Medical needle with self-destruction function for preventing puncture

Abstract

The medical needle with self-destruction and anti-stabbing function comprises a needle seat, a self-destruction mechanism and a needle core arranged in the needle seat. The self-destruction mechanism comprises a receiving tube, a self-destruction switch and an elastic member. The receiving tube comprises an outer receiving tube and an inner receiving tube. The inner receiving tube is movably arranged in the outer receiving tube. The self-destruction switch is controlled to start the elastic member to drive the needle core to retract into the receiving tube. Meanwhile, the inner receiving tube is arranged to protrude from the rear end of the outer receiving tube. The receiving tube is provided with an anti-rebound structure for preventing the inner receiving tube from rebounding forward. Compared with the prior art, the inner receiving tube is locked after protruding backward, so that the inner receiving tube cannot rebound forward, thereby avoiding the front end of the needle core from protruding from the front end of the receiving tube and eliminating the hidden danger of stabbing medical staff and causing infection.

Description

Technical Field

[0001] This invention relates to the field of medical needle technology, specifically to a medical needle with a self-destructing anti-puncture function. Background Technology

[0002] An indwelling intravenous catheter, also known as a venous cannula, consists of a stainless steel needle core, a cannula, and a plastic needle hub. During insertion, the stainless steel needle core and cannula are inserted together into the blood vessel. After insertion, the needle core is withdrawn, leaving the flexible cannula in place for intravenous infusion. Because the cannula is soft and flexible, it avoids damage to the blood vessel from the needle, allowing the patient to move slightly with the needle in place. Indwelling intravenous catheters are suitable for insertion at any site. A single insertion can be used repeatedly or intermittently over several days, reducing the pain of repeated punctures for patients and the workload of nursing staff. They are highly popular with both patients and nurses in clinical practice, while also saving significant medical and nursing resources, thus having significant medical and economic benefits.

[0003] Medical needles, including indwelling intravenous catheters and lumbar puncture needles, are widely used for intravenous infusions and blood collection, and are common medical instruments. To ensure patients are not infected during infusions or blood draws, and to prevent the malicious recycling and reuse of needles after use, which could lead to viral transmission, the Ministry of Health stipulates that medical needles must be used only once. Furthermore, to prevent medical staff from being accidentally injured or infected by needles during medical procedures or while handling used needles, it is required that used needles be destroyed.

[0004] Existing medical needles typically have a self-destruct switch and a compressed spring on the needle body, and a receiving tube at the rear end for retracting the needle core. When it is necessary to deform the needle, the self-destruct switch is manually triggered to release the spring, which then pushes the needle core back into the receiving tube, thus destroying the needle's structure and achieving the purpose of deforming the needle. However, because the receiving tube of existing medical needles needs to accommodate the entire needle core, its length must be longer than the needle core's length. An excessively long receiving tube makes operation very inconvenient for medical staff and increases the difficulty of medical work. Therefore, to facilitate needle placement, the applicant has designed the following undisclosed technology: the receiving tube consists of an outer receiving tube and an inner receiving tube, with the inner receiving tube movably inserted inside the outer receiving tube. When the spring pushes the needle core back into the inner receiving tube, the inner receiving tube extends out from the rear end of the outer receiving tube, like an umbrella handle, thus accommodating the entire needle core. However, a new problem has arisen with this structure: after the needle core retracts into the containment tube, the rear end of the inner containment tube collides with the outer containment tube, causing the inner containment tube to bounce back, resulting in the tip of the needle core (i.e., the sharp point) protruding from the front end of the containment tube, posing a significant risk of injuring medical personnel and causing infection. Summary of the Invention

[0005] In view of the above-mentioned technical problems in the existing technology, the present invention provides a medical needle with self-destruction anti-puncture function. The needle is easy to operate, reduces the workload of medical staff, and has a self-destruction function after use, which can effectively eliminate the safety hazard of the needle core rebounding and puncturing medical staff after self-destruction.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A medical needle with self-destructive anti-puncture function is provided, including a needle hub, a self-destruct mechanism, and a needle core inserted into the needle hub. The self-destruct mechanism includes a receiving tube, a self-destruct switch, and an elastic element. The receiving tube includes an outer receiving tube and an inner receiving tube, with the inner receiving tube movably inserted inside the outer receiving tube. By operating the self-destruct switch, the elastic element can be activated to drive the needle core to retract into the receiving tube, while the inner receiving tube extends out from the rear end of the outer receiving tube. The receiving tube is provided with an anti-rebound structure to prevent the inner receiving tube from springing forward.

[0007] The needle with self-destructive anti-puncture function also includes a needle handle located between the needle base and the receiving tube. The rear end of the needle core is connected to a needle fixing component. The needle core and the needle fixing component are inserted through the needle handle. The self-destruct switch is installed on the needle handle. The needle fixing component is provided with a slot. The self-destruct switch is locked in the slot. The elastic element is a thrust spring. The two ends of the thrust spring abut against the needle handle and the needle fixing component respectively. Moving the self-destruct switch can release the needle fixing component. Under the action of the thrust spring, the needle fixing component and the needle core retract into the receiving tube.

[0008] The anti-rebound structure includes a sliding guide post and a sliding guide groove that cooperate with each other. The sliding guide post is disposed in one of the outer receiving tube and the inner receiving tube, and the sliding guide groove is disposed in the other of the outer receiving tube and the inner receiving tube. The rear end of the sliding guide groove turns along the radial direction of the receiving tube to form a sloping step. When the inner receiving tube passes through the rear end of the outer receiving tube, the sliding guide post rotates along the sliding guide groove and gets stuck on the sloping step, thereby preventing the inner receiving tube from rebounding forward.

[0009] The anti-rebound structure includes a buckle on the outer receiving tube, and the inner receiving tube is secured by the buckle after extending a predetermined length from the outer receiving tube.

[0010] The needle fixing component is provided with a reflux channel. The front end of the reflux channel is connected to the needle core, and the rear end of the reflux channel is provided with an exhaust diaphragm and a fixing plug for fixing the exhaust diaphragm. The fixing plug is connected to the needle fixing component.

[0011] The outer receiving tube is provided with a clamping part for clamping the inner receiving tube, so that the inner receiving tube can only move backward when pushed by the elastic member.

[0012] The needle holder is provided with a main channel and a sleeve that communicates with the main channel. The needle core passes through the main channel and the sleeve. The front end of the needle core can extend out from the front end of the sleeve or retract into the sleeve. A flow stop switch is installed on the needle holder to radially compress and stop the flow in the main channel. The flow stop switch is connected to the needle holder. When the flow stop switch radially compresses and stops the flow, it presses down on the needle core to prevent it from being pushed by the elastic element.

[0013] The needle seat is provided with a switch seat, the switch seat is provided with a through hole, the stop switch includes a spiral cap, a pressure block and a valve core, the spiral cap is threaded to the through hole, the pressure block passes through the through hole, the valve core passes through the spiral cap and is fixedly connected to the pressure block, the spiral cap can rotate relative to the valve core, the spiral cap is provided with an inward protrusion, the top surface of the protrusion abuts against the valve core, and the bottom surface of the protrusion abuts against the pressure block.

[0014] The needle with self-destruct and anti-puncture function also includes a sheath that covers the tube and has side wings that shield the self-destruct switch.

[0015] The sheath is provided with a snap-fit ​​part that locks the needle handle, thereby preventing the needle handle from separating from the needle seat when the stop switch does not press the needle core.

[0016] The beneficial effects of this invention are: Compared with existing technologies, the medical needle of the present invention with a self-destructing anti-puncture function has a shorter overall length because the inner and outer receiving tubes are nested together. During insertion, the inner receiving tube is inserted inside the outer receiving tube, making it easier for medical personnel to operate. When the needle core retracts and self-destructs, the inner receiving tube protrudes from the rear end of the outer receiving tube, thus containing the entire needle core inside the receiving tube. Furthermore, due to the anti-rebound structure, the inner receiving tube is locked after extending backward, preventing it from rebounding forward and thus avoiding the tip of the needle core from rebounding out from the front end of the receiving tube, eliminating the risk of puncture wounds to medical personnel and infection. Attached Figure Description

[0017] Figure 1 This is a perspective view of a medical needle with self-destructive anti-puncture function according to an embodiment of the present invention.

[0018] Figure 2 This is a perspective view of a medical needle with self-destructive anti-puncture function after the sheath has been removed, according to an embodiment of the present invention.

[0019] Figure 3 This is a cross-sectional view of a medical needle with self-destructive anti-puncture function after removing its sheath, according to an embodiment of the present invention.

[0020] Figure 4This is an exploded view of the structure of a medical needle with self-destructing anti-puncture function after removing the sheath, according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure of one type of outer receiving tube in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of another type of receiving tube in an embodiment of the present invention.

[0023] Figure 7 This is a perspective view of a medical needle with self-destruction and anti-puncture function after self-destruction, according to an embodiment of the present invention.

[0024] Figure label: Needle handle 1; Self-destruct switch 2; Thrust spring 3; Needle core 4; 5. Fixing pin; 51. Slot; 52. Return channel; 6. Exhaust diaphragm; 61. Fixing plug; 7. Receiving tube 7, inner receiving tube 71, sliding guide post 711, outer receiving tube 72, sliding guide groove 721, inclined step 7211, clamping part 722, and buckle 723; Needle seat 8, cannula seat 81, switch seat 811, infusion seat 82, infusion channel 821; Sleeve 9; 10 sac-like tubes; Flow stop switch 11, screw cap 111, valve core 112, pressure block 113; Sheath 12, side wings 121, snap-fit ​​part 122. Detailed Implementation

[0025] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0026] This embodiment describes an indwelling needle with a self-destructing anti-puncture function, such as... Figures 1 to 4As shown, its structure includes a receiving tube 7, a needle handle 1, a needle seat 8, and a needle core 4. A needle fixing component 5 is connected to the rear end of the needle core 4. The needle fixing component 5 passes through the needle handle 1, and the needle core 4 passes through the needle handle 1 and the needle seat 8. The needle fixing component 5 is provided with a return channel 52, the front end of which communicates with the needle core 4. The rear end of the return channel 52 is provided with an exhaust diaphragm 6 and a fixing plug 61 for fixing the exhaust diaphragm 6. The fixing plug 61 is connected to the needle fixing component 5 for easy assembly. The needle fixing component 5 is fitted with a thrust spring 3 for pushing the needle fixing component 5 and the needle core 4 back into the receiving tube. The two ends of the thrust spring 3 abut against the needle handle 1 and the needle fixing component 5, respectively. A self-destruct switch 2 is installed on the needle handle 1. The needle fixing component 5 is provided with a slot 51. The self-destruct switch 2 locks into the slot 51. Pressing the self-destruct switch 2 releases the locking of the needle fixing component 5, allowing the needle fixing component 5 and the needle core 4 to be pushed backward by the thrust spring 3.

[0027] like Figure 3 As shown, the needle hub 8 includes a cannula seat 81 and an infusion seat 82 connected to each other. The infusion seat 82 is provided with an infusion channel 821. A cannula 9 is bonded and fixed to the front end of the cannula seat 81, and the cannula 9 communicates with the infusion channel 821. A balloon tube 10 is provided inside the cannula seat 81 and the infusion seat 82. The balloon tube 10 is a soft tube and is housed inside the needle hub 8. One end of the balloon tube 10 communicates with the infusion channel 821, and the other end of the balloon tube 10 communicates with the cannula 9. The infusion channel 821, the balloon tube 10, and the cannula 9 form a main channel. The needle core 4 passes through the main channel and the cannula 9. The front end of the needle core 4 can extend from the front end of the cannula 9 or retract into the cannula 9. A flow stop switch 11 is installed on the needle holder 8 to radially compress and stop the flow in the main channel. The flow stop switch 11 is connected to the needle holder 8 and can press down the balloon tube 10, thereby indirectly pressing down the needle core 4 to prevent it from being pushed by the thrust spring 3. Only when the pressure of the flow stop switch 11 on the needle core 4 is released can the thrust spring 3 push the needle fixing component 5 and the needle core 4 to retract and self-destruct. In the prior art, needles with self-destruct function immediately rebound and self-destruct after the self-destruct switch is activated. This structure has shortcomings in actual use: the needle core may completely self-destruct before the medical staff has adjusted the needle withdrawal state, resulting in the trouble of needing to puncture again. In this embodiment, after the self-destruct switch 2 is pressed, the needle core 4 will not be pushed immediately. At this time, the needle seat 8 can be adjusted appropriately to achieve the best needle placement state before slowly withdrawing the needle core 4. The needle core 4 will only be pushed back by the thrust spring 3 after it is no longer pressed by the stop switch 11. The needle core 4 will only retract after the front end is away from the patient, making it more convenient to operate and thus improving safety performance.

[0028] Specifically, such as Figure 3 and Figure 4As shown, the sleeve seat 81 is provided with a switch seat 811, and the switch seat 811 is provided with a through hole arranged in the radial direction of the tube 10. The outer side of the through hole is provided with an external thread. The flow stop switch 11 includes a spiral cap 111, a valve core 112 and a pressure block 113. The inner side of the spiral cap 111 is provided with an internal thread that matches the external thread. The pressure block 113 passes through the through hole. The valve core 112 passes through the spiral cap 111 and is fixedly connected to the pressure block 113. The spiral cap 111 is provided with an inward protrusion. The top surface of the protrusion abuts against the valve core 112 and the bottom surface of the protrusion abuts against the pressure block 113. When the balloon tube 10 needs to be compressed, the screw cap 111 is rotated clockwise, and then the protrusion presses down on the pressure block 113 to compress the balloon tube 10. When it is necessary to release the pressure of the pressure block 113 on the balloon tube 10, the screw cap 111 is rotated counterclockwise, and the protrusion pushes up the valve core 112. The valve core 112 drives the pressure block 113 to move upward, thereby releasing the pressure on the balloon tube 10. If other compression and propulsion methods other than the screw propulsion method are used, when the propulsion stroke stops, blood will be drawn back into the cannula due to the removal of the external force of the propulsion and compression, resulting in thrombus formation. However, the screw propulsion and compression method set in this embodiment does not produce retraction when the external force is removed; it generates positive pressure and has no rebound space, which can effectively prevent this phenomenon of blood flowing back into the cannula. Therefore, this screw propulsion method is preferred.

[0029] like Figures 3-5 As shown, the receiving tube 7 includes an outer receiving tube 72 and an inner receiving tube 71. The inner receiving tube 71 is movably inserted into the outer receiving tube 72. During self-destruction, when the fixing member 5 and the needle core 4 retract backward, the needle core 4 pushes the inner receiving tube 71 out from the rear end of the outer receiving tube 72, so that the entire receiving tube extends and accommodates the entire needle core 4 inside the receiving tube. The outer receiving tube 72 is provided with a clamping part 722 for radially pressing against the inner receiving tube 71. The clamping part 722 and the inner receiving tube 71 are clamped together so that the inner receiving tube 71 can only move backward under the push of the elastic member. During assembly, the inner receiving tube 71 is simply pressed into the outer receiving tube 72 to prevent loosening and make the structure more compact. The receiving tube 7 is provided with an anti-rebound structure to prevent the inner receiving tube 71 from springing forward. There are two types of anti-rebound structures: the first type is as follows... Figure 4 and Figure 5As shown, the anti-rebound structure includes a sliding guide post 711 and a sliding guide groove 721 that cooperate with each other. The sliding guide post 711 is disposed in the inner receiving tube 71, and the sliding guide groove 721 is disposed on the inner side of the outer receiving tube 72. The rear end of the sliding guide groove 721 turns radially along the receiving tube 7 to form a sloped step 7211. During the process of the inner receiving tube 71 passing through the rear end of the outer receiving tube 72, the sliding guide post 711 automatically rotates at a certain angle and locks onto the sloped step 7211 by the force of the thrust spring 3, which can prevent the inner receiving tube 71 from rebounding forward. Of course, in practice, the sliding guide groove can be replaced by being disposed in the inner receiving tube, and the sliding guide post can be replaced by being disposed in the outer receiving tube; the second type is as follows. Figure 6 As shown, the anti-rebound structure includes a buckle 723 disposed on the outer receiving tube 72. The free end of the buckle 723 is inclined toward the inside of the outer receiving tube 72. After the inner receiving tube 71 extends out of the outer receiving tube 72 by a predetermined length, the front end of the inner receiving tube 71 is pressed by the buckle 723, thus preventing the inner receiving tube 71 from rebounding.

[0030] In this embodiment, as Figure 1 As shown, the needle with self-destructive anti-puncture function also includes a sheath 12, which covers the tube 9. The sheath 12 is provided with a side wing 121 to block the self-destruct switch 2, preventing medical personnel from accidentally pressing the self-destruct switch 2. The sheath 12 is provided with a locking part 122, which locks the needle handle 1, thereby preventing the needle handle 1 from separating from the needle seat 8 when the stop switch 11 does not press the needle core 4. Because the screw cap 111 does not press the needle core 4 at the factory, the sheath 12 can temporarily connect the needle handle 1 and the needle seat 8.

[0031] The working principle of this embodiment is as follows: During use (conventional operating procedures such as disinfection will not be described in detail here), when intravenous infusion is required, prepare the needle with self-destructive anti-puncture function, remove the sheath 12, rotate the screw cap 111 of the stop valve 11 clockwise, causing the pressure block 113 to move downward and compress the balloon tube 10, thus blocking the channel at the balloon tube 10; then locate the patient's blood vessel, push the needle handle 1 to insert the tip of the needle core 4 into the patient's blood vessel, and observe blood return in the return channel 52 of the needle fixing component 5, indicating successful insertion of the blood vessel. (Because the rear end of the needle holder 5 is equipped with an exhaust diaphragm 6, the exhaust diaphragm 6 can allow the gas in the return channel 52 to be discharged, and the blood can flow smoothly from the needle core 4 to the return channel 52); then, the needle handle 1 is partially withdrawn relative to the infusion seat 82, causing the needle core 4 to retract into the cannula 9. The entire needle is pushed forward, causing the cannula 9 to be inserted into the blood vessel. Then, the self-destruct switch 2 is pressed to release the clamping constraint on the needle holder 5. However, at this time, the flow stop switch 11 still presses the needle core 4, so the needle core 4 will not be pushed back. Then, the needle handle 1 is pulled backward until the needle core 4 is retracted and is no longer pressed by the flow stop switch 11. Under the action of the thrust spring 3, the needle holder 5 and the needle core 4 move backward. At the same time, the inner receiving tube 71 passes through the rear end of the outer receiving tube 72. The receiving tube 7 extends to accommodate the entire needle core 4, forming a shape like... Figure 7 The structure after self-destruction is shown. When the inner receiving tube 71 retracts to the preset position, it extends backward and is locked to prevent it from springing back forward. This prevents the tip of the needle core 4 from rebounding out of the front of the receiving tube 7, eliminating the risk of puncture wounds to medical personnel and infection. Then, the outer infusion set is connected to the infusion base 82, and the screw cap 111 is rotated counterclockwise to release the pressure of the pressure block 113 on the balloon tube 10, allowing for normal infusion. In practice, this design, with the receiving tube 7 in two sections and an anti-rebound structure, can also be applied to needles with other functions, not just in the field of indwelling needles.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A medical needle with a self-destructing anti-puncture function, characterized in that: The device includes a needle holder and a needle core inserted through the needle holder, as well as a receiving tube, a self-destruct switch, and an elastic element. The receiving tube includes an outer receiving tube and an inner receiving tube, with the inner receiving tube movably inserted inside the outer receiving tube. By operating the self-destruct switch, the elastic element can be activated to drive the needle core to retract into the receiving tube. The retraction of the needle core pushes the inner receiving tube out from the rear end of the outer receiving tube, and the receiving tube is provided with an anti-rebound structure to prevent the inner receiving tube from springing forward after it has passed out from the rear end of the outer receiving tube. The needle with self-destruct anti-puncture function also includes a needle handle located between the needle base and the receiving tube. The rear end of the needle core is connected to a needle fixing component. The needle core and the needle fixing component are inserted through the needle handle. The self-destruct switch is installed on the needle handle. The needle fixing component is provided with a slot. The self-destruct switch is locked in the slot. The elastic component is a thrust spring. The two ends of the thrust spring abut against the needle handle and the needle fixing component respectively. Moving the self-destruct switch can release the needle fixing component. Under the action of the thrust spring, the needle fixing component and the needle core retract into the receiving tube. The needle seat is provided with a switch seat, the switch seat is provided with a through hole, and a flow stop switch for radially compressing and stopping the flow of the main channel is installed on the needle seat. The flow stop switch is connected to the needle seat. When the flow stop switch radially compresses and stops the flow, it presses down on the needle core to prevent it from being pushed by the elastic element. The flow stop switch includes a spiral cap, a pressure block and a valve core. The spiral cap is threadedly connected to the through hole. The pressure block passes through the through hole. The valve core passes through the spiral cap and is fixedly connected to the pressure block. The spiral cap can rotate relative to the valve core. The spiral cap is provided with an inward protrusion. The top surface of the protrusion abuts against the valve core and the bottom surface of the protrusion abuts against the pressure block. The anti-rebound structure includes a sliding guide post and a sliding guide groove that cooperate with each other. The sliding guide post is disposed in one of the outer receiving tube and the inner receiving tube, and the sliding guide groove is disposed in the other of the outer receiving tube and the inner receiving tube. The rear end of the sliding guide groove turns along the radial direction of the receiving tube to form a sloping step. As the inner receiving tube passes through the rear end of the outer receiving tube, the sliding guide post rotates along the sliding guide groove and gets stuck on the sloping step, thereby preventing the inner receiving tube from rebounding forward.

2. A medical needle with self-destructive anti-puncture function according to claim 1, characterized in that: The needle fixing component is provided with a reflux channel. The front end of the reflux channel is connected to the needle core, and the rear end of the reflux channel is provided with an exhaust diaphragm and a fixing plug for fixing the exhaust diaphragm. The fixing plug is connected to the needle fixing component.

3. A medical needle with self-destructive anti-puncture function according to claim 1, characterized in that: The outer receiving tube is provided with a clamping part for pressing against the inner receiving tube, so that the inner receiving tube can only move backward when pushed by the elastic member.

4. A medical needle with self-destructive anti-puncture function according to claim 1, characterized in that: The needle hub is provided with a main channel and a sleeve that communicates with the main channel. The needle core passes through the main channel and the sleeve, and the front end of the needle core can extend out from the front end of the sleeve or retract into the sleeve.

5. A medical needle with self-destructive anti-puncture function according to claim 1, characterized in that: The needle with self-destruct and anti-puncture function also includes a sheath that covers the front end of the needle core and has wings that shield the self-destruct switch.

6. A medical needle with self-destructive anti-puncture function according to claim 5, characterized in that: The sheath is provided with a snap-fit ​​part, which snaps the needle handle, thereby preventing the needle handle from separating from the needle seat when the stop switch does not press the needle core.

7. A medical needle with a self-destructing anti-puncture function, characterized in that: The device includes a needle holder and a needle core inserted through the needle holder, as well as a receiving tube, a self-destruct switch, and an elastic element. The receiving tube includes an outer receiving tube and an inner receiving tube, with the inner receiving tube movably inserted inside the outer receiving tube. By operating the self-destruct switch, the elastic element can be activated to drive the needle core to retract into the receiving tube. The retraction of the needle core pushes the inner receiving tube out from the rear end of the outer receiving tube, and the receiving tube is provided with an anti-rebound structure to prevent the inner receiving tube from springing forward after it has passed out from the rear end of the outer receiving tube. The needle with self-destruct anti-puncture function also includes a needle handle located between the needle base and the receiving tube. The rear end of the needle core is connected to a needle fixing component. The needle core and the needle fixing component are inserted through the needle handle. The self-destruct switch is installed on the needle handle. The needle fixing component is provided with a slot. The self-destruct switch is locked in the slot. The elastic component is a thrust spring. The two ends of the thrust spring abut against the needle handle and the needle fixing component respectively. Moving the self-destruct switch can release the needle fixing component. Under the action of the thrust spring, the needle fixing component and the needle core retract into the receiving tube. The needle seat is provided with a switch seat, the switch seat is provided with a through hole, and a flow stop switch for radially compressing and stopping the flow of the main channel is installed on the needle seat. The flow stop switch is connected to the needle seat. When the flow stop switch radially compresses and stops the flow, it presses down on the needle core to prevent it from being pushed by the elastic element. The flow stop switch includes a spiral cap, a pressure block and a valve core. The spiral cap is threadedly connected to the through hole. The pressure block passes through the through hole. The valve core passes through the spiral cap and is fixedly connected to the pressure block. The spiral cap can rotate relative to the valve core. The spiral cap is provided with an inward protrusion. The top surface of the protrusion abuts against the valve core and the bottom surface of the protrusion abuts against the pressure block. The anti-rebound structure includes a buckle installed on the outer receiving tube, and the inner receiving tube is locked by the buckle after passing through the outer receiving tube for a predetermined length.

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