Abstract: Steel pistons used in many internal combustion engines are generally composed of a skirt and a crown. The skirt's function is to reduce the lateral and rotational movement of the piston in the cylinder while the engine is in operation. Lateral and rotational frictional forces imparted to a piston during engine operation cause the piston to scrape off the lubricating oil film present on the cylinder wall. The reduced oil film thickness increases piston and cylinder wall wear due to metal to metal contact. The subsequent metal to metal contact produces a phenomenon called scuffing. This disclosure incorporates several design modifications to the piston and results in a significant reduction of the lateral and rotational motion of the piston during engine operation. The reduction of piston motion reduces the amount of oil film removed from the cylinder wall and increases lubrication efficiency. The Increased lubrication efficiency realized reduces frictional wear power loss and scuffing.

Abstract: A piston has a pair of diametrically opposite skirt portions with convex outer surfaces. Each skirt portion has opposite side edges extending substantially parallel to a central axis of the piston to a free end. The skirt portions each have a recessed slot extending radially into the convex outer surface to a recessed surface. The recessed surface extends fully across the convex outer surface to the side edges and separates an upper band section of the convex outer surface from a lower band section of the convex outer surface.

Abstract: A piston has a pair of diametrically opposite skirt portions each having an opening providing fluid communication between an outer surface of the skirt portions and an internal cavity. The openings provide the outer surfaces of the skirt portions with a circumferentially extending upper band portion above a horizontal plane extending through a pin bore axis and a circumferentially extending lower band portion below the horizontal plane.

Abstract: A piston having a head with ring grooves, a skirt having hub bores, and a pin, with the following dimensions:L/D=0.45-0.8H/D=0.25-0.5A/D=0.3-0.5T/D=0.45-0.8whereL=maxium length of the pistonD=maximum diameter of the pistonH=compression heightA=maximum skirt height below the bottom ring groove in a peripheral area having the approximate same skirt height of at least 45 degrees on the major thrust face of the piston with approximately symmetrical division of this area on both sides of a plane extending perpendicular to the pin axis and passing through the longitudinal axis of the piston,T=diametrically opposite distance between the hub bore ends located radially on the outside.The skirt bulges along the axis of the piston and has an oval cross-section. An axis of the hub bores is offset slightly towards the major thrust face. The piston includes a horizontal slit, which separates the head from the skirt. In a polar plane perpendicular to the piston axis the skirt has a greater ovality on the minor thrust face.

Abstract: A light-alloy piston for internal combustion engine, is formed in the piston head with a combustion chamber recess. The stresses which are induced at the rim of the combustion chamber recess by the ignition pressure are reduced by the provision of an inwardly extending blind hole in the portions between the ring groove for the lowermost compression ring and the top apex of the bores in the piston pin bosses.

Abstract: A piston assembly is disclosed which reduces the consumption of a lubricating agent circulated to provide lubrication between the outer sidewall of the piston assembly and the interior sidewall of a bore. This is accomplished by providing at least one aperture in at least one compression ring groove. The aperture is disposed in fluid communication with the interior of a hollow skirt portion of the piston for communicating such lubricating agent gathered in the compression ring groove into the interior of the hollow skirt portion of the piston so that the lubricating agent can return to the crankcase of an operating mechanism.

Abstract: A piston for an internal combustion engine has the conventional skirt replaced by top and bottom bearing surfaces spaced apart by a substantial gap of constant width. The top bearing surfaces are connected to the piston crown through the ring band whereas the bottom surfaces are attached to piston bosses by struts. The gap allows the passage of lubricant to the cylinder to ensure adequate lubrication of the bearing surfaces.

Abstract: To provide for separate expansion control actions at the top and bottom edges of the skirt of an expansion-controlled light alloy piston, to prevent a direct propagation of deformation between the top and bottom edges of the skirt and to reduce the skirt area between the top and bottom edges of the skirt, the skirt of the piston is provided at its periphery with a transverse slot, which extends around the entire periphery of the skirt or part thereof and is disposed on the level of the piston pin boss.

Abstract: This disclosure deals with a reciprocating piston for an internal combustion engine, particularly for a diesel engine. The piston is made of a relatively high strength metal such as iron, and no more material is used than is necessary to withstand the thermal and mechanical loads encountered in use. A circular piston dome is supported by a support part which extends between the dome and a pair of piston pin bosses. The bosses also support arcuate side thrust pads. A ring band is connected to the outer periphery of the dome by a connecting part which is relatively thin and flexible. The dome, the ring band and the support part are generally symmetrical about the axis of the piston. The support part is annular in cross section and may be conical, cylindrical, or partly conical and partly cylindrical.