Patent GB-1188070-A (GB)
Title: A Device for Determining Changes in the Rate of Rotation of Vehicle Wheels
Inventor: IMADA MITUO
IPC: G01L5/13
Filed: 1968-03-22
Abstract: 1,188,070. Accelerometers; dynamometers. IYASAKA SEIKI CO. Ltd. March 22, 1968 [March 23, 1967], No. 14071/68. Headings G1K and G1W. Apparatus for testing a wheeled vehicle dynamically includes a group of rollers for each wheel, each group comprising a front roller 2a (2b), a first roller 3a (3b) and a second roller 4a (4b) and all disposed under the vehicle wheel in contact with its periphery, and also includes means 10a (10b) for urging the rollers 3a, 4a (3b, 4b) against the wheel surface and means 10a (10b) for retracting the first rollers 3a (3b) from the wheel, means for measuring the rate of rotation e.g. a tachometer being associated with the second rollers 4a (4b). An adjustable front frame 1a supports the shafts 31 of the front rollers 2a and flywheels 7a, 8a and also an axle 9a which rigidly supports levers 10. The levers 10 carry the first and second rollers 3a, 4a and are rocked by means of piston and cylinder assemblies 10a to set coaxial wheels on the front sets of rollers. The front frame 1a can be moved relative to a rear frame 1b by a motor 27 and a screw-threaded system 44 to adapt the apparatus for vehicles and different length. The rear frame 1b supports front rollers 2b (with flywheels 7b, 8b) and an axle 9b which rigidly supports main levers 37. The main levers 37 carry the first and second rollers 3b, 4b and are rocked by means of piston and cylinder assemblies 10b. The levers 37 also carry axles 20 rotatably supporting levers 42 which carry the second rollers 4b and can be rocked relative to the main levers 37 by piston and cylinder assemblies 19 to adjust the apparatus for wheels of different diameter. Four conical side rollers 12 on each frame 1a, 1b prevent lateral displacement of the wheels. A stationary platform 23 and movable platform 24 lie between the frames 1a and 1b on the same level as the rollers, brake mechanism 18 lock the rollers 3a, 3b when the vehicle to be tested is moved on to the apparatus and vertically movable plates 15a, 15b also act as guides. A pair of rollers 22 each mounted at the upper ends of a pair of piston rods prevent the rear wheels from riding on to front rollers 2b during testing and are retracted by piston-cylinder assemblies 21 when the vehicle is moved on or off. The front rollers in each pair 3a, 3b are connected by couplings 11a, 11b, and the pairs cooperate through a shaft 25 and gearing. To test the overall effect of the vehicle brakes on all its wheels, the pistons in the cylinders 10a, 10b are retracted to urge both the first and second rollers 3a, 3b and 4a, 4b against the wheels so that the drive from the vehicle engine and load applied by the brakes is transmitted through the rollers 3a, 3b, couplings 11a, 11b and shaft 25 to all the wheels and second rollers, whose rotation is sensed by the measuring means. To sense individually the reduced rotation of the wheels when braked, the levers 10, 37 are swung anti-clockwise through the piston and cylinder assemblies 10a, 10b to withdraw the first rollers 3a, 3b from the wheels whilst pressing the second rollers 4a, 4b there against. The apparatus is also suitable for measuring starting acceleration and hill climbing power.