Patent ID: 9717857
Date: 2017-08-01
CPC Classifications: A61M

Claim:
1. A medical injection device, comprising: a container body having an inner wall, and a stopper in gliding engagement with the inner wall of the container body for expelling a fluid through an opening of said container body, wherein at least a distal portion of the stopper is made of a thermoplastic polyolefin, wherein the stopper defines at least one peripheral groove and the medical injection device further comprises at least one O-ring made of a butyl-type rubber maintained in the at least one peripheral groove, and wherein the at least one peripheral groove has a U-shaped cross-section comprising a sidewall extending axially a width w and two parallel lateral walls extending radially from the sidewall a height h, wherein the height h of the at least one peripheral groove is less than the width w of the at least one peripheral groove, and the cross-section of said at least one peripheral groove of the stopper compresses the at least one O-ring in an axial direction and a radial direction when said at least one O-ring is engaged in the peripheral groove between the stopper and the inner wall of the container body providing a progressive contact of the O-ring with the inner wall of the container body.