US3618308A - Dual layer line engaging device - Google Patents

Abstract

A LINE GRIPPING DEVICE HAVING AN UNDERLYING SET OF PREFORMED HELICAL WIRES APPLIED OVER THE LINE, AND A GRIPPING MEMBER HAVING HELICALLY FORMED WIRES GRIPPINGLY ENGAGING THIS UNDERLYING SET OF WIRES. THE GRIPPING MEMBER IS PROVIDED WITH MEANS FOR ENGAGING AN ANCHORING DEVICE.

Description

Nov. 9, 1971 J. c. LITTLE 3,613,308

DUAL LAYER LINE ENGAGING DEVICE Original F1led July 29, 1968 2 Sheets-Sheet z INVENTR. Jess C. Liflle l a. a

Unted States Patent 01 fice Patented Nov. 9, 1971 U.S. Cl. 57145 28 Clams ABSTRACT OF THE DISCLOSURE A lime gripping device having an umderlyimg set of preformed helical wires applied over the lime, and a gripping member having helically formed wires grippimgly engaging this underlying set of wires. The gripping member is provided with means for engagimg an anchoring device.

This is a continuation of application Ser. No. 748,502, filed July 29, 1968, and now abandoned.

This invention relates to mew different and unobvious lime emgagimg devices, and methods of usimg such devices for dead endimg and pulling limes.

Dead ends are used for gripping wires, cables, strands or other types of lines and find particular application in guying transmission towers, antenna towers, and other structures. The dead ends transfer the pull of the limes to the amchrimg structures at both ends of the line, and are also often used to interconmect segment of a lime.

There have been several prior art proposals for dead ends suit-able for such gripping of limes. One common form of these dead ends in that which utilizes helically formed resiliemt wires or wire elememts for gripping a line, which wires are bemt to form a bight for engaging theganchoring structure. One example of this type of dead end is disclosed in US. Pat. No. 3,295,311 in the name et T. E. Butz et al. This device has been extremely effective in dead end applications, especially in comjumctiom with stranded metal wire limes such as guystramd, single elememts lines and relatively stiff fiber glass rods. However, with certain types of limes such as fiber glass rope, which are sensitive to crushimg and longitudinal displacement of the strands, these devices, while being superior to other gripping devices, still had some tendenc to cause crushimg and longitudinal displacememt of the elememts especially under field applied conditions where extreme care was not exercised in applyimg the grip.

The sensitivity to crushing force is a characteristic of fiber glass rope, and also certain other types of rope formed of strands, each of which strands are made up relatively thin elememts. This semsitivity is characterized by a propemsity toward weakemed areas on the rope caused by concentrated compression forces acting on the rope over a constricted area, damaging the elememts. This weakemed area is then likely to fail before the rated breaking stremgth of the lime is reached.

Although the dead ends described in said Pat. No. 3,295,311 applied directly to the lime reduced the amount of this crushimg force as compared to many devices pre Viously available, crushing damage still was oftem imduced to a large degree when the dead ends of the Butz et al. patent were mot carefully installed particularly under field conditions. Also, prior pulling devices, such as comealongs, tended to induce crushing forces into the lime where the gripped the line to pull it.

Longitudinal displacement of the strands of a rope or similar stranded structure is a condition wherein the strands are displaced longitudinally with respect to each other. There may also be some longitudinal displacement of the elememts withim givem strands. This may be imduced by the gripping action of certain gripping devices, and is often encountered when care is not exercised in applyimg a helically performed dead end to a relatively flexible stranded structure. Although this displacement may take place to a minimum degree in metal ropes and strands, it is mormally mot of a sigmificamt nature. However, in fiber glass rope, this longitudinal displacement may be sufldent t0 permit substantial uneven or unequal longitudinal loading of the strands and elements comprising the line. When such unequal loading occurs, failure of the overloaded strands or elememts may occur resulting in overloading the remaiming strands or elememts which successively fail until ultimate failure of the lime coeurs.

Also other gripping and pulling problems are encountered whem usimg prior art gripping and pulling devices on certain roped structures. For example, fiber glass rope is normally provided with a jacket of plastic or elastomeric material for protection. With prior art gripping devices this jacket had to be stripped in the region to be gripped before applyimg the gripping device, simce application of gripping devices over this jacket produces widely varying failure loads. This stripping operation was time-consumimg and also the umderlying rope structure could be damaged by this removal operation.

One of the most widely used prior art techniques of securing the end of a fiber glass rope was potting or encapsulating. In a pottimg technique, the end portions of the fiber glass rope are first stripped of the jacketing material, and then encapsulated Withim a fitting by a resin which is allowed to cure inside of the fitting with the rope surrounded thereby, thus securing the fitting to the rope.

The emcapsulated, or potted fitting has been the conventional, or standard prior art fitting for many types of limes imcluding fiber glass rope. In fact this is the type of fitting mormally applied to test the stremgth of the fiber glass rope. These potted fittimgs while represemtimg the standard, have many serious limitations.

First, the fittimgs require a great deal of skill to apply properly, especially under field conditions. The line and the fittimgs must be properly prepared and imgrediemts must be CarefuHy measured. Also the process of applyimg potted fittimgs is time comsuming, mot omly in the prep aration of the fittimgs and the lime and the mixing of the ingrediemts, but also because of the time required for the encapsulating material to set. These drawbacks have restricted to some extemt the use of fiber glass rope.

Simce fiber glass rope has many attractive features for guying purposes for many structures, such as antenma towers, it is especially desirable t0 overcome these prob lems t0 permit eflective use thereof for these and other applications.

In accordance with the present invention, a line engagimg device is provided which is comprised of an imner layer of helically performed elememts, applied to the lime, and a gripping member having helically preformed elememts wrappimgly engaging the inner layer with means for attachment of the gripping member to an amchorimg structure. This configuration mimimizes the crushing forces imduced into the line and also mimimizes any longitudinal displacement of the strands or elements of the strands. Also, this arrangement can be applied over the jacketing material of the fiber glass limes.

This dual layer configuration of the gripping device also provides a useful device to grip limes for the pulling thereot, for applyimg tension thereto.

Still other advantages of the invention together with a fuller umderstanding thereof will become apparent from the followimg description t-aken in conjunction with the accompanying drawimgs in which:

FIG. 1 is a side elevatiomal view of a helically preformed elememt made from a wire;

FIG. 2 is a broken elevational view of several of the elements of FIG. 1, formed into a sub-set;

FIG. 3 is a broken elevational view of several sub-sets of the elements of FIG. 2, wrappingly engagimg a line to form a layering set;

FIG. 4 is an elevational view of a straight bight gripping member;

FIG. 5 is an elevational view of the member of FIG. 4, being wrappingly engaged onto a line over the layering set of elements;

FIG. 6 is a completed assembly of the gripping member applied over the layering set of elements;

FIG. 7 is an elevational view of the device of this invention being used as a line emgaging element for applyimg tension to a line; and

FIG. 8 is an elevational view of still another embodi ment of a gripping member applied over a layering set of elements on a line.

Referrimg now to the drawings, and for the present t0 FIG. 1, an individual resilient helically preformed wire element .10, is shown. This element 10 may be formed in several ways. However, preferably this forming is done as described in US. Pat. No. 2,588,663, issued to E. H. Schane. The helically bent wire is then severed into heli cally preformed elements -10 of the desired lengths. The elements may be stress relieved and the ends may be chamfered t0 eliminate sharp edges.

The element 10, thus formed is an open helix of hard drawn wire, such that it may be applied to a line from its side without permanent deformation of the helix.

A plurality of the elements 10, as shown in FIG. 1, are assembled into sub-sets as shown in FIG. 2, and these sub-sets can then be applied directly to a line L as shown in FIG. 3. If desired the elements in the subsets can have grit applied thereto to enhance the holding power as is well known in the art. As illustrated herein, three sub-sets of four elements each are applied to the line L. It is to be understood, however, that the number of elements in a sub-set as well as the number of sub-sets can also vary widely, as will be described presently. In the illustrated embodiment, the line takes the form of a fiber glass rope or cable. This particular material was selected for illustration inasmuch as the gripping devices of this invention are particularly useful with fiber glass rope or cable; however, it is to be understood that the device can be used effectively with amy type of wery flexible line. (As it is used herein the term line can include for example, a single wire or filament, a strand made up of a plurality of single wires, a cable or rope made from a plurality of strands, or wire made of a plurality of longitudinally extending elements. It applies to conductors of electricity as well as limes employed for guying purposes.)

Fiber glass rope is often supplied with a jacket formed of a plastic or elastomeric material such as urethane. Such a jacket is shown on the rope of FIG. 3, and designated with the reference character J. When such a jacket is supplied it is considered as part of the rope. As can be seen in FIG. 3, the layering elements 10 are applied over this jacket I. Hence, when such a jacket is supplied on the rope there is no necessity to remove the jacket, as with prier art gripping devices. (The reason why this device works eifectively over the jacket is not completely understood, and in fact constitutes an unexpected benefit; however, certain theories of this and other improved results will be discussed presemtly.)

It is preferable that the elements 10 be formed to the opposite hand of lay from the lay of the line; i.e., if the line is right hand of lay the elements 10 will be left hand of lay and vice versa. However, it is contemplated that in some instances the rods 10 may be of the same hand of lay as the lime and give satisfactory performance. Also, preferably the mumber of elements in a sub-set and the number of sub-sets is selected such that when they are applied they will cover at least fifty percent of the surface of the line, over which they extend, but have a total spacing between the elements, the extent of which would be sufficient for the introduction of at least one additional element of the same size. It is desirable that these elements cover at least fifty percent of the surface to provide a firm holding base for the gflppimg member to be applied later, but that they do not cover the surface s0 completely that an additional element could not be applied. This provides a spacing which allows for easy installation of the elements 10, and also prevents bridging, thus permitting each of the elements 10 to securely bear against the umderlyimg lime. Preferably the elements 10 of the sub-sets are relatively small cross section and are comprised of a relatively large number of wires. This is so that the elements can be applied easily and will mot exert excessive pressure on the line. Also, this will provide a certain amount of desirable flexibility to the rope although it will stiien the line suficiently for the case of applicadon of the gripping device thereover. Additionally, a large number of small elements provide greater contact area with the umderlyimg jacket, than a fewer number of larger size elements covering the same area.

The applied sub-sets of helically preformed elements 10, provide an umderlyimg or layering set of elements over which a gripping member or device can be applied. The gripping device can take one of many forms incorporating preformed helical elements for grippingly emgaging the set of layering elements. One desirable and preferred form is shown in FIG. 4, and designated by the reference character 12. As shown the gripping device 12 is comprised of a plurality of hard drawn wire elements l4, havimg helically preformed end portions 16, and an intermediate substantially straight portion 18, joining the helically preformed end; portions. The preformed portions 16, of each of the elements l4, substantially conform to each other as to pitch, length and internal diameter, The elements 14 are positioned in side-by-side relationship with one another to form a group, and the group of elements is bent within the intermediate straight portion to form a bight section 18, which is free of a complete revolution. The opposite end portions 16, of the elements 14, extend from the straight bight section 18 and form a pair of legs 16. This type of device is a conventional gripping device which, along with its method of manufacture, is described in said Pat. 3,295,311. The gripping device shown in FIG. 4 is then wrapped over the layering set of elements 10, as shown in FIG. 5, With the legs 16 being intertwisted With each other, until they have been completely applied as shown in FIG. 6. Preferably, as described in said Pat. 3,295,311, the legs of the gripping device when intertwisted with each other form more than a half lay, but less than full lay coverage of the layering set of elements 10. (It is to be understood that the gripping members are applied over a set of elements which themselves do not cover of the surface of the line, there being a space as described above; hence, when the definitions of half lay and full lay coverage of the legs 16 contained in said Pat. 3,295,311 include percent coverage of the legs, the percent must be based on 100% theoretical peripheral coverage of the line by the elements 10, i.e., as if there were sufiicient elements 10 applied to the lime to provide 100% coverage of the underlying line.)

As can be seen in FIGS. 5 and 6, the hand of lay of the legs 16 of the grippimg device 12 is opposite to that of the elements 10, and the same as that of the line L. This opposite hand of lay is preferable, but it is contemplated that in some instances the legs 16' may be of the same hand of lay as the umderlyimg elements 10 and still give satisfactory performance. Because of this opposite hand of lay of the layering elements and the legs of the gripping device, and also because of the rigidity which the layering elements 10 provide, the relatively large diameter of wires of the gripping device can be relatively easily applied without encountering the difficulty that is encountered when tryimg to apply such large diameter of wires directly to a flexible body, such as the underlying fiber glass rope and particularly when trying to apply the legs With the same hand of lay.

Also, as can be seen in FIG. 6, the underlying or layering set of elements 10 preferably extends past the end of the legs 16 of the grippimg device 12. This configuratien assures that the entire length of the grippimg device 12 will be in effective engagement with the umderlying structure. This extra length also provides for a stepped transition of flexibility; i.e., the line itself beyond the underlying set of elements is extremely flexible, while the line between the end of the layerimg elements and the end of the legs 16, is made somewhat less flexible by the layerimg elements 10, and the line covered by both the layerimg set of elements and the grippimg elements is quite stifi'.

As can be seen in FIGS. and 6, the bight 18' of the grippimg device 12 is disposed to engage an anchoring structure A, and thus form a dead end.

Tests performed demonstrated that fiber glass ropes dead ended according to this invention as shown in FIG. 6, consistently developed greater load carrying capacities than were developed With limes dead ended according to comvemtiomal prior art encapsulating or potting techniques. To test the strength of the dead end, the fittimgs (either the dead end fitting according to this invention or the potted fittimg according to prior teaching), are applied to opposite ends of the rope and gripped in a tensile testing device. Tension is applied until failure occurs. As can be seen from the table below, the fiber glass rope dead ended according to this invention consistently carried a higher load than fiber glass rope dead ended by conventional potting techniques.

TABLE.TENSILE TEST ON INCH FIBER GLASS ROPE MANUFACTURED BY PACKARD ELECTRIC DIVISION OF GENERAL MOTORS SOLD UNDER THE TRADEMARK GLASTRAN Rope breaking strength- Fitting pounds Test No.:

1 Potted fitting 1 .-do

Average et tests, 1, 2 and 3 Average of tests, 4, 5 and 6 1 Standard encapsulating technique employedmetal socket fitting for each end was degreased and acid treated, the jacket at each end of the strand was removed and the strands unwound; the unwound strands were degreased and then inserted into the fittings; epoxy resin and hardener poured into the socket and allowed to cure.

2 A layerimg set of helically preformed rods of the type shown in FIG. 1, was applied to each end of the strand over the jacket; the wires were of opposite hand of lay rom the strand. A grippimg member as shown in FIG. 4, was applied over the layerimg elements at each end, the hand o! lay of the legs was opposite to that oi the layerimg elements and the same as the stramd.

As can be seen from the table above, in each instance line grippimg devices formed according to this invention produced superior results to the standard prior art encapsulated devices and techniques. Further, fittings according to the invention not only develop a higher load carrying capacity, they can be simply and rapidly applied under virtually all field conditions.

Not only does the grippimg device formed according to this invention provide a superior device for securimg limes to an anchoring structure, it also provides a superior device for grippimg a lime to apply tension thereto during the installation of the line.

FIG. 7 shows somewhat diagrammatically grippimg devices according to this invention, used both to apply tension t0 a line and to secure the lime to an anchoring structure. First, ome end of the line is secured to an anchorimg point (mot shown) usually on the tower or pole. Then the point on the lime at which it is to be gripped to apply tension is selected, at which point a first set of layerimg elements 110, is applied over which a first grippimg device 112, is applied. The application of the layerimg elements and the grippimg device 112, is accomplished as described above. A tension applyng device in the form of a comeal0ng 2.0, is provided which has a hook 22, at one end, disposed to engage an eye 24, formed in the anchoring structure to which the other end of the lime is to be connected. The other end of the comealong is provided with a hook 26, attached to a ratcheting device 28, which in turn is connected to the hook 22 by a chain 30.

The ratchetimg device 28, is operable by a handle 32, which will move the ratcheting device 28, along the chain 30.

In order to apply the desired tension to the line, the hook 22, is engaged with the eye 24, and the hook 26, is engaged With the bight 118 of the grippimg device 112. The handle 32 is then operated to move the ratcheting device on the chain 30 which will tighten the line. When the desired tension has been applied to the line, the lime is out to the desired length. The end of the line is then dead ended. This dead ending preferably is done with layerimg and grippimg elements according to this inventien. A second set of layerimg elements 210 is applied, in a manner as described previously, over which a grip ping device 212, is applied also in a manner as previously described, engaging the anchoring structure A. The tension can be relieved from the temsioning device 20, transferring the load to the grippimg device 212. The first grippimg device 112 and the layerimg elements 110 can then be removed. These elements of course may be reused for additiomal temsioning operatioms if they are mot severely damaged.

One of the outstandimg advantages of using the mechamism of this invention for a device to apply tension, is that it does not cause any crushing damage to the underlying strand, such as is often the case with comvemtiomal prior art grippimg jaws of tensioming devices. Tests were performed to show the effect of using comvemtiomal prior art grippimg jaws to apply tension to a line as compared to the device of this invention. These tests were performed successively on test specimens of A inch Glastran fiber glass ropes. For each test ome end of the specimen Was first dead ended With similar layerimg elements and a straight bight grippimg device according to this invention as shown in FIG. 6. Next the specimem was wrapped with a set of layerimg elements 110 near the opposite end thereof at the place where it was to 'be gripped for tension to be applied. The same size and type of elements were used for each specimen. On ome specimen, a grippimg device 112, according to this invention was applied over the elements 110, in the manner as shown in FIG. 7 and engaged With the tensioning device 20. On the other specimen a comvemtiomal grippimg jaw comealong was applied over the set of elements 110 and engaged with a temsioning device 20. In each test the line was tensioned to about 5,000 pounds by the tensioning device.

In each test the other end of the specimen was dead ended with similar sets of layerimg elements and a grippimg device, according to this invention. The tension was released and the grippimg device, the temsioning device, and the layerimg elements underlying were removed.

The specimens were each tensle tested by applying force thereon through the grippimg devices at opposite ends. The specimen which had been gripped by a grippimg device according to this invention, did not break until it had exceeded its full rated breakage strength, in fact, breaking above 19,000 pounds with failure occurring at a location away from where it had'been gripped by the grippimg device for tensioning. On the other hand, the specimen that had been gripped with the comvemtiomal grippimg jaw type device failed at about 5,000 pounds, failure occurring at the place the where the jaws had gripped the specimen. These tests demonstrated that aven covering the line by a set of layerimg elements would not prevemt damage to the line by the jaws of conventional gripping devices to such an extent that it was materially weakemed and hence failed well below its rated breaking strength.

The gripping devices of this invention and method of using them in applying tension to a lime have been described in conjunction with using similar gripping devices for a dead end; however, it is to be understood that the gripping devices and their use in applying tension are not limited to situations where similar type of devices are used to dead end limes, and they can be used in conjunction with other dead ends or dead emding devices and techniques.

Referring now to FIG. 8, another form of a gripping device applied over the underlying sets of wires 10 is shown. In this embodiment the gripping device includes a plurality of helically preformed wires 34, which are secured together at one end portion thereof, by a socketing device 36. The helically preformed wires 34 are formed t a common pitch length and internal diameter to engage over the layering set of wires 10. The socket device includes attachment means, in the form of a clevis pin 38, which is adapted to engage an anchoring structure. The helically preformed wires 34, can be secured in the socketing device by any of several conventional means. For exainple, the wires may be held in the socket by a swaging or wedging action as shown in application Ser. No. 729,610, filed May 16, 1968, now Pat. No. 3,575,519 entitled Gripping Device, or they may be held in the device by encapsulating material as disclosed in application Ser. No. 729,618, filed May 16, 1968, entitled Dead -Ending Device, or application Ser. No. 729,619, filed May 16, 1968, now Pat. No. 3,551,959, entitled Detachable Socketed Dead End. These of course are just illustrations of types of socketing devices and not intended as limiting.

The illustration of both the socket type gripping devices, and the type where preformed wires are bemt to form a bight, are intended to be merely illustrative of the many configurations of gripping devices utilizing preformed helical elememts which may be used. These forms are especially desirable for fiber glass rope application since they minimize torsional stress induced to the line and fiber glass is especially torque sensitive. However, it will be readily apparent to those skilled in the art that there are many other configurations which will function as gripping devices for engaging over the layering elememts 10, the illustrated embodiments merely representing preferred structures which perform quite satisfactorily.

The exact reason for the excellent performance of the devices of this invention over other devices, particularly over helically formed devices applied directly to a line, is not completely understood. However, it is believed that there are several contributing factors which when taken together produce the outstandimg performance. First, rope made of a plurality of strands which in turn are made up of a plurality of elements is an extremely flexible structure. When it is attempted to place relatively stiff helically preformed wires on this flexible structure, dificulty is encountered in that the rope tends to flex excessively when the wires are being applied, which makes the installation diflicult. If under these circumstances, the grip is not carefully applied the operation tends to produce longitudinal displacement of the strands and elememts With respect to each other, which as described above, can contribute to premature failure of the structure, particularly in the case of fiber glass rope.

Also, when helically preformed wires which are to carry the pull are directly applied to rope structure, it is necessary that the wires have the sarne hand of lay as the rope structure. If they are opposite hand of lay and tension is applied, the result is that the gripping device tends to unravel the rope under tension which contributes t0 rope failure. Hence, it is necessary Whem applying gripping devices directly to stranded structures that the helically pref0rmed wires have the sarne hand of lay as the rope. This increases the difliculty of application and increases the chance of longitudinal displacement of the strands or elememts if care is not exercised in applying the device.

Further, when wires of the sarne hand of lay are used there is minimum number of pressure points where the wires are bearing agaimst the rope, which tends to increase the concentration of the forces rather than disperse them, contributing to or increasing the possibility of crushing damage.

The dual layers structure of the present invention overcomes these disadvantages.

First, the underlying set of wires can be formed of thinner, less rigid members which can be more easily applied to the flexible rope structure. This is possible since the gripping action is not generated by these wires, and hence, the great strength required to provide the gripping action is not required.

Also, the underlying wires 10, can be of the opposite hand of lay of the rope, which makes application to the rope much easier. This provides a much improved structure for distribution of forces since wires having the opposite lay have a greater number of contact points with a great number of strands, thus, increasing the force distribution. The heavier wires of the gripping device can then be applied over the underlying set of wires 10. This underlying set of wires 10, will greatly reduce the external flexibility of the wires to the desired amount, increasing the case of application of the gripping device, thereto.

Also, the wires of the overlying gripping device 12, will be the opposite hand of lay of the underlying wires 10, and the sarne hand of lay as the lime L. This then allows the gripping device to be more easily applied to the underlying set of wires 10 and still retain the same hand of lay as the underlying rope structure, so that detrimental umwinding does not occur under tension.

This structure of opposite hand of lay of underlying wires and rope on one hand and underlying wires and overlyimg gripping device on the other provides an extremely desirable configuration for preventing concentration of gripping forces in any one area widely distributing these forces so that they do not contribute or cause a crushing action of the underlying structure. It also provides a configuration which is relatively easily applied to the structure which will not tend to cause longitudinal displacement of the strands and elememts making up the underlying structure, and which will alford au extremely effective device for transferring load from the underlying rope structure up to the full potential of the rope itself.

While several embodiments of this invention have been shown and described various adaptations and modifications can be made without departimg from the scope of the invention.

What is claimed is:

1. A device for gripping an elongated body comprising, a first set of helically preformed resilient elememts formed to a common pitch length and internal diameter, said elements of the first set being of a size and adapted to be applied to wrappingly engage a body without permanent deformation of the elememts; a second set of resilient elememts, the elements of said second set having at least one end portion helically formed to a common pitch length and internal diameter and disposed for wrappingly engaging said first set of elememts in overlying relationship when said first set is applied to the elongated body, means connected to said helically formed portions of said second set of elememts for engagement with an anchoring structure.

2. The invention as defined in claim 1, wherein the first set of elememts is configured and arranged such that when they are applied to a line there will be unfilled space between the elements suflicient to accommodate at least one additional element of the same size.

3. The invention as defined in daim 2, wherein the configuration of the first set of elements provides at least 50 percent coverage of the underlying line of the portion of the line that will be covered thereby.

4. The invention as defined in claim 1, wherein the helically formed end portions of said second set of elements provide, upon intertwisting on the first set of dements, a less than whole lay gripping portion but more than half lay.

5. The invention as defined in daim 1 wherein the elements of said first set and the helically formed portions of said second set of elements are of opposite hand of lay.

6. The invention as defined in claim 1, wherein said first set of elements is longer than the helically formed portions of said second set of elements.

7. The invention as defined in daim 1, wherein the elements of said first set are substantially less rigid than the elements of said second set.

8. The invention as defined in daim 7, wherein the elements of said first set are of smaller diameter than the elements of said second set.

9. The invention as defined in claim 1, wherein said second set of elements are in side-by-side relationship defining a pair of helically formed leg portions connected 'by a bight portion.

10. The invention as defined in daim 9, wherein said bight portion is free of a complete helical revolution.

11. The invention as defined in claim 1, wherein the elements of said second set are secured by a socket member.

12. The combination comprising, a line, a gripping device therefore including a set of resilient layering elements and a set of resilient gripping elements, each of said layering elements being of similar size and helically preformed to a common pitch and internal diameter and wrappingly engaging said line, the elements of said gripping set having at least one end portion helically formed to a common pitch and internal diameter, said helically formed end portions of said gripping elements Wrappingly engaging said layering elements in gripping relationship therewith, and means connected to said helically formed end portions of said gripping elements engaging an anchoring structure.

13. The invention as defined in daim l2, wherein the elements of said layering set are arranged such that there will be unfilled space between the elements suflicient to accommodate at least one additional dement of the same size.

14. The invention as defined in daim 13, wherein the layering set of elements provided at least 50 percent coverage of the underlying line of the portion of the line covered thereby.

15. The invention as defined in daim 12, wherein the helically preformed end portions of said set of gripping elements provide, npon intertwisting on the first set of elements, a less than whole lay gripping portion, but more than half lay.

16. The invention as defined in daim 12, wherein the elements of said set of layering elements and the helically preformed end portions of the gripping elements are of opposite hand cf lay.

17. The invention as defined in daim l6, wherein the line is a stranded structure and of opposite hand of lay as the set of1ayering elements.

18. The invention as defined in claim 12, wherein said set of layering elements is longer than the intertwisted end portions of said set of gripping elements.

19. The invention as defined in daim 12, wherein the elements of said layering set are substantially less rigid than the elements of said gripping set.

20. The invention as defined in daim l9, wherein the elements of said layering set are of smaller diameter than the elements of said gripping set.

21. The invention as defined in daim 12, wherein the elements of said gripping set are in side-by-side relationship providing a pair of helically formed leg portions connected by a bight portion.

22. The invention as defined in daim 2l, wherein said bight portion is free of a complete helical revolution.

23. The invention as defined in daim 12, wherein elements of said gripping set are secured by a socket member.

24. A method of tensioning a line to a predetermined amount comprising the steps of: providing a set of layering elements, said layering elements being helically formed to a common pitch length and internal diameter and configured for wrappingly engaging the line to be tensioned, providing a gripping member including a plurality of elements having end portions helically formed t0 a common pitch length and internal diameter and configured for wrappingly engaging said layering elements, and engagement means connected to said helically formed end portions of said elements of the gripping member for engagement with a structure, wrappingly engaging said set of layering elements on said line at a selected location; wrappingly engaging the helically formed end portions of the elements of said gripping device around said layering elements, engaging an anchoring structure and the engagement means of said gripping device With a tension applying device, and applying the desired tension to said line.

25. The method as defined in daim 24, wherein said line is connected to an anchoring structure after the desired tension has been applied.

26. The method as defined in daim 25, wherein said line is connected to said anchoring structure by the steps of providing a second set of layering elements, wrappingly engaging said second set With said line, providing a second gripping member, wrappingly engaging said second gripping member With said layering elements and engaging said engagement means With said anchoring structure.

27. A device for gripping an elongated body comprising, a set of helically preformed resilient elements formed t0 a common pitch length and internal diameter, said elements of the set being of a size and adapted to be applied to wrappingly engage a body without permanent deformation of the elements; and gripping means disposed to grippingly engage said set of helically preformed elements when said set is applied to the body, said gripping means including means to engage an anchoring structure to secure the line thereto.

28. The combination comprising, a line, a gripping device therefore including a set of resilent layering elements, each of said layering elements =being of similar size and helically preformed to a common pitch and internal diameter and wrappingly engaging said line, and gripping means grippingly engaging said layering elements, said gripping means inclnding means engaging an anchoring structure and securing the line thereto.

References Cited UNITED STATES PATENTS 3,089,567 5/1963 Sullivan 57-145 UX 3,190,065 6/1965 Little 57-145 3,267,658 8/1966 Schlein 57-145 3,295,311 1/1967 Butz et al. 57-145 3,299,626 1/1967 Payer et al. 57-145 3,315,457 4/1967 Stirn 57-145 3,336,744 8/1967 Peene 57-145 3,355,542 11/1967 Finn 174-79 3,406,513 10/1968 Butz et al. 57-145 DONALD E. WATKINS, Primary Examiner U.S. Cl. X.R. 174-79; 248-63

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