GB1363922A - Motorised valve - Google Patents

Abstract

1363922 Valves ISIS TECHNICAL FINISHES Ltd 9 Oct 1972 [8 Oct 1971 14 Jan 1972 2 May 1972] 46855/71 1800/72 and 20326/72 Heading F2V [Also in Division H2] A rotary ball valve 2 is connected by sleeve coupling 10 and worm-and-wheel gearing 9 to the motor 7 whose windings are short-circuited, when the valve is in its open and closed positions, by a switch 16 operated by cams 17, the short-circuiting serving to produce a braking action. In Fig. 4, the motor is started by energizing solenoid 19 to move switch 18 to establish a power circuit including the motor windings, and when switch 16 has been moved to its other position the switch 18 is returned to the position shown to maintain a supply to the motor until the switch 16 is returned to the position shown in which the motor windings are short-circuited. A further switch 22 may be included to illuminate lamp 21 to indicate when the valve is open. The lamp may alternatively be located in the positive power line between socket 20 and switch 16. The solenoid 19 may be controlled through an R.C. circuit arranged to return switch 18 after a preset period sufficient to allow operation of switch 16 by the first cam to arrive after energization of the motor. Switch 28, 29 allows local manual control. Solenoid 24 is used either to produce a feedback signal indicating successful operation of the valve or to provide automatic reset of the starter switch, as in Fig. 5. By removing one pair of cams, the valve may be arranged to stop only in closed positions, and switch 18 may be held closed to provide a pulsed flow. In such latter case, the valve may deliver a dosing fluid to a liquid to control pH or redox value, and an electrode measuring the latter value may control switch 18 to maintain the value at a desired level. The motor may also serve to reciprocate the electrode through a cleaning bath or to reciprocate a cleaning collar along the electrode. Instead of mounting the motor, valve and selected switches in a two-part casing 15, the parts may be encapsulated, e.g. in foamed polyurethane. The valve may alternatively be multi-way, and the motor may be reversible.