摘要 |
1,143,559. Measuring acceleration electrically. WESTINGHOUSE BREMSEN UND APPARATEBAU G.m.b.H. April 24, 1968 (April 28, 1967], No.19368/68. Heading G1N. Acceleration responsive apparatus comprises a magnetizable strip relatively movable along a path with respect to a magnetizing device and a pick-up device, means for exciting the magnetizing device at a fixed frequency to produce an alternating magnetization along the length of the magnetizable strip, and means for comparing the frequency of the signal from the pick-up device with the frequency fed to the magnetizing device to produce an output signal if the frequencies differ by more than a predetermined amount due to acceleration. The invention is particularly useful for detecting skidding of the driving wheels of a railway locomotive, the magnetizable strip being arranged around the periphery of a driving wheel or a wheel driven in accordance with the driving wheel. As shown in Fig, 3, two pick-up devices 4', 4a are provided, one each side of the magnetizing device 3', one being selected for use depending on the direction of travel of the locomotive. A D.C. or high frequency A.C. wiping unit 2' is provided. The sensitivity of an amplifier 15 in the output circuit of the frequency discriminator 7' is controlled in dependence on the speed of the wheel 1' which is measured by a pick-up 20 co-operating with permanent magnets 19 on the wheel. The output of the amplifier 15 is fed to a regulating member 18 to reduce the output of the drive machine and to actuate a sand spraying device. The invention is responsive to negative as well as positive accelerations and may be used to monitor wheel slipping during braking. Other applications include measuring the acceleration of a vehicle moving on magnetizable rails and measuring the acceleration of a magnetizable tape. |