COOKING APPLIANCE LIGHT AND COOKING APPLIANCE WITH COOKING APPLIANCE LIGHT

Description

[0001] The invention relates firstly to a cooking appliance light, in particular a light for ovens, microwave ovens or steam cookers, comprising a light source in the form of a circuit board with an LED arranged thereon, comprising a light box into which the light emitted by the LED is fed, comprising a light guide rod arranged between the light source and the light box and guides the emitted light from the LED to the light box, comprising a protective tube which is also arranged between the light box and the light source and protectively surrounds the light guide rod, comprising a circumferential gap between the light guide rod and the protective tube so that the light guide rod is held contactlessly to the protective tube, comprising a mounting device which carries the light source and holds a first end of both the protective tube and the light guide rod, comprising at least one locating means which fixes the protective tube and the light guide rod to the light box, comprising at least one centering member,which surrounds the light guide rod and arranges the light guide rod in the protective tube while maintaining the circumferential gap.

[0002] The invention also relates to a cooking appliance with an aforementioned cooking appliance light.

[0003] Cooking appliance lights are known in a variety of forms from the prior art. They exist using traditional incandescent filament lamps, for example, as disclosed in EP 1 811 227 A1. However, cooking appliance lights using LED technology are increasingly being used, as disclosed, for example, in EP 3 819 545 A1.

[0004] Temperature management plays a particularly important role in the lighting of cooking appliances, which use LED technology as their light source. LEDs are comparatively temperature-sensitive, meaning their service life decreases drastically when a certain operating temperature is exceeded. This contrasts with the requirement that LED lighting cannot be replaced, especially by the user, and must therefore remain functional for the entire service life of the cooking appliance. Lighting technology for cooking appliances has two problems to solve. Firstly, the waste heat generated by the light source during operation of the LED must be dissipated. In addition, cooking appliances themselves generate a considerable amount of heat, particularly ovens such as steam cookers, but also modern microwave ovens with additional cooking functions such as the grill function.In this respect, a temperature-sensitive lamp must be used in an environment with a comparatively high temperature due to the system.

[0005] Therefore, there is an increasing trend to protect the LED light source from the cooking chamber's waste heat using technical means. For example, EP 3 139 096 B1 discloses the placement of staggered heat shields in front of the LED, thus protecting the LED from heat radiation. The aforementioned EP 3 819 545 A1 uses light-guiding elements, namely a light-guiding rod. This allows the LED to be positioned at a distance from the cooking chamber in the cooking appliance, thus directing the light emitted by the LED into the cooking chamber over a greater distance.

[0006] DE 10 2014 203 532 A1 and KR 2018 0104401 A show a cooking appliance light which feeds a light guide rod to a light box via a protective tube.

[0007] CN 210 069 592 U, CN 108 980 917 and US 10,655,863 B1 show cooking appliance lights with a light box and a light guide rod.

[0008] DE 10 2008 118 504 A1 shows a comparable solution. Here, the actual light source, an LED lamp, is located outside the cooking chamber. Light guide rods, arranged parallel to the cooking chamber wall and outside the cooking chamber wall, direct the light into light boxes, which are also located outside the cooking chamber. The light boxes themselves open into wall openings, accommodate reflectors, or have reflector properties themselves. In this way, the light fed into the light box via the light guide is fed into the cooking chamber via a wall opening, which may be closed with protective glass. The applicant itself presented a comparable solution at the International Consumer Electronics Exhibition (IFA) in 2015. Based on the applicant's own trade fair presentation and DE 10 2018 118 504 A1, the object of the invention is to create a cooking appliance light with improved temperature management and manufacturability.

[0009] This object is achieved by a cooking appliance light with the features of claim 1, in particular with its characterizing features, according to which the centering member is designed as a centering sleeve in which the light guide rod is seated, the light guide box has an insertion opening which receives the centering member, the centering member also forms the arrangement means for fixing the protective tube to the light box.

[0010] The invention advantageously uses the centering member to arrange the light rod on the light box and thus combines in one and the same component functions that were realized by different components in the prior art.

[0011] If the centering element is also made of a material with poor heat conduction, such as a plastic or elastomer, or even a graffiti ring surrounding the light guide rod, thermal decoupling between the light guide box and the heat guide rod is achieved particularly easily. This protects the LED light source from temperature influences from the cooking chamber.

[0012] In a particularly preferred embodiment, the centering element can additionally perform a sealing function. It is preferred if the centering element is a sleeve-like sealing element that sits in the circumferential gap between the light guide rod and the protective tube and seals the circumferential gap from a space formed by the light box. This prevents cooking vapors from the cooking chamber from penetrating the light box into the protective tube surrounding the light guide rod and settling on the light guide rod. The particles contained in the cooking vapors would adhere to the light guide rod, leading to light outcoupling. The resulting light losses can significantly reduce the efficiency of the cooking appliance light.

[0013] It is also planned to provide the protective tube with a reflective inner surface in order to redirect light coupled out of the light guide rod into the light guide rod.

[0014] If the light guide rod is secured in the light box by means of a centering element made of a damping material, such as an elastomer, the centering element also acts as a vibration dampener. It thus protects the light guide rod from impact forces both during transport and during everyday operation. Furthermore, such a centering element also compensates for different expansion behaviors of the materials under the influence of heat.

[0015] The centering element can be particularly easily fixed to the light box if the centering element has locking means, in particular a locking lip running around the outside, with which the centering element and the insertion opening of the light box lock.

[0016] In order to further simplify the installation of the cooking appliance light, it is provided that the centering member also forms the arrangement means for fixing the protective tube to the light box, in particular if the centering member forms an annular wall which sits in the protective tube for fixing to the light box and holds the protective tube at least frictionally.

[0017] If the centering element serves not only as an arrangement means for the light guide rod on the light box, but also for the protective tube, the numerous advantages mentioned above also apply to the protective tube. Both thermal decoupling and protection against vibrations can thus be achieved for the protective tube as well. The differing thermal expansion of the light guide rod, protective tube and light box can also be compensated for by the centering element. Furthermore, the placement of the protective tube on an annular wall and the frictional holding allow for a significant simplification of assembly. A positive connection between the centering element and the protective tube, for example using locking elements, is possible and advantageous. In addition, the centering element can also act as a seal against the protective tube, thus preventing the penetration of fluids between the centering element and the protective tube wall.

[0018] It is further provided that the locking means and the annular wall are arranged at opposite ends of the centering member.

[0019] In order to further simplify the installation of the cooking appliance light, in particular to ensure a purely plug-in installation, it is provided that the mounting device forms a hollow cylindrical nozzle, in the cylinder space of which the light guide rod is held and the cylinder wall of which is received by the protective tube at least in a frictionally engaged manner.

[0020] The invention then relates to a cooking appliance having the features of claim 7.

[0021] Further advantages of the invention and a better understanding of the same can be found in the following description of an exemplary embodiment. In the drawings: Figure 1 shows the cooking appliance light according to the invention in an exploded view, Figure 2 shows a first partial enlargement of the exploded view according to Figure 1, Figure 3 a second partial representation of the exploded view according to Figure 1 , Figure 4 a view of the cooking appliance light according to the invention looking into a space spanned by the light box, Figure 5 the cooking appliance light according to Figure 4 in view of the back of the light box, Figure 6 a partial view of the cooking appliance light according to Figure 4 , Figure 7 a sectional view according to section line VII - VII in Figure 6 , Figure 8 a schematic representation of a cooking appliance with the cooking appliance light according to the invention according to Figure 1 .

[0022] A cooking appliance light according to the invention is provided with the reference number 10 in the figures. The cooking appliance light 10 is in Figure 1 shown in exploded view.

[0023] The cooking appliance light 10 comprises a light box 11 with cover glass 12, a light rod 13 which is mounted in a protective tube 14, wherein a centering member 15 holds the light guide rod 13 and the protective tube 14 on the light box side.

[0024] The light source 16 is a circuit board 17 with an LED arranged thereon, which is supplied with electricity via connecting conductors 18 and is arranged on a heat sink 19.

[0025] A mounting device designated overall by reference number 20 serves to arrange the cooking appliance light 10 on a cooking appliance.

[0026] Figure 2shows the light source-side end of the cooking appliance light 10 in an exploded view. This first shows that the mounting device 20 has a mounting plate 21 in which a mounting cup 22 is arranged. For this purpose, bearing shells 23 are provided on the side of the mounting plate 21, into which pivoting axis stubs 24 are seated, so that the mounting cup 22 is pivotally seated in the mounting plate 21. The mounting cup 22 accommodates the circuit board 17 and holds the heat sink 19. On the other hand, the mounting cup 22, as part of the mounting device 20, has a hollow cylindrical socket 25. The light guide rod 13 dips into the hollow cylindrical socket 25 and is secured there by means of a retaining clip 26.

[0027] The light box end of the cooking appliance light 10 is shown as an enlarged exploded view in Figure 3shown. The light box 11 forms a reflector chamber 27, which is either provided with reflective surfaces or can accommodate reflector means. Light introduced into the light box 11 can be fed into a cooking appliance via a light exit opening 28, wherein the light exit opening 28 can be closed with a cover glass 29 to protect the reflector chamber 27. An insertion opening 30 of the light box 11 is flanked by two retaining tongues 31. The centering member 15 is designed as a centering sleeve, which Figure 3surrounds the light guide rod 13 (not shown). The centering member 15 has locking means 32 in the form of a circumferential locking lip 33 at its end facing the reflector chamber 27. The end facing away from the reflector chamber 27 forms an annular wall 34, which serves as a means of arranging the protective tube 14, which can be pushed onto the annular wall 34 with frictional engagement around its outer circumference. A stop disc 35 limits the sliding path of the protective tube 14 onto the annular wall 34.

[0028] The Figures 4 and 5 now show the assembled cooking appliance light 10 in view of the light exit opening 28 of the light box 11 ( Figure 4 ) or on its back wall ( Figure 5 ).

[0029] Both figures show that the protective tube 14 extends between the light box 11 and the mounting device 20 with the light source 16 arranged there, thus distancing the light source 16 from the light box 11 and its reflector space 27. In particular, based on Figure 4 It can be seen that the light guide rod 13 penetrates from the protective tube 14 and through the centering member 15 into the reflector space 27 of the light box 11 and otherwise extends to the light source 16 and is arranged within the protective tube 14.

[0030] By means of the light guide rod 13, the light emitted by the light source 16 is fed into the light box 11, so that from there it can be guided out of the light exit opening 28 via reflectors and thrown into a cooking chamber 40.

[0031] Figure 6 shows once again an enlarged detail of the lower end of the cooking appliance light 10 according to Figure 4. In particular, it can be seen once again how the light guide rod 13 is mounted in the centering member 15 and sits in the reflector space 27 of the light box 11.

[0032] Figure 7 shows a sectional view along line VII - VII in Figure 6 .

[0033] Based on Figure 7 The centering element 15 will now be described in detail in terms of its structure and function. The partial representation of the cooking appliance light 10 according to Figure 7 shows a section of the protective tube 14 and the light guide rod 13. The light guide rod 13 is immersed in the reflector chamber 27 of the light box 11. The light exit opening 28 is closed by the cover glass 29.

[0034] The centering member 15 is a sleeve component which, at its end facing the light box 11 or the reflector chamber 27, is provided with a locking lip 33 which engages behind the retaining tongues 31 of the light box 11. In this way, the centering member 15 is protected against being pulled out of the light box 11. Furthermore, the centering member 15, with its stop disk 35 arranged radially around the sleeve component, sits on the outside of the wall forming the light box 11 and is thus secured against further insertion into the light box 11 or the reflector chamber 27.

[0035] It can therefore be stated first of all that the centering member 15 can be fixed to the light box 11 in a particularly simple manner by inserting it into an insertion opening 30 in the light box wall until the stop disc 35 limits the insertion path and at the same time the locking lip 33 engages behind the retaining tongues 31 of the light box 11.

[0036] Figure 7 It can then be seen that the centering member 15 holds the light guide rod 13 in its hollow cylindrical interior and securely spaced it from the wall of the protective tube 14 via a circumferential gap 36. Contact between the light guide rod 13 and the protective tube 14, which would lead to light being coupled out of the light guide rod 13 and could possibly also damage the light guide rod 13, is reliably prevented by the centering member 15. Furthermore, the centering member 15 securely holds the light guide rod 13 on the light box 11.

[0037] The centering member 15 has in its Figure 7In the specifically illustrated embodiment, the centering member 15 also has a sealing function. This is ensured, on the one hand, by the sleeve's inner wall fitting against the light guide rod 13 in an essentially gap-free manner. In addition, the centering member 15 has at least one, in the exemplary embodiment actually two, sealing lips 41 running around the inside and pointing towards the light guide rod 13, which sealing lips bear against the outer circumferential surface of the light guide rod 13. The sealing lips 41 have the advantage, on the one hand, of being able to compensate for any dimensional and manufacturing tolerances. In addition, it is fundamentally possible to produce the centering member 15 using a two-component injection molding process and thus to mold elastic sealing lips 41 onto a body otherwise made of plastic, thus realizing the sealing function.

[0038] It is also theoretically conceivable to manufacture the centering member 15 from a ceramic or metallic material and to apply elastic sealing lips 41 around its inner circumference.

[0039] The formation of the centering member 15 from a thermally poorly conductive material such as plastic or ceramic is preferred, since in this way a thermal decoupling between the light guide rod 13 and the light box 11 can be realized.

[0040] The centering member 15 also has an axially directed annular wall 34 pointing away from the centering box 11, which originates from the stop disc 35 and is received by the light box-side end of the protective tube 14. The protective tube 14 encloses the annular wall 34 at least frictionally and is thus secured to the light box 11. A positive connection via locking means or locking contours for additional securing of the protective tube 14 on the centering member 15 is conceivable.

[0041] The light box-side end face of the protective tube 14 rests against the stop disk 35, which thus limits the sliding path of the protective tube 14 onto the annular wall 34. At the same time, the stop disk 35 distances the protective tube 14 from the light box wall, so that the centering member 15—if made of a suitable material—thermally decouples the protective tube 14 from the light box 11.

[0042] The annular wall 34 can also seal the circumferential gap 36 from the external environment by means of suitable sealing contours or a corresponding choice of material, by resting against the protective tube 14 without a gap. This prevents fluids or foreign bodies from penetrating the circumferential gap 36.

[0043] The sealing function of the centering element 15 is one of the preferred properties because the entry of foreign bodies or cooking vapors into the annular gap 36 can lead to particles adhering to the light guide rod 13. This results in light being extracted from the light guide rod 13, which reduces the overall efficiency of the cooking appliance light 10.

[0044] Figure 8 now schematically shows the arrangement of the cooking appliance light 10 according to the invention on a cooking chamber wall 37 of a cooking appliance 38. The cooking chamber wall 37 has a wall cutout 39 in which the light box 11 is held, wherein the light exit opening 28 of the light box 11 faces the cooking chamber 40 of the cooking appliance 38. In this way, light from the cooking appliance light can be supplied to the cooking chamber 40 through the light exit opening 28 and its cover glass 29.

[0045] On the outside of the cooking chamber, the protective tube 14 with the internal light guide rod 13 is guided along a cooking chamber side wall (not further designated) and is held in the mounting device 20 at its end facing away from the light box 11.

[0046] The mounting device 20, in turn, is attached to a suitable counterpart of the cooking appliance 38. In this way, the cooking appliance light 10 is securely arranged and held in the cooking appliance 38, with the light source 16 sufficiently spaced and optimally thermally decoupled, among other things, by the centering member 15. Excessive thermal stress on the light source 16 due to the heat generated in the cooking chamber 40 is thus reliably avoided.

[0047] Overall, the invention provides a cooking appliance light 10 that is advantageously configured with a centering member 15. In addition to centering the light guide rod 13 in the protective tube 14, the centering member 15 performs a variety of other important functions, thus combining a series of previously separate components. Thus, the centering member 15 serves to hold the light guide rod 13 and the protective tube 14 on the light box 11; it serves to thermally decouple both the light guide rod 13 and the protective tube 14 from the light box 11. Furthermore, the centering member 15 performs a sealing function with respect to both the protective tube 14 and the light guide rod 13, protecting the light guide rod 13 seated in the protective tube 14 from contamination, the resulting light extraction, and the resulting reduction in efficiency. List of reference symbols

[0048] 10 Cooking appliance light 11 Light box 12 Cover glass 13 Light guide rod 14 Protective tube 15 Centering element 16 Light source 17 Circuit board 18 Connecting conductor 19 Heat sink 20 Mounting device 21 Mounting plate 22 Mounting pot 23 Bearing shell 24 Swivel axle stub 25 Hollow cylindrical socket 26 Retaining clip 27 Reflector chamber 28 Light outlet opening 29 Cover glass 30 Insertion opening 31 Retaining tongue 32 Locking means 33 Locking lip 34 Ring wall 35 Stop disc 36 Circumferential gap 37 Cooking chamber wall 38 Cooking appliance 39 Wall cutout 40 Cooking chamber 41 Sealing lips

Claims

1. Cooking device light (10), in particular light for ovens, microwave cooking devices or steam cookers, - having a light source (16) in the form of a printed circuit board (17) with an LED arranged on it, - having a light box (11), into which the light emitted by the LED is fed, - having a light guide rod (13), which is arranged between the light source (16) and the light box (11) and guides the emitted light from the LED to the light box (11), - having a protective tube (14), which is also arranged between the light box (11) and the light source (16) and surrounds the light guide rod (13) in a protective manner, - having a peripheral gap (36) between the light guide rod (13) and the protective tube (14), such that the light guide rod (13) is held without touching the protective tube (14), - having a mounting device (20), which supports the light source (16) and holds a first end both of the protective tube (14) and of the light guide rod (13), - having at least one centring member (15), which surrounds the light guide rod (13) and arranges the light guide rod (13) in the protective tube (14) while maintaining the peripheral gap (36), - having at least one arranging means, which fixes the protective tube (14) and the light guide rod (13) on the light box (11), wherein - the centring member (15) forms an arranging means, by means of which the light guide rod (13) is arranged on the light box (11), characterised in that - the centring member (15) is formed as a centring sleeve, in which the light guide rod (13) rests, - the light box (11) has an insertion opening (30), which receives the centring member (15), - the centring member (15) also forms the arranging means for fixing the protective tube (14) on the light box (11).

2. Cooking device light (10) according to claim 1, characterised in that the centring member (15) is a sleeve-like sealing element, which seals the peripheral gap (36) between the light guide rod (13) and the protective tube (14) with respect to a chamber formed by the light box (11).

3. Cooking device light (10) according to claim 1, characterised in that the centring member (15) supports latching means (32), in particular an outer peripheral latching lip (33), with which the centring member (15) and the insertion opening (30) of the light box (11) latch.

4. Cooking device light (10) according to claim 1, characterised in that the centring member (15) forms an annular wall (34), which rests in the protective tube (14) for fixing on the light box (11) and holds the protective tube (14) at least in a frictionally engaged manner.

5. Cooking device light (10) according to claim 3 and 4, characterised in that the latching means (32) and the annular wall (34) are arranged on opposite ends of the centring member (15).

6. Cooking device light (10) according to one of the preceding claims, characterised in that the mounting device (20) forms a hollow cylindrical connecting piece (25), in the cylinder chamber of which the light guide rod (13) is held and whose cylinder wall is received by the protective tube (14) at least in a frictionally engaged manner.

7. Cooking device (38) - having a cooking chamber (40), which is surrounded by a cooking chamber wall (37), - having an opening in the cooking chamber wall (37), which serves to receive a cooking device light (10), - having a cooking device light (10) according to one of claims 1 to 6, characterised in that the light box (11) is arranged at the opening of the cooking device wall (37), and the protective tube (14) is guided along the cooking chamber wall (37) outside the cooking chamber (40).