Abstract: According to the invention, the braking system includes two tandem master cylinders (100, 200), the first (100) having a first pressure chamber (110) connected to the left brake (132) of the tractor and a second pressure chamber (112) connected to the trailer brakes (300), and the second having a first pressure chamber (210) connected to the right brake (232) of the tractor and a second pressure chamber (212) likewise connected to the trailer brakes (300). The invention may be utilized with certain vehicles, in particular agriculture tractors.

Abstract: The invention relates to a servomotor for assisting the operation of a power brake system. The servomotor includes in a housing a power-assisting part and a part forming a hydraulic master-cylinder. The power-assisting part is adapted in use to be connected to an external power source such as a vacuum source. A valve assembly operated by an operator-operated intake member controls the generation of a pressure differential across a driving piston by allowing air to replace the vacuum on one side of the piston. The master-cylinder part includes an assembly having two coaxial pistons. The first piston is attached to the driving piston of the power assist part whereas the second piston is actuated by the intake member. Both coaxial pistons project into a chamber which is divided by a sealing ring. The central piston is adapted to pass through the sealing ring in response to an input force from the input member to further pressurize the fluid in the outlet portion of the chamber.

Abstract: The invention relates to a hydraulic servomotor comprising a housing provided with a bore slidably receiving two pistons separating an actuating chamber from an utilization chamber, said pistons including an annular outer piston and an inner piston received within the annular piston. Releasable coupling means are provided between both pistons to permit said pistons to move in unison when high pressure fluid is available in the actuating chamber and to permit the inner piston to be moved alone by the push rod in the event of a high pressure failure in the actuating chamber. The motion of the outer piston towards the interior of the actuating chamber is limited by an abutment fixed to the housing.

Abstract: The invention relates to a tandem master-cylinder for a split braking system of an automotive vehicle. The master-cylinder comprises two pressure chambers, the first one between the control piston and the floating piston and the second or front chamber before the floating piston. The first chamber communicates with a first outlet port which is connected to a second outlet port through a by-pass valve. The by-pass valve is secured to a tappet-rod projecting into the second chamber to be engaged by the floating piston, upon pressure failure in the second chamber and so that the by-pass valve is opened. The first outlet port is adapted to be connected to a set of brake actuators through a braking correcting valve while the second outlet port is adapted to be directly connected to said set of brake actuators.

Abstract: A switch apparatus for detecting an imbalance condition between a first fluid circuit and a second fluid circuit. The switch apparatus has a housing with a bore therein in which a sleeve is located. The sleeve has a peripheral section which is electrically non-conductive and a central bore therethrough with a first diameter and a second diameter. A first piston is located in the first diameter and a second piston is located in the second diameter. A pin is connected to the second piston to limit the movement thereof in the central bore. When a pressure imbalance occurs, the sleeve will move and allow a plunger to move off the non-conductive peripheral surface to complete an electric circuit to inform an operator of a potential brake system failure.