GB725143A - Improvements in high-tension lead-in insulators - Google Patents

Abstract

725,143. Insulators. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. April 10, 1952 [April 14, 1951; July 4, 1951], No. 9198/52. Class 36. A lead-in insulator surrounding at least one conductor and having a metallized internal surface in contact therewith is formed with at least one metallized groove in the middle portion of its external surface which is in electric contact with a metallic member through which the insulator passes and which is preferably shaped so that at least one of its edges makes approximately a right-angle with the external surface of the insulator. In one embodiment the conductor C is secured within the insulator 5 by nuts 4 which make electrical contact with a layer 6 of silver paint. A supporting collar 8 is bordered by grooves 7, the edges of which meet the surface of the insulator at 90 degrees. The collar and grooves have a coating 9 of silver paint, and the insulator is held in plate 1 by claws 2. The edges of the silvered areas have a coating 10 of plastic material. The purpose of the arrangement is to ensure that in the atmosphere surrounding the insulator there is a weak potential gradient, thus retarding the occurrence of corona effects. The insulator may be modified to carry a conductor of non-circular cross-section, or more than one conductor. The collar 8 may be dispensed with, the insulator then being provided with a single groove, the claws 2 being shaped to engage the surface of the groove. A member having a conductive surface may be inserted in the grooves, in contact with the metallized surface. In order to secure the insulator to the plate a metallic ring in one or two pieces may be soldered or welded to the collar 8 or, where this is dispensed with, to the surface of the groove. Alternatively metal may be cast in the groove to form a mounting ring.