US3545334A - Braided rope sling - Google Patents

Description

United States Patent Inventor Raymond F. Dudley 1 1527 Maxwell, Warren, Michigan 48089 Appl. No. 881,956 Filed Dec. 4, 1969 Patented Dec. 8, 1970 BRAIDED ROPE SLING 1 Claim, 6 Drawing Figs.

U.S. Cl 87/8 Int. Cl. D04c 1/12 Field of Search 87/1, 5-11, 33,57/142, 159

References Cited UNITED STATES PATENTS 2,299,568 10/1942 Dickey 87/8 2,359,424 10/1944 Joy 87/8 2.410.416 I I/l946 .loy 87/8 2,418,524 4/1947 Peterson et al. 87/8 Primary Examiner-John Petrakes Attorney-Harness, Dickey & Pierce ABSTRACT: A flexible sling for heavy loads consists of eight ropes braided together in a manner which provides a member of square cross section having its greatest density and greatest strength per unit volume along its four corners, successive ropes being repeatedly and alternately plaited in a generally helical path at opposite but equal helix angles and each rope passing always under the same two of the other ropes and then around the other five of the ropes. Lateral displaceability of the ropes tends to distribute loadings among the several ropes and permits limited stretching to reduce shock.

BRAIDED RoPr: 'SLING BACKGROUND OF THE INVENTION In the lifting of heavy loads with ropes and slings, where unduly high localized stressings are apt to occur, as for example in the suspension of heavy cargo having sharp corners which cause the rope or sling to be bent about a short radius, the service life of ordinary wire rope is relatively short. Failure is particularly apt to occur in areas where sharp corners of a heavy load directly contact the rope and causeboth abrading and relatively small diameter, which reduces both the failure at the sharp bends and the tendency of the sling to twist and whip, endangering personnel. One such braided type which has been employed in the trade is disclosed in US. Pat. No. 2,082,828 to Garris. The braiding arrangement disclosed in the Garris patent, although an improvement upon ordinary wire rope, is still relatively short lived under severe service conditions. The object of the present invention may be summarized as comprising the provision of an improved construction which greatly prolongs the service life of such slings, as compared, for example, with the service life attainable under like conditions of use with constructions such as disclosed inthe aforementioned Garris patent.

Other objects and advantages will become apparent upon consideration of the present disclosure in itsentirely.

BRIEF DESCRIPTION OF FIGURES OF DRAWINGS FIG. 1 is an elevational view of a sling constructed in ac cordance with the present invention;

FIG. 2 is a side elevational view of apart of the braided suspension portion of the sling on a larger scale, showing the same straight and as it appears when not under load;

FIG. 3 im diagrammatic side elevational view of a partially plaited suspension portion, the ropes being shown as braided more tightly than the actual preferred braiding used with wire rope, showing progressive positions in which the ropes are successively overlaid in plaiting;

FIG. 4 is a cross-sectional view taken substantially on the line lV-IV of FIG. 2, and looking in the direction of the arrows; 7

FIG. 5- is an elevation of a portion of the sling under load, as viewed from the side and looking horizontally in a direction perpendicular to the sidewall of a rectangular load, near the bottom, the individual strands being shown only fragmentarily, and only in this view; and

FIG. 6 is a fragmentary perspective view of the same general area of the sling and load as seen from one side.

DETAILED DESCRIPTION OF PREFERRED FORM OF THE INVENTION In constructing my improved sling, four individual wire ropes of a length somewhat exceeding twice the desired length of the finished sling are passed through a tubular metal thimble 8 until the thimble is midway on the ropes, leaving eight rope end portions projectingfrom the thimble. The eight rope portions are then braided in a manner which has been found to have unique advantages where heavy loads having sharp corners must be handled.

In braiding the eight projecting rope portions, four are brought out toward the right and four toward the left, angularly downwardly, in a sequence which is maintained throughout the braiding, four of the ropes thus defining a right-hand group consisting of ropes 10, l2, l4 and 16, considered downwardly in that order, and the other four defining a similar lefthand group or series consisting of ropes 11, I3, 15 and 17,,as shown in FIG. 3. In order to show the braiding sequence diagrammatically, a color-designating overhatching has been applied to each rope in that view. In FIG. 3 the ropes are shown braided more tightly than the braiding I prefer to employ with wire rope, in order to better illustrate the relationship of the ropes. The other viewsillustrate a suitable tightness of braid for wire rope. The braiding shown in FIG. 3 however, is identical except as toxtiglhtness and is in fact suitable for nonmetallic rope. To further assist in illustrating the relationship between the several ropes, the ropes l0, l2, l4

and 16, which plait out to the right, are respectively hatched.

for orange, silver, brown and blue, and ropes ll, l3, l5 and 17, which plait out to the left, are respectively hatched for gold, red, purple and green. In FIG. 3, the braiding is shown as braiding, thence upwardly, through the middle of the left group, between ropes 13 and 15 (red and purple) and then rightward over ropes 15 and 17 (purple and green) and angularly downwardly to project againto the right at the bottom of the right group. Rope 11 (gold) is then similarly passed around under the braiding toward the right and angularly' downwardly, then upwardly between ropes l4 and 16 (brown and blue), and back to the left over ropes l6 and 10 (blue and orange) to project again tothe left as the bottom rope of the left group. The last (upper) rope l2 (sliver) of the right group, and then the last rope 13 (red) of the left group, and so on, are then alternately successively plaited in like manner in opposite angular directions and in the, sequence indicated by the reference numerals.

The completed braiding assumes a substantially square cross section. Each of the two groups referred to above and shown in FIG. 3 constitutes a series, as noted. On one pair of diagonally opposite comers theropes 10, 12, 14,and 16 of the right series lie successively and in thatsequence on the outside, close and substantially parallel to each other to define the corners, while on the other pair of diagonally opposite corners the ropes of the left series are similarly arranged. Beneath each corner each rope of the other series passes, in its sequential order, under two successive ropes of the series which defines the corner. Thus although each rope describes a substantial helix, and at the corners the ropes on the outside, which define the corner, lie adjacent and substantially parallel to each other, the rope portions spaced from the corners, including the interior portions, cross one another at greater angles and leave spaces into which parts can move when distorted by loading. The left group ropes define a right-hand helix, and the right group ropes define a left-hand helix. Under tension, the comer portions pull inwardly toward each other.

When the assembly is bent sharply around a corner or short radius under load, one of the flat sides orients its on the corner and the ropes on that side spread laterally apart in the corner region, as well as pulling toward the corner, thereby tending to bring more of the ropes into contact with the corner, and distributing the load.

The other thimble is attached by leaving suitable lengths of the two groups unbraided at the farther end, and passing the groups in opposite directions through the thimble, into which they may be secured by sweat soldering or brazing.

This detailed description of preferred form of the invention, and the accompanying drawings,have been furnished in compliance with the statutory requirement to set forth the best mode contemplated by the inventor of carrying out the invention. The prior portions consisting of the Abstract of the Disclosure and the Background of the Invention" are furnished without prejudice in an effort to comply with administrative requirements of the PatentOffice.

I claim:

l. A braided assembly of eight ropes for slinging heavy loads wherein the ropes are individually braided in two groups of the other group, each rope underpassing'a different pair but always underpassing the same pair and said pairs of the two groups being staggered to the extent of one rope.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,545,534 Dated Dec. 8, 1970 Inventor(x) Raymond F. Dudley It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Colurm 2, line 26, "(sliver)" should be --(si'1ver) Column 2, line 51, "its" should be -itse1f-- Signed and sealed this 13th day of April 1971.

(SEAL) Attest:

Attesting Officer Commissioner of Patents EDWARD M. FLETCHER,JR. WILLIAM E SCHUYLER, JR.

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