Patent GB-464591-A (GB)
Title: Improvements in or relating to elevator control systems
IPC: B66B1/18
Filed: 1936-01-02
Abstract: 464,591. Electric control systems for lifts. WESTINGHOUSE ELECTRIC & MANUFACTURING CO. Jan. 2, 1936, No. 209. Convention date, Jan. 2, 1935. [Class 40 (i)] In a control system for elevator cars operating past a plurality of floors means are provided for limiting the number of calls effective for stopping any car to those registered before said car leaves a terminal floor in the direction for which the calls are registered. The cars are controlled by " up " and " down " call buttons 2U, 2D, 4U, 4D, Fig. 4, which control master relays. 2UM, 2 DM ... 4UM 4DM. Each car is under the control of a group of floor relays 2UR 2DR ... 4UR 4DR which are provided with setting and resetting windings. Upon operation of a call button, the corresponding master relay operates and lock up, and assuming there is no car. present at the lower terminal floor and that car A is approaching it and is the next to leave, " up " zoning relay UT is energized over contacts 10, 11 of the floor selector as soon as the car arrives. The operation of the zoning relay UT opens contacts UT4 in the circuits of the zoning relays of other cars to prevent calls being assigned to those cars while car A is at the terminal. The zoning relay also closes contacts in the circuits of the floor relays for car A and a relay corresponding to the operated call button and master relay is operated and locked up. Operation of the floor relay de-engages the master relay and prevents re-operation thereof until the associated call is answered. The floor relay also operates a hall lantern in the group 2UL, 2DL ... 4UL, 4DL associated with car A. The cars are operated according to a time schedule and when the operator receives the dispatching signal to start, the master switch. MS is operated to the " up " position to pull up relays U, CR. The relay U releases the brake S on the motor shaft, and starts the motor M under the control of generator G. When the car leaves the terminal floor zoning relay UT is released to allow all subsequent calls to be assigned to car B when it arrives at the terminal. As the car A approaches the calling floor, the stopping relay T is operated over the contacts of the selected floor relay and the floor-selector. Relay T energizes slow-down induction switch winding E which is operated when car A passes slow-down inductor plates in the shaft to effect release of the high-speed switch V and thereby insert resistance in the field of the generator to cause slowing down of the motor. Release of switch V energizes winding of switch F which pulls up when the car passes the " stop " inductor plate in the shaft. Operation of switch F releases relays U, CR to stop the motor and bring the car to rest at the calling floor. In this position the floor selector prepares the circuit of the resetting winding of the floor selecting relay and as soon as the operator moves the master switch to restart the car, relay CR is again operated and resetting winding is energized to restore the floor relay and thereby extinguish' the hall lantern and re-establish the circuit of the master relay to permit further operation upon subsequent operation of the associated call button.