SPEED MONITORING OF IN-PLANT, OPERATOR CONTROLLED VEHICLES

The speed of in-plant vehicles such as forklift trucks and the like is monitored to provide for the lighting of a warning light where a first speed threshold is reached, the sounding of a horn when a second speed is reached, and for the disabling of the vehicle on the sustaining of the higher speed for a predetermined interval of time. This speed monitoring approach generates a signal having an intermittent monitor output corresponding with the speed of the vehicle and which exhibits a period of lessening duration in corresponding with increasing speeds. Timing of the occurrence of these signals is employed with an accumulator based logic to establish vehicle speed. To avoid apparatus reaction to noise based signals, a select number of occurrences of apparent speed excursions are required before the horn or lamp are activated. Remote supervisory resetting of the monitoring system following the occurrence of a latched warning output is provided through an IR based code transmitting and receiving arrangement.