Abstract: A method of operating a bimodal heat pump which in a first mode operates as an absorption heat pump and in a second mode operates as an evaporation-condensation device at a comparatively low ambient temperature. When switching from the first mode to the second mode, evaporator 15 and absorber 23 are uncoupled from generator 1 and condensor 7. The generator 1 and condensor 7 are operated in the second mode as an evaporation-condensation device, an extra quantity of working medium present in the condensor 7 being provided in the system. The heat pump comprises an overflow to the evaporator 15 the level 83 of which is a measure of an extra quantity of the working medium and has a closable transport pipe to the generator 1 for supplying extra working medium to the generator 1 when starting the second mode.The heat pump is meant in particular for heating spaces and presents the possibility of choosings from various working media and solvents having different decomposition temperatures.

Abstract: There is provided a shaving apparatus comprising a housing, a shaving head, and a resilient one-piece hinge element connecting the shaving head to the housing. The hinge element has a hinge pin portion and a connecting portion. The shaving head is formed to engage the hinge pin portion and retain the same under tension. The housing wall is provided with a slot to receive the connecting portion and to retain the same in place under elastic tension.

Abstract: There is provided a dry-shaving apparatus comprising a housing section having an opening formed therein. A trimmer constructed as a flat unit is arranged on the housing section so as to be slidable between at least two positions, the trimmer unit being mounted in the opening. Two lateral guide portions are formed on the trimmer unit and extend parallel to each other and to the sliding direction of the trimmer unit. Guides are formed on the housing section and respectively co-operate with the guide portions, the guides, viewed in the sliding direction, being arranged near one end of the opening. A bridge is arranged near the other end of the opening and extends across such opening transversely of the sliding direction, the bridge engaging the trimmer unit from the inside of the housing section.

Abstract: A shaving apparatus comprising a shear plate and an associated reciprocatory cutting member is provided with cutting elements each of which is constituted by a filamentary cutter positioned along the outer edge of a lamelliform support.

Abstract: There is provided a solar collector comprising a heat pipe having an evaporator section and a condenser section, together with an absorber plate thermally conductively connected to the evaporator section, one side of the absorber plate being provided with a layer for the selective absorption of incident solar heat. An evacuated transparent envelope encloses the absorber plate and the evaporator section. A part of the evaporator section is free of the absorber plate and is provided with a separate layer for the selective absorption of incident solar heat, such separate layer having the same heat absorption coefficient as but a higher heat emission coefficient than the layer on the absorber plate per unit of length of the evaporator section.

Abstract: There is provided an apparatus such as a dry shaver comprising a housing formed by two opposing housing shells. An electric motor is mounted on at least one support extending from one housing shell. Adjacent the support a resilient hook is formed integrally with, and projects from, such one housing shell in order to secure the motor to the shell, the resilient hook engaging an edge portion of the motor and urging the motor against the support. A projection extends inwardly from the other housing shell to engage the resilient hook and thereby constitute a stop for it and position the hook relative to the motor.