Abstract: A crawler tractor has an engine-driven fluid power shifted transmission for supplying motive power to left and right crawler tracks through spring-applied fluid-released left and right steering clutches and also has spring-applied fluid-released brake actuators for the track brakes. A hydraulic control system for steering and braking the tractor includes a combined steering and braking valve having a pair of lever operated valve spools, a shuttle valve, and a supplemental brake control valve operated by a single brake pedal. The combined steering and braking valve, which includes a flow divider, directs fluid from a pump to the brake actuators to maintain the brakes released when the valve spools are in neutral. When a lever operated valve spool is moved from neutral to some other position, the combined steering and braking valve directs fluid to disengage a clutch and causes the brake for the associated track to be applied.

Abstract: Modulated hydraulic clutch pack engagement is provided in a single valve body which includes a drive direction selector spool, a dump valve, a pressure modulating spool, a downstream system pressure regulator and a provision for continuous flow to a downstream torque converter. The modulator spool interrupts communication between a first and second chamber. Fluid pressure develops in the first chamber in response to selector spool initiation of clutch pack fill line pressure. A pressure differential is generated between the first and second chambers resulting in modulator spool displacement allowing equalization of chamber pressures. Metered flow to the back side of the modulator spool generates pressure that reseats the spool with the aid of spring pressure. Pressure then builds in the first chamber. The modulation is repeated rapidly resulting in the clutch pack being fully pressurized, however, the modulator will continue to regulate fluid to be supplied to the torque converter.

Abstract: A self-depressurizing hydraulic control valve having a sliding-type metering valve to control the flow of hydraulic fluid through the valve and also a shutoff valve to stop the flow automatically. The shutoff valve is responsive to the rate of flow of fluid through the control valve and stops the flow when the flow rate decreases to a preselected value. When the shutoff valve closes, the control edges of the metering valve are no longer exposed directly to high pressure fluid, and quiescent leakage across the edges is practically eliminated. Thus, electrochemical erosion of the metering edges resulting from such leakage is substantially reduced.

Abstract: This invention relates to a vented ball-type cock such as is used at each end of the brake pipe on a railway vehicle in which the brake pipe hose connected to the cock outlet is vented to atmosphere in the cock closed position via a passageway extending through the cock body, the cover therefor and a spiral groove of some suitable configuration formed on a cylindrical stem extending through the cover for rotating a ball-type valve within the cock body between an open and a closed position. A resilient seal obliquely mounted on the stem for rotation therewith is shifted thereby, relative to the cover, from the cock closed position in which a communication between the inlet and outlet of the cock is closed and the hose-venting passageway is open, to the open position in which the communication between the inlet and outlet of the cock is open and the hose-venting passageway is closed.

Abstract: A controller for fluid pressure operated devices such as power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member and including a fluid meter having a metering member coupled to the follow-up valve member. The valving defines a central reference plane perpendicular to the axis of rotation of the valving, the primary valve member defining a pair of meter grooves oppositely and equally disposed about the plane. The follow-up valve defines pressure porting adjacent the plane and connected to the fluid inlet port.

Abstract: The specification discloses an air logic circuit with two, five port valves connected between an air supply and a volume chamber for supplying an output signal at an output port when both valves are activated substantially simultaneously. When both valves are in a released condition there is no output signal and the air supply is connected through the serial combination of both valves to a volume chamber. When either of the two valves is activated alone, the volume chamber is coupled to the atmosphere through an exhaust orifice. When both valves are simultaneously activated, the volume chamber is coupled to an output through the serial combination of both valves.

Abstract: A control valve having a rotor for communicating outlet port or ports selectively to fluid drain port or to inlet port so as to change flow direction of fluid to be supplied to fluid operated apparatus. The control valve comprises first and second pistons inserted in a hollow space of the rotor and a compression spring arranged between the pistons. At the operation position(s) of the rotor or the valve, the first piston which is biased by the compression spring oscillatingly blocks and reopens fluid passage formed within the rotor outside the first piston for communicating the inlet port to the outlet port(s) under the influence of the compression spring and fluid pressure of the outlet port(s) from which fluid is constantly drained with a small rate through the valve. Fluid pressure of the outlet port may be varied by varying the force of the compression spring by an advance of the second piston.

Abstract: An hydraulic controller comprising: a casing; first and second inlets and a plurality of outlets associated with the casing; a flow-directing member rotatable in the casing; first and second passages extending through the flow-directing member, the flow-directing member being rotatable in the casing to each of a plurality of selected positions for directing liquid from the said inlets to selected ones of the outlets by way of said passages, each said first and second passage having an inlet end connected to a respective one of the first and second casing inlets, and having an outlet end connected to a selected one of the said several casing outlets according to the selected position of the said flow-directing member; first and second valves mounted in the flow-directing member and movable to open and close said first and second passages respectively; and locking means which operate in at least one of the said selected positions of the flow-directing member to prevent movement of the said first valve to a posi

Abstract: A fail-safe fluid control valve including a first sleeve fixedly accommodated in a valve housing, a second sleeve reciprocably movably received in the first sleeve. The first and second sleeves are suitably grooved and ported, and the valve spool is formed properly with annular flanges. When there occur such abnormal conditions that the second sleeve and the valve spool are jammed or stuck to each other, the second sleeve is adapted to be moved in unison with the valve spool to actuate the fail-safe fluid control valve under entirely the same conditions as normal conditions.

Abstract: A direction flow control valve for control of positive and negative loads equipped with a load responsive control which automatically blocks the pump flow to the motor while controlling negative load, providing the motor inlet with fluid from the motor exhaust.

Abstract: A boost valve device is described which comprises a valve body formed therein with three check valves and hydraulic circuit including the check valves, which circuit functions to recirculate oil discharged from one side of a cylinder during no load operation to the other side of the cylinder to thereby boost the operation velocity of the cylinder under no load operation and to return the discharge oil to an oil tank during load operation. The valve body has an upper surface provided with ports corresponding to ports of a directional control valve and a lower surface provided with ports corresponding to ports of a manifold and is sandwiched between the directional control valve and the manifold with the ports in alignment.

Abstract: A pair of fluid valves are formed in a common valve body. Movable pistons in the respective valves are normally biased by the fluid pressure input to closed positions whereby button-like or rod-like extensions of the pistons protrude through a top wall of the valve body to urge a pivotal valve operator to a neutral centered position. By manually pivoting the operator against one or the other of the extensions the respective pistons may be moved to open the respective valves.

Abstract: Installed co-axially in the valve body, along its axis, are two identical sockets with central holes in their bottoms, the holes forming seats closed by closing elements. The sockets are provided with annular seals which divide the valve body into three chambers, viz., an inlet chamber which receives the fluid under pressure, an outlet chamber communicating with the output element and a return chamber for draining the fluid from the output element back into the system. The sockets can be installed with their bottoms directed either towards each other to form a "normally-open" valve or away from each other to form a "normally-closed" valve. The closing elements are accommodated in cages and operated by a drive such as an electromagnetic drive. The critical limits of valve operation are set by springs.

Abstract: A hydraulic valve includes a valve body which is provided with a fluid inlet chamber, a pair of user chambers arranged for communication with users of the fluid admitted into the valve body and a pair of return chambers for recovering fluid from the users and recycling the fluid to a source of the same. The valve body further includes a longitudinal passage which connects the various chambers. A spool is slidably mounted in the longitudinal passage and, depending upon the position thereof, permits a user chamber to communicate with the fluid inlet chamber while the corresponding return chamber is sealed from the user chamber or permits the user chamber to communicate with the corresponding return chamber while the user chamber is sealed from the fluid inlet chamber. A flow channel extends across the width of the valve body and opens to either side of the latter. The flow channel is arranged for communication with the source of the fluid and with the fluid inlet chamber.

Abstract: A load responsive direction and flow control valve for use in fluid power load responsive system. The system is powered by a single fixed or variable displacement pump. The valve maintains a selected constant flow level during control of positive loads and automatically blocks pump flow to the actuator in presence of a negative load, providing the actuator inlet flow requirement from the valve exhaust manifold. The direction and flow control valve is equipped with a load responsive control which during control of positive load maintains a constant low pressure level at the actuator outlet and retains its control characteristics in a system in which multiple positive loads are simultaneously controlled.

Abstract: A compensated work port fluid valve is provided wherein a directional control valve having an inlet chamber, an outlet chamber and a work chamber is provided with a compensator valve connected to the work chamber and having a pressure sensing compensator valve controlling the flow of fluid from the work chamber to a work port to maintain constant pressure at the work port.

Abstract: A fail-safe fluid control valve including a first sleeve accommodated in and fixed to a valve housing, a second valve also accommodated in and fixed to the valve housing in parallel relation with the first sleeve, a first valve spool slidably accommodated in the first sleeve, and a second valve spool slidably accommodated in the second sleeve. The first and second sleeves are properly formed with grooves and ports while the first and second valve spools are properly formed with large diameter portions spaced. When there occurs such an abnormal condition that the first valve spool and the first sleeve are jammed or stuck to each other, the second valve spool is adapted to be moved for actuating the fail-safe control valve under entirely the same condition as a normal condition.

Abstract: A hydraulic system with a valve for controlling fluid flow to the two reversible hydraulic wheel motors in a hydrostatic drive vehicle includes a pair of valve spools axially slidable in bores in a valve body. Each spool has a pair of opposed notches. In one position of the spool, the notches provide separate paths for dual input flows to each of two passages to the wheel motors which differentially lock the wheel motors. In a second position, the notches act to exhaust the return flows in two passages to a single exhaust.

Abstract: A concentrating vortex shaker for the simultaneous shaking and concentration of a multiplicity of liquid samples comprises a heat-conductive block having a plurality of openings for receiving laboratory vessels containing sample liquids and removably mounted on a base provided with an adjustable eccentric drive for displacing the block in a gyrating motion. An airtight cover is removably mounted on the block and forms a chamber above the samples which can be controllably evacuated. The samples can be heated or cooled by a temperature-controlled liquid which is fed through a channel formed in the block or heated by an adjustable electrical heater provided in the block mounting or cooled by a cooling plate, upon which the block mounts.

Abstract: A controller for fluid pressure operated devices such as power steering systems is provided. The controller is of the type having an inlet for receiving a system fluid flow, an outlet, a pair of control fluid ports for connection to a primary fluid pressure operated device and an auxiliary fluid port for connection to an auxiliary fluid pressure operated device or system. The controller includes a valve means having a primary valve member and a follow-up valve member, the valve members defining a neutral position relative to each other. A fluid meter includes a movable member coupled to the follow-up valve member. The primary and follow-up valve members cooperate with the housing to define a first flow path including the inlet, one of the control fluid ports, the fluid meter, the other of the control fluid ports, and the outlet when the valve members are relatively displaced from the neutral position.

Abstract: Hydroponic nutrient solution is fed to a growing bed by means of a pump withdrawing liquid nutrient solution from a supply reservoir located below the bed. The nutrient solution is rapidly drained from the bed when the pump is de-energized through a dump valve having no moving parts which bypasses the solution draining from the bed directly into the supply reservoir. The dump valve consists of a hollow body having at least one drain aperture. A stream of nutrient solution under pressure passes through a nozzle in the inlet of the valve body and is discharged into the outlet of the valve body. When the pump is de-energized, a major portion of the solution draining from the growing bed passes through the aperture and drains directly into the reservoir.

Abstract: A hydraulic stack valve assembly for controlling the pressure and flow of hydraulic fluid in a hydraulic system. The stack valve assembly includes a valve body including flow control valves and a valve cover including pressure control valves and a flow director plate sandwiched between the flow control and the pressure control valves for directing modulated and regulated pressurized fluid through the flow control valves to hydraulic actuators in the hydraulic system. The stack valve has the provision of interchanging the flow director plate to modify the valve assembly and adapting the valve for use of the desired number of flow control valves and the pressure control valves best suited to the hydraulic system in which the valve assembly is used.

Abstract: A controller for fluid pressure operated devices such as hydrostatic power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member, and further comprising a fluid meter including a metering member coupled to the follow-up valve member. The controller is of the 5-port type, having a load signal port for communicating a steering load signal and maintaining a constant pressure drop across the main control orifice of the controller. The primary and follow-up valve members define a central reference plane oriented generally perpendicular to the axes of rotation of the valve members and the various ports and passages defined by the valve members are arranged in somewhat of a mirror image of each other about the reference plane.

Abstract: A controller for fluid pressure operated devices such as power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member, the valve members defining a neutral position. The follow-up valve member is coupled to the primary valve member for limited movement relative to the neutral position. The controller further comprises a fluid meter including a metering member for measuring the volume of fluid passing therethrough, the metering member being coupled to the follow-up valve member. The controller has an inlet port and first and second control fluid ports which may be connected to the opposite ends of the power steering cylinder.

Abstract: A steering spindle operated valve arrangement is used to control flow to and from an accumulator pressure source to a servo motor, with an upstream valve means in series with a flow control piston valve to ensure against leakage during times of straight ahead steering when no pressure is required. This is of importance in any vehicle accumulator system to guard against insufficiency of pressure due to leakage, especially where accumulator pressure is used for functions other than steering boost, e.g., brakes, and accessories. The series valve means takes the form of one or more conical valves which are spring and pressure biased to closed position but mechanically opened by manual force upon steering spindle operation. The arrangement is such that the upstream valve means opens prior to opening of the piston valve for pressure feed to a servo motor.

Abstract: A rotary spool is provided with four axially extending grooves in its outer peripheral surface. Alternating ones communicate with opposite ends of the spool and terminate short of the respective other ends. Each spool end communicates with a respective chamber. Each chamber is communicated to a check valve which may be opened by pressure in the chamber, or opened by a respective cam on the spool. By preference the spool has an operating handle, which, when in neutral, communicates the inlet with an outlet, and when rotated 45.degree. clockwise or counterclockwise communicates the inlet with a respective check valve and communicates the conduit beyond the other check valve with the outlet, while the respective cam holds said other check valve open.

Abstract: A self-depressurizing hydraulic control valve having a sliding-type metering valve to control the flow of hydraulic fluid through the valve and also a shutoff valve to stop the flow automatically. The shutoff valve is responsive to the rate of flow of fluid through the control valve and stops the flow when the flow rate decreases to a preselected value. When the shutoff valve closes, the control edges of the metering valve are no longer exposed directly to high pressure fluid, and quiescent leakage across the edges is practically eliminated. Thus, electrochemical erosion of the metering edges resulting from such leakage is substantially reduced.

Abstract: A lock-out valve for pneumatic systems which provides the operator with mechanical means to exhaust the system and lock it out with a padlock or similar device and, when unlocked, provides a valve to control automatically the gradual reset of working cylinders and the filling of the system with operating pressure to a safe percentage of line pressure before full line flow is established.

Abstract: A fill and relief valve arrangement for the introduction of fluid into and the selective venting of fluid from a fluid chamber includes a fill valve adjustably positioned within an open ended bore formed in a body with one end of the bore in communication with the fluid chamber. In one position of the fill valve, a flared end portion thereof is in sealing engagement with a valve seat formed at the one end of the bore for isolating the fluid chamber from a vent port open to the atmosphere with the fill valve being adjustable for moving the flared end portion inwardly away from the valve seat to establish communication between the fluid chamber and the vent port for venting the fluid chamber to the atmosphere.

Abstract: A hydraulic control valve comprises a housing having inlet and exhaust ports, first and second motor ports, and passageways interconnecting the ports. A shiftable valve element has an internal flow passage and four operative positions for controlling flow through said passageways. In the first position, the inlet and exhaust ports are interconnected and each motor port is isolated from the other ports. In the second and third positions, the inlet port is isolated from the exhaust port and is connected with the first and second motor ports, respectively, while the exhaust port is connected with the second and first motor ports, respectively. In the fourth position, the two motor ports are interconnected and this interconnection is in restricted communication with the exhaust port. A check valve is located in the internal flow passage for preventing flow from the first motor port to the exhaust port when the valve element is moved between the first and second positions.

Abstract: A load responsive direction and flow control valve for use in fluid power load responsive system. The valve maintains a selected constant flow level for control of both positive and negative loads, irrespective of the change in the load magnitude or change in the fluid pressure, supplied to the valve. When controlling positive or negative loads the valve maintains a constant pressure differential across a flow control metering orifice utilizing a single control slide member, first by throttling fluid entering the inlet chamber and then by throttling the fluid leaving the outlet chamber. The valve may be used with fixed displacement pumps, fixed displacement pumps equipped with differential pressure relief valves, with variable displacement pumps equipped with pressure compensators and variable displacement pumps equipped with differential pressure compensators.

Abstract: A pressure compensating valve spool for a hydraulic flow control valve, the valve spool being slidably positioned in the valve for movement from a neutral position wherein fluid will flow through the valve to operative positions in either direction to provide fluid communication from a fluid inlet passage to one of a pair of cylinder passages, the other of said cylinder passages being in fluid communication with a tank passage. The valve spool includes fluid pressure compensating members positioned within each end of the valve spool to vary the fluid flow rate to the cylinder passages, the fluid flow rate being varied to maintain a constant pressure differential between the pressure in the fluid inlet passage and the pressure of the fluid in the valve spool.

Abstract: A control valve for hydraulic servo-steering systems embodying connections for a pressure-source, a discharge and a servo-steering motor provided with a valve member, with the valve member being connected with one section of a divided steering shaft or spindle, in which one or a plurality of adjustable control pistons or reaction pistons are arranged preferably transverse and off-center to the axis of the valve member, and are activated by an activator device rotatable through a small angle relative to the valve member, and connected with the other section of the steering spindle, the activator means being positioned with one part of its length in or on the valve member, whereby the valve member is rotatably and axially immovably positioned in a generally affixed connection body, or in a sleeve connected therewith, in a manner so that the supply and release of a pressure medium into or out of the valve member, independent of the relative position of the connection body and valve member to each other, is guara

Abstract: A load responsive hydraulic system uses a signal supply restrictor, a synthetic signal generator and a unique directional control valve to provide a signal fluid having a pressure magnitude which is at a predetermined value above the load actuating pressure of the system and which is called a synthetic signal pressure. The effective output of the system's pump is controlled by the difference between the pressure of the pump and the pressure magnitude of this synthetic signal pressure. During pressure operation of the system, the directional control valve applies the synthetic signal pressure to the pump control mechanism; and during standby operation, the control valve applies a signal fluid to the pump control mechanism whose pressure magnitude is not increased by the synthetic signal generator.

Abstract: A valve section which establishes priority flow in a valve assembly having a plurality of directional control open-center valves each for controlling flow between an associated hydraulic motor and a common power passage from a single source of motive fluid, wherein flow to one of the motors is afforded priority during simultaneous operation of it and another motor. The associated valve section of the priority motor having a conventional load check valve opened by pressure in the common power passage while the load check of the non-priority valve section is opened by pilot pressure in its open-center passage.

Abstract: A method and apparatus for controlling speed and torque of hand held air driven vane type motors is available in several embodiments. For example, one embodiment is used in tool and die work and another embodiment is used in dental work. In reference to the latter, a foot operated control regulates the speed of an air driven handpiece, driving in turn various tools such as cutters and drills as they are generally used in a dental laboratory, by regulating the flow of compressed air both to and from the handpiece. Application of an operator's foot pressure on a floor level foot control, simultaneously depresses two valves which control the flow of compressed air. One valve controls the flow of compressed air from its source to the handpiece, and one valve controls the release into the atmosphere of compressed air from the handpiece.

Abstract: A fill and relief valve arrangement for the introduction of fluid into and the selective venting of fluid from a fluid chamber includes a body having a stepped open-ended bore extending therethrough and an annular shoulder formed at one end of the bore. A valve seat element is sealingly secured within the other end of the bore and has a passage formed therein communicating with a passageway which communicates the bore with the fluid chamber. A fill valve is adjustably positioned within the bore and has a first position in engagement with a valve seat element for isolating the fluid chamber from a vent port open to the atmosphere and a second position for establishing communication between the passageway and the vent port for venting the fluid chamber to the atmosphere. The fill valve is confined between the valve seat element and the annular shoulder.

Abstract: A spool type control valve mechanism for use with backhoes, front end loaders, and other apparatus having a number of hydraulic cylinder driven work performing members whose motions must be coordinated in order to produce a prescribed work operation. Pressure compensating valve means which provides for regulation of the rate of flow to the cylinders of pressure fluid from a common supply passage also functions automatically to control connection of the cylinders with the supply passage in accordance with the work load on the cylinders, at times when the valve spools of all the control valves are in their working positions.

Abstract: A valve for simultaneous valving in two separate hydraulic systems, the valve having two slides with each slide being attached to a bypass driving member through caged spring cartridges. If one of the slides jams the other slide is moved by the bypass driving member in the opposite direction to the direction in which the jam occurred. The jammed system slide includes a porting which is opened by the relative movement of the bypass driving member, placing that system in a bypass condition. The other slide is not effected and remains in full control of a tandem hydraulic cylinder to which such valves are connected. If each half of the tandem cylinder is sized for full thrust capacity, there is no degradation in performance during the jammed condition.

Abstract: A pressure reducing valve mechanism maintains pressure in one of the service passages of a control valve at a desirably low value except at times when the control valve element is actuated to a position effecting flow of pressurized supply fluid to said service passage for delivery to a motor governed by the control valve.

Abstract: A hydraulic system including a compensator connected between the service ports of the control valve and the load and arranged to restrict the flow in one or both of the service lines so as to maintain a constant pressure difference between the supply pressure and the pressure at the valve service port supplying fluid to the load. The compensator may be connected in both service lines and arranged to restrict the flow equally in each of them. Alternatively a single-sided compensator may be used, and if the load is liable to over-run it must be connected in the service line which is downstream of the load when over-running.