Patent ID: 7171936

Claim:
A piston adapted for reciprocal movement within a cylinder of an internal combustion engine, said piston comprising: a body defining a longitudinal axis of said piston extending in the direction of reciprocal movement and having a crown formed at the uppermost margins of said body and a skirt depending from said crown and adapted for relative sliding motion with respect to the cylinder, said skirt including an outer circumference having a major thrust side and a minor thrust side formed substantially opposite each other on said outer circumference of said skirt; a coating bonded to said skirt so as to be juxtaposed between said skirt and the cylinder, said coating having a plurality of recesses formed thereon so as to define a predetermined pattern of recesses on the surface of said skirt, said plurality of recesses including a series of lubrication grooves extending across said outer circumference of said piston skirt at a predetermined angle relative to said longitudinal axis such that said series of grooves collectively define a chevron formation that act to operatively engage lubricant between said skirt and the cylinder wall.