US3706436A

US3706436A - Conductor clamp with means for anchoring a conductor stringing assembly thereto

Info

Publication number: US3706436A
Application number: US155757A
Authority: US
Inventors: L E Lindsey
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-23
Filing date: 1971-06-23
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19

Abstract

A conductor clamp for pivoting support on the outer end of a power line insulator and including means for anchoring a conductor stringing assembly aligned with the clamp seating channel until the conductor has been seated in the clamp.

Description

United States Patent Lindsey 1 1 Dec. 19, 1972 [54] CONDUCTOR CLAMP WITH MEANS [56] ReferencesCited FOR ANCHORING A CONDUCTOR STRINGING ASSEMBLY THERETO UN'TED STATES PATENTS l,630,423 5/1927 Gothberg ..l74/l69 X [72] lnvemor- 11: 222 Pasadena 3,274,654 9/1966 Becker ..24/l25 K a l [22] Filed June 23 1971 FOREIGN PATENTS OR APPLICATIONS [zlj Appl No 155 757 20l,l5l l2/l958 Austria ..l7'4/4()R I Primary Examiner-Laramie E. Askin R I t d U.S. A l t D ta r e a e pp Ion a Attorney--W. D. Sellers et al. [62] Division of Ser. No. 845.960, July 30, 1969, Pat. No.

3,640,504. [57] ABSTRACT [52] U S C 248/63 24/125 K 174/169 A conductor clamp for pivoting support on the outer 51 I .t .Cl F16. 3100 A 7/00 end of a power line insulator and including means for 1 i 169 243125 E 135 anchoring a conductor stringing assembly aligned with R, 24/135 K; 248/63; 254/l34.3 R. 134.3 PA

the clamp seating channel until the conductor has been seated in the clamp.

5 Claims, 7 Drawing Figures PA'TEN-TEI] DEC 19 I972 sum 2 or 1 INVENTOR 4. 6. 4/A/056V PATENTEDnEc 19 1922 SHEET 3 BF 4 III INVENT OR w y w m w r N r a A a PATENTEU I97? 3, 706, 436

sum u 4 INVENTOR u/vp CONDUCTOR CLAMP WITH MEANS FOR ANCHORINGA CONDUCTOR STRINGING ASSEMBLY THERETO This application is a division of my copending application for United States Letters Patent Ser. No. 845,960, filed July 30, 1969 now US. Pat. No. 3,640,504.

This invention relates to power line conductor stringing facilities and more particularly to an improved method and apparatus designed to be mounted temporarily on the outer end of the insulator while supporting the conductor free of but ready to gravitate into the seating channel of a clamping unit.

The installation of long heavy power conductors to the free ends of insulators supported by power line poles, towersor the like presents many problems for which there have been numerous proposals. Resort has been had to many expedients for pulling the conductor lengthwise of the power line while supporting it close to the free end of the insulator. Thereafter the heavy and properly tensioned conductor must be transferred into the clamping means and secured in place. This can be anarduous and hazardous task using stringing equipment and procedures previously proposed.

To avoid the risks and the numerous disadvantages characterizing previous stringing operations there is provided by this invention a simple stringing block assembly and a companion conductor clamping unit designed to be supported in superimposed relationship directly on the outer end of a power line insulator. The clamping unit is secured to the insulator in conventional manner and a stringing block assembly is con toured to interlock with structural features of the conductor clamping unit with the conductor stringing passage of the block located above and in general alignment with the seating channel in the clamping unit. The conductor is then pulled along the power line through the similarly-equipped insulator at each pole or tower following which the conductor supporting rollers extending crosswise of the opposite ends of the stringing units are released allowing the conductor to drop into the seating channel. The release of simple latch means then frees the stringing block for removal after which the conductor clamping jaw is tightened against th conductor.

The stringing block is designed to hold the conductor in alignment with the clamp seating channel despite curves in the power line and irrespective of the direction or degree of curvature. To this end the stringing block is provided with a pair of heavy duty lateral restraint rollers at its opposite ends, the rollers additionally cooperating to hold the conductor straight throughout the length of the seating channel to facilitate transfer of the conductor into the channel. In the interests of minimum weight and cost, these roller guides are restricted to one side of the stringing block which is designed to be supported on the insulator with the guide rollers on that side of the line toward which the conductor curves.

Accordingly it is a primary object of this invention to provide a conductor clamp for use in securing a power line conductor to an insulator and designed for interlocking assembly to a conductor stringing unit while the conductor is being pulled into place along a power line.

Another object of the invention is the provision of an improved conductor clamp having means integral therewith for holding a conductor stringing unit properly aligned with the conductor seat in the clamp until the conductor is transfered into the clamp seat.

Another object of the invention is the provision of a conductor clamping unit securable to the outer end of an insulator and designed to interlock with a suitably designed cooperating stringing block assembly.

These and other more specific objects will appear upon reading the following specificationv and claims and upon considering in connection therewith the attached drawing to which they relate.

' Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

- FIG. 1 is a top plan view of a preferred embodiment of the invention stringingblock assembly attached to an open conductor clamping unit; 7 FIG. 2 is a side elevational view on an enlarged scale taken from the lower side of FIG. 1 and showing portions broken away;

FIGS. 3, 4 and 5 are fragmentary cross-sectional views taken along lines 3-3, 4-4 and 5-5 on FIG. 2;

FIG. 6 is a transverse vertical sectional view through the conductor clamping unit at its mid-length and showing the clamping jaw in assembled position; and

FIG. 7 is an exploded view in perspective of the cable clamping unit per se.

The invention conductor stringing block assembly, designated generally 10, is designed for usein stringing a single power conductor while the assembly is supported directly on the outer end of the insulator to which the conductor is to be secured. Assembly 10 is particularly suitable for use with rigidly supported insulators of either the upright or horizontal type, a fragmentary view of the outer free end 11 of the latter type being generally indicated in dot-and-dash lines in FIG. 3. If of the horizontal type, there is fixed to the outer end of insulator 11 a U-shaped bracket 12 well known to workers in this field. The inner cap end of such bracket is provided with an integral trunnion-like stud 13 aligned with the similarly-sized end 14 of a cap screw 15 mounted in the outer leg of bracket 12.

Pivotally supported between stud 13 and cap screw 14 is a conductor clamping unit, designated generally 16. This clamping unit has certain novel features but is otherwise generally similar to conductor clamping units well known in the power line art. If insulator 11 is of the upright type, then the bight portion of bracket 12 extends crosswise of the upper end of the insulator with the bracket legs projecting upwardly from the rim portions of the mounting cap so as to support the clamping unit 16 crosswise of the insulator end.

An understanding of the unique features of clamping unit 16 will facilitate an understanding of the stringing block assembly. It will be understood that one lateral sidewall of conductor seating channel 17 is provided with a pair of horizontally projecting

legs

18,18 there being one lug at either end of unit 16 each provided with a vertical opening 19. Each of these holes seats the lower end 38 of a shaft 36 fixed to and projecting downwardly from the main frame 26 of the stringing block assembly 10, as will be described in greater detail presently. Another special feature of clamping unit 16 is best shown in FIG. 2 and comprises an integral lug or The conductor clamping unit 16 is pivotally supported transversely of its mid-length on trunnions carried by the insulator end cap bracket 12, these trunnions comprising thestud 13 and the end 14 of cap screw 15. These trunnions extend into wells 13d (FIGS. 3,7) and 14a (FIG. 3) respectively opening outwardly from the outer ends of bosses 13b and 14b (FIG. 7) cast integral with and projecting laterally from the opposite sides of the main body of the clamping unit. The latch detent 20 referred to above is cast integral with and projects laterally from oneside of boss 14b. As clearly appears from FIGS. 3, 4 and 6, the conductor seating channel 17 is, of U-shape in cross section and has a depth substantially greater than the radius of the conductor 32 to be clamped therein. The generally upright upper portions of its sidewalls, and particularly the sidewall 17a, safeguards against the possibility of the tension in theconductor acting to pull or roll the conpower line which pullouts might otherwise occur. This likelihood is especially apt to occur where the curvein the line coincides with a rise in the terrain to one or both sides of the. clamping unit. The depth of channel 17 will therefore be understood as providing an important margin of safety for workmen required to be present while transferring a conductor into channel 17 and while assembling and tightening clamping jaw 63.

Stringing block assembly has a mainframe'26 formed by two castings 26a,26b secured together at their opposite ends by bolts 27 (FIGS. 1 and. 4). Castings 26a,26b are made of high-strength lightweight alloy with the metal distributed for maximum strength and minimum weight.. The two castings 26a,26b support upper and lower pairs of transverse rollers 30a,30b and "31a,31b best shown in-FIG. 2. Upperrollers 30a,30bfunction primarily as retainer rollers whereas the larger heavier duty rollers 3la,3lb carry the principal weight of the conductor 32. In addition there are two pairs of vertically disposed rollers journalled in the opposite ends of main frame 26, best shown in FIG. 1, namely, rollers 33a,33b and the relatively larger and heavier-duty rollers 34a,34b. The described four pairs of rollers cooperate in forming a stringing tunnel through which conductor 32 extends while being pulled into its installed position along the power line. As is made clear by FIGS. 2 through 5, conductor 32 is supported above and in general alignment with seating channel 17 of clamping unit 16 and is maintained in this elevated position until pulled into its fully installed position and properly tensioned.

Thereafter it is released and allowed to gravitate into seating channel 17 in a manner to be described presently. As is made clear by FIGS. 4 and 5, all rollers preferably include anti-friction bearing supports carried by shafts mounted in frame members 26a,26b.

. 4 Referring to FIG. 4, it is pointedout that the heavy duty rollers 34a are mounted on shafts 36secured to frame-26a by set screw 37. The reduced lower end portion 38 of each shaft projects downwardly beyond the adjacent portion of frame 260 and is sized and positioned to seat in one of theopenings 19 formed in a lug 18 projecting from one lateral side wallof the conductor clamping unit 16.

- ductor out of the seating channel 17 along curves .in the I Certain of these shafts are of special construction as will now be described;

Referring now to FIG. 5 itwill recognized that the lower transverse pair of rollers 3 1a,31b are mounted on shafts 40 having one end 'pivotaliy secured to main frame member 26b by a pivot pin 41. Rollers 31a are held in position on shaft 40 by

split ring keepers

43,43 seating in retainer grooves 44. The .left, hand end of shaft 40, viewed in FIG. 5, is flattened at 46 to provide an engaging surface for latch 47 carried by an operating lever 48 pivoted to main frame 26a by pin 50. Latch lever 48 is normally biased to latching position by means including a pin 51 loosely and slidably supported in the bore 52 of a tubular shaft 53 supporting the upper transverse rollers 30a,30b. Pin 51 is urged outwardly against latch lever 48 by compression spring 54.

It is pointed out that the opposite ends of shaft 40 supporting the lower transverse rollers 31,3lb project into downwardly opening

U-shaped channels

56, 57 respectively, permitting the shaft to swing through a arc in a vertical plane. The normal conductor supporting position of the rollers 31a is shown in fulllines in FIG. 5, whereas the release position of these rollers in which the conductor is allowed to drop into seating channel 17 is indicatedby the dot-and-dash lines in this same Figure.

Referring to FIGS. 3 and6, it is pointed out that the conductorseating unit 16 is provided with a threaded bore 60 for a cap screw 61. This cap screw extends downwardly through a flaring. bore, 62 formed in the conductor clamping jaw 63. This jaw includes a pair of lugs 64 positioned to either side of cap screw 61 and adapted to extend downwardly into a pair of notches 65,65 (FIG-1) openinglaterally outwardly from one sidewall of conductor seating unit 16. When the stringing block is mounted on the channel seating unit, clamping jaw 63 is detached, inverted-and held captive on the upper edge of frame member 26b inthe manner illustrated in FIGS. 1 and 2. For this purpose the upper edge of the frame is provided with a threaded bore 67 to receive cap screw 61. In this manner, the clamping jaw 63 is held captive in the vicinity of the insulator and its seating unit 16. After the conductor has been strung OPERATION The mode of utilizing the described stringing block assembly will be .quite evident from the foregoing detailed description of its components and their relationship to one another. Before installing stringing block assembly 10 on seating unit 16, clamping jaw 63 is removed and mounted along the top edge of the stringing block in the manner described above and illustrated in FIGS. 1 and 2. The assembly of the stringing block to seating unit l6.is then accomplished merely by lowering assembly over the seating unit with locator pins 38 (FIG. 4) aligned with a respective one of openings 19 in lugs 18. As this operation is performed the cammed nose 70 of

latch

21,22 cams over the similarly shaped upright edge of detent lug (FIG. 2) until'latch 21 seats beneath lug 20 under the urging of torsion spring 72 (FIG. 2). This spring is quite stiff and firmly holds

latch

21,22 engaged beneath lug 20 thereby locking the stringing assembly 10 to seating unit 16.

If the particular insulator on which the stringing assembly is to be mounted is located at a curve in the power line, then it is desirable and important that the heavy duty vertical pair of rollers 34a,34b be located on the inside of the curve as shown in FIG. 1. This is accomplished by making certain that lugs 18 on conductor seating unit 16 project from the inner side of the curve. To permit this, seating unit 16 is designed for support in the insulator mounting bracket 12 with its lugs 18 facing in either lateral direction, and accomplished by rotating unit 16 through 180 in a horizontal plane, if necessary, for lugs 18 to face in the desired direction. Stringing block assembly 10 is then similarly rotated, if necessary, to have locator pins 38 positioned to seat in openings 19 of lugs 18.

The hauling line for the conductor to be installed is attached to the advance end of conductor 32 and passed in succession through the stringing tunnels of stringing blocks 10 mounted on each insulator along the power line. The lead end of this line is attached to suitable winch equipment and used to haul the line and the attached conductor into place. Throughout this operation both the haul line and the conductor itself is supported on the lower transverse pair of rollers 3la,3lb with some lateral support being provided by upright pairs of rollers 33a,33b 34a,34b. Along straight sections of thepower line these rollers carry no particular load. However, along curved portions of the line, rollers 34a,34b are under very considerable stress and for this reason are of substantially heavier construction and are so positioned as to support the conductor in proper position for transfer into seating channel 17 at the end of the stringing operation. The manner in which this is accomplished is best illustrated in FIG. 1.

Lowering the strung and properly tensioned cable into the seating channel is accomplished readily and without tools by an operator climbing the pole and releasing

latches

48,48. Desirably this is done in succession allowing the associated one of the lower rollers 31a,31b to pivot downwardly about pins 41 and allowing the conductor to gravitate into channel 17. This operation opens the lower side of the stringing tunnel through assembly 10 thereby permitting the assembly to be detached from the conductor clamping unit 16 merely by lifting it upwardly while holding latch lever 22 pivoted to its unlatched position. Clamping jaw 63 is then removed from its captive position on assembly 10, inverted and secured in place over the conductor. The stringing assembly is now lowered to the ground and is available for further stringing operations.

While the particular conductor clamp with means for anchoring a conductor. stringing assembly thereto herein shown and disclosed in detail is fully capable of merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the detail of construction or design herein shown other than as defined in the appended claims.

I claim:

1. A conductor clamping unit adapted to be mounted on the outer end of a rigidly supported power line insulator, said clamping unit having an elongated horizontally-disposed main body formed lengthwise thereof with an upwardly opening conductor seating channel having a depth substantially greater than the radius of the conductor to be clamped therein, boss means projecting laterally from the opposite sides of the midportion of said main body having aligned wells in the outer ends thereof for pivotally securing said main body to the outer end of an insulator with said conductor seating channel facing upwardly and unobstructed to receive and seat a conductor in said channel, means carried by said main body outwardly of said conductor seating channel arranged to cooperate with juxtaposed portions of a conductor stringing unit to hold the latter firmly assembled there to with said conductor seating channel parallel to and positioned to receive a conductor from said stringing unit, conductor clamping jaw means extending across the mid portion of said conductor seating channel rigidly clampable thereacross by fastener means located adjacent the mid portion of said main body and functioning independently of stringing unit holding means.-

2. A conductor clamping unit as defined in claim 1 characterized in that said clamping jaw means is of inverted J-shape having a stem portion slotted upwardly from the lower end thereof and sized to straddle said boss means, and said fastener means comprising a cap screw seated in a threaded bore formed in said boss means.

3. A conductor clamping unit for power line conductors and designed to serve as a support for a conductor stringing block prior to use to clamp a conductor therein, said clamping unit having an elongated main body of generally U-shape in cross section to provide a deep conductor seating channel therealong and opening through the opposite ends thereof, said channel being substantially deeper throughout its length than the radius of the conductor to be seated therein to safeguard against the escape of a conductor being installed therein along curved sections of a power line, said channel opening upwardly and having lug means projecting from the lateral sides thereof sized and shaped to seat an accurately located conductor stringing block means above said main body and in position to release a strung conductor by gravity into said conductor seating channel, aligned boss means projecting laterally beyond the lower opposite sides of the mid portion of said main body having aligned wells in their outer ends adapted to seat trunnion supports of a conductor clamp support bracket embracing and confined to the underside of said clamping unit thereby leaving the area overlying the clamping unit unobstructed while stringing a conductor along the upper side of said seating channel, and clamping jaw means attached to said main body and adapted to be secured in place crosswise of the mid length of the upper portion of said conductor seating channel and including fastener means therefor securable to said main body independently of said lug means.

l060l l 0207 5.;A conductor clamping unit as defined in clairn 3 characterized in that said-clamping jaw' means includes a pair of lugs extending downwardly and straddling one of said boss means used to pivotally support said clamping unit.

I I I III

Claims

1. A conductor clamping unit adapted to be mounted on the outer end of a rigidly supported power line insulator, said clamping unit having an elongated horizontally-disposed main body formed lengthwise thereof with an upwardly opening conductor seating channel having a depth substantially greater than the radius of the conductor to be clamped therein, boss means projecting laterally from the opposite sides of the midportion of said main body having aligned wells in the outer ends thereof for pivotally securing said main body to the outer end of an insulator with said conductor seating channel facing upwardly and unobstructed to receive and seat a conductor in said channel, means carried by said main body outwardly of said conductor seating channel arranged to cooperate with juxtaposed portions of a conductor stringing unit to hold the latter firmly assembled there to with said conductor seating channel parallel to and positioned to receive a conductor from said stringing unit, conductor clamping jaw means extending across the mid portion of said conductor seating channel rigidly clampable thereacross by fastener means located adjacent the mid portion of said main body and functioning independently of stringing unit holding means.

4. A conductor clamping unit as defined in claim 3 characterized in that at least one of said aligned boss means includes latch detent means adapted to interlock with assembly latch means of a conductor stringing block unit to hold the latter detachably in place on said main body while a conductor is being strung.

5. A conductor clamping unit as defined in claim 3 characterized in that said clamping jaw means includes a pair of lugs extending downwardly and straddling one of said boss means used to pivotally support said clamping unit.