Smoke detecting apparatus

Claim 1

IN SMOKE DETECTING APPARATUS, THE COMBINATION OF A BASE HAVING AT LEAST EIGHT EQUIDISTANTLY CIRCUMFERENTIALLY SPACED APART PORTS THEREIN EACH PROVIDES WITH AN INLET AND WITH AN OUTLET FOR CONNECTION TO A CONDUIT FOR SUPPLYING AIR SAMPLES FROM A SPACE IN WHICH SMOKE IS TO BE DETECTED, A ROTOR MOUNTED FOR ROTATION WITH RESPECT TO SAID BASE INCLUDING A HEAD HAVING A GROUP OF THREE PORTS EACH PROVIDED WITH AN OUTLET AND WITH AN INLET ARRANGED SO THAT THREE HEAD PORT INLETS SIMULTANEOUSLY REGISTER WITH THREE BASE PORT OUTLETS RESPECTIVELY, THREE TUBES ARRANGED SIDEBY-SIDE FOR VISUALLY DETECTING SMOKE IN THE AIR SAMPLES AND EACH PROVIDED WITH AN INLET AND AN OUTLET, CONDUIT MEANS CONNECTING EACH OF SAID HEAD PORT OUTLETS WITH ONE OF SAID TUBE INLETS, AND MOTOR MEANS FOR EFFETINGH STEPWISE ROTATION OF SAID ROTOR TO SUCCESSIVELY PLACE THREE SAID HEAD PORT INLETS IN REGISTRY WITH THREE SAID BASE PORT OUTLETS, SAID CONDUIT MEANS BEING CONNECTED TO CAUSE AN AIR SAMPLE FROM THE SAME SPACE TO FLOW THROUGH EACH OF SAID TUBES AT A DEFFERENT TIME SO THAT A GROUP OF AIR SAMPLES IS VIEWED WITH EACH SAMPLE OF THE GROUP BEING VIEWED THREE TIMES BUT IN A DIFFERENT ONE OF SAID TUBES IN A GIVEN SEQUENCE.