Patent ID: 10213556

Abstract:
A dose control mechanism for a syringe includes an engaging screw thread arrangement between an exterior surface of a plunger and a longitudinally extending channel of a housing. The engaging screw thread arrangement includes at least one thread segment and a pitch guide including a variable pitch thread. At least a portion of the longitudinally extending channel of the housing including one of the pitch guide and the at least one thread segment, and the plunger includes the other of the pitch guide and the at least one thread segment. The plunger resides at least partially within the housing with the at least one thread segment engaged with the pitch guide. An accurate dose drug delivery syringe includes such a dose control mechanism, a barrel, a plunger seal, and a barrel adapter assembly having a barrel tip and a needle. The syringe may be a fill-at-time-of-use syringe, a pre-filled syringe, or a safety syringe having integrated needle retraction or needle sheathing safety features, or a combination thereof. Methods of assembly, manufacturing, and operation are similarly disclosed.