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: In expansion-controlled light alloy pistons for internal combustion engines, expansion control elements made of steel are bonded to the carrying portions of the cast skirt on the inside peripheral surface thereof and are embedded in the hubs of the piston pin bosses. To provide for an optimum expansion control action throughout the height of the piston skirt, the expansion control elements are provided on both sides of the plane of oscillation of the connecting rod with an aperture, which is open toward the end of the skirt and has a height amounting to at least 30% of the height of the expansion control elements. Said aperture has a peripheral dimension amounting to more than 10% of the piston diameter. Projections for supporting the expansion control element at its edges defining the aperture protrude into the latter.

Abstract: A piston rod for pistons of reciprocating piston machines is I-shaped in cross-section. In order to effect a reduction in weight that flange of the piston rod which is nearer to the connecting rod and is enbraced as by claws by the forked and hook-shaped end portion of the connecting rod has a smaller width than the flange which is nearer to the piston head.

Abstract: A roll-formed bushing for sliding surface bearings has no machining allowance in the bearing bore and is made of a strip section and has a butt joint that extends throughout the width of the bearing. In order to reduce the allowances of the bore diameter and the outside diameter of the bearing bushing, the butt joint has been closed by charge carrier beam welding.

Abstract: In a composite material for sliding surface bearings, a rough metallic surface is provided with a polymeric matrix, which forms a friction contact or sliding layer over the rough base surface. To increase the wear resistance, the matrix contains zinc sulfide and/or barium sulfate in a particle size from 0.1 to 1.0 .mu.m and an average particle size of 0.3 .mu.m.

Abstract: A safety steering wheel having an impact protector mounted on the hub of the steering wheel and which consists of a collapsed gas bag and a housing which contains a propellant for inflating the gas bag. The impact protector is covered by a cover hood, which is made of soft elastic plastic and reinforced by a reinforcing layer. In order to prevent a bulging of the cover hood by the forces which are exerted by the collapsed gas bag, a frame is provided, which is secured to the carrier for the housing which contains the propellant. The frame surrounds the housing and the gas bag and comprises at least one retaining member, which is integrally joined to the frame and attached to that edge of the frame which faces the driver's compartment. The retaining member when in a rest position extends in front of the collapsed gas bag and in the case of an impact is adapted to be bent up toward the driver's compartment along a straight line.

Abstract: A composite sliding surface bearing consisting of a backing layer of steel, a bearing alloy layer which consists of aluminum and has been applied to said backing layer, and a sliding surface layer which consists of zinc phosphate and has been deposited on said bearing alloy layer. The backing layer of steel is provided on its outside surface in a thickness between 0.5 and 5 .mu.m with a metallic protective layer in order to ensure a firm retention in the bearing housing.

Abstract: In a light alloy piston for internal combustion engines, a fibrous insert body is embedded in the cast material adjacent to each of the bosses defining the piston pin bores. In order to minimize the costs of manufacturing such piston, the fibrous body extends only above the horizontal plane which includes the piston pin axis between that plane and the piston head and on both sides of the plane which includes the piston pin axis and the piston axis extends over not more than the load-carrying length of the boss defining the piston pin bore.

Abstract: A piston-cylinder kit for internal combustion engines is designed for a top land clearance of 0.3 to 1.5% of the diameter of the piston. The sliding surface of the cylinder has adjacent to the combustion chamber a profiled marginal portion formed with at least one peripherally extending flute. In order to facilitate the installation of the piston the crests of said profiled portion are flush with the remaining portion of said sliding surface.

Abstract: A material for a low-maintenance sliding surface bearing comprises a metallic backing and on said backing a bearing layer comprising PVDF and an additive for improving the friction and sliding properties. To meet more stringent requirements regarding hygiene, the bearing layer is free of lead and contains 0.5 to 3% by weight of a non-toxic metal oxide power and 10 to 40% by weight of glass microspheres.

Abstract: In a light alloy piston each of the load-carrying skirt surfaces is divided into a plurality of load-carrying skirt surface portions. In order to ensure that the upper portion of the piston skirt will carry load on a large area even when the engine is warming up, a plurality of depressions extending in the peripheral direction of the piston skirt are formed in the latter between its clearance-defining top and bottom ends.

Abstract: A piston pin with a bore extending through it. To save weight and to optimize the shape of the pin with respect to accommodating stress, the diameter of the bore is increased to 75 to 90% of the outside diameter of the piston pin and reinforcing ribs are positioned in the bore in the vicinity of the inner edge of each hub.

Abstract: In a piston comprising a top part, which includes at least the piston head and the ring-carrying portion, and a bottom part, which is connected to the top part by suitable means, the adequate lubrication of the piston pin, which is firmly connected to the connecting rod is ensured in that the piston pin is movably mounted in hub segments, which are connected to the bottom part, and in a recess which has the shape of a segment of a cylinder and is formed in a plate that is made of heat-insulating material and inserted on the inside surface of the piston head.

Abstract: Light alloy components for internal combustion engines consist of castings in which reinforcing layers consisting of non-woven ceramic fibers are embedded in the stressed surface portions. In order to provide a prolonged protection against damage to the light alloy disposed under the reinforcing layer, the open interstices of the fibrous layer are impregnated with a layer of a ceramic material in the portion which is close to the stressed surface and with the light alloy of the component in the portion which is remote from the stressed surface.

Abstract: For an evaluation of the peel strength of a plastic sliding layer of a laminate for sliding surface bearings, which laminate comprises a steel backing, a porous sintered bronze layer on said steel backing, and a mixture of polytetrafluoroethylene which fills the pores of the bronze layer and constitutes a sliding layer on the bronze layer, the surface of the sliding layer of a sample that has been blanked from the laminate for sliding surface bearings is activated and adhesively joined to the end face of a testing bar of a testing apparatus in accordance with ISO Standard 4624. The ultimate tensile stress is then determined.

Abstract: In a piston for internal combustion engines the piston head is formed with a combustion chamber recess and is provided with a heat-insulating layer of ceramic material. To minimize the heat to be dissipated to the coolant, one part of the heat-insulating layer consists of a solid ceramic insert and the other part consists of a ceramic coating.

Abstract: In a piston and connecting rod assembly for reciprocating piston machines the bending load applied to the piston pin bosses owing to the deformation of the piston pin to an oval shape should be prevented and the weight should be reduced. This is accomplished in that the piston pin is I-shaped in cross-section with wide flanges, the outer surfaces of which are shaped in accordance with an arc of a circle.

Abstract: In a piston for internal combustion engines, a cover layer comprising a material having a relatively low thermal conductivity has been applied to the piston head by plasma or flame spraying. To increase the life of the cover layer until it separates from the body of the piston, the surface of the cover layer has a peak-to-valley height of 5 to 30 .mu.m.

Abstract: In a composite casting process for making aluminum alloy components for internal combustion engines, which components are provided at highly loaded surfaces with shaped elements which consist of fibers or whiskers and are bonded to the castings, the shaped elements consisting of fibers of whiskers are infiltrated with an aluminum alloy which has a higher melting point than the aluminum alloy of the casting. The infiltration is effected in such a manner that the infiltrated aluminum alloy forms a cover layer on the shaped element. In order to ensure the formation of a bond between the casting and the shaped element as the aluminum alloy for making the casting is cast in contact with the shaped element, the infiltrated shaped elements are dipped into a molten solder alloy before the aluminum alloy for making the casting is cast in contact with the shaped element, and the latter is subsequently placed into the heated mold for making the casting, whereafter the casting is made.

Abstract: A light alloy piston for internal combustion engines has a skirt which is closed at its lower end and at locations disposed adjacent to the bosses on both sides of the horizontal plane through the piston pin is set back so as to form respective recesses. In order to avoid a retention of oil in the recesses those end portions of the skirt which adjoin the recesses are inwardly offset from the outside peripheral surface of the piston.