Rail or telescopic extension

Abstract

A horizontal or vertical rail or telescopic extension of a cupboard element, a baking shelf or an oven door of a cooking or similar device. The extensions including at least one outer rail of bent sheet metal and a sliding rail of bent sheet metal, which partially surrounds the outer rail and can be displaced along the outer rail by an anti-friction bearing. The rail extension including an outer attachment rail which is connected to and reinforces the outer rail and/or a further attachment rail that is connected to and reinforces the sliding rail. The telescopic extension includes two interconnected rail extensions.

Description

The invention relates to a rail extension or a telescopic extension for the horizontal or vertical extension of an extendable element, especially a baking shelf of a cooker.

In known ovens it is usually possible to arrange the food on grids or sheets at various heights between underheat and overheat for which purpose guide rails for placing the grids or sheets are formed on the side walls of the cooking compartment. In order to achieve better accessibility and handling of the sheets or grids, extendable frames with a baking shelf are known which are connected to the cooking compartment by means of lateral guide rails or telescopic extensions and make it possible to displace the baking shelf horizontally together with the food.

Generic arrangements of baking ovens or cookers with rail or telescopic extensions are known, for example, from DE 198 17 499 C1 or from DE 100 51 153 A1. In addition to cookers with front-opening doors, those with downward-opening doors are also known in which the door can either be configured as downward-hinged or downward-extensible. Thus, for example, a cooker is described in DE 100 59 650 C1 in which a door for closing the cooking compartment is constructed as a housing base which closes the open underside of the oven housing and can be lowered vertically by means of guide elements.

Fairly long guide elements, rail extensions or telescopic extensions which can additionally be subjected to a bending load by relatively heavy baking shelves, must be designed as sufficiently stable and as a result are usually relatively voluminous. Telescopic extensions with rails made of bent sheet metal in some cases do not have the necessary stability and torsional resistance. An increase in the sheet metal thickness of the rails so that these can better withstand the loads which occur, would require new bending tools and larger presses to manufacture the rails. With increasing sheet metal thickness, the bending radii necessarily also become larger whereby the geometry of the rails varies accordingly. In some cases, therefore telescopic extensions with rails made of cold-drawn solid material are used which can absorb a higher load. However, such telescopic extensions have a relatively high weight and in addition, are expensive to manufacture.

It is the object of the invention to improve a known rail extension or telescopic extension with regard to its stability.

This object is achieved with a rail or telescopic extension according to the preamble of claim 1 according to the invention by additionally inserted attachment rails. The attachment rails bring about a significant stiffening for the same external dimensions whereby the extension can bear higher loads without any additional bending or distortion occurring. The U-shaped attachment rails are inserted inside or outside already existing sheet metal profiles of outer or sliding rails which can be displaced with respect to one another and are connected thereto. The external dimensions of the rail or telescopic extensions remain the same but the stability of the rails is significantly increased. The attachment rails can be welded, riveted, screwed or glued to the base rails. The connection points can be executed as punctual (e.g. welding or gluing points) or linear. An increased torsional resistance can be achieved by the base and also the legs of the interconnected rails each having joining points. The rails typically consist of bent steel sheet. The inner attachment rail can especially be constructed as a U-profile or as a hollow profile or as a D-profile or similar.

A telescopic extension is formed from at least two rail extensions of the same type which are joined together by the backs of their attachment rails.

These reinforcements are equally suitable for rail extensions (so-called partial extension) and for multi-part telescopic extensions (so-called full extension) which make it possible to achieve a horizontal or vertical displacement of an extendable element. Either a centrally attached rail or telescopic extension can be provided for guidance of an extendable element. Alternatively, two or more rail or telescopic extensions can be provided which are preferably attached to both longitudinal sides of the extendable element.

The invention is explained in detail in the following with reference to an exemplary embodiment with reference to the appended drawings. In the figures:

FIG. 1 is a cooker with a horizontal rail extension according to the invention,

FIGS. 2 and 3 each show a cooker with a vertical rail extension,

FIGS. 4 and 5 each show a schematic detailed view of two alternative variants of the rail extension according to the invention,

FIG. 6 shows a schematic detailed view of a telescopic extension and

FIG. 7 is a schematic diagram of an extendable element of a telescopic extension.

FIG. 1 shows a cooker 2 in conventional design with a door 23 at the front in the form of a front flap which can be hinged downwards. Provided on the side walls of a cooking compartment 22 are rail extensions 4 which make it possible to horizontally extend an extendable element 26, preferably a baking shelf 28 or similar. In the view shown the rail extensions 4 are each constructed as so-called partial extensions in which a short section of the baking shelf 28 stays inside the cooking compartment 22. A longer extension path of the baking shelf can be achieved with a so-called full extension which has telescopic extensions in each case instead of simply extendable rail extensions. This variant of an extension is described in detail with reference to FIGS. 6 and 7.

FIGS. 2 and 3 each show an alternative design of a cooker 2 which has a door 23 on an underside 24 of an oven housing 21 which can be displaced vertically downwards and thereby makes it possible to have access to a shelf 28 for food (see FIG. 3). Instead of the rail extensions 4 shown in FIGS. 2 and 3, the downward-extendable element 26 can also be constructed as extendable by means of a telescopic extension, as is described in detail in FIGS. 6 and 7.

FIG. 4 shows a schematic detailed view of a first variant of a rail extension 4 according to the invention, viewed from above. A U-shaped outer rail 41 is affixed to a side wall or other fixing point of an oven housing 21. The outer rail 41 is connected by a base 42 of its U profile to the oven housing 21 by means of a screwed, glued, riveted and/or welded joint. The legs 43 of the U-profile of the outer rail 41 are configured as running surfaces for rolling elements or balls 48 of an anti-friction bearing 47. They therefore have a slightly outwardly curved contour. For stiffening the outer rail 41 an attachment rail 49 is provided inside its U-profile, whose legs 51 are connected to the insides of the legs 43 of the outer rail 41 and whose base 50 is connected to the base 42 of the outer rail 41. These connections can be configured as welded, glued, riveted and/or screw connections as desired. An elevated torsional resistance can be achieved by providing a series of connecting points in the cross-section and not only, for example on the base 42 of the outer rail 41 between the base 50 of the outer attachment rail 49.

Whilst the rolling elements 48 of the anti-friction bearing 47 are supported internally on the legs 43 of the outer rail 41, on the outside they guide a sliding rail 44 whose two legs 46 are each slightly curved inwards and in this way provide for a fixing of the balls 48 on their provided races. One base 45 of the sliding rail 44 is connected to a base 53 of an attachment rail 52 whose legs 54 abut against the legs 46 of the sliding rail or are connected to this. These connections can also be configured as welded, glued, riveted and/or screw connections. The attachment rail 52 provides for a stiffening of the sliding rail 44 and prevents its distortion during an extension of the rail extension 4. Likewise, the outer attachment rail 49 provides for a stiffening and stabilisation of the outer rail 41.

The balls or rolling elements 48 are preferably guided in a cage 55 which ensures a uniform spacing of the balls from one another. Depending on the desired usage, the anti-friction bearing can have grease lubrication which is resistant to the temperatures prevailing in the cooking compartment. If the cooker is operated even temporarily in a pyrolysis mode, such grease lubrication is unsuitable since it cannot withstand the typical pyrolysis temperatures of around 500° C. In this case, for example, rolling elements and/or races made of ceramic or having a ceramic coating can be used.

FIG. 5 shows a schematic detailed view of a second variant of the rail extension 4 according to the invention. Affixed to a side wall of the oven housing 21 is an outer rail 41 with a D-shaped hollow profile. The outer rail 4 is connected by a back 56 of its D-profile to the oven housing 21 by means of a screwed, glued, riveted and/or welded connection. The legs 43 of the D-profile of the outer rail 41 are configured as in the first variant as races for balls 48 of the anti-friction bearing 47 and thus have a slightly concave profile.

The outer rail 41 is very rigid towards torsion and bending as a result of its closed profile. The closed profile is achieved by a base 50 which connects the legs 43, which in this variant corresponds to the outer attachment rail 49 according to the first variant.

The guidance of the extendable element 26 with the aid of the roller-mounted sliding rail 44, which is reinforced by the attachment rail 52, corresponds to the first variant which has already been described with reference to FIG. 4. The reasoning put forward there applies similarly here.

FIG. 6 shows a detailed view of a telescopic extension 6 which is substantially constructed of two interconnected rail extensions 4 according to FIG. 4. In this case, two attachment rails 52 are interconnected by the backs of their bases 53 so that the sliding rails 44 can be displaced longitudinally over the left portion of the telescopic extension 56 towards the oven housing 21 and the right portion of the telescopic extension 6 can be displaced longitudinally with the extendable element 26 towards the two sliding rails 44. The remaining structure corresponds to that of the rail extension 4 according to FIG. 4. In the same manner, a telescopic extension can be achieved with combined rail extensions according to the second variant (FIG. 5). A combination of both variants in a telescopic extension can also be meaningful.

FIG. 7 illustrates in a perspective schematic view an extended telescope extension 6 in which the outer rail 41 is affixed to the oven housing 21. The attachment rails 52 displaced downwards with respect to the outer rail 41 in turn hold the outer attachment rail 49 affixed thereto, to which the extendable element 26 is affixed. A support 28 of the extendable element 26, which points towards the front at right angles, causes possible bending of the rail or telescopic extension 6 under greater loading by a correspondingly heavy baking shelf, which is largely prevented by the outer attachment rails 49 or attachment rails 52 which are additionally present. The two arrows shown indicate this loading.

Basically, a single telescopic extension or rail extension can be provided for the support and displaceability of a baking shelf. Frequently, however, two parallel extensions are provided which are arranged on both sides of the door and ensure its better guidance.

Reference list

• 2 cooker
  • 21 oven housing
  • 22 cooking compartment
  • 23 door
  • 24 underside
  • 25 front
  • 26 extendable element
  • 27 longitudinal side
  • 28 support/baking shelf
• 4 rail extension
  • 41 outer rail
  • 42 base (outer rail)
  • 43 leg (outer rail)
  • 44 sliding rail
  • 45 base (sliding rail)
  • 46 leg (sliding rail)
  • 47 anti-friction bearing
  • 48 rolling element/ball
  • 49 outer attachment rail
  • 50 base (outer attachment rail)
  • 51 leg (outer attachment rail)
  • 52 attachment rail
  • 53 base (attachment rail)
  • 54 leg (attachment rail)
  • 55 cage
  • 56 back side
• 6 telescopic extension

Claims

1-16. (canceled)

17. A rail extension for the horizontal or vertical extension of an element such as a cupboard element, a baking shelf or an oven door of a cooking appliance or similar device, the extension comprising: at least one outer rail of bent sheet metal; a sliding rail of bent sheet metal that partially surrounds said outer rail; an anti-friction bearing by which said sliding rail can be displace along said outer rail; and an outer attachment rail connected to and reinforcing at least one of said outer rail or an attachment rail connected to said sliding rail.

18. The rail extension according to claim 17, including said outer rail and said sliding rail each having a pair of legs and said anti-friction bearing includes at least one rolling element which slides between one of said legs of each pair of legs of said outer rail and said sliding rail for mutual guidance of said outer rail and said sliding rail.

19. The rail extension according to claim 18, including said rolling element formed by a plurality of cage-mounted balls, roll or rollers.

20. The rail extension according to claim 17, including said outer rail has a U-shaped profile.

21. The rail extension according to claim 17, including said outer attachment rail has a U-shaped profile.

22. The rail extension according to claim 17, including said outer rail is connected to said outer attachment rail by at least one of welding, riveting, screwing or gluing.

23. The rail extension according to claim 17, including said outer rail is formed with a closed hollow profile.

24. The rail extension according to claim 23, including said outer rail is formed with a D-shaped profile.

25. The rail extension according to claim 17, including said sliding rail and said attachment rail are formed with a U-shaped profile.

26. The rail extension according to claim 17, including said sliding rail is connected to said attachment rail by at least one of welding, riveting, screwing or gluing.

27. The rail extension according to claim 17, including the horizontal or vertical extension element has a pair of longitudinal sides and each of said sides includes at least one rail extension connected thereto to form a partial extension.

28. A telescopic extension for the horizontal or vertical extension of an element such as a cupboard element, a baking shelf or an oven door of a cooking appliance or similar device, the telescopic extension comprising: a pair of interconnected rail extensions; each of said rail extensions including; at least one outer rail of bent sheet metal; a sliding rail of bent sheet metal that partially surrounds said outer rail; an anti-friction bearing by which said sliding rail can be displace along said outer rail; an outer attachment rail connected to and reinforcing at least one of said outer rail or an attachment rail connected to said sliding rail; each said attachment rail having a flat base section; and said flat base sections of said pair of attachment rails joined together to form said interconnection of said rail extensions.

29. The telescopic extension according to claim 28, including each of said attachment rails are formed with a U-shaped profile.

30. The telescopic extension according to claim 28, including said attachment rails are joined together by at least one of welding, riveting, screwing or gluing.

31. The telescopic extension according to claim 28, including the horizontal or vertical extension element has a pair of longitudinal sides and each of said sides includes at least one telescopic extension connected thereto.

32. The telescopic extension according to claim 31, including forming a full extension of said extension element.