GB330671A - Improved brake for use on road vehicles - Google Patents

Abstract

330,671. North, O. D., Hugh, P. G., and Scammell Lorries, Ltd. March 23, 1929. E n e r g y - absorbing elements. - A r o a d vehicle brake comprises rotary energy - absorbing means 1 of the kind used in fluidfriction dynamometers, coupled to a moving part of the vehicle and supplied with liquid by a pump 11, selectively operable valves 16, 17 being provided for isolating the source of liquid supply from the brake. The heat generated may be dissipated in the usual engine radiator. The rotor 30 of the dynamometer 1 is fixed on the main transmission shaft 2 and the dynamometer is connected by pipes 5, 6 to the water circulating system of the engine 3, the inlet pipe 5 being connected through the three-way valve 16 with the pump 11 and the bottom tank 9 of the radiator 4, while the outlet pipe 6 is connected through the valve 17 with the water outlet pipe 14 of the engine and the upper water tank 12 of the radiator. Gills 15 may be provided on the outlet pipe 6. The valves 16, 17 are connected together by a rod 18 and operated by a brake pedal 20 which when depressed opens the valve 17 and turns the valve 16 to connect the pipe 5 with the pipe 10 leading to the pump 11 and cut off the connection of the pipe 10 with the pipe 8 leading to the cylinder jackets. An auxiliary water tank 21 may be arranged in either of the pipes 5, 6. A separate water circulating pump may be employed for the brake and may be arranged to extract the water from the dynamometer when it is not in operation. A non-return valve may be arranged in the pipes leading to or from the dynamometer. For slow moving vehicles the dynamometer may be mounted on an independent shaft driven at an efficient speed by gearing from a moving part of the vehicle. The dynamometer casing may be free to swivel about the shaft, the pipe connections being flexible. The rotor 30 of the dynamometer has half ellipsoidal pockets 31, Fig. 2, arranged opposite pockets 33 on fixed rings 32 so that the water is driven by the rotor into the pockets of the stators and is returned to the rotor in a different direction.