Abstract:
The load sensing brake proportioning valve of a vehicle comprises a first piston (14) sliding in a stepped bore made in a body, and carrying a normally open shutter (18) arranged between a source of fluid under pressure and the associated brake circuit, the first piston (14) being moveable counter to a spring (16) under the effect of the pressure of the fluid which tends to close the shutter (18), a sliding rod (24) normally bearing between a pusher (20), the position of which is a function of the load of the vehicle, and the shutter (18). The proportioning valve comprises a locking mechanism immobilizing the sliding rod (24) as soon as the pressure of the fluid in the associated brake circuit exceeds a specific threshold.
Abstract:
Master cylinder assembly (1) for hydraulic control includes a master cylinder body (2) having a longitudinal bore (3). A piston (6) is arranged in the said bore and includes a seal packing (15) separating two chambers (16, 29) adapted to contain a liquid. The piston also includes a recovery conduit (36) connecting the chambers and by-passes the seal packing, and a valve (38). When the piston is in a rest position, an actuator (54) adjusts the position of the valve between an open position opening the recovery conduit and a closed position closing the recovery conduit.
Abstract:
A brake booster (10) comprising a housing (12); a diaphragm (16,18) mounted within the housing to define front and rear chambers (30-36) within the housing; and a cylindrical component (38) mounted within the housing and having an end (42) which passes through a sealing aperture (40) during installation within the housing to make a seal with the cylindrical component; wherein the cylindrical component has a plurality of fingers (46) extending away the said end, the fingers being circumferentially spaced apart around the end, and the outer surface (48) of each finger being chamfered such that the free ends (50) of each finger lie on a circle having an outer diameter (D1) which is less than the inner diameter (D2) of the sealing aperture prior to installation. Easier installation of the cylindrical component during booster assembly, especially where blind installation is required.
Abstract:
An automatically controlled braking system comprising a pneumatic vacuum servo and a pneumatic solenoid valve capable of selectively connecting the serov to first or second sources of pressure. The solenoid valve includes a flap valve which is subjected to a suction force proportional to the difference between the first and second source of pressured and acts in the same direction as an electromagnetic actuating force. Elastic means act on and apply a greater force to the flap valve to oppose the suction force. A current generator supplies a current having a predetermined maximum intensity to the solenoid to develop an actuation force overcome the elastic force and effect actuation of the vacuum servo.
Abstract:
A brake device having a pneumatic brake booster and a master cylinder. The master cylinder operates in response to a combined actuation force derived from a boost force and an input force. The input force is applied to a control rod for opening a valve to develop a pressure differential across a partition. The pressure differential acts on the partition to develop the boost force which is transmitted through a first hydraulic piston retained in the master cylinder. A movable pneumatic piston which carries the control rod is connected to the hydraulic piston and after an initial travel during which the valve is opened acts directly on the hydraulic piston to provide a portion of said actuation force. The input of the pneumatic piston to the hydraulic piston provides a way to operate a master cylinder in response to an input force in the event of a failure of a hydraulic circuit connected to the master cylinder.
Abstract:
The invention covers a brake-booster of the partial vacuum type comprising a direct braking control mechanism (hill-holder or traction control). In order to implement these functions, the piston (20, 22) of the booster is "double" through a partition (52) which is attached securely to the piston and defines with the piston a third chamber (50). This chamber is connected by a flexible pipe (66) and a double valve (72) either to partial vacuum (78) or to atmospheric pressure (76).
Abstract:
A master cylinder having first and second pressure chambers located parallel to each other and having first and second pistons, respectively, for pressurizing the parallel chambers and supplying pressure fluid to first and second brakes, and a third chamber with a third piston, the third piston being driven by an input shaft to the master cylinder for pressurizing the third chamber, the third chamber being connected to a third brake and to the first and second pistons of the parallel chambers, where the third piston abuts a balance arm which is connected to the first and second pistons for manual operation of the two pistons when a loss of pressure in the third chamber results.
Abstract:
The invention relates to a motor vehicle pneumatic brake booster, comprising a casing (10) inside which a piston (20) formed from a rear tubular part (22) supporting a skirt (14) defines, with the aid of an unrolling membrane (12), a front chamber (16), permanently connected to a vacuum source and a back chamber (18) alternately connected to the front chamber (16) or to the atmosphere via a valve (40) actuated by a control rod (34) capable of bearing, by a plunger (32), on one of the faces of a reaction disk (58) securely fastened to a thrust rod (56), the valve comprising a valve element interacting via an active part (40) with a first valve seat (32a) formed on the plunger (32) and a second valve seat (20a) formed on the piston (20), the valve element (40) normally being stressed forward by an elastic element (44). According to the invention, actuation apparatus (60, 100, 160) are provided in order to stress the active part of the valve element (40) forward in simultaneous interaction with the first (32a) and second (20a) valve seats.
Abstract:
The invention relates to a brake-booster comprising a casing (10) within which is found a piston structure which, with the help of an unrolling membrane (12), defines a front chamber (16) permanently connected to a partial vacuum source by a valve (17) and a back chamber (16) selectively connected to the front chamber (16) or to the atmosphere via a valve means (34) when a control rod (30) is actuated, and a device (36) for fastening the booster on a wall (38) adjacent to a first face of the casing (10). According to the invention, apertures (50, 60) are made in the piston structure (14) and in a second face of the casing (10) and are aligned in the axial direction of the booster so as to permit the actuation of the fastening device (36) through the aperture (60) made in the second face of the casing (10).
Abstract:
The invention relates to a vacuum-operated servo-brake comprising, in a casing consisting of a shell (10) and a cover (12), a piston (20) separating leaktightly two inner chambers (22, 24), a valve means controlled by a rod (32) projecting from the casing in order to ensure the operation of the servo-brake, and a prestressed spring (34) for returning the piston (20) to its rest position substantially abutting the cover (12), the spring (34) bearing on the shell (10). According to the invention, the spring (34) comprises a mechanism enabling its extension to be limited when the shell (10) and the cover (12) are not fixed to each other.