Device for controlling the air supply to a gas burner

A gas burner installation comprising:

• housing means formed with an air intake at atmospheric pressure, a combustion chamber, a passage connecting said intake with said combustion chamber and a passage connected to said combustion chamber for discharging combustion gases;
• a gas-supply conduit opening into said housing in the region of said combustion chamber for supplying fuel gas thereto;
• a flow-control member cooperating with one of said passages and displaceable to control the air flow from said intake to said combustion chamber, said member being provided with means for displacing said member as a function of the air flow rate;
• sensing means responsive to the gas pressure in said conduit;
• and
• means connected to said sensing means for displacing said member so as to maintain a substantially constant ratio of air to fuel gas supplied to said combustion chamber, said flow-control member being a swingable flap disposed in said passage between said intake and said combustion chamber, said sensing means comprising a manometer housing having a control membrane pressurized on one side by said gas pressure and on an opposite side by the pressure in said combustion chamber, said means connected to said sensing means including an element connected to said membrane and a lever connected to said flap and said element.