Abstract: Internal combustion engine pistons are provided with aluminum bodies with highly insulative ceramic inserts cast in place in the upper combustion chamber defining wall. In each of the disclosed embodiments, the ceramic insert has tapered edges to dovetail the insert in place. A fibrous ceramic cushioning layer applied around the insert edge before casting distributes cooling stresses and allows limited relative expansion and contraction of the aluminum body and ceramic insert without overstressing either of the members. Other features are also included.

Abstract: The disclosure illustrates an insulated composite piston comprising a crown of ceramic or other heat resistant material secured to an aluminum piston body by a bolt of temperature resistant alloy. A low conductivity interface between the crown and the body is provided by a series of stacked discs having low effective thermal conductivity. The relative thermal expansion of the parts is compensated for by bellville washers on the bolt. The above arrangement insulates the crown from the piston body thereby minimizing the temperature gradient across the crown so that its temperature can be maintained as high as necessary to increase efficiency and minimize noxious emissions.

Abstract: The piston for use in an internal combustion engine, more especially a diesel engine, is provided with a piston barrel consisting of light metal and a head plate which consists of a metal having a lesser thermal conductivity but a greater high-temperature strength, for example steel. The head plate is fastened to the piston barrel with the aid of retaining screws, which extend parallel to the piston axis and are preferably designed as expansion screws. The head plate is supported against the piston barrel only by a ring-shaped rib along a narrow ring rib through which the retaining screws pass. A radially outwardly widening gap is left free between the opposite faces of the ring-shaped rib formed on the head plate and the ring rib of the piston barrel at room temperature and when the retaining screws have not yet been tightened. The surface of the ring rib of the piston barrel is convexly curved in the radial direction.

Abstract: A piston incorporating a thermal barrier is produced by first making an annular piston ring carrier insert from steel. The insert comprises an annular body to the upper and lower radially-inner edges of which are secured the upper and lower edges of an annular element which is channel shaped in radial cross-section and the channel in which faces radially outward. The element is soldered or welded to the insert body so that an enclosed annular space is defined between the element and body. The insert thus formed is then heated in molten aluminium to "alfinize" its external surface. The treated insert is subsequently placed in a piston mold and the piston is molded about it from aluminium.

Abstract: An improved piston assembly comprising a generally cylindrical body having at one end a peripheral shoulder and at the other end a depending skirt, an annular ring groove protection band formed of hard metal and having a peripheral, radially outwardly opening ring receiving groove seated on the shoulder, and a crown secured to the body one end and having a radially outwardly extending flange engaging the band about its periphery and clamping the band against the shoulder. Insulating means are interposed between the crown and the band.

Abstract: An improved internal combustion engine of the type having a relatively high surface to volume ratio. An exemplary embodiment depicts the invention in a rotary engine having a rotor within a combustion chamber. The surfaces of the rotor that are exposed to the gases of combustion are provided with a plurality of pockets. Within each pocket is a heat insulating medium. The pockets are covered by a plurality of individual covers, one for each pocket. Heat flow to the rotor is thereby reduced to increase engine operating efficiency.

Abstract: A piston for a fluid actuator being formed of two annular sheet metal members having axially and radially extending portions whereby when said piston transmits force, a box-like sheet metal structure is formed.

Abstract: This invention relates to reciprocating piston engines using single acting pistons operating in liquid cooled and lubricated cylinders, said pistons have piston extensions slightly smaller in diameter than the main power pistons and the length of the stroke, operating inside slightly larger, insulated, hot cylinder extensions. Operating in co-operation with a cold air blocking system which fills the clearance space between the piston extension and the hot cylinder wall liner with cool air when the piston is at or near top dead center. Thus keeping the hot pressure fluid medium from coming in contact with the liquid cooled and lubricated cylinder walls in which the main power piston operates. Thereby cutting down the heat losses to the cooling medium.

Abstract: An internal combustion engine utilizes a combustion cylinder formed in part of material which can withstand high temperatures in conjunction with a displacement or power piston having a ringless section capable of withstanding high temperatures and being backed up by a relatively low temperature lubricated ringed piston section. Means to inject fuel and water into the combustion chamber is provided along with means to charge the combustion chamber with air and to exhaust the combustion chamber near the end of the power stroke.