Combination convection and microwave oven having improved microwave energy distribution

Claim 1

A cooking oven having both conventional heating using rotating heat, and microwave heating, comprising: a muffle having a front door, side walls, a lower sole plate and an upper vault, and a back wall; a metallic distribution sheet adjacent the back wall defining a cavity with said back wall in which there is mounted a bladed turbine; a shaft supporting said bladed turbine, passing through the back wall to be driven by an electrical motor on the opposite side of the cavity, said metallic sheet including orifices distributed so as to permit convection, forced by the turbine, of a stream of air drawn through the central part of the metallic sheet and expelled in the vicinity of its lateral sides; and, at least one source of microwave frequency waves situated outside the muffle having a waveguide output which opens into the muffle through at least one exit iris, the waveguide exit iris being situated in the back wall of the muffle facing a passage provided in the metallic distribution sheet, whereby a wave flux exiting said iris is divided into a first portion which exits said facing passage and a second portion, said second portion being distributed in the cavity behind the metallic sheet, where the turbine of the fan is situated, striking the blades of said turbine, and exiting holes pierced in the metallic sheet toward the interior of the muffle.