GB1227417A - - Google Patents

Abstract

1,227,417. Vehicle roofs. M. L. LACY. 1 April, 1968 [6 April, 1967], No. 15556/68. Heading B7B. [Also in Division G2] A solar energy screening and filtering device e.g. for use in windows, automobile tops, aeroplane canopies, space helmets, eyeglasses, windshields, and signs, comprises a hermetically sealed cavity 22, Fig. 3, formed between two transparent plates 18 and 20 and a reservoir 60, Fig. 4, containing two immiscible liquids connected to the cavity 22 by conduit 58 to a high gravity point 54, and by conduits 62, 64 and 66 to low gravity points 50 and 52. In one embodiment for use in the roof of a motor vehicle the reservoir 60 contains equal amounts of liquids such as a heavy glycol and a mineral oil. A pump 68, actuated by a solenoid switch 70 or 71, pumps the heavy liquid through conduit 66, filter 72 and conduits 62 and 64 into the low gravity openings 50 and 52 of cavity 22. The system is completely filled with liquid and air expelled from it by means of a bleeder valve 74. Expansion of the liquid is taken up by the expansion device 76 which consists of a rubber ball surrounded by a coarse mesh wire. Alternatively a rubber diaphragm plate over a hole in the side of the reservoir may be used. To assist heating of the vehicle by allowing infra-red rays to be transmitted through the cavity 22, the heavy liquid is pumped out of the cavity 22, and in so doing the light liquid is forced into the high point of gravity opening 54 thus presenting a cycling of the liquids with the interphase between them moving in the direction of the pumping so that the interphase in the reservoir rises to the high point of gravity 54. The system may employ three or more immiscible liquids and more than one reservoir.