Control circuit for electric furnace

Claim 1

A CONTROL CIRCUIT FOR AN ELECTRIC FURNACE COMPRISING A SOURCE OF CONTROL VOLTAGE, A FIRST RELAY MEANS ENERGIZED BY SAID, A FIRST CONTACT MEANS CONDITIONED IN RE SPONSE TO THE ENERGIZATION OF SAID FIRST RELAY MEANS, A PLURALITY OF INTERCONNECTED HEATER ELEMENTS, SAID HEATER ELEMENTS BEING INTERCONNETED IN A FIRST CONFIGURATION ON CONDITIONING OF SAID FIRST CONTACT MEANS TO APPLY A FIRST VOLTAGE VALUE TO SAID ELEMENTS; A TIMING RELAY ENERGIZED SIMULTANEOUSLY WITH SAID FIRST RELAY MEANS, A SECOND RELAY MEANS OPERATIVE RELATED TO SAID TIMING RELAY FOR CON NECTION TO SAID SOURCE AT A TIME AFTER THE ENERGIZATION OF SAID TIMING RELAY DEPENDENT ON THE CYCLE OF THE TIMING RELAY, MEANS FOR DE-ENERGIZING SAID FIRST RELAY MEANS ON ENERGIZATION OF SAID SECOND MEANS; A SECOND CONTACT MEANS CONDITIONED IN RESPONSE TO THE ENERGIZATION OF SAID SECOND RELAY MEANS, SAID HEATER ELEMENTS BEING INTERCON NECTED IN A SECOND CONFIGURATION ON CONDITIONING OF SAID SECOND CONTACT MEANS TO APPLY A SECOND VOLTAGE OF GREATER MAGNITUDE THAN SAID FIRST VOLTAGE TO EACH OF SAID HEATER ELEMENTS.