Abstract: A hydraulic force booster for actuating master cylinder pistons in brake systems of automotive vehicles, comprises a lever system including two levers (33,34) pivotably interconnected by way of a journal (35). The second lever, by way of a coupling (45) is in communication with a set element (46) provided at the control piston (13) of a brake valve (9). The coupling (45) comprises a coupling element (53) provided at the second lever (34), and at least one guide surface provided at the set element (46) is connected to the control piston (13) by way of joint (47) and, at the other end, by providing another joint (48), is guided in a substantially co-axial housing bore (49). The coupling element (53) can be formed by a loose roller thereby substantially precluding that transverse forces be exerted on the control piston (13) of the brake valve (9) likely to result in lockings.

Abstract: An electrohydraulic switching device for emitting electric control signals in dependence on supplied pressure signals. The switching device has a housing wherein a piston pressurizable by the inlet pressure is arranged so as to be axially displaceable. The piston is spring-loaded against the inlet pressure by means of a compression spring arranged between a spring plate and a guide means. The spring plate is secured at the piston by means of a snap ring, and the switching device has an actuating plate for actuating an electric switching mechanism. The actuating plate is positively connected with the piston, with the compression spring at its end facing the switching mechanism being axially guided by the guide sleeve.