A hydraulic control circuit for a hydraulic on-vehicle winch comprises a winch control circuit interposed between a main circuit pressure inlet and the hydraulic connectors on the winch and governed by a pilot-operated directional valve. When a reel-out pilot valve shifts the pilot-operated directional valve, hydraulic flow to a reel-out port is permitted while flow to a reel-in port is obstructed. Conversely, when a reel-in pilot valve shifts the pilot-operated directional valve, hydraulic flow to the reel-in port is permitted while flow to the reel-out port is obstructed. A selectively configurable enabling circuit is interposed between the main circuit pressure inlet and the winch control circuit. In an enabling configuration, hydraulic flow from the main circuit pressure inlet to the pilot-operated directional valve, the reel-out pilot valve and the reel-in pilot valve is permitted. In a disabling configuration in which hydraulic flow to the pilot-operated directional valve is obstructed.

The present disclosure provides a winch overload protection system, a workover system, and a method for operating a workover system. The winch overload protection system, in one embodiment, includes an overload detection unit operable to detect when a load on a winch of a workover system exceeds a safety load limit. The winch overload protection system, in this embodiment, further includes an overload control unit configured to receive an overload signal from the overload detection unit, and in response thereto release a brake on the winch.

A winch boom system and method includes a frame, a shaft supported by the frame, and a winch drum attached to the shaft such that rotation of the shaft about a shaft axis rotates the winch drum. A boom is pivotably coupled to the frame, the boom defining a cavity in which the winch drum is positioned. A winch rope is wound about the winch drum, passing through the cavity of the boom, and extending from the boom at a point distal from the winch drum.

A hydraulically actuated liftable and lowerable hook of a crane has a hydraulic system comprises at least one working machine with a hydraulic motor driving a winch. At least one drive machine comprising a pump is connected directly or indirectly to at least one of the working machines by means of two connections via corresponding working lines, which serve as a feed or return depending on the operating state of the working machine. A lowering brake valve is provided in one working line and is connected to the other working line via a control line such that the lowering brake valve is displaceable against a restoring force by pressure, which prevails in the other working line and is forwarded via the control line, from the blocking position of said valve into a through-flow position for lowering the hook by means of a primary winch.

A hydraulically actuated liftable and lowerable hook of a crane has a hydraulic system comprises at least one working machine with a hydraulic motor driving a winch. At least one drive machine comprising a pump is connected directly or indirectly to at least one of the working machines by means of two connections via corresponding working lines, which serve as a feed or return depending on the operating state of the working machine. A lowering brake valve is provided in one working line and is connected to the other working line via a control line such that the lowering brake valve is displaceable against a restoring force by pressure, which prevails in the other working line and is forwarded via the control line, from the blocking position of said valve into a through-flow position for lowering the hook by means of a primary winch.

A control valve assembly for indirect pneumatic control and method for controlling a working fluid pressure, which enable precise, sensitive and speed-variable controlling. The assembly includes two valve units, a working fluid inlet, and a control fluid inlet. A working fluid channel connects the working fluid inlet through the two valve units to an outlet. A valve piston arranged within a valve cylinder of the valve units is movable between open and closed positions. A spring element biases the valve piston toward the closed position, and a control pressure chamber applies a control pressure counteracting the spring element's bias. When a control pressure is applied in the first chamber, the first valve piston is moved to the open position. Two opposite valve surfaces form a valve opening opened at varying widths when the valve piston is moved in the valve cylinder because of a changing control pressure, and the working pressure can be finely adjusted corresponding to the valve opening width depending on the control pressure.

A device for supplying and modifying the cylinder cubic capacity of a hydraulic motor, comprising: a first conduit (1) for supplying and discharging an operating fluid to a first side of the hydraulic motor (M); a second conduit (2) for supplying and discharging an operating fluid to a second side of the motor (M); an actuator (3) provided to modify the cubic capacity of the motor (M); an increase conduit (31) for increasing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3) which produces an increase of the cubic capacity of the motor (M); a reduction conduit (32) for reducing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3), which produces a reduction of the cubic capacity of the motor (M). The device is structured to supply to the increase conduit (31) and to the reduction conduit (32) a proportional pressure to the load acting on the winch.

A device for supplying and modifying the cylinder cubic capacity of a hydraulic motor, comprising: a first conduit (1) for supplying and discharging an operating fluid to a first side of the hydraulic motor (M); a second conduit (2) for supplying and discharging an operating fluid to a second side of the motor (M); an actuator (3) provided to modify the cubic capacity of the motor (M); an increase conduit (31) for increasing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3) which produces an increase of the cubic capacity of the motor (M); a reduction conduit (32) for reducing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3), which produces a reduction of the cubic capacity of the motor (M). The device is structured to supply to the increase conduit (31) and to the reduction conduit (32) a proportional pressure to the load acting on the winch.

A track-type machine is disclosed. The track-type machine may comprise an electric drive powertrain including an internal combustion engine, a winch assembly having a drum rotatably supporting a cable so that the cable is reeled in or reeled out at a winch line speed when the drum is rotating, and an implement controller configured to activate the winch assembly for reeling in and reeling out the cable. The track-type machine may further comprise a hydraulic circuit driven by the internal combustion engine and configured to actuate a rotation of the drum when the winch assembly is activated by the implement controller. In addition, the track-type machine may further comprise a control system configured to increase an engine speed of the internal combustion engine when the winch assembly is activated by the implement controller.

The present invention is provided with: a manipulation unit; a winch device that operates with an actuation mode of either a high speed mode or a low speed mode, and winds in or reels out a wire rope; a selection unit for an operator to select either the high speed mode or the low speed mode; a load calculation unit calculating a suspended load; a tension calculation unit calculating the tension of the wire rope; and a control unit controlling the actuation of the winch device. If the mode selected by the selection unit is the high speed mode, the manipulation unit is manipulated from a neutral state to a non-neutral state, and the suspended load is smaller than a load threshold and the tension is smaller than a tension threshold, the control unit controls the winch device so as to operate in the high speed mode.