GB958711A - Device for changing the spring force acting on a rotatable system in a gauge or the like - Google Patents

Abstract

958,711. Torsion vibration-dampers. REGULATOR A.G. Jan. 12, 1962 [Jan. 16, 1961], No. 1183/62. Heading F2S. [Also in Division H2] A variable counterbalancing torsion spring, e.g. for a balance arm 11 and for obtaining different ranges of sensitivity without changing the state of equilibrium of the balance system, consists of a band of spring steel 21 which is screwed at 39, 41 to the ends 27, 29 of a frame 25 to extend parallel to the transverse horizontal axis 13 of the arm 11 and has its central portion clamped by one end of a lever 19, the other end of which rests, with an adjusting screw 23, against a support 17. A pair of clamping devices 47, 49, which are movable symmetrically toward or away from each other on opposite sides of the clamping point of the lever 19, threadedly engage right- and left-hand threaded portions respectively of an adjusting-spindle 43 which is rotatably mounted in the ends 27, 29. The clamping devices 47, 49 which are in the form of blocks non-rotatably slidable within a easing 25 of U-section which is fastened to the frame 25 by ears 37, carry clamps 53 which can be adjusted by screws to closely embrace and yet be slidable upon the spring 21. The spindle 43 has an operating knob 45 which may be provided with a pointer which can be set to provide the desired counterbalancing spring force by selection of the appropriate effective length of the torsion spring 21. A graduated scale 51 may also be provided in the edge of a recess at one end of the casing 35 adjacent one of the clamping devices 47 or 49. The spring band 21 may be tapered with straight or curved edges to obtain a non-linear spring characteristic. Electric contacts can be fastened to the balance arm 11 and, by adjusting the screw 23, a greater or lesser pre-loading of the spring can be attained.