Abstract: An apparatus for braking a rotating member which has a fluid pressure actuated brake cylinder for exerting force braking rotation of the member, a reservoir for supplying fluid to the actuated cylinder, a conduit for establishing operative communication between the actuated cylinder and the reservoir, and a sensor for detecting the rate of retardation of rotation of the member and for signalling the occurrence of a rate of retardation in excess of a predetermined rate, and an improvement in such apparatus in which a controllable anti-lock modulator is interposed in the conduit between the reservoir and the actuated cylinder for normally accommodating free flow of fluid between the reservoir and the actuated cylinder through the conduit and the modulator. The modulator is operatively connected to the sensor and responsive thereto for pumping fluid through the conduit in response to a signalled excessive rate of retardation and thereby for releasing braking force otherwise retarding rotation of the member.

Abstract: An improved anti-locking control of the type having a conduit through which hydraulic pressure is applied, a valve interposed in the conduit for controllably interrupting and releasing the application of pressure and an oscillating mass-spring actuator for the valve. In accordance with one aspect of this invention, reduction in braking force is carried out in a series of steps. In accordance with another aspect of the present invention, oscillation of the actuator mass is substantially limited to no more than a maximum amplitude. In each instance, greater efficiency is achieved in the use of energy required for operation of the anti-locking control.