Hypodermic syringe with separate piston and rod - rod end and piston end having segmental conical form

摘要

The operating rod and the piston of a syringe are inserted one into the other. The rod end profiled in a multiple conical segment 'fir-tree' shape which engages in a similarly-profiled hollow in the piston. Used for hypodermic injection syringes which are either machine-assembled, or hand-assembled by the user. Little force is required to assemble the piston rod to the piston, and the two can readily be sepd. again. The unit is self-centering and readily suited to automatic machine assembly.