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US 4,053,058 AGranted
Suspended extensible boom
AssigneeFMC Corporation
InventorsLyle B. Jensen, C. Wayne Powers
Life of this patent
Estimating the term…
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AssigneeFMC Corporation
InventorsLyle B. Jensen, C. Wayne Powers
Estimating the term…
An extensible boom has a base section that is pivotally connected to a machinery platform and at least one section that is movable axially relative to the base section. A cable system is provided for extending and for retracting the movable sections. The boom sections can be jammed together in either an extended position or a retracted position to resist compression axially of the boom, and to resist bending transversely of the longitudinal axis of the boom in a generally vertical plane. A live mast is offset from the base end of the boom in a vertical plane. Boom carrying ropes extend between the distal end of the base section and the live mast, while a boom pendant extends between the live mast and the distal end of the tip section of the boom. Support of the boom can be transferred by alternately tensioning and slackening the boom carrying ropes and the boom pendant. The boom is supported by the boom carrying ropes during traveling, unpinning, extension, retraction, and pinning of the boom sections, while the boom is supported by the boom pendant when the boom sections have been pinned together and are ready for supporting loads with the boom.
In a crane or the like, the combination comprising an extensible boom having at least two sections that include a fixed base section and a movable tip section, means for extending the tip section relative to the base section, means for pinning said boom sections together to resist bending transversely of the longitudinal axis of the boom in a generally vertical plane and to resist compression axially of the boom, a boom pendant connected to the distal end of the tip section, means for maintaining slack in the boom pendant while the tip section is being extended, means for tensioning the boom pendant to support the distal end of the boom when the boom sections are pinned together for supporting loads with the boom, said boom pendant slack maintaining means including a pendant storage drum about which a portion of the boom pendant is wrapped and a hydraulic motor that pays out the boom pendant only in response to a given pressure, said pendant storage drum being located at the proximate end of the base section, and a live mast assembly being connected to the proximate end of the base section for pivotal movement upwardly of the boom about a horizontal axis, said live mast assembly supporting the boom pendant between the distal end of the tip section and the pendant storage drum.
In a crane or the like, the combination comprising a machinery platform;
In a crane or the like, the combination comprising an extensible boom having at least two sections that include a fixed base section and a movable tip section, means for extending the tip section relative to the base section, means for pinning said boom sections together to resist bending transversely of the longitudinal axis of the boom in a generally vertical plane and to resist compression axially of the boom, a boom pendant connected to the distal end of the tip section, means for maintaining slack in the boom pendant while the tip section is being extended, means for tensioning the boom pendant to support the distal end of the boom when the boom sections are pinned together for supporting loads with the boom, a boom carrying rope connected to the distal end of the base section for supporting the base section as the boom is being extended or retracted, means for slackening the boom carrying rope when the boom pendant is tensioned to support the distal end of the boom, said means for slackening the boom carrying rope and said means for tensioning the boom pendant being operable simultaneously in response to a single control, and a boom hoist rope for raising and lowering the boom independently of the boom pendant and the boom carrying rope.
Dependencies are inferred from the claim text.