| 摘要 |
A display unit that can retract heavy monitors into a stowing cavity when the retracting actuator of the unit becomes inoperative. The display unit has a spring motor with at least two nested torsional springs attached in parallel to provide the torque necessary to retract the monitor. The monitor is connected to a frame such that the monitor can move from a first stowed position to a second viewing position. Attached to the frame and monitor is an actuator typically of the ball screw variety, that rotates the monitor into the two position described. The monitor moves into the viewing position when the ball screw is rotated in a first direction, the monitor further being lifted into the stowed position when the ball screw is rotated into a second opposite direction. The actuator is typically driven by an electric motor adapted to rotate the ball screw in both directions. The spring motor is connected to the actuator, such that the springs turn a predetermined number of turns in a first direction when the monitor is moved from the stowed to the viewing positions. Once turned the springs store potential energy that can be used to lift the monitor back into the stowed position. If the electric motor fails, or if there is a loss of power, the springs turn in a second opposite direction rotating the ball screw and moving the monitor from the viewing to the stowed position.
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