US2709058A - Insulator supporting rack - Google Patents

Description

M y 1955 F. c. VOSE ETAL INSULATOR SUPPORTING RACK Filed 17, 1950 5 6 Z M w 4 8 8 8 W 8 H w \I1II1iI1 0.x h 0. 7 4-. m m a 4 w 9 0. 4 i a H w w L 0 w J 6 ATTORNEY United States Patent IN SULATOR SUPPORTING RACK Fred C. Vose, Glen Burnie, and Bernard W. Ruth, Baltimore, Md., assignors to General Electric Company, a corporation of New York Application August 17, 1950, Serial No. 179,972

1 Claim. (Cl. 248-67.7)

This invention relates to an insulator supporting rack and, more particularly, to an insulator supporting rack of the type known as a secondary rack, or service rack and to a method of making the same.

The term secondary rack is generally used to describe an insulator support by which a plurality of insulators are supported in alignment and these insulators, in turn, support low voltage electric lines connected to the secondary system of a transformer. For the usual three wire low voltage distribution system, three spool type insulators are used and these insulators are supported in vertical alignment by means of a secondary rack which is mounted in upright position on a support pole, building, etc. These racks, when mounted on buildings to support wires serving the buildings, are also known as service racks.

Since secondary racks are used in large numbers, particularly in rural and suburban areas, cost is an important factor in their design. Factors such as simplicity of manufacture, the material needed for fabrication, etc. of course affect cost.

It is therefore an object of our invention to provide a new and improved light weight and inexpensive secondary rack particularly adapted for use in connection with rural electric power distribution systems; and it is a further object of our invention to provide a new and improved method for making such a secondary rack.

Briefly stated, a secondary rack constructed in accordance with the teaching of our invention comprises an elongated channel shaped member having laterally extending pairs of mounting pads spaced for mounting the secondary rack in upright position against a support pole or the like and correspondingly spaced pairs of arms extending perpendicularly from the web of the channel shaped member adjacent the mounting pads for supporting the insulators in properly spaced relation to each other and to the mounting pads. The channel member, mounting pads and insulator supporting arms are formed from a single piece of thin gauge sheet metal, the insulator supporting arms being formed adjacent the mounting pads by partially severing opposite portions of the channel web and bending these partially severed portions towards each other into proper position with respect to the web and to the mounting pads. By virtue of the unitary construction of the rack and the simplicity of manufacture, the cost is favorable as compared to racks wherein different parts have to be fitted together and yet, by suitable choice of materials, our rack will due to the integral coordination of the insulator supporting arms and the mounting pads have enough strength for normal applications despite its light weight and inexpensiveness.

These and other objects of our invention will become more apparent from the following detailed description taken in conjunction with the attached drawing in which Fig. 1 is a front elevation view of a secondary rack constructed in accordance with the teaching of our invention; Fig. 2 is a side elevation view of the secondary rack shown in Fig. 1; Fig. 3 is an end view of the secondary rack shown in Fig. 1; Fig. 4 is a view corresponding to that of Fig. 1 showing a blank formed during the process of our invention; and Fig. 5 is an end view of the blank shown in Fig. 4.

As shown in Figs. 1-3, a preferred embodiment of our secondary rack includes an elongated channel shaped member 1 having a web 2 and oppositely disposed sides 3. Each channel side 3 has a lateral flange 4 extending therefrom throughout its length, these flanges being of corresponding size and shape and being symmetrically disposed with respect to the channel web 2. The flanges 4 have further lateral extensions or spaced pairs of mounting pads 5 extending therefrom, these pairs of mounting pads 5 being positioned adjacent each end of channel member 1 and midway the length thereof as shown in Fig. 1. As will be noted from Fig. 1, corresponding extensions 5 forming each pair of mounting pads project in opposite directions and the pairs of mounting pads 5 are symmetrically disposed with respect to channel memher 1, thus giving the general appearance of pairs of sup porting ears. Each mounting pad extension 5 contains an aperture 6 which is adapted to receive a connecting member such as a bolt, screw or the like for attaching the secondary rack in upright position to a support ing structure such as a support pole.

At each end of channel member 1, an insulator supporting arm 7 extends at right angles with respect to the channel web 2 as shown in Figs. 2 and 3. Each insulator supporting arm is integral with channel web 2 and, in effect, is an end right angle confirmation of the web. The other insulator supporting arms 8 are of a size and shape corresponding to arms '7, are located at intervals along the length or" channel member 1 and between the ends thereof, and extend substantially at right angles from channel web 2 in the same direction as do arms 7. As explained more fully hereinafter the intermediate insulator supporting arms 8 are bent up portions of the channel web 2 integral with the portion of the channel web extending between the coordinate mounting pads 5 whereby said channel web contains gaps 9 corresponding in size and shape to the arms 8. Each of the arms 7 and 8 has an opening 10 adjacent its end and these openings are aligned to receive a supporting rod 11 which extends axially through spool type insulators 12 as shown in Fig. 2.

As will be seen from an inspection of Fig. 2, each end insulator supporting arm 7 and the supporting arm 8 associated therewith, and the two middle supporting arms 8, provide brackets consisting of pairs of complementary supporting arms and mounting pads. For each such bracket, the individual arms face toward each other and are spaced apart substantially the height of the insulator associated therewith so as to prevent this insulator from sliding along the supporting rod 11. Also, the respective pairs of insulator supporting arms and mounting pads comprising each bracket are spaced apart a predetermined distance from each other to provide proper spacing between individual insulators 12, and the rms are of suificient length to maintain these insulators at the proper distance from the channel member 1.

For example, in one size of a secondary rack made according to the present invention, the channel member 1 is 18%, inches long and the length of each supporting arm 7 and 8 is 2 inches. For each end pair of supporting arms 7 and 8 and the middle pair of supporting arms 8, the two arms making up the pair are spaced 2% inches apart.

In making the secondary rack described above, a piece of thin gauge sheet metal (for example No. 14 gauge sheet steel) is formed into an elongated blank having a channel shaped cross section and laterally extending flanges as shown in Figs. 4 and 5. This forming of the blank may be accomplished by die forming the metal into the shape described. Either before or after the aforementioned forming operation, the earlike spaced apart pairs of mounting pad extensions 5 and tongues in may be stamped or otherwise cut out to provide the configuration shown in Figs. 4 and 5.

The channel web 2 is then out along dotted lines 13 to form portions 8a which are of size and shape corresponding to tongues 7a. Being thus freed, portions 8a may then be bent up at right angles to the channel web 2 to provide the insulator supporting arms 8 previousiy described. Since these portions 8a are bent up it is obvious that the gaps 9 will be left in the channel web 2. The extending tongue portions 7a are also bent up at right angles to the channel web 2 to form insulator supporting arms 7. As previously mentioned, and as can be readily observed from an inspection of Pig. 3, the indivdual supporting arms in each pair of supporting arms are bent up to face each other. Thus, the end portions 7a are bent up toward each other, the web portions 3a adjacent the ends of channel member 1 are bent up away from each other, and the two middle web portions 8a are bent up toward each other. After being formed as thus described the secondary rack is preferably galvanized.

From the foregoing description it is seen that we provide a secondary rack in which the rack structure per se is formed entirely from a single sheet of metal. This is found to contribute to simplicity of manufacture and reduction in cost. Using No. 14 gauge sheet steel, as an example, it is found that the rack is relatively light weight as compared to comparable racks on the market and yet has sufficient strength for normal applications. It is particularly adapted for use to support low voltage electric distribution lines in rural regions.

Although, in the preceding description and attached drawing, we make reference to three pairs of insulator supporting arms, it is obvious that more or less than three pairs may be provided in a structure made according to the teaching of our invention. Also, these insulator supporting arms may be used to support other types of ina sulators than spool type insulators, for example, wire holder type insulators. While we have indicated thin gauge sheet steel as being a preferable material from which to form our secondary rack, it is obvious that other materials could be employed provided they have the requisite strength and workability.

Therefore, while we have described and illustrated a particular embodiment of our invention we wish it to be understood that we do not intend to be restricted solely thereto but that we do intend to cover all modifications thereof which would occur to one skilled in the art and which come within the spirit and scope of our invention.

Having thus described our invention, what is claimed as new and desired to be secured by Letters Patent is:

A supporting rack comprising an elongated channel shaped member having two lengthwise extending sides connected by a lengthwise extending integral web, each of said sides having a lengthwise extending integral flange thereon extending generally perpendicular therefrom, an endmost supporting arm disposed at each end of said elongated member, said two endmost arms comprising integral continuations of said web extending lengthwise beyond opposite ends of said elongated member and then bent towards each other, two other supporting arms, said other arms disposed inwardly of said opposite ends and spaced from and connected to said two endmost arms by a portion of said web, said two other arms comprising integral continuations of said web extending towards each other and then bent away from each other, and another two supporting arms disposed opposite to each other adjacent a central portion of said elongated member, said another two arms comprising integral continuations of said web extending away from each other and then bent towards each other, said another two arms spaced from each other and interconnected by a portion of said web, openings in said web formerly occupied by said two other and said another two supporting arms spaced from each other by continuations of said web, a pair of integral mounting pads extending from said flanges disposed adjacent each of said web portions, all of said bent continuations protruding from an identical surface of sai web.

References tilted in the file of this patent UNlTED STATES PATENTS 1,123,107 Darr Dec. 29, 1914 1,685,684 Smalley Sept. 25, 1928 1,779,489 Peirce Oct. 28, 1930 1,811,211 Peirce June 23, 1931 1,853,218 Miller Apr. 12, 1932 1,990,667 Peirce Feb. 13, 1935 2,103,415 Greenwood Dec. 28, 1937 2,300,673 Johns Nov. 3, 1942 2,300,674 Johns Nov. 3, 1942

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