US2868865A - Shunt for power line clamps - Google Patents

Description

Jan. I13, 1959 N. l... ILSSON ET AL 2,858,865

SHUNT FOR POWER LINE CLAMPS Filed Aug. 8, 1955 -Hornegs sHUNr ron rowsn LINE CLAMrs Nils L. Nilsson and `Samuel. J. Spurgeon, Birmingham,

Ala., assignors to Anderson Brass Works, a corporation of Alabama Application August 8 1955, Serial No. 526,891

2 Claims. (Cl. 174-140) Our invention relates to means providing continuously a low conductivity current path across-the connections of power line clamps and the like.

in present day electrical transmission and distribution systems the problem of radio and television interference due to the electrical discharge phenomena of the system is acute. For a discussion of this problem in general and for a discussion of some of its specific phases see an article entitled Solution to TV1 Problems on pages 74 to 77, inclusive, of the February 1954 issue of Electric Light and Power. It is recognized that a major source of such interference lies in loose joints in swinging line supporting clamps. Specifically, in the type of line clamp having a clevis and pin type of swinging or loose joint, the interference produced is unusually high. Apparently, the older and more corroded are such joints the greater is the Value of the resistance to ilow of current and hence greater interference is produced upon discharge across such joint. Various attempts have been made to solve the problem, but these have consisted essentially in attempting to maintain closer tolerances in the joint parts, putting the joints under additional pressure, and bypassing one of the clamp suspension joints, and so forth. Insofar as we are aware there has heretofore been no satisfactory way of eiectively eliminating such discharge across the joints of line clamps and the like.

In view of the foregoing the prime object of our invention is to provide an electrical connection between the loose or pivotally connected parts of a line clamp, thereby preventing arcing across the joints of the clamp and eliminating radio and television interference from this source.

A more specific object of our invention is to provide in combination with the parts of a loose joint line clamp, an electrical connection between these parts which in nowise aifects the swinging supporting action of the clamp and yet which provides a continuous low resistance path for the flow of current across such joints, eliminating arcing across the joints.

Another specific object of the invention is to provide means to shunt across the loose joints, which means cornprises essentially a ilexible conductor in the form of a thin strip, one end of which is electrically connected to the body of the clamp and the other end of which is connected to the supporting portion in such manner as to permit the portions to pivot relative to each other and in such manner as to assure good electrical connection between the two parts.

A device illustrating the features of our invention is shown in the accompanying drawings forming a part of this application in which:

Fig. 1 is a side elevational view of a typical form of swinging line clamp, partly broken away and in section, and showing our improved by-pass shunt in place thereon;

Fig. 2 is a detail sectional view taken generally along line II-Il of Fig. l; and,

Fig. 3 is an isometric view of our improved by-pass shunt removed from the clamp.

States Patent Mice ` Referring now to the drawings for a better understanding of our invention we show in Figs. l and 2 a typical form of swinging line clamp with which ourinvention may be advantageously associated. However, it will be seen that it also may 'be associated with other types of suchdevice, for instance, the clevis type. As shown, the clamp comprises the line supporting portion proper indicated generally by the numeral 1li. The conductor C is adapted to, lie in a groove in the portion 10. On top of the conductor is placed the clamping member 11. U- bolts 12 pass over the clamping member 11. When `nuts 13 on the lower ends thereof are run up, the U-bolts draw the member onto the top of conductor C, Ithus securing the latter rigidly in the body of the clamp.

The clamp is supported from an upper portion indicated generally by the numeral 14. The member 14 is connected to the body member 1t) by means of a pin 16. In'the upper end of the portion 14 is a recess 17 to receive the lower headed end 18a of a rod 18 which depends ordinarily from an insulator, not shown, in the manner Well understood. The conductor C thus is `mounted rigidly in the clamp and the clamp is free to pivot about the pin 16 and to a limited extent about the rounded head 13a of the rod 1S.

Our invention consists essentially of the by-pass shunt member indicated generally by the numeral 19. The member 19 preferably is made of a strip of metal which does not produce excessive corrosion due to galvanic action when placed in contact with the parts of the device. Further it is long enough and resilient enough to bend readily without interfering with the pivotal movement of the clamp relative to its supporting means. The member 19 may be provided at one end with a U-shaped seat 21 which is adapted to be engaged under one of the U-bolts 12, preferably the U-bolt on the opposite end of the clamp from which the upper end of the member 19 enters the portion 1d as will appear. The upper end of the by-pass shunt 19 may comprise generally a flat section 22 with a hook-like portion 22a on its end.

Our improved by-pass shunt may be applied to a clamp of the type shown by inserting the U-shaped end 21 under one of the U-bolts 12 prior to drawing down on the nuts 13 thereof. The member 11 may be provided with a notch 11a to receive the end 21 of the shunt. The other end may be inserted under the lowermost leg 23a of a spring type clip indicated generally by the numeral 23 and which is inserted between the bottom of the opening 17 and the lower. part ot the head 18a of the pin 13. The lower leg 23a of the clip 23 engages in the hook portion 22a so as to prevent the upper end 22 of the member 19 from being withdrawn. Therefore, it will be readily apparent that when in place the by-pass shunt 19 eiiectively electrically connects the two portions 10 and 14 of the clamp. Further, when in place the member 19 is rigidly positioned and does not interfere with the normal functioning of the swinging clamp.

From the foregoing it will be apparent that we have devised an improved by-pass shunt which is especially adapted for use in association with swinging line clamps. Our invention also is particularly adapted for association with those types of line clamps in which the clip 23 is employed. However, it will be apparent that means other than the clip 23 may be employed electrically to connect the upper end 22 of our improved by-pass shunt to the suspension portion 14.

ln actual practice we have found that the use of our by-pass shunt effectively eliminates television and radio interference which is occasioned by the arcing across the loose joints of line clamps.

While we have shown our invention in but one form it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What'we claim is:

1. In combination, a line clamp of the kind having a rst section connected to and suspended from an insulated rod togetherwith a second section pivotally connected to the iirst section by a cross pin, means urging the rod away from said cross pin, said means comprising a spring clip, a length of conducting material having one end engaged between the clip and the rst section of the clamp, a portion of the conducting material connected to said end extending outwardly of the clip and passing between the cross pin and the second section of the clamp, and means electrically connecting the end of said portion of the conducting material to the second section of the clamp at a position thereon laterally removed from the cross pin.

2. A suspended line clamp for a power line comprising a lower body portion having an upwardly opening groove therein for supporting the power line therein, a clamping member extending into said groove and contacting the power line, a U-bolt extending over the clamping member and secured to said body portion for pressing the clamping member against the power line and thereby holding it in secured position, an upper portion pivotally connected to the body portion and having a recess there'- in, a strip of exible conducting material extending between said U-bolt and said upper portion, one end of said strip having a generally U-shaped section tting under said U-bolt and secured thereby, and the other end of said strip extending Within said recess in Contact with the upper portion for electrically connecting the body portion to the upper portion, and means arranged in said recess for securing said other end in contact with the upper portion.

References Cited in the le of this patent UNITED STATES PATENTS 1,170,725 Austin Feb. 8, 1916 2,108,530 Ellis et al. Feb. 15, 1938 2,448,333 Walters Aug. 3l, 1948 2,523,083 Witkowski Aug. 20, 1948 2,576,929 Ercolino Sept. 2, 1949 2,699,462 Exner Jan. ll, 1955 OTHER REFERENCES Radio Interference (Merriman et al.), pub. by The Institute of Radio Engineers, vol. 27, No. 1, January 1939 (page 18).

Images