Microwave oven with a vertically translatable resistance heater or the like

A high frequency heating apparatus, comprising:

• an enclosure defining therein a heating chamber for accommodating therein an article to be heated and having an elongated opening extending therethrough;
• electromagnetic wave supply means for supplying electromagnetic waves of a substantially predetermined wave length into said heating chamber for dielectric heating of said article;
• a member movably extending through said elongated opening from interior to said heating chamber to exterior to said heating chamber;
• means for supporting and guiding said member with respect to said enclosure for a guided translational movement within and along said elongated opening in the enclosure;
• means for moving said guided member within said elongated opening and holding the member at at least two positions;
• and
• electromagnetic wave leakage preventing means for preventing an electromagnetic wave leakage from said heating chamber through said elongated opening, including means for defining a substantially elongated first annular space defined by an electrically conductive material and disposed along a periphery of said elongated opening, said first annular space having a circumferentially extending communication port at the inner periphery thereof for introducing therethrough the electromagnetic waves passing through said elongated opening into said first annular space, said first annular space being dimensioned to be effective for extinguishing, by means of the choke effect, the electromagnetic waves introduced therein;
• whereby said member is translatable within said heating chamber while the leakage of the electromagnetic waves through said elongated opening is substantially prevented;
• wherein said electromagnetic wave leakage preventing means comprises a plate member attached to said supporting means and movable with respect to said enclosure for substantially closing said elongated opening in the enclosure and the inner space defined by the inner periphery of said elongated first annular space, said plate member being dimensioned to substantially close said elongated opening and said inner space irrespective of the position of said supporting means;
• and wherein an electromagnetic wave absorbing material for absorbing and dissipating electromagnetic wave energy is disposed in an electromagnetic wave leakage path between said movable plate member and said elongated first annular space;
• and wherein said leakage preventing means comprises a second substantially annular space defined by an electrically conductive material and disposed on and about said extending member, said second annular space having a circumferentially extending communication port at the inner periphery thereof for introducing therethrough the electromagnetic waves passing through said inner space of said first annular space into said second annular space, said second annular space being dimensioned to be effective for extinguishing, by means of the choke effect, the electromagnetic waves introduced therein.

A high frequency heating apparatus, comprising:

• an enclosure defining therein a heating chamber for accommodating therein an article to be heatedd and having an elongated opening extending therethrough;
• electromagnetic wave supply means for supplying electromagnetic waves of a substantially predetermined wave length into said heating chamber for dielectric heating of said article;
• a member movably extending through said elongated opening from interior to said heating chamber to exterior to said heating chamber;
• means for supporting and guiding said member with respect to said enclosure for a guided translational movement within and along said elongated opening in the enclosure;
• means for moving said guided member within said elongated opening and holding the member at at least two positions;
• and
• electromagnetic wave leakage preventing means for preventing an electromagnetic wave leakage from said heating chamber through said elongated opening, including means for defining a substantially elongated first annular space defined by an electrically conductive material and disposed along a periphery of said elongated opening, said first annular space having a circumferentially extending communication port at the inner periphery thereof for introducing therethrough the electromagnetic waves passing through said elongated opening into said first annular space, said first annular space being dimensioned to be effective for extinguishing, by means of the choke effect, the electromagnetic waves introduced therein;
• whereby said member is translatable within said heating chamber while the leakage of the electromagnetic waves through said elongated opening is substantially prevented;
• wherein said electromagnetic wave leakage preventing means comprises a plate member attached to said supporting means and movable with respect to said enclosure for substantially closing said elongated opening in the enclosure and the inner space defined by the inner periphery of said elongated first annular space, said plate member being dimensioned to substantially close said elongated opening and said inner space irrespective of the position of said supporting means;
• and wherein an electromagnetic wave absorbing material for absorbing and dissipating electromagentic wave energy is disposed in an electromagnetic wave leakage path between said movable plate member and said elongated first annular space;
• and wherein said defining means comprises a portion of said enclosure around said elongated opening and said movable plate member covering said elongated opening and having a substantially annular flange portion extending from a major flat surface of said plate member toward said enclosure, said elongated first annular space being defined between said enclosure and said plate member.