A needle guard for an additive-type syringe includes a sidewall which extends beyond the needle point. The sidewall is joined to the syringe housing by spin welding or sonic welding an annular flange that extends axially rearward from the needle guard to contact the front wall of the housing. The needle...http://www.google.fr/patents/US5151090?utm_source=gb-gplus-shareBrevet US5151090 - Syringe and needle guard assembly
