Microwave oven with special rack designs

In an electronic heating apparatus, the combination comprising a metal enclosure defining a heating cavity for receiving therein a body to be heated, source means for transmitting microwave energy of a predetermined frequency into said heating cavity for establishing therein a predetermined electromagnetic field mode substantially at said predetermined frequency, a first metal rack disposed horizontally within said heating cavity and having a plurality of spaced-apart rods interconnected only adjacent to the ends thereof and extending substantially parallel to the direction of the electric field of said predetermined electromagnetic field mode, said first rack being dimensioned and positioned in said heating cavity for terminating said predetermined electromagnetic field mode substantially at said predetermined frequency, and a second metal rack disposed horizontally within said heating cavity in the wave pattern of said predetermined electromagnetic field mode terminated by said first rack and having a plurality of spaced-apart rods interconnected only adjacent to the ends thereof and extending substantially perpendicular to the direction of the electric field of said predetermined electromagnetic field mode, said second rack being movable among a plurality of different positions within said heating cavity for facilitating optimum heating of associated bodies of different impedances while having no adverse effect on the electromagnetic field pattern in said heating cavity, whereby said racks permit the supporting thereon of bodies to be heated in a plurality of different positions within the heating cavity while accommodating pyro-cleaning of the oven and terminating of said electromagnetic field mode without otherwise interfering with the electromagnetic wave pattern in said heating cavity.

In an electronic heating apparatus, the combination comprising a metal enclosure defining a heating cavity for receiving therein a body to be heated, source means including an antenna for transmitting microwave energy of a predetermined frequency into said heating cavity, a mode stirrer rotatably mounted in said heating cavity for cooperation with said antenna to establish in said heating cavity two predetermined electromagnetic field modes substantially at said predetermined frequency, a first metal rack disposed horizontally within said heating cavity and having a plurality of spaced-apart rods interconnected only adjacent to the ends thereof and extending substantially parallel to the direction of the resultant electric field of said predetermined electromagnetic field modes, said first rack being dimensioned and positioned in said heating cavity for terminating said two predetermined electromagnetic field modes substantially at said predetermined frequency, and a second metal rack disposed horizontally within said heating cavity in the wave pattern of said predetermined electromagnetic field modes terminated by said first rack and having a plurality of spaced-apart rods interconnected only adjacent to the ends thereof and extending substantially perpendicular to the direction of the resultant electric field of said predetermined electromagnetic field modes, said second rack being movable among a plurality of different positions within said heating cavity for facilitating optimum heating of associated bodies of different impedances while having no adverse effect on the electromagnetic field pattern in said heating cavity, whereby said racks permit the supporting thereon of bodies to be heated in a plurality of different positions within the heating cavity while accommodating pyro-cleaning of the oven and terminating of said electromagnetic field mode without otherwise interfering with the electromagnetic wave pattern in said heating cavity.