Patent GB-482960-A (GB)
Title: Improvements in apparatus for testing the brakes of vehicles
IPC: G01L5/28
Filed: 1936-10-09
Abstract: 482,960. Testing vehicle brakes dynamometrically. HEENAN & FROUDE, Ltd., and WALKER, G. H. Oct. 9, 1936, No. 27402. [Classes 106 (ii) and 106 (iv)] The indications from the apparatus associated with each of the four wheels are transmitted to four pointers of a centralized indicator having a single dial over which the four pointers are caused to travel. The wheels of the vehicle are supported by four pairs of fluted rollers A<1>, A<2>, A<3>, A<4>, the two front pairs A<1>, A<2> being carried by a trolley M. The front pairs of rollers are driven from an electric motor E through gear box Y gear wheels B and a chain, while the rear rollers are driven from a motor E<1> through gear box Y<1> gear wheels B<1> and a chain. Each pair of rollers and its connected gearing is carried by a bracket g free to rise and fall, but anchored from horizontal movement by a link h. A pointer j moves from the vertical through an angle indicating on a scale K the efficiency of the brake in the same manner as in Specification 361,524. The vehicle is prevented from running backwardly while the brakes are tested by anchor gear L3, L<4>, l<4> l<5> carried by the trolley and connected to the frame of the vehicle such gear being constructed so as to be lowered to allow the vehicle to run off the apparatus forwardly. The trolley M rims on wheels n on tracks t. It is moved by turning a shaft p<1> pinions p on which engage parallel inverted racks r and locked in adjusted position by swinging a lever S a cam s on which enters between the teeth of the wheel w. Plate u fixed to cross shafts u<1> may be swung angularly upwards to serve as chocks against which the front wheels abut and to centre the same. The angular movement of each pointer is transmitted to a centralized indicator G as follows : Each pointer j<1> is carried on a crank 1 pivoted on the axis of one of the fluted rollers, a similar crank 2 being arranged at the opposite end of the roller. The crank 2 transmits movement through arm 5, link 6, bell-crank 7 and link 8 to a lever 9 to a shaft 10. This is surrounded by a tube 11 to which the lever 9 of the other pair of rollers of the back axle transmits movement. From there by levers 12, 13 movement is transmitted to longitudinal parallel rods 14, 15. The transmitting mechanism on the trolley is similarly to rods 35, 35a except in view of the movement of the trolley clutches 30 and provided for connecting the shaft 10 and tube 11 to the corresponding rod, such clutches being worked by Bowden wire connecting them to lever S so that when the trolley is locked, the clutches engage the rods 35, 35a with their drives the pointers j being in zero position. The rods 14, 15, 35, 35a are supported by pivoted links 40, so that the motion transmitted to them by the levers 12, 13 will be substantially longitudinal and this motion is transmitted to the four pointers gl, g<2>, g<3>, g<4> of the centralized indicator G. Each pointer is normally held in zero position by a spring g<6>. The pointers g<1>, g<2> are arranged to move vertically, up and down over the face of the indicator C and the pointers g<3>, g<4> laterally over the face. The rods 14, 15 through connections 14a move vertical rods 16, 16a up and down and these rack pointers g<1>, g<2> about an axis 26. The ends of the pointers are bent over at right angles similarly to those of pointers g<3>, g<4>. These latter are attached to a tube 17a and shaft 17 rocked about their axis from rods 35, 35a. The casing 28 is illuminated by a lamp inside the casing so that the shadows made by the front ends of the pointers appear as dark lines on the dial. The Provisional Specification also describes a cable and pully transmission mechanism involving the provision of a differential gear.