Explosion internal-combustion engines

Claim 1

Improvements in or relating to explosion internal-combustion engines, comprising a cylinder having a cylinder head and a piston movable in said cylinder, having an axis in common therewith, and cooperating therewith to define a variable volume chamber, in which the motive fluid is effective, said cylinder head having an inner surface directed toward said piston and said piston having an end surface directed toward said cylinder head, and the latter surfaces respectively being formed each with a step extending transversely with respect to said axis and said steps overlapping each other as the variable volume chamber reaches its minimum volume, when the piston approaches an outer dead center position, said steps while extending across central portions of said piston and cylinder head surfaces being interrupted at least at one end in the region of side surfaces of said piston and cylinder for defining a barrier dividing said volume into two spaces or compartments which are intercommunicating for at least a fraction of the time during which said steps overlap each other to lengthen the path of fluid flow from one to the other of said spaces or compartments by requiring the fluid to travel around the barrier, at least one induction valve and at least one exhaust valve respectively situated on opposite sides of the step of said cylinder head, thereby causing gases to have an extended path of travel in order to move from said induction valve to said exhaust valve.