Process for applying a heat-barrier layer to a piston crown

摘要

The piston of a piston-type machine has on its surface a heat-barrier layer of plastic material which is cast into a recess formed in the piston crown. A pouring means formlockingly enclosing the upper edge is put on the piston, held in a vertical position, to permit the recess to be overfilled with the material. The pouring means is removed after the material has hardened. Due to the shrinkage of material when the material hardens, the material and the upper edge form a flat surface on the piston.