Abstract: A hydraulic control system for driving a plurality of actuators basically includes directional control valves, and pressure compensation valves, and at least one detection valve, the directional valves and the pressure compensation valves both corresponding in number to the actuators. These valves are mounted or incorporated in a body. The body has a plurality of regions corresponding in number to the actuators. Each of the regions of the body has a first hole, and a second hole substantially perpendicularly intersecting the first hole. A load pressure chamber for receiving a load pressure of the corresponding actuator is formed at the intersection between the first and second holes of each region. A spool of the directional control valve is received in the first hole. A balance piston of the pressure compensation valve is received in that portion of the second hole disposed on one side of the load pressure chamber.

Abstract: Presented is a fluid drive motor that may be attached to a conventional garden hose, for instance, to effect reciprocating motion of a drive shaft that may be connected to a utilitarian device, such as a scrub brush. The fluid drive motor is provided with a piston assembly that responds to the pressure of the fluid to translate the piston assembly from one position to another and in so doing imposes rotational reciprocation on a drive shaft that extends out of the motor block of the fluid drive motor. The reciprocating characteristics of the piston assembly are controlled by the imposition of fluid pressure, and the imposition of fluid pressure is controlled by a valve assembly cooperating with a reciprocable magnetic bar to channel fluid under pressure alternately to opposite ends of the piston assembly.

Abstract: In a brake apparatus for a hydraulic two-circuit brake installation of a road vehicle with static brake circuits, an outlet pressure space is provided for one of these brake circuits in which the brake pressure that is coupled into a static brake circuit of the vehicle, is adapted to be built up by the displacement in the same direction of a master cylinder piston which is also displaceable by the pedal force alone, and of a servo piston which is displaceable only when the brake force servo unit is intact.

Abstract: A blow-back circuit (10) comprising an accumulator (23) to build up system pressure during normal system operation and an accumulator shut-off valve (13) which prevents dissipation of the accumulator pressure during normal operation. Pressurized fluid is supplied to a fluid motor (11) through a direct drive valve (12). A directional control valve (28) is associated with a switching valve (34) and a stop mechanism (31) which mechanically feedbacks the position of a control surface to be blown back during an emergency. When the control surface is in or blown back to the neutral position, the stop mechanism (31) feeds that data back to the directional control valve (28) so that accumulator pressure will not be further delivered to the fluid motor (11) and a brake (14) will be allowed to prevent further movement of the control surface away from the neutral position. As a result, the control surface is moved to its neutral position with great accuracy and no flutter.

Abstract: A charge flow distribution valve routes all charge pump flow into a main pump until the main pump has sufficient inlet pressure. The valve opens to a first stage which routes excess charge flow to lubrication circuits. At a slightly higher main pump inlet pressure, it also routes oil to an inlet of the charge pump.

Abstract: A fluid-powered servo actuator having a body, an annular piston, and a shaft extending co-axially therewithin. The shaft has an interior chamber located within the body with two fluid channels extending to the chamber in which the piston is mounted. One channel communicates with each side of the piston. A valve spool is positioned in the shaft chamber, and a cam follower or threads are used to longitudinally move the valve spool therewithin in response to its selected rotation. The valve spool has a pair of valve lands which, when in a neutral position, close the two channels. When the valve spool is moved longitudinally, pressurized fluid is communicated with one or the other of the channels to cause the piston to move longitudinally. Splines or rollers convert the longitudinal movement of the piston into rotational movement of the shaft.

Abstract: A hydraulic control apparatus, more particularly for operating a motor vehicle clutch release mechanism, comprising a master cylinder, a slave cylinder and a conduit connecting the master cylinder to the slave cylinder. The apparatus is in the form of separate modular units which are separately filled with hydraulic fluid, and the filled modular units are shipped unconnected to a user. Each modular unit is provided with a leakproof quick-connect connector member, through which filling of the modular unit may be effected, and which mates with a complementary leakproof quick-connect connector member of another modular unit, such that after installation on a utilization device, a motor vehicle for example, complementary connector members are reconnected, thus opening ports in each connector member placing each member in fluid communication with the other. Preferably, the two connector members are provided with a one-way locking arrangement preventing separation of the connector members after coupling.

Abstract: A modular handling system is assembled from a plurality of linear drive, rotary drive, or tool modules. The linear drive used as a cylinder block with a cylindrical bore therein and cylinder heads sealing off the cylindrical bore. A pneumatically actuated piston travels within the cylindrical bore. A carriage runs on the cylinder block and is connected with the piston by means of a flexible belt attached to both the piston and the carriage and deflected by deflection rollers mounted on the cylinder heads. Cartridge-type valves are integrated into both cylinder heads for controlling displacement of the piston. One of the cartridge valves is made as a pressure-servo-valve allowing linear control of valve output pressure vs. valve operating current. The cartridge valve integrated into the opposite cylinder head may be either another pressure-servo-valve or a displacement-servo-valve allowing linear control of valve spool displacement vs. valve operating current.

Abstract: A piston and piston support rod assembly in which the piston is formed as a sheet metal stamping. A central sleeve is attached to the end wall of the stamped piston by a swaging operation performed on an annular section of the end wall. An undercut area of the sleeve defines a mandrel surface that effectively grips the end wall material deformed by the coining operation. A principal advantage of the new structure is a relatively low manufacturing cost.

Abstract: The problem of sealing a communication bore (56) in a port plate (40) is solved with a self-sealing transfer tube assembly (52). The transfer tube assembly (52) includes a coupling element (64) which is received in a supply bore (60) which intersects the communication bore (56). A relatively small window (78) is provided in the coupling element to provide hydraulic communication between the transfer tube assembly (52) and the port plate porting area (48), while its solid side wall (68) otherwise seals the outer portion of the communication bore (56).

Abstract: A throttle-controlled hydraulic power brake employing a pressurized fluid produced via a pump and preferably stored in an accumulator for enabling servo-assisted displacement of a push rod acting on the master cylinder of a brake pump (of the same type employed on vacuum-operated power brakes) subsequent to axial displacement of a second push rod controlled directly by the brake pedal. Displacement of the second push rod towards the first provides, against the action of elastic means, for opening a first face seal valve, which feeds the pressurized fluid into a variable-volume accumulating chamber, so as to displace a piston connected axially to the first push rod and defining a movable wall of the accumulating chamber, and so close the valve. Opposite displacement of the second push rod, on the other hand, provides for opening a second face seal valve connecting the accumulating chamber to a drain.

Abstract: The master cylinder (10) comprises a front or first housing part (12) which is generally U-shaped and a second or rear housing part (14) which is also generally U-shaped, the second housing part (14) being received within an end opening of the first housing part (12). The second housing part (14) has an end opening (16) opposite the first housing part (12) through which a first piston (18) is received. The first piston (18) and a second piston (22) are biased by respective resilient mechanisms (20, 24) disposed within a bore (26) defined by the parts (12, 14). Captured between the first and second housing parts (12, 14) are first and second interface members (80, 90) which have seals insert molded thereon. The first and second housing parts (12, 14) are held together by self-threading screws (100) such that a predetermined clamp load is imposed upon the interface members (80, 90). The master cylinder (10) has outlets (34, 36) all of which are oriented longitudinally toward the fron of the master cylinder.

Abstract: A hydraulic circuit suitable for use in a hydraulic operating circuit of a power shovel includes a hydraulic cylinder for driving a working component and a hydraulic change-over valve for selectively supplying the cylinder with a discharge oil pressure of a hydraulic pump driven from an engine.

Abstract: Device in a hydraulic power system connected to a load driving hydraulic motor (18; 32), comprising a pilot controlled flow regulating directional valve (1; 29) for alternative connection of the service ports of the motor (18; 32) to a pressure medium source and a tank. The directional valve (1; 29) comprises two opposite and by a pilot pressure activatable activating means (3, 4), and a pilot pressure means (84) is arranged to pressurize and activate the activating means (3, 4), alternatively, and drain one of the activating means to the tank through a flow restriction (5, 7) at activation of the other activating means (3, 4).

Abstract: An improved hydraulic apparatus is disclosed having a hydraulic device (14) receiving conditioned hydraulic fluid directly from an inlet port (62) in a case (12) full of hydraulic fluid (16) with the conditioned hydraulic fluid having a characteristic which is better than the characteristic of the fluid within the case. The characteristic may be that the hydraulic fluid is cooled to a temperature below the temperature of the hydraulic fluid within the case, is filtered, or is deaerated. Cooled hydraulic fluid is supplied from a heat exchanger (58) in fluid communication between an outlet port of the case and the inlet port of the case to supply the hydraulic fluid contained within the case. The hydraulic fluid is filtered by a filter (54) external to the case. A deaerator (65) may be located in a fluid circuit external to the case between a scavenge pump (50) and the inlet port (67). Hydraulic fluid is pumped by a charge pump (26) to the input port (72) of the hydraulic device.

Abstract: A method of controlling a speed reduction ratio in a continuously variable speed transmission comprises detecting a vehicle speed when a vehicle is decelerated by utilizing an engine brake with an accelerator opening being essentially zero, determining a reference speed reduction ratio corresponding to the detected vehicle speed, detecting an actual vehicle speed change rate, detecting an allowable vehicle speed change rate, comparing the actual change rate with said allowable vehicle speed change rate, determining a corrected speed reduction ratio by adding a correction to the reference speed reduction ratio based on a difference between the actual vehicle speed change rate and the allowable vehicle speed change rate, and controlling the speed reduction ratio of the continuously variable speed transmission so as to coincide with the corrected speed reduction ratio.

Abstract: There is provided control apparatus for controlling fluid flow between a bidirectional motor, a pump and a container, and includes a control valve that has a slide operative between neutral and first and second operative positions. A compensating valve is provided in the supply conduit that holds the upstream pressure drop at the control valve substantially constant and is controlled by load pressure sensing circuitry. The load pressure circuitry includes two branches that are connected through a change over valve to the compensating valve. There is provided an over pressure valve and a throttle point in each branch, each branch being connected to a load pressure sensing orifice of the control valve housing and fluidly connected through the slide to one of the housing motor orifices, the one depending upon whether the slide is in its first or in its second position.

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 brake pressure control device introduces pump pressure which is produced by a pump (16) into piping which connects a master cylinder (4) and wheel brakes (11, 11', 12, 12'). The increase, decrease and retention of the wheel brake pressure are effected by utilizing the pump pressure. Absorbers (19, 19') which consume hydraulic fluid are installed in branches from piping which connects the master cylinder (4) and the wheel brakes (11, 11', 12, 12'). 4-port 2-position control valves (5, 5') are installed in the hydraulic passages which connect the master cylinder (4) and the absorbers (19, 19') and at the inlet port for the pump pressure and at the outlet port to the absorbers (19, 19').

Abstract: Compression piston ring for internal combustion or compressor cylinder and piston comprising double layer of segmented ring sectors having free form circumferential curvature matching the cylinder bore. The double layers are adapted to effectively seal or minimize bypass with resilient means provided for maintaining ring cylinder engagement under light radial pressure.