Patent ID: 8128594
Filing Date: 2012-03-06
Classification: A61M

Abstract:
1. A safety syringe, comprising: a barrel; an inner tube movably mounted in the barrel; and an elastic member mounted on the barrel and connected with the inner tube to pull the inner tube outward relative to the barrel; wherein the barrel has an inner wall provided with a through hole; the barrel has a peripheral wall provided with two opposite guide tracks; each of the two guide tracks of the barrel includes a sliding slot, an anti-reverse channel connected to the sliding slot, and a flexible guide ramp located at a connection between the sliding slot and the anti-reverse channel; the anti-reverse channel of each of the two guide tracks has an end provided with an anti-reverse block; the barrel has an end portion provided with two opposite fixing posts and a flexible locking hook; the inner tube has a first end inserted into the through hole of the barrel and provided with a needle hub for mounting a needle; the inner tube has a second end protruding outward from the through hole of the barrel and provided with a perforated locking plate selectively snapped onto the locking hook of the barrel; the inner tube has a peripheral wall provided with two opposite guide rods slidable in the two guide tracks of the barrel respectively; the elastic member is received in the through hole of the barrel and has a middle portion provided with a locking ring locked onto the needle hub the elastic member has two opposite extension legs extending from the locking ring respectively; each of the two extension legs of the elastic member has a free end provided with a fixing hole fixed on a respective one of the two fixing posts of the barrel to lock each of the two extension legs of the elastic member onto the barrel; and the inner wall of the barrel has a surface provided with two opposite guide grooves; each of the two extension legs of the elastic member is limited in and guided by a respective one of the two guide grooves of the barrel.