Abstract: The invention relates to a hydraulic steering facility for mobile systems, with a steering circuit for a steering facility and a working circuit for a working hydraulic system, whereby the steering circuit and the working hydraulic system are connected to a supply pump via a shared flow dividing valve and the flow dividing valve is connected to a load signal connection of the steering device. It is provided that the steering facility has an adjustable input choke that is connected via an inflow connection of the steering facility to the flow dividing valve, between the load signal connection and downstream of the input choke, a parallel circuit consisting of a choke and an adjustable second load signal choke is arranged, and the load signal connection is further connected via an adjustable first load signal choke to a return flow connection of the steering facility.

Abstract: A door control system for a vehicle includes a compressor, an air dryer, a door control valve and at least one cylinder that can be actuated by compressed air. A piston of the cylinder can occupy a first functional position and a second functional position. The air dryer, in drying mode, is exposed to throughflow of the air flowing into the cylinder, and in regeneration mode is exposed to throughflow by the air discharging from the cylinder. The cylinder is pressurized only with compressed air from a compressed air accumulator.

Abstract: A user interface linkage system includes first and second user interfaces that are linked by a single hydraulic circuit. The system is configured to provide compensation for relatively slow changes in hydraulic fluid pressure due, for example, to temperature variations. The system is also configured to allow the user interfaces to be selectively unlinked from each other.

Abstract: A fluid controller (15a) in a multiple-input hydrostatic power steering system includes a check valve assembly (101), having a first fluid passage (111), defining a check valve seat (105) and a check valve (103) operably associated therewith, in fluid communication with a second fluid passage (109), with the second fluid passage (109) being in fluid communication with a return port (25a). In the left (L) and right (R) operating positions, return flow can flow from the interior region (114) of the valve (27), through the first fluid passage (111), past the check valve (103), and through the second fluid passage (109) to the return port (25a). In the neutral position (N), pressurized fluid can flow from an inlet port (19a) to the return port (25a), with the check valve (103) preventing fluid from flowing through the first fluid passage (111) and into the interior region (114) of the valve (27).

Abstract: An apparatus comprises first (3) and second (5) force-activated actuators, each having a fluid displacer (7, 9) and force control lever (19, 21) coupled to the fluid displacer, a conduit (15) for transporting fluid between the fluid displacers to couple motion of the fluid displacers, and a force controller (17) responsive to the pressure of the fluid for controlling a force opposing displacement of a fluid displacer.

Abstract: The invention relates to a device for telecontrolling a function of drives for vehicles or machines. Said device comprises at least two manual gearboxes which are arranged at a distance from the drive to be controlled, said gearboxes respectively having a double acting cylinder arrangement comprising two cylinder chambers which can be actuated in counterrotation for a hydraulic flow medium, in order to control at least one function of said drive.

Abstract: A control system controls actuation of a hydraulic cylinder on a skid steer loader. The control system includes a movable element, movable by an operator. A position sensor is coupled to the movable element and provides a position signal indicative of a position of the movable element. A controller is coupled to the position sensor to receive the position signal and provide a control signal based on the position signal. A valve spool controls flow of hydraulic fluid to the hydraulic cylinder. An actuator is coupled to the controller and the valve spool and moves the valve spool in response to the control signal from the controller.

Abstract: A steering control system for an autonomous machine has a manual steering control valve for directing fluid from a pump to either a head end chamber or a rod end chamber of a hydraulic steering actuator. In one embodiment, an electrically actuated steering valve device is disposed in series flow relationship between the pump and the manual steering control valve and is operative to direct fluid from the pump to the head end and rod end chambers. In another embodiment, a electrically actuated device mechanically actuates the manual steering control valve for steering the machine.

Abstract: An electro-hydraulic control system for a mineral mining installation has a series of valve blocks, each contain a number of valves which are operated in dependence on electrical signals to cause hydraulic appliances of roof supports to operate. To allow emergency operation, when there is a power failure or when the control system fails or is otherwise inoperative, further manually operable valves are connected by a flexible, multi-core connecting cable to the valve block of the associated support. The emergency control valves can operate hydraulically controllable direction control valves of the control system and by-pass the electrical controls. The support can then be controlled purely hydraulically, at least in its main functions, using the emergency device.

Abstract: A remote control modification (11) for a hydraulic steering system (13) of the type used to steer underground loaders and the like is disclosed. The remote control modification comprises a bidirectional, spring-loaded remote control valve (51) connected in parallel with the bidirectional, spring-loaded control valve (19) that normally responds to steering inputs created by the manual movement of a steering arm (25). The remote control valve (51) has outlet ports (75 and 77) that are smaller than the outlet ports (39 and 41) of the manual control valve (19). Movement of the piston of the remote control valve (51) is controlled by a slave hydraulic actuator (53). The flow of hydraulic fluid to the slave hydraulic actuator (53) is controlled by a solenoid-actuated valve (59). The solenoid (61) of the solenoid-operated valve (59), in turn, is controlled by a receiver (63) that responds to radio frequency control signals (105) generated by a remotely located transmitter (65).

Abstract: Apparatus for use in supporting a plurality of override control handles of a control valve assembly, the control handles supported for movement in a first direction between engagement and disengagement with the control valve spools and supported for movement in a second direction to cause controlled movement of the valve spools. The apparatus includes a plate having slots housing the control handles and the plate being supported for slideable movement such that movement of one control handle between a valve spool engaging position and a disengaged position causes movement of the other control handles between an engaged position and a disengaged position.

Abstract: A pneumatic door control equipped with a door control valve for operating a door drive to an open or a closed position. The door control valve has an opening and a closing solenoid-operated pilot valve and an opening and closing spool valve, each operable to a passage or a vent position. A shuttle valve is part of the control valve and works in conjunction with an operator-controlled emergency valve to vent both spool valves simultaneously. A differential pressure switch is connected to the door drive to sense abnormal pressure expended in a door-opening or closing movement. Such an occurrence will output a signal to an electronic switching device which also monitors, via limit switches, whether a door is fully opened or fully closed. If excess pressure occurs during a door-closing movement, the switching device will trigger the control valve to reverse to the opening position.

Abstract: Pressurization of closing and opening chambers of a door operator is controlled by first and second magnet valves coupled to the source of air. These valves are alternately energized by a switching network, e.g., a flip-flop, when sequentially actuated to close and open the door. The second magnet valve is biased to its vent position but the first valve is operated to its vent position by air through a double check valve when the second magnet valve is energized. Emergency and choke valves are inserted in series in the air supply to the magnet valves and normally pass air without restriction. Operation of the emergency valve, e.g., door blocked, shuts off air from the magnet valves and diverts that air to inhibit all output from the switching network and, through the check valve in opposite position, to operate the first magnet valve to vent position. Door operation is halted in position.

Abstract: Fluid control systems frequently eliminate use of fluid operated jack protecting relief valves because additional visibility blocking and damage prone conduits are required to connect the relief valves to the reservoir. A fluid operated system having a controlling valve, a selecting valve, a fluid operated jack, a relief valve, a reservoir and a bypass valve is provided to controllably connect the relief valve to other portions of the system in response to the position of controlling valve and selecting valve. Therefore, no additional conduits are required to connect the relief valve to the reservoir and thus the problems of reduced visibility, premature conduit leakage and conduit damage are eliminated. The fluid control system is particularly suited for use in a work vehicle such as a lift truck having a lift mast.

Abstract: An electro-hydraulic control system for an underground mineral mining installation employs individual control assemblies and devices on a series of support units which are interconnected to one another and to a central control station via lines conveying electrical control signals. Manually-operable selector switches on the units enable groups of the support units to be operated in sequence at will by operating the switches of adjacent units outside the group.

Abstract: A safety device for a fluid operated tool features a throttle lever which is always freely movable but is normally rendered inoperable to effect tool actuation except in response to a consciously deliberate two step action wherein a first valve control must be actuated before an on-off valve controlling fluid flow may be operated by a second valve control in response to throttle lever operation to drive the on-off valve from a normally closed position to an open position establishing an open fluid flow condition for tool start-up.

Abstract: A dual action trip and control valve is herein described which generally consists of a three way control valve which may be used to control the flow of fluid to and from a power piston. The valve is provided with a trip feature to cause the rapid dumping of the fluid from the power piston cylinder in response to the sensing of an emergency condition or the like.

Abstract: A loader/backhoe hydraulic system and control valve assembly therefor characterized in that each of a plurality of directional control valves is operative through an associated selector valve to control the operation of either of a pair of cylinders connected to said selector valve. The loader/backhoe herein is further characterized in that the control valve assembly and oil tank are unitized and mounted under the floor of the tractor for simplified piping and access for servicing.

Abstract: A self-advancing mine roof support is provided, in addition to the normal manually operable control valve means for controlling raising and lowering of the roof-engaging structure of the support and operation of the advancing means, with an automatic sequence control valve means operable in response to a control signal from a position removed from the support, for example from an adjacent support, and an isolating valve means arranged so that control of the various operations can be effected either by means of the manually operable means or from the safety of a location spaced away from the support being controlled by means of the automatic valve means each independently of the other.