| 摘要 |
A servo power system is provided for the heavy lid of a pit designed for installation below the surface of an aircraft docking and refueling area. For one embodiment, a counterbalancing system is shown. The lid is mounted for rotation at the top of a pit wall about lid hinges lying along a horizontal axis. A counterweight is secured for rotation about a horizontal counterweight axis which is located below and parallel to the lid axis. Meshed gear sections on the lid and on the counterweight couple the lid and counterweight to move together in counter-rotation relative to each other. The weight of the lid is largely balanced by the weight of the counterweight, thereby facilitating opening and closing of the pit lid. |
