Fire detecting unit

Claim 1

A FIRE DETECTING UNIT FOR ENERGIZING AN ELECTRICALLY OPERATED ALARM WHEN EITHER THE AMBIENT ATMOSPHERE IN A BUILDING IN WHICH SAID UNIT IS SITUATED RISES ABOVE A PREDETERMINED TEMPERATURE OR SMOKE IS PRESENT IN SAID ATMOSPHERE, INCLUDING: (A) A PLATE; (B) A CONTINUOUS WALL PROJECTING FROM A FIRST SIDE OF SAID PLATE; (C) AN OQAQUE HOUSING PROJECTING FROM SAID FIRST SIDE AND DISPOSED INSIDE SAID WALL, SAID WALL, PLATE AND HOUSING COOPERATING TO DEFINE AN ANNULUS-SHAPED SMOKE RECEIVING SPACE, SAID HOUSING HAVING LONGITUDINALLY SPACED FIRST AND SECOND CAVITIES THEREIN, AND A TRANSVERSE LIGHT TUNNEL THAT IS IN COMMUNICATION WITH SAID FIRST CAVITY AND SAID ANNULUS-SHAPED SPACE; (D) FIRST MEANS FOR SUPPORTING SAID PLATE AT A POSITION IN SAID STRUCTURE TOWARDS WHICH SMOKE WILL TEND TO MOVE IN CASE OF A FIRE; (E) A SOLENOID OPERATED RELAY THAT REMAINS OPEN ONLY SO LONG AS AN ELECTRIC CURRENT IS SUPPLIED TO SAID SOLENOID ABOVE A PREDETERMINED MINIMUM VOLTAGE; (F) A FIRST ELECTRIC CIRCUIT CAPABLE OF SUPPLYING ELECTRICAL ENERGY TO SAID SOLENOID OF SAID RELAY AT ABOVE SAID MINIMUM VOLTAGE; (G) ELECTRICALLY OPERATED LIGHT GENERATING MEANS IN SAID FIRST CAVITY THAT FORM A PART OF SAID FIRST CIRCUIT, WITH LIGHT FROM SAID GENERATING MEANS PASSING AS A BEAM FROM SAID TUNNEL INTO SAID SPACE; (H) PHOTO-ELECTRIC MEANS THAT FORM A PART OF SAID FIRST CIRCUIT SUPPORTED FROM SAID WALL AND IN RADIAL ALIGNMENT WITH SAID TUNNEL TO HAVE SAID BEAM OF LIGHT FALL THEREON, SAID PHOTO-ELECTRIC MEANS INCREASING IN RESISTANCE AS THE INTENSITY OF SAID BEAM DIMINISHES DUE TO PRESENCE OF SMOKE IN SAID ANNULUS-SHAPED SPACE; (I) A NORMALLY CLOSED THERMOSTAT THAT FORMS A PART OF SAID FIRST CIRCUIT AND DISPOSED IN SAID SECOND CAVITY, SAID THERMOSTAT OPENING TO BREAK SAID FIRST CIRCUIT WHEN SAID AMBIENT ATMOSPHERE RISES ABOVE SAID PREDETERMINED TEMPERATURE; (J) FIRST MEANS FORMING A PART OF SAID FIRST CIRCUIT FOR HOLDING THE VOLTAGE SUPPLIED TO SAID LIGHT GENERATING MEANS CONSTANT AND AT A MAGNITUDE GREATER THAN SAID PREDETERMINED MINIMUM VOLTAGE; AND (K) A SECOND NORMALLY OPEN ELECTRIC CIRCUIT OF WHICH SAID SOLENOID OPERATED RELAY AND ALARM FROM A PART, SAID SECOND CIRCUIT BEING CLOSED TO ENERGIZE SAID ALARM BY EITHER SAID THERMOSTAT OPENING TO BREAK SAID FIRST CIRCUIT TO SAID SOLENOID OPERATED RELAY DUE TO SAID AMBIENT ATMOSPHERE RISING ABOVE SAID PREDETERMINED TEMPERATURE, OR THE MAGNITUDE OF THE CURRENT IN SAID FIRST CIRCUIT DROPPING BELOW SAID PREDETERMINED VOLTAGE DUE TO INCREASE IN RESISTANCE OF SAID PHOTO-ELECTRIC MEANS BY SMOKE ACCUMULATING IN SAID ANNULUS-SHAPED SPACE TO LESSEN THE INTENSITY OF SAID BEAM OF LIGHT FALLING ON SAID PHOTO-ELECTRIC MEANS.