Abstract: The solar concentrator arrangement has a concentrating mirror (2) consisting of a metallised plastic shell to reflect parallel incident light. The concentrating mirror ( 2 ) forms part of a foil tube (1) and co-operates with a secondary concentrator (5) which deflects the parallel incident light beams (3,4) from the concentrating mirror concentrically on a heat exchanger. The heat exchanger (7) is placed on the focal line of the secondary concentrator (5) are rigidly secured together and can be automatically moved in relation to the heat exchanger (7) according to the position of the sun.

Abstract: In a Stirling engine having a housing chamber (1) which is divided by a reciprocating gas-permeable regenerator plate (4) into two part chambers (6, 7), of which one can be heated and the second is provided with cooling (13), the second part chamber (7) communicating with a working cylinder which acts on a working shaft (14) or a flywheel mass (10) via a first drive device (9) and on the regenerator plate (4) via a second drive device, it is proposed to design the housing chamber (1) in a wedge-shape and to mount the regenerator plate (4) pivotably about a pivoting axis (5) in the tip of the housing chamber. As a result of the proposed design of the housing chamber (1) with the pivotable fixing of the regenerator plate (4) which at the same time serves as a displacement piston, the displacement function of the regenerator plate (4) is fully effected by low-wear pivoting motion about the pivoting axis (5).

Abstract: The invention relates to an apparatus for heating water by solar energy, including a container made from a plastic film or sheeting for the water to be supplied to consumers, having a cold water inlet opening preceded by an inlet valve and having a withdrawal opening, wherein the top of the container is transparent and the bottom is dark in color. To further develop a known apparatus of this type such that water can be withdrawn even for relatively large-scale needs and it can be connected to an installed water system, it is provided that the outlet opening is followed by a pump and a check valve, that the inlet valve is electromagnetically actuatable, and that a sensor for measuring the instantaneous water temperature and an adjusting device for adjusting the desired temperature of the water to be supplied are connected to the inlet valve. The higher the instantaneous water temperature, the more cold water the inlet valve admits into the container.

Abstract: In the case of a heat engine, in particular a Stirling engine, comprising a displacement piston and a working piston which are coupled together in a housing sealed in a leak-proof manner against the outside so that they can oscillate in a linear direction, in which case the gas space between the displacement piston and the working piston is connected to the gas space between the displacement piston and the housing by way of a heater, a cooler and a regenerator arrangement to which an external source of heat may be connected, in order to make possible the take-off of mechanical energy from the closed housing for external use, provision is made for one magnetic or magnetizable coupling device (9, 15) located within the housing (1) to be connected at least with the working piston (2) and there is also a corresponding magnetic or magnetizable coupling device (8, 18) outside the housing (1) which is movably mounted in parallel with the piston travel.