| 摘要 |
1,196,719. Variable resistors. W. PREH, [trading as PREH ELEKTROFEINMECHANISCHEWERKE JAKOB PREH NACHFOLGER]. 6 Dec., 1968 [8 Dec., 1967], No. 58208/68. Heading H1S. A rotary rheostat comprises a resistance element 10 inside a rotor 16 carrying a wiper 17 which moves over the resistance element as the rotor is turned, via reduction gears 19, 20, by a spindle 5. The resistance element 6 may be a printed resistive layer 10. A collector arrangement is provided by an annular track 14. The rotor 16 is mounted on a spindle 3 and carries a spring wiper 17 which has a carbon contact 18. The toothed rim portion 19, extends over about 300 degrees around the inside periphery of the rotor. The device may be mounted by means of tapped studs 23 and the external cylindrical surface of the rotor or an additional ring 26 may act as the cord pulley for a cord operated scale pointer. |
