Axle loading instrument
Page 61
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Smiths Industries have developed and will be marketing equipment from March 1 1972 that will accurately indicate percentage of axle load on the individual axles of a vehicle.
Shown on the Smiths stand at the Scottish Show was the method this company considered to be most accurate -an accuracy of plus or minus two per cent at the point of calibration is claimed. The system comprises a transducer unit attached to the vehicle frame which has an arm extending to the centre of the axle, thus movement of the vehicle platform relative to the axle is monitored by movement of the arm which deflects a spring connected to a damped wiper arm on a variable resistance. A moving coil instrument in series with this resistance fed from a stabilized supply completes the system for one axle or a pair of balanced axles.
Up to three transducers can be connected to a common indicator in the cab and the percentage load on each axle can be obtained by the use of a selector switch incorporated in the indicator housing.
For use within a trailer combination a supplementary connector box for linking the transducers and the instrument head is required.
Calibration is completed with the axle at its maximum loading and the procedure is as follows: load axle to its plated weight; move the vehicle for at least 40yd: coming to rest gently. The transducer should then be connected (mechanically) to the axle and adjusted to obtain a 100 per cent reading on the indicator.
Final adjustment should then be made on a flat road while on overrun, the resistance control in the cab being adjusted to give 100 per cent calibration.
Made by: Smiths Industries Ltd. 50 Oxgate Lane, Cricklewood, London N.W,2