A retractable self-destructive safety syringe

Abstract

The present application discloses a retractable, self-destructive safety syringe, relating to the field of syringe technology. The syringe comprises an outer sleeve, a core rod movable within the outer sleeve, the core rod comprising a rod head and a rod body, the rod body comprising a front section, a middle section, and a rear section, a protective cap secured to the front end of the outer sleeve, a needle hub secured to the front opening of the outer sleeve, an internal cavity provided at the rear end of the needle hub, a needle tubing located at the front end of the needle hub, a closure located circumferentially around the rod head, the closure having a sealing bump and an O-ring located circumferentially around the front end of the needle hub. The retractable, self-destructive safety syringe of the present application improves safety and effectively prevents reuse, reducing the risk of cross-infection and the risk of needlestick injuries to personnel involved, and alleviating the psychological burden and fear of patients. The syringe does not require complex operating procedures or additional tools, making operation more stable and reliable, reducing accidents caused by improper operation, and reducing the amount of medical waste generated, thereby helping to alleviate the pressure on medical waste disposal.

Description

Technical Field

[0001] The present application belongs to the technical field of syringes, and in particular relates to a retractable self-destructive safety syringe. Background Art

[0002] In traditional medical injection practice, syringes, as indispensable medical devices, have always been the focus of attention for their safety and convenience.

[0003] After completing the injection task, the needle of a traditional syringe is often exposed to the external environment. This situation not only provides the possibility for the needle to be illegally used again or improperly handled, thereby causing a serious risk of cross-infection, which directly threatens public health and safety; at the same time, it also greatly increases the probability of medical staff being injured by needles during the operation, aggravating the risk of occupational exposure and infection, and posing a hidden danger to the health and safety of medical staff that cannot be ignored.

[0004] In light of this, the retractable, self-destructing safety syringe has emerged as an innovative solution to this problem. This type of syringe, through its ingenious design, can safely retract the needle into the syringe automatically or with a simple manual operation after the injection is completed, achieving an instant needle concealment and self-destruction mechanism. This fundamentally eliminates the reuse and improper disposal of needles, providing a strong guarantee for improving medical safety and public health.

[0005] However, although retractable self-destructive safety syringes have achieved remarkable results in improving injection safety and preventing cross-infection, some products on the current market still have technical defects that cannot be ignored.

[0006] Specifically, the structural design of some products is too complicated, which not only increases the manufacturing cost and process difficulty, but may also cause failures or damage during use, affecting the overall performance and safety of the syringe; at the same time, some syringes require medical personnel to perform specific operating steps or techniques during the retraction and self-destruction process, which places high demands on the operator's proficiency. Once the operation is improper, it may cause the syringe to fail or the needle to retract incompletely, thereby affecting the use effect and safety.

[0007] In addition, in the design and application of retractable self-destructive safety syringes, it is necessary to strictly comply with the relevant standard requirements of "GB15810-2019 Disposable Sterile Syringes" and "YY-T 0573.4-2020 Disposable Sterile Syringes Part 4: Preventing Reuse of Syringes" to ensure that the syringe has the function of preventing reuse, so as to protect public health safety and reduce the risk of cross-infection. Currently, some retractable syringe products on the market achieve needle retraction through an interlocking mechanism between the rubber stopper (rubber material) and the needle seat. However, this design places extremely high demands on the material selection and processing accuracy of the rubber stopper, which not only increases the manufacturing cost and difficulty, but may also cause retraction failure in actual application due to problems such as aging, wear or loose interlocking of the rubber stopper, seriously affecting the safety and effectiveness of use, thereby limiting the promotion and application of such products to a certain extent. Summary of the Invention

[0008] The purpose of this application is to provide a retractable self-destructive safety syringe. After use, the needle tube is retracted into the inner part of the outer sleeve by pulling back the core rod, and the design of the sealing protrusion makes the needle tube have an inclined angle after retraction, and this inclined angle makes it impossible to push the needle tube back into the outer sleeve when the core rod is pushed again.

[0009] In order to achieve the above objectives, the present invention provides a retractable self-destructive safety syringe, comprising:

[0010] The outer jacket has an open front and a rear end thereof and is interconnected. The front end of the outer jacket is provided with a needle seat. The front end and the rear end of the needle seat are open structures. The front end of the needle seat is provided with a needle tube, and the rear end of the needle seat is provided with an internal cavity.

[0011] The core rod includes a rod body and a rod head. The rod head is a barbed structure, and the cross-sectional area of ​​the rod head is smaller than that of the rod body. The core rod enters from the rear end of the outer sleeve. The outer sleeve of the rod head is provided with a sealing plug. The rod head passes through the sealing plug and is clamped in the internal cavity at the rear end of the needle seat through the barbed structure of the rod head.

[0012] The sealing protrusion is provided on either end face of the plug facing the needle seat. The sealing protrusion is used to press the needle seat against the plug by pulling back the core rod when the rod head is stuck in the internal cavity at the rear end of the needle seat. The plug and the sealing protrusion are both made of elastic material. The elasticity of the sealing protrusion causes the needle seat to tilt and causes the needle tube to retract into the interior of the outer sleeve to generate an inclination angle. The inclination angle is sufficient to prevent the needle tube from being pushed back out of the outer sleeve when the core rod is pushed again.

[0013] According to the above structure of the embodiment of the present application, the following additional technical features may also be provided:

[0014] Furthermore, the cross-sectional area of ​​the front end of the needle seat is smaller than the cross-sectional area of ​​the rear end of the needle seat, and the cross-sectional area of ​​the rear end of the needle seat is larger than the cross-sectional area of ​​the front end of the outer sleeve; the front end of the needle seat is provided with a raised snap ring, and the diameter of the snap ring is larger than the diameter of the front end of the outer sleeve; the end of the needle tube is connected to the needle seat through a liquid channel tube, and the diameter of the liquid channel tube is smaller than the diameter of the needle tube.

[0015] Furthermore, the opening at the rear end of the needle seat is a trapezoidal structure, the size of the opening close to the internal cavity is smaller than the size of the opening on the other side, and the size of the opening close to the internal cavity becomes larger as it moves away from the internal cavity.

[0016] Furthermore, the volume of the barb structure of the club head is smaller than the volume of the internal cavity.

[0017] Furthermore, the barb structure of the rod head is elastic. After passing through the opening at the rear end of the needle seat through its elastic deformation, it elastically recovers in the internal cavity and is stuck at the rear end of the needle seat; the elastic materials of the seal and the seal protrusion are both isoprene rubber.

[0018] Furthermore, an O-ring is provided around the front end of the needle holder, which increases the sealing performance with the outer sleeve when pushing and pulling the needle holder inside the outer sleeve. The sealing performance prevents leakage of the liquid while fixing the relative positions of the O-ring, the needle holder and the outer sleeve.

[0019] When the core rod is connected to the needle seat, when pushing and pulling inside the outer sleeve, the friction force generated by the O-ring and the outer sleeve is smaller than the binding force generated by the connection between the core rod and the needle seat. The size of the binding force is sufficient to pull the needle seat and the needle tube back to the inside of the outer sleeve when pulling back.

[0020] Furthermore, the rod body includes a front section, a middle section and a rear section; an annular concave notch is provided at the connection between the front section and the middle section, and the cross-sectional area of ​​the rear section is larger than the cross-sectional area of ​​the front section and the middle section.

[0021] Furthermore, a protruding structure extends to both sides of the rear end opening of the outer sleeve, and the cross-sectional area of ​​the protruding structure is larger than the cross-sectional area of ​​the rear section of the rod body, which is used to limit the pushing distance when pushing the core rod.

[0022] Furthermore, the annular inwardly concave notch is an inverted triangle structure, which reduces the external force required to be applied when the core rod self-destructs.

[0023] Furthermore, it includes a protective cap, the length of which is greater than the length of the needle tube, and the protective cap is clamped at the front end of the outer sleeve.

[0024] The retractable self-destructive safety syringe provided by the embodiment of the present application has the following beneficial technical effects compared with the prior art:

[0025] A retractable self-destructive safety syringe in an embodiment of the present application improves safety in use and prevents reuse. The needle tube can be retracted into the inner part of the outer sleeve after use, and the inclined angle generated by the sealing protrusion ensures that the needle tube cannot be extended again, thereby effectively preventing the reuse of the syringe and reducing the risk of cross infection.

[0026] The retractable self-destructive safety syringe in the embodiment of the present application greatly reduces the risk of needlestick injuries to medical staff or other personnel and protects their safety because the needle tube will be safely hidden inside the syringe after use. For patients who need frequent injections, the exposed needle of a traditional syringe may increase their fear and discomfort. Hiding the needle immediately after the injection is completed helps to reduce the patient's psychological burden and fear.

[0027] The main components of a retractable, self-destructing safety syringe, including the outer sleeve, needle hub, O-ring, core rod, and stopper, are designed to fit tightly together. This design eliminates the need for additional tools or complex procedures during assembly and use; the needle can be extended and retracted, as well as self-destructing, with a simple push-pull motion. The barbed design on the core rod's head allows it to easily pass through the inner cavity at the rear end of the needle hub when pushed forward, automatically locking after passage. When the core rod is pulled back, the stopper's raised point causes the needle to retract into the outer sleeve at a predetermined angle. This angle prevents the needle from being pushed out again, thus achieving the self-destructing function. This series of actions is automatically performed by the syringe's internal structural design, requiring no external tools or complex operations. The protruding structure at the rear end of the outer sleeve ensures that the outer sleeve tightly wraps around the core rod during use, making it easier to hold during clinical withdrawal and aspiration, further enhancing stability. This design allows the user to easily control the syringe's usage with a simple push-pull motion.

[0028] The design of the O-ring at the front end of the needle seat of a retractable self-destructive safety syringe in an embodiment of the present application cleverly balances the relationship between friction and binding force. During normal use, the sealing provided by the O-ring is sufficient to prevent the leakage of the drug solution and fix the relative positions of the various components; and when it is necessary to pull back the core rod, the binding force is sufficient to pull the needle seat together with the needle tube back to the inside of the outer sleeve. This design not only ensures the safety of use, but also simplifies the operating steps. The core rod is designed with a notch in an inverted triangle structure, which reduces the external force required to be applied when the core rod self-destructs. This means that when the self-destructive syringe needs to be broken, the user only needs to apply a small external force to destroy the core rod structure, making it unusable again, thereby realizing the self-destruction function of the syringe. This process also does not require complicated operating steps or additional tools.

[0029] The retractable self-destructive safety syringe of the embodiment of the present application is self-destructed after use and cannot be used again. The simplified design of the present application further reduces the manufacturing cost. From the overall effect of long-term use, considering that the additional waste and cost caused by repeated use are avoided, the amount of medical waste generated is reduced, which helps to alleviate the pressure of medical waste disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the overall structure of a retractable self-destructive safety syringe according to an embodiment of the present application is shown;

[0031] Figure 2 Shown Figure 1 An enlarged schematic diagram of a local structure of the overall structural diagram;

[0032] Figure 3 A schematic structural diagram of a retractable self-destructive safety syringe according to an embodiment of the present application when the rod head is locked is shown;

[0033] Figure 4 A schematic diagram showing a needle tube tilt of a retractable self-destructive safety syringe according to an embodiment of the present application is shown;

[0034] Figure 5 A schematic diagram of the self-destruction of the core rod of a retractable self-destructive safety syringe according to an embodiment of the present application is shown;

[0035] Figure 6 An enlarged schematic diagram showing a sealing stopper and sealing protrusion of a retractable self-destructive safety syringe according to an embodiment of the present application is shown;

[0036] Figure 7 A schematic structural diagram of a retractable self-destructive safety syringe according to an embodiment of the present application is shown;

[0037] Figure 8 The schematic diagram shows the structure of the rubber stopper and the pull-back rod of the prior art syringe.

[0038] Explanation of the accompanying reference numerals: 1. protective cap; 2. needle tube; 3. plug; 4. O-ring; 5. needle seat; 6. outer sleeve; 7. core rod; 8. plugging point; 9. rod head; 10. internal cavity; 11. rod body; 111 front section of the rod body; 112 middle section of the rod body; 113 rear section of the rod body; 12. prior art rubber plug; 13. prior art bite mechanism; 14. retaining ring; 15. liquid channel tube. DETAILED DESCRIPTION

[0039] like Figure 1 As shown, the embodiment of the present application provides a retractable self-destructive safety syringe, comprising:

[0040] The outer sleeve 6 is the main support structure of the syringe. Its front and rear ends are both open structures. This design facilitates the insertion of the needle seat 5 and the penetration of the core rod 7. The front end of the outer sleeve 6 is provided with a needle seat 5. The needle seat 5 also adopts a structural design with both the front and rear ends being open. A needle tube 2 is provided at the front end for injecting liquid medicine. The rear end of the needle seat 5 is provided with an internal cavity 10, such as Figure 2 As shown, the internal cavity 10 cooperates with the rod head 9 of the core rod 7 to realize the self-destruction function of the syringe.

[0041] In this embodiment, the opening structure of the outer sleeve 6 and the needle hub 5 allows the needle hub 5 to be stably fixed to the front end of the outer sleeve 6 after being combined with the O-ring 4, ensuring the stability and accuracy of the needle tube 2 during the injection process. Furthermore, the internal cavity 10 at the rear end of the needle hub 5 provides sufficient space for the rod head 9 of the core rod 7, allowing the rod head 9 to be smoothly inserted and fixed therein.

[0042] The core rod 7 is one of the core components of the syringe and consists of a rod body 11 and a rod head 9. The rod head 9 is designed as a barbed structure with a cross-sectional area smaller than that of the rod body 11. This design allows the rod head 9 to easily pass through the stopper 3 and be retained in the internal cavity 10 at the rear end of the needle hub 5.

[0043] like Figure 3 As shown, core rod 7 enters from the rear end of outer sleeve 6. By pushing core rod 7, rod head 9 gradually approaches and engages with internal cavity 10 at the rear end of needle hub 5. A seal 3 is also provided around rod head 9, tightly fitting over rod head 9 to prevent leakage of the drug solution during injection. Furthermore, the barbed structure of rod head 9 ensures that it is firmly fixed within internal cavity 10 once it is engaged, preventing it from falling out.

[0044] The core rod 7 of the present embodiment comprises a rod body 11 and a rod head 9. The rod body 11 provides sufficient strength and rigidity, making the core rod 7 less susceptible to bending or breaking during operation. The barbed structure of the rod head 9 enables the syringe's retractable self-destruct function. When self-destruction is required, simply pull back the core rod 7, and the barbed structure of the rod head 9 will engage the trapezoidal structure of the internal cavity 10 at the rear end of the needle hub 5, smoothly pulling the needle hub 5 and the needle tube 2 back into the outer sleeve 6.

[0045] The sealing protrusion 8 is provided on either end face of the sealing plug 3 facing the needle hub 5. Its function is to create an inclination angle when the core rod 7 is pulled back to retract the needle tubing 2 into the outer sleeve 6 when the rod head 9 is locked in the internal cavity 10 at the rear end of the needle hub 5. This inclination angle ensures that the needle tubing 2 cannot be re-extended from the outer sleeve 6 even if the core rod 7 is pushed again, thereby achieving the self-destruction function of the syringe and preventing reuse.

[0046] Both the seal 3 and the seal protrusion 8 are made of the elastic material isoprene rubber. Isoprene rubber is a high-performance rubber. It has excellent elasticity, cold resistance (glass transition temperature -68°C), and high tensile strength. Its resistance to incision and tearing under oxidation and repeated deformation conditions is higher than that of natural rubber. Isoprene rubber is also known as polyisoprene rubber, cis-1,4-polyisoprene rubber, isoprene rubber, and IR.

[0047] The sealing plug 3 and the sealing protrusion 8 are both made of isoprene rubber, an elastic material. When the rod head 9 is clamped in the internal cavity 10 at the rear end of the needle seat 5, the sealing protrusion 8 will be flattened due to elastic deformation. When the rod head 9 is pulled back, the needle seat 5 with the needle tube 2 is pulled into the outer sleeve 6. After the needle seat 5 is pulled into the outer sleeve 6, the sealing protrusion 8 will be elastically deformed, thereby exerting a lateral force on the needle seat 5, causing it to tilt, thereby causing the needle tube 2 to lean against one side of the outer sleeve 6, so that the needle tube 2 is retracted into the interior of the outer sleeve 6. The tilt angle is sufficient to prevent the needle tube 2 from being pushed out of the outer sleeve 6 again when the core rod 7 is pushed again.

[0048] like Figure 4 As shown, after the rod head 9 is inserted into the internal cavity 10, the core rod 7 is pulled back to retract the needle tube 2. Because the sealing protrusion 8 is separately provided on the end surface of the sealing plug 3 facing the needle seat 5, the rod head 9 can tightly press against the needle seat 5 after being inserted into the internal cavity 10, thereby forming an inclined angle. This angle not only prevents the needle tube 2 from extending again, but also ensures the safety and reliability of the syringe during the self-destruction process.

[0049] The cross-sectional area of ​​the front end of the needle hub 5 is smaller than that of the rear end of the needle hub 5. This design allows the needle hub 5 to be easily inserted into the outer sleeve 6 and remain stable. At the same time, the cross-sectional area of ​​the rear end of the needle hub 5 is larger than that of the front end of the outer sleeve 6, which provides sufficient space for the operation of the core rod 7 and ensures the stability of the needle hub 5 in the outer sleeve 6.

[0050] The front end of the needle seat 5 is provided with a circle of raised snap ring 14, the diameter of the snap ring 14 is larger than the diameter of the front end of the outer sleeve 6, and the snap ring 14 prevents the needle seat 5 from being easily pushed back into the outer sleeve 6. After actual inspection, the force used to force the needle seat 5 back into the outer sleeve 6 is much greater than the resistance encountered by the needle tube 2 when piercing the skin during subcutaneous injection.

[0051] The end of the needle tube 2 is connected to the needle seat 5 through a liquid channel tube 15. The diameter of the liquid channel tube 15 is smaller than the diameter of the needle tube 2. Such a physical design will not cause the needle tube 2 to retract when puncturing the skin during subcutaneous injection.

[0052] The opening at the rear end of the needle hub 5 is designed as a trapezoidal structure, with the opening closer to the internal cavity 10 being smaller than the opening on the other side, and the opening closer to the internal cavity 10 gradually increasing in size as it moves away from the internal cavity 10. This design allows the rod head 9 to smoothly pass through the opening at the rear end of the needle hub 5 and be retained in the internal cavity 10. The left and right sides of the internal cavity 10 are open on one side and closed on the other. This design facilitates the manufacture of the aforementioned trapezoidal structure.

[0053] The barb structure of the rod head 9 is smaller than the volume of the internal cavity 10, which allows the rod head 9 to be easily inserted into the internal cavity 10 without being unable to be fixed due to excessive volume. At the same time, the barb structure of the rod head 9 is elastic. After elastic deformation, it passes through the opening at the rear end of the needle hub 5 and then elastically recovers in the internal cavity 10, locking it at the rear end of the needle hub 5.

[0054] The barb structure of the rod head 9 of the embodiment of the present application not only realizes the self-destruction function of the syringe, but also ensures safety and reliability during the injection process. Its elastic design allows the rod head 9 to be firmly fixed in the internal cavity 10 after being inserted therein, and is not easy to fall off or loosen.

[0055] An O-ring 4 is provided around the front end of the needle seat 5. The function of the O-ring 4 is to make the fit between the needle seat 5 and the outer sleeve 6 tighter, increase the tightness of the device body, and reduce the risk of leakage caused by the pressure generated between the outer sleeve 6 and the closure 3 during injection.

[0056] The core rod 7 comprises a rod head 9, a front section 111, a middle section 112, and a rear section 113. The front section 111 is connected to the rod head 9, ensuring the integrity and stability of the core rod 7. An annular, inwardly recessed notch is provided at the junction of the front section 111 and the middle section 112. This design not only reduces the weight of the core rod 7 but also facilitates operation and control of the pushing distance, making it easier to hold during clinical aspiration and aspiration, further enhancing stability.

[0057] like Figure 7 As shown, the cross-sectional area of ​​the rear section 113 of the rod body is larger than the cross-sectional area of ​​the front section 111 and the middle section 112 of the rod body. This design provides sufficient gripping space, allowing the operator to easily grip and push the core rod 7. At the same time, the larger cross-sectional area of ​​the rear section 113 of the rod body also increases the stability and durability of the syringe.

[0058] The rear end opening of the outer sleeve 6 has protrusions extending to both sides, and the cross-sectional area of ​​the protrusions is larger than the cross-sectional area of ​​the rear section 113 of the rod body. This design is used to enhance the friction between the outer sleeve 6 and the core rod 7, thereby ensuring that the outer sleeve 6 can tightly wrap around the core rod 7 during use. At the same time, it is convenient to hold during clinical withdrawal and aspiration of liquid medicine, further enhancing the stability of use.

[0059] like Figure 5 and Figure 6 As shown, the annular indentation is designed as an inverted triangle structure. This design helps reduce the external force required when the core rod 7 retracts and self-destructs, making the operation easier and more convenient. At the same time, the inverted triangle structure design also increases the stability and reliability of the core rod 7 during the self-destruction process.

[0060] The embodiment of the present application also provides a protective cap 1, such as Figure 1 As shown, the protective cap 1 is longer than the needle tube 2 and is used to protect the needle tube 2 when not in use to prevent accidental punctures. The protective cap 1 can be clipped onto the front end of the outer sleeve 6 to ensure safety and convenience during carrying and storage.

[0061] like Figure 8 As shown, a syringe in the prior art achieves needle retraction through a prior art engagement mechanism 13 between a prior art rubber stopper 12 and a needle seat. Compared with the prior art retractable syringe product that is retracted after engagement of the rubber stopper with the needle seat, the present application provides a retractable self-destructive safety syringe that utilizes the mechanical structure of a plastic part to achieve engagement and retraction, thereby reducing the requirements on the rubber stopper material and processing accuracy, and improving the safety and stability of the retraction self-destruction.

[0062] This design of the present application not only simplifies the needle seat structure and smoothes the liquid channel, but also improves the efficiency of the production process and the one-time production qualification rate, thereby reducing production costs and enabling this patented product to be promoted and applied more quickly.

[0063] This application proposes an innovative retractable self-destructive safety syringe. Through structural innovation and the mechanical fit between the protrusions on the stopper and the needle seat, it not only meets the functional requirements of "GB15810-2019 Disposable Sterile Syringes" and "YY-T 0573.4-2020 Disposable Sterile Syringes Part 4: Prevention of Reuse of Syringes", but also achieves the superior performance of the needle tip automatically leaning against the wall after retraction and cannot be pushed back. This design goes beyond the limitations of existing standards and provides more reliable protection for the safe use of syringes.

[0064] In summary, the retractable, self-destructing safety syringe provided in the embodiments of the present application has the advantages of a sophisticated structural design, safe and reliable use, and convenient operation. Through the coordinated and cooperative design of components such as the outer sleeve 6, needle seat 5, core rod 7, sealing protrusion 8, sealing stopper 3, O-ring 4, core rod 7, rod body 11, the rear end structure of the outer sleeve 6, the internal concave notch, and the protective cap 1, the syringe's self-destruct function is achieved, ensuring safety and reliability during the injection process. Furthermore, its sophisticated structural design and convenient operation also make this syringe promising broad clinical applications.

Claims

1. A retractable self-destructive safety syringe, characterized in that: include: A jacket (6), wherein the front end and the rear end of the jacket (6) are both open structures and are interconnected, the front end of the jacket (6) is provided with a needle seat (5), the front end and the rear end of the needle seat (5) are both open structures, the front end of the needle seat (5) is provided with a needle tube (2), and the rear end of the needle seat (5) is provided with an internal cavity (10); A core rod (7), the core rod (7) comprising a rod body (11) and a rod head (9), the rod head (9) being a barb structure, and the cross-sectional area of ​​the rod head (9) being smaller than the cross-sectional area of ​​the rod body (11), the core rod (7) entering from the rear end of the outer sleeve (6), the outer sleeve of the rod head (9) being provided with a sealing plug (3), the rod head (9) passing through the sealing plug (3), and being clamped in the internal cavity (10) at the rear end of the needle seat (5) by the barb structure of the rod head (9); a sealing convex point (8), the sealing convex point (8) being arranged on any end face of the sealing plug (3) facing the needle seat (5), the sealing convex point (8) being used for causing the sealing convex point (8) on any end face of the sealing plug (3) to press against the needle seat (5) by pulling back the core rod (7) when the rod head (9) is clamped in the internal cavity (10) at the rear end of the needle seat (5), the sealing convex point (8) being used for causing the sealing convex point (8) on any end face of the sealing plug (3) to press against the needle seat (5), the sealing plug (3) and the sealing convex point (8) being both made of elastic material, the elasticity of the sealing convex point (8) causing the needle seat (5) to tilt, and causing the needle tube (2) to retract into the interior of the outer sleeve (6) to generate an inclination angle, the inclination angle being such that when the core rod (7) is pushed again, the needle tube (2) cannot be pushed out of the outer sleeve (6) again; The barb structure of the rod head (9) is elastic, and after elastic deformation passes through the opening at the rear end of the needle seat (5), it elastically recovers in the internal cavity (10) and is locked at the rear end of the needle seat (5).

2. A retractable self-destructive safety syringe according to claim 1, characterized in that: The cross-sectional area of ​​the front end of the needle seat (5) is smaller than the cross-sectional area of ​​the rear end of the needle seat (5), and the cross-sectional area of ​​the rear end of the needle seat (5) is larger than the cross-sectional area of ​​the front end of the outer sleeve (6); the front end of the needle seat (5) is provided with a raised snap ring (14), and the diameter of the snap ring (14) is larger than the diameter of the front end of the outer sleeve (6); the end of the needle tube (2) is connected to the needle seat (5) through a liquid channel tube (15), and the diameter of the liquid channel tube (15) is smaller than the diameter of the needle tube (2).

3. A retractable self-destructive safety syringe according to claim 1, characterized in that: The opening at the rear end of the needle seat (5) is a trapezoidal structure, the size of the opening close to the internal cavity (10) is smaller than the size of the opening on the other side, and the size of the opening close to the internal cavity (10) increases as it moves away from the internal cavity (10).

4. A retractable self-destructive safety syringe as claimed in claim 3, characterized in that: The volume of the barb structure of the rod head (9) is smaller than the volume of the internal cavity (10).

5. A retractable self-destructive safety syringe as claimed in claim 4, characterized in that: The elastic materials of the sealing plug (3) and the sealing protrusion (8) are both isoprene rubber.

6. The retractable self-destructive safety syringe according to claim 1, characterized in that: An O-ring (4) is provided on the circumference of the front end of the needle seat (5), and the O-ring (4) increases the sealing performance with the outer sleeve (6) when the needle seat (5) is pushed or pulled inside the outer sleeve (6). The sealing performance prevents the leakage of the liquid medicine and fixes the relative positions of the O-ring (4), the needle seat (5) and the outer sleeve (6); When the core rod (7) is connected to the needle seat (5) by a locking mechanism, when pushing and pulling are performed inside the outer sleeve (6), the friction force generated by the O-ring (4) and the outer sleeve (6) is smaller than the binding force generated by the locking mechanism between the core rod (7) and the needle seat (5), and the magnitude of the binding force is sufficient to pull the needle seat (5) together with the needle tube (2) back into the inner sleeve (6) when pulling back.

7. The retractable self-destructive safety syringe according to claim 1, characterized in that: The rod body (11) comprises a rod body front section (111), a rod body middle section (112) and a rod body rear section (113); an annular inwardly concave notch is provided at the connection between the rod body front section (111) and the rod body middle section (112); and the cross-sectional area of ​​the rod body rear section (113) is larger than the cross-sectional areas of the rod body front section (111) and the rod body middle section (112).

8. The retractable self-destructive safety syringe according to claim 7, characterized in that: A protruding structure extends to both sides of the rear end opening of the outer sleeve (6), and the cross-sectional area of ​​the protruding structure is larger than the cross-sectional area of ​​the rear section (113) of the rod body, and is used to limit the pushing distance when pushing the core rod (7).

9. The retractable self-destructive safety syringe according to claim 7, characterized in that: The annular inwardly concave notch is an inverted triangle structure, which reduces the external force required to be applied when the core rod (7) self-destructs.

10. The retractable self-destructive safety syringe according to claim 1, characterized in that: It comprises a protective cap (1), the length of the protective cap is greater than the length of the needle tube (2), and the protective cap is clamped at the front end of the outer sleeve (6).

Images