Retractable safety needle

This invention refers to a retractable safety needle comprising:a needle hub (36), a needle cannula (34) being mounted at said needle hub (36); a resiliently deflectable actuator arm (60) extending from said needle hub (36), an actuator button being formed on said actuator arm (60); a barrel (20,22), said needle hub (36) being disposed in said barrel (20,22) such that said needle hub (36), said needle cannula (34) and said actuator arm (60) are moveable relative to said barrel (20,22) from a distal position where said needle cannula (34) projects distally beyond said barrel (20,22) and a proximal position where said needle cannula (34) is disposed entirely in said barrel (20,22), said barrel (20,22) having an actuating opening extending therethrough, said actuator button projecting into said actuating opening when said needle hub (36) is in said distal position, said actuator button being resiliently deflectable out of engagement with said actuating open; a spring (18) disposed adjacent said needle hub (36) for propelling said needle hub (36) to said proximal position when said actuator button is deflected out of said actuating aperture; and wherein said barrel (20,22) includes an inwardly extending proximal flange (102) extending into said passage (98) at said proximal end of said barrel (20,22) for engaging the flange (56) of the needle hub (36) and limiting proximal movement of said needle hub (36).