Patent GB-830218-A (GB)
Title: Lift control device
IPC: B66B1/16
Filed: 1956-10-18
Abstract: 830,218. Automatic lifts. INVENTIO A.G. Oct. 18,1956 [Oct. 27, 1955], No. 31677/56. Class 78(3). The sequence in which landing calls are answered in lifts providing with landing call apparatus actuated by press buttons, is controlled by a pair of ganged rotary selectors interposed respectively in circuits of the landing call buttons and a motor driving the selectors, so that on depression of a landing call button connected with a contact on the associated selector which is about to be swept by its contact arm, such landing call received priority over other landing calls which are rendered ineffective until such call has been answered, while the rotary selectors are held stationary until such call has been answered. As shown in Fig. 1 operation of one landing call button 131-4, say 133, energizes the associated relay 143 over a circuit containing a floor-switch 20 which is open when the lift is occupied, slow to close contacts 18 which are closed when the car brake is applied, and shaft door contacts 19. Relay 143 locks over contacts 1431, closes the associated contacts 153, and, through means not shown, causes the car to move to the third floor. Simultaneously relay 16 is energized over contacts 21, which are closed when the car brake is released and floor switch 22 which is closed when the car is empty. Relay 16 opens contacts 161-4 thereby de-energizing relay 17 which allows normally closed contacts 171 to energize motor 9 so moving wipers 11, 12 to contacts. 114, 124. A circuit is thereby closed through contacts 124 and 153 to relay 17 which then opens contacts 171 and stops motor 9. When the brake is applied to stop the car at the third floor contacts 21 open so de-energizing relay 16. Relay 143 is de-energized by means not shown when the car stops thereby opening contacts 153. The circuit is now in such a condition that the supply point of the call button circuit is at contact 134, i.e. a call from the fourth floor now has preference and a call from the third floor can only be effective if there are no calls from the other floors. The circuit may include contacts 23 which are closed at predetermined intervals or after a desired number of calls to limit the operation of relay 16. In a modification (Fig. 2, not shown) contacts 131-4: are operated by relays which store the calls made on the call buttons. Fig. 3 shows an arrangement for ensuring that all the floors are served when there is a peak demand for down traffic which operates as follows. Assuming car to be parked at the first floor and all the down call contacts 251-254 to be operated, relay 17 is energized over contacts 124, 161 thereby opening contacts 171 and closing a circuit to relay 144 over contacts 254, 114, 172 and full load switch 26. The car then moves to the fourth floor and a wiper 280, which moves in accordance with the movement of the car, steps to contact 284. The " down " direction relay contacts 29 and contacts 30, which close when the car brake is applied, now close and a circuit is established for relay 16 through another full load switch 27. Relay 16 then opens contacts 161-4 de-energizing relay 17 and thereby opening contacts 172, which causes the release of relay 144, and closing contacts 171 which cause motor 9 to move wipers 11, 12 on to contacts 113, 123 where relay 17 is again energized and motor 9 is stopped. Relay 143 is then energized over contacts 172 and the car moves to the third floor where contacts 30 again close and energize relay 16 which in turn de-energizes relay 17 which over contacts 171 drives the arms 11, 12 to contacts 112, 122 so causing the car to move to the second floor directly, if  maximum load switches 26, 27 remain closed, or, if these switches have been opened due to the maximum load being attained in car, when the car next answers a landing call. In a modification (not shown) applicable to the arrangements shown in any of Figs. 1-3 extra contacts are provided in parallel with one or more contacts 111-114 and 121-124 to increase the service to one or more floors.