GB426362A - Improvements relating to electricity maximum demand indicators - Google Patents

Abstract

426,362. Supply meters. CHAMBERLAIN & HOOKHAM, Ltd., and JAMES, S., 4, New Bartholomew Street, Birmingham. Nov. 27, 1933, No. 33116. [Class 37] In order to give an alarm or reduce the load when a maximum demand indicator is approaching a predetermined position, an epicyclic mechanism is adapted to be driven by a meter and a constant-speed motor, the joint effect being to operate a circuit controlling mechanism for actuating a signal or opening the circuit of power-consuming apparatus. A pair of sun pinions a, b are connected by a planet pinion c carried by an arm on an arbor h, on which the sun pinions are freely mounted. The sun pinion a is driven by the meter through gearing d, e, the other sun pinion b being driven through gearing f, g by an electric or other constant speed motor. The speed of the sun pinion b is arranged to correspond with the speed of the sun pinion a when the load is slightly less than the predetermined maximum. In alignment with the arbor h, and connected to it by gearing j, k, is a second arbor i carrying an insulating drum l on which is mounted a metal ring m having an extension n at one side. Spring contacts o, p bear on the ring m and the cylinder l so as to close a circuit when the extension n engages the contact p. At predetermined time intervals the pinions k; j are separated momentarily, allowing a spring q to return the drum l to its initial position determined by the engagement of a projection r on the drum with a resilient or spring-controlled stop s. Instead of separating the wheels k any other parts of the train actuating the drum may be separated, for example, the wheels j or any of the wheels a, b, c. In place of the extension n a stepped segment may be provided so that a number of contacts may be closed successively so that machines may be successively cut out while the demand is rising in the neighbourhood of the maximum. Alternatively, a cam may lift a spring contact into engagement with another contact or contacts.