I.C. Engines

Claim 1

An internal combustion engine of reciprocating-piston type having a cylinder with a combustion chamber, and a piston with a crown in the cylinder, the major portion of the volume of said combustion chamber being afforded by a recess formed in the crown of the piston, the recess .Iadd.having an open mouth at its upper side and .Iaddend.having a bottom, a catalytic element .Iadd.of foraminous sheet construction through whose thickness gas can flow freely, said element being carried .Iaddend.in the cylinder .[.carried.]. by the piston, .[.and.]. .Iadd.said catalytic element being effective without additional ignition means to initiate combustion of a fuel vapour and air mixture and having a cover portion extending crosswise of said recess, said cover portion being .Iaddend.mounted in a position overlying .Iadd.and spaced from .Iaddend.the bottom of said recess .Iadd.and enclosing a space beneath it within the recess, and said element having at least one portion depending from said covered portion towards the bottom of said recess, means for introducing combustion air into the combustion chamber, .Iaddend.and means for injecting fuel into .Iadd.said space enclosed by said cover portion in .Iaddend.said recess, when the piston is at about its top-dead-centre position, .Iadd.in a manner .Iaddend..[.direction.]. such that substantially the whole of the injected fuel will .Iadd.travel into .Iaddend.contact .Iadd.with .Iaddend.the surface of the catalytic element to initiate its combustion. .[.