Patent ID: 7875006

Claim:
A needle protection device for a syringe ( 1 ) which comprises a needle ( 6 ), a tubular body ( 4 ), to the distal end of which the needle ( 6 ) is fixed, and an injection piston ( 8 ) which is slidingly arranged in the body ( 4 ), this device comprising a needle protector ( 22 ) which is substantially coaxial with the body ( 4 ) of the syringe ( 1 ); a protector support ( 20 ) which is fixedly joined to the body ( 4 ) or which is provided with means ( 30 ) for being fixedly joined to the body ( 4 ), wherein a spring ( 24 ) which is arranged between and in contact with the support ( 20 ) and the protector ( 22 ), the support and the protector being movable relative to each other between a retracted position of the protector, in which the needle ( 6 ) of the syringe ( 1 ) is disengaged and the spring ( 24 ) is locked in a compressed state, and a deployed position, in which the needle is arranged inside the protector ( 22 ) and the spring is, at least partially, relaxed; and means for unlocking the spring ( 24 ), characterised in that the spring ( 24 ) has, in the locked state, a predetermined force which is greater than the pushing force necessary for displacing the piston ( 8 ) of the syringe ( 1 ) over substantially the entire injection path, and in that the unlocking means comprise a finger-supporting flange ( 50 ), which is adapted to support a finger of a user, which is fixedly joined to an external surface of the protector ( 22 ), the finger-supporting flange ( 50 ) being located external to the protector support ( 20 ), and which is for, on the one hand, transmitting to the spring ( 24 ) a compression force less than that predetermined force when the piston ( 8 ) slides for the injection and, on the other hand, further compressing the spring ( 24 ) with a compression force greater than that predetermined force when the piston ( 8 ) is at the end of the injection path.