GB1208621A - Elevator-system controls - Google Patents

Abstract

1,208,621. Lift control systems. RELIANCE ELECTRIC & ENG. CO. 15 Jan., 1968 [20 Jan., 1967], No. 2065/68. Heading B8L. In a multicar lift system in which directional hall calls are allotted to individual cars, an artificial call is automatically made from one or more preferred landings (termed "queue calls") so that if a vacant car is available it will park at a preferred floor. This car is then said to be a "queue car", and only one car may be a queue car at any floor. The system generally is as described in Specification 1,163,727, in which hall calls are assigned to the car best able to provide service by a system in which the work load on the car is represented by a voltage analogue which is compared with a ramp voltage. The artificial "queue call" will thus be assigned to the car best available and on arrival at the preferred floor will become a queue car if it has no other assignment; it then parks with doors open and hall lantern on. Its analogue voltage is biased so that hall calls made at other floors are assigned to the queue car only if all the other cars have an exceptionally heavy work load. A queue car may also be sent to answer any hall call which has remained unanswered for an excessive time. Otherwise a queue car loses its queue status only in response to a car call made by a passenger entering at that floor, or if its M-G set is shut down; this occurs automatically if a car is not used for many minutes, but the queue car is shut down last. More than one floor can be made a "queue floor", and one of them can be given preferance over the others. Any floor may be made a queue floor temporarily if a car serving an actual call at that floor becomes overloaded, as detected by a weighing device, a passenger count, or doors kept open an exceptional time. Thus a second car is assigned to assist the first, which is treated as "out of service" by the allotting equipment. The doors are arranged to stay open longer at floors where both hall and car calls have been made, and except at a queue floor they will reopen for a late passenger. This feature is inhibited at queue floors as otherwise the artificial calls would prevent the doors from closing.