Fuel control device, fuel control system using the device and method of making the device

In a fuel control device comprising a housing means having a passage therethrough for interconnecting a fuel source with a main burner means, a throttle valve means disposed in said passage for throttling fuel flow through said passage to said burner means, and selector means operatively interconnected to said throttle valve means to operate the same, said throttle valve means comprising a pair of members one of which is substantially stationary and the other of which is rotatable relative to said one member, said one member having a face and having aperture means interrupting said face thereof and passing therethrough, said other member having a face means disposed in sliding engagement with said face of said one member for controlling the effective opening of said aperture means for fuel flow therethrough, said selector means being operatively interconnected to said other member to rotate the same relative to said one member and thereby control the flow of fuel through said passage, said other member having an opening interrupting said face means thereof and being adapted to overlap said aperture means in various positions therewith for controlling said fuel flow therethrough, the improvement wherein said other member comprises a generally conical plug valve member having an axis of rotation and having an end surface disposed substantially transverse to said axis and comprising said face means thereof, and a spring means carried by said housing means and acting on said one member to tend to force said face of said one member against said face means of said plug valve member, said spring means comprising a coiled compression spring having opposed ends one of which is interconnected to said one member and the other of which is interconnected to said housing means whereby said one member is carried by said spring, said spring having relatively little torsional movement whereby said spring holds said one member substantially rotationally stationary relative to said housing means while permitting axial movement of said one member relative to said housing means.