Lamp burn out monitoring device

Claim 1

A DEVICE FOR SEPARATELY AND INDEPENDENTLY INDICATING THE CONDITION OF EACH LAMP IN A MULTIPLE PARALLEL LAMP LIGHTING SYSTEM, WHICH COMPRISES IN COMBINATION WITH SAID LIGHTING SYSTEM A PLURALITY OF PAIRED FIRST AND SECOND PARALLEL CIRCUITS, EACH SAID FIRST CIRCUIT INCLUDING A MONITORED ILLUMINATING LAMP AND AN ELECTRICAL HEATER ELEMENT SERIES CONNECTED WITH SAID ILLUMINATING LAMP BUT PHYSICALLY REMOTE THEREFROM, EACH SAID SECOND CIRCUIT INCLUDING A NORMALLY CLOSED THERMAL SWITCH AND AN INDICATOR LAMP SERIES CONNECTED TO THE SWITCH CONTACT, THE HEATER ELEMENT IN EACH FIRST CIRCUIT BEING POSITIONED IN OPERATIVE HEAT TRANSFER RELATION TO THE THERMAL SWITCH IN THE RESPECTIVE SECOND CIRCUIT PAIRED THEREWITH, SAID SWITCH BEING OPENABLE BY HEAT GENERATED FROM CURRENT FLOW THROUGH SAID HEATER ELEMENT, AND A VOLTAGE SOURCE FOR ENERGIZING THE FIRST AND SECOND CIRCUITS WHEREBY THE INDICATOR LAMPS AR INITIALLY ILLUMINATED WHILE THE THERMAL SWITCHES ARE CLOSED AND THE INDICATING CIRCUITS ARE THEREBY SELF-CHECKING, AND THEREAFTER THE HEATER ELEMENTS IN OPERATIVE ILLUMINATING LAMP CIRCUITS OPEN THE THERMAL SWITCHES AND THE MONITORING INDICATOR LAMPS ARE EXTINGUISHED AND EACH REMAINS UNLIGHTED UNTIL A MONITORED ILLUMINATING LAMP BURNS OUT IN WHICH CASE THE THERMAL SWITCH AGAIN CLOSES AND THE ASSOCIATED INDICATOR LAMP GOES ON THE INDICATE THE INOPERATIVE CONDITION OF THE PARTICULAR MONITORED LAMP.

Claim 2

A DEVICE FOR SEPARATELY AND INDEPENDENTLY INDICATING THE CONDITION OF EACH LAMP IN A MULTIPLE PARALLEL LAMP LIGHTING SYSTEM, WHICH COMPRISES IN COMBINATION WITH SAID LIGHTING SYSTEM A PLURALITY OF PAIRED FIRST AND SECOND PARALLEL CIRCUITS, EACH SAID FIRST CIRCUIT INCLUDING A MONITORED ILLUMINATING LAMP AND AN ELECTRICAL HEATER ELEMENT SERIES CONNECTED WITH SAID ILLUMINATING LAMP BUT PHYSICALLY REMOTE THEREFROM, EACH SAID SECOND CIRCUIT INCLUDING A NORMALLY CLOSED THERMAL SWITCH AND AN INDICATOR LAMP SERIES CONNECTED TO THE SWITCH CONTACT, THE HEATER ELEMENT IN EACH FIRST CIRCUIT BEING POSITIONED IN OPERATIVE HEAT TRANSFER RELATION TO THE THERMAL SWITCH IN THE RESPECTIVE SECOND CIRCUIT PAIRED THEREWITH, SAID SWITCH BEING OPENABLE BY HEAT GENERATED FROM CURRENT FLOW THROUGH SAID HEATER ELEMENT, AND A VOLTAGE SOURCE FOR ENERGIZING THE FIRST AND SECOND CIRCUITS WHEREBY THE INDICATOR LAMPS AR INITIALLY ILLUMINATED WHILE THE THERMAL SWITCHES ARE CLOSED AND THE INDICATING CIRCUITS ARE THEREBY SELF-CHECKING, AND THEREAFTER THE HEATER ELEMENTS IN OPERATIVE ILLUMINATING LAMP CIRCUITS OPEN THE THERMAL SWITCHES AND THE MONITORING INDICATOR LAMPS ARE EXTINGUISHED AND EACH REMAINS UNLIGHTED UNTIL A MONITORED ILLUMINATING LAMP BURNS OUT IN WHICH CASE THE THERMAL SWITCH AGAIN CLOSES AND THE ASSOCIATED INDICATOR LAMP GOES ON THE INDICATE THE INOPERATIVE CONDITION OF THE PARTICULAR MONITORED LAMP.