A CONTROL system is described that has been successfully preventing premature rotation stoppage of airplane wheels when too much braking is used. The system has now been applied to a truck in a series of tests conducted on an icy roadway.
It is shown that wheels exert their greatest braking effect when the brakes are applied almost to the point where the wheels lock.
Thus, when used on airplanes, the device (1) detects when a brake is about to lock the wheel, (2) releases the brake pressure to allow the wheel to pick up speed, and (3) again permits brake application. This cycle is then repeated until a stop is attained.
Similarly, when used on ground vehicles, the device functions by sensing the impending wheel lock, and then relays a signal to actuate the brake valve. The tests showed that individual wheel control devices can prevent out-of-control skidding in trucks and buses, and jackknifing of tractor-trailers.
