US Patent 7819657 Gas burner with only an internal flame

A burner has a pot provided with an inlet for a gas mixture to be burned and a cap that sits on top of the pot. The pot and the cap define both a central zone for combustion of the gas mixture, and a peripheral chamber that extends around the central zone and communicates with the gas inlet. A plurality of passageways allow the gas mixture to flow from the peripheral chamber into the central zone. A deflector separates, in a non-leaktight manner, the chamber into a lower subchamber, located substantially in the extension of the inlet, and an upper subchamber adjacent said passageways.