WO2006119667A1

WO2006119667A1 - Disposable safety syringe

Info

Publication number: WO2006119667A1
Application number: PCT/CN2005/000647
Authority: WO
Inventors: Hsienwen Hsieh
Original assignee: Hsienwen Hsieh
Priority date: 2005-05-10
Filing date: 2005-05-10
Publication date: 2006-11-16

Abstract

A disposable safety syringe comprises a barrel (1), a plunger (2), a needle hub (41), a needle holder (42), and a needle (43). A cylindrical step (422) is provided on the back end of the needle holder (42). A top ring (21) is provided on the front end of the plunger (2). A seal lock ring (44) is provided on the distal end of the needle hub (41). At least a protuberance (212) which engages with the outer end face of the cylindrical step (422) is provided on the inner face of the top ring (21). After the seal lock ring (44) is pushed away by the top ring (21), the needle holder (42) and the needle (43) are withdrawn along with the plunger (2) into the barrel (1) by using the friction between the protuberance (212) and the cylindrical step (422). Meanwhile, the pawl (28) is retracted to snap into the lock slot of the plunger support, such that the plunger (2) can be broken at the V -shaped gap to avoid the reuse of the syringe.

Description

Single-use safety syringe

This invention relates to syringes in the field of medical devices, and more particularly to a disposable safety syringe. Background technique

As is well known, a syringe is a commonly used medical device. In order to prevent cross-infection, the one-time use of syringes has received increasing attention. However, the existing syringes generally do not have a self-destructive protective structure, so that the existing syringes are not "one-off" in the strict sense of use performance, and can be repeatedly used, leaving hidden dangers for cross-infection, easy Cause the spread of disease. In addition, the existing syringe is extremely easy to stab or scratch the surrounding person during the treatment after the injection, resulting in a new cross infection.

The safety syringe of Chinese Patent No. 98250220.6 consists of a syringe, a needle assembly, a snap seat, a push rod and a chuck. Wherein the engaging seat is located at the front end of the syringe, and the needle assembly is combined with the front end of the engaging seat. The rear end of the engaging seat has a hole. The chuck is placed at the front end of the push rod. When the push rod is advanced toward the front end of the injection cylinder, the chuck engages with the engaging seat. When the push rod is pulled back, the engaging seat is pulled together with the needle assembly into the housing of the syringe to prevent the needle from stabbing the human body for the purpose of single use. However, due to the unreasonable design structure of the syringe, there are technical defects such as large residual amount of liquid medicine and poor sealing after the injection, the product performance is not stable enough, and it is not in line with the state regarding the residual amount of the injected liquid. Provisions.

Also disclosed in the patent application of WO 02/087669 is a safety syringe comprising a needle cannula, a needle cannula, a needle hub, a sealing element, a spring. It has the function of automatically destroying the syringe after the injection is completed. However, the structure of the syringe is too complicated, increasing production costs. In addition, this structure also causes defects in which a large amount of liquid remains. Moreover, when the safety syringe is in use, when the injection action is completed, the needle automatically pops out of the patient's body and enters the syringe before the medical staff has unplugged the needle from the patient, thereby causing great pain to the patient. . Therefore, the practicality is poor. Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to provide a disposable safety syringe having a protective self-destructing structure and a thorough injection of the drug solution, in view of the drawbacks of the prior art syringe.

The present invention provides a disposable safety syringe including a syringe; a needle holder is formed at a front end of the syringe;

a needle portion is mounted on the needle seat, the needle portion includes a needle tube seat, a needle tube sleeve, and a needle tube, the rear end of the needle tube sleeve has a cylindrical step, and the center thereof is a through hole, and the needle tube is installed at In the through hole of the needle sleeve;

a push rod disposed in the syringe; the front end of the push rod has a top ring;

Piston, set at the front end of the push rod;

Sealing the lock ring, the seal lock ring is disposed at a distal end portion of the needle tube seat;

The utility model is characterized in that at least one protrusion is arranged on the inner wall surface of the top ring, and the protrusion cooperates with the outer end surface of the cylindrical step at the rear end of the needle sleeve, and when the top ring pushes the sealing ring away, The friction between the projection and the cylindrical step allows the needle cannula to enter the syringe with the pullback action of the push rod along with the needle.

The present invention further includes a push rod holder disposed at a rear end of the barrel, the push rod holder including a limit thrust groove, a fitting groove and a lock groove, and at least one card disposed on the connecting rod disposed in the middle of the push rod claw.

When the syringe of the present invention is assembled, the claw corresponds to the fitting groove of the push rod support, so that the claw passes smoothly through the push rod support, and the push rod support is set outside the push rod, and the push rod cannot exit the push rod support. The piston is arranged at the front end of the push rod to form a push rod assembly, the push rod assembly is set in the syringe body, and the push rod support of the push rod assembly is clamped on the open end of the needle holder body to form The syringe body assembly, the push rod thrust boss corresponds to the limit thrust groove of the push rod support, and prevents the top ring of the push rod from sliding forward by the accidental force to cause the seal lock ring to slide forward, so that the syringe self-destructs. The needle hub of the syringe body assembly is engaged with the needle portion and combined into a safety syringe having a self-destructing function.

Since the safety syringe of the present invention completely contacts the bottom of the syringe at the time of injection, the residue of the chemical solution is avoided. In addition, due to the special needle structure, it is beneficial to protect the entire syringe from self-destruction and truly achieve the purpose of single use. DRAWINGS

1 is a schematic view showing the appearance of a syringe according to an embodiment of the present invention;

2 is a schematic cross-sectional view of a syringe according to an embodiment of the present invention;

3 is a cross-sectional view showing a needle hub of an embodiment of the present invention;

4 is a cross-sectional view showing a needle sleeve of an embodiment of the present invention;

5A, FIG. 5B, and FIG. 5C are respectively schematic cross-sectional views of a seal ring according to an embodiment of the present invention; FIG. 6 is a cross-sectional view of the syringe of the embodiment of the present invention;

7A is a cross-sectional view showing a pusher according to an embodiment of the present invention;

Figure 7B is a partial enlarged view of a portion A of Figure 7A;

Figure 7C is an enlarged cross-sectional view taken along line C-C of Figure 7A;

Figure 7D is a cross-sectional view taken along line D-D of Figure 7B;

8A is a cross-sectional view showing a push rod holder according to an embodiment of the present invention;

Figure 8B is a schematic view of the direction A in Figure 8A; Figure 8C is a cross-sectional view of the BB direction of Figure 8B;

Figure 9 is a cross-sectional view showing a piston of an embodiment of the present invention;

FIG. 10 is a schematic diagram of a breaking operation according to an embodiment of the present invention; FIG.

Figure 11A is a cross-sectional view showing a syringe according to a second embodiment of the present invention;

Fig. 11B is a partial enlarged view of a portion A in Fig. 11A. In the drawings, the list of parts represented by each label is as follows:

1-syringe

I I-needle holder 12-conical surface 13-inner wall surface

I I I- front end inner wall surface 112-rear inner wall surface

2-push

21-Top ring 22-Tushing boss 23-Front end face 24-handle 25-linking rod

28-Claw 29-狢口 211-Notch 212-Postle

281-round hole 282-inner corner 283-outer corner 284-claw

285-The outermost end of the claw 286-Gap

3-push piston

32-rear rear end face

4-needle section

41-needle holder 42-needle sleeve 43-needle 44-seal lock ring 46-clamp 411-cavity 413-external thread 415-cylinder 416-outer cylindrical surface 421-through hole 422-cylindrical step 423-front end face

424-cylindrical through hole 425-conical through hole 426-spherical through hole 427-bottom

428-cylindrical through hole 429-cylindrical through hole 431-needle tip 441-groove

6-Pusher support

61-through hole 62- thrust groove 63-outer cone wall 64-inner ring surface

65-Assembly Groove 66-Lock Groove 67-Pusher Support Rear End 69-Slot

23 a-cylinder 429a-groove embodiment

As shown in Figures 1 and 2, the present invention provides a disposable self-destructing syringe comprising a syringe 1, a push rod 2, a push rod piston 3, a needle portion 4, and a push rod holder 6. The push rod piston 3 is fitted to the front end portion of the push rod 2. The largest portion of the outer diameter of the push rod piston 3 coincides with the inner wall of the barrel 1 and is slidable longitudinally along the inner wall. A needle holder 11 is provided at the front end of the syringe 1, and the needle holder 11 can be integrally molded with the syringe 1 during processing. The needle portion 4 is mounted on the needle hub 11. This part of the technology is similar to existing syringes and will not be described in detail here. As shown in FIG. 2, the needle portion 4 includes a needle hub 41, a needle cannula 42, a needle tube 43, and a seal lock ring 44.

As shown in Fig. 2 and Fig. 3, the center of the needle hub 41 is a through cavity 411 which can accommodate the needle can 42 and allow the needle can 42 to slide in the longitudinal direction. A hollow cylinder 415 extends integrally with the needle end seat 41 at an end surface of the rear end portion of the needle hub 41. The cylinder 415 is concentric with the needle hub 41, and has an inner diameter that closely matches the outer diameter of the seal lock ring 44, and the height is greater than the seal lock. The height of the ring 44 is twice. The outer cylindrical surface 416 of the circular cylinder 415 is a conical surface. An external thread 413 is provided on the outer circumferential surface of the joint between the cylinder 415 and the needle hub 41. Under the push of the push rod 2, in order to prevent the needle sleeve 42 from sliding forward, a stopper 46 that is contracted toward the center is provided at the front end of the cavity of the needle hub 41.

As shown in Fig. 2 and Fig. 4, the needle sleeve 42 has a hollow shape, and a central portion thereof is formed with a longitudinal through hole 421. A radially projecting cylindrical step 422 is formed at the rear end of the needle hub 42. The needle tube 43 is mounted in the through hole 421 of the needle cannula 42 such that the bottom surface thereof is flush with the bottom surface 427 of the needle cannula 42 to further reduce the residual of the chemical liquid at the time of injection. The needle tip 431 protrudes beyond the needle sleeve 42 for easy injection. The needle tube 43 is fixedly coupled to the needle tube sleeve 42, which is a phase bond. The diameter of the front end of the through hole 421 is varied, and is composed of the following five through holes: First, a cylindrical through hole 424 is formed inwardly from the front end surface 423, and the cylindrical through hole 424 extends inward to form a conical through hole 425, which is conical. The through hole 425 extends inwardly with a spherical through hole 426. The spherical through hole 426 further extends inwardly with a cylindrical through hole 429. Finally, the cylindrical through hole 429 extends inward to form a cylindrical through hole 428. The through hole 428 has the smallest diameter among the five through holes, and is the same as the outer diameter of the needle tube 43, and the two are tight fits. The center diameter of the spherical through hole 426 is the same as the diameter of the cylindrical through hole 424, and the diameters of the both ends are the same as the diameters of the small end of the cylindrical through hole 429 and the conical through hole 425, respectively, and the diameters of the above five through holes are smaller than The diameter of other portions of the through hole 421. The change diameter is designed such that when the needle tube 43 and the needle sleeve 42 are glued, the glue can smoothly enter the inner wall surfaces of the through holes 424, 425, 426, and 429, and the accumulation is formed in the spherical through holes 426. The needle tube 43 can be more firmly bonded in the through hole 421.

As shown in FIG. 2, the seal lock ring 44 is an annular body that is mounted on the outer end surface of the cylindrical step 422 at the rear end portion of the needle tube sleeve 42, and is caught at the rear end portion of the cavity 411 of the needle hub 41. That is, the seal lock ring 44 is fastened between the outer end surface of the cylindrical step 422 at the rear end portion of the needle hub 42 and the end portion of the inner wall of the cavity 411 of the needle hub 41. The sealing lock ring 44 on the one hand ensures a seal between the needle cannula 42 and the needle cannula 41, and on the other hand the needle cannula 42 (along with the needle cannula 43) is fixedly mounted on the needle cannula 41. The outer circumferential surface thereof is a conical surface whose diameter gradually decreases from the end opposite to the top ring 21. In a preferred embodiment of the present invention, in order to reduce the friction between the seal lock ring 44 and the needle sleeve 42 and the needle hub 41, the inner wall of the seal lock ring 44 and the cylindrical shape of the rear end portion of the needle sleeve 42 can be reduced. The contact area between the step 422 and the outer wall surface and the rear end portion of the cavity 411 of the needle hub 41, as shown in FIG. 5A, FIG. 5B and FIG. 5C, may be provided with at least one groove 441 on the inner wall and/or the outer wall surface. Slot 441 can be A variety of different geometric shapes, in this embodiment, are circular arcs.

The needle hub 41 has a mating connection structure with the needle hub 11 at the front end of the syringe 1. As shown in Fig. 6, the syringe 1 is a hollow cylinder integrally formed at a joint portion of the front portion thereof with the needle hub 41 to form a needle holder 11. The needle holder 11 is a hollow cylinder concentric with the barrel 1, and is provided with an internal thread on the inner wall surface 111 at the front end thereof; and the inner wall surface 112 at the rear end thereof is a conical surface. A conical surface 12 is formed on the inner wall surface of the rear end of the barrel 1.

As shown in Fig. 3 and Fig. 6, the mating connection structure between the needle hub 41 and the needle hub 11 can be a screw connection structure: In this embodiment, the needle hub 11 is an inner spiral, and the needle hub 41 is an outer spiral. Of course, it is also possible that the needle hub 11 is an outer spiral and the needle hub 41 is an inner spiral. The conical surface of the inner wall surface 112 at the rear end of the needle hub 11 is engaged with the conical surface of the outer cylindrical surface 416 of the cylindrical body 415 of the needle hub 41. Thereby, a tight fit can be produced when the needle hub 41 is coupled to the needle hub 11, and after the needle hub 41 and the needle hub 11 are screwed to each other, the distal end portion of the cavity 411 of the needle hub 41 can be produced to the seal lock ring 44. The radial pressure causes the seal lock ring 44 to be more closely fitted between the rear end step 422 of the needle cannula 42 and the distal end portion of the cavity 411 of the needle cannula 41.

In another embodiment of the invention, the mating connection structure is an embedded card structure. The front end 111 of the needle hub 11 is an embedded bayonet, and the rear end 413 of the needle hub 41 is a latch that cooperates with the bayonet.

The above structure of the present invention is assembled after the needle portion 4 is assembled, and the needle hub 41 is assembled with the syringe assembly through the needle hub 11 through its fitting structure.

As shown in FIGS. 7A, 7B, 7C, and 7D, a top ring 21 is formed at the front end of the push rod 2. The top ring 21 corresponds to the seal lock ring 44 for advancing the seal lock ring 44 in the needle hub 41. The top ring 21 is a torus in the preferred embodiment, and has at least one projection 212 made of an elastic material (e.g., medical plastic) on its inner wall surface. When the seal lock ring 44 is pushed away from the rear end step 422 of the needle cannula 42 by the top ring 21, the constraint on the needle cannula 42 can be released. At this time, the protrusion 212 is in contact with the outer end surface of the cylindrical step 422 at the rear end portion of the needle sleeve, so that the needle sleeve 42 (along with the needle tube 43) acts under the friction between the protrusion 212 and the outer end surface of the step 422. With the pullback of the push rod 2, it smoothly enters the inside of the syringe 1. Therefore, the protrusion 212 can be any number, any shape, any size, and is located at any position on the inner wall surface of the top ring 21, as long as it can contact the outer end surface of the step 422 to generate a friction force, the friction force can be as long as The needle cannula 42 (along with the needle cannula 43) can be moved into the syringe 1 following the pusher 2. In the preferred embodiment, the projections 212 are three spaced apart and identical prisms disposed uniformly on the inner wall surface of the top ring 21, the prisms having a triangular cross section. The top ring 21 and the prism 212 can be integrally formed with the push rod 2. The prisms 212 are distributed longitudinally along the top ring 21 and have a length equal to the height of the top ring 21. The diameter of the cylinder surrounded by the three edges of the three prisms 212 is slightly smaller than the inner diameter of the seal lock ring 44 to facilitate pushing the top ring 21 away from the seal lock ring 44. The height of the top ring 21 is equal to or greater than the height of the sealing lock ring 44. In this embodiment, The height of the top ring 21 is equal to the height of the seal lock ring 44. The outer diameter of the top ring 21 is slightly smaller than the outer diameter of the seal lock ring 44, or the outer surface of the top ring 21 may also be a tapered surface whose diameter decreases in the direction of the seal lock ring 44. Thereby, it can be ensured that when the top ring 21 pushes the seal lock ring 44, it does not rub against the inner cylindrical surface of the cylinder 415, only the prism 212 of the top ring 21 and the rear end step 422 of the needle sleeve 42 The cylindrical surface is rubbed to generate friction. When the seal lock ring 44 is pushed away from the rear end step 422 of the needle cannula 42 by the top ring 21, the constraint on the needle cannula 42 can be released. The three prisms 212 of the top ring 21 are in contact with the outer end surface of the cylindrical step 422 at the rear end of the needle sleeve 42 to generate friction, so that the needle sleeve 42 (along with the needle tube 43) is under the action of friction, with the push rod 2 Pull back and smoothly into the syringe 1. The front end surface 23 of the top ring 21 is provided with at least one notch 211. In the preferred embodiment, the two notches 211 are symmetrically distributed. When the medicine is injected, the liquid medicine flows into the needle tube 43 through the notch 211, thereby preventing the liquid residue from remaining. The top ring 21 may be formed by at least one top post, and the inner surface of the top post may be provided with a protrusion 212, which may be a columnar body or a partial toroidal body. There is a gap between the adjacent two top columns for the passage of the drug solution.

As shown in FIG. 2, FIG. 7A, FIG. 7B, FIG. 7C, and FIG. 7D, the push rod 2 is similar to the push rod of the conventional syringe, the rear end of which is an injection handle 24, the front end is provided with a piston 3, and the intermediate connecting rod 25 is a cross. Reinforcement structure. In order to cooperate with the pusher holder 6, four thrust bosses 22 are provided at one end of the connecting rod 25 near the handle 24. A top ring 21 is provided at the front end of the push rod 2, and the top ring 21 corresponds to the seal lock ring 44. At least one claw 28 is formed on the cross rib structure of the connecting rod 25 near one end of the top ring 21. In the present embodiment, there are two claws 28 which are formed integrally with the pusher 2 and which are located on the ribs of the cross structure and are symmetrically distributed. The shape is such that a V-shaped opening 286 is formed on the opposite cross ribs of the connecting rod 25 toward the top ring 21 end and the opening angle is small, and a circular hole 281 is opened at the bottom of the opening 286 to avoid the card. When the claw 28 is subjected to an external force, the stress at the notch concentrates, and when the claw 28 receives an external force, the cross rib of the connecting rod 25 is split along the bottom of the slit 286. It forms an outer corner 283 at the intersection of the cross ribs near the intersection of the cross ribs and the side away from the cross ribs. The inner corner 282 and the cross ring of the top ring 21 are at an acute angle. A trapezoidal claw body 284 is formed outwardly from the outer corner 283. In the natural state, the distance from the outermost end 285 of the claw body 284 to the intersection of the cross ribs is greater than the distance from the outermost end of the connecting rod 25 to the intersection of the cross ribs, and when the claw body 284 is subjected to the component force perpendicular to the outer corner 283, the claw 28 outer corner edge 283 moves inwardly. When outer corner edge 283 is parallel with inner corner edge 282, and is not in contact, the distance from the outermost end 285 of the claw body 284 to the intersection of the cross rib is equal to the outermost end of the connecting rod 25 to the cross rib. The distance of the line. Four symmetrically distributed V-shaped slits 29 are formed in the four ribs of the connecting rod 25 near the end 28 of the claw, and the size and position of the opening are as long as the strength of the pusher 2 for the proper working of the injector is ensured. The distance from the slit 29 to the piston 3 is slightly larger than the height of the pusher holder 6, so that the pusher 2 is broken outside the syringe 1 after the injection is completed.

As shown in FIG. 2, FIG. 6, FIG. 7A, FIG. 8A, FIG. 8B, FIG. 8C, in order to prevent the top ring 21 of the push rod 2 from being accidentally forced to push the seal lock ring 44 to slide forward, the rear end of the syringe 1 is disposed. Have limits The function of the push rod holder 6. The push rod holder 6 is a cylinder having a through hole 61 in the middle. The diameter of the through hole 61 is slightly larger than the diameter of the push rod 2, so that the push rod 2 can be inserted into the through hole 61 and can slide in the through hole. The push rod holder 6 is disposed inside the barrel 1, the outer wall surface 63 of the hollow cylinder is a conical surface, and the inner wall surface 12 of the barrel 1 in contact with the conical surface 63 of the push rod holder 6 is also the outer wall surface 63. The mating conical surface, and the small end diameter of the inner wall surface 12 is smaller than the large end diameter of the outer wall surface 63. Thereby, the push rod holder 6 can be locked to the rear end of the barrel 1 without being pushed into the barrel 1. The outer wall surface 63 of the push rod holder 6 extends outward to form an annular protrusion 67, and the annular protrusion 67 cooperates with the inner wall surface 13 of the barrel 1, so that the push rod holder cannot move to the outside of the barrel after assembly, and the push rod is assembled. The holder 6 is fixed to the open end of the barrel 1 and cannot be moved. At least one thrust groove 62, at least one fitting groove 65 and at least one locking groove 66 are formed in the inner wall surface of the hollow cylindrical portion of the push rod holder 6 disposed outside the barrel 1. In the preferred embodiment, two 180-degree symmetric thrust grooves 6 are provided with two 180-degree symmetrical mounting grooves 65 and four spaced apart between the thrust groove 62 and the fitting groove 65 to allow for injection. Pushing the locking groove 66 that the boss 22 passes and the jaws are fixed after the injection is completed. The above eight grooves are evenly distributed on the inner wall surface of the hollow cylindrical portion of the push rod holder 6. On the circumferential surface at the corresponding position of the rear end of the push rod 2, four thrust bosses 22 are provided which cooperate with the thrust groove 62 and the fitting groove 65. When the syringe is not in use or when the medical staff pulls the push rod 2 forward in order to suck the liquid medicine, the thrust boss 22 of the push rod 2 is pushed against the thrust groove 62 of the push rod support 6 and pushed forward. The rod 2, the thrust boss 22 will be blocked by the thrust groove 62 and will not continue to advance, thereby ensuring that the seal lock ring 44 will not be accidentally opened by the top ring 21. Wherein, the length of the thrust groove 62 is only required to ensure that the top ring 21 has no contact with the sealing lock ring 44 when the thrust boss 22 is completely inserted therein; the length of the fitting groove 65 is larger than the thrust groove 62, and the rear end thereof is formed. The inclined surface has a direction opposite to the opening direction of the claw 28, and the end thereof is flush with the inner wall surface of the hollow cylindrical body of the push rod holder 6; and the length of the locking groove 66 is only required to ensure that when the thrust boss 22 completely enters the same In the meantime, the top ring 21 can completely push the seal lock ring 44 away from the cylindrical step 422 at the rear end portion of the needle sleeve 42. For ease of assembly, at least one radially through slot 69 is provided in the axial direction of the pusher mount 6, in this embodiment two slots 69 which are 180 degrees apart. Due to the presence of the groove 69, when the push rod holder 6 is inserted into the rear end of the barrel 1, the push rod holder can be elastically deformed to be fixed to the rear end portion of the barrel 1 in a tight fit manner. When assembled, the two jaws 28 correspond to the fitting groove 65, and the pusher top ring 21 is pushed forward from the rear end 68 of the pusher holder 6, and when the claw 28 comes into contact with the fitting groove 65, the claw 28 is subjected to a radial force. The outer corner 283 of the claw 28 moves inwardly. When the distance between the outermost end 285 of the claw 284 and the intersection of the cross rib is equal to the distance from the outermost end of the connecting rod to the intersection of the cross rib, the claw 28 passes through the push rod smoothly. The support 6 is in a natural state, and the pusher support 6 is placed outside the pusher 2 and cannot be withdrawn from the pusher support 6. The thrust & table 22 cooperates with the thrust groove 62 to prevent the top ring 21 of the push rod 2 from being accidentally forced to push the seal lock ring 44 forward. When the injection is performed, it is only necessary to shift the thrust boss 22 and the thrust groove 62 to push the pusher 2, that is, to make the thrust boss 22 face the inner wall surface of the hollow cylindrical portion of the pusher holder 6. Lock slot 66 pushes Move, you can do the injection.

When the injection is completed, as the pusher 2 retreats, the needle cannula 42 (along with the needle cannula 43) is pulled back into the syringe 1, and the pusher 2 continues to move rearwardly, the inner surface 64 of the jaw 28 and the pusher holder 6 Upon contact, being squeezed, the outer corner 283 of the jaw 28 moves inwardly. When the distance from the outermost end 285 of the claw 284 to the intersection of the cross rib is equal to the distance from the outermost end of the connecting rod to the intersection of the cross rib, the claw 28 Smoothly retreating into the lock groove 66 of the push rod support 6, at this time, the piston is in contact with the push rod support 6, so that the push rod 2 cannot continue to retreat, and the claw body 284 completely enters the lock groove 66, so that the push rod 2 cannot Move again in the direction of the needle so that the lock pusher cannot move back and forth along the inner wall of the syringe 1. When the push rod 2 is locked, the push rod can be broken from the V-shaped opening 29 of the push rod, so that the syringe can not be used again, and the self-destruction safety is achieved.

As shown in FIG. 2, after the injection work of the syringe of the present invention, the push rod piston 3 is completely in contact with the bottom of the syringe 1, since the shape of the push rod piston 3 coincides with the shape of the inner wall of the syringe 1, and the top ring A notch 211 is formed in the opening 21, so that the liquid medicine outside the top ring 21 can enter the inside of the top ring 21 from the notch 211 and be injected into the needle tube 43, thereby avoiding the residue of the chemical liquid.

As shown in Fig. 11A and Fig. 11B, in the second embodiment of the present invention, the top ring 21 may have a shape in which a cylindrical body 23a is formed at the front end of the push rod 2, and is disposed on the outer circumferential surface of the cylindrical body 23a. There is at least one projection 212 described in the first embodiment of the present invention, and in addition, a top ring or top post 21 according to the first embodiment of the present invention is disposed at the periphery of the cylindrical body 23a. Correspondingly, a groove 429a corresponding to the cylindrical body 23a is formed in the cylindrical step 422 at the rear end portion of the needle sleeve 42, and the depth of the groove 429a is the same as the height of the cylindrical body 23a. The groove 429a and the protrusion 212 are tightly fitted. In order to reduce the residual of the chemical liquid, the height of the top ring 21 is small. The height of the cylinder 23a is as long as it can ensure that when the cylinder 23a is completely inserted into the groove 429a, the top ring The seal ring 44 provided on the cylindrical step 422 at the rear end portion of the needle hub 42 can be pushed away from the step 422. When the injection is completed, the cylinder 23a is completely inserted into the groove 429a. At this time, the protrusion 212 on the cylinder 23a is in contact with the inner wall surface of the groove 429a, and the capillary sleeve 42 can be obtained by the friction between the two. The needle tube 43 enters the barrel 1 as the push rod 2 is pulled back, and the effect described in the first embodiment of the present invention can also be achieved.

In summary, the present invention is a controllable self-destructive behavior. Since the retraction of the needle cannula 43 of the present invention is performed after the needle tip 431 is pulled out of the patient, it does not cause pain to the patient, and the syringe disclosed in WO 02/087669 overcomes the need for the syringe to rebound. Give patients a painful residual problem. , , ^Α , , ^

Claims

Rights request:

1. Single-use safety syringes, including:

a syringe (1); a needle holder (11) is formed at a front end of the syringe (1); and

The needle holder (11) is provided with a needle holder (41), a needle sleeve (42), and a needle tube (43), and the rear end of the needle sleeve (42) has a cylindrical step (422);

a push rod (2) disposed in the syringe (1); a front end of the push rod (2) having a top ring (21); a sealing lock ring (44), the sealing lock ring (44) being disposed at a distal end portion of the needle hub (41);

The utility model is characterized in that at least one protrusion (212) is arranged on the inner wall surface of the top ring (21), and the protrusion (212) cooperates with the outer end surface of the cylindrical step (422), and the top ring (21) After pushing the seal lock ring (44) away, the needle sleeve ( ⁴² ) can be pulled back with the push rod (2) by the friction between the protrusion (212) and the cylindrical step (422) The action, together with the needle ( ⁴ 3), enters the syringe (1).

2. A syringe according to claim 1, characterized in that the projections (212) are three ribs having a triangular cross section along the longitudinal direction of the inner wall surface of the top ring (21).

3. The syringe according to claim 1, further comprising a push rod holder (6) disposed at a rear end of the barrel (1), the push rod holder (6) having a through hole in the middle (61) The cylinder, the push rod support (6) is disposed on the outer wall surface (63) of the hollow cylinder inside the syringe (1) as a conical surface, and the circle of the syringe (1) and the push rod support (6) The inner wall surface (12) contacting the tapered surface (63) is also a conical surface matching the outer wall surface (63), and the small end diameter of the inner wall surface (12) is smaller than the diameter of the large end of the inner wall surface (63), and the push rod branch The outer wall surface (63) of the seat (6) extends outward to form an annular projection (67), and the annular projection (67) cooperates with the inner wall surface (13) of the syringe (1), and is disposed at the push rod support (6) At least one thrust groove (62), at least one fitting groove (65) and at least one lock groove (66) are opened on the inner wall surface of the hollow cylindrical portion outside the cylinder (1).

4. The syringe according to claim 3, wherein the thrust groove (62) and the fitting groove (65) are two thrust grooves (62) symmetrically disposed 180 degrees apart and two 180 degrees apart. a symmetrically disposed mounting groove (65), the locking groove (66) being a four locking groove disposed between the thrust groove (62) and the fitting groove 65 to allow the thrust boss 22 to pass during injection (66) The eight slots are uniformly distributed on the inner wall surface of the hollow cylindrical portion of the push rod holder (6); wherein the length of the thrust groove (62) is only required to ensure that the thrust boss (22) is completely When entering, the top ring (21) has no contact with the sealing lock ring (44); the length of the mounting groove (65) is larger than the thrust groove (62), and the rear end thereof is formed as a slope, the direction of the slope and the card The claw (28) has an opposite opening direction, and its end is flush with the inner wall surface of the hollow cylinder of the push rod holder (6); and the length of the lock groove (66) is only required to ensure that the thrust projection (22) completely enters therein. When the top ring (21) can completely push the sealing lock ring (44) away from the cylindrical step (422) at the rear end of the needle sleeve (42); With the push rod support (6) is provided with at least one radially through groove (69) in the axial direction.

5. The syringe according to claim 3, characterized in that the cross rib at the corresponding position of the rear end of the push rod (2) is provided with a thrust groove (62) on the push rod support (6) Matching thrust boss (22).

6. A syringe according to claim 1, characterized in that at least one jaw (28) is provided on the connecting rod (25) in the middle of the push rod (2).

7. The syringe according to claim 6, characterized in that the claw (28) is two claws (28) symmetrically distributed on the ribs of the cross structure of the connecting rod (25), which are combined with the push rod ( 2) - Body formation, the claw (28) is shaped to form a V-shaped opening toward the top ring (21) in an opening direction near the top ring (21) on the rib of the cross structure of the connecting rod (25) (286) ), a circular hole (281) is opened at the bottom of the slit (286), and a V-shaped slit (286) extends outward from the outer corner (283) to form a claw body (284), and a cross rib near the end of the claw (28) The connecting rod (25) is provided with at least one V-shaped opening (29,), and the distance between the opening (29) and the piston (3) is greater than the height of the push rod holder (6).

8. The syringe of claim 1 wherein said seal lock ring (44) is an annular body for reducing between the seal lock ring (44) and the needle hub (42) and the needle hub (41) Friction force, which can reduce the inner wall of the sealing lock ring (44) and the cylindrical step (422) at the rear end portion of the needle sleeve (42) and the rear end portion of the outer wall surface and the cavity (411) of the needle holder (41) The contact area has an outer circumferential surface which is a conical surface which is gradually reduced in diameter from an end opposite to the top ring (21), and at least one groove (441) is formed in the inner wall and/or the outer wall surface.

9. A syringe according to claim 8 wherein said groove (441) is arcuate.

10. The syringe according to claim 1, wherein the diameter of the front end of the through hole (421) is varied, and is composed of the following five through holes: First, a cylindrical shape is formed inward from the front end surface (423). a through hole (424), the cylindrical through hole (424) extends inward to form a conical through hole (425), and the conical through hole (425) extends inwardly with a spherical through hole (426), and the spherical through hole (426) A cylindrical through hole (429) extends inwardly, and finally, the cylindrical through hole (429) extends inward to form a cylindrical through hole (428). The through hole (428) is the smallest of all the through holes, and has the same outer diameter as the needle tube (43), the two are tight fit, the central diameter of the spherical through hole (426) and the cylindrical through hole (424) The diameters of the two ends are the same as the diameters of the small ends of the cylindrical through holes (429) and the conical through holes (425), and the diameters of the above five through holes are smaller than the diameters of other portions of the through holes (421). .

11. The syringe according to claim 1, wherein a hollow cylinder (415) integrally extends at a rear end portion of the needle hub (41), the cylinder (415) being concentric with the needle holder (41) The inner diameter is tightly matched with the outer diameter of the sealing lock ring (44), the height of which is greater than twice the height of the sealing lock ring (44), and the outer cylindrical surface (416) of the cylinder (415) is the needle seat (11) The inner wall surface (112) of the rear end is fitted with a conical surface.

12. Single-use safety syringes, including:

It is characterized in that a cylindrical body (23a) is formed at the front end of the push rod (2), and at least one protrusion (212) is provided on the outer circumferential surface of the cylindrical body (23a), in the cylindrical body (23a) The periphery of the sleeve is provided with a top ring (21). Correspondingly, a groove (429a) corresponding to the cylinder (23a) is formed on the cylindrical step (422) at the rear end of the needle sleeve (42). When the injection is completed, the cylinder (23a) is completely inserted into the groove (429a), at which time the projection (212) on the cylinder (23a) is in contact with the inner wall surface of the groove (429a), passing between The frictional force enables the needle cannula (42) and the needle cannula (43) to enter the syringe (1) as the pusher (2) is pulled back.

The syringe according to claim 12, wherein the groove (429a) has the same depth as the cylinder (23a), and the groove (429a) and the protrusion (212) are tightly fitted. The height of the top ring (21) is smaller than the height of the cylinder (23a).