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
  • H05B3/74—Non-metallic plates, e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B13/00—Rolling molten glass, i.e. where the molten glass is shaped by rolling
  • C03B13/08—Rolling patterned sheets, e.g. sheets having a surface pattern
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B13/00—Rolling molten glass, i.e. where the molten glass is shaped by rolling
  • C03B13/16—Construction of the glass rollers

Definitions

• the present invention relates to cooking plates made of glass ceramic or another similar material resistant to high temperature and having a coefficient of expansion zero or almost zero.
• These plates, planar or essentially planar, are intended to come to cover elements or cooking zones in order to constitute cooking tables.
• cooking zones electric cooking elements, such as electric resistance heating elements or radiant elements and halogen lamps; induction inductors or fireplaces contributing to induction heating; and gas burners
• the cooking zones of the same hob can be of the same type or of different types, such as radiant elements and gas burners (so-called “mixed” hobs).
• the cooktops also include control and regulation means making it possible to vary the power of the fireplaces (which are most of the time four in number) and possibly various indicator lights.
• Ceramic hobs or the like are extremely successful and are very widely used, in particular because they have a more modern exterior appearance than traditional electric hobs and are easier to clean because the surface of a ceramic hob. is planar or essentially planar.
• the glass-ceramic plate is flat but may also include in certain places deformations consisting either of concavities or recessed areas, or of bosses or reliefs or waves.
• FR-A-2 773 873 which comprise at least one concavity under which a cooking hearth is placed and in which the food can be cooked directly or placed a cooking container, the upper peripheral edge of the concavity being able to be raised in relation to the plane of the plate.
• the control and regulation means for a cooking or temperature-maintaining means notably consists of a pair of keys, one of which is used to increment the power delivered to the hearth associated with each contact of the user's finger on this key, while the other serves, conversely, to decrease step by step the power of this same hearth. It is also possible to provide a multiplicity of keys corresponding to distinct heating powers.
• the ceramic hob therefore no longer needs to be drilled as in the case of a button control.
• the keys on the top of the plate because the only finger contact creates a capacitance with the other armature of the capacitor which is under the plate, the glass ceramic serving as a dielectric.
• the production of glass ceramic plates generally comprises the following stages:
• the glass of composition chosen in a melting furnace, the glass of composition chosen is melted to form the glass ceramic, then the molten glass is laminated into a standard ribbon or sheet by passing the molten glass between two rolling rollers, generally a roller upper with smooth surface in order to obtain a smooth upper surface for the plate and a lower roller engraved in negative, so as to obtain a lower plate surface provided with a network of bumps or pins, for example semi-spherical or semi-elliptical.
• the height of these pins is in particular of the order of 0.10 - 0.30 mm; the distance between the pins is generally of the order of 1 to 5 mm; and the pins are generally staggered; the pin roller is generally the lower roller, the pins then making it easier to drive;
• - Ceramization a generally cut, and possibly screen-printed, baking is carried out, according to the thermal profile chosen to transform the glass made of polycrystalline material called "glass ceramic” whose coefficient of expansion is zero or almost zero and which withstands thermal shock of up to 700 ° C, while baking the enamel of the screen-printed patterns, thus allowing them to hang on the substrate.
• the manufacturing process would include an operation, which can be carried out at any time of the conventional process, of collapse, of molding or pressing with the use of a support or molding or pressing surfaces having the desired geometry, provided that the material which constitutes the plate is at a temperature high enough to allow its plastic deformation.
• the present invention relates to all the types of plates which have just been described, these plates possibly also having holes, and / or possibly. added elements such as frame, connector (s), etc.
• these ceramic hobs have a generally smooth upper surface and a lower surface generally provided with pins as previously described.
• the upper surface is preferably smooth in the case of electric plates to allow good contact with the cooking vessels and transfer the heat under the best conditions and in all cases for ease of cleaning and aesthetics. This surface will be protected during transport of the plates.
• the lower surface is provided with pins in order generally to improve the mechanical resistance of the plate.
• the pins also allow that there is no contact with the support plate during the ceramization.
• the surface bottom of the plate will be extended: if there is a defect in the plate, the microcrack will not propagate due to the presence of the pins. Furthermore, in the event of a scratch, it will be discontinuous and will therefore be less visible and will in any case be invisible if we look at the top of the plate. The pins therefore provide useful passive protection.
• the application of the index resin represents an additional step, in recovery, consisting of precision work, with special storage conditions (the silicone polymerizes in 24 hours in dust-free air). This operation is therefore expensive.
• the disadvantage of poor aging of the resin should not be excluded.
• the Applicant Company therefore sought to provide a satisfactory solution to this problem, which led it to modify the surface of the pinned rolling roller to remove the pins on at least one zone chosen to reserve on the lower surface of the plate.
• of ceramic glass at least one area without pins, advantageously in a location intended to come opposite an element such as a display which must be able to be seen from above the plate without blurring effect.
• the present invention overcomes the drawback of the blurred vision of the displays by manufacturing plates partially free of pins on the underside, without thereby altering the mechanical strength of the whole of the plate.
• the present invention therefore firstly relates to a vitroceramic plate, generally planar or substantially planar, comprising a surface provided with pins, said plate being intended to be fitted to a hob, characterized in that at least one smooth zone , free of spikes, has been reserved in a location, this location advantageously being a location intended to come, in the mounting position, facing one or more elements of said table for which the blurred vision due to spikes must be improved.
• Such elements are in particular the power displays, for example those called “7-segment", or other indicators, in particular text, intended to be read, for example giving an indication of a cooking program to be followed, or else various indicators.
• the smooth area of the surface provided with pins of the plate is parallel to the other surface of the plate.
• the desired vision then becomes clear because the two faces of the plate are parallel in the vision area.
• the smooth area of the spiked surface of the plate may lie in the plane of the projecting ends of the spikes; or in the plane of the bottoms of the recessed areas between the pins; or in an intermediate plane between the plane of the projecting ends of the pins and the plane of the bottoms of the recessed areas between the pins.
• a more perfect vision will be obtained, insofar as the thickness of the plate is less, which is sought in the case of a display.
• the pins generally have a height of 0.10 to 0.30 mm.
• the spike surface thereof comprises a smooth zone, without spikes, which is formed by a strip parallel to one of the edges of the plate, at in the vicinity of said border, said strip corresponding to the region of a series of displays of the heating powers or other indications for the user.
• the surface opposite to the studded surface of the plate may also have a boss or a groove parallel to the strip without studs in the region adjacent to it opposite to said edge.
• the formation of the strip without spikes can also lead to the surface opposite to the spiked surface of the plate the presence of one or more undulations (in particular of the order of 1 to a few microns in height relative to the plane of the plate), directly above the area without spikes and parallel (s) to the strip without pins.
• the plate according to the invention and obtained by rolling as mentioned is therefore generally distinguished from existing products not only by at least one zone without spikes but also by the presence, on the opposite surface, directly above the zone without pimples, of this or these undulations (generally a double row of undulations).
• the smooth zone (s) of its studded surface are protected during transport of the plate by a polymer, for example a transparent peelable protective sheet of polyethylene, which it is removed when the hob is assembled.
• a polymer for example a transparent peelable protective sheet of polyethylene
• the present invention also relates to a hob, in particular of the type with radiant element (s), with halogen element (s), with induction, with gas burner (s), or with mixed type, said cooktop being equipped a ceramic hob as defined above, the zone or zones without pins corresponding in particular to the regions of the display (s) of heating powers or other indications useful to the user.
• the present invention also relates to a method and an apparatus for the manufacture by melting-lamination of a glass-ceramic plate as defined above, comprising respectively a lamination step and a lamination device constituted by two rollers between which one makes pass the molten glass to be laminated to obtain a ribbon the length of which corresponds to one or more plates, one of the rollers, generally the lower roller, having a spiked surface, characterized in that the spiked roller has been modified to have at least one smooth zone, devoid of pins, the smooth zone or zones on the surface of said roll having been dimensioned and positioned to form, during rolling, at least one zone without pins on the surface of the ribbon, dimensioned and positioned to generally find, after the operation of cutting the ribbon into the plates having their final dimensions, opposite one or more eurs elements of said plates for which the blurred vision due to the pins must be improved.
• a method or apparatus according to the invention intended for the formation of a plate whose smooth zone is a strip as described above is characterized in that the zone without spikes of the lower rolling roll is formed by a strip or a portion of cylindrical strip located in the vicinity of an edge of the roller, to thereby obtain said lower strip without pins parallel to the edge of the plate.
• FIG. 1 is a schematic top view of a glass ceramic hob of the invention
• FIG. la is an enlarged view of an area for adjusting the heating power of a cooking hearth of the table of Figure 1;
• FIG. 1b is a sectional view along ld-ld of Figure 1, Figures le and lf showing two variants;
• - Figure 2 is a perspective view of a lower rolling roller, modified in accordance with the present invention
• - Figure 2a is, on a larger scale, a partial sectional view of the roller of Figure 2, showing the area without pins of the roller, and the corresponding region of the glass ceramic plate
• Figure 2b is a variant of Figure 2a
• - Figure 3 is a view showing the spiked side of the glass ribbon obtained after rolling with the lower roller of Figure 2, the plate cutting lines being symbolized in broken lines;
• FIG. 4 is a view similar to Figure 3 showing a ribbon obtained with a roller produced in accordance with a variant of the roller of Figure 2.
• FIG 1 there is shown a schematic view of a hob 1 according to the invention comprising a flat glass ceramic plate 2 on which have been delimited in a conventional manner, by screen printing, zones 3 to 6 of the four cooking zones , and, at the bottom border, zones 3a to 6a of the sensitive keys controlling the heating power of the respective homes.
• the upper part of the plate 2 may comprise, along its lower edge, a wave 7 or a groove 7 ′ as can be seen in Figures le and lf respectively, which separate the major surface comprising the zones of the hearths and the border strip which comprises the sensitive keys.
• the glass ceramic of plate 2 is colored (for example brown, white) and when plate 2 is in use, we can see by transparency each of the displays fitted to the hob 1 under each of the sensitive buttons 3a to 6a, as shown in FIG. 1a, as well as the general switch 8.
• the display represented in FIG. 1a is a conventional display with 7 segments, the figure formed indicating the heating power, the user pressing the + repeatedly on the right to increase the power or on the - to decrease it.
• the lower surface of the plate 2 is provided with a network of pins 9 (see Figure 1d) over its entire surface in the case of a traditional plate, while these pins 9 have been deleted in strip 10 opposite the displays in plate 2 according to the invention.
• the plane of the strip 10 is that of the bottoms of the hollow areas between the pins 9, which ensures perfect vision of the displays.
• the rolling with a set of rollers (smooth upper roller not shown and lower roller 11) of a glass ribbon 13 in which two plates 2 can be cut, will form the desired smooth strip 10 ( Figure 3).
• the glass ribbon of Figure 4 will be formed with a roller having two areas free of spikes, to form two spade plates.
• the depth of the smooth area of a lower roller 11 can vary in particular from 0 to p.
• the roller was machined in recovery by eliminating the pins in the smooth area.
• a roller 11 'engraved with pins except in the smooth zone 12' is provided.
• the studded surface has been described as being the lower surface only, but in the case where the upper surface has, or would also have, irregularities of the same type, the same solution of smooth area (s) corresponding to the region through which we want a clear vision of the LEDs, displays, ... is to be recommended, and therefore a suitable treatment of the corresponding laminating roller.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Ceramic Engineering (AREA)
• Induction Heating Cooking Devices (AREA)
• Electric Stoves And Ranges (AREA)
• Resistance Heating (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=28459720

Family Applications (1)

Country Status (7)

Families Citing this family (13)

Family Cites Families (11)

• 2002
  • 2002-04-10 FR FR0204472A patent/FR2838507B1/fr not_active Expired - Fee Related
• 2003
  • 2003-04-09 US US10/508,952 patent/US7375307B2/en not_active Expired - Fee Related
  • 2003-04-09 CN CNB038080133A patent/CN100471347C/zh not_active Expired - Fee Related
  • 2003-04-09 WO PCT/FR2003/001111 patent/WO2003086019A1/fr active Application Filing
  • 2003-04-09 EP EP03745836A patent/EP1493306A1/de not_active Withdrawn
  • 2003-04-09 JP JP2003583060A patent/JP2005522827A/ja active Pending
  • 2003-04-09 AU AU2003246797A patent/AU2003246797A1/en not_active Abandoned
• 2008
  • 2008-04-14 US US12/102,233 patent/US20080190142A1/en not_active Abandoned

Non-Patent Citations (1)

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