Abstract: A cooled multi-component piston is provided in which the hollow annular space in the piston head for the cooling oil is closed off underneath. This is achieved with a sheet-metal ring with a collet which fits in a recess in the piston-ring wall, the sheet metal ring being biased via a retaining clip against the shaft bush.

Abstract: A method for machining radial through-slots into a wall of a piston-ring groove which separates the ring groove from the piston interior. A piston for an internal combustion engine is provided in which the wall has varying thickness and is thinnest in the pressure and counterpressure sides of the piston. A cutting tool is held in a fixed position. The piston is rotated about its longitudinal axis. The rotating piston is brought into engagement with the fixed cutting tool so that slots of a predetermined axially height are machined into the ring-groove wall over the entire circumference of the piston. Also, radial through-slots are created only in the pressure and counterpressure sides of the piston.

Abstract: An extremely light and low friction plunger piston for internal combustion engines, particularly Otto-type engines for private cars. The piston has the following ratios and dimensions(H/D)=0.20-0.35(T/D)=0.22-0.38(A/D)=0.15-0.25(B/D)=(A/D)whereinD=piston diameterH=compression height between a top of the head and the gudgeon pin bore axisT=distance from the radially outer boss faces to the piston axisA=axial skirt dimension below annular groove nearest the pin bore axis at a peripheral zone of the skirt extending over an angle .alpha. of 15 to 60 degrees to either side of a connecting rod oscillating planeB=axial skirt dimension below said annular groove in a direction along said gudgeon pin axis;and further wherein the distal end of the skirt is reduced radially over an axial dimension of 10-25% of an axial length of the skirt in said direction along said gudgeon pin axis, said distal end being reduced at its edge by 0.01-0.15 mm.

Abstract: In a light plunger piston for internal combustion engines, in order further to save weight and to achieve an elastic running behaviour, the piston skirt is reduced to three relatively narrow guide plates. The guide plates are attached through longitudinal ribs to gudgeon pin bushes suspended freely from the piston crown. On the thrust side of the piston there are two of the three guide plates which extend, seen from a 45 degrees diagonal plane between gudgeon pin axial plane and connecting rod oscillation plane, through about 15-25 degrees to each of the two sides. On the counter-thrust side only one pressure plate is provided which extends circumferentially over about 50 degrees. There is preferably no direct connection between the guide plates and the lowermost ring land.

Abstract: In connection with a plunger piston for internal combustion engines, the connecting rod, which is hinged thereto via a gudgeon pin, is laterally guided at its small end by being in abutting contact with the internal faces of the gudgeon pin bosses. For this purpose, there are provided, only in the zone at the level of the gudgeon pin axis, limited contact surfaces between the connecting rod small end and the gudgeon pin bosses. By this means, the influence of deformations of the piston on the guidance of the connecting rod is eliminated to a very large extent.