WO2002068023A1

WO2002068023A1 - One use syringe

Info

Publication number: WO2002068023A1
Application number: PCT/IB2001/001191
Authority: WO
Inventors: Hans Olaf Hartmann; Jose Victor Alapont Boiguess; Rafael Serra Rodas
Original assignee: Hans Olaf Hartmann; Jose Victor Alapont Boiguess; Rafael Serra Rodas
Priority date: 2001-02-28
Filing date: 2001-06-18
Publication date: 2002-09-06

Abstract

One use syringe comprising a hollow cylinder to the distal end of which is connected a needle holder encompassing a needle in fluid communication with the interior of the cylinder and a sealing plunger head displaceable inside the cylinder by a thruster stem, the thruster stem having an inner cavity oriented along the longitudinal axis. The needle holder further includes a blocking piece having two blocking lips, both surrounded by an elastic ring, which lips hold the needle in place against the biasing force of a spring placed inside the needle holder. The plunger head engages with the needle holder in such a way that, at the end of the injection stroke, further pushing of the thruster against the needle holder results in rupturing a weakened portion of the distal plunger surface and radial spreading of the blocking lips. Once the needle is released from the blocking lips, it is projected inside the thruster cavity by the biasing spring. After this step the thruster, now containing the needle, the biasing spring and the cutout portion of plunger surface, remains locked inside the cylinder by locking notch and groove formations on the proximal end of the thruster and the cylinder, respectively, to avoid attempted thruster retraction.

Description

One use syringe

The technical sector of this patent is the sanitary field, the production and use of hypodermic syringes which contain a liquid and must be injected in a patient or user.

Indication of the former technical state.

EP0759789A1, safe syringe, made up of a mechanism that when activated by a spring, releases a liquid in a way that the plunger reaches the end of the release run involuntarily, remaining inserted in the needle.

ES P8900179, single use syringe, is made up of a hollow plunger sharing jointly a thruster hollow with a fixed nucleus, usually dragged to the end of the thruster by a spring; on emptying the liquid, it is embedded in the head of the mouthpiece, freeing the nucleus and taking the needle with it on withdrawal.

Hypodermic syringes present a double problem: On the one hand the need to be used only once to avoid contagion by members of groups who by habit tend to share syringes, even when they are offered free. On the other hand, the avoidance of risks that professionals and other sanitary personnel face, of being jabbed by an infected needle.

The aim of this invention is a one use syringe that comprises the disposal of the needle in such a way that once the jab is done it is unusable. The syringe also has measures that impede its reuse, although the needles retraction isn't activated, so that this double disabling is the guarantee of clinical safety that the syringe described brings.

In order to make the following explanation clearer, two sheets of drawings are attached in which three figures represent the essence of this invention. Figure 1 shows a view of the head of the syringe according to a sectional view of said part.

Figure 2 shows a complete view of the sectional plan of the syringe in use phase.

Figure 3 shows a complete view of the sectional plan of the syringe in self-destruct position.

In said figures, the following are represented by 1, the needle, 2, the open compressed spring, 3, the body of the syringe, 4, the coned stem at the end of the plunger, 5, the blocking piece of the body that holds the needle, 6, the silicon or soft material or elastic ring, 7, the plunger, 8, the slit for the weakening of the coned stem by the plunger, 9, the body that holds the needle, 10, the lips of the blocking piece, 11, ring-shaped space of short thickness arranged at the base of the coned stem 4, 12, the hollow body of the thruster, 13, the ring-shaped groove made in the rear part of the cylinder that makes up the syringe, 14, the tooth in the shape of a foremast that stops the plunger from going back once it has reached the end of its run.

Explanation of use. The syringe, object of this explanation guarantees the safety of the jab, impeding its reuse, and thus making the introduction of the needle into the cylinder easier, which impedes infection.

It can be deduced from the said two functions that although, in trying to reuse the syringe by not completely finishing the injection, the foremast formed by parts 13 and 14 would stop the plunger from returning. In this situation, it is thus more effective to finish the injection, free the needle 1, 9 from its place, where it is found held by the lips 10, so that it is pushed inside by the spring.

This function is done as all the liquid comes out when the last run of the plunger in its cylinder is pressed. The ring shaped slit 8, determines that this final pressure cuts the bond holding the plunger 7 and the coned stem 4 together; the coned stem is introduced into the complementary central space of the blocking piece of the needle 5, which in turn, on resting on the soft ring, elastic or silicone that helps said expansion, frees the lips 10 from the blocking piece. This produces the freeing of the spring 2 which pushes the body 9 which holds the needle. Given that the outline of the coned stem has been broken and partially or totally separated from the plunger 7, the needle can be placed in the inner part of the hollow body of the thruster, as can the coned stem if it is completely freed from the fore part of the plunger 7.

The ring shaped groove in the rear part of the cylinder has a fingernail, which could be a series of fingernails or teeth 14, so that the if the tooth or series of teeth are placed in the ring shaped space, the body of the thruster is stuck. This could happen after the freeing of the needle from its initial position. If this weren't the case, its special arrangement would allow it to be pressed again, introduce the coned stem 4 in the corresponding cavity to free the fastening of the needle; the thruster would be joined to the ring shaped groove again on trying to get it out.

Industrial applications are capable in the production of hypodermic syringes.

Claims

1. One use syringes, formed by a plunger attached to a thruster stem that acts in the inner part of a cylinder whose opposite end to the said thruster stem is made up of or is capable of holding a hypodermic needle, characterised as it possesses:

- a set in the fore part or head of the syringe formed by two parts that make up the set, that is: a ring of silicon or soft material or elastic (6) and a blocking piece for the needle (5), delimited by a trunco-conical space in its centre; a needle supported by a body (9) temporarily held by lips like a harpoon in the inner part of the blocking piece of the needle (5)

- a hollow thruster (12)

- a head of the thruster constituted by a plunger, the end of which is shaped like a coned stem (4)

- a shape of the head of the plunger complementary to the hollow delimited by the blocking piece (5)

- a ring shaped slit (8) around the perimeter of the head of the plunger

- a weakening in all the perimeter of the coned stem, corresponding to the ring shaped slit (8); so that the blocking piece of the needle retains the body (9) that holds the needle by the lips (10) and can be separated by extra pressure after injecting all the liquid, that by compression of the silicon or soft or malleable material ring (6), freeing the open compressed spring (2) that the needle has on the extreme front of the syringe; the plunger (7) has a ring shaped space (11) of short thickness that can be broken by pressure put on the ring shapes slit (8) of the thruster. The rear of the cylinder has a ring shaped protuberance (13) that can be a connection for a tooth (14) or series of teeth in a sectional shape of a harpoon.