EP0234373A2 - Cooking unit with radiant heating element - Google Patents

Abstract

In the case of a cooking unit (1), a support (4), which is subjected to tension, is attached to the underside of the hotplate (3) in the edge region, immediately adjacent to the outer circumference (8) of a radiant heater (2). The carrier (4) engages under a cover (l3) provided as a base plate for the insulation of the radiant heater (2) and at least one spring (22) is arranged between an edge strip (l6) and the lower leg (l9), so that a prestressed, in closed assembly or the like for mounting in a hob. is created. A plurality of closely spaced, rectangular radiant heaters (4) are expediently provided, each with separately switchable or controllable heating circuits, so that the hob can be directly heated on at least about 85% of its total area.

Description

The invention relates to a cooking unit, in particular for commercial kitchen stoves or the like, with a hotplate, for example made of glass ceramic, which is provided on its rear side with at least one radiant heater which has an insulating body with at least one radiant heating element.

The invention has for its object to provide a cooking unit of the type mentioned, which ensures simple assembly when the radiant heater is securely connected to the hotplate.

To achieve this object, the features according to claim 1 are provided according to the invention.

In the case of cooking units of the type mentioned, the glass ceramic plate can also be attached to the hob by itself, after which a number of radiant heaters corresponding to the number of hotplates to be provided on the hob are attached as separate assemblies. This can be done easily lead to assembly errors, it being particularly important when using radiant heaters as heating that the insulating body rests securely against the underside of the hotplate, which is achieved with the aid of the springs which are usually inserted or arranged during assembly.

To achieve the object according to the invention it is also advantageously possible in a cooking unit of the type described that at least one of the springs pressing it against the hotplate is arranged between the carrier and the radiant heater. In contrast to an assembly in which the radiant heater is rigidly connected to the hotplate without springs, this results in an arrangement in which the radiant heater is mounted within the assembly relative to the hotplate at least one spring travel perpendicular to the hotplate and with springs against the hotplate is pressed so that the resiliently pressed contact of the insulating body on the hotplate can be set and controlled even before the cooking unit is installed in the hob.

The training can be significantly simplified by not providing support brackets running across the underside of the radiant heater, but by the support being formed by at least one support frame extending from the hotplate to the rear of the radiant heater, in particular formed by an angled profile, which grips the radiant heater on the back only in the associated edge area, so that the cooking unit takes up very little space, especially at height. The spring can also be located between a leg of the carrier that engages around the back of the radiant heater and the back of the radiant heater, so that it is completely covered and space-saving only a very small spring extension is required in the spring direction, which makes it possible to use relatively hard springs.

In a particularly advantageous embodiment of the subject of the invention, the radiant heater is set down on the back in the area of the support surrounding it, preferably in such a way that the back of the radiant heater lies outside the offset area approximately in one plane with the surrounding part of the support. As a result, the underside of the cooking unit can be made essentially continuously flat over its entire extent, which above all benefits the stackability of the cooking unit, but also facilitates installation.

In a further embodiment of the invention, the spring is on a cover made of sheet metal or the like provided on the insulating body. supported, which, in contrast to a shell-shaped cover receiving the insulating body, is preferably formed by an approximately flat base plate leaving the insulating body free on the outer circumference, so that there is a further simplification in construction. This base plate expediently has the same layout as the insulating body, so that its outer edge surface is flush with its outer peripheral surface. This cover is also advantageously suitable for forming a holder for a connection body for the electrical connection of the radiant heater within the outer circumference, in particular in the area of a central cutout, which is substantially completely sunk inside the insulating body or a central one in the latter provided cutout may lie.

To protect the insulating body on the outer circumference, in particular if it is not surrounded by the cover, it is expedient if it supports the insulating body on the outer circumference, in particular approximately abuts the outer circumference, the carrier expediently over the outer circumference or the respective outer edge of the insulating body continuously going through.

A high mechanical strength of the self-contained assembly is achieved if the carrier forms a frame surrounding the radiant heater.

The carrier can be connected to the hotplate in an extremely simple manner in that it is heat-resistant to the hotplate, e.g. is glued with a silicone adhesive. The carrier is expediently completely within the outer edges of the hotplate, so that the gluing takes place only on the underside of the hotplate.

On the outer periphery of the hotplate, a supporting edge can be provided, which is likewise advantageously bonded to the support or to the hotplate or to both parts by gluing. is attached. In the case of gluing to the hotplate, this is expediently carried out in relation to its associated edge surface. It is particularly expedient here if the supporting edge engages under the support, in particular its outwardly directed leg, so that the supporting edge forms a support for the support and thus also for the hotplate lying directly above it.

The spring can in a simple manner as a leaf spring, wave spring, bow spring, plate spring or the like. be trained.

According to the invention, a hotplate of the cooking unit for forming a plurality of separately switchable hotplates located adjacent to one another within a hob can also have a corresponding number of separate radiant heaters, each of which is provided with at least one radiant heating element arranged in a carrier shell and forming a heating field and is pressed against the underside of the heating plate, supported on springs on a substructure.

Electric cookers for cooking large quantities of food, as is regularly the case in commercial kitchens, canteens and other facilities, generally have electric hotplates with hotplate bodies made of cast iron, which are inserted into a hob, as the cooking areas. Such stoves have proven themselves in many respects, but there is still a need for even easier handling, even lower energy consumption with faster responsive provision of power and easier maintenance or repair than, for example, that in GB-PS 714 373 known stove is the case.

The invention is therefore also based on the object to provide a cooking unit of the type described, which makes it possible to create continuously seamless use areas with substantially seamless and liquid-tight design of the hotplate, which can be heated so that one or more of them Numerous different thermal images can be set with regard to the heating.

This object is achieved in the cooking unit, in particular of the type described last according to the invention in that each radiant heater in one to its outside Measurements-adapted receptacle of the substructure is inserted essentially immovably and that the receptacles are almost immediately adjacent to one another in such a way that the hob is essentially seamless and can be heated to at least about 85% of its total area. The hob is the one that is bounded by the outer boundaries of an associated group of radiant heaters, such that the hob can be larger than this hob. Within the cooktop, each radiant heater can be operated independently of the other radiant heaters due to its regulation or control and based on its technical data, so that the radiant heaters can be set so that the cooktop is provided by seamlessly interconnecting or thermally merging heating fields of the same or different power is formed and cooking vessels can be transferred by moving or moving both into the desired heating field alone and into zones in which two or more adjacent heating fields are effective with different proportions depending on the position of the cooking vessel. Since cooking units with hot plates and radiant heaters respond much faster in terms of the provision of power than cast hot plates, this design also gives the essential advantage that, in order to achieve a reduced energy requirement, sensitive regulation or control which is adapted to the requirements can be carried out without increasing the cooking times and not , as previously common in commercial kitchens, the hotplates must be run at full power over their entire operating time.

For household stoves, cooking units with hot plates and radiant heaters have become known, for example from DE-OS 22 42 823, which can, however, be moved together to form a relatively large total heating surface due to this moving together, the cooktop is correspondingly smaller, which is disadvantageous in particular in commercial kitchen stoves because of the reduced heated area as a result. The use of hot plates made of glass ceramic or the like. avoided because of the rough operation in commercial kitchens, since such hot plates are relatively sensitive to impact or breakage. Due to the almost complete juxtaposition of the radiant heaters in a non-displaceable position, the hotplate can be supported so well by the support shells, which are usually provided with damping insulating material on the underside, even with a relatively large overall dimension on the underside, that the hotplate hardly breaks even under the toughest conditions is to be feared.

The advantages mentioned arise in particular if all radiant heaters are square, in particular square, and preferably only connect with slot-like gaps of the order of at most a few centimeters, in particular approximately one centimeter wide. It is particularly advantageous if all radiant heaters are of the same design and, for example, are interchangeable, although it is conceivable to provide different radiant heaters with regard to the nominal power and with regard to the control or regulation, but which expediently have the same layout dimensions, so that, for example, four, one rectangular or radiant heaters forming a square hob are provided. The size of the respective heating field is expedient in the order of 3OO × 3OO mm, for example 32O × 32O mm, while the edge dimension of the heated surface of the radiant heater is in the order of 29O × 29O mm, so that the grid size of the hob is similar to that of previous commercial herds results.

The recordings can be formed in a simple manner by angular profiles, on the approximately horizontal legs of which the radiant heaters are supported independently of one another by spring elements, so that for each radiant heater a backlash-free and tight system can be achieved on the underside of the hotplate with a low overall height of the cooking unit. The hotplate can expediently be removed or lifted off from the radiant heaters or from the cooking unit, which results in a very simple operation if the hotplate can be opened and when it is brought into its operating position by placing it on upper end faces of the outer edges of the carrier shells of the radiant heaters Preload of the spring elements presses down.

A particularly advantageous development of the subject matter of the invention is that the respective radiant heater is switched via a temperature controller, so that there is rapid operational readiness, i.e. heating with the highest possible output and nevertheless low energy consumption in the unloaded state, i.e. in the case in which no heat is removed by a cooking vessel, which results in a good power adjustment, which can be further improved, for example, by the continuously adjustable design of the temperature controller. In order to influence the temperature controller, which is preferably designed as a capillary tube controller, according to a further feature of the invention, a temperature sensor that is approximately parallel to the radiant heating element and the underside of the heating plate is provided, which is preferably rod-shaped and crosses the associated heating field over most of its associated width. Instead of a system filled with a high-temperature expansion liquid, an electrical or electronic temperature controller can also be provided, the sensor of which is temperature-sensitive over its entire length. It has been shown that the entire heating Field can be detected substantially uniformly and a particularly sensitive and thus quickly responsive control results with regard to the overall thermal image of the respective heating field.

In particular, in the case of a cooking unit of the type described, it is further provided according to the invention that the temperature sensor is assigned to a temperature controller, which is also designed to limit the temperature, ie ensures that the hotplate does not exceed a predetermined maximum temperature. This makes it possible to dispense with a separate temperature limiter switch and the associated separate sensor. Instead of the temperature-controlled operation of the respective radiant heater, a step switch, e.g. a four-stroke circuit or a seven-stroke circuit via a corresponding power control device, can be provided if the radiant heater is provided with the corresponding number of separately switchable radiant heating elements or heating circuits, which are then used for the individual switching stages are connected in parallel and / or in series. In this case, however, a fixed temperature regulator, for example a rod temperature regulator, must be provided as a temperature limiter to protect the hotplate, which has as a temperature sensor a rod of different thermal expansion axially superimposed in an outer tube, which rod is arranged in a housing at one end of the temperature sensor Snap switch works. In such a step switch, the idle temperature, that is the temperature of the heating field when there is no decrease in power, is given by the fixed adjustment of the temperature monitor set to a relatively high temperature. With a nominal power of, for example, about 4OOO W, energy savings occur especially when the power control device is set to at least about three quarters of the nominal power. In any case, as Temperature sensor also a tubular sensor similar to a tubular heater, but with temperature-dependent resistance wire can be used, which is embedded in a metallic pipe jacket without contact and thus isolated in an insulating compound.

In the case of temperature-controlled operation of the radiant heater, it is possible to adapt the thermal characteristics of the heating field to the requirements given in canteen kitchens in a surprisingly simple manner by the fact that the temperature controller only a part, e.g. half of the power of the radiant heater switches, while at least one further or the remaining part of the nominal power is switched on by an additional contact of the temperature controller in the upper temperature setting range. The temperature controller can switch one or more radiant heating elements while the additional contact switches the other radiant heating element (s). On the one hand, this results in a low idle power to save energy and to protect the hotplate, and on the other hand ensures that the highest possible power is provided almost without delay when the hotplate is used, since the temperature of the hotplate is always kept at a regulated level and a predetermined one if required Power is switched on. In addition to quick operational readiness, the adjustable control also enables a good output adjustment to the respective requirements, so that the cooking unit can be set to zones of different output or temperature, such as those required for parboiling, roasting, continued cooking and for keeping warm or Warming are needed.

Instead of or in addition to this, the temperature controller can also have at least two switching contacts that are influenced by the temperature sensor and one each separately Switch the third part, i.e. in particular separate radiant heating elements, of the radiant heater on and off at different temperature values. Each switching contact of the two-pole temperature controller expediently switches about half of the total output of the radiant heater, so that switching behavior similar to that of a conventional automatic cast-iron hotplate with a central sensor is achieved, i.e. that even with a low controller setting, it is first heated to full power and then with one Part of the service is continued. The radiant heater can therefore be provided with only two radiant heating elements or heating resistors, which are expediently laid parallel to the outside of the radiant heater in rectangular or square double spirals in the carrier shell, such that the radiant heater only connects four directly to the adjacent ends of the radiant heating elements To have connection points.

A particularly advantageous development of the subject matter of the invention is that at least one radiant heating element, in particular all radiant heating elements of the respective radiant heater, can be switched off via a cooking vessel detection sensor, which is preferably arranged approximately in the center of the heating field below the hotplate and shielded by an insulating jacket, in such a way that the Temperature sensor is located just outside the center of the radiant heater directly next to the insulating jacket and parallel to two outer sides of the radiant heater. The detection sensor, the snap switch of which is expediently connected in series with the temperature controller or the power control unit, makes it possible for there to be no energy consumption at all when the radiant heater is switched on when idling, while the full power is immediately available by fitting a cooking vessel. The detection sensor can at work optically, for example, but has a particularly safe function if it is designed as an inductive sensor.

So that the hot plate against spilled or spilled food and the like. is tight and can be easily cleaned at any time, it is expediently connected to a frame running around its outer edges in a liquid-tight manner, the frame reaching at most up to the level of the top of the hotplate or protruding only slightly above it, so that cookware is always above the edge of the cooking unit can be pushed without causing too hard impact stresses on the hotplate. In certain cases, namely, for example, where cast electric hotplates are to be exchanged for radiant heater hotplates, it is also possible to provide the respective radiant heater with a separate hotplate made of glass ceramic or the like, corresponding to the size of its heating field. to integrate and to mount this with a support rim provided on the circumference of the hotplate similar to cast electric hotplates on the edge of a mounting opening of a hob, whereby in this case also the zones of the hob adjacent to the heating field lie on one level and almost completely next to the hotplate can.

• Fig. l eine erfindungsgemäße Kocheinheit im Verti­kalschnitt,
• Fig. 2 die Kocheinheit gemäß Fig. l in Ansicht von unten,
• Fig. 3 einen Ausschnitt der Fig. l in vergrößerter Darstellung,
• Fig. 4 eine weitere Ausführungsform einer Feder im Längsschnitt,
• Fig. 5 eine weitere Ausführungsform in einer Dar­stellung entsprechend Fig. 4,
• Fig. 6 eine weitere Ausführungsform einer Feder in Draufsicht,
• Fig. 7 eine weitere Ausführungsform einer Feder in einer Darstellung entsprechend Fig. 3,
• Fig. 8 eine weitere Ausführungsform einer Feder in einer Darstellung entsprechend Fig. 3.
• Fig. 9 einen Ausschnitt eines mit einer erfindungs­gemäßen Kocheinheit versehenen Großküchen-­Herdes in perspektivisch vereinfachter Dar­stellung,
• Fig. lO einen Vertikalschnitt durch die Kocheinheit gemäß Fig. 9,
• Fig. ll einen Ausschnitt der Fig. lO in perspektivi­scher Darstellung,
• Fig. lla eine weitere Ausbildung gemäß Fig. ll,
• Fig. l2 ein weiteres Ausführungsbeispiel einer Koch­einheit im Vertikalschnitt,
• Fig. l3 ein Detail der Fig. l2 in vergrößerter Dar­stellung,
• Fig. l4 eine weitere Ausführungsform des Details gemäß Fig. l3,
• Fig. l5 einen Strahlheizkörper im Vertikalschnitt,
• Fig. l6 einen Ausschnitt der Fig. l5 in vergrößerter Darstellung,
• Fig. l7 den Aussschnitt gemäß Fig. l6 in Ansicht von links,
• Fig. l8 einen weiteren Strahlheizkörper im Vertikal­schnitt,
• Fig. l9 den Strahlheizkörper gemäß Fig. l8 in Drauf­sicht,
• Fig. 2O ein Schaltschema für einen Strahlheizkörper,
• Fig. 2l ein Beispiel für eine Temperatur-Kennlinie eines Heiz- bzw. Kochfeldes der Kochplatte,
• Fig. 22 und 23 zwei Beispiele für geregelte Leistungs-Kenn­linien eines Strahlheizkörpers.

These and further features of preferred developments of the invention are also apparent from the description and the drawings, the individual features being able to be implemented individually or in groups in the form of sub-combinations in one embodiment of the invention and in other fields. Embodiments of the invention are shown in the drawings and are explained in more detail below. The drawings show:

• 1 a cooking unit according to the invention in vertical section,
• 2 the cooking unit according to FIG. 1 in a view from below,
• 3 shows a detail of FIG. 1 in an enlarged view,
• 4 shows a further embodiment of a spring in longitudinal section,
• 5 shows a further embodiment in a representation corresponding to FIG. 4,
• 6 shows a further embodiment of a spring in plan view,
• 7 shows a further embodiment of a spring in a representation corresponding to FIG. 3,
• 8 shows a further embodiment of a spring in a representation corresponding to FIG. 3.
• 9 shows a detail of a commercial kitchen range provided with a cooking unit according to the invention in a perspective simplified representation,
• 10 shows a vertical section through the cooking unit according to FIG. 9,
• 11 shows a detail of FIG. 10 in perspective,
• Lla a further training according to FIG. Ll,
• L2 shows another embodiment of a cooking unit in vertical section,
• L3 shows a detail of FIG. L2 in an enlarged view,
• L4 shows a further embodiment of the detail according to FIG. L3,
• L5 a radiant heater in vertical section,
• L6 shows a detail of FIG. L5 in an enlarged view,
• L7 the detail according to FIG. L6 in a view from the left,
• L8 a further radiant heater in vertical section,
• L9 the radiant heater according to FIG. L8 in plan view,
• 2O is a circuit diagram for a radiant heater,
• 2l shows an example of a temperature characteristic of a heating or cooktop of the hotplate,
• 22 and 23 two examples of regulated performance characteristics of a radiant heater.

The cooking unit 1 according to FIGS. 1 to 3 has a radiant heater 2, a hotplate 3 applied to the upper side thereof, a support 4 which connects the hotplate 3 to the radiant heater 2 in a resilient manner and a supporting edge 5 located adjacent to the edge surface of the hotplate 3 for gripping over the opening edge a hob or the like. on. The cooking unit 1 is rectangular in plan in the exemplary embodiment shown, but it can also be round or circular for other applications.

The radiant heater 2 has an insulating body 6 made of mineral, pressed fiber material, which on its side facing the hotplate 3 of a base plate 9 approximately parallel to the hotplate, on a relatively large field, has at least one heating resistor 10 in the form of an alternating, held by partial embedding in the insulating material Direction heating coil. At the outer boundary of the base plate 9 there is an outer edge 7 which is formed in one piece and directed against the hotplate 3 and which forms the outer circumference 8 of the insulating body 6 which is rectangular in cross section to the hotplate 3 and with its end face essentially flat on the underside of the hotplate 3 under pressure. For central support in the central region of the insulating body 6, an annular inner ring 11, which is also formed in one piece with the base plate 9 and which limits the heating field in the inner region, is also provided, which is also resiliently supported with its end face on the underside of the hotplate 3 so that the is limited by this inner ring ll limited central area of the hotplate 3 against the radiant heat from the heating resistor 10. The insulating body 6 is with its flat underside placed on a plate-shaped insulating layer l2, has the same floor plan as the insulating body 6 and has a smaller height or thickness than this. On the underside of the insulating layer l2 there is an essentially flat cover l3 made of sheet metal, which also has the same layout as the insulating body 6 or the insulating layer l2. Both the insulating layer l2 and the cover l3 have cutouts lying approximately in register with the interior of the inner edge 11, which are slightly wider than this interior. This results in a receiving space for a connector l4 for the electrical connection of the heating resistors lO, which can lie completely recessed in this receiving space and can be moved or pulled down for the connection through the cutout l5 of the cover l3.

A narrow edge strip l6 of the cover l3 is offset on all of its outer edges or over its circumference essentially continuously in the direction of the hotplate 3 by a small amount, less than the thickness of the insulating layer l2, that it lies parallel to the rest of the cover l3 and in this passes over a gradation l7. This edge region l6 is flush with its outer edge with the outer circumference 8 of the insulating body 6 or the insulating layer l2. Immediately adjacent to this outer circumference 8 and parallel to it is a pull section 18 of the carrier 4, which is expediently provided by a sheet-metal profile or the like which is angled twice at the longitudinal edges. is formed. The one, longer leg l9 of the carrier 4 directly adjoining the traction section l8 engages under the edge strip l6 at a short distance and over a width which is approximately equal to the width of the edge strip l6, the leg l9 parallel to the cover l3 with its plane in the Level of the underside of the cover l3 lies. The other leg 20, which is directed outwards and also directly adjoins the pull section 18, lies adjacent to the outer circumference 8 or to the outer edge 7 on the underside of the hotplate 3 and is fastened thereto by gluing. This leg 2O extends approximately to the associated edge surface 2l of the hotplate 3. Between the leg l9 and the edge strip l6, springs 22 are arranged in the form of compression springs, wherein in the exemplary embodiment according to FIGS. 1 to 3 a large number in the longitudinal direction of the edge strip l6 Distance, short, preloaded coil springs are provided. By means of these springs 22, the radiant heater 2 is always pressed against the underside of the hotplate 3 under prestress. The thus also pressed against the underside of the hotplate 3, formed by the inner ring 11, ensures that even relatively hard impact effects to which the hotplate 3 is exposed are so damped that damage to the hotplate 3 is not to be feared. The edge strip l6, the leg l9, the gradation l7 and the pull section l8 delimit a cavity 23 which is elongate in cross-section parallel to the hotplate 3 and in which the springs 22 are arranged so as to be secured against falling out, since the gap between the end edge of the leg l9 and the gradation l7 of the cover l3 is substantially smaller than the width of the springs 22.

The supporting edge 5 has a leg 24 under the leg 2O of the carrier 4 and glued to it, a profile web 25 adjoining it and partially covering the edge surface 2l of the hotplate 3, and a flat cover profile 26 adjoining the latter, which faces outwards Extends over the edge area of an assembly opening in the associated hob.

The profile web 25, which is approximately parallel to the edge surface 2l, can also be secured to this edge surface 2l by gluing. Both the individual frames of the carrier 4 and those of the supporting edge 5 are each connected to one another to form a closed frame which corresponds to the basic shape of the hotplate 3 or the radiant heater 2.

In the embodiment according to FIG. 4, individual springs are not provided between the edge strip l6a and the leg l9a, but a corrugated spring 22a is arranged, which is expediently formed in one piece over the length of the associated outer edge of the radiant heater. This wave spring 22a is supported with the convex arc sides of its waves on the edge strip 16a and the leg 19a.

5, individual, bow-shaped leaf springs are provided as springs 22b, which are provided one behind the other in the longitudinal direction of the edge strip 16b and the leg 19b. The spring 22b according to FIG. 6 is likewise formed by a strip-shaped leaf spring which is cut out in a meandering manner along a longitudinal edge, so that spring legs which are bent out of their plane are formed and can be supported alternately, for example, on the edge strip l6 and on the leg l9.

As shown in FIG. 7, annular disc springs can also be provided as springs 22c, it being possible for only one disc spring or two or more disc springs lying axially to one another to be used between the edge strip l6c of the cover l3c and the leg l9c of the carrier 4c.

The springs 22d according to FIG. 8 are formed in one piece with the carrier 4d or its leg 19d and bent out of the latter. They have plug-in members 27 which are formed in one piece with them and are formed by knob-shaped features and which engage in corresponding plug-in openings in the edge strip l6d of the cover l3d, so that the carrier 4d or the springs 22d are latched with respect to the cover l3d. According to FIG. 8, the edge strip l6d lies in one plane with the remaining cover l3d, so that this remaining cover l3d is thus slightly offset above the leg l9d in the direction of the hotplate. As shown in FIG. 7, the remaining area of the cover l3c adjoining the edge strip l6c can also be offset slightly downwards relative to the leg l9c or relative to the carrier 4c.

The cover l3 forms a bracket 28 for the connecting piece l4, which projects freely in tab-like fashion, this bracket projecting freely into the receiving space formed by the inner edge 11 and the associated cutout of the insulating layer l2. In the exemplary embodiment shown, it is angled twice at a right angle and is so resilient that when the cooking unit 1 is placed on a surface, for example for stacking purposes, the connecting body l4 projecting slightly above the underside of the cooking unit 1 or the cover l3 is pushed so far upwards is that he no longer protrudes over the bottom of the cooking unit l. The holder 28 can also protrude obliquely upwards from the cover l3 into the receiving space. Furthermore, it can also be fastened as a separate tab on the cover 13, for example with screws. In particular, if the springs or the associated leg of the carrier can be snapped into the radiant heater, the carrier 4 can be attached to the hotplate 3 before the radiant heater is installed, after which it is pivoted outwards under resilient deformation so that the radiant heater can be used. The carrier is then pivoted back until it assumes its predetermined position and, if necessary, is locked into it.

As shown in FIGS. 9 to 11, a commercial kitchen stove 10 2 according to the invention is integrated on the top of its housing with a cooking unit 10 1, which essentially extends downward from a substructure 10 3 for receiving radiant heaters 10 4 and upwards from a hot plate parallel to it 105 is limited, so that there is a very flat design. The hotplate l05 essentially consists exclusively of a continuous, flat glass-ceramic plate lO6, which is gripped on the outer circumference with a profile frame lO7 and with its edge resting on profile legs of the frame, is glued to it in a liquid-tight manner. The open at the bottom, for example in cross-section U-shaped frame lO7 overlaps the upper edges of the housing walls of the stove lO2 in the operating position, so that no liquid or dirt can penetrate into the associated joints. The four radiant heaters lO4, which are square in plan, are each resiliently seated with a carrier shell lO9 on spring elements lO8, which are supported on the substructure lO3 and against whose spring force the radiant heaters lO4 with the plate lO6 are pressed down. Each carrier shell 10 has two radiant heating elements made of helically bent resistance wire, which is essentially exposed without protection, ie is not encapsulated as in the case of halogen bright spots. In the area of the upper side, each radiant heater 10 carries a temperature sensor 11 2, which is located in a contact-free manner underneath the plate 10 6 and is not shown in FIGS. 10 and 12 and via which a temperature associated with each radiant heater 10 4 temperature controller ll3 is controlled. The temperature regulators ll3 are arranged on the inside of a front housing panel of the cooker lO2 and can be adjusted via setting knobs ll4.

The substructure lO3 essentially consists only of angle profiles on two opposite outer sides of the field delimited jointly by the radiant heaters lO4 and a central profile, not shown in any more detail, which is arranged parallel to these angle profiles between the mutually facing sides of the adjacent radiant heaters. The profiles are expediently in the longitudinal direction of the sensor ll2 and can therefore be provided in the depth direction. A horizontal leg ll6 of each angle profile ll5 engages under the associated carrier shells l09, while the vertical leg ll7 lies immediately adjacent to the outside thereof. Plate-shaped spacers ll8 are fastened to the inside of the angle profiles, for example by welding, one of which is located between two adjacent radiant heaters l04 and the other two are adjacent to their outer sides facing away from one another. As a result, compartment-like receptacles 11 are formed, in which the radiant heaters 10 4 can be inserted from above onto the spring elements 10 8. For each radiant heater 10 four four identical spring elements 10 8 are provided in the corner regions of its support shell 10 9, on which the support shell 10 9 rests with its essentially flat underside freely or without separate attachment. According to Fig. Lla, only three-sided corner shells ll5 'are provided, for example, for direct attachment to the stove housing. The support shell l09 and thus the radiant heater lO4 are then secured against all lateral movements by the legs ll7 and the spacers ll8, against which they can have a small amount of movement, so that they are practically only in contact with the substructure lO3 on the spring elements lO8 and are otherwise contact-free are. The spring elements lO8 can be formed in a simple manner by helical springs, which are expediently placed on a centering mandrel l2O, which is fastened approximately in the middle of the width of the leg ll6 and adjacent to the associated spacer ll8. But it can also be used spring elements or spring assemblies, as described in patent application P 36 O6 ll7.4, to which reference is also made for further details for such a design in which the respective radiant heater with a separate heating or Glass ceramic plate is provided.

In FIG. 10, only a cup-shaped, thin-walled sheet metal component or the like is used as the outer shell 122 for the respective carrier shell 109. provided which is arranged on the underside of the bottom of an insulating shell l22. The insulating shell l22 has, in addition to the bottom, an outer edge l23 protruding upwards therefrom, which can be formed in one piece with the bottom or as a separate part, within which the radiant heating elements llO, lll lie at a distance below its upper end face l24 and with this end face l24 abuts the entire surface on the underside of the plate lO6, so that the radiant heater lO4 is supported on the plate lO6 exclusively with insulating material. An additional thermal insulation layer based on pyrogenic silica can be provided on the bottom of the outer shell, on which the thermally and electrically insulating molded body forming the insulating shell 122 lies on the entire surface. However, it is also conceivable to produce the insulating shell l22 from insulating material based on pyrogenic silica or to connect the radiant heating elements directly to the insulating shell l22 by embedding, for which further details refer to patent applications P 3l 29 239.9, P 35 l9 35O.6 and P 35 3l 88l.7 is referred to. In a very simple embodiment the insulating shell consists at least partially of vermiculite, which can be particularly advantageous for the outer edge l23.

As shown in FIG. 9, the heating plate l05 is mounted on the stove housing so as to be pivotable upward about an axis l25 from the horizontal operating position, the axis l25 advantageously being in the region of the rear of the stove lO2. After opening the heating plate lO5, the radiant heaters lO4 are completely exposed so that they can easily be lifted upwards. If their electrical connections are connected to the temperature controllers ll3 via simple couplings, in particular plug-in couplings, and in the case of capillary tube sensors, the temperature sensors ll2 are easily detachable from the radiant heaters lO4, then each radiant heater lO4 can be used in the event of inoperability or if a radiant heater is required, using the design described other characteristics, can be replaced at any time without any particular expenditure of time.

In FIGS. L2 to l9, parts that correspond to one another have the same reference numerals as in FIGS. 9 to 11, but in FIGS. L2 to l4 with the index "a", in FIGS. L5 to l7 with the index " b "and in FIGS. 18 and 19 with the index" c ".

In the embodiment according to FIGS. L2 and l3, each radiant heater l04a has an outer shell l2la with an upright jacket wall, which surrounds the associated insulating shell l22a practically without clearance on the outer circumference, but is slightly behind the end face l24a. The angle profiles ll5a are not formed by folded sheet metal profiles as in the embodiment according to FIGS. 10 and ll, but by, for example, rolled profiles, while in the middle between the angle profiles ll5a a T-profile ll8a is provided, whose upwardly projecting T-foot forms the spacer. The spring elements l08a can be supported directly on the leg ll6a with the associated end turn and are aligned and secured, for example according to FIGS. Ll and lla, with a centering mandrel. As shown in FIG. 14, a cup-shaped centering piece 122a, which receives this over a lower part of its length, can also be provided for centering the spring element IO8a, which, for example, has an outwardly flanged flange edge with which it is supported with respect to the angle profile II5a. In the illustrated embodiment, a bore adapted to the outer diameter of the centering piece l2Oa is provided in the leg ll6a of the angle profile ll5a, into which the centering piece l2Oa is inserted without further attachment such that its flange edge rests on the top of the leg ll6a and protrudes downward. A corner centering of the spring or mandrel is also conceivable for example in the corner shell ll5 'according to Fig. Lla.

FIGS. L5 to l7 clearly show the temperature sensor ll2b, which crosses the heating field of the radiant heater lO4b, which is delimited by the inner surface of the outer edge l23b, over its entire associated width, immediately below the plate lO6b and from it at a smaller distance than from the Radiant heating elements llOb, lllb is located and engages with its ends sunk into cutouts in the upper end face l24b of the insulating shell l22b. The temperature sensor ll2b has a sensor tube l26 connected to the associated temperature controller via a capillary tube l27, which is essentially contact-free in a protective tube l28 made of quartz or the like which is coaxial with it. is arranged, this protective tube l28 is only slightly shorter than the associated outer width of the insulating shell l26b, so that its ends within the associated cutouts l3O of the outside randes l23b. The ends of the sensor tube l26 are tapered by crushing and protrude through end caps l29 of the protective tube l28, such that the main part of the sensor tube l26, which has an outer diameter, extends into the area of the cutouts l3O or the outer edge l23b. A reduced sleeve extension l32 of the end flap l29 penetrated by the capillary tube engages in an opening l3l provided in the upper end face of the casing of the outer shell l2lb, which opening has a tapered section in such a way that the extension l32, for example in the manner of a snap connection or with a blocking position bendable tab is secured against accidental falling out. The cutouts l3O are wider than the opening l3l, namely adapted to the outer diameter of the protective tube l28. The connection-free end of the sensor tube or the protective tube lies completely within the outer shell l2lb and is held down with an angular securing element.

As shown in FIGS. L8 and l9, the two radiant heating elements llOc, lllc are each laid in a double spiral in the insulating shell l22c, the windings of the two double spirals interlocking, their individual sections lying parallel to the outer edges of the radiant heater and with the same spacing next to each other and that four ends of the two radiant heating elements llOc, lllc are provided in parallel next to one another adjacent to a corner of the radiant heater lO4c. These ends can be connected to plug-like connecting pins which penetrate the outer edge l23c and the outer shell l2lc, so that they can be connected by connection with a single plug. The radiant heating elements llOc, lllc are laid in such a way that in the center of the radiant heater lO4c a rectangular field l33 is formed which is not directly heated, ie free of radiant heating elements, in which chem a detection sensor l34 is arranged for cooking vessels. The pin-shaped detection sensor l34 is perpendicular to the plate lO6c directly on the underside thereof and can be pressed against the underside of the plate lO6c with a suitable spring, for example supported on the bottom of the outer shell l2lc. The detection sensor l34 is expediently surrounded by, for example, a truncated conical insulating jacket l35, which can extend to further support the plate lO6c to its underside or, as shown in FIG. L8, has a small gap distance from the plate lO6c. The insulating jacket l35 lying within the field l33 sits on the bottom of the insulating shell l22c as a separate part, but can also be formed in one piece with the insulating shell l22c. The insulating jacket l35 can also be used to shield the plate lO6c against excessive heating in the central region of the heating field, for which reference is made to patent application P 35 26 783.6 for further details. Due to the arrangement of the detection sensor l34 or the insulating jacket l35, the temperature sensor ll2c is shifted slightly from the center of the radiant heater lO4c to one side in such a way that it lies directly adjacent to the outer circumference of the insulating jacket l35, whereby it is additionally at least from below through the insulating jacket l35 can be supported or is non-contact with the insulating jacket l35. As also shown in FIG. L9, the sections of the radiant heating elements llOc, lllc are located next to one another with a relatively small clear distance and at approximately the same small distance from the inner surface of the outer edge l23c, these distances being at most in the order of magnitude of the spiral diameter of the radiant heating elements, in particular are at least a third smaller, so that there is a very high heating density. This essential arrangement, as well as the almost seamless arrangement of the radiant heaters next to one another, guarantees the entire hob very even, intensive heating, whereby the hob can be heated directly to at least approximately 90% of its total area or even more. With a helix diameter of about 8 mm, the clear helix distance is expediently about 5 mm.

In FIG. 20, the same reference numerals are used for corresponding parts as in the figures from FIG. 9, but with the index "d". The two radiant heating elements llOd, llld are arranged in parallel in separate circuits, a radiant heating element llOd being switched via a contact l36 of the temperature controller ll3d actuated by the temperature sensor ll2d. A switch l37 designed in the manner of a power control device is placed on the temperature controller ll3d in such a way that it can be actuated via the same setting button ll4d as the temperature controller ll3d. The switch l37 has at least one additional contact l38, which is closed via the area of the setting of the setting button ll4d which corresponds to the higher temperature setting area of the temperature controller ll3d. Additional contact l38 is open in the lower area. In addition, the switch l37 has an isolating contact l39, which is closed in addition to the switch-off position of the setting button ll4d or the temperature controller ll3d and, in this switch-off position, is used for all-pole separation of the radiant heating elements llOd, llld from the current source l4O. The additional contact l38 is arranged in the circuit of the second radiant heating element llld. If a two-pole temperature controller is used, the additional contact l38 could also be part of the temperature controller. In series with the isolating contact l39 there is a switching contact l4l influenced by the detection sensor l34, which is open when the heating field is unoccupied and closes on the heating field when a cooking vessel is set up. This solution also offers the possibility for the automatic preparation of dishes, ie when the temperature controller is set to a temperature corresponding to continued cooking, a high heating power is initially released when a cold saucepan is placed on the pan, which is then reduced to continued cooking power as the temperature of the food or cooking vessel increases. A major advantage of temperature control is therefore that with a given temperature setting there is a higher power release as soon as a cold cooking vessel is placed, whereas the output drops as soon as the cooking vessel is removed and the heating field is operated in idle mode. This applies to every setting of the temperature controller, so that there is an energy saving in idle with all radiant heaters regardless of the setting of the temperature controller. As a rule, it should be expedient to set the front radiant heater, that is to say on the operator side, to a very high or the highest temperature so that it can be boiled over them. The rear radiant heaters are then expediently set to a boiling temperature so that the cooked dishes can be cooked on them by moving the cooking vessels on the hotplate from front to back.

An advantageous adjustment of the control or regulation of the radiant heating elements can be provided, for example according to FIG. 2l, such that when the setting knob 114d is set, in which it has been rotated by 90 ° from the switch-off position, a temperature of approximately 90 ° on the heating plate C is given. After a further rotation of, for example, approximately 90 degrees to 180 °, a temperature of approximately 30 ° C. is obtained, with the radiation heating element llld being switched on via the additional contact l38 when the adjusting knob is turned further, so that a temperature of over 500 ° C. can be reached . As long as only the radiant heating element llOd, which is regulated as a function of temperature, is operated 22, in which the power of the entire radiant heater 10d is switched off completely each time after the set temperature has been reached. As soon as the power-controlled radiation heating element llld is switched on by closing the additional contact l38, a basic output of the radiant heater lO4d according to FIG. 23 is constantly maintained, while the radiation heating element llOd is clocked by the temperature controller ll3d.

Claims (12)

1. Cooking unit, especially for commercial kitchen stoves or the like. with a hotplate (3, lO5) consisting, for example, of glass ceramic, which is provided on its rear side with at least one radiant heater (2, lO4), which has an insulating body (6, l22) with at least one radiant heating element (lO; 1lO, lll), characterized in that the respective radiant heater (2, lO4) is supported for holding on a side remote from the hotplate (3, lO5) and in that resilient elements (22, lO8) are provided which elastically counteract the insulating body (6, l22) place the back of the hotplate (3, lO5). 2. Cooking unit, in particular according to claim l, characterized in that the radiant heater (2), with the hotplate (3) forms a closed assembly, that the hotplate (3) is fastened to a carrier (4) which the insulating body (6th ) of the radiant heater (2) on its rear side facing away from the hotplate (3) encompasses and that between the support (4) and the radiant heater (2) at least one spring (22) pressing the latter against the hotplate (3) is arranged, the insulating body (6) in particular being pressed onto the hotplate in the middle area apart from the edge area (3) is present. 3. Cooking unit, in particular according to claim l or 2, characterized in that a carrier (4) of the hotplate (3) by at least one from the hotplate (3) to the rear of the radiant heater (2) extending, in particular formed by an angled profile support frame is formed, which surrounds the radiant heater (2) on the back only in the associated edge area, that preferably the spring (22) between a leg (19) encompassing the rear of the radiant heater (2) of the carrier (4) and the rear of the radiant heater ( 2) is that the radiant heater (2) is preferably set down on the back in the area of the support (4) surrounding it, in particular in such a way that the back of the radiant heater (2) outside the offset area approximately in one plane with the surrounding part (l9) of the support (4) lies in that, preferably, the spring (22) is arranged so as to be secured against falling out and is arranged in a cavity (23), in particular ere is approximately flat-rectangular in cross-section and / or that the spring (22) is preferably provided on a cover (l3) made of sheet metal or the like provided in the insulating body (6). is supported, which is formed in particular by a base plate leaving the insulating body (6) free on the outer circumference and possibly within the outer circumference, in particular in the area of a central cutout (l5), a holder (28) for a connecting body (l4) for the electrical connection of the radiant heater (2). 4. Cooking unit, in particular according to one of the preceding claims, characterized in that a carrier (4) of the hotplate (3) covers the insulating body (6) on the outer circumference, in particular approximately on the outer circumference (8), that preferably the carrier (4) forms a frame surrounding the radiant heater (2), that further preferably the support (4), in particular with an outwardly directed leg (2O), is connected to the hotplate (3) in a load-bearing manner, for example heat-resistant glued, and that it is also preferably on the outer circumference of the Cooking plate (3) provided a support edge (5) and in particular on the carrier (4) and / or on the hot plate (3) by gluing or the like. is attached, in particular the supporting edge (5) engages under the carrier (4), preferably its leg (20) attached to the hotplate (3), with an approximately equally wide leg (24). 5. Cooking unit, in particular according to one of the preceding claims, characterized in that the spring or the like as leaf spring, wave spring, bow spring, plate spring or the like. is trained. 6. Cooking unit, in particular according to one of the preceding claims, characterized in that the hotplate has a corresponding number of separate radiant heaters (lO4), each with at least one in to form several separately switchable and adjacent to each other within a cooktop hotplates on its underside a radiant heating element (lO9, lll) arranged on a carrier shell (lO9) form a heating field and are pressed against the underside of the hotplate (lO5) by means of spring elements (lO8) supported on a substructure (lO5), each radiant heater (lO4) having an outer dimension adapted receptacle (ll9) of the substructure (lO3) is inserted immovably and the receptacles (ll9) adjoin each other almost immediately, in such a way that the hob is essentially seamless and can be heated to at least about 85% of its total area. 7. Cooking unit, in particular according to one of the preceding claims, characterized in that all radiant heaters (lO4) are square or square and in particular connect only with slot-like gaps of the order of about one centimeter in width, that preferably the receptacles (ll9) by angular components, in particular the corners of the radiant heaters, are formed, on the approximately horizontal surfaces (ll6) of which the radiant heaters (lO4) are supported independently of one another via the spring elements (lO8) and in particular the hotplate (lO5.) ) the radiant heater (lO4) is pressed against the upper end faces (l24) of the outer edges (l23) of the carrier shells (lO9) and presses the radiant heater (lO4) against the spring elements (lO8). 8. Cooking unit, in particular according to one of the preceding claims, characterized in that between the radiant heating element (lO4) and the underside of the hotplate (lO5) an approximately parallel to this temperature sensor (ll2) of a temperature controller (ll3) is provided, which is in particular rod-shaped and the associated Heating field crosses over most of its associated width, preferably the temperature sensor (ll2b) with at least one end of a sensor tube (l26) or a protective tube (l28), an opening (l3l) of the jacket of a sheet metal or the like. existing outer shell (l2lb) of the carrier shell (lO9b) is used and in particular at least in the area of the heating field in the protective tube (l28), such as a quartz tube, which is closed at the ends, is essentially contact-free. 9. Cooking unit, in particular according to one of the preceding claims, characterized in that a temperature sensor (ll2) is assigned a temperature controller (ll3) provided for the radiant heater (lO4), which is also designed for temperature limitation, preferably both for temperature control and for Temperature limitation only a single temperature sensor (II2) is provided and / or the respective temperature sensor (II2) is part of a system filled with an expansion liquid, which is preferably filled with high-temperature resistant expansion liquid, such as sodium-potassium. lO. Cooking unit, in particular according to one of the preceding claims, characterized in that at least one temperature controller (113d) provided for a radiant heater (lO4d) switches only part, for example half, of the output of the radiant heater (lO4d) and that the other part of the output switches through an additional contact (l38) of the temperature controller (ll3d) is switched on in the upper temperature setting range, a switch (l37) having the additional contact (l38) in particular being saddled axially on the temperature controller (ll3d) and / or that at least one temperature controller provided for a radiant heater has several, in particular has two switching contacts, both of which are influenced by the temperature sensor and which switch different radiant heating elements on and off at different temperature values. 11. Cooking unit, in particular according to one of the preceding claims, characterized in that at least one radiant heating element (llOc, lllc), in particular all radiant heating elements (llOc, lllc), of the respective radiant heater (lO4c) can be switched off via a cooking vessel detection sensor (l34), which is preferably arranged approximately in the center of the heating field below the heating plate (lO5c) and shielded by an insulating jacket (l35) and is preferably an induction sensor which is preferably resiliently applied to the underside of the heating plate (lO5c). 12. Cooking unit, in particular according to one of the preceding claims, characterized in that at least two radiant heating elements (llOc, lllc) are laid in rectangular or square, interlocking double spirals in the carrier shell (lO9c) and preferably with a large heating density essentially over the entire heating field are distributed.

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