DK164431B

DK164431B - Electrical radiant heating unit for glass ceramic hotplate

Info

Publication number: DK164431B
Application number: DK531486A
Authority: DK
Inventors: Karl Fischer
Original assignee: Ego Austria Elektrogeraete
Priority date: 1977-07-02
Filing date: 1986-11-06
Publication date: 1992-06-22
Also published as: DK157284B; DK531486D0; DK164431C; DK383883A; DK531486A; DK157284C; DK383883D0

Description

iin

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Opfindelsen angår et elektrisk strålevarmelegeme for glaskeramiske kogeplader af den i indledningen til krav 1 angivne art, der kendes fra DE OS 2.339,768.This invention relates to an electric radiator heater for glass ceramic hobs of the kind set forth in the preamble of claim 1, known from DE OS 2,339,768.

5 Fra DE-PS 25 51 137 kendes endvidere et strålevarmelegeme, hvis varmefelt er forsynet med en varmeleder og er omgivet af en ring af et isolationsmateriale, der ligger på en isolering, på hvis overflade varmelederen er anbragt. Det er ønskeligt ved en sådan fordelagtig udførelsesform af et strålevarmele-10 gerne også at tilvejebringe et kogeapparat eller et komfur med flere varmeflader eller kogeplader, ved hvilke de enkelte var-mefelter kan indkobles hver for sig eller sammen.Further, from DE-PS 25 51 137 there is known a radiant heater whose heating field is provided with a heat conductor and is surrounded by a ring of an insulating material which lies on an insulation on whose surface the heat conductor is arranged. In such an advantageous embodiment of a radiant heater it is desirable to also provide a cooker or stove with several heating surfaces or hotplates, in which the individual heating fields can be connected separately or together.

DE-PS 26 53 389 beskriver et kogeapparat eller komfur, ved 15 hvilket flere varmefelter er tilpasset hinanden ved deres udformning og kan kobles hver for sig eller sammen af koblingsorganer, der hører til de enkelte varmefelter for at tilvejebringe et sådant kogeapparat med flere kogeenheder.DE-PS 26 53 389 discloses a cooker or stove at which several heat fields are adapted to each other in their design and can be coupled separately or together by coupling means belonging to the individual heat fields to provide such a cooker with several cooking units.

20 Det er formålet med opfindelsen at videreudvikle et strålevarmelegeme til glaskeramikkogeplader således, at de enkelte dele fastholdes i deres tilsigtede positioner i et komfur med flere kogeplader, og både under fremstilling, montering, transport og reparation. Desuden skal varmelegemet have en ringe tabs-25 varme og en lav byggehøjde bevares.It is an object of the invention to further develop a radiator heater for glass ceramic hobs so that the individual parts are retained in their intended positions in a stove with several hobs, and both during manufacture, assembly, transport and repair. In addition, the heater must have a low loss-of-heat and a low building height.

Dette formål opnås ifølge opfindelsen ved et strålevarmelegeme af den i indledningen angivne art, der er ejendommeligt ved de træk, der er angivet i den kendetegnende del af krav 1.This object is achieved according to the invention by a radiant heater of the kind specified in the introduction, which is characterized by the features defined in the characterizing part of claim 1.

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Det isolerende underlag kan med fordel bestå af et eller flere isolationslag, der dækker bunden af bæreskålen, og af en ring af isolationsmateriale, der omgiver hvert varmefelt og strækker sig op til glaskeramikken. Ringen kan gribe ind over rand-35 området af den skive, hvorpå varmelederen er anbragt, og derved også under transport fastholde skiven. Ringen kan bestå af et materiale, der kan tåle en højere mekanisk belastning end 2The insulating substrate may advantageously consist of one or more insulating layers covering the bottom of the carrier bowl, and of a ring of insulating material that surrounds each heating field and extends up to the glass ceramic. The ring may engage over the edge region of the disk on which the heat conductor is placed, thereby also holding the disk during transport. The ring may consist of a material which can withstand a higher mechanical load than 2

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den øvrige isolering. Derved undgås revnedannelse i randen og hertil bidrager også udformningen af ringen, der er adski1t fra den øvrige isolation. Alligevel isolerer ringen varmefel-tet udadtil, og ved et komfur med flere kogeflader, også over 5 for de tilstødende varmefelter.the other insulation. This avoids cracking in the rim and also contributes to the design of the ring, which is separate from the other insulation. Nevertheless, the ring insulates the heat field externally, and by a stove with several cooking surfaces, also above 5 for the adjacent heat fields.

Fortrinsvis kan bæreskålen i hvert fald gribe ind over ringen i det område, hvor ringen styres af bæreskålen. Derved forbindes hele isolationen, også den som omgiver ringen, med bæ-10 rerskålen til en enhed.Preferably, the support bowl can at least engage the ring in the area where the ring is controlled by the support bowl. Thereby, the entire insulation, including the ring surround, is connected to the carrier bowl to a unit.

Isoleringen kan i hvert fald delvis bestå af et pulverformet isolationsmateriale, fortrinsvis af findelt kiselsyre. Ved denne udførelse er udformningen af den rand, der omgiver hvert 15 varmefelt, særlig fordelagtig som en særskilt ring, eftersom pulvermateriale har udmærkede isolationsegenskaber og tempera-turbestandighed, men derimod ikke er særlig mekanisk stærk og især i randområderne kan være tilbøjeligt til revnedannelse.The insulation may at least partially consist of a powdery insulating material, preferably of finely divided silicic acid. In this embodiment, the design of the rim surrounding each heating field is particularly advantageous as a separate ring, since powder material has excellent insulation properties and temperature resistance, but is not particularly mechanically strong and may be prone to cracking, especially in the peripheral regions.

20 De enkelte varmefelter kan med fordel afpasses i form efter hinanden, og de mellemliggende områder af ringene kan have en form, der er afpasset efter varmefelterne. I den forbindelse kan de skiver, som danner varmefelterne med derpå anbragte varmeledere have en rund eller firkantet form, og også ringene 25 kan have en forskellig form, f.eks. cirkelrund eller firkan tet. I det område, der danner broen mellem to varmefelter, kan det derimellem brodannende område have en form, der udadtil er firkantet og indadtil er rund. 1 2 3 4 5 6Advantageously, the individual heat fields can be matched in shape to one another, and the intermediate regions of the rings may have a shape adapted to the heat fields. In this connection, the discs which form the heat fields with heat conductors arranged thereon may have a round or square shape, and also the rings 25 may have a different shape, e.g. circular or square. In the area forming the bridge between two heat fields, the intermediate bridging area may have a shape which is outwardly square and inwardly round. 1 2 3 4 5 6

Selv om det er muligt at udforme skiven på sædvanlig måde og 2 f.eks. at indlægge varmelederen i noter i denne skive eller på 3 anden måde fastgøre varmelederne til den, foretrækker man en 4 udførelsesform af skiven, ved hvilken denne er forsynet med 5 forhøjninger, der er udformet af selve skiven, og at varmemod- 6 standene er delvis indlejret i disse forhøjninger og i øvrigt i hovedsagen ligger frit på overfladen af skiven, også kaldet en isolerende bærer. Ringen kan også med sin omkreds ligge på forhøjningerne.Although it is possible to design the disc in the usual manner and 2 e.g. inserting the heat conductor into notes in this disk or otherwise attaching the heat conductors to it, a 4 embodiment of the disk is preferred, in which it is provided with 5 elevations formed by the disk itself and the heat resistors are partially embedded in these elevations and otherwise generally located freely on the surface of the disk, also called an insulating carrier. The ring can also lie on its elevations with its circumference.

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Yderligere fordele og kendetegn fremgår af underkravene og af beskrivelsen i forbindelse med tegningen. Udførelseseksempler for opfindelsen er vist på tegningen, og skal i det følgende forklares nærmere. På tegningen viser 5 f i g. 1 et snit gennem en strålevarmeenhed til et glaskeramik-kogeapparat afskåret således, at man kun ser venstre halvdel og et randparti i højre side, 10 fig. 2 en isolationsplade anvendt i strålevarmeenheden i fig.Further advantages and characteristics appear from the subclaims and the description in connection with the drawing. Embodiments of the invention are shown in the drawing, and will be explained in more detail below. In the drawing, 5 f in g. 1 shows a section through a radiator heating unit for a glass ceramic cooker cut off so that only the left half and an edge portion are seen on the right side; 2 shows an insulation plate used in the radiant heating unit of FIG.

1, set i perskeptiv, fig. 3 et forstørret udsnit af fig. 1, som angivet med den stiplede cirkel III, 15 fig, 4 en anden udførelsesform af den i fig. 1 viste strålevarmeenhed eller kogeplade, fig. 5 et snit gennem en strålevarmeenhed med en bærerskål til 20 et kogeapparat med flere varmeflader og fig. 5a en strålevarmeenhed svarende til fig. 5, med en kombination af en rektangulær og en cirkelrund kogeflade.1, in perspective, fig. 3 is an enlarged sectional view of FIG. 1, as indicated by the dotted circle III, FIG. 4, another embodiment of the FIG. 1, radiant heating unit or hob; FIG. 5 is a section through a radiant heating unit with a support bowl for a multi-surface cooker; and FIG. 5a shows a radiant heat unit similar to FIG. 5, with a combination of a rectangular and a circular cooking surface.

25 I fig. 1 er vist en glaskeramikplade 11, der udgør kogefladen i et i øvrigt ikke vist elektrisk kogeapparat også kaldet komfur. Under glaskeramikpladen er anbragt en varmeenhed 12, som fortrinsvis trykkes imod glaskeramikpladens underside med ikke viste fjederelementer. Varmeenheden 12 har en bærerskål 13 af 30 plade, og denne består af en nedre pladedel 14 i form af en flad skål med jævn bund og en øvre pladedel 15 i form af en ring med et Z-formet tværsnit. Begge pladedele er forbundet indbyrdes langs ringflanger, som ligger op mod hinanden. 1 Bærerskål 13 er beklædt med en isolation, der består af to isolationslag eller -skiver 17, 18, der løber parallelt med bunden 16 af bærerskålen, og med en isolationsring 19. DisseIn FIG. 1, there is shown a glass ceramic plate 11 which constitutes the cooking surface of an otherwise electric cooker, also known as a stove. Under the glass ceramic plate is arranged a heating unit 12, which is preferably pressed against the underside of the glass ceramic plate with spring elements not shown. The heater unit 12 has a support plate 13 of 30 plate, and this consists of a lower plate part 14 in the form of a flat plate with a smooth bottom and an upper plate part 15 in the form of a ring with a Z-shaped cross section. Both plate parts are interconnected along annular flanges which are adjacent to each other. 1 Carrier bowl 13 is lined with an insulation consisting of two insulation layers or washers 17, 18 running parallel to the base 16 of the carrier bowl and with an insulation ring 19. These

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4 isolationslag kan være opbygget af meget forskellige materialer. Da de varmeisolerende egenskaber ved højvarmebestandige isolationsmaterialer, af den art som her må anvendes, aftager med voksende mekanisk styrke, kan man ved isolationslagene 17, 5 18, da de i styrkemæssig henseende praktisk taget er ubela stet, anvende et materiale med en relativ ringe mekanisk styrke, men med en høj varmeisoleringsevne. I denne forbindelse kan det nederste lag 17 f.eks. endog bestå af et slet ikke eller kun svagt komprimeret pulverformet isolationsmateriale 10 (f.eks. findelt kiselsyre) eller, da man her finder varmeen-hedens "koldeste" sted, af et materiale med en mindre høj var-mebestandighed. Derimod skal isolationsringen 19, der har en bestemt bærerfunktion, kunne tåle en noget større mekanisk belastning. Den kan bestå af et fiberholdigt isolationsmateria-15 le, f.eks. af al umi niumoxidfiber, som sammenpresset under tilsætning af et tilsvarende bindemiddel får en papiriignende struktur. Et lignende materiale er i handelen under betegnelsen "Fiberfrax". Der kan dog også anvendes andre mineralske fibre som basis for isoleringen.4 insulation layers can be made of very different materials. Since the heat-insulating properties of high-heat-resistant insulating materials, of the kind which may be used here, decrease with increasing mechanical strength, the insulating layers 17, 5 18, since they are practically unrelated in strength, can be used with a material with a relatively low mechanical strength. strength, but with a high thermal insulation ability. In this connection, the lower layer 17 can e.g. even consist of not at all or only slightly compressed powdery insulating material 10 (e.g., finely divided silicic acid) or, since the "coldest" location of the heating unit is here, of a material with a less high heat resistance. In contrast, the insulating ring 19, which has a specific support function, must be able to withstand a somewhat greater mechanical load. It may consist of a fibrous insulating material, e.g. of aluminum oxide fiber, which compressed while adding a corresponding binder, has a paper-like structure. A similar material is commercially known as "Fiberfrax". However, other mineral fibers can also be used as the basis for the insulation.

20 På det øverste isolationslag 18 og inden for isolationsringen 19, med sin rand i ndes 1 uttet i en ri ngformet udsparing i isolationsringen, ligger en isolerende bærer 20, der har form som en cirkelrund skive. Ved et almindeligt varmelegeme til et 25 glaskeramikkomfur ligger dimensionerne i størrelsesordenen omkring 15 cm i diameter og 5 mm i tykkelse. Denne isolerende bærer består ligeledes af et presset fiberholdigt isolationsmateriale med en meget høj varmebestandighed og bærer på sin overflade varmemodstande 21, der består af trådspiraler, der 30 forløber spiralformet, således at der dannes et ringformet varmeområde, der kun lader en uopvarmet midterzone 22 stå fri.20 On the upper insulating layer 18 and within the insulating ring 19, with its rim at end 1 cut into a ring-shaped recess in the insulating ring, lies an insulating support 20 which has the shape of a circular disc. In the case of a conventional heater for a 25 ceramic hob, the dimensions are in the order of about 15 cm in diameter and 5 mm in thickness. This insulating carrier also consists of a pressed fiber-containing insulating material with a very high heat resistance and carries on its surface heat resistances 21, which consist of wire coils extending spirally so that an annular heating area is formed leaving only an unheated middle zone 22 .

Varmemodstanden 21 ligger med den største del af deres udstrækning på overfladen 23 af den isolerende bærer 20 eller et 35 lille stykke over overfladen. Forhøjninger eller fremspring 24, 25 rager op fra den i det væsentlige plane overflade 23. Disse forhøjninger forløber radialt. Forhøjningerne 24 løber 5The heat resistance 21 lies with the greater part of its extent on the surface 23 of the insulating support 20 or a small distance above the surface. Elevations or projections 24, 25 protrude from the substantially planar surface 23. These elevations extend radially. The elevations 24 run 5

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fra yderkanten til den uopvarmede midterzone, mens forhøjningerne 25 stopper på halvvejen. Dermed sikrer man sig, at afstandene mellem forhøjningerne ligger inden for et bestemt område. Disse forhøjninger fremstilles ved prægning af den iso-5 lerende bærer ved dens fremstilling ved presning af en med bindemiddel forsynet fibermasse. Dermed presses varmemodstan-dene ind, således at de trænger ind i forhøjningerne og fastholdes i disse. Som det især fremgår af fig. 2 og 3, er varme-modstandene i området ved forhøjningerne fortrinsvis indlejret 10 med noget mere end halvdelen af deres spiralomkreds, idet de res øverste krumning og næsten hele den øverste halvdel af spiral vi ndi ngen såvel som det indre af spiralen forbliver fri.from the outer edge to the unheated middle zone, while the elevations 25 stop halfway. This ensures that the distances between the elevations are within a certain range. These elevations are made by embossing the insulating support in its manufacture by pressing a binder fiber pulp. Thus, the heat resistors are pressed in so that they penetrate into the elevations and are retained therein. As can be seen in particular from FIG. 2 and 3, the heat resistors in the region of the elevations are preferably embedded 10 with somewhat more than half of their spiral circumference, the upper curvature of the remaining and almost all of the upper half of the spiral as well as the interior of the spiral remaining free.

Derved fastholdes varmemodstanden særdeles godt samtidig med, 15 at deres varmeudstråling næppe hæmmes. I hele området mellem forhøjningerne kan varmemodstandene udstråle uhindret, og i området ved forhøjningerne er det kun den nederste vinding, som hindres i udstråling. Der tilvejebringes således et meget effektivt varmeelement, som sikrer de bedst mulige udstrå-20 lingsforhold i opadgående retning.In this way, the heat resistance is maintained very well at the same time that their heat radiation is hardly inhibited. In the entire region between the elevations, the heat resistances can radiate unobstructed, and in the region of the elevations only the lower windings are obstructed by radiation. Thus, a very efficient heating element is provided which ensures the best possible radiation conditions in the upward direction.

Den isolerende bærer 20 bør f.eks. ved et passende valg af materiale eller ved en stærkere komprimering af materialet, have en større mekanisk styrke end den øvrige isolation. Den danner 25 dermed en skive, som ganske vist stadig har en vis paplignende struktur, men ved fremstilling, montering og reparation uden videre kan håndteres. Varmemodstandene er så fast forbundne med denne plade, at der ikke er nogen risiko for, at de på en eller anden måde løsnes ved rystelser eller varmeudvidel ser.The insulating carrier 20 should e.g. by a suitable choice of material or by a stronger compression of the material, have a greater mechanical strength than the other insulation. It thus forms a disc, which, while still having a certain cardboard-like structure, can be handled by manufacturing, assembly and repair. The heat resistors are so firmly connected to this plate that there is no risk that they will somehow be loosened by shaking or heat expansion.

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Prægningerne, som skaber forhøjningerne 24, 25, danner fordybninger 26 på undersiden af den isolerende bærer. Fortrinsvis er der på oversiden af det øvre isolationslag 18 ligeledes indrettet udsparinger eller udskæringer 27, således at disse 35 eventuelt krydsende udsparinger danner et luftrum, der yderligere bidrager til isolering. Den elektriske tilslutning af spiralen sker fortrinsvis gennem den isolerende bærer nedefra, 6The embossments which create the elevations 24, 25 form recesses 26 on the underside of the insulating support. Preferably, recesses or cut-outs 27 are also provided on the upper side of the upper insulation layer 18, so that these possibly intersecting recesses form an air space which further contributes to insulation. The electrical connection of the coil is preferably through the insulating carrier from below, 6

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således at tilslutningstrådene f.eks. kan forløbe i en af udsparingerne 26. De tilsvarende tilslutningsben eller tunger kan allerede under komprimeringen trykkes gennem det endnu bløde materiale til den isolerende bærer. Efter komprimeringen 5 udsættes den isolerende bærer normalt for en tørrings- eller brændi ngsproces.so that the connecting wires e.g. may extend in one of the recesses 26. The corresponding connecting legs or tongues may already be pressed through the still soft material to the insulating support during compression. After compaction 5, the insulating support is usually subjected to a drying or burning process.

Montering af varmeenheden sker ved at isolationslagene 17 og 18 først hældes eller rystes ned i den nederste pladedel 14 10 og/eller i tilfælde af, at det drejer sig om forpressede skiver, indlægges, og derpå lægges den isolerende bærer 20. Tilslutningstrådene 28 føres ud til siden gennem en udskæring 29 i området ved skillelinien mellem pladedelene 14, 15. Derefter påsættes isolationsringen 19, og varmeenheden færdiggøres ved 15 påsætning og fastgørelse af den øvre pladedel 15. Isolationsringen 19 har også en opstående ringformet kant 30, som ligger an imod glaskeramikpladens underside.The heating unit is mounted by first pouring or shaking the insulation layers 17 and 18 into the lower plate part 14 10 and / or in the case of pre-pressed discs, inserting and then insulating the carrier 20. The connecting wires 28 are removed laterally through a cutout 29 in the region at the dividing line between the plate parts 14, 15. Then the insulation ring 19 is applied and the heating unit is completed by attaching and fixing the upper plate part 15. The insulation ring 19 also has an upright annular edge 30 which abuts the glass ceramic plate. underside.

I f i g. 1 er vist en udførelsesform, hvor der er anvendt en 20 temperaturbegrænser eller temperaturregulator 31 på en sådan måde, at dens stavformede temperaturføler 32 rager diametralt gennem strålingsrummet 33, som dannes mellem varmemodstandene 21 og undersiden af keramikpladen 11. Temperaturføleren løber gennem en åbning i pladedelen 15 og isolationsringen 19. I 25 denne udførelsesform må temperaturføleren isoleres elektrisk af hensyn til berøringssikkerheden ved et eventuelt brud på glaskeramikpaden, f.eks. kan temperaturføleren være overtrukket med et kvartsrør. Af denne årsag kan temperaturregulatoren 31 ved den i fig. 4 viste udformning, der i øvrigt er opbygget 30 på samme måde, være anbragt således, at den ligeledes rager igennem i skillelinien mellem de to pladedele 14, 15 og ligger i en udsparing på undersiden af isolationsringen 19' og på oversiden af isolationslaget 18'. Også den isolerende bærer 20 har en udskæring 34 til temperaturføleren 32 langs en diame-35 ter, således at denne kan afføle opvarmningstemperaturen relativt godt, da den isolerende bærer på grund af sin høje mekaniske styrke og dermed noget ringere termiske isolationsvirk- 7Fig. 1 shows an embodiment in which a temperature limiter or temperature controller 31 is used in such a way that its rod-shaped temperature sensor 32 projects diametrically through the radiation space 33 which is formed between the heat resistors 21 and the underside of the ceramic plate 11. The temperature sensor runs through an opening in the plate portion 15 and the insulation ring 19. In this embodiment, the temperature sensor must be electrically insulated for the sake of touch safety in the event of a breakage of the glass ceramic pad, e.g. For example, the temperature sensor may be coated with a quartz tube. For this reason, the temperature controller 31 at the 4, which is otherwise constructed 30 in the same manner, so arranged that it also protrudes in the dividing line between the two plate parts 14, 15 and lies in a recess on the underside of the insulation ring 19 'and on the upper side of the insulation layer 18'. . Also, the insulating support 20 has a cut-out 34 for the temperature sensor 32 along a diameter 35 so that it can sense the heating temperature relatively well, since the insulating support, due to its high mechanical strength and thus some poor thermal insulation effect, is sufficient.

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ning meget hurtigt antager temperaturen af opvarmningsaggregatet .heating very quickly assumes the temperature of the heater.

Ved denne udformning holdes strålingsrummet 33 i vid udstræk-5 ning frit, og man kan indføre et jordingsgitter 35, der ligger på en skulder af isolationsringen 19', og lige under glaskera-mikpladen danner en berøringsbeskyttelse imod varmemodstandene 21, som er spændingsførende.In this embodiment, the radiation compartment 33 is largely held free, and a grounding grid 35, which is located on a shoulder of the insulating ring 19 ', can be inserted, and just below the glass ceramic plate provides contact protection against the heat resistors 21, which are live.

10 Da den samlede isolation 17, 18, 19 og ligeledes den isolerende bærer 20 kun skal komprimeres så meget, som dette er nødvendigt for den mekaniske styrke, kan overfladen af isolationsdelene ved berøring få slidmærker. Af denne^ årsag er det muligt at behandle overfladerne af isolationsdelene på særlig 15 måde, f.eks. at forsyne dem med en større tilsætning af bindemiddel eller at sprøjte dem med en varmebestandig lak. Det er endvidere særlig fordelagtigt at forsyne den isolerende bærers overside med en lak, som over for varmeudstråling virker sort for at forbedre de varmeudstrålende egenskaber i opadgående 20 retning.10 As the overall insulation 17, 18, 19 and likewise the insulating support 20 are only to be compressed as much as is necessary for the mechanical strength, the surface of the insulation parts may be subject to wear marks. For this reason, it is possible to treat the surfaces of the insulation parts in particular manner, e.g. to provide them with a greater addition of binder or to spray them with a heat-resistant varnish. Furthermore, it is particularly advantageous to provide the top surface of the insulating carrier with a varnish which acts black against heat radiation to improve the heat radiating properties in the upward direction.

Normalt har varmeenhederne en cirkelrund form, og da er det også hensigtsmæssigt at udforme den isolerende bærer cirkelrund. Det kan dog være en fordel med henblik på en bedre til-25 pasning af den normale placering af fire kogeplader at anvende rektangulære eller kvadratiske varmeenheder. I så fald kunne isolationsringen til brodannelse have en udadtil firkantet og en indadtil rund form ved anvendelse af en rund isolerende bærer.Usually, the heating units have a circular shape, and then it is also convenient to design the insulating support circular. However, using rectangular or square heaters may be advantageous for a better fit of the normal location of four hotplates. In that case, the insulation ring for bridging could have an outwardly square and inwardly round shape using a round insulating support.

30 I tilfælde af en firkantet isolationsbærer eller isolationsring med runde varmeringsområder, kunne der i de derved opståede uopvarmede hjørner være anbragt overvågnings- eller følerudstyr for temperaturovervågningen. Den særlige fordelagtige 35 mulighed for at anvende et pulveragtigt eller kornet isolationsmateriale ved isolationslagene 17, 18, der har fordelen af en meget høj varmeisoleringsevne, muliggøres gennem anbrin-In the case of a square insulating support or insulation ring with round heating areas, monitoring or sensing equipment for the temperature monitoring could be provided in the resulting unheated corners. The particularly advantageous possibility of using a powdery or granular insulating material at the insulating layers 17, 18, which has the advantage of a very high thermal insulation capacity, is made possible by the application of

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8 gelsen af varmeelementer på en isolerende bærer, som mekanisk er ret stiv, og som danner en tæt tillukning. Ved forskellige netspændinger eller varmeeffekter skal der blot fremstilles en anden isolerende bærer med varmemodstande, mens de øvrige dele 5 i varmeenheden kan være de samme og kan fremstilles i en serieproduktion. Dette er også vigtigt for lagerføringen og ved reparationer (færre dele, som skal lagerføres). Den spiralformede anbringelse af varmemodstandene kan ske bifilært, dvs. varmetrådene kan ligge dobbelt, således at begge ender af var-10 memodstanden ligger ved randen af skiven, og den spiralformede varmemodstand løber som to indbyrdes parallelle strenge spiralformet imod skivens midte. Den isolerende bærer med den radiale udragende tilledninger kan slutte tæt op til hinanden og kan uden videre stables, således at transporten forenkles.8 provides the heating elements of an insulating support which is mechanically quite rigid and which forms a tight seal. At different mains voltages or heat effects, only another insulating carrier with heat resistances has to be produced, while the other parts 5 of the heating unit may be the same and can be produced in a series production. This is also important for stocking and for repairs (fewer parts to stock). The helical application of the heat resistors can be bifilar, ie. the heating wires may be double so that both ends of the heat resistance lie at the edge of the disk, and the helical heat resistance runs as two mutually parallel strands helically against the center of the disk. The insulating carrier with the radially protruding leads can close up close to each other and can be easily stacked so that transport is simplified.

1515

Varmemodstanden på den isolerende bærer er normalt udlagt spiralformede med cirkelrunde trådvindinger. Det kan dog være fordelagtigt at gøre trådvindingen oval, og fortrinsvis således at den har sin mindste udstrækning i retning mod glaskera-20 mikpladen. Dermed kan strålingsrummet selv ved større vindinger få en tilstrækkelig størrelse, som blandt andet også er nødvendig for gennemslagsstyrken. Det er dog altid vanskeligt til trods for god isolation og tilstrækkelig gennemslagsstyrke at fremstille varmeenheder med en ringe tykkelse, der samtidig 25 på deres underside har en tilstrækkelig lav temperatur til at kunne grænse op til brændbare dele af køkkenskabe.The heat resistance of the insulating support is usually laid out helically with circular wire turns. However, it may be advantageous to make the wire winding oval, and preferably such that it has its smallest extension towards the glass ceramic plate. In this way, even in larger windings, the radiation space can get a sufficient size, which is also necessary for the impact strength. However, despite good insulation and sufficient impact strength, it is always difficult to produce low-thickness heating units which, at the same time, have at their underside a sufficiently low temperature to be able to adjoin combustible parts of kitchen cabinets.

Ved en yderligere ikke vist variant kan spiralen på enkelte steder være nedlagt noget dybere i den isolerende bærer (eller 30 på den isolerende bærer), f.eks. for at skaffe plads til en stavtemperaturføler. Ved en sådan fordybning kan den nødvendige isolationsafstand opnås uden at hale strålingsfladen skal lægges dybere. 1In a further variant not shown, in some places the coil may be deposited somewhat deeper in the insulating carrier (or 30 on the insulating carrier), e.g. to provide room for a rod temperature sensor. In such a recess, the required insulation distance can be obtained without having to lower the radiating surface. 1

Ved det beskrevne udførelseseksempel har hver varmeenhed en særlig bærerskål, som trykkes op imod glaskeramikpladen. Det er dog også muligt på fordelagtig måde kun at anvende én bæ-In the described embodiment, each heating unit has a special support bowl which is pressed up against the glass ceramic plate. However, it is also advantageous to use only one carrier.

Claims

1. Electric radiator heater for glass ceramic hobs 10 having a disc (20) consisting of a high temperature resistant insulating material and disposed in a support bowl (13), to which is mounted a heat resistance (21) and with a ring (19) of a insulating material, the upper side of which abuts the underside of the glass ceramic plate, the ring (19) protruding over the upper edge of the rim of the support bowl, characterized in that the ring (19) determines the height of the space (33, 33a, 33b) formed between the disc (20) and the glass ceramic plate, whereby the underside of the ring substantially along its entire circumference abuts against the disc (20), whereby the ring (19) is guided by the rim protruding from the support cup (13) so that in the support cup (13) ) is provided with an insulation (17, 18, 19, 20a, 20b) with several bowl-shaped compartments (33a, 33b), and each compartment (33a, 33b) surrounded by the ring (19) defines a heating field for a stove with several hobs. 25

Radiator heater according to claim 1, characterized in that the ring (19) consists of a material which can withstand a greater mechanical load than the other insulation (17, 18, 20a, 20b). 30

Radiant heater according to claim 1 or 2, characterized in that the support bowl (13) at least partially engages the ring (19) in the region of the ring controlled by the carrier bowl (13). 35

Radiant heater according to one or more of the preceding claims, characterized in that the electrical conductors (28) for the heat resistors (21) and optionally for a temperature sensor (30) are passed between the ring (19) and the insulating substrate (18).

Radiant heater according to one or more of the preceding claims, characterized in that the ring (19) carries an earthing grid (35).

Radiator heater according to one or more of the preceding 10, characterized in that the underside of the disc (20) and / or the upper side of the up to adjacent insulating substrate is profiled such that spaces (27) are formed along the dividing line between the two parts.

Radiant heater according to one or more of the preceding claims, characterized in that the insulation (17, 18) consists at least in part of a rice-resistant or powdery insulating material, preferably of finely divided silicic acid.

Radiant heater according to claim 7, characterized in that the rice-resistant or powdery insulating material is slightly compressed.

Radiator heater according to one or more of the preceding 25, characterized in that parts of the insulation (17, 18, 20) and / or the ring (19) are provided with a surface coating for protection against wear.

9 DK 164431 Bearing bowl for a cooker with several heating surfaces or several units (Fig. 5), in which there is an insulation defining several bowl-shaped cuts which can accommodate the insulating carrier. 5 Patent claims.

Radiant heater according to one or more of the preceding 30, characterized in that the top surface (23) of the disc (20) is provided with a surface coating suitable for emitting heat radiation.

Radiator heater according to one or more of the preceding claims, characterized in that the heat fields in their design are aligned with each other and that any intermediate regions of the rings (19) have a shape which fits the heat fields.