Patent GB-456191-A (GB)
Title: Improvements in or relating to controlling systems for lifts
IPC: B66B1/18
Filed: 1935-09-18
Abstract: 456,191. Electric lifts. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and SMART, N. C., c/o General Electric Co., Ltd., Stoke, Coventry. Sept. 18, 1935, No. 25870. [Class 78 (ii)] In an electric lift system in which a number of lifts situated contiguously serve a number of floors, when a call for a lift is made a link circuit finds the calling floor, selects a suitable lift for answering the call and advises the caller which lift is to be used. The allocator switch is arranged to move to the position corresponding to the calling floor before beginning to allocate the call to a particular lift. The lifts are allocated in the following order of priority : (1) lifts moving towards the floor from which the call is made and moving in the direction in which the caller wishes to travel, or stationary lifts ; (2) lifts travelling away from the floor at which the call is made and located in a direction opposite to that in which the passenger intends to travel; (3) lifts in any condition in the direction in which the passenger wishes to proceed. Buttons PA, PB, PC for each direction of travel are provided on each floor, the " up " buttons only being shown. When button PC is depressed relay FC energizes and locks. Switch FS steps over wiper FS5 until it reaches contact 4, from which earth has been removed by fc2. Relay C energized and remained energized whilst FS was stepping to hold relay ST which is normally energized over FS6, but when stepping stops relay C releases and relay ST falls away. Relays DA and DB energize and switch LS steps by self-interruption. When wiper LS5 reaches the contact marked by FS6, relay SF energizes and switch LS now commences to hunt for a lift. The wiring of bank LS1 associated with lift M1 only is shown and it is assumed that this lift is to be selected. The wiper of switch M1 moves up and down with the lift and marks the position of the lift in the bank LS1, the two halves of which bank are jointed to the contacts of bank M1 in direct and reverse order respectively. The lift is provided with call storage relays UA,UB and UC and also with contact 3 which indicates direction of travel, contact 4 which is closed when the lift is moving, contact 5 which is closed when the lift is stationary and contact 6 which is closed when the lift is parking. If lift M1 is moving upwards, contact 3 is to the right and contact 4 is closed. The lift is assumed to be at the lowest floor so that when wiper LS1 reaches its seventh position relay W is operated and locks. Switch LS is stopped relay S pulls up and relay UC is energized to register a call from floor 3. Lamp GC is lit to indicate to the caller that lift M1 is answering the call. Relays DA and DB fall away, relays C and ST operate and relays SF, S, FC and C release, relay C holding until switch FS homes so that relay ST remains energized. The apparatus can then receive another call. If no lift is in the most suitable position to receive the call, the switch LS searches for a lift in a less suitable position. In positions 5, 6 and 7, wiper LS tested for lifts at floors below the call which were stationary or travelling upwards. For the second half of the movement of switch LS relay R is energized over wiper LS5 so that switches 3, 4, 5 and 6 are shorted. If no lift is found in positions 5, 6 and 7 of LS1, the switch continues to move and in positions 8, 9 and 10 wiper LS 1 hunts for a lift which is below the third floor and is travelling downwards. If no lift exists below the call, the switch LS continues to step and selects a lift above the third floor irrespective of its position or condition. The system described can deal with one call at a time only, but further links could be provided so that multiple calls can be dealt with. The caller, instead of pressing an " up " or " down " button could press a button indicating the floor to which he requires to go, the switches being designed to register a call for the floor at which the call is made and a call for the destination. Specification 432,593 is referred to.