US2792445A - Transposition bracket - Google Patents

Description

May 14, 1957 F. G. RIDGERS 2,792,445

TRANSPOSITION BRACKET Filed Nov. 16, 1953 Fig. 3

nit ed States PatentO TRANSPOSITION BRACKET Frederick G. Ridgers, Hamilton, Ontario, Canada, assignor to N. Slater Company Limited, Hamilton, ntario, Canada Application November 16, 1953, Serial No. 392,378 8 Claims. (Cl. 174-147) This invention relates to a carrier type transposition bracket.

As is well known, a transposition bracket is used where two wires have to be crossed over, whether at the cross arm or at mid-span.

There are several known communication types of transposition brackets, all of which include a bracket and four separate insulators. The insulators are disposed in a rectangular arrangement, two diagonally opposite insulators being associated with one wire, and the other two being associated with the other wire.

On the other hand, a transposition bracket made according to this invention, includes but two insulators, and a bracket or mount to which the insulators are fastened or assembled.

The objects of the invention, generally, are to provide a novel and improved transposition bracket, and one which is very appreciably less costly to manufacture than any known bracket.

A specific object of the invention is to provide a transposition bracket which includes but two insulators, and a bracket proper or insulator support which is simple to manufacture and requires appreciably less material or metal than is required to make the brackets proper of the known types of transposition brackets.

Another specific object of the invention is to provide a transposition bracket having but two insulators, both assuming the same and exact form; the insulator is thus interchangeable.

Another specific object of the invention is to provide a transposition bracket having but two insulators, both assuming the same and exact form and being so designed that the lateral thrust imposed upon the insulator because of the bend or change in direction which the wire subtends at the insulator, subjects the insulator to compression and not to tension, so that the insulator, which in practice is made of a brittle material, is not apt to break.

Another specific object of the invention is to so design the insulator that it is easily and quickly assembled to the bracket proper or insulator support, and is as easily and quickly disassembled, and remains securely in assembled position.

In the drawing, wherein is shown a transposition bracket made in accordance with this invention, and wherein like numerals of reference indicate corresponding parts of the various figures,

Figure 1 is a plan view, parts being broken away;

Figure 2 is an end view of Figure 1, as seen from right to left, and

Figure 3 is a side elevation of Figure 1.

Referring now by numerals to the drawing, indicates the bracket proper or insulator support, and 11 and 11A the two insulators.

The bracket proper 10 is mounted upon and secured to a conventional cross arm A, as by a conventional bolt (not shown). Two wires, W-W, engaging the opposite ends of the insulators, are crossed over at the transposition bracket. If the transposition bracket is used at 2,792,445 7 Patented May 14, 1957 ice ' 2 mid-span, then obviously the bracket proper 10 is not supported by the cross arm, but is instead suspended from the wires by the engagement of the insulators therewith.

The bracket proper 10, which in practice, is made preferably from a length of steel bar or strap, but may consist of other suitable material, is formed with a middle, substantially U-shaped portion 12 adapted to rest upon the cross arm, and end, oppositely-disposed substantially C-shaped portions 13-13A in which the insulators 11 and 11A, respectively, are seated and embraced.

The portion 13 (and 13A) is defined by parallel lower and upper iixed jaws 16 and 17, respectively, and a vertical abutment piece or web 18. The jaws 16 and 17 are provided with aligned apertures to receive a pin or the like 19 (to be referred to).

The insulators, which are alike and are made of porcelain or other suitable non-conducting material, each comprises a middle portion 20 which may be termed a block portion, in part defined by two parallel upper and lower faces and a rear face 22. The face 22 is adapted to lie along and engage the rear face of the abutment or web 18 aforesaid. Extending laterally from the central or block portion 20 are two opposed wings or limbs 23 and 23A. The wings, the longitudinal median lines of which are indicated as LL, L-L, are directed at an angle to the plane of the rear face 22 of the central portion 20. The extremities of the wings 23 and 23A are formed with grooves 25 and 25A, respectively, adapted to receive the tensioned wires W-W.

The groove is curved laterally (horizontally) so that the segment of the wire engaging a groove lies in a horizontal plane parallel with the plane of the jaws 16 and 17 of the bracket proper 10.

The grooves 25 and 25A are in spaced vertical relationship, that is, the groove 25 is at a higher level than the groove 25A, so that one wire, where it engages one wing of an insulator, is at a higher level than the other wire where it engages the other or opposite wing of the same insulator.

The insulator is formed to present a shallow V-shaped face in part defined by a groove 26 adapted to receive the shank of the pin 19 aforesaid, and retain the insulator in operative position, seated in its associated C-shaped portion of the bracket proper, against substantial bodily lateral displacement and substantial bodily displacement longitudinally, of the length of the bracket proper.

It is proposed to make the insulator and the bracket proper 10 such that each wire, will subtend, at each insulator, an angle of roughly Accordingly, the median line (L-L) of each wing should be directed at an angle of 67 /2 (one-half of 135) to the plane of the rear face 22 of the insulator (or of the plane of the abutment 18), so that the resultant thrust of the tensioned wire against the wing will act through or as nearly so as possible, the median line LL of the wing. The wings will thus be subject to a compression, and not to tension. This is particularly desirable, obviously, since the insulator is usually made of a brittle material.

As will have already been clearly gathered, the two insulators are assembled to the support bracket proper 10 so that their V-shaped front faces are presented one toward the other (see Figure 1). Therefore, the grooves 25 of the insulators, respectively, will be in a same horizontal plane, and parallel with jaws 16 and 17 of the bracket proper, similarly, the grooves 25A will be in a same horizontal plane. It follows that the wires, where they cross at the center of the bracket proper 10, will be spaced from one another to the extent of the distance between the grooves 25 and 25A, measured in a vertical direction.

The two insulators being identical in structure, obviousawait 1y are interchangeable. That is to say, one insulator operable" ia'oaeead of tli bracloet may be transferred to and be operable in the other end merely by reversing it back to front and inverting it.

I claim:

1. In a transposition bracket, an elongate member having a middle portion adapted to be secured to a cross arm and oppositely-disposed end portions having fixed jaws, a pair of similar insulators havin a middle portion seated in said end portions, respectively, and means removably retaining said insulators in seated position; each of said insulators having wings extending laterally beyond said end portions and formed with a groove adapted to receive one of a pair of tensioned and transposed wires, said grooves being in spaced vertical relationship with respect to said member as to dispose the wires at said wings, respectively, at different levels.

2. In a transposition bracket, an elongate member having oppositely-disposed end portions each in part defined by a vertical abutment piece, insulators each consisting of a middle portion seated in each of said end portions and wings extending laterally beyond said end portions, the outer end of each of said wings having a groove adapted to receive one of a pair of tensioned and transposed wires, the forward face of each of said insulators having a substantially vertical groove, and a removable pin through said memberv co-operating with the groove in each of said insulators to retain each said insulator in seated position within one of said end portions and against said abutment.

3. In a transposition bracket, an elongate member having oppositely-disposed end portions in part defined by a vertical abutment piece, a pair of similar insulators seated in said end portions, respectively, and in part defined by a face adapted to engage said abutment and each having a wing extending laterally beyond said elongate member, each of said wings having in its outer end a groove adapted to receive one of a pair of tensioned and transposed wires, and removable pins through said member co-operating with said insulators, respectively, to retain said insulators in seated position and against displacement laterally and lengthwise of said elongate member,

the arrangement being such that when the pair of Wires are crossed over the transposition bracket, the middle portion of the insulator bears against said abutment.

4- I a r nrp si n basket as i cla m 3 ea h at said wings being directed at an angle to the plane of said abutment so that the thrust imposed by the tensioned crossed wires against the end of each of said wings acts substantially through the median line of said wing and through said abutment.

5. In a transposition bracket, an elongate member having a middle portion and oppositely-disposed substantially C-shaped portions, a pair of insulators seated in said C-shaped portions, means securing said insulators in seated position, each of said insulators including a middle body portion in part defined by a flat surface presented to one of said C-shaped portions and a pair of oppositelydisposed wings projecting laterally from said middle body portion, said wings having their ends formed each with a groove adapted to receive a pair of tensioned wires.

6. A device as in claim 5 in which the wings project at an angle to said face,

7. A device as in claim 5 in which the groove in one wing lies at a difierent'level than the groove in the opposite'wing. l

8. An insulator for a transposition bracket, compris; ing a body having a middle portion formed with a rear fiat face and having oppositely-disposed wings extending laterally from said middle portion, each of said wings being formed with a horizontal groove adapted to receive one of a pair of tensioned wires, and the forward face of said insulator being formed with means co-operating to secure said insulator to a bracket, said means consisting of a vertical groove adapted to receive the shank of a pin.

References Cited in the file of this patent UNITED STATES PATENTS 138,115 Austin Apr. 22, 1873 902,455 Skinner Oct. 27, 1908 2,248,044 Dehmel July 8, 1941' 2,437,593 Case Mar. 9, 19 48 2,526,9l7 Wheeler et al. Oct. 24, 1950 OTHER REFERENCES Publication: Line Construction Blueprints" from Ry. Signaling, April 1953, page 119.

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