CA1122637A - Cooking apparatus with flat tubular heating bodies - Google Patents
Cooking apparatus with flat tubular heating bodiesInfo
- Publication number
- CA1122637A CA1122637A CA316,546A CA316546A CA1122637A CA 1122637 A CA1122637 A CA 1122637A CA 316546 A CA316546 A CA 316546A CA 1122637 A CA1122637 A CA 1122637A
- Authority
- CA
- Canada
- Prior art keywords
- plate
- heating bodies
- disc
- grooves
- tubular heating
- 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
Links
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
- H05B3/00—Ohmic-resistance heating
- H05B3/68—Heating arrangements specially adapted for cooking plates or analogous hot-plates
- H05B3/76—Plates with spirally-wound heating tubes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C15/00—Details
- F24C15/10—Tops, e.g. hot plates; Rings
- F24C15/102—Tops, e.g. hot plates; Rings electrically heated
- F24C15/106—Tops, e.g. hot plates; Rings electrically heated electric circuits
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electric Stoves And Ranges (AREA)
- Baking, Grill, Roasting (AREA)
- Cookers (AREA)
- Control Of Resistance Heating (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A cooking unit comprises a substantially flat, thin-walled plate provided with helical grooves.
Heating elements in the form of helical, flattened, tubular bodies are received in the grooves and provide a heating surface in which cooking vessels can stand.
A cooking unit comprises a substantially flat, thin-walled plate provided with helical grooves.
Heating elements in the form of helical, flattened, tubular bodies are received in the grooves and provide a heating surface in which cooking vessels can stand.
Description
~ZZt;37 TITIE
Cooking Apparatus FIELD OF T!~ INVFNTION
The invention relates to a cooking apparatus with a cooking surface formed by flattened tubular heating bodies, on which cooking vessels can stand and in which the tubular heating bodies rest on a support and are arranged above a closed surface.
BACKGI~OUND O~ TI~E INVENTION
Cooker plates of this type, for example as described in German Patent No. 1,189,217, have a relatively small thermal capacity and are therefore quite suitable for rapid initial cooking procedures when small amounts of product are to be cooked.
They do however have the substantial drawback that they do not form a cloæd cooking surface so that if material which is being cooked overflows, it can run past them into the interior of the cooker whence it can be removed later on only with difficulty. The ~o entire cooker surface is therefore made to be pivotal so that the interior of the cooker can be cleaned.
The cooker unit has a dish which collects the material which has overflowed. This dish lies at a substantial distance below the spirally wound twbular heating bodies.
~oreover, these known tubular cooker plates have the l~ZZ637 disadvalltage that -their temperaturc can be controlled ollly poorly.
A cooker unit is also known from U S. Patent No. 1,979,471, in which the cooking surLace is formed by a ceramic plate with deep spiral grooves which are open at the top and in which lie heating coils~
A radiant heating means is thus formed since the ceramic plate transfers the heat only poorly. In this case, cooking material wllich has overflowed is particularly unpleasant because it runs directly on to the open heating elemen-ts and sticks to them or shor-t-circuits them under certain circumstances.
Moreoever, heating elements of this type in the form of open resistance wires are objectionable for safe-ty reasons.
_ .
BRIEF SUMMW~Y OF TIE INVENrrION
An object of the present invention is to provide a cooker unit with a cooking surface formed by tubular heating bodies, which is superior to known cooker units, in particular with respect to the ability to keep it clean According to the invention there is provided a cooking apparatus comprising a substantially flat, thin-walled pla$e provided with grooves, and forming a closed surface, and flattened tubular heatin6 bodies arranged in the grooves and forming a cooking surface 1~226:~7 for receiving cooking vessels.
In accordance with a particular embodiment of the invention, a cooking apparatus comprises a plate extending in a generally flat plane, provided with grooves, and forming a closed surface a plurality of longitudinally spaced support projections disposed in the grooves' and electrically heated tubular heating bodies with flat upper surfaces, the heating bodies being arranged on the support projections in the grooves and forming a cooking surface for receiving cooking vessels, substantially point contacts being made between the plate and the heating bodies.
The apparatus according to the invention has the advantage over conventional tubular cooker plates that it has a substantially closed cooking surface beyond which the tubular heating bodies need project only slightly.
The tubular heating bodies can penetrate the thin-walled plate in a sealed manner so that there is no fear of cooking material running through in a downward direction. Al-though the tubular heating bodies lie partially in the grooves, sufficient lies beyond them for them to form the coo~ing surface.
The plate reaches high temperatures very rapidly owing to its thinness, forms an additional reflecting and radiating surface, and allows food which overflows and which collects in the grooves to be baked into fine ash which can be removed, for example, by being blown or brushed out. The cooker plate is thus preferably self-cleaning.
In order to keep the transfer of heat by contact between the flat thin-walled plate and the tubular heating bodies rélatively low, the tubular heating bodies can be supported by support projections lying at a distance from each other and arranged in the grooves. The projections are preferably formed by stampings on the base of the grooves.
The generally flat, thin-walled plate, which is ~L~2Z637 preLcrably produced from stainless steel, can withstand the considerable thermal and mcchanical stresses caused by thermal expansion particularly well if the grooves are arranged spirally to correspond to the tubular heating bodies containe~ in them and impart to the plate a radial elasticity for taking up the thermal stresses. In this arrangement, the plate works as a diaphragm with corrugated profiling.
The thin diaphragm-like plate is prelerably borne by an internal support which can lie, for example, in a substantially closed -trough of the cooker plate.
The cooker plate thus needs to have only relatively small openings and this increases its stability. Good insulating material can also be inserted there, and this increases ef~iciency and keeps small the thermal load on the cooker or on items of kitchen furniture lying beneath a fitted cooker trough, even in the case of a very small structural height. As the diaphragm-like plate with the tubular heating body arranged on it - 20 forms a thermally substantially coherent but tight uni-t, it is also possible to arrange temperature monitoring instruments9 for example temperature limiters, beneath the plate without their temperature sensors being exposed to dirt or damage. 'rhe above-mentioned small structural height should ba mentioned because there is no need for a :
~2;2~37 collectillg di6h Lor iood whicll hus ovcrLlowcd, with a throw-away i`oil which can be optionally insel ted.
An embodiment of the invention is 5ShO~l in the acco~npanying drawings.
BRIEr'' I)ESCT~Il'TION ol? TEIE DI~AWINGS
Figure 1 shows a cross-section throu~h a cooker unit according to the invention;
Figure 2 shows a plan view o~ the cooker unit l0according to Figure l;
Figure 3 shows a view along the line III-lII
in Figure 1 (view from below a unit);
Figure 4 shows an enlarged cross-section of the detail lying in the dash-dotted circle IV in Figure l;
Figure 5 shows a longitudinal section thereof;
and Figure 6 shows a schematic circuit diagram of the cooker unit.
DETAILED l)ESCllIP'rION OF PI~EEE~ ED EMBODIMENT
The cooker unit 11 illustrated in the draw~ings has tubular heating bodies 12 which have a substantiall~
triangular cross-section which is flattened on their upper side. The upper fla-ttened side forms the cooking surface 13 on which cooking ~essels 14 can s-tand. The 25tubular heating bodies 12 form two heating resistances which are wound spirally. An internal heating resistance 15 112;2~37 is surroullded by an external heating resistance 16, the internal elld oi` the heating resistance 16 being connected directly to the external end of the heating resistance 15. The heating rcsistance 15 thus 5 forms a central heating zone while the heatin6 resistance 16 forms an external heating ring.
The tubular heating bodies have relatively small cross-sectional dime~sions, the largest dimension of which (a triangular side) amounts to about 5 mm, lO and are therefore ~ite flexible and are well adapted to the heated surface of the cooking vessel 14. They can be made of a rust-resistant metallic casing and substantially coil-shaped hea-ting conductors in an insulating embedding composition embedded therein.
15 Owing to the triangular shaping, the cross-section of the coil is also approximately triangular.
The tubular heating bodies lie on a thin plate 17 which is made of very thin stainless steel p~te with thicknesses of the order of 0.2 to 0.4 mm.
20 Spiral grooves 18 having a substantially triangular cross-sectional shape (with rounded corners) are shaped - into the circular pla-te 17 to correspond to the spiral JS /G
shape of th0 heating resistances ~ land ~. Support projections 19 are arranged on th0 bottom of these grooves ~5 at intervals of a few centimetres. In the illustrated ' ':
~12Z6~7 embodimcllt, eight support pr~jections 19 are pro~ided round the circumference d`the grooves, with the exception of the internal spiral windings.
The support projections 19 are formed by the fact that in each case the bot-tom of each groove is not 5shaped to the full depth over a distance o~ a few millimetres.
As shown, in particular, in Figure 4, the lower triangular edge of the tubular heating bodies lies virtually in point contact on the support projection 19 which is also rounded in side view (Figure 5).
The groove 18 is sufficiently large for -the tubular hea-ting body to lie in it at a distance of from 1 to a few millimetres and with the cooking surface 1513 projects somewhat beyond the flat surface of the plate 17.
~ he two ends ol` each heating resistance 15,16 are passed in a sealed manner through openings 20.
In the embodiment illustrated, they are soldered 20into these openings. A completely sealed cooker unit is thus produced so that overflowing ioods cannot run inside the cooker or cooker trough. Although some overflowing food will stick in the grooves and under the tubular heating bodies, this space in the grooves is designed 25to be such that, havïng regard to the thinness of the wall ~ZZ637 of the plate 17 it cleans itself as a result oL the carbonisation of the food which has overflowed. A line ash which can be blown or brushed out is thus Iormed.
The extremely high temperatures which produce this self-cleanin~ effect are produced only when there is 5 dirt in these positions. If the blank metal surLace is exposed, the groove acts as a reflector which irradiates the heat radiation ori~inating fro~ the underside of the tubular heating body upward toward the bottom of the cooking vessel. The groove can al~ be designed in other ways 10 so as to obtain specific coefficients of reflection and so as not to fall below desired minimum distances between tubular heating bodies and plate. Thus, for e~ample, it could also be of substaltially semi-circular cross-section in the case of a tubular heating body designed 15 semi-circularly on its underside. The support projections could also have another sequence or design. However, it is preferable to stamp them directly from the material of the plate.
The plate 17 has a relatively wide unheated 20 edge region 21 between the outermost spiral winding of the heating resistance 16 and its external edge, which ensures that only a very little heat can be conducted toward the edge, owing to the relatively poor heat conducting properties of stainless steel. On the outer ~5 circumference, the plate 17 is beaded downward round the --~12~637 cxt,~rllal ~ge 21 of a dish-like disc 22 and thus joined to it. The disc 2'' Lorl~s a sup~)ortillg s-truc-ture for the plate 17. It has a projection 24 directed wpwar~s in its centre so that its recess 23 surrounclsthe projection 24 in the manner of a groove. The recess 23 in the disc 22 5 is relatively flat. Support projections 25 are shaped Lrom the disc, which project upwards into its reces~ 23 and are dimensioned in such a way that the underside of the grooves 18 rest on them. As shown in Figure 3, the support projections are formed by cutting into the material of the disc and formed upwardly directed flanges which run radially. The pla-te 17 is borne by the support projections, as well as by tlle central projectionformed by deep stamping of the material of the disc so that even heavy cooking vessels do not produce unacceptable deformation of the plate 17. It should be noted that the plate 17 acquires the properties of a corrugated diaphragm owing to the spiral grooves 18 so that it can compensate even extreme temperature differences without unacceptable deformations. The pxojection 21~ can he welded to the plate 17.
The disc 22 is produced from thicker and more rigid material than thc plate 17 and can have a reflecting surface in its interior. It is also possible to insert an insulating material 26 in it (shown in part in Figure 1~.
~2~37 A tempera-ture limiter 27 can be arrange~ in the cavity 23 between plate 17 and disc 22, preferably in the edge region, and serves to switch off the cooker unit when an excessive temperature occurs (Lor example 5 in no-load operation).
A fixing bolt 28 with which the unit 11 can be fixed on a cooker or a cooker trough, is arranged-in the region of the central projection 24.
As shown in Figure 1, the plate 29 in which the unit is fitted can have a relatively flat trough 30 which need be, for example, only 20 to 30 mm deep.
This trough 30 can -be substantially uninterrupted up to the openings for the ends of the tubular heating body and the central bolt so that the plate 29 has a 15high inherent stability~ Insulating material 31 can be inserted between the trough and the unit 11 lying in it at a small distance (indicated in part in Figure 1).
On its encircling edge, the trough has an encircling shoulder 32 lying somewhat deepended, on which 20the edge 21 of the unit 11 is supported with interpesition of a sealing ring 33. The unit 11, which is~ furthermore, only kept down by the fixing bolt 28 is there~ore tightly inserted into the plate 29. The surface of the plate 17 can therefore lie flush with the surface of the plate 29 25to form a surface on which saucepans can be slid to and fro without encounte~ing ledges. The small distance ' ,:
- ' ' ~ ' :
~2'~637 tWCell the plate 17 and tlle heatin~ surrace 13 on the tubular hea-ting bodies 1'' is thus easily overcome.
It should also par-ticularly be no-ted that -the unit 11 forms a separate unit which can be mounted in advance and produced separately from the re6t oL
the cooker and which can easily be placed on the cooker and exchanged if in need of repair. The total height oI the cooker trough can be kept very small owing to the good and multiple means of insulation wi-thout the temperature exceeding an allowable value on its underside.
Flat incorporation in kitchen furniture is thus possible.
As shown in Figure 6, the two hea-ting resist-ances 15,16 can be switched on separately. The temper-ature limiter 27 and a power control instrument 36 which usually operates by quantization, lies in a common supply line 35. A bimetallic member 38 heated by a control heating resistance 37 which is connected in parallel with thel-eating resistances activates a switch 39 of the power control instrument. The power control instrument can be set by means of an actuating button 40.
A manually activatable mechanical switch 41 which lies in the supply line to the external heating resistance 16 is also provided. If~ for example, the external diameters of the internal heating resistance 15 and the external heating resistance 16 are 140 and 180 mm, 1~22~37 houscwivcs call choosc whc1llcl they wisll to use only a slllall or a large hcated diamcter, de~erlding upon the si~e of the saucepan use~ A very adal)tablc cooking unit with which energy can bc saved iS thus provided.
It would also be possible to have the.switch 5 41 switched automatically by activating the activating button 40 in such a way that the heating resistance 16 is only connected in the uppcr power range, i.e. when the power control instrument 36 has controlled the internal heating resistance to lrom 15 to 100% power.
10 Control is continued as a result of a l~ink in the corresponding control curve of the power control instrument 36 once the heating resistance 16 has been connected in the case of the corresponding power value.
It is however also possible -to design the circuit in such a way that the heating ~ody 15 remains entirely connected in the higher power range and the energy controller merely controls t~le heating resistance 16. :
IIowever, in each case, the advantage is achieved that only the internal heating resistance is effective at 20 low power This promotes saving in energy, i.n particular ~-~ because, at the very moment when only small power is necessary, i.e. small amounts of food are to be heated, coo~ing vessels which are small and which do not cover the entire cooker unit are frequently selected. Moreover, 25 particularly in the lower power range which is difficult ~ to start up, the power control instrument controls only .
.
1122~;37 -tlle power of the heating resistance 15 and thus receives higher relative switc~hing times than would correspond to the respective portion oL thc total power of the cooker plate.
The use of two heating resistances 15, 16 in the case of a normal or large plate diameter also has the advantage that only the central heating resistance 15 need be provided ior s~all plate diameters. A
reduction in the number of types of heating resistances with corresponding advantages for production and storage can be achieved in this way.
.
-15~
Cooking Apparatus FIELD OF T!~ INVFNTION
The invention relates to a cooking apparatus with a cooking surface formed by flattened tubular heating bodies, on which cooking vessels can stand and in which the tubular heating bodies rest on a support and are arranged above a closed surface.
BACKGI~OUND O~ TI~E INVENTION
Cooker plates of this type, for example as described in German Patent No. 1,189,217, have a relatively small thermal capacity and are therefore quite suitable for rapid initial cooking procedures when small amounts of product are to be cooked.
They do however have the substantial drawback that they do not form a cloæd cooking surface so that if material which is being cooked overflows, it can run past them into the interior of the cooker whence it can be removed later on only with difficulty. The ~o entire cooker surface is therefore made to be pivotal so that the interior of the cooker can be cleaned.
The cooker unit has a dish which collects the material which has overflowed. This dish lies at a substantial distance below the spirally wound twbular heating bodies.
~oreover, these known tubular cooker plates have the l~ZZ637 disadvalltage that -their temperaturc can be controlled ollly poorly.
A cooker unit is also known from U S. Patent No. 1,979,471, in which the cooking surLace is formed by a ceramic plate with deep spiral grooves which are open at the top and in which lie heating coils~
A radiant heating means is thus formed since the ceramic plate transfers the heat only poorly. In this case, cooking material wllich has overflowed is particularly unpleasant because it runs directly on to the open heating elemen-ts and sticks to them or shor-t-circuits them under certain circumstances.
Moreoever, heating elements of this type in the form of open resistance wires are objectionable for safe-ty reasons.
_ .
BRIEF SUMMW~Y OF TIE INVENrrION
An object of the present invention is to provide a cooker unit with a cooking surface formed by tubular heating bodies, which is superior to known cooker units, in particular with respect to the ability to keep it clean According to the invention there is provided a cooking apparatus comprising a substantially flat, thin-walled pla$e provided with grooves, and forming a closed surface, and flattened tubular heatin6 bodies arranged in the grooves and forming a cooking surface 1~226:~7 for receiving cooking vessels.
In accordance with a particular embodiment of the invention, a cooking apparatus comprises a plate extending in a generally flat plane, provided with grooves, and forming a closed surface a plurality of longitudinally spaced support projections disposed in the grooves' and electrically heated tubular heating bodies with flat upper surfaces, the heating bodies being arranged on the support projections in the grooves and forming a cooking surface for receiving cooking vessels, substantially point contacts being made between the plate and the heating bodies.
The apparatus according to the invention has the advantage over conventional tubular cooker plates that it has a substantially closed cooking surface beyond which the tubular heating bodies need project only slightly.
The tubular heating bodies can penetrate the thin-walled plate in a sealed manner so that there is no fear of cooking material running through in a downward direction. Al-though the tubular heating bodies lie partially in the grooves, sufficient lies beyond them for them to form the coo~ing surface.
The plate reaches high temperatures very rapidly owing to its thinness, forms an additional reflecting and radiating surface, and allows food which overflows and which collects in the grooves to be baked into fine ash which can be removed, for example, by being blown or brushed out. The cooker plate is thus preferably self-cleaning.
In order to keep the transfer of heat by contact between the flat thin-walled plate and the tubular heating bodies rélatively low, the tubular heating bodies can be supported by support projections lying at a distance from each other and arranged in the grooves. The projections are preferably formed by stampings on the base of the grooves.
The generally flat, thin-walled plate, which is ~L~2Z637 preLcrably produced from stainless steel, can withstand the considerable thermal and mcchanical stresses caused by thermal expansion particularly well if the grooves are arranged spirally to correspond to the tubular heating bodies containe~ in them and impart to the plate a radial elasticity for taking up the thermal stresses. In this arrangement, the plate works as a diaphragm with corrugated profiling.
The thin diaphragm-like plate is prelerably borne by an internal support which can lie, for example, in a substantially closed -trough of the cooker plate.
The cooker plate thus needs to have only relatively small openings and this increases its stability. Good insulating material can also be inserted there, and this increases ef~iciency and keeps small the thermal load on the cooker or on items of kitchen furniture lying beneath a fitted cooker trough, even in the case of a very small structural height. As the diaphragm-like plate with the tubular heating body arranged on it - 20 forms a thermally substantially coherent but tight uni-t, it is also possible to arrange temperature monitoring instruments9 for example temperature limiters, beneath the plate without their temperature sensors being exposed to dirt or damage. 'rhe above-mentioned small structural height should ba mentioned because there is no need for a :
~2;2~37 collectillg di6h Lor iood whicll hus ovcrLlowcd, with a throw-away i`oil which can be optionally insel ted.
An embodiment of the invention is 5ShO~l in the acco~npanying drawings.
BRIEr'' I)ESCT~Il'TION ol? TEIE DI~AWINGS
Figure 1 shows a cross-section throu~h a cooker unit according to the invention;
Figure 2 shows a plan view o~ the cooker unit l0according to Figure l;
Figure 3 shows a view along the line III-lII
in Figure 1 (view from below a unit);
Figure 4 shows an enlarged cross-section of the detail lying in the dash-dotted circle IV in Figure l;
Figure 5 shows a longitudinal section thereof;
and Figure 6 shows a schematic circuit diagram of the cooker unit.
DETAILED l)ESCllIP'rION OF PI~EEE~ ED EMBODIMENT
The cooker unit 11 illustrated in the draw~ings has tubular heating bodies 12 which have a substantiall~
triangular cross-section which is flattened on their upper side. The upper fla-ttened side forms the cooking surface 13 on which cooking ~essels 14 can s-tand. The 25tubular heating bodies 12 form two heating resistances which are wound spirally. An internal heating resistance 15 112;2~37 is surroullded by an external heating resistance 16, the internal elld oi` the heating resistance 16 being connected directly to the external end of the heating resistance 15. The heating rcsistance 15 thus 5 forms a central heating zone while the heatin6 resistance 16 forms an external heating ring.
The tubular heating bodies have relatively small cross-sectional dime~sions, the largest dimension of which (a triangular side) amounts to about 5 mm, lO and are therefore ~ite flexible and are well adapted to the heated surface of the cooking vessel 14. They can be made of a rust-resistant metallic casing and substantially coil-shaped hea-ting conductors in an insulating embedding composition embedded therein.
15 Owing to the triangular shaping, the cross-section of the coil is also approximately triangular.
The tubular heating bodies lie on a thin plate 17 which is made of very thin stainless steel p~te with thicknesses of the order of 0.2 to 0.4 mm.
20 Spiral grooves 18 having a substantially triangular cross-sectional shape (with rounded corners) are shaped - into the circular pla-te 17 to correspond to the spiral JS /G
shape of th0 heating resistances ~ land ~. Support projections 19 are arranged on th0 bottom of these grooves ~5 at intervals of a few centimetres. In the illustrated ' ':
~12Z6~7 embodimcllt, eight support pr~jections 19 are pro~ided round the circumference d`the grooves, with the exception of the internal spiral windings.
The support projections 19 are formed by the fact that in each case the bot-tom of each groove is not 5shaped to the full depth over a distance o~ a few millimetres.
As shown, in particular, in Figure 4, the lower triangular edge of the tubular heating bodies lies virtually in point contact on the support projection 19 which is also rounded in side view (Figure 5).
The groove 18 is sufficiently large for -the tubular hea-ting body to lie in it at a distance of from 1 to a few millimetres and with the cooking surface 1513 projects somewhat beyond the flat surface of the plate 17.
~ he two ends ol` each heating resistance 15,16 are passed in a sealed manner through openings 20.
In the embodiment illustrated, they are soldered 20into these openings. A completely sealed cooker unit is thus produced so that overflowing ioods cannot run inside the cooker or cooker trough. Although some overflowing food will stick in the grooves and under the tubular heating bodies, this space in the grooves is designed 25to be such that, havïng regard to the thinness of the wall ~ZZ637 of the plate 17 it cleans itself as a result oL the carbonisation of the food which has overflowed. A line ash which can be blown or brushed out is thus Iormed.
The extremely high temperatures which produce this self-cleanin~ effect are produced only when there is 5 dirt in these positions. If the blank metal surLace is exposed, the groove acts as a reflector which irradiates the heat radiation ori~inating fro~ the underside of the tubular heating body upward toward the bottom of the cooking vessel. The groove can al~ be designed in other ways 10 so as to obtain specific coefficients of reflection and so as not to fall below desired minimum distances between tubular heating bodies and plate. Thus, for e~ample, it could also be of substaltially semi-circular cross-section in the case of a tubular heating body designed 15 semi-circularly on its underside. The support projections could also have another sequence or design. However, it is preferable to stamp them directly from the material of the plate.
The plate 17 has a relatively wide unheated 20 edge region 21 between the outermost spiral winding of the heating resistance 16 and its external edge, which ensures that only a very little heat can be conducted toward the edge, owing to the relatively poor heat conducting properties of stainless steel. On the outer ~5 circumference, the plate 17 is beaded downward round the --~12~637 cxt,~rllal ~ge 21 of a dish-like disc 22 and thus joined to it. The disc 2'' Lorl~s a sup~)ortillg s-truc-ture for the plate 17. It has a projection 24 directed wpwar~s in its centre so that its recess 23 surrounclsthe projection 24 in the manner of a groove. The recess 23 in the disc 22 5 is relatively flat. Support projections 25 are shaped Lrom the disc, which project upwards into its reces~ 23 and are dimensioned in such a way that the underside of the grooves 18 rest on them. As shown in Figure 3, the support projections are formed by cutting into the material of the disc and formed upwardly directed flanges which run radially. The pla-te 17 is borne by the support projections, as well as by tlle central projectionformed by deep stamping of the material of the disc so that even heavy cooking vessels do not produce unacceptable deformation of the plate 17. It should be noted that the plate 17 acquires the properties of a corrugated diaphragm owing to the spiral grooves 18 so that it can compensate even extreme temperature differences without unacceptable deformations. The pxojection 21~ can he welded to the plate 17.
The disc 22 is produced from thicker and more rigid material than thc plate 17 and can have a reflecting surface in its interior. It is also possible to insert an insulating material 26 in it (shown in part in Figure 1~.
~2~37 A tempera-ture limiter 27 can be arrange~ in the cavity 23 between plate 17 and disc 22, preferably in the edge region, and serves to switch off the cooker unit when an excessive temperature occurs (Lor example 5 in no-load operation).
A fixing bolt 28 with which the unit 11 can be fixed on a cooker or a cooker trough, is arranged-in the region of the central projection 24.
As shown in Figure 1, the plate 29 in which the unit is fitted can have a relatively flat trough 30 which need be, for example, only 20 to 30 mm deep.
This trough 30 can -be substantially uninterrupted up to the openings for the ends of the tubular heating body and the central bolt so that the plate 29 has a 15high inherent stability~ Insulating material 31 can be inserted between the trough and the unit 11 lying in it at a small distance (indicated in part in Figure 1).
On its encircling edge, the trough has an encircling shoulder 32 lying somewhat deepended, on which 20the edge 21 of the unit 11 is supported with interpesition of a sealing ring 33. The unit 11, which is~ furthermore, only kept down by the fixing bolt 28 is there~ore tightly inserted into the plate 29. The surface of the plate 17 can therefore lie flush with the surface of the plate 29 25to form a surface on which saucepans can be slid to and fro without encounte~ing ledges. The small distance ' ,:
- ' ' ~ ' :
~2'~637 tWCell the plate 17 and tlle heatin~ surrace 13 on the tubular hea-ting bodies 1'' is thus easily overcome.
It should also par-ticularly be no-ted that -the unit 11 forms a separate unit which can be mounted in advance and produced separately from the re6t oL
the cooker and which can easily be placed on the cooker and exchanged if in need of repair. The total height oI the cooker trough can be kept very small owing to the good and multiple means of insulation wi-thout the temperature exceeding an allowable value on its underside.
Flat incorporation in kitchen furniture is thus possible.
As shown in Figure 6, the two hea-ting resist-ances 15,16 can be switched on separately. The temper-ature limiter 27 and a power control instrument 36 which usually operates by quantization, lies in a common supply line 35. A bimetallic member 38 heated by a control heating resistance 37 which is connected in parallel with thel-eating resistances activates a switch 39 of the power control instrument. The power control instrument can be set by means of an actuating button 40.
A manually activatable mechanical switch 41 which lies in the supply line to the external heating resistance 16 is also provided. If~ for example, the external diameters of the internal heating resistance 15 and the external heating resistance 16 are 140 and 180 mm, 1~22~37 houscwivcs call choosc whc1llcl they wisll to use only a slllall or a large hcated diamcter, de~erlding upon the si~e of the saucepan use~ A very adal)tablc cooking unit with which energy can bc saved iS thus provided.
It would also be possible to have the.switch 5 41 switched automatically by activating the activating button 40 in such a way that the heating resistance 16 is only connected in the uppcr power range, i.e. when the power control instrument 36 has controlled the internal heating resistance to lrom 15 to 100% power.
10 Control is continued as a result of a l~ink in the corresponding control curve of the power control instrument 36 once the heating resistance 16 has been connected in the case of the corresponding power value.
It is however also possible -to design the circuit in such a way that the heating ~ody 15 remains entirely connected in the higher power range and the energy controller merely controls t~le heating resistance 16. :
IIowever, in each case, the advantage is achieved that only the internal heating resistance is effective at 20 low power This promotes saving in energy, i.n particular ~-~ because, at the very moment when only small power is necessary, i.e. small amounts of food are to be heated, coo~ing vessels which are small and which do not cover the entire cooker unit are frequently selected. Moreover, 25 particularly in the lower power range which is difficult ~ to start up, the power control instrument controls only .
.
1122~;37 -tlle power of the heating resistance 15 and thus receives higher relative switc~hing times than would correspond to the respective portion oL thc total power of the cooker plate.
The use of two heating resistances 15, 16 in the case of a normal or large plate diameter also has the advantage that only the central heating resistance 15 need be provided ior s~all plate diameters. A
reduction in the number of types of heating resistances with corresponding advantages for production and storage can be achieved in this way.
.
-15~
Claims (28)
1. A cooking apparatus comprising a plate extending in a generally flat plane, provided with grooves, and forming a closed surface; a plurality of longitudinally spaced support projections disposed in the grooves; and electrically heated tubular heating bodies with flat upper surfaces, the heating bodies being arranged on the support projections in the grooves and forming a cooking surface for receiving cooking vessels, substantially point contacts being made between the plate and the heating bodies.
2. An apparatus according to claim 1, wherein the support projections are formed by stampings at the bottoms of the grooves.
3. An apparatus according to claim 2, wherein the tubular heating bodies penetrate in a sealed manner through the said plate.
4. An apparatus according to claim 3, wherein the tubular heating bodies are soldered to the plate where they pass there-through.
5. An apparatus according to claim 4, wherein the grooves and tubular heating bodies are spiral in shape, the grooves imparting to the plate a radial elasticity for relieving thermal stresses.
6. An apparatus according to claim 5, wherein the tubular heating bodies project above the upper plane of the plate.
7, An apparatus according to claim 6, wherein the said plate is incorporated with its upper plane substantially flush in a cooker plate.
8. An apparatus according to claim 7, wherein the cooker plate is in the form of a flat-bottomed trough of circular cross-section which is covered by the said plate.
9. An apparatus according to claim 8, wherein the said plate has an edge region which lies on a shoulder which is formed in the said cooker plate and encircles the trough.
10. An apparatus according to claim 9, wherein the first mentioned plate is fixed on the cooker plate by connecting means which comprise a central bolt.
11. An apparatus according to claim 10, wherein the first mentioned plate has an unheated edge region surrounding the region occupied by the tubular heating bodies.
12. An apparatus according to claim 11, wherein the heating bodies comprise a plurality of individually connectable heating resistances arranged concentrically, a central one of the heating resistances being capable of being switched on alone.
13. An apparatus according to claim 12, wherein the electrical power of the tubular heating bodies and the thickness of the first mentioned plate are such as to provide for the conversion into ash of spilt food.
14. An apparatus according to claim 13 further comprising a support structure for supporting the first mentioned plate.
15. An apparatus according to claim 14, wherein the support structure is formed by a dish-shaped disc.
16. An apparatus according to claim 15, wherein the first mentioned plate is received in an annular recess of the disc.
17. An apparatus according to claim 16, wherein the central bolt engages in the central region of the disc.
18. An apparatus according to claim 17, wherein the disc has a surface which reflects heat radiation.
19. An apparatus according to claim 18, wherein the disc is joined to the first mentioned plate by beading on the edge of the first mentioned plate.
20. An apparatus according to claim 19, wherein the first mentioned plate is supported by substantially radial support projections in the disc.
21. An apparatus according to claim 20, wherein the support projections are formed by shaping of the disc.
22. An apparatus according to claim 21, wherein heat insulation is provided on at least one side of the disc.
23. An apparatus according to claim 22, wherein the first mentioned plate, the disc and tubular heating bodies together form a single removable unit.
24. An apparatus according to claim 23 comprising a tem-perature limiter arranged beneath the first mentioned plate.
25. An apparatus according to claim 24, wherein the tem-perature limiter is arranged adjacent an edge region of the plate.
26. An apparatus according to claim 25 wherein the tubular heating bodies are flexible and have external dimensions of 5mm or less.
27. An apparatus according to claim 26 wherein the grooves, heating bodies and point contacts define free air spaces there-between open to both lateral sides of the heating bodies.
28. An apparatus according to claim 27 wherein said plate has a thickness of not substantially more than 0.4 mm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2751991.1 | 1977-11-22 | ||
| DE19772751991 DE2751991A1 (en) | 1977-11-22 | 1977-11-22 | COOKING UNIT WITH A COOKING SURFACE formed by flattened tubular heating elements |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1122637A true CA1122637A (en) | 1982-04-27 |
Family
ID=6024260
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA316,546A Expired CA1122637A (en) | 1977-11-22 | 1978-11-21 | Cooking apparatus with flat tubular heating bodies |
Country Status (14)
| Country | Link |
|---|---|
| JP (1) | JPS5481968A (en) |
| AT (1) | AT373991B (en) |
| AU (1) | AU518113B2 (en) |
| CA (1) | CA1122637A (en) |
| CH (1) | CH633626A5 (en) |
| DE (1) | DE2751991A1 (en) |
| ES (1) | ES475280A1 (en) |
| FR (1) | FR2409656A1 (en) |
| GB (1) | GB2010060B (en) |
| GR (1) | GR66041B (en) |
| IT (1) | IT1100168B (en) |
| SE (1) | SE440437B (en) |
| YU (1) | YU40727B (en) |
| ZA (1) | ZA786366B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3140074A1 (en) * | 1981-10-08 | 1983-04-28 | Fischer, Karl, 7519 Oberderdingen | ELECTRIC COOKER |
| EP0079483B1 (en) * | 1981-11-10 | 1986-02-26 | E.G.O. Elektro-Geräte Blanc u. Fischer | Control device for an electrical cooking plate |
| DE3378516D1 (en) * | 1982-09-16 | 1988-12-22 | Ego Elektro Blanc & Fischer | Heating element, especially radiant heating element for the heating of ceramic plates |
| DE3315438A1 (en) * | 1983-04-28 | 1984-10-31 | E.G.O. Elektro-Geräte Blanc u. Fischer, 7519 Oberderdingen | HEATING ELEMENT FOR HEATING COOKING, HEATING PLATES OR THE LIKE |
| JPS60146207U (en) * | 1984-03-09 | 1985-09-28 | 三洋電機株式会社 | Sheathed heater type electric stove |
| DE8901361U1 (en) * | 1989-02-07 | 1989-03-23 | E.G.O. Elektro-Geräte Blanc u. Fischer, 7519 Oberderdingen | Electric frying plate |
| DE29515668U1 (en) * | 1995-09-30 | 1996-10-31 | AEG Hausgeräte GmbH, 90429 Nürnberg | Built-in hob, in particular glass ceramic hob with a frame |
| DE19829807A1 (en) * | 1998-07-03 | 2000-01-05 | Bsh Bosch Siemens Hausgeraete | Cooker plate with elastically deformable cover plate |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH91299A (en) * | 1920-11-06 | 1921-10-17 | Rob Miesch | Electric heating plate. |
| DE636652C (en) * | 1933-08-15 | 1936-10-12 | Siemens Schuckertwerke Akt Ges | Electrically heated hotplate with tubular heating element |
| GB522609A (en) * | 1938-12-12 | 1940-06-21 | Gen Electric Co Ltd | Improvements in and relating to electric heating devices |
| GB543318A (en) * | 1940-09-06 | 1942-02-19 | Gen Electric Co Ltd | Improvements in electrical hot-plates |
| US2361874A (en) * | 1941-04-03 | 1944-10-31 | Westinghouse Electric & Mfg Co | Heater unit construction |
| CH391913A (en) * | 1960-08-09 | 1965-05-15 | Fischer Karl | Electric heating tube hotplate on a hotplate |
| US3243578A (en) * | 1963-10-28 | 1966-03-29 | Ferro Corp | Support for surface units |
| US3246122A (en) * | 1963-11-29 | 1966-04-12 | Gen Electric | Temperature controlled surface heating unit |
| US3569672A (en) * | 1969-05-01 | 1971-03-09 | Gen Electric | Low thermal mass, plate surface heating unit |
| DE2205132C3 (en) * | 1972-02-03 | 1980-09-04 | E.G.O. Elektro-Geraete Blanc U. Fischer, 7519 Oberderdingen | Electric cooker |
-
1977
- 1977-11-22 DE DE19772751991 patent/DE2751991A1/en active Granted
-
1978
- 1978-11-07 AT AT0796278A patent/AT373991B/en not_active IP Right Cessation
- 1978-11-13 AU AU41529/78A patent/AU518113B2/en not_active Expired
- 1978-11-13 ZA ZA00786366A patent/ZA786366B/en unknown
- 1978-11-14 CH CH1168778A patent/CH633626A5/en not_active IP Right Cessation
- 1978-11-20 FR FR7832648A patent/FR2409656A1/en active Granted
- 1978-11-21 CA CA316,546A patent/CA1122637A/en not_active Expired
- 1978-11-21 ES ES78475280A patent/ES475280A1/en not_active Expired
- 1978-11-21 YU YU2711/78A patent/YU40727B/en unknown
- 1978-11-21 SE SE7811984A patent/SE440437B/en unknown
- 1978-11-22 GB GB7845555A patent/GB2010060B/en not_active Expired
- 1978-11-22 JP JP14348278A patent/JPS5481968A/en active Pending
- 1978-11-22 IT IT30072/78A patent/IT1100168B/en active
- 1978-11-22 GR GR57714A patent/GR66041B/el unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU4152978A (en) | 1979-05-31 |
| ATA796278A (en) | 1983-07-15 |
| YU40727B (en) | 1986-04-30 |
| GB2010060A (en) | 1979-06-20 |
| SE7811984L (en) | 1979-05-23 |
| GB2010060B (en) | 1982-03-24 |
| FR2409656B1 (en) | 1984-10-12 |
| GR66041B (en) | 1981-01-14 |
| AT373991B (en) | 1984-03-12 |
| ES475280A1 (en) | 1979-04-16 |
| SE440437B (en) | 1985-07-29 |
| CH633626A5 (en) | 1982-12-15 |
| DE2751991C2 (en) | 1987-10-08 |
| ZA786366B (en) | 1979-10-31 |
| IT7830072A0 (en) | 1978-11-22 |
| IT1100168B (en) | 1985-09-28 |
| YU272278A (en) | 1982-06-30 |
| DE2751991A1 (en) | 1979-05-23 |
| FR2409656A1 (en) | 1979-06-15 |
| JPS5481968A (en) | 1979-06-29 |
| AU518113B2 (en) | 1981-09-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |