US3592502A - Sling - Google Patents

Abstract

A multiple-ply, flexible load-lifting sling of improved strength capable of lifting heavier loads for the same size band plies comprises two superposed woven bands or belts, preferably of synthetic material, which are interwoven together during the fabrication of the respective bands. The two separate bands are formed in concentric but oppositely formed loops without folds or any mutual tension causing creases, and are interwoven ad stitched only in intermediate areas or near the loop ends and not throughout the loop portions of the sling.

Description

United States Patent [72] Inventor Adolf Bolllger Landvetter. Sweden [21 Appl. No 790,238 [22] Filed Jan. 10,1969 [45] Patented July 13, 197i [731 Assignee Goteborgs Bandvaveri AB Goteborg, Sweden [32] Priority Jan. 10, 1968 [33] Sweden [31 1 279/68 [54] SLING 4 Claims, 2 Drawing Figs.

[52] U.S. Cl 294/74, 224/49 [51] lnt.CI Bfic 1/12 [50] Field of Search 294/74, 77; 198/193; 224/49 [56] References Cited UNlTED STATES PATENTS 2,985,480 5/1961 Otlez 294/74 3,197,021 7/1965 Williams 198/193 3,368,664 2/1968 Skinner 198/193 Primary Examiner-Evon C. Blunk Assistant Examiner-Douglas D. Watts Anorney--Wenderoth, Lind and Ponack ABSTRACT: A multiple-ply, flexible load-lifting sling of improved strength capable of lifting heavier loads for the same size band plies comprises two superposed woven bands or belts, preferably of synthetic material, which are interwoven together during the fabrication of the respective bands. The two separate bands are formed in concentric but oppositely formed loops without folds or any mutual tension causing creases, and are interwoven ad stitched only in intermediate areas or near the loop ends and not throughout the loop portions of the sling.

ATENTED JUL 1 3 |97| INVENTOR. ADOLF LLlfiER Emma ml Attorneys achieved by a superposing 'of two bands interconnected medially by meansof threads respectivelybound to both of them during the weaving of the bands. The sling is very flexible andhas a remarkable strength. The bands are situated or superposed exactly over each other without any mutual tensions and in a manner not requiring an extra fabrication operation.

Slings intended for lifting loads in harbors and the like should have a certain flexibility not only for being laid around the load, but also to render them susceptible of easier handling. For this reason they may not be woven in any great thickness and to permit them being adapted'to lift the load in question, two or more bands often are required to be sewn together for forming one sling. However, this involves considerable difficulties for the reason that expensive labor has to be employed for the sewing, and in spite of great care duringthe sewing, it nevertheless is quite impossible to bring the bands to correspond exactly to each other with the attendant result that due to displacements occurring between the slightly unaligned bands tensions or stresses are created in their use. These-difficulties will be more pronounced where slings are terconnect the intermediate areas of same. Thus, inasmuch as additional operation for the connectiom and on the other mostly manufactured from synthetic materials-having a low friction, and therefore would tend to slide apart during passage through the stitching machine.

One object of the present'invention is not only to reduce the cost of the manufacture of the sling, but also to ensure fabricaparticularly tion of bands without tensions by being situated exactly over or adjacent one another, and at the same time the present invention ensures facilitating formation ofa loop at the end or ends of the sling which loop formation is more stable and more flexible than has been previously possible.

This and other objects according to the invention are obtained by the bands being interconnected by means of threads which, at the weaving of the bands, have been bound to or.integrally woven into both the bands.

The invention will be elucidated with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of one end of a sling according 7 invention comprises two elongate superposed bands 1 and 2 each having intermediate and terminal end portionsfDuring the weaving of these two bands a number of threads 3 are woven into each of the two bands 1 and 2 and are used to inhand this ensures that the bands are situated exactly over each other without inducing any mutual tensions or folds.

At a distance from one end which'is suitable for the formation of aloop 4, one ceases with the interweaving of the two 2 bands 1 and 2 such that one of the bands 1 is laid to form an external loop 5'with its end 6 abutting against the outer side of the sling constituted essentially by the bands I, 2, and the by this description or otherwise, except as defmed in the'ap pended claims. Thus, the number of interconnectin threads 3 IS independent of the Invention. Further, the ban s l and 2 may be manufactured from different materials, but synthetic material is preferable due to its strength. Reinforcements may also be applied on the inside of the loop 4, e.g. in the shape of a leather patch 10, which may envelop or form a .sleeve around a portion of the internal loop 7. It is further understood that the sling may comprise loops formed in the same manner at its opposite ends.

' lclaim:

l. 'A sling comprising two separate superposed elongate woven bands (1,2) having intermediate and terminal end portions,-and formed into inner and outer concentric loops, reenforcing'material embracing a portion of said inner loop, said bands being respectively interconnected during fabrication by means of interwoven threads (3) integrally interconnecting the two plies as one, and saidbands joined in loop form by stitches applied adjacent the loop. I

2. A sling as defined in claim 1 wherein the bands are formed in oppositely directed loops, one inside the other with a-free end of the innermost loop terminating adjacent the loop and being sandwiched directly between intermediate, nonterany interwoven threads.

4. A sling as defined in claim 1 wherein the sling is provided with loops at each end thereof.

in the foregoing forfpur-

Claims (4)

1. A sling comprising two separate superposed elongate woven bands (1,2) having intermediate and terminal end portions, and formed into inner and outer concentric loops, reenforcing material embracing a portion of said inner loop, said bands being respectively interconnected during fabrication by means of interwoven threads (3) integrally interconnecting the two plies as one, and said bands joined in loop form by stitches applied adjacent the loop.

2. A sling as defined in claim 1 wherein the bands are formed in oppositely directed loops, one inside the other with a free end of the innermost loop terminating adjacent the loop and being sandwiched directly between intermediate, nonterminal end portions of the respective bands.

3. A sling as defined in claim 2 wherein the loop portions of the respective bands are not integrally or otherwise joined by any interwoven threads.

4. A sling as defined in claim 1 wherein the sling is provided with loops at each end thereof.

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