JPH0568994B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a disposable hypodermic syringe, and more specifically, it is a disposable hypodermic syringe. This relates to a disposable syringe that is designed to protect the needle by covering it.

[Prior Art and Problems to be Solved by the Invention] In the medical field, there is a medical gamble that is feared as a "needle stick". This gamble stems from the fact that hypodermic syringes carry a fatal risk in the following sense. That is, in any case, there is no guarantee that disinfection treatment such as heat treatment is performed before injection.

There is a risk of "needle pricking" when using a syringe, as well as the risk of contracting diseases such as hepatitis, AIDS, and herpes. The only way to actively prevent infection from these etiologies is to avoid contact with the source of infection. The non-contaminating safe hypodermic syringe provided by the present invention, which can be discarded with a capped needle, proactively prevents "needle stick" accidents from the viewpoint of the structure of the syringe, thereby creating a barrier against this danger.

The following techniques are known to date. That is, US Patent No. 1378806; No. 2400722; No.2571653; No.3890971; No.4356822; No.4425120; No.2752920; No.3937211; No.4026287；No.4425120； and No.4507117.

Also, when the piston moves inside the cylinder,
It should be noted that the method of a piston spreading the cylinder wall to create a seal is not necessarily considered new.

The essential problem of this invention is to provide a disposable, non-contaminated hypodermic syringe to prevent "needle stick" infections. The present invention has yet another objective, which is that it is reliable and simple to use.
A further object is to create a disposable, non-contaminating, safe hypodermic syringe that is easy and inexpensive to manufacture.

[Means for Solving the Problems] The above object can be achieved by creating a disposable hypodermic syringe having the following structure at the tip of the cylinder. That is, it is satisfactory to create a mechanism in which the needle support with the needle attached is taken into the cylinder by unlatching it and fixed there. That is, the injection piston is moved by pulling back the piston rod so that it can be received at the other end of the cylinder. The piston section is harder than the cylinder section and has a diameter that allows the cylinder section to be slightly expanded during piston movement to maintain a sealing relationship. An outline of its handling is described below.

The injection piston and needle support come together to form a first latch when the piston rod is depressed. That is, (1) the needle support is hooked onto the piston head, (2) the needle support is separated from the collar provided at the tip of the cylinder, and finally (3) the piston and needle are integrated and placed inside the cylinder. Pull it into a safe position. The second latch mechanism is activated in this position. That is, a latch is activated between the piston and the elastic support provided inside the cylinder, so that the piston is fixed. At this time, the needle support and, of course, the needle are attached to the piston.

The elastic support mechanism provided at the end of the cylinder is composed of an elastic support portion, a ring-shaped protrusion, and a groove formed therebetween. The protruding part has a diameter smaller than the inner diameter of the cylinder, and after the piston has temporarily pushed it apart and passed through it, it sinks into the groove, preventing it from moving any further.

In another alternative, the hypodermic syringe is constructed of a cylinder having a needle support collar at the distal end of the cylinder and a needle support collar that releasably catches and holds a needle attached thereto; The other end is adapted to receive a resilient piston. The piston is carried by being attached to the head of the piston rod, and the piston rod head and the needle support unite together to create a single latch, and the needle support is hooked onto the piston rod head to release the needle support. The needle support is separated from the collar, and finally the piston rod head, needle support, and needle can be pulled together into a safe position inside the cylinder. The piston is held in its safe position by a hook-type latch mechanism.

[Examples and Effects of the Invention] See FIG. 1. A syringe 10 of the present invention is shown therein as a diagram. syringe 10
The cylinder body 12 is elastic and has a needle support collar 14 at its tip. A needle support 16 for attaching a hypodermic syringe from the inside is attached to the needle support collar 14. Plug-in sheath 20
is provided to protect the needle 18 and protect the needle support 16 until the syringe 10 is used.

See FIG. 5 and FIG. 5A. Needle support 1
6 is attached to the mounting collar 14 from the inside of the syringe body 12. As shown, the needle support 16 has an integral bayonet pawl 22 and, when pushed into the slot 23, rotates along an angled groove guide 24 before being seated in the latch mechanism of FIG.
The needle support 16 has a resilient flange 26 on its shoulder, and as the claw 22 is dropped along the groove 24, it comes into close contact with the recessed female hole 28. This assembly and latching is done inside the cylinder body when the needle is installed as shown in FIG. 1 before use.

A piston rod 30 made of several longitudinal reinforcements 30A is inserted into the cylinder and moved. The piston rod is located inside the cylinder 12 and has a piston plate 32 and a convex latch at its tip. This situation is shown in detail in FIGS. 3-5 and 8.

Syringe piston 32 is preferably made of a relatively stiff material, such as nylon. Piston rod 30 is made of a non-resilient material such as acrylic or polystyrene and is joined to piston 32 by ultrasonic welding. The circumference of the piston 32 is smoothly rounded and made to fit snugly against the inner wall of the cylinder. Cylinder 12, on the other hand, is made of a resilient material such as polyserine or polypropylene.
All these materials must be of food grade or better quality. syringe piston 32
has a diameter slightly larger than the inner diameter of the cylinder, and when moving inside the cylinder 12 from end to end,
It acts to push and expand the cylinder. piston 32
for the purpose of drawing liquid from another container and injecting it into a patient through a hypodermic needle;
It is important that the cylinder has the appropriate shape and size to move the liquid inside the cylinder.

As shown in FIGS. 3, 5 and 8, the latch 34 on the piston rod moves with the piston 32. The shape of the latch is a cone with a holding gill 34A formed around the shoulder, and a rotating pawl 34B is provided along the axial direction on the surface of the cone.

As shown in FIGS. 5 and 8 to 10, the latch 34 is pushed into the needle support by pushing out the bulge formed inside the resilient flange 26. It is pushed into the female hole provided inside 16. Then, the pawl 34B follows the sloped groove on the receiving side and matches the position of the latch receiving seat 40. When the latch 34 is pressed down in this manner, the latch 34 rotates as necessary, as the case may be, to move the pawl 34B into the groove 42, as shown in FIGS. 9 and 10.
and is carried so as to fit into the storage seat 40.

From this position, the piston rod further rotates, and the piston 32, needle support 16, and needle 18 rotate together as one (see FIGS. 5, 5A, and 6). That is, as the piston rod 30 and piston 32 move, the pawl 32 of the needle support 16 moves along the opposing groove 24 and rotates 90 degrees until it is aligned with the slot 23. After that, insert the piston 3 into the cylinder.
When the needle 2 is pulled back, the needle support 16 and the needle 18 are pulled together into the cylinder. In this way, the risk of being caught or poked by the needle 18 is completely eliminated.

The inside of the upper part of the cylinder 12 has an inner diameter smaller than the cylinder diameter and forms a support portion 46 . A latch groove 48 is formed by this portion and a ring-shaped protrusion 50 having an inner diameter smaller than the cylinder inner diameter. The diameter of the groove may be approximately the same as the inner diameter of the cylinder 12. Here you need to pay attention to the following: That is, the material of the support part 46 and the protrusion part 50 that make up the latch part is elastic, similar to the material of the cylinder, and is required to be expanded with a certain degree of force in the direction of the diameter of the cylinder.

When the injection piston 32 is pulled against the protrusion 50 with a force greater than the force of movement within the cylinder, the protrusion 50 expands and the piston passes through it until it is seated completely within the groove 48. . Once seated in groove 48, piston 32 has a sufficiently large resistance to move in either direction.

There are perforations 52 in the reinforcement 30A of the piston rod 30.
will be applied. When the piston 32 is seated in the groove, the perforation is placed at a height that almost touches the edge of the cylinder 12. If a lateral force is now applied to the piston rod 30, it will break along the perforation, leaving the piston rod remaining inside the cylinder at the same height as the edge of the cylinder 12 (see Figures 11 and 12). (see ). As a method of fixing the piston rod 32, the protrusion 5 as described above is used.
Support part 4 where the cylinder becomes narrower even if 0 is not applied
It is also conceivable that the support portion 46 is expanded after the piston reaches the point 6, and the piston sinks into the support portion 46 and accumulates therein. However, it is preferable to add the protrusion 50 as described above.

It also describes the preferred method of using the syringe. The syringe 10 is distributed to the user in a state as shown in FIG. 1, that is, in a state where the shoulder flange portion 26 of the needle support is fitted into the female hole 28 on the cylinder side and is assembled into the needle support collar 14. . The injection piston 32 is the second
As shown in FIGS. 7, 11 and 12, the distance from the bottom of the protrusion 50 to the position just before the piston latch 34 is hooked onto the flange 26 can be moved.

The user removes the sheath 20 from the needle, sticks the needle 18 into the container, and draws the injection into the cylinder 12.
The needle 18 is then inserted into the patient and the drug is injected. Alternatively, the needle may be inserted into the subject with the cylinder 12 empty to collect blood, and the blood may then be poured into another container for testing or the like.

After using the syringe 10, remove the piston rod 30.
Push in, attach it to the tip of the piston 32, and tighten the latch 34.
is passed through the flange 26 and dropped into the interior of the needle support 16 (FIG. 8). The piston rod is then rotated to bring pawl 34A into alignment with slot 42.

Subsequently, the piston rod is rotated according to the movement of the pawl 22 guided by the groove 24, and finally the piston rod is rotated by the pawl 22 as a guide.
2 reaches the position of the disconnection slot 23.

The piston 32 at the head of the piston rod is then pulled back inside the cylinder so that the piston 32 engages the latch projection 5.
Moved to the 0 position. When the piston 32 is pulled with a slightly strong force, the piston 32 pushes out the protrusion 50 and slides into the groove 48. There piston 3
2 will not be able to move back out of the groove 48 due to the protrusion 50.

When a lateral force is applied to the end of the piston rod, the piston rod breaks at perforation 52 and the fragments are attached to cylinder 1.
2 remain so that their edges coincide with each other (Figures 11 and 12).

The piston 32 and its associated needle support 16 and needle 18 will now be secured within the cylinder.

In this way, the used syringe 10 can be discarded without the risk of "needle sticks".

Next, another embodiment method will be explained.

A syringe 110 of the present invention is shown schematically in FIG. The cylinder 112 of the syringe 110 has a needle support collar 114 at its tip. Needle support 11 for installing a hypodermic syringe 118 inside this collar
6 will be installed. A plug-in sheath 120 is provided to protect the needle 118 and needle support 116 until just before use.

See Figures 14-17A. The needle support 116 is inserted into the needle support collar 1 from inside the cylinder 112.
It is installed within 14. As shown, needle support 116 has an integral bayonet pawl 122 that slides down slot 123 and rotates 90 degrees along concave guide 124 into the latched position as shown in FIG. However, the needle support 116 has a somewhat resilient flange portion 126 at its upper portion, and the pawl 122 passes through the groove 124 into the latching position and fits tightly into the recessed female hole. Such assembly and setting are performed when the needle 118 is installed from inside the cylinder 112 in the shape shown in FIG. 13.

Piston rod 13 made of several vertical reinforcements 130A
0 is inserted into cylinder 112 and moved. A latch flange 14 is provided at the tip of the piston rod 130.
4, a piston rod head 132 and another latch 134. This is most clearly shown in FIGS. 15 and 20.

The syringe piston portion is made of a soft, resilient material such as rubber, butyl or latex and is attached to the piston rod head 132.
The piston is shaped and sized so that it can move within the cylinder to draw liquid from another container and inject it into a patient through a hypodermic needle.

A thin septum 138 is formed at the front end of the piston 136 to securely cover the piston rod latch 134 while the hypodermic syringe is drawing or injecting fluid.

As shown in FIG. 18 and further in FIGS. 20-22, when the piston rod latch 134 is pressed, the bulkhead 1
38 is pushed out and brought into close contact with the position of the piston rod latch seat 140. The partition wall may then be torn.

As shown in FIG. 20, latch 134 carried by piston head 132 is rotated 90 degrees (as shown between FIGS. 21 and 22) into tight contact with latch end 142. do. As a result, the needle support 116 and the needle 118 are attached to the piston head 132.
It will be fixed at

See FIGS. 17, 18, 20 and 22. Further, the piston head 132 rotates the needle support 116 90 degrees so that its pawl 122 follows the guide in the groove 124 until it lines up with the slot 123. Then, when the piston rod 132 is pulled back into the cylinder, the needle support 116 and the needle 118 are taken into the cylinder together. In this way, the needle 118 can be delivered in a completely isolated state where it will not catch or sting. That is, the piston rod 130 is connected to the cylinder 112.
As the distance from the tip of the piston rod head 13 increases,
2 and the piston 136 are pulled up together.

The following points need to be noted in FIGS. 15 and 24. That is, it is important that the piston 136 is provided with an inclined latch flange 144 at its upper portion.

A recessed pocket 150 is provided at the upper end of the cylinder 112 and has at least two latch hooks 146 incorporated therein. 14
8 is the arm of the hook. As the piston rises, the flange 144 rises and slides the latch 146, so that the latch 146 is caught on the latch 144. In this way, the piston 136 is engaged to prevent it from moving back toward the needle support collar 114.

In this manner, the hook 146 snaps into the latch flange 144 after the piston 136 has been retracted internally and the piston rod head 132 has brought the needle support 116 and needle 118 to a safe position inside the cylinder. As a result, the needle support 116 and the piston rod head 13
2 becomes impossible to go back.

We will also describe how to use the latter syringe. Syringe 1
10, as shown in FIG. 13, is distributed to users in a state where it is assembled into the needle support collar 114, with the flange portion 126 of the needle support device being fitted into the female hole 128 on the cylinder side. The piston 136 can be freely moved by the piston rod 130 from just in front of the pocket 150 to the position where the partition wall 138 is pushed out or broken (see FIGS. 14 and 2).
(See Figure 4). The user first removes the needle 118 from the sheath 1.
20 is removed, the needle 118 is inserted into the container, and the injection solution is drawn up into the cylinder. Then, the user inserts the needle 118 into the subject and injects the medicine.

Alternatively, the user inserts the needle into the subject with the cylinder 112 empty and draws up blood for the purpose of testing or the like.

After the syringe is used, the piston rod 130
By pushing down the piston rod head 132
Then, the piston 136 is further moved, and the septum 138 is pushed out or broken, and the piston rod latch 134 is firmly attached to the needle support collar 114 until it falls into the recessed hole in the needle support 116 (Fig. 20). ).
The piston rod is then rotated 90 degrees to bring latch 134 into tight contact with latch seat 140 and latch stop 142.
Here, the piston rod head 132 and the needle support collar 114
(Figures 21 and 22).

Subsequently, the piston rod 132 is connected to the needle support 11
6 engages with the piston rod head 132, the latch pawl 122 rotates another 90 degrees and the latch pawl 122 engages with its guide 124.
rotate along. There, the pawl 122 lines up with the cutting slot 123 (FIGS. 17, A, and 18).

The piston rod 132 then connects to the cylinder 112
When retracted internally, latch flange 144 on injection piston 136 mates with hook 146 (FIGS. 19 and 23).

The piston rod 130 and the needle support 116 and needle 118 attached thereto are then permanently captured inside the cylinder 112 (23rd
figure).

As described in detail in the embodiments of the present invention, after using the syringe, the piston is pushed toward the needle support, and the latch provided at the tip of the piston is engaged with the needle support. By retracting the needle into the cylinder, the needle support and needle become trapped inside the cylinder. Therefore,
In this state, or if necessary, by breaking off the piston through the perforation, the used syringe can be made compact and thrown away. Thus,
This makes it possible to avoid the danger of needle sticks caused by the used syringe.

Note that this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[Brief explanation of drawings]

FIG. 1 is a sketch of a hypodermic syringe according to the present invention. 2 is a partial cross-sectional view of the cylinder upper retaining latch mechanism along line 2--2 of FIG. 1; FIG. FIG. 3 is a cross-sectional view of the syringe piston taken along line 3--3 of FIG. FIG. 4 is a sketch of the piston shown in FIG. 3. 5 is a front view of the needle support and needle support collar taken along line 5--5 of FIG. 1; FIG. FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. FIG. 7 shows the movement of the piston until the needle support latching mechanism is engaged, as will be explained in further detail in FIGS. 8-10. FIG. 8 is a cross-sectional view of the piston and needle support arrangement as shown in FIG. FIG. 9 is a sectional view taken along line 9--9 in FIG. 8, showing the state of the latch groove inserted into the needle support collar just before the latch pawl is rotated and fitted into the latch groove. FIG. 10 is similar to FIG. 9, but shows the state after being fitted. FIG. 11 shows the piston and piston rod retracted into their final safe position within the cylinder. Figure 12 shows the latch removed, the needle placed in a safe haven, and the piston rod destroyed so that it cannot be used again. 13th
The figure is a schematic diagram of another type of hypodermic syringe of the present invention. FIG. 14 is a cross-sectional view of another type of upper retention latch taken along line 14--14 of FIG. FIG. 15 shows a cross-sectional view of the piston rod head and movable piston of the present invention, taken from 15--15 in FIG. 13. FIG. 16 is a sketch of the piston rod head in FIG. 15. FIG. 17 is a sectional view of the needle support collar and needle support taken along line 17--17 in FIG. 13. 1st
FIG. 7A is a diagram showing the needle support removed to show the structure of the support. FIG. 18 shows a cross-sectional view taken along line 18-18 of FIG. 17. FIG. 19 shows a cross-sectional view of the syringe in which the moving piston and piston rod head have been moved to connect directly with the needle support and then actuated the latch, resulting in the assembled syringe as shown in FIGS. 20-22. FIG. 20 is a detailed cross-sectional view of the moving piston and needle support shown in FIG. 19; FIG. 21 is a cross-sectional view taken along the line 21--21 shown in FIG. Thus, it shows a latch protruding from the head of the piston rod. FIG. 22 is the same view as FIG. 21, but shows the piston side latch rotated 90 degrees to engage the piston rod head in the needle support. Figure 23 is similar to Figure 19, but the piston rod and its head rotate through the first 90 degrees, the piston side latch engages the needle support, and the second 90 degree rotation moves the needle support into the cylinder. It is a figure which shows the state when it detaches from the latch support in the collar of a needle support device. FIG. 24 is an enlarged view of the upper part of the moving piston and the upper part of the cylinder shown in FIG. 23. Here, the upper cylinder latch mates with a latch flange provided on the top of the piston. Description of symbols, 10...Syringe, 12...Cylinder, 14...Needle support flange, 16...Needle support, 1
8...needle, 20...sheath, 22...bayonet claw,
23...Slot, 24...Groove guide, 26...
...Flange, 30... Piston rod, 32... Piston plate, 34... Latch, 40... Latch catch, 46
...Support portion, 48... Latch groove, 50... Projection.

Claims (1)

[Claims] 1. A disposable safety syringe comprising: (a) a resilient hollow cylinder; It is made of a material that is softer than the syringe piston.
It has a needle support flange at its distal end, and a needle support for attaching the needle is built into the collar, and is incorporated in a latch type so that it can be separated. (b) a syringe piston inserted from the other end of said cylinder; This is made of a harder material than the cylinder, and its diameter is made slightly larger than the inner diameter of the cylinder so as to create a sealing relationship with the cylinder in the path of movement by the piston rod. (c) said syringe piston and said needle support; These combine to form a first latch mechanism. This is because the needle support latch mechanism for hooking and detaching the needle support into the needle support collar has a bayonet pawl provided on the needle support, and a bayonet pawl that guides the bayonet pawl to connect the needle support to the needle support. It consists of a guide groove for dropping the needle into the needle support collar, and a latch is provided at the tip of the piston rod.
The latch is rotated after being carried by the movement of the piston, and the latch is hooked to the needle support within the piston rod latch receiver provided in the needle support, and the syringe piston further rotates, causing the needle support to rotate. The injection piston and the needle support are configured to be able to be pulled into the cylinder by separating the tool from the needle support collar and integrating the injection piston and the needle support. (d) a second latching mechanism comprising a resilient buttress at the second end of said injection piston and said cylinder; This consists of an elastic ring-shaped protrusion inside the cylinder and an elastic support part which together forms a groove. The protrusion has a diameter slightly smaller than the inner diameter of the cylinder, and is made such that the injection piston temporarily expands it, passes through it, and falls into the groove, and connects the injection piston, needle support, and needle. together serve to hold the cylinder in a safe position within the cylinder. A safe, non-contaminating, disposable hypodermic syringe consisting of the above (a), (b), (c), and (d). 2. The piston rod part has a perforation or other frangible part for easy separation at the second end of the cylinder when the injection piston is in the safe position. The safety syringe described in item 1. 3. The safety syringe of claim 1, wherein said injection piston is made of nylon and said cylinder is made of a material softer than nylon. 4. A safety syringe according to claim 1, wherein said cylinder is made essentially of a material selected from the class of polyserine, polystyrene, etc. 5 Disposable safety syringes, which are (a) hollow cylinders; This is provided with a needle support flange at its distal end into which a needle support for attaching a needle is housed, and is of a latch type so that the needle support can be separated. (b) an injection piston inserted from the other end of said cylinder; This is attached to the piston rod head of the piston rod. (c) said piston rod and needle support together constitute a first latching mechanism; This is because the needle support latch mechanism for hooking and detaching the needle support into the needle support collar has a bayonet pawl provided on the needle support and guides the bayonet pawl to hold the needle support. It consists of a guide groove for falling into the needle support collar, and furthermore, the latch provided at the tip of the piston rod is caught on the needle support by the piston rod latch receiver when the piston moves, and furthermore, the needle support is rotated. The needle support is separated from the needle support flange, and the piston rod and the needle support are integrated so that they can be pulled into the cylinder. (d) a second latching mechanism formed when said piston rod is retracted into the cylinder; This is configured such that the piston is provided with a latch flange, and when the piston is pulled into the cylinder, the latch flange is hooked onto a hook provided in the cylinder, preventing the piston rod from moving within the cylinder. has been done. A safety syringe consisting of a combination of (a), (b), (c), and (d) above. 6 The needle support mentioned above is incorporated in the front. This method of assembling is of a latch type and can be internally separated from the needle support collar by rotation of the piston rod head. Safety syringe as described. 7. The above-mentioned needle support is assembled at the front and forms a latch with the needle support collar, and can be separated from the needle support collar on the inside by rotation of the piston rod head. 7. The safety syringe according to claim 1, wherein the first latching mechanism comprises a latching pawl and a guide on the side receiving the latching pawl. 8. The above-mentioned needle support is assembled at the front, and forms a latch with the needle support collar, and is structured so that it can be separated from the needle support collar on the inside by pulling back the piston rod. This is the first latch mechanism described above, and is composed of a latch pawl and a guide portion for the pawl. At this time, the piston rod head rotates and is caught inside the needle support by the piston rod latch seat, and further rotates to separate the needle support from the needle support collar, and the piston rod head 6. A safety syringe according to claim 1, wherein the needle support and the needle support can be retracted into the cylinder as a unit. 9. The above-mentioned needle support is attached to the front, forming a latch mechanism with the needle support collar, and can be separated from the needle support collar on the inside by the piston rod head. This first latching mechanism is composed of a latching pawl and a pawl guide on the receiving side thereof. At this time, the piston rod head rotates and is caught on the piston rod latch seat inside the needle support, and further rotates to separate the needle support from the needle support collar, and the piston rod head and the needle support described above are pulled into the cylinder together. A second latch mechanism is then configured. That is, a latch hook attached to the second end of said hollow cylinder mates with a latch flange moving on the piston rod head, bringing the piston head, said needle support and needle together into said cylinder. 6. A safety syringe according to claim 5, wherein the safety syringe is fixed within the safety syringe. 10 The first latching mechanism consists of a latching pawl and a pawl guide that receives the pawl, and the piston head rotates to engage the seat of the piston rod latching inside the needle support, and further rotates to engage the piston rod latching seat within the needle support. 6. The safety syringe according to claim 5, wherein the needle support is separated from the needle support collar and the piston rod head and needle support are pulled into the cylinder as a unit. 11. The following latch mechanism shall be constructed. That is, a latch hook attached to the second end of said hollow cylinder mates with a latch flange attached to the piston rod head, so that the piston rod head, said needle support and needle are integrated into said cylinder. The safety syringe according to claim 10, which is fixed. 12. Claim 1, wherein the piston rod portion has a perforation or other frangible portion for easy separation at the second end of the cylinder when the injection piston is in the safe position. The safety syringe described in item 5.