US3008287A

US3008287A - Wire rope sling

Info

Publication number: US3008287A
Application number: US15384A
Authority: US
Inventors: Walter F Crandall
Original assignee: Wire Rope Corp of America Inc
Current assignee: Wire Rope Corp of America Inc
Priority date: 1960-03-16
Filing date: 1960-03-16
Publication date: 1961-11-14
Anticipated expiration: 1978-11-14

Description

NOV. 1961 w. F. CRANDALL 3,008,287

WIRE ROPE SLING Filed March 16, 1960 5 Sheets-Sheet 1 I UALTE F. CRHNDHLL Z0 INVENTOR nTToRn/E Y5 Nov. 14, 1961 w. F. CRANDALL 3,00

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UHLTER F. CRHNVH L INVENTOR.

14f fay/162's 3,008,287 WEE ROPE SIJ G Walter F. Crandall, St. Joseph, Mo assignor to Wire Rope Gotporation of America, St. .Ioseph, M0,, a corporation of Connecticut Filed Mar. I6, 1959, No. 15,384- 6 Glairns. (til. 57142) This invention relates to a material hoisting or handling sling.

A particular feature of the present invention is the method of making slings having varying cross-sectional configurations and physical characteristics whereby the sling has enhanced strength and wearing qualities.

Wire ropes are usually made from a plurality of primary composite wire strands wound or twisted upon each other. In turn, each strand comprises a plurality of individual secondary wires similarly wound or twisted about each other. When used for hoisting or for material handling, a sling is made of such wire rope by forming a loop at either end. In the present invention this tear-shaped eye or loop is formed by first separating one of the primary ropes that make up the base fabric from other primary ropes at a point removed from the free end of the fabric. The extent or length of this separation is sufiicient to form the desired area of eye upon forming the loop. The end of this separated rope is now re-entered upon the remaining unseparated ropes which have been formed into a loop and rewound with the same about the loop to about the point of initial separation of the ropes. This re-entering and rewinding is carried out with the separated primary ropes being spirally wound in the opposite direction to that in which the other ropes are looped, and its re-entered and rewound portion extends to about the point of initial separation of the primary ropes, as stated. The free ends of the loop constituted by the other primary ropes terminate likewise substantially at this point of separation. That is, at the free end of the separated primary rope and the free end of the remaining primary ropes, these ends of all of the primary ropes are adjacent to the base fabric and these free ends are entwined with the base fabric with their free ends protruding. This construction is now tightly clamped together and held by a usual band or ferrule so that the loop will additionally be prevented from becoming disengaged at this po nt of juncture. In brief, since the separated primary rope extends continuously in one direction to the point of juncture and the remaining primary ropes extend continuously in the opposite direction to the point of jmieture, and the respective ropes are re-entered and rewound upon each other substantially throughout the length of the looped portion, it is ditlicult, if not impossible, for the loop to be opened at the point of juncture unless the fabric breaks. Of course, the usual clamp or ferrule enhances this holding power and prevents the free ends from slipping.

It is thus a secondary primary object of the present invention to provide a loop or sling in which entire dependence on a ferrule for clampin of the end of all of the ropes of the loop to the base fabric in the usual manner is eliminated. Instead, a construction is provided in which one or more ropes of the base fabric cannot be separated in the clamping area should the customary ferrule become loosened. This is not the case in conventional forms of slings or hoist loops as stated, where all of the free ends of the wire or cable are clamped to the base fabric at the point of juncture by the ferrule. That is, there is always the likelihood that the free ends would become disengaged from the clamping means or the ferrule will slip under the weight or pressure to which the sling is subjected in use.

The invention and novel features thereof will be made EEG clear from the following description and the accompanying drawings, in which:

FIGURE 1 is a side elevational view of the base fabric made in accordance with this invention;

FIGURE 2 is a side elevational view of the base fabric of FIGURE 1, but showing one of the component ropes separated from the others;

FIGURE 3 is a side elevational view of the base fabric of FIGURE 2 showing the loop formation, and particularly showing the separated rope re-entered upon and rewound with the remaining ropes to extend in a direction opposite the direction in which the loop is being formed toward the point of initial separation;

FIGURE 3:: is a fragmentary view of the completed loop of FIGURE 3 showing the free ends of the base fabric ropes prior to their being bound to the base fabric, the said free ends being entwined with the base fabric and their protruding ends being entwined with each other, the point of juncture being at about the point of initial separation, as shown, and a band or ferrule shown in FIGURE 4 clamping the base fabric and free ends at the point of juncture;

FIGURE 4 is an elevational view of one end of a sling;

FIGURE 5 is a cross-sectional view taken along line 55 of FIGURES 1 and 3 showing the composite structure of the

primary ropes

22, 24, 26 and secondary strands 2S and the tertiary wires 36 FIGURE 6 is a side elevational view corresponding to FIGURE 2, but showing additional lengths of wire rope inserted in one end of the base fabric;

FIGURE 7 is a side elevational view showing one step in forming the reinforced material handling loop of FIG- URE 6;

FIGURE 8 is a side elevational view showing the formation of the loop from the altered base fabric of FIG- URE 7;

FIGURE 9 is a cross-sectional view taken along line 99 of FIGURE 8 and generally similar to FIGURE 5, but showing also two additional ropes 38 and 40';

FIGURE 10 is a view generally corresponding to FIG- URE 6, but showing a further modification of the base fabric; 7

FIGURE 11 is a view generally corresponding to FIG- URE 7, but showing the modified base fabric of FIG- URE 10;

FIGURE 12 is a side elevational view showing the formation of the loop of the modified base fabric of FIG- URE 11:

FIGURE 13 is a cross-sectional view taken along line I3i3 of FIGURE 12; and

FIGURE 14 is a view corresponding to FIGURE 5, but showing still another modification of this invention.

Referring now to the drawings and in particular to FIGURES 1 through 5, there is shown the basic form of the present invention, namely, a base fabric having a loop or eye at one or both ends to form a sling. In FIGURE 1, the base fabric is indicated at 24) and comprises a plurality of individual primary

composite wire ropes

22, 24 and 2 6 interwound about each other along a common axis as also shown in FIGURE 5.

In FIGURE 5, there is shown, for illustrative purposes only, that each base fabric rope 22, 24 and 26 comprises a plurality of smaller diameter Wire strands 23 inter- Wound about each other and wherein each of the smaller strands 23 in turn is made from a plurality of even smaller diameter wires 30. It is to be understood, of course, that the construction of the base fabric ropes 2 2, 24 and 26 may be of. the many various known types of wire rope currently in use.

Referring to FIGURES 2, 3 and 4, in forming the basic material handling eye or loop 32, one of the base fabric ropes 26 is separated from the other

base fabric ropes

22 and 24 at a point 34 removed from one end of the base 20. The free end portions of the base fabric ropes 22, 24 and 26 extend beyond the point of separation '3 of the base fabric, for example, approximately twice the length of the finally desired length of eye or loop 32. The separated primary rope 26 and the other

primary ropes

22 and 24 are then returned and inter wound with each other, as shown in FIGURE 3, to form a material handling loop or eye 32 integral with the base fabric 20. The free ends of each of the

ropes

22, 24 and 26 are then disposed adjacent the point 34 of the base fabric 20 and may be there crossed over, interwoven or otherwise engaged as shown in FIGURE 3a, and suitably bound to the base fabric 20 adjacent the point of juncture 34' by means of a ferrule or sleeve member 36. With the basic sling loop thus formed, it will beseen that the loop portion 32 has a cross-sectional configuration, as shown in FIGURE 5, which is the identical crosssectional configuration as the original base fabric 20 from which the sling is made. It will be noted, as shown in FIGURES 2 and 3, that the primary rope 26 is separated at the point 34 and returned to extend counterclockwise in spirally wound relation upon the remaining

primary ropes

22, 24, while the latter are returned to extend clockwise. Thus, the respective ropes are interwound and twisted while extending in opposite directions and with their free ends terminating at 34', as shown in FIGURE 30, adjacent the point of separation 34. There, the free end portions are interwound with the base fabric and this juncture and the protruding portions of the free ends are clamped in their crossed over or twisted condition by the ferrule 36.

By following the above-described basic method for forming the loop 32 and the base fabric 20 and by adding additional lengths of Wire rope within the base fabric 20 and loop 32, various modifications of the material handling sling may be made in accordance with this invention to provide slings having stronger physical properties and varying characteristics, depending upon the load which is to be handled by the sling composed of base fabric 20 and loop or loops 32..

Such a modified sling is disclosed in FIGURES 6 through 9 in which FIGURE 6 illustrates a base fabric 20 generally corresponding to the base fabric of FIG- URE 1 wherein one of the base fabric ropes 26 has been unlaid or'separated from the other

base fabric ropes

22 and 24. In this particular modification, an additional wire rope 38 of the same character as the base fabric ropes has one of its ends interwoven or suitably inserted at the point 34 of the base fabric 20, which essentially represents the end of the original base fabric before modification in accordance with this invention. A further addition of rope 40 having a different characteristic or structure or different cross-sectional configuration than that of each of the

base fabric ropes

22, 24

and 26'is similarly inserted at the end 34 of the base fabric 20. Each of the

wire ropes

38 and 40 is substantially coextensive with the

base fabric ropes

22, 24 and 26 throughout the length of the sling and extend beyond the point 34 of the base fabric 20 to the free ends of the primary ropes. In forming this particular loop the additional rope 38 is wound about the separated primary. rope 26 and the additional different diameter wire rope 40 serves as a core aboutwhich the other

primary ropes

22 and 24 are wound, as shown in FIGURE 7. With the ropes of the base fabric 20 thus modified, the separated primary rope 26 with the additional rope 38 wound thereabout, and the other

primary ropes

22 and 24 with the additional rope 40 as a core are returned about and interwound with each other to form a loop 42 in the same manner as was the loop 32 formed; The free ends of all of the

ropes

22, 24, 26, 38 and-40 are then disposed adjacent the point 34 of the base fabric 20, as described above, and may be suitably boundthereat by means of the ferrule or sleeve 36 in the manner shown in the previous figures. The modified loop 42 thus formed now comprises four

ropes

22, 24, 26 and 38, all having the same cross-sectional configuration and physical properties as the other, and a core rope 4t arranged within the four similar ropes.

There is shown in FIGURES 10 through 13 another modification of the material handling sling which has in the sling portion five lengths of wire rope, each having the same configuration as the other and each being the same as the individual

primary Wire ropes

22, 24 and 26 which constitute the base fabric 2!). The formation of this modified form of sling is accomplished by

first insertropes

22, 24, and 26 throughout the length of the sling and extend beyond the point 34 of the base fabric 21 to the free ends of the primary ropes. As shown in FIGURE 11 the next step in the formation of the loop of this modification of the sling is to interwind the

ropes

38 and 44 about the additional different diameter rope 40 which will serve as a core, the

primary ropes

22, 24 and 26 are wound about'each other. The intertwined ropes 33 and 44 and the core rope 4d are then Wound about the

primary ropes

22, 24 and 26 to form the loop 46 as shown in FIGURE 12. As in the case of the previously described modified

loops

32 and 42, the free ends of each of the ropes have portions which are interwound with the base fabric and protruding portions inter-wound with each other. At this point of juncture 34' the end portions are additionally bound to the base fabric 24) and each other by means of the ferrule or sleeve 36, as described. The resultant loop 46 now comprises five lengths of

rope

22, 24, 26, 38 and 44, each having the same cross-sectional configuration and physical characteristics as the other and wound about a core of rope 46 having a difierent cross-sectional configuration and physical characteristics than the others. Thus, it will be seen that the base fabric 20 may be still further modified by the interwinding of additional lengths of rope with the ropes that constitute the base fabric and the insertion of a core rope to provide a strong material handling or hoisting sling.

Although there has been shown here and described a base fabric 20 comprising three

primary ropes

22, 24 and 26 which are in turn made from a plurality of

smaller diameter strands

28 and 30, respectively, the base fabric may take various forms and the practice of this invention is not limited to a basefabric comprising three wire ropes. Any base fabric which has more than one wire rope may be altered in accordance with the present invention without departing from its teachings, a base fabric made from three individual ropes here being shown and described for illustrative purposes only.

Various modifications of the above described slings may be accomplished by adding to the base fabric 20 additional lengths of wire rope of the same cross-sectional configuration as the

primary ropes

22, 24, and 26 and the insertion of an additional different diameter wire rope similar to 40 as a core to produce sling bodies with the cross-sectional configuration as shown in FIGURES 9 and 13. The further modification of this invention is shown in FIGURE 14. The drawing illustrates a cross sectional View of three lengths of a base fabric 20 interwound about each other on a common axis to form a new sling. A loop may be formed using the compound base fabric in the same manner as the loop 32 was formed as illustrated in FIGURES 1 through 5. That is one of the lengths of the base fabric 2tlis unwound to a point, as point 34 in FIG- URE 2, removed from one end of the compound fabric and the free end of the remaining interwound lengths of the base fabric are looped and interwound with the single lengths to form a loop such as 32 shown in F16 URE 4. This looping and interwinding using the compound base fabric is accomplished in the identical manner as the looping and winding shown in FIGURES 2 and 3 where a single length of base fabric is used to form the loop.

The invention, it will be observed, essentially comprises three wire ropes having a plurality of wire strands interwound about each other along a common axis to form a base fabric 20, a loop $2 at one or both ends of said base fabric, said sling including at least one of said base fabric ropes 26 separated from the base fabric 20 at a point 34 removed from the adjacent end of the fabric enough to form a loop of the desired area and thereafter returned and wound about other of said

base fabric ropes

22, 24 in one direction extending from said point to substantially the free end of said separated rope at 34', and the other of said

base fabric ropes

22, 24 being wound about said separated rope 26 and extending in the opposite direction, from said point of separation 34, to substantially the free end of said other rope 26 at 34, the free ends of all of said ropes being joined with each other and said base fabric adjacent the point of separation, as by a band or ferrule 3 6.

In general, the slings of this invention are produced from a base fabric prepared by interwinding a plurality of wire ropes about a common axis to form a base fabric 29, by a method comprising separating one of said ropes 26 from said other rope at a point 34 sufhciently removed from one end of said base fabric to form a loop 32 of desired area, returning and interwinding said separated rope 26 with remaining

strands

22, 24 in a direction toward the point of separation 34 with its free end terminating adjacent said point; returning and rewinding said

other ropes

22, 24 with said separated rope 26 in the direction opposite that of the separated rope 26 until the free ends of said other ropes are adjacent the point 34 of separation, and with the free ends of all of said ropes being disposed adjacent said point 34 of said base fabric, and joining at 34 the free ends of all of said ropes with each other and said base fabric adjacent the said point of separation.

It thus will be seen that there has been provided by this invention a rope sling in which the various objects hereinbefore set forth, together with many practical advantages, are successfully achieved. As various possible embodiments may be made of the novel features of the above invention, all without departing from the scope thereof, it is to be understood that all matter hereinbefore set forth is to be interpreted as illustrative, and not in a limiting sense.

What is claimed is:

1. The method of forming a material handling sling from wire rope prepared by interwinding a plurality of wire ropes about a common axis to form a base fabric comprising: separating one of said ropes from said other ropes at a point sufficiently removed from one end of said base fabric to form a loop of desired area, separating the other of said ropes and inserting an additional wire rope, interwinding said separated ropes about said inserted additional rope, said additional rope forming a core returning and interwinding said separated rope with remaining ropes in a direction toward the point of separation with its free end terminating adjacent said point; returning and rewinding said other ropes with said separated rope in the direction opposite to that of the separated rope until the free ends of said other ropes are adjacent the point of separation, and the free ends of all of said ropes being disposed adjacent said point of separation of said base fabric, and joining the free ends of all of said ropes with each other and said base fabric adjacent the said point of separation.

2. The method as defined in claim 1 further comprising the step of interwinding a second wire rope about said first separated rope along that portion of said rope extending from said point of separation to the free end thereof.

3. A sling fabric comprising a plurality of wire ropes interwound about each other along a common axis to form a base fabric, a loop at one or both ends of said fabric, said loop including at least one of said base fabric ropes separated from said base fabric and interwound about the others of said base fabric ropes, said separated rope extending in wound relation in one direction adjacent the point of separation from said base fabric to its free end, a first additional wire rope about which said base fabric ropes are wound and a second additional wire rope inserted and interwound with said separated rope, said first and second additional wire ropes being substantially coextensive with the rope of the base fabric for the full length of the sling.

4. A sling fabric as defined in claim 3 wherein the first additional wire rope is of a smaller diameter than the rope of said base fabric.

5. A sling fabric as defined in claim 3 in which the second additional wire rope is of the same diameter as the ropes of said base fabric.

6. A sling fabric comprising: a plurality of wire ropes interwound about each other along a common axis to form a base fabric, each rope comprising a multiplicity of interwound strands which in turn comprise. a multiplicity of wires; a loop at at least one end of said base fabric,

said loop having at least one of said base fabric ropes including said multiplicity of strands and Wires separated from the base fabric at a point removed from the adjacent end of the rope enough to form a loop of the desired area and thereafter returned and wound about the remainder of said base fabric ropes in one direction extending from said point of separation to substantially the free end of said separated rope, and the remainder of said base fabric ropes being wound about said separated rope and extending in the opposite direction from said point of separation to substantially the free end of said other rope, the free ends of all the said ropes being joined with each other and said base fabric adjacent the point of separation.

References Cited in the file of this patent UNITED STATES PATENTS 1,334,244 Howe Mar. 16, 1920 1,839,698 Novotny Jan. 5, 1932 2,454,592 Budzinski Nov. 23, 1948 2,463,199 Peterson Mar. 1, 1949