Single-injection syringe

Details Single-injection syringe Single-injection syringe

1990-02-02

1993-01-05

Yasko, John D.

Surgery

Means for introducing or removing material from body for...

Treating material introduced into or removed from body...

604228, 604236, A61M 5315

Patent

active

051766396

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to a disposable syringe, that is one that can be used only once, and relates more precisely to a device that renders the sealing joint inoperative after a first injection.


BACKGROUND OF THE INVENTION

In the field of therapeutics, the use of syringes for injecting fluids into tissues or natural cavities in the body is extremely widespread. A syringe is known to be composed essentially of a cylindrical barrel in which a plunger slides, a body whose base bears a nozzle of a suitable shape to which can be fitted a hollow needle, for example a needle made of steel or nickel, the barrel thus forming a reservoir for the fluid to be injected. The structure or composition of the plunger can vary according to the model. It is, in any case, provided at one of its ends with a joint to ensure sealing with the barrel of the syringe and, at its other end, which is always external to the barrel of the syringe, a plunger head to facilitate its handling. This classical syringe makes it possible to perform in the habitual manner the operations required for an injection as commonly practised, that is in the first place, detaching the joint at the bottom of the syringe and then, by applying traction to the plunger to extract it from the barrel of the syringe, drawing in a certain quantity of fluid. Then, with the syringe in inverted position, that is with the needle pointing upwards, a slight pressure on the plunger causes any air remaining in the reservoir to be discharged, this operation possibly being followed by the drawing in of a complementary quantity of fluid and again the essential discharge of the air.
Before injection properly speaking, slight re-aspiration is practised after insertion for checking purposes.
There are known disposable syringes used for vaccinations which are pre-filled in the laboratory and with which it is no longer possible to draw in fluid after the injection. However, as most syringes used are not pre-filled and since it has to be possible for the to and fro movements of the plunger to be performed for the operations described above, or for manipulations in an empty condition, it is not possible to adopt this system.


SUMMARY OF THE INVENTION

One object of the present invention is thus to provide a device adaptable to any syringe, which permits the performance of all the operations necessary for a complete injection and thus including the to and fro movements of the plunger or its manipulation in an empty condition as described above, but which strictly precludes re-use for a second injection, the device rendering the sealing joint inoperative after the first injection by making use of the action of the pressure exerted by the fluid, during injection, on a flexible part of the joint to detach the joint from its driving plunger, or to destroy its function as a sealing member.
The invention thus relates to a disposable syringe comprising a cylindrical syringe barrel to the base of which can be fixed different sorts of sampling and/or injection needles, as well as a plunger sliding inside the syringe barrel and whose end bears a joint the slides sealingly over the internal wall of the syringe, a syringe in which the joint comprises at least one member capable of being deformed or displaced from its position of equilibrium through the action of the pressure exerted by the fluid contained in the syringe at the time of the injection stage, the sliding plunger being associated with the joint via components that react to the deformation or the displacement of the member and which render the joint inoperative for the purposes of refilling after the injection.
According to the special features of the invention, the joint is a hollow cylindrical component whose lower face is formed by a flexible membrane that constitutes the deformable member and which ensures sealing between the syringe barrel and the chamber inside the joint and whose annularly shaped upper portion bears against the plunger, which plunger extends, through the orifice in the annul

REFERENCES:
patent: 4059109 (1977-11-01), Tischlinger
patent: 4233975 (1980-11-01), Yerman
patent: 4687487 (1987-08-01), Cygielski
patent: 4863427 (1989-10-01), Cocchi
patent: 4880410 (1989-11-01), Rossmark
patent: 4973308 (1990-11-01), Borras et al.

Affiliated with

Also associated with

Rating

Single-injection syringe does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Single-injection syringe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single-injection syringe will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2388508