Improved means for connecting overhead high tension electrical cables to the insulators of transmission towers

摘要

889,961. Supporting cables. FRASER, H., and CANTLAY, W. G. Nov. 27, 1959 [April 27, 1959], No. 14240/59. Class 36. A suspension unit for connecting a cable to an insulator comprises an upper part 12 and a lower part 10, 11, the lower part being so supported by the upper that if the cable breaks the lower part becomes detached from the upper, at least one coil of ductile metal 31 interconnecting the two parts to limit the amount by which the lower part may drop and to absorb the shock. The lower part has the usual type of cable clamp 11 pivotally connected at 26 to a part 10 consisting of two opposed side members 21 each with two laterally extending arms 22. The upper part 12 has a foot extending into the lower part between the sides 21 and carrying two rollers 28 which engage under curved roller tracks 23 formed on the sides 21 and thereby support the lower part. A bolt 30 extends through the lower part and through a bight in the foot of the upper part, and a shear pin 29 extends through both parts, helical springs of annealed mild steel 31 connecting the two parts. If the cable on one side breaks, the clamp 14 swings, engages the end of an arm 22 and the resultant torque about the bolt 30 shears the pin 29 so that the rollers 28 run off the curved track 23 and the lower part separates from the upper. The springs 31 extend to limit the drop of the lower part and attached cable. In a modification the upper part is adapted for connection to two insulators (Figs. 4 to 8, not shown) which are suspended from the arm of a tower to form two sides of a vertically disposed triangle. The upper part is pivotally connected to the insulators by links in such a way that, when the device is tilted due to the cable breaking, the link connecting the insulator on the side furthest from the break is freed whilst the other insulator swings into line with the unbroken section of cable, the suspension device separating to absorb the shock as previously described. Specification 800,980 is referred to.