Patent GB-908680-A (GB)
Title: Electrical space heating system
IPC: F24H9/20
Filed: 1959-03-03
Abstract: 908,680. Electric heating resistances. EISLER, P. Feb. 26, 1960 [March 3, 1959], No. 7288/59. Class 39 (3). An electrical space heating system for heating an at least partially enclosed space bounded by boundary walls e.g. a room garage or greenhouse comprises electrical heating films carried by and at the surface of at least one of the walls, electrical power supply means which supply the electrical heating films with a normal quantity of power for normal operation of the heating films and with an excess of power for a predetermined initial period. Switch means are provided for connecting and disconnecting the power supply means to and from some of the heating films whereby when the switch means are closed the films are initially supplied with the excess of power. The power supply is so disconnected by a transformer or by the switch means and automatic means for reducing the power supplied to the films to the normal quantity at the end of the initial period. The ceiling of the room has an elongated electrical heating film serving also as ceiling paper the walls have wallpaper covering or containing heating film or the film has decorative covers. The linoleum has heating film beneath or embedded therein. Current is supplied to the films by a series of vertical and horizontal bus-bars connected to the films by strips. The metal heating film has staggered slits and is disposed between two insulating layers; it has Z-shaped ends some of which have a paper inlay and some strips connected to the bus-bars. The switches are bimetallic and comprise a rubber block with a metal plate on one side and a foil on the other side which snaps into and out of contact with the bus-bar contacts. Alternatively the switch comprises foil 77, Fig. 6, extending about plate 78, a carbon wedge 80, insulating backing 81, rubber plate 82 and spring steel plate 83. The bus-bars are supplied by a transformer, rectifier and accumulator arrangement, Fig. 7 (not shown) provided with a " switch plate ", Fig. 8 (not shown), made up of foil resistors. The film and bus-bars may have decorative covers and may be slit and crimped. A plug and socket device, Fig. 9, connects the film 123 to the busbars 40. Film 124 on the plug 122 comprises resistance foil mounted on an insulated backing and cut or etched along a sinuous path. Insulating strips are inserted between the folds of the foil. The invention may also be applied to a bath or to a hot-water system feeding a sink, Figs. 12-15 (not shown), and also to cookers, lighting, bells, heating blankets, shavers, hair dryers, toys. The metal foils may be faced with a layer of insulating material. The electric supply means comprises a main and subsidiary source, current being drawn from the subsidiary source only when the capacity of the main source is exceeded. The main and subsidiary sources may heat two different spaces. The transformer of Fig. 7 (not shown) may have only one secondary winding instead of two. The subsidiary source is an accumulator and pulsed D.C. is supplied when both the accumulator and transformer are effective. The transformer may be built up as a fiat wall radiator. The Provisional Specification states in addition that the heating foils are mounted on or embedded in thermoplastic or elastomeric films, crepe paper or textile ribbons. The bus-bars are copper foil strips covered by a decorated cover of paper, plastic film or textile. The foil heater is clamped and crimped to the support. The foil resistor of the switches has arms of increasingly larger surface and cross-section from the joint of the resistor with the " shunting foil strip." The switches may be spring loaded instead of bimetallic. The accumulator is a box. The switch plate is a foil resistor strip produced as a tape. Eight tapes are placed side by side, with copper strip contacts soldered on to them. Plastic sheet is placed on top and bonded to them. The invention is also applicable to ironing devices, washing-machines, refrigerators. Specifications 900,515, 900,516, 900,518 and 905,867 are referred to.