US2897256A

US2897256A - Line wire support

Info

Publication number: US2897256A
Application number: US601309A
Authority: US
Inventors: Harry L Kitselman; Alvin W Holmes
Original assignee: Indiana Steel & Wire Co I
Current assignee: Indiana Steel & Wire Co I; Indiana Steel & Wire Company Inc
Priority date: 1956-07-31
Filing date: 1956-07-31
Publication date: 1959-07-28
Anticipated expiration: 1976-07-28

Description

July 28, 1959 1.. KITSELMANI ETAL LINE WIRE SUPPORT Filed July 51, 1956 5 SheetsSheet l Wall 1E5,

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LINE WIRE SUPPORT Filed July 31, 1956 5 Sheets-Sheet 3 HRRRI ITSELMIN y Fm; 716' hoL/ ss,

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United States Patent C LINE WIRE SUPPORT Harry L. Kitselman and Alvin W. Holmes, Muncie, Ind., assignors to Indiana Steel & Wire Company, Inc.,

Muncie, Ind., a corporation of Indiana Application July 31, 1956, Serial No. 601,309

8 Claims. (Cl. '174173) This invention relates to overhead electrical lines such as telephone and like lines, and more particularly to ties for use in securing an overhead conductor to its supports.

.had provisions which, by engagement with the insulator,

tend to locate the reinforcement axially of the conductor. This method of supporting an overhead conductor has several disadvantages. Frequently, the tie wire or strap employed to secure the reinforcement and conductor to the insulator abrades the surface of the conductor at its points of contact therewith. Again, the operations of applying the reinforcement to the conductor and then securing the assembly to the insulator must both be performed under unfavorable conditions at the pole-top; and once the reinforcement is applied to the conductor its grip thereon is so firm that it cannot be adjusted therealong if such adjustment should be necessary to bring its insulator-engaging provisions into proper relation with the insulator.

It is an object of this invention to produce a conductor support and reinforcing means which will overcome the above noted disadvantages of means heretofore employed for the same purpose. Another object of the invention is to produce a combined reinforcement and insulator or other support which can be preassembled as a unit prior to the application of the reinforcement to the conductor. Further objects include facilitating the operation of resagging of the line and inspecting the connection of the reinforcement to the insulator or other support.

In carrying out the invention, we employ as a reinforcement a length of hard wire formed at its midpoint to adapt it for application to a support which, if the line and reinforcement are bare, will usually be an insulator of one form or another. The end portions of the wire are formed into a relatively long-pitch helix of the type adapted for manual wrapping around the conductor. The internal diameter of each preformed helix is such that it will-grip the conductor tightly; and preferably, although not necessarily, the two helixes are of opposite hand. If the reinforcement is to be used in association with the conventional pin-mounted, grooved glass insulator, the

imiddle'portion of the wire may be formed to provide two longitudinally spaced, V-shaped ears or other offsets adapted to enter the groove of the insulator and engage the base thereof .to locate the reinforcement longitudinally of the conductor. In any event, the middle portion of the wire will be formed to accommodate itself to its support and to the means employed for securing it to the the support beforeits application to the conductor. When "ice the conductor is strung and subjected to the proper tension, each reinforcement is then applied to the conductor by wrapping its helically formed ends thereabout.

When the reinforcement is to be attached to a conventional pin-mounted, grooved insulator, that portion of the reinforcement lying between the helically formed ends is conveniently formed into a general M-shape the tips of which constitute the V-shaped ears mentioned above, and the reinforcement is secured in position by a tie wire which embraces the insulator within the groove therein and which passes through the offsets out of contact with the line conductor. Most desirably, the overall width of the M-shaped intermediate portion is greater than the Width of the insulator groove and such that when the ears are in contact with the base of the insulator-groove adjacent one of the side walls of the groove the intervening central part of the M-shaped portion will engage the other side wall of the groove. With such an arrangement, the tie wire may pass through the offsets or ears and across the aforesaid central part to seat the reinforcement firmly against the insulator at the three non-linearly arranged points where the ofisets and center part engage the walls of the insulator groove.

In the accompanying drawings which illustrate different embodiments of the invention by way of example:

Fig. 1 is a plan view of a conventional glass insulator and an associated reinforcement;

Fig. 2 is a fragmental view similar to Fig. 1 but on an enlarged scale and with the insulator shown in section on the line 22 of Fig. 3;

Fig. 3 is a side elevation of the structure of Figs. 1 and Fig. 4 is a side elevation of a modified form of reinforcement and support;

Fig. 5 is an endelevation of the structure of Fig. 4;

Fig. 6 is a view similar to Fig. 1 showing a modified, and preferred, arrangement for securing the reinforcement to a grooved insulator;

Fig. 7 is a view similar to Fig. 2, but showing the securing means of Fig. 6;

Fig. 8 is an isometric view of the arrangement of Figs. 6 and 7 with the upper portion of the insulator broken away;

Fig. 9 is an elevational view of the arrangement of Figs. 6 to 8; and

Fig. 10 is a view similar to Figs. 2 and 7 showing still another arrangement of the tie wire.

The tie illustrated in Figs. 1, 2 and 3, is one adapted for use with the common form of pin-mounted insulator 10 having an annular groove 11. The reinforcement is formed, as above indicated, from a length of hard wire and is provided near its midpoint with a pair of laterally spaced, offset portions 12, adapted to enter the groove 11 and seat against the base thereof. Outwardly beyond the offsets 12, each end of the Wire is formed into a longpitch helix 13 adapted for manual application in known manner to a conductor 14 and of such diameter that when so applied it will grip the conductor firmly. The wireportion 15 extending between the two offsets 12 may be substantially straight and may be offset from the common axis of the helical portions 13 if contact between ,it and the conductor is not desired.

In use of the reinforcement shown in Figs. 1, 2 and 3, it is first secured to the insulator 10, conveniently through the medium of a strap of relatively soft wire 17. The strap 17, which may be preliminary bent into a general U-shape as indicated in dotted lines in Fig. 2, is placed in the groove 11 of the insulator, the two legs of the strap are then wrapped around the offset portions 12 for a turn or two, as indicated at 17', and the ends of the strap are then brought around the insulator in the groove 11 and twisted together as indicated at 18. The reinforcement 3 may be applied to the insulator 10 either before or after the latter is applied to its mounting.

With the insulators supported and having the ties attached to them, the conductor 14is strung'and subjected to the desired tension. To secure theconductor at each point of support, it is brought into juxtaposition with the reinforcement, and the helically coiled portions 13 are wrapped about it in known manner.

The offsetting of the reinforcement-portions 12 is su'fiicient in extent to provide clearance between the conductor '14 and the turns 17' of the strap 17, thus eliminating all possibility that the strap will abrade the conductor.

The reinforcement illustrated in Figs. 4 and comprises a straight center portion 26 oifset laterally by a considerable distance from the common axis of its helical end portions 27. This tie is suitable for use with an insulator 28 which is adapted at its upper end for connection to a cross arm 29 of a pole (not shown) and which, in its lower face, has a groove adapted to receive the straight center portion 26 of the tie. A clamp plate '30 and clamp screw 31 serve to retain the central portion of the tie in the groove of the insulator. i

It will be noted from Figs. 2 and 3 that in the arrangement there illustrated the centers of the tie-wire loops 17' are approximately co-linear with the points at which the cars 12 engage the base of the insulator-groove 11. As a result, little resistance is offered to swinging of the reinforcement andthe conductor as a unit about the common axis of such tie-wire loops. Such swinging would involve wear of the tie wire and the reinforcement at points where they interengage and also Wear of the reinforcement at the point where it engages the base ofthe groovewall 11. If such wear is deemed objectionable, the arrangement illustrated in Figs. 6 to 9 may be employed.

In the arrangement shown in Figs. 6 to 9, the reinforcement is formed as before of a length of hard wire having preformed end portions 33 similar in structure and purpose to the end portions 13 in the drawing illustrated in Fig. 3. Intermediate the two helically formed end portions, the intermediate portion of the reinforcement is offset laterally into a general M-shape (Fig. 7) providing axially spaced

cars

34 and 35 in an intervening central part or tongue 36. The reinforcement is so disposed relative to the insulator that the central part 36 engages one of the opposed side walls of the groove 11 near the periphery thereof while the

ears

34 and 35 engage the base of the groove at two points spaced considerably away from that side wall of the groove which is engaged by the central part 36. The intermediate portion of the reinforcement therefore has a three-point support from the insulator and, as long as it is held firmly in contact with the groove-walls at such three points, cannot swing as can the reinforcement arranged as shown in Figs. 1 and 2.

To secure a firm engagement of the reinforcement with the insulator at the three points mentioned above, the means for attaching the reinforcement to the insulator is arranged to act on the reinforcement intermediate its three points of contact with the insulator. As shown in Figs. 7, 8 and 9, the attaching means is in the form of a tie wire which has two

turns

38 and 39 embracing the insulator within the groove ll. One end of the tie wire is located at the back of the insulator, and the wire extends clockwise from such end, forming the turn 38, along the base of the groove 11, crossing over the eat 34 and central part 36, and then passing downwardly through the ear 35 to continue around the insulator and then, as the turn 39, upwardly through the ear 34 and across the central portion 36 and ear 35. Beyond the ear 35 the turn 39 continues to the back of the insulator where its end is twisted together with the other end of the wire to draw the tie wire tight. In this tightening of the tie Wire, the turn 38 thereof is drawn tightly against the center part 36 at the ipoint'indicated by the reference numeral 49 in Fig. 7,

while the other tie wire turn 39 is drawn tightlyagainst such central part at the corresponding point 41 on the opposite side thereof. The two forces applied to the center part 36 at the

points

40 and 41 have a resultant which is located intermediatethe three points of contact of the reinforcement with the insulator and which is directed toward the insulator-axis and somewhat downwardly. Such resultant effort applied to the reinforcement by the tie Wire tends to rock the reinforcement in a counterclockwise direction about its points of contact with the base of the groove 11; but as such rocking is limited by engagement of the center part 36 with the side of the groove, pressure of the tie wire at the

points

40 and 41 has the effect of urging the tips of the

cars

34 and 35 upwardly. As the tie wire is tightened, the tips of the

ears

34 and 35 will rise along the base of the groove 11 until they encounter the upper wall of such groove or, in the construction of Figs. 6 to 9, turns of the tie wire- The arrangement shown in Fig. 10 is the same as that of Figs. 6 to 9 except that the tie wire 45-employed embodies a single turn which overlies the central part 36 of the reinforcementand passes downwardly through both the

ears

34 and 35. The resultant of the forces'applied by the tie wire 45 is essentially the same as that existing in Figs. 6 to 8; but in this instance the-tie wire does'not intervene between the tips of the ears and the upper wall of the groove 11, and such ear tips will therefore be forced against such upper wall.

In the reinforcement used in the arrangements of Figs. 6 to 10, the central part or tongue 36 is definitely formed and positioned with respect to the end portions33 to be out of contactwith the conductor 14. In order to preserve the non-linear disposition of the three points at which the reinforcements of Figs. 6 to 9 engage the insulator it is important that the overall transverse dimension of the M-shaped intermediate portion of the reinforcement be greater than the effective width of theinsulator-groove so asto insure that. when-the tie wire is tightened the intermediate reinforcement ;portionwill occupy an oblique position such as is shown in Fig. 9.

In all forms of the invention illustrated and described, the reinforcement is secured to theinsulator or other support independently of the conductor; and the means employed to interconnect the reinforcement and its support does not engage the conductor, and hence cannot abrade it. Application or removal of the reinforcement to or'from its support requires no deformation of the reinforcement, and the reinforcement may therefore be of uniform hardness throughout. Pre-assembly of the insulator and reinforcement in proper relative position can be aifected and the assembly inspected without need for the services of skilled linemen. With the reinforcement already connected to the insulator or other support, the operation of securing the line requires no more than wrapping the helically formed reinforcement-ends about it. It is not necessary, in resagging a line, to disturb the connection of the reinforcement to its support.

It will be noted that in each of the embodiments illustrated and above described thetwo helical end portions, 13, 27, or 33 of the reinforcement are of opposite hand. This feature not only' facilitates simultaneously manual application of the reinforcement to the'line but also provides a stress-distributionwhich is symmetrical with reference to the center of the reinforcement and its point of attachment to the support.

This application is a continuation-impart of our prior and copending application Serial No. 513,294, filed June 6, 1955, and now abandoned.

We claim as our invention:

1. In combination with a line conductor, means for supporting and securing said conductor at an intermediate point of its length, said means comprising a supporting member, a unitary reinforcement of hard wire having helically formed end portions surrounding said condu t a dv and Po i n hav a PM PPe S E to permit their ready application to or removal from the conductor and a diameter such that they elastically grip the conductor, a pair of axailly spaced offsets intermediate said end portions and between which a portion of the supporting member is received to locate the reinforcement in fixed position axially of itself with respect to the supporting member, that portion of the reinforcement lying between said spaced offsets being displaced far enough from the axis of said end portions to be out of contact with the conductor, and a tie member extending around said supporting member and through said OflSCtS to draw the offsets into engagement with the supporting member, said tie member being free from contact with said conductor.

2. In combination with a support for a line conductor, a unitary reinforcement of hard wire having axially spaced, helically formed end portions of coarse pitch and adapted to be readily wrapped about the line conductor into gripping engagement therewith, an intermediate portion of said reinforcement lying between said spaced end portions being displaced laterally with respect thereto and formed to engage said support at three spaced, non-linearly disposed points, and securing means acting between said support and the reinforcement and engaging the latter intermediately with respect to said three spaced points for drawing the reinforcement into firm contact with the support at all of said points.

3. The invention set forth in claim 2 with the addition that said intermediate portion is formed to provide two longitudinally spaced offsets and an intervening central portion, said two offsets and central portion respectively providing said three points of engagement with the support.

4. The invention set forth in claim 3 with the addition that said support is provided with an annular groove having two walls disposed at an angle to each other, said offsets engaging one of said walls and said central portion engaging the other, said securing means including a wire embracing said support within the groove and passing through said offsets.

5. The invention set forth in claim 3 with the addition that said support is provided with an annular groove having two walls disposed at an angle to each other, said offsets engaging one of said walls and said central portion engaging the other.

6. In combination with a support for a line conductor, said support being provided with an annular groove having a bottom wall and two opposed side walls, a reinforcement of hard wire having axially spaced, helically formed end portions of coarse pitch and adapted to be readily wrapped about the line conductor, an intermediate portion of said reinforcement being formed to provide a pair of offsets engaging said bottom wall at spaced points and an intervening central portion engaging one of said opposed side walls, and a tie wire embracing said support within said groove, passing through said oifsets, and across said central portion to exert on the latter a force holding both the ofisets and the central portion in firm engagement with the groove walls they respectively engage.

7. The invention set forth in claim 6 with the addition that said tie wire embodies two turns about said support, one of said turns passing through one of said offsets and the other turn passing through the other offset.

8. The invention set forth in claim 2 with the addition that said intermediate portion is formed into a general M shape to provide two spaced ears and an intervening tongue, said ears and tongue respectively providing said three points of engagement with the support, the axis of the helically formed end portions of the reinforcement being ofiset from the plane of the ears and tongue to maintain the conductor out of contact with the ears and tongue and also out of contact with the support.

References Cited in the file of this patent UNITED STATES PATENTS 753,446 Swartwout Mar. 1, 1904 878,520 Gerdon Feb. 11, 1908 2,230,611 Collin et a1. Feb. 4, 1941 2,263,728 Gordon et a1. Nov. 25, 1941 2,421,286 Pyle May 27, 1947