Abstract: An exemplary hydraulic system includes a plurality of digital valves, each valve fluidly connectable to a corresponding hydraulic load. The digitals valves are operable to fluidly connect the corresponding hydraulic load to a pressure source. The hydraulic system further includes a digital controller operably connected to the plurality of digital valves. The digital controller is configured to assign a priority level so that it is associated with each of a plurality of hydraulic loads, and to formulate a pulse width modulated control signal based on the assigned priority levels. The digital controller transmits the control signal to the plurality of digital valves for controlling the operation of the valves.

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: An exemplary hydraulic system includes a plurality of digital valves, each valve fluidly connectable to a corresponding hydraulic load. The digitals valves are operable to fluidly connect the corresponding hydraulic load to a pressure source. The hydraulic system further includes a digital controller operably connected to the plurality of digital valves. The digital controller is configured to assign a priority level so that it is associated with each of a plurality of hydraulic loads, and to formulate a pulse width modulated control signal based on the assigned priority levels. The digital controller transmits the control signal to the plurality of digital valves for controlling the operation of the valves.

Abstract: An apparatus and method for providing enhanced vacuum to a brake booster of a braking system under certain operational conditions. Vacuum is stored in a reservoir and is controllably released to the brake booster to provide a brake booster vacuum level of at least a predetermined vacuum level threshold in order to avoid brake pedal performance issues being perceived by the driver of motor vehicles utilizing engines utilizing a supplemental brake assist system under conditions where the brake booster vacuum level is less than the predetermined vacuum level threshold.

Abstract: A hydraulic grip-control unit provided with at least two gripping arms driven hydraulically to seize loads while cooperating with a striker arm of the grip with the control unit in use being connected hydraulically between a hydraulic fluid source under pressure and hydraulic cylinders each of which drives a gripping arm to form a closed supply circuit in which the source feeds fluid to the cylinders connected hydraulically in parallel and with the unit including a flow divider connected along said supply circuit between said source and said cylinders to apportion the flow of the circuit between the cylinders in parallel.

Abstract: A hydraulic drive with a flow divider and a bypass wherein fluid can either be allowed to flow from a flow divider to hydraulic actuators in parallel or the fluid can be allowed to bypass the flow divider and flow directly to the hydraulic actuators in parallel.

Abstract: A valve for controlling the flow of hydraulic fluid from a hydraulic pump to and back from a pair of hydraulic motors. The valve includes a selector spool for selectively energizing and de-energizing the motors. A pair of flow dividers each include a pair of flow divider spools which are slidingly longitudinally arranged. A pair of poppets, also longitudinally slidingly arranged, are located between the spools are selectively shifted in response to the hydraulic fluid flow and pressures within the motors. The spools and poppets longitudinally shift to equalize the pressure of the hydraulic fluid delivered to each motor and minimize loses. An override spool is selectively shiftable for bypassing the flow dividers and directly connecting the pump to the motors.

Abstract: Cylinder head (81) of a hydraulic lift cylinder (39) includes a fluid input port (74) and first fluid output port (75) to be connected respectively to a pump (46) and to a power steering mechanism (40). These ports preferably open at one and the other side surfaces of the head. The head further includes a second fluid output port (83) and fluid inlet port (84) which open at a front surface of the head. These ports are connected through an inside of a cover member (49a, 50a; 201; 250a) detachably mounted on the front surface of head. The head includes therein a flow divider (47) which divides inflow of the input port into first and second flows directed respectively to the first and second output ports. Fluid returned into the inlet port is directed towards a first control valve assembly (48) for the lift cylinder.

Abstract: A brake valve (45) is disclosed of the type which permits communication from a source (11) of pressurized fluid to a brake actuator (47) in response to manual movement of a valve spool (57) from a neutral position (FIG. 2) to a power brake position (FIG. 5). In the power brake position, the valve spool permits fluid communication between a work port (53), which communicates with a brake actuator, and a brake load signal chamber (87), the brake load signal controlling the fluid output of the source. As the valve spool moves toward a manual brake position (FIG. 6) communication between the work port and the brake load signal chamber is blocked. In the manual brake position, movement of the valve spool causes a large piston (63) to displace fluid from its piston bore (73) into a piston bore (75) in which is disposed a small piston (61), the small piston being operable in response to movement of the valve spool to build brake pressure in the work port (53).

Abstract: A hydraulic apparatus for an industrial vehicle adapted for enabling to carry out a pump capacity control whenever necessary, and including a variable capacity type hydraulic pump driven by an engine, a flow dividing valve disposed in an outlet pipe line of the pump and adapted for dividing a flow of a pressurized hydraulic oil into a flow required for a power steering hydraulic circuit and a balance flow for a cargo handling hydraulic circuit, a switching valve pilot-operated by a pressure of the cargo handling hydraulic circuit and adapted for selecting a supply pilot pressure between a pressure of the power steering hydraulic circuit downstream with respect to the flow dividing valve and a pressure of the outlet pipe line upstream with respect to the flow dividing valve, and a capacity control valve pilot-operated by a differential pressure between the supply pilot pressure and the pressure of the outlet pipe line and adapted for controlling a capacity varying mechanism of the pump.

Abstract: A vacuum supply system for a brake power assist unit of a motor vehicle and at least one additional vacuum consuming device, is achieved by a parallel arrangement of two pipes leading from a vacuum generating device one to the brake power assist unit and one to the additional consuming device. Both pipes are equipped with flow control devices one of which is blockable by means of a check valve with an increased restoring or closing force for securing a vacuum supply priority for the brake power assist unit.

Abstract: A hydraulic-control system for a hydraulic press utilizes a main power unit consisting of a pump and a flywheel which delivers the energy necessary for a working stroke to at least one cylinder of the press. An auxiliary power unit consisting of an electric motor and another pump driven thereby is connected to the hydraulic network to drive the first mentioned pump as a motor and rotate the flywheel to increase the energy stored therein.

Abstract: The present invention relates to, in combination, a vehicle utilizing a first hydraulic cylinder to operate lifting means and a second hydraulic cylinder to operate end effector means, each of the cylinders including a piston, the pistons when moved toward their "up" sides causing the lifting means and end defector means to move in a first direction and when moved toward their "down" sides causing the lifting means and means to move in a second direction, and a load self-leveling system for the vehicle, the system comprising a pair of fluid flow dividers interposed in flow lines between a source of hydraulic fluid under pressure and the first and second hydraulic cylinders, the flow dividers being structured to direct a greater flow of hydraulic fluid to the first cylinder and a lesser flow to the second cylinder, each of the flow dividers comprising adjustable spool valve means located in flow passages between the source of hydraulic fluid and the first and second hydraulic cylinders.

Abstract: The sweeping roller of a sweeping machine is held on the ground in sweeping operation by two hydraulic cylinders in such a manner that the degree of wear is small. For this purpose in each cylinder a static and different holding pressure must be set. The higher pressure is set at a pressure-limiting valve and the lower pressure at the series circuit parallel thereto of a nozzle with an adjustable throttle.

Abstract: In a working vehicle comprising a hydraulic power steering cylinder (25) and hydraulic lift cylinder (31), a novel hydraulic system is employed which comprises first and second flow control valve means (47, 48; 147, 148; 247, 248; 347, 348), each dividing its inflow into two flows. These valve means are connected in a fashion such that output flow of a single pump (43) driven by engine (10) is first divided into two output flows one of which is then divided by the second valve means. Further, one of the output flows of the second valve means is directed towards the steering cylinder whereas the other of output flows of the both valve means are directed towards the lift cylinder.The connection is such that, while a predetermined constant flow is secured for the steering cylinder at the normal engine speeds, a flow is necessarily secured for a relatively quick operation of the lift cylinder already at a low engine speed.

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: There is provided an improved fluidic drive circuit for a fluid powered vehicle arranged to limit flow to an unloaded drive wheel. A restricting orifice is mounted in parallel with a pressure sensitive control valve to provide fluid power to the motor. A trickle flow is provided through the restricting orifice to maintain a minimum pressure to the fluid motor. The control valve, sensitive to pressure at the fluid motor, provides full flow only when the pressure in the fluid motor is sufficient.

Abstract: A log debarker of the hollow-head type having a rotor journaled in a stator for rotation about a longitudinal axis of the rotor. A plurality of debarking tools are attached to the rotor for debarking a log being moved axially through the rotating rotor. Three independently and hydraulically-powered infeed spiked rollers are positioned on the infeed end of the stator for feeding logs into the rotor and three independently and hydraulically-powered outfeed spiked rollers are positioned on the outfeed end. The rollers are powered at differing rotational speeds to accommodate logs of uneven surfaces. An air-operated tensioning system including a quick release valve adjusts the position of the infeed and the outfeed rollers urging them towards the longitudinal axis and automatically jogs the rollers open when they are unable to mount a log. A lubricating system having lubricant filtering and flow control capabilities lubricate and flushes the bearings for the rotating rotor.

Abstract: A hydraulic apparatus for a vehicle having a propulsion engine comprises a control valve, a flow dividing valve, pumps driven by the engine for delivering fluid to the valves, and steering and implement circuit operatively connected to the control and flow dividing valves. The control valve includes plunger provided with orifices having variable degrees of openings and a spool connected to the plunger and the flow dividing valve includes a spool. With the hydraulic apparatus this constructed, fluid having an amount necessary for operating the steering circuit is always fed thereinto by operatively connecting the spools of the control and flow dividing valves and sharing the fluid into the steering and implement circuit by controlling the fluid dividing valve in accordance with pressure difference between the upstream and downstream portions of the orifices in the control valve.

Abstract: A log debarker having a frame, a stator supported by the frame, a rotor journaled in the stator for rotation about a longitudinal axis of the rotor, a rotating mechanism for rotating the rotor about the longitudinal axis, a plurality of debarking tools attached to the rotor, and a feeding system for feeding logs axially through the rotor. The feeding system includes a plurality of log gripping rollers positioned for rolling contact with the log, and individual hydraulic motors are operatively connected to the log gripping roller for rotating the log gripping roller. Each of the hydraulic motors is adapted to rotate its log gripping roller at different and variable rotation speeds to accommodate logs of uneven surfaces. A hydraulic fluid supply system supplies each of the hydraulic motors with fluid so that the different and variable hydraulic fluid requirements of each of the hydraulic motors necessitated by uneven log surfaces are satisfied.

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 log debarker of the hollow-head type having a rotor journaled in a stator for rotation about a longitudinal axis of the rotor. A plurality of debarking tools are attached to the rotor for debarking a log being moved axially through the rotating rotor. Three independently and hydraulically-powered infeed spiked rollers are positioned on the infeed end of the stator for feeding logs into the rotor and three independently and hydraulically-powered outfeed spiked rollers are positioned on the outfeed end. The rollers are powered at differing rotational speeds to accommodate logs of uneven surfaces. An air-operated tensioning system including a quick release valve adjusts the position of the infeed and the outfeed rollers urging them towards the longitudinal axis and automatically jogs the rollers open when they are unable to mount a log. A lubricating system having lubricant filtering and flow control capabilities lubricate and flushes the bearings for the rotating rotor.

Abstract: All but the circle drive motor of the implement actuators of a motor grader are divided into two groups each consisting of those which need not be operated simultaneously. The power system has three fixed displacement pumps for driving the circle drive motor via a circle control valve and the two implement actuator groups via respective implement control valve arrangements of carry-over parallel configurations. One of the pumps is connected to the two implement control valve arrangements via a restriction and a flow divider. A first demand valve controls communication between the other two pumps and the implement control valve arrangements in response to the pressure differential across the restriction, maintaining constant fluid flow to the valve arrangements regardless of engine speed or the loads on the implement actuators.

Abstract: A hydraulic press has lowering and lifting cylinders, a controlled pressure-limiting valve connected to the high-pressure hydraulic supply, and a shuttle valve with its operating inlets connected respectively to the hydraulic supply and to the lifting cylinders and its outlet connected to the pressure-limiting valve to control it. Further valves responsive to a disturbance of hydraulic equilibrium in the hydraulic circuit operate switches controlling the hydraulic fluid supply.

Abstract: An overload relief valve for use in preventing damage to the hydraulic system for adjustably positioning a working element, such as a blade. A single relief valve permits relief of high fluid pressure developed in either of the control cylinders by providing a crossover function therebetween under such conditions, as well as to relieve the fluid to tank in the event of a high pressure condition existing in both cylinders concurrently. The crossover relief may be effected by a similar first preselected high pressure condition in either of the cylinders.