DISPOSABLE SYRINGE WITH ASPIRATION MECHANISM Russian patent published in 2001 - IPC

FIELD: subcutaneous injection equipment in medicine. SUBSTANCE: disposable syringe 10 has plunger 14 formed as stem equipped with ratchet teeth 28 made in the form of truncated cone or beams. Springy locking clamp 40 is freely hanging from plunger portion having ratchet teeth. Position of clamp 40 defines maximum value of dose that may be injected by means of syringe. Before filling syringe with medicinal preparation and dispensing it, aspiration gaps 114 may be formed on plunger stem upon user's request. During usage of syringe, first withdrawal of plunger from cylinder 12 is allowed for aspiration, with following filling of cylinder cavity with medicinal preparation due to radial flexure and sliding of tooth 83 of locking clamp 40 over ratchet teeth surfaces. Locking springy clamp 40 is held in predetermined site along cylinder length by means of contacting acute ends bent outside and incised into inner side wall of cylinder. Such construction prevents syringe from repeated usage. EFFECT: increased efficiency, simplified and low-cost manufacture method and enhanced reliability in operation. 19 cl, 34 dwg