Elapsed time indicator

Claim 1

IN A MERCURY COULOMETER FOR MEASURING AND INDICATING THE ELAPSE OF TIME DURING WHICH A FIXED CURRENT IS APPLIED THERETO OF THE TYPE INCLUDING A HOUSING HAVING A FIRST INTERNAL CHAMBER, A FILTER ADAPTED TO PREVENT THE PASSAGE OF MERCURY, EXCEPT ELECTROLYTICALLY, SEPARATING SAID CHAMBER INTO AN ANODE SECTION AND CATHODE SECTION, SAID CATHODE SECTION HAVING AN ELONGATED TUBULAR MEMBER ADAPTED TO RECEIVE AND CONCENTRATE A PREDETERMINED PORTION OF MERCURY OF MEASUREMENT, A BODY OF MERCURY SUBSTANTIALLY FILLING SAID ANODE SECTION, AND ELECTROLYTE SOLUTION FILLING THE REMAINDER OF SAID ANODE SECTION AND SAID CATHODE SECTION, CONTACTS EXTENDING INTO EACH SAID SECTION, ILLUMINATING AND VOLTAGE REGULATING APPARATUS FOR SAID COULOMETER COMPRISING, A SECOND INTERNAL CHAMBER IN SAID HOUSING FOR RECEIVING VOLTAGE REGULATING COMPONENTS THEREIN, SAID HOUSING HAVING INDICIA SELECTIVELY POSITIONED ON THE OUTER SURFACE THEREOF, SAID TUBULAR MEMBER BEING DISPOSED PROXIMATE THE INNER WALL OF SAID SECOND CHAMBER IN A ASSOCIATEION WITH SAID INDICIA, A GAS DISCHARGE DEVICE POSITIONED IN SAID SECOND CHAMBER ADJACENT SAID TUBULAR MEMBER, LIGHT FROM SAID DISCHARGE DEVICE BEING EFFECTIVE TO ILLUMINATE THE LEVEL OF MERCURY IN SAID TUBULAR MEMBER AND SAID INDICIA, A SOURCE OF VOLTAGE FOR ENERGIZING SAID COULOMETER, VOLTAGE REGULATING MEANS FOR SAID COULOMETER DISPOSED IN SAID SECOND CHAMBER AND CONNECTED TO SAID SOURCE OF VOLTAGE AND SAID CONTACTS, SAID REGULATING MEANS INCLUDING SAID DISCHARGE DEVICE CONNECTED IN SHUT ACROSS SAID VOLTAGE SOURCE, THE DISCHARGE DEVICE BEING OPERATIVE TO ILLUMINATE SAID TUBULAR MEMBER AND SAID INDICIA AND ESTABLISH A SOURCE OF CONSTANT VOLTAGE FOR SAID COULOMETER.