EP3527896A1 - Telescopic rail for a microwave oven - Google Patents

Abstract

The invention relates to a telescopic rail (1, 1 ') for a microwave oven (1) with at least a first rail element (4) made of an electrically conductive material and a second rail element (2) made of an electrically conductive material, the first and the second Rail element (2, 4) each have two running surfaces, at least the first rail element (4) having a back section (6) connecting the two running surfaces, with rolling elements (4) accommodated in a rolling body cage (13) on the two running surfaces of the first rail element (4). 11) and are arranged on the two running surfaces of the second rail element (2) in a roller body cage (12) housed rolling elements (11), and wherein the first and the second rail element (2, 4) against each other between a retracted position and an extended position an extension direction (28) can be moved. In order to shield the rail elements and possibly the rolling element cages and the rolling elements from microwave radiation, it is proposed according to the invention that the first rail element (2) has a shielding element (14) which is moved with the first rail element (2) and is made of a material which is non-transparent to microwave radiation from the microwave oven, wherein the shielding element (14) has a connecting section (15) which extends substantially parallel to the back section (6) of the first rail element (4) and a first leg section (17) and a second leg section (18), so that the shielding element (14) engages around the first and the second rail element (2, 4) with a substantially U-shaped cross-section, the connecting section (15), the first leg section (17) and the second leg section (18) having a length in the pull-out direction ( 28), so that the shielding element (14) in the retracted position is the first and the second rail element (2, 4) covers its entire length in the pull-out direction (28), and the shielding element (14) has a curved first transition section (20) connecting the connecting section (15) and the first leg section (17) ,

Description

The present invention relates to a telescopic rail having at least one first rail element of an electrically conductive material and a second rail element made of an electrically conductive material, wherein the first and the second rail element each have two running surfaces, wherein received on the two running surfaces of the first rail element in a Wälzkörperkäfig Rolling elements are arranged and arranged on the two running surfaces of the second rail member in a rolling element cage rolling elements are arranged, and wherein the first and the second rail element against each other between a retraction position and a pull-out position along a pull-out direction are movable.

Telescopic rails with at least two rail elements and a rolling element cage with rolling elements accommodated therein for reducing the friction between the rail elements during an extension movement are known in various embodiments from the prior art. They are used in various household appliances but also in the automotive industry and in many other applications.

While a variety of applications can already be addressed with the known telescopic rails, telescopic rails have not been able to establish in microwave ovens so far. If a telescopic rail is produced whose rail elements are made of an electrically conductive material, in particular of a metal sheet, the microwave radiation impinging on the telescopic rail during operation of the microwave oven leads to a local charging of the rail elements and to a sufficiently large potential difference between the individual rail elements a spark discharge between them.

To avoid a spark discharge, for example, from the EP 2 988 068 A1 , Constructions known in which the rail elements by the formation of sufficiently large and electrically insulating rolling elements have a sufficiently large distance from each other. However, these telescopic rails have a very large installation dimension.

Therefore, there is a need for a telescopic rail which at least partially avoids the aforementioned disadvantages.

Therefore, the invention proposes to design a telescopic rail of the type mentioned above for a microwave oven in such a way that the first rail element has a shielding element moving with the first rail element from a material which is intransparent for microwave radiation of the microwave oven, the shielding element having a connecting section which is substantially parallel extends to the back portion, has a first leg portion and a second leg portion, so that the shielding member surrounds the first and the second rail member having a substantially U-shaped cross section, wherein the connecting portion, the first leg portion and the second leg portion has a length in the extension direction so that the shielding member in the retracting position covers the first and second rail members over their entire length in the extension direction, and wherein the shielding member exposes the connecting rod has cut and the first leg portion connecting, curved first transition section.

The energy of the microwave radiation within the furnace muffle of a microwave oven is partially reflected and partially absorbed by all metallic surfaces. The absorption of the microwave radiation leads to a heating and as described above to an electrical charge of the metallic parts. The labyrinth-like geometries of telescopic rails have proved to be critical. The electromagnetic microwave radiation is reflected back and forth between the individual elements of a telescopic rail made of an electrically conductive material until it is finally completely absorbed by one of the elements of the telescopic rail. The aim of the present invention is therefore to shield the rail elements and optionally the Wälzkörperkäfige and the rolling elements from the microwave radiation. This task is performed by the shielding element according to the invention.

Decisive for the function of the shielding element is the need for the shielding element to cover the first and the second rail element over their entire length during operation of the microwave oven. For this purpose, the shielding element has a length in the extension direction, so that the shielding element completely covers the two rail elements in the pull-in position. Microwave ovens can usually only be put into operation when the door of the microwave oven is closed. Only then can the electromagnetic microwave radiation act on the telescopic rail. However, closing the door presupposes that the rail elements of the telescopic rail no longer protrude beyond the muffle of the microwave oven. Therefore, the shielding element is arranged on the first rail element in such a way that it is moved along with it during a pull-out movement of the first rail element. In one embodiment of the invention, the shielding element is a part made separately from the first rail element, which is then connected to the first rail element. In this case, the connection between the shielding element and the first rail element can be released be designed. In one embodiment, however, the shielding element, for example by welding, is firmly connected to the first rail element.

The shielding element obtains its effectiveness as a shielding of the first and the second rail element from the microwave radiation in the furnace muffle by its geometry in a cross section perpendicular to the extension direction. The shielding element is designed such that it surrounds the first and the second rail element with a substantially U-shaped cross-section (in a cross-sectional plane perpendicular to the extension direction). In this case, the shielding member has a connecting portion which extends substantially parallel to the back portion of the first rail member. In one embodiment, the shielding element is connected at its connecting portion with the back portion of the first rail element.

When installed, the first and the second leg section then extend, starting from the connecting section, in the direction of the oven muffle. In one embodiment of the invention, the first leg section and the second leg section are substantially perpendicular to the connecting section.

In one embodiment of the invention, the surface of the connecting portion of the shielding member facing away from the first rail member is a flat extended surface. Such reflects the microwave radiation in an advantageous manner. Similarly, in one embodiment of the invention, the surfaces of the first leg portion and the second leg portion facing away from the first rail member have planar extended surfaces to provide good reflection of the microwave radiation.

For the shielding effect of the shielding element, it is crucial that the shielding element has a material which is intransparent for the microwave radiation of the microwave oven. Such opaque materials absorb or preferentially reflect the microwave radiation.

In one embodiment of the invention, the microwave radiation of the microwave oven has a frequency of 2.4 GHz. It is understood that in such an embodiment, the shielding element comprises a material which is opaque to microwave radiation at a frequency of 2.4 GHz.

Examples of materials that are opaque to the microwave radiation of a microwave oven are metals and materials such as glass, in which metallic materials are embedded.

In one embodiment of the invention, at least the surfaces of the shielding element pointing away from the first and second rail elements, preferably a shielding element made of metal, are provided with a coating, for example an easy-to-clean coating, a coating with SiO ₂ or a ceramic.

In a further embodiment of the invention, the shielding element is made of a solid sheet metal without perforations in the material or with only a small number of openings.

For the purposes of the present application, the pull-in position is understood to mean the position of the first and the second rail element relative to one another, in which the telescopic rail is completely inserted. Typically, the retraction position is characterized by the achievement of an end stop.

If in the sense of the present application of a telescopic rail is mentioned, this term is to be understood in such a general way that not only rails are included, in which the first rail element and the second rail element have approximately the same length, but also linear guides, in which the first rail element is significantly shorter than the second rail element. Even in such an embodiment, the shielding element covers the first rail element and the second rail element in the pull-in position over their entire length in the extension direction.

If it is stated in the present application that the telescopic rail according to the invention has a first rail element and a second rail element, this does not exclude that the telescopic rail comprises further rail elements, in particular for providing a full extension.

For the purposes of the present application, the first rail element of the telescopic rail according to the invention is the moving rail element which receives the food support in the installed state of the telescopic rail and is pulled out of the oven muffle relative to the second rail element and optionally one or more further rail elements. In this case, in the installed state of the telescopic rail, the first leg portion of the shielding element of the upper leg portion and this takes in one embodiment, the food support.

In the context of the present application, a rolling element is understood to mean a rotary body which, as an element of a guide, is the friction between the various rail elements considerably reduced and thus facilitates a relative movement of two rail elements to each other. Rolling elements are, for example, balls, rollers, barrels, needles or cones. In one embodiment of the present invention, the rolling elements are balls. It is understood that in this case the rolling element cage is a ball cage. In particular, in one embodiment of the invention, the rolling elements may be made of an electrically conductive material, for example of steel.

In one embodiment of the invention, the first rail element and / or the second rail element and / or the shielding element are made of a material which is selected from a group consisting of sheet steel, aluminized steel sheet and stainless steel.

It is understood that in an embodiment of the invention in which the shielding element is formed from a sheet metal material, all elements or sections of the shielding element can be produced by corresponding bending or bending of a sheet metal section previously cut to the corresponding dimension.

In one embodiment of the invention, the shielding element is made of a ferritic steel. Ferritic steel has less heating than austenitic steel under the action of microwave radiation.

In a further embodiment of the invention, the first rail element, the second rail element and the shielding element are made of an austenitic steel. Austenitic steel leads to improved corrosion resistance.

In one embodiment of the invention, at least the first rail element or the second rail element has two legs, which form the running surfaces for the rolling elements, and a back section connecting the two legs.

It has been found that, for the function of the shielding element as a shield for the microwave radiation, the design of a first transition section, which connects the connecting section and the first leg section of the shielding element, is of crucial importance. In the region of this transition section, increased heating and electrical charging of the shielding element occurs. Only the inventive design of the transition section with a curved in cross-section perpendicular to the extension direction shape causes a reflection of the microwave radiation in this transition section.

In one embodiment, the first transition section has a radius of curvature of 4 mm or more, preferably 5 mm or more and particularly preferably 6 mm or more.

Due to the geometry of the furnace muffle and the arrangement of a typical microwave source relative to the telescopic rails already causes the inventive design of the first transition section between the connecting portion and the first leg portion, i. the transition section to the upper leg portion in the installed state of the telescopic rail, a strong reduction of the electrical charge of the telescopic rail.

However, in one embodiment of the invention, in addition, the shielding member is configured to have a curved second transition portion connecting the connecting portion and the second leg portion, the second transition portion having a radius of curvature of 4 mm or more, preferably 5 mm or more, and more preferably of 6 mm or more.

In one embodiment of the invention, the first leg portion, the second leg portion and the connecting portion of the shielding element are formed by planarized members and the first and second transition portions are formed by portions adjacent to these surface portions in a cross-sectional plane perpendicular to the extension direction.

In order to achieve the best possible shielding effect, in one embodiment of the invention, the first leg portion and the first transition portion together have a depth in a direction perpendicular to the extension direction which is substantially equal to the depth of all the rail members together in the direction perpendicular to the extension direction. wherein preferably the second leg portion and the second transition portion together have a depth in the direction perpendicular to the extension direction which is substantially equal to the depth in the direction perpendicular to the extension direction of all rail members. In this way, the rail elements are completely enclosed on three sides thereof by the shielding element.

In a further embodiment of the invention, the shielding member at a front end in the extension direction has a cover portion extending substantially perpendicular to the connection portion, the cover portion having a surface substantially all of the connection portion and the first and the second leg portion defined cross-section of the shielding covers.

It is understood that the cover portion is arranged in an installed state of the telescopic rail at the end facing the door of the microwave oven towards the end of the first rail element. This cover section prevents the entry of microwave radiation into the area between the rail elements from the door of the microwave oven. The cover section thus completes the shielding effect of the shielding element. In addition, the cover portion may have a projection with respect to an upper surface of the first leg portion, so that the cover also serves as a front stop for a food support.

It is important to largely reduce gaps between the first and second leg portion and the first and second transition portion and the cover. Therefore, in one embodiment of the invention, the shielding element has a curved third transition section connecting the connecting section and the cover section, this third transition section having a radius of curvature of less than 6 mm, preferably less than 5 mm and more preferably less than 4 mm. It has been found that a small radius of curvature of the third transition section has a greater effect than a reduced reflection on the fourth transition section with a large radius of curvature by associated closing of any gaps through which the microwave radiation can enter the region of the rail elements this place.

In a further embodiment of the invention, the shielding element at a rear end in the extension direction of the first leg portion a Gargutträgeranschlag, wherein the Gargutträgeranschlag extends substantially perpendicular to the first leg portion. As a result of this configuration of the shielding element with a food support stop perpendicular to the first leg section, a corresponding design of the first rail element can be dispensed with.

The Gargutträgeranschlag projects relative to the shielding, in particular with respect to the first leg portion of the shielding, and therefore unfolds an antenna effect for the microwave radiation of the microwave oven. Therefore, it is important to design the Gargutträgeranschlag reflective as possible for the microwave radiation. This is achieved by a curved outer contour with a preferably large radius of curvature. Therefore, the Gargutträgeranschlag in one embodiment of the invention has a curved outer contour, wherein preferably the radius of curvature of the outer contour is 4 mm or more, preferably 5 mm or more and more preferably 6 mm or more.

In one embodiment of the invention, the product support stopper has a depth in a direction perpendicular to the extension direction, which is at least equal to 2/3 of the depth of the first leg portion in the direction perpendicular to the extension direction. Preferably, however, the depth of Gargutträgeranschlags in the direction perpendicular to the extension direction equal to the depth of the first leg portion in the direction perpendicular to the extension direction.

In one embodiment of the invention, the shielding member has a connected to the first leg portion or with the second leg portion, extending substantially parallel to the connecting portion rear portion. This rear portion surrounds the rail members and forms a wall portion of the shield member on a fourth side.

In this case, has proved to be particularly useful an embodiment in which the rear portion is connected to the first leg portion and the first rail member has a greater distance from the first leg portion of the shield than the second rail member. In this way, the rear portion closes the volume not covered by the back portion of the second rail member within the shield member.

In an alternative embodiment, the first rail element has a smaller distance from the first leg section of the shielding element than the second rail element, wherein in this embodiment preferably no rear section connected to the second leg section is provided.

It is understood that in one embodiment of the invention the shielding element has a fourth transition section connecting the first or the second leg section to the rear section. In one embodiment, the fourth transitional section is again curved and has a large radius of curvature, preferably a radius of curvature of 4 mm or more, more preferably 5 mm or more, and most preferably 6 mm or more.

In one embodiment of the invention, the telescopic rail is configured such that the first rail element has at least one electrically conductive contact element and the second rail element has at least one electrically conductive contact element, wherein the contact element of the first rail element and the contact element of the second rail element configured and on the rail elements are arranged that in the retraction position, either the contact element of the first rail element and the contact element of the second rail element are in engagement with each other or that the contact element of the first rail element and the contact element of the second rail element each with a with the Wälzkörperkäfig mitbewegten electrically conductive guide element are engaged, so that in the retracted position there is an electrically conductive connection between the first and the second rail member.

Such an embodiment causes an equipotential bonding of at least one rail element which is exposed to the microwave radiation. It is initially irrelevant whether the resulting local charges drain on an immediately adjacent rail element or another rail element. In the case of a full extension with three rail elements, the charges can alternatively flow onto the middle rail element or onto the inner rail element. It has been found that such contact elements in the retraction position can not only effectively prevent sparking between edges and tips of adjacent rail elements, but also a punctual flow of current through the rolling elements of the telescopic rail. The latter proves to be particularly advantageous because punctual currents, which flow over the points of contact of the rolling elements with the running surfaces of the rail elements, can lead to damage of the rolling elements and the running surfaces and beyond lubricant in the vicinity of the rolling elements can be destroyed by thermal influence ,

The combination of the provision of an equipotential bonding and a shielding element has proven to be particularly advantageous in the case of telescopic rails whose rail elements are made of an austenitic steel.

In one embodiment, in at least one position other than the retraction position, the contact element of the first rail element and the contact element of the second rail element are not engaged with each other, or at least the contact element of the first rail element or the contact element of the second rail element are not engaged with the guide element in the at least one other position, the electrically conductive connection is interrupted. Decisive for this embodiment of the invention is the recognition that the mechanical engagement and thus the direct electrically conductive connection between the contact elements are required only in the inserted state. Closing the door of a microwave oven requires that the rail elements of the telescopic rail no longer project beyond the muffle of the microwave oven. The contact elements according to the invention provide in this embodiment, at least in a different than the retraction position, no electrically conductive connection, i. the electrically conductive connection is then interrupted.

In the sense of the present application, an engagement between the contact element of the first rail element and the contact element of the second rail element is understood to be a direct mechanical contact of its surfaces, which is such that an electric current between the contact elements and the engagement point, ie via the contact point between the two contact elements, can flow.

It is understood that the contact elements are electrically conductively connected to the rail elements in order to provide the potential equalization can. In one embodiment, at least one of the contact elements is formed integrally with the respective rail element.

In one embodiment, at least one of the contact elements is formed by a projection on the first or second rail element. It is expedient if the projection in the extension direction has a greater extent than in a direction perpendicular to the extension direction. A greater extension of the projection in the extension direction than in a direction perpendicular to the extension direction ensures the function of the contact elements, even if the telescopic rail is not fully retracted, i. in the retraction position.

In a further embodiment of the invention, the contact element of the first rail element is formed by a projection and the contact element of the second rail element is formed by a projection, wherein the projection on the first rail element in the extension direction has a greater extent than in a direction perpendicular to the extension direction and wherein the projection on the second rail element in the extension direction has a smaller extent than in the direction perpendicular to the extension direction. Arranged crosswise to each other on the two rail elements, elongated projections as contact elements capable of compensating the tolerances of the profiles of the rail elements and the assembly. In one embodiment, the tolerance chain to be taken into consideration also includes the dimensions of the construction space of a household appliance, in particular the muffle of a microwave oven, and the door closing it.

In one embodiment of the invention, the telescopic rail provides a full extension, wherein the telescopic rail has two outer rail elements and a middle rail element and wherein the projection is provided with the expansion in the greater extension than the extension in the direction perpendicular to the extension direction of the middle rail element.

In one embodiment of the invention, the contact elements are exclusively in the pull-in position, i. upon reaching the end stop with each other or both with the guide element in engagement.

One of the aforementioned objects is also achieved by a microwave oven having a telescopic rail in an embodiment thereof as previously described.

In one embodiment of the invention, the shielding element has a distance from a side wall of a furnace muffle of the microwave oven of 5 mm or more.

In one embodiment of the invention, the lengths of the rail elements of the telescopic rail are chosen so that it is in the retracted position or in an only partially extended position with the door closed of the microwave oven.

In one embodiment, the microwave oven has a source of microwave radiation having a frequency of about 2.4 GHz.

Figur 1

zeigt eine perspektivische Ansicht einer Ausführungsform einer erfindungsgemäßen Teleskopschiene in der Einzugsposition.

Figur 2

zeigt eine Draufsicht auf die Stirnseite der Teleskopschiene aus Figur 1.

Figur 3

zeigt eine Querschnittsansicht der Teleskopschiene aus Figur 1 in einer Ebene senkrecht zu der Auszugsrichtung.

Figur 4

eine Querschnittsansicht einer alternativen Ausführungsform einer Teleskopschiene gemäß der vorliegenden Erfindung in einer Ebene senkrecht zu der Auszugsrichtung.

Further advantages, features and possible applications of the present invention will become apparent from the following description of embodiments of the telescopic rail according to the invention and the associated figures.

FIG. 1

shows a perspective view of an embodiment of a telescopic rail according to the invention in the retraction position.

FIG. 2

shows a plan view of the front side of the telescopic rail FIG. 1 ,

FIG. 3

shows a cross-sectional view of the telescopic rail FIG. 1 in a plane perpendicular to the extension direction.

FIG. 4

a cross-sectional view of an alternative embodiment of a telescopic rail according to the present invention in a plane perpendicular to the extension direction.

In the figures, like elements are designated by like reference numerals.

Both telescopic rails 1, 1 'according to FIGS. 1 to 3 on the one hand and according to FIG. 4 On the other hand, each have three rail elements 2, 3, 4. The telescopic rails 1, 1 'are therefore both full extensions, ie a food support accommodated on them can be pulled out over a length of the oven muffle of a microwave oven, which is at least equal to the length of the food support in the extension direction.

For the purposes of the present application, the rail element shown in the two embodiments, which can be completely pulled out, as the first rail element 4, while the rail element designated 2 forms the second rail element. The second rail element 2 is in the illustrated embodiment, directly or indirectly connected to the muffle of the microwave oven and therefore forms the stationary rail element. Between the first rail element 4 and the second rail element 2, a further, third rail element 3 is arranged, which forms the middle rail element of the full extension. The first rail element 4 and the second rail element 2 each consist of a back section 5, 6 and two legs 7, 8 and 9, 10. The inner surfaces of the legs 7, 8, 9, 10 each form the running surfaces of the rail elements 2, 4. The third, middle rail element 3, in contrast, has four running surfaces which respectively point outwards. Between the running surfaces of the second rail element 2 and two running surfaces of the middle rail element 3 and between the running surfaces of the first rail element 4 and two further running surfaces of the middle rail element 3 balls 11 are arranged as rolling elements. The balls 11 are guided in ball cages 12, 13, which extend between the rail elements 2, 3, 4.

The rail elements are designed so that they are in the in FIG. 1 shown pull-in position provide electrically conductive contacts, so that a potential equalization between the three rail elements 2, 3, 4 can be done. In this way, the probability of a sparkover, in particular at corners and edges of the rail elements 2, 3, 4 and the ball cages 12, 13 is reduced. Such potential differences between the rail elements 2, 3, 4 may occur when the telescopic rail 1, 1 'arranged in the muffle of a microwave oven is exposed to the microwave radiation. In addition, it must be prevented by the electrically conductive contacts that there is a substantially punctiform flow of current through the balls 11 between the rail elements 2, 3, 4.

However, it has been found that, in particular, depending on the metal used for the production of the rail elements 2, 3, 4, the electrically conductive contacts between the rail elements may not be sufficient to completely prevent a sparking or a current flow over the balls 11. Therefore, the telescopic rails 1, 1 'according to the embodiments of the present invention additionally comprise a shielding element 14 made of sheet metal. This completely surrounds the rail elements 2, 3, 4 in the pull-in position on at least four sides thereof.

For this purpose, the shielding element 14 has a just extended connecting section 15 extending parallel to the back section 6 of the first rail element 4. In the cross-sectional view FIG. 3 It can be seen that the connecting portion 15 viewed in a plane perpendicular to the extension direction 28 substantially from a portion of a straight line is formed. On the upper or lower side, the shielding element has a first leg section 17 and a second leg section 18. These extend in the illustrated embodiment perpendicular to the connecting portion 15. On the surface 19 of the first leg portion 17 of the food support is receivable.

As the cross-sectional view FIG. 3 can be seen, the first and second leg portions 17, 18 extend in cross section in the form of straight sections and just form extensive outer surfaces (16, 19, see FIG. 1 ). The connecting section 15 is connected, on the one hand, to the first leg section 17 via a first curved transition section 20 and, on the other hand, to the second leg section 18 via a second curved transition section 21. In the cross-sectional view FIG. 3 in the plane perpendicular to the extension direction 28, both transition sections 20, 21 as part of a circular arc, here quarter circle arches, recognizable. Decisive for the mode of operation of the shielding element as an effective reflector for the microwave radiation of the microwave oven is now that the transition sections 20, 21 have a large radius of curvature, in the illustrated embodiments of the figures a radius of curvature of 6 mm.

For the effective shielding of the rail elements 2, 3, 4 from the microwave radiation, it is also important that the leg portions 17, 18 together with the transition portions 20, 21 have a depth in a direction 22 perpendicular to the extension direction 28, which is approximately the depth all three rail elements 2, 3, 4 in the assembled state in the direction 22 corresponds. In this way, the rail elements 2, 3, 4 are completely shielded.

When installed, the first and second leg portions 17, 18 of the shielding member 14 have a minimum distance from the side wall of the furnace muffle of 5.5 mm.

In the in the FIGS. 1 to 3 In the embodiment shown, the first rail element 4 is arranged below the second rail element 2. In this way, the back section 5 of the second rail element 2 closes off the space formed by the shielding element 14 in the upper half of the telescopic rail in the direction of the side wall of the oven muffle out. The back portion 5 prevents at this point an entry of microwave radiation in the area between the rail elements 2, 3, 4 and shields the interior of the shielding element 14 from the rear ..

Alternatively, it is possible to arrange the second rail element 2 below the first rail element 1, as in the embodiment according to FIG FIG. 4 is shown. In this embodiment, the one of the leg portions 17, 18 and the connecting portion 15 defined space of the telescopic rail 1 'by an additional rear portion 23 in the upper half of the telescopic rail 1' shielded.

In both embodiments discussed here, the first, in the installed state upper leg portion 17 of the shielding element 14 at the rear end 24 of the telescopic rail 1, 1 'in the extension direction 28 a Gargutträgeranschlag 25 on.

The Gargutträgeranschlag 25 acts for the microwave radiation in the microwave oven as an antenna and therefore basically leads both to increased heating of the telescopic rail 1 in this area as well as to increased electrical charge. To minimize this effect, the Gargutträgeranschlag 25 has a width which is equal to the width of the first leg portion 17 in the direction 22 perpendicular to the extension direction 28. In addition, the outer contour 26 is curved with a large radius of curvature. In the illustrated embodiment, the outer contour 26 is semi-circular arc with a radius of curvature of 5 mm.

Both embodiments of the telescopic rails 1, 1 'also have an end-side cover section 27, which shields the end face of the rail elements 2, 3, 4. For this purpose, the cover section 27 has a surface which is approximately as large as the cross-sectional area which is spanned by the back section 5 of the second rail element 2 and by the leg sections 17, 18 and the connecting section 15 of the shielding element 14. In order to close any gaps between the cover section 27 on the one hand and the end faces of the first and second leg sections 17, 18 and the end faces of the first and second transition sections 20, 21, the third transition section 29 is designed with a small radius of curvature, here of 4 mm.

The cover portion 27 also forms by its projection relative to the surface 19 of the first leg portion 17 a front Gargutträgeranschlag for receiving a food support between the rear Gargutträgeranschlag 25 and the cover 27th

For purposes of the original disclosure, it is to be understood that all such features as will become apparent to those skilled in the art from the present description, drawings, and claims, even if concretely described only in connection with certain other features, both individually and separately any combinations with other of the features or feature groups disclosed herein can be combined, unless this has been expressly excluded or technical conditions such combinations make impossible or pointless. On the comprehensive, explicit representation of all conceivable combinations of features is omitted here only for the sake of brevity and readability of the description.

While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description is exemplary only and is not intended to limit the scope of the protection as defined by the claims. The invention is not limited to the disclosed embodiments.

Variations of the disclosed embodiments will be apparent to those skilled in the art from the drawings, the description and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are claimed in different claims does not exclude their combination. Reference signs in the claims are not intended to limit the scope of protection.

LIST OF REFERENCE NUMBERS

1, 1 '

telescopic rail

2

second rail element

3

middle, third rail element

4

first rail element

5

Back section of the second rail element 2

6

Back section of the first rail element 4

7, 8, 9, 10

Legs of the first and second rail elements 2, 4th

11

Bullet

12, 13

ball cage

14

shielding

15

Connecting portion of the shielding 14th

16

Outer surface of the second leg portion 18th

17

first leg portion of the shielding element 14

18

second leg portion of the shielding 14th

19

Outer surface of the first leg portion 17

20

first transitional section

21

second transitional section

22

Direction perpendicular to the extension direction 28th

23

rear section

24

rear end of the telescopic rail

25

Gargutträgeranschlag

26

outer contour

27

cover

28

extraction direction

29

third transitional section

Claims (15)

Telescopic rail (1, 1 ') for a microwave oven (1) with
at least one first rail element (4) made of an electrically conductive material and
a second rail element (2) made of an electrically conductive material,
wherein the first and the second rail element (2, 4) each have two running surfaces, wherein at least the first rail element (4) has a back section (6) connecting the two running surfaces,
wherein on the two running surfaces of the first rail member (4) in a rolling body cage (13) received rolling elements (11) are arranged and arranged on the two running surfaces of the second rail element (2) in a rolling body cage (12) rolling elements (11) are arranged, and
wherein the first and the second rail element (2, 4) are movable relative to one another between a pull-in position and a pull-out position along a pull-out direction (28),
characterized in that
the first rail element (2) has a shielding element (14), which is moved along with the first rail element (2), of a material which is opaque to microwave radiation of the microwave oven,
wherein the shielding member (14) has a connecting portion (15) extending substantially parallel to the back portion (6) of the first rail member (4) and a first leg portion (17) and a second leg portion (18) such that Shielding element (14) surrounds the first and the second rail element (2, 4) with a substantially U-shaped cross-section,
wherein the connecting portion (15), the first leg portion (17) and the second leg portion (18) have a length in the extension direction (28), so that the shielding member (14) in the retracted position, the first and the second rail element (2, 4 ) covers over its entire length in the extension direction (28), and
wherein the shielding member (14) has a curved first transition portion (20) connecting the connecting portion (15) and the first leg portion (17). Telescopic rail (1, 1 ') according to the preceding claim, characterized in that the first transition section (20) has a radius of curvature of 4 mm or more, preferably a radius of curvature of 5 mm or more and more preferably a radius of curvature of 6 mm or more , Telescopic rail (1, 1 ') according to one of the preceding claims, characterized in that the shielding element (14) has a curved second transition section (21) connecting the connecting section (15) and the second leg section (18), the second transition section (14) 21) has a radius of curvature of 4 mm or more, preferably a radius of curvature of 5 mm or more, and more preferably has a radius of curvature of 6 mm or more. Telescopic rail (1, 1 ') according to the preceding claim, characterized in that the connecting portion (15), the first leg portion (17) and the second leg portion (18) are formed in a sectional plane perpendicular to the extension direction (28) of straight lines and the first transition section (20) and the second transition section (21) in the sectional plane perpendicular to the extension direction (28) are substantially semicircular arc-shaped. Telescopic rail (1, 1 ') according to one of the preceding claims, characterized in that the first leg portion (17) and the first transition portion (20) together have a depth in a direction perpendicular to the extension direction (22) substantially equal to Depth of all rail elements (2, 3, 4) together in the direction (22) perpendicular to the extension direction (28) and preferably wherein the second leg section (18) and the second transition section (21) together have a depth in the direction (22) perpendicular to the extension direction (28), which is substantially equal to the depth of all the rail elements (2, 3, 4) together in the direction (22) perpendicular to the extension direction (28). Telescopic rail (1, 1 ') according to one of the preceding claims, characterized in that the shielding element (14) has a cover section (27) at a front end in the extension direction (22), which is substantially perpendicular to the connecting section (15). wherein the cover portion (27) has a surface covering substantially all of the cross section of the shield member (14) defined by the connection portion (15) and the first leg portion (17) and the second leg portion (18). Telescopic rail (1, 1 ') according to the preceding claim, characterized in that the shielding element (14) has a curved third transition section (29) connecting the connecting section (15) and the cover section (27), wherein the third transition section (29) has a radius of curvature of less than 6 mm, preferably less than 5 mm, and more preferably less than 4 mm. Telescopic rail (1, 1 ') according to any one of the preceding claims, characterized in that the shielding element (14) at a rear end (24) of the first leg portion (17) in the extension direction (22) has a Gargutträgeranschlag (25), wherein the Gargutträgeranschlag (25) extends substantially perpendicular to the first leg portion (17). Telescopic rail (1, 1 ') according to the preceding claim, characterized in that the Gargutträgeranschlag (25) has a curved outer contour (26), wherein preferably the radius of curvature of the outer contour (26) 4 mm or more, preferably 5 mm or more, and especially preferably 6 mm or more. Telescopic rail (1, 1 ') according to one of the preceding claims, characterized in that the shielding element (14) connected to the first leg portion (17) or the second leg portion (18) extending substantially parallel to the connecting portion (15) rear portion (23). Telescopic rail (1, 1 ') according to the preceding claim, characterized in that the shielding element (14) has a rear portion (23) connected to the first leg portion (17) and extending substantially parallel to the connecting portion (15) the first rail element (4) has a greater distance from the first leg section (17) of the shielding element (14) than the second rail element (2). Telescopic rail (1, 1 ') according to one of claims 1 to 9, characterized in that the first rail element (4) has a smaller distance from the first leg portion (17) of the shielding element (14) than the second rail element (2). Telescopic rail according to one of the preceding claims, characterized in that the first rail element (4) has at least one electrically conductive contact element and the second rail element (2) has at least one electrically conductive contact element,
wherein the contact element of the first rail element (4) and the contact element of the second rail element (2) are configured and arranged on the rail elements (2, 3, 4), that in the retraction position, either the contact element of the first rail element (4) and the contact element of the second rail member (2) are engaged with each other or the contact member of the first rail member (4) and the Contact element of the second rail element (2) in each case with a with the Wälzkörperkäfig (12, 13) co-moving electrically conductive guide element are engaged, so that in the retracted position an electrically conductive connection between the first and the second rail element (2, 4). Microwave oven with a telescopic rail (1, 1 ') according to one of the preceding claims. Microwave oven according to the preceding claim, characterized in that the first rail element (4) is the movable rail element of a partial extension or the outer movable rail element of a full extension.

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