GB1021531A - Control systems - Google Patents

Abstract

1,021,531. Selective signalling. R. G. MALING. May 31, 1962 [April 18, 1961; May 3, 1961], Nos. 14024/61 and 19635/61. Heading G4H. A control system operable by a partially paralysed person comprises an electric transducer responsive to relatively small pressures exerted by the person and means for selecting a required controlled circuit, which means is controlled by the period of operation of the transducer. In one form of apparatus the operator sucks on a rubber pipe thereby closing a vacuum switch and causing a uni-selector to start stepping. As the uni-selector steps it sequentially lights a row of white lamps so that the operator can see how far it has stepped. Each white lamp corresponds to one of the various devices that can be controlled and has adjacent to it a green lamp and a red lamp one of which is always lit to indicate whether the corresponding device is on or off. When the uniselector reaches the position corresponding to the device that is to be controlled, the operator stops sucking, the vacuum switch opens, and, after a short delay, the operative condition of the device to be controlled is reversed, i.e. if it was on it is turned off and vice versa. The uni-selector then automatically homes. In a second form of apparatus a suction switch and a pressure switch are connected to the operator by a single rubber tube. The control panel is in the form of a rectangular array and the suction switch is closed to select a column of the array after which the pressure switch is closed to select a particular function in that column. A relay which is energized by the suction switch ensures that the pressure switch has no effect until a column has been selected. To assist in selection a different aural signal is given for each column scanned and further aural signals one octave lower are emitted as the units of the column are scanned. The controlled circuits may include a typewriter. In a third form four switches comprising two pressure switches which operate at different pressures, and two suction switches which operate at different pressures, are connected to the operator by a single tube.