Dosage adjustment mechanism and injection pen
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-26
- Publication Date
- 2026-08-14
Smart Images
Figure CN224628320U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of syringe technology, and particularly relates to a dosage adjustment mechanism and an injection pen. Background Technology
[0002] In related technologies, Chinese patent application CN201324413Y discloses a quantitative adjustable pen syringe, including a fixed tube, a pusher, a sleeve, a clutch sleeve, rotating teeth, a screw, a transmission tube, a stop ring, a fixed ring, a rotating tube, a central rotating toothed cylinder, a transmission toothed cylinder, and a sleeve. It adjusts the pre-pressure dose during injection by rotating the end of the rotating tube to adjust its position relative to the sleeve. During the process of pressing the rotating tube inward, the rotating tube drives the central rotating toothed cylinder, the transmission toothed cylinder, the transmission tube, the rotating teeth, and the screw to rotate, thereby causing the screw to advance forward relative to the sleeve and inject the needle placed in the fixed tube into the human body in a quantitative manner. It has an internal anti-reverse mechanism, so that even if the rotating tube is adjusted backward during the next injection, the pusher will not retract.
[0003] The aforementioned adjustable-quantity pen syringe actually rotates the central gear cylinder, transmission gear cylinder, transmission tube, rotating gear, and screw by rotating the tube, thereby advancing the screw relative to the socket. However, this adjustable-quantity pen syringe requires at least three sets of ratchet structures (central gear cylinder, transmission gear cylinder, and rotating gear) to achieve forward and reverse adjustment, resulting in a complex structure. Furthermore, this structure leads to a large volume of forward and reverse adjustment mechanism, requiring a larger internal space within the syringe.
[0004] Therefore, how to solve the above-mentioned defects is a technical problem that urgently needs to be solved in this field.
[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Utility Model Content
[0006] This disclosure provides at least one dosage adjustment mechanism.
[0007] In a first aspect, embodiments of this disclosure provide a dosage adjustment mechanism, including: a coil spring bracket slidably disposed within a pen body, and a ratchet provided at the end of the coil spring bracket; The dosage knob is located at the end of the pen body; The rotating cylinder has a gear whose rotation is set inside the dosage knob, and the end wall is symmetrically provided with racks that are adapted to the ratchet. The push rod rotary drum is coaxially arranged with the coil spring bracket, and its outer wall is symmetrically provided with a second adjusting tooth that meshes with the dosage knob and a first adjusting tooth that meshes with the gear on the rotary drum; When the dosage knob is rotated in the forward direction, the gear on the rotating drum drives the push rod rotating drum to rotate in the forward direction, so as to wind the coil spring in the coil spring bracket; When the dosage knob is rotated in the reverse direction, the push rod cylinder drives the coil spring bracket to move axially towards the pen body, so that the ratchet and rack disengage, and the dosage knob drives the push rod cylinder to rotate in the reverse direction.
[0008] In one optional embodiment, the push rod rotary drum includes: The central cylinder is coaxially arranged with the coil spring bracket; Positioning discs are arranged around the circumference of the central cylinder; A first positioning platform is disposed on the side wall of the positioning disk, and several first adjustment teeth are evenly distributed on the outer side wall of the first positioning platform. The second positioning platform is disposed on the first positioning platform, and a plurality of the second adjusting teeth are evenly distributed on the outer side wall of the second positioning platform. When the dosage knob pushes the gear on the rotating drum to rotate in the forward direction, the gear on the rotating drum drives the first adjusting tooth to rotate in the forward direction, and the rack strikes the ratchet to produce a sound.
[0009] In one optional embodiment, the inner wall of the dosage knob is provided with a plurality of positioning teeth that mesh with the second adjustment teeth, and the positioning teeth are provided with a first inclined surface; The end of the second adjusting tooth is provided with a second inclined surface, the second inclined surface having the same inclination angle as the first inclined surface and abutting against it; When the dosage knob is rotated in the opposite direction, the first inclined plane pushes the second inclined plane to move axially towards the pen body, so that the ratchet and the rack disengage.
[0010] In one optional embodiment, the inner wall of the gear on the rotating drum is provided with a plurality of limiting strips that are adapted to the first adjusting tooth, and the first adjusting tooth is adapted to be inserted into the gap between two limiting strips.
[0011] In one optional embodiment, the positioning disc is positioned to fit the end of the coil spring. When the dosage knob drives the push rod cylinder to move axially along the pen body, the positioning disc pushes the coil spring, causing the coil spring bracket to move axially along the pen body. In another optional embodiment, two limiting grooves are symmetrically provided on the side of the gear on the cylinder near the rack, and the limiting grooves are spaced apart from the rack.
[0012] In one optional embodiment, two push blocks are symmetrically arranged on the inner wall of the dosage knob, one push block corresponds to one limiting groove, and the push block is slidably disposed in the limiting groove; When the dosage knob is rotated in the forward direction, a push block abuts against one side of the circumferential end wall of the limiting groove to drive the limiting groove to rotate synchronously. When the dosage knob is turned in the reverse direction, during the period when the push block rotates to abut against the circumferential end wall on the other side of the limiting groove, the first inclined surface pushes the second inclined surface, causing the push rod cylinder to move along the pen body axis, so that the ratchet and the rack disengage.
[0013] In one optional embodiment, the circumferential length of the push block is 4 / 5 to 9 / 10 of the circumferential length of the limiting groove.
[0014] Secondly, embodiments of this disclosure also provide an injection pen, including: a button disposed at the outer end of the plunger cylinder and slidable axially relative to the dosage knob.
[0015] In one optional embodiment, a drive cylinder is provided inside the pen body, and the drive cylinder abuts against the coil spring bracket; A return spring is provided inside the drive cylinder, and the return spring is adapted to push the drive cylinder to move towards the coil spring bracket.
[0016] The beneficial effects of this invention are that it provides a dosage adjustment mechanism and injection pen. Through the cooperation of a coiled spring bracket, a gear on the rotating cylinder, a dosage knob, a push rod rotating cylinder, and an adjustment gear assembly, forward and reverse adjustment can be achieved using only the push rod rotating cylinder. Compared to traditional syringes that rely on multiple sets of ratchet structures to achieve forward and reverse adjustment, this invention significantly simplifies the internal structure, reduces the number of parts, and compresses the internal space occupied by the pen body.
[0017] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.
[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0020] Figure 1 An unfolded perspective view of the dose adjustment mechanism provided in an embodiment of this disclosure; Figure 2 A perspective view of the push rod cylinder and adjusting gear assembly provided in an embodiment of this disclosure; Figure 3 A perspective view of the gear on the rotating drum provided in an embodiment of this disclosure; Figure 4 A perspective view of the dosage knob provided in an embodiment of this disclosure; Figure 5 A perspective view of the unfolded state of the dosage knob, the gear on the rotating cylinder, and the push rod rotating cylinder provided in the embodiments of this disclosure; Figure 6 This is a perspective view of the internal cross-section of the pen body provided in an embodiment of this disclosure.
[0021] In the picture: 1. Pen body; 10. Button; 2. Spring support; 20. Ratchet; 21. Spring; 3. Gear on the rotating drum; 30. Rack; 31. Limiting strip; 33. Limiting groove; 4. Dosage knob; 40. Positioning teeth; 41. First inclined plane; 42. Push block; 5. Push rod rotary cylinder; 50. Center cylinder; 51. Positioning plate; 501, First positioning stage; 502, Second positioning stage; 503, First adjusting tooth; 504, Second adjusting tooth; 505, Second inclined plane. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0023] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.
[0024] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.
[0025] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.
[0026] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.
[0027] Research has revealed that a Chinese patent application with related technical announcement number CN201324413Y discloses a quantitative adjustable pen syringe, including a fixed tube, a pusher, a sleeve, a clutch sleeve, rotating teeth, a screw, a transmission tube, a stop ring, a fixed ring, a rotating tube, a central rotating toothed cylinder, a transmission toothed cylinder, and a sleeve. It adjusts the pre-injection dose by rotating the end of the rotating tube to adjust its position relative to the sleeve. During the inward pressing of the rotating tube, the rotating tube drives the central rotating toothed cylinder, the transmission toothed cylinder, the transmission tube, the rotating teeth, and the screw to rotate, thereby propelling the screw forward relative to the sleeve and quantitatively injecting the injection solution placed in the fixed tube into the human body. It also has an internal anti-reverse mechanism, preventing the pusher from retracting even when the rotating tube is adjusted backward for the next injection.
[0028] The aforementioned adjustable-quantity pen injector actually rotates by rotating the tube, driving the central gear cylinder, transmission gear cylinder, transmission tube, rotating gears, and screw, thereby propelling the screw forward relative to the socket. However, the aforementioned adjustable-quantity pen injector has the following shortcomings: 1. The forward and reverse adjustment mechanism is bulky, requiring a larger internal space in the syringe, which limits the portability design.
[0029] 2. Multiple sets of ratchet structures are required to achieve forward and reverse rotation, which is complex, has a large number of parts, and a high assembly error rate, affecting dosage accuracy.
[0030] Therefore, how to solve the above-mentioned defects is a technical problem that urgently needs to be solved in this field.
[0031] The defects in the above solutions and the reasons for their occurrence are the results of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventors' contributions to this disclosure.
[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0033] The following detailed description, with reference to the accompanying drawings, describes some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0034] like Figures 1 to 6 As shown, at least one embodiment provides a dose adjustment mechanism, including: A spring support 2 is axially slidably disposed within the pen body 1, and a ratchet 20 is provided at the end of the spring support 2; the ratchet 20 faces the rack 30. A dosage knob 4 is rotatably disposed at the end of the pen body 1; a rotating gear 3 is rotatably disposed within the dosage knob 4, and a rack 30 adapted to the ratchet 20 is symmetrically disposed at its end; a push rod rotating cylinder 5 is coaxially disposed with the spring support 2, and a second adjusting tooth 504 meshing with the dosage knob 4 and a first adjusting tooth 503 meshing with the rotating gear 3 are symmetrically disposed on its outer wall; the rotating gear 3 rotates forward to drive the push rod rotating cylinder 5 to rotate to wind the spring 21 inside the pen body 1, thereby adjusting the injection dosage of the syringe. Specifically, when the dosage knob 4 rotates forward, the rotating gear 3 drives the push rod rotating cylinder 5 to rotate forward to wind the spring 21 inside the pen body 1, thereby pressurizing the spring 21 inside the pen body 1. When the dosage knob 4 is rotated in the reverse direction, the push rod cylinder 5 drives the coiled spring support 2 to move axially towards the pen body 1, so that the ratchet 20 disengages from the rack 30. The dosage knob 4 then drives the push rod cylinder 5 to rotate in the reverse direction to release the coiled spring and reduce the injection dosage. Through the cooperation of the coiled spring support 2, the gear 3 on the cylinder, the dosage knob 4, the push rod cylinder 5, and the adjusting gear group 50, the forward and reverse adjustment of the coiled spring support 2 can be achieved using only the push rod cylinder 5. Compared with traditional syringes that rely on multiple sets of ratchet structures to achieve forward and reverse adjustment, this invention significantly simplifies the internal structure, reduces the number of parts, and compresses the internal space occupied by the pen body 1.
[0035] Reference Appendix Figure 2 The push rod rotating cylinder 5 includes: a central cylinder 50, coaxially arranged with the coil spring bracket 2; a positioning disk 51, arranged circumferentially along the central cylinder 50; a first positioning platform 501, disposed on the side wall of the positioning disk 51, with a plurality of first adjusting teeth 503 evenly distributed on the outer side wall of the first positioning platform 501; and a second positioning platform 502, disposed on the first positioning platform 501, with a plurality of second adjusting teeth 504 evenly distributed on the outer side wall of the second positioning platform 502. When the dosage knob 4 pushes the gear 3 on the rotating cylinder to rotate forward, the gear 3 on the rotating cylinder drives the first adjusting teeth 503 to rotate forward, and the rack 30 strikes the ratchet 20 to produce a sound. Both the first adjusting teeth 503 and the second adjusting teeth 504 extend axially along the pen body 1. The radial length of the first positioning platform 501 is greater than the radial length of the second positioning platform 502. The rack 30 prevents the gear 3 on the rotating cylinder from rotating in the opposite direction after adjusting to a certain dosage, thus ensuring the accuracy of the adjusted dosage.
[0036] Reference Appendix Figure 4 The inner wall of the dosage knob 4 is provided with a plurality of positioning teeth 40 that are adapted to the second adjustment teeth 504, and each positioning tooth 40 has a first inclined surface 41 on its side wall; the second adjustment teeth 504 are adapted to the positioning teeth 40. The end of the second adjustment tooth 504 is provided with a second inclined surface 505, and the second inclined surface 505 has the same inclination angle as the first inclined surface 41 and abuts against it.
[0037] When the dosage knob 4 is rotated in the forward direction, the side wall of the positioning tooth 40 pushes the second adjusting tooth 504 to make the push rod cylinder 5 rotate synchronously; the push rod cylinder 5 rotates synchronously in the forward direction to press the coil spring in the pen body 1, thereby increasing the injection dose.
[0038] When the dosage knob 4 is rotated in the reverse direction, the first inclined surface 41 pushes the second inclined surface 505 to move axially towards the pen body 1, and the push rod cylinder 5 pushes the coil spring bracket 2 to move axially in sync, so that the ratchet 20 disengages from the rack 30. At this time, the gear 3 on the cylinder is adapted to rotate in the opposite direction relative to the coil spring bracket 2 to release the coil spring and reduce the injection dosage.
[0039] Reference Appendix Figure 3The inner wall of the upper gear 3 of the rotating drum is provided with several limiting strips 31 that are adapted to the first adjusting tooth 503. The gap between two adjacent limiting strips 31 is not less than the axial width of the first adjusting tooth 503. The first adjusting tooth 503 is adapted to be inserted into the gap between two limiting strips 31. When the dosage knob 4 is rotated in the forward direction, it drives the upper gear 3 of the rotating drum to rotate. The upper gear 3 of the rotating drum rotates synchronously with the first adjusting tooth 503 through the cooperation of the limiting strips 31. At the same time, the side wall of the positioning tooth 40 also pushes the second adjusting tooth 504 to rotate synchronously with the push rod rotating drum 5. During the rotation of the upper gear 3 of the rotating drum, the rack 30 strikes the ratchet 20 at the end of the coil spring bracket 2 to make a sound to warn the user.
[0040] Reference Appendix Figure 3 The gear 3 on the rotating drum has two symmetrically arranged limiting grooves 33 on the side near the rack 30, and the limiting grooves 33 are arranged at intervals with the rack 30.
[0041] Reference Appendix Figure 4 Two push blocks 42 are symmetrically arranged on the inner wall of the dosage knob 4, and the push blocks 42 are slidably disposed in the limiting groove 33. The circumferential length of the push block 42 is 4 / 5 to 9 / 10 of the circumferential length of the limiting groove 33. When the dosage knob 4 rotates in the forward direction, one push block 42 abuts against one side of the circumferential end wall of the limiting groove 33 to drive the limiting groove 33 to rotate synchronously; when the dosage knob 4 rotates in the reverse direction, during the period when the push block 42 rotates to abut against the other side of the circumferential end wall of the limiting groove 33, the first inclined surface 41 pushes the second inclined surface 505, so that the push rod cylinder 5 moves along the axial direction of the pen body 1, so that the ratchet 20 disengages from the rack 30.
[0042] Reference Appendix Figure 6 The positioning disk 51 is set at the end of the coil spring 21. When the dosage knob 4 drives the push rod cylinder 5 to move along the pen body axis, the positioning disk 51 pushes the coil spring 21 to drive the coil spring bracket 2 to move along the pen body axis.
[0043] Reference Appendix Figure 1 and Figure 6 At least one embodiment provides an injection pen, comprising: Button 10 is located at the outer end of the push rod rotating cylinder 5 and can slide axially relative to the dosage knob 4. When button 10 is pushed towards the pen body 1, button 10 pushes the push rod rotating cylinder 5 axially into the pen body 1 to activate the coil spring. A drive cylinder 11 is provided inside the pen body 1, and the drive cylinder 11 abuts against the coil spring support 2; a return spring 12 is provided inside the drive cylinder 11, and the return spring 12 is adapted to push the drive cylinder 11 towards the coil spring support 2. When the coil spring support 2 moves axially towards the pen body 1, it drives the drive cylinder 11 to compress the return spring 12; at the instant that the rack 30 on the side wall of the gear 3 on the rotating cylinder meshes with the next tooth of the ratchet 20, the return spring 12 resets as it drives the coil spring support 2.
[0044] The working principle is as follows: Before injecting the medication, rotate the dosage knob 4 clockwise. The dosage knob 4 drives the push rod cylinder 5 and the gear 3 on the cylinder to rotate synchronously, thus compressing the torsion spring 21. After the dial rotates to the required scale, press the button 10. The button 10 activates the coil spring 21, thereby driving the transmission linkage inside the pen body 1 to drive the pen refill inside the pen body 1 to inject the medication in a measured amount. The push rod cylinder 5 drives the gear 3 on the cylinder to rotate synchronously, and the rack 30 strikes each ratchet 20 to prevent the push rod cylinder 5 from retracting in the opposite direction.
[0045] If the dosage knob 4 is rotated excessively, i.e., the dial rotates beyond the required scale, the dosage knob 4 is rotated in the opposite direction. The push rod cylinder 5 drives the coiled spring support 2 to move axially towards the pen body 1, so that the ratchet 20 disengages from the rack 30. The dosage knob 4 then drives the push rod cylinder 5 to rotate in the opposite direction. At this time, the dosage knob 4 rotates in the opposite direction relative to the gear 3 on the cylinder, and the push block 42 moves from one end of the limiting groove 33 to the other end. At this time, the first inclined surface 41 pushes the second inclined surface 505, and the push rod cylinder 5 drives the coiled spring support 2 to move axially towards the pen body 1, so that the ratchet 20 disengages from the rack 30. This causes the push rod cylinder 5 to rotate in the opposite direction relative to the coiled spring support 2, releasing the elastic force on the torsion spring, until the dial reaches the preset scale. When the dosage knob 4 rotates in the forward direction, it is used to increase the injection dose of the syringe; when the dosage knob 4 rotates in the reverse direction, it is used to decrease the injection dose of the syringe.
[0046] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0047] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as the second element, component, region, layer, or segment.
[0048] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A dose adjustment mechanism, characterized by include: A spring support (2) is axially slidably disposed inside the pen body (1), and a ratchet (20) is provided at the end of the spring support (2). The dosage knob (4) is located at the end of the pen body (1); The gear (3) on the rotating drum is set inside the dosage knob (4), and the end is symmetrically provided with racks (30) that are adapted to the ratchet (20). The push rod rotary drum (5) is coaxially arranged with the coil spring bracket (2), and its outer wall is symmetrically provided with a second adjusting tooth (504) that meshes with the dosage knob (4) and a first adjusting tooth (503) that meshes with the gear (3) on the rotary drum. When the dosage knob (4) is rotated in the forward direction, the gear (3) on the rotating drum drives the push rod rotating drum (5) to rotate in the forward direction, so as to wind the coil spring (21) inside the coil spring bracket (2). When the dosage knob (4) is rotated in the reverse direction, the push rod cylinder (5) drives the coil spring bracket (2) to move axially toward the pen body (1) so that the ratchet (20) and the rack (30) disengage. The dosage knob (4) then drives the push rod cylinder (5) to rotate in the reverse direction.
2. The dosage adjustment mechanism as described in claim 1, characterized in that, The push rod rotary cylinder (5) includes: The center cylinder (50) is coaxially arranged with the coil spring bracket (2); Positioning disc (51) is arranged circumferentially along the central cylinder (50); The first positioning platform (501) is set on the side wall of the positioning disk (51), and a plurality of the first adjusting teeth (503) are evenly distributed on the outer side wall of the first positioning platform (501). The second positioning platform (502) is disposed on the first positioning platform (501), and a plurality of the second adjusting teeth (504) are evenly distributed on the outer side wall of the second positioning platform (502); When the dosage knob (4) pushes the gear (3) on the rotating drum to rotate in the forward direction, the gear (3) on the rotating drum drives the first adjusting tooth (503) to rotate in the forward direction, and the rack (30) strikes the ratchet (20) to make a sound.
3. The dosage adjustment mechanism as described in claim 2, characterized in that, The inner wall of the dosage knob (4) is provided with a plurality of positioning teeth (40) that mesh with the second adjustment teeth (504), and the end of the positioning teeth (40) is provided with a first inclined surface (41). The end of the second adjusting tooth (504) is provided with a second inclined surface (505), the second inclined surface (505) has the same inclination angle as the first inclined surface (41) and abuts against it; When the dosage knob (4) is rotated in the opposite direction, the first inclined plane (41) pushes the second inclined plane (505) to move axially toward the pen body (1) so that the ratchet (20) disengages from the rack (30).
4. The dosage adjustment mechanism as described in claim 2, characterized in that, The inner wall of the upper gear (3) of the rotating drum is provided with a plurality of limiting strips (31) that are adapted to the first adjusting tooth (503), and the first adjusting tooth (503) is adapted to be inserted into the gap between the two limiting strips (31).
5. The dosage adjustment mechanism as described in claim 2, characterized in that, The positioning disk (51) is set at the end of the coil spring (21). When the dosage knob (4) drives the push rod cylinder (5) to move along the pen body axis, the positioning disk (51) pushes the coil spring (21) to drive the coil spring bracket (2) to move along the pen body (1) axis.
6. The dosage adjustment mechanism as described in claim 1, characterized in that, The gear (3) on the rotating drum has two symmetrically arranged limiting grooves (33) on the side near the rack (30), and the limiting grooves (33) are arranged at intervals with the rack (30).
7. The dosage adjustment mechanism as described in claim 6, characterized in that, The inner wall of the dosage knob (4) is symmetrically provided with two push blocks (42), one push block (42) corresponds to one limiting groove (33), and the push block (42) is slidably disposed in the limiting groove (33); When the dosage knob (4) is rotated in the forward direction, a push block (42) abuts against the circumferential end wall of the limiting groove (33) to drive the limiting groove (33) to rotate synchronously. When the dosage knob (4) is rotated in the opposite direction, the push block (42) rotates to abut against the circumferential end wall on the other side of the limiting groove (33), and the first inclined surface (41) pushes the second inclined surface (505) to move the push rod cylinder (5) axially along the pen body (1) so that the ratchet (20) disengages from the rack (30).
8. The dosage adjustment mechanism as described in claim 7, characterized in that, The circumferential length of the push block (42) is 4 / 5 to 9 / 10 of the circumferential length of the limiting groove (33).
9. An injection pen characterized in that include: The dose adjustment mechanism as described in any one of claims 1-8 includes a button (10) disposed at the outer end of the push rod cylinder (5) and axially slidable relative to the dose knob (4).
10. The injection pen as described in claim 9, characterized in that, A drive cylinder (11) is provided inside the pen body (1), and the drive cylinder (11) abuts against the coil spring bracket (2); A reset spring (12) is provided inside the drive cylinder (11), and the reset spring (12) is adapted to push the drive cylinder (11) to move in the direction of the coil spring bracket (2).
Citation Information
Patent Citations
Adjustable pen-type injector for quantitative injection
CN201324413Y