Patent ID: 6766820
Filing Date: 2004-07-27
Classification: F23N,F23Q,Y10T

Abstract:
A pilot guard for controlling the flow of gaseous fuel to both a pilot burner and a main burner comprising:a housing having an inlet port, a pilot port, and a main burner port; a bore extending through said housing between said pilot port and said main burner port; a stop shuttle normally biased to a seated position in which it blocks communication between said inlet port and said bore and prevents the flow of gaseous fuel to both said pilot port and said main burner port; a reset shuttle positioned in said bore for lifting said stop shuttle from its seated position, said reset shuttle supporting a sealing member for sealing the inlet port from the main burner port but permitting communication between said inlet port and said pilot port when said reset shuttle lifts said stop shuttle from its seated position; a thermocouple capable of generating a voltage from the heat of the pilot burner; an electromagnet connected to said thermocouple and capable, when energized by a predetermined current produced by said thermocouple, of holding said stop shuttle from moving to its seated position; and a current adjustor connected between said thermocouple and said electromagnet by which the current applied to said electromagnet by said thermocouple can be adjusted; said reset shuttle being movable by the force of gas pressure from said inlet port to a position in which said sealing member permits both said main burner port and said pilot port to communicate with said inlet port: whereby, said stop shuttle moves to said seated position when said thermocouple does not produce at least said predetermined current to said electromagnet.