GB387371A - Improvements in apparatus for testing motor vehicles - Google Patents

Abstract

387,371. Dynamometers ; systems for testing motor vehicles. HEENAN & FROUDE, Ltd. and WALKER, G. H., Worcester Engineering Works, Worcester. Aug. 4, 1931, No. 22050. [Class 106 (ii).] Relates to apparatus of the type having a drum or drums upon which the vehicle wheels are mounted and a brake or dynamometer for applying a measured braking force to oppose rotation of the drum, and consists in mounting the drums in cradles movable about an axis coinciding with the axis of the wheels of the vehicle. In the form shown in Fig. 3, the vehicle is run over ramps L so that the back wheels 1 rest on drums A, D carried by a cradle S having a track T, T concentric with the axis of the wheels 1 and movable on rollers tl, t<2> supported in the frame B. The brake or dynamometer C is rigidly attached to the cradle S and its rotor is driven by the shaft a of the drums. A device E, preferably as described in Specification 361,524 for indicating the efficiency of the vehicle brakes is fitted. At a point s<7> corresponding with the point of contact between the tyres and the drum A the cradle is connected by a link s<8> to the short arm of a lever weighing machine s<1>. A speedometer driven from the shaft a is fitted. By supporting the drum shaft bearings at each end in cradles and carrying a dynamometer on the cradle, two separate measurements of power are obtainable, one total tractive effort including tyre losses, and the other the net power reaching the drum after tyre losses. In a modification, the rear wheels are held on the drum A by a stop or strut engaging the back axle, the cradle being connected by linkage to a weighing machine. In the form shown in Figs. 5 and 6 one cradle S is suspended on links s from the underframe B and is attached by a link s<8> and a bell crank s<9> to the short arm of a weighing machine s<1>. The drum shaft a is coupled to the rotating member of the dynamometer C, the stator of which is carried by bearings upon a second cradle S. The stator c is connected by an arm c<1> attached to a weighing machine s<4>. Arms extend from the cradles to an axis s<2> and are pivotally connected by a link s<6> to a fixed anchorage s<5>. A point s<7> coinciding with the point of contact between tyre and drum is connected by a link s<8> and levers s<9> with a weighing machine s<1>. Both lever arms s<9> are keyed to a common shaft s<11>. In a further form, the drum A is carried by the cradle S suspended by links and an arm extends upward to bear against the back axle casing, retaining ropes preventing forward movement of the axle. The cradle is connected through a link and bell crank to a weighing machine, an indicator pointer being provided to show when the long arm of the bell crank is horizontal. For testing the efficiency of the front brakes, the front wheels are carried on drums supported in a trolley which can be adjusted to accommodate vehicles of varying wheel-base. A flow meter is provided to give' rate of feed of fuel from the carburetter and a fan or external water cooling system or both used.