Abstract: A hydraulic circuit for controlling the deck swiveling speed of a working vehicle comprises a hydraulic actuator for driving the swivel deck, a flow control valve for controlling a rate of oil flow to the hydraulic actuator, and a direction control valve for switching an operating direction of the hydraulic actuator. The flow control and direction control valves are operatively connected to a swivel control lever. The greater amount of swivel control lever is operated toward a right or left swivel position, to the greater extent the flow control valve is shifted in a flow increasing direction. The direction control valve is operable to switch oil lines in response to an operation of the swivel control lever.

Abstract: An electrohydraulic system for control of a variable output pump includes a microprocessor-based controller receiving inputs from condition sensors coupled to the pump and command inputs from a remote master controller. The controller supplies outputs to an electrohydraulic valve for metering hydraulic fluid to a pump control port and thereby controlling pump operation in any one of a number of preselected and prestored pump control modes. A hydromechanical valve is connected in parallel with the electrohydraulic valve for controlling pump operation in the event of electrical malfunction or failure. Circuitry connected between the pump condition sensors and the control computer prevents aliasing errors due to mismatch between the computer sampling frequency and pump speed.

Abstract: A control device transmits hydraulic pressure from a continuously circulating pump to a hydraulic device. A pressure limiting valve communicates with the pump to exhaust the pump to reservoir when the system is in a stand-by mode. The control device includes a servo valve and a directional control valve. Movement of the latter relative to the former is possible in order to create a pressure back-up in a load indicating line which closes the pressure limiting valve, thereby increasing the pump pressure supplied to the servo valve when it is desired to initiate a working mode. Subsequent actuation of the servo valve causes hydraulic pressure to be supplied to or exhausted from the hydraulic device. Actuation of the servo valve is produced by hydraulic pressure which also communicates with the load indicating line via a one-way valve.

Abstract: A tandem master cylinder in which the primary piston and the secondary piston are configured in the shape of plunger pistons which are captivated to each other in the longitudinal bore of the cylinder housing. A cylindrical bushing is provided in the housing longitudinal bore and accommodates sealing cups sealing off the two pistons. The two valves which control hydraulic fluid flow are actuatable independently of each other.

Abstract: In order to reduce the number of component parts required for the simultaneous ventilation of two power chambers of a tandem brake power booster and to avoid sealing problems. A booster, according to the invention, provides for the transmission of the boosting power of the master cylinder-side movable wall of the booster to be directly to the control housing.

Abstract: A hydraulic lift is raised by hydraulic fluid which passes through a servo valve and is lowered when the servo valve exhausts the hydraulic lift to a reservoir. The hydraulic fluid travels to and from the lift through a service line in which a blocking valve is disposed. A control unit opens the blocking valve against a spring bias in response to the application of a control pressure to a control element disposed on one side of the control unit. The control pressure is supplied via a control line which also actuates the servo valve. A branch control line branches from the control line and applies pressure to another control element which acts counter to the first-mentioned control element. The branch control line includes tow throttles between which a discharge line is connected and communicates with the reservoir.

Abstract: A fluid pressure booster device includes a booster body, a control piston in the booster body for forward and rearward movements to define a boosting chamber between the control piston and a rear surface of a master piston of a master cylinder, a valve piston in the control piston for forward and rearward movements and communicating at its front face with the boosting chamber, a reaction piston in the control piston for forward and rearward movements and connected to an operating member, the reaction piston defining a reaction chamber between itself and a rear face of the valve piston, a stroke accumulator having an accumulation chamber connected to the reaction chamber, an inlet valve disposed between the control piston and the valve piston and interposed in a flow passage extending between the boosting chamber and a fluid pressure source, the inlet valve being closed when the valve piston is retracted and opening when the valve piston advances, and an outlet valve disposed between the control piston and the

Abstract: A double-cylinder construction which can be used not only in large-sized compression molding machines but also in small-sized or medium-sized compression molding machines. In the double-cylinder construction of the present invention, a ram slidably fitted within an outer cylinder is provided in the center thereof with a hollow part. A rod slidably fitted in said hollow part is fixed to the bottom of said outer cylinder without penetrating said bottom thereof, and said rod does not contain an oil passage within. The double-cylinder construction always contains a certain amount of oil within and this self-contained oil is moved back and forth within the double-cylinder construction when the ram is being moved up and down. Therefore, the amount of oil supplied to the double-cylinder construction from outside is very small.

Abstract: The bleed valve (22) especially for a hydraulic brake circuit, comprises a fluid reservoir (20), a hydraulic motor (26) and a mechanism for putting the fluid under pressure (24), and has a first port (42) connected to the motor (26) and to the mechanism (24) by way of a first conduit (62) and a second port (54) connected by way of a second conduit (60) to the reservoir (20) which is likewise connected to the inlet of the mechanism (24) by way of a third conduit (64), the first and second conduits (60,62) communicating with one another by way of the valve (22) during the initial bleeding phase of the hydraulic circuit, and no longer communicating from the moment when the fluid is first put under pressure. The valve (22) comprises a piston (36) capable of sliding in a bore (32,34) and keeping the shutter (44,42) of the valve open during the bleeding phase counter to a compressed spring (46 ).

Abstract: A double operate check valve used in a hydraulic pressure circuit for locking and unlocking a vibration absorbing hydraulic cylinder included in a wheel suspension mechanism of a vehicle, which includes an improvement in its structure for providing the suspension with improved compliance with respect to road surface undulation and corresponding comfortable drive of the vehicle. The check valve pilot pistons have fluid conducting surfaces which are connected by a valve body passageway and which communicate the main fluid paths when hydraulic pressure in the pilot chamber urges the pilot pistons to open the check valves.

Abstract: A remote control shifting system for a mechanical transmission. The transmission is operated by two pneumatic cylinders, a selecting cylinder operating in the direction of shift path selection and a shifting cylinder acting in the direction of shifting. The shifting cylinder operates with two force stages, a lower force for effecting synchronization of gears about to be engaged, and a higher force level for actually engaging or disengaging the selected gears. A remote shift control unit is designed to closely emulate the action of a direct-operating manual shift level. During the synchronizing phase, the shift lever moves easily in the shifting direction. After a preliminary movement, however, further movement is allowed only against considerable resistance, as if conventionally mechanically forcing gears into meshing engagement.

Abstract: An actuating arrangement for a compact master cylinder includes a foot pedal pivotably connected to support bracket. The cylinder is pivotably connected at its lower end to the foot pedal and at its upper end to the bracket so that movement of the pedal causes movement of the piston into the cylinder and also moves the entire cylinder in relation to the supporting structure.

Abstract: The invention provides a brake booster including in a preferred embodiment a housing, first and second annular flexible diaphragms spaced from one another forming a sealed second chamber within the housing and a sealed first chamber between the first diaphragm and the first end of the housing, a generally annular shaped power piston for connection with the master cylinder piston, a chamber valve seat separating the first and second chambers, an inlet valve slidably mounted within the power piston, and a control valve spring biased away from the power piston and connected with the pedal linkage and being slidably and sealably mounted within first end of the housing.

Abstract: The position (x) of a hydraulic press or punch press is controlled highly dynamically, by a controller which uses the velocity (v) and the acceleration (a.sub.B) of a piston. While the position (x) and the velocity (v) are sensed by customary measuring devices, the acceleration (a.sub.B) is determined by means of a sensor (B) from the pressure (p) of the hydraulic fluid and the piston velocity (v). Thereby, an expensive acceleration measurement can be dispensed with by utilizing the already existing pressure measuring arrangement. The sensor (B) can further determine an interference quantity signal (f.sub.zB) which can be fed to the control element (SG) for the purpose of generating a compensating interference signal.

Abstract: A boot (19) protecting the pedal-sided end (18) of the control valve housing (5) of a vacuum brake force booster is fixed by a spacer. The spacer is preferably configured as a dual-walled annular sleeve (20). It is axially secured in the same position as a ring sealing the control valve housing (5) against the booster housing (1). An axial extension (26) of sleeve (20) insures that the boot (19) is kept remote from the booster housing (1) and from the control valve housing (5), respectively, so that air can be taken in between boot (19) and control valve housing (5) for ventilating the working chamber (3). This design allows the air required for ventilation to travel very closely to the baffle wall, thereby minimizing noise in the passenger cabin of the automobile.

Abstract: A hydraulic actuator system, for use in an aircraft, and in which the servo fluid supply to the system is used to provide for the operation and cooling of the system. The system comprises a hydraulically operated piston mechanism including at least one hydraulically operated piston, a servo vluid input to the system, which is connected in a ring main to a first side of the hydraulically operated piston, a servo fluid output from the system, which is connected in a ring main to a second side of the hydraulically operated piston, a variable restrictor arrangement which provides an interface between the servo fluid input ring main and the servo fluid output ring main, and a restrictor arrangement positioned in the servo fluid output side of the system. The position of the piston of the hydraulic piston and the adjustment thereof, are controlled by the restriction applied on the system by the variable restrictor arrangement.

Abstract: The invention relates to a braking device for a motor vehicle having a bulkhead (1) separating the passenger compartment (5) from the engine compartment (3). The device comprises a master cylinder (7) having a flange (13), via which it is fastened by means of a screw/nut assembly (15) to the front wall of a pneumatic brake booster (9) controlled as a result of the action on a tappet (11) passing through the rear wall of a brake booster, and a mechanism for fastening the device to the bulkhead (1) such that the brake booster (9) is arranged on the same side as the passenger compartment (5). The master cylinder (7) is partially arranged in the passenger compartment (5) and passes through an opening made in the bulkhead (1) for this purpose.

Abstract: The combination diaphragm and valve body comprises a plastic vacuum booster valve body (32) which has molded integrally therewith via living hinges (34) a plurality of diaphragm arms (36). The diaphragm arms (36) may be disposed initially in a position substantially parallel to a longitudinal axis (A) of said valve body (32). The diaphragm arms (36) are pivoted to a position substantially orthogonal relative to the longitudinal axis (A) of the valve body (32) and ultrasonically welded to the valve body (32). Each of said diaphragm arms (36) includes a plurality of radial openings (38) at a radial end (39) thereof for receiving a metal connection member (40). The metal connection member (40) is snap-fitted into associated radial openings (38) in the diaphragm arms (36), and a diaphragm (50) is compression molded about the valve body (32) and over the surface of the diaphragm arms (36). The diaphragm arms (36) may be manufactured separately and then welded to the valve body (32).

Abstract: A hydraulic braking system includes a tandem master cylinder having a bore with an opening and a closed wall at opposite ends thereof which formed in a housing, a first piston slidably fitted in the bore so as to define a first pressure chamber and a first fluid chamber therein and operatively connected to a brake pedal, a second piston slidably fitted in the bore so as to define a second fluid chamber adjacent to the first pressure chamber and a second pressure chamber and operatively connected to the first piston. A normally open valve communicates with each piston so as to close passages formed in the each pistons and communication between each fluid chambers and each pressure chambers, respectively, when each piston is moved in response to the depression of the brake pedal. A power source generates a hydraulic power pressure.

Abstract: A brake master cylinder reservoir diaphragm has a vent slit therein to operate as a vent valve to equalize air pressure when a pressure differential is impressed across the diaphragm as the brake fluid level in the reservoir changes. The vent slit has an omega or bell curve shape so that the movable valve member is the tongue-like part formed on the inner curvilinear part of the curved vent slit. The tongue valve member acts as a cantilever supported valve which bends at its base to open in either direction under a differential pressure acting on one side or the other of the diaphragm. The opening and closing action of the tongue valve member can be fine tuned by modifying the bending resistance of the base of that member. Such modifications can include a partial base slit extending only part way into the thickness of the base to form a groove in alignment with the straight ends of the omega slit and located between them.