Patent GB-601470-A (GB)
Title: Improvements in or relating to electric elevator control systems
IPC: B66B1/18
Filed: 1945-08-10
Abstract: 601,470. Push-button lifts. WESTING- HOUSE ELECTRIC INTERNATIONAL CO. Aug. 10, 1945, No. 20539. Convention date, Aug. 10, 1944. [Class 40 (i)] In a lift system, when a floor call is unanswered for a predetermined time, a lift moving in the opposite direction to that desired by the originator of the floor call is stopped at the floor and reverses its movement. The invention is described with reference to a system having two lifts, A, B, Fig. 1, serving seven floors and in which the second, third and fourth floors are given this priority. General operation.-A call from a non- priority floor stops a lift travelling in the desired direction at the floor or causes a lift at top or bottom to move and stop at the floor when the attendant starts it. A call from a priority floor if unanswered for the predetermined time stops the first lift to approach the floor and despatches it in the desired direction, but this action is inoperative for lifts which are moving in the opposite direction to a floor selected by a passenger (or by the attendant) by depression of a selecting button within the lift. If the sum of the delays at two or more priority floors exceeds the predetermined time, the first lift to approach the floors will stop and be despatched in the desired direction, stopping at priority floors, unless it is exempt by depression of a button within the lift. Operation when no calls are registered.- When both lifts are at the lowest floor with doors closed, door relay DR, Fig. 3, is energized, and the shaft switch 30B is open de-energizing relay X which completes a circuit for relay W. Since no calls are registered, relays K and KN Fig. 6, are energized. Operation of hand controller CS, Fig. 3; energizes relays U and M to remove the brake 15, to start the generator GA driving the motor 14 and to energize relay V to short-circuit resistance R1 to run the motor at top speed. Response of lift A to a call from a non-priority floor, e.g. 6th floor.-When button 6D, Fig. 4, is depressed, relay 6DR operates and locks to energize segments f6, g6, Bf6, Bg6 of boards, Fig. 2, each traversed by brushes moving in accordance with the lifts. Relay 6DR opens contacts 6DR2, Fig. 6, to de-energize segments d1 ... d5 and Bd1 ... Bd5 so that only segments d6 and Bd6 are energized. Relay 6DR also de-energizes relays K, KN, Fig. 6, preparing the circuit of relay J so that as the lift approaches the 6th floor from below, brush 34, Figs. 2 and 6, contacts segments d6 to energize relay K to complete a circuit for relay J which prepares the slow-down inductor E, Fig. 3, so that it is operated as the lift passes the 6th floor shaft plate UEP, Fig. 1, to deenergize relay V, inserting resistance R1 in the generator circuit and slowing the lift. Relay J also operates relay G, Fig. 3, to prepare inductor F for operation by the 6th floor shaft plate UFP, Fig. 1, to de-energize relay U and stop the lift. Relay J further de-energizes relay W, Fig. 3, and energizes relay X so that when the hand-controller CS is operated, relays D and M are operated to reverse the supply to the generator GA so that the lift goes down. At the lowest floor, switch 30B in the shaft is opened to de-energize relay X and energizes relay W for upward travel. If the lift approached the 6th floor from above, brushes 41, 42, Fig. 4, would contact segments f6, g6 to stop the lift at the floor by energizing relays S, SA as described below. Response to lift A to unanswered call from a priority floor, e.g. 4th floor.-When floor-button 4D, Fig. 4, is depressed, relay 4DR lock-up, and segments g4, Bg4, Figs. 2 and 4 are energized, while relays K, KN, Fig. 6, for lift A, and relays BK, BKN for lift B are de-energized. Relay 4DR further de-energizes slow-release relay 4TI, Fig. 5, which, after e.g. 15 secs. releases to short-circuit resistances 4RI, B4RI and de-energize slow-release relay 4TI-1 which similarly 15 secs. later, short-circuits resistances 4R2, B4R2 and de-energizes slow-release relay 4TI-2 which 15 secs. later short-circuits resistance 4R3, B4R3. As a result, when lift A starts upwards, e.g. to ansert a call from the 6th floor, the closure of shaft switch e4, Fig. 5, as the lift approaches the 4th floor completes the circuit of relay DM and the residual resistance 4R allows relay DM to operate to energize relay Y which connects resistance BR7 in parallel with relay BDM to prevent its operation when lift B ascends unless further calls are made from the second or third floors. Relay Y also prepares the circuit of relay SA, Fig. 4, for operation when brush 42 contacts segment g4, and relay SA prepares inductors E and F for operation by the shaft plates UEP, UFP, Fig. 1, at the 4th floor to slow and stop the lift. Relay SA further prepares the circuit of relay W, Fig. 3, for de-energization when the lift stops, so that on re-starting, relays X and D operate to send the lift down. The de-energization of relay M on stopping causes the operation of relay 4DRN, Fig. 4, which releases button 4D, de-energizes segments g4, Bg4, Fig. 4, and relay DM, Fig. 5. Over-riding the priority call by depression ot lift button.-If a passenger enters Lift B at the ground floor and wants the 6th floor, the attendant depresses button B6c, Fig. 5, to energize segments Ba6, and energize relay BH, which opens the circuits of relay BJ, Fig. 6, and BY, Fig. 5. As a result, although priority calls exist, relay BY is prevented from operating and the lift ascends until brush B43, Fig. 5, engages segment Ba6 to energize relay BT, which energizes relay BG to stop the lift as described above for lift A and relay G. Summation of priority calls.-Since the shaft switch e3, Fig. 5, is in circuit with both resistances 3R and 2R, relay DM will actuate if the total delay on both floors is 45 seconds. If, however, the total delay is less than 45 seconds the lift will pass the second and third floors and close shaft switch C4, thus adding the circuit 4R to relay DM, so that relay DM will operate and the lift stop at the 4th floor if the total delay in calls at the 2nd, 3rd and 4th floors is 45 seconds or more. The lift will then reverse and stop at 3rd and 2nd floors as it descends. Adjustment of priority level.-By closing switch 65, Fig. 5, lift B will be adjusted to respond to a total delay of 75 seconds, so that with delays of 45 seconds at the 2nd floor, and 15 seconds at the 3rd and 4th floors, lift B will will pass the 2nd and 3rd floors, but stop at the 4th floor, reverse and stop at 3rd and 2nd floors on the way down. By closing one or more of switches 60 ... 63, the delay necessary to produce priority is reduced. By opening switch 19, Fig. 5, or switch B19, relay Y can be prevented from operating to render either lift immune from priority calls. Specification 604,455 is referred to.