Patent ID: 6575938
Filing Date: 2003-06-10
Classification: A61M

Abstract:
A syringe comprising a cylinder for containing liquid therein and a piston which is reciprocally disposed within said cylinder, said piston including a piston main body and a piston head made of a resin which is secured to a front end of the piston main body and slides along the inner wall of said cylinder while keeping the liquid-tightness therewith,wherein said piston head is formed on the periphery thereof with collar means which contacts with the inner wall of the cylinder, at least the peripheral edge of said collar means being thin walled, said collar means being slidable on and along the inner wall of said cylinder while keeping the liquid-tightness, and said collar means comprises collars which are spaced in a direction of sliding of said piston, a first collar adjacent a second collar, said first collar positioned on a front side in the sliding direction, and said second collar positioned on a rear side in the sliding direction, and said first collar being supported by said second collar when said piston slides.