Patent Application
20180324907
The invention relates to a food treatment appliance, having a muffle interior enclosed by a muffle and a light-generating facility arranged outside the muffle for radiating light into the muffle interior through an opening in the muffle. The invention can in particular be advantageously applied to cooking appliances with an oven functionality and/or microwave functionality.
DE 10 2012 223 465 A1 discloses a cooking appliance with a cooking appliance muffle and a light source arranged outside the muffle for lighting the muffle interior through an opening in a muffle wall, the light source being arranged below the opening and at least one optical element being provided to deflect the beam of light from the light source into the muffle interior.
DE 10 2012 223 678 A1 discloses a lighting apparatus for a cooking chamber of a cooking appliance, comprising at least one light source and at least one light guide. The at least one light guide is shown as an elongated element and at least one structured region incorporating at least one structure is provided on at least one part of the periphery of the light guide. A cooking appliance with a lighting apparatus is also described.
DE 10 2005 005 267 A1 discloses an apparatus for heating food with a housing wall, which defines a cooking chamber, and a lighting facility for the cooking chamber, having a light source with at least one light outlet opening and a diffuser, preferably a diffusing panel or plate, made of a temperature-resistant material, adjoining the light outlet opening to diffuse light from the light source into the cooking chamber.
DE 10 2013 005 988 A1 discloses an electric domestic appliance, specifically a refrigerator and/or freezer or oven, with at least one light panel lighting an interior of the appliance and a light source apparatus coupling light into the light panel on at least one of its narrow faces. The light source apparatus has at least one light-emitting diode and a lens system, which brings together at least a majority of the light emitted by the light-emitting diode and directs it onto at least one narrow face of the light panel.
It is the object of the present invention to at least partially eliminate the disadvantages of the prior art and in particular to provide an improvement.
This object is achieved according to the features of the independent claims. Preferred embodiments will emerge in particular from the dependent claims.
The object is achieved by a food treatment appliance, having a muffle interior enclosed by a muffle and a light-generating facility arranged outside the muffle for radiating light into the muffle interior through an opening in the muffle, a light-distributing element for distributing light that can be radiated in through the opening being arranged in the muffle interior and a gap being present between the light-generating facility and the light-distributing element.
It is one advantage of this food treatment appliance that adjustments can be made in a particularly simple manner for different—in particular also functional—configurations of the food treatment appliance (for example with or without microwave function), as a light-emitting region of the light-generating facility is not connected to the muffle in a fixed manner but is at a distance therefrom. This in particular assists a functionally modular structure of the food treatment appliance. The light-generating facility can be a prefabricated module. Lighting can also be brought about particularly economically and in a manner that is less affected by tolerances due to the greater mechanical decoupling of the light-generating facility from the muffle. It also means that there is no need to clamp the light-generating facility during assembly.
In one development the food treatment appliance is a domestic appliance. The food treatment appliance can generally be a cooking appliance for cooking or heat-treating food. The food treatment appliance in particular has an oven or is an oven. The food treatment appliance can have a steam cooking functionality and/or a microwave functionality, together with or without an oven functionality.
A muffle generally refers to a housing or wall, which delimits the muffle interior. The muffle interior can also be referred to as a food treatment chamber or—in the case of an oven—an oven chamber and serves to treat food present in the muffle interior. If the treatment chamber is an oven chamber, the muffle can also be referred to as an oven muffle.
The light-generating facility is in particular not connected directly to the muffle.
The light-generating facility can have one or more light sources, for example LEDs, for generating the light, which can be radiated into the muffle interior through the opening (which can also be referred to as an aperture).
In one development the opening is located in the gap between the light-generating facility and the light-distributing element and therefore the light guiding facility ends in front of the opening and the light-distributing element is accommodated in its entirety in the muffle interior. This allows particularly simple mechanical decoupling of muffle and light-generating facility.
Alternatively the gap can be located in its entirety within the muffle interior. The light-guiding facility can then also reach or project into or through the opening into the muffle interior, while the light-distributing element is accommodated in its entirety in the muffle interior.
Alternatively the gap can be located in its entirety outside the muffle interior. The light-distributing element can then reach into the opening or project outward through the opening, while the light-guiding facility is located in its entirety outside the muffle interior.
The opening can have a single aperture or a number of apertures (for example a number of slits or round holes). For example the round holes can have a diameter between 0.5 mm and 10 mm (in particular 5+−0.5 mm).
In one configuration the light-generating facility has a light-guiding facility for guiding the light generated by it to the opening, the light-guiding facility ending in front of the opening. This allows the light to be guided specifically to the opening so that its loss of light up to the opening is minimal and the light-guiding facility can also be mechanically decoupled from the muffle in a simple manner.
In an alternative or additional development the light-generating facility has a light-guiding facility for guiding the light generated by it to the opening, the light-guiding facility projecting into the opening or projecting through the opening into the muffle. This allows light loss to be prevented particularly effectively.
In one development the light-guiding facility has a light guide or light wave guide or is such, guiding light coupled in at an—in particular end—light inlet surface by means of total internal reflection to an—in particular end—light outlet surface and coupling it out there. The light guide can be just one light guide or can have a number of light guides. The light guide can in particular be shaped in the manner of a bar. Alternatively the light guide can be at least one hollow, internally mirrored tube or solid body or the like, which can also be referred to in the following as a “light guiding channel”.
The light guide can be made of plastic. The light guide is advantageously made of glass, as glass is particularly thermally resistant.
In one configuration the light-generating facility ends in front of the opening and the food treatment appliance has a reflector, which laterally encloses a region between the light-generating facility, in particular its light-guiding facility, and the opening. The light emitted by the light-guiding facility therefore passes through the spatial region enclosed by the reflector to the opening. This reduces or even prevents light loss, which would otherwise result with light radiated by the light-guiding facility adjacent to the opening or reflected by the opening (for example an edge thereof). The reflector also prevents insulating material passing between the light outlet surface of the light-generating facility and the opening. The reflector can also be used to aid assembly, particularly incorporation, when assembling the light-generating facility.
In one development the reflector is shaped in the manner of a funnel and the light-generating facility, in particular its light-guiding facility, for example enters its narrower aperture and the wider aperture of the reflector adjoins the opening. The reflector therefore widens out from the light-generating facility, in particular its light-guiding facility, toward the opening. This is particularly advantageous if a light outlet surface of the light-guiding facility is smaller than a surface of the opening. If a light outlet surface of the light-guiding facility is larger than a surface of the opening, the reflector can narrow from the light-guiding facility to the opening.
In another configuration the reflector is connected in a fixed manner to the muffle and has an insertion aperture for the light-generating facility, in particular its light-guiding facility. This has the advantage that the light-generating facility, in particular its light-guiding facility, can be arranged particularly easily on the—for example funnel-shaped—reflector. With this configuration the reflector can also be seen as an external attachment or fronting element for the opening. The insertion aperture can enclose light-generating facility, in particular its light-guiding facility, in a close or distant manner. In particular a lateral gap between them does not allow the passage of microwaves.
In one development the insertion aperture can be widened elastically. This allows a close fit for the light-generating facility, in particular its light-guiding facility. It also allows light loss to be kept particularly minimal. The insertion aperture can also have for example at least one resilient flap.
In another configuration the opening is covered by a cover element. This prevents unwanted passage of material and/or radiation outward through the opening out of the muffle interior and/or from outside into the muffle interior in a particularly reliable manner. The fact that the opening is covered by the cover element can mean in particular that the cover element is a separately produced element, which is inserted into the opening and/or positioned on the opening. The cover element can in particular reduce or even completely prevent passage of air and/or radiation from a spectral range outside the light that can be radiated in. This configuration has the further advantage that a, for example large, opening in the muffle can be adjusted for desired functionalities of the food treatment appliance by the cover element with little outlay, thus providing further improved modularity.
In a further configuration the cover element has or is a light-permeable panel. This has the advantage that the light generated by the light-generating facility can penetrate through the panel into the muffle interior practically without loss but heat, vapor, steam, etc. present in the muffle interior cannot leave the muffle. The panel is advantageously transparent to prevent light loss. The panel can be made of glass or silicone for example.
In an alternative or additional configuration the cover element has or is a light-permeable metal cover element. Light permeability can be provided for example by breaks or holes in the cover element. Such a cover element has the advantage that it can be used as a microwave seal. The light generated by the light-generating facility can pass through the microwave seal into the muffle interior but microwave radiation cannot leave the muffle. The microwave-proof cover element is in particular also connected electrically to the muffle, in order for example to make it more microwave-proof.
The metal light-permeable cover element can be or have for example a perforated plate or a metal mesh or metal web. The light generated by the light-generating facility can then pass for example through the holes in the perforated plate or through gaps in the metal mesh into the muffle interior. The perforated plate can be a perforated sheet. The size and density of the holes can be selected for example to tailor the perforated plate for the microwave radiation. The perforated sheet can be configured as a metal film, the thickness of which is smaller than a wall thickness of the muffle, allowing a particularly high degree of freedom of configuration in respect of the density of the holes. The metal mesh can be present in the form of a mat.
The cover element can be a multilayer element, for example having one layer in the form of a transparent silicone plate and one layer in the form of a perforated plate.
Alternatively or additionally the opening formed or integrated in the muffle is microwave-proof, for example due to the provision of a number of round holes, in particular with a diameter between 0.5 mm and 10 mm (specifically 5+−0.5 mm).
In another configuration one of the side walls of the muffle has an outward facing depression, in which the opening is located, and the light-generating facility is arranged such that its main emission direction is parallel to the side wall of the muffle having the depression. This has the advantage that the food treatment appliance can have a particularly compact structure and also a particularly large area of light radiation can be achieved from the depression into the remainder of the muffle interior with simple means. A main emission direction can refer to a direction of the light component generated by the light-generating facility with the highest light intensity or light density. A main emission direction can also refer to a direction along an axis of symmetry of the light cone emitted by the light-generating facility. The depression can also be referred to as a bulge. The fact that the main emission direction is aligned parallel to the side wall of the muffle can mean in particular that it lies in a vertical plane.
In yet another configuration the depression is an elongated depression, which is incorporated in a vertically aligned wall (in other words in a left-hand side wall, a right-hand side wall and/or the rear wall) of the muffle and is aligned vertically, horizontally or at an angle there. Because the depression is an elongated depression, light can advantageously be radiated in a particularly high or wide manner into the remainder of the muffle interior. Its horizontal alignment advantageously allows homogeneous, wide lighting of an insertion level (at its level or at the level of an associated food). Vertical alignment of the depression advantageously allows homogeneous lighting of a number of insertion levels.
In one development the depression has a rectangular top surface and an adjoining side surface connecting the top surface to the right-hand side wall and the opening is located in the side surface. This allows particularly easy incorporation of the depression, for example by deep drawing, and a particularly compact structure. In particular the light can be radiated into the muffle without beam deflection, for example by means of a straight light-guiding facility, even when the light is guided parallel to the associated side wall of the muffle.
In a further configuration the light-distributing element is arranged in the depression and can be radiated with the light through the opening. This has the advantage that the light-distributing element does not compete with the region of the muffle interior provided to accommodate the food. The light-distributing element can in particular be arranged in its entirety in the depression. The light-distributing element can be radiated in particular directly through the opening, for example without an intermediate optical deflection element. The light-distributing element can thus be arranged in particular in a direct line of sight from the light outlet surface of the light-generating facility through the opening. This configuration can also achieve the object on its own. Said object is also achieved by a food treatment appliance having a muffle interior enclosed by a muffle and a light-generating facility arranged outside the muffle for radiating light into the muffle interior through an opening in the muffle, a light-distributing element for distributing light that can be radiated in through the opening being arranged in the muffle interior, the muffle having an outward facing depression, in which the depression is located, in one of its side walls and the light-distributing element being arranged in the depression and being able to be radiated with the light through the opening.
In a further configuration the light-distributing element is an optical transmitted light element that shields the depression from the remainder of the muffle interior. This protects the depression to a greater degree from the penetration of vapor, steam, microwave radiation, etc.
In yet another configuration the light-distributing element has a rear face facing away from the muffle interior and having a lighting surface that can be lit by the light radiated in. This food treatment appliance has the advantage that the light-distributing element can be produced and incorporated in the muffle in a particularly simple and compact manner. To cover the depression, the light-distributing element has an outer contour matched to the depression. The light-distributing element can be for example screwed, latched, clamped, plugged, bonded, etc. to the muffle.
In a further configuration the light-distributing element has an in particular stepped surface structure on its lighting surface. This advantageously deflects the light radiated in to a significant degree locally in a small space. In particular it allows the light-distributing element to be kept particularly narrow.
In one development the surface structure is configured such that a light beam striking the lighting surface is deflected downward at an angle, in other words into a half space below a horizontal plane, in which plane a light outlet point of a pertaining light beam is located. This has the advantage that food present in the muffle interior can be lit particularly effectively.
In a further configuration the light-distributing element has an elongated lighting surface that is curved over its longitudinal extension. The curvature is advantageously parabolic in cross section. For example the steps can be arranged one behind the other on a parabolic contour. In particular the entire rear face, in particular the entire light-distributing element, can be curved along its longitudinal extension, allowing particularly constant lighting over its length.
In a further configuration the light-distributing element has an elongated lighting surface that is curved over its transverse extension. The curvature can in particular be curved in a circular manner in cross section. Steps here can have a curved shape or transverse extension for example.
In a further configuration the depression, in particular its top surface, is covered at least partially by a reflector element on the inside. This reduces light loss due to light emitted backward at the light-distributing element or radiated out of the muffle interior onto the light-distributing element, as such light is thrown back at the reflector element and can then re-enter the muffle interior, for example through the light-distributing element. The reflector element can be a reflector sheet. The reflector element, in particular reflector sheet, can be polished to reflect and/or be coated with a reflective or diffusively reflecting reflective layer.
In one development that advantageously enhances lighting efficiency the light-distributing element is at least partially printed.
The food treatment appliance described above has inter alia one or more of the following advantages: a dedicated microwave seal is no longer needed or a simpler microwave seal than hitherto can be used. Lighting efficiency is enhanced, in particular if light is only radiated downward into the muffle interior (for example due to the zig-zag surface structure). A modular structure (oven, pyrolysis, microwave, steam, etc.) is supported. The decoupling of the light guide from the muffle allows the design to be particularly unaffected by tolerances. Heating due to microwave radiation is also reduced in the depression. The light guide can also be configured more simply (for example shorter, without printing, no phase, thicker, etc.). Also standardization with a holder and a light guide of a top light of the muffle is also simplified or made possible. The reflector sheet can also be simplified (for example with embossing, flaps, bolts). The problem of clamping light guides that arose hitherto during assembly is eliminated. Costs are reduced (for example relating to a microwave seal, reflector, light guide, holder, assembly, etc.).
The characteristics, features and advantages of the present invention as described above and the manner in which these are achieved will become clearer and easier to understand in conjunction with the following schematic description of an exemplary embodiment, which is explained in more detail in conjunction with the drawings, in which:
The left-hand side wall 4 has a bulge or depression 8 that extends longitudinally in a vertical direction and faces outward. The depression 8 is approximately box-shaped with a top surface 9 extending vertically and an adjoining peripheral side surface 10. The side surface 10 is at an angle to the vertical.
The light-generating facility 3 is arranged above the depression 8 and has one or more light sources in the form of LEDs (not shown), which are accommodated in a light source unit 11 here so that they cannot be seen. The light generated by the LEDs of the light source unit 11 is coupled in at the front of a light-guiding facility in the form of a short bar-shaped light guide 12 made of glass. The light is guided in the light guide 12 and emitted again at an opposing end surface that serves as the light outlet surface 13. An electrical connector 14 and a fastening flap 15 of the light-generating facility 3 are also shown here. The light-generating facility 3 is not fastened directly to the muffle 2.
The light guide 12 ends in front of the side surface 10, in which there is an opening 16 opposite the light outlet surface 13. The light outlet surface 13 is thus at a distance from the opening 16 and not in mechanical contact therewith. The light guide 12 can radiate light through the opening 16 into the muffle interior M, principally or even solely into the associated depression 8. To this end the light guide 12 is aligned vertically so that the main emission direction of the light coupled out or emitted by the light outlet surface 13 is also aligned vertically downward.
The light-distributing element 18 is configured in the manner of an elongated plate and closes an aperture in the depression 8 off from the remainder of the muffle interior M. It can therefore also serve as a cover glass. It is arranged to stand upright, it being possible for a rear face 19 of the light-distributing element 18 to be radiated with the light L radiated in from the opening 16 (“lighting surface”). The light L is deflected by the light-distributing element 18 into the remainder of the muffle interior M (essentially downward at an angle, as shown by the associated dotted arrows). The light-distributing element 18 is therefore an optical transmitted light element. It has a surface structure 21 to deflect the light L at the associating lighting surface 20.
The lighting surface 20 extends with only a slight angle of inclination to the vertical over practically the entire length of the light-distributing element 18, so that the light L from the opening 16 strikes the rear face 19 in a sweeping manner and lights it over practically its entire height. The light-distributing element 18 therefore also emits the light L over its entire length or height at its front face 22. Because the light-distributing element 18 is so long or high that it extends over almost the entire height (i.e. over at least 60%, in particular over at least 75% of the height) of the muffle interior M, a number of insertion levels of the cooking appliance 1 can be lit at the same time, even if a number of inserts are in place.
The cover element 41 is made of metal and is connected to the depression 8 in an electrically conducting manner. To this end the cover element 41 has four longitudinal holes 43 and 44, which can be used to screw it to the depression 8, as shown in
The cover element 41 has flaps 45 bent in the direction of the depression 8 at the edges, in order to achieve elastically resilient and therefore particularly secure positioning on the depression 8.
The cover element 41 can also be implemented in the form of a simpler—for example straight—perforated sheet 46 (as shown during positioning from the inside in
With the muffle 32 shown as semi-transparent
The reflector sheet 47 can be used in the muffle 2 in a similar manner. In particular the bolts 51 can also then be used to fasten the cover element 41 (see also
In an alternative development the sheet is not a reflector sheet 47 but just has a mounting function without an essential reflection function (“mounting sheet”).
The reflector attachment 52 allows light L, which exits at an angle from the light guide 12 and does not pass directly through the holes 34 into the muffle interior M but is reflected off the enclosing material of the depression 8, to be reflected back onto the opening 33, so that the light output increases. The reflector attachment 52 also serves as an incorporation aid when assembling the light guide 12 and ensures that no insulating material passes between the light guide 12 and the holes 34. This structure is affected by tolerances to a much lesser degree than a long light guide which is fastened to a fan and at the same time is concealed in the muffle 32 (which expands when the temperature increases).
A—for example transparent—cover for example in the form of a steam seal (not shown) can be arranged between the reflector attachment 52 and the muffle 32, being made of silicone or glass for example.
The reflector attachment 52 can also be used with the cooking appliance 1.
The light L coupled out by the light guide 12 generates a light spot in the region of the surface structure 21. The light spot corresponds to a projection of the incident light beam onto the light-distributing element 18 and the lighting surface 20 also has the surface structure 21. The surface structure 21 has a stepped shape or zig-zag shape in cross section, causing the light L that is incident vertically from above to be emitted in a downward direction at an angle (as shown by the dotted arrow) from the front face 22 into the muffle interior M. This increases the efficiency of the manner in which food present in the muffle interior M is lit.
In order for the light L to be deflected downward at the front, an angle α of an angled sub-region 55 of the stepped surface structure 20 is advantageously 45° or more to a main radiation direction of the light S (in this instance corresponding to the vertical), as outlined in
The light-distributing element 18 can couple the light out homogeneously over its height at the front. To achieve particularly homogeneous lighting, the lighting surface 20 or the surface structure 21 can have a parabolic basic shape or profile along its length (in this instance in the vertical direction). The individual steps are then arranged one behind the other along a parabolic path.
In order to distribute the light L even more effectively—in particular even more homogeneously—the structure can also be bent in the transverse direction, as shown in the top view in
If individual spatial regions of the muffle interior M are to be lit particularly in a specific manner, for example only spatial regions next to and/or above baking sheets—this can be achieved for example by way of suddenly increasing steps or a zig-zag structure, in which in particular the depth of adjacent steps changes significantly.
A for example surface-type structure can also be provided on the front face 59 and/or on the rear face 60.
The above cooking appliances 1, 21 and 57 can be configured correspondingly in particular on their right-hand side walls.
The present invention is of course not restricted to the illustrated exemplary embodiment.
The light-generating facility can also radiate its light from below or from the side into the depression and be arranged correspondingly below or to the side of the depression.
A number of light-generating and light-distributing structures can also be present on a side wall, for example a number of light-generating facilities 3, depressions 8 and light-distributing elements 18 or 58, etc.
Generally “one” can refer to a single one or a number, in particular in the sense of “at least one”, “one or more”, etc., unless this is specifically excluded, for example by the expression “just one”, etc.
Also a number can cover both the number specified as well as a standard tolerance range, unless this is specifically excluded.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 225 992.7 | Dec 2015 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/079131 | 11/29/2016 | WO | 00 |
