JPH0747123A - Throw-away injector - Google Patents

Abstract

PURPOSE: To prevent a continuous use of a syringe by preventing the piston from coming out of the inside. CONSTITUTION: A tightly sealed device is constituted of a disc part 7 comprising a slightly bent material and provided with a hole in its center which receives the head part 5 of a needle. The disc part 7 has an addition in its tip and, when the pressurizing operation of the piston 4 is completed, its tip pushes the disc part 7 frontward. A holding device is constituted of a lot of tongue- shaped materials 12 which rise from the wall of the tube 1 at an inclined angle, face to the front and inside, and are set to be fitted into a ring outer groove in the outer circumference of the head part 5 of the needle so that, when the tongue-shaped materials 12 are bent by operation of the addition of the tightly sealed disc part 7, these are all removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-use hypodermic syringe, which is of a type that cannot be used after being used once. The syringe consists of a tube and a hollow piston, the tip of the tube is tapered to receive an injection needle, and the piston slides inside the tube. Inside the front part of the tube, there is provided a sealing device which is laid horizontally in the operating position and which is held by the head part of the injection needle. The head portion of the injection needle is pressed inward of the tube by a spring and is held by an interlock holding device located inside the front of the tube. In addition, there is an irreversible bond retainer which seals the piston cavity and cooperates with other auxiliary bond devices at the head of the needle, when the piston has finished the pushing operation and these bonds The devices are in contact with each other.

[0002]

BACKGROUND OF THE INVENTION As is known, single-use hypodermic syringes are sold unit by unit in sterile, sealed packages and are discarded once used.

However, while syringes are manufactured and sold for single use only, in practice, due to their structural nature, they can be easily reused from a mechanical standpoint. , It has caused a lot of problems in terms of health.

These problems have become urgent since the advent of AIDS. Occasionally, the benefits and inoculations that kill the patient and stop its spread are unknown.

There have been plans for single-use syringes to avoid reuse. However, in the actual work, the subsequent use is only avoided automatically and because the user does not handle it again.

[0006]

Among the known ones, the most rare but most effective one is the syringe described in Japanese Patent No. 8900179 of the present inventor. It presses with a spring a mechanism that automatically introduces the needle into the axial cavity inside the piston when the piston has finished pushing, preventing the needle from slipping out of the cavity.
This movement is assisted in such a way that the piston does not come out of the interior of the syringe, thus making subsequent use impossible.

Although the general principles of the above-noted US Pat. No. 8,900,179 are very effective, the patent description refers to a multi-part syringe, which adds to the manufacturing cost.

[0008]

The hypodermic syringe, which is the subject of the present invention, solves the above-mentioned problems at a significantly lower cost than in Japanese Patent No. 8900179.

[0009] Basically, the syringe of the present invention comprises a closed-loop device composed of a disc portion made of a slightly bending substance, the edge portion of which comes into contact with the inner wall of the front portion of the tube to form a tight sealing. It is characterized by The disc part has a countersink in its center, which receives the head part of the needle and again forms a tight sealing at the conical end.
The disk part has an accessory at its front end, and when the piston is pressed, the disk part is pressed forward by the piston front end, and the accessory acts on the interlock holding device at the front end inside the tube. Since the disk part and the needle are pressed by the piston, they move forward lightly. The above mentioned attachment presses on the holding device, thereby releasing the needle, which is introduced into the piston cavity by the force of the spring.

According to another feature of the invention, the retaining attachment for the interlock at the front end of the tube of the syringe comprises a multiplicity of flexible tongues which rise from the wall of the tube at an angle of inclination. , The front and the inside are set so that they fit into the ring-shaped outer groove around the outer side of the needle head, so that the tongue is pressed by the accessory of the closed disk. These are removed as they are bent.

Considering still other characteristics, the device for closing the cavity of the syringe tube described above is composed of a disk-shaped button, and its edge pressure causes a ring-shaped device formed around the opening of the cavity of the piston. It is designed to fit in the groove. The disk-shaped button has a protrusion at its tip, which constitutes the above-mentioned irreversible coupling device and has an edge protruding outward in a stepwise manner and is formed on the head portion of the needle. Due to the pressure fit in the countersink, it will not be pulled out by the counter-action of the auxiliary interlocking retainer consisting of a notched step.

Another feature of the invention is a set of piston retaining devices, which are provided in the cavity opening of the tube such that the piston cannot be withdrawn from the tube.

The drawing shows a single-use hypodermic syringe which is the subject of the present invention, and comprises a tube 1 and a piston 4, the tip 2 of the tube 1 being tapered so as to receive a hypodermic needle 3. The piston 4 slides inside the tube 1.

A sealing device is set inside the distal end of the tube 1 and is horizontally held in the operating position and held by the head portion 5 of the injection needle 3.

The head part 5 of the needle is pressed toward the inside of the tube 1 by a spring 6, preferably a helical compression spring, and is held by an interlock holding device located inside the tube 1.

At the front end of the piston 4, there is a device for sealing the cavity 11 of the piston 4, which is the head 5 of the needle 3.
And has an irreversible coupling device for fitting another auxiliary coupling device.

The above-mentioned sealing device is composed of a disk portion 7 made of a slightly bendable substance, the edge portion of which is in contact with the inner wall of the front stage of the tube 1, and tight sealing is obtained with the tube 1.

There is a countersink 8 in the center of the disc portion 7 where the head 5 of the needle 3 is received and further tight sealing with the conical end 9 is obtained.

The disc portion 7 also has an accessory 10 at its front end, and when the pushing operation is completed, the disc portion 7 is pushed forward by the front end portion of the piston 4, and this is at the inner front end portion of the tube 1. It is adapted to act on the locking retaining device.

At this stage, the disc portion 7 is pushed by the piston 4 together with the needle 3 and slightly moved forward. Attachment 10 mentioned above
Causes the holding device to be pushed, thereby releasing the needle 3, which is caused by the force of the spring 6 to move into the cavity 1 of the piston 4.
Introduced in 1.

The interlocking retainer at the front end of the tube 1 comprises a number of flexible tongues 12 which rise up from the wall of the tube 1 at an angle of inclination.
The tongue is pressed so that the accessory 10 of the hermetic disk 7 is pushed by the tongue-shaped object because it is set so as to face forward and inward and fit in the ring-shaped outer groove 13 around the outer side of the head 5 of the needle 3. They are bent by action and are removed.

The device for closing the cavity 11 of the piston 4 is composed of a disk-shaped button 14, and the cavity 11 is formed by its edge pressure.
It fits in the ring-shaped groove 15 around the opening.

The disk-shaped button 14 has a protrusion 1 at its tip.
6, which constitutes the above-mentioned irreversible coupling device, has an outwardly protruding stepped edge 17, which pressurizes a countersink 18 formed in the head 5 of the needle 3 As it fits, it cannot be pulled out by the counter-action of the auxiliary interlocking retainer consisting of a notched step.

A set of devices for holding the piston 4 is provided in the hollow mouth of the tube 1 and is preferably composed of joining ribs 19 and 20 so that the piston 4 cannot be pulled out of the tube 1. Has become.

The nature of the present invention and the method for carrying out the invention are as described above, and the main principle of the invention is changed,
Unless it is converted or controlled, it belongs to the variations of the present invention. What is summarized in the claims is the essence of the present invention, and the claims are claimed.

[0026]

The single-use hypodermic syringe of the present invention has a tube that is tapered and receives an injection needle, a hollow piston that slides inside the tube, and a head portion of the needle that is placed horizontally on the operating portion. To hold the closure device, the spring that presses the needle toward the inside of the tube, the device that closes the piston cavity, and the head of the needle to fit other auxiliary coupling devices. And an irreversible bond retainer. The closure consists of a disk-shaped part made of a slightly flexible substance, which has a countersink in its center to receive the head of the needle. This disk portion has an appendage at its tip, and when the pressing operation of the piston is completed, the disk portion is pushed forward by the tip. The holding device consists of a number of tongues, rising up from the wall of the tube at an angle of inclination, facing forward and inward, in a ring-shaped outer groove around the outside of the needle head. Being set to fit, the tongues are bent and removed by the action of the appendages of the sealing disc.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a syringe before use.

FIG. 2 is a view similar to that shown in FIG. 1, but showing the syringe disabled.

[Explanation of Codes] 1 Syringe tube 2 Tube tip 3 Injection needle 4 Piston 5 Injection needle head portion 6 Spring 7 Disk portion 8 Countersink 9 Conical end portion 10 Attachment 11 Piston internal cavity 12 Tongue portion 13 Ring groove 14 Disc-shaped button 15 Ring-shaped groove 16 Protrusion 17 Edge part 18 Countersink 19 and 20 Joining rib

Claims (4)

[Claims] 1. A tube which is tapered and adapted to receive a hypodermic needle, a hollow piston which slides inside the tube, and a horizontal portion which is laid across the operating part and is held by the head part of the needle and set inside the tube tip. It consists of a sealed device, a device that seals the cavity of the piston, and an irreversible coupling holding device, the head part of the needle is pressed by a spring that tries to push the needle into the tube, The pressed needle is held by an interlock holding device located inside the front end of the tube, and the device for sealing the cavity of the piston is installed in the front part of the piston by the non-reversible coupling holding device, and the head part of the needle is held. The other auxiliary coupling device, and when the pushing operation of the piston ends, they act so as to contact each other, and the sealing device bends slightly. It is composed of a disc part made of quality, its edge part contacts the inner wall of the front part of the tube to form a tight ceiling, and the disc part has a countersink in its center to receive the head part of the needle and the conical end part. A tight sealing is formed by the disc part has an accessory at its front end, and when the piston pressing operation ends, the disc part is pressed forward by the piston front end part, and the accessory is inside the tube. At the front end of the device, the holding device for the interlock is actuated, whereby the disc portion and the needle are pushed forward by the piston and lightly advanced, and the above attachment pushes the holding device, thereby releasing and releasing the needle. A single-use hypodermic syringe characterized in that the needle is introduced into the cavity of the piston by the force of the spring. 2. The interlocking retention device at the front end of the syringe tube consists of a number of bendable tongues, rising up from the wall of the tube at an angle of inclination, facing forward and inward, the head of the needle. 2. The holding device is adapted to be fitted into an outer circumferential groove of the outer periphery of the portion and to be removed when bent by a pressing force of an accessory of the hermetic disc portion. Single-use hypodermic syringe. 3. A device for closing a piston cavity is constituted by a disc-shaped button, and the edge pressure thereof is fitted into a ring-shaped groove formed around an opening of the piston cavity. It has a projection at the tip, constitutes the above-mentioned irreversible coupling device, has a circular edge projecting outward in a stepwise manner, and is pressure-fitted into a countersink formed in the head portion of the needle. The disposable hypodermic syringe according to claim 1, characterized in that the withdrawal is prevented thereby despite the counter-action of the auxiliary interlocking device consisting of a notched step. 4. The single-use hypodermic syringe of claim 1, wherein the piston retaining device is provided in the opening of the tube cavity to prevent the piston from being withdrawn from the tube.