US3816706A - Heating member for a hair dryer - Google Patents

Heating member for a hair dryer Download PDF

Info

Publication number
US3816706A
US3816706A US00333735A US33373573A US3816706A US 3816706 A US3816706 A US 3816706A US 00333735 A US00333735 A US 00333735A US 33373573 A US33373573 A US 33373573A US 3816706 A US3816706 A US 3816706A
Authority
US
United States
Prior art keywords
panels
member according
heating
heating member
wire
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
US00333735A
Other languages
English (en)
Inventor
K Meywald
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US3816706A publication Critical patent/US3816706A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A45—HAND OR TRAVELLING ARTICLES
    • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
    • A45D20/00—Hair drying devices; Accessories therefor
    • A45D20/04—Hot-air producers
    • A45D20/08—Hot-air producers heated electrically
    • 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
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/16—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor the conductor being mounted on an insulating base

Definitions

  • ABSTRACT A heating member for a hair dryer or other bloweroperated heating appliance, whose wire heating element is disposed in a flow duct formed by a boxshaped frame of insulating panels and comprises a heating wire helically wound on a self-supporting core which is coiled to a diameter corresponding to the distance between opposite panels and is disposed with its transverse axis transverse 'to the flow direction.
  • the element is attached to the frame only by its terminals which are secured to one of the panels.
  • One embodiment has one such helical coil, while another has two such coils which are located by notches on opposite sides of a central spacer penel.
  • a tapping resistor for the blower motor, and a thermal cut-out, are provided on the panels. 1
  • the invention relates to a heating member for blow er-operated heating appliances, more particularly a miniature heating element for hair drying appliances, the wire heating element thereof being disposed in a box-shaped frame of insulating material panels which form the flow duct.
  • Heating appliances of the kind described hereinabove at present are generally provided with plastics casings which should have the smallest possible dimensions in order to obtain a handy size on the one hand and to minimize space requirements on the other hand.
  • the material plastics on the one hand and the effort to achieve a small physical size on the other hand give rise to difficulties regarding the construction and arrangement of the heating elements.
  • the heating power must be kept low in order not to endanger the plastics casing, on the other hand such heating power rating must be accommodated in a comparative small space.
  • the casing is particularly at risk if only narrow flow cross-sections are available to the heated air or if the said air is baffled on bring discharged, a feature which often occurs when supplementary appliances are used, for example drying combs.
  • the fact that the heated air is subjected to very intense baffling when the comb is placed on the hair is a further feature which increases the difficulties.
  • the heating wire thereof is disposed within the flow duct in a plurality of turns in the form of a helix, a pluralityof parallel helices being provided.
  • the heating wire is usually so thin that it has insufficient intrinsic stability and must therefore be supported at several positions within the flow duct. This support is also provided because the heating wire is elongated during operation and would sag. Such supports represent internal fittings which hinder flow and generate noise.
  • the wire heating element comprises a heating wire coiled in helical form on a self-supporting core and the core in turn being coiled in a helix of a diameter which corresponds to the distance between the insulating material panels and whose longitudinal axis is disposed transversely to the flow direction in the flow duct.
  • This construction dispenses with the need for flowobstructing fittings, at least in single-stage appliances, because the wire heating element has sufficient intrinsic stability despite the thin heating wire. For this reason it is sufficient to secure the wire heating element merely by its two ends within the flow duct so that the assembling costs may be substantially reduced. Coiling the heating wire on to the core and coiling the latter into a helix may be performed mechanically without difficulty and with low production costs.
  • the construction of the frame, which forms the flow duct and provides the necessary insulation relative to the ambient zone may be of conventional kind. Sagging of the heating wire as a result of temperature rise is not possible in the wire heating element constructed in accordance wih the invention so that it is possible to dispense with the precautions necessary to this end in the prior art.
  • the heating rating may be adjusted to any desired low values by appropriate reduction of the wire diameter.
  • the core may comprise a steel wire on which insulating lapping, for example of glass fibre silk, is applied and on which the heating wire is coiled. It is an advantage of such a wire heating element that the ual wire turns and between the turns of the entire helix because of the wire elongation. Since the helices do not have sufficient stability there is a risk in such wire heating-elements, more particularly in the zone in which they bear upon the support, that the turns become displaced or are short-circuited due to vibrations or after prolonged use.
  • At least two wire heating elements are coiled in bifilar configurations, the turns being spaced by means of an insulating material panel which is dis posed in a diametral plane of the two helices.
  • At least two stages may be switched with a heating element constructed in the'manner described above for example, by connecting only one wire heating element in the first stage while both wire heating elements are connected in parallel in the second stage. Since the helices are practically self-supporting it is possible for their turns to be disposed extremely close to each other. Accordingly, a two-stage heating element will be hardly larger in practice than the previously described single-stage heating element.
  • the insulating material panel preferably disposed parallel to the flow direction, offers an exceptionally low resistance to flow because the said panel may be very thin. It therefore also causes hardly any noise.
  • the said insulating material panel which ensures that the turns are always uniformly spaced, in practice functions only as a manufacturing and assembling aid because it defines the shape of the two helices.
  • the said panel has practically no supporting function.
  • the insulating panel may be provided with cuts disposed on opposite sides, the turns of the helices being inserted into the said cuts. These cuts may have any desired shape.
  • each helix is preferably eyeletted on to the insulating material panel. If both or more helices are connected in parallel they will have a common terminal contact at one end and separate contacts at the other end.
  • the insulating panel may be secured in recesses of the side members of the heating element frame.
  • the said panel may be inserted into the said recesses or each side member may be slid by means of its recesses on to the insulating material panel.
  • the connecting leads may be brought out from the terminal contacts on the insulating panel through the recesses.
  • the precise manner of guiding the aforementioned insulating material panels will however depend substantially on the installation conditions of the heating element in the casing and on the configurations of the conductors therein.
  • a further feature of the invention provides that the insulating material panel which accommodates the terminal contacts of the wire heating element is provided with a resistance section with a tapping for the blower motor.
  • Heating elements of the kind described hereinabove are usually provided with a thermal cut-out to protect the appliance against overheating, for example, in the event of failure of the blower.
  • the aforementional thermal cut-out is mounted within the helices on the insulating material panel so that it is fixed in position prior to installation of the entire heating element. The precise choice of location for mounting the aforementioned thermal cut-out will depend on the flow conditions.
  • FIG. 1 is a partially sectioned side view of one embodiment of the heating element
  • FIG. 2 is an enlarged view
  • FIG. 3 is a cross-section through the wire heating element
  • FIG. 4 is a plan view of the frame panel along the line IVIV of FIG. 1 as shown at the bottom of FIG. 1;
  • FIG. 5 is a side view of another embodiment of the heating elementin the flow direction.
  • FIG. 6 is a section along the line VI-Vl of FIG. 5.
  • the heating unit comprises a frame 1 which forms a flow duct 2 for the air delivered by the blower and a wire heating element 3 which is disposed in the flow duct.
  • the frame 1 comprises a lower and an upper covering plate 4' and 5 respectively and two spacer plates 6 which maintain the former plates at a distance from each other and engage in recesses 8 of the said covering plates by means of projections 7.
  • the coveringplates and spacer plates are constructed of an electrically and thermally insulating material, for example mica.
  • the frame I is completed by metal clips 9 disposed on the side to provide the frame with the necessary stability.
  • the wire heating element 3 comprises a selfsupporting core 10, for example a metal wire, which is surrounded by an insulating stratum 11, for example of glass fibre silk or the like.
  • the heating wire 12 is coiled in close turns on to the aforementioned stratum.
  • the wire heating element itself is coiled in a helix and is provided at its ends with press-mounted terminal contacts l3, 14.
  • the wire heating element 3 is mounted by means of these terminal contacts on the lower frame plate 4, for example by pivoting or eyeletting.
  • One terminal contact 14 is preceded by a thermal switch 15 which disconnects the heating member from the mains connection 16 in the event of an excess temperature occurring.
  • a resistor section 17 is connected to the other terminal contact 13 to supply the necessary voltage, for example 12V, and is disposed on the interior of the lower covering plate 4 to provide the tapping for the miniature blower motor 18.
  • the thermal switch is mounted by means of its terminals 19,
  • the connecting leads are preferably formed not by wires but by thin metal rails because these may be more readily installed.
  • the heating member21 is provided with a frame comprising two covering plates 22 and two side members 23 which space the former.
  • the covering plates 22 may be mounted by means of eyelets or rivets on the side members 23.
  • the heating member also has a wire heating element, reference in its entirety by the numeral 24 and whose cross-section has already been described by reference to FIG. 3.
  • the wire heating element 24 in this case comprises two helices 28, 29 which are coiled in bifilar configuration into one helix.
  • An insulating material panel 30, disposed in one diametral plane of the two helices is provided in order to maintain the turns of the two helices 28, 29 at a uniform spacing.
  • the said panel is also disposed parallel to the covering plates 22'and therefore parallel to the flow direction so as to offerv an exceptionally low resistance to air flow. Practically the entire length of the helices 28, 29 is disposed in the free air stream.
  • Each end 31, 32 of the helices 28, 29 is provided with a terminal contact to which the connecting leads 33, 34 are connected.
  • a separate terminal contact is also provided at the other ends 35, 36.
  • the said two terminal contacts may be electrically connected to each other by means of an eyelet and may be connected to a single conductor 37. This permits parallel connection of the two helices 28, 29 so that only one helix may be connected to the current source in a first stage and both helices may be connected to the current source in a second stage.
  • the heating applicance into which the heating member 21 is installed may therefore be operated with two output stages. A plurality of output stages may of course be obtained by providing a plurality of helices and by appropriate switching.
  • the insulating material plate 30 may be secured in recesses 38 of the two side members 23.
  • the side members may be slid on to the ends of the insulating material panel and may be subsequently connected to the covering panels 22.
  • the connecting leads 33, 34 or 37 respectively are also brought outside through the aforementioned recesses 38.
  • the insulating panel in the illustrated embodiment is provided with equally spaced cuts 41 on its two longitudinal sides 39, 40, the turns being inserted into said recesses in the diametral plane and being thus maintained at a constant distance from each other.
  • a thermal cutout 42 is also mounted on the insulating material panel 30 in the middle zone thereof. If a miniature motor with a low-voltage connection is used instead of a splitphase mains operated motor it is possible for a resistor tapping, derived from the helices, to be mounted on one of the two covering plates as already described by reference to the first embodiment.
  • Heating member for blower-operated heating'devices comprising box-shaped frame means having a plurality of insulated panels for forming a flow duct,
  • said wire heating element mounted in said box-shaped frame means, said wire heating element including self-supporting core means having sufficient intrinsic stability to maintain its shape,
  • s'aid wire heating element being provided in a coiled form and being supported in said flow duct with the axis of the coiled form being transverse to the flow direction in said flow duct.
  • a heating member according to claim 2 wherein said terminal contacts are secured to at least one of said plurality of insulating panels of said box-shaped frame means.
  • a heating member according to claim 4 wherein said first and second covering panels are secured with respect to said two spacer panels by means of metal clips.
  • thermal switch means are connected to one of said first and second terminal contacts for disconnecting said wire heating element upon the occurrence of a perdetermined temperature excess.
  • a heating member according to claim I wherein said at least one wire heating element includes two helical coiled sections formed in a bifilar configuration.
  • a heating member according to claim 9 wherein an additional insulating panel is disposed in the diametral plane of said two helical coiled sections for spacing the coil turns.
  • a heating member according to claim 10 wherein said additional insulating panel is provided with notches along opposite longitudinal edges for uniformly spacing said coil turns.
  • each of said two helical coiled sections have first and second terminal contacts at opposite ends thereof with said first and second terminal contacts being mounted on said additional insulating panel.
  • a heating member according to claim 10 wherein a thermal cut-out means is secured on said additional insulating panel within the helices of said two helical coiled sections.
  • said plurality of insulating panels include first and second covering panels and two spacer panels secured perpendicularly to said first and second covering panels for spacing said first and second covering panels from one another, said two spacer panels having recesses to secure said additional insulating panel to said two spacer panels.
  • a heating member according to claim 16 wherein connecting leads are passed through said recesses of said two spacer panels and connected to said at least one wire heating element.

Landscapes

  • Resistance Heating (AREA)
  • Cleaning And Drying Hair (AREA)
  • Finger-Pressure Massage (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
US00333735A 1972-12-23 1973-02-20 Heating member for a hair dryer Expired - Lifetime US3816706A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2263260A DE2263260C3 (de) 1972-12-23 1972-12-23 Heizkörper für gebläsebetriebene Heizgeräte, insbesondere Kleinheizkörper für Haartrockner o.dgl.

Publications (1)

Publication Number Publication Date
US3816706A true US3816706A (en) 1974-06-11

Family

ID=5865364

Family Applications (1)

Application Number Title Priority Date Filing Date
US00333735A Expired - Lifetime US3816706A (en) 1972-12-23 1973-02-20 Heating member for a hair dryer

Country Status (6)

Country Link
US (1) US3816706A (enrdf_load_stackoverflow)
DE (1) DE2263260C3 (enrdf_load_stackoverflow)
ES (1) ES411531A1 (enrdf_load_stackoverflow)
FR (1) FR2211833B1 (enrdf_load_stackoverflow)
GB (1) GB1418928A (enrdf_load_stackoverflow)
IT (1) IT977302B (enrdf_load_stackoverflow)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4144445A (en) * 1977-12-27 1979-03-13 Emerson Electric Co. Open coil electric heaters
US4247842A (en) * 1978-10-09 1981-01-27 Ford Motor Company Cut-in resistance for motor vehicle heating fans
US4321456A (en) * 1978-11-14 1982-03-23 Firma Fritz Eichenauer Electrical hot air appliance
US4557205A (en) * 1983-08-26 1985-12-10 J. Strobel & Sohne Gmbh & Co. Fur sewing machine with heated air blower
US4629864A (en) * 1983-12-23 1986-12-16 Black & Decker, Inc. Hot air gun
DE4032875A1 (de) * 1990-10-17 1992-04-23 Teves Gmbh Alfred Hydraulikspeicher fuer eine hydraulische anlage, insbesondere bremsanlage
US6137092A (en) * 1998-10-22 2000-10-24 I.R.C.A S.P.A.-Industria Resistenze Corazzate Affini Resistance heating element, in particular for clothes dryers
US6737616B1 (en) * 2003-04-02 2004-05-18 Tutco, Inc. Open coil electric resistance heater using twisted resistance wires and methods of making
US20040134480A1 (en) * 2003-01-07 2004-07-15 Micropyretics Heaters International (Mhi) Inc. Convective system
US20050217138A1 (en) * 2003-12-02 2005-10-06 Dbk David + Baader Gmbh Cover for a clothes dryer and assembling method thereof
US20050252033A1 (en) * 2004-05-07 2005-11-17 Dbk David + Baader Gmbh Heating assembly for a tumble dryer
US20070116442A1 (en) * 2005-11-22 2007-05-24 York International Corporation Air handler heat kit installation and mounting
US20070145038A1 (en) * 2003-01-07 2007-06-28 Micropyretics Heaters International, Inc. Convective heating system for industrial applications
US20140110398A1 (en) * 2012-10-24 2014-04-24 Tokyo Electron Limited Heater apparatus
US11153936B2 (en) * 2018-03-26 2021-10-19 Leister Technologies Ag Ceramic heating resistor, electrical heating element, and device for heating a fluid
US11166533B2 (en) * 2018-10-31 2021-11-09 Shenzhen Soocas Technology Co., Ltd. Over-temperature protection structure and hair drying apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2296342A1 (fr) * 1974-12-28 1976-07-23 Eichenauer Fritz Element chauffant pour appareils electriques munis d'un ventilateur
DE2849266C2 (de) * 1978-11-14 1982-02-04 Fritz Eichenauer GmbH & Co KG, 6744 Kandel Elektrischer Heizkörper für gasförmige Medien
DE102007003906A1 (de) 2007-01-19 2008-07-24 Dbk David + Baader Gmbh Heizwendelanordnung zum Erwärmen vorbeiströmender Gasstoffe

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2247869A (en) * 1940-02-28 1941-07-01 John R Beers Heater element for cathodes used in radio tubes and method of making the same
US2727979A (en) * 1953-01-06 1955-12-20 Dominion Textile Co Ltd Immersion heaters
US2730609A (en) * 1951-09-18 1956-01-10 Yorkshire Copper Works Ltd Blowpipes
US2899526A (en) * 1959-08-11 Defroster
US3227986A (en) * 1962-06-22 1966-01-04 Beckman Instruments Inc Single-turn annular resistance elements
US3237142A (en) * 1960-03-05 1966-02-22 Eichenauer Fritz High capacity electric heater
US3298111A (en) * 1963-09-06 1967-01-17 Westinghouse Electric Corp Hair dryer heater assembly
DE1440404A1 (de) * 1962-10-24 1969-01-23 Fritz Eichenauer Fabrik Elektr Hochbelastbarer Elektroheizkoerper

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE99641C (enrdf_load_stackoverflow) *
DE1413910A1 (de) * 1961-01-07 1969-10-09 Nikolaus Laing Temperaturschutzschalter

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2899526A (en) * 1959-08-11 Defroster
US2247869A (en) * 1940-02-28 1941-07-01 John R Beers Heater element for cathodes used in radio tubes and method of making the same
US2730609A (en) * 1951-09-18 1956-01-10 Yorkshire Copper Works Ltd Blowpipes
US2727979A (en) * 1953-01-06 1955-12-20 Dominion Textile Co Ltd Immersion heaters
US3237142A (en) * 1960-03-05 1966-02-22 Eichenauer Fritz High capacity electric heater
US3227986A (en) * 1962-06-22 1966-01-04 Beckman Instruments Inc Single-turn annular resistance elements
DE1440404A1 (de) * 1962-10-24 1969-01-23 Fritz Eichenauer Fabrik Elektr Hochbelastbarer Elektroheizkoerper
US3298111A (en) * 1963-09-06 1967-01-17 Westinghouse Electric Corp Hair dryer heater assembly

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4144445A (en) * 1977-12-27 1979-03-13 Emerson Electric Co. Open coil electric heaters
US4247842A (en) * 1978-10-09 1981-01-27 Ford Motor Company Cut-in resistance for motor vehicle heating fans
US4321456A (en) * 1978-11-14 1982-03-23 Firma Fritz Eichenauer Electrical hot air appliance
US4557205A (en) * 1983-08-26 1985-12-10 J. Strobel & Sohne Gmbh & Co. Fur sewing machine with heated air blower
US4629864A (en) * 1983-12-23 1986-12-16 Black & Decker, Inc. Hot air gun
DE4032875A1 (de) * 1990-10-17 1992-04-23 Teves Gmbh Alfred Hydraulikspeicher fuer eine hydraulische anlage, insbesondere bremsanlage
US6137092A (en) * 1998-10-22 2000-10-24 I.R.C.A S.P.A.-Industria Resistenze Corazzate Affini Resistance heating element, in particular for clothes dryers
EP0995830A3 (en) * 1998-10-22 2002-01-02 I.R.C.A. S.p.A. INDUSTRIA RESISTENZE CORAZZATE E AFFINI Resistance heating element, in particular for clothes dryers
US20070145038A1 (en) * 2003-01-07 2007-06-28 Micropyretics Heaters International, Inc. Convective heating system for industrial applications
US8119954B2 (en) 2003-01-07 2012-02-21 Micropyretics Heaters International, Inc. Convective heating system for industrial applications
US20040134480A1 (en) * 2003-01-07 2004-07-15 Micropyretics Heaters International (Mhi) Inc. Convective system
WO2004093496A1 (en) * 2003-04-02 2004-10-28 Tutco, Inc. Open coil electric resistance heater using twisted resistance wires and methods of making the same
US6737616B1 (en) * 2003-04-02 2004-05-18 Tutco, Inc. Open coil electric resistance heater using twisted resistance wires and methods of making
US20050217138A1 (en) * 2003-12-02 2005-10-06 Dbk David + Baader Gmbh Cover for a clothes dryer and assembling method thereof
US8371040B2 (en) 2003-12-02 2013-02-12 Dbk David + Baader Gmbh Cover for a clothes dryer and assembling method thereof
US20050252033A1 (en) * 2004-05-07 2005-11-17 Dbk David + Baader Gmbh Heating assembly for a tumble dryer
US7425688B2 (en) 2004-05-07 2008-09-16 Dbk David + Baader Gmbh Heating assembly for a tumble dryer
US20070116442A1 (en) * 2005-11-22 2007-05-24 York International Corporation Air handler heat kit installation and mounting
US20140110398A1 (en) * 2012-10-24 2014-04-24 Tokyo Electron Limited Heater apparatus
US11153936B2 (en) * 2018-03-26 2021-10-19 Leister Technologies Ag Ceramic heating resistor, electrical heating element, and device for heating a fluid
US11166533B2 (en) * 2018-10-31 2021-11-09 Shenzhen Soocas Technology Co., Ltd. Over-temperature protection structure and hair drying apparatus

Also Published As

Publication number Publication date
FR2211833B1 (enrdf_load_stackoverflow) 1978-05-26
DE2263260C3 (de) 1982-01-28
DE2263260A1 (de) 1974-06-27
FR2211833A1 (enrdf_load_stackoverflow) 1974-07-19
GB1418928A (en) 1975-12-24
DE2263260B2 (de) 1981-05-14
IT977302B (it) 1974-09-10
ES411531A1 (es) 1976-05-01

Similar Documents

Publication Publication Date Title
US3816706A (en) Heating member for a hair dryer
US4350872A (en) Electrical heating element for fluid media and method for producing same
US5296685A (en) Heating coil structures
US4122329A (en) Electrical air heating appliance
US2438345A (en) Crystal oven
US2514528A (en) Hair drier
US20120061379A1 (en) Ceramic Monolith and an Electric Heating Device Incorporating the Said Monolith
KR100761115B1 (ko) 트위스트 저항선을 이용한 개방형 코일 전기 저항 히터 및그 제조 방법
US2502044A (en) Resistor support
US3610882A (en) Electric space heater
US3307017A (en) Electric infrared emitter
US2494861A (en) Electrically heated airer
US20100078420A1 (en) Electric heater for tumble dryers
EP0664662B1 (en) Sheathed heater
US2041352A (en) Electrical heating unit
US2834867A (en) Resistance heating element
US2275840A (en) Electric resistor
US1756444A (en) Electric heating means
US1520241A (en) Electric heater
US1516970A (en) Electric furnace for heating soldering coppers
USRE22313E (en) Electric resistor
US716048A (en) Electric heater.
US2245085A (en) Liquid heater
JPH05288355A (ja) 遠赤外線発熱ヒータを有する電子レンジ
US1513210A (en) Thermal relay