Abstract: A primary piston component for a master cylinder of a hydraulic brake system includes a primary piston housing and an additional piston component, which is configured to be at least partially movable into a cavity of the primary piston housing. An inner piston body extends through the cavity along a central line of the primary piston component. A braking force applied on a brake actuating element is transferable at least partially on the inner piston body, and further on the primary piston housing. The additional piston component is at least partially movable into the cavity between the inner piston body and the primary piston housing, and a brake booster force is transferable at least partially on the additional piston component, and via the inner piston body on the primary piston housing. A method of operating a hydraulic brake system is also described.

Abstract: A brake fluid reservoir is connected to a master cylinder by a neck which is arranged in an upper chamber of the master cylinder. Holes extend through a surface of a piston, opening to a pressure chamber. The piston extends through a bore hole of the master cylinder. A drill hole extends through an interior wall of the master cylinder, opening into the bore hole, thereby providing communication between the fluid reservoir and the pressure chamber. A floating orifice plate is arranged within the upper chamber, between the neck of the brake fluid reservoir chamber and the drill hole, such that the orifice plate forms a baffle that limits a flow rate of liquid from the brake fluid reservoir chamber to the pressure chamber; and includes supports pressing against a surface of the interior wall of the master cylinder and arranged around the first side of the drill hole.

Abstract: A twin power valve assembly (10) for a hydraulic braking system having a single body (16) with twin power valve arrangements, each having a spool (36, 36?) with a longitudinally extending passageway (36D, 36D?) for providing a modulation of the pressure applied to the brakes, and an integral balance piston (60, 60?) contained within the body (10) that equalizes the pressure applied to the left and right hand brakes when both brakes are applied.

Abstract: A vehicle brake device includes an input shaft coupled to a brake pedal, a pedal operation detector, a pedal simulator coupled to the input shaft in a control housing, a master cylinder, a control piston, a control chamber, and a hydraulic pressure supply, wherein the pedal simulator includes a pedal simulator piston, a pressing member, a simulator piston provided in the pedal simulator piston, and a push rod which is accommodated in the pressing member while being spaced apart from a bottom wall of a guide groove by passing through the pedal simulator piston and the simulator piston from the control piston to the input shaft, and wherein a diameter of the master cylinder is greater than a diameter of the simulator piston, and a diameter of the control piston is greater than a diameter of the master cylinder.

Abstract: A vehicle brake control valve includes a piston assembly which is movable a stepped cylindrical bore of a valve housing in response to an actuating force against the force of a spring. The piston assembly includes port control edges which control communication between a brake pressure chamber which can be connected to the vehicle brakes, a reservoir, and a pump. Both the pump and the actuating force contribute to the brake pressure which builds up in the brake pressure chamber. The piston assembly includes an actuator piston and an annular piston that sealingly slides within a larger portion of the stepped bore. After the actuator piston moves a pre-set distance (H) it carries with it the annular piston. The annular piston, the actuator piston and a wall of the larger diameter portion of the stepped bore enclose a fill pressure chamber which is separated from the brake pressure chamber to achieve two-stage pressure build-up during manual braking (emergency braking) when the pump is inoperative.

Abstract: A master cylinder and emulator includes a primary piston and a secondary piston which are movable to provide fluid pressure to effect wheel braking in a vehicle. In addition, the master cylinder includes an emulator assembly which supplies conventional pedal feel and travel characteristics when the primary and secondary pistons are substantially immovable due to isolation of the master cylinder from the wheel brakes. The emulator assembly includes a piston that is movable against a selected amount of fluid pressure and spring force while the primary piston remains stationary. The fluid force is supplied by controlling the flow of fluid from behind the piston through a flow restrictive orifice to a conventional fluid reservoir on the master cylinder assembly. The master cylinder and emulator assembly is operable to provide brake actuation assist to an electric or electro-hydraulically controlled braking system.

Abstract: An intensifier type of fluid actuator includes a body including a first manifold connected by a first tube to a second manifold to define an intensifier chamber, a third manifold connected by a second tube to the second manifold to define a reservoir chamber, and a fourth manifold connected by a third tube to the third manifold to define a work chamber. A reservoir piston is disposed within the reservoir chamber and has an outer surface in sealing and sliding engagement with the second tube. The reservoir piston includes an inner surface defined by a central opening formed therethrough which extends from a first end of the reservoir piston adjacent to the second manifold to a second end of the reservoir piston adjacent to the third manifold. A passageway is formed in the reservoir piston which extends from the inner surface to the outer surface, thereof.

Abstract: According to an illustrative example of the invention, a foot pedal acts upon a first master cylinder and with delay upon a second master cylinder. Both master cylinders are connected with a slave cylinder which acts upon a clutch releaser. In a first range of movement adjacent the clutch engagement condition, the foot pedal acts only upon the first master cylinder such that there is a small transmission ratio between the movement of the clutch pedal and the movement of the clutch releaser. In as second range of movement subsequent to the first range of movement, the clutch pedal acts upon both master cylinders so that there is a higher transmission ratio between the movement of the clutch pedal and the movement of the releaser.

Abstract: A hydraulic braking system includes the third piston slidably disposed between the first piston and the second piston of the tandem master cylinder so as to define the third pressure chamber between the third piston and second piston. The third pressure chamber is communicated with the dynamic hydraulic pressure generator. Thereby, due to supply the output hydraulic pressure of the dynamic hydraulic pressure generator to the third pressure chamber, the initial stroke of the brake pedal is reduced and the braking force is ensured as the ordinaly tandem master cylinder when the dynamic hydraulic pressure generator is not operated. Moreover, if the leakage of the brake fluid generates in the wheel cylinders, the flow of the brake fluid of the dynamic hydraulic pressure generator does not generate.

Abstract: A pressure intensifier comprising a housing incorporating a first floating piston-cylinder unit with means to supply a primary pressure fluid medium to one side of the piston to apply pressure to a fluid medium in contact with the other side of the first piston, a second floating piston unit provided with a fluid medium communication port therethrough, there being direct communication between the medium contacting the other side of the first floating piston with one side of the second floating piston and through the port thereof to a fluid medium pressure power take-off chamber, the port of the second floating piston being closeable by means of a valve comprising two active parts, one part of which is incorporated in the second floating piston and the other part of which is provided with limited movement with respect thereto, there being means to apply primary fluid pressure to the other side of the said second floating piston to maintain the communication port open, the other part of the valve being constitu

Abstract: A hydraulic brake system includes a hydraulic power booster (11) and a master cylinder (12) connected downstream of the power booster (11). The pressure chamber (21) of the power booster (11) is pressurized by an auxiliary pressure which is dependent on the position of a pedal-actuated brake valve (19). A fast-fill cylinder (40) is can be pressurized by the dynamic pressure and with its aid the working chamber (16) of the master cylinder (12) can be supplied with additional pressure fluid in the initial phase of braking. The chamber (48) between the two piston steps (57, 58) of the fast-fill cylinder connects to the unpressurized supply reservoir (3) by way of a valve assembly (51) for synchronizing the movements of the master cylinder piston (43) and of the stepped piston (45) of the fast-fill cylinder (40). The valve assembly (51) is furnished with the wheel cylinder pressure as a control variable.

Abstract: A braking pressure generator with a master brake cylinder (2) and a hydraulic brake power booster (1) connected upstream thereof and comprising a piston (16) of larger effective surface which latter is incorporated axially movably within limits in a bore (15) in a stepped piston (10) of smaller effective surface extending through the booster chamber (8). The piston (16) serves to actuate a master cylinder piston (31). During an actuating action the two pistons (10, 16) are maintained in their position moved apart from one another even in the event of pressure drop in the booster chamber or in excess of the point of maximum boosting. This is accomplished in that both pistons (10, 16) enclose a pressure chamber (23) which is connectible to the booster chamber (8) through a valve passage (19) closable by the actuating element (6) of the brake power booster (1) as well as through a non-return valve (25) in parallel relationship thereto.

Abstract: A maximum displacement, reciprocating air operated demand only hydraulic power unit for supplying hydraulic fluid under pressure to one or more hydraulic motors, comprising a pneumatic power cylinder having a power piston therein, a hydraulic slave cylinder having a slave piston therein powered by said power piston, said slave cylinder being connected to each said hydraulic motor to power same, a valve mechanism for controlling the supply of air and oil to said power and slave cylinders, a mechanism to control the valve mechanism to operate the unit in a steady reciprocating motion, and an intensifier for two stage operation of said motors in either operating direction of the unit. An accumulator may also be included to supply fluid when the unit changes direction.

Abstract: A master cylinder for a hydraulic brake system includes a piston which divides a primary bore into a primary chamber and a secondary chamber. The piston rod sealingly slides in a secondary bore of smaller cross-sectional area than the primary bore. An expander piston sealingly slides in a bore and defines a primary expander chamber and a secondary expander chamber. In use, initial movement of the piston causes fluid to be displaced from the primary chamber to the brake circuit at a rate corresponding to the area of the primary bore. When the pressure in primary chamber becomes sufficiently large the expander piston is moved to the right against the bias of a spring to allow fluid to flow out of primary chamber into primary expander chamber via a passage. An equal volume of fluid is displaced from secondary expander chamber into secondary chamber via a passage.

Abstract: Actuating equipment for a gate valve or penstock uses both compressed air and hydraulic oil to obtain the advantages of both. A control valve directs air to a hydraulic reservoir so as to drive oil at the air pressure into one chamber of a double acting cylinder and piston connected to the gate. When the gate is not being moved it is locked in position by an air operated valve preventing oil flow. A normally energized solenoid operated control valve opens when electrical power fails so as to direct stored air from a reservoir to move the gate to a fail-safe position.Air pipelines may provide communication over some distance from the control valves to the gate valve or penstock.

Abstract: A master cylinder for a hydraulic brake system of an automotive vehicle having front and rear sets of brake cylinders is disclosed, in which during the application of brake pressure above a predetermined value at which modulation and reduction of the rate at which pressure is fed to the rear brake cylinders occurs, the rate at which pressure is fed to the front brake cylinder is increased as compared with the rate before the modulation point.

Abstract: A master cylinder includes a master cylinder piston which is slidable by a booster with a hydraulic transmission interposed between the booster and the master cylinder piston. The booster includes two booster pistons the first of which has the same effective area as the master cylinder piston. With the system intact, the master cylinder piston is shifted as a result of the pressure fluid displaced by the two booster pistons to provide the hydraulic transmission. In the event of failure of the booster, the master cylinder piston is actuated directly by mechanical means through the first booster piston with the hydraulic transmission thereby being omitted.

Abstract: A controllable hydraulic valve mechanism for reciprocating engines or pumps including a drive piston, operable by a cam is provided with control edges and projects into a drive cylinder; a working piston which operates the valve directly and is guided in a working cylinder. The valve mechanism provides a continuous communication between the drive cylinder interior and a second reservoir which absorbs a substantial part of the energy produced by the lift of a cam. Control sleeves surround the drive piston and are operable by actuating means operable from outside the drive cylinder. Each of the control sleeves has a control ring groove which cooperates with control edges provided in the drive piston. A further sleeve in the working cylinder surrounds the working piston, is rotatable by actuating means operable from outside the working cylinder, and is provided with a control ring groove for varying the valve lift.

Abstract: A brake booster includes a booster piston adapted to be acted upon by the pressure fluid metered through a valve device and displacing a master cylinder piston. A pressure chamber is formed between the booster piston and the master cylinder piston. An additional stepped piston is provided whose larger surface is exposed to the metered pressure fluid and whose smaller surface feeds a predetermined amount of pressure fluid into the pressure chamber so that the brakes are applied after only a short brake pedal travel.

Abstract: A servo-assisted hydraulic master cylinder has a variable ratio effect so that brake fluid is initially displaced to the brakes at a high rate with respect to driver pedal movement and then at a low rate when an appropriate pressure has developed. A stepped piston assembly comprising a first piston slidable in a second piston defines a first chamber which is directly connected to the brakes and a second chamber in which a variable pressure is developed. The first piston is operated directly by the pedal through the servo valve and is subject only to brake pressure in the first chamber so that brake pressure is proportional to driver effort during normal operation. The second piston is operated by the servo diaphragm through the servo valve housing.

Abstract: A servo-assisted hydraulic master cylinder has a variable ratio effect so that brake fluid is initially displaced to the brakes at a high rate with respect to driver pedal movement and then at a low rate when an appropriate pressure has developed. A stepped piston assembly comprising a first piston slidable in a second piston defines a first chamber which is directly connected to the brakes and a second chamber in which a variable pressure is developed. The first piston is operated directly by the pedal through the servo valve and is subject only to brake pressure in the first chamber so that brake pressure is proportional to driver effort during normal operation. The second piston is operated by the servo diaphragm through the servo valve housing.