Patent 7313999 was granted and assigned to Sanden Corporation on January, 2008 by the United States Patent and Trademark Office.
A piston includes a piston body fitted into a cylinder bore and having a sliding peripheral surface disposed in sliding contact with the inner peripheral surface of the cylinder bore. The sliding peripheral surface of the piston body and the inner peripheral surface of the cylinder bore each have a noncircular cross-sectional form. The sliding peripheral surface of the piston body is formed by an elastically deformable sealing member.