US3678238A - High frequency heating apparatus - Google Patents

High frequency heating apparatus Download PDF

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Publication number
US3678238A
US3678238A US110009A US3678238DA US3678238A US 3678238 A US3678238 A US 3678238A US 110009 A US110009 A US 110009A US 3678238D A US3678238D A US 3678238DA US 3678238 A US3678238 A US 3678238A
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US
United States
Prior art keywords
enclosure
door
transmission line
gap
characteristic impedance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US110009A
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English (en)
Inventor
Yoshio Yasuoka
Yoshiaki Shirakami
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanyo Electric Co Ltd
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Sanyo Electric Co Ltd
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Filing date
Publication date
Application filed by Sanyo Electric Co Ltd filed Critical Sanyo Electric Co Ltd
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Publication of US3678238A publication Critical patent/US3678238A/en
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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/76—Prevention of microwave leakage, e.g. door sealings
    • H05B6/763—Microwave radiation seals for doors

Definitions

  • a high frequency heating apparatus such as an oven, using microwave energy having an enclosure with an opening into the heating cavity which is to be sealed by the door. Peripheral metallic surfaces of the enclosure surrounding the opening and the door are spaced apart to leave a gap when the door is closed, the surfaces defining a parallel plate transmission line.
  • the gap includes a first narrow portion of a quarter wavelength of the frequency of the energy from the heating source originating from an origin, which is the closest point to the entry into the heating cavity, which origin point serves as the input to the transmission line.
  • a wide gap portion of a quarter wavelength has one end located adjacent the first narrow gap and a second narrow gap portion is located adjacent the other end of the wide gap portion.
  • the second narrow gap portion is of a length less than a quarter wavelength long and is the output point of the transmission line. Due to the step down ratio of the transmission line the input point at the first narrow gap portion has a relatively low impedance which prevents energy from leaking out of the cavity.
  • a typical conventional seal means for. preventing leakage of radiation is a metallic spring contact means provided either on the door of the heating apparatus or on the front of the enclosure.
  • the contact is likely to become poor, unless the spring is kept clean with special care, resulting in leakage of electromagnetic energy.
  • a gap is provided between the metal peripheral wall surface surrounding the opening of the oven enclosure of a high frequency heating apparatus and the metal peripheral surface of the door for closing the said opening in order to dispense with a conventional metal-tometal contacts and to avoid generation of an electric arc between the door and enclosure.
  • the peripheral wall surface encompassing the opening of the enclosure and the peripheral surface of the door are so constructed that they are opposite to each other, but not in contact, when the door is closed, to
  • a groove of a quarter wavelength in width is provided in the peripheral surface of the door and/or enclosure spaced a quarter wavelength away from the origin of the gap defined by the door and the enclosure at the entrance into the cavity.
  • the origin of the gap is effectively the input to the transmission line.
  • the gap from the origin to the groove is a quarter wavelength in length.
  • the width of the gap in the first narrow groove portion is substantially smaller than that formed by the groove.
  • a second narrow output gap portion is located adjacent the groove at a point remote from the origin and serves as the output point of the transmission line. This second narrow gap is substantially small in length with respect to a quarter wavelength of the operating frequency.
  • a quarter wavelength is preferred for the length of each of the wide and narrow (origin) gap portions they may be an odd number times the quarter wavelength of the electromagnetic wave in question.
  • the characteristic impedance of each narrow gap portion is relatively small, while that of the wide gap portion is relatively large.
  • the transmission line serve as an impedance transformer with respect to the high frequency energy.
  • the impedance at the output point which is comparatively small due to narrowness of the gap at this point, but not zero due to non-metallic contact of the two opposing surfaces, is transformed step-down-wise at the input point into an impedance much smaller than the impedance at the output point.
  • the extremely small impedance at the gap origin, or the input point efi'ectively prevents leakage of the high frequency energy through the gap.
  • the door in accordance with the invention may be opened'and closed just in the same conventional way, while the heating apparatus is not operating.
  • a dielectric material may be inserted into the gap between all or a portion of the two opposing surfaces so that thegap can be made small enough to avoid generation of an arc and at the same time the efiective wavelength of the energy from the apparatus in connection with the transmission line is shortened.
  • the word wavelength" used in connection with this invention means the wavelength of the high frequency electromagnetic energy generated in the high frequency heating apparatus and transmitted through the transmission line formed between the peripheral surfaces of the door and the enclosure of the said heating apparatus. For instance, therefore, if a high frequency energy supply apparatus generating such energy at the frequency of about 2,450 magahertz is used, one wavelength in this case corresponds to ca. 122.4 mm in the air.
  • the space between the surfaces may be filled with a dielectric material, in which case the wavelength of radiated energy may be made even shorter.
  • the word wavelength should not be construed to means only the wavelength of the high frequency energy propagated in the air but also in a dielectric medium.
  • the principal object of the invention is to provide a seal means for a microwave type heating device having a comparatively simplified structure, which is easy to manufacture, for efiectively preventing leakage of high frequency energy'through a gap formed between opposing surfaces of the periphery of the door and the periphery of the opening of the oven enclosure of the high frequency heating apparatus, which surfaces are not in metallic contact with each other.
  • FIG. 1 shows a sectional view of a high frequency heating apparatus in accordance with the invention
  • FIG. 2 shows an enlarged sectional view of the seal means of the upper left portion of the FIG. 1,
  • FIG. 3 shows an enlarged sectional view of the seal means of another embodiment of the invention
  • FIG. 4 shows an enlarged sectional view of the seal means of a further embodiment of the invention
  • FIG. 5 shows an enlarged sectional view of the seal means of a still firrther embodiment of the invention
  • FIG. 6 shows a sectional view of a parallel-plate transmission line for explanation of a principle of the invention.
  • a housing 1 in a housing 1 is provided a hollow rectangular enclosure 3, made from a thin metal material, hav-v ing an opening or apperture 2 in front of it, this enclosure 3 being adapted to be a cooking oven.
  • the opening 2 of this enclosure 3 is provided with a door 4, so that it can be opened or closed, for insertion or removal of a material being heated or cooked, in such a way that the door is hinged at the lower part of the said housing 1.
  • the door 4 is provided with a number of small holes 5 for inspection of the state of the material being heated in the enclosure 3 and also for discharge of the vapor generated inside the enclosure 3.
  • the enclosure 3 is provided at its top wall with a hole 6 for supplying high frequency energy and is also provided at its back wall with a number of small holes '1 for ventilation. Positioned between the back wall of the enclosure 3 and the housing 1 is provided a high frequency generating apparatus 8, comprised of a conventional magnetron tube and the high frequency energy generated therein is transmitted through a waveguide 9 into the enclosure 3 from the said hole 6.
  • the magnetron tube 8 is an air-cooled type in the embodiment shown and is cooled by means of a blower lo provided in the housing 1. After cooling the tube 8, the air blown is sent through the holes 7 into the enclosure 3 and by this air the vapor generated from the material is discharged through the small holes 5 of the door 4. Inside the enclosure 3 is provided a the enclosure 3 may be avoided.
  • the door 4 comprises a frame 12, an outer moulding type cover 13 which is preferably made of aluminum, covering frame 12 and a knob 14 for opening and closing the door 4 manually.
  • the peripheral surface of the door 4 and the peripheral wall surface of the enclosure 3 encompassing the opening 2 are so constructed-that both surfaces lie opposite to each other, but not in metallic contact, with the door 4 closed, to form a gap 16 therebetween.
  • the gap extends from an origin point a which is effectively the entrance to the heating cavity, and the outer wall of the enclosure and the door. Both of these surfaces defining the gap serve as a parallel-plate transmission line for the high frequency energy of magnetron 8
  • the spacing of both surfaces and the gap formed thereby is shown in greater detail in FIG. 2. Referring to FIG.
  • the door 4 is indented at its periphery so that the periphery of the enclosure 3 encompassing the opening 2 may fit in the door indent. It is seen that there is a peripheral non-metallic contact, defining the gap, between two sets of right angled surface elements.
  • the first set of elements is on the door and comprises a first surface element 28 substantially perpendicular to the plane of the frame 12 and the other is a second surface 29 substantially parallel to but stepped outwardly with respect to the plane of the frame 12.
  • the second set of similar right angled surface elements 18 and 19 are on the enclosure 3.
  • each of the surface elements 18 and 28 is chosen to be a quarter wavelength of the electromagnetic wave radiated into the enclosure 3.
  • a groove 15, a quarter wavelength in length is provided in the surface of element 29 of the peripheral surface of the door 4 in a position next to the surface of element 28.
  • the groove 15 constitutes a wide gap portion of a quarter wavelength in length between the surfaces of elements 29 and 19.
  • the opposing pair of surface elements 28 and 18 form a narrow gap portion 16 a quarter wavelength in length.
  • the beginning of the groove, or wide gap portion, 15 begins a quarter wavelength away from the origin a of the gap 16 defined by surfaces of elements l8'and 28. In the case of the door 4 being closed, origin a constitutes an input point of a transmission line.
  • a second narrow output gap portion (between points 30 and 31 in FIG. 2) which is substantially small in length as compared with a quarter wavelength.
  • This second narrow output gap portion constitutes an output point of the transmission line.
  • FIG. 2 there is also shown a dielectric spacer 21 attached to the surface element 19 in a position just outside of the groove l5,in the second narrow gap portion. Spacer 21 serves to keep both surfaces of the door 4 and enclosure 3 very close to each other, but spaced to prevent metallic contact when the door 4 is closed. As a result, the impedance at the output point with respect to the high frequency is kept very low or small, but not zero, when the door 4 is closed.
  • the gap 16 or transmission line, act as an impedance transformer.
  • the small impedance at the output point is transformed step-down-wise at the gap origin a, or the input point, into a much smaller impedance,
  • the gap 16 serves to prevent the leakage of the high frequency energy therethrough.
  • FIG. 3 another embodiment of the invention is shown, in which both the peripheral surface of the door 4 and the peripheral wall surface of the enclosure 3 encompassing the Opening 2 are made substantially parallel to the plane of door frame 12.
  • a groove or wide gap portion 17 of a quarter wavelength in length is provided on the peripheral surface of the enclosure 3 starting a quarter wavelength away from the origin a of the gap 16 and OF THE INVENTION, is that the geometry of a quarter wavelength in the dielectric material is substantially made smaller as compared to air.
  • the dielectric material can have diflerent constants along its length.
  • the material in the narrow gap portions of low characteristic impedance can have a relatively low dielectric constant and the material in the higher characteristic impedance gap portion can have a higher dielectric constant.
  • FIG. 4 illustrates a further embodiment of the invention, in which opposing grooves 15 and 17 are respectively provided on the peripheral surface of the door 4 and the peripheral wall surface of the enclosure 3, both being substantially parallel to the plane of the frame 12. Both grooves 15 and 17 are located a quarter wavelength away from the origin a, when the door 4 is closed, so that both grooves 15 and 17 constitute a single common wide gap portion. The two narrow gap portions are provided on each side of the wide gap portion in the same manner as previously described. The embodiment is also shown employing the dielectric'material 20 for the same purpose as mentioned previously.
  • FIG. 5 shows a still further embodiment of the invention.
  • the embodiment shown is substantially the same as that shown in FIG. 2, except that FIG. 5 embodiment dispenses with the spacer 21 and instead employs the dielectric material 20 for the purposes previously mentioned.
  • FIG. 6 Let it be assumed that the enclosure 3 and door 4 are replaced with the high frequency energy transmission line of upper and lower parallel plates 22 and 23, respectively, in FIG. 6.
  • the gap spacing of the first quarter wavelength portion a-b from the origin a of the gap 16 is small and the charac teristic impedance of this portion is denoted as Z0
  • the gap spacing of the next quarter wavelength portion b-c is wide, and the characteristic impedance of this portion is denoted as Z0
  • the quarter wavelength portions c-d and e-i of narrower gap spacing and the quarter wavelength portions d-e and f-g of wider gap spacing are alternately provided to form a multi-stage standing wave circuit.
  • the input impedance at the point d is calculated as follows:
  • the input impedance at the point b is:
  • the line act as an impedance transformer.
  • the greater the number of stages of the narrower gap portion (the characteristic impedance of which is 20, and of the wider gap portion (the characteristic impedance of which is 20;) and the smaller the value of Z is as compared to that of 20, the more possible it is to make the input impedance at the origin a of the gap closer to zero meaning that less of the high frequency energy can escape from the open end of the gap.
  • the narrower the gap spacing is in a high frequency transmission line, the smaller is the value of the characteristic impedance.
  • Leakage of electromagnetic wave can be efi'ectively prevented by making the value of 20 /20 as small as possible and nearer to zero, where Z0 is the characteristic impedance of the narrow gap portion and Z0 is the characteristic impedance of the wide gap portion, in the case of the door 4 closing the opening of the enclosure.
  • Z0 is the characteristic impedance of the narrow gap portion
  • Z0 is the characteristic impedance of the wide gap portion, in the case of the door 4 closing the opening of the enclosure.
  • Each of the embodiments of high frequency heating apparatus shown in FIGS. 1 through 5 has only one narrow (from the origin) and one wide gap portion.
  • the second narrow gap portion between points 30-31, in FIG. 2 correspond to the output impedance Z of FIG. 6.
  • itistobepointedoutthat the wide and narrow gap portions may be any odd number times a quarter wavelength of the frequency used in length
  • FIG. 2 shows an embodiment in which a dielectric spacer 21 is provided at the output point to keep both surfaces as close as possible, but out of metallic contact.
  • This spacer may be any materials, such as a ferrite magnetic rubber, which serve to decrease the impedance of the transmission line, in order to make the impedance at the output point even lower.
  • High frequency heating apparatus comprising:
  • a door for closing said opening having a portion of conductive material opposing the peripheral portion of the enclosure and forming a seal to electromagnetic energy at the peripheral portion of the enclosure, means for holding the portion of the surface of the door opposing the surface of the peripheral portion of the enclosure in spaced relationship from each other vQren the door is closed and leaving a gap therebetween, said opposing surface portions and the gap therebetween forming a transmission line at the wavelength of said electromagnetic wave energy whose characteristic impedance at the opening of the enclosure is relatively low to thereby act to prevent electromagnetic energy from leaking out of the enclosure, said opposing surface portions being shaped so that:
  • the gap therebetween is of a first width to provide a first transmission line section of relatively low characteristic impedance originating from the opening to be sealed,
  • the surfaces are spaced by a second width greater than said first width to form a second transmission line section adjacent said first section having a relatively high characteristic impedance as compared to the characteristic impedance of said first section, and
  • the surfaces are spaced by a third width which is less than said second width to form a third transmission line section adjacent said second section of shorter electrical length than both said fast and second transmission line sections and having a relatively low chacteristic impedance as compared to the characteristic impedance of said second section to terminate said first and second transmission line sections.
  • Apparatus as in claim 1 wherein a dielectric material with a high dielectric constant is located in the gap at the high characteristic impedance second transmission line section and a dielectric material with a low dielectric constant is provided at at least one of the low characteristic impedance first and third transmission line section.
  • Apparatus as in claim 1 wherein said means for holding the door and enclosure in spaced relationship comprises means made of a material for lowering the characteristic impedance located in the gap between the opposing surfaces of the door and enclosure forming the low characteristic impedance third transmission line section.
  • each of the opposing surfaces of the door means and enclosure has a first surface element of a quarter wavelength in length next to the origin of the gap which is generally transverse to the plane of the door and a second surface element generally parallel to the plane of the door, the wide gap portion being provided in the second surface element of at least one of the door and enclosure surfaces.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)
US110009A 1970-04-23 1971-01-27 High frequency heating apparatus Expired - Lifetime US3678238A (en)

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JP45035211A JPS4939571B1 (enrdf_load_stackoverflow) 1970-04-23 1970-04-23

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Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809843A (en) * 1970-06-01 1974-05-07 Gen Corp Microwave heating apparatus
US3846608A (en) * 1974-02-11 1974-11-05 Litton Systems Inc High temperature resistant door seal for a microwave oven
US3943319A (en) * 1974-02-26 1976-03-09 Matsushita Electric Industrial Co., Ltd. Microwave oven with hinged door and latch means
US3956608A (en) * 1971-10-19 1976-05-11 U.S. Philips Corporation Energy seal for a microwave oven
FR2321227A1 (fr) * 1975-03-31 1977-03-11 Amana Refrigeration Inc Joint de porte de four a hyperfrequences
US4053731A (en) * 1974-06-14 1977-10-11 Amana Refrigeration, Inc. Microwave energy oven seal
US4059742A (en) * 1975-07-09 1977-11-22 Litton Systems, Inc. Microwave seal for combination cooking apparatus
FR2365269A1 (fr) * 1976-09-21 1978-04-14 Purfuerst Kg Ing Buero Dispositif pour le chauffage dielectrique continu a l'aide d'une energie hyperfrequence
DE2705983A1 (de) * 1977-02-12 1978-08-17 Litton Industries Inc Mikrowellendichtung fuer kocheinrichtungen
US4166207A (en) * 1977-05-31 1979-08-28 Whirlpool Corporation Microwave generating device--door seal
US4211910A (en) * 1977-12-21 1980-07-08 Matsushita Electric Industrial Co., Ltd. High frequency heating apparatus with improved door arrangement
US4334136A (en) * 1979-10-01 1982-06-08 Douglas P. Mahan Microwave treating mechanism
US4398651A (en) * 1978-08-17 1983-08-16 Kumpfer Beverly D Microwave food dispensing machine
EP0088175A1 (en) * 1982-03-08 1983-09-14 Douglas Powell Mahan Tumble drying apparatus
US4449025A (en) * 1980-10-03 1984-05-15 Matsushita Electric Industrial Co., Ltd. Door seal construction for high frequency heating appliance
EP0122647A1 (en) * 1983-03-15 1984-10-24 Philips Norden AB A sealing arrangement in microwave ovens
US4510361A (en) * 1982-05-03 1985-04-09 Mahan Douglas P Horizontal axis tumbler type microwave drying mechanism
US4525614A (en) * 1982-05-28 1985-06-25 Tdk Corporation Absorber device for microwave leakage
DE3521666A1 (de) * 1984-06-15 1985-12-19 Sharp K.K., Osaka Mikrowellenherd
DE3644920A1 (de) * 1986-03-07 1987-12-23 Bosch Siemens Hausgeraete Mikrowellenofen
DE3607557A1 (de) * 1986-03-07 1987-12-23 Bosch Siemens Hausgeraete Mikrowellenofen
EP0985329A4 (en) * 1997-04-29 2004-03-10 Ind Microwave Systems Inc METHOD AND DEVICE FOR ELECTROMAGNETIC IRRADIATION OF FLAT MATERIALS OR THE LIKE
DE102004052798A1 (de) * 2004-11-02 2006-05-11 Electrolux Home Products Corp. N.V. Garofen
EP2285181A1 (en) 2009-08-14 2011-02-16 Electrolux Home Products Corporation N.V. A wave choke system for a microwave oven
WO2015066600A1 (en) * 2013-11-01 2015-05-07 Richards Corporation Microwave oven door seals
US20150327336A1 (en) * 2013-01-25 2015-11-12 Electrolux Home Products Corporation N.V. A microwave oven or a multifunctional oven with microwave heating function
US9913323B2 (en) * 2013-03-04 2018-03-06 Electrolux Appliances Aktiebolag Door for a microwave appliance
CN108781488A (zh) * 2016-03-10 2018-11-09 松下知识产权经营株式会社 高频加热装置
EP4271132A1 (en) * 2022-04-29 2023-11-01 Electrolux Appliances Aktiebolag Cavity assembly for an oven with microwave heating function for heating comestible
EP4492919A1 (de) * 2023-07-11 2025-01-15 Rational Aktiengesellschaft Kombinationsgargerät mit ringmodenunterdrücker

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2956154A (en) * 1953-12-23 1960-10-11 Ericsson Telefon Ab L M Device for separating and transforming time phase modulated pulse trains
US3351730A (en) * 1964-03-10 1967-11-07 Philips Corp Energy seal for microwave ovens
US3511959A (en) * 1968-02-16 1970-05-12 Varian Associates Microwave cavity having a varied impedance transmission line microwave energy seal around the access door opening

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500676A (en) * 1947-01-14 1950-03-14 Raytheon Mfg Co Heating apparatus
US3182164A (en) * 1962-02-28 1965-05-04 Raytheon Co Electromagnetic energy seal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2956154A (en) * 1953-12-23 1960-10-11 Ericsson Telefon Ab L M Device for separating and transforming time phase modulated pulse trains
US3351730A (en) * 1964-03-10 1967-11-07 Philips Corp Energy seal for microwave ovens
US3511959A (en) * 1968-02-16 1970-05-12 Varian Associates Microwave cavity having a varied impedance transmission line microwave energy seal around the access door opening

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809843A (en) * 1970-06-01 1974-05-07 Gen Corp Microwave heating apparatus
US3956608A (en) * 1971-10-19 1976-05-11 U.S. Philips Corporation Energy seal for a microwave oven
US3846608A (en) * 1974-02-11 1974-11-05 Litton Systems Inc High temperature resistant door seal for a microwave oven
US3943319A (en) * 1974-02-26 1976-03-09 Matsushita Electric Industrial Co., Ltd. Microwave oven with hinged door and latch means
US4053731A (en) * 1974-06-14 1977-10-11 Amana Refrigeration, Inc. Microwave energy oven seal
FR2321227A1 (fr) * 1975-03-31 1977-03-11 Amana Refrigeration Inc Joint de porte de four a hyperfrequences
US4059742A (en) * 1975-07-09 1977-11-22 Litton Systems, Inc. Microwave seal for combination cooking apparatus
FR2365269A1 (fr) * 1976-09-21 1978-04-14 Purfuerst Kg Ing Buero Dispositif pour le chauffage dielectrique continu a l'aide d'une energie hyperfrequence
DE2705983A1 (de) * 1977-02-12 1978-08-17 Litton Industries Inc Mikrowellendichtung fuer kocheinrichtungen
US4166207A (en) * 1977-05-31 1979-08-28 Whirlpool Corporation Microwave generating device--door seal
US4211910A (en) * 1977-12-21 1980-07-08 Matsushita Electric Industrial Co., Ltd. High frequency heating apparatus with improved door arrangement
US4398651A (en) * 1978-08-17 1983-08-16 Kumpfer Beverly D Microwave food dispensing machine
US4334136A (en) * 1979-10-01 1982-06-08 Douglas P. Mahan Microwave treating mechanism
US4449025A (en) * 1980-10-03 1984-05-15 Matsushita Electric Industrial Co., Ltd. Door seal construction for high frequency heating appliance
EP0088175A1 (en) * 1982-03-08 1983-09-14 Douglas Powell Mahan Tumble drying apparatus
US4510361A (en) * 1982-05-03 1985-04-09 Mahan Douglas P Horizontal axis tumbler type microwave drying mechanism
US4525614A (en) * 1982-05-28 1985-06-25 Tdk Corporation Absorber device for microwave leakage
EP0122647A1 (en) * 1983-03-15 1984-10-24 Philips Norden AB A sealing arrangement in microwave ovens
DE3521666A1 (de) * 1984-06-15 1985-12-19 Sharp K.K., Osaka Mikrowellenherd
GB2161349A (en) * 1984-06-15 1986-01-08 Sharp Kk Microwave oven door
DE3644920A1 (de) * 1986-03-07 1987-12-23 Bosch Siemens Hausgeraete Mikrowellenofen
DE3607557A1 (de) * 1986-03-07 1987-12-23 Bosch Siemens Hausgeraete Mikrowellenofen
EP0985329A4 (en) * 1997-04-29 2004-03-10 Ind Microwave Systems Inc METHOD AND DEVICE FOR ELECTROMAGNETIC IRRADIATION OF FLAT MATERIALS OR THE LIKE
DE102004052798A1 (de) * 2004-11-02 2006-05-11 Electrolux Home Products Corp. N.V. Garofen
DE102004052798B4 (de) * 2004-11-02 2006-08-31 Electrolux Home Products Corp. N.V. Garofen
EP1653781A3 (de) * 2004-11-02 2008-07-09 Electrolux Home Products Corporation N.V. Garofen
EP2285181A1 (en) 2009-08-14 2011-02-16 Electrolux Home Products Corporation N.V. A wave choke system for a microwave oven
EP2466991A1 (en) 2009-08-14 2012-06-20 Electrolux Home Products Corporation N.V. A wave choke system for a microwave oven
US10448464B2 (en) * 2013-01-25 2019-10-15 Electrolux Home Products Corporation N.V. Microwave oven or a multifunctional oven with microwave heating function
US20150327336A1 (en) * 2013-01-25 2015-11-12 Electrolux Home Products Corporation N.V. A microwave oven or a multifunctional oven with microwave heating function
US9913323B2 (en) * 2013-03-04 2018-03-06 Electrolux Appliances Aktiebolag Door for a microwave appliance
AU2018201173B2 (en) * 2013-03-04 2019-08-15 Electrolux Appliances Aktiebolag A Door for a Microwave Appliance
US20150122805A1 (en) * 2013-11-01 2015-05-07 Richards Corporation Microwave oven door seals
WO2015066600A1 (en) * 2013-11-01 2015-05-07 Richards Corporation Microwave oven door seals
CN108781488A (zh) * 2016-03-10 2018-11-09 松下知识产权经营株式会社 高频加热装置
CN108781488B (zh) * 2016-03-10 2021-03-09 松下知识产权经营株式会社 高频加热装置
EP4271132A1 (en) * 2022-04-29 2023-11-01 Electrolux Appliances Aktiebolag Cavity assembly for an oven with microwave heating function for heating comestible
WO2023208595A1 (en) * 2022-04-29 2023-11-02 Electrolux Appliances Aktiebolag Cavity assembly for an oven with microwave heating function for heating comestible
EP4492919A1 (de) * 2023-07-11 2025-01-15 Rational Aktiengesellschaft Kombinationsgargerät mit ringmodenunterdrücker

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Publication number Publication date
JPS4939571B1 (enrdf_load_stackoverflow) 1974-10-26

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