GB599216A - Intermittent driving mechanism - Google Patents

Abstract

599,216. Intermittent driving mechanism BENDIX AVIATION CORPORATION. Aug. 9, 1945, No. 20450. Convention date, Aug. 30, 1944. [Class 80(i)] [Also in Group XXXVIII] Intermittent driving mechanism, particularly for the remote control of variable condensers in radio apparatus comprises a continuous drive shaft 14, Figs. 2, 3, carrying a number of axially and circumferentially spaced pins 26-31 which co-operate successively with corresponding arm s 26a-31a on a driven shaft 15 to impart a step-by-step rotation thereto. The engaging surfaces of the arms 26a-31a are arcuate and of a curvature corresponding to the path of the pins 26-31 so that over a substantial angle of movement of the engaging pin 26 as shown no movement is transmitted to the corresponding arm 26a and shaft 15. During this period of no drive the arm is kept in contact with the pin by a spring detent 44, 45 operated by the preceding pin 31. The mechanism may be operated by an electric motor 17 under remote control through a circuit shown in Fig. 6. A manually operable switch 63 for selecting a desired position to which the mechanism is to be operated completes the motor circuit through one of a number of contacts engaging a conducting disc 64 secured to the driving shaft 14, and the motor is rotated until a notch 72 in the disc reaches the operative contact and breaks the circuit to stop the motor. The step-by-step mechanism allows for a certain amount of over-run of the motor without further operation of shaft 15 and the tuning mechanism driven thereby. The pins 26 - 31 are shown equally spaced but any other suitable spacing may be provided so long as there is no interference between successive arms and that one arm is always in a position to be engaged. A driving motor having a permanent magnetic field may be braked by shortcircuiting the brushes by a relay actuated when the current is switched off.