Patent GB-465480-A (GB)
Title: Improvements in or relating to systems of control for electrically operated lifts
IPC: B66B1/16
Filed: 1935-11-07
Abstract: 465,480. Electric control systems for lifts. GENERAL ELECTRIC CO., Ltd., and SMART, N. C. Nov. 7, 1935, No. 30785. [Class 40 (i)] In an electrically operated lift system of the type wherein the lift is operated in response to " up " and " down " calls from any of the landings similar groups of apparatus are provided each comprising means for call storage of a particular type, means for following the motion of the lift and means for signalling to a group of co-ordinating apparatus which controls the operation of the lift in accordance with the calls in a predetermined order of priority. The groups of apparatus are mounted on plates provided with terminals which cooperate with jacks on a rick on which the plates are mounted. This facilitates interchangeability and easy rearrangement of connections. Figs. 2, 3, 4 show the separate groups of apparatus, Fig. 2, showing the detailed arrangements. The circuit arrangements below the terminals shown in Figs. 3 and 4 are the same as that shown in Fig. 2. Fig. 1 shows the co-ordinating equipment and Fig. 5 the driving control circuits of the lift associated with calls originating in the car while that shown in Figs. 3 and 4 are associated respectively with " down " and " up " calls from the landings. Each group of apparatus comprises a direction determining relay DR and group of storage relays A ... D and a step-by-step switch W having wipers W1 .. W4, for respectively initiating operation of the lift, cancelling stored calls, synchronizing the switch with the lift and determining the stopping point of the lift. The wiper W4 is bifid, each arm co-operating respectively with groups of " up " and " down " contacts. The co-ordinating apparatus includes three pairs of relays AC, BC; AD, BD; and AU, BU corresponding to the groups Figs. 2, 3 and 4 respectively and the arrangement of the relays is such that calls from landings for travel in a direction opposite to the direction of movement in response to previous calls are rendered inoperative until the previous calls are answered. Operation of lift in response to operation of car button. Normally when the lift is standing at a floor and no calls are present in the system the pairs of relays AC, BC; AD, BD ; AU, BU ; are energized from the wiper W4 over chain circuits including the contacts of the call storage relays ; for example relays AC, BC are operated over contacts a<2> .. d<3>, Fig. 2, when a car call is made, the corresponding relay in the group A .. D pulls up and the chain circuit of one or other of the relays AC, BC is opened depending on the position of the lift and the relay released. The selected storage relay also operates contacts connected to wiper W4 to determine the stopping-point of the lift. The de-energized relay AC or BC prepares relay DR, if the direction is opposite to the last direction of travel, and operates relay E which allows R to pull up and complete the circuit of the appropriate motor contactor UD, DD and the corresponding driving magnet of the stepping switch. The lift is then driven and no further control is effected until the lift is one- and-a-half floors away from its distination. At this position the wiper W4 is in circuit with the contact operated by the call storage relay, the switch being stepped midway between floors by a relay Z operated by an inductor relay ZR. A circuit is then completed over wiper W4 for relay PS and the lift commences to slow down by retarding means not shown. When the lift is half-a-floor away from the destination relay Z is again operated and stopping relay SP is operated, and the lift decelerates until it reaches a point just prior to the selected floor when relay S is operated to shortcircuit relay R and effect the release of the operated motor contactor UD or DD. Control of lift in response to landing calls. Other stopping conditions are available besides those provided in connection with car calls. For example any landing call which is ahead of the lift and for the same direction of travel is capable of stopping the lift although a call ahead of it for the opposite direction is not effective. These facilities are provided by means of the wipers W4, Figs. 3 and 4, and different arrangements of interconnections for the terminal groups 26 .. 32. Further, if calls from a number of floors in advance of a lift moving-in a direction opposite to that required by the calls, the lift moves to the furthermost floor before reversal. When a landing call originates from pushes UC, UB, UA or DB, DC, DD, a relay in the corresponding pair AU, BU or AD, BD and depending on the lift position is released to initiate the operation and the subsequent control of the lift in a manner similar to that previously described. The released relay also prevents release of the other pair of relays in response to calls for the other direction. If after the lift has responsed to the landing call, the passenger operates a car button, the lift is driven to the corresponding floor but calls for the same direction from intermediate floors are answered during its journey. Similarly, in the event of calls for opposite directions, the lift responds first to the calls corresponding to the existing or previous direction of travel of the lift. Synchronizing the switches W with the lift. When the lift stands at any floor other than a terminal, both windings of relay T, Fig. 2, are connected to negative over wiper W3 but operation is prevented by short-circuits provided by the limit switches LU, LD. If, however, the lift operates a limit switch while wiper W3 engages a contact corresponding to an intermediate floor, relay T is operated to close a self-driving circuit for synchronizing the switch. Lift gate control arrangements. The control circuits for the lift are controlled by a relay G the circuit of which includes contacts on the landing and lift gates. Thus when any gate is opened relay G releases and the control circuits are rendered inoperative. A short delay however, is given to the user to open the lift gate when the lift arrives, by a relay DY which holds operated for a predetermined time under the discharge of a condenser CL. Specification 453,723 is referred to.