Abstract: A spring loaded fluid operated valve for use in sensing the speed or rotation of a rotating member, shaft or collar is disclosed. The valve features fluid inlet, outlet and storage chambers, each of which have openings spaced from and selectively aligned relative to one another. A rotating body whose speed of rotation is to be sensed, slidably engages the chamber openings in a fluid tight manner and defines a slot or recess therein which communicates with each of the openings in a repetitive and sequential manner to alternately transfer a portion of the fluid introduced into the inlet chamber to the storage chamber and, thereafter, from the storage chamber to the outlet chamber. In the particular embodiment of the valve disclosed herein, the openings are disposed on a concave base of a housing containing the chambers so as to conform to the circular periphery of the rotating shaft or collar defining the slot. The slot rotates across each of the openings during each revolution of the shaft or collar.

Abstract: A device for monitoring a difference between the speeds of rotation of two rotating members featuring a differential gear assembly having two driven gears and at least one follower gear intermeshed and disposed within a rotatable housing is disclosed. The follower gear is rotatably connected to the housing to permit the housing to rotate at a speed proportional to a difference in speed between the two driven gears, the driven gears being connectable, respectively, to two different rotating members whose speeds are to be compared. A rotary fluid valve is disclosed which responds to the rotation of the rotatable housing to generate fluid output signals indicative of a difference in speed between the two rotating members. A system for automatically controlling the application of brakes to a wheeled vehicle traveling in either a forward or reverse direction which employs the monitoring device and the fluid valve to generate a fluid signal to correct a wheel skid or spin condition is also disclosed.