GB606430A - Improvements in or relating to apparatus for the manufacture of potentiometers and rheostats - Google Patents

Abstract

606,430. Coiling, SPERRY GYROSCOPE CO., Inc. June 11, 1945, No. 14803. Convention date, June 9, 1944. [Class 83 (iv)] [Also in Groups XXXVI [Appx.], XXXVII and XXXVIII] In a potentiometer winder, resistance cards are automatically wound to conform to a master potentiometer. During winding the potentiometer is continuouslv balanced in a bridge against the appropriate fraction of the standard, the out-ofbalance voltage operating a motor which varies the winding pitch in the corrective sense and so balances the bridge automatically. In Fig. 1, the winding former 27 is rotated by shaft 16 driven through gears 51, 52 and differential 45 from motor 12 which also operates the lead screw 21 through gearing 44. The bare resistance wire 26 is fed from a supply spool (not shown) to the former 27 by carriage 28, movably supported on crossrod 19 and lead screw 21, and provided with thread-engaging mechanism 29. To vary the speed of rotation of former 27 with respect to that of the lead screw 21, the error correction motor 13 is coupled to shaft 16 through gears 46 and differential 45. Speed control thereof is achieved by two permanent-magnet generators 53, 54 driven by motors 12, 13 respectively in conjunction with the control apparatus 14, [see Group XXXVII]. The master potentiometer 55 is varied progressively, as wire is fed to the cord 27, by lead screw 21 through gearing 59 and cam 61 which is shaped to give the desired function.