Abstract: A method of detecting a fluid leak in a hydraulic fluid circuit includes preventing fluid from entering the circuit when an actual outlet flow rate from a pump is positive while a requested outlet flow rate to a hydraulic machine is zero. An outlet port of a variable displacement port can be selectively blocked, while in a fixed displacement pump (FDP) fluid can be diverted from the outlet port to a secondary fluid circuit. The actual outlet flow rate can be measured using a flow sensor or a swash plate angle depending on the pump design. A hydraulic fluid circuit includes a hydraulic machine, a pump, a valve at an outlet port of the pump, and a controller. The controller determines the requested flow rate, and actuates the valve to prevent fluid from entering the circuit whenever the actual outlet flow rate is positive during zero requested flow rate.

Abstract: An actuator system and a method for assembling the same are provided. An actuator system includes a housing and a cap. The housing includes a cavity defined by the housing and an opening defined in a wall of the housing. The housing encases an actuator within the cavity. The cap is coupled to the housing to facilitate shielding the opening from a surrounding environment.

Abstract: A control system for a hydraulic servomotor (13) is disclosed. The control system comprises an electro hydraulic actuator (2) comprising a number of valves (9, 10, 11, 12, 18) for controlling fluid flows, a main control module (1), and one or more connectors. The control system further comprises at least one extension control module (3) comprising one or more connectors. Finally, the control system comprises means (6) for communicating signals between the main control module (1) and each of the extension control module(s) (3). Since the main control module (1) and the extension control module(s) (3) are able to communicate signals, it is possible to provide signals to/from the main control module (1) via an extension module (3), thereby in effect providing additional connectors to the main control module (1). Thereby the main control module (1) may be able to perform additional functions as compared to similar prior art control modules.

Abstract: A hydraulic system for a work vehicle including a manifold assembly configured to prioritize hydraulic fluid flow to priority functions over a wide range of engine speeds.

Abstract: A hydraulic system includes at least one hydraulic circuit with at least one pump, one or more consumer equipment units, at least one HP discharge line comprising at least one bypass, the bypass being located between the pump and the units, at least one return line including at least one bypass, the bypass being located between a tank and the units. The hydraulic system further includes at least one closure element on the at least one HP line between the bypass and the units, and at least one nonreturn valve on the at least one return line between the bypass and the units. The closure element is placed automatically in the closed position when a break of the HP line is detected downstream of the closure element of the HP line.

Abstract: A working machine control device is provided which can surely determine whether working equipment attached to a working machine is in an operation state. The working machine control device is configured to control a vibration generating device that is supplied with pressure oil from a hydraulic pump to generate vibration to operate working equipment attached to a working machine. The working machine control device includes a controller that is configured to obtain frequency characteristic of the pump pressure based on a pump pressure value that is detected by a pressure sensing section, and to determine whether said working equipment is in an operation state or not based on said frequency characteristic.

Abstract: A valve that keeps a electro-hydraulic servo valve (EHSV) controlled device such as a fuel metering valve or actuator at the last commanded position upon loss of input command in the EHSV is described. The valve fixes the position of the positioning device within a tolerance of the position the positioning device was at prior to the loss of the position command.

Abstract: The invention relates to an electrohydraulic valve system comprising a feeding duct (P), a working duct (A), and a discharge duct (T), a first and a second valve mechanism (20, 30), each of which is provided with a valve piston (3.1), a control device, and a magnetic regulating device for impinging the valve piston (3.1, 3.2) with a controlled actuating force. The first and the second valve mechanism (20, 30) are placed parallel to each other. The first valve mechanism or the second valve mechanism is active and performs the function of the electrohydraulic valve system while the other valve mechanism is passive during operation. The control device of the active valve mechanism activates the passive valve mechanism and deactivates itself when said control device recognizes a fault while the control device of the passive valve mechanism activates itself and deactivates the active valve mechanism when the control device of the passive valve mechanism recognizes a fault.

Abstract: A hydraulic system provides failure protection by incorporating an isolator adjacent a hydraulic actuator. The isolator has a first port connected to the hydraulic actuator and a second port with an electrically operated isolation valve connected between those ports. A pressure relief valve responds when pressure in the hydraulic actuator exceeds a given level by relieving pressure thereby enabling the isolation valve to open without application of electricity and release the pressure in the hydraulic actuator. A control valve assembly is remote from the hydraulic actuator and connected to the second port for metering flow of fluid between a source and the hydraulic actuator.

Abstract: A hydraulic stabilizing device for vehicles having an actuator which can be acted on in opposite directions comprises a switching device, which is formed by a directional control valve, and, in series with the switching device, a switching apparatus, which is formed by two separate directional control valves which are connected in parallel and correspondingly have a blocking position and different pass-through positions.

Abstract: A system to lock a roll-suspension arrangement operatively connected to allow pivotal movement of a boom assembly about a fore-and-aft axis independent of a carrier frame is provided. The system includes an actuator cylinder having an end movable in a linear direction relative to a fixed end. The fixed end of the actuator cylinder is connected at the carrier frame, and the movable end is connected at the boom assembly. The system further includes a lock valve located in fluid communication with the actuator cylinder. The lock valve in a closed position prevents a fluid flow therethrough so as to restrain movement of the actuator cylinder and rotation of the boom assembly with respect to the carrier frame. In an open position, the lock valve releases movement of the actuator cylinder so that the boom assembly freely pivots independently of the carrier frame.

Abstract: The invention relates to a hydraulic circuit for a steer-by-wire steering system which includes a hydraulic pump, a reservoir, a bi-directional steering actuator, a pair of electronic control units (ECU) for generating electrical steering control signals in response to an operator-generated steering command. There is a need for such a circuit which des not require large expensive valves. The hydraulic circuit includes a pair of solenoid operated directional control valve units and a pair of solenoid operated shut-off valves. Each directional control valve unit and a corresponding one of the shut-off valves are connected in series between the pump, the reservoir and the steering actuator, and are connected to a respective one of the ECUs and controlled thereby. In the absence of a fault condition both shut-off valves are open so that hydraulic flow to and from the actuator is shared by both the first and second directional control valve units.

Abstract: A controlled piston (20, 62, 102) having a first end (24, 64, 104) mounted in a controlled piston sleeve (22) and a spool (16) movably mounted in a spool sleeve (18), a first fluid passage (40, 66, 108) from the spool (16) to the controlled piston first end (24, 64, 104), the position of the spool (16) affecting a position of the controlled piston (20, 62, 102), an FFV (42, 68, 110) in an FFV sleeve (44, 70, 112) in the first fluid passage (40, 66, 108) having a first end section (46, 74, 116), a second end section (48, 78, 120) and a central section (50, 82, 126) having a third diameter less than the diameters of the first and second sections, the FFV (42, 68, 110) being shiftable between a first position blocking the first fluid passage (40, 66, 108) and a second position allowing fluid flow past the central section (50, 82, 126) to the controlled piston (20, 62, 102), and a second fluid passage (56, 88, 134) from the spool (16) to the FFV first end section (46, 74, 116).

Abstract: A pressurized-medium-driven apparatus including an actuator articulately mounted a line segment and a connecting element. The line segment and the connecting element are connected so as to be mutually pivotable with respect to each other around a swing axis. The connection is provided by a junction means between the line segment and the connecting element, wherewith the connecting element and or the line segment are rigid components, preferably a rigid tube or pipe. The junction means is a swiveling junction connection.

Abstract: Provided are a hydraulic pump 7, an electromagnetic flow rate control valve 2 that controls the flow rate of hydraulic oil supplied from the hydraulic pump 7 to a power steering device PS, and a pressure compensating valve 4 that maintains a fixed pressure difference between upstream and downstream sides of the electromagnetic flow rate control valve 2 and bypasses an excess flow rate. The electromagnetic flow rate control valve 2 maintains a predetermined initial opening when a control current is zero, while an opening of the electromagnetic flow rate control valve decreases to become a minimum opening when the control current increases from zero, and the opening gradually becomes larger toward a maximum opening when a predetermined control current is exceeded.

Abstract: An electro-hydraulic steering control system for directing fluid to steering actuators on a work machine may include a main valve configured to control fluid flow to the steering actuators. Left and right primary steering valves may be in communication with and configured to affect the main valve to control fluid flow to the steering actuators. Left and right redundant steering valves may be in communication with and configured to affect the main valve to control fluid flow to the steering actuators. A shuttle valve may be operably disposed between one of the right primary and the right redundant steering valves and the left primary and left redundant steering valves. The shuttle valve may be operable to selectively control fluid from the one of the right primary and the right redundant steering valves and the left primary and left redundant steering valves to the main valve to control the main valve.

Abstract: The system includes a hydraulic powered actuator. A pump system having first and second hydraulic lines is coupled to the first and second ports, respectively and is capable of providing hydraulic fluid to either the first and second lines. First and second pressure sensors are coupled to the first and second lines, respectively. A third line is coupled between the first and second lines and includes first and second valves mounted in series therein. Preferably, the first and second valves are capable of latching in the open position. A reservoir is coupled to the third line between the first and second valves. A shut off valve is included for cutting off the flow from the reservoir.

Abstract: A failure detection device for a hydraulic motor according to the present invention comprises a hydraulic pump 3 that is driven by a prime mover 2; a hydraulic motor 1 for traveling that is driven by hydraulic oil discharged from the hydraulic pump 3; a transmission 7 that is connected with an output shaft of the hydraulic motor 1 for traveling; a stopping detection device 26 that detects that a traveling vehicle has stopped; a fluid level detection device 35 that detects an oil level in the transmission 7; and a warning device 39, 40 that issues a warning when the stopping detection device 26 detects that the traveling vehicle has stopped, and also the fluid level detection device 35 detects that the oil level in the transmission 7 has reached a predetermined value La.

Abstract: A wing driving apparatus is made up of a flight controller part for generating a drive signal, first and second servo actuators, a first controller unit having a first drive circuit, and a second controller unit having a second drive circuit. The first controller unit includes a follower signal generator circuit for generating a follower signal. The second servo actuator includes a solenoid valve for invalidating a control to the second serve actuator based on the drive signal from the second drive circuit in response to the follower signal, whereby the second second servo actuator follows the steering wing when the first drive circuit is able to operate the first servo actuator to drive the steering wing.

Abstract: A steering system for a work machine having a hydrostatic transmission is disclosed. The steering system has a primary source of pressurized fluid and a steering control valve. The steering system also has a first fluid passageway fluidly connecting the primary source of pressurized fluid to the steering control valve and a second fluid passageway fluidly connecting the hydrostatic transmission to the steering control valve.

Abstract: In a hydraulic power steering system employing a power cylinder accommodating therein a piston connected to a steering mechanism for steering assistance, and having first and second hydraulic chambers defined on both sides of the piston, hydraulic pressure is supplied through first and second fluid lines to the respective hydraulic chambers. A communicating circuit is provided to intercommunicate the first and second fluid lines therevia. A directional control valve, disposed in the communicating circuit, has a poppet valve mechanism, which is switched to a valve-open position in presence of a hydraulic power steering system failure, to intercommunicate the first and second fluid lines with the poppet valve mechanism opened.

Abstract: A hybrid actuation system comprises first and second actuator arrangements (10, 12) arranged to apply first and second output loads respectively to a common element (14). A control method for controlling the operation of the hybrid actuation system includes the steps of supplying first and second demand signals to the first and second actuator arrangements (10, 12) respectively to cause movement of the common element (14) into a demanded position, monitoring the first and second output loads applied by the first and second actuator arrangements (10, 12) and generating an output signal indicative of the difference between the first and second output loads. The first and second demand signals are corrected in response to the output signal to compensate for any difference between the first and second output loads, thereby to ensure the first and second output loads applied to the common element (14) are substantially identical and synchronized.

Abstract: A hydraulic arrangement is provided with at least one pressure accumulator for a hydraulic fluid, a hydraulic cylinder with at least one chamber to which pressure can be applied, a connecting line, on the basis of which the at least one accumulator is connected with the chamber, and a control unit. In order to provide an electronic pipe break safety device, an electronically controlled on-off valve is mounted in the connecting line and coupled for receiving control signals from the control unit, and a signal transmitter, which is coupled for monitoring the pressure in the connecting line is also connected to the control unit. If a pressure drop occurs in the connecting line, a signal change is generated by means of the signal transmitter, whereupon the control unit sends a signal effecting movement of the shut-off valve to its closed position.

Abstract: A failure detection device for a hydraulic motor of the present invention comprises a hydraulic pump 3 that is driven by a prime mover 2; a hydraulic motor 1 that is driven by hydraulic oil discharged from the hydraulic pump 3; an abnormality detection device 35 that detects an abnormal operation of the hydraulic motor 1; and a warning device 30, 39, 40 that issues a warning when the abnormal operation of the hydraulic motor 1 is detected by the abnormality detection device 35.

Abstract: The invention relates to a method for controlling a pressure supply device in a hydraulic circuit, especially in a hydraulic circuit in an automatic gearbox which comprises an hydraulic pump, a pressure control valve and a consumer. The hydraulic pump is controlled if the system pressure falls below a specific lower threshold value and is switched off if a specific higher threshold value of the system pressure is reached or exceeded. In the data on the system pressure is not available, the current system pressure is calculated.

Abstract: Two or more flow control valves may be used to provide redundant flow control for a hydraulic actuator or servoactuator. The flow control valves include a sleeve, a bypass control spool, and a primary control spool. Under normal operating conditions, each bypass control spool is stationary relative to the sleeve and the flow control valve functions as a four-way hydraulic flow control valve. Each flow control valve is connected to a bypass-shutoff valve including a bypass spool that is moveable from a shut-off position to a bypass position. Upon supply pressure failure to one flow control valve, the bypass spool moves to the bypass position, reducing pressure in the corresponding actuator piston chambers. When a primary control spool becomes jammed, the corresponding bypass control spool moves within its sleeve allowing a bypass groove to port control pressure to the return line, thereby reducing pressure in the corresponding actuator piston chambers.

Abstract: An oleopneumatic actuator cylinder device for steering and self-centering for the alignment to a straight drive of steering or self-steering axles, in particular for rear axles of vehicles, is constituted by a single oleopneumatic actuator cylinder for each rear steering axles. The actuator cylinder comprises a pneumatic sector communicating with a respective pneumatic circuit, an oleodynamic sector communicating with a respective oleodynamic circuit, a stem kinetically connected to the a mechanical driving element to move the wheels of the vehicle, and a central body that delimits the pneumatic sector and the oleodynamic sector.

Abstract: In order to provide an operation and maintenance planning aiding system for a power generation installation which prepares an operation plan for a plurality of power generation units by making use of actual plant data and based on a total judgment including a variety of circumstances of the machine and apparatus or the parts thereof in the power generation units, in the system the plurality of power generation units 41, 42, 51 and 52, a power supply command center 3 and a service center 1 are arranged and connected via a communication network 6, the service center 1 obtains the plant data via the communication network 6 from the plurality of power generation units 41, 42, 51 and 52, calculates in real time a power generation efficiency of a concerned power generation unit for every plurality of power generation units 41, 42 51 and 52 by making use of the obtained plant data and design data of the concerned power generation unit and prepares an operation and maintenance plan for each of the power generation un

Abstract: In an electrohydraulic lifting control device (S) for stacker trucks, which comprises, for lifting control, an electrically operable three-way flow regulator (R1) in a lifting branch (1) between a pressure source (P) and a hydraulic cylinder (Z) as well as, for lowering control, an electrically operable two-way flow regulator (R2) in a lowering branch (2) which branches off from the lifting branch (1) and leads to the reservoir, a redundancy switching element (A) is provided, which is actively electrically operable between closed and open positions, said redundancy switching element (A) being provided between the control pressure circuit of the two-way flow regulator (R2) and/or the control pressure circuit of the three-way flow regulator (R1) and the reservoir (T).

Abstract: An integrated three function valve (ITFV) that combines the functions of a bypass valve (e.g. 183a, 185a, 161a) into a single assembly is disclosed. The ITFV allows continued operation after any two failures.

Abstract: A failure detection device for a hydraulic motor of the present invention comprises a hydraulic pump 3 that is driven by a prime mover 2; a hydraulic motor 1 that is driven by hydraulic oil discharged from the hydraulic pump 3; an abnormality detection device 35 that detects an abnormal operation of the hydraulic motor 1; and a warning device 30, 39, 40 that issues a warning when the abnormal operation of the hydraulic motor 1 is detected by the abnormality detection device 35.

Abstract: A fluid control system for security relevant control and a fluid control actuator, a local control means for a fluid control system, a software module for a local control means of a fluid control system and a method for the operation of a fluid control system. The fluid control actuator (10) is controlled by control instrumentality means (30) of a local control means (50). A sensor (16, 17, 27, 41 and 42) transfers information concerning operational states of the fluid control system to the local control means (50). For this purpose there is a provision such that the local control means (50) determines from such information whether there is a security relevant situation and if necessary performs a predetermined function. The security relevant functions are integrated in the fluid control system so that same is able to be employed as prefabricated unit.

Abstract: A collapsible push rod for a brake booster in a vehicle is provided, having first and second telescoping members, and retractable locking means for selectively locking the first and second members together against telescoping. During a frontal impact collision, the members telescope into one another to shorten the length of the push rod and compensate for rearward movement of the brake booster and forward movement of the driver. The push rod is operable in the collapsed state. The push rod is also re-settable after the collision, and includes features for returning the push rod to its normal un-telescoped length following the collision, if the push rod is not damaged in the collision. The retractable locking means includes an electrically actuated solenoid for selectively locking and unlocking the first and second members against telescoping, in response to an electrical signal applied to the solenoid.

Abstract: The invention concerns a hydraulic dual circuit steering system with first circuit having a first control unit and a first steering motor connected with the control unit via working connections, a second circuit having a second control unit and a second steering motor connected with the control unit via working connections, a changeover valve, which in a first position activates the first circuit and deactivates the second circuit and in a second position activates the second circuit and deactivates the first circuit. To improve the steering behaviour, in the first position of the changeover valve the working connections of the second circuit and in the second position of the changeover valve the working connections of the first circuit are connected with a pressure source.

Abstract: A hydraulic drive system includes a hose rupture control valve unit 200 having a poppet valve member 5 serving as a main valve for opening and closing communication between a cylinder connection chamber 8 and a hose connection chamber 9, a spool valve member 6 disposed in pilot passages 15a, 15b connecting a back pressure chamber 10 and the hose connection chamber 9 of the poppet valve member 5. The spool valve member is operated by a pilot pressure supplied as an external signal and operates the poppet valve member 5, and a small relief valve 7 having the function of an overload relief valve. A check valve 39 is disposed in the pilot passage 15b for cutting off a flow of the hydraulic fluid from the hose connection chamber 9 to the back pressure chamber 10.

Abstract: A device for preventing the unintentional restarting of motors or machines is proposed, it being possible to control the supply of energy to the motor or to the machine by means of a control valve with a mechanically adjustable control element and it being possible to connect the control valve non-detachably to the motor or to the machine, the energy for the motor being generated by means of compressed air, and in that a pneumatic piston, to which the primary air pressure prevailing upstream of the motor and upstream of the control valve can be applied, being arranged as a restarting inhibitor between the control valve and the motor, and in that, in order to apply the primary air pressure, a connecting line being arranged between the motor and the piston.

Abstract: A hydraulic circuit comprises first and second cylinders, and a piston disposed in each of the cylinders. A pump communicates with one side of one of the pistons, and a pressure relief valve has a position wherein the pump communicates with another side of the one piston and with the other piston.

Abstract: An industrial lift truck has a boom that is raised and lowered by a first hydraulic actuator and a load carrier that is pivoted with respect to the boom by a second hydraulic actuator. In the event that the supply of hydraulic fluid for powering the actuators fails, the boom may be lowered by gravity by draining fluid from the first hydraulic actuator. To prevent a load from sliding off the load carrier as the boom descends, the load carrier is pivoted to maintain a substantially constant angular relationship to the ground. This is accomplished by selectively conveying fluid drained under pressure from the first hydraulic actuator into the second hydraulic actuator. Changes in the position of the boom are sensed and, in response, the flow of fluid into the second hydraulic actuator is controlled to produce corresponding changes in the load carrier position.

Abstract: A switching system is described herein for an engine having redundant control components. The switching system generally includes an actuator, a control system, inlet and outlet lines, and a transfer valve. The actuator is operable to control an engine parameter. The control system includes a first electrohydraulic servo valve and a second electrohydraulic servo valve, the first and second servo valves being fluidically connected to the actuator for operating the actuator. The inlet line supplies pressurized fluid and the outlet line drains fluid. The transfer valve is positioned between the first and second servo valves and the inlet and outlet lines. The system may further include additional control systems with redundant EHSVs. This invention minimizes size and space requirements, and allows nearly simultaneous transfer of all control systems, while minimizing the transient disturbance to the control system(s).

Abstract: An electrically controlled hydraulic actuating system includes a servocontrol including a cylinder, a piston dividing the cylinder into two chambers each provided with a hydraulic connection port, a control valve connected to a hydraulic circuit. A two-way hydraulic pump is driven in rotation by an electric motor driven by power electronics. A switching device allows the connection ports of the chambers to be connected either to the control valve or the pump. The switching device connects the hydraulic connection ports both to the control valve and the pump, so as to allow the servocontrol to be supplied the sum of the hydraulic power delivered by the hydraulic circuit and the hydraulic power generated by the pump actuated by the electric motor.

Abstract: A switching system is described herein for an engine having redundant control components. The switching system generally includes an actuator, a control system, inlet and outlet lines, and a transfer valve. The actuator is operable to control an engine parameter. The control system includes a first electrohydraulic servo valve and a second electrohydraulic servo valve, the first and second servo valves being fluidically connected to the actuator for operating the actuator. The inlet line supplies pressurized fluid and the outlet line drains fluid. The transfer valve is positioned between the first and second servo valves and the inlet and outlet lines. The system may further include additional control systems with redundant EHSVs. This invention minimizes size and space requirements, and allows nearly simultaneous transfer of all control systems, while minimizing the transient disturbance to the control system(s).

Abstract: The invention concerns a hydraulic line coupling arrangement of a consumer, with a pump line, a tank line and a safety valve in the pump line, the valve element of the safety valve being acted upon in the opening direction by an opening pressure from the pump line and in the closing direction by a closing pressure of a closing pressure connection. In such an arrangement it is desired to prevent overloading of the consumer. For this purpose, a pilot valve is provided for controlling the closing pressure, the position of the pilot valve being controlled by the pressure in the tank line.

Abstract: A binary voting solenoid arrangement 10 is provided which operates in a “2 out of 3” manner to provide relatively high safety, low spurious tripping and a relatively low installation cost, while also enabling on-line testing of each solenoid individually without process interruption. Solenoid arrangements 10, 10′ and 10″ are preferably used in a three-way configuration, while solenoid 10′″ may be used in a two-way configuration.

Abstract: A hydraulic emergency control (10, 10a, 10b, 10c) for a hydraulically actuated clutch (14) arranged between an internal combustion engine (12) is proposed. A pump (16) driven by the internal combustion engine (12) feeds a work line (18) in which a choke (20, 20b, 20c) is arranged. A regulating valve (22, 22a, 22b, 22c) is provided for controlling the clutch (14) at least in the event of failure of the electric supply. A first control line (26) is connected by a first control input (S1) of the regulating valve (22, 22a, 22b, 22c) with the work line (18) in front of the choke (20, 20b, 20c) with respect to the feed direction. A second control line (30) is connected by a second control input (S2) of the regulating valve (22, 22a, 22b, 22c) with the work line (18) behind the choke (20, 20b, 20c) with respect to the feed direction. Through the use of a regulating valve (22, 22a, 22b, 22c), a variable control of the clutch (14) is possible also in emergency operation.

Abstract: A fluid device includes a rotationally oscillating piston within a sector-shaped chamber, a reciprocating ram for performing work and a link pivotally connected to both the piston and the ram. The piston moves the ram through the link to an extended position and a retracted position. When the ram is in its extended position, the link is moved to an over-center position locking the ram in the extended position. A manually operated unlocking device is provided for moving the piston to eliminate the over-center condition of the link.

Abstract: A binary voting solenoid arrangement 10 is provided which operates in a “2 out of 3” manner to provide relatively high safety, low spurious tripping and a relatively low installation cost, while also enabling on-line testing of each solenoid individually without process interruption. Solenoid arrangements 10, 10′ and 10″ are preferably used in a three-way configuration, while solenoid 10′″ may be used in a two-way configuration.

Abstract: Main piston servo-actuation system, with hydromechanic self-contained failure detection device, working with hydraulic fluid supplied by a pump, including two servovalves (1 and 2) which are identical in design, controlling a piston (3) mechanically linked to a position transducer (4) according to the electrical demand (6, 7) supplied by the feedback position control loops (8 and 9) for the servovalves (1 and 2) to the torque motors (12 and 13) of the servovalves. These loops (8 and 9) receive the same piston position request, and they are given feedback at the same time with the same position signal fed by the position transducer (4). The system is furthermore compensated by two pressure selection valves (14 and 15) and by its own interconnection servo lines.

Abstract: A binary voting solenoid arrangement 10 is provided which operates in a "2 out of 3" manner to provide relatively high safety, low spurious tripping and a relatively low installation cost, while also enabling on-line testing of each solenoid individually without process interruption. Solenoid arrangement 10 is preferably manifolded (not shown), to facilitate maintenance on any detected failure, and to simplify installation and replacement.

Abstract: A pump drive assembly is disclosed. The assembly includes a driver, a pump drive member driven by the driver, and a decoupler that decouples the drive member from the driver when a force acting upon the drive member exceeds a threshold force. The pump drive member can be a piston rod, and the decoupler can be a magnet attached to the piston rod and coupled to a magnetically attracted plate driven by the driver. When a force resisting movement of the piston rod exceeds the magnetic force coupling the magnet to the plate, the magnet decouples from the plate, and the pumping operation ceases.

Abstract: An apparatus and method for preparing a hydraulic work machine for towing in response to a dead engine condition. The apparatus includes a source of hydraulic fluid, a standby pump system hydraulically connected to the source, a plurality of pilot controls adapted for electrical activation by the standby pump system, and a hydraulic brake system. The apparatus also includes a supply valve connected to the pilot controls, and at least one lift cylinder connected to the supply valve and adapted to lift an implement on the work machine. The hydraulic brake system and the lift cylinder are enabled for hydraulic control in response to activation of the standby pump system.