Insulin injection pen with retractable needle head storage function and needle head stretching and retracting method of insulin injection pen

Abstract

The insulin injection pen comprises a pen body, a switching plate is movably arranged in the pen body through an elastic piece, a control groove is formed in the switching plate, a control rod is arranged in the control groove in a sliding fit mode, an injection cylinder is arranged in the pen body, and a needle is installed at the end of the injection cylinder. The end parts of the plurality of control rods are respectively connected with the syringe and the needle head; through the telescopic needle head storage design, direct contact between a user and the needle head is thoroughly eliminated, the risk of puncture of the needle head is remarkably reduced, the safety of medical staff and patients is guaranteed, stretching and storage of the needle head can be controlled only through simple sliding operation, the needle head does not need to be manually mounted and dismounted, the operation process is simplified, and the working efficiency is improved. The use efficiency is improved, the needle head is sealed in the pen body when the needle head is not used, the needle head is prevented from making contact with the external environment, attachment of pollutants such as dust and bacteria is effectively prevented, and the cleanliness of injection every time is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of insulin pen structure technology, specifically to an insulin pen with a telescopic needle storage and a needle telescopic method thereof. Background Technology

[0002] An insulin pen is an injection device that combines a pen syringe and insulin solution, allowing patients to self-inject insulin at home or on the go to control their blood sugar levels. This device is particularly suitable for patients with type 1 and type 2 diabetes who require long-term insulin therapy.

[0003] Most insulin pens currently on the market do not have a retractable needle storage function; Before and after injection, users need to manually install and remove the needle in these types of insulin pens. This process not only increases the complexity of the operation but also significantly increases the risk of accidental needle puncture. Insulin pens without retractable storage function usually have their needles exposed when not in use. This not only makes the needles susceptible to physical damage and contamination but also adds the step of additional cleaning and inspection of the needles by patients before use. Due to the lack of effective protection mechanisms, medical staff and patients face serious threats of cross-infection and biohazards.

[0004] Therefore, we propose an insulin pen with a telescopic needle storage and a method for needle telescopic extension. Summary of the Invention

[0005] The purpose of this invention is to provide an insulin pen with a retractable needle storage to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides an insulin pen with a retractable needle storage, comprising a pen body, a switching plate movably disposed within the pen body via an elastic element, a control groove formed on the switching plate, a control rod slidably fitted within the control groove, an injection cartridge disposed within the pen body, a needle mounted at the end of the injection cartridge, and multiple control rods respectively connected to the injection cartridge and the needle; by sliding different control rods, the extension, injection, and storage of the needle can be achieved.

[0007] Preferably, the pen body includes a first housing and a second housing, which are fixed together by a connecting rod; the two are fixed together by the connecting rod to form a complete pen body structure, which is convenient for assembly and disassembly, and at the same time protects the internal mechanism from external influences.

[0008] Preferably, the control groove includes a first sliding groove, a second sliding groove, and a third sliding groove. The first and second sliding grooves have triangular blocks in the middle, and the third sliding groove has a bent line shape in the middle. The three control rods slide in the first, second, and third sliding grooves respectively. The control rods slide in these sliding grooves and achieve different control functions by pressing against the triangular blocks or sliding along a specific path.

[0009] Preferably, the control rod has a sliding component in the middle, the sliding component including a first connecting rod, a second connecting rod, and a third connecting rod. The first and second connecting rods are respectively connected and fixed to the control rod, and the third connecting rod is movably engaged with the control rod. The first connecting rod is installed and connected to the sleeve of the syringe, the second connecting rod is installed and connected to the piston plate of the syringe, and the needle is installed and connected to the third connecting rod. The pen body has three limiting grooves that are respectively slidably engaged with the control rod. An elastic pull member is attached between the end of the sliding component and the pen body: the limiting grooves on the pen body are slidably engaged with the control rod, and the elastic pull member attached between the end of the sliding component and the pen body provides a restoring force.

[0010] Preferably, the third connecting rod has a movable groove, and the control rod slides within the movable groove; the third connecting rod slides relative to the first connecting rod during its movement, thereby achieving precise control of the needle.

[0011] Preferably, the control rods located on both sides have an L-shaped structure to avoid space occupation and accumulation, which would make operation inconvenient. A sealing plate is fixedly connected to the control rod, and multiple sealing plates slide and cooperate with each other. The length of the sealing plate is greater than twice the length of the limiting groove; the length of the sealing plate is greater than twice the length of the limiting groove to ensure sealing.

[0012] Preferably, the elastic element includes a tension spring connected to the switching plate, the other end of the tension spring being connected to the pen body, and a sliding plate that slides within the pen body being fixedly connected to the bottom of the switching plate; the tension spring provides the force for the switching plate to reset, ensuring that each component can accurately return to its initial position after completing its action.

[0013] Preferably, the second connecting rod includes a first connecting rod fixedly connected to the control rod and a second connecting rod fixedly connected to the piston plate of the syringe. A first rotating plate is rotatably connected to the first connecting rod via a torsion spring, and a second rotating plate is hinged to the second connecting rod. The ends of the first rotating plate and the second rotating plate are hinged together. A wedge plate is fixedly connected to the side of the first connecting rod, and the hinge joint between the ends of the first rotating plate and the second rotating plate slides with the wedge plate. The fixed connection of the wedge plate to the side of the first connecting rod and the sliding engagement between the hinge joint of the first rotating plate and the second rotating plate allows for a large-distance movement of the piston plate to facilitate injection.

[0014] Preferably, the needle tip is equipped with an inclined pressure plate, and the third connecting rod is in contact with the pressure plate to facilitate disengagement.

[0015] A needle extension method for an insulin pen with a retractable needle storage, the specific needle extension method according to the above-mentioned insulin pen with a retractable needle storage includes the following steps; S1. Installation: First, open the first housing. At this time, the second connecting rod is installed with the piston plate of the syringe, and the first connecting rod is installed with the syringe. Install the needle to the end of the syringe, and the needle is in the state of being stored in the pen body. S2. Extend the needle: Then slide the control rod located in the first sliding groove. The control rod presses against the triangular block, thereby causing the first connecting rod to move the syringe and the needle, so that the needle extends out of the pen body. The first connecting rod and the second connecting rod rotate adaptively. The piston plate in the syringe will not move relative to the syringe, that is, the insulin injection action will not occur. S3, Injection: Next, insert the extended needle into the patient's skin; Then slide the control rod located in the second sliding groove. During this process, the hinge of the first link and the second link contacts the wedge plate, increasing the range of motion of the second link, thereby moving the piston plate relative to the syringe and injecting insulin into the patient's body. Although the first connecting rod disengages from the triangular block in the first sliding groove, neither the injection cylinder nor the first connecting rod will return to its original position due to the compression of the piston plate. S4. Needle removal: Pull the needle out of the patient's body, then press the control rod located in the third sliding groove to make the switching plate slide. On the one hand, the first connecting rod and the second connecting rod are reset, thereby allowing the syringe to be stored. The first connecting rod and the second connecting rod are disengaged from the wedge plate and rotated to the reset angle. On the other hand, the needle that is performing the reset and storage movement is pushed out by the third connecting rod that is performing the extension movement, so that the needle is detached from the syringe.

[0016] Compared with the prior art, the beneficial effects of the present invention are: Slide the control rod located in the first sliding groove. The control rod presses against the triangular block, causing the first connecting rod and the syringe to move, so that the needle extends out of the pen body. When injecting, the extended needle is inserted into the patient's skin. Slide the control rod located in the second sliding groove. The hinge of the second connecting rod contacts the wedge plate, increasing the range of motion, so that the piston plate moves relative to the syringe to complete the insulin injection. After the injection is completed, pull out the needle and press the control rod located in the third sliding groove to slide the switching plate, causing the first and second connecting rods to reset and the syringe to be stored. At the same time, the third connecting rod pushes out the needle, causing it to detach from the syringe. This application, through its retractable needle storage design, completely eliminates direct contact between the user and the needle, significantly reducing the risk of needlestick injuries and ensuring the safety of medical staff and patients. The extension and retraction of the needle can be controlled with a simple sliding operation, eliminating the need for manual installation and removal, thus simplifying the operation process and improving efficiency. When not in use, the needle is sealed within the pen body, preventing contact with the external environment and effectively preventing the adhesion of dust, bacteria, and other contaminants, ensuring the cleanliness of each injection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the disassembled structure of the first housing and the second housing of the present invention; Figure 3 This is a schematic diagram showing the disassembled structure of the first housing, the injection cylinder, and the switching plate of the present invention; Figure 4 This is a schematic diagram of the mating structure of the sealing plate, control rod, and limiting groove of the present invention; Figure 5 This is a schematic diagram showing the disassembled structure of the injection cylinder, the first connecting rod, and the piston plate of the present invention; Figure 6 For the present invention Figure 5 A schematic diagram of the mid-structure viewed from below; Figure 7 This is a schematic diagram of the cooperative structure of the switching plate, control lever, and sliding member of the present invention; Figure 8 This is a schematic diagram of the disassembled structure of the control rod and the movable groove of the present invention; Figure 9 This is a schematic diagram showing the disassembled structure of the first connecting rod, the second connecting rod, and the control rod of the present invention; Figure 10 This is a schematic diagram of the mating structure of the control groove and control rod of the present invention; Figure 11 This is a schematic diagram of the mating structure of the first connecting rod and the second connecting rod of the present invention.

[0018] In the diagram: 1. Pen body; 101. First housing; 102. Second housing; 2. Switching plate; 3. Control groove; 301. First sliding groove; 302. Second sliding groove; 303. Third sliding groove; 304. Triangular block; 4. Control rod; 5. Injector; 501. Piston plate; 6. Needle; 7. First connecting rod; 8. Second connecting rod; 801. First connecting rod; 802. Second connecting rod; 803. First rotating plate; 804. Second rotating plate; 805. Wedge plate; 9. Third connecting rod; 10. Limiting groove; 11. Elastic pull member; 12. Movable groove; 13. Sealing plate; 14. Tension spring; 15. Slide plate; 16. Pressure plate. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figures 1-11 The present invention provides an insulin injection pen with a telescopic needle 6 storage, including a pen body 1. The pen body 1 includes a first shell 101 and a second shell 102. The first shell 101 and the second shell 102 are installed and fixed by a plug rod. The first shell 101 and the second shell 102 are installed and fixed by a plug rod to form a complete pen body 1 structure, which is convenient for assembly and disassembly, so as to facilitate the installation and replacement of the injection cartridge 5. Needle 6 installation operation: Open the first housing 101. At this time, the second connecting rod 802 is installed with the piston plate 501 of the syringe 5, and the first connecting rod 7 is installed with the syringe 5 (installed by screw connector). Install the needle 6 to the end of the syringe 5. The needle 6 is in the state of being stored in the pen body 1. Finally, reconnect the second housing 102 with the first housing 101 to complete the installation of the needle 6 and the syringe 5. It is worth noting that the third connecting rod 9 has a movable groove 12. The control rod 4 located in the third sliding groove 303 slides along the movable groove 12. When the needle 6 is installed into the injection molding cylinder, the contact position of the third connecting rod 9 is prevented from interfering with the installation of the needle 6.

[0021] A switching plate 2 is movably provided inside the pen body 1 via an elastic element. A control groove 3 is provided on the switching plate 2. A control rod 4 is slidably fitted inside the control groove 3. An injection cylinder 5 is provided inside the pen body 1. A needle 6 is installed at the end of the injection cylinder 5. The ends of multiple control rods 4 are respectively installed and connected to the injection cylinder 5 and the needle 6. By sliding different control rods 4, the extension, injection, storage, and disposal / replacement of the needle 6 can be realized.

[0022] The control groove 3 includes a first sliding groove 301, a second sliding groove 302, and a third sliding groove 303. A triangular block 304 is provided in the middle of the first sliding groove 301 and the second sliding groove 302. The middle of the third sliding groove 303 is in the shape of a bent line. The three control rods 4 slide in the first sliding groove 301, the second sliding groove 302, and the third sliding groove 303 respectively. The control rods 4 slide in these sliding grooves and realize different control functions by pressing against the triangular block 304 or sliding along a specific path. The control lever 4 has a sliding component in the middle, which includes a first connecting rod 7, a second connecting rod 8, and a third connecting rod 9. The first connecting rod 7 and the second connecting rod 8 are respectively connected and fixed to the control lever 4, and the third connecting rod 9 is movably engaged with the control lever 4. The first connecting rod 7 is installed and connected to the sleeve of the syringe 5, and the second connecting rod 8 is installed and connected to the piston plate 501 of the syringe 5. The needle 6 is installed and connected to the third connecting rod 9. The pen body 1 has three limiting grooves 10 that are slidably engaged with the control lever 4. An elastic puller 11 is attached between the end of the sliding component and the inside of the pen body 1. The elastic element includes a tension spring 14 connected to the switching plate 2, the other end of the tension spring 14 being connected to the inside of the pen body 1, and a sliding plate 15 that slides in cooperation with the inside of the pen body 1 being fixedly connected to the bottom of the switching plate 2.

[0023] Instructions on how to extend the stored needle 6: Slide the control lever 4 located in the first sliding groove 301. The control lever 4 passes over the triangular block 304 (the switching plate 2 moves adaptively along the direction of the slide plate 15 against the tension of the tension spring 14 and then resets), and presses against the bottom of the triangular block 304. Under the action of the tension spring 14, the control lever 4 is prevented from resetting upward, so that the first connecting rod 7 drives the syringe 5 and the needle 6 to move a certain distance and then stays in that position, so that the needle 6 extends out of the pen body 1. The second connecting rod 8 includes a first connecting rod 801 fixedly connected to the control rod 4 and a second connecting rod 802 fixedly connected to the piston plate 501 of the syringe 5. A first rotating plate 803 is rotatably connected to the first connecting rod 801 via a torsion spring rod. A second rotating plate 804 is hinged to the second connecting rod 802. The ends of the first rotating plate 803 and the second rotating plate 804 are hinged together. A wedge plate 805 is fixedly connected to the side of the first connecting rod 7. The hinge joints at the ends of the first rotating plate 803 and the second rotating plate 804 are slidably engaged with the wedge plate 805.

[0024] As the needle 6 extends out of the pen body 1, the injection cylinder moves downward, causing the piston plate 501 to move synchronously, thereby causing the first connecting rod 801 and the second connecting rod 802 to rotate adaptively. The first connecting rod 801 overcomes the torsion of the torsion spring rod, causing the tilt direction of the first connecting rod 801 to switch to the opposite direction. During this process, the piston plate 501 inside the injection cylinder 5 will not move relative to the injection cylinder 5, that is, no insulin injection action will occur. It is worth noting that after the hinge of the first link 801 and the second link 802 is adjusted by rotation, the hinge of the first link 801 and the second link 802 contacts the inclined surface of the wedge plate 805.

[0025] Instructions on how to administer the injection: First, insert the extended needle 6 into the patient's skin; Then slide the control rod 4 located in the second sliding groove 302. Since the hinge of the first link 801 and the second link 802 presses against the inclined surface of the wedge plate 805 (the tilt angle of the first link 801 will not rotate in the direction of the reset angle due to the pressing action of the wedge plate 805), the first link 801 moves with the control rod 4. The hinge of the first link 801 and the second link 802 moves in the wedge plate 805. Under the action of the inclined surface, the first link 801 and the second link 802 rotate in a straight line. In this way, while the first link 801 and the second link 802 move downward, the second link 802 moves further relative to the first link 801, increasing the range of motion of the second link 802. This allows the piston plate 501 to move relative to the syringe 5, and ensures the movement distance of the piston plate 501 in the syringe 5, so that insulin can be injected into the patient's body. After insulin injection is completed, the control lever 4 located in the second sliding groove 302 passes over the triangular block 304 in the second sliding groove 302 and is located at the bottom of the triangular block 304. During this process, the switching plate 2 moves back and forth in the horizontal direction (the sliding plate 15 moves along the direction of the pen body 1). During the injection process, the horizontal reciprocating motion of the switching plate 2 causes the first connecting rod 7 to disengage from the triangular block 304 in the first sliding groove 301. However, the first connecting rod 7 will not reset at this time. This is due to the squeezing action of the piston plate 501 and the reaction force when injecting into the body (making the pushing pressure when injecting into the human body greater than the pushing pressure when not injecting), so that neither the syringe 5 nor the first connecting rod 7 will reset. It is worth noting that in this application, the first connecting rod 7, the second connecting rod 8, and the third connecting rod 9 slide smoothly vertically along the direction of the pen body 1, while the switching plate 2 slides smoothly horizontally along the direction of the pen body 1.

[0026] After the final injection is completed, the instructions for removing the needle 6 are as follows: pull the needle 6 out of the patient's body, and then press the control lever 4 located in the third sliding groove 303 to make the switching plate 2 slide horizontally. On the one hand, the two control levers 4 are moved away from the triangular block 304. Under the action of the elastic puller 11, the first connecting rod 7 and the second connecting rod 8 move upward to reset, thereby allowing the syringe 5 to be stored. Among them, the first connecting rod 801 and the second connecting rod 802 are disengaged from the wedge plate 805 and rotate to reset the angle (because the piston plate 501 moves with less force along the empty syringe 5 after being pulled out of the body, the angle of the first connecting rod 801 is reset under the action of the torsion spring rod). On the other hand, the end of the needle 6 is equipped with an inclined pressure plate 16, and the third connecting rod 9 is in a pressing fit with the pressure plate 16. The third connecting rod 9 moves towards the needle 6, contacts the pressure plate 16, and drives the pressure plate 16 to move, so that the needle 6 is pushed out by the third connecting rod 9 which has an extension movement, thereby completing the separation of the needle 6 from the syringe 5.

[0027] The control levers 4 located on both sides are L-shaped, which distributes the three control levers 4 in three directions, avoiding the three control levers 4 being clustered together, which would limit the operating space and make operation inconvenient. Sealing plates 13 are fixedly connected to the control levers 4. Multiple sealing plates 13 slide and cooperate with each other. The length of the sealing plate 13 is more than twice the length of the limiting groove 10. With the setting of the sealing plate 13, when the control lever 4 moves, the sealing plate 13 that moves with it always blocks the limiting groove 10 to prevent dust and other impurities from entering. Moreover, the three sealing plates 13 slide and limit each other to ensure the stability of movement. The three control levers 4 or the sealing plate 13 may be provided with corresponding identification structures (identification text or identification layers with prompts) to distinguish or indicate the pressing sequence.

[0028] In this application, the tension spring 14 is pressed against the control rod 4 located in the third sliding groove 303. When the control rod 4 slides along the third sliding groove 303, it will contact the tension spring 14, causing the middle part of the tension spring 14 to bend, thereby increasing the tension of the tension spring 14 and facilitating the reset of the switching plate 2. The length of the third sliding groove 303 is greater than the length of the first sliding groove 301, so that the extension length of the third connecting rod 9 can ensure that the needle 6 is disengaged from the syringe 5.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, needle retraction method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, needle retraction method, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An insulin pen with a retractable needle (6) for storage, characterized in that, include: The pen body (1) has a switching plate (2) that is movably provided inside the pen body (1) through an elastic element. The switching plate (2) has a control groove (3) and a control rod (4) that is slidably fitted inside the control groove (3). The pen body (1) has an injection cylinder (5) and a needle (6) is installed at the end of the injection cylinder (5). The ends of multiple control rods (4) are respectively connected to the injection cylinder (5) and the needle (6).

2. The insulin pen with a retractable needle (6) for storage according to claim 1, characterized in that: The pen body (1) includes a first housing (101) and a second housing (102), which are fixed together by a plug rod.

3. The insulin pen with a retractable needle (6) for storage according to claim 2, characterized in that: The control groove (3) includes a first sliding groove (301), a second sliding groove (302), and a third sliding groove (303). A triangular block (304) is provided in the middle of the first sliding groove (301) and the second sliding groove (302). The third sliding groove (303) has a bent line shape in the middle. The three control rods (4) slide in the first sliding groove (301), the second sliding groove (302), and the third sliding groove (303), respectively.

4. The insulin pen with a retractable needle (6) for storage according to claim 3, characterized in that: The control lever (4) is provided with a sliding member in the middle. The sliding member includes a first connecting rod (7), a second connecting rod (8), and a third connecting rod (9). The first connecting rod (7) and the second connecting rod (8) are respectively connected and fixed to the control lever (4). The third connecting rod (9) is movably engaged with the control lever (4). The first connecting rod (7) is installed and connected to the sleeve of the syringe (5). The second connecting rod (8) is installed and connected to the piston plate (501) of the syringe (5). The needle (6) is installed and connected to the third connecting rod (9). The pen body (1) is provided with three limiting grooves (10) that are respectively slidably engaged with the control lever (4). An elastic puller (11) is attached between the end of the sliding member and the inside of the pen body (1).

5. The insulin pen with a retractable needle (6) for storage according to claim 4, characterized in that: The third connecting rod (9) has a movable groove (12) and the control rod (4) slides in the movable groove (12).

6. The insulin pen with a retractable needle (6) for storage according to claim 5, characterized in that: The control rods (4) located on both sides are L-shaped. A sealing plate (13) is fixedly connected to the control rod (4). Multiple sealing plates (13) slide and cooperate with each other. The length of the sealing plate (13) is more than twice the length of the limiting groove (10).

7. The insulin pen with a retractable needle (6) for storage according to claim 6, characterized in that: The elastic element includes a tension spring (14) connected to the switching plate (2), the other end of the tension spring (14) being connected to the inside of the pen body (1), and a sliding plate (15) that slides in cooperation with the inside of the pen body (1) being fixedly connected to the bottom of the switching plate (2).

8. The insulin pen with a retractable needle (6) for storage according to claim 7, characterized in that: The second connecting rod (8) includes a first connecting rod (801) fixedly connected to the control rod (4) and a second connecting rod (802) fixedly connected to the piston plate (501) of the syringe (5). A first rotating plate (803) is rotatably connected to the first connecting rod (801) via a torsion spring rod. A second rotating plate (804) is hinged to the second connecting rod (802). The ends of the first rotating plate (803) and the second rotating plate (804) are hinged together. A wedge plate (805) is fixedly connected to the side of the first connecting rod (7). The hinge joints at the ends of the first rotating plate (803) and the second rotating plate (804) are slidably engaged with the wedge plate (805).

9. The insulin pen with a retractable needle (6) for storage according to claim 8, characterized in that: The needle (6) is fitted with an inclined pressure plate (16) at its end, and the third connecting rod (9) is in a pressure-fitting relationship with the pressure plate (16).

10. A method for extending and retracting the needle (6) of an insulin pen that houses the retractable needle (6), characterized in that, An insulin pen for storing a telescopic needle (6) according to any one of claims 1-9, wherein the specific needle (6) telescopic method includes the following steps; S1. Installation: First, open the first housing (101). At this time, the second connecting rod (802) is installed with the piston plate (501) of the syringe (5), and the first connecting rod (7) is installed with the syringe (5). Install the needle (6) to the end of the syringe (5). The needle (6) is stored in the pen body (1). S2, Extend the needle (6): Then slide the control rod (4) located in the first sliding groove (301). The control rod (4) presses against the triangular block (304), thereby causing the first connecting rod (7) to drive the syringe (5) and the needle (6) to move, thereby causing the needle (6) to extend out of the pen body (1). The first connecting rod (801) and the second connecting rod (802) make adaptive rotations. The piston plate (501) in the syringe (5) will not move relative to the syringe (5), that is, the insulin injection action will not occur. S3, Injection: Then insert the extended needle (6) into the patient's skin; Then slide the control rod (4) located in the second sliding groove (302). During this process, the hinge of the first link (801) and the second link (802) contacts the wedge plate (805), increasing the range of motion of the second link (802), thereby moving the piston plate (501) relative to the syringe (5) and allowing insulin to be injected into the patient's body. Although the first connecting rod (7) disengages from the triangular block (304) in the first sliding groove (301), neither the injection cylinder (5) nor the first connecting rod (7) will reset due to the compression of the piston plate (501); S4, Disconnecting the needle (6): Pull the needle (6) out of the patient's body, and then press the control rod (4) located in the third sliding groove (303) to make the switching plate (2) slide. On the one hand, the first connecting rod (7) and the second connecting rod (8) are reset, so that the syringe (5) is stored. On the other hand, the needle (6) that is resetting and storing is pushed out by the third connecting rod (9) that is extending, so that the needle (6) is disconnected from the syringe (5).

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