Hypodermic needle safety apparatus includes an embodiment having a shield which includes a longitudinal slot and a cover which rotates on the shield and an embodiment in which the shield must be moved axially, along the longitudinal axis of the syringe and needle, to allow the needle to be moved through...http://www.google.fr/patents/US5405332?utm_source=gb-gplus-shareBrevet US5405332 - Shield apparatus for syringe needle
