Abstract: A manual valve device including: a plurality of air bags provided inside a vehicle seat; a valve main body including a plurality of flow passages communicating with the plurality of air bags, respectively; a plurality of valve bodies movable inside the valve main body so as to open and close the plurality of flow passages, respectively; a plurality of valve shafts coupled to the plurality of valve bodies, respectively, and configured to be manually operated to move the plurality of valve bodies in a stroke; and an operation lever configured to press any one of the plurality of valve shafts or any combination of the plurality of valve shafts in an axial direction, in which the operation lever includes an adjustment mechanism configured to adjust an air flow rate per unit time flowing in the plurality of flow passages by changing a stroke amount in the axial direction.

Abstract: A method of actuating an assembly of a transmission, with which are associated a plurality of actuators with whose help the assembly can in principle be actuated, such that out of the actuators available in principle for actuation, a control unit selects at least one actuator for the actual actuation and activates the selected actuator with an output signal in such manner that a status parameter of the actuated assembly corresponds to or follows a control-side nominal value, such that out of the actuators available in principle for actuating the assembly, the control unit selects at least one actuator for the actual actuation of the assembly in such manner that, for all the actuators available in principle for actuating the assembly over the operating life of the transmission, the extent of their utilization is approximately uniform.

Abstract: A front lifting device for a tractor, for hitching a tool thereto and controlling the same, includes: a chassis to be attached to the bodywork of the tractor; two lower arms hinged to the chassis and including, at the end thereof furthest from the chassis, a hitching element for the tool; at least one working jack in which one of the elements, a cylinder or rod, is connected to the chassis and in which the other element, a rod or cylinder, is connected to one of the coupling arms, the working jack providing the movements of the arm or arms in a working stroke between a bottom position and a raised position; the device includes a length-adjustable linking member between one of the elements, a cylinder or rod, of the working jack and one of the parts made up of the chassis or an arm, the linking member being held in an extended state during normal working mode, and in a retracted state to enable the arm or arms to enter a retracted position.

Abstract: Disclosed is a hydraulic system for controlling the degree of openness of an arm regeneration valve by driving an electronic proportional control valve during a combined operation of simultaneously operating an arm and a swing device.

Abstract: In a hydraulic excavator, a hydraulic cylinder drives a boom via a hydraulic fluid discharged from a first hydraulic pump. A first hydraulic circuit connects the first hydraulic pump and the hydraulic cylinder and forms a closed circuit therebetween. A hydraulic motor rotates a revolving upper unit with hydraulic fluid discharged from a second hydraulic pump. A second hydraulic circuit independent from the first hydraulic circuit connects the second hydraulic pump and the hydraulic motor. A motor hydraulic pressure reduction unit reduces the driving hydraulic pressure of the hydraulic motor when a predetermined condition is satisfied. The predetermined condition is a condition in which an operation of the boom operating member to raise the boom and an operation of the rotation operating member to rotate the revolving upper unit are conducted together and an operation amount of the boom operating member is equal to or greater than a predetermined threshold.

Abstract: A fluid control or actuation system providing selective recruiting of actuators antagonistic to one another to provide variable output power, such as that used to drive a load. The actuators are intended to comprise different sizes, and to be operable with one or more pressure control valves capable of providing displacement of a non-recruited actuator without requiring active input to cause such displacement. Being able to selectively recruit different sized actuators to drive the load, and being able to displace non-recruited without active input, effectively incorporates a gearing function into the fluid control system.

Abstract: A fluid pressure circuit that can, in either case where a first actuator that is fed from a first pump or a second actuator that is fed from a second pump is operated, by allowing feeding of the hydraulic fluid to a specific actuator from either the first or second pump, improve interlockability with the specific actuator. A control valve is incorporated with a plurality of first-group spools fed from a drive pump and a plurality of second-group spools fed from an idle pump. A solenoid selector valve unit switches a pilot line of a second-group tool controlling spool to a communicating state at the time of detection of a spool operation by a first pressure switch and switches a pilot line of a first-group tool controlling spool to a communicating state at the time of detection of a spool operation by a second pressure switch.

Abstract: A valve circuit, including a first and second circuit portion, for hydraulically controlling a loading dock vehicle restraint. The first circuit portion permits raising and lowering of the vehicle restraint. The second circuit portion permits extension and retraction of the vehicle restraint. Preferably, the first and second circuit portion are separate and are configured on the same valve block.

Abstract: A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.

Abstract: A system for simultaneously operating first and second hydraulic cylinders has an inlet node for connection to a source of pressurized fluid and an outlet node for connection to a tank. A two-position, three-way primary control valve has a first port connected to the inlet node, a second port connected to the outlet node, and a common port. A first electrohydraulic proportional valve connects the common port to a first port of the first cylinder, and a second electrohydraulic proportional valve connects the common port to a first port of the second cylinder. A third electrohydraulic proportional valve connects the inlet node to a second port of the first cylinder and a second port of the second cylinder. Selectively operating the primary control valve and one of the third and fourth electrohydraulic proportional valves determines the direction in which the first and second cylinders move.

Abstract: A hydraulic boom control system has two valves controlling linear hydraulic actuators, one for pivoting a hoist boom relative to a machine and one for pivoting a stick boom relative to the hoist boom. The bore sides of the actuators are hydraulically connected and the rod side of the hoist actuator is connected to the first port of the first valve and to the second port of the second valve. Operating the first valve moves the boom end generally horizontally and operating the second valve moves it generally vertically.

Abstract: A lifting device for lower steering arms of a tractor has a position recording device (25). The position recording device (25) generates a position signal representing the pivot position of the lower steering arms (2, 3). A piston-cylinder unit (11, 12) acts on the tractor and on the lower steering arm (2, 3). A switching circuit is provided per piston-cylinder unit (11, 12). The switching circuit includes a directional valve (33, 33′) with four ports and four switching positions. In a first position of the directional valve (33, 33′) all ports are blocked. In a second position, the cylinder chamber at the piston end is connected to the pressure agent supply source and the cylinder chamber at the piston rod end is connected to the return line. In a third position, the cylinder chamber at the piston rod end is connected to the pressure agent supply source and the cylinder chamber at the piston end is connected to the return line.

Abstract: The invention relates to a hydraulic multiposition valve, in particular a valve for selecting the steering modes of vehicles with multi-axle steering, having one or more position-seat valves (31, 33, 35, 37, 39, 41, 43), which have at least two switching positions and which communicate via lines for the hydraulic medium with one another and with a number of controlled connections (A, B, C, D; L, R) in such a manner that the desired switching positions of the multiposition valve (13) can be selected by the actuation of the seat valves (31-43); and having an actuating arrangement (29) for actuating the seat valves (31-43); the actuating arrangement (29) can be locked in detent fashion in the switching positions of the multiposition valve (13).

Abstract: The telescoping system includes a first and second fluid motor. The first fluid motor includes a first cylinder and a second cylinder nested in the first cylinder. The second fluid motor includes the second cylinder and a piston disposed in the second cylinder. The second cylinder has a double barrel outer wall forming a hydraulic fluid passageway. A hydraulic control system in the telescoping system includes a single control valve, solenoid valves, and holding valves, and controls extension and retraction of the telescoping system.

Abstract: A pneumatic brake booster having a right casing (10) divided in a leaktight fashion by a first moving partition (12) into a front chamber (14) and a rear chamber (16). The front chamber (14) being permanently connected to a source of low pressure (V) with the rear chamber (16) being selectively connected to the front chamber (12) and as source of high pressure by a three-way valve (40) operated by an operating rod (34). A three-way and two position solenoid valve (68) has a first inlet connected to the source of low pressure (V), a second inlet connected to a source of high pressure (A) and outlet connected to the rear chamber (14). A second moving partition (54,54') divides the rear chamber (14) into a working chamber (16) and a control chamber (50,50') with the outlet of the solenoid valve (68) being connected to the control chamber (50,50').

Abstract: An apparatus for hydraulically operating a rear cover, covering top or the like (1) on a vehicle, with at least one double-acting hydraulic working cylinder (3), which, on the one hand, is connected to the vehicle and, on the other hand, to the covering top, includes working chambers (8, 9) in connection with each one side of a switched pressure source (12) via one check valve (10, 11) each, wherein both of the check valves have an mutually releasing device and each of the working chambers parallel with respect to the check valves is kept via a pre-stress valve (15, 16), which steers into the tank, at a specified pressure level. To realize, in a simple and safe way, a passive wedging protection, in at least one connection line (4, 5) to the working cylinder (3), a line (22) enters the tank (17), in which a proportional pressure valve (23) is inserted which is controlled by the control electronics and is equal to the exact pressure that is necessary for the movement of the covering top (1) or the like.

Abstract: A hydraulic control for operating an automatic transmission, especially a continuously variable transmission, has at least one first and one second switching component (1, 2) for forward or reverse drive from a neutral position (N) to a drive (D) or reverse (R) position and vice versa. The switching components (1, 2) can be actuated by pressure via pressure lines (24, 25) by a selector slide (15) and by a switching device (26) between the selector slide (15) and the switching components (1, 2) which has a switching valve (27, 28) and a damper, switching and vent valve (29, 30) for a switching component (1, 2). The switching device (26) has a safety and vent device designed in a manner such that when one of the switching components (1, 2) is actuated, the other switching component(s) is/are automatically disengaged.

Abstract: The telescoping system includes a first fluid motor and a second fluid motor. The first fluid motor includes a first extension chamber and a first retraction chamber, and the second fluid motor includes a second extension chamber and a second retraction chamber. A hydraulic control system in the telescoping system controls the supply of hydraulic fluid to the first fluid motor and between the first fluid motor and the second fluid motor such that the first and second fluid motors operate independently.

Abstract: An apparatus for hydraulic actuation of a hinged cover on a vehicle having a working cylinder such that work spaces within the cylinder are respectively connected, via check valves, to a reversible pressure source. The check valves respectively contain a reciprocal unclosing facility, and the work spaces are connected, via a pilot valve, in parallel to the check valves. Between the one of the work space and one of the check valves, an emergency valve guiding off to the tank is interposed and is shut off during normal operation of the apparatus to allow a safe emergency actuation of the hinged cover.

Abstract: In a working vehicle including a first control valve assembly (15) for controlling the operation of a hydraulic lift cylinder (14), a cylinder case (13) of the lift cylinder includes, at one of its side surfaces, a vertical seating surface (52) on which a second control valve assembly (20) for controlling the operation of plural another hydraulic actuators (18, 19) is mounted. The second valve assembly includes plural control valve spools (31, 32) which extend in the valve case axially of the vehicle at levels different from one another.

Abstract: In a hydraulic apparatus for traveling, a left direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a first valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, a right direction switching valve is formed by forming a spool bore having a pump port, an actuator port and a return port in a second valve block, and by disposing a spool within the spool bore for establishing and blocking communication of respective of the ports to another of the ports, and a switching valve is formed by forming a spool bore having a primary port and a drain port in a third valve block, and by disposing a spool within the spool bore for establishing and blocking communication between respective of the ports and another of the ports.

Abstract: An apparatus generates power at micro-scale dimensions that is sufficient to simulate the muscle activity required by the joints of robotic fingers. The apparatus includes a bellows device for generating a motion stimulus in response to pressure changes within the bellows. A configuration of programmable micromachined valves is used to regulate the flow of pressurized fluid within the bellows. A microprocessor is responsive to motion commands for controlling the operation of the apparatus. The apparatus is configured as an integrated device that is coupled to the articulations of a robotic hand via suitable attachment mechanisms.

Abstract: The invention relates to a hydraulic circuit for the sequential control of two or more hydraulic cylinders and more particularly for opening and closing the folding roof a cabriolet type vehicle, in which the cylinder space under the piston of each piston cylinder device is selectively connectable to a hydraulic pressure source or to a reservoir for hydraulic fluid, and an additional valve device is provided by which the cylinder space above the piston is also connectable to the pressure source for at least some of the piston cylinder devices. The cylinder spaces above the pistons are hydraulically connected and the additional valve device is constituted by a common electrically operated valve for the piston cylinder devices, by which the cylinder spaces above the pistons are jointly connectable to either the pressure source or the reservoir.

Abstract: An interlocking change-over valve system for use in a hydraulically controlled mechanism includes a plurality of hydraulic actuators and at least one valve corresponding to each actuator for controlling the hydraulic pressure supplied to each actuator. A hydraulic cylinder communicates with each valve for opening and closing the valve. A control device remotely activates the hydraulic cylinder to selectively supply hydraulic pressure to some of the hydraulic actuators.

Abstract: A telescoping robot arm with singularity-free three degrees of motion freedom spherical joints is disclosed. The telescoping section and spherical joints are hydraulically operated to achieve a high power-to-weight ratio and use conventional seals of the type normally used on hydraulic pistons. The spherical joints of the instant invention are comprised of a generally spherical cavity containing a tiltable member with integral a retractable arcuate vanes interdigitized with retractable arcuate vanes in a non-tiltable member. A plurality of cavities is formed within the spaces between the interdigitized arcuate vanes of the instant invention, with the volume of these intervane cavities being controlled with an equal plurality of hydraulic valves. A plurality of spherical joints of the present invention may be interconnected with double acting telescoping sections of the present invention to form a robotic arm assembly.

Abstract: A partial width seeding attachment includes electronically controlled solenoids which activate hydraulic flow control valves connected to the hydraulic cylinders on respective implement sections. Switches in the tractor cab control the rockshaft of one or more selected sections independently of the other sections to raise the openers on the selected section or sections from contact with the soil. An electronically activated flow reversing valve is connected between the source of hydraulic fluid under pressure and the lift cylinder for each of the sections. Activation of a selected valve after the selective control valve on the tractor is moved to the normal field working position pressurizes the side of the cylinder that raises the openers on the section. The remaining cylinders operate normally to maintain preselected down pressure on the other openers. A master raise switch provides implement lift independent of the position of the individual rockshaft control switches.

Abstract: A control change system for a hydraulic working vehicle having a plurality of hydraulic actuators operable by control levers each shiftable to a plurality of control positions. This system includes a plurality of pilot-operated control valves for controlling pressure oil supply to the hydraulic actuators, respectively, pilot pressure generating valves for generating a pilot pressure in accordance with the control positions of the control levers, and a pilot pressure switching unit for receiving the pilot pressure from the pilot pressure generating valves and outputting the pilot pressure selectively to the control valves. The pilot pressure switching unit includes a plurality of spools slidable to change communicating passages between a pilot pressure input section and a pilot pressure output section of the switching unit.

Abstract: This invention relates to a multiple jack incorporating at least three elements, viz. two pistons and two cylinders which define large and small chambers of a first cylinder, and large and small chambers of a second cylinder.According to the invention: a) a first inner conduit connects the large chamber of the first cylinder to a first outer conduit; b) a second inner conduit connects the small chamber of the first cylinder to a second outer conduit; c) a third inner conduit connects the large chamber of the second cylinder to a third outer conduit; and d) a fourth inner conduit connects the small chamber of the second cylinder to a fourth outer conduit.One application is the production of a telescopic jib presenting a satisfactory flexibility of use.

Abstract: An articulated mechanism for use as an articulated arm of an industrial robot, for example, includes a plurality of arms interconnecting articulations having respective fluid pressure angular displacement motors for angularly displacing the arms relatively to each other. A plurality of pipes are positioned in the arms, respectively, for supplying a fluid under pressure to the articulations, and a plurality of oil passages are disposed in the articulations, respectively, and branched from the pipes, respectively, to supply the fluid under pressure to the fluid pressure motors.

Abstract: A system includes two lower articulated longitudinal arms (6, 7) provided on their front ends with two bottom hitching points (8, 9), and an upper arm (10) in the middle, for hitching an implement at a third point; valves for controlling the rise and descent of the two lower arms and of the upper arm are provided, and the implement (3) is equipped with hitching members (11) corresponding to the three point hitch of a tractor; a rigid intermediate support frame (12) is provided for connection between the implement and the arms (6, 7, 10); the frame includes two bottom lateral points (13, 14) and one top middle point (15) for hitching the implement, and two lateral top points (16, 17) intened to be connected to the third top hitching point (10) of the tractor by connection jacks of variable length; the two lower arms (6, 7) are independent and can assume different inclinations, and the two lower lateral portions (22, 23) of the frame (12) are hitched to the two bottom points (8, 9), the assembly being such that

Abstract: Fluid systems having fluid motors which control aiding type loads many times have problems with cavitation in one end of the fluid type motor during lowering thereof. It is desirable to eliminate all cavitation in the fluid motor during operation. In order to eliminate cavitation during lowering of an aiding type load and to provide a positive pressure therein, the subject arrangement provides an exhaust pressurizing control for use in a fluid system. The exhaust pressurizing control includes an exhaust manifold means having selector means to provide a positive pressure in the exhaust manifold means during lowering of an aiding type load. The selector means includes pressure limiting and unloading means operative to provide a positive pressure in the exhaust manifold means during lowering of the aiding type load and to unload the pressurized fluid in the exhaust manifold means during raising of a resisting type load.

Abstract: A hydraulic circuit for a backhoe comprising a first multiple valve, a second multiple valve, and a confluence mechanism mounted between the first and second multiple valves. The first multiple valve includes control valves connected to a first pump in parallel to one another for driving working implements. The second multiple valve includes further control valves connected to a second pump in parallel to one another for driving other working implements. The confluence mechanism is connected to a rear end of a center bypass line of the first multiple valve and to a rear end of a center bypass line of the second multiple valve. Further, the confluence mechanism, in neutral position, is connected to a return oil line for confluently returning oil from the first and second multiple valves to a tank.

Abstract: For converting a stepwise translation movement into a continuous translation movement and arrangement and a method is provided which have at least two fluid-operated cylinder-piston units with cylinders are rigidly mechanically connected with one another and pistons movable in the cylinders between end positions and having piston rods, removably arranging clamping mechanisms on the pistons of the cylinder-piston units, arranging end position sensors in the regions of the end positions of the piston of a respective one of the cylinder-piston units, arranging end position pre-signal sensors so that they are axially spaced relative to the end position sensors, connecting the sensors with electronic a control unit, and producing by the electronic control unit signals for supplying a working fluid to the cylinders of the cylinder-piston units in an alternating manner.

Abstract: A rotary actuator includes a shaft rotatably mounted on a body, and a servovalve arranged to operate a vane motor for selectively rotating the shaft relative to the body. A portion of the shaft extends beyond the body. Supply and return passages are provided to the body and shaft so that fluid power supplied to the body is supplied to the servovalve and is also available at the end of the shaft beyond the body. Two or more such rotary actuators may be connected by intermediate brackets to provide a wrist actuator capable of movement about axes.

Abstract: A multiple frequency range hydraulic actuator includes a low frequency cylinder with a low frequency actuator piston within. The low frequency piston operates as a high frequency cylinder having a high frequency piston within. The low frequency piston, and high frequency piston operate in conjunction to generate low frequency movement. The high frequency piston operates independently to generate high frequency movement.

Abstract: In a hydraulic control device having at least one distributing valve (2m, ) connected upstream of a consuming point (35), a more effective energy utilization is achieved by means of a pressure step (D) provided for the input pressure of a second throttling point (15), which can be switched in stroke-dependent fashion by means of a control element (17, 17') of the distributing valve (2, 2') so that the maximum difference in pressure between the pump line pressure P.sub.(4) and the consumer pressure P.sub.(3) is only controlled shortly before the need of a high conveying amount. Before this the difference in pressure is kept smaller.

Abstract: An hydraulic system for operating double acting piston/cylinder assemblies and for effecting automatic transition from a regenerative mode of operation of a double acting piston/cylinder assembly to a non-regenerative mode of operation thereof. Pressure responsive valve means automatically converts the hydraulic system from one initially being a high-speed/low force operation to a high force/low speed operation.

Abstract: A hydraulic dual-circuit external power brake valve of tandem design has a primary control piston and a secondary control piston, both of which are located in a valve bore of the dual-circuit external power brake valve. The control pistons are provided with bores for connection of a primary brake circuit and a secondary brake circuit to a pressure reservoir and an equalizing tank, and are movable within the valve bore. The regulating force necessary for the motion is introduced into the dual-circuit external power brake valve by a regulating spring. A pressure-transmitting piston between the primary control piston and the regulating spring. The primary control piston on its two end faces, and the pressure-transmitting piston on its face toward the primary piston, are subjected to the pressure acting in the primary brake circuit. When the primary brake circuit is intact, the pressure-transmitting piston is actuated by the regulating spring.

Abstract: A system reduces force fight between hydraulic actuators (22, 24) operated on independent hydraulic circuits (29, 49) which position a control surface (20) of an aircraft. Each circuit includes a hydraulic supply (30, 50). A pressure equalization valve (70) is connected to first sides (42, 62) of the actuators. In the event of a pressure imbalance, a spool (82) shifts in the pressure equalization valve. Movement of the spool enables fluid from the circuit supply to be delivered through the equalization valve to the actuator at the lower pressure, rapidly eliminating the imbalance.

Abstract: Hydraulic assistance device for brake actuation comprising a body (10) having a bore (12) in which first and second piston mechanisms (34, 56) are slidably mounted, the first piston mechanism (34) being displaceable under the effect of the actuation of a third piston (16) mounted slideably in the bore (12), and the second piston mechanism (56) being displaceable by way of a hydrostatic connection formed in a presure chamber (60) defined between the first and the second piston mechanism (34, 56), there being associated with each piston mechanism (34, 56) a respective valve mechanism (52, 78) in a respective hydraulic circuit between a fluid source under pressure (54, 84) and a respective brake circuit (62,88), and a third chamber (30) defined in the bore (12) between the first piston mechanism (34) and the third piston (16), characterized in that the third chamber (30) is partially delimited by a fourth piston (92) which is displaceable under the effect of the pressure in the third chamber (30) as it meets a f

Abstract: Apparatus, and a related method, for controlling a moving floor having multiple sliding slats, to produce a practically continuous load-moving force on a load carried on the apparatus. The slats are reciprocated back and forth by hydraulic cylinders, each of which controls a group of slats that are moved together. At any given time, a majority of slats are moving together in the desired direction, and carry a load in this direction at a nearly uniform velocity. The remainder of the slats are moved in a reverse direction, but at a speed that is a multiple of the forward speed of the majority of the slats. Each group of slats is moved through a forward stroke at a relatively low speed; then through a backward stroke at a higher speed.

Abstract: A control block is made up of a plurality of directional valves which serve to actuate a plurality of hydraulic drives to which in some cases a different pressure is to be supplied. For this purpose two pressure-limiting valves adjustable to different pressures are provided, the valve adjustable to the lower pressure being connected to the last valve unit. This gives a simple construction and substantial freedom in the association of the drives.

Abstract: A multiple stage telescoping cylinder assembly, which provides full stage selection capability without the need for external hoses or reels, comprises a base; an inner cylinder attached at its rearward end to the base and first and second stage cylinders of successively greater diameter mounted on the inner cylinder in telescoping relationship for extension during their forward strokes and retraction during their rearward strokes, the first and second stage cylinders each having an extend facing surface relatively adjacent its forward end for fluid pressure to contact to effect extension thereof and a retract facing surface relatively adjacent its rearward end for fluid pressure to contact to effect retraction thereof; and plural fluid passages for directing fluid under pressure from the rearward end of the inner cylinder forwardly through the interior of the inner cylinder and then into contact with respective ones of the facing surfaces for selective extension and retraction of the first and second stage cy

Abstract: A contractility actuator includes a longitudinal quadrilateral mesh of relatively inelastic segments with anchor points at either end, an expandable bladder confined within the mesh and means for introducing and inflating the bladder with a liquid for generating a contractile force between the anchor points mechanically analogous to a muscle but of much greater magnitude. Two or more of the contractile actuators are arranged in a system for precisely articulating one or more arms pivotally secured at the distal ends of a structural member.

Abstract: A self-leveling series type hydraulic system including boom and bucket valves which separately control boom and bucket cylinders and a flow divider valve positioned in the exhaust flow path from the rod end of the boom cylinder. The flow divider valve splits the flow sending a portion of it to the cap end of the bucket cylinder so as to maintain the bucket in a level condition during raising of the boom with the remaining flow returning to the control valve downstream of the boom valve along with the return flow from the rod end of the bucket cylinder which is also returned to the control valve downstream of the boom valve whereby the bucket valve can be separately actuated concurrent with the boom valve and supplied with oil so as to override the self-leveling function if desired.

Abstract: In a method of and device for adjusting the feed movement of a drill rod for drilling a rock, the drill rod is rotated by a pressure-medium-operated rotary motor and fed in a drilling direction and in the opposite direction by a pressure-medium-operated feed motor. A pressure change on the pressure side of the rotary motor due to a change in the rotation resistance on the rotary motor acts oppositely on the pressure and outlet sides of the feed motor toward reversing the feed force of the feed motor, i.e. in inverse and direct dependence on the pressure change, respectively. The pressures on the pressure side and the outlet side of the feed motor are, therefore, controlled so that, when the pressure on one side increases because of the pressure change, the pressure on the other side decreases and vice versa.

Abstract: A hydraulic adjustment apparatus for use in adjusting and positioning microwave radiating antenna or any other treatment monitoring device is disclosed. The hydraulic adjustment apparatus, generally comprises an upper portion having a box-like member suitable for accommodating therein a mounting member; a plurality of upper adjustable leg member means; a plurality of upper switch valve means with associated plurality of upper tubular means attached thereto; as well as a plate member for joining said upper portion to a lower portion of said hydraulic adjustment apparatus. Said lower portion, generally comprises a plurality of lower tubular members; and lower adjustable leg member means operably coupled to a base member having a preferable microwave radiating antenna or any other treatment monitoring device integrally coupled thereto.

Abstract: The invention relates to a method for the simultaneous actuation of a plurality of hydraulic consumers by means of intrinsically-safe electro-hydraulic valves. The consumers are connected by hydraulic directional control valves to a pressure line and/or a return line. These hydraulic directional control valves can be connected in a predetermined manner, via pre-control valves to a control line. The pre-control valves are pressureless, and possess electro-magnets with a current consumption of less than 50 milliamps. By connection of a series-connected electro-hydraulic directional control valve means, the pre-control valves are connected to the control line, and at the same time are hydraulically locked.

Abstract: Hydraulic assistance device, comprising a body (10) comprising a bore (12) in which a first piston mechanism and a second piston mechanism (18, 20) are slideably mounted, the first piston mechanism (18) being movable under the effect of the actuation of a third piston (16) slidably mounted in the body (10), and the second piston mechanism (20) being movable by the intermediary of a hydrostatic connection formed in a pressure chamber (22) defined between the first and the second piston mechanism (18, 20), a respective valve mechanism (60, 100) being associated with each piston mechanism (18, 20) in a respective hydraulic circuit between a source of fluid under pressure (52, 96) and a respective braking circuit (74, 110); and a third chamber (36) defined in the bore (12) between the first piston mechanism (18) and the third piston (16), the third chamber (36) being connected to a low pressure reservoir (25) through a passage in which a valve mechanism (42 ) is mounted, characterized in that the device incorpora

Abstract: In a working vehicle having hydraulic lift cylinder (39) on the top of rear end of the vehicle and seat (34) above the cylinder case (33) of such cylinder, fluid supply system is provided which supplies fluid from a single pump (47) to both of the lift cylinder and fluid-operated working implements. This system comprises first and second valve assemblies (49, 50), connected in series and mounted on the cylinder case (33), for controlling operation of the lift cylinder and working implements, respectively. The second valve assembly (50) is particularly disposed, for an easy mounting and piping, horizontally along a lateral direction within large open space before the cylinder head (81) of cylinder case (33) and below the seat (34) by mounting same to the front of head (81). For this, stop valve (52) for lift cylinder (39) is disposed within the head (81) so as to be displayed laterally and a vertical seating surface (96) is formed to the front of head (81).