| 摘要 |
1. Syringe intended for the ultra-ligamentary injection of liquid products, especially anaesthetic products, of the type composed of a body the forward portion of which, to which the injection needle is fitted, serves as housing for a container of the said liquid product, constituted by a glass tube the rear extremity of which is closed by a plug (7) of rubber or analogous material, while the rear portion of the body serves as guide for a piston (6) actuated by a rack (4), in such manner that when the operator operates the syringe, the piston progresses forward step by step, thrusting the said plug forward into the interior of the container, and consequently the liquid product into the injection needle, the piston (6) being terminated, at its forward extremity, by a head (12, 12') of a diameter substantially equal to the internal diameter of the container (8), characterised in that the head forwardly presents a concavity causing migration of the material of the plug (7) towards the axis in the advance of the piston (6). |
