GB193123A - New or improved instrument or apparatus for indicating the rate of flow or consumption of liquids, such as liquid fuel - Google Patents

Abstract

193,123. Mitchell, W. B. Nov. 14, 1921. Liquid-fuel-consumption rate indicators.- Comprises apparatus for giving an indication of the rate of consumption of liquid fuel, for example, in a motor vehicle the number of miles per gallon, or, in a motor vehicle, stationary engine or motor boat, the number of revolutions per unit of fuel or, in oil furnace steam ships, the number of nautical miles per unit of fuel. The fuel is admitted to a chamber intermediate between the reservoir and the place of consumption, under control of means driven either by a road or similar wheel when the instrument is calibrated for distances per unit of fuel, or directly from the engine when calibrated for revolution per unit. A cam u on a shaft t driven from the road wheel or engine reciprocates a piston o against a spring p in a barrel g which communicates with the fuel reservoir and chamber a through ports k and l respectively. A float b in the chamber a carries a rack y meshing with a pinion z to move a pointer over a graduated scale x and a wedge cam 1 coacting with a slot v in the piston rod q. The frequency of the pump is thus determined by the speed of the shaft t and its stroke by the height of liquid in the chamber a which also determines the position of the pointer and which is, moreover, determined by the relative rates of supply and withdrawal of fuel therefrom. Modifications are described involving the use of differently shaped cams and dispensing with the toothed rack. In these constructions, moreover, the pump draws fuel from the reservoir at each alternate stroke but delivers it to the chamber a at each stroke.