Abstract: A yoghurt-making machine comprises an enclosure inside which a receptacle containing milk pots is disposed above a basin. The space between the receptacle and basis is partly filled with a fusible material, such as commercial paraffin wax which has a cooling curve exhibiting a solidification plateau at a temperature near to the optimum temperature of yoghurt formation. A heating resistor attached to the basin is immersed in the fusible material which is thereby heated. The basin has a bottom defining with the enclosure a closed chamber completely separated from the fusible material. A temperature-limiting element is connected to the resistor and disposed so as to be responsive only to the air temperature within the chamber and is operable to terminate the heating of the fusible material when the temperature in the chamber is higher than the solidification plateau of the fusible material.

Abstract: A thermostatic regulating device for the surface of a heating cylinder of a cooking appliance consisting essentially of a stretched metal wire applied along a spiral path with a wide helix angle to the surface of the cylinder, the variations in the length of the wire due to heat-induced expansion or contraction acting after amplification on a microswitch incorporated in the heating circuit for said cylinder.