Patent ID: 8443715

Claim:
A piston with a piston boss in which a piston-pin bore is located to accommodate a piston pin, wherein the piston-pin bore has an inner section extending in a direction of a piston inner area, the widening of the inner section above the piston-pin bore axis, with respect to a piston stroke axis, being less than the widening of the inner section below the piston-pin bore axis, an outer section extending in a direction of a piston outer area, and a middle section disposed between the inner and outer sections concentrically disposed about a piston-pin bore axis, the inner section widening in the direction of the piston inner area wherein each pair of diametrically opposed points in each plane perpendicular to the piston-pin bore axis along the inner section asymmetrically disposed with respect to the piston-pin axis so that one point of each pair of diametrically opposed points in each plane is disposed closer to the piston-pin bore axis and the other point of the pair of diametrically opposed points is disposed farther away from the piston pin bore axis.