A safety self-destructing syringe

Abstract

The present invention discloses a safe self-destructing syringe. At the upper end of the needle structure, there are a first hook and a second hook. During the injection process, the first boss of the needle structure restricts its retraction into the syringe barrel, enabling safe injection. After the injection is completed, the first inner hole and the second inner hole of the sealing plug cooperate with the first hook and the second hook respectively. The inclined surface on the second hook abuts against the second convex ring of the sealing plug, and there is an avoidance space below the first hook for the second convex ring to abut against, causing the central axis of the needle structure to deflect from the central axis of the syringe barrel and enabling it to be pulled into the syringe barrel along with the push rod to achieve self-destruction. This safe self-destructing syringe solves the contradictions in the use process of traditional retractable self-destructing syringes. During the injection process, the needle can withstand a large resistance from the skin and tissue without retracting, and after the injection is completed, only a small pulling force is required to pull back the needle to complete the retraction and self-destruction of the needle.

Description

Technical Field

[0001] The present invention relates to the technical field of syringes, and particularly to a safe self-destructing syringe. Background Art

[0002] After the syringe injection is completed, the needle tip will be contaminated with the patient's body fluid or tissue, and the needle tip is relatively sharp, making it inconvenient to discard and handle, increasing the risk of infection or stabbing for medical staff and cleaning staff.

[0003] Self-destructing syringes generally adopt the form of retracting the needle into the syringe barrel. The push rod in the syringe barrel pushes the sealing plug, so that the sealing plug squeezes the liquid medicine to the needle tip to achieve injection. Since a fastening structure that can cooperate with the tail end of the needle tip is provided at the front end of the sealing plug, after the injection is completed, the sealing plug and the needle tip are tightly fastened together. When pulling the push rod back, the sealing plug drags the needle tip to retract the needle tip into the syringe barrel. This design has an inevitable contradiction in use, that is, during the needle injection process, the needle tip is subjected to resistance from the skin tissue, and the needle tip has a tendency to move into the syringe barrel. If the needle tip retracts at this time, it will cause liquid leakage from the syringe barrel, resulting in a medical accident; on the other hand, when the injection is completed, the sealing plug and the tail end of the needle tip are tightly fastened. At this time, it is necessary to pull the push rod to drag the needle tip to the retracted state, but the force for pulling the push rod back cannot be too large. First, the sealing plug is generally made of silica gel. After being fastened to the tail end of the needle tip, the structure cannot withstand such a large pulling force. Second, the force for pulling the push rod back should not be too large for the convenience of medical staff. In order to achieve the effect of convenient use by medical staff, the static friction required to prevent the needle tip from retracting during the needle injection process is generally greater than the pulling force required to retract the needle tip by pulling the push rod back.

[0004] In order to balance the above contradictions, the existing retractable self-destructing syringes have a relatively complex structure, it is difficult to guarantee the product quality, and the actual use effect is not good, often having the following problems:

[0005] 1. The sealing effect between the needle tip and the front end of the syringe barrel is not good, and the front end of the syringe barrel is prone to liquid leakage during the injection process;

[0006] 2. After the needle tip injection is completed, during the process of pulling the push rod back, the cooperation between the sealing plug and the tail end of the needle tip is not firm, and the needle tip cannot be pulled back into the syringe barrel;

[0007] 3. When the needle tip is pulled back into the syringe barrel, the needle tip is easily pushed forward again by the push rod and pushed out of the syringe barrel, without achieving complete self-destruction. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide a safe self-destructing syringe, which has the characteristics of safe injection, and the needle tip is relatively easy to be pulled back into the syringe barrel and self-destruct.

[0009] The technical solution adopted by the present invention to solve its technical problems is:

[0010] A safety self-destructing syringe, comprising a syringe barrel, a push rod arranged inside the syringe barrel, an elastic sealing plug arranged at the lower end of the push rod, and a needle head structure installed at the lower end of the syringe barrel. The needle head structure includes a first hook arranged at the upper end, a second hook arranged below the first hook and on the opposite side, an inclined surface is formed between the second hook and the upper end surface of the needle head, a first boss is arranged directly below the same side of the second hook, and a first convex ring capable of being stuck on the boss to limit the movement of the needle head structure in the direction of the syringe barrel is arranged on the inner wall of the syringe barrel. A first inner hole capable of cooperating with the first hook is arranged at the lower end of the sealing plug, a second inner hole capable of cooperating with the second hook is arranged below the first inner hole, a guiding tapered hole is arranged below the second inner hole, a second convex ring is arranged between the first inner hole and the second inner hole, an avoidance space allowing the second convex ring to abut below the first hook is arranged below the first hook, and the second convex ring can abut on the inclined surface, causing the central axis of the needle head structure to deviate from the central axis of the syringe barrel.

[0011] The needle head structure below the boss is in a conical shape with a diameter gradually decreasing from top to bottom, and a sealing ring is arranged outside the conical body, and there are at least two sealing rings.

[0012] A liquid medicine cavity is formed between the sealing plug and the needle head structure, an injection cavity communicated with the liquid medicine cavity is arranged at the upper end of the needle head structure, and the cross-sectional area of the cavity of the injection cavity gradually increases from top to bottom.

[0013] A number of sealing convex rings in interference fit with the inner side wall of the syringe barrel are arranged outside the sealing plug.

[0014] A guiding tapered surface is formed between the first hook and the upper end surface of the needle head structure.

[0015] A third hook is arranged at the lower end of the push rod, an annular barb side edge is formed outside the third hook, and a third inner hole cooperating with the third hook is arranged at the upper end of the sealing plug.

[0016] The syringe barrel includes a syringe barrel cavity where the sealing plug is located and a needle head cavity for installing the needle head structure. The inner diameter of the syringe barrel cavity is larger than the inner diameter of the needle head cavity, and a step surface is formed between the syringe barrel cavity and the needle head cavity.

[0017] The needle head structure includes a needle orifice. When the needle head structure is located in the syringe barrel cavity, the step surface can abut against the needle orifice to limit its downward movement.

[0018] The beneficial effects of the present invention at least include:

[0019] 1. The liquid suction and injection processes of this syringe are the same as those of a common syringe. After the injection is completed, first, the first hook engages into the first inner hole of the sealing plug. The inclined surface on the opposite side of the first hook is abutted by the second convex ring, and a force is applied to this inclined surface. There is an avoidance space below the first hook on the opposite side. When the second convex ring abuts against the first hook, the first hook firmly engages into the first inner hole. At this time, the needle structure has a tendency to tilt towards the first hook. Since the sealing plug is elastic, as the sealing plug continues to move downward, the second hook engages into the second inner hole of the sealing plug, and the sealing plug and the needle structure complete the snap-fit. Then, the push rod is pulled upward. As the sealing plug drives the needle structure to gradually move upward, the inclined surface at the upper end (right side) of the needle structure is subjected to the elastic force of the abutment of the second convex ring, causing the needle structure to tilt around the intersection of the central axis and the upper end surface of the needle structure, resulting in the boss of the needle structure disengaging from the first convex ring of the needle barrel, that is, the first convex ring can no longer hold the boss to restrict the upward movement of the needle structure. Finally, the needle structure is pulled upward with the push rod and smoothly retracts into the syringe cavity. The advantages of this design are as follows. First, the design of the boss and the first convex ring effectively prevents the needle from retracting due to the resistance of the skin and tissue during the injection process, achieving safe injection. Second, the first hook and the second hook ensure the tight fit between the sealing plug and the needle structure during the process of pulling back the push rod. Third, it solves the contradiction in the use process of traditional retractable self-destruct syringes. During the injection process, the needle can withstand a large resistance from the skin and tissue without retracting, and after the injection is completed, only a small pulling force is required to pull back the needle to complete the retraction and self-destruction of the needle.

[0020] 2. The first barb enables the first hook to be tightly snap-fitted with the first inner hole, and the second barb enables the second hook to be tightly snap-fitted with the second inner hole. The guiding conical surface formed between the first hook and the upper end face of the needle structure makes it easier for the first hook to engage into the first inner hole.

[0021] 3. The second boss is used to abut against the upper surface of the first convex ring, which can limit the downward movement of the needle assembly and prevent the needle assembly from falling off from the needle cavity.

[0022] 4. The design of several sealing rings further prevents the liquid medicine from flowing out of the syringe on the one hand, and increases the static friction between the needle structure and the syringe on the other hand. The sealing rings are designed outside the conical needle structure. When the needle structure is subjected to a downward pressure, the greater the static friction, the less likely the needle structure is to retract due to resistance. When the needle structure is subjected to an upward pulling force, the smaller the static friction, the easier it is for the needle structure to be pulled back.

[0023] 5. The cavity volume of the injection chamber gradually increases from top to bottom, so that at the beginning of the injection, the large liquid pressure of the sealing plug squeezing the liquid medicine chamber into the injection chamber is slowed down, and the pressure of the fluid at the needle opening on the human internal environment during the injection is buffered.

[0024] 6. A number of sealing convex rings can enhance the sealing performance of the sealing plug. On the other hand, it can reduce the frictional resistance from the inner wall of the syringe barrel when the push rod is pushed and pulled.

[0025] 7. The barb side of the third hook of the push rod strengthens the tightness when the push rod cooperates with the sealing plug.

[0026] 8. When the needle structure is pulled into the syringe barrel cavity, the needle structure is in a skewed shape, and the end of the needle opening abuts against the step surface between the syringe barrel cavity and the needle head cavity, so that it cannot extend out any further to complete the self-destruction of the needle. Description of the Drawings

[0027] Figure 1 is a cross-sectional view of the present safety self-destructing syringe;

[0028] Figure 2 is a partial cross-sectional view of the present safety self-destructing syringe;

[0029] Figure 3 is a schematic structural view of the needle structure;

[0030] Figure 4 is a partial cross-sectional view of the syringe barrel;

[0031] Figure 5 is a partial cross-sectional view when the sealing plug cooperates with the needle structure;

[0032] Figure 6 is a cross-sectional view when the needle structure is pulled back into the syringe barrel cavity along with the sealing plug. Detailed Embodiments

[0033] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention clearer, the technical solutions of the present invention will be further described below with reference to the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings rather than all of them.

[0034] Refer to Figure 1 、 Figure 2 and Figure 4, the present invention provides a safety self-destructing syringe, which includes a syringe barrel 1, a push rod 2 arranged in the syringe barrel 1, an elastic sealing plug 3 arranged at the lower end of the push rod 2 and connected thereto, and a needle head structure 4 installed at the lower end of the syringe barrel 1. The needle head structure 4 includes a first hook 40 arranged at the upper end, and a second hook 41 arranged below the first hook 40 and on the opposite side. A slope 410 is formed between the second hook 41 and the upper end surface of the needle head structure 4. A boss 43 is arranged directly below the same side of the second hook 41. An inner wall of the syringe barrel 1 is provided with a first convex ring 110 that can be stuck on the boss 43 to limit the movement of the needle head structure 4 in the direction of the syringe barrel 1. A first inner hole 301 that can cooperate with the first hook 10 is arranged at the lower end of the sealing plug 3, and a second inner hole 302 that can cooperate with the second hook 41 is arranged below the first inner hole 301. A guiding tapered hole 304 is arranged below the second inner hole 302. A second convex ring 300 is arranged between the first inner hole 301 and the second inner hole 302. An avoidance space 47 is arranged below the first hook 40 to allow the second convex ring 300 to abut against the lower part of the first hook 40. The second convex ring 300 can abut against the slope 410, causing the central axis of the needle head structure 4 to deviate from the central axis of the syringe barrel 1.

[0035] Furthermore, the design of the boss 43 and the first convex ring 110 effectively prevents the needle from retracting due to the resistance of the skin and tissue during the injection process, achieving safe injection; the first hook 40 and the second hook 41 can ensure the tight cooperation between the sealing plug 3 and the needle head structure 4 during the process of pulling back the push rod 2; this safety self-destructing syringe solves the contradiction in the traditional retractable self-destructing syringe during use. During the injection process, the needle can withstand a large resistance from the skin and tissue without retracting, and after the injection is completed, only a small pulling force is required to pull back the needle to complete the retraction and self-destruction of the needle.

[0036] Refer to Figure 2 or Figure 3 , the first hook 40 includes a first barb 401 and a guiding tapered surface 400 arranged on the first barb 401, and the second hook 41 includes a second barb 411 arranged at the lower end of the slope 410.

[0037] Refer to Figure 2 , a second boss 46 that can abut against the upper surface of the first convex ring 110 is arranged directly below the same side of the avoidance space 47. The second boss 46 can limit the downward movement of the needle assembly 4 to prevent the needle assembly 4 from falling off from the needle cavity 11.

[0038] Refer to Figure 3, the needle structure 4 below the boss 43 is in the shape of a cone with a diameter gradually decreasing from top to bottom. A sealing ring 42 is provided outside the cone. There are at least two sealing rings 42. Preferably, there are two sealing rings 42, which are respectively arranged at different upper and lower positions outside the needle structure 4. The diameter of the sealing ring 42 arranged below is smaller than that of the sealing ring 42 above.

[0039] Furthermore, the design of the sealing ring 42 further prevents the liquid medicine from flowing out of the syringe barrel 1 on the one hand, and increases the static friction between the needle structure 4 and the syringe barrel 1 on the other hand. The sealing ring 42 is designed outside the conical needle structure 4. When the needle structure 4 is subjected to a downward pressure, the greater the static friction, the less likely the needle structure 4 is to be retracted due to resistance. When the needle structure 4 is subjected to an upward pulling force, the smaller the static friction, the easier it is for the needle structure 4 to be pulled back.

[0040] Refer to Figure 2 , a liquid medicine cavity 5 is formed between the sealing plug 3 and the needle structure 4. An injection cavity 44 communicating with the liquid medicine cavity 5 is provided at the upper end of the needle structure 4. The cross-sectional area of the cavity of the injection cavity 44 gradually increases from top to bottom, so that at the beginning of injection, the large liquid pressure when the sealing plug 4 squeezes the liquid medicine cavity 5 into the injection cavity 44 is slowed down, and the pressure of the fluid at the needle opening 45 on the human internal environment during injection is buffered.

[0041] Refer to Figure 2 , a number of sealing convex rings 31 that are in interference fit with the inner side wall of the syringe barrel 1 are provided outside the sealing plug 3. The number of sealing convex rings 31 can increase the sealing performance of the sealing plug 3, and on the other hand, reduce the frictional resistance from the inner wall of the syringe barrel 1 when the push rod 2 is pushed and pulled.

[0042] Preferably, refer to Figure 2 , a guiding conical surface 400 is formed between the first hanging hook 40 and the upper end face of the needle structure 4. The guiding conical surface 400 makes it easier for the first hanging hook 40 to be embedded into the first inner hole 301.

[0043] Refer to Figure 2 , a third hanging hook 20 is provided at the lower end of the push rod 2. An annular barb side 200 is formed on the outside of the third hanging hook 20. A third inner hole 303 that cooperates with the third hanging hook 20 is provided at the upper end of the sealing plug 3. The barb side 200 of the third hanging hook 20 of the push rod 2 strengthens the tightness when the push rod 2 and the sealing plug 3 cooperate.

[0044] Refer to Figure 4, the syringe barrel 1 includes a syringe chamber 10 where the sealing plug 3 is located and a needle chamber 11 for installing the needle structure 4. The inner diameter of the syringe chamber 10 is larger than that of the needle chamber 11, and a step surface 12 is formed between the syringe chamber 10 and the needle chamber 11. The needle structure 4 includes a needle 45. When the needle structure 4 is pulled into the syringe chamber 10, the needle structure 4 is in a skewed shape, and the end of the needle 45 abuts against the step surface 12 between the syringe chamber 10 and the needle chamber 11, making it unable to extend further, thus completing the self-destruction of the needle.

[0045] The usage process and principle of this safety self-destruction syringe are as follows:

[0046] The liquid suction and injection processes of the syringe are the same as those of a common syringe. After the injection is completed, first, the first hook 40 is inserted into the first inner hole 301 of the sealing plug 3, and the inclined surface 410 on the side opposite to the first hook 40 is abutted by the second convex ring 300. Refer to Figure 5 , a force is exerted on the inclined surface, and there is an avoidance space 47 below the first hook 40 on the opposite side. The second convex ring 300 abuts against the first hook 40, causing the first hook 40 to be firmly inserted into the first inner hole 301. At this time, the needle structure 4 has a tendency to tilt in the direction of the first hook 40 ( Figure 5 clockwise upward). Since the sealing plug 3 is elastic, as the sealing plug 3 continues to move downward, the second hook 41 is inserted into the second inner hole 302 of the sealing plug 3, and the sealing plug 3 and the needle structure 4 complete the snap-fit. Then, the push rod 2 is pulled upward. The sealing plug 3 drives the needle structure 4 to gradually move upward while the inclined surface 410 at the upper end (right side) of the needle structure 4 is subjected to the elastic force of the abutment of the second convex ring 300, causing the needle structure 4 to tilt around the intersection point of the central axis and the upper end surface of the needle structure 4, resulting in the boss 43 of the needle structure 4 being disengaged from the first convex ring 110 of the needle barrel 11, that is, the first convex ring 110 can no longer hold the boss 43, enabling the needle structure 4 to move upward. Finally, the needle structure 4 is pulled upward with the push rod 2 and smoothly retracts into the syringe chamber 10.

Claims

1. A safety self-destructing syringe, comprising a syringe barrel (1), a push rod (2) arranged in the syringe barrel (1), an elastic sealing plug (3) arranged at the lower end of the push rod (2) and connected thereto, and a needle structure (4) installed at the lower end of the syringe barrel (1), characterized in that, The needle structure (4) includes a first buckle (40) provided at the upper end, and a second buckle (41) provided below the first buckle (40) and on the opposite side. A slope (410) is formed between the second buckle (41) and the upper end surface of the needle structure (4). A first boss (43) is provided directly below the same side of the second buckle (41). An inner wall of the syringe barrel (1) is provided with a first convex ring (110) that can be stuck on the upper surface of the first boss (43) to limit the movement of the needle structure (4) in the direction of the syringe barrel (1). A first inner hole (301) that can cooperate with the first buckle (40) is provided at the lower end of the sealing plug (3), and a second inner hole (302) that can cooperate with the second buckle (41) is provided below the first inner hole (301). A guiding tapered hole (304) is provided below the second inner hole (302). A second convex ring (300) is provided between the first inner hole (301) and the second inner hole (302). An avoidance space (47) is provided below the first buckle (40) to allow the second convex ring (300) to abut against the lower part of the first buckle (40). The second convex ring (300) can abut against the slope (410), causing the central axis of the needle structure (4) to deviate from the central axis of the syringe barrel.

2. The safety self-destructing syringe according to claim 1, wherein The first buckle (40) includes a first barb (401) and a guiding tapered surface (400) provided on the first barb (401). The second buckle (41) includes a second barb (411) provided at the lower end of the slope (410).

3. A safety self-destructing syringe according to claim 1, wherein, A second boss (46) that can abut against the upper surface of the first convex ring (110) is provided directly below the same side of the avoidance space (47). The second boss (46) can limit the downward movement of the needle assembly (4).

4. A safety self-destructing syringe according to claim 1, characterized in that, The needle structure (4) below the first boss (43) is in the shape of a cone with a diameter gradually decreasing from top to bottom. A sealing ring (42) is provided outside the cone, and there are at least two sealing rings (42).

5. A safety self-destructing syringe according to claim 1, characterized in that, A liquid medicine cavity (5) is formed between the sealing plug (3) and the needle structure (4). An injection cavity (44) communicating with the liquid medicine cavity (5) is provided at the upper end of the needle structure (4). The cross-sectional area of the cavity of the injection cavity (44) gradually increases from top to bottom.

6. The safety self-destructing syringe according to claim 1, wherein, A plurality of sealing convex rings (31) that are in interference fit with the inner side wall of the syringe barrel (1) are provided outside the sealing plug (3).

7. The safety self-destructing syringe according to claim 1, wherein A third buckle (20) is provided at the lower end of the push rod (2). An annular barb side (200) is formed outside the third buckle (20). A third inner hole that cooperates with the third buckle (20) is provided at the upper end of the sealing plug (3).

8. The safety self-destructing syringe according to claim 1, characterized in that, The syringe barrel (1) includes a syringe barrel cavity (10) where the sealing plug (3) is located and a needle cavity (11) for installing the needle structure (4). The inner diameter of the syringe barrel cavity (10) is larger than the inner diameter of the needle cavity (11). A step surface (12) is formed between the syringe barrel cavity (10) and the needle cavity (11).

9. The safety self-destructing syringe according to claim 8, characterized in that, The needle structure (4) includes a needle (45). When the needle structure (4) is located in the syringe barrel cavity (10), the step surface (12) can abut against the needle (45) to limit its downward movement.

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