Clamping structure and injection pen
By introducing a snap-fit structure into the injection pen and utilizing the convex rib design of the first and second snap-fit tongues, the problem of poor connection reliability of existing injection pens is solved, and convenient installation and disassembly operations are achieved.
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
The connection structure between the cartridge holder and the inner liner of existing injection pens is poorly designed, resulting in poor reliability and affecting the efficiency of installation and disassembly.
It adopts a snap-fit structure, including a first snap-fit tongue and a second snap-fit tongue. Through the cooperation design of the ribs and the snap-fit, it can achieve detachable connection, and achieve snap-fit and separation through relative rotation, so as to ensure reliability.
The installation and disassembly process of the snap-fit structure is simplified, improving the reliability and convenience of the connection, and is suitable for the convenient installation and disassembly of injection pens.
Smart Images
Figure CN224099771U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to medical instrument technical field especially, and it is a kind of clamping structure and injection pen. BACKGROUND
[0002] At present, in some application scenarios, patients often need to inject various drugs by themselves, in order to make the patient injects drug more accurately and conveniently, people have invented injection pen or various devices similar to injection pen. The pen shell of the existing injection pen usually includes a cartridge holder and an inner sleeve that can be assembled together, and the connection structure between the cartridge holder and the inner sleeve is not reasonable, has poor reliability, is not convenient to install and disassemble, and affects the installation and disassembly efficiency of the cartridge holder in actual application. SUMMARY
[0003] The utility model provides a kind of clamping structure and injection pen, to at least solve or improve the problem that the connection structure suitable for the assembly of two components exists poor reliability and is not convenient to install and disassemble in prior art.
[0004] In a first aspect, the utility model provides a kind of clamping structure, comprising:
[0005] First clamping structure, including multiple first clamping tongues, multiple first clamping tongues are sequentially spaced along the circumference, and the middle region of each first clamping tongue is provided with a socket;
[0006] Second clamping structure, including multiple second clamping tongues, multiple second clamping tongues are sequentially spaced along the circumference, and the outer wall surface of each second clamping tongue is provided with a convex rib;
[0007] The clamping structure can be rotated and switched between first state and second state;In the first state, first clamping tongue and second clamping tongue are sequentially and alternately arranged along the circumference;In the second state, multiple second clamping tongues are inserted on the inner side of multiple first clamping tongues one by one, and the convex rib of second clamping tongue is clamped in the socket of first clamping tongue.
[0008] According to the clamping structure provided by the utility model, the convex rib extends along spiral line trajectory, and the shape of the socket is matched with the shape of the convex rib.
[0009] According to the clamping structure provided by the utility model, the first clamping tongue is provided with first inclined surface, and the first inclined surface is located at the side of the first clamping tongue along its extension direction;The convex rib is provided with second inclined surface, and the second inclined surface is arranged at at least one end of the convex rib along its extension direction;
[0010] During the switching of the clamping structure from the first state to the second state, the first inclined surface and the second inclined surface slide in contact to guide the second clamping tongue to rotate to the inner side of the first clamping tongue.
[0011] In a second aspect, the utility model also provides a injection pen, include: pen shell, the pen shell includes the inner bushing and the cartridge holder, the cartridge holder and the inner bushing are connected through the clamping structure as the above.
[0012] According to the injection pen provided by the utility model, the pen shell further comprises:
[0013] A main shell is arranged on the outer side of the inner bushing and on one side of the cartridge holder;
[0014] The peripheral wall of the cartridge holder is provided with a position indication, the peripheral wall of the main shell is provided with an opening mark and a closing mark, and the opening mark and the closing mark are arranged at intervals along the circumference of the main shell.
[0015] When the clamping structure is in the first state, the position indication points to the opening mark; when the clamping structure is in the second state, the position indication points to the closing mark.
[0016] According to the injection pen provided by the utility model, the pen shell comprises a containing cavity, and a first port and a second port communicated with the containing cavity;
[0017] The injection pen further comprises an injection assembly, a button assembly and a pawl assembly; the injection assembly is arranged in the containing cavity, the injection assembly comprises a push rod and a dosing assembly, the push rod comprises a rod body and a reverse tooth structure, the reverse tooth structure is arranged on the peripheral wall of the rod body, the first end of the rod body is in abutment with the dosing assembly, and the dosing assembly is in abutment with the first port; the button assembly is inserted into the second port, the button assembly and the second end of the rod body are in sliding fit along the axial direction of the pen shell and can drive the rod body to rotate; the pawl assembly is arranged in the containing cavity, the pawl assembly comprises a first pawl, a second pawl and a 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 respectively configured to be engaged with the reverse tooth structure, and the clutch structure is formed between the pen shell and the first pawl.
[0018] In the case that the button assembly rotates, the first pawl can be engaged with or separated from the reverse tooth structure through the clutch structure, and the second pawl can be engaged with or separated from the reverse tooth structure.
[0019] According to the injection pen provided by the utility model, the clutch structure comprises:
[0020] The guide groove has 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 less than that of the second groove bottom relative to the push rod.
[0021] The contact is connected with the first pawl, and the contact is configured to be inserted into the guide groove.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] The limiting protrusion cooperates with the first limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
[0027] 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 circumference of the pen shell.
[0028] 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.
[0029] 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.
[0030] The limiting protrusion cooperates with the second limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.
[0031] 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 circumference of the pen shell.
[0032] When the indicator mark and the third position mark are opposite, the first pawl and the second pawl are separated from the ratchet structure, respectively.
[0033] The clamping structure and the injection pen are provided with the first clamping structure and the second clamping structure, the clamping structure can be switched to the second state by controlling the relative rotation of the first clamping structure and the second clamping structure when the clamping structure is assembled, and the clamping operation of the clamping structure is completed, and when the clamping structure is disassembled, 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, the plurality of first clamping tongues and the plurality of second clamping tongues are one-to-one correspondingly arranged, and the clamping is realized by the cooperation of the ribs and the sockets, and the first clamping structure and the second clamping structure are difficult to separate from each other when the relative rotation does not occur, the clamping strength between the first clamping structure and the second clamping structure is ensured by the clamping design, and the reliability of mutual clamping is also ensured.
[0034] Therefore, the clamping and separation of the clamping structure can be conveniently realized in the relative rotation mode, the reliability of clamping can be ensured in the clamping state, and the two components can be conveniently installed and disassembled. BRIEF DESCRIPTION OF DRAWINGS
[0035] In order to more clearly illustrate the technical scheme of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.
[0036] Figure 1 is a schematic diagram of the three-dimensional structure of the injection pen provided by the present application.
[0037] Figure 2 is a schematic diagram of the cross-sectional structure of the injection pen provided by the present application.
[0038] Figure 3 is a schematic diagram of the explosion structure of the injection pen provided by the present application.
[0039] Figure 4 is a schematic diagram of the connection between the inner sleeve and the cartridge holder in the injection pen provided by the present application.
[0040] Figure 5 is a schematic diagram of the structure of the injection pen provided by the present application after hiding the cap.
[0041] Figure 6It is the structure schematic drawing of the injection pen after hiding the pen shell and the pen cap provided in the utility model.
[0042] Figure 7 It is the structure schematic drawing of the push rod provided in the utility model.
[0043] Figure 8 It is the structure schematic drawing of the first pawl provided in the utility model.
[0044] Figure 9 It is the structure schematic drawing of the second pawl provided in the utility model.
[0045] Figure 10 It is the local enlarged schematic drawing of the clutch structure provided in the utility model.
[0046] Figure 11 It is one of the structure schematic drawings of the inner bush provided in the utility model.
[0047] Figure 12 It is the second structure schematic drawing of the inner bush provided in the utility model.
[0048] Figure 13 It is the third structure schematic drawing of the inner bush provided in the utility model.
[0049] Figure 14 It is the structure schematic drawing of the cartridge holder provided in the utility model.
[0050] Figure 15 It is one of the structure schematic drawings of the pen shell provided in the utility model.
[0051] Figure 16 It is the second structure schematic drawing of the pen shell provided in the utility model.
[0052] Figure 17 It is one of the structure schematic drawings of the button assembly provided in the utility model.
[0053] Figure 18 It is the second structure schematic drawing of the button assembly provided in the utility model.
[0054] Figure 19 It is the structure schematic drawing of the push rod being pulled out when the indication mark is opposite to the first position mark, and the injection pen is prepared for the exhaust operation provided in the utility model.
[0055] Figure 20 It is the structure schematic drawing of the push rod being reset to complete the exhaust operation of the injection pen when the indication mark is opposite to the first position mark provided in the utility model.
[0056] Figure 21 It is the structure schematic drawing of the indication mark being opposite to the second position mark by rotating the button assembly provided in the utility model.
[0057] Figure 22 is a structure schematic view that the push rod is pulled out when the indication mark is opposite to the second position mark, and the injection pen is prepared to control injection operation.
[0058] Figure 23 is a structure schematic view that the push rod is reset to complete injection operation when the indication mark is opposite to the second position mark.
[0059] Figure 24 is a structure schematic view that the indication mark is opposite to the third position mark by rotating the button assembly.
[0060] Figure 25 is a structure schematic view that the push rod is reset when the indication mark is opposite to the third position mark.
[0061] Reference signs:
[0062] 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, pen core frame; 110, first clamping structure; 1101, first clamping tongue; 1102, first notch; 11010, clamping opening; 1111, position indication; 12, inner bushing; 120, second clamping structure; 1201, second clamping tongue; 1202, second notch; 12010, protruding rib; 13, main shell; 131, opening mark; 132, closing mark;
[0063] 2, injection assembly; 21, push rod; 211, rod body; 2111, first segment; 2112, second segment; 2113, positioning structure; 212, reverse tooth structure; 22, drug delivery assembly; 221, drug delivery bottle; 222, needle;
[0064] 3, button assembly; 31, insertion barrel; 311, first protrusion; 312, second protrusion; 3101, clamping protrusion; 32, pressing head; 301, indication mark;
[0065] 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;
[0066] 5, pen cap. DETAILED DESCRIPTION
[0067] In order to make the purpose, technical scheme and advantages of the utility model clearer, the technical scheme of the utility model will be described clearly and completely in combination with the drawings in the utility model below. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.
[0068] The utility model embodiment provides a clamping structure and an injection pen, which will be described in detail in combination with specific embodiments and application scenarios. Figures 1-25
[0069] In the first aspect, as shown in Figure 3 , Figure 4 and Figure 12 , the utility model embodiment provides a clamping structure, which is applied to an injection pen, and the clamping structure comprises a first clamping structure 110 and a second clamping structure 120.
[0070] The first clamping structure 110 comprises a plurality of first clamping tongues 1101, and the plurality of first clamping tongues 1101 are sequentially and circumferentially spaced apart, and the middle region of each first clamping tongue 1101 is provided with a clamping opening 11010.
[0071] The second clamping structure 120 comprises a plurality of second clamping tongues 1201, and the plurality of second clamping tongues 1201 are sequentially and circumferentially spaced apart, and the outer wall surface of each second clamping tongue 1201 is provided with a convex rib 12010.
[0072] The clamping structure can be switched between a first state and a 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 arranged on the inner side of the plurality of first clamping tongues 1101, and the convex rib 12010 of the second clamping tongue 1201 is clamped in the clamping opening 11010 of the first clamping tongue 1101.
[0073] It can be understood that the first clamping structure 110 can be arranged at the end of a first component on the injection pen, the second clamping structure 120 can be arranged at the end of a 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. The first clamping structure 110 and the second clamping structure 120 can both be made of a plastic piece with a certain elasticity.
[0074] For the first clamping structure 110, at least two first clamping tongues 1101 can be provided, and a first gap 1102 is formed between any two adjacent first clamping tongues 1101, and each first clamping tongue 1101 extends in a tile shape along the circumferential direction relative to the central axis of the first clamping structure 110.
[0075] For the second clamping structure 120, at least two second clamping tongues 1201 can be provided, and a second gap 1202 is formed between any two adjacent second clamping tongues 1201, and each second clamping tongue 1201 extends in a tile shape along the circumferential direction relative to the central axis of the second clamping structure 120. The number of first clamping tongues 1101 provided is the same as the number of second clamping tongues 1201 provided.
[0076] 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 alternately arranged along the circumferential direction, 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 inserted one by one on the inner side of the plurality of first clamping tongues 1101, until the convex rib 12010 of each second clamping tongue 1201 is clamped in the clamping opening 11010 of the corresponding first clamping tongue 1101. Figure 4 The rotation direction of the first clamping structure 110 is shown.
[0077] 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 first set to the first state, 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 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 arranged one by one, and the clamping is realized by the cooperation of the convex rib 12010 and the clamping opening 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 guaranteed.
[0078] Therefore, the utility model can conveniently realize the clamping and separation of the clamping structure in a relative rotation manner, and can ensure the reliability of the clamping in the clamped state, and is suitable for conveniently installing and disassembling two components.
[0079] In some embodiments, as shown in Figure 4 The convex rib 12010 extends along a spiral line trajectory, and the shape of the notch 11010 is adapted to the shape of the convex rib 12010.
[0080] It can be understood that, by defining the corresponding shapes of the convex rib 12010 and the notch 11010, it is not only beneficial to reduce the difficulty of operation for 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 convex rib 12010 and the notch 11010.
[0081] The convex rib 12010 is in a strip shape 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 notch 11010 is a through hole arranged on the first clamping tongue 1101, and the notch 11010 has an opening shape substantially the same as that of the convex rib 12010.
[0082] In some embodiments, as shown in Figure 14 In order to further reduce the difficulty of operation for 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 at a side edge of the first clamping tongue 1101 along the extension direction thereof, wherein both 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.
[0083] As shown in Figure 12 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 extension direction thereof, for example, both ends of the convex rib 12010 along the extension direction thereof can be provided with the second inclined surface X2.
[0084] It can be known from Figure 4 , Figure 12 and Figure 14 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.
[0085] In the 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 inner bush 12;The cartridge holder 11 and inner bush 12 are connected by the clamping structure as described above.
[0086] It can be understood that the refill holder 11 and the inner sleeve 12 are both in a cylindrical shape and can be coaxially arranged; the first clamping structure 110 can be arranged at one end of the refill holder 11 facing the inner sleeve 12, and the second clamping structure 120 can be arranged at one end of the inner sleeve 12 facing the refill holder 11.
[0087] Since the injection pen includes the clamping structure, the specific structure of the clamping structure is referred to the above-mentioned embodiments, the injection pen of the present embodiment includes all the technical solutions of the above-mentioned embodiments, and therefore at least has all the beneficial effects achieved by all the technical solutions of the above-mentioned embodiments, which will not be repeated here.
[0088] In some embodiments, as shown in Figure 3 and Figure 5 , the pen shell 1 further includes: a main shell 13, which is sleeved outside the clamping structure and the inner sleeve 12 and arranged at one side of the refill holder 11;
[0089] The circumferential wall of the refill holder 11 is provided with a position indication 1111, and the circumferential 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”;
[0090] 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.
[0091] It can be understood that after the assembly of the main shell 13 is completed, it is difficult for the operator to intuitively understand the assembly state of the refill holder 11 and the inner sleeve 12 because the main shell 13 covers the clamping structure, and considering that the clamping structure realizes clamping and unclamping through relative rotation, the assembly state of the refill holder 11 and the inner sleeve 12 can be judged according to the indication state of the position indication 1111 by arranging the position indication 1111 on the refill holder 11 and arranging the opening mark 131 and the closing mark 132 on the circumferential wall of the main shell 13.
[0092] As shown in Figure 5 , when the position indication 1111 points to the opening mark 131, it can be determined that the clamping structure is in the first state, and 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 Figure 5 , and when the position indication 1111 points to the closing mark 132, the connection between the refill holder 11 and the inner sleeve 12 can be realized.
[0093] In some embodiments, asFigure 1 、 Figure 2 、 Figure 7 and Figure 10 The utility model embodiment provides a kind of injection pen, comprising: pen shell 1, injection assembly 2, button assembly 3 and pawl assembly 4;
[0094] Pen shell 1 includes containing cavity and the first port and the second port being communicated with containing cavity;
[0095] Injection assembly 2 is set in containing cavity, and injection assembly 2 includes push rod 21 and administration assembly 22, push rod 21 includes stem body 211 and back tooth structure 212, back tooth structure 212 is located the peripheral wall of stem body 211, the first end of stem body 211 is abutted with administration assembly 22, and administration assembly 22 is abutted on the first port;
[0096] Button assembly 3 is inserted in the second port, and button assembly 3 and the second end of stem body 211 are slidably fitted along the axial direction of pen shell 1, and can drive stem body 211 to rotate;
[0097] Pawl assembly 4 is set in containing cavity, and pawl assembly 4 includes first pawl 41, second pawl 42 and clutch structure 43, first pawl 41 is connected with button assembly 3, second pawl 42 is connected with pen shell 1, first pawl 41 and second pawl 42 are configured to engage with back tooth structure 212 respectively, and clutch structure 43 is formed between pen shell 1 and first pawl 41;
[0098] Wherein, under the condition that button assembly 3 rotates, first pawl 41 can engage or separate with back tooth structure 212 by clutch structure 43, and second pawl 42 can engage or separate with back tooth structure 212.
[0099] It can be understood that pen shell 1 can be configured as a cylindrical structure to form a containing cavity in pen shell 1, and the two ends of pen shell 1 are formed as the first port and the second port respectively. Wherein, the first port can be provided as a closed end, that is, the diameter of the first port is smaller than the diameter of the second port.
[0100] For injection assembly 2, the corresponding stem body 211 of push rod 21 can be configured as a cylindrical shape, and back tooth structure 212 can be provided as an integral structure with stem body 211, and back tooth structure 212 is provided along the axial direction of stem body 211.
[0101] Exemplarily, back tooth structure 212 includes a plurality of back teeth, and the plurality of back teeth are provided side by side along the axial direction of stem body 211, and the direction of the back teeth is opposite to the advancing direction of push rod 21 towards administration assembly 22, and first pawl 41 and second pawl 42 are configured to engage with each back tooth.
[0102] The one or more reverse tooth structures 212 can be arranged on the peripheral wall of the rod body 211 along the circumferential direction of the rod body 211, and no specific limitation is made to this.
[0103] 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 into a spout, the second end of the administration bottle 221 is open, a piston is arranged in the administration bottle 221, 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 barrel 1, and the spout of the administration bottle 221 is inserted into the first port.
[0104] The needle 222 includes a seat body and a needle pin, the needle pin is inserted into the middle of the seat body, the seat body can be encapsulated in the first port of the pen barrel 1 by means of threaded connection, and one end of the needle pin is inserted into the administration bottle 221.
[0105] 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 slidably fitted with the button assembly 3 along the axial direction of the pen barrel 1.
[0106] Exemplarily, the first end of the rod body 211 is provided with a push head, and the push head abuts against the piston.
[0107] Exemplarily, the second end of the rod body 211 is provided with an adapter, and the peripheral wall of the adapter and the inner wall of the button assembly 3 are slidably fitted through a guide structure to guide the button assembly 3 and the rod body 211 to be slidably fitted along the axial direction of the pen barrel 1 and ensure that the button assembly 3 can drive the rod body 211 to rotate.
[0108] The guide structure can be a guide groove and a guide rib, the guide groove is arranged on the peripheral wall of the adapter, the guide rib is arranged on the inner wall of the button assembly 3, the guide groove and the guide rib both extend along the axial direction of the pen barrel 1, and the guide rib is inserted into the guide groove.
[0109] As shown in Figure 1 , Figure 2 and Figure 3 The first port of the pen barrel 1 is formed at the end of the cartridge holder 11 away from the inner sleeve 12; the injection pen further includes a pen cap 5, the pen cap 5 is arranged on the outer side of the cartridge holder 11 to provide protection for the needle 222 of the administration assembly 22.
[0110] For the button assembly 3, the button assembly 3 is configured to be movably inserted into the second port of the pen barrel 1 along the axial direction of the pen barrel 1, and the button assembly 3 can also drive the push rod 21 and the first pawl 41 to rotate a small range relative to the pen barrel 1.
[0111] For the pawl assembly 4, the clutch structure 43 can be considered to include 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 inverted tooth structure 212.
[0112] 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 be kept unchanged. Since the inverted tooth 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 engagement or disengagement of the second pawl 42 and the inverted tooth structure 212 can be realized.
[0113] As can be seen from the above, the injection pen of the utility model, by setting the injection assembly 2, the button assembly 3 and the pawl assembly 4 based on the pen shell 1, the pawl assembly 4 includes the first pawl 41, the second pawl 42 and the clutch structure 43, since the button assembly 3 is configured to be capable of moving along the axial direction of the pen shell 1 and also capable of driving the push rod 21 and the first pawl 41 to rotate relative to the pen shell 1, when it is needed to control the injection pen to be in the injection state, the button assembly 3 can be controlled to rotate relative to the pen shell 1, so that the first pawl 41 and the second pawl 42 are engaged with the inverted tooth structure 212 respectively, by pressing the button assembly 3, it can be ensured that the first pawl 41 applies a propelling force to the push rod 21 towards the side of the drug delivery assembly 22, it can be ensured that the push rod 21 moves relative to the pen shell 1 towards the side of the drug delivery assembly 22, the push rod 21 applies a force to the drug delivery assembly 22, so as to drive the drug delivery assembly 22 to perform the injection operation, when the injection operation is completed and it is needed to control the injection pen to be in the reset state, the button assembly 3 can also be controlled to rotate relative to the pen shell 1, so that the first pawl 41 and the second pawl 42 are disengaged from the inverted tooth structure 212 respectively, at this time, the push rod 21 can be manually reset to the initial position, so as to prepare for the re-injection operation of the injection pen.
[0114] Therefore, the injection pen shown in the utility model can realize the reciprocating movement of the push rod 21 in the pen shell 1, after the injection operation of the injection pen is completed based on the push rod 21, the reset of the push rod 21 is performed again, so that 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.
[0115] In some embodiments, as Figure 2 , Figure 8 , Figure 10 and Figure 11As shown, the clutch structure 43 comprises a guide groove 431 and a contact head 432; the guide groove 431 has a first groove bottom and a second groove bottom, which are sequentially arranged along the circumference of the pen barrel 1, and the radial distance of the first groove bottom relative to the push rod 21 is smaller than that of the second groove bottom relative to the push rod 21; the contact head 432 is connected with the first pawl 41 and is configured to be inserted into the guide groove 431.
[0116] The button assembly 3 is configured to drive the first pawl 41 to rotate, so as to realize the movement of the contact head 432 between the first groove bottom and the second groove bottom.
[0117] 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 barrel 1, so as to switch the injection pen between the injection state and the reset state.
[0118] As shown in Figure 10 and Figure 13 , the pen barrel 1 comprises an inner sleeve 12, the push rod 21 is arranged in the inner sleeve 12 along the central axis of the pen barrel 1, the guide groove 431 is arranged at one end of the inner sleeve 12 towards the first pawl 41, and the guide groove 431 is arranged along the circumference relative to the central axis of the pen barrel 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 head 432 can move between the first groove bottom and the second groove bottom through the transition surface.
[0119] 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 head 432 is on the transition surface of the guide groove 431, and the radial distance of the contact head 432 relative to the central axis of the pen barrel 1 is substantially the same as that of the first groove bottom relative to the central axis of the pen barrel 1, which can ensure that the first pawl 41 is engaged with the ratchet structure 212.
[0120] 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 barrel 1 by the button assembly 3, so that the contact head 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 ratchet structure 212.
[0121] As shown in Figure 1 , Figure 6 and Figure 13As shown, after the injection pen completes the injection, the author can rotate the button assembly 3 counterclockwise until the indication mark 301 is opposite the third position mark 103, and the push rod 21 and the first pawl 41 are synchronously rotated relative to the pen shell 1 driven 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, 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 away from the push rod 21 to achieve disengagement with the ratchet structure 212.
[0122] In some embodiments, as shown in Figure 11 and Figure 13 The first pawl 41 includes a plurality of first claw bodies 411, and each first claw body 411 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 along the circumference of the pen shell 1, and the plurality of guide grooves 431 are one-to-one opposite to the plurality of contacts 432.
[0123] It can be understood that the inner sleeve 12 is provided with a plurality of guide grooves 431, and the plurality of guide grooves 431 are sequentially and spaced apart along the circumference of the pen shell 1 at one end of the inner sleeve 12 facing the first pawl 41, and each guide groove 431 has a first groove bottom, a transition surface and a second groove bottom sequentially connected along the circumference.
[0124] The first pawl 41 further includes a first annular seat body 412, and the 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 to the first annular seat body 412, the second ends of the plurality of first claw bodies 411 are provided with contacts 432, and the second ends of the plurality of first claw bodies 411 are configured to be one-to-one engaged with the plurality of ratchet structures 212.
[0125] At the same time, the plurality of first claw bodies 411 are one-to-one correspondingly arranged in the plurality of guide grooves 431, so as to realize one-to-one opposite arrangement of the plurality of guide grooves 431 and the plurality of contacts 432. In actual application, based on the cooperation of the oppositely arranged guide grooves 431 and contacts 432, 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 groove 431, so as to realize engagement or disengagement with the ratchet structure 212.
[0126] In some embodiments, as shown in Figure 7 and Figure 10 The ratchet structure 212 is provided with a plurality of ratchet structures 212, and the plurality of ratchet structures 212 are sequentially and spaced apart along the circumference of the rod body 211, and the plurality of ratchet structures 212 are configured to be one-to-one opposite to the plurality of first claw bodies 411 of the first pawl 41.
[0127] As shown in Figure 2 andFigure 9 As shown, 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 pawl bodies 421, the plurality of second pawl bodies 421 are sequentially and spacedly arranged along the circumference of the pen barrel 1, the first ends of the plurality of second pawl bodies 421 are respectively connected with the second annular seat body 422, and the second ends of the plurality of second pawl bodies 421 are arranged in meshing with the plurality of ratchet structures 212.
[0128] In actual application, when the injection pen is in the injection state, the plurality of second pawl bodies 421 are arranged in meshing 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 dosing assembly 22 by pressing the button assembly 3, that is, the meshing between the second pawl 42 and the ratchet structure 212 does not affect the normal movement of the push rod 21 toward the dosing assembly 22, but prevents the push rod 21 from moving toward the side away from the dosing assembly 22 when the operator drives the first pawl 41 to move toward the side away from the dosing assembly 22 by the button assembly 3.
[0129] When the injection pen is in the reset state, since each second pawl body 421 is distributed between two adjacent ratchet structures 212, the second pawl 42 is separated from the ratchet structure 212 on the push rod 21, and each second pawl body 421 of the second pawl 42 is opposite to the region on the push rod 21 where the ratchet structure 212 is not arranged, at this time, the operator can manually control the push rod 21 to move toward the side of the button assembly 3, and reset the push rod 21 to the initial position, so as to prepare for the re-injection operation of the injection pen.
[0130] In some embodiments, as shown in the drawings, Figure 7 The rod body 211 comprises a first segment 2111, a second segment 2112 and a positioning structure 2113, the first end of the first segment 2111 abuts against the dosing assembly 22, the first end of the second segment 2112 is connected with the second end of the first segment 2111, and the plurality of ratchet structures 212 are arranged on the circumferential wall of the second segment 2112;
[0131] The positioning structure 2113 comprises 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 respectively connected with each ratchet structure 212, and the wedge-shaped protrusion is arranged on the circumferential wall of the second segment 2112 and located between two adjacent ratchet structures 212;
[0132] When the injection pen is in the reset state, the wedge-shaped protrusion is used to guide the second pawl 42 to move along the axial direction of the push rod 21 to realize the meshing with the annular tooth groove.
[0133] It can be understood that the positioning structure 2113 includes a plurality of wedge-shaped protrusions, each of which is located between two adjacent inverted tooth structures 212, and each of which forms an inclined surface between an end away from the annular tooth groove and an end close to the annular tooth groove, and the distance of the inclined surface with respect to 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.
[0134] In the process of resetting the push rod 21 to the initial position, the second end of the second pawl 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 pawl 42 slides into the annular tooth groove. This design can produce a damping and jumping feeling during the reset of the push rod 21, giving the operator tactile feedback.
[0135] 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.
[0136] As shown in Figure 8 The circumferential wall of the first pawl 41 is provided with a limiting protrusion 4101; as shown in Figure 15 and Figure 16 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 an identification indication shaped as “ The inner side wall of the pen shell 1 is provided with a first limiting groove 111, and the first limiting groove 111 extends along the axial direction of the pen shell 1.
[0137] When the indication mark 301 is opposite to the first position mark 101, the first pawl 41 and the second pawl 42 are engaged with the inverted tooth structure 212 respectively; the limiting protrusion 4101 cooperates with the first limiting groove 111 to limit the stroke of the push rod 21 moving towards the dispensing assembly 22.
[0138] In actual application, as shown in Figure 19 The operator can manually rotate the button assembly 3 so that the indication mark 301 is opposite to the first position mark 101, at this time, the first pawl 41 and the second pawl 42 are in engagement with the inverted tooth structure 212 respectively, and the operator can pull the button assembly 3 away from the dispensing assembly 22 to a small extent, so as to drive the first pawl 41 to move away from the dispensing assembly 22 relative to the push rod 21, and the push rod 21 cannot move away from the dispensing 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.
[0139] For example, by setting the length of the first limiting groove 111 extending axially along the pen shell 1, it can be ensured that the first pawl 41 moves one reverse tooth stroke relative to the reverse tooth structure 212 on the side away from the drug delivery component 22. That is, the length of the first limiting groove 111 extending axially along the pen shell 1 can be set to be equal to the distance between two adjacent reverse teeth of the reverse tooth structure 212.
[0140] like Figure 20 As shown, when the operator presses the button assembly 3 again, under the limitation of the first limiting groove 111, the first pawl 41 drives the push rod 21 to move toward one side of the drug delivery assembly 22 through the reverse tooth structure 212. For example, the movement stroke of the push rod 21 is the stroke of one reverse tooth of the reverse tooth structure 212, so as to realize the drug delivery assembly 22 to perform the venting operation by being driven by the push rod 21.
[0141] In some embodiments, such as Figure 15 and Figure 16 As 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.
[0142] 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.
[0143] 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.
[0144] 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.
[0145] As Figure 23 shown, when the operator presses the button assembly 3 again, the first pawl 41 is driven by the ratchet structure 212 to move the push rod 21 towards one side of the drug delivery assembly 22 under the limitation of the second limiting groove 112, so as to realize the injection operation driven by the push rod 21 to the drug delivery assembly 22. During the injection operation of the injection pen, the second pawl 42 and the ratchet structure 212 remain in engagement and relative movement, but the presence of the second pawl 42 does not affect the normal movement of the push rod 21 towards the drug delivery assembly 22.
[0146] In some embodiments, as Figure 1 and Figure 15 shown, the outer side wall of the pen shell 1 is further provided with a third position identifier 103, for example, the third position identifier 103 can adopt an identification sign shaped as “ ”. The first position identifier 101 and the third position identifier 103 are arranged along the circumference of the pen shell 1. When the indication identifier 301 is opposite to the third position identifier 103, the first pawl 41 and the second pawl 42 are separated from the ratchet structure 212, respectively.
[0147] In actual application, as Figure 24 shown, the operator can manually rotate the button assembly 3 so that the indication identifier 301 is opposite to the third position identifier 103; as Figure 10 and Figure 13 shown, during the switching process that the indication identifier 301 is opposite to the third position identifier 103, the button assembly 3 drives the first pawl 41 to rotate relative to the pen shell 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 Figure 7 and Figure 9 shown, during the switching process that the indication identifier 301 is opposite to the third position identifier 103, the button assembly 3 also drives the push rod 21 to rotate relative to the pen shell 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.
[0148] As Figure 25 shown, after the indication identifier 301 is opposite to the third position identifier 103, the operator can manually control the push rod 21 to move towards one side of the button assembly 3, so as to reset the push rod 21 to the initial position, in order to prepare for the re-injection operation of the injection pen.
[0149] Since the administration bottle 221 of the administration assembly 22 is located in the pen barrel 11 of the pen shell 1, and the push rod 21 extends into the administration bottle 221 at one end of the administration assembly 22, 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 shell 1 to 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.
[0150] 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 shell 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. Wherein, the first end of the plug barrel 31 and the first pawl 41 can be detachably connected.
[0151] It can be understood that, as shown in Figure 6 、 Figure 8 and Figure 17 , the peripheral wall of the plug barrel 31 is provided with a clamping protrusion 3101, and the peripheral 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 shell 1 until the clamping protrusion 3101 is embedded in the clamping hole 4102, so that the first end of the plug barrel 31 and the first pawl 41 are connected as a whole.
[0152] At the same time, the second end of the rod body 211 is provided with an adapter, and the peripheral wall of the adapter and the inner wall of the plug barrel 31 are in sliding fit through a guide structure, so as 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 ensure that the button assembly 3 can drive the rod body 211 to rotate.
[0153] In some embodiments, as shown in Figure 15 and Figure 17As shown, the peripheral wall of the insert 31 is provided with a first protrusion 311, which is an elastic protrusion; the inner wall of the pen shell 1 is provided with a plurality of first grooves 121, which can be arc-shaped grooves. The plurality of first grooves 121 are connected sequentially along the circumference of the pen shell 1, and each first groove 121 extends along the axial direction of the pen shell 1; the first protrusion 311 and the first groove 121 slide in cooperation along the axial direction of the pen shell 1, and can move sequentially into each first groove 121 as the insert 31 rotates. This design ensures that the button assembly 3 moves axially relative to the pen shell 1, and also ensures that when the button assembly 3 is manually controlled to rotate relative to the pen shell 1, the button assembly 3 rotates a fixed angle relative to the pen shell 1 each time, based on the cooperation between the first protrusion 311 and the first groove 121.
[0154] The central angles of the first position mark 101 and the second position mark 102 relative to the central axis of the pen shell 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 shell 1, are respectively equal to the central angles of the centers of the two adjacent first grooves 121 relative to the central axis of the pen shell 1.
[0155] In some embodiments, such as Figure 15 and Figure 17 As shown, the peripheral wall of the insert 31 is provided with a second protrusion 312, and the inner wall of the pen shell 1 is provided with a second groove 122. The second protrusion 312 is movably disposed in the second groove 122. The second protrusion 312 and the second groove 122 cooperate to limit the position of the button assembly 3 relative to the pen shell 1.
[0156] Understandably, the second protrusion 312 extends along the axial direction of the insert 31, and the second groove 122 extends along the axial direction of the pen shell 1. The central angle formed by the second protrusion 312 relative to the central axis of the pen shell 1 is smaller than the central angle formed by the second groove 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 set angle range, ensuring that the first protrusion 311 will not detach from each of the first grooves 121 during the rotation of the button assembly 3.
[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such 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 this utility model.
Claims
1. A snap-fit structure, characterized by, The application relates to a card joint structure. The card joint structure comprises a first card joint structure and a second card joint structure. The first card joint structure comprises a plurality of first card lugs which are sequentially and circumferentially arranged, and each of the first card lugs is provided with a card hole in a middle region. The second card joint structure comprises a plurality of second card lugs which are sequentially and circumferentially arranged, and each of the second card lugs is provided with a convex rib on an outer wall surface.
2. The card coupling structure according to claim 1, wherein The card joint structure can be switched between a first state and a second state.
3. The card coupling structure according to claim 1, wherein In the first state, the first card lugs and the second card lugs are sequentially and circumferentially arranged alternately. In the second state, the second card lugs are sequentially and oppositely arranged on the inner side of the first card lugs, and the convex ribs of the second card lugs are arranged in the card holes of the first card lugs.
4. An injection pen characterized in that The convex rib extends along a spiral line, and the shape of the card hole is matched with the shape of the convex rib. The first card lug is provided with a first inclined surface which is located on a side of the first card lug along an extending direction of the first card lug.
5. The injection pen of claim 4, wherein, The second card lug is provided with a second inclined surface which is located on at least one end of the second card lug along an extending direction of the second card lug. During the switching of the card joint structure from the first state to the second state, the first inclined surface and the second inclined surface are in sliding contact to guide the second card lugs to rotate to the inner side of the first card lugs. The application also relates to a pen shell. The pen shell comprises a pen core holder and an inner sleeve.
6. The injection pen of claim 4, wherein, The pen core holder and the inner sleeve are detachably connected through the card joint structure. The pen shell further comprises a main shell. The main shell is arranged on the outer side of the inner sleeve and on one side of the pen core holder. The pen core holder is provided with a position indication. The main shell is provided with an opening mark and a closing mark which are arranged on the circumferential wall of the main shell. When the card joint structure is in the first state, the position indication points to the opening mark. When the card joint structure is in the second state, the position indication points to the closing mark. The pen shell comprises a containing cavity, a first port and a second port which are in communication with the containing cavity. The injection pen further comprises an injection assembly, a button assembly and a pawl assembly. The injection assembly is arranged in the containing cavity. The injection assembly comprises a push rod and a dosing assembly. The push rod comprises a rod body and a reverse tooth structure. The reverse tooth structure is arranged on the circumferential wall of the rod body. The first end of the rod body is in abutment with the dosing assembly. The dosing assembly is in abutment with the first port. The button assembly is arranged in the second port. The button assembly and the second end of the rod body are in sliding fit along the axial direction of the pen shell and can drive the rod body to rotate. The pawl assembly is arranged in the containing cavity. The pawl assembly comprises a first pawl, a second pawl and a 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 respectively configured to be engaged with the reverse tooth structure. The clutch structure is formed between the pen shell and the first pawl. In the case that the button assembly rotates, the first pawl can be engaged with or separated from the ratchet structure through the clutch structure, and the second pawl can be engaged with or separated from the ratchet structure.
7. The injection pen of claim 6, 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 the circumference of the pen shell, the radial distance of the first slot bottom relative to the push rod being less than the 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.
8. The injection pen of claim 6, 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 slot 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 ratchet structure respectively; wherein the limiting protrusion cooperates with the first limiting slot to limit the stroke of the push rod moving towards the drug delivery assembly.
9. The injection pen of claim 8, 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 circumference of the pen shell; the inner side wall of the pen shell is further provided with a second limiting slot extending along the axial direction of the pen shell, and the extension length of the second limiting slot is greater than the extension length of the first limiting slot; when the indication mark and the second position mark are opposite, the first pawl and the second pawl are engaged with the ratchet structure respectively; wherein the limiting protrusion cooperates with the second limiting slot to limit the stroke of the push rod moving towards the drug delivery assembly.
10. The injection pen of claim 8, 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 circumference 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 ratchet structure respectively.