Injection pen
By designing the engagement and disengagement of the pawl and reverse tooth structure of the injection pen, the reciprocating movement of the push rod is achieved, solving the problem that existing injection pens cannot be reused, reducing usage costs and environmental pollution.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGCHUN GENESCIENCE PHARM CO LTD
- Filing Date
- 2025-04-09
- Publication Date
- 2026-04-10
AI Technical Summary
Existing injection pens are for single use, resulting in high operating costs and environmental pollution problems.
An injection pen has been designed, comprising a pen shell, an injection component, a button component, and a pawl component. The reciprocating movement of the push rod is achieved by the engagement and disengagement of the pawl with the reverse tooth structure, allowing the injection pen to be reused.
It enables the reuse of injection pens, reduces resource waste, lowers usage costs, and is simple and convenient to operate.
Smart Images
Figure CN224099765U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to medical instrument technical field especially, and it is an injection pen. BACKGROUND
[0002] At present, in some application scenes, patients often need to inject various medicines by themselves, in order to make the patient injects medicine more accurately and conveniently, people have invented injection pen or various devices similar to injection pen. However, in practical application, it is found that the existing injection pen is a disposable product, after the injection of medicine is finished, the injection pen is usually discarded, which is not only not conducive to reducing the use cost, but also may exist the problem of environmental pollution, so that an injection pen which can be reused is urgently needed. CONTENT OF THE UTILITY MODEL
[0003] The utility model provides a kind of injection pen, to at least solve or improve the problem of high use cost of existing disposable injection pen, difficult to reuse.
[0004] The utility model provides a kind of injection pen, comprising:
[0005] Pen shell, including accommodating cavity and with the first port and second port of accommodating cavity communication;
[0006] Injection assembly is set in the accommodating cavity, and the injection assembly includes push rod and dosing assembly, the push rod includes stem and back tooth structure, the back tooth structure is located in the peripheral wall of the stem, the first end of the stem is in abutment with the dosing assembly, and the dosing assembly is in abutment with the first port;
[0007] Button assembly is inserted in the second port, and the button assembly and the second end of the stem are slidably matched along the axial direction of the pen shell and can drive the stem to rotate;
[0008] Pawl assembly is set in the accommodating cavity, and the pawl assembly includes first pawl, second pawl and clutch structure, the first pawl is connected with the button assembly, the second pawl is connected with the pen shell, the first pawl and the second pawl are configured to engage with the back tooth structure respectively, and the clutch structure is formed between the pen shell and the first pawl;
[0009] Wherein, in the case that the button assembly rotates, the first pawl can engage or separate with the back tooth structure through the clutch structure, and the second pawl can engage or separate with the back tooth structure.
[0010] According to the injection pen provided by the utility model, the clutch structure comprises:
[0011] The guide groove is provided with a first groove bottom and a second groove bottom, which are arranged in sequence along the circumference of the pen shell, and the radial distance of the first groove bottom relative to the push rod is smaller than that of the second groove bottom relative to the push rod.
[0012] A contact is connected with the first pawl, and the contact is configured to be inserted into the guide groove.
[0013] The button assembly is configured to drive the first pawl to rotate, so as to drive the contact to move between the first groove bottom and the second groove bottom.
[0014] According to the injection pen provided by the utility model, the first pawl comprises a plurality of first claw bodies, and each first claw body is provided with the contact.
[0015] The guide groove is provided with a plurality of guide grooves, which are arranged in sequence and at intervals along the circumference of the pen shell, and the plurality of guide grooves are arranged in one-to-one correspondence with the plurality of contacts.
[0016] According to the injection pen provided by the utility model, the plurality of inverted tooth structures are arranged in sequence and at intervals along the circumference of the rod body.
[0017] The second pawl comprises a plurality of second claw bodies, which are arranged in sequence and at intervals along the circumference of the pen shell.
[0018] When the injection pen is in an injection state, the plurality of second claw bodies are in one-to-one engagement with the plurality of inverted tooth structures, and when the injection pen is in a reset state, each second claw body is distributed between two adjacent inverted tooth structures.
[0019] According to the injection pen provided by the utility model, the rod body comprises:
[0020] A first section, a first end of the first section is in abutment with the drug delivery assembly.
[0021] A second section, a first end of the second section is connected with a second end of the first section, and the plurality of inverted tooth structures are arranged on the circumferential wall of the second section.
[0022] A positioning structure, comprising an annular tooth groove and a wedge-shaped protrusion, the annular tooth groove is arranged between the first section and the second section and is connected with each inverted tooth structure, and the wedge-shaped protrusion is arranged on the circumferential wall of the second section and located between two adjacent inverted tooth structures.
[0023] Wherein, in the injection pen is in the reset state, the wedge-shaped protrusion is used for guiding the axial movement of the second pawl along the push rod, to achieve engagement with the ring-shaped gear slot.
[0024] According to the injection pen provided by the utility model, the button assembly is provided with an indication mark, and the circumferential wall of the first pawl is provided with a limiting protrusion.
[0025] The outer side wall of the pen shell is provided with a first position mark, and the inner side wall of the pen shell is provided with a first limiting groove, which extends along the axial direction of the pen shell.
[0026] When the indication mark is opposite to the first position mark, the first pawl and the second pawl are engaged with the inverted tooth structure respectively.
[0027] Wherein, the limiting protrusion cooperates with the first limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
[0028] According to the injection pen provided by the utility model, the outer side wall of the pen shell is further provided with a second position mark, and the first position mark and the second position mark are arranged at intervals along the circumferential direction of the pen shell.
[0029] The inner side wall of the pen shell is further provided with a second limiting groove, which extends along the axial direction of the pen shell, and the extension length of the second limiting groove is greater than that of the first limiting groove.
[0030] When the indication mark and the second position mark are opposite, the first pawl and the second pawl are engaged with the inverted tooth structure respectively.
[0031] Wherein, the limiting protrusion cooperates with the second limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
[0032] According to the injection pen provided by the utility model, the outer side wall of the pen shell is further provided with a third position mark, and the first position mark and the third position mark are arranged at intervals along the circumferential direction of the pen shell.
[0033] When the indication mark and the third position mark are opposite, the first pawl and the second pawl are separated from the inverted tooth structure respectively.
[0034] According to the injection pen provided by the utility model, the button assembly comprises:
[0035] The plug-in barrel is inserted into the pen shell, the first end of the plug-in barrel is connected with the first pawl, and the second end of the rod body is inserted into the plug-in barrel and is in sliding cooperation with the inner wall of the plug-in barrel.
[0036] A pressing head is exposed from the second port and is connected with the second end of the insertion barrel.
[0037] According to the injection pen provided by the utility model, the injection assembly, the button assembly and the pawl assembly are arranged based on the pen shell, the pawl assembly comprises a first pawl, a second pawl and a clutch structure, the button assembly is configured to be movable along the axial direction of the pen shell and to drive the push rod and the first pawl to rotate relative to the pen shell, when it is required to control the injection pen to be in the injection state, the button assembly can be controlled to rotate relative to the pen shell, so that the first pawl and the second pawl are engaged with the ratchet structure, the push rod is pressed to exert a propelling force on the push rod from the side of the injection assembly, the push rod is moved relative to the pen shell from the side of the injection assembly, the push rod exerts a force on the injection assembly, and the injection assembly is driven to perform an injection operation, when the injection operation is completed and it is required to control the injection pen to be in the reset state, the button assembly can be controlled to rotate relative to the pen shell, so that the first pawl and the second pawl are disengaged from the ratchet structure, and the push rod can be manually reset to the initial position, so as to prepare for the injection operation of the injection pen again.
[0038] And / or, the circumferential wall of the insertion barrel is provided with a second protrusion, the inner wall of the pen shell is provided with a second groove, the second protrusion is movably arranged in the second groove, and the second protrusion and the second groove are matched to limit the rotating position of the button assembly relative to the pen shell.
[0039] The injection pen provided by the utility model can realize the reciprocating movement of the push rod in the pen shell, the reset of the push rod can be performed again after the injection operation of the injection pen is completed based on the push rod, and therefore the repeated use of the injection pen is realized without increasing the cost, and the resource waste existing in the use of the existing disposable injection pen is overcome.
[0040] Therefore, the injection pen provided by the utility model can realize the reciprocating movement of the push rod in the pen shell, the reset of the push rod can be performed again after the injection operation of the injection pen is completed based on the push rod, and therefore the repeated use of the injection pen is realized without increasing the cost, and the resource waste existing in the use of the existing disposable injection pen is overcome. BRIEF DESCRIPTION OF DRAWINGS
[0041] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the premise of not paying creative effort.
[0042] Figure 1 It is the schematic diagram of the three-dimensional structure of the injection pen provided by the present application.
[0043] Figure 2 It is the schematic diagram of the sectional structure of the injection pen provided by the present application.
[0044] Figure 3 It is the schematic diagram of the explosion structure of the injection pen provided by the present application.
[0045] Figure 4 It is the schematic diagram of the connection between the inner bushing and the cartridge holder in the injection pen provided by the present application.
[0046] Figure 5 It is the schematic diagram of the structure of the injection pen after hiding the cap provided by the present application.
[0047] Figure 6 It is the schematic diagram of the structure of the injection pen after hiding the shell and the cap provided by the present application.
[0048] Figure 7 It is the schematic diagram of the structure of the push rod provided by the present application.
[0049] Figure 8 It is the schematic diagram of the structure of the first pawl provided by the present application.
[0050] Figure 9 It is the schematic diagram of the structure of the second pawl provided by the present application.
[0051] Figure 10 It is the partial enlarged schematic diagram of the clutch structure provided by the present application.
[0052] Figure 11 It is one of the schematic diagrams of the structure of the inner bushing provided by the present application.
[0053] Figure 12 It is the second schematic diagram of the structure of the inner bushing provided by the present application.
[0054] Figure 13 It is the third schematic diagram of the structure of the inner bushing provided by the present application.
[0055] Figure 14 It is the schematic diagram of the structure of the cartridge holder provided by the present application.
[0056] Figure 15 is a structural schematic view of a pen shell provided by the present application.
[0057] Figure 16 is a structural schematic view of a pen shell provided by the present application.
[0058] Figure 17 is a structural schematic view of a button assembly provided by the present application.
[0059] Figure 18 is a structural schematic view of a button assembly provided by the present application.
[0060] Figure 19 is a structural schematic view of the present application, when the indication mark is opposite to the first position mark, the push rod is pulled out, and the injection pen is prepared for exhaust operation.
[0061] Figure 20 is a structural schematic view of the present application, when the indication mark is opposite to the first position mark, the push rod is reset to complete the exhaust operation of the injection pen.
[0062] Figure 21 is a structural schematic view of the present application, the indication mark is opposite to the second position mark by rotating the button assembly.
[0063] Figure 22 is a structural schematic view of the present application, when the indication mark is opposite to the second position mark, the push rod is pulled out, and the injection pen is prepared for injection operation.
[0064] Figure 23 is a structural schematic view of the present application, when the indication mark is opposite to the second position mark, the push rod is reset to complete the injection operation.
[0065] Figure 24 is a structural schematic view of the present application, the indication mark is opposite to the third position mark by rotating the button assembly.
[0066] Figure 25 is a structural schematic view of the present application, when the indication mark is opposite to the third position mark, the push rod is reset for operation.
[0067] Reference signs:
[0068] 1, pen shell; 101, first position mark; 102, second position mark; 103, third position mark; 111, first limiting groove; 112, second limiting groove; 121, first groove; 122, second groove; 11, refill holder; 110, first clamping structure; 1101, first clamping tongue; 1102, first gap; 11010, clamping hole; 1111, position indication; 12, inner sleeve; 120, second clamping structure; 1201, second clamping tongue; 1202, second gap; 12010, protruding rib; 13, main shell; 131, opening mark; 132, closing mark;
[0069] 2, injection assembly; 21, push rod; 211, rod body; 2111, first segment; 2112, second segment; 2113, positioning structure; 212, reverse tooth structure; 22, administration assembly; 221, administration bottle; 222, needle;
[0070] 3, button assembly; 31, insertion barrel; 311, first protrusion; 312, second protrusion; 3101, clamping protrusion; 32, pressing head; 301, indication mark;
[0071] 4, pawl assembly; 41, first pawl; 4101, limiting protrusion; 4102, clamping hole; 411, first claw body; 412, first annular seat body; 42, second pawl; 421, second claw body; 422, second annular seat body; 43, clutch structure; 431, guide groove; 432, contact;
[0072] 5, pen cap. DETAILED DESCRIPTION
[0073] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0074] The following will be combined Figures 1-25 with specific embodiments and application scenarios to describe the clamping structure and injection pen provided by the utility model embodiments in detail.
[0075] In the first aspect, as shown in Figure 3 , Figure 4 and Figure 12 , the utility model embodiment provides a clamping structure applied to an injection pen, which comprises: a first clamping structure 110 and a second clamping structure 120.
[0076] The first clamping structure 110 comprises a plurality of first clamping tongues 1101 which are sequentially and circumferentially spaced apart, and each of the first clamping tongues 1101 is provided with a clamping opening 11010 in the middle region; the second clamping structure 120 comprises a plurality of second clamping tongues 1201 which are sequentially and circumferentially spaced apart, and each of the second clamping tongues 1201 is provided with a protruding rib 12010 on the outer wall surface; the clamping structure can be switched between the first state and the second state; in the first state, the first clamping tongues 1101 and the second clamping tongues 1201 are sequentially and circumferentially alternately arranged; in the second state, the plurality of second clamping tongues 1201 are sequentially and oppositely inserted into the inner side of the plurality of first clamping tongues 1101, and the protruding rib 12010 of the second clamping tongue 1201 is clamped in the clamping opening 11010 of the first clamping tongue 1101.
[0077] It can be understood that the first clamping structure 110 can be arranged at the end of the first component on the injection pen, the second clamping structure 120 can be arranged at the end of the second component on the injection pen, and based on the cooperation of the first clamping structure 110 and the second clamping structure 120, the detachable connection of the first component and the second component can be realized. Wherein, the first clamping structure 110 and the second clamping structure 120 can be made of plastic pieces with certain elasticity.
[0078] For the first clamping structure 110, at least two first clamping tongues 1101 can be arranged, and a first gap 1102 is formed between any two adjacent first clamping tongues 1101, and each first clamping tongue 1101 extends in the circumferential direction relative to the central axis of the first clamping structure 110 to form a tile shape.
[0079] For the second clamping structure 120, at least two second clamping tongues 1201 can be arranged, and a second gap 1202 is formed between any two adjacent second clamping tongues 1201, and each second clamping tongue 1201 extends in the circumferential direction relative to the central axis of the second clamping structure 120 to form a tile shape. Wherein, the number of first clamping tongues 1101 arranged and the number of second clamping tongues 1201 arranged are the same.
[0080] In actual application, the first clamping structure 110 and the second clamping structure 120 can be first controlled to approach along the axial direction, to ensure that the first clamping tongue 1101 is inserted into the second gap 1202, and the second clamping tongue 1201 is inserted into the first gap 1102, so as to realize that the first clamping tongue 1101 and the second clamping tongue 1201 are sequentially and circumferentially alternately arranged, then the first clamping structure 110 and the second clamping structure 120 are controlled to rotate relatively, to realize that the plurality of second clamping tongues 1201 are sequentially and oppositely inserted into the inner side of the plurality of first clamping tongues 1101, until the protruding rib 12010 of each second clamping tongue 1201 is clamped in the clamping opening 11010 of the corresponding first clamping tongue 1101. Wherein, Figure 4The rotation direction of the first clamping structure 110 is shown.
[0081] As can be seen from the above, the clamping structure shown in the utility model, by setting the first clamping structure 110 and the second clamping structure 120, when assembling the clamping structure, the clamping structure can be set to the first state first, then by controlling the relative rotation of the first clamping structure 110 and the second clamping structure 120, the clamping structure can be switched to the second state, and the clamping operation of the clamping structure is completed, and when disassembling the clamping structure, the clamping structure can be switched from the second state to the first state only by rotating, which is simple and convenient to operate, and when the clamping structure is clamped, since the plurality of first clamping tongues 1101 and the plurality of second clamping tongues 1201 are set one by one, and the clamping is realized by the cooperation of the ribs 12010 and the sockets 11010, the first clamping structure 110 and the second clamping structure 120 are difficult to separate from each other when there is no relative rotation, and the clamping strength between the first clamping structure 110 and the second clamping structure 120 is ensured, and the reliability of the clamping of each other is also ensured.
[0082] In some embodiments, as shown in Figure 4 The rib 12010 extends along a spiral line trajectory, and the shape of the socket 11010 is adapted to the shape of the rib 12010.
[0083] It can be understood that by limiting the corresponding shapes of the rib 12010 and the socket 11010, it is not only beneficial to reduce the operation difficulty of controlling the relative rotation of the first clamping structure 110 and the second clamping structure 120, but also ensures the reliability of the clamping cooperation of the rib 12010 and the socket 11010.
[0084] The rib 12010 is in the form of a strip and is configured to extend along a spiral line trajectory around the central axis of the second clamping structure 120 on the outer wall surface of the second clamping tongue 1201, and the socket 11010 is a through hole provided on the first clamping tongue 1101, and the socket 11010 has an opening shape that is substantially the same as the shape of the rib 12010.
[0085] In some embodiments, as shown in Figure 14 In order to further reduce the operation difficulty of controlling the relative rotation of the first clamping structure 110 and the second clamping structure 120, the first clamping tongue 1101 is provided with a first inclined surface, and the first inclined surface is located on the side of the first clamping tongue 1101 along the extension direction thereof, wherein the two side edges of the first clamping tongue 1101 extending in the axial direction can be provided with the first inclined surface, and the first inclined surface is formed on the inner side surface of the first clamping tongue 1101.
[0086] As shown in Figure 12As shown, the convex rib 12010 is provided with a second inclined surface X2, and the second inclined surface X2 is arranged at at least one end of the convex rib 12010 along the extending direction thereof, for example, both ends of the convex rib 12010 along the extending direction thereof can be provided with the second inclined surface X2.
[0087] In combination Figure 4 , Figure 12 and Figure 14 , it can be known that, in the process of switching the clamping structure from the first state to the second state, the first inclined surface X1 and the second inclined surface X2 are in sliding contact to guide the second clamping tongue 1201 to rotate to the inner side of the first clamping tongue 1101.
[0088] In a second aspect, as shown in Figure 1 , Figure 2 and Figure 3 , the utility model embodiment further provides an injection pen, comprising: a pen shell 1, the pen shell 1 includes a cartridge holder 11 and an inner bush 12;The cartridge holder 11 and the inner bush 12 are detachably connected by the clamping structure as described above.
[0089] It can be understood that the cartridge holder 11 and the inner bush 12 are both cylindrical and can be coaxially arranged;The end of the cartridge holder 11 facing the inner bush 12 can be provided with the first clamping structure 110, and the end of the inner bush 12 facing the cartridge holder 11 can be provided with the second clamping structure 120.
[0090] Since the injection pen comprises the clamping structure, and the specific structure of the clamping structure refers to the above-mentioned embodiments, the injection pen of the present embodiment comprises all the technical solutions of the above-mentioned embodiments, and therefore at least has all the beneficial effects obtained by the above-mentioned embodiments, which will not be repeated here.
[0091] In some embodiments, as shown in Figure 3 and Figure 5 , the pen shell 1 further comprises: a main shell 13, the main shell 13 is sleeved outside the clamping structure and the inner bush 12, and is arranged on one side of the cartridge holder 11.
[0092] The peripheral wall of the cartridge holder 11 is provided with a position indication 1111, and the peripheral wall of the main shell 13 is provided with an opening mark 131 and a closing mark 132, which are arranged at intervals along the circumference of the main shell 13, for example, the opening mark 131 is indicated by the character mark "O", and the closing mark 132 is indicated by the character mark "C".
[0093] When the clamping structure is in the first state, the position indication 1111 points to the opening mark 131;When the clamping structure is in the second state, the position indication 1111 points to the closing mark 132.
[0094] It can be understood that after the assembly of the main shell 13 is completed, the operator is difficult to intuitively understand the assembly state of the refill holder 11 and the inner sleeve 12 because the main shell 13 forms a cover to the clamping structure. Considering that the clamping structure is clamped and released by relative rotation, the opening mark 131 and the closing mark 132 are arranged on the circumferential wall of the main shell 13, and the position indication 1111 is arranged on the refill holder 11, and the assembly state of the refill holder 11 and the inner sleeve 12 can be determined according to the indication state of the position indication 1111.
[0095] As shown in Figure 5 , the position indication 1111 points to the opening mark 131, and it can be determined that the clamping structure is in the first state. Since the refill holder 11 is connected with the first clamping structure 110, and the inner sleeve 12 is connected with the second clamping structure 120, the clamping structure can be switched from the first state to the second state by driving the refill holder 11 to rotate in the direction indicated by the arrow in the middle of the figure when the position indication 1111 points to the closing mark 132, so as to realize the connection between the refill holder 11 and the inner sleeve 12. Figure 5
[0096] In some embodiments, as shown in Figure 1 , Figure 2 , Figure 7 and Figure 10 , the utility model discloses an injection pen, comprising: pen shell 1, injection assembly 2, button assembly 3 and pawl assembly 4.
[0097] The pen shell 1 comprises a containing cavity, and a first port and a second port communicated with the containing cavity.
[0098] The injection assembly 2 is arranged in the containing cavity, and the injection assembly 2 comprises a push rod 21 and a dosing assembly 22, the push rod 21 comprises a rod body 211 and a reverse tooth structure 212, the reverse tooth structure 212 is arranged on the circumferential wall of the rod body 211, the first end of the rod body 211 abuts against the dosing assembly 22, and the dosing assembly 22 abuts against the first port.
[0099] The button assembly 3 is inserted into the second port, the button assembly 3 and the second end of the rod body 211 are slidably connected along the axial direction of the pen shell 1, and the button assembly 3 can drive the rod body 211 to rotate.
[0100] The pawl assembly 4 is arranged in the containing cavity, and the pawl assembly 4 comprises a first pawl 41, a second pawl 42 and a clutch structure 43, the first pawl 41 is connected with the button assembly 3, the second pawl 42 is connected with the pen shell 1, the first pawl 41 and the second pawl 42 are respectively configured to be engaged with the reverse tooth structure 212, and the clutch structure 43 is formed between the pen shell 1 and the first pawl 41.
[0101] In the case that the button assembly 3 rotates, the first pawl 41 can engage or disengage with the ratchet structure 212 through the clutch structure 43, and the second pawl 42 can engage or disengage with the ratchet structure 212.
[0102] It can be understood that the pen shell 1 can be configured as a cylindrical structure to form a containing cavity in the pen shell 1, and two ends of the pen shell 1 are respectively formed as a first port and a second port. The first port can be provided as a closed port, that is, the caliber of the first port is smaller than the caliber of the second port.
[0103] For the injection assembly 2, the rod body 211 corresponding to the push rod 21 can be configured as a cylindrical shape, and the ratchet structure 212 can be provided as an integral structure with the rod body 211 and extends along the axial direction of the rod body 211.
[0104] Exemplarily, the ratchet structure 212 includes a plurality of ratchets, and the plurality of ratchets are arranged side by side along the axial direction of the rod body 211. The direction of the ratchets is opposite to the advancing direction of the push rod 21 towards the administration assembly 22, and the first pawl 41 and the second pawl 42 are configured to engage with each ratchet.
[0105] Along the circumferential direction of the rod body 211, one or more ratchet structures 212 can be arranged on the peripheral wall of the rod body 211, which is not specifically limited.
[0106] As shown in Figure 2 and Figure 3 The administration assembly 22 can be configured to include an administration bottle 221 and a needle 222. The first end of the administration bottle 221 is formed as a spout, and the second end of the administration bottle 221 is open. A piston is arranged in the administration bottle 221, and the piston is embedded in the administration bottle 221 from the second end of the administration bottle 221. The first end of the administration bottle 221 abuts against the first port of the pen shell 1, and the spout of the administration bottle 221 is inserted into the first port.
[0107] The needle 222 includes a seat body and a needle, and the needle is inserted into the middle part of the seat body. The seat body can be encapsulated in the first port of the pen shell 1 by a threaded connection, and one end of the needle is inserted into the administration bottle 221.
[0108] The first end of the rod body 211 is inserted into the second end of the administration bottle 221 and abuts against the piston, and the second end of the rod body 211 is inserted into the button assembly 3 and is in sliding cooperation with the button assembly 3 along the axial direction of the pen shell 1.
[0109] Exemplarily, the first end of the rod body 211 is provided with a push head, and the push head abuts against the piston.
[0110] Exemplarily, the second end of the rod body 211 is provided with an adapter, the peripheral wall of the adapter and the inner wall of the button assembly 3 are in sliding fit through a guide structure to guide the sliding fit of the button assembly 3 and the rod body 211 along the axial direction of the pen shell 1, and to ensure that the button assembly 3 can drive the rod body 211 to rotate.
[0111] The guide structure can be a guide groove provided on the peripheral wall of the adapter and a guide rib provided on the inner wall of the button assembly 3, both extending along the axial direction of the pen shell 1, and the guide rib is inserted into the guide groove.
[0112] As shown in Figure 1 , Figure 2 and Figure 3 , the first port of the pen shell 1 is formed at one end of the cartridge holder 11 away from the inner sleeve 12; the injection pen further comprises a cap 5, which is arranged on the outer side of the cartridge holder 11 to protect the needle 222 of the administration assembly 22.
[0113] For the button assembly 3, the button assembly 3 is configured to be movably inserted into the second port of the pen shell 1 along the axial direction of the pen shell 1, and the button assembly 3 can also drive the push rod 21 and the first pawl 41 to rotate relative to the pen shell 1 within a small range.
[0114] For the pawl assembly 4, the clutch structure 43 can be considered to comprise a limiting structure connected with the pen shell 1, when the button assembly 3 drives the first pawl 41 to rotate, the first pawl 41 can be guided by the limiting structure to approach or move away from the push rod 21, so as to realize the engagement or disengagement of the first pawl 41 and the ratchet structure 212.
[0115] The second pawl 42 is connected with the pen shell 1, and the position of the second pawl 42 relative to the pen shell 1 can be considered to remain unchanged, since the ratchet structure 212 is arranged on the peripheral wall of the rod body 211, when the button assembly 3 drives the push rod 21 to rotate relative to the pen shell 1, the second pawl 42 can be engaged or disengaged with the ratchet structure 212.
[0116] From the above, the injection pen of the utility model, through setting injection assembly 2, button assembly 3 and pawl assembly 4 based on pen shell 1, setting pawl assembly 4 includes first pawl 41, second pawl 42 and clutch structure 43, because button assembly 3 is configured to be able to move along the axial direction of pen shell 1, and also can drive push rod 21 and first pawl 41 to rotate relative to pen shell 1, when needing to control injection pen to be in injection state, button assembly 3 relative to pen shell 1 can be rotated to make first pawl 41 and second pawl 42 respectively with ratchet structure 212 meshing, by pressing button assembly 3, it can ensure that first pawl 41 towards the side of dosing assembly 22 exerts advancing force on push rod 21, ensures that push rod 21 moves relative to pen shell 1 towards the side of dosing assembly 22, exerts force on dosing assembly 22 by push rod 21 to drive dosing assembly 22 to carry out injection operation, after completing injection operation, and needing to control injection pen to be in reset state, button assembly 3 relative to pen shell 1 can also be rotated to make first pawl 41 and second pawl 42 respectively with ratchet structure 212 separate, at this time, push rod 21 can be manually reset to the initial position to prepare for the re-injection operation of injection pen.
[0117] Therefore, the injection pen can realize the reciprocating movement of the push rod in the pen shell, and the push rod can be reset after the injection operation of the injection pen is completed, so that the injection pen can be reused without increasing the cost, and the resource waste in the use of the existing disposable injection pen is overcome.
[0118] In some embodiments, as shown in Figure 2 , Figure 8 , Figure 10 and Figure 11 , the clutch structure 43 includes a guide slot 431 and a contact 432; the guide slot 431 has a first slot bottom and a second slot bottom, which are sequentially arranged along the circumference of the pen shell 1, and the radial distance of the first slot bottom relative to the push rod 21 is less than that of the second slot bottom relative to the push rod 21; the contact 432 is connected with the first pawl 41, and the contact 432 is configured to be inserted into the guide slot 431.
[0119] The button assembly 3 is configured to drive the first pawl 41 to rotate, so as to realize the movement of the contact 432 between the first slot bottom and the second slot bottom driven by the first pawl 41.
[0120] It can be understood that the operator can rotate the button assembly 3 to drive the push rod 21 and the first pawl 41 to rotate relative to the pen shell 1, so as to switch the injection pen between the injection state and the reset state.
[0121] As shown in Figure 10 and Figure 13As shown, the pen shell 1 comprises an inner sleeve 12, the push rod 21 is arranged in the inner sleeve 12 along the central axis of the pen shell 1, the guide groove 431 is arranged at one end of the inner sleeve 12 towards the first pawl 41, the guide groove 431 is arranged in a circumferential direction relative to the central axis of the pen shell 1, and a smooth transition surface is arranged between the first groove bottom and the second groove bottom of the guide groove 431, so as to ensure that the contact 432 can move between the first groove bottom and the second groove bottom through the transition surface.
[0122] As shown in Figure 1 , Figure 6 and Figure 13 , when the indication mark 301 is opposite to the first position mark 101, the injection pen can be vented, at this time the contact 432 is on the transition surface of the guide groove 431, and the radial distance of the contact 432 relative to the central axis of the pen shell 1 is substantially the same as the radial distance of the first groove bottom relative to the central axis of the pen shell 1, which can ensure that the first pawl 41 is engaged with the inverted tooth structure 212.
[0123] As shown in Figure 1 , Figure 6 and Figure 13 , when the injection pen is controlled to perform an injection operation, the operator can rotate the button assembly 3 clockwise until the indication mark 301 is opposite to the second position mark 102, and the push rod 21 and the first pawl 41 are synchronously rotated relative to the pen shell 1 by the button assembly 3, so that the contact 432 is at the first groove bottom of the guide groove 431, and at this time the position of the first pawl 41 relative to the push rod 21 remains unchanged, which can ensure that the first pawl 41 remains in the engaged state with the inverted tooth structure 212.
[0124] As shown in Figure 1 , Figure 6 and Figure 13 , after the injection pen completes the injection, the operator can rotate the button assembly 3 counterclockwise until the indication mark 301 is opposite to the third position mark 103, and the push rod 21 and the first pawl 41 are synchronously rotated relative to the pen shell 1 by the button assembly 3, so that the contact 432 is at the second groove bottom of the guide groove 431, and in this process, at this time the axial position of the first pawl 41 relative to the push rod 21 remains unchanged, but the first pawl 41 is driven by the contact 432 to move radially to a position away from the push rod 21, so as to realize disengagement from the inverted tooth structure 212.
[0125] In some embodiments, as shown in Figure 11 and Figure 13 , the first pawl 41 comprises a plurality of first pawl bodies 411, each of which is provided with a contact 432; the guide groove 431 is provided with a plurality of guide grooves 431, and the plurality of guide grooves 431 are sequentially and spaced apart in a circumferential direction of the pen shell 1, and the plurality of guide grooves 431 are arranged opposite to the plurality of contacts 432 one by one.
[0126] It can be understood that the inner sleeve 12 is provided with a plurality of guide grooves 431, which are sequentially and spaced apart along the circumference of the pen barrel 1 at one end of the inner sleeve 12 facing the first pawl 41. Each guide groove 431 has a first groove bottom, a transition surface and a second groove bottom sequentially connected along the circumference.
[0127] The first pawl 41 further comprises a first annular seat body 412, a plurality of first claw bodies 411 are arranged along the circumference of the first annular seat body 412, the first ends of the plurality of first claw bodies 411 are respectively connected with the first annular seat body 412, the second ends of the plurality of first claw bodies 411 are respectively provided with contacts 432, and the second ends of the plurality of first claw bodies 411 are configured to be meshed with the plurality of ratchet structures 212 one by one.
[0128] At the same time, the plurality of first claw bodies 411 are correspondingly arranged in the plurality of guide grooves 431 to realize the one-to-one relative arrangement of the plurality of guide grooves 431 and the plurality of contacts 432. In actual application, based on the cooperation of the guide grooves 431 and the contacts 432 arranged in relative positions, when the button assembly 3 drives the first pawl 41 to rotate, the second ends of the plurality of first claw bodies 411 of the first pawl 41 can be controlled to move closer to or away from each other based on the guiding action of the guide grooves 431, so as to realize meshing or disengaging with the ratchet structure 212.
[0129] In some embodiments, as shown in Figure 7 and Figure 10 The ratchet structure 212 is provided with a plurality of ratchet structures 212, which are sequentially and spaced apart along the circumference of the rod body 211, and are configured to be arranged in relative positions with the plurality of first claw bodies 411 of the first pawl 41.
[0130] As shown in Figure 2 and Figure 9 The second pawl 42 is arranged in the inner sleeve 12, and the second pawl 42 comprises a second annular seat body 422 and a plurality of second claw bodies 421, the plurality of second claw bodies 421 are sequentially and spaced apart along the circumference of the pen barrel 1, the first ends of the plurality of second claw bodies 421 are respectively connected with the second annular seat body 422, and the second ends of the plurality of second claw bodies 421 are configured to be meshed with the plurality of ratchet structures 212 one by one.
[0131] In actual application, when the injection pen is in the injection state, the plurality of second claw bodies 421 are arranged in relative positions with the plurality of ratchet structures 212, at this time, the operator can drive the push rod 21 to smoothly advance toward one side of the drug delivery assembly 22 by pressing the button assembly 3, that is, the meshing arrangement between the second pawl 42 and the ratchet structure 212 will not affect the normal movement of the push rod 21 toward the drug delivery assembly 22, but will prevent the push rod 21 from moving toward the side away from the drug delivery assembly 22 when the operator drives the first pawl 41 to move toward the side away from the drug delivery assembly 22 by the button assembly 3.
[0132] When the injection pen is in the reset state, since each second claw body 421 is distributed between two adjacent inverted tooth structures 212, the second ratchet 42 is separated from the inverted tooth structure 212 on the push rod 21, and each second claw body 421 of the second ratchet 42 is opposite to the area on the push rod 21 where no inverted tooth structure 212 is arranged, at this time the operator can manually control the push rod 21 to move towards one side of the button assembly 3, reset the push rod 21 to the initial position, in order to prepare for the re-injection operation of the injection pen.
[0133] In some embodiments, as shown in Figure 7 The rod body 211 includes a first segment 2111, a second segment 2112, and a positioning structure 2113; the first end of the first segment 2111 is in abutment with the administration assembly 22, the first end of the second segment 2112 is connected with the second end of the first segment 2111, and a plurality of inverted tooth structures 212 are arranged on the peripheral wall of the second segment 2112;
[0134] The positioning structure 2113 includes an annular tooth groove and a wedge-shaped protrusion, the annular tooth groove is arranged between the first segment 2111 and the second segment 2112 and is connected with each inverted tooth structure 212 respectively, and the wedge-shaped protrusion is arranged on the peripheral wall of the second segment 2112 and is located between two adjacent inverted tooth structures 212;
[0135] Wherein, when the injection pen is in the reset state, the wedge-shaped protrusion is used to guide the second ratchet 42 to move along the axial direction of the push rod 21 to achieve engagement with the annular tooth groove.
[0136] It can be understood that the positioning structure 2113 includes a plurality of wedge-shaped protrusions, each wedge-shaped protrusion is located between two adjacent inverted tooth structures 212, and each wedge-shaped protrusion forms an inclined surface between the end away from the annular tooth groove and the end close to the annular tooth groove, and the distance of the inclined surface from the central axis of the rod body 211 gradually increases in the direction from the end away from the annular tooth groove to the end close to the annular tooth groove.
[0137] In the process of resetting the push rod 21 to the initial position, the second end of the second ratchet 42 first moves along the inclined surface of the wedge-shaped protrusion, and gradually moves away from the central axis of the rod body 211 under the guidance of the inclined surface of the wedge-shaped protrusion, until the second end of the second ratchet 42 falls into the annular tooth groove, which can generate a damping and jumping feeling in the process of the push rod 21 returning and resetting, giving the operator tactile feedback.
[0138] In some embodiments, as shown in Figure 1 The button assembly 3 is provided with an indication mark 301, for example, the indication mark 301 is a triangular protrusion, and the tip of the triangular protrusion is arranged towards the pen shell 1.
[0139] As shown in Figure 8As shown, the peripheral wall of the first pawl 41 is provided with a limiting protrusion 4101; as Figure 15 and Figure 16 As shown, the outer side wall of the pen shell 1 is provided with a first position mark 101, for example, the first position mark 101 can adopt a mark with a shape of “ As shown, the inner side wall of the pen shell 1 is provided with a first limiting groove 111, the first limiting groove 111 extends along the axial direction of the pen shell 1.
[0140] When the indication mark 301 is opposite to the first position mark 101, the first pawl 41 and the second pawl 42 are respectively engaged with the inverted tooth structure 212; the limiting protrusion 4101 cooperates with the first limiting groove 111 to limit the movement stroke of the push rod 21 towards the side of the drug delivery assembly 22.
[0141] In actual application, as shown, Figure 19 the operator can manually rotate the button assembly 3 to make the indication mark 301 opposite to the first position mark 101, at this time, the first pawl 41 and the second pawl 42 are respectively kept in the engaged state with the inverted tooth structure 212, the operator can slightly pull the button assembly 3 away from the side of the drug delivery assembly 22, so as to drive the first pawl 41 to move relative to the push rod 21 away from the side of the drug delivery assembly 22, while the push rod 21 cannot move towards the side away from the drug delivery assembly 22 under the limitation of the second pawl 42. The stroke of pulling the button assembly 3 is determined by the length of the first limiting groove 111 extending along the axial direction of the pen shell 1.
[0142] Exemplarily, by setting the length of the first limiting groove 111 extending along the axial direction of the pen shell 1, it can be ensured that the first pawl 41 moves relative to the inverted tooth structure 212 by one tooth stroke away from the side of the drug delivery assembly 22, that is, the length of the first limiting groove 111 extending along the axial direction of the pen shell 1 can be set as equal to the interval between two adjacent teeth of the inverted tooth structure 212.
[0143] As shown, Figure 20 when the operator presses the button assembly 3 again, the first pawl 41 drives the push rod 21 to move towards the side of the drug delivery assembly 22 through the inverted tooth structure 212 under the limitation of the first limiting groove 111, for example, the movement stroke of the push rod 21 is one tooth stroke of the inverted tooth structure 212, so as to drive the drug delivery assembly 22 to perform the exhaust operation.
[0144] In some embodiments, as shown, Figure 15 and Figure 16As shown, the outer side wall of the pen shell 1 is also provided with a second position mark 102. For example, the second position mark 102 can be indicated by a mark shaped like "1unt". The first position mark 101 and the second position mark 102 are arranged at intervals along the circumference of the pen shell 1. The inner side wall of the pen shell 1 is also provided with a second limiting groove 112. The second limiting groove 112 extends along the axial direction of the pen shell 1, and the extension length of the second limiting groove 112 is greater than the extension length of the first limiting groove 111.
[0145] When the indicator 301 and the second position indicator 102 are opposite each other, the first pawl 41 and the second pawl 42 respectively engage with the reverse tooth structure 212, and the limiting protrusion 4101 cooperates with the second limiting groove 112 to limit the stroke of the push rod 21 toward the drug delivery component 22.
[0146] In practical applications, such as Figure 21 As shown, the operator can manually rotate the button assembly 3 so that the indicator mark 301 is opposite to the second position mark 102. At this time, the first pawl 41 and the second pawl 42 are engaged with the reverse tooth structure 212 respectively.
[0147] like Figure 22 As shown, the operator can pull the button assembly 3 significantly away from the drug delivery component 22, causing the button assembly 3 to move the first pawl 41 relative to the push rod 21 towards the side away from the drug delivery component 22. The push rod 21, however, will not move towards the side away from the drug delivery component 22 due to the constraint of the second pawl 42. The stroke of the button assembly 3 is determined by the length of the second limiting groove 112 extending axially along the pen shell 1. Since the extension length of the second limiting groove 112 is greater than the extension length of the first limiting groove 111, it can be ensured that the stroke of the first pawl 41 relative to the reverse tooth structure 212 is at least greater than the distance between two adjacent reverse teeth of the reverse tooth structure 212.
[0148] like Figure 23 As shown, when the operator presses the button assembly 3 again, under the constraint of the second limiting groove 112, the first pawl 41 drives the push rod 21 to move towards the side of the drug delivery assembly 22 through the reverse tooth structure 212, so that the push rod 21 drives the drug delivery assembly 22 to perform the injection operation. During the injection process, the second pawl 42 and the reverse tooth structure 212 remain engaged and generate relative movement; however, the presence of the second pawl 42 does not affect the normal movement of the push rod 21 towards the drug delivery assembly 22.
[0149] In some embodiments, such as Figure 1 and Figure 15 As shown, the outer wall of the pen casing 1 is also provided with a third position mark 103. For example, the third position mark 103 can be shaped like a " The first position mark 101 and the third position mark 103 are arranged along the circumference of the pen barrel 1; when the indication mark 301 is opposite to the third position mark 103, the first pawl 41 and the second pawl 42 are separated from the ratchet structure 212 respectively.
[0150] In actual application, as shown in Figure 24 , the operator can manually rotate the button assembly 3 so that the indication mark 301 is opposite to the third position mark 103; as shown in Figure 10 and Figure 13 , in the process of switching to the indication mark 301 opposite to the third position mark 103, the button assembly 3 drives the first pawl 41 to rotate relative to the pen barrel 1, so that the contact 432 on the first pawl 41 moves to the second groove bottom of the guide groove 431, causing the first pawl 41 to be driven by the contact 432 to move radially to a position away from the push rod 21, so as to realize the separation of the first pawl 41 from the ratchet structure 212; as shown in Figure 7 and Figure 9 , in the process of switching to the indication mark 301 opposite to the third position mark 103, the button assembly 3 also drives the push rod 21 to rotate relative to the pen barrel 1 until each second claw body 421 of the second pawl 42 is opposite to the area on the push rod 21 where no ratchet structure 212 is arranged, so as to realize the separation of the second pawl 42 from the ratchet structure 212 on the push rod 21.
[0151] As shown in Figure 25 , after the indication mark 301 is opposite to the third position mark 103, the operator can manually control the push rod 21 to move towards the side of the button assembly 3 to reset the push rod 21 to the initial position, so as to prepare for the re-injection operation of the injection pen.
[0152] Since the drug delivery assembly 22 is located in the pen barrel 1, and the end of the push rod 21 towards the drug delivery assembly 22 extends into the drug delivery bottle 221, when the push rod 21 is reset, the pen barrel 11 needs to be removed first, and then the push rod 21 is manually controlled to move relative to the pen barrel 1 towards the side of the button assembly 3 until the second pawl 42 is engaged with the annular tooth groove corresponding to the positioning structure 2113, so as to reset the push rod 21 to the initial position.
[0153] In some embodiments, as shown in Figure 2 , Figure 17 and Figure 18 , the button assembly 3 comprises a plug barrel 31 and a pressing head 32; the plug barrel 31 is inserted into the pen barrel 1, the first end of the plug barrel 31 is connected with the first pawl 41, and the second end of the rod body 211 is inserted into the plug barrel 31 and is in sliding fit with the inner wall of the plug barrel 31; the pressing head 32 is exposed to the second port and is connected with the second end of the plug barrel 31.
[0154] It can be understood that the first end of the plug barrel 31 and the first pawl 41 can be detachably connected.
[0155] Exemplarily, as shown in Figure 6 , Figure 8 and Figure 17 , the circumferential wall of the plug barrel 31 is provided with a clamping protrusion 3101, and the circumferential wall of the first annular seat body 412 corresponding to the first pawl 41 is provided with a clamping hole 4102. The first end of the plug barrel 31 can be inserted into the first annular seat body 412 along the axial direction of the pen barrel 1 until the clamping protrusion 3101 is embedded in the clamping hole 4102, so as to realize the connection of the first end of the plug barrel 31 and the first pawl 41 as a whole.
[0156] At the same time, the second end of the rod body 211 is provided with an adapter, and the circumferential wall of the adapter and the inner wall of the plug barrel 31 are slidably connected through a guide structure, so as to guide the sliding connection of the button assembly 3 and the rod body 211 along the axial direction of the pen barrel 1, and ensure that the button assembly 3 can drive the rod body 211 to rotate.
[0157] In some embodiments, as shown in Figure 15 and Figure 17 , the circumferential wall of the plug barrel 31 is provided with a first protrusion 311, and the first protrusion 311 is an elastic protrusion; the inner wall of the pen barrel 1 is provided with a plurality of first grooves 121, and the first grooves 121 can be arc-shaped grooves, and the plurality of first grooves 121 are sequentially connected along the circumferential direction of the pen barrel 1, and each first groove 121 extends along the axial direction of the pen barrel 1; the first protrusion 311 and the first groove 121 are slidably connected along the axial direction of the pen barrel 1, and can be sequentially moved into each first groove 121 along with the rotation of the plug barrel 31. This design not only ensures the axial movement of the button assembly 3 relative to the pen barrel 1, but also ensures that the button assembly 3 rotates a fixed angle relative to the pen barrel 1 each time when the button assembly 3 is manually controlled to rotate relative to the pen barrel 1 based on the cooperation between the first protrusion 311 and the first groove 121.
[0158] Among them, the central angles of the first position mark 101 and the second position mark 102 relative to the central axis of the pen barrel 1, and the central angles of the first position mark 101 and the third position mark 103 relative to the central axis of the pen barrel 1 are equal to the central angles of the centers of the adjacent two first grooves 121 relative to the central axis of the pen barrel 1.
[0159] In some embodiments, as shown in Figure 15 and Figure 17 , the circumferential wall of the plug barrel 31 is provided with a second protrusion 312, and the inner wall of the pen barrel 1 is provided with a second groove 122, and the second protrusion 312 is movably arranged in the second groove 122. The second protrusion 312 and the second groove 122 cooperate to limit the position of the rotation of the button assembly 3 relative to the pen barrel 1.
[0160] It can be understood that the second protrusions 312 are arranged along the axial extension of the plug-in barrel 31, the second grooves 122 are arranged along the axial extension of the pen shell 1, and the central angle of the second protrusions 312 relative to the central axis of the pen shell 1 is smaller than the central angle of the second grooves 122 relative to the central axis of the pen shell 1. This design can limit the rotation of the button assembly 3 relative to the pen shell 1 within a certain angle range, and ensure that the first protrusions 311 do not disengage from the first grooves 121 during the rotation of the button assembly 3.
[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. An injection pen, characterized in that, The injection pen comprises: a pen shell comprising a receiving cavity, a first port and a second port in communication with the receiving cavity; an injection assembly arranged in the receiving cavity, the injection assembly comprising a push rod and a dosing assembly, the push rod comprising a rod body and an inverted tooth structure, the inverted tooth structure being arranged on a peripheral wall of the rod body, a first end of the rod body being in abutment with the dosing assembly, the dosing assembly being in abutment with the first port; a button assembly inserted into the second port, the button assembly and a second end of the rod body being in sliding fit along an axial direction of the pen shell and capable of driving the rod body to rotate; a pawl assembly arranged in the receiving cavity, the pawl assembly comprising a first pawl, a second pawl and a clutch structure, the first pawl being connected with the button assembly, the second pawl being connected with the pen shell, the first pawl and the second pawl being respectively configured to engage with the inverted tooth structure, the clutch structure being formed between the pen shell and the first pawl; wherein, in a case where the button assembly rotates, the first pawl is capable of engaging with or disengaging from the inverted tooth structure through the clutch structure, and the second pawl is capable of engaging with or disengaging from the inverted tooth structure.
2. The injection pen of claim 1, wherein, The clutch structure comprises: a guide slot having a first slot bottom and a second slot bottom, the first slot bottom and the second slot bottom being sequentially arranged along a circumferential direction of the pen shell, a radial distance of the first slot bottom relative to the push rod being smaller than a radial distance of the second slot bottom relative to the push rod; a contact head connected with the first pawl, the contact head being configured to be inserted into the guide slot; wherein, the button assembly is configured to drive the first pawl to rotate, so as to realize the first pawl driving the contact head to move between the first slot bottom and the second slot bottom.
3. The injection pen of claim 2, wherein, The first pawl comprises a plurality of first pawl bodies, each of the first pawl bodies being provided with the contact head; a plurality of the guide slots are sequentially and spacedly arranged along the circumferential direction of the pen shell, and a plurality of the guide slots are arranged opposite to a plurality of the contact heads one by one.
4. The injection pen of claim 1, wherein, a plurality of the inverted tooth structures are sequentially and spacedly arranged along a circumferential direction of the rod body; the second pawl comprises a plurality of second pawl bodies, the plurality of second pawl bodies being sequentially and spacedly arranged along a circumferential direction of the pen shell; wherein, in a case where the injection pen is in an injection state, the plurality of second pawl bodies engage with the plurality of inverted tooth structures one by one; in a case where the injection pen is in a reset state, each of the second pawl bodies is distributed between two adjacent inverted tooth structures.
5. The injection pen of claim 4, wherein, the rod body comprises: a first segment, a first end of the first segment being in abutment with the dosing assembly; a second segment, a first end of the second segment being connected with a second end of the first segment, and a plurality of the inverted tooth structures being arranged on a peripheral wall of the second segment; a positioning structure comprising an annular tooth groove and a wedge-shaped protrusion, the annular tooth groove being arranged between the first segment and the second segment and being connected with each of the inverted tooth structures respectively, and the wedge-shaped protrusion being arranged on the peripheral wall of the second segment and being located between two adjacent inverted tooth structures. The wedge-shaped protrusion is used to guide the axial movement of the second pawl along the push rod to achieve engagement with the ring-shaped tooth groove when the injection pen is in a reset state.
6. The injection pen of claim 1, wherein, The button assembly is provided with an indication mark, and the circumferential wall of the first pawl is provided with a limiting protrusion. The outer side wall of the pen shell is provided with a first position mark, and the inner side wall of the pen shell is provided with a first limiting groove extending along the axial direction of the pen shell. When the indication mark is opposite to the first position mark, the first pawl and the second pawl are engaged with the reverse tooth structure, respectively. The limiting protrusion cooperates with the first limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
7. The injection pen of claim 6, wherein, The outer side wall of the pen shell is further provided with a second position mark, and the first position mark and the second position mark are arranged at intervals along the circumferential direction of the pen shell. The inner side wall of the pen shell is further provided with a second limiting groove extending along the axial direction of the pen shell, and the extension length of the second limiting groove is greater than that of the first limiting groove. When the indication mark and the second position mark are opposite, the first pawl and the second pawl are engaged with the reverse tooth structure, respectively. The limiting protrusion cooperates with the second limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
8. The injection pen of claim 6, wherein, The outer side wall of the pen shell is further provided with a third position mark, and the first position mark and the third position mark are arranged at intervals along the circumferential direction of the pen shell. When the indication mark and the third position mark are opposite, the first pawl and the second pawl are separated from the reverse tooth structure, respectively.
9. The injection pen according to any one of claims 1 to 8, characterized in that The button assembly comprises: The plug barrel is inserted into the pen shell, the first end of the plug barrel is connected with the first pawl, and the second end of the rod body is inserted into the plug barrel and is in sliding cooperation with the inner wall of the plug barrel; The pressing head is exposed to the second port and is connected with the second end of the plug barrel.
10. The injection pen of claim 9, wherein, The circumferential wall of the plug barrel is provided with a first protrusion, which is an elastic protrusion; the inner wall of the pen shell is provided with a plurality of first grooves, which are connected in sequence along the circumferential direction of the pen shell, and each first groove extends along the axial direction of the pen shell; the first protrusion and the first groove are in sliding cooperation along the axial direction of the pen shell and can be moved into each first groove in sequence with the rotation of the plug barrel; And / or, the circumferential wall of the plug barrel is provided with a second protrusion, the inner wall of the pen shell is provided with a second groove, the second protrusion is movably arranged in the second groove, and the second protrusion and the second groove cooperate to limit the position of the button assembly relative to the pen shell.