Energy seal for a microwave oven

A microwave oven comprising in combination, an enclosure including top, bottom, side and rear walls forming a cooking cavity having an access opening in the front thereof, a door operable between a closed position over said access opening and an open position, a source of microwave energy, means supplying said microwave energy to said cavity, said top, bottom and side walls including flange portions forming an annular flange surrounding said access opening, said door having a portion facing said annular flange when in the closed position and forming a gap between said door and enclosure, a primary energy seal interposed in said gap proximate said cavity, said primary energy seal including conductive means surrounded by dielectric means interposed between the oven door and flange means for forming a capacitance across the transmission path formed by said gap, said primary seal being resilient but tending to oppose compression so that closing of said door causes said primary seal to closely conform to the gap filling the portion of said gap proximate said cavity, resilient outboard seal means interposed in said gap outboard of said primary seal for presenting a very small impedance to the transmission path formed in said gap, and choke means comprising a cavity having a predetermined depth and an aperture into said gap interposed between said primary and outboard means.

In a microwave oven having an enclosure forming a cooking cavity, a door operable between an open position to allow access to said cavity and a closed position to close said cavity, said door in its closed position forming a gap between the enclosure and door and providing an enclosure-interface surface and a door-interface surface at the door-enclosure interface and an energy seal coextensive with the door-enclosure interface, wherein the improvement comprises:

• the energy seal comprising in combination, a conformable capacitive tube-like primary seal positioned in the gap proximate said cavity, said primary seal including an inner metallic layer encompassed by a dielectric layer, said primary seal being compressible but serving to resist compression thereby to fill the gap proximate the cavity when the door is in its closed position, a secondary choke seal outboard of said primary seal, said secondary seal including a cavity of predetermined depth having an aperture into the gap outboard of the primary seal, and outboard seal means positioned outboard of the secondary seal for presenting a very small impedance to the transmission path formed in said gap thereby to increase the effectiveness of said secondary seal.