摘要 |
<p>A bell crank and a mechanical link are included in an aerial lift system to mechanically constrain motion of a two-boom aerial lift mechanism to prevent the aerial lift system from accessing unstable positions. Typically an aerial lift is coupled to a vehicle via a turntable. The turntable includes a counterweight on a rearward side of the turntable to balance the booms and associated hardware as they are extended in a forward direction. If the booms are in certain rearward, or even vertical positions, the counterweight can cause the vehicle to tip and such unstable positions are to be avoided. By providing the bell crank proximate the pivot joint between upper and lower booms, with the bell crank coupling at pivot joints with: the lower boom, the mechanical link, and an upper hydraulic cylinder, the booms of the aerial lift system are mechanically constrained to avoid vehicle tipping.</p> |