Injection structure and injection device

Abstract

The utility model provides an injection structure and an injection device.The injection device comprises a medicine storage structure and the injection structure, and the injection structure comprises a shell assembly, a rotating cylinder, a rotary knob, a tension spring and a center push rod; the knob is installed at the far end of the shell assembly and forms circumferential limiting connection and axial sliding connection with the rotating cylinder, the far end of the tension spring is fixedly connected with the shell assembly, and the near end of the tension spring is fixedly connected with the rotating cylinder; the knob is used for driving the rotating cylinder and the near end of the tension spring to positively rotate so as to positively adjust injection metering, and the shell assembly is used for limiting reverse rotation of the rotating cylinder; the rotating cylinder is pushed towards the near end direction so that the rotating cylinder can be separated from rotation limitation of the rotary knob and the shell assembly till the rotating cylinder and the center push rod form circumferential limiting connection, the tension spring releases rotating elastic force so as to drive the center push rod to rotate reversely, and the plunger is pushed to move towards the near end while the center push rod rotates reversely so that injection can be achieved. Before injection, the central push rod does not need to stretch out to the far end for a long time to achieve large-dose injection, and a user can complete the injection process by himself / herself.

Description

Technical Field

[0001] This application belongs to the field of medical device technology, and more specifically, relates to an injection structure and injection device. Background Technology

[0002] An insulin injector is a medical device specifically designed for injecting insulin, primarily used by diabetic patients to help control their blood sugar levels.

[0003] Different doses of insulin are needed for diabetic patients at different stages, and long-term injections are required. There are many types of syringes on the market for this type of drug, mainly disposable single-dose syringes, disposable single-dose multiple-explosion syringes, and reusable syringes with single-dose multiple-explosion capabilities.

[0004] For existing reusable syringes with single-dose, multiple-dispense capabilities, dosage adjustment is typically achieved using a plunger. Specifically, extending the plunger distally adjusts the injection dose, and pushing the plunger back during injection completes the corresponding dose. However, the demand for large single-dose injections is limited by the plunger's extension length. Using the existing design for large-dose injections results in an excessively long plunger, which is inconvenient for users with small hands and children, making it difficult for them to complete the injection independently, especially for syringes with single-dose doses of 80U or higher. Utility Model Content

[0005] The purpose of this application is to provide an injection structure and injection device to solve the technical problem that users cannot complete the injection process themselves when injecting large doses in existing injection devices.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: An injection structure is provided for use in conjunction with a drug storage structure. The drug storage structure includes a drug storage bottle for containing drugs, a plunger for sealing one end of the drug storage bottle, and an injection needle installed at the other end of the drug storage bottle. The injection structure includes a housing assembly, a rotating cylinder, a knob, a tension spring, and a central push rod. The central push rod, the rotating cylinder, and the housing assembly are arranged sequentially from the inside to the outside. The central push rod is threadedly connected to the housing assembly. The knob is installed at the distal end of the housing assembly and forms a circumferential limiting connection and an axial sliding connection with the rotating cylinder. The tension spring is sleeved on the outside of the rotating cylinder. The distal end is fixedly connected to the housing assembly, and the proximal end of the tension spring is fixedly connected to the rotating cylinder; the knob is used to drive the rotating cylinder and the proximal end of the tension spring to rotate forward to adjust the injection metering, and the housing assembly is used to restrict the reverse rotation of the rotating cylinder driven by the forward rotation of the tension spring; during injection, the rotating cylinder is pushed towards the proximal end to disengage the rotating cylinder from the rotation restriction of the knob and the housing assembly until the rotating cylinder forms a circumferential limiting connection with the central push rod, and the tension spring releases rotational elastic force to drive the rotating cylinder and the central push rod to rotate in the reverse direction. While the central push rod rotates in the reverse direction, it pushes the plunger to move towards the proximal end to realize the injection.

[0007] In some embodiments, the injection structure further includes a button and a first elastic element. The button is axially limited and rotatably connected to the distal end of the rotating cylinder. The first elastic element is connected to the button and is used to axially reset the button and the rotating cylinder to the distal end when pushed in the proximal direction.

[0008] In some embodiments, the injection structure further includes a first fixing sleeve and a second fixing sleeve, the first fixing sleeve and the second fixing sleeve being axially spaced and located between the housing assembly and the rotating cylinder, the first fixing sleeve being fixedly connected to the housing assembly, the second fixing sleeve being fixedly connected to the rotating cylinder, the proximal end of the tension spring being fixedly connected to the second fixing sleeve, and the distal end of the tension spring being fixedly connected to the first fixing sleeve.

[0009] In some embodiments, the injection structure further includes a dose rotating cylinder, which forms a circumferential limiting connection and an axial sliding connection with the second fixed sleeve. The dose rotating cylinder is threadedly connected to the housing assembly, and a dose mark is provided on the surface of the dose rotating cylinder. The housing assembly is provided with a window for reading the dose mark.

[0010] In some embodiments, the first fixing sleeve has a first limiting portion, the dose rotating cylinder has a second limiting portion, the first limiting portion and the second limiting portion cooperate to limit the return of the dose rotating cylinder when it is at zero position; the housing assembly has a third limiting portion, the dose rotating cylinder has a fourth limiting portion, the third limiting portion and the fourth limiting portion cooperate to limit the maximum stroke of the dose rotating cylinder in the forward direction.

[0011] In some embodiments, the injection structure further includes a memory element, which is sleeved between the rotating cylinder and the central push rod. The memory element and the rotating cylinder form a circumferential limiting connection and an axial sliding connection. The memory element and the central push rod are threadedly connected. During forward adjustment, the memory element is driven by the rotating cylinder to move distally on the central push rod. During reverse adjustment, the memory element is driven by the rotating cylinder to move proximally on the central push rod. During injection, the memory element and the central push rod rotate synchronously and move proximally together. The distal end of the central push rod is an unthreaded end to limit the memory element located at the unthreaded end of the central push rod from continuing to rotate forward for forward adjustment, thereby limiting further adjustment of the set dose beyond the dose of the storage bottle.

[0012] In some embodiments, a rotation limiting component is provided inside the housing assembly. The rotation limiting component is used to limit the reverse rotation of the rotating cylinder driven by the forward rotational force storage of the tension spring. When the rotating cylinder moves a preset distance to the proximal end, the rotation limiting component disengages axially from the housing assembly to release the restriction on the reverse rotation of the rotating cylinder.

[0013] In some embodiments, the rotation limiting component includes a rotation limiting movable member and a rotation limiting fixed member. The rotation limiting movable member is sleeved between the rotating cylinder and the rotation limiting fixed member. The rotation limiting fixed member forms a circumferential limiting connection and an axial sliding connection with the housing assembly. The inner circumferential wall of the rotation limiting fixed member has a plurality of first positive teeth, and the outer circumferential wall of the rotation limiting movable member has second positive teeth. The forward rotation of the rotating cylinder can drive the rotation limiting movable member to rotate in the forward direction, and the second positive teeth are sequentially engaged between each of the first positive teeth. When the rotating cylinder moves to the proximal end, it will drive the rotation limiting fixed member to move together. When it moves a preset distance, the rotation limiting fixed member can be released from the circumferential restriction of the housing assembly, so that the rotation limiting fixed member, the rotation limiting movable member, and the rotating cylinder can synchronously reverse under the drive of the storage torsion spring.

[0014] In some embodiments, the portion of the second forward tooth connected to the limited-rotation movable member is elastic, the second forward tooth is also connected to a first guide rod, the rotating cylinder has a first guide groove, the first guide rod is slidably disposed in the first guide groove, the first guide groove guides the first guide rod toward the center of the rotating cylinder when the rotating cylinder rotates in the opposite direction, so as to drive the second forward tooth to retract toward the center of the rotating cylinder to reduce the distance with the first forward tooth, thereby allowing the second forward tooth to rotate and bounce in the opposite direction on the first forward tooth to achieve a reversal when over-measurement is adjusted.

[0015] In some embodiments, the injection structure further includes an outer push rod, which is sleeved outside the central push rod and forms a circumferential limiting connection with the central push rod. The distal end of the outer push rod is provided with a first meshing tooth, and the proximal end of the rotating cylinder is provided with a second meshing tooth. During injection, after the rotating cylinder moves a preset distance towards the proximal end, the first meshing tooth and the second meshing tooth engage axially to form a circumferential limiting connection. At this time, the rotating cylinder is released from the rotational restriction of the knob and the housing assembly. The tension spring releases the rotational elastic force to rotate the rotating cylinder, the outer push rod, and the central push rod in the opposite direction. While the central push rod rotates in the opposite direction, it pushes the plunger to move towards the proximal end to achieve injection.

[0016] In some embodiments, the injection structure further includes an anti-reset component, which is used to restrict the forward rotation of the central push rod to limit the axial reset of the central push rod; and when the drug storage structure is separated from the housing assembly, the anti-reset component releases the restriction on the forward rotation of the central push rod.

[0017] In some embodiments, the anti-reset assembly includes an anti-forward rotation movable member, an anti-forward rotation fixed member, an anti-reverse rotation movable member, a second elastic member, and a third elastic member; the anti-reverse rotation movable member forms an axial sliding connection and a circumferential limiting connection with the central push rod; the anti-forward rotation fixed member is fixed to the housing assembly; the anti-forward rotation movable member is sleeved outside the outer push rod and forms an axial sliding connection and a circumferential limiting connection with the outer push rod; the second elastic member is sleeved outside the outer push rod; the third elastic member is sleeved outside the second elastic member and abuts against the anti-forward rotation fixed member and the anti-reverse rotation movable member; the anti-forward rotation movable member has a third reverse tooth, the anti-forward rotation fixed member has a fourth reverse tooth, the anti-reverse rotation movable member has a third forward tooth, and the outer push rod has a fourth forward tooth; when the drug storage structure is installed on the housing assembly, the drug storage structure pushes the anti-reverse rotation movable member distally so that both the second elastic member and the third elastic member are in position. In a compressed state, the second elastic element abuts against the anti-rotation movable element and the outer push rod, so that the third reverse tooth and the fourth reverse tooth engage axially, and the third forward tooth and the fourth forward tooth engage axially. When the drug storage structure is detached from the housing assembly, the anti-rotation movable element is pushed proximally by the third elastic element, the third elastic element is in a naturally stretched state, the second elastic element is in a naturally stretched state and at least one end is suspended, so that the third forward tooth and the fourth forward tooth are in a non-engaged state axially. When the central push rod rotates forward, it can rotate the anti-rotation movable element forward, realizing the axial reset of the central push rod; or, so that the third reverse tooth and the fourth reverse tooth are in a non-engaged state axially, when the central push rod rotates forward, it can rotate the anti-rotation movable element, the outer push rod and the anti-rotation movable element forward, realizing the axial reset of the central push rod.

[0018] On the other hand, this application also provides an injection device, including a drug storage structure and the above-mentioned injection structure, wherein the injection structure and the drug storage structure cooperate to realize drug injection.

[0019] The beneficial effects of the injection structure and device provided in this application are as follows: Through the arrangement of the housing assembly, rotating cylinder, knob, tension spring, and central push rod, during positive dose adjustment, only the rotation of the knob is needed to drive the rotating cylinder and tension spring to rotate forward by a first angle to achieve positive dose adjustment, utilizing the rotational elastic force of the tension spring for energy storage. During injection, only the rotating cylinder needs to be pushed proximally to connect the rotating cylinder and the central push rod, so that when the tension spring releases its rotational elastic force to drive the rotating cylinder to rotate in the opposite direction, it simultaneously drives the central push rod to rotate in the opposite direction. Simultaneously, the central push rod's reverse rotation pushes the plunger proximally to achieve injection. Overall, in this application, the central push rod is driven by the rotational elastic force of the tension spring to axially push the plunger to achieve injection. For large-dose injections, only the rotation angle of the knob needs to be increased; before injection, it is not necessary to extend the central push rod a long distance to the distal end of the housing assembly to achieve a large dose. Therefore, even when large doses are required, users with small hands and children can easily complete the injection process themselves, making operation convenient. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A perspective view of the injection device provided in the embodiments of this application;

[0022] Figure 2 This is a cross-sectional view of the injection device provided in the embodiments of this application;

[0023] Figure 3 for Figure 2 An enlarged structural diagram of the proximal portion of the injection device;

[0024] Figure 4 This is a three-dimensional schematic diagram of the button in the injection structure provided in the embodiments of this application;

[0025] Figure 5 This is a three-dimensional schematic diagram of the tension spring in the injection structure provided in the embodiments of this application;

[0026] Figure 6 A three-dimensional schematic diagram of the knob in the injection structure provided in the embodiments of this application;

[0027] Figure 7 This is a three-dimensional schematic diagram of the knob in the injection structure provided in the embodiment of this application from another perspective;

[0028] Figure 8A three-dimensional schematic diagram of the first fixing sleeve in the injection structure provided in the embodiments of this application;

[0029] Figure 9 This is a three-dimensional schematic diagram of the first fixing sleeve in the injection structure provided in the embodiments of this application from another perspective;

[0030] Figure 10 for Figure 2 An enlarged schematic diagram of the second fixing sleeve portion of the injection device;

[0031] Figure 11 This is a three-dimensional schematic diagram of the rotating cylinder in the injection structure provided in the embodiments of this application;

[0032] Figure 12 This is a three-dimensional schematic diagram of the rotating cylinder in the injection structure provided in the embodiment of this application from another perspective.

[0033] Figure 13 A three-dimensional schematic diagram of the second fixing sleeve in the injection structure provided in the embodiments of this application;

[0034] Figure 14 This is a three-dimensional schematic diagram of the second fixing sleeve in the injection structure provided in the embodiment of this application from another perspective;

[0035] Figure 15 This is a three-dimensional schematic diagram of the dosage rotating cylinder in the injection structure provided in the embodiments of this application;

[0036] Figure 16 This is a three-dimensional schematic diagram of the dosage cylinder in the injection structure provided in the embodiments of this application from another perspective;

[0037] Figure 17 for Figure 2 Enlarged schematic diagram of the rotation limiting component of the injection device;

[0038] Figure 18 A three-dimensional schematic diagram of the memory element in the injection structure provided in the embodiments of this application;

[0039] Figure 19 This is a three-dimensional schematic diagram of another orientation of the memory element in the injection structure provided in the embodiments of this application;

[0040] Figure 20 A three-dimensional schematic diagram of the central push rod in the injection structure provided in the embodiments of this application;

[0041] Figure 21 A three-dimensional schematic diagram of the magnifying glass and viewing window in the injection structure provided in the embodiments of this application;

[0042] Figure 22 This is a three-dimensional schematic diagram of the window in the injection structure provided in the embodiments of this application;

[0043] Figure 23 A three-dimensional schematic diagram of the limited-rotation movable component in the injection structure provided in the embodiments of this application;

[0044] Figure 24 This is a three-dimensional schematic diagram of another orientation of the limited-rotation movable component in the injection structure provided in the embodiments of this application;

[0045] Figure 25 A three-dimensional schematic diagram of the rotation-limiting fixing member in the injection structure provided in the embodiments of this application;

[0046] Figure 26 This is a three-dimensional schematic diagram of another orientation of the rotation-limiting fixing member in the injection structure provided in the embodiments of this application;

[0047] Figure 27 for Figure 2 Enlarged schematic diagram of the anti-reset component of the injection device;

[0048] Figure 28 This is a three-dimensional schematic diagram of the outer push rod in the injection structure provided in the embodiments of this application;

[0049] Figure 29 This is a three-dimensional schematic diagram of the outer push rod in the injection structure provided in the embodiment of this application from another perspective;

[0050] Figure 30 A three-dimensional schematic diagram of the anti-rotation movable component in the injection structure provided in the embodiments of this application;

[0051] Figure 31 This is a three-dimensional schematic diagram of another orientation of the anti-rotation movable component in the injection structure provided in the embodiments of this application;

[0052] Figure 32 This is a three-dimensional schematic diagram of the anti-reverse fixing member in the injection structure provided in the embodiments of this application;

[0053] Figure 33 This is a three-dimensional schematic diagram of the anti-reverse movable component in the injection structure provided in the embodiments of this application;

[0054] Figure 34 A three-dimensional schematic diagram of the first inner shell in the injection structure provided in the embodiments of this application;

[0055] Figure 35 This is a three-dimensional schematic diagram of the first inner shell in the injection structure provided in the embodiments of this application from another perspective;

[0056] Figure 36 A three-dimensional schematic diagram of the second inner shell in the injection structure provided in the embodiments of this application;

[0057] Figure 37 This is a three-dimensional schematic diagram of the second inner shell in the injection structure provided in an embodiment of this application;

[0058] Figure 38 A three-dimensional schematic diagram of the injection shell in the injection structure provided in the embodiments of this application;

[0059] Figure 39 A three-dimensional schematic diagram of the pusher in the injection structure provided in the embodiments of this application;

[0060] Figure 40 This is a three-dimensional schematic diagram of the pusher in the injection structure provided in an embodiment of this application;

[0061] Figure 41 This is a three-dimensional schematic diagram of the mounting component in the injection structure provided in the embodiments of this application;

[0062] Figure 42 This is a three-dimensional schematic diagram of the pressure component in the injection structure provided in the embodiments of this application.

[0063] The following are the labeling elements in the figure:

[0064] 1. Injection structure; 100. Shell assembly; 110. First inner shell; 111. First inner shell body; 112. Annular rib; 113. First groove; 114. Second slot; 115. First internal thread; 116. Sixth groove; 1161. Third stepped surface; 117. Third slot; 118. Second sleeve part; 119. Fifth rib; 120. Second inner shell; 121. Second inner shell body; 122. Inner shell bottom plate; 123. Connecting part; 1231. Third external thread; 124. First sleeve part; 130. Injection shell; 131. Positioning hole; 132. Fifth groove; 140. Window; 200. Rotating cylinder; 210. Rotating cylinder body; 220. First limiting ring; 230. Second limiting rib. ; 240, Fourth annular plate; 241, First slot; 242, First guide groove; 243, Second guide groove; 250, Fourth limiting rib; 260, Second meshing tooth; 270, Third hook; 300, Knob; 310, Inner cylinder; 320, Outer cylinder; 321, Friction rib; 322, Third annular groove; 330, Connecting plate; 340, First center hole; 350, First limiting rib; 360, First limiting groove; 370, First annular groove; 380, Second annular groove; 400, Tension spring; 410, First hook; 420, Second hook; 500, Center push rod; 510, Rod body; 520, Second external thread; 530, Third groove; 540, Unthreaded end; 550, Small diameter part; 5 60. Large diameter section; 600. Button; 610. Pressing plate; 620. First enclosure plate; 630. Central column; 640. First locking block; 700. First elastic element; 800. Second fixing sleeve; 810. Second sleeve body; 820. Third annular plate; 821. Opening groove; 830. First hook; 840. Third limiting rib; 850. Second protrusion; 900. First fixing sleeve; 910. First sleeve body; 920. First annular plate; 921. Irregular hole; 922. First hook groove; 930. First flange; 931. First protrusion; 932. Second locking block; 940. Second annular plate; 950. Third protrusion; 951. First inclined surface; 1000. Dosing cylinder; 1001. Dosing mark; 1002 1003. Second groove; 1004. First external thread; 1005. First cross section; 1006. Second inclined surface; 1100. Magnifying glass; 1101. First lens body; 1102. Second lens body; 1200. Viewing window; 1201. Positioning post; 1202. First through groove; 1203. Second through groove; 1300. Rotation limiting component; 1310. Rotation limiting movable part; 1311. Rotation limiting body; 1312. Second forward tooth; 1313. First guide rod; 1314. Second guide rod; 1315. Third flange; 1316. First stepped surface; 1320. Rotation limiting fixing part; 1321. Base plate; 1322. Second enclosure plate; 1323. Third enclosure plate; 1324. First forward tooth;1325. Second step surface; 1326. Second center hole; 1327. Sixth protrusion; 1400. Outer push rod; 1410. Push rod cylinder; 1411. Fourth groove; 1420. Fifth annular plate; 1430. Sixth annular plate; 1440. First meshing tooth; 1450. Fourth forward tooth; 1500. Pushing component; 1510. Small diameter hole; 1520. Large diameter hole; 1530. Side hole; 1550. Pushing body; 1560. Abutment plate; 1600. Anti-reset assembly; 1610. Anti-forward rotation fixing component; 1611. Fixed base plate; 1612. Fixed surrounding plate; 1613. Fourth reverse tooth; 1614. Third locking block; 1620. Anti-forward rotation movable component; 1621. Anti-forward rotation body; 1622. Third reverse tooth; 1623. Fourth convex strip; 1630. Second elastic element; 1640. Third elastic element; 1650. Anti-reverse moving part; 1651. Adapter base plate; 1652. Adapter cylinder; 1653. Third convex strip; 1654. Third forward tooth; 1655. Third center hole; 1700. Mounting part; 1710. Insert block; 1720. Fourth annular groove; 1800. Memory element; 1810. Memory cylinder body; 1820. Seventh convex strip; 1830. Fourth internal thread; 1900. Pressing part; 1910. Slot; 1920. Pressure plate; 1930. Pressure ring; 2000. Drug storage shell; 2. Drug storage structure; 201. Drug storage bottle; 202. Plunger; 203. Injection needle. Detailed Implementation

[0065] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0066] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0067] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0069] Please see Figure 1 and Figure 2 The injection structure 1 provided in the embodiments of this application will now be described. The injection structure 1 is used in conjunction with the drug storage structure 2, which includes a drug storage bottle 201 for containing drugs, a plunger 202 for sealing one end of the drug storage bottle 201, and an injection needle 203 installed at the other end of the drug storage bottle 202.

[0070] The injection structure 1 is roughly pen-shaped and has an axial direction. The two opposite ends of the injection structure 1 along the axial direction are referred to as the proximal end and the distal end, respectively. The proximal end is the end that is inserted into the human body during injection, and the distal end is the end that is away from the human body.

[0071] The injection structure 1 includes a housing assembly 100, a rotating cylinder 200, a knob 300, a tension spring 400, and a central push rod 500. The central push rod 500, rotating cylinder 200, and housing assembly 100 are arranged sequentially from the inside out. The central push rod 500 is threadedly connected to the housing assembly 100. The knob 300 is installed at the distal end of the housing assembly 100 and forms a circumferential limiting connection and an axial sliding connection with the rotating cylinder 200. The tension spring 400 is sleeved on the outside of the rotating cylinder 200, with its distal end fixedly connected to the housing assembly 100 and its proximal end fixedly connected to the rotating cylinder 200. The knob 300 is used to drive the rotating cylinder 200 and the proximal end of the tension spring 400 to rotate forward for positive adjustment. In the injection metering process, the housing assembly 100 is used to limit the reverse rotation of the rotating cylinder 200 driven by the forward rotational force stored by the tension spring 400. During injection, the rotating cylinder 200 is pushed proximally to disengage it from the rotational restriction of the knob 300 and the housing assembly 100 until the rotating cylinder 200 forms a circumferential limiting connection with the central push rod 500. The tension spring 400 releases its rotational elastic force to rotate the rotating cylinder 200 and the central push rod 500 in the opposite direction. As the central push rod 500 rotates in the opposite direction, it pushes the plunger 202 proximally to achieve injection.

[0072] It should be noted that "forward" and "backward" here refer to two opposite directions. Forward can be either clockwise or counterclockwise; when forward is clockwise, backward is counterclockwise; when forward is counterclockwise, backward is clockwise.

[0073] It should be noted that the circumferential limiting connection between the knob 300 and the rotating cylinder 200 means that the relative movement of the knob 300 and the rotating cylinder 200 in the circumferential direction is restricted, allowing the knob 300 and the rotating cylinder 200 to rotate synchronously. The axial sliding connection between the knob 300 and the rotating cylinder 200 means that the knob 300 and the rotating cylinder 200 can slide relative to each other in the axial direction; for example, when the rotating cylinder 200 slides in the axial direction, the knob 300 remains stationary.

[0074] It should be noted that the distal end of the tension spring 400 is fixedly connected to the housing assembly 100, and the proximal end of the tension spring 400 is fixedly connected to the rotating cylinder 200. When the rotating cylinder 200 rotates forward relative to the housing assembly 100, the proximal end of the tension spring 400 follows the rotation of the rotating cylinder 200 in the forward direction, and the tension spring 400 accumulates a reverse rotational elastic force. When the rotating cylinder 200 is freed from the rotational restriction of the knob 300 and the housing assembly 100, the tension spring 400 can release the reverse rotational elastic force to rotate the rotating cylinder 200 in the reverse direction until the proximal end of the tension spring 400 is reset. That is, when the dosage is set, the rotating cylinder 200 rotates forward by a first angle, and when injected, the tension spring 400 can rotate the rotating cylinder 200 and the central push rod 500 in the reverse direction by a first angle. At this time, the tension spring 400 and the rotating cylinder 200 reset circumferentially. Since the central push rod 500 is threadedly connected to the housing assembly 100, its reverse rotation by a first angle simultaneously pushes the plunger 202 proximally to achieve injection. This converts the rotational motion of the central push rod 500 into axial sliding to push the plunger 202, thus eliminating the need for the central push rod 500 to extend distally into the housing assembly 100 for positive dose adjustment. Specifically, a relationship can be established between the first reverse rotation angle of the central push rod 500 and the first axial movement of the plunger 202 by the central push rod 500. This allows the design of the first reverse rotation angle of the central push rod 500 based on the required injection volume, thereby obtaining the first forward rotation angle of the knob 300 during positive dose adjustment.

[0075] It should be noted that the housing assembly 100 is used to limit the reverse rotation of the rotating cylinder 200 driven by the forward rotation of the tension spring 400, so that when the rotating cylinder 200 rotates forward by a first angle, it can be limited by the housing assembly 100 and stay at that position, instead of being pulled by the tension spring 400 to rotate in the reverse direction.

[0076] It should be noted that pushing the rotating cylinder 200 towards the proximal end to disengage the rotating cylinder 200 from the rotational restriction of the knob 300 and the housing assembly 100 means that when the rotating cylinder 200 is moved a preset distance towards the proximal end, the circumferential limiting connection between the rotating cylinder 200 and the knob 300 will be released, and the circumferential restriction of the housing assembly 100 on the rotating cylinder 200 will also be released, so that the rotating cylinder 200 can be reversed and reset by the tension spring 400.

[0077] The injection structure 1 in this embodiment, through the arrangement of the housing assembly 100, rotating cylinder 200, knob 300, tension spring 400 and central push rod 500, allows for positive dose adjustment by simply rotating the knob 300 to drive the rotating cylinder 200 and tension spring 400 to rotate forward by a first angle, utilizing the rotational elastic force of the tension spring 400 for energy storage. During injection, the rotating cylinder 200 is pushed proximally to connect the rotating cylinder 200 and the central push rod 500, so that when the tension spring 400 releases its rotational elastic force to drive the rotating cylinder 200 to rotate in the opposite direction, it can simultaneously drive the central push rod 500 to rotate in the opposite direction. Simultaneously, the central push rod 500, while rotating in the opposite direction, can push the plunger 202 proximally to achieve injection. In general, in this application, the central push rod 500 is driven by the rotational elastic force of the tension spring 400 to push the plunger 202 axially to achieve injection. When injecting a large dose, it is only necessary to increase the rotation angle of the knob 300. Before injection, it is not necessary to extend the central push rod 500 a long distance to the distal end of the housing assembly 100 to achieve a large dose injection. This makes it easy for users with small hands and children to complete the injection process even when a large dose injection is required.

[0078] In some embodiments, please refer to Figure 3 and Figure 4 The injection structure 1 also includes a button 600 and a first elastic element 700. The button 600 and the distal end of the rotating cylinder 200 form an axial limiting connection and a rotational connection. The first elastic element 700 is connected to the button 600 and is used to axially reset the button 600 and the rotating cylinder 200 pushed in the proximal direction to the distal end.

[0079] The button 600 and the rotary cylinder 200 form an axial limiting connection and a rotational connection at their far ends. This means that the button 600 and the rotary cylinder 200 move synchronously along the axial direction, and the button 600 and the rotary cylinder 200 can rotate relative to each other. So when the knob 300 rotates with the rotary cylinder 200, the button 600 will not rotate with the rotary cylinder 200.

[0080] In practical applications, the first elastic element 700 is initially in a naturally stretched state. During injection, pressing the button 600 axially moves the rotating cylinder 200 a preset distance towards the proximal end. At this time, the first elastic element 700 is compressed axially and accumulates axial force. After the rotating cylinder 200 and the button 600 are rotated in the opposite direction by the tension spring 400 to complete the circumferential reset, the first elastic element 700, along with the rotating cylinder 200 and the button 600, resets axially. In this embodiment, the first elastic element 700 is used to achieve the axial reset of the rotating cylinder 200, and the button 600 is used to connect the rotating cylinder 200 and the first elastic element 700. The button 600 facilitates the axial pushing of the rotating cylinder 200, making the pushing convenient and effortless. It is understood that in other embodiments of this application, the button 600 may not be provided, and the rotating cylinder 200 may be directly connected to the first elastic element 700; this is not a unique limitation.

[0081] For some specific embodiments, please refer to Figure 3 and Figure 4 The button 600 includes a pressing plate 610, a first surrounding plate 620 formed on the periphery of the proximal end face of the pressing plate 610, and a central post 630 forming the center of the proximal end face of the pressing plate 610. A first locking block 640 is formed on the proximal outer peripheral surface of the central post 630. A first limiting ring 220 is protruding from the inner peripheral wall of the rotating cylinder 200 near its distal end. During assembly, the central post 630 is inserted into the rotating cylinder 200, the first locking block 640 is engaged from the distal side of the first limiting ring 220 and abuts against the proximal side of the first limiting ring 220, and the proximal end face of the pressing plate 610 abuts against the distal end face of the rotating cylinder 200, thereby forming an axial limiting connection between the button 600 and the rotating cylinder 200, so that the button 600 and the rotating cylinder 200 move synchronously along the axial direction. Meanwhile, since the first locking block 640 abuts against the near side of the first limiting ring 220, there is no circumferential limitation between the first locking block 640 and the first limiting ring 220, and the outer peripheral surface of the central column 630 rotates and engages with the inner peripheral surface of the first limiting ring 220, thereby forming a rotational connection between the button 600 and the rotating cylinder 200.

[0082] In some embodiments, please refer to Figure 3 , Figure 6 and Figure 7The knob 300 has a first central hole 340. The distal end of the rotating cylinder 200 passes through the first central hole 340. The inner wall of the first central hole 340 is provided with first limiting ribs 350 distributed circumferentially. The first limiting ribs 350 extend axially. A first limiting groove 360 ​​is formed between two adjacent first limiting ribs 350. The outer peripheral wall of the rotating cylinder 200 is provided with a second limiting rib 230. The second limiting rib 230 can be inserted axially into the first limiting groove 360. The second limiting rib 230 and the first limiting groove 360 ​​form an axial sliding fit to realize the axial sliding connection between the knob 300 and the rotating cylinder 200. The first limiting rib 350 and the second limiting rib 230 form a circumferential limit to realize the circumferential limiting connection between the knob 300 and the rotating cylinder 200. Furthermore, the first limiting rib 350 and the second limiting rib 230 have a first length along the axial direction. When the rotating cylinder 200 is driven to move a preset distance axially towards the proximal end by the button 600, the second limiting rib 230 disengages axially from the first limiting rib 350, causing the rotating cylinder 200 to disengage from the rotation restriction of the knob 300. Additionally, when the tension spring 400 rotates the rotating cylinder 200 in the opposite direction to reset, the second limiting rib 230 on the rotating cylinder 200 corresponds to the first limiting groove 360 ​​of the knob 300, allowing the rotating cylinder 200 to reset axially under the action of the first elastic element 700, so that the first limiting rib 350 and the second limiting rib 230 re-achieve circumferential limiting.

[0083] Preferably, the first limiting ribs 350 are evenly distributed along the circumference of the knob 300, the number of the second limiting ribs 230 is less than the number of the first limiting ribs 350, and the second limiting ribs 230 are connected to a portion of the first limiting ribs 350.

[0084] For some specific embodiments, please refer to Figure 3 , Figure 6 and Figure 7The knob 300 includes an inner cylinder 310, an outer cylinder 320, and a connecting plate 330. The inner cylinder 310 and the outer cylinder 320 are coaxially arranged, and the connecting plate 330 connects the inner cylinder 310 and the outer cylinder 320. The distal end of the inner cylinder 310, the distal end of the outer cylinder 320, and the connecting plate 330 together form a first annular groove 370, and the proximal end of the inner cylinder 310, the proximal end of the outer cylinder 320, and the connecting plate 330 together form a second annular groove 380. The inner cylinder 310 is sleeved on the outside of the rotating cylinder 200, and a first limiting rib 350 is formed on the inner peripheral wall of the inner cylinder 310. The outer cylinder 320 is sleeved on the button 60. The first enclosure plate 620 and the outer distal end of the housing assembly 100 are respectively; the first elastic element 700 is disposed in the first annular groove 370, the proximal end of the first elastic element 700 abuts against the connecting plate 330, and the distal end of the first elastic element 700 abuts against the pressing plate 610, so as to limit the first elastic element 700 and prevent the button 600 and the first elastic element 700 from shaking; the first enclosure plate 620 is inserted into the first annular groove 370, the outer peripheral surface of the first enclosure plate 620 is clearance-fitted with the inner peripheral surface of the outer cylinder 320, and the proximal end face of the first enclosure plate 620 abuts against the connecting plate 330 to limit the axial travel of the first enclosure plate 620.

[0085] For details, please refer to Figure 6 The outer cylinder 320 has multiple friction ribs 321 distributed on its outer circumferential surface. Each friction rib 321 extends along the axial direction and is distributed at intervals along the circumference. The friction ribs 321 are used to increase the friction of the outer cylinder 320, making it easier for the user to rotate the knob 300, which is non-slip and saves effort.

[0086] For details, please refer to Figure 3 , Figure 7 and Figure 34 The inner peripheral wall of the outer cylinder 320 is recessed with a third annular groove 322, and the outer peripheral wall of the far end of the housing assembly 100 is provided with an annular rib 112. The annular rib 112 and the third annular groove 322 are engaged to form an axial limit between the knob 300 and the housing assembly 100.

[0087] In some embodiments, please refer to Figure 2The injection structure 1 further includes a second fixing sleeve 800 and a first fixing sleeve 900. The second fixing sleeve 800 and the first fixing sleeve 900 are axially spaced and located between the housing assembly 100 and the rotating cylinder 200. The second fixing sleeve 800 is fixedly connected to the rotating cylinder 200, and the first fixing sleeve 900 is fixedly connected to the housing assembly 100. The proximal end and the distal end of the tension spring 400 are respectively housed in the second fixing sleeve 800 and the first fixing sleeve 900. The proximal end of the tension spring 400 is fixedly connected to the second fixing sleeve 800, and the distal end of the tension spring 400 is fixedly connected to the first fixing sleeve 900. The second fixing sleeve 800 and the first fixing sleeve 900 are provided to limit and fix the tension spring 400. It is understood that in other embodiments of this application, the second fixing sleeve 800 and the first fixing sleeve 900 may not be provided, and the proximal end and the distal end of the tension spring 400 may be directly connected to the rotating cylinder 200 and the housing assembly 100, respectively. This is not a unique limitation.

[0088] For some specific embodiments, please refer to Figure 3 , Figure 8 and Figure 9 The first fixing sleeve 900 includes a first annular plate 920, a first sleeve body 910 formed at the proximal end of the first annular plate 920, and a peripheral first flange 930 formed at the distal end of the first annular plate 920. Both the first sleeve body 910 and the first flange 930 are cylindrical, with the outer diameter of the first sleeve body 910 being smaller than the outer diameter of the first flange 930. The distal end face of the first annular plate 920 and the first flange 930 enclose a receiving space for accommodating the second limiting rib 230. A second annular plate 940 extends radially outward from the distal end of the first flange 930, and the distal end face of the second annular plate 940 abuts against the proximal end face of the connecting plate 330 to achieve axial positioning of the knob 300 and the first fixing sleeve 900. The first annular plate 920 has a shaped hole 921 for the rotating cylinder 200 and the second limiting rib 230 to pass through. The first body 910 is sleeved outside the rotating cylinder 200, and the distal end of the tension spring 400 is stored between the first body 910 and the rotating cylinder 200.

[0089] For details, please refer to Figure 5 and Figure 9 A first hook groove 922 is formed on the distal side of the first annular plate 920, and a first hook portion 410 is provided at the distal end of the tension spring 400. The first hook portion 410 is fixed in the first hook groove 922 via a shaped hole 921.

[0090] For details, please refer to Figure 8 and Figure 34The outer peripheral wall of the first flange 930 is provided with a first axially extending protruding strip 931, and the inner peripheral wall of the housing assembly 100 is also provided with a first axially extending groove 113 that penetrates the distal end of the housing assembly 100. The first protruding strip 931 and the first groove 113 are inserted into each other to guide the axial assembly of the first fixing sleeve 900 and the housing assembly 100. In addition, the outer peripheral wall of the first flange 930 is provided with a second locking block 932, and the inner peripheral wall of the housing assembly 100 is provided with a second locking groove 114. The second locking block 932 and the second locking groove 114 are engaged to achieve a fixed connection between the first fixing sleeve 900 and the housing assembly 100.

[0091] In some embodiments, please refer to Figures 10 to 14 The second fixing sleeve 800 includes a cylindrical second sleeve body 810 and a third annular plate 820 extending radially inward from the proximal end of the second sleeve body 810. A first hook 830 protrudes from the side of the third annular plate 820 opposite to the second sleeve body 810. A fourth annular plate 240 protrudes from the outer peripheral wall of the rotating cylinder 200, forming a first groove 241. The first hook 830 engages with the first groove 241 to form a fixed connection between the second fixing sleeve 800 and the rotating cylinder 200. Furthermore, a third limiting rib 840 protrudes from the inner peripheral surface of the second sleeve body 810, and a fourth limiting rib 250 protrudes from the outer peripheral wall of the rotating cylinder 200. The third limiting rib 840 is inserted between two adjacent fourth limiting ribs 250 to form a circumferential limiting connection between the rotating cylinder 200 and the second fixing sleeve 800, thereby enabling the rotating cylinder 200 and the first fixing sleeve 900 to rotate synchronously.

[0092] For details, please refer to Figure 14 The third annular plate 820 has an opening groove 821 formed on the side opposite to the second sleeve 810. The proximal end of the tension spring 400 has a second hook portion 420. The proximal end of the tension spring 400 is limited between the rotating cylinder 200 and the second sleeve 810. The proximal end of the tension spring 400 abuts against the bottom surface of the third annular plate 820. The second hook portion 420 of the tension spring 400 is fixed in the opening groove 821 so that the tension spring 400 is fixedly connected to the second fixed sleeve 800.

[0093] In some embodiments, please refer to Figure 10 The injection structure 1 also includes a dose rotating cylinder 1000, which forms a circumferential limiting connection and an axial sliding connection with the second fixed sleeve 800. The dose rotating cylinder 1000 is threadedly connected to the housing assembly 100. The surface of the dose rotating cylinder 1000 is provided with a dose mark 1001, and the housing assembly 100 is provided with a window 140 for reading the dose mark 1001.

[0094] Because the dose-dispensing cylinder 1000 and the second fixed sleeve 800 form a circumferential limiting connection, when the rotating cylinder 200 rotates forward with the second fixed sleeve 800, the second fixed sleeve 800 can also rotate forward with the dose-dispensing cylinder 1000. Furthermore, because the dose-dispensing cylinder 1000 is threadedly connected to the housing assembly 100, it can move proximally along the housing assembly 100 when rotating forward. This allows different axial positions of the dose-dispensing cylinder 1000 to correspond to different dose markers 1001, enabling the user to read different dose markers 1001 outside the housing assembly 100. For example, initially, the dose marker 1001 facing the window 140 is 0. As the dose-dispensing cylinder 1000 is moved proximally by the rotating cylinder 200, the value of the dose marker 1001 facing the window 140 gradually increases until the desired dose is reached, at which point the rotation of the knob 300 stops.

[0095] In practical applications, the rotation angle of knob 300 can be converted and matched one-to-one with the value of dose mark 1001, so that the value of dose mark 1001 corresponds exactly to the injection volume, thus making it easier for users to control the injection volume each time.

[0096] Furthermore, since the dose rotating cylinder 1000 and the second fixed sleeve 800 form an axial sliding connection, when the dose rotating cylinder 1000 slides axially, the second fixed sleeve 800 and the rotating cylinder 200 will not slide axially along with the dose rotating cylinder 1000.

[0097] For some specific embodiments, please refer to Figures 13 to 16 The outer peripheral wall of the second fixed sleeve 800 is provided with a plurality of second protrusions 850 distributed sequentially along the circumference. The second protrusions 850 extend axially. The inner peripheral wall of the dose rotating cylinder 1000 is provided with a second groove 1002. The second groove 1002 extends axially. Each second protrusion 850 and each second groove 1002 correspond to each other and slide in axial direction, thereby forming a circumferential limiting connection and an axial sliding connection between the dose rotating cylinder 1000 and the second fixed sleeve 800.

[0098] Preferably, when the second protrusion 850 engages with the second groove 1002, the outer peripheral surface of the second fixing sleeve 800 does not fully contact the inner peripheral surface of the dose rotating cylinder 1000, thereby reducing the friction between the dose rotating cylinder 1000 and the second fixing sleeve 800.

[0099] Specifically, the widths of the second protrusions 850 along the circumference are not exactly the same, and the widths of the second grooves 1002 along the circumference are not exactly the same, which can play a role in preventing mistakes and preventing incorrect assembly.

[0100] For details, please refer to Figure 15 and Figure 35The outer peripheral surface of the dose cylinder 1000 has a first external thread 1003, and the inner peripheral wall of the housing assembly 100 has a first internal thread 115. The dose cylinder 1000 and the housing assembly 100 are connected by a threaded connection through the first external thread 1003 and the first internal thread 115.

[0101] In some embodiments, the housing assembly 100 has a third limiting portion and the dose rotating cylinder 1000 has a fourth limiting portion. The third limiting portion and the fourth limiting portion cooperate with each other to limit the maximum stroke of the dose rotating cylinder 1000 in the forward direction, that is, to limit the maximum dose in a single dose.

[0102] For details, please refer to Figure 15 The dose cylinder 1000 has a first cross-section 1004 extending axially at the proximal thread stop position. The distal end face of the first internal thread 115 rotates and contacts the first cross-section 1004 of the dose cylinder 1000 to limit further rotation of the dose cylinder 1000 proximally. The third limiting portion includes the distal end face of the first internal thread 115, and the fourth limiting portion includes the first cross-section 1004.

[0103] In some embodiments, the first fixing sleeve 900 has a first limiting part, and the dosing cylinder 1000 has a second limiting part. The first limiting part and the second limiting part cooperate with each other to limit the retraction of the dosing cylinder 1000 when it is at the zero position. When the dosing cylinder 1000 is at the zero position, it indicates that the normal adjustment has not yet started or the medicine in the medicine bottle 201 has been used up. At this time, the first limiting part and the second limiting part can be used to limit the retraction of the dosing cylinder 1000.

[0104] In some embodiments, please refer to Figure 8 and Figure 15 The distal end of the dose rotating cylinder 1000 has a second cross section 1005. The outer peripheral surface of the first fixing sleeve 900 is provided with a third protruding rib 950. The third protruding rib 950 has a longitudinal side facing the second cross section 1005 in the circumferential direction. The longitudinal side is used to contact and cooperate with the second cross section 1005 to circumferentially limit the zero-scale return of the dose rotating cylinder 1000. That is, when the dose rotating cylinder 1000 is in the zero-degree return state, the longitudinal side abuts against the second cross section 1005.

[0105] Specifically, the proximal end of the third rib 950 has a first inclined surface 951, the second cross-section 1005 has a notch, and the distal end of the notch has a second inclined surface 1006. The first inclined surface 951 and the second inclined surface 1006 abut against each other for axial and circumferential fixation of the first fixing sleeve 900 and the dosing cylinder 1000 during assembly. The second limiting part includes the second cross-section 1005 and the second inclined surface 1006, and the first limiting part includes the third rib 950 and the first inclined surface 951.

[0106] In some embodiments, please refer to Figures 17 to 20 The injection structure 1 also includes a memory element 1800, which is sleeved between the rotating cylinder 200 and the central push rod 500. The memory element 1800 and the rotating cylinder 200 form a circumferential limiting connection and an axial sliding connection. The memory element 1800 and the central push rod 500 are threadedly connected. During forward adjustment, the memory element 1800 is driven by the rotating cylinder 200 to move distally on the central push rod 500. During reverse adjustment, the memory element 1800 is driven by the rotating cylinder 200 to move proximally on the central push rod 500. During injection, the memory element 1800 and the central push rod 500 rotate synchronously and move proximally together. The distal end of the central push rod 500 is a threadless end 540 to limit the memory element 1800 located at the threadless end 540 of the central push rod 500 from continuing to rotate forward for forward adjustment, thereby limiting the continued adjustment of the set dose beyond the dose of the drug reservoir 201.

[0107] Specifically, during forward adjustment, because the memory element 1800 and the rotating cylinder 200 form a circumferential limiting connection, the rotating cylinder 200 can rotate forward along with the memory element 1800. The memory element 1800 is threadedly connected to the central push rod 500, allowing the memory element 1800 to move a second distance distally along the central push rod 500 while rotating forward. During injection, the rotating cylinder 200, the memory element 1800, and the central push rod 500 synchronously reverse direction. Simultaneously, the central push rod 500 moves a second distance proximally. At this time, because the memory element 1800 and the rotating cylinder 200 form an axial sliding connection, the memory element 1800 follows the central push rod 500 proximally, moving a second distance back to its initial position relative to the rotating cylinder 200, while the axial position of the rotating cylinder 200 remains unchanged. In general, after each adjustment and injection, the axial position of the memory element 1800 relative to the rotating cylinder 200 remains unchanged, and the memory element 1800 moves a second distance distally relative to the central push rod 500. After the dose in the reservoir 201 is injected, the memory element 1800 moves to the unthreaded end 540 of the central push rod 500, preventing the memory element 1800 from rotating forward relative to the central push rod 500. In other words, the unthreaded end 540 of the central push rod 500 prevents the memory element 1800 and the rotating cylinder 200 from rotating forward for adjustment. This design prevents the user from continuing to adjust or reverse the dosage after it has been used up. Furthermore, the memory element 1800 enables the reservoir 201 to retain its memory function. Also, after the medication is used up, the reservoir 201 can be reinstalled by rotating the central push rod 500, thus allowing the syringe to be reused.

[0108] In some embodiments, please refer to Figure 18 and Figure 19The memory element 1800 includes a memory cylinder 1810, a seventh protrusion 1820, and a fourth internal thread 1830. The memory cylinder 1810 is cylindrical, the seventh protrusion 1820 protrudes from the outer circumferential surface of the memory cylinder 1810, and the fourth internal thread 1830 is formed on the inner circumferential surface of the memory cylinder 1810. The memory cylinder 1810 is sleeved around the central push rod 500. The fourth internal thread 1830 is used for threaded connection with the second external thread 520 of the central push rod 500. The seventh protrusion 1820 is axially slidably disposed in the seventh groove (not shown) of the rotating cylinder 200, forming a circumferential limiting connection and an axial sliding connection between the memory element 1800 and the rotating cylinder 200.

[0109] In some embodiments, please refer to Figure 10 , Figure 21 and Figure 22 The injection structure 1 also includes a magnifying glass 1100 and a viewing window 1200. The viewing window 1200 is mounted on the outside of the housing assembly 100, and the magnifying glass 1100 is mounted on the viewing window 1200. The magnifying glass 1100 is positioned facing the window 140 to magnify the dose value for easy observation by the user.

[0110] In some embodiments, please refer to Figure 10 , Figure 21 and Figure 22 The window 1200 has an arc-shaped sheet structure and is attached to the outer peripheral surface of the housing assembly 100. A positioning post 1201 protrudes from the inner surface of the window 1200, and a positioning hole 131 is formed in the side wall of the housing assembly 100. The positioning post 1201 and the positioning hole 131 engage in a recessed-convex fit to position the window 1200 on the housing assembly 100. Furthermore, the positioning post 1201 is welded to the positioning hole 131 to fix the window 1200 to the housing assembly 100.

[0111] For details, please refer to Figure 10 , Figure 21 and Figure 22 The window 1200 has a first through slot 1202 and a second through slot 1203. The first through slot 1202 extends from the outer side of the window 1200 to the second through slot 1203, and the second through slot 1203 extends from the inner side of the window 1200 to the first through slot 1202. The length and width of the second through slot 1203 are larger than the length and width of the first through slot 1202. The first through slot 1202 is directly opposite to the window 140. The magnifying glass 1100 is a convex lens. The magnifying glass 1100 includes a first lens body 1101 and a second lens body 1102 connected to each other. The first lens body 1101 is accommodated in the first through slot 1202 and extends outward from the first through slot 1202. The second lens body 1102 is accommodated in the second through slot 1203. The inner side of the second lens body 1102 abuts against the outer peripheral surface of the housing assembly 100.

[0112] In some embodiments, please refer to Figure 17 The housing assembly 100 also includes a rotation limiting component 1300. The rotation limiting component 1300 restricts the reverse rotation of the rotating cylinder 200 driven by the forward rotation of the tension spring 400. When the rotating cylinder 200 moves a preset distance proximally, the rotation limiting component 1300 axially disengages from the housing assembly 100, releasing the restriction on the reverse rotation of the rotating cylinder 200. Specifically, when the knob 300 drives the rotating cylinder 200 to rotate forward by a first angle, the rotation limiting component 1300 prevents the rotating cylinder 200 from being reverse-reset by the tension spring 400. During injection, when the rotating cylinder 200 is moved a preset distance proximally, the rotation limiting component 1300 is also moved axially by the rotating cylinder 200 and disengages from the housing assembly 100. This removes the restriction on the reverse rotation of the rotating cylinder 200, allowing it to be reverse-reset by the tension spring 400 and rotate in the opposite direction with the central push rod 500 to achieve injection. It is understood that in other embodiments of this application, the rotation limiting component 1300 may not be provided, and the rotating cylinder 200 may be directly limited to the reverse rotation by the housing component 100. This is not the only limitation.

[0113] In some embodiments, please refer to Figures 23 to 26 The rotation limiting assembly 1300 includes a rotation limiting movable member 1310 and a rotation limiting fixed member 1320. The rotation limiting movable member 1310 is sleeved between the rotating cylinder 200 and the rotation limiting fixed member 1320, and the rotation limiting fixed member 1320 forms a circumferential limiting connection with the housing assembly 100. The inner circumferential wall of the rotation limiting fixed member 1320 has a plurality of first positive teeth 1324, and the outer circumferential wall of the rotation limiting movable member 1310 has second positive teeth 1312. The forward rotation of the rotating cylinder 200 can drive the rotation limiting movable member 1310 to rotate in the forward direction. The first forward teeth 1312 sequentially engage with the first forward teeth 1324, and the first forward teeth 1324 restrict the second forward teeth 1312 from rotating in the opposite direction. The rotation-limiting fixing member 1320 forms an axial sliding connection with the housing assembly 100. When the rotating cylinder 200 moves towards the proximal end, it will drive the rotation-limiting fixing member 1320 to move together. When it moves a preset distance, the rotation-limiting fixing member can disengage from the circumferential restriction of the housing assembly 100, so that the rotation-limiting fixing member 1320 and the rotating cylinder 200 can synchronously reverse under the drive of the storage torsion spring 400. In this embodiment, the reverse rotation of the rotating cylinder 200 is limited by the interaction between the first forward teeth 1324 and the second forward teeth 1312.

[0114] In addition, please see Figure 11 and Figure 12The rotating cylinder 200 extends with a third hook 270, which is used to hook onto the rotation-limiting fixing member 1320 so that the rotation-limiting fixing member 1320 can move axially synchronously with the rotating cylinder 200. Specifically, the third hook 270 is formed on the proximal end face of the fourth annular plate 240 and hooks onto the proximal end face of the base plate 1321.

[0115] In some embodiments, please refer to Figure 12 , Figures 23 to 26 The portion connected to the second forward tooth 1312 of the rotation limiting component 1310 is elastic. The second forward tooth 1312 is also connected to a first guide rod 1313. The rotating cylinder 200 has a first guide groove 242, and the first guide rod 1313 is slidably disposed in the first guide groove 242. When the rotating cylinder 200 rotates in the reverse direction, the first guide groove 242 guides the first guide rod 1313 towards the center of the rotating cylinder 200, thereby causing the second forward tooth 1312 to retract towards the center of the rotating cylinder 200 to reduce the distance between it and the first forward tooth 1324. This allows the second forward tooth 1312 to rotate and bounce in the reverse direction on the first forward tooth 1324 to achieve a correction when overdosing is adjusted. This configuration ensures that when a user adjusts the dose in the forward direction by rotating the knob 300, and the user rotates the knob too far, requiring a reverse correction of the dose, the rotation limiting component 1300 restricts the reverse rotation of the rotating cylinder 200. The first guide groove 242 and the first guide rod 1313 are designed to guide the first guide rod 1313 and the second forward tooth 1312 to move away from the first forward tooth 1324 when the rotating cylinder 200 rotates in the opposite direction, thereby reducing the resistance of the first forward tooth 1324 to the second forward tooth 1312. As a result, the rotating cylinder 200 and the rotation limiting movable member 1310 can rotate in the opposite direction relative to the rotation limiting fixed member 1320. When rotating, the tips of the second forward teeth 1312 are sequentially engaged with the tips of the first forward teeth 1324, which can also produce a clicking sound.

[0116] For some specific embodiments, please refer to Figure 12 , Figures 23 to 26The movable limiting member 1310 includes a cylindrical limiting body 1311. The outer circumferential surface of the limiting body 1311 is clearance-fitted with the tooth end face of the first positive tooth 1324 to achieve relative rotation between the movable limiting member 1310 and the fixed limiting member 1320. The limiting body 1311 has two second positive teeth 1312 distributed circumferentially. The limiting body 1311 has an opening near the two second positive teeth 1312, which penetrates the distal end face of the limiting body 1311 so that the limiting body 1311 has elasticity at the position corresponding to the second positive teeth 1312. The first guide rod 1313 protrudes from the distal end face of the limiting body 1311. The first guide groove 242 is formed on the proximal end face of the fourth annular plate 240 of the rotating cylinder 200. The first guide groove 242 is an irregular groove that extends from the position near the outer edge of the rotating cylinder 200 towards the center to guide the first guide rod 1313 to slide towards the center.

[0117] Please see Figure 12 , Figures 23 to 26 The distal end face of the rotation-limiting movable part 1310 also has a second guide rod 1314, and the proximal end face of the fourth annular plate 240 also has a second guide groove 243. The second guide groove 243 extends circumferentially, and the second guide rod 1314 is slidably disposed in the second guide groove 243 circumferentially to ensure the rotational stability of the rotating cylinder 200 and the rotation-limiting movable part 1310.

[0118] In some embodiments, please refer to Figures 23 to 26 The rotation limiting movable member 1310 also includes a third flange 1315, which is cylindrical. The third flange 1315 extends axially from the proximal inner peripheral wall of the rotation limiting body 1311 and extends beyond the proximal end face of the rotation limiting body 1311. A first stepped surface 1316 is formed between the third flange 1315 and the rotation limiting body 1311. The rotation limiting fixed member 1320 has a second stepped surface 1325. The first stepped surface 1316 abuts against the second stepped surface 1325. The distal end face of the rotation limiting body 1311 abuts against the proximal end face of the fourth annular plate 240 to form an axial limit of the rotation limiting movable member 1310.

[0119] In some embodiments, please refer to Figure 25 , Figure 26 and Figure 34The rotation limiting fastener 1320 includes a base plate 1321, a second surrounding plate 1322 formed on the proximal end face of the base plate 1321, and a third surrounding plate 1323 formed on the distal end face of the base plate 1321. First positive teeth 1324 are formed on the inner circumferential surface of the third surrounding plate 1323 and the distal end face of the base plate 1321. A sixth protrusion 1327 is formed on the outer circumferential surface of the third surrounding plate 1323 and the distal end face of the base plate 1321. A sixth groove 116 is formed on the inner circumferential surface of the housing assembly 100. The sixth protrusion 1327 and the sixth groove 116 are in a convex-concave fit. The base plate 1321 has a second central hole 1326 at its center. A third flange 1315 is inserted into the second central hole 1326. The second stepped surface 1325 is the distal end face of the base plate 1321. In addition, the distal end face of the base plate 1321 abuts against the third step surface 1161 at the location where the sixth groove 116 is formed on the housing assembly 100, so as to restrict the movement of the rotation limiting fastener 1320 in the distal direction.

[0120] In some embodiments, please refer to Figure 27 The injection structure 1 also includes an outer push rod 1400, which is sleeved outside the central push rod 500. The outer push rod 1400 and the central push rod 500 form a circumferential limiting connection. The distal end of the outer push rod 1400 is provided with a first meshing tooth 1440, and the proximal end of the rotating cylinder 200 is provided with a second meshing tooth 260. During injection, after the rotating cylinder 200 moves a preset distance towards the proximal end, the first meshing tooth 1440 and the second meshing tooth 260 mesh axially to form a circumferential limiting connection. At this time, the rotating cylinder 200 is released from the rotation restriction of the knob 300 and the housing assembly 100. The tension spring 400 releases the rotational elastic force to rotate the rotating cylinder 200, the outer push rod 1400 and the central push rod 500 in the opposite direction. While the central push rod 500 rotates in the opposite direction, it pushes the plunger 202 to move towards the proximal end to realize the injection. The outer push rod 1400 is provided to facilitate the circumferential limiting connection between the rotating cylinder 200 and the central push rod 500. It is understood that in other embodiments of this application, the outer push rod 1400 may not be provided, and the rotating cylinder 200 and the central push rod 500 may be directly connected in a circumferential limiting manner; this is not the only limitation.

[0121] In some embodiments, please refer to Figure 27The injection structure 1 also includes an anti-reset component 1600, which restricts the forward rotation of the central push rod 500 to prevent its axial reset. Furthermore, when the drug reservoir 2 is separated from the housing assembly 100, the anti-reset component 1600 releases the restriction on the forward rotation of the central push rod 500. This configuration ensures that the central push rod 500 will not reset axially after each injection. During the next injection, the central push rod 500 can be directly pushed proximally for injection. Moreover, after the dose is administered, the central push rod 500 can only be reset by detaching the drug reservoir 2 and removing the empty drug reservoir 201, thus enabling the reuse of the syringe.

[0122] In some embodiments, please refer to Figure 27The anti-reset assembly 1600 includes an anti-forward rotation fixed member 1610, an anti-forward rotation movable member 1620, an anti-reverse rotation movable member 1650, a second elastic member 1630, and a third elastic member 1640. The anti-reverse rotation movable member 1650 forms an axial sliding connection and a circumferential limiting connection with the central push rod 500. The anti-forward rotation fixed member 1610 is fixed to the housing assembly 100. The anti-forward rotation movable member 1620 is sleeved outside the outer push rod 1400 and forms an axial sliding connection and a circumferential limiting connection with the outer push rod 1400. The second elastic member 1630 is sleeved outside the outer push rod 1400. The third elastic member 1640 is sleeved outside the second elastic member 1630 and abuts against the anti-forward rotation fixed member. Between 1610 and the anti-reverse movable member 1650; the anti-forward rotation movable member 1620 has a third reverse tooth 1622, the anti-forward rotation fixed member 1610 has a fourth reverse tooth 1613, the anti-reverse movable member 1650 has a third forward tooth 1654, and the outer push rod 1400 has a fourth forward tooth 1450; when the drug storage structure 2 is installed on the housing assembly 100, the drug storage structure 2 pushes the anti-reverse movable member 1650 to the distal end so that the second elastic member 1630 and the third elastic member 1640 are both in a compressed state, so that the second elastic member 1630 abuts against the anti-reverse movable member 1620 and the outer push rod 1400, so that the third reverse tooth 1622 and the fourth reverse tooth 1654 are compressed. 613 engages axially, causing the third forward tooth 1654 and the fourth forward tooth 1450 to engage axially; when the drug storage structure 2 is detached from the housing assembly 100, the anti-reverse movable member 1650 is pushed proximally by the third elastic member 1640, the third elastic member 1640 is in a naturally stretched state, and the second elastic member 1630 is in a naturally stretched state with at least one end suspended. Specifically, when the injection structure 1 is placed with the distal end facing down, the proximal end of the second elastic member 1630 does not abut against the outer push rod 1400, and the distal end of the second elastic member 1630 contacts the anti-forward movable member 1620, so that the third forward tooth 1654 and the fourth forward tooth 1450 engage axially. In the non-engaged state, when the central push rod 500 rotates forward, it can rotate the anti-reverse rotating member 1650 forward, thereby achieving the axial reset of the central push rod 500; or, when the injection structure 1 is placed with its proximal end facing down, the proximal end of the second elastic member 1630 abuts against the outer push rod 1400, and the distal end of the second elastic member 1630 does not contact the anti-forward rotating member 1620, so that the third reverse tooth 1622 and the fourth reverse tooth 1613 are in a non-engaged state along the axial direction. When the central push rod 500 rotates forward, it can rotate the anti-reverse rotating member 1650, the outer push rod 1400 and the anti-forward rotating member 1620 forward, thereby achieving the axial reset of the central push rod 500.

[0123] It should be noted that the forward teeth and reverse teeth described in this application are specifically different inclination directions of the tooth surfaces. When two forward teeth mesh, the two structures can rotate relative to each other in the forward direction, but cannot rotate relative to each other in the reverse direction and can only move synchronously. When two reverse teeth mesh, the two structures can rotate relative to each other in the reverse direction, but cannot rotate relative to each other in the forward direction and can only move synchronously.

[0124] Specifically, the third forward tooth 1654 is formed on the distal end face of the anti-reverse moving part 1650, and the fourth forward tooth 1450 is formed on the proximal end face of the fifth annular plate 1420 of the outer push rod 1400.

[0125] When the drug storage structure 2 is installed on the housing assembly 100, the drug storage structure 2 has a pushing force toward the distal end on the anti-reverse moving member 1650, so that the second elastic member 1630 is compressed to press the anti-forward moving member 1620 and the anti-reverse moving member 1650 against the anti-forward fixing member 1610 and the outer push rod 1400 respectively along the axial direction, so that the third reverse tooth 1622 and the fourth reverse tooth 1613 engage, and the third forward tooth 1654 and the fourth forward tooth 1450 engage. The third reverse tooth 1622 and the fourth reverse tooth 1613 mesh, allowing the anti-rotation movable member 1620 to rotate in the opposite direction relative to the anti-rotation fixed member 1610 but not in the forward direction relative to the anti-rotation fixed member 1610. The third forward tooth 1654 and the fourth forward tooth 1450 mesh, allowing the anti-reverse movable member 1650 to rotate in the forward direction relative to the outer push rod 1400 but not in the reverse direction relative to the outer push rod 1400. Therefore, when the outer push rod 1400 is driven to rotate in the opposite direction by the rotating cylinder 200, the anti-rotation movable member 1620 can rotate in the opposite direction with the rotating cylinder 200, and the anti-reverse movable member 1650 can rotate in the opposite direction synchronously with the outer push rod 1400, thereby driving the central push rod 500 to rotate in the opposite direction to achieve injection. However, when the center push rod 500 needs to be rotated in the forward direction to reset, the third forward tooth 1654 and the fourth forward tooth 1450 cannot be separated due to the abutting action of the second elastic element 1630, which causes the anti-reverse moving part 1650 to be unable to rotate in the forward direction relative to the outer push rod 1400. At the same time, due to the meshing action of the third reverse tooth 1622 and the fourth reverse tooth 1613, the center push rod 500 cannot be reset in the forward direction.

[0126] When the drug storage structure 2 is detached, the pushing force of the drug storage structure 2 on the anti-reverse movable member 1650 disappears. The anti-reverse movable member 1650 moves to the proximal end under the push of the third elastic member 1640, so that the two opposite ends of the second elastic member 1630 cannot abut against the anti-reverse movable member 1650 and the outer push rod 1400 respectively. The third forward tooth 1654 and the fourth forward tooth 1450 are in a relaxed state along the axial direction, so that when the central push rod 500 rotates in the forward direction, it can rotate the anti-reverse movable member 1650 in the forward direction. When the anti-reverse movable member 1650 rotates in the forward direction, the third forward tooth 1654 on the anti-reverse movable member 1650 jumps out of the gap between two of the fourth forward teeth 1450 of the outer push rod 1400 and jumps into the next set of fourth forward teeth 1450, thereby realizing the axial reset of the central push rod 500.

[0127] In some embodiments, please refer to Figure 27 The anti-reverse movable component 1650 forms an axial sliding connection and a circumferential limiting connection with the central push rod 500. Specifically, the anti-reverse movable component 1650 ensures an axial sliding connection between the outer push rod 1400 and the central push rod 500. This means that when the rotating cylinder 200 rotates in the opposite direction with the outer push rod 1400, the anti-reverse movable component 1650 can also cause the central push rod 500 to rotate in the opposite direction. Simultaneously, the central push rod 500 pushes the plunger 202 proximally to achieve injection. At this time, the anti-reverse movable component 1650, the outer push rod 1400, and the rotating cylinder 200 will not move axially with the central push rod 500, thus preventing them from moving proximally and causing structural interference with the housing assembly 100.

[0128] In some embodiments, please refer to Figure 20 , Figure 27 and Figure 30 The anti-reverse movable component 1650 is sleeved between the central push rod 500 and the outer push rod 1400. The inner peripheral wall of the anti-reverse movable component 1650 is provided with a third protrusion 1653. The central push rod 500 includes a rod-shaped rod body 510 and a second external thread 520 formed on the outer peripheral wall of the rod body 510. A third groove 530 is formed on the outer peripheral surface of the rod body 510. The third groove 530 disconnects the second external thread 520. The third protrusion 1653 is slidably inserted into the third groove 530 to form a circumferential limiting connection and an axial sliding connection between the anti-reverse movable component 1650 and the central push rod 500.

[0129] Specifically, the anti-reverse movable component 1650 includes a base plate 1651 and a transfer cylinder 1652 formed on the proximal end face of the base plate 1651. The anti-reverse movable component 1650 also has a third central hole 1655, which penetrates the transfer cylinder 1652 and the base plate 1651. A third protrusion 1653 is formed on the inner peripheral wall of the third central hole 1655.

[0130] In some embodiments, please refer to Figure 28 and Figure 29 The outer push rod 1400 includes a push rod cylinder 1410, a fifth annular plate 1420 formed on the outer peripheral surface of the push rod cylinder 1410 near the proximal end face, and a sixth annular plate 1430 formed on the inner peripheral surface of the push rod cylinder 1410. The central push rod 500 is disposed through the sixth annular plate 1430. The adapter cylinder 1652 of the anti-reverse movable member 1650 is inserted into the push rod cylinder 1410. The outer peripheral surface of the adapter cylinder 1652 is clearance-fitted with the inner peripheral surface of the push rod cylinder 1410, and the distal end face of the adapter cylinder 1652 is clearance-fitted with the proximal end face of the sixth annular plate 1430 to limit the axial movement of the anti-reverse movable member 1650.

[0131] In some embodiments, please refer to Figure 27 The injection structure 1 also includes a mounting member 1700, which is axially slidably disposed at the proximal opening of the housing assembly 100. A central push rod 500 passes through the mounting member 1700 and is threadedly connected to it. An anti-reverse movable member 1650 is mounted on the mounting member 1700. A third elastic member 1640 abuts between the anti-forward rotation fixing member 1610 and the mounting member 1700. The proximal end face of the mounting member 1700 abuts against the distal end face of the medicine storage bottle 201. The mounting member 1700 is configured to achieve the threaded connection between the central push rod 500 and the housing assembly 100, allowing the central push rod 500 to move proximally while rotating in the reverse direction. Furthermore, the mounting member 1700 is slidably disposed on the housing assembly 100 along the axial direction, and the proximal end face of the mounting member 1700 abuts against the distal end face of the medicine storage bottle 201, thereby enabling the mounting member 1700 to be pushed to the distal end during the installation of the medicine storage structure 2 to push the anti-reverse movable member 1650 to the distal end.

[0132] In some embodiments, please refer to Figure 27The injection structure 1 also includes a pressure member 1900, which is mounted on the distal end face of the mounting member 1700. A third elastic member 1640 abuts between the pressure member 1900 and the anti-rotation fixing member 1610. The pressure member 1900 is used to press the anti-reverse movable member 1650 against the mounting member 1700. The pressure member 1900 is configured such that when the drug storage structure 2 is installed, the pressure member 1900 can push the anti-reverse movable member 1650 to move distally; and when the liquid storage structure 2 is disassembled, the third elastic member 1640 can push the pressure member 1900, the anti-reverse movable member 1650 and the mounting member 1700 to move proximally, while the second elastic member 1630 is in a relaxed state, allowing relative movement between the outer push rod 1400 and the anti-reverse movable member 1650, that is, allowing the anti-reverse movable member 1650 to rotate forward relative to the outer push rod 1400.

[0133] In some embodiments, please refer to Figure 41 and Figure 42 The distal end face of the mounting member 1700 is provided with a protruding insert 1710, and the periphery of the pressing member 1900 has an axially penetrating slot 1910. The insert 1710 is interference-fitted into the slot 1910 to fix the pressing member 1900 onto the mounting member 1700. In addition, a fourth annular groove 1720 is formed at the center of the distal end face of the mounting member 1700. The adapter base plate 1651 of the anti-reverse movable member 1650 is inserted into the fourth annular groove 1720, and the proximal end face of the adapter base plate 1651 abuts against the bottom surface of the fourth annular groove 1720. The pressure member 1900 includes a pressure plate 1920 and an annular pressure ring 1930 protruding from the center of the near end face of the pressure plate 1920. The pressure ring 1930 is inserted into the fourth annular groove 1720 and abuts against the far end face of the adapter base plate 1651, thereby confining the anti-reverse movable member 1650 in the fourth annular groove 1720.

[0134] In some embodiments, please refer to Figures 28 to 31The outer peripheral surface of the push rod cylinder 1410 of the outer push rod 1400 has a fourth groove 1411. The anti-rotation movable member 1620 includes an anti-rotation body 1621, a third reverse tooth 1622, and a fourth protrusion 1623. The third reverse tooth 1622 is formed on the distal end face of the anti-rotation body 1621. The housing assembly 100 has a third slot 117. The anti-rotation fixing member 1610 includes a fixing base plate 1611, a fixing surrounding plate 1612, a fourth reverse tooth 1613, and a third locking block 1614. The fixing surrounding plate 1612 is formed on the distal end face of the fixing base plate 1611, the third locking block 1614 is formed on the outer peripheral surface of the fixing surrounding plate 1612, and the fourth reverse tooth 1613 is formed on the proximal end face of the fixing base plate 1611. The second enclosure 1322 of the rotation limiting fastener 1320 is inserted into the fixing enclosure 1612 of the anti-rotation fastener 1610 and is fitted with a clearance. The third locking block 1614 is inserted into the third locking groove 117 to form a fixed connection between the anti-rotation fastener 1610 and the housing assembly 100. The anti-rotation body 1621 is cylindrical and sleeved on the outside of the push rod cylinder 1410 of the outer push rod 1400. The fourth protrusion 1623 on the anti-rotation body 1621 and the fourth groove 1411 of the push rod cylinder 1410 are fitted together to form a synchronous rotational connection between the outer push rod 1400 and the anti-rotation movable part 1620. The second elastic member 1630 abuts against the proximal end face of the anti-rotation body 1621 so that the third reverse tooth 1622 and the fourth reverse tooth 1613 mesh. The third elastic member 1640 abuts against the proximal end face of the fixed base plate 1611 and the mounting part 1700.

[0135] In some embodiments, please refer to Figure 2 , Figure 3 , Figure 10 and Figure 17 The housing assembly 100 includes an injection outer shell 130, a first inner shell 110, and a second inner shell 120. The first inner shell 110 and the second inner shell 120 are axially distributed, with the proximal end of the first inner shell 110 fixedly connected to the distal end of the second inner shell 120. The first inner shell 110 and the second inner shell 120 are together sleeved on the outside of the rotating cylinder 200 and the central push rod 500. The injection outer shell 130 is sleeved on the outside of the first inner shell 110 and the second inner shell 120 to form an overall appearance. The knob 300 forms a rotational engagement with the first inner shell 110 and abuts against the distal end face of the injection outer shell 130 axially. The first fixing sleeve 900 is fixedly connected to the first inner shell 110. The first inner shell 110 is threadedly connected to the dosing cylinder 1000. The rotation limiting fixing member 1320 forms a circumferential limiting connection with the first inner shell 110. The anti-rotation fixing member 1610 is snapped into the first inner shell 110. The second elastic element 1630 and the third elastic element 1640 are both housed in the second inner shell 120. The mounting component 1700 is mounted on the second inner shell 120, and the second inner shell 120 is connected to the drug storage structure 2. The injection shell 130 is a metal injection shell 130.

[0136] For details, please refer to Figure 34 and Figure 35 The first inner shell 110 includes a cylindrical first inner shell body 111. A first internal thread 115 is formed on the inner circumferential surface of the first inner shell body 111 for threaded connection with the dosing cylinder 1000. An annular rib 112 is formed on the distal outer circumferential wall of the first inner shell body 111 for axial positioning with the knob 300. A first groove 113 is formed on the inner circumferential wall of the first inner shell body 111 for axial assembly with the first fixing sleeve 900. A second slot 114 is formed on the outer circumferential wall of the first inner shell body 111 for fixed connection with the first fixing sleeve 900. A sixth groove 116 is formed on the inner circumferential surface of the first inner shell body 111 for circumferential positioning with the rotation limiting fixing member 1320. The sixth groove 116 has a proximal opening, and a sixth protrusion 1327 can be inserted into the sixth groove 116 from the proximal port and can also be withdrawn from the sixth groove 116 from the proximal port. The third slot 117 is formed in the first inner shell body 111 to form a fixed connection with the anti-rotation fixing member 1610.

[0137] For some specific embodiments, please refer to Figure 27 , Figures 34 to 37 The second inner shell 120 includes a second inner shell body 121, an inner shell bottom plate 122, and a connecting portion 123. Both the second inner shell body 121 and the connecting portion 123 are cylindrical. The inner shell bottom plate 122 is connected between the second inner shell body 121 and the connecting portion 123. The second inner shell body 121 is connected to the distal end face of the inner shell bottom plate 122, and the connecting portion 123 is connected to the proximal end face of the inner shell bottom plate 122. The inner diameter of the second inner shell body 121 is larger than the outer diameter of the connecting portion 123. A second elastic element 1630 and a third elastic element 1640 are housed in the second inner shell body 121. A first socket portion 124 extends from the distal end face of the second inner shell body 121, and a second socket portion 118 extends from the proximal end face of the first inner shell body 121. The first socket portion 124 and the second socket portion 118 are interlocked and connected by ultrasonic welding.

[0138] For details, please refer to Figure 34 , Figure 35 and Figure 38 The distal end of the injection shell 130 also has a fifth groove 132 that penetrates the distal end face. The distal outer peripheral surface of the first inner shell 110 has a fifth protrusion 119. The fifth protrusion 119 and the fifth groove 132 are in concave-convex fit to form a circumferential positioning of the first inner shell 110 and the injection shell 130, so that the windows 140 on the first inner shell 110 and the injection shell 130 correspond to each other.

[0139] Specifically, the positioning hole 131 is formed in the injection shell 130 and the first inner shell 110, and the window 140 penetrates the first inner shell 110 and the injection shell 130.

[0140] For details, please refer to Figure 27 The injection structure 1 also includes a drug storage shell 2000 sleeved outside the drug storage bottle 201. The drug storage bottle 201 is housed in the drug storage shell 2000, and the proximal end face of the drug storage bottle 201 abuts against the proximal inner wall of the drug storage shell 2000. Specifically, the connecting part 123 has a third external thread 1231, and the proximal end of the drug storage shell 2000 has a third internal thread. When the drug storage shell 2000 and the connecting part 123 form a threaded connection, the distal end face of the drug storage bottle 201 abuts against the mounting member 1700 and pushes the mounting member 1700 to a preset height distally.

[0141] In some embodiments, please refer to Figure 27 The distal end of the central push rod 500 is connected to a pusher 1500. The pusher 1500 and the central push rod 500 form an axial limiting connection. When the central push rod 500 moves to the proximal end, the pusher 1500 can push the plunger 202 to move to the proximal end of the drug storage bottle 201, thereby realizing drug injection.

[0142] For details, please refer to Figure 39 and Figure 40 The pusher 1500 has a small-diameter bore 1510 and a large-diameter bore 1520. The small-diameter bore 1510 extends from the distal end face of the pusher 1500 to the large-diameter bore 1520. The large-diameter bore 1520 extends proximally from the small-diameter bore 1510 but does not penetrate the proximal end face of the pusher 1500. The inner diameter of the large-diameter bore 1520 is larger than the inner diameter of the small-diameter bore 1510. The pusher 1500 also has a side bore 1530, which extends from the outer peripheral surface of the pusher 1500 to both the small-diameter bore 1510 and the large-diameter bore 1520, and penetrates the distal end face of the pusher 1500. Please refer to [link / reference]. Figure 20 The proximal end of the central push rod 500 has a small-diameter portion 550 and a large-diameter portion 560, with the small-diameter portion 550 connected between the rod body 510 and the large-diameter portion 560. During assembly, the small-diameter portion 550 and the large-diameter portion 560 are inserted into the small-diameter hole 1510 and the large-diameter hole 1520 respectively through the side hole 1530, so that the small-diameter portion 550 is rotatably positioned in the small-diameter hole 1510, and the large-diameter portion 560 is rotatably positioned in the large-diameter hole 1520, with the large-diameter portion 560 axially confined in the large-diameter hole 1520.

[0143] Specifically, the pusher 1500 includes a pusher body 1550 and an abutment plate 1560. The pusher body 1550 is cylindrical, and a small-diameter hole 1510, a large-diameter hole 1520, and a side hole 1530 are all formed in the pusher body 1550. The abutment plate 1560 is round and flat and covers the proximal end face of the pusher body 1550 to block the large-diameter hole 1520. The outer diameter of the abutment plate 1560 is larger than the outer diameter of the pusher body 1550. The proximal end face of the abutment plate 1560 is used to abut against the distal end face of the plunger 201. The outer peripheral surface of the abutment plate 1560 is adapted to the inner peripheral surface of the medicine bottle 201 to radially limit the movement of the pusher 1500 toward the distal end of the syringe. The distal end face of the abutment plate 1560 contacts and engages with the proximal end face of the mounting member 1700, and prevents liquid or dust from entering the interior of the housing assembly 100.

[0144] On the other hand, this application also provides an injection device, including a drug storage structure 2 and the above-mentioned injection structure 1, wherein the injection structure 1 and the drug storage structure 2 cooperate to realize drug injection.

[0145] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An injection structure for use in conjunction with a drug storage structure, the drug storage structure comprising a drug storage bottle for containing a drug, a plunger for sealing one end of the drug storage bottle, and an injection needle mounted on the other end of the drug storage bottle, characterized in that, The injection structure includes a housing assembly, a rotating cylinder, a knob, a tension spring, and a central push rod. The central push rod, the rotating cylinder, and the housing assembly are arranged sequentially from the inside to the outside. The central push rod is threadedly connected to the housing assembly. The knob is installed at the distal end of the housing assembly and forms a circumferential limiting connection and an axial sliding connection with the rotating cylinder. The tension spring is sleeved on the outside of the rotating cylinder, with its distal end fixed to the housing assembly and its proximal end fixed to the rotating cylinder. The knob is used to drive the rotating cylinder and the proximal end of the tension spring to rotate forward to adjust the injection metering. The housing assembly is used to limit the reverse rotation of the rotating cylinder driven by the forward rotation of the tension spring. During injection, the rotating cylinder is pushed proximally to disengage from the rotational limitation of the knob and the housing assembly until the rotating cylinder forms a circumferential limiting connection with the central push rod. The tension spring releases its rotational elastic force to rotate the rotating cylinder and the central push rod in the reverse direction. Simultaneously, the central push rod rotates in the reverse direction, pushing the plunger proximally to achieve injection.

2. The injection structure as described in claim 1, characterized in that, The injection structure further includes a button and a first elastic element. The button and the distal end of the rotating cylinder form an axial limiting connection and a rotational connection. The first elastic element is connected to the button and is used to axially reset the button and the rotating cylinder to the distal end when pushed in the proximal direction.

3. The injection structure as described in claim 1, characterized in that, The injection structure further includes a first fixing sleeve and a second fixing sleeve, which are axially spaced and located between the housing assembly and the rotating cylinder. The first fixing sleeve is fixedly connected to the housing assembly, and the second fixing sleeve is fixedly connected to the rotating cylinder. The proximal end of the tension spring is fixedly connected to the second fixing sleeve, and the distal end of the tension spring is fixedly connected to the first fixing sleeve.

4. The injection structure as described in claim 3, characterized in that, The injection structure further includes a dose rotating cylinder, which forms a circumferential limiting connection and an axial sliding connection with the second fixed sleeve. The dose rotating cylinder is threadedly connected to the housing assembly. The surface of the dose rotating cylinder is provided with a dose mark, and the housing assembly is provided with a window for reading the dose mark. The first fixed sleeve has a first limiting part, and the dose rotating cylinder has a second limiting part. The first limiting part and the second limiting part cooperate with each other to limit the return of the dose rotating cylinder when it is at the zero position. The housing assembly has a third limiting part, and the dose rotating cylinder has a fourth limiting part. The third limiting part and the fourth limiting part cooperate with each other to limit the maximum stroke of the dose rotating cylinder in the forward direction.

5. The injection structure as described in claim 1, characterized in that, The injection structure also includes a memory element, which is sleeved between the rotating cylinder and the central push rod. The memory element and the rotating cylinder form a circumferential limiting connection and an axial sliding connection. The memory element and the central push rod are threadedly connected. During forward adjustment, the memory element is driven by the rotating cylinder to move distally on the central push rod. During reverse adjustment, the memory element is driven by the rotating cylinder to move proximally on the central push rod. During injection, the memory element and the central push rod rotate synchronously and move proximally together. The distal end of the central push rod is an unthreaded end to limit the memory element located at the unthreaded end of the central push rod from continuing to rotate forward for forward adjustment, thereby limiting further adjustments to the dosage beyond the dosage of the drug reservoir.

6. The injection structure according to any one of claims 1 to 5, characterized in that, The housing assembly is provided with a rotation limiting component inside. The rotation limiting component is used to limit the reverse rotation of the rotating cylinder driven by the forward rotation of the tension spring. When the rotating cylinder moves a preset distance to the proximal end, the rotation limiting component disengages from the housing assembly axially to release the restriction on the reverse rotation of the rotating cylinder. The rotation limiting component includes a rotation limiting movable component and a rotation limiting fixed component. The rotation limiting movable component is sleeved between the rotating cylinder and the rotation limiting fixed component. The rotation limiting fixed component forms a circumferential limiting connection and an axial sliding connection with the housing assembly. The inner circumferential wall of the rotation limiting fixed component has a plurality of first positive teeth, and the outer circumferential wall of the rotation limiting movable component has second positive teeth. The forward rotation of the rotating cylinder can drive the rotation limiting movable component to rotate in the forward direction, and the second positive teeth sequentially engage between each of the first positive teeth. When the rotating cylinder moves to the proximal end, it will drive the rotation limiting fixed component to move together. When it moves a preset distance, the rotation limiting fixed component can disengage from the circumferential restriction of the housing assembly, so that the rotation limiting fixed component, the rotation limiting movable component, and the rotating cylinder can synchronously reverse under the drive of the storage torsion spring.

7. The injection structure as described in claim 6, characterized in that, The portion of the second forward tooth connected to the limited-rotation movable component is elastic. The second forward tooth is also connected to a first guide rod. The rotating cylinder has a first guide groove. The first guide rod is slidably disposed in the first guide groove. When the rotating cylinder rotates in the reverse direction, the first guide groove guides the first guide rod toward the center of the rotating cylinder, thereby causing the second forward tooth to retract toward the center of the rotating cylinder to reduce the distance between it and the first forward tooth. This allows the second forward tooth to rotate and bounce in the reverse direction on the first forward tooth to achieve a reversal when over-measurement is adjusted.

8. The injection structure according to any one of claims 1 to 5, characterized in that, The injection structure also includes an outer push rod, which is sleeved outside the central push rod. The outer push rod and the central push rod form a circumferential limiting connection. The distal end of the outer push rod is provided with a first meshing tooth, and the proximal end of the rotating cylinder is provided with a second meshing tooth. During injection, after the rotating cylinder moves a preset distance towards the proximal end, the first meshing tooth and the second meshing tooth engage axially to form a circumferential limiting connection. At this time, the rotating cylinder is released from the rotation restriction of the knob and the housing assembly. The tension spring releases the rotational elastic force to rotate the rotating cylinder, the outer push rod, and the central push rod in the opposite direction. While the central push rod rotates in the opposite direction, it pushes the plunger to move towards the proximal end to achieve injection.

9. The injection structure as described in claim 8, characterized in that, The injection structure also includes an anti-reset component, which is used to restrict the forward rotation of the central push rod to limit the axial reset of the central push rod; and when the drug storage structure is separated from the housing assembly, the anti-reset component releases the restriction on the forward rotation of the central push rod. The anti-reset assembly includes an anti-forward rotation movable component, an anti-forward rotation fixed component, an anti-reverse rotation movable component, a second elastic component, and a third elastic component. The anti-reverse rotation movable component forms an axial sliding connection and a circumferential limiting connection with the central push rod. The anti-forward rotation fixed component is fixed to the housing assembly. The anti-forward rotation movable component is sleeved outside the outer push rod and forms an axial sliding connection and a circumferential limiting connection with the outer push rod. The second elastic component is sleeved outside the outer push rod. The third elastic component is sleeved outside the second elastic component and abuts against the anti-forward rotation fixed component and the anti-reverse rotation movable component. The anti-forward rotation movable component has a third reverse tooth, the anti-forward rotation fixed component has a fourth reverse tooth, the anti-reverse rotation movable component has a third forward tooth, and the outer push rod has a fourth forward tooth. When the drug storage structure is installed on the housing assembly, the drug storage structure pushes the anti-reverse rotation movable component distally so that both the second elastic component and the third elastic component are in a compressed state. The second elastic element is pressed against the anti-rotation movable element and the outer push rod, so that the third reverse tooth and the fourth reverse tooth are engaged axially, and the third forward tooth and the fourth forward tooth are engaged axially. When the drug storage structure is detached from the housing assembly, the anti-rotation movable element is pushed to the proximal end by the third elastic element, the third elastic element is in a naturally stretched state, the second elastic element is in a naturally stretched state and at least one end is suspended, so that the third forward tooth and the fourth forward tooth are in a non-engaged state axially. When the central push rod rotates forward, it can rotate the anti-rotation movable element forward, realizing the axial reset of the central push rod; or, so that the third reverse tooth and the fourth reverse tooth are in a non-engaged state axially, when the central push rod rotates forward, it can rotate the anti-rotation movable element, the outer push rod and the anti-rotation movable element forward, realizing the axial reset of the central push rod.

10. An injection device, characterized in that, It includes a drug storage structure and an injection structure as described in any one of claims 1 to 9, wherein the injection structure and the drug storage structure cooperate to achieve drug injection.

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