Safety syringe characterised by multiple bossed coupling to the needle retaining portion which is further connectable with a resilient push rod on retraction of the needle will off-set the needle to the side of the syringe preventing re-use

摘要

A safety syringe has a retaining device formed on a front end of a barrel, multiple bosses formed on the needle hub to rotatably correspond to the retaining device, multiple recesses defined inside the needle hub and multiple inclined teeth formed on the plunger to correspond to the recesses, such that the engagement between the retaining device and the bosses of the needle hub is able to be released by the rotational movement of the plunger together with the needle hub due to the combination of the inclined teeth and the recesses.