US2937226A - Conductor spreader - Google Patents

Description

May 17, 1960 J. KAMINSKI, JR.. ETAI- 2,937,226

CONDUCTOR SPREADER Filed July 12, 1957 l 2 Sheets-Sheet 1 May 17, 1960 J. KAMINSKI, JR., FAL

CONDUCTOR SPREADER 2 Sheets-Sheet 2 Filed July l2, 1957 WWW/MMM United States Patent O CONDUCTOR SPREADER Joseph iJr., Baltimore, Robert L. McCoy, Elli- .cott City,- and Milton G. Nauman, Baltimore, Md., as# As ignors to General Electric Company, a corporation of 'New York Application. July 12, 1957,-Serial No. 671,483

` 2 Claims. (c1. 17e-4o) vThis invention relates to a conductor spreader, and

more particularly, fto a spreader for spreading the con-y ductors of an' electrical line installation which utilizes multiple conductors for each phase of electrical energy.

,`A- satisfactory conductor spreader should meet several requirements. The spreader should be stiff enough to keep the conductors suitably spread apart. However, it should not be too stiff but ,have enough resiliency so that the conductors can move with respect to each other. That is, they should be free to behave as individual conductors without dan-ger, of becoming tangled together..

Another requirement is for the spreaders to be lightweight.. ln order.A to properly safeguard the conductors from .becoming twisted together several spreaders may have to be used between adjacent line poles or tower structures. Therefore, the spreaders should add as little weight to the conductors aspossible.

The-means forV connecting. the spreaders tothe conductorsshould yfirmly clamp the conductors and fspreaders withlow unit pressure. If high unit clamping pressures.

are utilized then the ensuing stress concentrations on the conductors and spreaders will cause them to fail.

Still other desirablecharacteristics of a satisfactory spreader are low cost, ease in fabrication and assembly, and a minimum number of separate parts.

It is an object .ofthis invention toprovide a conductor spreader which meets the above mentioned requirements and characteristics..

In ourinve'ntion the. spreader may comprise 'a ring or strut which is made from resilient stranded material such as -steel cablei The .spreader .is lightweight since the clamping means is made fromv ay lightweight material such a's'aluminum. Since they clamping means is lightweight larger clamping surfaces can be provided than would be possible with heavier materials. Additionally, since theringor strut is made from a hard material such as steelfand the` clamping Vmeans is made from a softer material such as aluminum the spreader can have a low cost and small number of separate parts and be easily fabricated and assembled. For instance, the aluminum clamping means is firmly gripped to the steel cable by compressing the aluminum about the cable and causing the softer aluminum to tlow between the strands of the harder cable.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which we regard as our invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

Figure 1 is a partly broken away top view of one form of our invention; and

Figure 2 is a sectional view taken along the line 2 2 of Figure 1; and

Figure 3 is a perspective view of another form of our invention; and

Figure 4 is an enlarged view of our second form of invention when looking in the direction of arrow 4 of Figure 3.

In Figs. 1 and 2 is illustrated one form of our invention in which the spreader comprises a ring 1 which is made from a hard tiexible stranded material such as steel cable. The ring 1 may have a circular, oval, oblong or other closed shape. The ring 1 is connected to a pair of spaced and generally parallel electrical conductors 2 by a saddle type clamping means.

.The clamping means comprises a saddle element 3, a

keeper element 4, and suitable means for drawing the saddle and keeper together such asa pair of U-bolts 5 and nuts 6 and; lock washers- 7. The back of the keeper 4 and the side edges of the saddle 3 can have a pair of grooves 8 and 9 respectively f ormed therein for seating the bolts 5 and keeping the saddle and keeper from t sliding with respect to eachother. The bolts 5 are arranged to have their curved bridge portions located at the outside of the keeper 4.whereas they threaded ends of the bolts point toward the inside of the spreader. This 'is because the threaded ends of the bolts and the nuts 6 have sharp edges which may be sources of corona. By pointing these parts toward each other and locating them between the twol conductors they are shielded by the yfield of the two conductors.

At least the saddle is made from a lightweight material such as aluminum which is softer than the hard stranded steel cable 1. This is because the saddle 3 is connected to ring 1 by compressing the part 10,011 the underside of keeper 3 about the ring 1 soas vto-cause the softer aluminum to ow between the strands of the harder steel cable 1. In this manner the saddle is'very firmly gripped toy the. ring 1. This is an interlocked .compression type connection 'since pressure is used and ow of the alumiparts. Because of this very firm bond the ring 1 does.,

not have. to be woven-as a continuous ring, but it can 'be split with the opposite ends of the ring being tiXed inside part 10. e v

v Since the keeper 3 is made from lightweight material such as aluminum it can bemade larger than the keepers of conventional saddle type metallic clamps without any increase in weight. This way the clamp canbe provided withlarge clamping surfaces ywhich reduce the unit clamping pressure. Also, the cla-mpvcan then be provided with gradually .curved surfaces and edges which will be less apt to constitute sources of corona. For similar ,reasons the keeper 4 is-preferably also made from a lightweight material such as aluminum. However, since the keeper of saddle type clamps is usuallymuch smaller in volume than the saddle a considerable saving in weight can still be obtained by making only the saddle from aluminum. Since the bolts 5 and nuts 6 likewise do not constitute a major portion of the clamping means it is not necessary `to make these parts from laluminum.

In the Figs. 3 and 4 form of our invention the spreader comprises a strut 11 which is made from a stranded resilient material such as steel cable. Saddle type clamps are used at opposite ends of the strut 11 to connect it to the conductors. Only one end of the spreader has been illustrated since both ends will be similar.

The clamps comprise saddle elements 12 and keeper elements 13. As in the earlier form of the invention the saddles and keepers are elongated and the main body portion of the saddles are concave whereas the keepers are convex.

The saddle 12 is made from a lightweight material such as aluminum and it is connected to the harder steel cable 11 by compression clamping. The saddle has an integral tubular portion 14 which extends generally perpendicular from the concave body portion of the saddle.

3 This tubular extension 14 is fastened to the strut 1l as by crimping so as to cause the aluminum to ow between the strands of cable 11.

On an opposite side of the saddle is formed an integral apertured tab 15 which registers with a similar integral tab 16 formed on the keeper 13. These apertured tabs are for the purpose of drawing the keepers and saddles together as by nut and bolt means.

As in the previous form of the invention the keepers and nut and bolt means do not necessarily have to be made from aluminum. The means for connecting the opposite sides of the saddles and keepers comprise the tubular extension 14 and an integral apertured right angle tab 17 formed on the keeper. We prefer to give the outer surface of the extension 14 and the aperture in tab 17 a square configuration so as to help keep the saddles and keepers parallel with each other. However, other configurations such as rectangular, triangular or hexagonal ones will accomplish the same purpose. The tabs 17 will have to be slipped on the extension 1-4 before they are compressed around cable 1. This means that keepers 13 cannot be removed from the strut. However, this -is an advantage since it reduces the number of loose parts. Of course, the aperture in tab 17 should be made slightly larger than the extension 14 so that the keeper and saddle can be opened up to enable the conductors to be slipped between the tabs 15 and 16. If so desired the keeper could be turned around with respect to the saddle and bolted on the inside between the conductors. This change in position would place the apertured tab 17 on the outside and permit detaching the keeper from the saddle.

Although stranded steel cables and aluminum clamps have been used in the illustrated forms of the invention other materials can be used in the practice of our invention. For instance, the saddles could be constructed from other lightweight metals or electrical insulating materials which can be compressed about and caused to ow between the strands of the cable. Additionally, these lightweight metals or non-metals could be caused to ow between the strands of the cable by molding or casting the saddles about the cable. However, using molding or casting methods would be more difficult to practice in the tield or at the service shop since these methods may require rather expensive equipment as contrasted to a compression tool for compressing the saddles on the cables.

Furthermore, spreaders other than those made out of stranded steel cable could be used with our invention. That is, other metallic or nonmetallic resilient spreaders could be used. A stranded cable is successful since a plurality of interstices are defined by the strands into which the material of the saddles can ilow. However, interstices could be provided in other ways. For instance, the spreader could be solid and have interstices provided by barbs, teeth, threads, indentations, depressions or other equivalent means. Additionally, these interstices could be formed in the saddle and the material of the spreader could be the one caused to flow. However, We prefer to cause the material of the saddle to flow into the material of the spreader since this may be easier to do with a hand compression tool and will be less apt to weaken the spreader at its area of connection to the saddles. For this reason we prefer to make the saddle from a material which is softer than the material of the spreader.

While there have been shown and described particular embodiments of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and therefore it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A conductor spreader comprising an elongated piece of stranded steel cable and a pair of aluminum conductor clamps connected to opposite ends of said cable, said clamps comprising elongated and superposed saddle and keeper elements and means for drawing said elements together about an electrical conductor, said clamps extending generally at right angles to said cable, and said saddle elements being connected to said cable by the disposition of the aluminum of integral portions of said saddle elements between the strands of said cable, each said saddle elements comprising a concave body portion and said integral portion thereof comprising a tubular member which extends generally normal to said concave body portion and from a side thereof, and said tubular member and body portion being disposed in the same general plane.

2. In a conductor spreader as in claim 1, wherein each keeper element comprises a convex body portion, said convex body portion having connection means along its opposite sides, and the connection means of each keeper element being connected to the tubular member and other side of its respective saddle element.

References Cited in the le of this patent UNITED STATES PATENTS 1,668,346 Varney May l, 1928 `1,959,402 Anderson May 22, 1934 2,294,398 Ferguson Sept, l, 1942 2,425,764 Tenney Aug. 19, 1947 2,692,376 Van Dusen Oct. 19, 1954 2,699,462 Exner Jan. l1, 1955 FOREIGN PATENTS 730,579 Great Britain May 25, 1955 739,796 Great Britain Nov. 2, 1955

Images