US2655553A - Line transposition bracket with reinforcing gussets - Google Patents

Description

Oct. 13, 1953 LINE TRANSPOSITION BR Filed June 21, 1951 R. cAsE ACKET WITH REINFORCING GUSSETS 2 Sheets-Sheet l I I I 1 [Mi/V7013 @gyefs Case a, qxwamza 41% Oct. 13, 1953 R. CASE 2,655,553

LINE TRANSPOSITION BRACKET WITH REINFORCING GUSSETS Filed June 21, 1951 2 Sheets-Sheet 2 [NM/Wag @WSIZS' Case Patented Oct. 1 3, 1953 UNITED STATES PATENT OFFICE LINE TRANSPOSITI REINFORCI ON BRACKET WITH NG' GUSSE'I'S Rogers Case, Orange, N. J Application June 21, 1951, Serial-N0. 232,738 6 Claims (01. 174-147) This invention relates to a bracket for transl posing paired line wires of communication lines.

Specifically considered the disclosure herein relates to an improvement in the brackets disclosed in my issued Patents No. 2,455,228, dated November 30, 1948 and No. 2,455,229, dated Noplained in those patents, it is a matter of necessity in the more efficient systems of long distance electrical communication along wires that paired wires be transposed at intervals by crossing them and the brackets disclosed in those patents are constructed easily and accurately to effect such transposition. Also as explained in those patents, it is of great assistance in making the transposition that the insulators on which: the wires are trained be mounted rotatably in four outwardly open clevises in which the insulator pins are supported.

In service there is a very substantial pressure of the wires against the structure of the brackets and such pressure creates the problem of providing brackets of adequate strength with economy in-the weight of metal included in the bracket and the provision of brackets so light as to facilitate their installation in the line.

The object of my invention is therefore to provide transposition brackets primarily in accordance with the disclosure of the above-noted patexert a maximum resistance to the stress-creating thrust of the wires transposed by the bracket in conjunction with themclusion of a minimum weight ofmetal in the bracket.

2,455,228, which is a bracket ofthe: span ty That is, it is purposed particularly for insertion in an electrical line between the line: poles. As indicated above, the improvement ofthis invention is equally applicable to the bracket of my prior Patent No. 2,455,229; which is purposedpa-rticularly for direct mounting on the cross arm of a line pole.

In the accompanying drawings; illustrativeof one embodiment of myinvention:

2 Fig. I is a plan view of myimproved transposition bracket.

Fig. II is across sectional View taken in the plane of the section line II-II of- Fig. I and looking toward the upper edge ofthe sheet of drawmgs.

rig. III is an end elevation of the bracket frame structure as seen at the lower larly extended leg 70.

Clevises8=and 9: bear respectively the same relation to the end reach 2 as do clevises 7 and 6 to end'reach I.

or' conversely rising seen that insulator ga ses from the lower fork of clevis to the upper fork of clevis I.

Spool-form insulators Ni, H, 12 and i3 are mounted respectively in clevises t, l, 8 and 8. Desirably as is shown in the drawings, insulator pins M are of such form that the insulators are freely rotatable on them. These insulators which are of primarily spool-form and which may be composed of glass, porcelain, rubber, fiber or plastic composition or other material having suitable physical and electrical-insulating properties are carried each by its insulator pin I l which has a head 14a resting on and a shank Mb which projects below the underfork of the clevis. Su'table means for engaging the insulator pin in the clevis in which it is mounted is shown as a cotter pin ldc, but such engagement may be provided by means of a nut having threaded engagement with the projecting end of the pin or by any other suitable engagement.

In the arrangement of the insulators it will be it has its wire-receiving groove ltd above the base, or median, plane of the bracket frame and that the wire-receiving groove Ila of insulator it lies below the base, or median, piane of the frame. The wire-receiving grooves of insulators l3 and i2 are in vertical alignment with the wire-receiving grooves of insulators it and II respectively.

It will be seen that the arrangement of the clevises and insulators mounted in them is diagonal. Thus the high clevises B and t are diagthe upper fork of the clevis onally opposite each other in the bracket assembly and the low clevises l and 8 similarly are diagonally opposite each other. As viewed in the drawings, the high and low clevises, and insulators mounted in them are staggered relatively in the bracket. This arrangement conforms to the crossing of line wires within the bounds of the bracket frame. Together with the fact that all the clevises open outwardly of the frame structure, it conforms the paired line wires on the insulators of the bracket without interrupting the span or disassembling the bracket.

In the relation of the paired line wires with the bracket, the wire A is shown as trained on the low insulators II and i2 and the wire B is shown as trained on the high insulators la and 13. In their crossed relation the two wires are spaced vertically a distance equal to the distance between the wire-receiving grooves of the diagonal pair of high insulators and the wire-receiving grooves of the diagonal pair of low insulators, as for example the vertical distance between the wire-receiving grooves Ba and i la. in Fig. I of the drawings. Because the insulators are mounted in the clevises, the wires trained on the insulators in their wire-receiving grooves are confined within the clevises. There is therefore no likelihood that there will be a floater, that is an upwardly escaped wire, if an insulator should be broken in service.

i The entire frame structure of the bracket being a one-piece casting possesses in a very high order the properties of rigidity, strength and endurance. The clevises being integrated in the frame structure by casting, there are no bolts or rivets to shear or work loose in service and the insulator pins are supported in clevises which minimize spring or other relative movement between parts or regions of the structure. The insulator pins are thusprotected against the thrust to the operation of threadin V Of these I have found aluminum alloy to be of the line wire on the insulators which are mounted on them.

As to the vertical spacing between the line wires in their crossed relation, that vertical spacing is modified by deflecting the lower fork of each of the clevises for the high insulators slightly below the base plane of the frame and by elevating the upper forks of the clevises for the low insulators slightly above the base plane of the frame. Thi accommodation in the organization of the frame permits the use of insulators having a desirable structural contour while obtaining a desired spacing of the wires. That is, a de sirable form of insulator having been selected, the frame of the bracket can be cast to give a determined vertical spacing of the crossed wires while using insulators of the specific selected form, by casting the one-piece frame with the forks of its clevises deflected appropriate distances from the base plane of the frame.

As indicated above, it is desirable that the bracket as described be integrally cast of one of the light metals such as aluminum or an alua magnesium alloy.

preferable. Also as above indicated, I have found that a slight additional mass of metal placed most advantageously in the structure of the bracket adds stress resistance far out of proportion to the added weight.

Such reinforcement consists of relatively thin, triangular ribs or gussets integrated between the median or base portions of each of the end reaches l and 2 of the bracket and along the adjacent surfaces of the longer angularly extended legs of the clevis-forming portions of those reaches. These triangular gussets I5 and it have relatively long free edges Mia and Zila so that they each integrate with the median portion of the reach and one of the angularly extended legs of a clevis throughout the major proportion of the length of those members. The gussets l5 and as have their edges approximately parallel so that with minum alloy, magnesium or the included median portion of the reach, they form an approximately rhombic reinforcement extended between and integrated with the angularly extended legs of the clevis. As shown in Fig. II of the drawings this gusset structure comprising gussets l5 and 28 extends between the inner face of leg to of outwardly open clevis 6 and the inner face 10 of outwardly open clevis '5. Similarly, as shown in Fig. III of the drawings with respect to reach 2 of the bracket, gussets It and H are arranged with their free edges its and l'ia approximately parallel and with the gusset structure standing between angularly extended leg 8c of outwardly open clevis 3 and leg of outwardly open clevis 9. As with the gusset structure made part of reach I, each of gussets l6 and I! is integrated with the median portion 5 of the reach.

This relatively small mass of metal because of its position and its integration with the fundamental structures of the bracket, presents a maximum opposition to the thrust of the line wires transposed by the bracket and thus counteracts the stress-creating effects of such thrust. It has been found by test that the regions in which the stresses caused by the thrust of the wires are concentrated in a bracket lacking this reinforcement are adjacent the corners at which the forks of the clevises join the median portions of the reaches and particularly adjacent the junction of bracket structure to the same specific metal as on the tests is as follows:

addition of the gusset structures jfailui'e takes place only at muchhighe'r load and at the holes I pins 'or adjacent such holes in the end reaches 3 and I of the bracket, It is to he understood that without such reinforcement the bracket as cast from a suitable aluminum al- ,l oy is amply able to sustain the. henna load im' posed by the line wires, which is about 2000 pounds. The reinforcement provided by the gusset structure does, however, give increased assurance against bracket 'failu' eunder the exigencies of continuedservice. V Also, the reinforcement to the brackets gives assurance against disruption of V the line by bracket failure under abnormal eonditions, such as unus'ually high wind pre'ssures and abnormal accumulations of ice on the brackets.

To determine the resistance of the fundamental load imposed by the line wires and to show comparatively the increase in such resistance obtained by adding the gusset for the insulator structure of this invention, tests were made on three types of the bracketas follows:

, Typ e A.Thisbracket was integrallycast from a suitable aluminum alloy, which metaispec ficaily was Alcoa 356T6 -alloy. It was close to the exact disclosure of Patent No. 2,455,228 comprising no reinforcing gussets as herein disclosed.

Type B.- This bracket was made of the same alloy as the type A bracket, and in its initial'stru'cture corresponded exactly to that bracket. This type B bracket was, however, reinforced by gussets shaped and arranged as herein disclosed. Those gussets were welded to the longerangular'lyextended legs of the clevises and to the median or base portions of the side reachesof the bracket.

Type (IQ-This bracket was identical with the specific disclosure herein, with the reinforcing gussets cast integrally with the fundamental structure of the bracket. It was composed of the the type A and type B brackets. o.

The fundamental structure of the type 'B bracket, like the type A bracket was obtained by permanent mold casting, and the entire structure of the type C bracket includingthegussets was obtained by permanent mold casting as'an initially integral structure. v type B, primarily because the manufacture of the bracket is simplified by eliminating the step of\llelding- For loading the brackets, the Baldwin -southwark 300, 000pound testmachinejwas used. in place of the standard-glass insulators. aluminum replacements were used because it wasfound that the glass insulators failed before any damageoccurred to the brackets. Two A; inch steel'cable of approximately 8 foot length were attached to steel bars with theproper line spacing for jthe brackets to be tested and the cable tension was 6 equalized by pivoting the upper bar at its center. The lower bar was pivoted at its center so that it was free to move in the opposite plane allowingthe cables "to twist if the'loading' resulted in that type of moment. The loading of all three brackets was carriedto destruction. The data Weight, Loadat Type pounds pounds Per CO the.

Type C is preferred to failure,

they may be rotatable "the said longer and shorter economical to provide for the formation of the gussets in the permanent mold than to make such gussets separately and to weld them into place after casting.

Whereas the primary intent of my invention is to reinforce the fundamental structure of a transposition bracket frame made by the permanent mold casting of one of the light metals and by strengthening such frame to decrease the total weight of metal desirably included in the bracket, my invention maybe utilized in brackets which are of the same form but which are difierently made. Thus gussets of the same shape as above described may be integrated in re same described positions in a bracket of the same described shape and structural arrange-- ment but which is fabricated of steel or other suitable metal instead of being integrally cast. In such brackets the gussets by reinforcing the structure of the bracket frame, serve similarly to reduce the total weight of metal necessarily or desirably included in thebracket.

As used herein the terms vertical. lower. and the like refer to what may be considered the normal position of the bracket in a line the wires of which aretransposed by the bracket ina'ccordanc'e with preexisting general practice. It is to be understood that the insulators either may rotate-on their pins, in the clevises or'both the pins and the insulators may be rotatable with respect to each other -andto the frame structure of the bracket.

Having ttion, it is in the statement-of the claims appended hereto.

I claim as my invention: 1. A wire-transposingbracket adapted for the crossing of paired line wires comprising a frame integrally cast from tral base region to provide four outwardly'open insulator-mounting clevises, the longer and shorter legs of the clevises'ofeach said reach being oppositely arranged and the arrangement of ing clevises in thebracket frame, two-reachesint ereonnecting the said two forked reaches, 'spoolf form insulators having circumferential'wire receivin'g grooves r'otatably mounted in'thesaid of, 'said two gussets of each'sai'd reach being tively to each other to provide reinforcement in the structure of the bracket frame and composite stress resistance against the load imposed by wires transposed by the bracket.

terconnecting the said 2. In a wire-transposing bracket adapted for the crossing of paired line wires, a frame integrally cast from a light metal selected from aluminum, magnesium and their alloys and having two generally parallel reaches terminally forked at both ends of each by means of longer and shorter legs angularly extended from a central base region to provide four outwardly open insulator-mounting clevises, the longer and shorter legs of the clevises of each said reach being oppositely arranged and the arrangement of the said longer and shorter legs being reversed in the said two forked reaches to give a diagonal matching of higher and lower insulator-mounting clevises in the bracket frame, two reaches interconnecting the said two forked reaches; and

.two strengthening gussets extended between and integrated with the longer legs of the said clevises of each forked reach and adjacent surfaces of the said base region thereof, said two gussets of each said reach being arranged in an approximately diagonal line relatively to each other to provide reinforcement in the structure of the bracket .frame and composite stress resistance against the load imposed by wires trained on insulators mounted in the said clevises and transposed by the bracket.

3. A wire-transposing bracket adapted for the crossing of paired line wires comprising a frame integrally cast from a light metal selected from aluminum, magnesium and their alloys and having two generally parallel reaches terminally forked at both ends of each by means of longer 7 and shorter legs angularly extended from a central base region to provide four outwardly open insulator-mounting clevises, the longer and shorter legs of the clevises of each said reach being oppositely arranged and the arrangement of the said longer and shorter legs being reversed in the said two forked reaches to give a diagonal matching of higher and lower insulator-mounting clevises in the bracket frame, two reaches intwo forked reaches, spoolform insulators having circumferential wire-receiving grooves rotatably mounted in the said four clevises; and two strengthening gussets extended between the longer legs of the clevises of each forked reach and adjacent surfaces of the said base region thereof and cast integral therewith, said two gussets of each said reach being arranged in an approximately diagonal line relatively to each other to provide reinforcement in the structure of the bracket frame and composite stress resistance against the load imposed by wires transposed by the bracket.

4. In a wire-transposing bracket adapted for the crossing of paired line wires, a frame integrally cast from a light metal selected from aluminum, magnesium and their alloys and having two generally parallel reaches terminally forked at both ends of each by means of longer and shorter legs angularly extended from a central base region to provide four outwardly open insulator-mounting clevises, the longer and shorter legs of the clevises of each said reach being oppositely arranged and the arrangement of V the said longer and shorter legs being reversed in the said two forked reaches to give a diagonal matching of higher and lower insulator-mounting clevises in the bracket frame, two reaches in- 'longer legs of the terconnecting the said two forked reaches; and two strengthening gussets extended between the longer legs of the said clevises of each forked reach and adjacent surfaces of the said base region thereof and cast integral therewith, said two gussets of each said reach being arranged in an approximately diagonal line relatively to each other to provide reinforcement in the structure of the bracket frame and composite stress resistance against the load imposed by wires trained on insulators mounted in the said clevises and transposed by the bracket.

5. A wire-transposing bracket adapted for the crossing of paired line wires comprising a frame having two generally parallel reaches terminally forked at both ends of each by means of longer and shorter legs angularly extended from a central base region to provide four outwardly open insulator-mounting clevises, the longer and shorter legs of the clevises of each said reach being oppositely arranged and the arrangement of the said longer and shorter legs being reversed in the said two forked reaches to give a diagonal matching of higher and lower insulator-mounting clevises in the bracket frame, two reaches interconnecting the said two forked reaches, spool-form insulators having circumferential wire-receiving grooves rotatably mounted in the said four clevises; and two strengthening gussets extended between and integrated with the said clevises of each forked reach and adjacent surfaces of the said base region thereof, said two gussets of each reach being arranged in an approximately diagonal line relatively to each other to provide reinforcement in the structure of the bracket frame and composite stress resistance against the load imposed by wires transposed by the bracket.

6. In a wire-transposing bracket adapted for the crossing of paired line wires, a frame having two generally parallel reaches terminall forked at both ends of each by means of longer and shorter legs angularly extended from a central base region to provide four outwardly open insulator-mounting clevises, the longer and shorter legs of the clevises of each said reach being reversed in the said two forked reaches to give a diagonal matching of higher and lower insulator-mounting clevises in the bracket frame, two reaches interconnecting the said two forked reaches; and two strengthening gussets extended between and integrated with the longer legs of the said clevises of each forked reach and adjacent surfaces of the said base region thereof, said two gussets of each said reach being arranged in an approximately diagonal line relatively to each other to provide reinforcement in the structure of the bracket frame and composite stress resistance against the load imposed by wires trained on insulators mounted in the said clevis and transposed by the bracket.

ROGERS CASE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name 7 Date 2,261,597 Sutherland Nov. 4, 1941 2,455,228 Case Nov. 30, 1948

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