Abstract: A lifting cylinder unit (1) has a plunger design, and includes a stationary rod tube (2) having a longitudinal axis (3), two axial end regions, and an outer surface (26). A rod head (4) is arranged in one of the axial end regions of the rod tube (2), the rod head (4) being fixedly connected to the rod tube (2) and including a connecting bore (7). A cylinder tube (14) having two axial end regions and an outer surface (22) is arranged outside the rod tube (2). The cylinder tube (14) is designed and arranged to be movable with respect to the rod tube (2) in the direction of the longitudinal axis (3) of the rod tube (2). A cylinder bottom (15) is arranged in one of the axial end regions of the cylinder tube (14), and is fixedly connected to the cylinder tube (14). A guide bush (18) having an inner surface (23) and including a surface (30) for the application of a force is fixedly connected to the outer surface (26) of the cylinder tube (2).

Abstract: A hydraulic synchronizing circuit includes at least one master cylinder unit including a primary chamber, a secondary chamber, a piston and at least one piston rod, the piston having a primary effective surface and a secondary effective surface. The hydraulic synchronizing circuit further includes at least one slave cylinder unit including a primary chamber, a secondary chamber, a piston and at least one piston rod, the piston having a primary effective surface and a secondary effective surface. The master cylinder unit and the slave cylinder unit are arranged to be single-acting. The secondary effective surface of the master cylinder unit and the primary effective surface of the slave cylinder unit are substantially equal. A tank at least partially formed by the secondary chamber of the slave cylinder unit and containing a fluid is provided. A pump sucks the fluid from the tank. A first conduit operatively connects the tank to the primary chamber of the master cylinder unit via the pump.

Abstract: A hydraulic system is provided for powering a steering unit, a trailer brake and an auxiliary power unit from a single pump. A control circuit ensures that the hydraulic trailer brake and/or the power steering unit on the vehicle will operate on a preferential basis over the auxiliary power unit. The hydraulic control circuit has two priority valves connected in series. The upstream priority valve has a priority position in which it makes the pump fluid available to a supply line for the common priority flow for the steering and braking apparatus and a non-priority position for powering the auxiliary power unit. The common priority flow is passed through the second or downstream priority valve for priority powering of the power steering circuit.

Abstract: An off-road vehicle has ground supports on each side which can be simultaneously braked, or independently braked to aid in steering. A braking system includes a brake valve device which feeds high fluid pressure to a pair of reversing valves. The reversing valves deliver the high pressure to respective wheel brake cylinders disposed on opposite sides of the vehicle. The reversing valves and brake valve device are controlled by a common pedal which comprises separately or simultaneously actuable half-pedals. Each half-pedal actuates the brake valve device and a respective reversing valve such that when both half-pedals are depressed the system operates in a dual-sided braking mode, and when only one half-pedal is depressed the system operates in a braked-steering mode. The system can be shifted directly from the dual-sided braking mode to a brake-steering mode by simply releasing one of the half-pedals without having to first release all braking action.

Abstract: A hydraulic dual-circuit external power brake valve of tandem design has a primary control piston and a secondary control piston, both of which are located in a valve bore of the dual-circuit external power brake valve. The control pistons are provided with bores for connection of a primary brake circuit and a secondary brake circuit to a pressure reservoir and an equalizing tank, and are movable within the valve bore. The regulating force necessary for the motion is introduced into the dual-circuit external power brake valve by a regulating spring. A pressure-transmitting piston between the primary control piston and the regulating spring. The primary control piston on its two end faces, and the pressure-transmitting piston on its face toward the primary piston, are subjected to the pressure acting in the primary brake circuit. When the primary brake circuit is intact, the pressure-transmitting piston is actuated by the regulating spring.

Abstract: In a brake valve of the type in which a given ratio is maintained between a master pressure developed by a brake pedal and an actual brake pressure, an arrangement is provided for continuous, rather than stepwise, adjustment of this ratio. The brake valve includes a control piston which is subjected to the master pressure and which, by the displacement thereof, opens and closes connecting channels between an accumulator containing a primary pressure fluid and a brake, as well as between the brake and a fluid collecting tank. The control piston and a measurement piston apply counter forces to the arms of a balance beam whose lever ratio determines the degree of feedback of the instantaneous brake pressure to the control piston. A stop is provided in the path of the axis of the control piston, which limits the stroke of the piston, to prevent the overloading of the balance beam during abnormally high braking pressures such as occur, for instance, during panic braking.

Abstract: A reservoir loading valve accomplishing a pressure protection of the reservoir circuit comprises a pre-control valve subject to the pressure of the control circuit and which controls depending on this pressure a switching valve the piston of which in turn controls the connection between a pump and a working hydraulic and the reservoir circuit. The reservoir circuit is supplied with pressure fluid through a blind bore and a transverse bore in the piston of the switching valve, while a flow control orifice is provided in the blind bore and controls the size of the flow of volume flowing to the reservoir circuit. When the reservoir is loaded and the working hydraulic circuit is connected, the piston of the switching valve will be displaced by the high pressure delivered by the pump into a position in which the connection between the pump and the reservoir circuit is completely interrupted.

Abstract: A vehicle, such as a tractor, has an attachment implement, such as a plow. An automatic controller acts upon a power lift of the plow, which moves the plow during operation in trenching position. In a first control, this motion of the plow ensues relative to the tractor, so that the vertical absolute velocity component of the plow becomes approximately zero. The plow is so moved relative to the vehicle that it moves upward during a downward motion of the plow-tractor joint and downward during an upward motion of such joint. The tractor is this completely disconnected dynamically from the plow, so that the pitching vibration behavior of the tractor is not subjected to a negative change due to the moments resulting from the forces of acceleration of the plow and affecting the plow, as is the case with a vehicle having a rigidly connected attachment implement. In a second control, the plow is moved in opposite phase to the tractor to counteract a change of its pitching angle coordinate.

Abstract: A parking brake valve cooperates with a spring loaded cylinder which releases a parking brake when pressurized. The valve includes a shaft with an eccentric section, and this shaft may be turned by an actuating lever from a position in which the brake is engaged to a released position. In the released position, the eccentric section of the shaft causes the movement of a control piston, permitting the spring loaded cylinder to be pressurized, releasing the brake. The pressure applied to the spring loaded cylinder is also provided to a radial surface on the shaft, causing the shaft to be friction locked in the released position, despite a spring force applied by a control spring tending to return it to the braking position. If a breakdown occurs in the parking brake system, however, the pressure to the spring loaded cylinder will drop, releasing the friction lock.

Abstract: An apparatus for positioning an adjustable member as a function of a command signal and a control condition, especially for the positioning of a hoisting mechanism on a tractor or the like, comprises an operating circuit and a control circuit. The operating circuit has a bidirectional positionable valve with a valve side and first and second control devices for regulating flow of pressure medium from a supply tank to the adjustable member. The control circuit connects a control pressure medium source to the control devices at first and second junctions and includes adjustable throttles and a flow-regulating valve. A first adjustable throttle is connected between the supply tank and the first junction. The second adjustable throttle is connected between the control pressure medium source and the first junction and in series with the first adjustable throttle.