Abstract: A solar panel carrier T is provided at a sub-structure U such that it can be rotated and tilted by means of hydrostatic rotation and tilt motors M, M?. In an electrohydraulic adjusting device for the solar panel carrier T a motor pump aggregate 8 is connected to the hydrostatic motors. Within working lines A, B of the tilt hydrostatic motor M at least one tilt control system K is provided, which comprises valve components and a pilot pressure circuit. The tilt control system K comprises pressure actuated blocking valves or load holding valves LHVA, LHVB. For automatically adjusting a protected position S of the carrier T a suction line N is provided at the side of the hydrostatic tilt motor facing to the blocking valves or load holding valves. The suction line N is surveyed by a monitoring solenoid 18 and is opened depending on initial pressure conditions in case of switching off the electric power and/or in case of an electric breakdown.

Abstract: A fluid circuit is provided to independently control the flow of fluid into and out of each end of an actuator. This is accomplished by having two different independently controlled valves controlling the flow of fluid into and out of one end of the actuator and by having two other independently controlled valves controlling the flow of fluid into and out of the other end of the actuator. Regeneration of the fluid flow from one end of the actuator to the other end of the actuator is provided by blocking the exhaust flow of fluid to the reservoir by one of the independently controlled valves and redirecting the flow across the other of the independently controlled valves to join with the flow of the pump that is being directed to the other end of the actuator. This arrangement permits a portion or all of the fluid from one end of the actuator to be regenerated to the other end of the actuator.

Abstract: The hydraulic distributor exhibits a cylindrical and internally-hollow body (2) having an inlet chamber (3) for a fluid and an outlet chamber (4) which are interconnected directly (by a communication conduit), or indirectly by an external distributor. A cursor (7) is axially mobile in the hollow body (2) and a closing element (12) is associated to the cursor (7) by elastic elements (11). The closing element (12) is mobile in the inlet chamber (3) between a first position in which it occludes the inlet chamber (3) and a second position in which it permits passage of fluid from an antechamber (3a) to a second opening (3b).

Abstract: A switching device controlling at least one hydraulically operating apparatus has two check valves working in opposition to one another in a feed conduit and a discharge conduit, respectively. The conduits are connected to the operating apparatus, as well as to a pilot valve. Two openable nonreturn valves are connected parallel to the two check valves. The control line of one openable nonreturn valve is connected to the blocking connection of the other openable nonreturn valve. The switching device is especially for controlling a hydraulic cylinder to provide a float setting at low cost, with reliable operation, and with few components.

Abstract: Fluid regeneration circuits are useful for filling expanding sides of a hydraulic cylinder with fluid being exhausted from the other side. The currently available circuits pass the excess fluid not needed for filling the expanded side of the cylinder through the directional control valve to the tank such that the directional control valve must be actuated for the regeneration valve assembly to function. A combined meter-out and regeneration valve assembly of the present invention is used in a hydraulic system having a directional control valve for metering in pump to cylinder fluid flow and includes a meter-out valve to meter-out cylinder to tank fluid flow from a head end actuating chamber. The fluid passing through the meter-out valve passes through an exhaust conduit to a tank bypassing the directional control valve. This permits the meter-out valve to be used independently of the directional control valve to retract a hydraulic cylinder.

Abstract: A quick drop valve is electrically actuated by a switch located adjacent to the implement positioning control lever. The quick drop valve is a pilot operated spring biassed valve. When the electric switch is closed a solenoid valve is energized redirecting fluid between the pilot control lines. The quick drop valve is shifted short circuiting the flow of fluid from the lift side of the hydraulic cylinder to the reservoir and redirects it to the drop side of the hydraulic cylinder for quickly dropping the working implement.

Abstract: In combination with a double-acting cylinder having pressure and exhaust ports, a cylinder control valve having a spool having a pair of control positions with pressure, cylinder and exhaust ports, and conduits between the valve cylinder ports and cylinder ports, and a source of compressed air connected to the valve pressure port, a safety control system which comprises a pilot-operated valve housing having a pressure port connected to the source of compressed air, a pilot port and a pair of cylinder ports connected to the cylinder conduits. A valve spool within said housing has first and second control positions with an operative device on the housing which normally biases the safety valve spool to a first control position pressurizing opposite ends of the cylinder and with the pilot port connected to the source of compressed air. A build up of pressure to the pilot port moves the safety valve spool to its second control position, blocking communication between the safety valve and the cylinder ports.