GB563684A - Improvements in or relating to electric elevator systems - Google Patents

Abstract

563,684. Lift control systems. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. Jan. 14, 1943, No. 746. Convention date, Jan. 14, 1942. [Class 40 (i)] In a lift system comprising two or more cars serving a number of floors including a dispatching floor, e.g. the lowest floor, the earliest car to arrive at the dispatching floor is selected as the next to leave, and a call from another floor gives a start signal to that car, which then answers that call and any subsequent calls that are made ahead of it during the trip. In a system for two cars, each of which is provided with a floor selector, Fig. 2, the next car to start is determined by relays P, BP, each of which becomes operative when the corresponding car reaches the dispatching floor provided the other car is not already standing there. These relays when operative light next to leave lamps NL, BNL and prepare circuits for start lamps SL, BSL. A start signal is given under the control of call-above relays C, BC, each of which is normally maintained by circuits over the floor selector of the other car, these circuits being controlled by auxiliary direction relays Q, BQ which are operative when the corresponding car is descending and also when both cars are standing at the lowest floor. Assuming for example that both cars are at the lowest floor and that car A is the next to start, so that relay P is up, the operation of a call relay releases both C and BC, but only the former is effective to give a start signal. As soon as the attendant starts car A on its trip, relay BP energizes in place of P and lights next to leave lamp BNL, and relays C, BC re-operate, the latter being held over brush 31 of the floor selector of car A and contact Q2 during the upward movement and over brush 41 and contact Q1 during the downward movement, so that a start signal can be given to car B only by a call behind car A.