Electronic oven with mode exciter

Claim 2

Electronic heating apparatus comprising an enclosure including two opposed parallel walls and defining a heating cavity for receiving therein a body to be heated, an antenna disposed in said cavity adjacent to one of said opposed walls and having a longitudinal axis substantially perpendicular to said one wall, said antenna being adapted for coupling to an associated source of electromagnetic energy of a predetermined ultra-high frequency for transmitting said energy into said cavity to excite therein a predetermined primary electromagnetic field mode, a grounded conductive member disposed in said cavity adjacent to the other of said opposed walls, and drive means coupled to said conductive member for effecting rotation thereof about said axis of said antenna for exciting in said cavity a predetermined secondary mode complementary to said primary mode, whereby there is established within said cavity a substantially uniform time-averaged field distribution thereby to facilitate uniform heating of the associated body.

Claim 3

The electronic heating apparatus set forth in claim 1, wherein said enclosure includes six walls arranged substantially to form a rectangular parallelepiped, said antenna being disposed centrally of the bottom wall of said enclosure and said conductive member being disposed centrally of the top wall of said enclosure.

Claim 4

The electronic heaTing apparatus set forth in claim 1, wherein said antenna includes a cylindrical post having the longitudinal axis thereof disposed substantially normal to said one wall, and a capacitive disk-like member connected to said post at the inner end thereof substantially coaxially therewith.

Claim 5

The electronic heating apparatus set forth in claim 1, wherein said antenna includes a cylindrical post having the longitudinal axis thereof disposed substantially normal to said one wall, and a capacitive disk-like member connected to said post at the inner end thereof substantially coaxially therewith, said drive means including a grounded shaft extending inwardly of said other wall substantially coaxially with said antenna post, said shaft being connected to said conductive member for effecting rotation thereof.

Claim 6

The electronic heating apparatus set forth in claim 1, and further including a rack mounted in said cavity for supporting an associated body to be heated, said rack including a plurality of spaced-apart parallel rods interconnected at the opposite ends thereof, said rods being disposed in use substantially parallel to the direction of propagation of said primary and secondary mode electromagnetic energy thereby freely to accommodate excitation of said primary and secondary modes without interference therewith.

Claim 7

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a generally L-shaped conductive member disposed in said cavity and having two interconnected leg portions intersecting at an angle and lying in a common plane substantially normal to the axis of said shaft, said shaft being connected to said conductive member at the free end of one of the said leg portions thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interaction with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 8

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a generally L-shaped conductive member disposed in said cavity and having two interconnected leg portions intersecting at an angle and lying in a common plane substantially normal to the axis of said shaft, said shaft being connected to said conductive member at the free end of one of the said leg portions thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interaction with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 9

The electronic heating apparatus set forth in claim 6, wherein said source means transmits into said heating cavity electromagnetic energy at a frequency of approximately 915 MHz.

Claim 10

The electronic heating apparatus set forth in claim 6, wherein said enclosure includes six walls arranged substantially to form a rectangular parallelopiped having internal dimensions greater than said predetermined wave length, said source means being disposed adjacent to the bottom wall of said enclosure and said conductive member being disposed adjacent to the top wall of said enclosure.

Claim 11

The electronic heating apparatus set forth in claim 6, wherein the sum of the electrical lengths of said shaft and the leg portions of said conductive member is approximately equal to 3/4 of said predetermined wave length.

Claim 12

The electronic heating apparatus set forth in claim 6, wherein said enclosure includes six walls arranged substantially to form a rectangular parallelepiped having dimensions greater than said predetermined wave length, said source means being disposed adjacent to the bottom wall of said enclosure and said conductive member being disposed adjacent to the top wall of said enclosure, said shaft having an electric length approximately equal to 1/8 of said predetermined wave length, said oNe leg portion of said conductive member having an electrical length approximatly equal to 3/8 of said predetermined wave length, the other leg portion of said conductive member having an electrical length approximately equal to 1/4 of said predetermined wave length.

Claim 13

The electronic heating apparatus set forth in claim 6, wherein said conductive member is responsive to rotation thereof for exciting in said cavity two secondary electromagnetic field modes.

Claim 14

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a conductive member disposed in said cavity and including two interconnected generally L-shaped sections, each of said sections including first and second leg portions intersecting at an angle and lying in a common plane substantially normal to the axis of said shaft, said the first leg portions of said sections being interconnected at the free ends thereof and with said second leg portions of said sections extending in opposite directions, said shaft being connected to said conductive member at the intersection of said first leg portions thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interaction with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, said conductive member being further responsive to continuous rotation thereof by said drive means for periodically reversing the phase relationships the electric field components of said primary and secondary modes, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 15

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a conductive member disposed in said cavity and including two interconnected generally L-shaped sections, each of said sections including first and second leg portions intersecting at an angle and lying in a common plane substantially normal to the axis of said shaft, said the first leg portions of said sections being interconnected at the free ends thereof and with said second leg portions of said sections extending in opposite directions, said shaft being connected to said conductive member at the intersection of said first leg portions thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interaction with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, said conductive member being further responsive to continuous rotation thereof by said drive means for periodically reversing the phase relationships the electric field components of said primary and secondary modes, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 16

The electronic heating apparatus set forth in claim 12, wherein the sum of the electrical lengths of said shaft plus either one of said L-shaped sections is approximately equal to 3/4 of said predetermined wave length.

Claim 17

The electronic heating apparatus set forth in claim 12, and further including a balance member connected to said conductive member at the point of interconnection of said first leg portions thereof and bisecting the external angle therebetween, said balance member having an effective electrical length approximately equal to one-half of said predetermined wavelength and mechanically counterbalancing said conductive member during high speed rotation thereof.

Claim 18

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a conductive member including four straight segments all disposed in said cavity in a common plane substantially normal to the axis of said shaft and being interconnected to form a hollow rectangle, said shaft being connected to said conductive member at one of the corners thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interactioN with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, said conductive member being further responsive to continuous rotation thereof by said drive means for periodically reversing the phase relationships of the electric field components of said primary and secondary modes, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 19

Electronic heating apparatus comprising an enclosure defining a heating cavity for receiving therein a body to be heated, source means electrically coupled to said heating cavity for transmitting thereinto ultra-high frequency electromagnetic energy of a predetermined wavelength to excite a predetermined primary electromagnetic field mode in said cavity, drive means including a rotatably driven grounded conductive shaft extending into said cavity with the longitudinal axis thereof disposed substantially parallel to the electric field component of said primary mode, a conductive member including four straight segments all disposed in said cavity in a common plane substantially normal to the axis of said shaft and being interconnected to form a hollow rectangle, said shaft being connected to said conductive member at one of the corners thereof for effecting rotation thereof about the axis of said shaft, said conductive member being responsive to continuous rotation thereof by said drive means for interactioN with said primary mode electric field periodically to excite in said cavity predetermined secondary electromagnetic field modes complementary to said primary mode, said conductive member being further responsive to continuous rotation thereof by said drive means for periodically reversing the phase relationships of the electric field components of said primary and secondary modes, whereby there is established within said cavity a substantially uniform time-averaged field distribution to facilitate uniform heating of the associated body.

Claim 20

The electronic heating apparatus set forth in claim 15, wherein the sum of the electrical lengths of said shaft plus any two adjacent segments of said conductive member extending from said one corner to the opposite corner thereof is approximately equal to 3/4 of said predetermined wavelength.