Patent ID: 7544182

Claim:
A single use syringe which comprises: a syringe body which contains a front end area containing a longitudinal passageway which has a front portion and a rear portion, a plunger which contains a front face which extends into the syringe body, a pierceable seal extending over the front face of the plunger, a needle holder that is attached inside and in the front area of the syringe body, a needle that is attached to the needle holder, a spring in the front of the syringe body and that is biased to shoot the needle holder through the pierceable seal in the front face of the plunger and into the plunger, the needle holder comprising an inner part and an outer part, the inner part containing the needle, the outer part engaging with a wall of the longitudinal passageway and initially in a rear portion of the passageway, a frangible portion between the inner part and the outer part, the frangible portion adapted to be broken to allow the needle holder to shoot into the plunger, the outer part containing a raised portion directed towards the seal of the plunger, the raised portion extending only partway about the outer part, the raised portion functioning to provide an initial contact area of the plunger with the outer part of the needle holder, thereby reducing the force required to break the frangible portion thereby allowing the needle holder to shoot through the seal.