Abstract: A slip control system for a hydraulic brake system of a vehicle, which comprises a pressure generator having a plunger piston, which plunges into a cylinder filled with brake fluid and is connected to a rack. For the forward drive of the plunger piston, an electric drive motor is provided, which via a gear drive drives a pinion meshing with the rack. For the return drive of the plunger piston, a spiral spring is used that engages on one end with pinion shaft and on the other is supported on the pressure generator housing. The use of the spiral spring makes a short axial structural length of the pressure generator attainable. A grip roller free-wheel clutch is also provided in the drive train between the motor and the rack. The grip roller free-wheel clutch effects an uncoupling of the gear drive and the drive motor when the rack, at the end of the return stroke, strikes a stop of the pressure generator housing. This prevents damage to the gear drive and motor.

Abstract: A brake system including an apparatus for limiting drive slip at drivable vehicle wheels by feeding brake pressure into wheel brakes associated with these vehicle wheels. The brake pressure is generated in a pressure modulator having a spring-loaded stepped piston including a primary piston. The primary piston can be acted upon by pressure fuid from a supply container by a motor which drives a pump. A secondary piston of the stepped piston effects the brake pressure and feeds it via a valve assembly into a brake line extending between the master brake cylinder of the brake system and a wheel brake. The brake pressure can be diminished by controlling the drive motor of the pump. The pump is embodied with reversible pumping directions, and the pressure fluid flows through it both during a working stroke and a return stroke of the stepped piston. The valve assembly is actuatable by the stepped piston as a function of the position thereof.

Abstract: A brake system including a traction control apparatus having at least one pressure generator 35, which has a cylinder 60 for receiving and expelling brake fluid by means of a piston 60. The cylinder 60 is connected, with a valve 72 actuatable as a function of the motion of the piston 50, to a pressure course between the master brake cylinder and a wheel brake cylinder. To attain a short structural length, on the one hand, and a long stroke of the pressure generator on the other, the piston is embodied as a rod piston; it is connected to a coaxially extending hollow cylinder 40 that envelops the piston 50 in the cylinder 60; the hollow cylinder 40 is longitudinally guided and is provided with a racklike set of teeth 41 on its outside for the engagement of a motor drive mechanism 43 for driving the piston relative to the cylinder.