Alarm system for refrigerators

Claim 1

IN COMBINATION: A REFRIGERATOR HAVING IN IT A PRODUCT AREA, SAID REFRIGERATOR HAVING A CONTROLLABLE COOLING MEANS HAVING A COOLING SURFACE DISPOSED IN COOLING RELATIONSHIP WITH RESPECT TO SAID PRODUCT AREA, SAID REFRIGERATOR HAVING A CONTROLLABLE HEATING MEANS DISPOSED IN A POSITION TO CAUSE DEFROSTING OF SAID COOLING SURFACE, A FIRST THERMAL SWITCH MEANS FOR OPERATING WHILE SAID COOLING MEANS IS IN OPERATION, SAID FIRST THERMAL SWITCH MEANS HAVING A FIRST TEMPERATURE CHANGE SENSING ELEMENT DISPOSED IN A POSITION FOR BEING AFFECTED BY A TEMPERATURE CHANGE IN SAID PRODUCT AREA, A SECOND THERMAL SWITCH MEANS TO PREVENT ALARM WHILE SAID HEATING MEANS IS IN DEFROSTING OPERATION, SAID SECOND THERMAL SWITCH MEANS HAVING A SECOND TEMPERATURE CHANGE SENSING ELEMENT DISPOSED IN A POSITION FOR BEING AFFECTED BY TEMPERATURE CHANGE IN SAID PRODUCT AREA, A CONTROLLABLE ALARM SYSTEM, A FIRST CONTROL CIRCUIT INTERCONNECTING SAID ALARM SYSTEM AND SAID FIRST THERMAL SWITCH FOR THE ACTUATION OF ALARM IN THE EVENT OF A TEMPERATURE RISE IN SAID PRODUCT AREA, A SECOND CONTROL CIRCUIT CONNECTED TO SAID SECOND SWITCH AND CONNECTED IN SERIES TO AND INTERRUPTING SAID FIRST CONTROL CIRCUIT SO THAT SAID SECOND SWITCH OPENS SAID FIRST CIRCUIT DURING DEFROSTING OF SAID REFRIGERATOR BY OPERATION OF SAID HEATING MEANS TO PREVENT UNDESIRED ALARM, SAID FIRST SWITCH BEING SUFFICIENTLY FAR FROM SAID HEATING MEANS AS TO NOT CLOSE BEFORE SAID SECOND SWITCH OPENS SAID FIRST CONTROL CIRCUIT.