WO2011012014A1

WO2011012014A1 - Improved safety syringe

Info

Publication number: WO2011012014A1
Application number: PCT/CN2010/073276
Authority: WO
Inventors: 林作钱
Original assignee: 温岭市千禧光医疗器械有限公司
Priority date: 2009-07-30
Filing date: 2010-05-26
Publication date: 2011-02-03
Also published as: CN201469833U

Abstract

An improved safety syringe comprises a hollow barrel (1), a push rod (2), a rubber plug (3) and a needle hub (4). A locking ring (7) under the needle hub movably matches the inner wall of the barrel. The front end of the push rod is formed with a conical platform (211). Elastic supporting claws (6) at the lower end of the needle hub, clamp into grooves set in the inner wall of the barrel. The outer wall of the locking ring presses against the elastic supporting claws. At least two flanges (612) set at the lower end of the needle hub match with shoulders (613) on the inner wall of the barrel. An inner hole of the locking ring is provided with an elastic detent (8) that can be clamped with the conical platform. After injecting, the conical platform in the front end of the push rod is clamped with the elastic detent in the locking ring, and the locking ring slides downward by pulling the push rod down to make the needle hub separate from the inner wall of the barrel. By using the syringe with the above structure, the needle hub won't rush out of the barrel under the pushing force after injecting because the flanges set on the needle hub match with the shoulders on the wall of the barrel, and there will be less injection liquid remained in the barrel after injecting.

Description

An improved safety syringe

Technical field

The utility model belongs to a medical appliance, in particular to a safe self-destructing injector.

Background technique

Syringes are an indispensable tool for medical treatment. In order to avoid cross-contamination of blood, today's syringes use disposable products, but such disposable syringes can be reused if they are not artificially destroyed. Disposable syringes have been reused to cause cross-contamination, spread diseases, and many syringes have emerged. For example, a pull-back safety syringe, when the push rod is pulled back, the needle is followed into the syringe, but when pushed by external force, the needle will come out, which will also lead to cross infection. There is also a pullback safety syringe

200410017938. 0, When the push rod is pulled back, the injection needle will follow the needle into the syringe. The needle will be tilted to the side and not easy to pull out, but the needle tip is sharp. The plastic syringe is usually made of ordinary PP. The material is very soft and the external force is used. Under the needle, the needle tube is easily punctured, and the needle tip will be exposed, which will also lead to cross-infection. For safety, the following three methods are used in combination with the trial: 1. Increase the wall thickness of the syringe. 2. Add a steel filler to the PP material. 3. Select a rigid needle tube, which increases the cost, reduces the sharpness of the needle tube, and brings pain to the patient. There is also a defect part on the push rod. After the injection, the push rod is broken and the push rod is broken to achieve self-destruction. Although the push rod is destroyed, the syringe can still be used after the push rod is replaced. For the purpose of complete safety, in addition, the front end of the piston is not on the zero line before the pumping (blood) (ie, the piston is not pushed to the bottom), so the pumping (especially in the blood drawing) causes the pumping on the one hand. The (blood) dose is not standard. On the other hand, the air in the syringe remains more when the syringe is not in use. There is no boss on the needle holder of this type of syringe. It is not effective to prevent the needle holder from punching out of the syringe after the injection is completed. .

Summary of the invention

The technical problem to be solved by the present invention is to provide an improved safety syringe. After the syringe is injected, the needle holder does not punch out of the syringe. In order to solve the above technical problems, the present invention adopts the following technical solutions: An improved safety syringe includes a hollow syringe, a push rod sliding in the syringe, a rubber plug installed at the front end of the push rod, and a front end of the syringe There is a needle seat detachable from the syringe, and a lock ring that is in dynamic engagement with the inner wall of the syringe is disposed under the needle seat, and a frustum is formed at the front end of the push rod, wherein: the lower end of the needle seat is provided with at least two elastic supports The claw, correspondingly the inner wall of the syringe is provided with a groove into which the elastic claw is engaged, the outer wall of the locking ring is pressed against the elastic claw, and the lower end of the needle seat is further provided with at least two bosses, correspondingly the inner wall of the barrel is provided with the boss The mating shoulder, the inner ring of the locking ring is provided with a first elastic pawl that can be engaged with the frustum. After the injection is completed, the frustum at the front end of the push rod is engaged with the first elastic pawl in the locking ring. The pull-down push rod drives the lock ring to slide down, so that the needle seat is separated from the inner wall of the syringe.

The hollow cavity of the rubber plug is formed with a hollow boss, and the push rod is provided with a stopper, and the stopper is located below the hollow boss, and the stopper abuts against the bottom of the hollow boss, and the rubber plug is counteracted by the injection liquid during injection. The force and the thrust of the stopper are compressed and deformed. At this time, the frustum at the front end of the push rod extends forward in the axial direction of the push rod, and the frustum can be engaged with the first elastic pawl after the injection is completed.

The push rod is provided with a round table, and the round table is provided with a second elastic pawl extending obliquely to the inner wall of the barrel, and the end of the barrel is provided with an enlarged diameter portion, and the diameter and the diameter of the needle barrel are increased. A portion of the transition portion is provided with a slanting step, a second recess in which the second elastic pawl can be engaged when the pull-down push rod is arranged under the inclined step, and a retaining ring which can be pressed against the bottom of the round table in the enlarged portion.

The retaining ring is dynamically matched with the inner wall of the enlarged diameter end of the syringe, and can move up and down along the axial direction of the push rod without coming out of the syringe. The upper end of the retaining ring is provided with elastic claws which are gathered toward the center and can abut against the bottom of the round table.

The number of the second elastic pawls is at least two and symmetrically disposed, and the distance between the symmetric two claw tips is smaller than the inner diameter of the non-diameter enlarged portion of the syringe, which is larger than the minimum inner diameter at the oblique step in the inner cylinder.

The second groove is a ring of card grooves, the upper end surface of which is an oblique angle or a plane extending from the inside to the outside and along the direction of the second elastic pawl head, and the diameter of the side wall is larger than the distance between the symmetrical two pawl tips. .

The syringe of the above structure is provided, because the boss is provided with a boss, the boss and the wall of the syringe The shoulders are matched. After the injection, the needle seat does not punch out of the syringe under the action of the thrust. After the injection is completed, the lock ring is engaged with the needle seat, and the lock ring drives the needle seat to move downward, due to the needle seat. The lower end elastic claw has an inward movement tendency under the action of the elastic force, so that a small pulling force can be used to disengage the needle seat from the inner wall of the syringe to achieve the purpose of retracting the needle into the barrel. The end of the syringe is provided with an enlarged diameter portion, and the self-locking mechanism can be disposed at the rear end of the syringe. The push rod is provided with an elastic pawl extending toward the inner wall of the syringe. When the push rod is pulled down, the elastic pawl is engaged with the groove to prevent pushing. The rod moves upward, and the retaining ring below the elastic pawl abuts against the bottom of the pusher round table to prevent the push rod from moving downward. Due to the action of the groove, the elastic pawl cannot move in the radial direction, thereby achieving the purpose of locking the push rod. When the needle is not injected, the front end of the piston is on the zero line (that is, the piston is pushed to the bottom), and the exhaust gas is unobstructed after the liquid is pumped, and the residual amount of the injection liquid in the syringe is small after the injection.

DRAWINGS

Figure 1 is a cross-sectional view showing the installed and unused state of the push rod;

Figure 2 is a cross-sectional view of the pumping state;

Figure 3 is a cross-sectional view showing the state of completion of injection;

Figure 4 is a cross-sectional view of the needle retracted;

Figure 5 is a cross-sectional view showing the state of self-destruction;

Figure 6 is a schematic structural view of the push rod;

Figure 7 is a cross-sectional view of the syringe;

Figure 8 is a cross-sectional view of the arrow B in Figure 7;

Figure 9 is a cross-sectional view taken along line A-A of Figure 7;

Figure 10 is a cross-sectional view of the hub;

Figure 11 is a cross-sectional view taken along line C of Figure 10;

Figure 12 is a plan view of the needle hub;

Figure 13 is a cross-sectional view of the retaining ring;

Figure 14 is a cross-sectional view of the lock ring;

Figure 15 is a plan view of the lock ring;

Figure 16 is a schematic structural view of a rubber stopper;

Figure 17 is a partial enlarged view of Figure 1;

Figure 18 is a partial enlarged view of Figure 5; Figure 19 is a partial enlarged view of Figure 7;

Figure 20 is a partial enlarged view of Figure 4.

detailed description

Referring to Figures 1 and 2, a safety syringe includes a hollow syringe 1, a push rod 2 sliding in the syringe 1, and a rubber plug 3 mounted on the front end of the push rod 2. The front end of the syringe 1 is mounted The needle holder 4 is separated from the syringe, and the needle holder 4 is mounted on the needle holder 4. To ensure the sealing between the needle holder 4 and the syringe 1, the injection liquid does not leak during the injection, and the needle holder 4 and the syringe 1 are installed between the needle holders 4. Type 0 seal 41.

Referring to Figures 6, 7, 8, 9, 10, 11, 11, 12, 15, and 17, the lower end of the hub 4 is provided with at least two elastic claws 6 (see Figure 6). Correspondingly, the inner wall of the barrel is provided with a groove 611 (see FIG. 7) in which the elastic claw 6 is inserted, and when the injection is subjected to liquid pressure, in order to prevent the needle holder 4 from punching out of the syringe 1, at least two lower ends of the needle holder 4 are provided. The bosses 612 (see Fig. 11), correspondingly the inner wall of the barrel is provided with a shoulder 613 (see Fig. 8) that cooperates with the boss. A locking ring 7 (see FIG. 20) that is movably engaged with the inner wall of the barrel 1 is disposed under the needle holder 4. The outer wall of the locking ring touches the elastic claw 6 to be restrained in the groove 611, and the needle holder 4 is fixed. The front end of the push rod 2 is formed with a frustum 211 (see FIG. 6), and the inner hole of the lock ring 7 is provided with a first elastic pawl 8 (see FIG. 14, FIG. 15) that can be engaged with the frustum 211, first The number of the elastic pawls 8 is at least two. After the injection is completed, the frustum 211 at the front end of the push rod engages with the first elastic pawl 8 in the lock ring 7, and the elastic pawl 8 abuts against the lower end surface of the frustum 211. The pull-down push rod drives the lock ring 7 to slide down, and the elastic claw 6 is ejected from the groove 611 under the action of its own elastic force, so that the needle seat 4 is separated from the inner wall of the syringe.

Referring to FIG. 16 and FIG. 20, the hollow cavity of the rubber plug 3 is formed with a hollow boss 311, and the push rod 2 is provided with a stopper 212 (see FIG. 6). The stopper 212 is located below the hollow boss 311, and the stopper 212 is It abuts against the bottom of the hollow boss 311. At the time of injection, the rubber stopper 3 is compressed and deformed by the reaction force generated by the injection liquid and the thrust of the stopper 212. At this time, the frustum 211 at the front end of the push rod extends forward in the axial direction of the push rod, and the frustum 211 can be first elastic after the injection is completed. The pawl 8 is engaged. The push rod 2 is disposed below the rubber plug 3 with a circular table 19 (see FIG. 6). The round table 19 is provided with a second elastic pawl 20 extending obliquely to the inner wall of the syringe, and the second elastic pawl 20 has a pawl tip. The bevel direction of the front end of the syringe rises. Referring to Figure 19, the end of the barrel is provided with an enlarged diameter portion 21, The transition portion of the non-diameter-increased portion 22 of the syringe and the enlarged-diameter portion 21 is provided with a slanted step 23, and the groove 24 into which the elastic pawl 20 can be engaged when the pull-down pusher is provided is provided below the inclined step 23, and the diameter-increased portion 21 A retaining ring 25 (see Fig. 18) is formed inside the bottom of the truncated cone 19, and the upper end of the retaining ring 25 is provided with elastic claws 26 that are gathered toward the center to abut against the bottom of the truncated cone 19 (see Fig. 13). The outer diameter of the truncated cone 19 is less than or equal to the minimum inner diameter of the helical step 23 of the syringe, and is greater than the minimum inner diameter of the retaining ring 25 at the tip of the elastic retainer 26. The number of the elastic pawls 20 is at least two and symmetrically arranged, preferably four and symmetrically disposed, and the distance between the symmetric two claw tips is smaller than the inner diameter of the syringe non-diameter increasing portion 22, which is larger than the inner cylindrical inclined step 23 The minimum inner diameter.

Referring to Fig. 19, the groove 24 is a circular groove in the circumferential direction, and the upper end surface 91 is an oblique angle or a plane extending from the inside to the outside and in the direction of the head of the elastic pawl 20, and the diameter of the side wall 92 is larger than the symmetric elasticity. The distance between the claws of the pawl 20. The retaining ring 25 is movably matched with the inner wall of the enlarged diameter end portion 21 of the syringe, and can move up and down in the axial direction without coming out of the syringe, and the moving distance is greater than the tip of the elastic pawl 20 on the push rod 2 to the bottom of the round table 19 With the distance of the length of the inclined step 23 of the syringe, the upper end of the retaining ring 25 can abut against the bottom of the truncated cone 19. The truncated cone 19 can push the elastic claws 26 of the retaining ring 25 into a large position. The inner wall of the barrel end diameter increasing portion 21 is provided with a large groove 61 (see Fig. 7) which is fitted with the retaining ring 25, and the upper end 62 thereof can be engaged with the upper end 121 of the retaining ring 25, in the large groove 61. The lower end is provided with a flange step 28, and the outer ring of the upper end of the retaining ring 25 is provided with a flange 29 (see Fig. 13), the flange step 28 is in contact with the bottom end surface 122 of the flange 29, and the step 28 prevents the retaining ring 25 from the needle Slip off inside the cylinder.

Referring to Fig. 18, when the injection is completed, the push rod 2 is pulled to move toward the bottom of the barrel, and the bottom plane of the round table 19 on the push rod 2 hits the elastic claws 26 of the retaining ring 25 mounted inside the barrel 1. The top end, and thus the inner diameter is smaller than the outer diameter of the circular table 19, thereby driving the retaining ring 25 to move downward, continuing to pull the push rod 2 downward, and the elastic pawl 20 is in contact with the upper inclined surface 81 (see FIG. 19) of the inclined step 23, and Under the action of the inclined surface 81, elastic deformation occurs in the direction of the central portion of the push rod, and the inner diameter of the inclined step 23 is minimized as the push rod moves downward, and the elastic pawl 20 passes over the innermost diameter of the inclined step 23, When the elastic state returns to the original natural state, the claw tip of the elastic pawl 20 is caught in the groove 24 below the inclined step 23. When the push rod 2 continues to move downward, the bottom end surface 122 of the upper end flange 29 of the retaining ring 25 and the needle The inner wall flange step 28 of the barrel end diameter increasing portion 21 is engaged to prevent the push rod from moving downward, and if a certain external force pushes the push rod in the injection direction, the elastic pawl 20 is prevented by the groove 24. Therefore, the side wall 92 of the groove 24 can prevent the elastic pawl from turning in the direction of the cylinder wall to achieve the purpose of locking the push rod.

When the utility model is used, firstly, as shown in FIG. 1, this is a state of use, and the elastic pawl 20 smoothly passes through the inclined step 23 into the non-diameter increasing portion 22 of the syringe under the action of the retaining ring 25, and the circular table 19 also The retaining claw 26 of the retaining ring 25 is squeezed into the non-diameter increasing portion 22 of the syringe, as shown in Fig. 2, which is the pumping state; as shown in Fig. 3, the injection is completed at this time; Continue to push forward against the push rod 2, the rubber plug 3 is compressed and deformed by the reaction force generated by the injection liquid and the thrust of the stopper 212. At this time, the frustum 211 at the front end of the push rod extends forward in the axial direction of the push rod, as shown in FIG. The pull-down lever is pulled back, the frustum 211 is engaged with the first elastic pawl 8 on the locking ring 7, and the pull-down push rod is continued to drive the locking ring 7 to slide down, and the needle seat 4 is separated from the inner wall of the syringe. 5, continuing to pull down the push rod, causing the needle seat to retract, and the second elastic pawl 20 slides down the inclined step 23, at which time the elastic pawl 20 snaps into the groove 24 below the inclined step 23, and the push rod 2 is Locked, the defect is placed on the push rod, and the push rod is broken after the injection is completed. Bad putter, self-destruction is complete.

Claims

1. An improved safety syringe comprising a hollow syringe (1), a push rod (2) sliding in the barrel (1), a rubber plug (3) mounted on the front end of the push rod (2), a needle The needle end (4) is detached from the barrel at the front end of the barrel, and a locking ring (7) is arranged under the needle seat (4) to cooperate with the inner wall of the barrel. The front end of the push rod is formed with a frustum (211). The utility model is characterized in that: the lower end of the needle seat (4) is provided with at least two elastic claws (6), and correspondingly, the inner wall of the needle cylinder is provided with a groove (611) into which the elastic claw (6) is engaged, and the outer wall of the locking ring is touched. Pressure elastic claw (6), needle seat

(4) At the lower end, at least two bosses (612) are further disposed. Correspondingly, the inner wall of the syringe barrel is provided with a shoulder (613) which cooperates with the boss (612), and the inner hole of the lock ring (7) is provided with a cone The first elastic pawl (8) that is engaged with the table (211), after the injection is completed, the frustum (211) at the front end of the push rod is engaged with the first elastic pawl (8) in the lock ring (7) The pull-down push rod drives the lock ring (7) to slide down, so that the needle seat is separated from the inner wall of the syringe.

2. The improved safety syringe according to claim 1, wherein: the hollow cavity of the rubber plug is formed with a hollow boss (311), and the push rod is provided with a stopper (212) and a stopper ( 212) is located below the hollow boss (311), the stopper (212) is opposite to the bottom of the hollow boss (311), and the rubber plug (3) is subjected to the reaction force generated by the injection liquid and the thrust compression of the stopper (212) during injection. Deformation, at this time, the frustum (211) at the front end of the push rod extends forward in the axial direction of the push rod, and the frustum (211) can be engaged with the first elastic pawl (8) after the injection.

3. A safety syringe according to claim 1 or 2, characterized in that: the push rod (2) is provided with a round table (19), and the round table (19) is provided with an oblique angle to the inner wall of the barrel a second elastic pawl (20) having an enlarged diameter portion (21) at the end of the barrel, and an inclined step at a transition between the non-diameter enlarged portion (22) and the enlarged diameter portion (21) of the syringe

(23), a second recess (24) into which the second elastic pawl (20) can be engaged when the pull-down step is provided below the inclined step (23), and the enlarged diameter portion (21) is provided to be able to abut the round table (19) Retaining ring (25) at the bottom.

4. An improved safety syringe according to claim 3, wherein: said retaining ring (25) is movably coupled to the inner wall of the enlarged diameter end portion (21) of the barrel, and is movable up and down along the axial direction of the push rod. And does not come out of the syringe, the upper end of the retaining ring (25) is provided with a center that can be gathered against the center The elastic claws (26) at the bottom of the table (19).

5. An improved safety syringe according to claim 3, wherein: said second resilient pawl (20) is at least two and symmetrically disposed, and the distance between the symmetrical two claw tips is less than the syringe The inner diameter of the non-diameter enlarged portion (22) is larger than the inclined step inside the syringe

(23) The minimum internal diameter at the location.

6. A modified safety syringe according to claim 3, wherein: said second recess (24) is a ring of card slots, the upper end surface (91) of which is from the inside to the outside and along the second elastic spine The bevel or plane extending in the direction of the claw head has a diameter at the side wall (92) that is greater than the distance between the symmetrical two pawl tips.