Patent ID: 8701619

Claim:
An internal combustion engine piston comprising: a piston crown defining a combustion chamber; a thrust-side skirt formed integrally with the piston crown, and adapted to be in sliding contact with a cylinder wall, the thrust-side skirt having an arc-shaped cross-section; an anti-thrust-side skirt formed integrally with the piston crown, and adapted to be in sliding contact with the cylinder wall, the anti-thrust-side skirt having an arc-shaped cross-section; a first apron formed with a first piston pin boss; a second apron formed with a second piston pin boss; a first connecting section connecting the first apron to a first circumferential end of the thrust-side skirt; a second connecting section connecting the second apron to a second circumferential end of the thrust-side skirt; a third connecting section connecting the first apron to a first circumferential end of the anti-thrust-side skirt; and a fourth connecting section connecting the second apron to a second circumferential end of the anti-thrust-side skirt, wherein each of the thrust-side and anti-thrust-side skirts has a characteristic that as followed from a proximal longitudinal end to a distal longitudinal end in a piston longitudinal direction, an amount of deformation of the each of the thrust-side and anti-thrust-side skirts increases in a section from the proximal longitudinal end toward a first position slightly below the proximal longitudinal end, and decreases in a section from the first position to a second position below the first position, and increases in a section from the second position toward the distal longitudinal end.