| 摘要 |
1,196,981. Lift control systems. WESTING- HOUSE ELECTRIC CORP. 6 Dec., 1967 [30 Dec., 1966], No. 55394/67. Heading B8L. Call memories BK11 are scanned sequentially by a pulse-operated scanner BK13 (typically at 1000 pulses per second) and when coincidence is detected between a call signal and a car position signal from BK9 the car is caused to stop. Scanning may be always in the same direction or alternatively in a direction corresponding to that of the travel of the car. For high-speed lifts the car or call signals are delayed for the time required for the scanner to interrogate one or more floors; this initiates stopping one or more floors ahead of the destination floor. To economize on signal circuit wiring these circuits operate on square pulses generated from an A.C. supply, distinction being made between pulses generated by positive half-cycles and those by negative half-cycles, and for reliability these pulses are interrogated during a " reference notch," i.e. a short period adjacent the peaks of the A.C. supply (Fig. 4, not shown). The complete control system is fully described, and uses logic elements such as NOT, OR, NOR gates and bi-stable memory devices. It provides for door opening when the car reaches a levelling zone, the door being held open for a predetermined " non-interference " time. An 80% loaded car will ignore landing calls and there is provision for " hospital emergency " despatch to a desired floor and for manual operation. If the scanner fails to locate a call within a prescribed time, or if the selector gets out of step with the car, the car automatically travels to a terminal floor, stopping at every landing. In multi-car systems a landing call is normally assigned to a car which has a car call for that landing, unless the car is fully loaded or is a substantial distance away. In addition, a reversible counter determines whether calls for landings between two cars travelling in the same direction are in excess of those ahead of the leading car; if they are, the leading car will stop for a call previously assigned to the second car under the arrangement above. Conversely, if there are more calls ahead than between, the lead car is made to by-pass a landing call which it otherwise would answer; this is to avoid " bunching " of cars. Any floor may receive preferential treatment by " weighting " it, i.e. associating more than one pulse with it. |
