US1708876A - Insulator - Google Patents

Description

Patented Apr. 9, 1929.

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1 and G-RAIIDON E. ECKERE, 033 EAST LIVERPQOL, 01-110) ASSEGNOB 'ITO THE E. THOMAS & SONS COMPANY, OF EAST LIVERPOOL, 03:10, A CORPOHATIGN 0F OHIO.

' INSU'LATOR.

Application filed June 21,

My invention relates to insulators, and particularly to suspension insulators ot the link type. The object of my my non is to improve the construction of the link, not only to facilitate its assembly with the insu lator, but also to effect a more uniform distribution of the stresses imposed upon the insulator under load.

in the accompanying drawings Fig. 1 is a broken side elevation of a suspension insulator with which is associated a link in which my invention is embodied in one form;

Fig. 2 is a side elevation of the link alone, drawn to a larger scale;

Fig. 3 is a section on the line 33, Fig. 2;

Fig. l is an enlar ed cross section through the bearing area or the link prior to load strain;

Fig. 5 is a similar view showing its detorrnation under load;

Figs. 6 and 7, Figs. 8 and 9, Figs. 10 and 11, and Figs. 12 and 13 are views c0rresponding to Figs. eland 5, but illustrating various modifications.

The link commonly used with suspension insulator units of the Hewlett type, comprises merely a copper rod of appropriate diameter bent to horse-shoe shape and headed at its opposite ends. For some conditions this construction is satisfactory. l/Vhen the insulators are called upon to stand heavy strains, however, a link of round cross section is objectionable by reason of its rigidity, and ti e fact that its contour is such that the stresses imposed on the porcelain are concentrated in a narrow area, with the result that fractures or" the porcelain not infrequently occur.

Again, it has been customary to form at the ends oi the link shanks cylindrical heads of considerable depth for engagement with either connectors between adjacent insulator units, or adapters at the top and bottom of the insulator string. These heads not only considerably increase the necessary diameter oi the passageway through the insulator body, but add to the diiiicu ty of threading the link therethrough.

The present invention provides a link structure which not only facilitates the threading of the link through the passage in the insulator, but is of such shape in its bearing area that the strains under load are more widely and evenly distributed up- 1928. Serial 1T0. 646,8 i4.

on the insulator body. For the latter purpose the bearing area of the link is so shaped that it possesses markedly greater pliability and is deformable under load and furthermore, its shape is so predetermined that upon deformation under load its bearing area is so increased that a distribution of load strains over a larger of the insulator results, and thus prevents the concentration of stresses which has heretofore resulted in injury to the insulator.

in the accompanying drawings, I have illustrated in Fig. 1 a string of Hewlett infacilitates the strin n or" the link through g the passage 16, since iio sharp edge is presented at the outer margin of the head, but the rounded corner slides freely throughithe passageway 16. The, support afforded by the head is not materially lessened since the shoulder which engages the connector or terminal fitting is retained, except for a slight arcuate extent. 7 I

The loop 21 of the link constitutes the portion thereof which lies within the passageway 16 and bears against the hub 25 of the insulator, transmitting to the latter the heavy mechanical strains of the line load. In order to distribute these strains as widely possible, the loop of the link is so preshapcd that under suflicient load it is de formed and aitords a transverse bearing area of much greater extent than has heretofore been usual. This may be accomplished in various ways. In the construction shown in Figs. 1 to 5 the loop of the link is deformed from its normal circular cross section to an approximate arcuate section, the curvature of the bearing face having a greater radius than that of the shank. This taco ot the link is scored by longitudinally extending lateral recesses 26. An intermediate longitudinally extending recess 27 is also formed in the outer surface of the loop.

Inasmuch as the deformation of the loop is effected Without reducing the total cross sectional areathat is to say, Without reducing the amount of metal in the link, or materially lengthening the latte 'the full mecl'ianical strength of the link is nraiir tained, although its cross sectional contour is so altered that the loop is more pliable. This characteristic renders it possible to maintain the normal cross sectional dimensions of the loop Well Within the diameter of the passage 16, so that the link may be readily threaded therethrough While when the link is placed under load the bearing area is deformed by the strain from its normal contour, indicated in Fig. l, to its stressed contour, indicated in F ig. 5. In the latter condition a much greater bearing area is ailorded. Thus, the longitudinally extending Wings 28 are drawn against the wall. of the passageway 16, and the channels- 26 are practically closed. It will be obvious from Fig. 5 that the str ssed area of the hub 25 of the insulator increases from the relatively narrow band indicated 29, Fig. 4, to the broad band 80 of Fig.- 5, through which the heretofore concentra'ed strains are now disseminated.

Thisresult can be accomplished. in many ways. Thus, as shown in Figs. 6 and 7, the

initial cross section of the link-loop may be substantially U-shaped, the sides 31 and 32 flattening out under stress as indicated in Fig. 7.

The single central channel 33', shown in Figs. 6 and 7 may be supplemented by lateral channels Set and 35, as indicated in Figs. 8 and 9.

In Figs. 10 and 11, the channels of Figs. 8 and 9 are supplemented by complementary channels 36 and37, formed in the bearing face of the link.

In Figs. 12 and 13 the shape of the channels is further modified. Thus, the bearing surface is cut by narrow channels 38, 39 and 40, While the opposite face of the link body is indented by narrow channels ll and 41-2, staggered With relation to those on the opposite face ofthe link, and producing in effect a corrugated Web loop.

The increased pliability in the loop area of-the link, Which is as usual of copper or the like, has the further advantage of can?- ing the loop to hug the bearin surface of the passageway evenly at all points. This is not the case With links of round or other semi-rigid cross section, unless the longitudinal curvature of the loop corresponds exactly to the longitudinal curvature of the passagcway-and this seldom happensi. With the old type of link, the lack of :sact coincidence at all points between the cooperating surfaces results in localized strains by reason of the unyielding cross sectional contour of the loop. These localized strains occi, rrin; g at different points in both the same and in the opposed passagewayshave proved one of the great some of mechanical injury to insulators of this type.

By the presert invention the loop of the link is rendered suliiciently pliable under strain to adapt itself to the curvature of the passageway, and thus, as above stated, hugs it at all points. At the same time, the transverse stress area is markedly increased overtlie old cylindrical loop. Again, the initial. cross sectional contour of the present loop is so restricted that the link may be readily threaded through its passageway 16, While its full transverse bear ng area does not become effective until the loop is flattened under strain.

These features are susceptible of e1nbodiment in various other forms of construction, and consequently the details shown are to be regarded as merely illustrative of tie broader thoughts Which I claim as my in.- vcntion.

I claim-- 1. A ink for insulators, comprising a bearing loop area. longitudinally channelled to facilitate its transverse deformation under load.

2. A. link for insulators, comprising a bearing loop area longitudinally channelled on both faces to facilitate its transverse deformation under load.

3. For use in a supporting fitting provided with seats, generally horseshoe shape, comprisingra bar of metal having its ends oilset toward each other to form shouldered heads adapted to freely engage the seats of said supporting fittings, the outer surfaces of said heads being rounded and slabbed off, said surf ces merging substantially Without break with the outside of the link to facilitate the threading of the link through a curved pasforincd in the insulator.

In testimony whereof I have signed my name to this specification.

GRANDON E. EGKElt'l.

an insulatorengaging link of

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