Sprinkler head

Abstract

The present invention is to discharge the fire extinguishing water by accurately opening the valve, using a shape-memory alloy at a predetermined temperature in a fire. When a shape-memory alloy in a first heat sensitive operation part is heated to a predetermined memory restoring temperature, a pilot valve is operated by the restoring force thereof so that a spool valve can be in a state capable of being opened by an actuator. When a second heat sensitive operation part reaches a predetermined water discharge starting temperature higher than the memory restoring temperature, a fusible alloy provided inside is thermally decomposed so that the first heat sensitive operation part maintained in the closed state is released so as to discharge the fire extinguishing water. When the temperature becomes lower than the memory restoring temperature by the fire extinguishment by the water discharge, a restoring spring deforms the shape-memory alloy into the initial shape so as to drive the valve mechanism into the closed state for stopping the water discharge. Accordingly, since the start of the water discharge can be controlled by the water discharge starting temperature having less fluctuation with respect to the memory restoring temperature, the water can be discharged further accurately. Moreover, since the memory restoring temperature needs not be set accurately, the production efficiency of the sprinkler head can be improved to facilitate the mass productivity.

Dependencies are inferred from the claim text.