Patent ID: 6129710
Filing Date: 2000-10-10
Classification: A61M

Abstract:
A safety syringe comprising:a syringe cylinder and a needle cannula capable of being retracted into said syringe cylinder; anda plunger assembly movable in said syringe cylinder, said assembly comprising:a piston stem;a piston mountable on a distal end of said piston stem, said piston having a void formed therein; anda needle capture member received within said void, said needle capture member being arranged such that, in use, a proximal end of the needle cannula is passed through and secured within the capture member at the end of an injection stroke; anda needle cannula attachment hub capable of attachment to said syringe cylinder, said hub attaching said needle cannula to said syringe such that said needle cannula is retractable into said syringe cylinder, said hub comprising a passageway through said hub with said needle cannula received therein, said passageway comprising:an adhesive well area and adhesive received therein to releasably attach said needle cannula to said hub such that said needle cannula and said adhesive are pulled away from said hub upon retraction of said needle cannula; anda narrow distal portion having at least one annular groove and adhesive received therein to further releasably attach said needle cannula to said hub, and;said adhesive well area being disposed proximal to said narrow distal portion, said well area having a larger diameter than said narrow distal portion;wherein said adhesive in said adhesive well area necessitates a significant force being used to pull said needle in a distal direction and said adhesive in said at least one annular groove necessitates a lesser force being used to pull said needle in a proximal direction.