Lifting frame

Abstract

A lifting frame used for lifting structures by using two cranes. The lifting frame is preferably triangular in cross section and is laterally and diagonally braced. The lifting frame is designed for temporary attachment directly to the structure to be lifted and installed. Crane attachment points are provided at opposite ends of the lifting frame.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention is generally related to the lifting of large objects and more particularly to a frame for lifting a large structure and then installing the structure on a substructure.

[0003] 2. General Background

[0004] Lifting large heavy objects is an integral part of every type of construction and is especially important in the marine construction industry. Lifts on the order of twenty-five short tons up to thousands of short tons are commonplace.

[0005] Spreader frames and bars are used extensively to avoid interference between the lifting slings and objects/equipment on the lifted item. Spreader bars and frames are used by a single lifting device to achieve sling clearances and brace lateral loading such that the rigging below the spreader bar or frame can be vertical. A reusable end cap for spreader bars that facilitates simple length adjustments is commonly used.

[0006] The known art of lifting members tends to be two-dimensional, does not necessarily provide optimal spacing for crane connection points, and may require additional bracing in the structure being lifted.

SUMMARY OF THE INVENTION

[0007] The invention addresses the above needs. What is provided is a lifting frame that is used for lifting structures by using two cranes. The lifting frame is formed from a three-dimensional lattice frame. The frame is laterally and diagonally braced. The lifting frame is designed for temporary attachment directly to the structure to be lifted and installed in a manner such that the structure does not require additional bracing. Crane attachment points are provided at each end of the lifting frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a further understanding of the nature and objects of the present invention reference should be made to the following description, taken in conjunction with the accompanying drawings in which like parts are given like reference numerals, and wherein:

[0009] FIG. 1 is a perspective view of the invention.

[0010] FIG. 2 is a perspective view of the invention connected to a deck to be installed on a substructure.

[0011] FIG. 3 is an elevation view that illustrates use of the invention during installation of a deck on a substructure.

[0012] FIG. 4 is an elevation view that illustrates use of the invention to set the deck on the substructure.

[0013] FIG. 5 is an elevation view that illustrates removal of the invention after the deck has been set on the substructure.

[0014] FIG. 6 is a perspective view that illustrates an alternate means of connecting the invention to the deck.

[0015] FIG. 7 is a perspective view that illustrates another alternate means of connecting the invention to the deck.

[0016] FIG. 8 is a perspective view that illustrates an alternate means of lifting the invention and deck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] Referring to the drawings, it is seen in FIG. 1 that the invention is generally indicated by the numeral 10. As seen in FIG. 1 lifting frame 10 is a lattice frame that is preferably triangular in shape.

[0018] Two bottom cords 12 are rigidly attached together in a parallel spaced apart arrangement at the same elevation by lateral braces 14. The bottom cords 12 are rigidly attached to a top cord 16 by a plurality of vertical braces 18 and diagonal braces 20. The top cord 16 is preferably centered above the top cords 12. The cords and braces are sized to accommodate the weight of the structure 22 (seen in FIG. 2) to be lifted and installed. As best seen in FIG. 2 the end of each bottom cord 12 provides connecting points 24 for one or more cranes.

[0019] The bottom cords 12 are provided with means 26 temporarily connecting the lifting frame 10 to the structure 22 to accomplish the lift. In the preferred embodiment, this is comprised of a plurality of padeyes 28 and links 30. The padeyes 30 are rigidly attached to the bottom cords 12. The links 30 are provided with a bore at each end. Corresponding padeyes 32 are provided on the structure 22 to be lifted and installed. The bores in the padeyes are sized to receive pins for temporarily locking the links 30 to the lifting frame 10 and the structure 22.

[0020] In operation, slings 34 suspended from crane blocks 36 by two separate cranes 38 are attached to the crane connecting points 24. The cranes 38 are used to lift the lifting frame 10. The links 30 are pinned to the bottom cords 12 at the padeyes 28. The lifting frame 10 is then positioned above the structure 22 so that the links 30 are aligned with the padeyes 32 in the structure 22. The lifting frame 10 is lowered such that the bores in the links are aligned with the bores in the padeyes 32 in the structure 22. The links 30 are then temporarily connected (locked) to the structure 22 by inserting pins through the bores. As seen in FIG. 2, the lifting frame 10 may be designed with an overhang section 52 that extends beyond the end of structure 22 to provide clearance between the crane and structure 22. Although only shown on one end of the lifting frame 10, the overhand section 52 may be provided on each end. The lifting frame 10 and structure 22 are lifted by the cranes 38 and positioned above the substructure 40 such that the lower stabbing receptacles 42 on structure 22 are aligned with the stabbing posts 44 on substructure 26 as seen in FIG. 3. The structure 26 is lowered onto the substructure 26 to receive the stabbing posts 42 in the lower stabbing receptacles 40 as seen in FIG. 4. The links 30 are then unlocked from the padeyes 32 on the structure 22 and the lifting frame 10 is lifted away from the structure 22 as seen in FIG. 5.

[0021] FIG. 6 illustrates an alternate means of temporarily connecting the links 30 between the lifting frame 10 and structure 22. Instead of using padeyes, the links 30 may be welded to the lifting frame 10 and structure 22 as indicated at points 46.

[0022] FIG. 7 illustrates an alternate means of temporarily connecting the lifting frame 10 to the structure 22. Instead of using rigid links 30, slings 48 are pinned between the padeyes 28 and 32 on the bottom cords 12 and structure 22.

[0023] FIG. 8 illustrates an alternate means of accomplishing the lift of the lifting frame 10 and structure 22. Booms 50 are attached to the bottom cords 12 by the use of padeyes in a manner such as that illustrated in U.S. Pat. No. 6,149,350.

[0024] The invention provides several advantages. The connection points for the cranes are optimally spaced for the lift. This increases the capacity of the lifting equipment. The lifting frame of the invention is connected to the structure at multiple points and the lifting frame is laterally and diagonally braced. This minimizes the bracing required in the structure that is a strict function of the lifting operation and thus reduces the weight and cost of the structure.

[0025] Because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.

Claims

1. A lifting frame for use in lifting and installing a structure on a substructure, comprising:

a. a lattice frame; and

b. means provided on said lattice frame for temporarily connecting the frame to the structure to be lifted.

2. The lifting frame of claim 1, wherein said lattice frame is triangular in cross section.

3. The lifting frame of claim 1, wherein said means for temporarily connecting the frame to the structure to be lifted comprises a plurality of links designed to be pinned to said frame and the structure to be lifted.

4. The lifting frame of claim 1, wherein said means for temporarily connecting the frame to the structure to be lifted comprises a plurality of links welded to said frame and to the structure to be lifted.

5. The lifting frame of claim 1, wherein said means for temporarily connecting the frame to the structure to be lifted comprises a plurality of slings attached between said frame and the structure to be lifted.

6. A lifting frame for use in lifting and installing a structure on a substructure, comprising:

a. a lattice frame that is triangular in cross section; and

b. means provided on said lattice frame for temporarily connecting the frame to the structure to be lifted comprising a plurality of links designed to be pinned to said frame and the structure to be lifted.

7. A method for lifting and installing a structure on a substructure, comprising the steps of:

a. providing a lattice frame that includes means for temporarily connecting the frame to the structure to be lifted;

b. positioning the lattice frame over the structure to be lifted;

c. connecting the lattice frame to the structure;

d. lifting and positioning the structure over a substructure;

e. lowering the structure onto the substructure;

f. disconnecting the lattice frame from the structure; and

g. lifting the lattice frame away from the structure.