Abstract: A piston for an internal combustion engine comprising a piston head provided with at least one piston ring groove and a piston body having a piston pin bore, and a compression height of less than 40% of the piston diameter. In order to be able to equalize the influences of thermal expansion as well as possible and to enable a quiet operation of the piston in a cylinder, the invention provides that the largest diameter region of the piston body is arranged in a plane which extends perpendicularly to the body-generating line and which includes the piston pin axis.

Abstract: Piston for internal combustion engines, with an oil scraper ring disposed in an annular groove at the circumference of its head portion. The outer edge of the annular groove adjacent to the piston skirt which adjoins the head portion is bevelled to form a chamfer. In order to ensure the maintenance of an oil film sufficient to prevent dry running of the piston, on the cylinder wall, the width of the chamfer is greater on the thrust side of the piston. The width of the chamfer may decrease essentially continuously from the counter-thrust side to the pressure side.

Abstract: Light-metal piston for combustion engines, having a sleeve-like insert embedded therein and controlling its heat expansion and being formed of a metal of smaller heat expansion coefficient than the piston base material. The insert is arranged in the solid material of the piston crown and extends around the entire piston periphery. Behind the insert, the piston base material is self-contracted to form a gap delimited by the insert on one side. On at least one edge or one side, the insert is not covered by piston base material, i.e. it extends up to the piston surface, this occurring however only in certain segments and not along the entire piston periphery. In the other segments, the insert lies beneath the piston surface and is thus covered by piston base material. To the extent that the insert is exposed on the piston end face, it is provided with an edge zone covering the depth of the self-contraction gap.

Abstract: A hollow body, especially a pressure vessel, which includes two hollow outer parts abutting with annular end faces against each other, which define together a substantially V-shaped groove ending at its apex short of the inner surfaces of the outer parts. The outer parts are aligned with each other by an inner tubular part which extends to opposite sides of the end faces of the outer parts in close proximity with the inner surfaces of the latter. A weld seam filling the V-shaped groove connects the outer parts to each other and fusible material between the outer surface of the inner part and the inner surfaces of the outer parts join these parts to each other. The pressure vessel preferably includes also a flexible membrane having adjacent its outer edge a bead located in a groove formed in the inner part and held therein by a retaining ring.