A dose adjustment mechanism and injection pen

Abstract

The application discloses a dose adjusting mechanism and an injection pen, relates to the technical field of medical devices, and comprises a torsional spring support, a bidirectional stop, a knob and a power sleeve. The torsional spring support is provided with a bidirectional ratchet meshing groove, and the bidirectional stop is provided with bidirectional ratchet meshing teeth and a first driving groove. The knob is rotatable and is provided with a second driving groove, a ratchet window, a first spade tooth and a second spade tooth. The bidirectional ratchet meshing teeth are arranged to pass through the ratchet window and mesh with the bidirectional ratchet meshing groove. The power sleeve is provided with a first driving protrusion which is in transmission with the first driving groove and a second driving protrusion which is in transmission with the second driving groove. When the dose is corrected, the second spade tooth of the knob exerts a force on the bidirectional stop, and the force can be decomposed into two components along the tangential direction and the axial direction of the knob. The component along the axial direction can lift the bidirectional stop, and the meshing between the bidirectional stop and the torsional spring support can be smoothly disengaged, so that the torsion of the knob is reduced, and the smoothness of operation is improved.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more specifically, to a dosage adjustment mechanism and an injection pen. Background Technology

[0002] Reusable injection pens are suitable for treatment scenarios requiring high-frequency, multiple-dose administration. Their reusability reduces the cost of long-term medication, while offering flexible dosage adjustment and the ability to be discarded after one use cycle, providing significant application advantages. However, current injection pens with self-driving (energy storage) structures generally suffer from a technical shortcoming: their dosage correction function is unsatisfactory. Specifically, they either lack dosage correction capabilities entirely, making it irreversible after setting errors, or the correction process is cumbersome and involves significant resistance, severely impacting the smoothness of user operation and overall user experience.

[0003] Therefore, how to effectively improve the smoothness of the dose correction process has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a dose adjustment mechanism to effectively improve the smoothness of the dose correction process.

[0005] Another object of this application is to provide an injection pen including the above-described dosage adjustment mechanism.

[0006] A dose adjustment mechanism, comprising:

[0007] A torsion spring bracket, wherein the torsion spring bracket is provided with a bidirectional ratchet engagement groove;

[0008] A bidirectional stop, wherein the bidirectional stop is provided with bidirectional ratchet meshing teeth and a first driving groove;

[0009] A knob is rotatably fitted outside the torsion spring bracket, and the knob is provided with a second drive groove, a ratchet window, a first shovel tooth and a second shovel tooth. The bidirectional stop is provided inside the knob, and the bidirectional ratchet meshing teeth pass through the ratchet window and mesh with the bidirectional ratchet meshing groove.

[0010] A power sleeve is used for transmission connection with a dosage injection mechanism, and the power sleeve is provided with a first driving protrusion and a second driving protrusion. The power sleeve drives the bidirectional stop rotation through the insertion of the first driving protrusion and the first driving groove, and the knob drives the power sleeve to rotate through the insertion of the second driving protrusion and the second driving groove.

[0011] When the knob rotates around the first direction, the knob first drives the power sleeve to rotate and pushes the bidirectional ratchet meshing teeth to move axially and disengage from the current bidirectional ratchet meshing groove through the first shovel teeth. Then, the power sleeve drives the bidirectional stop to rotate around the first direction to the next bidirectional ratchet meshing groove.

[0012] When the knob rotates around the second direction, the knob first drives the power sleeve to rotate and pushes the bidirectional ratchet engagement tooth to move axially away from the current bidirectional ratchet engagement groove through the second shovel tooth, and then drives the bidirectional stop to rotate around the second direction to the previous bidirectional ratchet engagement groove through the power sleeve.

[0013] In some embodiments, the first driving groove is provided with a first forward rotation transmission position and a first reverse rotation transmission position, and the first driving protrusion can move between the first forward rotation transmission position and the first reverse rotation transmission position; the second driving groove is provided with a second forward rotation transmission position and a second reverse rotation transmission position, and the second driving protrusion can move between the second forward rotation transmission position and the second reverse rotation transmission position.

[0014] When the second drive protrusion is in the second forward rotation transmission position and the knob rotates around the first direction, the power sleeve rotates around the first direction to first move the first drive protrusion from the first reverse rotation transmission position to the first forward rotation transmission position, and then drive the bidirectional stop to rotate around the first direction.

[0015] When the second drive protrusion is in the second reverse transmission position and the knob rotates around the second direction, the power sleeve rotates around the second direction to first move the first drive protrusion from the first forward transmission position to the first reverse transmission position, and then drive the bidirectional stop to rotate around the second direction.

[0016] In some embodiments, the ratchet window has a first end and a second end arranged opposite to each other. The first shovel tooth is disposed at the first end of the ratchet window and extends from the side away from the ratchet window to the side closer to the ratchet window. The tooth surface of the first shovel tooth is inclined in the direction of the torsion spring bracket and extends to the ratchet window for pushing the bidirectional ratchet meshing tooth to move axially.

[0017] The second shovel tooth is disposed at the second end of the ratchet window and extends from the side away from the ratchet window to the side closer to the ratchet window. The tooth surface of the second shovel tooth is inclined in the direction of the torsion spring bracket and extends to the ratchet window to push the bidirectional ratchet meshing tooth to move axially.

[0018] In some embodiments, the bidirectional ratchet meshing teeth have a first tooth surface, a second tooth surface, and a third tooth surface, wherein the first tooth surface and the second tooth surface are arranged at an angle to the third tooth surface;

[0019] The first tooth surface is arranged opposite to the first shovel tooth, the second tooth surface is arranged opposite to the second shovel tooth, and the third tooth surface abuts against the braking surface of the bidirectional ratchet engagement groove.

[0020] In some embodiments, the angle between the first tooth surface and the central axis of the torsion spring bracket is greater than the angle between the third tooth surface and the central axis of the torsion spring bracket;

[0021] The angle between the second tooth surface and the central axis of the torsion spring bracket is greater than the angle between the third tooth surface and the central axis of the torsion spring bracket.

[0022] In some embodiments, the bidirectional ratchet engagement groove has a braking surface and a guide surface arranged at an angle, the bidirectional ratchet engagement teeth move along the guide surface, and the angle between the braking surface and the central axis of the torsion spring bracket is smaller than the angle between the guide surface and the central axis of the torsion spring bracket.

[0023] In some embodiments, a mounting groove is formed between the side of the second drive protrusion facing the torsion spring bracket and the power sleeve; the knob includes:

[0024] A ring-shaped main body structure is rotatably fitted outside the torsion spring bracket, and the bidirectional stop is disposed inside the ring-shaped main body structure;

[0025] The mounting plate is disposed on the inner wall of the annular main structure. The second drive groove, the first shovel tooth, and the second shovel tooth are all disposed on the side of the mounting plate facing away from the torsion spring bracket. The ratchet window passes through the mounting plate axially. The power sleeve passes through the mounting plate, and the mounting plate is engaged with the mounting slot.

[0026] In some embodiments, the side of the second driving protrusion facing away from the torsion spring bracket is a sloping structure, and it is inclined towards the direction of the torsion spring bracket from the side close to the central axis of the power sleeve to the side away from the central axis of the power sleeve.

[0027] The mounting plate has a chamfer on the side facing the torsion spring bracket and is arranged axially along the annular main structure. The chamfer is opposite to the second driving protrusion and is used to slide into the mounting slot along the inclined structure.

[0028] In some embodiments, the bidirectional ratchet engagement teeth are two circumferentially spaced teeth arranged around the bidirectional stop axis;

[0029] The ratchet window, the first shovel tooth, and the second shovel tooth are all two that correspond one-to-one with the bidirectional ratchet meshing teeth.

[0030] In some embodiments, the first driving groove is two symmetrically arranged relative to the bidirectional stop axis, and the first driving protrusion is two corresponding to the first driving groove;

[0031] The second driving groove consists of two symmetrically arranged relative to the central axis of the knob, and the second driving protrusion consists of two corresponding to the second driving groove.

[0032] In some embodiments, it also includes:

[0033] A button, which is movably disposed at the end of the knob away from the torsion spring bracket;

[0034] A button cover is disposed at the end of the button away from the torsion spring bracket;

[0035] A compression spring, the two ends of which abut against the bidirectional stop and the button, respectively.

[0036] An injection pen comprising the dosage adjustment mechanism described in any of the preceding claims.

[0037] The dosage adjustment mechanism provided in this application includes a torsion spring bracket, a bidirectional stop, a knob, and a power sleeve. The torsion spring bracket is provided with a bidirectional ratchet engagement groove and is used to mount on the outer shell of the injection pen. The bidirectional stop is provided with bidirectional ratchet engagement teeth and a first drive groove. The knob is rotatably mounted on the outside of the torsion spring bracket and is provided with a second drive groove, a ratchet window, a first shovel tooth, and a second shovel tooth. The bidirectional stop is located inside the knob, and the bidirectional ratchet engagement teeth can pass through the ratchet window to engage with the bidirectional ratchet engagement groove. The first shovel tooth and the second shovel tooth... The spade teeth are used to push the bidirectional ratchet meshing teeth axially and disengage from the current bidirectional ratchet meshing groove when the dose adjustment is increased and decreased, respectively; the power sleeve is used for transmission connection with the dose injection mechanism, and a first drive protrusion and a second drive protrusion are provided on the power sleeve. The power sleeve can drive the bidirectional stop to rotate synchronously through the fitting of the first drive protrusion and the first drive groove. The knob can drive the power sleeve to rotate synchronously through the fitting of the second drive protrusion and the second drive groove. The rotation angle of the power sleeve determines the set dose or the corrected dose.

[0038] Specifically, when the knob rotates around the first direction, the knob continuously drives the power sleeve to rotate around the first direction through the engagement between the second drive protrusion and the second drive groove. Simultaneously, the first shovel tooth pushes the bidirectional ratchet engagement teeth axially to disengage from the current bidirectional ratchet engagement groove. After disengagement, the knob no longer directly drives the bidirectional stop to move. Instead, through the transmission engagement between the second drive protrusion and the second drive groove, and the transmission engagement between the first drive protrusion and the first drive groove, a rotational power transmission path is formed from the knob to the power sleeve and then to the bidirectional stop, thereby causing the bidirectional stop to rotate around the first direction to the next bidirectional stop. The dosage is increased by adjusting the ratchet engagement groove. When the knob rotates around the second direction, the knob continuously drives the power sleeve to rotate. First, the second shovel tooth pushes the bidirectional ratchet engagement tooth to move axially and disengage from the current bidirectional ratchet engagement groove. After disengagement, the knob no longer directly drives the bidirectional stop to move. Instead, the rotational power transmission path from the knob to the power sleeve and then to the bidirectional stop is formed through the transmission cooperation between the second drive protrusion and the second drive groove, and the transmission cooperation between the first drive protrusion and the first drive groove. This causes the bidirectional stop to rotate around the second direction to the previous bidirectional ratchet engagement groove, thereby reducing the dosage.

[0039] Compared to existing technologies, the dosage adjustment mechanism provided in this application effectively improves the smoothness of the dosage correction process by optimizing the mechanical transmission structure. This solves the problem of excessive knob torque in traditional injection pens during dosage correction, thus significantly improving the user experience and user-friendliness of the injection pen. Furthermore, the dosage adjustment mechanism disclosed in this application, while ensuring the accuracy of dosage setting and correction, also reduces the risk of internal component damage due to strenuous operation, enhancing product reliability. It is particularly suitable for applications requiring large doses or frequent adjustments.

[0040] The injection pen provided in this application includes the aforementioned dose adjustment mechanism, and therefore also possesses the aforementioned structure and beneficial effects. Other structures refer to the prior art and will not be described in detail here. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is an isometric view of the dose adjustment mechanism disclosed in the embodiments of this application;

[0043] Figure 2 This is an exploded view of the dose adjustment mechanism disclosed in the embodiments of this application;

[0044] Figure 3 A cross-section of the dose adjustment mechanism disclosed in the embodiments of this application. Figure 1 ;

[0045] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0046] Figure 5 A cross-section of the dose adjustment mechanism disclosed in the embodiments of this application. Figure 2 ;

[0047] Figure 6 A cross-section of the dose adjustment mechanism disclosed in the embodiments of this application. Figure 3 ;

[0048] Figure 7 This is a schematic diagram of the assembly of some components in the dose adjustment mechanism disclosed in the embodiments of this application. Figure 1 ;

[0049] Figure 8 This is a schematic diagram of the assembly of some components in the dose adjustment mechanism disclosed in the embodiments of this application. Figure 2 ;

[0050] Figure 9 This is a schematic diagram of the assembly of some components in the dose adjustment mechanism disclosed in the embodiments of this application. Figure 3 ;

[0051] Figure 10 This is a schematic diagram of the structure of the torsion spring bracket disclosed in the embodiments of this application;

[0052] Figure 11 This is a schematic diagram of the bidirectional stop structure disclosed in the embodiments of this application;

[0053] Figure 12 This is a schematic diagram of the structure of the knob disclosed in the embodiments of this application;

[0054] Figure 13 This is a schematic diagram of the power sleeve structure disclosed in an embodiment of this application;

[0055] Figure 14 This is a schematic diagram of the button structure disclosed in the embodiments of this application;

[0056] Figure 15 This is a schematic diagram of the structure of the button cover disclosed in an embodiment of this application.

[0057] Among them, 100 is a torsion spring bracket, 110 is a two-way ratchet engagement groove, 111 is a braking surface, and 112 is a guide surface;

[0058] 200 is a bidirectional stop, 210 is a bidirectional ratchet meshing tooth, 211 is the first tooth surface, 212 is the second tooth surface, 213 is the third tooth surface, and 220 is the first drive groove.

[0059] 300 is a knob, 310 is a second drive groove, 320 is a ratchet window, 330 is a second shovel tooth, 331 is a first shovel tooth, 340 is a clearance groove, 350 is a mounting plate, and 351 is a chamfer.

[0060] 400 is the power sleeve, 410 is the first drive protrusion, 420 is the second drive protrusion, 421 is the mounting slot, and 430 is the transmission gear.

[0061] 500 is the button, 510 is the button cover, and 520 is the compression spring. Detailed Implementation

[0062] The core of this application is to disclose a dose adjustment mechanism to effectively improve the smoothness of the dose correction process.

[0063] Another key aspect of this application is the disclosure of an injection pen that includes the aforementioned dose adjustment mechanism.

[0064] The embodiments will now be described with reference to the accompanying drawings. Furthermore, the embodiments shown below do not limit the scope of the invention as described in the claims. Additionally, the complete contents of the structures represented in the embodiments below are not limited to those necessary for the solution of the invention as described in the claims. It should be noted that, for ease of description, only the parts relevant to the invention are shown in the drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0065] It should be noted that in this application, the first direction and the second direction are opposite, for example, Figures 1-15 The diagram illustrates a technical solution where the first direction is clockwise and the second direction is counterclockwise. For ease of explanation, the following description will use the example where the first direction is used to adjust the increase in dosage and the second direction is used to adjust the decrease in dosage.

[0066] In existing technologies, to achieve precise dosage setting and maintenance, the dosage adjustment mechanism of an injection pen typically includes a bidirectional stop mechanism linked to a knob and a fixed torsion spring support. The meshing teeth on the bidirectional stop mechanism engage with the grooves on the torsion spring support. This serves to lock the knob after dosage setting via a ratchet effect, preventing accidental rotation and ensuring the stability of the set dosage. However, when the user needs to correct the dosage (i.e., adjust the dosage back), the meshing teeth and grooves must be forcibly disengaged. This disengagement process requires the user to apply significant torque to overcome the tight meshing force, directly resulting in a stiff and difficult-to-operate knob during adjustment, severely impacting the user experience.

[0067] Based on this, this application discloses a dosage adjustment mechanism that splits the original knob into two parts: a power sleeve and a knob. The knob is operated by the user, and the power sleeve is used to transmit power to the dosage injection mechanism. When making dosage corrections, the rotation of the knob applies a force to the bidirectional stop. This force can be decomposed into two components: one along the tangential direction and the other along the axial direction. The axial component lifts the bidirectional stop, which allows the bidirectional stop to disengage smoothly from the torsion spring support, thereby reducing the torque of the knob and improving the smoothness and stability of operation.

[0068] Combination Figures 1-15 The dosage adjustment mechanism disclosed in this application includes a torsion spring bracket 100, a bidirectional stop 200, a knob 300, and a power sleeve 400. The torsion spring bracket 100 is provided with a bidirectional ratchet engagement groove 110 and is used to mount on the outer shell of the injection pen. The bidirectional stop 200 is provided with bidirectional ratchet engagement teeth 210 and a first drive groove 220. The knob 300 is rotatably sleeved on the outside of the torsion spring bracket 100 and is provided with a second drive groove 310, a ratchet window 320, a first shovel tooth 331, and a second shovel tooth 330. The bidirectional stop 200 is located inside the knob 300, and the bidirectional ratchet engagement teeth 210 can pass through the ratchet window 320 to engage with the bidirectional ratchet engagement groove 110. The first shovel tooth 331 and the second shovel tooth 330 are used to push the bidirectional ratchet engagement tooth 210 to move axially and disengage from the current bidirectional ratchet engagement groove 110 when the dose adjustment is increased and decreased, respectively. The power sleeve 400 is used to drive the dose injection mechanism, and a first drive protrusion 410 and a second drive protrusion 420 are provided on the power sleeve 400. The power sleeve 400 can drive the bidirectional stop 200 to rotate synchronously through the fitting of the first drive protrusion 410 and the first drive groove 220. The knob 300 can drive the power sleeve 400 to rotate synchronously through the fitting of the second drive protrusion 420 and the second drive groove 310. The rotation angle of the power sleeve 400 determines the set dose or the corrected dose.

[0069] Specifically, in combination Figures 6-9 When the knob 300 rotates around the first direction, through the engagement between the second drive protrusion 420 and the second drive groove 310, the knob 300 continuously drives the power sleeve 400 to rotate around the first direction. At the same time, the first shovel tooth 331 first pushes the bidirectional ratchet engagement tooth 210 to move axially to disengage from the current bidirectional ratchet engagement groove 110. After disengagement, the knob 300 no longer directly drives the bidirectional stop 200 to move. Instead, through the transmission engagement between the second drive protrusion 420 and the second drive groove 310, and the transmission engagement between the first drive protrusion 410 and the first drive groove 220, a rotational power transmission path is formed from the knob 300 to the power sleeve 400 and then to the bidirectional stop 200, thereby causing the bidirectional stop 200 to rotate around the first direction to the next bidirectional stop. The ratchet engagement groove 110 enables dosage increase adjustment. When the knob 300 rotates around the second direction, the knob 300 continuously drives the power sleeve 400 to rotate. First, the second shovel tooth 330 pushes the bidirectional ratchet engagement tooth 210 to move axially and disengage from the current bidirectional ratchet engagement groove 110. After disengagement, the knob 300 no longer directly drives the bidirectional stop 200 to move. Instead, through the transmission cooperation between the second drive protrusion 420 and the second drive groove 310, and the transmission cooperation between the first drive protrusion 410 and the first drive groove 220, a rotational power transmission path is formed from the knob 300 to the power sleeve 400 and then to the bidirectional stop 200. This causes the bidirectional stop 200 to rotate around the second direction to the previous bidirectional ratchet engagement groove 110, thereby achieving dosage decrease adjustment.

[0070] Compared to existing technologies, the dosage adjustment mechanism disclosed in this application improves the smoothness of the dosage correction process by optimizing the mechanical transmission structure. This solves the problem of excessive torque (300 rpm) required by the knob in traditional injection pens during dosage correction, significantly improving the user experience and user-friendliness of the injection pen. Furthermore, the dosage adjustment mechanism disclosed in this application, while ensuring the accuracy of dosage setting and correction, also reduces the risk of internal component damage due to strenuous operation, enhancing product reliability. It is particularly suitable for applications requiring large doses or frequent adjustments.

[0071] Among them, the bidirectional stop 200 and the bidirectional ratchet meshing teeth 210 can be integral structures formed by injection molding or other methods, and the first drive protrusion 410 and the second drive protrusion 420 and the power sleeve 400 can be integral structures formed by injection molding or other methods to ensure structural rigidity and dimensional stability, simplify the manufacturing process, and reduce production costs.

[0072] In some embodiments disclosed in this application, combined with Figure 5The first driving groove 220 is provided with a first forward rotation transmission position and a first reverse rotation transmission position. The first driving protrusion 410 can move between the first forward rotation transmission position and the first reverse rotation transmission position. When the first driving protrusion 410 is in the first forward rotation transmission position, the power sleeve 400 can drive the bidirectional stop 200 to rotate synchronously around the first direction. When the first driving protrusion 410 is in the first reverse rotation transmission position, the power sleeve 400 can drive the bidirectional stop 200 to rotate synchronously around the second direction. Figure 5 The first drive protrusion 410 is in the first reverse transmission position; combined with Figure 6 The second drive groove 310 is provided with a second forward drive position and a second reverse drive position. The second drive protrusion 420 can move between the second forward drive position and the second reverse drive position. When the second drive protrusion 420 is in the second forward drive position, the knob 300 can drive the power sleeve 400 to rotate synchronously around the first direction. When the second drive protrusion 420 is in the second reverse drive position, the knob 300 can drive the power sleeve 400 to rotate synchronously around the second direction. Figure 6 The second drive protrusion 420 is in the second forward rotation transmission position. Specifically, referring to Table 1 below, when the second drive protrusion 420 is in the second forward rotation transmission position and the knob 300 rotates around the first direction, the power sleeve 400 rotates around the first direction to first move the first drive protrusion 410 from the first reverse rotation transmission position to the first forward rotation transmission position, and then drive the bidirectional stop 200 to rotate synchronously around the first direction. During the process of the first drive protrusion 410 moving from the first reverse rotation transmission position to the first forward rotation transmission position, the first shovel tooth 331 synchronously pushes the bidirectional ratchet meshing tooth 210 to move axially to disengage from the current bidirectional ratchet meshing groove 110. When the second drive protrusion 420 is in the second reverse transmission position and the knob 300 rotates around the second direction, the power sleeve 400 rotates around the second direction to first move the first drive protrusion 410 from the first forward transmission position to the first reverse transmission position, and then drive the bidirectional stop 200 to rotate around the second direction. During the process of the first drive protrusion 410 moving from the first forward transmission position to the first reverse transmission position, the knob 300 pushes the bidirectional ratchet meshing teeth 210 to move axially and disengage from the current bidirectional ratchet meshing groove 110 through the second shovel teeth 330.

[0073] Table 1. Changes in the motion or position of each component during dose increase and dose decrease.

[0074]

[0075] It should be noted that after the dose increase adjustment is completed, the second drive protrusion 420 is in the second forward rotation transmission position. If a dose decrease adjustment is required at this time, the knob 300 must be rotated around the second direction to move the second drive protrusion 420 to the second reverse rotation transmission position. During this process, the bidirectional stop 200 may or may not move along the axial direction. Conversely, after the dose decrease adjustment is completed, the second drive protrusion 420 is in the second reverse rotation transmission position. If a dose increase adjustment is required at this time, the knob 300 must be rotated around the first direction to move the second drive protrusion 420 to the second forward rotation transmission position. During this process, the bidirectional stop 200 may or may not move along the axial direction.

[0076] The shapes of the first driving protrusion 410 and the second driving protrusion 420 can be adjusted according to actual conditions. The first driving groove 220 and the second driving groove 310 can respectively allow the first driving protrusion 410 and the second driving protrusion 420 to be embedded in the transmission and switch the transmission position. This application does not limit this. In some embodiments, the power sleeve 400 passes through the middle of the knob 300, and the first driving protrusion 410 and the second driving protrusion 420 are both disposed on the outer wall of the power sleeve 400 and combined with Figure 12 The knob 300 is provided with a clearance groove 340 through which the first drive protrusion 410 passes and rotates.

[0077] Combination Figure 3 and Figure 4 The second drive protrusion 420 has a mounting groove 421 between the side of the torsion spring bracket 100 facing the power sleeve 400; the knob 300 includes an annular main structure and a mounting plate 350. The annular main structure is rotatably sleeved on the outside of the torsion spring bracket 100, and the bidirectional stop 200 is set inside the annular main structure; the mounting plate 350 is set on the inner wall of the annular main structure, and can be integrally formed with the annular main structure. The second drive groove 310, the first shovel tooth 331 and the second shovel tooth 330 are all set on the side of the mounting plate 350 facing away from the torsion spring bracket 100. The ratchet window 320 passes through the mounting plate 350 axially. The power sleeve 400 passes through the middle position of the mounting plate 350, and the mounting plate 350 is engaged with the mounting groove 421, thereby realizing the axial positioning and installation of the knob 300 and the power sleeve 400.

[0078] Furthermore, the mounting plate 350 has a certain degree of elasticity, and the side of the second drive protrusion 420 facing away from the torsion spring bracket 100 has an inclined structure, and it is inclined towards the direction of the torsion spring bracket 100 from the side close to the central axis of the power sleeve 400 to the side away from the central axis of the power sleeve 400. A chamfer 351 is provided on the side of the mounting plate 350 facing the torsion spring bracket 100, and the chamfer 351 is arranged opposite to the second drive protrusion 420 along the axial direction of the annular main structure. During the assembly process, when the knob 300 is pressed down in the direction of the torsion spring bracket 100, the mounting plate 350 moves along the inclined structure of the second drive protrusion 420, and achieves position locking by deforming and locking into the mounting slot 421 and then restoring its original position. The chamfer 351 can reduce friction and improve assembly efficiency.

[0079] Combination Figure 6 and Figure 7 The ratchet window 320 has a first end and a second end arranged opposite to each other. A first shovel tooth 331 is disposed at the first end of the ratchet window 320 and extends from the side away from the ratchet window 320 to the side closer to the ratchet window 320. The tooth surface of the first shovel tooth 331 is inclined in the direction of the torsion spring bracket 100 and extends to the ratchet window 320. It is used to abut against the tooth surface of the bidirectional ratchet meshing tooth 210 and push the bidirectional ratchet meshing tooth 210 to move axially. A second shovel tooth 330 is disposed at the second end of the ratchet window 320 and extends from the side away from the ratchet window 320 to the side closer to the ratchet window 320. The tooth surface of the second shovel tooth 330 is inclined in the direction of the torsion spring bracket 100 and extends to the ratchet window 320. The tooth surface of the second shovel tooth 330 is used to abut against the tooth surface of the bidirectional ratchet meshing tooth 210 and push the bidirectional ratchet meshing tooth 210 to move axially.

[0080] Combination Figure 11 The bidirectional ratchet meshing tooth 210 has a first tooth surface 211, a second tooth surface 212, and a third tooth surface 213. The first tooth surface 211, the second tooth surface 212, and the third tooth surface 213 are all arranged at an angle. The first tooth surface 211 is arranged opposite to the first shovel tooth 331 so that it is pushed to move axially by the first shovel tooth 331 during the adjustment of the dosage increase. The second tooth surface 212 is arranged opposite to the second shovel tooth 330 so that it is pushed to move axially by the second shovel tooth 330 when the adjustment of the dosage decreases. The third tooth surface 213 abuts against the braking surface 111 of the bidirectional ratchet meshing groove 110 to prevent the bidirectional ratchet meshing tooth 210 from automatically rotating around the second direction.

[0081] Furthermore, the angle between the first tooth surface 211 and the central axis of the torsion spring support 100 is greater than the angle between the third tooth surface 213 and the central axis of the torsion spring support 100; the angle between the second tooth surface 212 and the central axis of the torsion spring support 100 is greater than the angle between the third tooth surface 213 and the central axis of the torsion spring support 100, so that the first shovel tooth 331 and the second shovel tooth 330 respectively push the bidirectional ratchet meshing tooth 210 to move axially. The first tooth surface 211 and the second tooth surface 212 can be arranged parallel or at an angle.

[0082] Combination Figure 10 The bidirectional ratchet engagement groove 110 has a braking surface 111 and a guide surface 112 arranged at an angle. The bidirectional ratchet engagement teeth 210 can move along the guide surface 112, and the angle between the braking surface 111 and the central axis of the torsion spring support 100 is smaller than the angle between the guide surface 112 and the central axis of the torsion spring support 100, so as to facilitate the increase of the adjustment dose of the bidirectional ratchet engagement teeth 210 rotating around the first direction and restrict the rotation of the bidirectional ratchet engagement teeth 210 around the second direction.

[0083] To achieve stable and reliable dose adjustment, the two bidirectional ratchet engagement teeth 210 are arranged circumferentially around the central axis of the bidirectional stop 200; the ratchet window 320, the first shovel tooth 331 and the second shovel tooth 330 are two corresponding to the two bidirectional ratchet engagement teeth 210.

[0084] To achieve reliable transmission, there are two first drive grooves 220 arranged symmetrically with respect to the central axis of the bidirectional stop 200, and two first drive protrusions 410 corresponding to the first drive grooves 220; there are two second drive grooves 310 arranged symmetrically with respect to the central axis of the knob 300, and two second drive protrusions 420 corresponding to the second drive grooves 310.

[0085] Combination Figure 13 A transmission gear 430 is provided on the inner wall of the power sleeve 400. The transmission gear 430 is used to mesh with the dosage injection mechanism to complete the power storage for dosage setting.

[0086] Combination Figures 1-3 The dosage adjustment mechanism may further include a button 500, a button cover 510, and a compression spring 520. The button 500 is movably disposed at the end of the knob 300 away from the torsion spring support 100. The button cover 510 is disposed at the end of the button 500 away from the torsion spring support 100, for user operation by pressing to initiate injection. The two ends of the compression spring 520 abut against the bidirectional stop 200 and the button 500 respectively, providing pressure to the bidirectional stop 200 to maintain its compression in the direction of the torsion spring support 100, while simultaneously providing pressure to the button 500. The compression spring 520 can be configured with an appropriate force value to avoid excessive pressure on the bidirectional stop 200, which would affect the user's adjustment feel.

[0087] Combination Figure 14 and Figure 15 One of the buttons 500 and the button cover 510 is provided with a snap-fit ​​protrusion, and the other of the buttons 500 and the button cover 510 is provided with a snap-fit ​​groove into which the snap-fit ​​protrusion can be inserted. The button 500 and the button cover 510 are connected through the assembly of the snap-fit ​​protrusion and the snap-fit ​​groove. There are at least two snap-fit ​​protrusions, and the number of positioning grooves corresponds one-to-one with the number of snap-fit ​​protrusions to ensure a reliable connection between the button 500 and the button cover 510. Alternatively, the button 500 and the button cover 510 can also be positioned by the structural cooperation of positioning protrusions and positioning grooves, which will not be elaborated further here.

[0088] In a specific adjustment process, when the knob 300 is rotated clockwise by one unit, the knob 300 forces the power sleeve 400 to rotate clockwise. At the same time, the first tooth 331 of the knob 300 abuts against the bidirectional ratchet engagement tooth 210 of the bidirectional stop 200, so as to first push the bidirectional ratchet engagement tooth 210 axially upward until it disengages from the current bidirectional ratchet engagement groove 110. After the upward push is completed, the bidirectional stop 200 no longer rises. At this time, the bidirectional stop 200 can align with the next bidirectional ratchet engagement groove 110 of the torsion spring bracket 100 as the knob 300 and the power sleeve 400 rotate, and press against the pressure. Under the action of spring 520, it engages with the spring to complete the setting of the dose increase of one cell. When the knob 300 is rotated counterclockwise by one cell, the knob 300 forces the power sleeve 400 to rotate counterclockwise, and the knob 300 presses the bidirectional ratchet engagement tooth 210 through the second shovel tooth 330, causing it to move axially to disengage from the current bidirectional ratchet engagement groove 110. After disengagement, the power sleeve 400 pushes the bidirectional stop 200 to retract counterclockwise to the previous bidirectional ratchet engagement groove 110 of the torsion spring bracket 100 and engages with it under the action of compression spring 520 to complete the correction of the dose of one cell.

[0089] The injection pen disclosed in this application includes the dosage adjustment mechanism described above, and therefore also has the structure and beneficial effects described above. Other structures refer to the prior art and will not be described in detail here.

[0090] The terms "first" and "second," etc., used in the specification and claims of this application are used to distinguish different objects, not to describe a specific order, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units may include steps or units not listed, but rather steps or units not listed. Additionally, in the description of embodiments in this application, "a plurality of" means two or more.

[0091] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Specific technical means in some embodiments may be incorporated, in whole or in part, into another embodiment unless explicitly excluded by another embodiment. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dosage adjustment mechanism, characterized in that, include: A torsion spring bracket, wherein the torsion spring bracket is provided with a bidirectional ratchet engagement groove; A bidirectional stop, wherein the bidirectional stop is provided with bidirectional ratchet meshing teeth and a first driving groove; A knob is rotatably fitted outside the torsion spring bracket, and the knob is provided with a second drive groove, a ratchet window, a first shovel tooth and a second shovel tooth. The bidirectional stop is provided inside the knob, and the bidirectional ratchet meshing teeth pass through the ratchet window and mesh with the bidirectional ratchet meshing groove. A power sleeve is used for transmission connection with a dosage injection mechanism, and the power sleeve is provided with a first driving protrusion and a second driving protrusion. The power sleeve drives the bidirectional stop rotation through the insertion of the first driving protrusion and the first driving groove, and the knob drives the power sleeve to rotate through the insertion of the second driving protrusion and the second driving groove. When the knob rotates around the first direction, the knob first drives the power sleeve to rotate and pushes the bidirectional ratchet meshing teeth to move axially and disengage from the current bidirectional ratchet meshing groove through the first shovel teeth. Then, the power sleeve drives the bidirectional stop to rotate around the first direction to the next bidirectional ratchet meshing groove. When the knob rotates around the second direction, the knob first drives the power sleeve to rotate and pushes the bidirectional ratchet engagement tooth to move axially away from the current bidirectional ratchet engagement groove through the second shovel tooth, and then drives the bidirectional stop to rotate around the second direction to the previous bidirectional ratchet engagement groove through the power sleeve.

2. The dosage adjustment mechanism as described in claim 1, characterized in that, The first driving groove is provided with a first forward rotation transmission position and a first reverse rotation transmission position, and the first driving protrusion can move between the first forward rotation transmission position and the first reverse rotation transmission position; the second driving groove is provided with a second forward rotation transmission position and a second reverse rotation transmission position, and the second driving protrusion can move between the second forward rotation transmission position and the second reverse rotation transmission position. When the second drive protrusion is in the second forward rotation transmission position and the knob rotates around the first direction, the power sleeve rotates around the first direction to first move the first drive protrusion from the first reverse rotation transmission position to the first forward rotation transmission position, and then drive the bidirectional stop to rotate around the first direction. When the second drive protrusion is in the second reverse transmission position and the knob rotates around the second direction, the power sleeve rotates around the second direction to first move the first drive protrusion from the first forward transmission position to the first reverse transmission position, and then drive the bidirectional stop to rotate around the second direction.

3. The dosage adjustment mechanism as described in claim 1, characterized in that, The ratchet window has a first end and a second end arranged opposite to each other. The first shovel tooth is disposed at the first end of the ratchet window and extends from the side away from the ratchet window to the side closer to the ratchet window. The tooth surface of the first shovel tooth is inclined in the direction of the torsion spring bracket and extends to the ratchet window to push the bidirectional ratchet meshing tooth to move axially. The second shovel tooth is disposed at the second end of the ratchet window and extends from the side away from the ratchet window to the side closer to the ratchet window. The tooth surface of the second shovel tooth is inclined in the direction of the torsion spring bracket and extends to the ratchet window to push the bidirectional ratchet meshing tooth to move axially.

4. The dosage adjustment mechanism as described in claim 1, characterized in that, The bidirectional ratchet meshing teeth have a first tooth surface, a second tooth surface, and a third tooth surface, wherein the first tooth surface and the second tooth surface are arranged at an angle to the third tooth surface; The first tooth surface is arranged opposite to the first shovel tooth, the second tooth surface is arranged opposite to the second shovel tooth, and the third tooth surface abuts against the braking surface of the bidirectional ratchet engagement groove.

5. The dosage adjustment mechanism as described in claim 4, characterized in that, The angle between the first tooth surface and the central axis of the torsion spring bracket is greater than the angle between the third tooth surface and the central axis of the torsion spring bracket; The angle between the second tooth surface and the central axis of the torsion spring bracket is greater than the angle between the third tooth surface and the central axis of the torsion spring bracket.

6. The dosage adjustment mechanism as described in claim 4, characterized in that, The bidirectional ratchet engagement groove has a braking surface and a guide surface arranged at an angle. The bidirectional ratchet engagement teeth move along the guide surface, and the angle between the braking surface and the central axis of the torsion spring bracket is smaller than the angle between the guide surface and the central axis of the torsion spring bracket.

7. The dosage adjustment mechanism as described in claim 1, characterized in that, The second drive protrusion has a mounting groove formed between its side facing the torsion spring bracket and the power sleeve; the knob includes: A ring-shaped main body structure is rotatably fitted outside the torsion spring bracket, and the bidirectional stop is disposed inside the ring-shaped main body structure; The mounting plate is disposed on the inner wall of the annular main structure. The second drive groove, the first shovel tooth, and the second shovel tooth are all disposed on the side of the mounting plate facing away from the torsion spring bracket. The ratchet window passes through the mounting plate axially. The power sleeve passes through the mounting plate, and the mounting plate is engaged with the mounting slot.

8. The dosage adjustment mechanism as described in claim 7, characterized in that, The second driving protrusion has a sloping structure on the side facing away from the torsion spring bracket, and it tilts from the side close to the central axis of the power sleeve to the side away from the central axis of the power sleeve towards the direction where the torsion spring bracket is located. The mounting plate has a chamfer on the side facing the torsion spring bracket and is arranged axially along the annular main structure. The chamfer is opposite to the second driving protrusion and is used to slide into the mounting slot along the inclined structure.

9. The dosage adjustment mechanism as described in claim 1, characterized in that, The bidirectional ratchet engagement teeth are two circumferentially spaced teeth arranged around the bidirectional stop axis; The ratchet window, the first shovel tooth, and the second shovel tooth are all two that correspond one-to-one with the bidirectional ratchet meshing teeth.

10. The dose adjustment mechanism as claimed in claim 1, characterized in that, The first driving groove consists of two symmetrically arranged relative to the bidirectional stop axis, and the first driving protrusion consists of two corresponding to the first driving groove. The second driving groove consists of two symmetrically arranged relative to the central axis of the knob, and the second driving protrusion consists of two corresponding to the second driving groove.

11. The dose adjustment mechanism as claimed in claim 1, characterized in that, Also includes: A button, which is movably disposed at the end of the knob away from the torsion spring bracket; A button cover is disposed at the end of the button away from the torsion spring bracket; A compression spring, the two ends of which abut against the bidirectional stop and the button, respectively.

12. An injection pen, characterized in that, Includes the dose adjustment mechanism as described in any one of claims 1-11.

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