| 摘要 |
<p>A syringe having an extremely simple structure which allows a gasket of the syringe to slide smoothly and provides excellent liquid tightness and air tightness. The syringe (1) is provided with a barrel (3) in which liquid (L) is placed, a plunger (5) for discharging the liquid (L) placed in the barrel (3), and a gasket (9) mounted to the front end (7) of the plunger (5). On the front end (7) of the plunger (5), there are provided a male screw thread (27) to which the gasket (9) is mounted and a supporting projection (33) having a diameter smaller than the root diameter (D2) of the male screw thread (27) in contact with an inner wall surface (31) of a top surface section (29) of the gasket (9) to support the gasket (9). A female screw thread (47) engaging with the male screw thread (27) is formed in the inner peripheral surface of the gasket (9). A receiving recess (49) having a smaller diameter than the inner diameter (D4) of the female screw thread (47) and receiving the supporting projection (33) is formed in the top surface section (29). A first annular projection (39) in sliding contact with the inner peripheral surface (14) of the barrel (3) is provided at that position of the outer peripheral surface (37) of the gasket (9) which is close to the top surface section (29).</p> |
