Condenser bushing having longitudinally extending ducts therethrough for the flow of oil to remove heat resulting from dielectric losses

Claim 1

A CONDENSER BUSHING COMPRISING, IN COMBINATION, A CONDUCTOR STUD, A LAYER OF INSULATING MATERIAL DISPOSED ADJACENT THE STUD, SAID LAYER OF INSULATING MATERIAL BEING COMPOSED OF A PLURALITY OF LAYERS OF PAPER HAVING A COAT OF RESIN ON ONE SIDE THEREOF TO BOND THE LAYERS OF PAPER INTO A FIRM LAYER OF INSULATION, SAID LAYER OF INSULATING MATERIAL HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED LONGITUDINALLY EXTENDING DUCTS EXTENDING THE ENTIRE LENGTH THEREOF FOR THE FLOW OF OIL TO CONDUCT HEAT GENERATED IN THE DIELECTRIC OF THE BUSHING AWAY FROM THE BUSHING, A LAYER OF CONDUCTIVE MATERIAL AROUND SAID LAYER OF INSULATING MATERIAL HAVING THE DUCTS THEREIN, SAID LAYER OF CONDUCTIVE MATERIAL BEING ELECTRICALLY CONNECTED TO THE CONDUCTOR STUD, A PLURALITY OF ALTERNATE LAYERS OF OTHER INSULATING MATERIAL AND LAYERS OF CONDUCTIVE MATERIAL DISPOSED AROUND SAID FIRST-NAMED LAYER OF CONDUCTIVE MATERIAL AND FORMING SOME OF THE CAPACITY STEPS OF A CONDENSER BUSHING, THE OTHER INSULATING MATERIAL BEING OIL IMPREGNATED PAPER, AN ADDITIONAL LAYER OF SAID FIRST-NAMED INSULATING MATERIAL HAVING A PLURALITY OF LONGITUDINALLY EXTENDING DUCTS THEREIN AT SPACED CIRCUMFERENTIAL INTERVALS FOR VENTILATING THE BUSHING, THE NEXT OUTERMOST LAYER OF CONDUCTIVE MATERIAL BEING CONNECTED ELECTRICALLY TO THE NEXT INNERMOST LAYER OF CONDUCTIVE MATERIAL SO THAT NO ELECTRICAL STRESS IS APPLIED TO THE LAST-NAMED LAYER OF INSULATING MATERIAL HAVING DUCTS THEREIN, THE ADDITIONAL LAYER OF THE FIRST-NAMED INSULATING MATERIAL BEING DISPOSED SUBSTANTIALLY AT THE RADIAL CENTER OF THE BUSHING, AND FURTHER ALTERNATE LAYERS OF THE OTHER INSULATING MATERIAL AND CONDUCTIVE MATERIAL WITH MEANS FOR MAKING AN ELECTRICAL CONNECTION OF THE OUTERMOST LAYER OF CONDUCTIVE MATERIAL, THE CAPACITY BETWEEN ANY TWO ADJACENT ELECTRICALLY DISCONNECTED LAYERS OF CONDUCTIVE MATERIAL BEING SUBSTANTIALLY THE SAME THROUGHOUT THE BUSHING.