Injection pen

Abstract

The invention relates to the technical field of medical instruments, and provides an injection pen which comprises a pen shell, an injection assembly, a button assembly and a pawl assembly. The pen shell comprises an accommodating cavity, and a first port and a second port which are communicated with the accommodating cavity; the injection assembly comprises a push rod and a dosing assembly, the push rod comprises a rod body and an inverted tooth structure, the inverted tooth structure is arranged on the peripheral wall of the rod body, the first end of the rod body abuts against the dosing assembly, and the dosing assembly abuts against the first port; the button assembly is inserted into the second port, and the button assembly is in sliding fit with the second end of the rod body in the axial direction of the pen shell and can drive the rod body to rotate; 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 used for being meshed with the pawl structure, and the clutch structure is formed between the pen shell and the first pawl. Under the condition that cost is not increased, repeated use of the injection pen is achieved, and the defect of resource waste of an existing disposable injection pen is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular, to an injection pen. Background Art

[0002] Currently, in some application scenarios, patients often need to inject various drugs by themselves. In order to make it more accurate and convenient for patients to inject drugs by themselves, injection pens or various devices similar to injection pens have been invented. However, in actual applications, it is found that existing injection pens are all disposable products. After the drugs are injected, the injection pens are usually discarded, which not only is not conducive to reducing the use cost but also may cause environmental pollution problems. Therefore, there is an urgent need for a reusable injection pen. Summary of the Invention

[0003] The present invention provides an injection pen to at least solve or improve the problems of high use cost and difficulty in reuse existing in disposable injection pens.

[0004] The present invention provides an injection pen, including: A pen housing, including a receiving cavity and a first port and a second port communicating with the receiving cavity; An injection assembly disposed in the receiving cavity. The injection assembly includes a push rod and a drug delivery assembly. The push rod includes a rod body and an inverted tooth structure. The inverted tooth structure is disposed on the peripheral wall of the rod body. The first end of the rod body abuts against the drug delivery assembly, and the drug delivery assembly abuts against the first port; A button assembly inserted into the second port. The button assembly and the second end of the rod body are slidably matched along the axial direction of the pen housing and can drive the rod body to rotate; A pawl assembly disposed in the receiving cavity. The pawl assembly includes a first pawl, a second pawl and a clutch structure. The first pawl is connected to the button assembly, the second pawl is connected to the pen housing, the first pawl and the second pawl are respectively configured to engage with the inverted tooth structure, and the clutch structure is formed between the pen housing and the first pawl; Wherein, when the button assembly rotates, the first pawl can engage with or disengage from the inverted tooth structure through the clutch structure, and the second pawl can engage with or disengage from the inverted tooth structure.

[0005] According to an injection pen provided by the present invention, the clutch structure includes: A guiding groove having a first groove bottom and a second groove bottom. The first groove bottom and the second groove bottom are sequentially arranged along the circumferential direction of the pen housing. The radial distance of the first groove bottom relative to the push rod is less than the radial distance of the second groove bottom relative to the push rod; A contact, which is connected to the first pawl and configured to be inserted into the guiding groove. Wherein, the button assembly is configured to drive the first pawl to rotate so that the first pawl drives the contact to move between the bottom of the first groove and the bottom of the second groove.

[0006] According to an injection pen provided by the present invention, the first pawl includes a plurality of first pawl bodies, and each first pawl body is provided with the contact. There are a plurality of guiding grooves, and the plurality of guiding grooves are sequentially arranged at intervals along the circumferential direction of the pen housing, and the plurality of guiding grooves are arranged in one-to-one correspondence with the plurality of contacts.

[0007] According to an injection pen provided by the present invention, there are a plurality of reverse tooth structures, and the plurality of reverse tooth structures are sequentially arranged at intervals along the circumferential direction of the rod body. The second pawl includes a plurality of second pawl bodies, and the plurality of second pawl bodies are sequentially arranged at intervals along the circumferential direction of the pen housing. Wherein, when the injection pen is in the injection state, the plurality of second pawl bodies are engaged with the plurality of reverse tooth structures one by one; when the injection pen is in the reset state, each second pawl body is distributed between two adjacent reverse tooth structures.

[0008] According to an injection pen provided by the present invention, the rod body includes: A first section, the first end of the first section abuts against the drug delivery assembly. A second section, the first end of the second section is connected to the second end of the first section, and the plurality of reverse tooth structures are arranged on the circumferential wall of the second section. A positioning structure, including 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 respectively connected to each of the reverse tooth structures. The wedge-shaped protrusion is arranged on the circumferential wall of the second section and is located between two adjacent reverse tooth structures. Wherein, when the injection pen is in the reset state, the wedge-shaped protrusion is used to guide the second pawl to move along the axial direction of the push rod so as to be engaged with the annular tooth groove.

[0009] According to an injection pen provided by the present invention, the button assembly is provided with an indication mark, and a limit protrusion is arranged on the circumferential wall of the first pawl. A first position mark is arranged on the outer side wall of the pen housing, and a first limit groove is arranged on the inner side wall of the pen housing, and the first limit groove extends along the axial direction of the pen housing. When the indication mark is opposite to the first position mark, the first pawl and the second pawl are respectively engaged with the reverse tooth structures. Wherein, the limiting protrusion is matched with the first limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.

[0010] According to an injection pen provided by the present invention, a second position mark is further provided on the outer side wall of the pen casing, and the first position mark and the second position mark are arranged at intervals along the circumferential direction of the pen casing; A second limiting groove is further provided on the inner side wall of the pen casing, the second limiting groove extends along the axial direction of the pen casing, and the extension length of the second limiting groove is greater than the extension length of the first limiting groove; When the indicating mark and the second position mark are opposite to each other, the first pawl and the second pawl are respectively engaged with the reverse tooth structure; Wherein, the limiting protrusion is matched with the second limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.

[0011] According to an injection pen provided by the present invention, a third position mark is further provided on the outer side wall of the pen casing, and the first position mark and the third position mark are arranged at intervals along the circumferential direction of the pen casing; When the indicating mark and the third position mark are opposite to each other, the first pawl and the second pawl are respectively separated from the reverse tooth structure.

[0012] According to an injection pen provided by the present invention, the button assembly includes: An insertion cylinder, the insertion cylinder is inserted into the pen casing, the first end of the insertion cylinder is connected to the first pawl, and the second end of the rod body passes through the insertion cylinder and is slidably matched with the inner wall of the insertion cylinder; A pressing head, the pressing head is exposed at the second port and is connected to the second end of the insertion cylinder.

[0013] According to an injection pen provided by the present invention, a first protrusion is provided on the circumferential wall of the insertion cylinder, and the first protrusion is an elastic protrusion; a plurality of first grooves are provided on the inner wall of the pen casing, the plurality of first grooves are sequentially connected along the circumferential direction of the pen casing, and each first groove extends along the axial direction of the pen casing; the first protrusion is slidably matched with the first groove along the axial direction of the pen casing and can move into each first groove sequentially along with the rotation of the insertion cylinder; And / or, a second protrusion is provided on the circumferential wall of the insertion cylinder, a second groove is provided on the inner wall of the pen casing, the second protrusion is movably arranged in the second groove, and the second protrusion and the second groove are matched to limit the position of the button assembly relative to the pen casing from rotating.

[0014] The injection pen provided by the present invention is provided with an injection component, a button component and a ratchet component based on the pen shell. The ratchet component is provided with a first ratchet, a second ratchet and a clutch structure. Since the button component is configured to be able to move axially along the pen shell and can also drive the push rod and the first ratchet to rotate relative to the pen shell, when it is necessary to control the injection pen to be in the injection state, the button component can be controlled to rotate relative to the pen shell so that the first ratchet and the second ratchet are respectively engaged with the reverse tooth structure. By pressing the button component, it can be ensured that the first ratchet applies a pushing force to the push rod on the side facing the drug delivery component, ensuring that the push rod moves relative to the pen shell towards the side of the drug delivery component, and the push rod applies a force to the drug delivery component to drive the drug delivery component to perform an injection operation. When the injection operation is completed and it is necessary to control the injection pen to be in the reset state, the button component can also be controlled to rotate relative to the pen shell so that the first ratchet and the second ratchet are respectively separated from the reverse tooth structure. At this time, the push rod can be manually reset to the initial position to prepare for the next injection operation of the injection pen.

[0015] It can be seen that the injection pen shown in the present invention can realize the reciprocating movement of the push rod in the pen shell, and can reset the push rod again after the injection operation of the injection pen is completed based on the push rod, so as to realize the repeated use of the injection pen without increasing the cost, overcoming the waste of resources existing in the use of existing disposable injection pens. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a three-dimensional structural schematic diagram of the injection pen provided by the present invention.

[0018] Figure 2 It is a cross-sectional structural schematic diagram of the injection pen provided by the present invention.

[0019] Figure 3 It is an exploded structural schematic diagram of the injection pen provided by the present invention.

[0020] Figure 4 It is a schematic diagram of the connection between the inner liner and the pen core holder in the injection pen provided by the present invention.

[0021] Figure 5 It is a structural schematic diagram of the injection pen provided by the present invention after hiding the pen cap.

[0022] Figure 6It is a schematic structural diagram of the injection pen provided by the present invention after hiding the pen case and the pen cap.

[0023] Figure 7 It is a schematic structural diagram of the push rod provided by the present invention.

[0024] Figure 8 It is a schematic structural diagram of the first pawl provided by the present invention.

[0025] Figure 9 It is a schematic structural diagram of the second pawl provided by the present invention.

[0026] Figure 10 It is a partially enlarged schematic structural diagram of the clutch structure provided by the present invention.

[0027] Figure 11 It is one of the schematic structural diagrams of the inner lining sleeve provided by the present invention.

[0028] Figure 12 It is another schematic structural diagram of the inner lining sleeve provided by the present invention.

[0029] Figure 13 It is still another schematic structural diagram of the inner lining sleeve provided by the present invention.

[0030] Figure 14 It is a schematic structural diagram of the pen core holder provided by the present invention.

[0031] Figure 15 It is one of the schematic structural diagrams of the pen case provided by the present invention.

[0032] Figure 16 It is another schematic structural diagram of the pen case provided by the present invention.

[0033] Figure 17 It is one of the schematic structural diagrams of the button assembly provided by the present invention.

[0034] Figure 18 It is another schematic structural diagram of the button assembly provided by the present invention.

[0035] Figure 19 It is a schematic structural diagram of the present invention when the push rod is pulled out with the indication mark opposite to the first position mark to prepare for the exhaust operation of the injection pen.

[0036] Figure 20 It is a schematic structural diagram of the present invention when the push rod is reset to complete the exhaust operation of the injection pen with the indication mark opposite to the first position mark.

[0037] Figure 21 It is a schematic structural diagram of the present invention when the indication mark is made opposite to the second position mark by rotating the button assembly.

[0038] Figure 22It is a schematic structural diagram provided by the present invention for pulling out the push rod when the indication mark is opposite to the second position mark and preparing to control the injection pen for injection operation.

[0039] Figure 23 It is a schematic structural diagram provided by the present invention for resetting the push rod to complete the injection operation when the indication mark is opposite to the second position mark.

[0040] Figure 24 It is a schematic structural diagram provided by the present invention for making the indication mark opposite to the third position mark by rotating the button assembly.

[0041] Figure 25 It is a schematic structural diagram provided by the present invention for performing a reset operation on the push rod when the indication mark is opposite to the third position mark.

[0042] Reference numerals: 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. Cartridge holder; 110. First clamping structure; 1101. First tongue; 1102. First notch; 11010. Bayonet; 1111. Position indication; 12. Liner sleeve; 120. Second clamping structure; 1201. Second tongue; 1202. Second notch; 12010. Rib; 13. Main housing; 131. Open mark; 132. Closed mark; 2. Injection assembly; 21. Push rod; 211. Rod body; 2111. First section; 2112. Second section; 2113. Positioning structure; 212. Reverse tooth structure; 22. Drug delivery assembly; 221. Drug delivery bottle; 222. Needle; 3. Button assembly; 31. Insertion cylinder; 311. First protrusion; 312. Second protrusion; 3101. Clamping protrusion; 32. Pressing head; 301. Indication mark; 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 head; 5. Pen cap. Detailed implementation manners

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] The following will be combined with Figures 1 - 25 , and through specific embodiments and their application scenarios, the snap-fit structure and injection pen provided by the embodiments of the invention will be described in detail.

[0045] In the first aspect, as Figure 3 , Figure 4 and Figure 12 shown, an embodiment of the present invention provides a snap-fit structure applied to an injection pen. The snap-fit structure includes: a first snap-fit structure 110 and a second snap-fit structure 120; The first snap-fit structure 110 includes a plurality of first lugs 1101, and the plurality of first lugs 1101 are sequentially arranged at intervals in the circumferential direction. A bayonet 11010 is provided in the middle region of each first lug 1101; the second snap-fit structure 120 includes a plurality of second lugs 1201, and the plurality of second lugs 1201 are sequentially arranged at intervals in the circumferential direction. A rib 12010 is provided on the outer wall surface of each second lug 1201; the snap-fit structure can rotate and switch between a first state and a second state; in the first state, the first lugs 1101 and the second lugs 1201 are alternately arranged in the circumferential direction in sequence; in the second state, the plurality of second lugs 1201 are inserted into the inner sides of the plurality of first lugs 1101 one by one, and the rib 12010 of the second lug 1201 is clamped in the bayonet 11010 of the first lug 1101.

[0046] It can be understood that the first snap-fit structure 110 can be arranged at the end of the first component on the injection pen, and the second snap-fit structure 120 can be arranged at the end of the second component on the injection pen. Based on the cooperation of the first snap-fit structure 110 and the second snap-fit structure 120, detachable connection of the first component and the second component can be realized. Among them, both the first snap-fit structure 110 and the second snap-fit structure 120 can be made of plastic parts with a certain elasticity.

[0047] For the first snap-fit structure 110, at least two first lugs 1101 can be provided. A first notch 1102 is formed between any two adjacent first lugs 1101, and each first lug 1101 extends in a circumferential direction relative to the central axis of the first snap-fit structure 110 in a tile shape.

[0048] For the second snap - fit structure 120, at least two second tongues 1201 can be provided. A second notch 1202 is formed between any two adjacent second tongues 1201. Each second tongue 1201 extends circumferentially relative to the central axis of the second snap - fit structure 120 in a tile - like shape. Among them, the number of the first tongues 1101 provided is the same as the number of the second tongues 1201 provided.

[0049] In practical applications, the first snap - fit structure 110 and the second snap - fit structure 120 can be first controlled to approach each other along the axial direction to ensure that the first tongue 1101 is inserted into the second notch 1202 and the second tongue 1201 is inserted into the first notch 1102, so as to realize that the first tongue 1101 and the second tongue 1201 are alternately arranged circumferentially in sequence. Then, the first snap - fit structure 110 and the second snap - fit structure 120 are controlled to rotate relative to each other, so that multiple second tongues 1201 are inserted into the inner sides of multiple first tongues 1101 one by one until the rib 12010 of each second tongue 1201 is engaged in the bayonet 11010 of the corresponding first tongue 1101. Among them, Figure 4 shows the rotation direction of the first snap - fit structure 110.

[0050] As can be seen from the above, for the snap - fit structure shown in the present invention, by providing the first snap - fit structure 110 and the second snap - fit structure 120, when assembling the snap - fit structure, the snap - fit structure can be first set to the first state. Then, by controlling the relative rotation of the first snap - fit structure 110 and the second snap - fit structure 120, the snap - fit structure can be switched to the second state to complete the snap - fit operation of the snap - fit structure. When disassembling the snap - fit structure, it only needs to be rotated to switch the snap - fit structure from the second state to the first state. Its operation is simple and convenient. And when the snap - fit structure is completed, since multiple first tongues 1101 and multiple second tongues 1201 are arranged in one - to - one correspondence and the snap - fit is realized by the cooperation of the rib 12010 and the bayonet 11010, it is difficult for the first snap - fit structure 110 and the second snap - fit structure 120 to separate from each other without relative rotation. This snap - fit design ensures the snap - fit strength between the first snap - fit structure 110 and the second snap - fit structure 120, and the reliability of their snap - fit with each other is also guaranteed.

[0051] In some embodiments, as Figure 4 shown, the rib 12010 extends along a spiral - shaped track, and the shape of the bayonet 11010 is adapted to the shape of the rib 12010.

[0052] It can be understood that by defining the corresponding shapes of the rib 12010 and the bayonet 11010, it is beneficial to reduce the operation difficulty of controlling the relative rotation of the first snap - fit structure 110 and the second snap - fit structure 120, and at the same time ensures the reliability of the snap - fit between the rib 12010 and the bayonet 11010.

[0053] Among them, the convex rib 12010 is strip-shaped and is configured to extend along a spiral trajectory on the outer wall surface of the second locking tongue 1201 around the central axis of the second locking structure 120. The bayonet 11010 is a through hole provided on the first locking tongue 1101, and the bayonet 11010 has an opening shape substantially the same as the shape of the convex rib 12010.

[0054] In some embodiments, as Figure 14 shown, in order to further reduce the operation difficulty of controlling the relative rotation of the first locking structure 110 and the second locking structure 120, the first locking tongue 1101 is provided with a first inclined surface, and the first inclined surface is located on the side of the first locking tongue 1101 along its extending direction. Among them, both side edges of the first locking tongue 1101 extending along 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 locking tongue 1101; As Figure 12 shown, the convex rib 12010 is provided with a second inclined surface X2, and the second inclined surface X2 is provided at at least one end of the convex rib 12010 along its extending direction. For example, both ends of the convex rib 12010 along its extending direction can be provided with the second inclined surface X2; Combined with Figure 4 、 Figure 12 and Figure 14 it can be seen that during the process of the locking structure switching 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 locking tongue 1201 to rotate to the inner side of the first locking tongue 1101.

[0055] In a second aspect, as Figure 1 、 Figure 2 and Figure 3 shown, an embodiment of the present invention further provides an injection pen, including: a pen housing 1, and the pen housing 1 includes a cartridge holder 11 and an inner liner 12; the cartridge holder 11 and the inner liner 12 are detachably connected through the locking structure as described above.

[0056] It can be understood that both the cartridge holder 11 and the inner liner 12 are cylindrical and can be configured to be coaxially arranged; one end of the cartridge holder 11 facing the inner liner 12 can be provided with a first locking structure 110, and one end of the inner liner 12 facing the cartridge holder 11 can be provided with a second locking structure 120.

[0057] Since the injection pen includes a locking structure, and the specific structure of the locking structure refers to the above embodiments, the injection pen of this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects obtained by all the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0058] In some embodiments, as Figure 3 and Figure 5As shown, the pen shell 1 further includes: a main shell 13, which is sleeved outside the clamping structure and the inner lining sleeve 12 and is disposed on one side of the pen core holder 11; A position indicator 1111 is provided on the circumferential wall of the pen core holder 11, and an opening mark 131 and a closing mark 132 are provided on the circumferential wall of the main shell 13. The opening mark 131 and the closing mark 132 are arranged at intervals along the circumferential direction 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"; When the clamping structure is in the first state, the position indicator 1111 points to the opening mark 131; when the clamping structure is in the second state, the position indicator 1111 points to the closing mark 132.

[0059] It can be understood that after the assembly of the main shell 13 is completed, since the main shell 13 covers the clamping structure, it is difficult for the operator to intuitively understand the assembly state of the pen core holder 11 and the inner lining sleeve 12. Considering that the clamping structure realizes clamping and unclamping through relative rotation, by providing the position indicator 1111 on the pen core holder 11 and the opening mark 131 and the closing mark 132 on the circumferential wall of the main shell 13, the assembly state of the pen core holder 11 and the inner lining sleeve 12 can be judged according to the indication state of the position indicator 1111.

[0060] As Figure 5 shown, when the position indicator 1111 points to the opening mark 131, it can be determined that the clamping structure is in the first state. Since the pen core holder 11 is connected to the first clamping structure 110 and the inner lining sleeve 12 is connected to the second clamping structure 120, at this time, by driving the pen core holder 11 to rotate along the Figure 5 direction indicated by the arrow in the figure, when the position indicator 1111 points to the closing mark 132, the clamping structure can be switched from the first state to the second state to realize the connection between the pen core holder 11 and the inner lining sleeve 12.

[0061] In some embodiments, as Figure 1 、 Figure 2 、 Figure 7 and Figure 10 shown, an embodiment of the present invention provides an injection pen, which includes: a pen shell 1, an injection assembly 2, a button assembly 3 and a ratchet pawl assembly 4; The pen shell 1 includes a receiving cavity and a first port and a second port communicating with the receiving cavity; The injection assembly 2 is disposed in the receiving cavity. The injection assembly 2 includes a push rod 21 and a drug delivery assembly 22. The push rod 21 includes a rod body 211 and an inverted tooth structure 212. The inverted tooth structure 212 is disposed on the circumferential wall of the rod body 211. The first end of the rod body 211 abuts against the drug delivery assembly 22, and the drug delivery assembly 22 abuts against the first port; 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 engaged along the axial direction of the pen shell 1 and can drive the rod body 211 to rotate. The ratchet assembly 4 is disposed in the accommodation cavity. The ratchet assembly 4 includes a first ratchet 41, a second ratchet 42, and a clutch structure 43. The first ratchet 41 is connected to the button assembly 3, the second ratchet 42 is connected to the pen shell 1, the first ratchet 41 and the second ratchet 42 are respectively configured to engage with the reverse tooth structure 212, and the clutch structure 43 is formed between the pen shell 1 and the first ratchet 41. Wherein, when the button assembly 3 rotates, the first ratchet 41 can be engaged with or disengaged from the reverse tooth structure 212 through the clutch structure 43, and the second ratchet 42 can be engaged with or disengaged from the reverse tooth structure 212.

[0062] It can be understood that the pen shell 1 can be configured as a cylindrical structure to form an accommodation cavity in the pen shell 1. The two ends of the pen shell 1 are respectively formed as a first port and a second port. Among them, the first port can be set to a closed shape, that is, the diameter of the first port is smaller than the diameter of the second port.

[0063] For the injection assembly 2, the rod body 211 corresponding to the push rod 21 can be configured as a cylindrical shape. The reverse tooth structure 212 can be integrally formed with the rod body 211, and the reverse tooth structure 212 extends along the axial direction of the rod body 211.

[0064] Exemplarily, the reverse tooth structure 212 includes a plurality of reverse teeth. The plurality of reverse teeth are arranged side by side along the axial direction of the rod body 211. The orientation of the reverse teeth is opposite to the advancing direction of the push rod 21 towards the drug delivery assembly 22. The first ratchet 41 and the second ratchet 42 are configured to be able to engage with each reverse tooth.

[0065] Wherein, along the circumferential direction of the rod body 211, one or more reverse tooth structures 212 can be provided on the circumferential wall of the rod body 211, and no specific limitation is made thereto.

[0066] Such as Figure 2 and Figure 3 As shown, the drug delivery assembly 22 can be configured to include a drug delivery bottle 221 and a needle 222. The socket formed at the first end of the drug delivery bottle 221, the second end of the drug delivery bottle 221 is in an open shape. A piston is provided in the drug delivery bottle 221. The piston is installed in the drug delivery bottle 221 from the second end of the drug delivery bottle 221. The first end of the drug delivery bottle 221 abuts against the first port of the pen shell 1, and the socket of the drug delivery bottle 221 is inserted into the first port.

[0067] The needle 222 includes a seat body and an insertion needle. The insertion needle penetrates through the middle of the seat body. The seat body can be encapsulated in the first port of the pen shell 1 by means of threaded connection. One end of the insertion needle is inserted into the drug delivery bottle 221.

[0068] Among them, the first end of the rod body 211 is inserted into the second end of the drug administration bottle 221 and abuts against the piston. The second end of the rod body 211 is inserted into the button assembly 3 and is in sliding fit with the button assembly 3 along the axial direction of the pen shell 1.

[0069] Exemplarily, a push head is provided at the first end of the rod body 211, and the push head abuts against the piston.

[0070] Exemplarily, a adapter is provided at the second end of the rod body 211. A sliding fit is formed between the peripheral wall of the adapter and the inner wall of the button assembly 3 through a guiding 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 ensure that the button assembly 3 can drive the rod body 211 to rotate.

[0071] Among them, the guiding structure can be a guiding groove and a guiding rib. The guiding groove is provided on the peripheral wall of the adapter, and the guiding rib is provided on the inner wall of the button assembly 3. Both the guiding groove and the guiding rib extend along the axial direction of the pen shell 1, and the guiding rib is inserted into the guiding groove.

[0072] Such as Figure 1 、 Figure 2 and Figure 3 As shown, the first port of the pen shell 1 is formed at one end of the pen core holder 11 away from the inner liner 12; the injection pen further includes a pen cap 5, and the pen cap 5 covers the outside of the pen core holder 11 to provide protection for the needle 222 of the drug administration assembly 22.

[0073] 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.

[0074] For the pawl assembly 4, the clutch structure 43 can be considered to include a limiting structure connected to the pen shell 1. When the button assembly 3 drives the first pawl 41 to rotate, the first pawl 41 can approach or move away from the push rod 21 under the guidance of the limiting structure to achieve engagement or separation between the first pawl 41 and the reverse tooth structure 212.

[0075] The second pawl 42 is connected to the pen shell 1. It can be considered that the position of the second pawl 42 relative to the pen shell 1 remains unchanged. Since the reverse tooth structure 212 is provided 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, engagement or separation between the second pawl 42 and the reverse tooth structure 212 can be achieved.

[0076] As can be seen from the above, for the injection pen of the present invention, by providing an injection assembly 2, a button assembly 3, and a ratchet assembly 4 based on the pen shell 1, and the ratchet assembly 4 includes a first ratchet 41, a second ratchet 42, and a clutch structure 43. Since the button assembly 3 is configured to be able to move axially along the pen shell 1 and can also drive the push rod 21 and the first ratchet 41 to rotate relative to the pen shell 1, when it is necessary 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 ratchet 41 and the second ratchet 42 are respectively engaged with the reverse tooth structure 212. By pressing the button assembly 3, it can be ensured that the first ratchet 41 applies a pushing force to the push rod 21 on the side facing the drug delivery assembly 22, ensuring that the push rod 21 moves relative to the pen shell 1 toward the side of the drug delivery assembly 22, and the push rod 21 applies a force to the drug delivery assembly 22 to drive the drug delivery assembly 22 to perform an injection operation. When the injection operation is completed and it is necessary 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 ratchet 41 and the second ratchet 42 are respectively separated from the reverse tooth structure 212. At this time, the push rod 21 can be manually reset to the initial position to prepare for the next injection operation of the injection pen.

[0077] Thus, it can be seen that the injection pen shown in the present invention 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 push rod 21 can be reset again, thereby realizing the repeated use of the injection pen without increasing costs and overcoming the waste of resources existing in the use of existing disposable injection pens.

[0078] In some embodiments, as Figure 2 、 Figure 8 、 Figure 10 and Figure 11 shown, the clutch structure 43 includes: a guiding groove 431 and a contact 432; the guiding groove 431 has a first bottom and a second bottom, the first bottom and the second bottom are arranged in sequence along the circumferential direction of the pen shell 1, and the radial distance of the first bottom relative to the push rod 21 is less than the radial distance of the second bottom relative to the push rod 21; the contact 432 is connected to the first ratchet 41, and the contact 432 is configured to be inserted into the guiding groove 431; wherein, the button assembly 3 is configured to drive the first ratchet 41 to rotate so as to realize the movement of the first ratchet 41 driving the contact 432 between the first bottom and the second bottom.

[0079] It can be understood that the operator can rotate the button assembly 3, and the button assembly 3 can drive the push rod 21 and the first ratchet 41 to rotate relative to the pen shell 1 to realize the switching between the injection state and the reset state of the injection pen.

[0080] As Figure 10 and Figure 13As shown, the pen casing 1 includes a lining sleeve 12. The push rod 21 passes through the lining sleeve 12 along the central axis of the pen casing 1. The guiding groove 431 is provided at one end of the lining sleeve 12 facing the first pawl 41. The guiding groove 431 extends circumferentially relative to the central axis of the pen casing 1. A smooth transition surface is provided between the first bottom of the guiding groove 431 and the second bottom of the guiding groove 431 to ensure that the contact 432 can move between the first bottom and the second bottom through the transition surface.

[0081] As Figure 1 , Figure 6 and Figure 13 shown, when the indicating 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 guiding groove 431. The radial distance of the contact 432 relative to the central axis of the pen casing 1 is substantially the same as the radial distance of the first bottom of the guiding groove 431 relative to the central axis of the pen casing 1, which can ensure that the first pawl 41 meshes with the reverse tooth structure 212.

[0082] As Figure 1 , Figure 6 and Figure 13 shown, when controlling the injection pen to perform an injection operation, the operator can rotate the button assembly 3 clockwise until the indicating mark 301 is opposite to the second position mark 102. The button assembly 3 drives the push rod 21 and the first pawl 41 to rotate synchronously relative to the pen casing 1, so that the contact 432 is at the first bottom of the guiding groove 431. 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 engaged with the reverse tooth structure 212.

[0083] As Figure 1 , Figure 6 and Figure 13 shown, after the injection pen completes the injection, the operator can rotate the button assembly 3 counterclockwise until the indicating mark 301 is opposite to the third position mark 103. The button assembly 3 drives the push rod 21 and the first pawl 41 to rotate synchronously relative to the pen casing 1, so that the contact 432 is at the second bottom of the guiding groove 431. During this process, at this time, the axial position of the first pawl 41 relative to the push rod 21 remains unchanged. However, the first pawl 41 is driven by the contact 432 to move radially to a position away from the push rod 21 to achieve separation from the reverse tooth structure 212.

[0084] In some embodiments, as Figure 11 and Figure 13 shown, the first pawl 41 includes a plurality of first pawl bodies 411, and each first pawl body 411 is provided with a contact 432; a plurality of guiding grooves 431 are provided, and the plurality of guiding grooves 431 are sequentially arranged at intervals along the circumferential direction of the pen casing 1, and the plurality of guiding grooves 431 are arranged in one-to-one correspondence with the plurality of contacts 432.

[0085] It can be understood that a plurality of guiding grooves 431 are provided on the inner lining sleeve 12. The plurality of guiding grooves 431 are arranged at intervals in sequence along the circumferential direction of the pen shell 1 at one end of the inner lining sleeve 12 facing the first pawl 41. Each guiding groove 431 has a first groove bottom, a transition surface and a second groove bottom that are connected in sequence along the circumferential direction.

[0086] The first pawl 41 further includes a first annular seat body 412. A plurality of first pawl bodies 411 are arranged along the circumferential direction of the first annular seat body 412. The first ends of the plurality of first pawl bodies 411 are respectively connected to the first annular seat body 412. Contact heads 432 are provided at the second ends of the plurality of first pawl bodies 411, and the second ends of the plurality of first pawl bodies 411 are configured to be engaged with the plurality of reverse tooth structures 212 one by one.

[0087] Meanwhile, the plurality of first pawl bodies 411 are respectively inserted into the plurality of guiding grooves 431 one by one, so that the plurality of guiding grooves 431 and the plurality of contact heads 432 are arranged opposite to each other one by one. In practical applications, based on the mutual cooperation of the relatively arranged guiding grooves 431 and the contact heads 432, when the button assembly 3 drives the first pawl 41 to rotate, the second ends of the respective first pawl bodies 411 of the first pawl 41 can be controlled to approach or separate from each other based on the guiding effect of the guiding grooves 431, so as to achieve engagement or separation with the reverse tooth structure 212.

[0088] In some embodiments, as Figure 7 and Figure 10 shown, there are a plurality of reverse tooth structures 212. The plurality of reverse tooth structures 212 are arranged at intervals in sequence along the circumferential direction of the rod body 211, and the plurality of reverse tooth structures 212 are configured to be arranged opposite to the plurality of first pawl bodies 411 of the first pawl 41 one by one.

[0089] As Figure 2 and Figure 9 shown, the second pawl 42 is arranged inside the inner lining sleeve 12. The second pawl 42 includes a second annular seat body 422 and a plurality of second pawl bodies 421. The plurality of second pawl bodies 421 are arranged at intervals in sequence along the circumferential direction of the pen shell 1. The first ends of the plurality of second pawl bodies 421 are respectively connected to the second annular seat body 422, and the second ends of the plurality of second pawl bodies 421 are configured to be engaged with the plurality of reverse tooth structures 212 one by one.

[0090] In practical applications, when the injection pen is in the injection state, the plurality of second pawl bodies 421 are engaged with the plurality of reverse tooth structures 212 one by one. At this time, the operator can press the button assembly 3, and the button assembly 3 can drive the push rod 21 to smoothly advance toward the side of the drug delivery assembly 22. That is, the meshing setting between the second pawl 42 and the reverse tooth structure 212 will not affect the normal movement of the push rod 21 toward the drug delivery assembly 22. Instead, when the operator drives the first pawl 41 to move toward the side away from the drug delivery assembly 22 through the button assembly 3, it will prevent the push rod 21 from moving toward the side away from the drug delivery assembly 22.

[0091] When the injection pen is in the reset state, since each second pawl body 421 is distributed between two adjacent reverse tooth structures 212, the second pawl 42 is separated from the reverse tooth structures 212 on the push rod 21, and each second pawl body 421 of the second pawl 42 faces the area on the push rod 21 where no reverse tooth structure 212 is provided. At this time, the operator can manually control the push rod 21 to move towards the button assembly 3 to reset the push rod 21 to its initial position, so as to prepare for another injection operation of the injection pen.

[0092] In some embodiments, as Figure 7 shown, the rod body 211 includes: a first section 2111, a second section 2112, and a positioning structure 2113; the first end of the first section 2111 abuts against the drug delivery assembly 22, the first end of the second section 2112 is connected to the second end of the first section 2111, and a plurality of reverse tooth structures 212 are provided on the circumferential wall of the second section 2112; The positioning structure 2113 includes an annular tooth groove and a wedge-shaped protrusion. The annular tooth groove is provided between the first section 2111 and the second section 2112 and is respectively connected to each reverse tooth structure 212. The wedge-shaped protrusion is provided on the circumferential wall of the second section 2112 and is located between two adjacent reverse tooth structures 212; Wherein, 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 achieve meshing with the annular tooth groove.

[0093] 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 reverse tooth structures 212, and each wedge-shaped protrusion is formed with an inclined surface between the end far from the annular tooth groove and the end close to the annular tooth groove. In the direction from the end far from the annular tooth groove to the end close to the annular tooth groove, the distance of the inclined surface relative to the central axis of the rod body 211 gradually increases.

[0094] During the process of resetting the push rod 21 to its 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 generate a sense of damping and jumping during the process of the push rod 21 retracting and resetting, giving the operator a tactile feedback.

[0095] In some embodiments, as Figure 1 shown, 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 faces the pen shell 1.

[0096] As Figure 8 shown, a limit protrusion 4101 is provided on the circumferential wall of the first pawl 41; asFigure 15 and Figure 16 As shown, a first position identifier 101 is provided on the outer sidewall of the pen case 1. For example, the first position identifier 101 can be in the form of an identifier shaped like " ". A first limiting groove 111 is provided on the inner sidewall of the pen case 1, and the first limiting groove 111 extends along the axial direction of the pen case 1; When the indicating identifier 301 is opposite to the first position identifier 101, the first pawl 41 and the second pawl 42 are respectively engaged with the reverse tooth structure 212; the limiting protrusion 4101 cooperates with the first limiting groove 111 to limit the stroke of the push rod 21 moving towards the drug delivery assembly 22.

[0097] In practical applications, as Figure 19 shown, the operator can manually rotate the button assembly 3 to make the indicating identifier 301 opposite to the first position identifier 101. At this time, the first pawl 41 and the second pawl 42 are respectively in an engaged state with the reverse tooth structure 212. The operator can slightly pull the button assembly 3 on the side away from the drug delivery assembly 22, so that the first pawl 41 is driven by the button assembly 3 to move relative to the push rod 21 towards the side away from the drug delivery assembly 22, while the push rod 21 is restricted by the second pawl 42 and will not move towards the side away from the drug delivery assembly 22. Among them, the pulling stroke of the button assembly 3 is determined by the length of the first limiting groove 111 extending along the axial direction of the pen case 1.

[0098] Exemplarily, by setting the length of the first limiting groove 111 extending along the axial direction of the pen case 1, it can be ensured that the first pawl 41 moves a stroke of one reverse tooth relative to the reverse tooth structure 212 towards the side away from the drug delivery assembly 22. That is, the length of the first limiting groove 111 extending along the axial direction of the pen case 1 can be set to be equal to the distance between two adjacent reverse teeth of the reverse tooth structure 212.

[0099] As Figure 20 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 towards the side of the drug delivery assembly 22 through the reverse tooth structure 212. For example, the moving stroke of the push rod 21 is the stroke of one reverse tooth of the reverse tooth structure 212, so as to realize the exhaust operation of the drug delivery assembly 22 driven by the push rod 21.

[0100] In some embodiments, as Figure 15 and Figure 16As shown, a second position identifier 102 is further provided on the outer sidewall of the pen shell 1. For example, the second position identifier 102 can be indicated by an identifier shaped like "1unt"; the first position identifier 101 and the second position identifier 102 are arranged at intervals along the circumferential direction of the pen shell 1; a second limiting groove 112 is further provided on the inner sidewall of the pen shell 1. 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; When the indicating identifier 301 and the second position identifier 102 are opposite to each other, the first pawl 41 and the second pawl 42 are respectively engaged 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 moving towards the drug delivery assembly 22.

[0101] In practical applications, as Figure 21 shown, the operator can manually rotate the button assembly 3 to make the indicating identifier 301 opposite to the second position identifier 102. At this time, the first pawl 41 and the second pawl 42 are respectively kept in an engaged state with the reverse tooth structure 212.

[0102] As Figure 22 shown, the operator can pull the button assembly 3 significantly towards the side away from the drug delivery assembly 22, so that the first pawl 41 is driven by the button assembly 3 to move relative to the push rod 21 towards the side away from the drug delivery assembly 22, while the push rod 21 is restricted by the second pawl 42 and will not move towards the side away from the drug delivery assembly 22. Among them, the pulling stroke of the button assembly 3 is determined by the extension length of the second limiting groove 112 along the axial direction of 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 moving 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.

[0103] As Figure 23 shown, when the operator presses the button assembly 3 again, under the limitation 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 as to realize the injection operation of driving the drug delivery assembly 22 by the push rod 21. Among them, during the injection process of the injection pen, the second pawl 42 and the reverse tooth structure 212 remain in an engaged state and have relative movement. However, the presence of the second pawl 42 does not prevent the normal movement of the push rod 21 towards the drug delivery assembly 22.

[0104] In some embodiments, as as Figure 1 and Figure 15 shown, a third position identifier 103 is further provided on the outer sidewall of the pen shell 1. For example, the third position identifier 103 can be shaped like " The indication of the " is shown; the first position identifier 101 and the third position identifier 103 are arranged at intervals along the circumferential direction of the pen shell 1; when the indication identifier 301 and the third position identifier 103 are opposite to each other, the first pawl 41 and the second pawl 42 are separated from the reverse tooth structure 212 respectively.

[0105] In practical applications, such 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 process of switching to the indication identifier 301 being 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 head 432 on the first pawl 41 moves to the second bottom of the guiding groove 431, causing the first pawl 41 to be driven by the contact head 432 to move radially away from the push rod 21 to achieve the separation of the first pawl 41 from the reverse tooth structure 212; as Figure 7 and Figure 9 shown, during the process of switching to the indication identifier 301 being 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 of the push rod 21 where there is no reverse tooth structure 212, so as to achieve the separation of the second pawl 42 from the reverse tooth structure 212 on the push rod 21.

[0106] Such 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 the side of the button assembly 3 to reset the push rod 21 to the initial position, so as to prepare for the next injection operation of the injection pen.

[0107] Since the medicine bottle 221 of the medicine delivery assembly 22 is located in the pen core holder 11 of the pen shell 1, and one end of the push rod 21 facing the medicine delivery assembly 22 extends into the medicine bottle 221, when resetting the push rod 21, it is necessary to first remove the pen core holder 11, and then manually control the push rod 21 to move towards the side of the button assembly 3 relative to the pen shell 1 until the second pawl 42 meshes with the annular tooth groove corresponding to the positioning structure 2113, so as to achieve resetting the push rod 21 to the initial position.

[0108] In some embodiments, such as Figure 2 、 Figure 17 and Figure 18 shown, the button assembly 3 includes: an insertion cylinder 31 and a pressing head 32; the insertion cylinder 31 is inserted into the pen shell 1, the first end of the insertion cylinder 31 is connected to the first pawl 41, the second end of the rod body 211 passes through the insertion cylinder 31 and is slidably matched with the inner wall of the insertion cylinder 31; the pressing head 32 is exposed at the second port and is connected to the second end of the insertion cylinder 31.

[0109] It can be understood that the first end of the insertion tube 31 and the first pawl 41 can be set to be detachably connected.

[0110] Exemplarily, as Figure 6 , Figure 8 and Figure 17 shown, a clamping projection 3101 is provided on the peripheral wall of the insertion tube 31, and a clamping hole 4102 is provided on the peripheral wall of the first annular seat body 412 corresponding to the first pawl 41. The first end of the insertion tube 31 can be inserted axially into the first annular seat body 412 along the pen shell 1 until the clamping projection 3101 is fitted into the clamping hole 4102, so as to integrally connect the first end of the insertion tube 31 and the first pawl 41.

[0111] Meanwhile, a adapter is provided at the second end of the rod body 211, and the peripheral wall of the adapter and the inner wall of the insertion tube 31 are slidably matched through a guiding structure to guide the button assembly 3 and the rod body 211 to slide axially along the pen shell 1, and to ensure that the button assembly 3 can drive the rod body 211 to rotate.

[0112] In some embodiments, as Figure 15 and Figure 17 shown, a first protrusion 311 is provided on the peripheral wall of the insertion tube 31, and the first protrusion 311 is an elastic protrusion; a plurality of first grooves 121 are provided on the inner wall of the pen shell 1, and the first grooves 121 can be arc-shaped grooves. The plurality of first grooves 121 are sequentially connected along the circumferential direction 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 are slidably matched axially along the pen shell 1, and can move into each first groove 121 sequentially along with the rotation of the insertion tube 31. This design can ensure that the button assembly 3 moves axially relative to the pen shell 1, and at the same time, based on the cooperation between the first protrusion 311 and the first groove 121, it can ensure that when the button assembly 3 is manually controlled to rotate relative to the pen shell 1, the button assembly 3 rotates by a fixed angle relative to the pen shell 1 each time.

[0113] 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 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 two adjacent first grooves 121 relative to the central axis of the pen shell 1.

[0114] In some embodiments, as Figure 15 and Figure 17 shown, a second protrusion 312 is provided on the peripheral wall of the insertion tube 31, and a second groove 122 is provided on the inner wall of the pen shell 1. The second protrusion 312 is movably arranged in the second groove 122, and the second protrusion 312 and the second groove 122 cooperate to limit the rotation position of the button assembly 3 relative to the pen shell 1.

[0115] It can be understood that the second protrusion 312 is arranged to extend along the axial direction of the insertion cylinder 31, and the second groove 122 is arranged to extend 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 does not disengage from each of the first grooves 121 during the rotation of the button assembly 3.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An injection pen, characterized in that, Comprising: A pen shell, including a receiving cavity and a first port and a second port communicating with the receiving cavity; An injection assembly disposed in the receiving cavity, the injection assembly including a push rod and a drug delivery assembly, the push rod including a rod body and an inverted tooth structure, the inverted tooth structure being disposed on the circumferential wall of the rod body, a first end of the rod body abutting against the drug delivery assembly, and the drug delivery assembly abutting against the first port; A button assembly inserted into the second port, the button assembly and a second end of the rod body being slidably engaged along the axial direction of the pen shell and capable of driving the rod body to rotate; A ratchet pawl assembly disposed in the receiving cavity, the ratchet pawl assembly including a first ratchet pawl, a second ratchet pawl and a clutch structure, the first ratchet pawl being connected to the button assembly, the second ratchet pawl being connected to the pen shell, the first ratchet pawl and the second ratchet pawl being respectively configured to engage with the inverted tooth structure, and the clutch structure being formed between the pen shell and the first ratchet pawl; Wherein, when the button assembly rotates, the first ratchet pawl can be engaged with or separated from the inverted tooth structure through the clutch structure, and the second ratchet pawl can be engaged with or separated from the inverted tooth structure.

2. The injection pen according to claim 1, wherein The clutch structure includes: A guiding groove having a first groove bottom and a second groove bottom, the first groove bottom and the second groove bottom being sequentially arranged along the circumferential direction of the pen shell, and a radial distance of the first groove bottom relative to the push rod being smaller than a radial distance of the second groove bottom relative to the push rod; A contact head connected to the first ratchet pawl, the contact head being configured to be inserted into the guiding groove; Wherein, the button assembly is configured to drive the first ratchet pawl to rotate so as to enable the first ratchet pawl to drive the contact head to move between the first groove bottom and the second groove bottom.

3. The injection pen according to claim 2, characterized in that, The first ratchet pawl includes a plurality of first pawl bodies, and each of the first pawl bodies is provided with the contact head; A plurality of the guiding grooves are provided, and the plurality of guiding grooves are sequentially and spaced apart along the circumferential direction of the pen shell, and the plurality of guiding grooves are arranged in one-to-one correspondence with the plurality of contact heads.

4. The injection pen according to claim 1, characterized in that, A plurality of the inverted tooth structures are provided, and the plurality of inverted tooth structures are sequentially and spaced apart along the circumferential direction of the rod body; The second ratchet pawl includes a plurality of second pawl bodies, and the plurality of second pawl bodies are sequentially and spaced apart along the circumferential direction of the pen shell; Wherein, when the injection pen is in an injection state, the plurality of second pawl bodies are engaged with the plurality of inverted tooth structures in one-to-one correspondence; when 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 according to claim 4, characterized in that, The rod body includes: A first section, a first end of the first section abutting against the drug delivery assembly; A second section, a first end of the second section being connected to a second end of the first section, and the plurality of inverted tooth structures being disposed on the circumferential wall of the second section; A positioning structure, including an annular tooth groove and a wedge-shaped protrusion, the annular tooth groove being disposed between the first section and the second section and respectively connected to each of the inverted tooth structures, and the wedge-shaped protrusion being disposed on the circumferential wall of the second section and located between two adjacent inverted tooth structures; Wherein, when the injection pen is in the reset state, the wedge-shaped protrusion is used to guide the second pawl to move along the axial direction of the push rod so as to engage with the annular tooth groove.

6. The injection pen according to claim 1, wherein The button assembly is provided with an indication mark, and a limiting protrusion is arranged on the peripheral wall of the first pawl; A first position mark is arranged on the outer side wall of the pen housing, and a first limiting groove is arranged on the inner side wall of the pen housing, and the first limiting groove extends along the axial direction of the pen housing; When the indication mark is opposite to the first position mark, the first pawl and the second pawl are respectively engaged with the reverse tooth structure; Wherein, the limiting protrusion is matched with the first limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.

7. The injection pen according to claim 6, characterized in that, A second position mark is further arranged on the outer side wall of the pen housing, and the first position mark and the second position mark are arranged at intervals along the circumferential direction of the pen housing; A second limiting groove is further arranged on the inner side wall of the pen housing, and the second limiting groove extends along the axial direction of the pen housing, and the extension length of the second limiting groove is greater than that of the first limiting groove; When the indication mark is opposite to the second position mark, the first pawl and the second pawl are respectively engaged with the reverse tooth structure; Wherein, the limiting protrusion is matched with the second limiting groove to limit the stroke of the push rod moving towards the drug delivery assembly.

8. The injection pen according to claim 6, characterized in that, A third position mark is further arranged on the outer side wall of the pen housing, and the first position mark and the third position mark are arranged at intervals along the circumferential direction of the pen housing; When the indication mark is opposite to the third position mark, the first pawl and the second pawl are respectively separated from the reverse tooth structure.

9. The injection pen according to any one of claims 1 to 8, characterized in that, The button assembly includes: An insertion cylinder, the insertion cylinder is inserted into the pen housing, the first end of the insertion cylinder is connected to the first pawl, and the second end of the rod body penetrates into the insertion cylinder and is slidably matched with the inner wall of the insertion cylinder; A pressing head, the pressing head exposes from the second port and is connected to the second end of the insertion cylinder.

10. The injection pen according to claim 9, characterized in that, A first protrusion is arranged on the peripheral wall of the insertion cylinder, and the first protrusion is an elastic protrusion; a plurality of first grooves are arranged on the inner wall of the pen housing, and the plurality of first grooves are sequentially connected along the circumferential direction of the pen housing, and each first groove extends along the axial direction of the pen housing; the first protrusion is slidably matched with the first groove along the axial direction of the pen housing and can sequentially move into each first groove along with the rotation of the insertion cylinder; And / or, a second protrusion is arranged on the peripheral wall of the insertion cylinder, a second groove is arranged on the inner wall of the pen housing, the second protrusion is movably arranged in the second groove, and the second protrusion and the second groove are matched to limit the rotational position of the button assembly relative to the pen housing.

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