High voltage current measuring device employing means responsive to the electromagnetic field generated by the current

Claim 1

HIGH VOLTAGE CURRENT MEASURING APPARATUS COMPRISING, IN COMBINATION, AN INSULATOR STRUCTURE ADAPTED TO BE SECURED TO A HIGH VOLTAGE LINE, AND A PICKUP DEVICE MOUNTED IN THE INSULATOR STRUCTURE IN POSITION FOR HAVING A SIGNAL INDUCED THEREIN BY MAGNETIC LINES OF FORCE CAUSED BY CURRENT FLOWING IN THE LINE, THE INSULATOR STRUCTURE BEING COMPOSED OF A PLURALITY OF DISCRETE LAYERS OF INSULATING MATERIAL AND A PLURALITY OF SEMICONDUCTIVE JOINTS SECURING THE LAYERS OF INSULATING MATERIAL TOGETHER, THE LAYERS OF INSULATING MATERIAL BEING SMOOTH ON BOTH SIDES THEREOF, SAID SEMICONDUCTIVE JOINTS SERVING AS ELECTROSTATIC SHIELDS WHILE PERMITTING THE PASSAGE OF THE MAGNETIC LINES OF FORCE THERETHROUGH, SAID SEMICONDUCTIVE, JOINTS PROVIDING A POTENTIAL FIELD WHICH HAS A SUBSTANTIALLY UNIFORM GRADIENT TO PROVIDE EFFICIENT USE OF THE INSULATION, SAID SEMICONDUCTIVE JOINTS SUBSTANTIALLY EVENLY DISTRIBUTING THE POTENTIAL STRESS AROUND THE PERIPHERY OF THE JOINTS AND OVER THE OUTSIDES OF THE INSULATOR LAYERS THEREBY TO PROVIDE MAXIMUM FLASHOVER.