Abstract: An internal combustion engine piston is fitted with bushes between its piston pin and the cross bore in the piston. The diameters of the piston pin and the piston cross bore are dimensioned independently of each other to meet the requirements imposed upon them, which allows the piston pin to be dimensioned only to such size as is required to withstand the bending stress imposed by the connecting rod, thus permitting the size of the piston pin and the reciprocating mass to be reduced in relation to conventional practice.

Abstract: Disclosed is a method of reinforcing an aluminium alloy piston ring groove wherein the piston body is fused to a certain depth around the periphery thereof in the zone where the ring groove is to be cut, with simultaneous introduction of an alloying addition into the fused aluminium alloy of the piston body, thus forming an annular wear-resistant weld therein, whereupon the ring groove is cut in the periphery of said weld.

Abstract: An improved piston construction comprising a piston body having a crown and a depending skirt, a peripheral groove about the body intermediate the crown and the skirt closely adjacent the crown, a grooved insert band in the groove and adapted to receive at least one piston ring, and at least one frustoconical washer in the groove abutting the insert band on the side thereof closest the crown, the washer having its minor base directed toward the skirt and its major base directed toward the crown and being stressed into a substantially planar configuration to store energy to tightly clamp the insert band within the groove to preclude loosening of the band during operation of an engine employing the piston. Also disclosed is a method of fabricating the improved piston construction.

Abstract: An aluminum piston for use in heavy duty internal combustion engines is disclosed, in which the grooves for receiving the piston rings are formed in stainless steel inserts fusion bonded directly to the aluminum without an intermediate metallic layer other than the resulting alloy of the steel and aluminum. The method of making such piston is described in which austenitic stainless steel powder deposited in an oversize groove in the aluminum piston is melted in situ by a laser beam to simultaneously form the stainless steel insert and alloy it with the aluminum to provide a fusion bond, the piston ring groove being subsequently formed in the stainless steel insert.

Abstract: A down-the-hole hammer of the type adapted for receiving a bit at the lower end and for being connected to the lower end of a drill string through which compressed air is supplied to the hammer. The supply of air to the hammer when the bit at the lower end is resting on the bottom of the hole causes a piston in the hammer to reciprocate and to beat upon the upper end of the bit so that the material at the bottom of a hole is reduced. The piston, by reciprocating in the hammer, accomplishes the valving of the fluid which causes the piston to reciprocate, and when the hammer is lifted from the bottom of the hole and the bit moves downwardly, the piston ceases reciprocation while air blows off through the bit to the bottom thereof to clear debris from the hole being drilled.

Abstract: A motor or processing machine, such as a lowspeed radial piston motor, having a piston with a socket formed therein operatively contacting a ball formed on one end of a piston rod, to form a ball-and-socket joint with articulated movement, and a shoe on the other end of the piston rod, adapted to glide on a rotating element of the machine, such as a crankshaft eccentric, in which the entire piston rod is formed from a bronze-base bearing metal, such as steel bronze. At least the shoe of the piston rod may be coated with a thin, soft run-in layer, such as tin, and a pocket may be formed in the shoe of the piston rod to provide hydrostatic relief.