Needle protection device for a pre-filled syringe with staked needle, and syringe comprising such a device

A needle protection device for a pre-filled syringe with staked needle, the device comprising:

• a blocking mechanism, comprising means for fastening to a syringe body,
• a needle shield, into which the needle can be driven,
• an after-use safety system, comprising a sleeve defining a central axis along which it is movable and means for elastically loading the sleeve in a forward direction in which it is able to cover the needle,
• wherein the sleeve comprises an outer tube and a coaxial inner tube that are manufactured in one piece by injection molding, and wherein the outer tube is arranged so as to cooperate with the blocking mechanism, while the inner tube is detachable from the outer tube and axially connected in translation with the needle shield,
• wherein the needle shield is arranged with a radial play inside the inner tube of the sleeve, such that the inner tube can rotate freely around the needle shield,
• wherein the needle shield comprises a collar, interposed axially between a distal end part of the blocking mechanism and a proximal end of the inner tube of the sleeve, and
• wherein an axial play is arranged between the proximal end of the inner tube and the collar.