Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Patent
1989-06-28
1991-08-06
Pellegrino, Stephen C.
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
604218, A61M 500
Patent
active
050373935
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a syringe element for an autoblocking, non-reusable syringe, that is a syringe the piston of which blocks automatically at the end of the injection and also to a syringe having an undetachable needle.
BACKGROUND OF THE INVENTION
A conventional syringe has a needle and a syringe element comprising a syringe body the lower extremity of which is provided with a base on which the needle may be fitted and a piston mounted at the end of a shaft. This piston is introduced through the upper extremity of the syringe body and is able to slide freely therewithin. In a syringe of this kind the body of the syringe and the piston can be reused.
This syringe is not satisfactory from the hygienic point of view since it introduces the risk, if used successively by several different people, of transmitting microbial germs or viruses between these people.
DESCRIPTION OF RELATED ART
Non reusable syringes are described especially in patents Nos. CH-A-478354, CH-A-620126, U.S. Pat. Nos. 469,614 and 468,467. The syringes described in these documents comprise means for destroying the piston seal or for separating the piston and the shaft, thereby preventing reuse of the syringe.
The first disadvantage of these known syringes lies in their complexity, which is reflected in their high basic cost.
A second disadvantage is the insufficient safety of these syringes. To prevent reuse of these syringes it is necessary for the piston to be pushed down to the lower extremity of the syringe body during injection. However, provided the piston is not pushed down to the base of the syringe body the syringe can be reused numerous times.
A lens complicated non-reusable syringe is described in patent No. FR-A-2181580. This syringe comprises a flexible resilient washer disposed around the shaft in the syringe body. FIGS. 1 and 2 of the accompanying drawings respectively illustrate a longitudinal section of such a syringe and a plan view of the washer.
This syringe conventionally comprises a syringe body 2 provided with a base 4, a piston 6 able to slide tightly within the syringe body and a shaft 8 for moving the piston. It also comprises a washer 10 disposed around the shaft in the proximity of the piston and a cover 12 which closes the syringe body and thereby prevents removal of the washer and the piston from the syringe body.
The washer 10 has an outer diameter greater than the inner diameter of the syringe body. It is provided with slits 14, 16 which give it a certain flexibility and make it possible to bend it in order to place it in the syringe body. It is also provided with points 18 on its inner edge in order to be able to catch onto the shaft.
The syringe is assembled with the washer in position 20 and the shaft retracted inside the syringe body. In this position the outer edge of the washer exerts a friction which only permits movement of the shaft in the direction indicated by the arrow 22. When the shaft is retracted completely the washer reaches a groove 24 in which its outer edges is no longer in contact with the syringe body. The shaft can then be pushed in the direction shown by the arrow 26 and the washer adopts the configuration shown at 28. As from this moment, it is no longer possible to displace the shaft in the direction of the arrow 22 since, if such a movement is attempted, the outer edge of the washer catches onto the wall of the syringe body and, through deformation of the washer, the points 18 penetrate into the shaft and finally shatter it.
This syringe is simpler than the syringes described in the patents cited above, but it is still nevertheless not entirely satisfactory.
Its selling price remains high because it is necessary to machine the washer carefully to produce the points 18, the role of which is essential both for causing the washer to catch onto the shaft in normal use and for shattering the shaft in the event of attempted second use of the syringe.
Moreover, the syringe is difficult to produce in practice since the washer has to possess two opposing properties: it has
REFERENCES:
patent: 4493703 (1985-01-01), Butterfield
patent: 4731068 (1988-03-01), Hesse
patent: 4775364 (1988-10-01), Alles
patent: 4781684 (1988-11-01), Trenner
Pellegrino Stephen C.
Rafa Michael
LandOfFree
Non-reusable 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 Non-reusable syringe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-reusable syringe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1984001