GB194945A - Improvements in and relating to vibration indicators - Google Patents

Abstract

194,945. British Thomson - Houston Co., Ltd., (General Electric Co.). March 27, 1922. Vibrations, indicating. - An instrument for indicating the amplitude and frequency of vibrations in one direction only comprises a base, a heavy weight suspended from a support on the base by a vertical plate spring, and means for indicating movements of the base relatively to the weight, the arrangement being such that the flexure of the spring always takes place at the same point and in one plane only- The weight 12 is shown suspended from the top wall of the casing 10 by a rod 13, a short plate spring 16, and a clip or bracket 17. The spring 16 is thin and wide so as to be flexible only at right angles to its plane. The heavy base of the casing is provided with sloping toothed ridges 20 so that the instrument may be used on curved surfaces. A pointer 21, Fig. 3, for indicating amplitude and frequency is attached to a shaft 25 and moves over a scale 23 visible through a glazed opening in a cover plate 11. The shaft 25 passes through a large hole 27 in the weight and is supported by threads 26 passing through holes in the shaft and having a half turn round it, the ends being fastened to heads 29 on spring arms 28. The shaft 25 is centred and the tension of the threads regulated by adjusting the arms 28 by. means of screws 34. The shaft 25 is connected to the weight 12 bv similar threads 38 adjustably secured beneath clips 40 and arranged so as to prevent axial movement of the shaft. A thumbscrew 43 is provided for clamping the weight against a block 44 when not in use. As the instrument only responds to vibrations at right angles to the spring it may be used for ascertaining the direction of the vibrations of a body on which it is placed.