Patent GB-230410-A (GB)
Title: Improvements in and relating to valve and other driving mechanisms
IPC: F16K31/04
Filed: 1924-09-30
Abstract: 230,410. Dean, P. P. March 7, 1924, [Convention date]. Gearing for stopping and starting machinery.- In driving-mechanism for valves and other devices of the type in which a rotatable member is stopped to establish a connection between a reversible driving-member and a driven member, the stopping-member is actuated by an electromagnetically operated toggle. A driving-sleeve 2 driven from the motor 4 by a worm 6 and wormwheel 5 carries a sun wheel 3<a> engaged by planet pinions 3<b>, which are carried by the driven shaft 1 and engage a loose annulus 3<c>. To start the drive, the annulus is stopped by a latch 16 turning on a pivot 17 and controlled by a toggle 23, 24 of which the arm 24 is influenced to annulus-releasing position by a tension spring 27, motion being limited by a stop-arm 29. The plunger 32 of a solenoid 31 is connected to the toggle point 25 by a link 32<a>, its inward movement being limited by a magnetic plug 35 secured adjustably in the framing to prevent the toggle 23, 24 from crossing the straight-line position. The action of the spring 27 is assisted by bevelling the engaging surfaces of the catch 16 and annulus 3<c> so as to produce a lifting thrust on the catch. An extension 10 of the driven shaft drives a shaft 45 through epicyclic reduction gearing comprising double planet pinions 41, 42 driven by the shaft 10 and gearing respectively with a pinion 40 on the framing 39 and a pinion 44 on the shaft 45. A limit switch, Fig. 4, is provided to stop the drive when the valve &c. reaches the end of its travel. The shaft 45 carries adjustable cams 49, 50 adapted respectively to engage with rollers 67, Fig. 4, on contact arms 51, 52 turning on fixed pivots 53, 54. The arms carry respectively contact fingers 55, 56 and 57, 58 adapted to engage stationary contacts 59, 60 and 62, 63. Springs 70 bear on lugs 71 on the arms 51, 52 and upon adjustable arms 73 carrying latches 68, which maintain the contacts normally in closed position against the action of the springs 70. At the end of the travel of the valve &c. in either direction, one of the cams 49, 50 engages one of the lugs 74 on the catch arms 73, so that the corresponding contact arm 51, 52 is released and the switch is opened. When the valve &c. returns, the cams return and the corresponding cam strikes its its appropriate roller 67 and closes the switch. The driving-motor 4 is controlled by a drum controller, which is biassed to its central no-circuit position and at its two end positions provides respectively for forward and reverse drive, each of which end positions is maintained by a magnetic latch in circuit with the motor. The controller is so arranged in circuit with the stationary contacts 59 and 62 of the limit switch and with the solenoid 31, that upon disengagement of the fingers 55 or 57 from the contacts 59 or 62 at the limit of travel of the valve, the circuits through the motor, the solenoid 31, and the magnetic latch are broken, the controller drum returns to central position, and the latch 16 is lifted to stop the drive. To indicate the position of the valve, lamps are arranged in circuit with the contacts 60 and 63, the flow of current through which is stopped as the fingers 55 and 57 are lifted. The controller may be operated to stop the drive when desired.