Door assembly for microwave heating apparatus

Claim 1

A heating apparatus employing high frequency electromagnetic wave energy, said apparatus comprising: a heating chamber in which the high frequency electromagnetic wave energy is employed for heating, said heating chamber having an access opening thereto; a door hinged to said heating chamber for opening and closing over said access opening, the periphery of said door surrounding said access opening when said door is closed, at least a portion of said periphery comprising an inner side wall extending away from said heating chamber, a bottom wall continuous with and extending from said inner side wall, and an outer side wall continuous with and extending from said bottom wall back toward said heating chamber thereby defining a groove facing and open to said heating chamber; and a generally elongated metallic element fixed to the periphery of said door in said groove and defining with said groove an attenuator for attenuating electromagnetic wave energy leaking from said heating chamber out said access opening surrounded by the periphery of said door, said elongated metallic element comprising a base extending along said bottom wall, a lateral wall continuous with and extending from said base toward said heating chamber and abutting said outer side wall where said outer wall extends from said bottom wall, a rear wall continuous with and extending from said lateral wall toward said inner side wall, and a partition wall continuous with and extending from said rear side wall, said partition wall, said rear wall, and said lateral wall having a plurality of spaced apart recesses each of which extends continuously through said partition wall and said rear wall and said lateral wall to respective locations spaced on said lateral wall above said base whereby a plurality of projections of said elongated metallic elements are defined between said spaced apart recesses.