Dose accumulation mechanism and injection device

Abstract

The utility model relates to a dose accumulation mechanism and an injection device, the dose accumulation mechanism comprises a first element capable of rotating around a first axis, the first element is provided with a driving rib, and the driving rib spirally extends on the first element around the first axis; the second element is connected with the first element in a sleeving manner and can rotate around a first axis; the accumulation element is connected to the second element and can rotate around a second axis relative to the second element, the accumulation element is provided with a plurality of meshing teeth, and a meshing groove allowing the driving rib to be meshed in is formed between every two adjacent meshing teeth; during dose setting, the first element and the second element are rotatable relative to each other; during dose injection, the first element is in rotationally fixed connection with the second element, and the accumulation element is stationary relative to the first element and the second element. According to the injection device, the sum of the doses set by a user gradually can be accumulated and recorded through the circular motion of the accumulation element, so that the occupation of the axial space in the injection device is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of injection devices, and in particular to a dose accumulation mechanism and an injection device. Background Art

[0002] Medication injections are performed with a specific injection device, often called a pen injector or injection pen. This device allows the user to set a desired dose and then administer the dose. The process of setting and administering the dose is considered a complete injection. Accordingly, injection devices often incorporate a dose accumulation mechanism that accumulates the user's doses and limits the accumulated dose to no more than the total amount of medication contained in the cartridge. This ensures that each dose set by the user does not exceed the remaining dose in the cartridge, ensuring that each injection is consistent with the set dose.

[0003] In the prior art, a dose accumulation mechanism for an injection device typically includes a scale element, a transmission element, and an integral nut. The scale element and transmission element are capable of rotating relative to each other during dose setting, while forming a non-rotational connection with the transmission element during dose injection, allowing for synchronous rotation. The integral nut is threadedly mounted on the transmission element and is non-rotationally connected to the scale element, enabling axial relative movement.

[0004] In the aforementioned related art, during dose setting, the graduated element drives the integrating nut to rotate relative to the transmission element, causing the integrating nut to displace axially on the transmission element, with the displacement of the integrating nut being correlated with the set dose. During injection, the graduated element, transmission element, and integrating nut remain relatively stationary. Therefore, the axial displacement of the integrating nut can be used to accumulate the set dose, but this also requires the integrating nut to occupy a larger axial space within the injection device to accommodate its axial movement. Utility Model Content

[0005] In a first aspect, the present application provides a dose accumulation mechanism that can accumulate and record the sum of doses set successively by the user through the circular motion of an accumulation element, thereby reducing the occupation of the axial space in the injection device.

[0006] The dose accumulation mechanism provided in this application adopts the following technical solution:

[0007] A dose accumulation mechanism comprises: a first element capable of rotating around a first axis, the first element being provided with a driving rib, the driving rib spirally extending on the first element around the first axis; a second element being socketed with the first element and capable of rotating around the first axis; an accumulation element being connected to the second element and capable of rotating around a second axis relative to the second element, the second axis being arranged crosswise with the first axis, the accumulation element being provided with a plurality of meshing teeth, the plurality of meshing teeth being arranged at intervals along the circumferential direction of the second axis, and an engagement groove for the driving rib to engage with being formed between two adjacent meshing teeth; wherein, during dose setting, the first element and the second element are capable of rotating relative to each other, the driving rib is used to cooperate with the meshing teeth to drive the accumulation element to rotate; during dose injection, the first element and the second element are anti-rotationally connected, and the accumulation element is stationary relative to the first element and the second element.

[0008] By adopting the above technical solution, during dose setting, the first and second elements rotate relative to each other, causing the accumulator element to rotate along the second axis, with the rotation angle of the accumulator element corresponding to the dose setting amount. During dose injection, the first, second, and accumulator elements all remain relatively stationary. Thus, during a complete injection, the accumulator element can set the dose setting amount through its own circular rotational motion. Accordingly, as the user performs successive injections, the accumulator element can gradually convert the total dose setting amount into the accumulator element's circular motion, thereby achieving the purpose of accumulating and recording the total dose setting amount. Furthermore, compared to an axially movable integral nut, the accumulator element of this solution can reduce the axial space occupied in the injection device.

[0009] Furthermore, the driving rib has a first end and a second end opposite to each other along its extension direction, and a surrounding angle formed by the first end and the second end based on the first axis is less than or equal to 360°.

[0010] By adopting the above technical solution, there is no overlapping area in the axial projection of the driving ribs. Therefore, when the first element and the driving ribs thereon are prepared by injection molding, axially opposing mold cores can be used to form the axially opposite side walls of the driving ribs. After injection molding, the mold can be easily demolded by simply axially pulling out the axially opposing mold cores.

[0011] Furthermore, the driving rib includes a driving section and an engaging section at the end of the driving section. The process from the engagement section starting to engage into the engaging groove to the driving section starting to engage into the engaging groove is defined as the engagement process, and the process from the driving section completely disengaging from the engaging groove to the engagement section completely disengaging from the engaging groove is defined as the disengagement process. During the engagement process and the disengagement process, the accumulation element and the second element remain relatively stationary.

[0012] Further, the driving section is configured as a spiral section spirally arranged around the first axis, the spiral section is used to engage with the engagement groove, and is used to drive the accumulating element to rotate when the spiral section rotates synchronously with the first element.

[0013] Further, the engaging segment is configured as an arc segment circumferentially arranged around the first axis.

[0014] Furthermore, the driving rib has a first end and a second end opposite to each other along its extension direction, the first end and the second end form a surrounding angle greater than 360° based on the first axis, and the driving rib spirally extends from the first end to the second end around the first axis.

[0015] Furthermore, the central angle formed by two adjacent meshing teeth on the accumulator element is defined as a reference angle. When the first element and the second element rotate 360° relative to each other, the rotation angle of the accumulator element is a reference angle.

[0016] Furthermore, the first element is sleeved on the outside of the second element, and the driving rib is arranged on the inner side wall of the first element.

[0017] Furthermore, the second element is provided with an escape area for the accumulating element to rotate.

[0018] Furthermore, the second element is sleeved outside the first element, and the driving rib is provided on the outer side wall of the first element.

[0019] Furthermore, an outer side wall of the first element and an inner side wall of the second element are spaced apart from each other and form a movable cavity for the accumulating element to rotate.

[0020] In a second aspect, the present application provides an injection device comprising a clutch element and the dose accumulation mechanism described above, wherein during dose setting, at least one of the first element and the second element is capable of rotating relative to the clutch element; during dose injection, the clutch element is connected to the first element and the second element in a rotationally non-resistant manner in the dose injection direction.

[0021] In summary, the present invention provides at least the following advantages: During a complete injection, the accumulator element can adjust the dose setting through its own circular rotational motion. Accordingly, as the user performs successive injections, the accumulator element gradually converts the total dose setting into the accumulator element's circular motion, thereby achieving the purpose of accumulating and recording the total dose setting. Furthermore, compared to an axially movable integral nut, the accumulator element of this embodiment can reduce the axial space occupied by the injection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of an injection device with a dose accumulation mechanism in an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of another injection device with a dose accumulation mechanism in an embodiment of the present application;

[0024] Figure 3 This is a schematic diagram for showing the second element and the cumulative element in the embodiment of the present application. Figure 1 ;

[0025] Figure 4 is a schematic diagram for illustrating a first element and an accumulation element in an embodiment of the present application;

[0026] Figure 5 This is a schematic diagram for showing the second element and the cumulative element in the embodiment of the present application. Figure 2 ;

[0027] Figure 6 is a schematic diagram for illustrating the first element, the second element, and the clutch element in the embodiment of the present application;

[0028] Figure 7 1 is an exploded schematic diagram of the first element, the second element and the clutch element in the embodiment of the present application;

[0029] Figure 8 is a schematic diagram for illustrating the axial gear ring on the second element in an embodiment of the present application;

[0030] Figure 9 is a schematic diagram for illustrating the formation of a starting position by the second element and the accumulation element in an embodiment of the present application;

[0031] Figure 10 is a schematic diagram used to illustrate the formation of a termination position by the second element and the accumulation element in an embodiment of the present application;

[0032] Figure 11 This is a schematic diagram used to illustrate the formation of a starting position between the first element and the accumulation element in the embodiment of the present application. Figure 1 ;

[0033] Figure 12This is a schematic diagram used to illustrate the termination position formed by the first element and the accumulation element in the embodiment of the present application. Figure 1 ;

[0034] Figure 13 This is a schematic diagram of the embodiment of the present application in which a partial side wall of the first element is hidden to show the first element and the accumulation element forming the starting position. Figure 2 ;

[0035] Figure 14 This is a schematic diagram used to illustrate that meshing teeth are provided on the circumference of the accumulator element in the embodiment of the present application;

[0036] Figure 15 is a schematic diagram for illustrating that the accumulating element includes a stop arc segment and an engaging arc segment in an embodiment of the present application;

[0037] Figure 16 This is a schematic diagram of the embodiment of the present application in which a partial side wall of the first element is hidden to show the termination position formed by the first element and the accumulation element. Figure 2 ;

[0038] Figure 17 is a schematic diagram of an embodiment of the present application in which a partial side wall of the first element is hidden to reveal the driving ribs;

[0039] Figure 18 is a schematic diagram for illustrating a reference angle on an accumulation element in an embodiment of the present application;

[0040] Figure 19 It is a schematic diagram used to illustrate the mating teeth on the clutch element in the embodiment of the present application.

[0041] Explanation of reference numerals: 1. first element; 11. driving rib; 111. driving section; 112. engaging section; 12. ratchet tooth ring; 13. initial interference portion; 14. termination interference portion; 15. first starting portion; 16. first termination portion; 2. second element; 21. radial through groove; 22. axial tooth ring; 23. stop bar; 231. first stop surface; 232. second stop surface; 24. support seat; 3. accumulator; 31. meshing teeth; 32. Engaging groove; 33, rotating shaft; 34, convex strip; 341, first abutting surface; 342, second abutting surface; 35, stop strip; 36, second starting portion; 37, second ending portion; 38, engaging arc segment; 39, stop arc segment; 4, clutch element; 41, ratchet arm; 42, mating tooth; 421, right-angle surface; 422, inclined surface; 5, driving rod; 6, push rod; 7, housing; 8, cartridge bottle; 81, movable piston; 9, button; 10, spring. DETAILED DESCRIPTION

[0042] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0044] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0045] The present application provides a dose accumulation mechanism, which can accumulate and record the sum of doses set successively by the user through the circular motion of an accumulation element, thereby reducing the occupation of the axial space in the injection device.

[0046] Reference Figure 1 and Figure 2 The dose accumulation mechanism includes a first element 1, a second element 2 and an accumulation element 3, and the dose accumulation mechanism is installed in a housing 7 of the injection device, and the central axis of the housing 7 is defined as a first axis.

[0047] Among them, the first element 1 can rotate around the first axis, and the first element 1 is provided with a driving rib 11, which extends on the first element 1 around the first axis; the second element 2 is socketed with the first element 1, and the second element 2 can rotate around the first axis; the accumulation element 3 is connected to the second element 2, and the accumulation element 3 can rotate around the second axis relative to the second element 2, the second axis is the central axis of the accumulation element 3, and the second axis is arranged crosswise with the first axis; at the same time, the accumulation element 3 is provided with a plurality of meshing teeth 31, and the plurality of meshing teeth 31 are arranged at intervals along the circumferential direction of the second axis, so that an engagement groove 32 for the driving rib 11 to engage is formed between two adjacent meshing teeth 31.

[0048] Specifically, during dose setting, the first element 1 and the second element 2 are capable of rotating relative to each other, and dose setting includes both increasing and decreasing the dose. Accordingly, rotation of the first element 1 relative to the second element 2 in a first direction is used to increase the dose, and rotation of the first element 1 relative to the second element 2 in a second direction is used to decrease the dose, the first direction being opposite to the second direction. Simultaneously, throughout the dose setting process, the drive rib 11 is configured to engage with the meshing teeth 31 to drive the accumulator element 3 to rotate. During dose injection, the first element 1 and the second element 2 are non-rotatably connected, enabling synchronous rotation or synchronous stationary motion of the first and second elements 1, 2. During this period, the accumulator element 3 is stationary relative to the first and second elements 1, 2, and does not rotate about the second axis.

[0049] Using this solution, during dose setting, the first element 1 and the second element 2 rotate relative to each other, causing the accumulator element 3 to rotate along the second axis, with the rotation angle of the accumulator element 3 corresponding to the dose setting amount. During dose injection, the first element 1, the second element 2, and the accumulator element 3 all remain relatively stationary. Therefore, during a complete injection, the accumulator element 3 can set the dose setting amount through its own circular rotation. Accordingly, as the user performs successive injections, the accumulator element 3 can gradually convert the total dose setting amount into the amount of the accumulator element 3's circular motion, thereby achieving the purpose of accumulating and recording the total dose setting amount. Furthermore, compared to an axially movable integral nut, the accumulator element 3 using this solution can reduce the axial space occupied by the injection device.

[0050] Furthermore, in some embodiments, the accumulator element 3 has a starting position and an ending position. The range of motion of the accumulator element 3 between the starting position and the ending position corresponds to the total amount of drug that can be injected by the injection device. When the accumulator element 3 is in the ending position, further rotation of the first element 1 relative to the second element 2 in the first direction is restricted, thereby limiting further dose increases. When the accumulator element 3 reaches the ending position, the first element 1 and the second element 2 cannot rotate further in the dose-increasing direction, thereby limiting further increases in the set dose. Furthermore, the amount of motion of the accumulator element 3 between the starting position and the ending position corresponds to the total amount of drug that can be injected by the injection device. As the accumulator element 3 moves from the starting position to the ending position, the remaining amount of motion between the accumulator element 3 and the ending position always corresponds to the remaining dose of drug that can be injected in the injection device. Therefore, each set dose is ensured to never exceed the remaining dose of drug that can be injected by the injection device, ensuring that the actual injected dose matches the set dose, avoiding the possibility of injecting an incorrect dose, and thereby ensuring that the drug injection achieves its intended effect.

[0051] It should be noted that the movement stroke of the accumulator 3 between the starting position and the ending position corresponds to the total amount of drug that can be injected by the injection device, indicating that the movement stroke of the accumulator 3 corresponds to the total amount of drug in the injection device. For ease of description, the movement stroke of the accumulator 3 is defined as U, and the ratio of the set dose to the movement amount of the accumulator 3 is defined as T, that is, the total set dose represented by the accumulator 3 throughout its entire movement stroke is UT, and the total amount of drug in the injection device is defined as S. In some specific embodiments, UT=S, indicating that the total set dose corresponding to the accumulator 3 throughout its entire movement stroke is equal to the total amount of drug in the injection device, so that the drug in the injection device can be completely injected during the last injection. In other specific embodiments, UT<S, indicating that the total set dose corresponding to the accumulator 3 throughout its entire movement stroke is less than the total amount of drug in the injection device, so that after the last injection, some drug will remain in the injection device and not be injected. In other specific embodiments, the dose accumulation mechanism is assembled to the injection device and the matching size is adjusted, which causes the accumulation element 3 to move from the starting position to the ending position. The movement amount of the accumulation element 3 during assembly and debugging is defined as u. In some embodiments, the equation (Uu)T=S is satisfied, that is, the drug in the injection device can be completely injected at the last injection; in other embodiments, the inequality (Uu)T<S is satisfied, that is, after the last injection, some drug will remain in the injection device and has not been injected.

[0052] It should also be noted that the intersecting arrangement of the first and second axes indicates that they are not parallel, that is, they are not in the same plane. Specifically, if the plane in which the first axis lies is defined as the first plane, then the second axis intersects the first plane at a point. In a specific embodiment, the first axis is configured to be perpendicular to the second axis to achieve better transmission efficiency of the driving force between the first element 1 and the accumulator element 3.

[0053] It can be understood that the second element 2 and the first element 1 can be sleeved together in such a way that the first element 1 is sleeved outside the second element 2 , or the second element 2 is sleeved outside the first element 1 .

[0054] Reference Figure 1 and Figure 3 In some embodiments, the first element 1 is sleeved on the outside of the second element 2. The first element 1 is roughly cylindrical, and the driving rib 11 is arranged on the inner wall of the first element 1; the second element 2 is roughly cylindrical and at least partially accommodated in the first element 1. The accumulation element 3 is completely accommodated in the first element 1 and is roughly worm-shaped. At the same time, the accumulation element 3 is rotatably connected to the second element 2 via a rotating shaft 33. Accordingly, a clearance area is provided on the second element 2 for the accumulation element 3 to rotate without restriction. In some specific embodiments, the second element 2 is provided with a radial groove 21 in a direction perpendicular to the first axis and the second axis. The accumulation element 3 is installed in the radial groove 21, and the radial groove 21 serves as a clearance area on the second element 2 for the accumulation element 3 to rotate freely. In addition, the area of ​​the accumulation element 3 installed in the radial groove 21 with the engagement groove 32 can protrude from a notch of the radial groove 21 and engage with the driving rib 11 on the inner wall of the first element 1.

[0055] In the above embodiment, during dose setting, the first element 1 rotates about the first axis while the second element 2 remains stationary. During dose injection, the first element 1 and the second element 2 rotate synchronously. It will be understood that, if the first element 1 is defined as rotating clockwise relative to the housing 7 when adjusting the dose up and rotating counterclockwise relative to the housing 7 when adjusting the dose down, then rotation of the first element 1 relative to the second element 2 in a first direction corresponds to the second element 2 being stationary while the first element 1 rotates clockwise, and rotation of the first element 1 relative to the second element 2 in a second direction corresponds to the second element 2 being stationary while the first element 1 rotates counterclockwise. Furthermore, the first direction is clockwise, and the second direction is counterclockwise.

[0056] Reference Figure 2 、 Figure 4 and Figure 5In other embodiments, the second element 2 is sleeved on the outside of the first element 1. The second element 2 is roughly cylindrical, and the accumulation element 3 is completely contained within the second element 2 and is roughly worm-shaped. At the same time, a support seat 24 is provided on the inside of the second element 2, and the accumulation element 3 is rotatably mounted on the support seat 24 of the second element 2. The first element 1 is at least partially contained within the second element 2, and the driving rib 11 is disposed on the outer wall of the first element 1. Accordingly, a movable cavity is formed between the first element 1 and the second element 2 for the accumulation element 3 to rotate freely. In some specific embodiments, there is a gap between the inner wall of the second element 2 and the outer wall of the first element 1 on which the driving rib 11 is provided, so that an annular cavity is formed between the first element 1 and the second element 2, which serves as a movable cavity for the accumulation element 3 to rotate freely.

[0057] In the above embodiment, during dose setting, the second element 2 rotates about the first axis while the first element 1 remains stationary. During dose injection, the second element 2 and the first element 1 rotate synchronously. If the second element 2 is defined as rotating clockwise relative to the housing 7 when adjusting the dose up and rotating counterclockwise relative to the housing 7 when adjusting the dose down, it can be understood that rotation of the first element 1 relative to the second element 2 in a first direction corresponds to the first element 1 being stationary while the second element 2 rotates clockwise, and rotation of the first element 1 relative to the second element 2 in a second direction corresponds to the first element 1 being stationary while the second element 2 rotates counterclockwise, with the first direction being counterclockwise and the second direction being clockwise.

[0058] Reference Figure 1 and Figure 6 It should be noted that when the dose accumulation mechanism is configured in an injection device, the first element 1 and the second element 2 are selectively connected in the rotational direction via the clutch element 4, thereby enabling relative rotation of the first element 1 and the second element 2 during dose setting and synchronous rotation during dose injection. During dose setting, at least one of the first element 1 and the second element 2 is able to rotate relative to the clutch element 4, enabling relative rotation of the first element 1 and the second element 2. During dose injection, both the first element 1 and the second element 2 are anti-rotationally coupled to the clutch element 4, enabling synchronous rotation or synchronization of the first element 1 and the second element 2.

[0059] Reference Figure 6 and Figure 7In some embodiments, the first element 1 is sleeved around the second element 2, with the proximal end of the second element 2 accommodated within the proximal end of the first element 1. Furthermore, the clutch element 4 is located at the proximal end of the first element 1 and presses against the proximal end of the second element 2. Furthermore, when increasing the dose, the first element 1 rotates in a third direction. When decreasing the dose, the first element 1 rotates in a fourth direction opposite to the third direction. When injecting a dose, both the first element 1 and the second element 2 rotate in the fourth direction. Specifically, the third direction is clockwise, and the fourth direction is counterclockwise.

[0060] Accordingly, refer to Figure 6 A ratchet tooth ring 12 is provided on the inner wall of the proximal end of the first element 1, and a ratchet arm 41 is provided which cooperates with the ratchet tooth ring 12. The ratchet tooth ring 12 and the ratchet arm 41 cooperate to form a first connection. The first connection allows the first element 1 to rotate relative to the clutch element 4 in the third direction, while preventing the first element 1 from rotating relative to the clutch element 4 in the fourth direction.

[0061] Reference Figure 7 and Figure 8 The proximal portion of the second element 2 is provided with an axially protruding axial toothed ring 22, and the clutch element 4 is provided with mating teeth 42 that mesh with the axial toothed ring 22. The axial toothed ring 22 and the mating teeth 42 cooperate to form a second connection. This second connection prevents the clutch element 4 from rotating in the third direction relative to the second element 2, while allowing relative axial movement between the clutch element 4 and the second element 2, thereby rotating the clutch element 4 in the fourth direction relative to the second element 2. Simultaneously, during dose injection, the clutch element 4 is pressed against the proximal end of the second element 2 by an axial force, preventing axial movement between the clutch element 4 and the second element 2, and maintaining relative static position between the clutch element 4 and the second element 2.

[0062] In summary, when the first element 1 rotates in the third direction to increase the dose, the clutch element 4 and the second element 2 remain stationary, and the first element 1 rotates relative to the second element 2 and the clutch element 4. When the first element 1 rotates in the fourth direction to decrease the dose, the first element 1 drives the clutch element 4 to rotate in the fourth direction, while the second element 2 remains stationary. At this time, the first element 1 and the clutch element 4 rotate relative to the second element 2. During the dose injection, the first element 1, the clutch element 4, and the second element 2 rotate synchronously in the fourth direction.

[0063] It is understood that the accumulating element 3 can move relative to the first element 1 and can also move relative to the second element 2. Accordingly, the starting position of the accumulating element 3 can be composed of the accumulating element 3 and the first element 1, or the accumulating element 3 and the second element 2, and the ending position of the accumulating element 3 can be composed of the accumulating element 3 and the first element 1, or the accumulating element 3 and the second element 2.

[0064] In some embodiments, an offset structure is provided between the accumulating element 3 and the second element 2 to form a starting position and / or an ending position of the accumulating element 3 .

[0065] Reference Figure 9 In some embodiments where the accumulator element 3 cooperates with the second element 2 to form a starting position, the accumulator element 3 has two sidewalls disposed opposite each other along the second axis. A protrusion 34 is disposed on one of the sidewalls of the accumulator element 3. The protrusion 34 is capable of rotating with the accumulator element 3 and has a first abutment surface 341. Accordingly, the second element 2 is provided with a stop bar 23 having a first stop surface 231. When the first abutment surface 341 of the protrusion 34 abuts the first stop surface 231 of the stop bar 23, the accumulator element 3 becomes stationary relative to the second element 2, forming the starting position of the accumulator element 3.

[0066] Reference Figure 10 In some embodiments where the accumulator element 3 cooperates with the second element 2 to form a stop position, the accumulator element 3 has two sidewalls arranged opposite each other along the second axis. A protrusion 34 is provided on one of the sidewalls of the accumulator element 3. The protrusion 34 is capable of rotating with the accumulator element 3 and has a second abutment surface 342. Accordingly, the second element 2 is provided with a stop bar 23 having a second stop surface 232. When the second abutment surface 342 of the protrusion 34 abuts the second stop surface 232 of the stop bar 23, the accumulator element 3 is stationary relative to the second element 2, forming the stop position of the accumulator element 3.

[0067] Reference Figure 9 and Figure 10 In some embodiments where the accumulator element 3 cooperates with the second element 2 to form a starting position and an ending position, the accumulator element 3 has two side walls arranged opposite each other along a second axis. A protrusion 34 is provided on one of the side walls of the accumulator element 3. The protrusion 34 can rotate with the accumulator element 3 and has a first abutting surface 341 and a second abutting surface 342 opposing each other along its direction of movement. Correspondingly, the second element 2 is provided with a stop bar 23 having a first stop surface 231 and a second stop surface 232 opposing each other. When the first abutting surface 341 of the protrusion 34 abuts the first stop surface 231 of the stop bar 23, the starting position of the accumulator element 3 is formed. When the second abutting surface 342 of the protrusion 34 abuts the second stop surface 232 of the stop bar 23, the ending position of the accumulator element 3 is formed.

[0068] In other embodiments, an abutting structure is provided between the accumulating element 3 and the first element 1 to form a starting position and / or an ending position of the accumulating element 3. Specifically, the first element 1 is provided with a first stop portion that moves with the first element 1 around a first axis, and the accumulating element 3 is provided with a second stop portion that moves with the accumulating element 3 around a second axis; when the first stop portion abuts the second stop portion, the starting position is formed, and when the first stop portion abuts the second stop portion, the ending position is formed.

[0069] In some embodiments where the accumulator element 3 cooperates with the first element 1 to form a starting position, the first stop portion blocks the second stop portion from continuing to move along with the accumulator element 3 around the second axis to form the starting position; Figure 11 In a specific embodiment, the first stop portion includes an initial interference portion 13 provided on the side wall of the first element 1. The initial interference portion 13 can be configured as an arc-shaped protrusion or as a convex ring surrounding the first element 1. The second stop portion includes a stop bar 35 protruding radially from the accumulation element 3. When the stop bar 35 moves with the accumulation element 3 to abut against the initial interference portion 13, it prevents the accumulation element 3 from further rotation, thereby forming the starting position of the accumulation element 3.

[0070] In some embodiments where the accumulator element 3 cooperates with the first element 1 to form a stop position, the first stop portion blocks the second stop portion from continuing to move along with the accumulator element 3 around the second axis to form the stop position; Figure 12 In a specific embodiment, the first stop portion includes a termination interference portion 14 provided on the side wall of the first element 1. The termination interference portion 14 can be configured as an arc-shaped protrusion or as a protruding ring surrounding the first element 1; the second stop portion includes a stop bar 35 protruding radially from the accumulation element 3; when the stop bar 35 moves with the accumulation element 3 to abut against the termination interference portion 14, it prevents the accumulation element 3 from further rotation, thereby forming the termination position of the accumulation element 3.

[0071] In other embodiments of the accumulation element 3 and the first element 1 cooperate to form the starting position, the second stop portion blocks the first stop portion from continuing to move with the first element 1 around the first axis to form the starting position; Figure 13 In a specific embodiment, the first stop portion includes a first starting portion 15, and the second stop portion includes a second starting portion 36. The movement direction of the first starting portion 15 during the dose reduction is defined as the starting approach direction. When the second starting portion 36 moves to block the first starting portion 15 from continuing to move in the starting approach direction, the starting position of the accumulating element 3 is formed.

[0072] Specifically, in some embodiments, the first starting portion 15 is configured as an end portion of the driving rib 11 .

[0073] Specifically, refer to Figure 14In some embodiments, the meshing teeth 31 are provided on the entire circumference of the accumulating element 3, that is, the meshing teeth 31 are arranged in a full circle on the main body of the accumulating element 3; accordingly, the second starting portion 36 is provided between two adjacent meshing teeth 31. Figure 15 In other embodiments, the outer circumference of the accumulating element 3 includes an engaging arc segment 38 provided with engaging teeth 31 and a stop arc segment 39 not provided with engaging teeth 31 ; accordingly, the side wall of the stop arc segment 39 serves as the second starting portion 36 .

[0074] In other embodiments where the accumulator element 3 cooperates with the first element 1 to form a starting position, the second stopper blocks the first stopper from continuing to move along with the first element 1 around the first axis to form a terminal position; Figure 16 In a specific embodiment, the first stop portion includes a first stop portion 16, and the second stop portion includes a second stop portion 37; the movement direction of the first stop portion 16 when increasing the dose is defined as the terminating approach direction, and when the second stop portion 37 moves to block the first stop portion 16 from continuing to move along the terminating approach direction, the terminating position of the accumulating element 3 is formed.

[0075] Specifically, in some embodiments, the first termination portion 16 is configured as an end portion of the driving rib 11 .

[0076] Specifically, refer to Figure 14 In some embodiments, the meshing teeth 31 are provided on the entire circumference of the accumulating element 3, that is, the meshing teeth 31 are arranged in a full circle on the main body of the accumulating element 3; accordingly, the second terminating portion 37 is provided between two adjacent meshing teeth 31. Figure 15 In other embodiments, the outer circumference of the accumulating element 3 includes an engaging arc segment 38 provided with engaging teeth 31 and a stop arc segment 39 not provided with engaging teeth 31 ; accordingly, the side wall of the stop arc segment 39 serves as the second termination portion 37 .

[0077] It should be noted that the driving rib 11 extending on the first element 1 around the first axis means that the driving rib 11 is arranged on the first element 1 and extends in a circular manner along its axial direction with the first axis as the spiral axis; accordingly, for the convenience of expression, the two opposite ends of the driving rib 11 along its extension direction are defined as the first end and the second end, and the first end and the second end have an axial spacing in the direction of the first axis.

[0078] In some embodiments, the driver rib 11 wraps around the first element 1 more than once, meaning that the wrap angle formed by the first and second ends about the first axis is greater than 360°. As will be appreciated, this results in the driver rib 11 appearing as a closed circular ring when projected along the first axis, with overlapping regions present in the axial projection when the wrap angle is greater than 360°. Furthermore, the driver rib 11 is configured as a spiral segment, meaning that the driver rib 11 spirals around the first axis from the first end to the second end.

[0079] In other embodiments, the number of turns of the driving rib 11 around the first element 1 is less than or equal to one, that is, the angle formed by the first end and the second end about the first axis is less than or equal to 360°. It is understood that this ensures that the axial projection of the driving rib 11 along the first axis does not have any overlapping areas, that is, the axial projection appears as an arc with a gap or forms a complete circular ring; thus, when the first element 1 and the driving rib 11 thereon are prepared by injection molding, axially opposed mold cores can be used to form the axially opposed side walls of the driving rib 11. After injection molding, the mold can be easily demolded by simply axially withdrawing the axially opposed mold cores.

[0080] Further, refer to Figure 17 In some specific embodiments in which the driving rib 11 rotates less than one circle, the driving rib 11 includes a driving section 111 and two engaging sections 112 at the ends of the driving section 111, that is, the driving rib 11 includes an engaging section 112, a driving section 111, and an engaging section 112 connected in sequence along its extension direction; wherein the engaging section 112 is the portion of the driving rib 11 that first engages with the engaging groove 32 on the accumulating element 3 or last disengages from the engaging groove 32 on the accumulating element 3, and the driving section 111 is the portion of the driving rib 11 used to drive the accumulating element 3 to rotate.

[0081] Similarly, for the convenience of subsequent description, the process from the engagement section 112 starting to engage into the engagement groove 32 to the driving section 111 starting to engage into the engagement groove 32 is defined as the engagement process, the process from the driving section 111 starting to engage into the engagement groove 32 to the driving section 111 completely disengaging from the engagement groove 32 is defined as the driving process, and the process from the driving section 111 completely disengaging from the engagement groove 32 to the engagement section 112 completely disengaging from the engagement groove 32 is defined as the disengagement process; accordingly, the accumulation element 3 and the second element 2 remain relatively stationary during the engagement process and the disengagement process.

[0082] If the driving rib 11 spirals less than one turn, there is a possibility that the driving rib 11 will completely disengage from the meshing groove 32 on the accumulating element 3, that is, the first end may disengage from the meshing groove 32 while the second end has not yet engaged with another meshing groove 32. In this case, the accumulating element 3 remains stationary. If the driving rib 11 is configured as a continuous spiral segment, the end of the driving rib 11 may not be fully aligned with the meshing groove 32 when it reengages the meshing groove 32 on the accumulating element 3. This may cause the accumulating element 3 to rotate excessively, thereby resulting in a cumulative error in the accumulating element 3. By adopting the above solution, the driving rib 11 can only drive the accumulating element 3 to rotate during the driving process of the driving segment 111, while the accumulating element 3 remains stationary during the engagement and disengagement processes of the engagement segment 112. This ensures that the end of the driving rib 11 remains aligned with the meshing groove 32 when it reengages the meshing groove 32 on the accumulating element 3, thereby preventing the accumulating element 3 from rotating excessively and causing a cumulative error in the accumulating element 3.

[0083] It should be noted that the total angle rotated by the first element 1 relative to the second element 2 during dose setting is defined as the total setting angle, and the total dose that can be cumulatively set for the injection device corresponds to the total setting angle; at the same time, in the embodiment where the drive rib 11 includes the drive segment 111 and the engagement segment 112, the total setting angle is set to an integer multiple of 360°, that is, when the maximum set dose is reached, the first element 1 rotates an integer number of turns relative to the second element 2.

[0084] Furthermore, in some embodiments where the driving rib 11 includes a driving segment 111 and an engagement segment 112, the engagement segment 112 is configured as an arc segment circumferentially disposed about the first axis, i.e., the engagement segment 112 is entirely located on a circle whose center is located on the first axis. It should be noted that the driving rib 11 includes two engagement segments 112, both of which are arc segments, but are located at different axial positions on the first axis.

[0085] Furthermore, in other embodiments where the driving rib 11 includes a driving segment 111 and an engaging segment 112, the driving segment 111 is configured as a spiral segment spirally arranged around the first axis; the spiral segment is used to engage with the engaging groove 32, and is used to drive the accumulation element 3 to rotate when the spiral segment rotates synchronously with the first element 1.

[0086] Further, refer to Figures 16 to 18 In some embodiments, when the first element 1 rotates one circle relative to the second element 2, the cumulative element 3 is driven to rotate one tooth angle; specifically, the central angle formed by the center points of two adjacent meshing grooves 32 on the cumulative element 3 relative to the second axis is defined as the reference angle a. When the first element 1 and the second element 2 rotate one circle relative to each other, that is, 360°, the rotation angle of the cumulative element 3 is a reference angle a.

[0087] In a second aspect, an embodiment of the present application discloses an injection device that can ensure that the set dose is less than or equal to the remaining dose of the drug that can be injected, so that the actual injection dose is consistent with the set dose.

[0088] Reference Figure 1 The injection device includes a housing 7, a clutch element 4, the aforementioned dose accumulation mechanism, a drive rod 5, and a push rod 6. The clutch element 4, dose accumulation mechanism, drive rod 5, and push rod 6 are all disposed within the housing 7. Furthermore, during dose setting, at least one of the first element 1 and the second element 2 can rotate relative to the clutch element 4. During dose injection, the clutch element 4 is non-rotatably coupled to the first and second elements 1 and 2 in the dose injection direction. The first element 1, the second element 2, the drive rod 5, and the push rod 6 are sleeved together from the outside to the inside. The drive rod 5 is axially fixed and rotatably disposed within the housing 7 and non-rotatably coupled to the second element 2. The push rod 6 is threadedly coupled to the drive rod 5 and forms an axially guided engagement with the housing 7. Therefore, during dose injection, the first element 1 drives the second element 2 and the drive rod 5 to rotate in the dose injection direction, thereby driving the push rod 6 axially. Accordingly, the distal end of the injection device is connected to a cartridge 8 containing a drug, a movable piston 81 is provided at the proximal end of the cartridge 8, and a needle assembly is connected to the distal end. The axially fed push rod 6 is used to push the movable piston 81 of the cartridge 8 toward the distal end, thereby expelling the drug in the cartridge 8 through the needle assembly.

[0089] Specifically, refer to Figure 1 、 Figure 6 and Figure 7 The proximal end of the second element 2 is accommodated within the proximal end of the first element 1. The clutch element 4 is located within the proximal end of the first element 1 and presses against the proximal end of the second element 2. To increase the dose, the first element 1 rotates in a third direction. To decrease the dose, the first element 1 rotates in a fourth direction opposite the third direction. To inject a dose, both the first and second elements 1 and 2 rotate in the fourth direction. The injection device also includes a button 9 and a spring 10. The button 9 and the proximal end of the first element 1 form a retaining mechanism. The spring 10 is located between the button 9 and the clutch element 4 and is used to maintain the clutch element 4 against the proximal end of the second element 2.

[0090] Correspondingly, a ratchet tooth ring 12 is provided on the inner wall of the proximal end of the first element 1, and a ratchet arm 41 is provided to cooperate with the ratchet tooth ring 12. The ratchet tooth ring 12 and the ratchet arm 41 cooperate to form a first connection. The first connection allows the first element 1 to rotate in a third direction relative to the clutch element 4, and prevents the first element 1 from rotating in a fourth direction relative to the clutch element 4.

[0091] The proximal end of the second element 2 is provided with an axially protruding axial toothed ring 22, and the clutch element 4 is provided with mating teeth 42 that mesh with the axial toothed ring 22. Under the elastic force of the spring 10, the axial toothed ring 22 cooperates with the mating teeth 42 to form a second connection. This second connection prevents the clutch element 4 from rotating in the third direction relative to the second element 2, while allowing relative axial movement between the clutch element 4 and the second element 2, thereby rotating the clutch element 4 in the fourth direction relative to the second element 2. Simultaneously, during dose injection, the clutch element 4 is pressed against the proximal end of the second element 2 by the axial force transmitted by the button 9. At this time, the clutch element 4 and the second element 2 cannot undergo axial movement, and the clutch element 4 and the second element 2 remain relatively stationary.

[0092] Combine Figure 19 It should be noted that the axial gear ring 22 and the mating teeth 42 are configured as inclined teeth with a cross-section similar to a right-angled triangle, and the inclined teeth have a right-angled surface 421 and an inclined surface 422. During dose setting, when the right-angled surface 421 of the inclined tooth on the axial gear ring 22 abuts against the right-angled surface 421 of the mating tooth 42, the clutch element 4 is prevented from rotating in the third direction relative to the second element 2. When the inclined surface 422 of the inclined tooth on the axial gear ring 22 abuts against the inclined surface 422 of the mating tooth 42, the clutch element 4 and the second element 2 experience relative axial movement and "tooth jumping" occurs under the action of the elastic force of the spring 10, that is, the tooth jumps from one slot to an adjacent slot.

[0093] In summary, when the first element 1 rotates in the third direction to increase the dose, the clutch element 4 and the second element 2 remain stationary, and the first element 1 rotates relative to the second element 2 and the clutch element 4. When the first element 1 rotates in the fourth direction to decrease the dose, the first element 1 drives the clutch element 4 to rotate in the fourth direction, while the second element 2 remains stationary. At this time, the first element 1 and the clutch element 4 rotate relative to the second element 2. During the dose injection, the first element 1, the clutch element 4, and the second element 2 rotate synchronously in the fourth direction.

[0094] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0095] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A dose accumulation mechanism, characterized in that: include: A first element is rotatable about a first axis, wherein the first element is provided with a driving rib, and the driving rib spirally extends on the first element around the first axis; a second element, sleeved with the first element and capable of rotating about the first axis; an accumulator element connected to the second element and capable of rotating relative to the second element about a second axis, the second axis being arranged crosswise with the first axis, the accumulator element being provided with a plurality of meshing teeth, the plurality of meshing teeth being arranged at intervals along the circumferential direction of the second axis, and a meshing groove for the driving rib to engage with being formed between two adjacent meshing teeth; wherein, during dose setting, the first element and the second element are rotatable relative to each other, and the drive rib is configured to cooperate with the engaging teeth to drive the accumulator element to rotate; During dose injection, the first element is rotationally fixedly connected to the second element and the accumulator element is stationary relative to the first element and the second element.

2. The dose accumulation mechanism according to claim 1, characterized in that: The driving rib has a first end and a second end opposite to each other along its extending direction, and a surrounding angle formed by the first end and the second end based on the first axis is less than or equal to 360°.

3. The dose accumulation mechanism according to claim 2, characterized in that: The driving rib includes a driving section and an engaging section at the end of the driving section. The process from the engagement section starting to engage with the engaging groove to the driving section starting to engage with the engaging groove is defined as the engagement process. The process from the driving section completely disengaging from the engaging groove to the engagement section completely disengaging from the engaging groove is defined as the disengagement process. During the engagement process and the disengagement process, the accumulating element and the second element remain relatively stationary.

4. The dose accumulation mechanism according to claim 3, characterized in that: The drive segment is configured as a helical segment helically disposed about the first axis.

5. The dose accumulation mechanism according to claim 3, characterized in that: The engaging segment is configured as an arc segment circumferentially arranged around the first axis.

6. The dose accumulation mechanism according to claim 1, characterized in that: The driving rib has a first end and a second end opposite to each other along its extension direction. The first end and the second end form a surrounding angle greater than 360° based on the first axis, and the driving rib spirally extends from the first end to the second end around the first axis.

7. The dose accumulation mechanism according to claim 1, characterized in that: The central angle formed by two adjacent meshing teeth on the accumulator element is defined as a reference angle. When the first element and the second element rotate 360° relative to each other, the rotation angle of the accumulator element is a reference angle.

8. The dose accumulation mechanism according to any one of claims 1 to 7, characterized in that: The first element is sleeved on the outside of the second element, and the driving rib is arranged on the inner side wall of the first element.

9. The dose accumulation mechanism according to any one of claims 1 to 7, characterized in that: The second element is sleeved on the outside of the first element, and the driving rib is arranged on the outer side wall of the first element.

10. An injection device, characterized in that: comprising a clutch element and a dose accumulation mechanism according to any one of claims 1 to 9, wherein during dose setting, at least one of the first element and the second element is capable of rotating relative to the clutch element; During dose injection, the clutch element is connected to the first element and the second element in a rotationally fixed manner in the dose injection direction.

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