the ratchet tooth and the jumping tooth are connected in a clutching manner through a negative rotation sound emitting part, the knob is provided with a first positive rotation cooperative part and a first negative rotation cooperative part, the jumping tooth is provided with a second positive rotation cooperative part and a second negative rotation cooperative part, and the injection spring makes the ratchet tooth engage with the jumping tooth; when the knob is positively rotated, the first positive rotation cooperative part and the second positive rotation cooperative part are blocked by each other, the knob drives the ratchet tooth and the jumping tooth to be positively rotated synchronously, and the positive rotation sound emitting part emits sound; when the knob is negatively rotated, the first negative rotation cooperative part and the second negative rotation cooperative part slide relative to each other, the jumping tooth moves axially upward to separate the ratchet tooth and the jumping tooth from each other, the injection spring makes the jumping tooth move downward to engage with the ratchet tooth again, and the negative rotation sound emitting part emits sound due to the engagement of the jumping tooth and the ratchet tooth.

[0006] Further, the positive rotation sound part includes a sound tooth ring arranged on the ratchet seat or the ratchet tooth, and at least one flexible ratchet arm is arranged on the ratchet tooth or the ratchet seat, and a sound tooth block is arranged on the flexible ratchet arm and engages with the sound tooth ring; when the sound tooth ring is arranged on the ratchet seat, the flexible arm is arranged on the ratchet tooth, and vice versa, when the sound tooth ring is arranged on the ratchet tooth, the flexible arm is arranged on the ratchet seat. The reverse rotation sound part includes a first connecting part arranged on the ratchet tooth and a second connecting part arranged on the jumping tooth, and the first connecting part and the second connecting part are connected in a clutching manner; the first positive rotation cooperation part and the second positive rotation cooperation part are vertical surface cooperation parts arranged on the knob and the jumping tooth respectively, and the first reverse rotation cooperation part and the second reverse rotation cooperation part are inclined surface cooperation parts arranged on the knob and the jumping tooth respectively. When the knob rotates in the positive direction, the first positive rotation cooperation part blocks the second positive rotation cooperation part, the first connecting part connects the second connecting part, so that the knob drives the jumping tooth and the ratchet tooth to rotate synchronously, the sound tooth block on the flexible ratchet arm slides on the sound tooth ring, and a positive rotation prompt sound is emitted; when the knob rotates in the reverse direction, the first reverse rotation cooperation part and the second reverse rotation cooperation part slide relative to each other, so that the jumping tooth moves axially upward, the first connecting part on the ratchet tooth and the second connecting part on the jumping tooth are thus separated from each other, but the jumping tooth rotates by a certain angle after being separated from the ratchet tooth, and under the action of the injection spring, the jumping tooth moves downward again, the first connecting part and the second connecting part are reconnected, and a reverse rotation prompt sound is emitted when the ratchet tooth and the jumping tooth collide.

[0007] Further, the positive rotation surface of the tooth shape of the sound tooth ring and the sound tooth block is an inclined surface, and the reverse rotation surface is a vertical surface, when the sound tooth block fully engages with the sound tooth ring, the vertically arranged reverse rotation surface makes the ratchet tooth unable to rotate freely in the reverse direction; when the knob rotates in the positive direction (clockwise), the jumping tooth and the ratchet tooth rotate synchronously in the positive direction, and due to the elasticity of the flexible ratchet arm, the sound tooth block slides on the sound tooth ring, so that the sound tooth block and the tooth surface of the sound tooth ring continuously engage and collide, and a positive rotation prompt sound "dada" is emitted when the knob rotates in the positive direction.

[0008] Further, the first positive rotation cooperation component and the first reverse rotation cooperation component and the second positive rotation cooperation component and the second reverse rotation cooperation component can be a continuous control tooth ring structure, or a single driving tooth block or a tooth groove structure, and the positive rotation cooperation component and the reverse rotation cooperation component can be on the same tooth shape or can be separately arranged on separate components. The positive rotation surface on the control tooth ring structure, the driving tooth block or the tooth groove structure or the separate components is a vertical surface, forming the vertical surface cooperation part; the reverse rotation surface on the control tooth ring structure, the driving tooth block or the tooth groove structure or the separate components is an inclined surface, forming the inclined surface cooperation part. The axial height of the first reverse rotation cooperation component and the second reverse rotation cooperation component is greater than the axial connection height of the first connecting part and the second connecting part. When the knob is rotated in the positive direction (clockwise), the first positive rotation cooperation component and the second positive rotation cooperation component are in contact, and the vertically arranged vertical surface cooperation part can transmit the rotation force, so that the knob can drive the jumping tooth to rotate in the positive direction synchronously; when the knob is rotated in the reverse direction (counterclockwise), the first reverse rotation cooperation component will slide relative to the inclined surface cooperation part arranged on the second reverse rotation cooperation component, so that the jumping tooth is lifted in the axial direction by a distance, so that the second connecting part of the jumping tooth is separated from the first connecting part of the ratchet tooth, and after the separation, the jumping tooth rotates, and after the jumping tooth rotates by a certain angle, the second connecting part of the jumping tooth is connected to the first connecting part of the ratchet tooth again due to the action of the injection spring clamping the jumping tooth, and the ratchet tooth and the jumping tooth collide to produce a "click" reverse rotation prompt sound.

[0009] Further, the upper end of the ratchet seat is provided with a counterbore, the ratchet seat is provided with the sound generating tooth ring at the counterbore, the lower end of the ratchet tooth is embedded in the counterbore, the sound generating tooth ring is arranged in a radial distribution on the side wall of the counterbore, and the flexible ratchet arm is arranged in an arc shape at the lower end of the ratchet tooth. The radially arranged sound generating tooth ring not only facilitates production and assembly, but also enables the knob to be twisted with less force when adjusting the dose in the positive direction, thereby optimizing the positive rotation dose adjustment feel. Preferably, the number of flexible ratchet arms is at least two, and all the flexible ratchet arms are arranged in a circumferential distribution at the lower end of the ratchet tooth.

[0010] Further, the first connecting part comprises a first spline groove and a first spline tooth, the second connecting part comprises a second spline tooth and a second spline groove matched with the first spline groove and the first spline tooth respectively, the first spline groove is matched with the second spline tooth, and the first spline tooth is matched with the second spline groove, preferably, the first spline tooth is slightly smaller than the first spline groove, and the second spline tooth is slightly smaller than the second spline groove, so that the matching of the spline tooth and the spline groove is smoother. The end faces of the first spline tooth and the second spline tooth are provided with inclined parts matched with each other and arranged in an inclined downward manner. The two sides of the first spline groove, the first spline tooth, the second spline tooth and the second spline groove are respectively provided with rotating vertical cooperation parts.

[0011] Further, the torsional spring and a torsional spring driving member are further included, the driving connecting part of the torsional spring driving member is arranged on the jumping tooth, and the torsional spring is connected with the torsional spring driving member. The driving connecting part adopts a connecting key or a connecting spline tooth, and the torsional spring driving member can rotate synchronously with the jumping tooth.

[0012] Further, the injection button is further included, the two ends of the injection spring are respectively abutted against the jumping tooth and the injection button, and the buckle connecting part of the torsional spring driving member is arranged on the injection button.

[0013] Further, the outer surface of the knob is provided with concave-convex patterns facilitating rotation.

[0014] Compared with the prior art, the beneficial effects of the present application are as follows: the design structure is simple, production and assembly are very convenient, the structure is compact, and stability is good; the flexible ratchet arm is adopted in the radial sound generating tooth ring jumping engagement sound generation in the forward rotation, the reverse rotation adopts the jumping tooth axial jumping collision to emit the reverse rotation prompt sound, so that different hand feelings are generated when the user rotates the knob in the forward and reverse directions, different prompt sounds emitted by different parts can be well distinguished, the dose adjustment hand feeling can be well optimized, the structure that the ratchet tooth and the jumping tooth are pushed open in the reverse rotation is more convenient and easier to operate, and the matching of the spline tooth and the spline groove of the ratchet tooth and the jumping tooth makes the dose correction more accurate and stable. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is an explosion view of the overall structure of the embodiment 1 of the present application; Figure 2 It is a sectional view of the overall structure of the embodiment 1 of the present application; Figure 3a It is a perspective view of the overall structure of the embodiment 1 of the present application; Figure 3b It is a perspective view of the overall structure of the embodiment 1 of the present application from another angle; Figure 4a It is an explosion view of the ratchet seat, the ratchet tooth and the jumping tooth of the embodiment 1 of the present application; Figure 4b Figure 1 is a perspective view of the ratchet teeth of the present application embodiment 1; Figure 5a Figure 2 is a schematic view of the ratchet seat and ratchet teeth assembly structure of the present application embodiment 1; Figure 5b Figure 3 is a schematic view of the ratchet teeth and jump teeth assembly structure of the present application embodiment 1; Figure 6 Figure 4 is a schematic view of the ratchet seat, ratchet teeth and knob assembly structure of the present application embodiment 1; Figure 7a Figure 5 is a schematic view of the knob and jump teeth assembly structure of the present application embodiment 1; Figure 7b Figure 6 is a schematic view of the knob and jump teeth assembly structure of the present application embodiment 1 in transverse section; Figure 8 Figure 7 is an exploded view of the overall structure of the present application embodiment 2; Figure 9 Figure 8 is a sectional view of the overall structure of the present application embodiment 2; Figure 10 Figure 9 is an exploded view of the ratchet seat and ratchet teeth of the present application embodiment 2; Figure 11 Figure 10 is a schematic view of the knob structure of the present application embodiment 3; Figure 12 Figure 11 is a schematic view of the jump teeth structure of the present application embodiment 3; Figure: 1, ratchet seat; 11, sound tooth ring; 2, ratchet teeth; 21, ratchet arm; 22, sound tooth block; 23, first connecting part; 231, first spline groove; 232, first spline tooth; 233, inclined part; 3, knob; 301, first forward rotation cooperative component; 302, first reverse rotation cooperative component; 4, jump teeth; 401, second forward rotation cooperative component; 402, second reverse rotation cooperative component; 41, second connecting part; 411, second spline tooth; 412, second spline groove; 5, injection spring; 6, injection button; 61, buckle connection part; 30, drive connection part. DETAILED DESCRIPTION

[0016] The present application will be further described below in conjunction with the drawings and specific embodiments. It is worth noting that the following specific embodiments are only representative of the present application, and the specific methods, devices, conditions, materials, etc. shown in the examples are not intended to limit the present application or the corresponding specific embodiments.

[0017] Embodiment 1 A dosage adjustment forward and reverse rotation structure for a drug delivery device, such as Figures 1 to 7b As shown, the device includes a ratchet seat 1, ratchet teeth 2, a knob 3, a jumping tooth 4, an injection spring 5, and an injection button 6. The ratchet seat 1 is connected to the torsion spring pen body housing. In other embodiments, the ratchet seat 1 can also be designed to be integrally formed with the torsion spring pen body housing. The knob 3 is sleeved on the outer periphery of the ratchet seat 1, and the knob 3 can also be sleeved on the torsion spring pen body. The ratchet seat 1 and the ratchet teeth 2 are connected via a forward-rotating sound part, and the ratchet teeth 2 and the jumping tooth 4 are disengaged via a reverse-rotating sound part. The knob 3 is provided with a first forward-rotating cooperating component 301 and a first reverse-rotating cooperating component 302. The jumping tooth is provided with a second forward-rotating cooperating component 401 and a second reverse-rotating cooperating component 402 that respectively cooperate with the first forward-rotating cooperating component 301 and the first reverse-rotating cooperating component 302.

[0018] In this embodiment, the forward-rotating sound-generating part includes a sound-generating toothed ring 11 disposed on the ratchet seat 1. The ratchet tooth 2 has at least one flexible ratchet arm 21, and the flexible ratchet arm 21 has a sound-generating tooth block 22 that meshes with the sound-generating toothed ring 11. The reverse-rotating sound-generating part includes a first connecting portion 23 disposed on the upper end face of the ratchet tooth 2 and a second connecting portion 41 disposed on the lower end face of the bouncing tooth 4. The first forward-rotating cooperating component 301 and the second forward-rotating cooperating component 401 are vertical cooperating portions respectively disposed on the knob 3 and the bouncing tooth 4, and the first reverse-rotating cooperating component 302 and the second reverse-rotating cooperating component 402 are inclined cooperating portions respectively disposed on the knob 3 and the bouncing tooth 4.

[0019] In this embodiment, the upper end of the ratchet seat 1 is provided with a countersunk hole, and the ratchet seat 1 is provided with a sound-generating tooth ring 11 at the countersunk hole. The lower end of the ratchet tooth 2 is embedded in the countersunk hole, and the lower end of the ratchet tooth 2 is provided with at least one flexible ratchet arm 21. The outer surface of the end of the flexible ratchet arm 21 is provided with a sound-generating tooth block 22 that meshes with the sound-generating tooth ring 11. The forward rotation surfaces of the tooth profiles of the sound-generating tooth ring 11 and the sound-generating tooth block 22 are both inclined planes, and the angle between the inclined plane and the horizontal plane is preferably 120° to 140°. The reverse rotation surfaces are vertical planes. The upper end of the ratchet tooth 2 is provided with a first connecting part 23, and the lower end of the jumping tooth 4 is provided with a second connecting part 41 that cooperates with the first connecting part 23. The first forward rotation cooperating component 301 and the first reverse rotation cooperating component 302, as well as the second forward rotation cooperating component 401 and the second reverse rotation cooperating component 402, can be a continuous control tooth ring structure, or a separate drive tooth block or tooth groove structure, or vertical and inclined surfaces on different components.

[0020] In this embodiment, the first forward rotation cooperating component 301 and the first reverse rotation cooperating component 302 are control tooth block structures formed on the knob 3, while the second forward rotation cooperating component 401 and the second reverse rotation cooperating component 402 are control tooth groove structures formed on the jumping tooth 4. In other embodiments, such as Figures 11-12 As shown, the first forward rotation cooperating component 301 and the first reverse rotation cooperating component 302 are control gear ring structures formed on the knob 3, and the second forward rotation cooperating component 401 and the second reverse rotation cooperating component 402 are also control gear ring structures formed on the jumping tooth 4. The forward rotation tooth surfaces of the control gear ring structure and the drive tooth block or tooth groove structure are vertical, forming the vertical cooperating part. The angle between the vertical cooperating part and the vertical plane is preferably +5° to -5°. A slight angle will not affect the transmission of rotational torque after the first forward rotation cooperating component 301 and the second forward rotation cooperating component 401 are engaged. The reverse rotation tooth surfaces of the control gear ring structure and the drive tooth block or tooth groove structure are inclined, forming the inclined cooperating part. The angle between the inclined cooperating part and the horizontal plane is preferably 120° to 140°. The purpose of the inclined first reverse rotation cooperating component 302 and the second reverse rotation cooperating component 402 is to convert a portion of the rotational torque into axial torque to push open the jumping tooth 4. The axial height of the first reversing cooperative component 302 and the second reversing cooperative component 402 is greater than the axial connection height between the first connecting part 23 and the second connecting part 41. A drive connecting part 30 for connecting a torsion spring drive is also provided on the inner wall of the jumping tooth 4. The drive connecting part 30 uses a connecting key or connecting spline teeth, and a torsion spring is connected to the torsion spring drive. The structure of the torsion spring drive and the dosage adjustment principle can be referred to in the applicant's earlier invention patent application with publication number CN119770799A, entitled "A Torsion Spring Automatic Injector." In the earlier application, the upper end of the clutch cylinder is provided with connecting spline teeth, which can be used to connect with the drive connecting part 30 of this application, realizing synchronous rotation of the torsion spring drive and the jumping tooth 4. At the same time, the torsion spring drive drives the torsion spring to rotate and adjust the dosage setting value. The two ends of the injection spring 5 respectively abut against the jumping tooth 4 and the injection button 6. The injection button 6 is provided with a snap-fit ​​connecting part 61 for connecting the torsion spring drive.

[0021] In this embodiment, the injection spring 5 pushes the upper surface of the jumping tooth 4 to provide torque to make the ratchet tooth 2 engage with the jumping tooth 4. In other embodiments, a spring connecting the ratchet tooth 2 and the jumping tooth 4 or a spring pushing upward at the lower end of the ratchet tooth 2 can also be provided to make the ratchet tooth 2 engage with the jumping tooth 4. Under the action of the injection spring 5, the first forward rotation cooperating part 301 and the second forward rotation cooperating part 401 are in contact in the original state, the first reverse rotation cooperating part 302 and the second reverse rotation cooperating part 402 are in contact, and the first connecting part 23 keeps connecting the second connecting part 41.

[0022] When the knob 3 rotates forward, the first forward rotation cooperating part 301 and the second forward rotation cooperating part 401 are in contact, the vertically arranged vertical surface cooperating part can transmit rotation force, the knob 3 drives the jumping tooth 4 to rotate forward synchronously, the jumping tooth 4 connects the ratchet tooth 2 to rotate forward synchronously, the tooth surface of the sound generating tooth ring 11 and the sound generating tooth block 22 is inclined, and the flexibility of the flexible ratchet arm 21 makes the sound generating tooth block 22 slide on the sound generating tooth ring 11, so that the sound generating tooth block 22 on the flexible ratchet arm 21 continuously engages and collides with the tooth surface of the sound generating tooth ring 11 to make the knob 3 emit a forward rotation reminder sound when rotating forward, the reverse rotation surface of the sound generating tooth ring 11 and the sound generating tooth block 22 is vertical, the ratchet tooth 2 cannot rotate reversely, and the jumping tooth 4 connected with the ratchet tooth 2 also cannot rotate reversely freely, so that the knob 3 can drive the torsion spring driving part to rotate forward to accumulate energy and increase the set dose when rotating forward, the scale of the energy accumulated by the torsion spring driving part during the forward rotation process is set by the structure of the torsion spring driving part, which is not described here, and the ratchet tooth 2 will emit a forward rotation reminder sound due to the flexibility of the flexible ratchet arm 21 when rotating synchronously.

[0023] When the knob 3 is reversed (counterclockwise), at the beginning of the reverse rotation, the ratchet teeth 2 cannot be reversed, and the jump teeth 4 connected with the ratchet teeth 2 also cannot be reversed. The first reverse cooperation component 302 on the knob 3 will slide relative to the second reverse cooperation component 402 on the jump teeth, so that the jump teeth 4 are pushed upward in the axial direction. After the knob 3 is reversed by a certain angle, the jump teeth 4 are pushed upward in the axial direction by a distance, so that the second connecting part 41 of the jump teeth 4 is separated from the first connecting part 23 of the ratchet teeth 2, that is, the connection between the jump teeth 4 and the ratchet teeth 2 is invalid. Due to the force storage of the torsional spring, the torsional spring drive member drives the jump teeth to reverse to reduce the energy and reduce the set dose. Since the axial height of the first reverse cooperation component 302 and the second reverse cooperation component 402 is greater than the axial connection height of the first connecting part 23 and the second connecting part 41, after the jump teeth 4 are separated from the ratchet teeth 2, the first reverse cooperation component 302 and the second reverse cooperation component 402 are still in a sliding connection state. After the jump teeth 4 are separated from the ratchet teeth 2, the first connecting part 23 and the second connecting part 41 are no longer connected. The jump teeth 4 are pushed downward in the axial direction after being reversed by a certain angle due to the action of the injection spring 5. The first connecting part 23 and the second connecting part 41 are connected again. During the reverse rotation of the knob 3, the above actions will be repeated. The first reverse cooperation component 302 will slide back and forth relative to the second reverse cooperation component 402. The jump teeth 4 will be pushed up and then rotate and fall after the knob 3 is reversed by a certain angle. Since the jump teeth 4 are pushed up and then rotate and fall during the reverse rotation, the user can clearly feel that the force is stuck. The reverse rotation reminding sound caused by the collision of the jump teeth 4 improves the user's hand feeling and experience.

[0024] Further, the sound generating tooth ring 11 is arranged in a radial direction on the side wall of the counterbore, and the flexible ratchet arm 21 is arranged in an arc shape at the lower end of the ratchet tooth 2. The radial arrangement of the sound generating tooth ring 11 can facilitate production and assembly. Compared with the upward / dwelling mechanism in the prior art, the knob 3 can be twisted with less force during the forward rotation for dose adjustment, and the hand feeling during the forward rotation for dose adjustment is optimized. In this embodiment, the number of flexible ratchet arms 21 is preferably three, and the three flexible ratchet arms 21 are arranged in a circumferential distribution at the lower end side wall of the ratchet tooth 2.

[0025] Further, the first connecting part 23 comprises first spline teeth 232 arranged continuously and at intervals, and a first spline groove 231 is formed between two adjacent first spline teeth 232. The second connecting part 41 comprises a second spline tooth 411 and a second spline groove 412 which are matched with the first spline groove 231 and the first spline tooth 232 respectively. In the embodiment, the first spline tooth 232 and the second spline groove 412 are matched with clearance, and the first spline tooth 232 and the second spline groove 412 are designed to be slightly smaller than the corresponding second spline groove 412 and the first spline groove 231, so that the connection is smoother and the assembly is more convenient. However, in other embodiments, the sizes of the spline teeth and the spline groove can have other relationships, such as being the same, as long as the detachable connection can be achieved. The end faces of the first spline tooth 232 and the second spline tooth 411 are provided with inclined portions 233 which are matched with each other and are arranged downwardly and obliquely. In this way, when the jump tooth 4 slides and falls into the engagement with the ratchet tooth 2, the end faces of the first spline tooth 232 and the second spline tooth 411 can play a guiding role, so that the second spline tooth 411 can slide and fall into the adjacent first spline groove 231.

[0026] In the embodiment, the first spline groove 231 and the second spline groove 412 are also provided with inclined portions, but in other embodiments, the design of the spline groove only needs to meet the detachable connection of the spline tooth, and does not require the inclined portion. The first spline groove 231, the first spline tooth 232, the second spline tooth 411 and the second spline groove 412 are respectively provided with rotating vertical cooperation portions on both sides. When the knob 3 starts to reverse, the right longer vertical cooperation portions are blocked with each other, so that the jump tooth 4 cannot rotate relative to the ratchet tooth 2, and after the jump tooth 4 and the ratchet tooth 2 are separated, the jump tooth 4 can rotate.

[0027] Further, the upper end face of the jump tooth 4 is provided with a groove for mounting the injection spring 5, which is convenient for assembly and positioning, and makes the overall structure more stable and firm.

[0028] Further, the outer surface of the knob 3 is provided with concave-convex patterns for convenient rotation.

[0029] Embodiment 2 A dose adjustment forward and reverse rotation structure of a drug delivery device, comprising a knob 3, a ratchet tooth 2 and a jump tooth 4. Figures 8 to 10As shown, the device includes a ratchet seat 1, ratchet teeth 2, a knob 3, a jumping tooth 4, an injection spring 5, and an injection button 6. The structure of this embodiment is similar to that of Embodiment 1, except that in this embodiment, the forward-rotating sound part includes a sound-generating toothed ring 11 disposed on the ratchet teeth 2, and at least one flexible ratchet arm 21 provided on the ratchet seat 1. The flexible ratchet arm 21 is provided with a sound-generating toothed block 22 that meshes with the sound-generating toothed ring 11. Compared to Embodiment 1, the same forward-rotating sound purpose can be achieved by interchanged positions of the sound-generating toothed ring 11 and the flexible ratchet arm 21 on the ratchet seat 1 and the ratchet teeth 2. Simple adaptive changes can be made to the shape and angle of the sound-generating toothed ring 11 and the sound-generating toothed block 22.

[0030] Example 3 A dosage adjustment forward and reverse rotation structure for a drug delivery device, such as Figure 11 and Figure 12 As shown, it includes a ratchet seat 1, ratchet teeth 2, a knob 3, a jumping tooth 4, an injection spring 5, and an injection button 6. The structure of this embodiment is similar to that of Embodiment 1, except that in this embodiment, the first forward rotation cooperating component 301 and the first reverse rotation cooperating component 302 are control toothed ring structures formed on the knob 3, and the second forward rotation cooperating component 401 and the second reverse rotation cooperating component 402 are also control toothed ring structures formed on the jumping tooth 4.

[0031] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the description of the invention shall still fall within the scope of the patent of the present invention.

Claims

1. A dose setting forward and reverse rotation structure of a drug delivery device, characterized in that, The device comprises a knob (3), a ratchet seat (1), a ratchet tooth (2), a jumping tooth (4) and an injection spring (5), the ratchet seat (1) is connected with the ratchet tooth (2) through a forward rotation sound emitting part, the ratchet tooth (2) and the jumping tooth (4) are connected through a reverse rotation sound emitting part, the knob (3) is provided with a first forward rotation cooperative part (301) and a first reverse rotation cooperative part (302), the jumping tooth (4) is provided with a second forward rotation cooperative part (401) and a second reverse rotation cooperative part (402), the injection spring (5) makes the ratchet tooth (2) and the jumping tooth (4) engage; the forward rotation sound emitting part comprises a sound emitting tooth ring (11) and at least one flexible ratchet arm (21), the sound emitting tooth ring (11) and the at least one flexible ratchet arm (21) are arranged on the ratchet seat (1) and the ratchet tooth (2) respectively, the flexible ratchet arm (21) is provided with a sound emitting tooth block (22) engaged with the sound emitting tooth ring (11); the reverse rotation sound emitting part comprises a first connecting part (23) arranged on the ratchet tooth (2) and a second connecting part (41) arranged on the jumping tooth (4), the first connecting part (23) and the second connecting part (41) are connected in a detachable manner; when the knob (3) rotates forward, the first forward rotation cooperative part (301) and the second forward rotation cooperative part (401) are blocked with each other, the knob (3) drives the ratchet tooth (2) and the jumping tooth (4) to rotate forward synchronously; when the knob (3) rotates reversely, the first reverse rotation cooperative part (302) and the second reverse rotation cooperative part (402) slide relative to each other, so that the jumping tooth (4) moves axially to separate the ratchet tooth (2) and the jumping tooth (4) from each other.

2. A dose setting mechanism for a drug delivery device according to claim 1, wherein The first forward rotation cooperative part (301) and the second forward rotation cooperative part (401) are vertical surface cooperative parts arranged on the knob (3) and the jumping tooth (4) respectively, and the first reverse rotation cooperative part (302) and the second reverse rotation cooperative part (402) are inclined surface cooperative parts arranged on the knob (3) and the jumping tooth (4) respectively.

3. The dose setting mechanism of a drug delivery device according to claim 1, wherein The upper end of the ratchet seat (1) is provided with a counterbore, the lower end of the ratchet tooth (2) is embedded in the counterbore, and the sound emitting tooth ring (11) is arranged on the side wall of the counterbore in a radial distribution.

4. The dose setting mechanism of a drug delivery device according to claim 1, characterized in that The first connecting part (23) comprises a first spline groove (231) and a first spline tooth (232), and the second connecting part (41) comprises a second spline tooth (411) and a second spline groove (412) matched with the first spline groove (231) and the first spline tooth (232) respectively.

5. A dose dialling reverse rotation structure of a drug delivery device according to claim 4, wherein, Inclined parts matched with each other are arranged on the end faces of the first spline tooth (232) and the second spline tooth (411).

6. A dose dialling reverse rotation structure of a drug delivery device according to claim 5, wherein, Rotary vertical cooperative parts are arranged on both sides of the first spline groove (231), the first spline tooth (232), the second spline tooth (411) and the second spline groove (412).

7. A dose dialling reverse rotation structure of a drug delivery device according to any of claims 1-6, characterized in that, The torsion spring is connected with the torsion spring driving member.

8. A dose dialling reverse rotation structure of a drug delivery device according to any of claims 1-6, characterized in that, The injection button (6) is further included, and two ends of the injection spring (5) are respectively abutted with the jump tooth (4) and the injection button (6).

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