US3455099A - Dead end - Google Patents

Description

T. E. BUTZ DEAD END July 15, 1969 Sheet 1 S'Sheets INVENTOIR. TOM E. BUTZ Filed March 29, 1968 July 15, 1969 T. E. BUTZ I 3, 9

Filed March 29, 1968 5 Sheets-Sheet 2 July 15, 1969 T. E. BUTZ 3,455,099

I DEAD END Filed March 29, 1968 5 Sheets-Sheet 4 mveuron. I TOM a BUTZ United States Patent US. Cl. 57145 17 Claims ABSTRACT OF THE DISCLOSURE A dead end for lines and the like having a set of elements each having helically formed end portions and straight central portions. The central portion may have a strap member and also the central portion of the elements may be in crossing relationship.

This invention relates to new, different, and unobvious dead ends and method of manufacturing the same and more particularly to new, different, and unobvious dead ends made of preformed helical wires, rods or elements.

Although the principal use of dead ends is for the dead ending of lines, they are also useful as cable suspension means, for use with come-alongs for pulling conductors or lines for service drop grips. The dead ends of this invention are an improvement over those shown in US. Patent 3,295,311, dated Jan. 3, 1967 and issued in the name of Tom B. Butz and Seymour N. Schlein.

Dead ends made in accordance with the above entitled patent are formed with a plurality of elements having helically formed leg sections and straightened bight sections. These dead ends have found widespread use in the pole line hardware field and have proved to be superior in most respects to the helical bight dead ends which were in common use prior to the introduction of the straight bight dead ends formed according to said patent.

A dead end having a straightened bight section has many advantages over the prior art helical bight dead ends. The fact that the bight has a relatively thin flat configuration, as opposed to a relatively thick configuration of the helical bight dead end, is advantageous in certain aspects; but with certain types of clamps complete fail-safe grounding was not attainable with this flat configuration of a bight.

In guying electrical poles or towers, a dead end is placed on one end of the guy line which is attached to a pole or tower to be guyed and a dead end is applied to the other end of the line which engages some type of ground anchoring device. These guy lines are tensioned to the proper tension and normally the dead end will bear tightly against the bearing surface thus assuring a positive electrical and mechanical contact with the ground. This positive contact is important since in some installations the guy wire is part of the electrical grounding system; also even if the guys are not a part of the ground ing system electricity may accidentally be introduced into the guy. Thus, if electricity is introduced into the guy, the well grounded condition will render the guy safe.

However, in some instances the guy may become slack either momentarily due to wind or vibration effect, or because of other change in forces; or, the guy may be permanently slack because of improperly applied-tensioning forces during installation. When the guy is slack, the dead end may not be in solid firm contact with the bearing surfaces, particularly at the anchoring device. If under these slack conditions, between the dead end and the ground anchor, electricity is introduced into the guy wire, the grounding of the guy will be improper and any 3,455,099 Patented July 15, 1969 person touching the guy may be injured or killed due to electric shock.

In order to assure that the guy remains positively and firmly in contact with the ground anchor many anchor rods have bonding clamps installed which tightly clamp the bight of the dead end against the bearing surface of the anchor rod. This assures that even if the guy goes slack there will be positive pressure to afford sufficient contact between the anchor rod and the dead end to provide a positive solid ground. Yet, certain types of bonding clamps do not extend sufficiently into the anchor rod eye to engage the straightened bight dead end of the type shown in said Patent No. 3,925,311 since this configuration is fiat and thin as compared to the thicker, twisted configuration of the helical bight.

In order to assure a positive adequate ground of a straight bight dead end, one of the features of this invention is the provision of a band or strap, in the bight portion of a straight bight dead end which will assure a positive adequate clamping action between the bonding clamp and the bearing surface of the anchor rod.

Another feature of this invention contemplates the provision of a dead end formed of a multiplicity of elements having helically formed legs and straight bight sections arranged in a set such that the elements are in crossing relationship with each other in the bight portion. This arrangement may also utilize a strap or band device which in this embodiment not only provides a positive clamping action between the bonding clamp and the bearing surface of an anchor rod, but also may serve to keep the elements arranged in a compact group and also to maintain the cross-over location of the elements at a selected position. It has been found that the use of dead ends having elements in crossing relationship in proper position increases the resistance to failure of a dead end due to vibration. Hence, this arrangement may be desirable if excessive vibration is being encountered with attendant failures.

These and other objects together with a fuller understanding of the invention may he had by referring to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is an elevational view of a set of elements having helically formed leg portions and a straight central portion; 1

FIGURE 2 shows the set of FIGURE 1 having a band applied to the central portion;

FIGURE 3 shows the set of FIGURE 2 bent to form a dead end ready for installation;

FIGURE 4 is the device of FIGURE 3 rotated FIGURE 5 shows a dead end with a gripping band installed on a line and secured to a ground anchor having a clamping device;

FIGURE 6 shows an installed dead end having a different configuration of a gripping band; 7

FIGURE 7 shows a set of elements having helically formed ends and straightened central portions which central portions are in crossing relationship in the middle;

FIGURE 8 shows the set of FIGURE 7 bent to form a dead end ready for application to a line;

FIGURE 8a shows a device similar to FIGURE 8 rotated 90 but wherein the wires in the bight section are spread or spaced;

FIGURE 8b shows a fragmentary perspective view of the device of FIGURE 8a;

FIGURE 9 is a set of elements similar to FIGURE 7, but having a gripping band applied to the central portion thereof;

FIGURE 10 is the set of elements shown in FIGURE 9 bent to form a dead end ready for application to a line;

FIGURE 11 shows a device similar to FIGURE 8 with the location of the cross-over being located at a point spaced from the bearing area of the bight;

FIGURE 12 is a device similar to FIGURE 10 with the cross-over point of the elements in the bight being located at a location spaced from the bearing point of the bight portion of the dead end;

FIGURE 13 is the dead end of FIGURE 11 applied to a line;

FIGURE 13a is the dead end of FIGURE 8w applied to a line;

FIGURE 14 is the dead end device of FIGURE 12 applied to a line;

FIGURE 15 is a sectional view taken substantially along the plane designated by the line 1515 of FIG- URE FIGURE 16 is a sectional view taken substantially along the plane designated by the line 1616 of FIGURE 13.

FIGURE 17 is the device of FIGURE 8 applied to a line.

Referring now to the drawings and for the present to FIGURES 1 through 4, one embodiment of a dead end with a gripping strap device, according to the present invention is shown. FIGURE 1 shows a set of three elements 20A, 20B, 20C, which have been formed into a group having helically formed end portions 22A, 22B and 22C at opposite ends thereof and straightened central portions 24A, 24B and 24C. The helically formed end portions substantially conform to each other with respect to pitch length and internal diameter. This figure represents an intermediate step in the forming of the dead end and preferably this set is made as disclosed in said Patent 3,295,311. The central portions 24A, 24B and 24C are generally parallel being free of a complete helical revolution. (If this set is formed according to the teachings of the 3,295,311 patent the central portion may have some slight inside curvature as disclosed therein.) The central portion being free of a complete helical revolution, there is no cross-over relationship of the wires with respect to each other.

In FIGURE 2 a gripping strap 26 is shown applied around the central section of the straightened portions 24A, 24B and 24C. When this gripping strap has been applied the elements with the strap thereon are bent to. the configuration shown in FIGURE 3 to form a dead end with the opposite helically formed ends 22A, 22B and 22C becoming the legs of the dead end and the straightened central portions 24A, 24B and 24C becoming the bight portion of the dead end with the strap 26 being located centrally of the bight and in the area which will normally engage Whatever anchoring device to which the dead end is secured. The legs are preferably configured such that when they are both applied to a line in gripping relationship they will provide more than half-lay coverage but less than whole-lay coverage.

A whole-lay is one where the helical wire elements, when wrapped around the line, completely encompass the line to which they are applied. A half-lay of helical wi-re elements is one where the elements, when Wrapped around the line, will cover one-half of the line. For example, a dead end that provides whole-lay coverage when assembled on the line cannot accommodate another wire of the same size in each of its legs and at the same time allow all of the elements of the intertwisted legs to maintain gripping contact with the line. When two legs are assembled on the line and the coverage of the circumference of the line is less than about 80-85 percent, the two legs do not form a whole-lay and each leg may be considered to he less than a half-lay. This definition, of course, ap-

plies to practical commercial installations and does not apply to situations in which the diameter of the wire elements in the legs of the dead end are very small (nonconventional) or very large (non-conventional) in relation to the diameter of the line.

FIGURE 4 which is a view of FIGURE 3 rot ted 90 shows that the strap 26 adds substantially to the thickness of the central bight portion of the dead ending device.

Alternately, with respect to the manufacture of the device of this invention, the elements as shown in FIGURE 1 can be bent prior to the application of the gripping strap to essentially the formation shown in FIGURES 3 and 4 and then a gripping strap which has been pre-bent and preformed to the required shape can be applied after this bending operation has taken place. In either event the strap is crimped on so that it tightly engages the central portion of the bight and will securely grip the elements in the bight section.

The dead end as shown in FIGURES 3 and 4 can be applied to the end of a line as shown in FIGURE 5 with the bight portion engaging an anchor rod designated generally as 28. This is one conventional type anchoring device which has a projection 30 adapted to be embedded in the earth which extends from an eye portion 32 having a bearing surface 34 against which the dead and bears. A bonding clamp 36 is installed on the eye portion 32. One type of bonding clamp which is widely used, and which is shown in FIGURE 5, is sold by the A. B. Chance Co. of Centralia, M0. The clamp 36 is secured to the anchor rod eye 32 and has a pair of split blocks 37 movable toward and away from the bearing surface 34 and for the purpose of firmly securing the bight thereagainst. As explained above, some of these clamps will move sufficiently to contact a thickened bight dead end such as the dead ends with cabled loops, but will not move far enough to engage flattened configurations of the straight bight. How ever, the strap 26 provides additional thickness so that blocks 37 will bear against the gripping strap 26 to provide good solid contact for the grounding function. Thus, the strap 26 provides this solid contact necessary for adequate grounding.

In addition to providing a solid grounding contact for the device, the gripping strap 26 also serves the function of holding the set of elements together so they will maintain their integrity during shipping and while they are being installed. This assures that the elements of the set will not become separated during handling or installation and that the set will be maintained with the elements as an integral unit.

The gripping strap 26 may be formed of a variety of different materials. The only requirement is that it be electrically conductive and that it not react either with the dead end or the anchor rod to cause rapid corrosive deterioration of either. Aluminum is well adapted for this purpose and makes an excellent gripping strap, but galvanized steel as well as many other materials may be used.

Referring now to FIGURE 6, another embodiment of the gripping strap is shown applied to a dead end. In this embodiment, a single strap member 38 is placed on th exterior of the bight and held thereto by a pair of bands 40 and 42 at opposite ends thereof. These bands 40 and 42 could be formed integrally with the strap 38 as tabs which are bent. This particular configuration reduces somewhat the amount of material needed and still adequately performs the function. The additional thickness is provided exteriorly of the bight to provide the necessary contact. In this case the elements will bear against the bearing surface 34 of the ground anchor 32 and the bonding clamp 36 will bear against the strap.

Referring now to FIGURES 7 and 8, another embodiment of this invention is shown. In this embodiment elements 20A, 20B and 20C are shown arranged in a subset, the elements having helically formed end portions 22A, 22B and 220 at opposite ends thereof and straight central portions 24A, 24B and 24C between said end portions. However, in this embodiment instead of the elements lying parallel as was the case in FIGURE 1, the elements are arranged in crossing relationship at the cen ter of the central sections 24A, 24B and 24C, as indicated at 44. When the device of FIGURE 7 is bent to the form shown in FIGURE 8. it is suitable for applying to a line figuration. The device of FIGURES 8a and 8b is shown applied to a line in FIGURE 13a. However, under tension load the wires will pull together in the bight section so that it will assume the configuration of the bight shown a helically formed bight portion. The tests were performed on galvanized steel dead ends made from the same element specification for the different bight or loop designs and were tested on 1% pins. The tests were performed on extra high strength steel strand. Dead ends of the same design were placed on opposite ends of the strand and the strand tensioned to 40% of its rated breaking strength. The strand was then vibrated at a given power and frequency. The results of these vibration tests in FIGURE 17. The legs may have whole-lay coverage 10 are shown in the table below:

TABLE Average Average A power input frequency Cycles to Sample Loop configuration (watts) (hertz) failure Analysis A 14.5 70. 416, 000 Broke 1 wire of dead end where dead end Straight bight parallel Wires started engagement of strand. B uncrossed configuration. 12.1 71. 7 1 4, 620,000 Test discontinued. C 12.0 71. 9 812,000 Broke 1 wire of dead end where dead end started engagement of strand. Average 2 614, 000

D Helical bight (twisted or 12. 3 72. 7 691,000 Broke 1 wire in loop of dead end. E cabled) confi uration 5 6 F g 12. 0 72. 7 503, 000 Do.

Average 3 531, 000

G Straight bight crossed were 13. 7 72.0 1 1,125.000 Test discontinued. H configuration crossed away 12.0 72.3 1 2, 747, 000 Do. from bearing surface. 12.0 71. 9 1 1, 061, 000 Do. J Straight bight wires crossing 12.0 71. 7 695,000 Broke 1 wire in loop of dead end.

at bearing surface.

1 No failure.

2 Average of Samples A and C.

3 Average of Samples D, E and F. or may be less than whole-lay but more than half-lay coverage.

A gripping strap may be used when the wires in th bight have a crossing configuration, if desired. In fact, such a strap is particularly desirable when the wires tend to spread as in FIGURES 8a and 8b to group or bunch them together. Such a strap is shown applied to the elements in FIGURE 9, and FIGURE 10 shows the device with a gripping strap bent to form a dead end. Again, it is to be understood that the strap 26 could be ap lied after the elements were bent into the form shown in FIGURE 8 rather than before as shown in FIGURE 7.

FIGURE 11 shows a device similar to that shown in FIGURE 8 except that the cross-over point 44 of the wires is not located in the middle of the bight, but is located at a place between the middle and the start of one of the legs. FIGURE 12 is a device similar to FIG- URE 11 with the cross-over point 44 removed from the middle of the bight but having a gripping strap applied thereto. FIGURES l3 and 14 show the devices of FIG URES 11 and 12 respectively, applied to the lines.

The devices having the crossed over configuration as illustrated in FIGURES 7 through 14 and FIGURE 17 and especially those in FIGURES 11 through 14, are particularly useful where excessive vibration is likely to be encountered and maximum vibration resistance is required. It has been theorized in the past that dead ends with straightened central sections having crossing relationships of the elements would be very poor because upon application of tensile pull one of the elements would assume most of the initial load and fail. Immediately thereafter, another element would pick up the load and fail followed by another element picking up the load and failing until all had failed. It was also thought that elements having cross-over relationship would have poor resistance to breaking due to vibration as a result of chafiing. However, tests were performed using dead ends with crossing element configuration similar to those shown in FIGURES 8, 8a, 8b, 10, 11, 12 and the dead ends not only held the rated breaking strength of the line, they also held until the line broke. Also, tests were performed which compared the resistance of vibration of the dead ends similar to those shown in FIGURES 8 and 11 with a dead end formed according to the 3,295,311 patent and also with a conventional prior art dead end having An examination of this table shows that in all tests the dead ends with straightened bight configuration with the elements in crossing relationship at a location spaced from the bearing surface never failed up to the end of the testing period. With three devices made according to the 3,295,311 patent, one did not fail whereas the remaining two failed at cycles substantially below the number of cycles which the straightened bight dead ends with cross ing configuration exceeded. In two out of the three tests, the devices with the straight bight without a crossing configuration lasted longer than any of the devices with a helical bight. The one test performed on the device with a straightened bight configuration having the cross-over at the bearing surface was better than any device with the helical bight configurations and better than one test of the straight bight non-crossing configuration.

This excellent resistance to vibration of devices having the straightened bight cross-wire configuration in the bight is not completely understood.

As indicated above, it has been theorized that the crossed configuration of the wires would contribute to an early failure due to chafing of the Wires and the like. It is still not completely understood why such a crossed configuration is so substantially more resistant to vibration. However, it is believed that this superiority is in part due to the more balanced phase relationship of the opposite legs of each element as they are applied to the line. This can be demonstrated by an examination of FIGURES 15 and 16. FIGURE 15 is a sectional view taken through a device as applied to a line wherein the device has a straightened bight configuration but does not have a crossing relationship of the wires in the bight. Also, it should be noted that the elements in the legs of a helical bight dead end have substantially this same relationship. FIGURE 16 is a sectional view taken through a device wherein the straightened wires in the bight are in crossing relationship and each wire crosses every other wire in the bight.

The dotted lines in both FIGURES 15 and 16 connect the opposite legs of the same elements. Thus, when examining FIGURE 15 it can be seen that phase displacement of angle X between the opposite legs of the elements of 20C is different than phase displacement or angle Y between the opposite legs of the elements 20B and depending on how the elements are applied, may or may not be the same as the phase displacement or angle Z between the opposite legs of element 20A. Further, it can be seen that no matter how the legs are applied or shifted with the elements lying in an uncrossed relationship as shown in FIGURE 15, it is impossible for the opposite legs of each of the three elements to have the same phase displacement.

However, as can be seen in FIGURE 16, when the elements are in crossing relationship with each element crossing each other element the phase displacement or angle X between the opposite legs of the element 20C is equal to the phase displacement or angle Y of the opposite legs of the element 20B which is equal to phase angle Z between the opposite legs of the element 20A. Thus, the phase displacement of helically formed portions of one leg of any one element with respect to the other leg is substatnially the same for every element.

Because of the equality of phase displacement of the opposite legs of the elements 20A, 20B and 20C in the straightened bight crossing wire configuration, each element will share approximately equally the forces in the dead end, including the torque or twisting forces. Conversely, because of the unequal phase displacement of the elements in 20A, 20B, and 20C in the straightened bight non-crossing configuration there may well be different loading of the different elements. When the wires cross at the bearing surface, as in the case of the helical bight configuration and in the case of the straight bight crosswire configuration wherein the wires cross at the bearing surface, this crossing relationship tends to contribute to the failure of the device at this point before any difference in loading of the wires become significant. However, where there is no cross-over bight configuration at the bearing surface, such as in the straight bight dead end with the wires parallel in the loop, this different loading may become significant and because of this, failure occurs. This is evidenced by the fact that the dead ends having straightened bight parallel element relationship tended to break adjacent the region where they first contact the strand, as opposed to breaking in the loop as did those where there was a crossing of the wires in the loop at the bearing surface. It is theorized that the crossing configuration of the wires when at a location spaced from the bearing surface does not have any overriding significant effect on failure, and because of the equal loading, the straightened bight configuration with the opposite legs of each of the elements in equal phase displacement, the resistance to vibration failure is outstanding.

What is claimed is:

'1. Means for holding a line to a support, said means being characterized in that it has resistance to peeling and slippage when applied to said line, said means comprising; a plurality of resilient elements; said elements each having helically preformed end portions and an intermediate substantially straight portion joining said helically preformed end portions; each of said elements of said helically preformed end portions substantially conforming as to pitch length and internal diameter; said elements being positioned to form a group with one another; said group of elements being bent within said intermediate straight portion to form a substantially straight bight section being free of a complete helical revolution; at least one member in abutting relationship with at least a portion of said bight section and formed of an electrically conductive material, said member being configured and arranged to increase the thickness of the bight section where said bight section is adapted to engage a bearing surface, legs extending from the respective ends of said straight bight section, each of said legs comprising said helically preformed portions of said elements.,

2. The device of claim 1 wherein said member includes a strap at least partially surrounding and grippingly engaging said elements.

3. The device of claim 1 wherein said member includes a band, and clamping means securing said strap to said bight.

4. The device of claim 3 wherein said strap is positioned on the surface of said bight and is adapted for engagement with a bonding clamp.

5. The device of claim 1 in combination with an anchor device having a bearing surface and a bonding clamp, said bight section with said member thereon being secured between said bearing surface and said bonding clamp.

6. The combination of claim 5 wherein said member at least partially surrounds said bight section at the location said bight section is gripped between said bonding clamp and said bearing surface.

7. The combination of claim 5 wherein said member includes a flat band located between the elements of said bight section and the bonding clamp.

8. Means for holding a line to a support, said means being characterized in that it has resistance to peeling and slippage when applied to said line, and will sustain at least the rated breaking strength of the line when loaded and is extremely resistant to vibration failure, said means comprising: a plurality of resilient elements; said elements each having helically preformed end portions and an intermediate substantially straight portion joining said helically preformed end portions; each of said elements of said helically preformed end portions substantially conforming as to pitch length and internal diameter; said elements positioned to form a group with one another, said group of elements being bent within the intermediate straight portion to form a bight section wherein each element is free of a complete helical revolution; said elements being positioned such that a crossing relationship exists between said elements in the bight section, legs extending from the respective ends of said straight bight section each of said legs comprising said helically preformed portions of said elements.

9. The invention as defined in claim 8 wherein each each element crosses each other element in the bight section, and phase displacement between the helically preformed end portions of one element is substantially the same as the phase displacement between the helically preformed end portions of the other elements of said holding means when said holding means is applied to a 10. The device of claim 8 wherein the crossing relationship of the elements occurs in said bight section at a location spaced from the position where said bight section is adapted to engage a bearing surface.

11. The device of claim 8 further characterized by strap means for engaging said elements in said bight section and maintaining them as a group.

12. The device of claim 8 in combination with a line and anchoring device having a bearing surface.

13. The combination of claim 12 wherein said crossover relationship of the elements is at a location spaced from the bearing surface.

14. For use with means for holding a line to a support, said means being characterized in that it has resistance to peeling and slippage when applied to said line, said means comprising; a plurality of resilient elements; said elements each having helically preformed end portions and an intermediate substatnially straight portion joining said helically preformed end portions; each of said elements of said helically preformed end portions substantially conforming as to pitch length and internal diameter; said elements being positioned to form a group with one another; said group of elements being bent within said intermediate straight portion to form a substantially straight bight section being free of a complete helical revolution; legs extending from the respective ends of said straight bight section each of said legs comprising said helically preformed portions of said elements; the

improvement which comprises at least one member adapted to be secured in abutting relationship with at least a portion of said bight section and formed of an electrically conductive material, said member being configured and arranged to increase the thickness of the bight section where said bight section is adapted to engage a bearing surface.

15. The device of claim 14 wherein said member includes a strap configured to at least partially surround and grippingly engage said elements.

16. The device of claim 14 wherein said member includes a band, and clamping means configured to secure said strap to said bight.

17. The device of claim 16 wherein said strap is configured to engage the surface of the bight and adapted for engagement with a bonding clamp.

10 References Cited UNITED STATES PATENTS 2,918,783 12/1959 Little. 2,943,135 6/1960 Bertling 57-145 XR 2,947,504 8/1960 Ruhlman 57145 XR 3,018,319 1/1962 Quayle 174--79 3,042,745 7/1962 Williams 174-173 3,080,631 3/1963 Ruhlman 57145 XR 3,295,311 1/1967 Butz et al 57-145 3,299,626 l/1967 Payer et a1. 57-145 3,347,980 10/1967 Reese 248-63 XR DONALD E. WATKINS, Primary Examiner US. Cl. X.R. 17479 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,455 ,099 July 15 1969 Tom B. Butz It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 2, "band" should read strap Signed and sealed this 9th day of June 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

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