Means for controlling electric currents in a glass furnace

Claim 1

IN A FEEDER FOREHEARTH FOR A GLASS MELTING FURNACE HAVING A DELIVERY OUTLET THEREIN, SAID FOREHEARTH CONNECTED AT ONE END TO A BODY OF REFINED GLASS AND RECEIVING SAID GLASS THEREFROM AND DISCHARGING IT AT SAID DELIVERY OUTLET TO GLASS WORKING MEANS, THE COMBINATION OF ELECTRIC MEANS COMPRISING AN ELECTRIC POWER SOURCE, A SET OF FIRST ELECTRODES CONNECTED TO SAID POWER SOURCE, A AND SUBMERGED IN THE GLASS IN SAID FOREHEARTH FOR HEATING SAID GLASS BY JOULE EFFECT OF ELECTRIC CURRENT PASSED THERETHROUGH BETWEEN SAID ELECTRODES, SAID ELECTRODES SO POSITIONED THAT THE DELIVERY OUTLET LIES THEREBETWEEN, A SECOND SET OF ELECTRODES SUBMERGED IN SAID GLASS AND POSITIONED SO THAT EACH OF SAID SECOND ELECTRODES LIES BETWEEN ONE OF THE FIRST ELECTRODES AND THE DELIVERY OUTLET, AND SWITCHING MEANS RESPONSIVE TO GLASS WORKING MEANS TO CONNECT THE SECOND ELECTRODES TO THE GROUND WHEN THE WORKING MEANS ARE IN CONTACT WITH THE REFINED GLASS AND ARE UNGROUNDED WHEN THE WORKING MEANS ARE OUT OF CONTACT WITH THE GLASS.