GB656067A - Improvements in driving mechanisms - Google Patents

Abstract

656,067. Control of motors; actuation of switches. IGRANIC ELECTRIC CO., Ltd. Sept. 2, 1948, No. 23165. Convention date, Sept. 5, 1947. [Classes 38(iii) and 38(v)] [Also in Group XXIV] A driving mechanism comprises a drive shaft, a coupling for connecting a driven device to the drive shaft and an intermittent gear operating connection between the coupling and the drive shaft to control the coupling to maintain the coupling in released position while the angular position of the drive shaft lies within a prescribed range and for engaging the coupling when the angular position lies outside that range, whereby the driven device is driven only when the drive shaft is rotated outside the range. The driving mechanism may form part of control apparatus for an electric motor-driven sluice gate which has a long range of travel between upper and lower limits and is accurately controlled within zones near such limits by means of a switch which may be of the travelling-nut type. The operating screw 5 of the limit switch LS is coupled to the gate through mechanism 6 which drives the screw during movement of the gate in the extreme zones and locks it during the remainder of the range. A shaft 7 is driven by a pinion 9, which meshes with a rack fixed to the gate, and is adapted to be coupled to a shaft 8 to drive the screw 5. A circular cam 11 operates the coupling which comprises flanges 13, 14 fixed to shafts 7, 8, respectively, pins 15, 17 being adapted alternatively to engage apertures in flange 13 or stops 19. The cam 11 comprises segments 26, 27, having bevelled faces 26a, 26b, and 27a, 27b cooperating with rollers 24 and 25 respectively so as to move element 20 to alternate positions and adjust the position of the flange 14 by means of rollers 22, 23. An intermittent gear drive between cam 11 and shaft 7 comprises three sets, each comprising a gear wheel, operating arm, and locking disc. Arm 30a is driven from shaft 7 through gears 39, 40, and when moved in either direction, steps gear wheel 29c through one-fifth of a revolution for twenty-five revolutions of the arm. The gear wheel 29c is fixed to cam 11, so that, when the gate moves upwardly from its lower zone, the segment 26 engages roller 24 to disengage the coupling and to maintain it disengaged until the gate is moved into one of the extreme zones, whereupon segment 27 moves the flange 14 into the engaged position for operation of the limit ,switch in these zones. The relative lengths of the two extreme zones of travel may be adjusted by means of the setting of the switch LS.