Patent GB-1283638-A (GB)
Title: Improvements in or relating to arrangements for controlling the operation of a lift
IPC: B66B1/40
Filed: 1970-11-16
Abstract: 1283638 Lift control systems INVENTIO AG 16 Nov 1970 [18 Nov 1969] 54434/70 Heading B8L For journeys of less than three floors, a lift car 3 is operated towards, or at a lower speed (V1), Fig. 11 (not shown), and receives control signals from cabin switches MV1u, or MV1d, in dependence upon the direction of movement, engaging lugs (F1u2-F1u9, F1d1-F1d8), Fig. 4 (not shown), fixed in the shaft 2. For three or more floors, the lift operates towards or at a higher speed (V2), Fig. 11 (not shown), receiving signals from switches MV2u, or MV2d, engaging lugs (F2u4-F2u9-F2d1, F2d6), Fig. 4 (not shown), more distant from their respective floors than are the lugs (F1u, F1d). Calls for service are received in a store 12, from indicators Su1- Su8, Sd2-Sd9, and C1-C9, whose locations are interrogated in sequence by means of signals from control device 11, see also Fig. 10 (not shown), which also provides signals for the time dependent acceleration-distance dependent deceleration generator 6 controlling the lift motor 4, retroactively, via direction control 9; amplifier 8, and tachogenerator 7. A photoelectric, or inductive scanner A co-operating with a perforated or inductively susceptible tape 10 provides distance pulses to the generator 6 for deceleration control. The tape 10, lugs F, and switches MV may be replaced by perforated, slotted or graduated discs, containing coded information, and detectors, in the motor room. Operation, see also Figs. 2, 10 (not shown). (a) Less than three floors. Unit 12 emits a signal Lu or Ld, and a signal to terminal (6.10) operates relay ST opening contacts (STK), initiating charging of capacitor (CT1) the increasing voltage, fed to terminals (6.5, 6.6) causing the lift to accelerate. Opening of contacts (KV) in unit 11 when lift motion is established enables oscillator (OZ5.1) causing interrogation of the next location in store 12. The voltage on capacitor (CW1) is communicated, via a profiling network (6.3) comprising an amplifier with non-linear feedback to a potentiometer (PD2), so that capacitor CT1 can only charge to a voltage less than that on (CW1) by an amount (UPD2), Fig. 11 (not shown), before leakage via diode (DD) renders the charge on CT1 constant, corresponding to the speed (V1). If store 12 has been counted on to a location where service is required, a stop signal on lead (LH) is emitted, and when the next signal from MV1u or MV1d is received, signals from the other switches being suppressed by selector (11.1), signals on leads (LSW1 and LSW2) disconnect capacitor (CW1) from its supply, and enable its discharge in pulses, via transistor (TW1) under the control of scanner A. When the voltage across (CW1) reaches that on CT1, output (6.5, 6.6) is taken from (CW1), relay SD having changed over, giving distance dependent deceleration. (b) Three or more floors. Upon starting of the lift, counter (MV4.1-MV4.2) comprising two bi-stable multivibrators is advanced by the oscillator (OZ5.1). If the count of three is attained, a signal on lead (LV2) causes switching of contacts (V2WK), the lift speed (V2), and deceleration now being determined by the higher charged capacitor (CW2). Interrogation in store 12 is now controlled directly by switch MV2u or MV2d, one of which is now selected by selector (11.1) to control unit 6. The motor drive may be D.C. or A.C., and the distance determination may be made by velocity integration. Gating unit (11.3) ensures that signals from the cabin switches MV can reach unit 6 only when store 12 is emitting a stop signal.