Current-limiting fuse with dual element release and having extensions of the current-limiting elements cut by arc blasts in arc chutes and by a mechanical cutter

Claim 1

A CURRENT-LIMITING FUSE INCLUDING: AN ELONGATED INSULATING HOUSING WITH END TERMINALS, AN INTERMEDIATE TERMINAL IN SAID HOUSING INSULATED FROM SAID END TERMINALS, FUSIBLE ELEMENT MEANS INTERCONNECTING ONE END TERMINAL AND SAID INTERMEDIATE TERMINAL, A PLURALITY OF CURRENT-LIMITING FUSIBLE ELEMENTS EMBEDDED IN AN INERT FILLING IN SAID HOUSING AND CONNECTED IN PARALLEL CIRCUIT RELATION BETWEEN SAID INTERMEDIATE TERMINAL AND THE OTHER END TERMINAL, A MINOR PORTION OF EACH CURRENT-LIMITING FUSIBLE ELEMENT ADJACENT SAID INTERMEDIATE TERMINAL CONSTITUTING AN EXTENSION OF A MAJOR PORTION THEREOF, MEANS PROVIDING A SPARK GAP INDIVIDUAL TO EACH CURRENTLIMITING FUSIBLE ELEMENT, ONE TERMINAL OF EACH SPARK GAP BEING CONNECTED TO THE JUNCTION BETWEEN THE RESPECTIVE EXTENSION AND THE MAJOR PORTION OF ITS CURRENT-LIMITING FUSIBLE ELEMENT, THE OTHER TERMINAL OF EACH SPARK GAP INCLUDING CONDUCTOR MEANS CONNECTED TO SAID ONE END TERMINAL THEREBY PLACING SAID SPARK GAPS IN SHUNT CIRCUIT RELATION TO THE GAP FORMED ON BLOWING OF SAID FUSIBLE ELEMENT MEANS ON FLOW OF FAULT CURRENT THERETHROUGH, AN AUXILIARY TERMINAL CONNECTED TO THE JUNCTION OF ONE OF SAID CURRENT-LIMITING ELEMENTS, MEANS INTERCONNECTING SAID INTERMEDIATE TERMINAL AND SAID AUXILIARY TERMINAL, AND MEANS RESPONSIVE TO BLOWING OF AT LEAST ONE OF SAID CURRENT-LIMITING FUSIBLE ELEMENTS FOR INTERRUPTING THE CONNECTION BETWEEN SAID INTERMEDIATE TERMINAL AND SAID AUXILIARY TERMINAL.