Patent ID: 8100865
Filing Date: 2012-01-24
Classification: A61M

Abstract:
1. A hypodermic syringe comprising: an axially extending barrel filled with injectant, which injectant is sealedly contained in the barrel between a fixed seal closing a forward end of the barrel and a slidable bung closing a rearward end of the barrel, a connecting arrangement mounted on and extending forwardly from the forward end of the barrel for locking a hypodermic needle thereto so that the needle pierces said seal, a plunger stem extending rearwardly from the bung to be manually pressed to slide the bung axially into the barrel to displace injectant therefrom by way of the needle piercing the same, wherein the bung has a periphery in sealing engagement with the barrel and an inner face comprising a resiliently deformable portion which is elastically deformed axially forwardly when the plunger stem is manually pressed and which resiles axially rearwardly if the manual pressure is removed thereby to effect passive aspiration in use, the bung includes an arrangement within said periphery that applies radial pressure on said periphery to strengthen the sealing engagement thereof with the barrel, and the needle is locked to the barrel, the bung is retained in the barrel and the plunger stem is formed as a single unitary structure with the bung such that the plunger stem is unreleasably secured to the bung so that the assembly thereof cannot be dismantled and is thereby disposable as a whole after use.