MANUFACTURE OF SYRINGE AND PISTON USED IN THE SYRINGE

摘要

PURPOSE: To provide a piston for syringe by which a sealing plug is not necessary to be attached to a piston body, and a manufacture of the syringe provided with this piston and of the piston. CONSTITUTION: This syringe is composed of a cylinder 1 and a piston 2 loaded in the cylinder 1, and the piston 2 is composed of the piston body 21 made of a resin and an elastic seal member 22 which is attached on the piston body 21 and keeps airtightness between the cylinder wall and itself. The diameter of the piston body 21 at the head part 21a is set smaller than it at the body part 21b, and a stage 21c is formed around the overall circumference between the head part 21a and the body part 21b, and the elastic seal material 22 is fittedly-attached to the overall area from the steps 21c of the piston body 21 to the head part 21a.