| 摘要 |
543,574. Selective control systems. PHILIPS LAMPS, Ltd. June 3, 1940, No. 9703. Convention date, June 5, 1939. [Class 40 (i)] [Also in Group XXXVI] An arrangement for adjusting a sliding electrode condenser 35 comprises a small electric motor which drives a wheel 23 on a hollow spindle 25 having a friction drive to a spindle 26 carrying a gear wheel 27 in engagement with a wheel 29 to which is fixed a member 30 formed with helical cam surfaces 31, 32. A roller 33 is mounted in a gap in body 30 so as to roll on the outer surface of a cylindrical metal body 19 freely mounted on the same spindle 47 as the wheel 29. The body 19 has bearing on it a number of contact springs corresponding to individual push buttons '(not shown) the arrangement being such that when a particular button is pressed, the motor is energized until the corresponding contact spring engages an insulating part 20 on body 19. When the motor is energized, body 30 is turned through parts 23, 25 and 27 and 29 until roller 33, which normally is diametrically opposed to spindle 25 moves up to engage spindle 25 after which wheel 29 cannot move, and clutch 28 slips. The cam body 30 has acted through roller 34 to move the condenser shaft against spring 36 to a datum position, and now the roller 33 acted on by spindle 25 turns body 19 until the appropriate contact spring engages insulating part 20. This positions an appropriate stop 43 opposite the end of shaft 42 so that when the motor is de-energized condenser shaft 42 returns under the action of spring 36 to its correct setting. At the same time a spring- mounted locating member 37 engages an appropriate recess 40. According as the stations corresponding to the push buttons are in one or other of two wave bands, the motor is arranged to turn in one or other direction to operate the condenser, and this alternative movement of wheel 29 is made use of to operate a wave range switch. |
