Ring derrick with stationary counterweight
AssigneeBigge Crane & Rigging Co.
InventorsWeston J. Settlemier, Vaughn L. Hersey
Life of this patent
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Abstract
A ring derrick includes a carriage which moves on a fixed circular track around a stationary counterweight. A tension and compression column assembled from transportable tubular segments is affixed to the counterweight by a universal swivel joint. The back mast of the derrick is secured at its upper end to the tension column, while the main boom of the derrick extends radially away from the tension column. The main boom and back mast are hinged directly together at the carriage by massive hinge pins which pass through spherical bearings mounted on the carriage. The carriage's suspension distributes the load from the boom and mast to an array of trucks and has an automatic stabilizing system that compensates for uneven track.
Claims12
A hoisting device comprising
- a mobile slewing carriage constrained to move around a geographically fixed axis of revolution,
- a geographically stationary counterweight lying on said axis of revolution,
- a tension column, capable of withstanding substantial axial compression, connected to the counterweight and extending upward from said counterweight along said axis of revolution,
- a swivel joint connecting the counterweight to the tension column, which permits the tension column to deviate slightly from vertical,
- a back mast extending from said slewing carriage to the tension column, the back mast being connected to the slewing carriage at one end and to the tension column at its other end, and
- a main boom pivotally connected to the slewing carriage and extending from the slewing carriage in a direction away from said tension column,
- wherein both the main boom and the back mast are joined to the slewing carriage by hinges, each said hinge comprising a hinge pin supporting both the back mast and the main boom, and a spherical bearing affixed to the slewing carriage and supporting the hinge pin.
Dependencies are inferred from the claim text.