Patent GB-996009-A (GB)
Title: Improvements in or relating to apparatus for measuring and recording railway axle dimensions
IPC: G01M99/00
Filed: 1961-10-27
Abstract: 996,009. Measuring electrically. SOC. NATIONALE DES CHEMINS DER FER FRANCAIS, J. JEAN-MARIE. Oct. 27, 1961 [April 24, 1961], No. 38494/61. Heading G1N. Apparatus for use in surveying a railway axle assembly comprises a plurality of transmitters for gauging the critical dimensions of the assembly and signalling the results to recording receivers, each transmitter having a feeler which contacts a part of the assembly being gauged and which positions the slider of a potentiometer, the output of the potentiometer being compared with that of a second potentiometer associated with the corresponding receiver, the unbalance signal being fed to a polarised relay to control the operation of a servomotor which drives the slider of the second potentiometer to a null position and simultaneously positions the stylus of the recording receiver. As shown, Fig. 1, the test assembly 3 is mounted for rotation on stocks 2. A carriage 9, supported for horizontal movement along the upper crossmember of a frame 5, carries two blocks 7, 7<SP>1</SP>, each comprising two horizontally adjustable transmitters for gauging the spindle. The vertical distance through which the blocks 7, 7<SP>1</SP> are lowered by power means to engage the feeler of one transmitter on the spindle at its zero setting, is shown on a rev counter; this indicates the diameter of the spindle and the deviation from zero of the other transmitter indicates spindle taper. A sub-carriage 11, also supported by carriage 9, carries two blocks 6, 6<SP>1</SP>, each comprising four transmitters for gauging rolling circle diameter, flange thickness, flange height, and the inner surface of the wheel. Sub-carriage 11 is vertically displaceable by power means, a rev counter being used to indicate the amount of such displacement. Each feeler has a small wheel at the end which engages the wheel or spindle. The receivers are located at a recording and control board 8, where the styli trace records of transmitter outputs during one rotation of the test assembly. Transmitters. Fig. 7. In these, displacements of feeler T are transmitted to the slider 37 of the potentiometer via a spring-biased rack 35 and gears 33, 34. Adjustable stops 46, 47 co-operate with a finger 36 on the rack 35 to limit the range of movement of the feeler, and a local indicator (not shown) has its pointer mounted on the shaft of slider 37 to indicate feeler displacement. Receivers. Fig. 8. A servomotor 45 drives, through gears 48, 51 and worm 49, the slider 38 of the follow-up potentiometer, and, through gearing 50 and threaded shaft 52, a non-revolving nut 53 on which a stylus 55 is mounted. An electro-mechanical brake 54 having its energizing coil in the motor circuit stops the motor when the motor circuit opens. In a modification, the stylus is driven by a cable which is moved by a driving pulley on the potentiometer shaft. Circuitry. Fig. 10. Out-of-balance current flowing between sliders 37, 38 energizes the coil 39 of a differential relay to connect one terminal of servo motor 45, via relay contact 31 or 32, to the negative or positive terminal of two series connected rectifier bridges 68, 69, the other motor terminal being connected to the common point of the bridges. The potentiometers are supplied from a third rectifier bridge 67.