Abstract: The invention relates to a method for producing a component by reshaping a coated plate consisting of tempering steel, said plate being austenitized before the reshaping by means of a first heat treatment, followed by the growth of the layer thickness. The aim of the invention is to optimize the process and to prevent the production of scrap plates caused by interruptions to the process. To this end, after being rapidly cooled, the heat-treated plate is temporarily stored, and is briefly heated again to the austenitization temperature, directly before being reshaped to form the component. Once the structure has been modified, the plate is reshaped and hardened. Preferably, the plate is heated a second time by induction.

Abstract: A process of forming a sheet of metal having varying material thickness corresponding to selected strength and/or stiffness requirements generally consisting of varying the degree of heat applied during drawing of the metal to correspondingly vary the elongation coefficient of the sheet across the surface thereof.

Abstract: In a hot gas or Stirling engine conventional regenerators for engines with a large displacement, designed for axially directed flow and usually lacking sufficient mechanical strength with respect to the high working gas pressures, have been replaced by radial flow regenerators. In the respective receiving spaces, the radial flow regenerators are surrounded externally and internally by an annular duct for the supply and discharge of the working gas. Thus, it is possible to ensure a larger flow area for the working gas and to design the engine with the desired mechanical strength.

Abstract: A thermally insulating lining for the housing of the heater system ensures that on the outside of the heater system only low temperatures are reached which are not dangerous to operators in the vicinity of the engine. Combustion air duct means between an air preheater and a burner is formed by a large number of tubes arranged alongside each other in at least one row and along an inside wall of the combustion chamber. These tubes ensure that the flow state remains satisfactory and constant and they are substantially more durable than sheet metal duct means as used hitherto.

Abstract: A thermally insulating lining for the housing of a heater system for a Stirling, or hot air engine ensures that only safe temperature will be reached on the outside of the heater system. The insulating lining is arranged in two parts. An insulating wall is made up of individually adjacentely placed, replaceable insulating elements in the form of ceramic tiles, and/or ceramic tubes, and an intermediate space between the tiles and the outer wall. The intermediate space is separated, if desired, from the insulating elements by a ceramic paper. The intermediate space is packed with ceramic fiber batts, or loose, lump ceramic insulating material.

Abstract: To permit high-temperature differential cross flow of an initially cool, heat absorbing medium and an initially hot, heat releasing medium, with temperature differences in the order of 1000.degree. and higher, and to prevent localized thermal overload, the heat exchanger is a two-stage heat exchanger, with plate packages (5, 6) which are serially passed by the media, typically gaseous media. The first package (5) forms a preheater stage and the second package (6) forms a final heater stage. Connecting ducts (9, 10) are provided and so arranged that the initially hot fluid medium is conducted through flow channels in the second heater stage which receives heat absorbing medium which has already passed through the preheater stage, so that it has already been preheated, thereby reducing the temperature difference between the preheated heat absorbing medium and the initially hot, heat releasing medium.

Abstract: The invention provides a method for the production by welding of a heat exchanger pipe starting with a round metallic pipe onto which external metallic fins are secured so as to be perpendicular to the axis of the pipe. Each metallic fin is produced in two halves in such a manner each fin has a coxial semicircular recess or bay whose radius mateches the external diameter of the metallic pipe and on each side of such recess there are two side surfaces so that after mounting the fin halves on the pipe there is a small gap at the parting line between the two halves. After mounting the two fin halves on the metallic pipe the respectively radially outer and parts of the gap are spot welded together and on cooling down the fin the fins shrinkage at the weld spots causes the two fin halves to pressed on the pipe with their recess boundaries engaging the outer surface of the pipe.