Piston of refractory materials, particularly for compression-ignition engines

Claim 1

A piston comprising: a cylindrical piston head formed entirely of a refractory material having low coefficients of thermal expansion and conduction, said piston head having a longitudinal axis and first and second end faces; a combustion chamber formed by a recess in said first end face of said piston head; a plurality of recesses circumferentially distributed about said longitudinal axis of said piston head and opening on said second end face of said piston head; a cylindrical piston skirt formed entirely of refractory material having low coefficients of thermal expansion and conduction, said piston head having a longitudinal axis and first and second end faces; means for coaxially securing said second piston head face and said first piston skirt face to one another; a plurality of ribs formed on a peripheral surface of said skirt; and a spherical cavity in said piston skirt, said spherical cavity intersecting said skirt longitudinal axis and opening on said second end face of said skirt, whereby said spherical cavity may receive a small end of a piston rod, wherein said piston skirt is formed of two semi-cylindrical skirt halves assembled into said skirt at mutually contacting surfaces defining a plane containing said skirt axis, each of said skirt halves including said ribs and a semi-spherical half of said spherical cavity.