The present disclosure relates to a display device. A display device according to one embodiment of the present disclosure comprises: a housing; a plurality of display elements disposed in the housing in a first mode and configured to project out of the housing in a second mode; and a driving device configured to fold the plurality of display elements in a first axial direction in the first mode, and unfold at least a portion of the plurality of display elements in the second mode to form a polyhedral display. Accordingly, it is possible to implement a display device that is folded or unfolded by using the plurality of elements.

An HST circuit has a hydraulic pump that converts a drive force of an engine into energy of oil, and a hydraulic motor that converts the energy of the oil converted by the hydraulic pump into drive energy. Pressure sensors detect a pressure of the oil within the HST circuit. A variable charge pump replenishes the oil into the HST circuit. A controller controls a capacity of the variable charge pump based on the pressure of the oil within the HST circuit detected by the pressure sensors.

An HST circuit has a hydraulic pump that converts a drive force of an engine into energy of oil, and a hydraulic motor that converts the energy of the oil converted by the hydraulic pump into drive energy. Pressure sensors detect a pressure of the oil within the HST circuit. A variable charge pump replenishes the oil into the HST circuit. A controller controls a capacity of the variable charge pump based on the pressure of the oil within the HST circuit detected by the pressure sensors.

A directly-controlled hydraulic directional valve includes a housing, control piston, first and second springs, double-stroke solenoid, spring plate, adjustment device, and electronics. The piston is longitudinally displaceable in a bore in the housing, either directly or via a control sleeve. The springs are positioned in a region of an end of the piston remote from the solenoid. One end of each spring is supported on the spring plate, which is clamped between the springs and the piston. The other end of the first spring is fixed to the housing, and the other end of the second spring is fixed to the adjustment device. The first spring exerts a force on the piston in a first direction, and the second spring exerts a force on the piston in a second opposite direction, so as to bias the piston into a preferred position. The solenoid is mounted on a side of the housing, and is operable to move the piston out from the preferred position in opposite directions proportional to an electric current from the electronics, such that the piston moves to the preferred position in response to each of non-actuation of the solenoid and a fault in the electronics. The adjustment device is operable to alter a position of the other end of the second spring to adjust the preferred position of the piston.

A directly-controlled hydraulic directional valve includes a housing, control piston, first and second springs, double-stroke solenoid, spring plate, adjustment device, and electronics. The piston is longitudinally displaceable in a bore in the housing, either directly or via a control sleeve. The springs are positioned in a region of an end of the piston remote from the solenoid. One end of each spring is supported on the spring plate, which is clamped between the springs and the piston. The other end of the first spring is fixed to the housing, and the other end of the second spring is fixed to the adjustment device. The first spring exerts a force on the piston in a first direction, and the second spring exerts a force on the piston in a second opposite direction, so as to bias the piston into a preferred position. The solenoid is mounted on a side of the housing, and is operable to move the piston out from the preferred position in opposite directions proportional to an electric current from the electronics, such that the piston moves to the preferred position in response to each of non-actuation of the solenoid and a fault in the electronics. The adjustment device is operable to alter a position of the other end of the second spring to adjust the preferred position of the piston.

An HST circuit has a hydraulic pump that converts a drive force of an engine into energy of oil, and a hydraulic motor that converts the energy of the oil converted by the hydraulic pump into drive energy. Pressure sensors detect a pressure of the oil within the HST circuit. A variable charge pump replenishes the oil into the HST circuit. A controller controls a capacity of the variable charge pump based on the pressure of the oil within the HST circuit detected by the pressure sensors.

An HST circuit has a hydraulic pump that converts a drive force of an engine into energy of oil, and a hydraulic motor that converts the energy of the oil converted by the hydraulic pump into drive energy. Pressure sensors detect a pressure of the oil within the HST circuit. A variable charge pump replenishes the oil into the HST circuit. A controller controls a capacity of the variable charge pump based on the pressure of the oil within the HST circuit detected by the pressure sensors.

A raising assembly for use with a gangway connected for rotation between a raised stowed position and a lowered deployed position. The raising assembly comprises at least one fluid actuated cylinder connected to the gangway. A raising actuator is operative to cause operation of the cylinder in a manner that rotates the gangway toward the stowed position while the raising actuator is continuously activated by an operator. A lowering actuator is operative to cause operation of the cylinder in a manner that rotates the gangway toward the deployed position due to gravitational forces while the lowering actuator is continuously activated by the operator. The raising assembly is configured to maintain the gangway at a current position between the stowed position and the deployed position if the operator does one of ceasing to activate the raising actuator while raising the gangway or ceasing to activate the lowering actuator while lowering the gangway.

A raising assembly for use with a gangway connected for rotation between a raised stowed position and a lowered deployed position. The raising assembly comprises at least one fluid actuated cylinder connected to the gangway. A raising actuator is operative to cause operation of the cylinder in a manner that rotates the gangway toward the stowed position while the raising actuator is continuously activated by an operator. A lowering actuator is operative to cause operation of the cylinder in a manner that rotates the gangway toward the deployed position due to gravitational forces while the lowering actuator is continuously activated by the operator. The raising assembly is configured to maintain the gangway at a current position between the stowed position and the deployed position if the operator does one of ceasing to activate the raising actuator while raising the gangway or ceasing to activate the lowering actuator while lowering the gangway.

A balancing valve includes four ports. While the pressures at a pair of balancing ports of a hydraulic balancing valve are equal, the valve maintains two other ports in a closed position. Upon a pressure differential between the balancing ports, fluid communication can occur between one of the balancing ports and either of the other ports based upon the direction of the pressure differential. A hydraulic ride control system utilizes the balancing valve together with other control valves to provide ride control functionality.