PATENT OF THE WEEK – ELEVATOR SYSTEM

The ELEVATOR SYSTEM was invented by Matthew Martin (Randolph, NJ), Richard H. Ludwig, NJ) on 10^th of March 1987, bearing patent number US4648488A.

The invention relates in general to elevator systems, and more specifically to methods and apparatus for handling stuck call pushbuttons in an elevator system.

The present invention detects the presence of a call button being stuck by determining if the button activated immediately after being reset. When a stuck pushbutton is detected, its associated call is immediately masked and prevented from being considered. So as not to completely exclude the elevator service to the floor, reduced or partial service is provided on a predetermined schedule. To prevent needlessly sending a car to the floor of a stuck pushbutton, however, the predetermined schedule is operative only when there is elevator activity in the building. Hence, ht system would not start an idle elevator car and send it to the floor of the masked call. This is to be done is order to prevent degraded elevator service to remaining floors and unnecessarily subjecting the elevator door to excessive use.