EP0723382A1 - Four à micro-ondes - Google Patents

Four à micro-ondes Download PDF

Info

Publication number
EP0723382A1
EP0723382A1 EP95119451A EP95119451A EP0723382A1 EP 0723382 A1 EP0723382 A1 EP 0723382A1 EP 95119451 A EP95119451 A EP 95119451A EP 95119451 A EP95119451 A EP 95119451A EP 0723382 A1 EP0723382 A1 EP 0723382A1
Authority
EP
European Patent Office
Prior art keywords
shutter
shutter plate
oven
motion
microwave oven
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.)
Granted
Application number
EP95119451A
Other languages
German (de)
English (en)
Other versions
EP0723382B1 (fr
Inventor
Fredriksson c/o Whirpool Europe s.r.l. Ove
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.)
Whirlpool Europe BV
Original Assignee
Whirlpool Europe BV
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 Whirlpool Europe BV filed Critical Whirlpool Europe BV
Publication of EP0723382A1 publication Critical patent/EP0723382A1/fr
Application granted granted Critical
Publication of EP0723382B1 publication Critical patent/EP0723382B1/fr
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
    • 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
    • H05B6/642—Cooling of the microwave components and related air circulation systems

Definitions

  • This invention relates to a microwave oven comprising an oven cavity, a microwave radiation source for feeding microwaves to the cavity, and an oven door for closing the cavity, at least part of the oven door forming a window for optical inspection of food placed in the cavity, and mist formation on the inside of the window facing the cavity being prevented by an air stream, which can be shut off by means of a shutter device having an adjustable shutter plate, which is pivotable about a pivot axis between an open position, in which the air stream is allowed to pass, and a closed position, in which the air stream is shut off.
  • the door of a microwave oven of the above type is provided with a window enabling the user to see the food being cooked.
  • food When cooked, food emits water vapour, which tends to condense when coming into contact with the less hot surfaces of the oven, including the window in the oven door.
  • mist will form on the inside of the window, thus obstructing or preventing observation of the food in the oven cavity.
  • an air stream is directed towards the inside of the window.
  • the air stream can be supplied through a perforation in one side wall of the cavity adjacent to the oven door.
  • the air stream After absorbing the mist on the inside of the window, the air stream is drawn off through a corresponding perforation in the opposing side wall of the cavity.
  • the air stream may, for example, be generated by drawing off part of the cooling air used for cooling a transformer in the power unit of the microwave oven, as well as the magnetron serving as microwave radiation source.
  • Modern microwave ovens further have access to a hot-air function, which means that a flow of hot air is produced in the cavity in order to heat the food.
  • the hot-air function may be used either separately or in combination with microwave heating.
  • Hot-air heating is typically used when baking buns. If hot-air heating is to yield good results, the flow of hot air has to be evenly distributed in the cavity.
  • the above-mentioned air stream used for obviating mist formation on the window of the oven door disturbs the flow of hot air in the oven and impairs the cooking results in those parts of the oven cavity where the air stream passes, for instance such that the buns located in these parts of the cavity are not done.
  • the disturbance caused is due to the air stream having a lower temperature than the flow of hot air. In order to avoid any such disturbance, the air stream has to be shut off when the hot-air function of the oven is used.
  • the prior art encompasses the use of a shutter device having a shutter plate that can be opened and closed in order to shut off the air stream mentioned above.
  • a shutter device having a shutter plate that can be opened and closed in order to shut off the air stream mentioned above.
  • the shutter plate can be manually operated via a control provided at the front of the oven, the movement of the control being transferred to the shutter plate via levers and link arms.
  • a return spring serves to return the shutter plate to the open position.
  • a common denominator of the prior-art mechanisms for operating the shutter plate is that they are fairly bulky and thus more or less unsuitable for today's compact oven designs.
  • the object of the invention is to provide a shutter device having an operating mechanism that does not suffer from the drawbacks of the prior art.
  • a microwave oven which is of the type mentioned by way of introduction and is characterised in that the shutter device comprises, for adjusting the shutter plate, an electrically-controllable operating means having a motion means, which is located in the extension of the pivot axis and which, upon actuation of the operating means, is displaced in the direction of the pivot axis; and a mechanical motion converter for converting the axial movement of the motion means to a pivotal movement for pivoting the shutter plate, the motion converter having an inlet engaging the motion means so as to take up the axial movement thereof, as well as an outlet engaging the shutter plate for transmitting the pivotal movement.
  • the combination of an operating force in the direction of the pivot axis and the above motion converter enables a production-friendly motion mechanism having a compact design and few component parts and being suited for automatic adjustment of the shutter plate.
  • a special object of the invention is to provide adjustment of the shutter plate with no noise coming either from the motion mechanism itself or from the shutter plate when passing to the open or the closed position.
  • the operating means comprises a component having a heat-sensitive body and an electric heating element, said body being heated and expanded upon the supply of an actuating signal and causing the displacement of the motion means, thereby producing a closing movement of the shutter plate, whereas an opening movement of the shutter plate is produced when the actuating signal ceases and said body contracts.
  • the thermal operating means is essentially soundless.
  • the opening and closing movements of the shutter plate become fairly slow, so that as little noise as possible is produced at the end positions of the shutter plate.
  • This operating means further has the advantages of a very compact design, a high reliability as well as a good precision in the opening and closing movements.
  • the fact that the thermal operating means is fairly slow is of no practical importance in view of the cooking times involved when using the hot-air function of the oven.
  • FIG. 1 shows the oven components that are relevant to the invention.
  • the oven cavity and the associated parts of the oven chassis are designated 1.
  • the cavity opening, which is closed by the oven door (not shown) when the oven is being used, is designated 2.
  • Reference numeral 3 designates a rotary bottom plate provided at the bottom of the cavity.
  • reference numeral 4 designates a waveguide for feeding microwaves to the oven cavity.
  • a magnetron 5 serves as the microwave radiation source of the oven, and its underside carries an aerial which, when the magnetron is mounted on the waveguide 4, is introduced into the marked hole therein.
  • Reference numeral 6 designates the power unit of the oven, which includes a transformer. Further, a cooling-fan device 7 is provided for cooling the magnetron 5 and the transformer. The cooling air is drawn in through the hole 7' and is discharged essentially horizontally at 7'' on the fan device. A first air interceptor 8 is arranged to intercept part of the air flow from the fan device and direct it towards the magnetron 5 and into a second air interceptor 9, which serves to intercept part of the flow of cooling air and form the above-mentioned air stream for obviating any mist on the window of the oven door. This part of the air flow is, by the air interceptor 9, directed towards the shutter device of the microwave oven.
  • the shutter device consists of a shutter housing 10, a shutter plate 11, a motion converter 12 and an electrically-controllable operating means 13.
  • the shutter housing 10 is intended to be mounted over perforations 14 in the side wall of the cavity. Through the perforations 14, there arises an air stream directed towards the window (not shown) of the oven door. In the opposing side wall of the cavity, there are corresponding outlet perforations 15 for the air stream.
  • Fig. 2 is a side view of the shutter device comprising the shutter housing 10, the shutter plate 11, the motion converter 12 and the electric operating means 13.
  • the shutter plate 11 is shown in closed position, in which it closes the opening of the shutter housing. Further, the shutter housing is provided with a circumferential flange 16 to be applied against the cavity wall.
  • the shutter plate 11 has an upper pivot pin 17 and a lower pivot pin 18 (see Fig. 3).
  • the pivot pin 17 is equipped with a flange 19, and the pivot pin 18 is equipped with two flanges 20, 21, which are spaced apart by an intermediate bearing member 22.
  • the pivot pin 17 is inserted in a bearing hole 23 (see Fig. 2) in the bearing housing, while the bearing member 22 rests in an open bearing groove 24 in the shutter housing.
  • the motion converter 12 is slidably mounted in the shutter housing so as to be displaceable in the direction of the pivot axis 25.
  • the motion converter is in the form of an elongate cylinder having two diametrically longitudinal raised portions 26, 27.
  • the cylindrical body has an internal hollow cylinder, which has two opposed helical grooves 28, 29 (indicated by dashed lines in Fig. 5). At the bottom, the helical grooves 28, 29 end in a transversal hole 30 through the cylindrical body.
  • the cylindrical element of the motion converter 12 rests in a correspondingly-shaped slide-bearing member in the shutter housing, while the raised portions 26, 27 rest on adjoining, straight bearing surfaces.
  • a bridge element with corresponding bearing surfaces (not shown in Fig. 2) forms a slide bearing for the motion converter, whose surrounding bearing surface has a shape that corresponds to the outline of the cross-section of Fig. 6. Owing to this bearing arrangement, the motion converter can be displaced in relation to the shutter housing in the direction of the pivot axis 25, while any pivotal movement of the motion converter in relation to the shutter housing is prevented by the raised ortions 26, 27 and the corresponding guide grooves in the shutter housing.
  • the motion converter comprises a groove-following means having a shaft member, whose centre coincides with the pivot axis 25.
  • the shaft member and the groove-following means are formed of, respectively, the pivot pin 18 and a T-shaped end portion 31 thereon (see Fig. 3).
  • the arms of the T-shaped end portion 31 are inserted in the respective helical grooves when the motion converter 12 is placed in the above-mentioned slide bearing.
  • the T-shaped end portion 31 follows the helical grooves 28, 29 and thus causes the shutter plate 11 to pivot.
  • the shutter housing 10 is provided with a fastening device 32 for the operating means 13.
  • the operating means has fastening lugs 33, 34 enabling it to be screwed into corresponding screw holes 35, 36 in the fastening device 32.
  • the operating means comprises a cylindrical motion means 37, which is equipped with an upper and a lower flange 38 and 39, respectively.
  • the motion converter 12 has hook-equipped, flexible gripping arms 37a, 38a, as well as a centre hole 40. When the motion converter 12 is mounted, the gripping arms 37a, 38a are pressed over the flange 38, such that their hooks are brought into engagement with the underside of the flange. At the same time, the motion means 37 is inserted in the centre hole 40 to engagement therewith.
  • the distance between the points of attachment of the gripping arms 37a, 38a on the motion converter is smaller than the diameter of the flange 38, such that the gripping arms are directed obliquely outwards when engaging the flange 38. This ensures the capacity of the gripping arms to take up tractive forces, and hence ensures the closing movement of the shutter plate, also at temperatures at which the material of the gripping arms softens somewhat.
  • the operating means 13 includes a component marketed under the tradename of "Termoactuator".
  • This component comprises a wax body, which expands when heated, and a heating element, which is actuated by the supply of mains voltage via connectors 41.
  • the motion means of the component at issue is displaced approximately 5 mm.
  • the pitch of the helical grooves 28, 29 is so designed that there is a certain play between the grooves and the T-shaped end portion 31 at the end positions of the shutter plate.
  • the shutter plate 11 is equipped with a circumferential, upright edge 42 close to its edge sides. This edge is indicated by a dashed line in Fig. 3.
  • the edge 42 is introduced in the opening of the shutter housing when the plate is closed and there generates a flow resistance to air trying to pass the closed plate. As a result, the air generates a compressive force that is applied against the shutter plate, which contributes to seal the plate without the use of any special seals.
  • the shutter plate may be sealed by replacing the pivot pins 17, 18 with a shaft that is movable in relation to the plate blade and is biased against the blade in customary fashion. By adjusting the pivoting angle of the shutter plate, the latter can be maintained pressed against the shutter housing by the bias when in its closed position.
  • the shutter device When the oven is in operation, the shutter device operates as follows.
  • the control unit of the oven sees to it that mains voltage is automatically supplied to the "Termoactuator".
  • the wax body of the "Termoactuator” is heated, and the motion means 37 is displaced upwards, as seen in the drawing, as is the motion converter 12 while sliding in the slide bearing mentioned above.
  • the T-shaped end portion 31 follows the helical grooves 28, 29 and thus produces a closing movement of the shutter plate 11.
  • the shutter housing and the shutter plate are preferably made of injection-moulded plastics, which enables good dimensional accuracy. All in all, this means that the construction is favourably loaded, which naturally contributes to the good reliability of the construction. From the point of view of production, the shutter device according to the invention is advantageous in that it can be mounted as a prefabricated module containing all the component parts involved.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)
EP19950119451 1995-01-17 1995-12-11 Four à micro-ondes Expired - Lifetime EP0723382B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9500138A SE503829C2 (sv) 1995-01-17 1995-01-17 Mikrovågsugn
SE9500138 1995-01-17

Publications (2)

Publication Number Publication Date
EP0723382A1 true EP0723382A1 (fr) 1996-07-24
EP0723382B1 EP0723382B1 (fr) 2003-04-02

Family

ID=20396844

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19950119451 Expired - Lifetime EP0723382B1 (fr) 1995-01-17 1995-12-11 Four à micro-ondes

Country Status (4)

Country Link
EP (1) EP0723382B1 (fr)
DE (1) DE69530171T2 (fr)
ES (1) ES2194883T3 (fr)
SE (1) SE503829C2 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2760518A1 (fr) * 1997-03-10 1998-09-11 Daewoo Electronics Co Ltd Dispositif de protection des pieces electroniques de l'air chaud dans un four a micro-ondes
GB2331218A (en) * 1997-08-23 1999-05-12 Samsung Electronics Co Ltd Microwave oven with drainage means
EP1067823A2 (fr) * 1999-07-06 2001-01-10 Lg Electronics Inc. Conduit d'air pour four à micro-ondes à usage multiple
GB2352604A (en) * 1999-07-28 2001-01-31 Samsung Electronics Co Ltd Microwave oven air inlet duct control flap location
EP1389894A2 (fr) 2002-08-15 2004-02-18 Samsung Electronics Co., Ltd. Four à micro-ondes
CN112263155A (zh) * 2020-10-15 2021-01-26 广东美的厨房电器制造有限公司 烹饪设备及其控制方法和控制器

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783219A (en) * 1970-11-11 1974-01-01 Sharp Kk Air cooled microwave cooking oven and door
EP0248580A2 (fr) * 1986-05-31 1987-12-09 Kabushiki Kaisha Toshiba Appareil de cuisson à micro-ondes

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3783219A (en) * 1970-11-11 1974-01-01 Sharp Kk Air cooled microwave cooking oven and door
EP0248580A2 (fr) * 1986-05-31 1987-12-09 Kabushiki Kaisha Toshiba Appareil de cuisson à micro-ondes

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2760518A1 (fr) * 1997-03-10 1998-09-11 Daewoo Electronics Co Ltd Dispositif de protection des pieces electroniques de l'air chaud dans un four a micro-ondes
GB2331218A (en) * 1997-08-23 1999-05-12 Samsung Electronics Co Ltd Microwave oven with drainage means
GB2331218B (en) * 1997-08-23 1999-09-29 Samsung Electronics Co Ltd Microwave oven
EP1067823A2 (fr) * 1999-07-06 2001-01-10 Lg Electronics Inc. Conduit d'air pour four à micro-ondes à usage multiple
EP1067823A3 (fr) * 1999-07-06 2005-07-13 Lg Electronics Inc. Conduit d'air pour four à micro-ondes à usage multiple
GB2352604A (en) * 1999-07-28 2001-01-31 Samsung Electronics Co Ltd Microwave oven air inlet duct control flap location
EP1389894A2 (fr) 2002-08-15 2004-02-18 Samsung Electronics Co., Ltd. Four à micro-ondes
EP1389894A3 (fr) * 2002-08-15 2006-04-12 Samsung Electronics Co., Ltd. Four à micro-ondes
CN112263155A (zh) * 2020-10-15 2021-01-26 广东美的厨房电器制造有限公司 烹饪设备及其控制方法和控制器

Also Published As

Publication number Publication date
SE9500138D0 (sv) 1995-01-17
ES2194883T3 (es) 2003-12-01
SE503829C2 (sv) 1996-09-16
EP0723382B1 (fr) 2003-04-02
SE9500138L (sv) 1996-07-18
DE69530171T2 (de) 2003-12-24
DE69530171D1 (de) 2003-05-08

Similar Documents

Publication Publication Date Title
EP1067823B1 (fr) Conduit d'air pour four à micro-ondes à usage multiple
EP0723382B1 (fr) Four à micro-ondes
GB2123688A (en) Hair-drier with valve members for controlling the air flow
US10278240B2 (en) Cooking appliance
JPS61276629A (ja) 閉鎖可能な調理室を備えたオ−ブンレンジ
US11841144B2 (en) Cooking appliance
EP0075309B1 (fr) Dispositif de verrouillage d'une porte de four de cuisson
US6966582B1 (en) Lock rod clutch for oven latch
EP3112764B1 (fr) Système de fermeture d'échappement pour un four de cuisson
KR100377728B1 (ko) 전자레인지의 댐퍼장치
CZ207195A3 (en) Thermostatic controller of air passage
KR100377732B1 (ko) 전자레인지의 댐퍼장치
US4136667A (en) Oven door latch mechanism
JPS60157188A (ja) 電気加熱手段を備えた高周波加熱装置
GB2258126A (en) Cooling and ventilating oven heated with micrwaves and other means
US5193522A (en) Electric, gas, combination or similar oven provided with a door, the glass surface of which is kept at a low temperature
KR960009855Y1 (ko) 전자렌지용 흡기덕트의 플랩개폐장치
GB2173588A (en) An electric oven
IE52778B1 (en) A gas burner which is suitable in particular for low-temperature cooking
US11540363B2 (en) Microwave appliance having a secondary cooking chamber
CN217524630U (zh) 一种电热水壶
US1625846A (en) Cooking oven
EP1508749B1 (fr) Mécanisme d'actionnement pour une hotte aspirante
KR950013658B1 (ko) 전자렌지용 흡기덕트의 플랩개폐장치
GB2309766A (en) Shape memory activation of steam vents

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT

17P Request for examination filed

Effective date: 19970114

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

RIN1 Information on inventor provided before grant (corrected)

Inventor name: OVE, FREDRIKSSON,C/O WHIRLPOOL EUROPE S.R.L.

AK Designated contracting states

Designated state(s): DE ES FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69530171

Country of ref document: DE

Date of ref document: 20030508

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031212

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20040105

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20031212

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20090202

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20081229

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20081224

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20081217

Year of fee payment: 14

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20091211

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091211

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091211