WHEEL MOTION INDICATOR

摘要

A device for sensing wheel rotation includes a cylindrical casing with a frusto-conical bottom end, which defines a ramp for a steel ball in the casing; a shaft connected to the casing top for rotation by a vehicle wheel to cause the ball to ride up the ramp; a pair of annular contacts at the bottom of the ramp which are electrically interconnected by the ball when the wheel and consequently the shaft and casing stop rotating, whereby an electrical circuit including the contacts is closed to provide a signal indicating that rotation of the wheel has ceased.