Abstract: An electro-hydraulic control system includes a plurality of two-position control valves, each controlling fluid flow into and out of a corresponding one of a plurality of hydraulic functions. First and second pressure responsive servo actuators associated with each control valve operate to move each control valve to first and second positions, respectively. A two-position, solenoid-operated, pilot valve controls fluid flow into and out of a pilot circuit. The pilot circuit communicates fluid to and from the second servo actuator of each control valve and to and from a plurality of two-position, soleniod-operated, pilot valves. Each pilot valve controls fluid flow into and out of the first servo actuator of a corresponding one of the control valves. A detent mechanism holds each control valve in either its first or its second position in the absence of fluid pressure in the servo actuators.

Abstract: A switch and valve assembly for inflating or deflating a pair of bladders mounted in the back and seat regions of a vehicle seat. The assembly houses two normally-closed valve assemblies and two normally-open electrical switch assemblies, with two pushbutton-actuated stems adapted to selectively either partially open the valve assemblies by partial depression of the pushbuttons to thereby bleed-off fluid under pressure from respective bladders, or to fully open the valve assemblies while closing the switch assemblies by full depression of the pushbuttons to thereby actuate the pump to provide fluid under pressure to fill the respective bladders as desired for operator riding comfort or support. Pressures in the two bladders may be changed individually or concurrently.

Abstract: A hydraulic circuit for a self-undecking crane having retractable legs with extendable jacks for elevating and supporting the crane upper. Hydraulic cylinders move the legs between a retracted position and an extended position in which the jacks are engageable with the ground and isolation valve devices in the hydraulic circuit prevent retraction of said legs when the crane upper is supported on the extendable jacks.

Abstract: A hydraulic control circuit system comprises first and second double-acting cylinders, a hydraulic pump for supplying the double-acting cylinders with pressure oil, and directional control valves respectively associated with the cylinders for controlling the supply of pressure oil to the latter. The hydraulic control circuit system has a circuit for independently operating the individual cylinders and also a circuit for causing the rod advancing and retracting actions of the first cylinder to be followed by the rod advancing and retracting actions of the second cylinder. The system is applied to the hydraulic control circuit of, e.g., a front loader for controlling a hydraulic cylinder used for lifting and lowering the loader arm and another hydraulic cylinder used for turning the bucket pivotally connected to the free end of the arm.

Abstract: A hydraulic circuit system for civil engineering and architectural machinery having at least first and second hydraulic pumps, a plurality of actuators driven by hydraulic fluid from said pumps, and a plurality of directional control valves for controlling the direction and flow rate of the hydraulic fluid supplied from the pumps to the actuators. In the directional control valves, a first boom directional control valve and one of right and left travelling directional control valves are connected to the first pump in parallel with each other, a swing directional control valve, an arm directional control valve and a second boom directional control valve are connected to the second pump in parallel with one another, and the other of the right and left travelling directional control valve is connected in tandem to the swing, arm and second boom directional control valves at a location downstream thereof.

Abstract: A self-leveling series type hydraulic system with a float position 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 in one position 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 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. The flow divider valve having a second position which bypasses all of the flow from the boom cylinder to reservoir when the boom control valve is in a float position.

Abstract: A hydraulic drive system for civil engineering and construction machinery in which at least first and second hydraulic circuits having at least first and second hydraulic pumps, respectively, are provided for driving a plurality of actuators such as left and right travelling actuators, a boom actuator and an arm actuator. The first circuit includes a first travelling directional control valve for one of the left and right travelling actuators located downstream of a first boom directional control valve for the boom actuator and a first arm directional control valve for the arm actuator that the latter to receive a hydraulic fluid supply from the first pump by taking priority over the first travelling valve.

Abstract: A multiple control valve system comprises a multiple control valve as a main body, an additional attachment valve operatively connected to the multiple control valve, a logic valve oil-tightly fitted to the multiple control valve so as to be communicated with oil passages formed in the multiple control valve, and a change-over valve operatively connected to a spool located in the attachment valve so as to be communicated with oil passages of the attachment valve and connected to the logic valve through a conduit.

Abstract: A hydraulic fluid circuit of a hydraulic shovel including a first directional control valve group connected to a first hydraulic pump and including a first directional control valve and a second directional control valve respectively connected to a first hydraulic cylinder and a second hydraulic cylinder. A second directional control valve group, connected to a second hydraulic pump, includes a third directional control valve having a first working port connected to one cylinder chamber of the first hydraulic cylinder and a second working port connected to one cylinder chamber of the second hydraulic cylinder.

Abstract: A force transmitting fluid actuator for use with a control device wherein an actuator member, movable within an actuator housing, actuates the control device due to the urging force of a plurality of pistons which can be selectively pressurized in unitary increments. The plurality of pistons are disposed within pressure chambers formed in the actuator housing in a symmetrical ring-shaped arrangement concentric to a single pressure chamber disposed on the vertical axis of the housing. A number of passageways interconnect the plurality of pressure chambers to form groupings of pressure chambers which act simultaneously in response to operation of a solenoid valve associated with each passageway. In addition to the symmetrical arrangement of the pressure chambers, the valve and passageway arrangement provide for a symmetric pressurization of the pressure chambers thereby resulting in a balanced force being exerted on the actuator.

Abstract: The present invention relates to a device for controlling two fluid-controlled drive members, one of which is double-acting, wherein a communication conduit connects the supply conduits of said double-acting drive member, a non-return valve being disposed in said communication conduit and allowing the passage of the fluid solely from the small chamber towards the large chamber of said double-acting drive member, while another conduit is adapted to connect the large chamber of the double-acting drive member to the chamber of the second drive member. The result of the invention is the elimination of lift of a hydraulic loading shovel when digging.

Abstract: An electric hydraulic control device for controlling hydraulic cylinders of work tools in a construction vehicle, in which control valves of the hydraulic cylinders are controlled in two ways. For some work tools which need not be controlled smoothly and finely, the corresponding control valves are controlled directly by an electric signal outputted according to the position of the operation levers, and for other work tools which must be controlled smoothly and finely, the corresponding control valves are controlled through an electric servo mechanism which is operated by an electric signal representative of the amount by which the operation lever is manipulated. In addition, there is provided a detector for detecting as to whether the transmission lever is in the locked condition, and electric systems of all of the control valves are rendered inoperative when the transmission lever is in the locked condition.

Abstract: An electrohydraulic control system for a pair of hydraulically actuated vehicle transmission clutches operable to effect high and low speed ranges. High and low hydraulic clutch valves are pilot operated by a solenoid valve which delivers pressurized fluid to pressure chambers associated with the flow control elements of the clutch valves. The solenoid valve is controlled by a circuit which includes a relay operated switch, a manually operated switch controlling the relay operated switch and a clutch pedal operated switch in series with the manually operated switch. The relay operated switch opens when the clutch pedal is operated thereby causing the transmission to be in a low speed condition when inching the vehicle.

Abstract: A multiple control valve for operating a civil construction machine or the like comprises a valve body, at least two parallel direction change-over plungers assembled in the valve body, by-pass passages and fluid supply passages formed in the valve body and operatively communicated with the plungers for feeding fluid from an external source to the plungers. One of plungers disposed most downstream side of the multiple control valve is provided with inner passages arranged on both sides thereof, a passage crossing the plunger, an axial passage having one end closed and the other end opened towards one of the inner passages, and a lateral port communicated with the inner passage. The crossing passage is communicated with the axial passage at a portion near the closed end thereof.

Abstract: A flow regulating channel in a servo steering valve controls exhaust flow with varying restriction from a fluid operating motor while controlling operation of a separate steering servo motor on a priority basis. An operational control valve for the fluid operating motor has a valve passage that is open only in the neutral position to complete a recirculating flow path from a common servo pump through the flow regulating channel that is fully open in the neutral position of the steering valve.

Abstract: A double acting hydraulic actuator for operating in a power shift transmission. An accumulator operates with two hydraulic clutches to dampen surges in pressures and to store energy in the hydraulic system during operation of the hydraulic system.

Abstract: A single lever pilot control system (10) controls the simultaneous operation of two actuators (16,18). A mechanism (48) holds a first control valve (20) in an actuated position in response to movement of the handle (29) along a first axis (44) while freeing the handle (29) to return to a neutral position. Further movement of the handle (29) along a different axis to operate the second actuator (18) does not override the automatic stopping of the first actuator (16). The mechanism (48) provides a more precise control of automatically stopping one actuator while simultaneously operating the second actuator.

Abstract: A wrist mechanism in an industrial robot comprises a wrist, a rotary type actuator which is rotatable in clockwise and counter-clockwise directions, a first positioning board which can define arbitrary angular stopping positions, sensing devices, and a second positioning board which is arranged facing the first positioning board, wherein the sensing devices detect the angular position of the wrist, which is driven by the rotary type actuator, the rotary type actuator is stopped by signals produced by the sensing devices, and the second positioning board with tapered receptacles is pressed to the first positioning board with tapered pins, whereby the positioning of the wrist mechanism is carried out.

Abstract: A sectional hydraulic valve has clamped together an inlet section, an outlet section and at least one working section which can be integral with the inlet and/or outlet sections. Fluid supply and return passages are formed in the sections and are in register at each junction where there are formed contiguous planar sealing surfaces. A depressed area is provided in one of the surfaces surrounding the contiguous planar sealing surfaces of the supply and return passages and a groove containing a sealing ring is formed in one of surfaces around the depressed area. A drain passage leading to a low pressure region opens into the depressed area and should there be leakage between the sealing surfaces of the supply and return passages, particularly as a result of the presence of high pressure in said passages, the leaked fluid merely passes into the depressed area and flows through the drain passage to the low pressure region without subjecting the sealing ring to pressure and possible leakage there past.

Abstract: A control linkage for a round bale wagon is disclosed wherein both the operation of the bale pickup mechanism to squeeze a bale of crop material for firm engagement between a pair of projecting arms and the operation to lift a bale so engaged onto the load bed can be controlled by a single control lever. The squeeze and lift operations are powered by separate hydraulic cylinders operatively controlled by respective control valves having three position spools, spring loaded to the central, neutral position. The control linkage includes a cross link interconnecting the two respective control valves and a connecting link extending from a point on the cross link, closer to the squeeze valve than to the lift valve, for connection to the control lever.

Abstract: A displacement mechanism for effecting both rotary movement of a movable member (for example a fin) with respect to a fixed member (for example a flight vehicle body) from a first, inoperative position to a second, operative position about a longitudinal axis and axial movement of the movable member along that axis to effect subsequent locking in the second position, comprises a fluid operated vane motor to effect rotation and a fluid operated piston/cylinder arrangement to effect the axial movement. Preferably the vane motor and the piston/cylinder arrangement are closely integrated one with another.

Abstract: In a high pressure hydraulic system wherein a source supplies pressurized fluid to a slave unit through a control valve operative to maintain the slave unit in a desired condition, leakage from the slave unit past the control valve when the source is inoperative is prevented by a control valve comprising two solenoid-operated valves, oppositely acting and arranged in series between the source and the slave unit, each valve being closed to prevent flow through the valve in a direction towards the other valve and opened to permit flow in both directions, under the control of a solenoid and the pressure differential acting across the valve. A seating portion on the valve located between the other valve and the slave unit is of elastomeric material to provide a leakproof seal when that valve is closed.

Abstract: An adjustable flow restricting valve for speed control of a pneumatic motor, comprising a tube shaped valve body which is rotatably supported in a boring and which is provided with a recess for uncovering fully or partly an outlet opening in the boring. The restricting valve is associated with a control valve for operation of a pneumatic motor. The tube shaped valve body is rotatable by means of a maneuver screw which extends transversely relative to the valve body and which forms a worm gear with the latter. The high gear ratio of the worm gear enables a precise setting of the valve body. In a multiple arrangement of control valves, the tubular valve body of one flow restricting valve forms part of the exhaust passage from one or more flow restricting valves, located upstream thereof.

Abstract: A hydraulic control valve provides controlled fluid supply for two hydraulic services having different flow and pressure requirements, as for example a lift service of a lift truck for lifting loads vertically and a tilting service for tilting loads forwardly and rearwardly. Two landed spools operate in parallel adjacent bores each joining a plurality of chambers and connected to fluid pressure supply and tank service ports. The supply to port communicating with one of the bores through two of the chambers, so that flow area is increased and the pressure drop of fluid flowing through them is reduced, and is connected through the bore and chambers to the tank port when the respective spool is in a neutral position and selectively to the service ports by movement of the spool.

Abstract: Conditional exchanging of working fluid between plural fluid circuits (13A, 13B) having separate supply pumps (18A, 18B) is provided for without continuously bleeding fluid from the pump control pressure lines (21A, 21B). Each circuit (13A, 13B) has a pump control (19A, 19B) responsive to a control pressure, a plurality of fluid motors (14A, 15A, 16A, 14B, 15B, 16B), and a group of resolver valves (38A, 38B) which compare motor pressures and intercommunicate the pump control (19A, 19B) with the most highly pressurized motor (14A, 15A, 16A, 14B, 15B, 16B). At times when fluid from one circuit (13A, 13B) is being delivered to a motor (16A, 16B) of another circuit (13A, 13B), the pressure comparing function of the resolver group (38A, 38B) of the one circuit (13A, 13 B) is extended to include the motor (16A, 16B) of the other circuit (13A, 13B). Among other uses, the system (11) may be used on excavator vehicles having plural fluid motors performing a variety of different functions.

Abstract: A circuit for hydrostatically operable devices, especially hydraulic dredges, with at least two working circuits each of which comprises a plurality of hydraulic cylinders and/or hydraulic motors as well as a hydraulic pump while, depending on the requirement, the delivery of the pertaining hydraulic pump is conveyed to each hydraulic cylinder or hydraulic motor and while by means of a plurality of tie lines the deliveries of the remaining hydraulic pumps are selectively conveyed to one of two or more selected hydraulic cylinders or hydraulic motors. The deliveries of the hydraulic pumps flow to the tank after having passed through the control valves associated with the hydraulic cylinders and controlling each of the hydraulic pumps.

Abstract: A number of systems exist wherein a plurality of hydraulic motors (28a, 28b, 28c) receive pressurized fluid from a single pump (14) which is itself driven by an electric motor (12). Apparatus has been available for adjusting the power supplied to the electric motor (12), and thereby adjusting the pump (14) flow rate, in response to the operator activating one or more of the hydraulic motors (28a, 28b, 28c). However, such apparatus has generally been bulky, complicated and/or difficult to install and/or service. An improvement is provided wherein a single switch (22) is placed in either an open or closed position as an elongated member (34) placed transversely to a plurality of generally parallel rod member (20a, 20b, 20c) is rotated in response to longitudinal travel in either direction from a neutral position (32) of one of the rod member (20a, 20b, 20c).

Abstract: A hydraulic control system is provided for a mine roof support assembly constituted by a plurality of roof support units positioned side-by-side. The control system comprises a respective control valve assembly having a plurality of similar control valves each of which controls a respective hydraulic appliance associated with the corresponding roof support unit. Each control valve can be actuated optionally by an actuator mounted on either one of the two adjacent roof support units, or by either one of two actuating devices mounted one on each of said two adjacent roof support units. Each control valve includes two servo valves having a pair of first and second axially aligned servo-pistons which are separate and independently operable with respect to each other.

Abstract: A pressure converter valve suitable for use in fluid flow systems. The pressure converter valve comprises a solid body having a plurality of interconnected bores formed therein with unidirectional flow devices located within certain of the bores to form parallel flow paths between the inlet and outlet ports of the pressure converter valve such that fluid flows in a first direction through one of the outlet ports and in a second direction through the other of the outlet ports regardless of the direction of fluid flow through the inlet ports. The pressure converter valve is adapted to have an auxiliary fluid control valve mounted thereto in fluid flow communication with the outlet ports of the pressure converter valve and, further, includes fluid flow paths connecting the outlet ports of the auxiliary valve to an auxiliary fluid operated device which is controlled by the auxiliary valve.

Abstract: A hydraulic control circuit especially for use with multi-function hydraulic devices, such as for industrial lift truck attachments, in which a combination of valve means are adapted to operate two or more hydraulic systems, the valve system being designed such that a minimum number of hydraulic conduits are required to connect the main hydraulic system to the hydraulic devices, as from a lift truck to an attachment supporting carriage on a lift truck upright, and no electric lines are required to be connected to switching devices between the hydraulic devices, such as to solenoid operated valves.

Abstract: A hydraulic control arrangement for hydraulic consumer includes a multiple position valve having a control slide movable by proportional magnets between a neutral position and a plurality of working positions, in which the magnets may be remote controlled from an analog desired value signal and in which a stop valve is provided in a control circuit leading from the consumer to an over-pressure valve, which in turn is connected, upstream of the multiple position valve, parallel to the consumer between a pressure conduit connected to a source of pressure and a return conduit connected to a tank.

Abstract: A hydraulic control system for distributing pressure fluid to at least two systems, that is a first system including a first pump supplying pressure fluid through a first conduit to a first consumer and a second system including a second pump for supplying pressure fluid to a second conduit, in which a plurality of multiple position valves are arranged, each movable between a neutral position providing free flow of fluid through the second conduit and at least one working position respectively directing pressure fluid to the additional consumer respectively connected to said plurality of multiple position valves. A regulating valve is located in the first conduit and the second conduit is connected by a cross-conduit to the first conduit at a point upstream of the regulating valve therein.

Abstract: A valve block for hydraulic excavators having at least two sets of valves which are each coupled to their pump. The valves are of the type which, in the unactuated state, allows the passage of pressure medium. The hydraulic devices for executing working movements of the excavator are each coupled to their valve in each set. The valves in the one set are coupled in series, counted from the pump in the sequence the valve which is coupled to the hydraulic device for the first working movement of the excavator, the valve which is coupled to the hydraulic device for the second working movement of the excavator, and the valve which is coupled to the hydraulic device for the third working movement of the excavator.

Abstract: An integrated control mechanism for regulating the communication of pressurized fluid from a source to a brake system and a steering system of a vehicle in response to independent operator brake and steering signals. The integrated control mechanism has a housing with a bore therein connected to a single source of fluid under pressure. A rotary valve located in the bore is rotated in response to an operator steering signal to control the communication of the pressurized fluid to the steering system from the bore and thereby provide a power assist in steering the vehicle. A spool valve, concentrically located in said bore with respect to said rotary valve, linearly moves in response to an operator braking signal to control the communication of the pressurized fluid from the bore to the brake system and thereby provide a power assist in effecting a brake application.

Abstract: A control device serves to control the fluid flow to and from double-acting rams, especially the rams of mining machinery, the control device having various internal ducts which are defined between two plates connected together. One of the two plates (a duct plate) has a main face formed with channels, some of which radiate outwardly from a ring of bores, and two of which are `T`-shaped and extend generally tangential to the ring of bores. The other plate (a connecting plate) closes the channels to define ducts and has bores communicating with the various ducts. Control valve units are detachably connected to the connecting plate, the control valve units being arranged to be actuated to effect desired connections between the various ducts by way of the bores in the connecting plate.

Abstract: A control device for controlling hydraulically actuated equipment, the device comprising a fluid distributing block and a plurality of control valve units detachably mounted side-by-side on the block, the block being formed with an inlet opening, an outlet opening, a plurality of control line openings, a plurality of delivery openings, a plurality of return openings, a plurality of valve unit communicating openings, and internal passage means, the said internal passage means connecting the inlet opening with each of the delivery openings, connecting the outlet opening with each of the return openings, and connecting the control line opening with respective corresponding ones of the valve unit communicating openings.

Abstract: A device for separating the platens of a press so that wooden blanks in an unpressed form can be readily loaded therebetween. The device includes outwardly extending arms carried on the corners of each of the platens. Pneumatically operated bellows are provided between cooperating pairs of outwardly extending arms which are carried on diagonally opposite corners of each of the platens for separating the platens when pressurized. Alternate pairs of platens have pairs of bellows interposed between the outwardly extending arms carried on different diagonals. A switch is carried below the press for disengaging the pneumatic system when the press is being closed.

Abstract: A fluid control system includes a directional control valve assembly adapted for use in either an open center or a closed center configuration. The assembly is capable of incorporating one or more control sections, each with a manual control valve having its own variable pressure compensated flow controlling mechanism. Motor port lock-out valves are associated with each manual control valve, and a pressure responsive logic circuit automatically actuates the lock-out valves to hold them open when their associated manual control valve is in the power or float positions. When any manual control valve is in the float position, any other manual control valve may be operated in the power positions.

Abstract: An electro-hydraulic control system to enable either simultaneous extension or retraction of all boom sections in a telescopic crane boom or independent extension or retraction of one or more individual boom sections comprises a valve assembly, including solenoid-operated extend and retract valves, on each boom section cylinder; a manually operable three-position (neutral, extend, retract) main control valve for connecting the valve assemblies to a pressurized fluid source and to a reservoir; a relay for energizing all solenoid valves simultaneously when the main control valve is operated to extend or retract positions to thereby effect simultaneous extension or retraction, respectively, of all boom sections; and manually actuatable selector switches, one for each movable boom section, which, when any one selector switch is actuated while the main valve is operated, override the relay and energize only the solenoid valves in a selected valve assembly thereby enabling independent extension or retraction of a s

Abstract: an open center hydraulic system in which a pair of flow divider valves is connected in series with the system's hydraulic pump to create a parasitic pressure upstream of these flow valves and the feeder and separator clutches are controlled remotely by simple solenoid actuated two-position valves. The cylinders actuating the clutches are of sufficient size upon application of the minimum parasitic pressure to hold the clutches in a given position so that no center neutral position is necessary on the two-position valves.