US2757224A - Transposition bracket - Google Patents

Description

United States Patent O TRANSPOSITION BRACKET Winford G. Milne and Frederick G. Ridgers, Hamilton,

Ontario, Canada, assignors to N. Slater Company Limited, Hamilton, Ontario, Canada Application November 7, 1952, Serial N 0. 319,217

2 Claims. (Cl. 174-33) This invention relates to a transposition bracket.

As is known, a transposition bracket is used where one conductor of a line has to cross over the other conductor of the line. Each conductor thus subtends two angles at the transposition bracket. Whether the bracket is at a cross arm or at mid-span, the tension in each of the conductors causes a resultant bending moment on the pin supporting the insulator to which the conductor is attached.

Thus, the insulator-supporting pins of one pair of insulators (say on one side of the cross arm), tend to bend one toward the other; likewise, the insulator-supporting pins of the other pair of insulators (on the other side of the cross arm) tend to bend one toward the other.

As a conductor sometimes bodily moves longitudinally, it is desirable that the insulators, if of the pin type, which support the conductors should be free to rotate on their supporting pins; otherwise, one insulator screws itself tightly on its pin, while the other insulator unscrews itself, a condition which may cause failure.

The objects of the invention, therefore, are to improve on known transposition brackets.

Being filed concurrently herewith is another application in which is disclosed another form of transposition bracket which also constitutes an improvement on known brackets.

A specific object is to provide a transposition bracket in which pairs of insulator supports are connected together, respectively, the insulator-supporting pins of each pair which tend to bend one toward the other being, in effect, rigidly connected one to the other.

Another specific object is to provide a transposition bracket in which the pairs of insulator supports are, in effect, connected together by composite structures comprising a compression member and a tension member.

Another specific object is to provide a light, simple but sturdy transposition bracket.

Still another specific object is to provide a transposition bracket in which the insulators, in the form of spools, are freely rotatably supported.

Still another specific object is to provide a transposition bracket having a relatively few number of separate components, one of which may be cast.

In the drawing, wherein like numerals of reference indicate corresponding parts in the various figures,

Figure 1 is a plan view of a transposition bracket made according to this invention;

Figure 2 is a side elevation of Figure 1; and,

Figure 3 is an end view of Figure 1, as seen from right to left in Figure 1.

Referring now by numerals to the drawings, the bracket, designated as 10, is shown as secured to a cross arm M as by bolts N.

The bracket proper assumes generally the form of a rectangular four-sided member, as seen in plan, presenting two parallel channels 11 and 11A adapted to rest upon the cross arm M, that is, when the bracket is associated with a cross arm and not suspended at mid-span, and two ice parallel channels or members 12, corner perforated or tubular bosses 13 cast integrally with the channels completing the bracket proper.

The bosses 13 extend below the adjacent ends of the channels. The upper faces of the bosses serve effectively to support the insulators, shown as spool insulators and designated by the reference characters A, B, C, and D.

The channel 11A is so formed, as seen in elevation, that its associated bosses are vertically offset one relatively to the other; that is, one boss of the channel, say the right hand boss, as best seen in Figure 2, is at a higher level than that of the other boss, so that the insulator A lies at a higher level than the insulator C. Similarly, the channel or member 11 is so formed that its associated bosses are at different levels, so that (again as best seen in Figure 2) the insulators D and B are at different levels. The arrangement is such that the insulators D and A on the one hand, and the insulators C and B on the other hand, are at a same level.

The insulators D and C are rotatably mounted on their respective bosses by a skewed or distorted U-shaped member 14. The parallel vertical legs 15 of the member pass through the tubular bosses associated with the channel 12 and serve as journals around which the insulators may freely rotate.

The insulators are held in operative position as by washers 16 and cotter pins 17 passed through the vertical legs of the U-shaped member 14 adjacent their upper ends.

The U-shaped member 14 is thus suspended from the insulators D and C.

The other two insulators A and B are likewise journalled on a skewed U-shaped member 14A suspended from the insulators in the manner of the U-shaped member 14.

When the bracket is used as a mid-span bracket the channels 11 and 11A each merely connect a low-level boss with a high-level boss, and not being supported by a cross arm obviously these channels may be of any desired shape as seen in elevation, and moreover they may be of uniform dimensions (not shown) throughout their length.

The tension in the wires attached to the insulators D and C imposes a thrust or force tending to displace the insulators one toward the other, and thereby to bend or distort the channel 12. However, the transverse leg of the U-shaped member 14 now comes into play, acting in tension to prevent distortion of the ends of the channel. In effect, there is provided a composite structure wherein the channel 12 acts as a compression member and the transverse member acts as a tension member. The other U-shaped member 14A, associated with the other two insulators A and B, likewise performs the same function.

We claim:

1. In a transposition bracket, the combination of a rigid frame including a rigid member having upright end tubular bosses on which a pair of insulators are adapted to be supported, and a removable U-shaped member the two parallel legs of which are adapted to be inserted upwardly through said bosses to provide journals for the pair of insulators, said bosses being so formed and so disposed relatively to said rigid member that said rigid member and the transverse leg of said U-shaped member are spaced one from the other when said rigid member and said U-shaped member are operatively assembled, thereby providing tension and compression members, respectively, tending to resist displacement of the upper ends of said parallel legs one toward the other.

2. In combination, a rigid frame including an integral channel member having end apertured bosses extending below the adjacent ends of said rigid member, a U-shaped member the two parallel legs of which extend upwardly through said bosses, spool insulators effectively supported by said bosses and journalled on said parallel legs, and

means throughLsaid parallel legs above said spools sup- References Cited in the file of this patent porting said .U-shaped'member by said spools, the trans UNrrElTSTKTESTATENTS" verse leg of said U-shaped member and said channel member providing tension and compression members, re-

spectively, tending to resist displacement of said spools-" 5 onetoward'the other as urged bythe two wires'supported' thereby.

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