Disposable safety syringe with automatically guided outer sleeve

摘要

A disposable syringe (100) comprises a syringe body (1) hollow on the inside, a plunger (4) sliding inside the syringe body (1) and provided at the rear with a stem (41) that can be operated manually, an injection needle that can be attached to the front end (13) of the syringe body (1), by means of a needle-carrier (3), a sleeve (5) mounted slidably over the syringe body (1) to pass from a retracted position of use of the syringe to a forward position of safety in which it covers the needle (2), spring means (7) disposed under compression between the sleeve (5) and the syringe body (1), locking means (56, 58, 12) provided in the rear part of the sleeve (5) and of the syringe body (1) in mutual engagement to lock the sleeve in a retracted position of use, operating means (44) disposed in the stem (41) to disengage the locking means when the plunger (4) reaches the end of the injection stroke, and guide means (60) disposed in the sleeve and cooperating with complementary guide means (33) integral with the syringe body (1) to guide the axial movement of the sleeve (5) with respect to the syringe body. <IMAGE>