US2050564A - Wire rope - Google Patents

Description

, c. DODGE WIRE ROP Filed April 1935 NI/g Patented Aug. 11, 1936 PATENT OFFICE WIRE ROPE Milo C. Dodge, Auburn, N. Y., assignor to Columbian Rope Company, Auburn, N. Y., a corporation of New York Application April 4, 1935, Serial No. 14,716

2 Claims. (Cl. 11759) This invention relates to improvements in wire ropes.

Generally, wire ropes or cables are made with a core or center confined in the interior thereof, 5 such core or center being compressible so that the wire strands, in being formed into the rope, will be cushioned on said center. In, most instances, these cores or centers have been made of fibrous materials, such as hemp fiber ropes, but in order to reduce their cost it has been proposed to make such centers of paper. Both of these forms of centers are open to certain objections. Furthermore, centers made of hemp or other fibers must be water-proofed to protect them against exposure to moisture and the cross-rubbing or cross-cutting of individual fibers under flexing strains materially afiects the life of the center and, consequently, the entire wire rope construction. The paper center reduces the 33 cost item, but requires the same treatment to prevent deterioration when subjected to moisture. In addition, the paper center requires care in the production thereof to obtain the proper density or compactness in the finished center. Fur- :3 thermore, the tensile strength of the paper center is considerably less than that of a hemp fiber center.

With these factors in mind, the primary object of the present invention is to provide a wire rope 3:) center which can be produced at a very favorable cost compared to that of a paper center; that will not possess the absorptive properties of a hemp or paper center; and which will possess greater density and greater tensile strength than a paper 3.; center.

A further object is to form a wire rope center from material which heretofore has been looked upon as a waste product. More specifically, the invention contemplates a wire rope center formed 40 of a regenerated cellulose material, such as that now found on the market under the trade name cellophane.

With these and other objects in view, the invention consists in certain details of construc- 45 tion and combinations and arrangements of parts, all as will hereinafter be more fully described and the novel features thereof particularly pointed out in the appended claims.

In the accompanying drawing, wherein the 50 preferred embodiment of the invention is illustrated,-

Figure 1 is a perspective view of an end of a wire strand cable with the present center incorporated therein; but with some of the wire 55 strands opened up to facilitate illustration oi the surface of the center as it appears when compressed by the strands; and

Fig. 2 is a detail view of a length of center with one end thereof opened up to fully disclose its construction.

As illustrated in Fig. 1, the strands ID of the cable are laid or assembled spirally on the center ll. During this operation, the center is placed under compressive strains, the individual strands forming spiral depressions l2 in the center. Such depressions l2 are, for convenience, sometimes termed contlines. In other words, it is necessary that the center have a certain amount of resiliency or compressibility in order that the strands may embed themselves in the surface of the center during the production of the cable. On the other hand, it is also necessary that, after this initial compression of the center, further. compression thereof be resisted. For instance, the cable, in passing over a sheave or being flexed otherwise, will tend to further compress the strands and, if such action is not properly-resisted by the center, injury to adjacent strands by nicking, cutting or the like, is almost inevitable.

For this reason a center of regenerated cellulose is of great advantage.

Preferably, the center is made of a plurality of regenerated cellulose elements I l twisted together, as illustrated in Fig. 2. Each element I I may be made of a number of ribbons or strips of regenerated cellulose twisted or crimped together. The density of the regenerated cellulose material, as such, is much greater than that of paper, so that, when the center is formed up, the resulting article will possess suflicient compressibility to meet the requirements of wire cable constructions, but it will reach its'theoretical limit of compression before a center made of paper of the same size and formed of elements associated with the same degree of twist. This is undoubtedly 40 due to the porosity of paper, as compared with regenerated cellulose, the porosity of the paper making it much more compressible, so that of two bodies, one of paper and one of regenerated cellulose, of equal cross section, the later is less compressible or will reach its theoretical limit of compression before the former. Hence, the present center may be of less diameter than a paper center for a given size wire cable, and will still function as a proper foundation or support for the wire strands after the latter have embedded themselves in the surface thereof.

Again, the regenerated cellulose center will not be afiected to the same extent as paper, so far as moisture is concerned. The regenerated cellulose strips used in the present center are usually considered as waste material, as the strips actual- 1y used are produced in the truing up of rolls of material and are never of uniform width, so that their use is very limited. The cost thereof is, consequently far below that of paper or other fibrous materials commonly used in wire rope centers.

The use of regenerated cellulose in the present center is of further advantage in that the center can withstand greater tensile strains. This is important, not only in connection with the usage of the cable, but also in the manufacture of the center itself, wherein the individual ribbons or tapes must be placed under tensile stresses in being fed through the machines by which they are twisted into the individual elements composing the center.

It is also desirable that the center be lubricated and, in the present instance, a cordage oil having a parafiin base is utilized. It is found to give the center the necessary lubrication and, in addition, increases the water-repellent properties of the center.

It will be appreciated that the density of the center, and its compressibility, can be varied by altering the degree of twist of the individual elements [HI during their formation, or the twist given them as they are formed into the center. This, of course, does not have any hearing on the density of the regenerated cellulose material, as such.

If desired, the central portion of the center may be formed of a rather large core l l and the smaller elements ill twisted thereon.

It will also be appreciated that the higher density of the regenerated cellulose permits less tension to be used in twisting up the individual elements M. This, in addition to the greater tensile strength of strips of such material, as compared to paper, is another factor bearing on the manufacturing phase, as the use of less tension will result in less breakage of the strips and,

accuser therefore, reduce the interruptions of operations.

While cordage oil haying a paramn base is specifically mentioned above, other forms of lubricant can be substituted.

What I claim is:

l. A wire rope comprising wire strands and a center, said strands carrying the tensile stresses on the rope and imposing compressive stresses on the center, said center consisting of a multiplicity of elements twisted together to the desired degree of compactness, said elements being composed of strips of regenerated cellulose and said center possessing suificient compressibility to permit the rope strands to embed themselves in the surface thereof when said strands are wound thereon, the inherent density of said cellulose augmenting the resistance of said center to compressive stresses, whereby the compressibility of thecenter is :n In and said center will reach its theoretical limit of compression before a center made of paper of the same size and formed of elements associated with the same degree of twist.

2. A wire rope comprising wire strands and a center, said strands carrying the tensile stresses on the rope and imposing compressive stresses on the center, said center consisting of a multiplicity of elements twisted together to the desired degree of compactness, said elements being composed of regenerated cellulose and said cenmr memo C. DCI DGE.

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