Patent ID: 8353356

Claim:
A residential flat plate concealed sprinkler for the fire protection of an area ranging from about 144 square feet to about 400 square feet, the sprinkler comprising: an outer housing having an inner surface defining a chamber; a body at least partially disposed within the chamber, the body having an inlet and an outlet spaced along a longitudinal axis, the outlet having a minimum design fluid flow ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20gpm) and the inlet having a minimum design input fluid pressure ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.), the body including an inner surface defining a passageway for communication between the inlet and the outlet; at least one guide member having a proximal end and a distal end, the proximal end being coupled to the body and the distal end having telescopic movement relative to the outlet in direction parallel to the longitudinal axis; and a deflector assembly for distributing a flow of fluid over the protected area, the protection area ranging from about 144 square feet to about 400 square feet (144-400 ft. 2 ), the fluid distribution having a density of at least 0.05 gallons per minute per square foot (0.05 gpm/ft 2 ) for a minimum operating pressure and a minimum operating fluid flow each being a function of the size of the protection area, the minimum operating pressures ranging from about seven pounds per square inch to about seventeen pounds per square inch (7-17 psi.) and the range of minimum operating fluid flows ranging from about thirteen gallons per minute to about twenty gallons per minute (13-20gpm), the deflector assembly being coupled to the distal end of the at least one guide member so that the deflector assembly has a first position distal of the outlet and a second position distal of the first position, the deflector assembly including in each of the first and second positions: a plate member; a projection member coupled to the plate member, wherein the protection member and the plate member defines a proximal surface substantially orthogonal to the longitudinal axis and spaced axially from the outlet, a distal surface of the proximal surface and orthogonal to the longitudinal axis, arid an intermediate surface between the proximal surface and the distal surface, the intermediate surface being substantially orthogonal to the longitudinal axis, the distal surface defining an substantially oval perimeter circumscribed about the longitudinal axis and further including a plurality, of slots substantially equiradially spaced about the longitudinal axis, each slot having a substantially straight portion initiating from the perimeter and extending radially toward the longitudinal taxis to define a slot length and further having a slot width, the plurality of slots also further defining a first slot group having a first slot length; and at least a second slot group having a second slot length smaller than the first slot length.