GB331799A - - Google Patents

Abstract

331,799. Associated Electrical Industries, Ltd., (Assignees of Burr, G. A.). Jan. 10, 1929, [Convention date]. Insulators; electric cables, carrying through partitions; insulation.- In a condenser type of bushing insulator having conducting and dielectric layers held together by a binding agent, the dielectric layers are formed of a, slightly porous and relatively dense material which is penetrated to only a small depth by the binding material. In the construction shown in Figs. 1 and 2, the device comprises a central conductor 2 and a plurality of alternate conducting and dielectric layers 3 and 4 respectively. stepped as shown at 7 and 8 to provide a grading of capacities between the conducting layers 3. The dielectric layers 4 are preferably wound of several layers of paper treated on one or both sides with a binder such as shellac, the paper being substantially 0.125 mm. in thickness and penetrated to less than half its depth by the shellac. The conducting layers 3 may be formed of lead or tin foil but are preferably of embossed aluminium foil coated on one or both sides with the binding material. The layers are wound under heat and pressure in order to unite the conducting and dielectric layers.