GB304485A - Improvements in or relating to an apparatus or machine for testing the efficiency ofbrakes of automotive vehicles - Google Patents

Abstract

304,485. Jackson, L. Mellersh-, (Brake Synchrometer Co.). Jan. 28, 1928. Dynamometers; systems for testing motor vehicles.-For testing the brakes of a motor vehicle, the wheels are rotated in contact with independently rotatable. rotors moving solely by kinetic energy, and means are provided for measuring the movement of each rotor after the vehicle brakes are applied. The vehicle A is run over ramps 24 on to a platform 21 so that the wheels rest on four rotors or flywheels 32, 34, 45, 46 the surfaces of which protrude above the platform. The rear rotors are carried on aligned independent shafts 29, 31 the inner ends of which carry half pulleys 7, 8. The front rotors are similarly mounted and carry half pulleys 9, 10. An endless belt passes over the pulleys, over a jockey pulley 75 and a pulley 76. The pulley 75 is moved by a lever 81 to tighten the belt which equalizes the speeds of the pulleys and rotors. Each of the shafts 29, 31, 40, 41 is connected by a gear 49, 5 and a flexible shaft 51 to a speedometer on an instrument board 54. Pivotally mounted on a fixed plate is a four-armed spider 56 each arm of which carries a friction disc 57 adapted to engage a disc on the shaft 51. A spring 59 tends to pull the spider so that the friction wheels engage, but a stronger spring 64 acting on a pivoted latch 62 causes the latter to engage a lug 63 and hold the friction wheels 57, 58 out of engagement. The wheels 57 are connected by flexible shafts to tachometers 53 on the instrument board. The latch 62 is connected by a cable with the brake rod 65 operated by the brake lever 66. In use, the frame is adjusted longitudinally to suit the wheel base of the car, the belt 74 is tightened, the cable 6 is connected to the brake mechanism and the engine is started. Cables 104, 105 anchor the vehicle to the support. The speed of each fly-wheel is independently indicated, and when all rotate at a predetermined speed, the lever 81 is operated to loosen the belt, the clutch is thrown out, and the brake applied. The latch 62 is consequently released and the tachometers are set in motion to indicate the travel of each wheel from which readings the brakes may be adjusted and the distance which the vehicle will travel under braking action obtained. The speedometers indicate the speed of the vehicle when braking takes place. Supplementary fly-wheels 36, 37 may be coupled to the fly-wheels 32, 34 in the case of a heavy vehicle. The tachometers may be replaced by a recording device comprising a tape driven at constant speed marked by sparkgap devices timed from each fly-wheel.