Syringe with a slidable needle protection device

Claim 1

A needle apparatus including a support body having a cylindrical wall and an end transverse wall in which a needle is implanted, a needle protector slidable along an external cylindrical surface of the support body between two positions, with respect to the support body which are axially distant each from the other, said protector forming a moving protective sheath for an end of the needle, guiding and indexing elements being provided between support body and the protector to allow the needle to be uncovered and subsequently covered again by the sheath once only, said indexing elements including a locking member secured to the protector and projecting inwardly to engage resiliently a groove formed on said external cylindrical surface of said support body and a recess for irreversibly receiving said locking member of the protector as the needle is fully covered by said protector, wherein said protector comprises an inner portion and an outer portion engaged one in the other, said inner portion being entirely housed in said outer portion and said locking member being constituted by a free end of a resilient tongue projecting radially inside the protector and carried by said inner portion while said outer portion forms a sleeve that prevents access to the inner portion, and wherein said groove has two parallel longitudinal branches interconnected by a circumferential portion at ends thereof furthest from said needle, one of the longitudinal branches of said groove including said recess at an end opposite to said circumferential portion for receiving the free end of said resilient tongue.