GB661076A - Improvements in or relating to scale indicator devices - Google Patents

Abstract

661,076. Indicating-apparatus. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Jan. 27, 1950 [June 14, 1949], No. 15859/49. Class 106 (iv). [Also in Group XL (c)] Indicating-apparatus suitable for use with tuning controls in radio receivers comprises a radial pointer 3, which may be engraved on a transparent disc 4, moved over a scale 1 at the speed of a driven shaft, whose position is to be indicated, e.g. the shaft of a condenser gang, upon which the pointer may be mounted, and a second pointer member comprising an equally spaced series of pointers 6, preferably engraved lines on a transparent disc 7, driven at the same speed as and preferably mounted on the shaft of a control knob 5 which drives the driven shaft through reduction gearing, so as to cooperate with a second scale 8 having ten subdivisions and embracing an angle equal to that between the pointers 6 which is equal to xn/y degrees where x is the number of degrees embraced by the first scale 1, n is the reduction ratio and y the number of sub-divisions of the first scale, so that the second scale reads in tenths of a sub-division of the first scale. Further decimal sub-divisions may be obtained by providing vernier scales between the pointers 6 for co-operation with the scale 8.