GB471720A - An improved method of and means for indicating the amount of liquid, granular or pulverulent material in a tank - Google Patents

Abstract

471,720. Indicating liquid - levels. NEUMANN, G. Feb. 18, 1937, Nos. 4940 and 4941. Convention dates, Feb. 18, 1936 and June 22, 1936. [Class 123 (i)] [Also in Group XIX] The volume of liquid, granular or pulverulent material in a tank 1 is measured by connecting through pipes 4, 4a the tank and an auxiliary vessel 3 at regular intervals to the same source of pressure and using the difference in the rate of pressure change in the two vessels to actuate an indicating device. The periodical connection with a pressure source is provided by a rotating valve 6 communicating alternately with the source and the atmosphere, and the ratio of the flow resistance of the two pipes 4, 4a may be varied by an adjustable needlevalve 35. The pressures in the two vessels act on opposite sides of a diaphragm 11 which according to its direction of movement closes contacts to drive the rotor 27 of an electric motor in one direction or the other and thus move up or down a pointer 31 on a nut 30, which also moves a piston 34 to equalize the pressures in the two vessels. The motor circuit is periodically opened, while the valve 6 communicates with the atmosphere, by a cam 24 engaging a spring contact 22. The vessel 3 may have an invariable volume, the valve 35 being connected to the nut 30. On an aircraft the pressure may be obtained by utilizing the wind of travel. Alternatively, the cock 6 may be dispensed with and the pressure changes produced by a reciprocating piston. The diaphragm may operate through hydraulic or mechanical transmission. In a modification, the needle-valve 35 is omitted and the two vessels communicate with cylinders containing pistons periodically reciprocated by the same driving device.