Fire sprinkler control system

Claim 1

IN A FIRE EXTINGUISHING SYSTEM INCLUDING A FLUID ACTUATED MAIN CONTROL VALVE HAVING A BODY FORMING AN INLET PASSAGEWAY CONNECTED TO A SOURCE OF FLUID UNDER PRESSURE AND AN OUTLET PASSAGEWAY CONNECTED TO A SPRINKLER NETWORK AND AN OPERATING PORTION, SAID MAIN CONTROL VALVE BEING RESPONSIVE IN OPENING AND CLOSING OPERATION TO A RESPECTIVE DECREASE AND INCREASE OF FLUID PRESSURE IN SAID OPERATING PORTION THEREOF; (A) MEANS FOR NORMALLY MAINTAINING A PRESSURE IN SAID OPERATING PORTION SUFFICIENT TO MAINTAIN SAID MAIN CONTROL VALVE CLOSED, (B) A NORMALLY CLOSED RELEASE FLOW LINE COMMUNICATING WITH SAID OPERATING PORTION AND ADAPTED TO REDUCE THE PRESSURE IN SAID OPERATING PORTION TO OPEN SAID MAIN CONTROL VALVE IN THE EVENT OF FLOW THROUGH SAID RELEASE FLOW LINE, (C) SINGLE OPERATION HEAT RESPONSIVE RELEASE MEANS ASSOCIATED WITH SAID RELEASE FLOW LINE FOR PERMITTING FLOW THROUGH SAID RELEASE FLOW LINE, (D) MEANS COMMUNICATING WITH SAID RELEASE FLOW LINE FOR SENSING A PRESSURE DROP SIGNIFYING THE OPENING OF SAID MAIN CONTROL VALVE, (E) A NORMALLY OPEN VALVE OPERATIVELY CONNECTED IN SERIES IN SAID RELEASE FLOW LINE BETWEEN SAID HEAT RESPONSIVE RELEASE MEANS AND SAID OPERATING PORTION AND ADAPTED WHILE CLOSED TO BLOCK FLOW PAST SAID NORMALLY OPEN VALVE, (F) MEANS OPERATIVELY CONNECTING SAID PRESSURE SENSING MEANS AND SAID NORMALLY OPEN VALVE AND RESPONSIVE UPON THE SENSING OF A PRESSURE DROP BY SAID PRESSURE SENSING MEANS TO DELAY FOR A PRE-SET TIME PERIOD AND THEN CAUSE THE CLOSING OF SAID NORMALLY OPEN VALVE, (G) A NORMALLY CLOSED VALVE OPERATIVELY CONNECTED IN PARALLEL TO SAID RELEASE FLOW LINE BETWEEN SAID NORMALLY OPEN VALVE AND SAID OPERATING PORTION AND BEING ADAPTED WHILE OPEN TO PERMIT MAIN CONTROL VALVE OPENING FLOW FROM SAID RELEASE FLOW LINE UPSTREAM FROM SAID NORMALLY OPEN VALVE, AND (H) HEAT SENSING MEANS OPERATIVELY CONNECTED TO SAID NORMALLY CLOSED VALVE AND ADAPTED TO OPEN SAID NORMALLY CLOSED VALVE ABOVE A PREDETERMINED TEMPERATURE AND CLOSE SAID NORMALLY CLOSED VALVE BELOW SAID PREDETERMINED TEMPERATURE, (I) WHEREBY AFTER FIRE EXTINGUISHING FLOW CAUSED BY SAID HEAT RESPONSIVE RELEASE MEANS SAID MAIN CONTROL VALVE IS AUTOMATICALLY RECLOSED AFTER A PREDETERMINED TIME PERIOD TO LIMIT FLUID DAMAGE UNLESS THE TEMPERATURE REMAINS SUFFICIENTLY HIGH FOR ACTUATING SAID HEAT SENSING MEANS, AND SAID MAIN CONTROL VALVE IS AUTOMATICALLY REOPENED AFTER BEING RECLOSED IN CASE OF A REIGNITION AFTER THE TEMPERATURE HAS BEEN LOWERED.