US3819899A - Double unit microwave oven having an energy seal therebetween - Google Patents

Double unit microwave oven having an energy seal therebetween Download PDF

Info

Publication number
US3819899A
US3819899A US00208599A US20859971A US3819899A US 3819899 A US3819899 A US 3819899A US 00208599 A US00208599 A US 00208599A US 20859971 A US20859971 A US 20859971A US 3819899 A US3819899 A US 3819899A
Authority
US
United States
Prior art keywords
housing
oven
wall
cavity
oven cavity
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
US00208599A
Other languages
English (en)
Inventor
H Wallin
L Malmquist
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.)
US Philips Corp
Original Assignee
US Philips Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3819899A publication Critical patent/US3819899A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • H05B6/6426—Aspects relating to the exterior of the microwave heating apparatus, e.g. metal casing, power cord

Definitions

  • a quarter wave choke is formed at the area where both units are Field of Search 219/1055 lowed- 10 Claims, 4 Drawing Figures uril 25 W16 E-23 12 2 I ⁇ 22 l1'- 13 43 Ill Pmminwm 1914 18191899 sum 1 n; 4
  • the present invention relates to a microwave oven comprising a magnetron which is included in an electrical supply circuit and an oven cavity which is connected to the magnetron via a wave guide for feeding microwave energy.
  • the invention has for its object to provide a construction for such an oven which can be inexpensively manufactured and which can be readily repaired and serviced.
  • the magnetron constitutes, together with its electrical supply circuit, a first structural unit in which the said components are accommodated in a common housing.
  • An antenna of the magnetron projects from one wall of the housing.
  • the first structural unit is combined with a second structural unit comprising the oven cavity.
  • the second unit includes plates projecting therefrom and enveloping a space for accommodating the housing.
  • the housing has a position in this space such that the wall of the housing from which the antenna projects is situated adjacent to and confronting one wall of the oven cavity but at some distance from and opposite to the one wall of the oven cavity so that at least a portion of the said wave guide is formed 'by the space between the said oppositely arranged walls.
  • a cavity which is formed as a quarter wave choke and which extends along the entire circumference of the housing so as to prevent radiation of microwave energy from the wave guide.
  • the housing preferably has the shape of a container having a lid to which the magnetron is secured, said container being situated directly below the oven cavity, the space between the lid and the bottom of the oven cavity forming at least a portion of the waveguide for feeding microwave energy to the oven cavity.
  • the cavity which serves as a quarter wave choke can then be formed by a groove which is delimited by appropriately shaped portions of the lid and the container and which has a slit-shaped opening at the outside, said opening being closed by the plates projecting from the second unit.
  • Simple attachment means will suffice for fixing the housing in the correct position in the second unit, said position not being subject to very severe accuracy requirements. If the electrical unit is to be repaired, the entire unit may be replaced by a spare unit, if desired,
  • FIGS. la and lb are perspective views of a container and a lid, respectively, which together form a housing accommodating a magnetron and a supply circuit and constituting a first structural unit for a microwave oven according to the invention.
  • FIG. 2 is a perspective view of a second structural unit for the microwave oven according to the invention, consisting of an oven cavity, a wave guide system and projecting plates, and
  • FIG. 3 is a sectional view of the microwave oven after assembly of the two units shown in FIGS. 1 and 2.
  • FIG. lathe reference numeral 10 denotes a watertight container having two successive projecting shoulders l1 and 12 at its upper side.
  • FIG. lb shows a bowlshaped lid 13 which fits into the container 10 and which has a projecting shoulder 14 at its upper side which corresponds to the upper shoulder 12 of the container.
  • the container 10 and the lid 13 together constitute a first structural unit for a microwave oven, said unit comprising virtually all electrical components of the oven, including the magnetron and its supply circuit.
  • the magnetron 15 is secured to the lower side of the lid 13, its antenna 16 projecting through an aperture 17 in the centre of the lid.
  • the supply circuit for the magnetron comprises a high voltage transformer 18, capacitors l9 and a high voltage rectifier 20. As appears from FIG. Ia, these components are arranged in-the container such that they leave a space for the magnetron 15.
  • the container furthermore houses a filament transformer (not shown) and preferably also a switching element in the form of a variable thyristor or a socalled triac for switching on and off the magnetron l5, and any other electrical components suitable for mounting in the container.
  • a lead-through 21 is provided for connecting the interior of the container to the supply voltage and to any switching members mounted outside the container. All lead-throughs are grounded via a capacitor so as to prevent interference.
  • the container 10 can be filled with oil, paraffin or the like for cooling purposes.
  • the lid is placed on the container, as shown in FIG. 3, after the magnetron 15 has been mounted against the lower side of the lid 13, the remaining electrical components have been arranged in the container 10 and all interconnections have been made.
  • the dimensions of the lid 13 are such that its lower portion bears on the lower shoulder 11 of the container 10, thus closing the container.
  • the lid 13 is preferably soldered to the shoulder 11 so that a watertight seal is obtained.
  • the container l0 and the lid 13 are further shaped such that a groove 22 remains between the second shoulder 12 of the container and the shoulder 14 of the lid, said groove extending along the entire circumference of the container and having a slit-shaped opening 23 at the outside.
  • FIG. 2 shows a second structural unit for the microwave oven comprising an oven cavity, a wave guide system and an outer envelope.
  • the oven cavity 24 (see FIGS. 2 and 3) is defined by a bottom plate 25, an
  • the oven cavity 24 is situated within an outer envelope 30 consisting of an upper plate 31, side plates 32, 33 and a rear plate (not shown). Both side plates 32, 33 and the rear plate extend into plates 32', 33' which project downwards from the second unit, a space 36 being formed below the oven cavity for accommodating the housing l0, 13 shown in FIGS. la and lb.
  • the side walls 27, 28 of the oven cavity 24 are situated at some distance from the side plates 32, 33 of the outer envelope so that therebetween slit-shaped spaces 37, 38 are present.
  • the upper wall 26 of the oven cavity 24 is situated at some distance from the upper plate 31 of the outer envelope so that therebetween a space 39 exists which communicates with both side spaces 37, 38.
  • these spaces outside the walls of the oven cavity form a portion of a wave guide system During the manufacture of the oven, first the electrical unit is produced in that the electrical components are mounted in the container and are electrically interconnected, after which the container is filled with oil or paraffin and is closed.
  • the second structural unit comprising the oven cavity and the wave guide system, is manufactured in a separate manufacturing process.
  • the units are then combined in that the housing l0, 13 with the electrical components is placed in the space 36 below the oven cavity via recesses 41, 42 and is secured in the correct position by means of suitable fixing materials.
  • a space 43 exists between the lid 13 of the housing and the bottom 25 of the oven cavity, said space communicating with both side spaces 37, 38, thus completing the wave guide system.
  • the magnetron antenna 16 which projects through the lid 13 transfers microwave energy to the wave guide system and this energy leaks into the oven cavity 24 through the slits 40.
  • the dimensions and the position of the housing l0, 13 below the oven cavity. 24 are such that the upper side of the housing closely adjoins the projecting plates of the outer envelope along three sides, the slitshaped opening 23 of the groove 22 being closed by these projecting plates.
  • a special strip projects downwards from the second unit, said strip closing the slit-shaped opening at the front of the housing so that the groove is closed along the entire circumference.
  • the depth of the groove 22, taken from the slit-shaped opening to the bottom of the groove, i.e., the shoulder 12, is substantially equal to one quarter of the wavelength of the microwaves.
  • the groove thus constitutes a so-called quarter wave choke for the microwave energy which otherwise tends to leak from the wave guide system between the outer envelope and the housing, so that this leakage is prevented. Due to the presence of this quarter wave choke along the entire circumference of the housing, this housing need not be in galvanic contact with the interior of the outer envelope.
  • the housing l0, 13 may thus be secured in the space 36 so as to be readily detachable. After the slit-shaped opening 23 the leakage energy has to pass a second slit between the outer envelope and the oppositely situated portion of the housing, said slit also having a length of approximately one quarter wavelength, thus also contributing towards prevention of energy leakage.
  • a microwave oven comprising a first structural unit that includes a magnetron and its electrical supply circuit accommodated Within a common enclosed housing, an antenna of the magnetron projecting outwardly from one wall of the housing, means for combining said first structural unit with a second structural unit comprising wall means defining an oven cavity which includes a pair of plates projecting from said second unit so as to enclose a space for accommodating the housing of said first unit, said housing being positioned within said space such that the one wall of the housing from which the antenna projects is spaced apart from and adjacent to one wall of the oven cavity, a waveguide for coupling the microwave energy from the magnetron antenna to the oven cavity, at least a portion of said wave guide being formed by the space between the said oppositely arranged one walls of the housing and the oven cavity, means providing a cavity in the area where the housing and the plates are joined and which extends along the entire circumference of the housing, said cavity being dimensioned to form a quarter wave choke at the magnetron frequency thereby to prevent radiation of microwave energy from the wave guide
  • a microwave oven as claimed in claim 2 characterized in that said quarter wave cavity is formed as a groove delimited by step shaped portions of the lid and the container and having a slit-shaped opening around the outside circumference, the plates projecting from the second unit so as to overlap said opening and close same.
  • a microwave oven as claimed in claim 1 characterized in that at least two other walls of the oven cavity are arranged in spaced relationship to at least two other walls of the second unit to form passageways that communicate with the space between said one wall of the oven cavity and said one wall of the housing so that a complete wave guide system for coupling microwave energy to the oven cavity is formed, at least the bottom and the upper wall of the oven cavity being provided with slits for allowing microwave energy to pass into the oven cavity.
  • a microwave oven comprising first and second structural units joined together to form said oven, said first unit comprising a housing for the oven electrical components and including a magnetron with an antenna projecting outwardly from one wall thereof, and said second unit comprises an oven heating cavity, a wave guide system for coupling microwave energy from the antenna to the oven cavity and an outer container for said cavity and wave guide system, at least two walls of said container extending therefrom so as to define a space for accomodating said housing of the first unit, said housing being mounted within said space with said one wall spaced apart from and adjacent to one wall of the oven cavity to define therewith a portion of said wave guide system, the walls of said outer container and said oven cavity being spaced apart to further define the waveguide system, said housing and container being shaped to form a gap in the area where they are joined together and dimensioned so as to form a quarter wave choke at the magnetron frequency, said gap extending about the periphery of the housing to prevent the escape of microwave energy between the housing and the container.
  • a microwave oven as claimed in claim 5 wherein said first structural unit comprises a boxlike housing open at one end and said one wall of the housing comprises a cover for the open end of the housing on which the magnetron is mounted with its antenna outwardly protruding therefrom.
  • said first structural unit comprises a boxlike housing open at one end with the upper edges thereof extending laterally outward to define a step-like edge portion
  • said one wall of the housing comprises a cover for said open end with an outwardly extending peripheral steplike edge portion arranged and dimensioned so as to fonn with the upper edge of the housing said quarter wave gap.
  • a microwave oven as claimed in claim 7 wherein the extending wall portions of said outer container overlap said quarter wave gap when said first and second units are joined together.
  • a microwave oven as claimed in claim 5 wherein said one wall of the oven cavity and a second oven cavity wall opposite to said one cavity wall contain openings therein to allow the microwave energy to pass into the oven cavity.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)
US00208599A 1970-12-21 1971-12-16 Double unit microwave oven having an energy seal therebetween Expired - Lifetime US3819899A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE17333/70A SE349134B (fr) 1970-12-21 1970-12-21

Publications (1)

Publication Number Publication Date
US3819899A true US3819899A (en) 1974-06-25

Family

ID=20303521

Family Applications (1)

Application Number Title Priority Date Filing Date
US00208599A Expired - Lifetime US3819899A (en) 1970-12-21 1971-12-16 Double unit microwave oven having an energy seal therebetween

Country Status (9)

Country Link
US (1) US3819899A (fr)
JP (1) JPS519934B1 (fr)
CA (1) CA951795A (fr)
DE (1) DE2159550C3 (fr)
FR (1) FR2119478A5 (fr)
GB (1) GB1312540A (fr)
IT (1) IT945533B (fr)
NL (1) NL7117224A (fr)
SE (1) SE349134B (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4571581A (en) * 1984-03-05 1986-02-18 General Electric Company Apparatus and method for production line leakage testing of microwave oven cavities
US6452142B2 (en) * 2000-02-02 2002-09-17 Apollo Usa Inc. Microwave ovens and sub-assemblies therefor
EP1357565A2 (fr) * 2002-04-23 2003-10-29 Puretec Co., Ltd. Procédé et appareil pour le refroidissement d'un transformateur haute tension pour four à micro-ondes
US20040104218A1 (en) * 2002-12-03 2004-06-03 Samsung Electronics Co., Ltd. Transformer assembly for microwave oven, method for manufacturing the same, and microwave oven having the same
EP1427261A1 (fr) * 2002-12-05 2004-06-09 Samsung Electronics Co., Ltd. Four à micro-ondes

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0000797A1 (fr) * 1977-08-04 1979-02-21 THE PROCTER & GAMBLE COMPANY Modérateur pour énergie à micro-ondes
DE3124319A1 (de) * 1981-06-20 1983-01-05 Buderus Ag, 6330 Wetzlar Geraet zum garen, backen oder braten von speisen
DE3644435A1 (de) * 1986-12-24 1988-07-07 Gaggenau Werke Mikrowellenofen
KR100324507B1 (ko) * 1997-11-15 2002-06-24 구자홍 전자레인지
KR100301902B1 (ko) * 1997-11-15 2001-11-22 구자홍 전자레인지의 마그네트론 장착구조

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3182164A (en) * 1962-02-28 1965-05-04 Raytheon Co Electromagnetic energy seal
US3497656A (en) * 1967-09-05 1970-02-24 Gen Electric Electronic range
US3531613A (en) * 1968-08-22 1970-09-29 Raytheon Co Capacitive filter for suppression of spurious electrical radiation
US3576417A (en) * 1969-09-17 1971-04-27 Roper Corp Construction for electronic oven appliances

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3182164A (en) * 1962-02-28 1965-05-04 Raytheon Co Electromagnetic energy seal
US3497656A (en) * 1967-09-05 1970-02-24 Gen Electric Electronic range
US3531613A (en) * 1968-08-22 1970-09-29 Raytheon Co Capacitive filter for suppression of spurious electrical radiation
US3576417A (en) * 1969-09-17 1971-04-27 Roper Corp Construction for electronic oven appliances

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4571581A (en) * 1984-03-05 1986-02-18 General Electric Company Apparatus and method for production line leakage testing of microwave oven cavities
US6452142B2 (en) * 2000-02-02 2002-09-17 Apollo Usa Inc. Microwave ovens and sub-assemblies therefor
EP1357565A2 (fr) * 2002-04-23 2003-10-29 Puretec Co., Ltd. Procédé et appareil pour le refroidissement d'un transformateur haute tension pour four à micro-ondes
EP1357565A3 (fr) * 2002-04-23 2004-07-14 Puretec Co., Ltd. Procédé et appareil pour le refroidissement d'un transformateur haute tension pour four à micro-ondes
SG116486A1 (en) * 2002-04-23 2005-11-28 Puretec Co Ltd Method and device for cooling high voltage transformer for microwave oven.
US20040104218A1 (en) * 2002-12-03 2004-06-03 Samsung Electronics Co., Ltd. Transformer assembly for microwave oven, method for manufacturing the same, and microwave oven having the same
EP1426984A1 (fr) * 2002-12-03 2004-06-09 Samsung Electronics Co., Ltd. Dispositif transformateur pour four à micro-ondes, son procédé de fabrication et four à micro-ondes muni d'un tel dispositif transformateur
US20070158341A1 (en) * 2002-12-03 2007-07-12 Samsung Electronics Co., Ltd. Transformer assembly for microwave oven, method for manufacturing the same, and microwave oven having the same
US7253383B2 (en) 2002-12-03 2007-08-07 Samsung Electronics Co., Ltd. Transformer assembly for microwave oven, method for manufacturing the same, and microwave oven having the same
EP1427261A1 (fr) * 2002-12-05 2004-06-09 Samsung Electronics Co., Ltd. Four à micro-ondes
CN1313772C (zh) * 2002-12-05 2007-05-02 三星电子株式会社 微波炉和温度灵敏开关及微波炉用变压器组件
US7365294B2 (en) 2002-12-05 2008-04-29 Samsung Electronics Co., Ltd. Microwave oven

Also Published As

Publication number Publication date
NL7117224A (fr) 1972-06-23
CA951795A (en) 1974-07-23
DE2159550A1 (de) 1972-07-13
JPS519934B1 (fr) 1976-03-31
GB1312540A (en) 1973-04-04
FR2119478A5 (fr) 1972-08-04
DE2159550B2 (de) 1977-08-25
SE349134B (fr) 1972-09-18
IT945533B (it) 1973-05-10
DE2159550C3 (de) 1978-04-20

Similar Documents

Publication Publication Date Title
US3819899A (en) Double unit microwave oven having an energy seal therebetween
US3767884A (en) Energy seal for high frequency energy apparatus
US3584177A (en) Energy seal for microwave oven apparatus
EP0196214B1 (fr) Blindage contre l'énergie électromagnétique
US4523069A (en) Microwave oven door seal
US3819900A (en) Waveguide filter for microwave heating apparatus
US3846667A (en) Magnetron having external choke structure
US2716694A (en) Combination electric and ultra-high frequency heating apparatus
US4053731A (en) Microwave energy oven seal
US3835283A (en) Partition and front wall forming choke structure for a microwave oven
US5021713A (en) Magnetron
US4104561A (en) Magnetron operating circuit
JPS6114627B2 (fr)
US3758737A (en) Waveguide filter for microwave heating apparatus
KR900008074B1 (ko) 초고주파 가열장치
US3838368A (en) Waveguide filter for microwave heating apparatus
US4371848A (en) Magnetron having a filter on the output probe
US3531613A (en) Capacitive filter for suppression of spurious electrical radiation
US3739225A (en) Microwave magnetron
US2538087A (en) Electron discharge device of the magnetron type
US3242303A (en) Microwave heating apparatus
JPS6019355Y2 (ja) マイクロ波加熱装置
US20210352781A1 (en) Oven having multiple chokes
KR100251565B1 (ko) 마그네트론
KR960014522B1 (ko) 마그네트론의 노이즈 차폐장치