Patent ID: 7748577
Filing Date: 2010-07-06
Classification: A61M,B05C,B65D

Abstract:
1. A cartridge piston comprising an outer peripheral wall haying a radially outwardly projecting upper rim at an upper side for forming a sealing lip to engage a wall of a cartridge, and a radially outwardly projecting lower rim at a lower side for forming a support lip for guiding the piston within the cartridge; an inner support body within said outer peripheral wall of predetermined height; an annular stiffening body concentrically between said outer wall and said inner support body, said stiffening body being of a height equal to said predetermined height of said inner support body and haying a lower side flush with the lower side of said lower rim; radially disposed connection webs between said outer wall and said stiffening body and between said stiffening body and said inner support body, at least one of said connection webs between said outer wall and said stiffening body defining a gap extending at least up to half the height of the cartridge piston at the lower side of the cartridge piston; and a cover transverse to said outer peripheral wall and said inner support body, said upper rim of said outer peripheral wall being spaced from said cover to define an annular groove therebetween of V-shaped cross-section.