| 摘要 |
<p>An extension and retraction mechanism for a three section extensible boom is disclosed utilizing an internally disposed hydraulic cylinder connected between a stationary boom section and an intermediate boom section with a cable connection located entirely interior of the boom having opposite ends anchored to opposite ends of the stationary section with the cable routed around sheaves on the moving end of the hydraulic cylinder and a base end of the intermediate boom section with a cable attachment to the base end of the inner boom section, the inner boom section being the most extensible boom section.</p> |
