Veraenderbarer elektrischer Widerstand

965,036. Variable resistors; inductors. SPERRY RAND CORPORATION. Sept. 6, 1962 [Sept. 20, 1961], No. 34200/62. Headings HIS and H1T. In a variable resistor or inductor which comprises a helical winding 34, Fig. 1, on a former 18 the adjustable contact member 54 is of gear-wheel form and rotatably mounted on a carriage 44 so that the contact member engages the winding in the manner of a worm gear arrangement. The former 18 may be continuously rotated by the motor 30 via the gear train 28, 26, in which case the contact member 54 rotates and ensures good contact and even wear. In addition, the carriage 44 may be moved along shaft 14 to vary the position of contact, the contact member rotating as the carriage moves. It is stated that this form of contact member is of advantage where the member is lifted out of contact with the winding since it cannot, as opposed to a normal grooved pulley member, be replaced in the wrong position, e.g. between turns.