Patent GB-436558-A (GB)
Title: Improvements in or relating to electrical systems of lift control
IPC: B66B1/16
Filed: 1934-09-17
Abstract: 436,558. Lifts. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and CHUBB, A. A., c/o General Electric Co., Stoke, Coventry. Sept. 17, 1934, No. 26617. [Class 78 (ii)] [See also Group XXXVIII] Electric plant.-In an electrical system of lift control, a call for the lift, made by depressing one of a number of call buttons or the like, is stored by causing such depression to position a step-by-step switch at a point corresponding to the call button depressed, the storage switch being so interconnected with a floor-selector switch which moves in synchronism with the lift, that movement of the lift in the appropriate direction is initiated when the two switches are out of correspondence. As shown, a bank of call buttons PA-PG in the lift car, a car floor-switch FS, and gate call buttons having normally closed contacts, are connected with a contact bank C2 of a step-by-step call-storage switch C such as that described in Specification 426,386, so that, when a button is depressed, the corresponding contact on C2 is de-energized, and switch C steps by self-interruption at contacts c until it reaches this contact. Contact banks C1, F1, of the call-storage switch and floor-selector, are so interconnected that lack of correspondence between switches C and F causes energization of a polarized relay B from a potentiometer PT in a direction to operate one or other of relays UR, DR which control the " up " and " down " drive contactors U, D, and select the appropriate driving magnet FA, FB of the floor selector. Relay E controlling the brake magnet BR is also operated when B is energized. The floor selector is maintained in synchronism with the lift by an inductor relay R, which operates to close contacts r1 controlling the selected driving magnet FA, FB as the lift passes suitable points between each floor. When UR or DR operate to cut off the motor, the motor contactor U or D is maintained operated over contacts br2 or br3 operated by the brake magnet BR ; as the lift reaches the required floor, an inductor relay Q operates its contacts q1 to break the circuit of the brake magnet BR which stops the lift. Fig. 2 shows additional gear to provide for high speed when passing one or more floors ; further banks F4, F5 on the floor-selector are interconnected with a further bank C3 on the call-storage switch, and are brought into operation by closure of contacts v1 and v2 when the lift exceeds a certain speed. As the lift approaches one floor before that for which the call is made, relay SE operates, transferring the control of the lift to contact banks F1, C1 as before, and inserting resistance in the motor circuit by means of a contactor W. A modification is referred to in which a plurality of call-storage switches C are provided, so that more than one call can be stored at once, the calls being answered by the lift in the order in which they are made. A further modification in which the call buttons are connected with the bank C2 through the intermediary of relays whose contacts are interconnected with the bank in the manner described in Specification 219,079, [Class 40 (iv)], is also described.