Filling aid for medicant syringe

Claim 1

An aid device for use with a medicant syringe which includes an elongated barrel, a needle projecting axially from one end of the barrel, and a plunger projecting from the other end of the barrel; said device comprising: an elongated body including a hollow sleeve and an end piece secured to one end of the sleeve; said body end piece having means for clamping the barrel of a medicant syringe thereto, with the longitudinal axis of the syringe barrel aligned in parallel relation with the longitudinal axis of said body, and including means for preventing axial movement of the syringe barrel relative to said aid device; an elongated, threaded shaft disposed longitudinally within said body, and mounted in said end piece for relative rotation and limited relative axial movement; said body sleeve having a longitudinal slot in one side wall; a lug threadedly mounted on said threaded shaft having a tab projecting radially through said body slot, whereby rotation of said shaft effects longitudinal movement of said lug along said body; said lug tab being disposed to be engaged by the plunger of said medicant syringe clamped to said device; and said lug being selectively positionable relative to said body end piece, to limit the extent of withdrawal of the syringe plunger; said threaded shaft being mounted within said device end piece for limited axial reciprocating movement, said end piece and said shaft having coacting stop means for limiting said reciprocating movement; spring means for normally urging said shaft to its limiting position toward the end piece end of said device; and said reciprocating shaft movement defining an overfill control, allowing overfill of the syringe and subsequent ejection of the overfill medicant to remove any entrapped air.