DISPOSABLE SYRINGE Russian patent published in 2006 - IPC A61M5/32 A61M5/50 

FIELD: medical equipment, in particular, disposable syringes unfit for repeated usage due to employment of automatically retractable needle.

SUBSTANCE: syringe has outer cylinder with first and second ends, inner cylinder longitudinally sliding within outer cylinder and adapted for fastening needle at its one end, said needle protruding through opening provided in first end of outer cylinder and communicating with inner cylinder reservoir, and piston located within said reservoir and actuated for drawing in and ejecting of liquid through needle into and outside said reservoir. Piston is connected to driven stem extending from other end of inner cylinder and second end of outer cylinder. Outer cylinder has holder placed on inner surface of its wall. Inner cylinder has locking device for engagement with holder and retention of inner cylinder in one of two retaining positions with respect to outer cylinder. In first retaining position needle protrudes from outer cylinder and is in state fit for usage, and in second retaining position needle is fully retracted into outer cylinder. Device for moving inner cylinder toward second retaining position and driven stem of piston are provided with means for bringing into contact with locking device, when piston is fully retracted into outer cylinder, for decoupling of locking device from holder to thereby bring locking device into constant engagement with holder. End retainer is provided on driven stem for preventing piston from full retraction and for releasing locking device from holder, upon primary actuation of piston, and for allowing piston to be moved inward by distance sufficient for releasing of locking device during next retraction of piston. Syringe of such construction does not need any actions which should be performed by user for disabling repeated employment of syringe in the future and early retraction of needle.

EFFECT: enhanced reliability in operation and increased efficiency.

11 cl, 14 dwg