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US 4,378,933 AGranted
Crane assembly
AssigneeThe United States of America as represented by the Secretary of the Army
InventorRobert E. Holston
Life of this patent
Estimating the term…
Abstract
The device features the elimination of bending moments in all members to ow a design of minimal weight, and depends on the use of an existing structure to provide stabilizing reactions when erected. A rigid mast is pivoted at its lower end on the existing structure, and supports a block and tackle at its upper end. A rigid triangular spreader and cable assemblies support the mast.
Claims3
A crane assembly for use with a structure having a mounting hole and an attachment point, with the mounting hole located vertically above the attachment point;
- said crane assembly comprising:
- a rigid mast having upper and lower ends;
- a spreader having three rigid sides joined at first, second and third corners, with the first corner attached to the lower end of said mast;
- a pivot post for insertion in said mounting hole, the pivot post being attached to the lower end of the mast by a hinge pin;
- a lower cable assembly comprising two cables attached respectively to the second and third corners of said spreader, and attached at the other ends to connecting means, which in turn is attached to said attachment point;
- an upper cable assembly comprising two cables attached respectively to the second and third corners of said spreader, and attached at the other ends to the upper end of said mast;
- and hoisting means including at least one pulley attached to the upper end of said mast.
4 more elements
Dependencies are inferred from the claim text.