In the rest state, retracting spring 160 is in a relaxed, unbiased or unloaded state and the retraction member 158 is moved proximally until stop member 190 abuts the rear wall of the hub 136 carrying with it the needle 132, it being noted that operating spring 154 is similarly in an unbiased state in a rest position and the pin is disposed at a proximal end of the longitudinal slot portion.