EP1589289A1 - Pull-out system for household appliance - Google Patents

Abstract

Extraction system comprises a fixed rail (23) and a movable rail (27) for holding a cooker support (13). The fixed rail has an optional coating (34). An independent claim is also included for a household appliance with the above extraction system. Preferred Features: A movable intermediate rail (25) is arranged between the fixed rail and the movable rail. The movable layer is coated with a lubricant layer (33), preferably made from graphite, molybdenum sulfide or boron nitride.

Description

The invention relates to a pull-out system for a household appliance, in particular cooking appliance, the at least one stationary holding rail and a movable pull-out rail for mounting a Gargutträgers, of which at least a first rail with a coated first layer, which has a lubricant.

From EP 0 994 309 A2 a generic extension device is known which partially From a cooking chamber has pull-out rails. These are in fixed guides guided smoothly. The rails and / or the guides are at least on their sliding surfaces provided with a sliding material.

From DE 102 11 470 A1 a generic pull-out system is known, which is a stationary inner rail, a movable intermediate rail and a movable outer rail having. The rails are easy to clean based on PTFE Layer provided. Depending on the accessibility of the rails or of components for food and / or the user different coating qualities are provided. Let it be component areas facing down, with a view to cleanability and / or abrasion resistance lower coating qualities equip than upward pointing component areas that are directly exposed to Gargutspritzern.

DE 199 49 239 A1 discloses a pull-out device, in particular a telescopic pull-out device, known in the rails by means of ball bearings or roller bearings to stationary Guides are guided. The balls of the ball bearings or the rollers of the roller bearings consist at least on its surface of a self-lubricating material.

From DE 38 15 440 a telescopic insertion device is known which acts as a telescopic extension with a fixed inner rail, a rollable middle rail and a rollable outer rail is formed for the food support. At the middle rail each two rollers are supported by bolts. In the bolt grooves are formed, the Take high-temperature-resistant grease or lubricating paste.

The object of the invention is to provide a pull-out system for a household appliance, which permanently has good running or sliding properties.

The object of the invention is with a household appliance having the features of the patent claim 1 solved. According to claim 1 of the rails is at least one first rail coated with a first layer having a lubricant. On the other hand At least a second rail is coated with a second layer or uncoated. According to the invention it has been recognized that it is sufficient for lubrication the entire extension system is sufficient, only one of the rails with a To provide lubricant layer. Lubricant particles rubbed off by the lubricant layer can in the pull-out system according to the invention also running or sliding surfaces reach, which are not in contact with a lubricant layer. This is sufficient for the task to maintain a smooth running of the extension system.

Next arise according to claim 1 for the rails different surface properties. As a result, the running or sliding behavior of the extension system be increased significantly. The running or sliding behavior improves in particular then when the rails are coated with layers of different surface hardness are. In view of a favorable production, it is preferred if at least one the track is uncoated, i. has a metallic surface.

It is particularly preferred if the first coated with the lubricant layer Rail is a moving rail. By means of the movable rail will be a good distribution of the lubricant in the extension system. Consisting of a pull-out system It is sufficient from a stationary holding rail and a movable pull-out rail therefore, when the movable drawer rail is coated with the lubricant layer is. The stationary holding rail, however, may be coated with another layer or uncoated.

In the event that between the movable drawer rail and the stationary retaining rail an intermediate rail is mounted, it is sufficient according to the invention, if only one of the three rails is coated with the lubricant layer. Especially preferred it is there when the intermediate rail is coated with the lubricant layer. In In this case, the intermediate rail both the drawer rail and the support rail supply approximately the same amount of lubricant. This can manufacturing technology advantageous to a coating of the retaining rail and / or the pull-out rail be waived. Alternatively, the outer pull-out rail and / or the stationary inner Retaining rail be provided with another, approximately corrosion-resistant layer.

It is particularly preferred if the lubricant is an inorganic solid lubricant is. Such a lubricant is unlike many other lubricants, such as such as liquid lubricants of oil or fat, physiological even at high temperatures harmless.

It is advantageous if the lubricant is chemically resistant, in particular alkali-resistant is to allow a cleaning in dishwasher. In this case The extraction system can also chemically aggressive media, such as alkalis in a dishwasher.

Inorganic solid lubricants can be particularly easy from a layer structure to solve. Distributing the inorganic solid lubricant on components that are not compatible with the Solid lubricant coated, is therefore particularly easy. squeaking or a stiffness of the extension system are therefore reliably prevented.

According to the invention it may be advantageous if the lubricant is resistant to high temperatures. For this purpose, all lubricants come into question, which are up to maximum cooking temperatures of up to 300 ° C and optionally up to 500 ° to 600 ° C in the pyrolysis resistant. It is particularly preferred if graphite is used as the solid lubricant. Graphite can be used even at very high temperatures as well as chemically resistant and cost-effective. Furthermore, molybdenum disulfide can be used as the solid lubricant. In this case, however, it may become problematic at very high temperatures because of the generation of S ₂ . If the manufacturing costs are only of secondary importance, as a solid lubricant and boron nitride is conceivable that is resistant and physiologically harmless in all temperature ranges. The same applies to tungsten disulfide.

It is advantageous if the lubricant layer has a binder, the Keeps lubricant on the rail. The binder causes an improved connection of the lubricant with the rail surface. Such a connection is different not given if the lubricant only in a roughened rail surface Stop finds. Particularly advantageous with regard to a lubricant layer with uniform layer thickness and uniform surface properties, when the binder is a paint. This can be sprayed on the rail, for example which results in a uniform layer thickness. Subsequently, the on the paint applied to the rail is burned into the rail together with the lubricant become. Advantageously, the lubricant is suspended in the paint. By the Burning in can achieve permanently reliable lubrication properties of the rail Even if the telescopic extension chemically aggressive media or high Temperatures is exposed.

In order to adjust the abrasion resistance of the rail coating or its layer quality to the requirements, combinations of the abovementioned solid lubricants made of graphite, molybdenum disulfide (MoS ₂ ), boron nitride or tungsten disulfide are also conceivable.

Compared to a slide bearing can with a rolling bearing in the extension system a improved pull-out behavior can be achieved. Unlike a plain bearing is generated between the moving components no frictional force, but roll the movable components via rolling elements against each other. This is in a pull-out system with plain bearing significantly less lubricant required. It can therefore also a lubricant layer can be used with lower quality requirements.

According to the invention, the lubrication of the extension system via a only on the intermediate rail provided lubricant layer can be achieved. Other components in the Pull-out system, such as rails, rolling elements or Wälzkörperkäfige therefore no need Take over the lubricating function. The rolling elements and / or their Wälzkörperkäfige can Therefore be specially designed as limit stops. Occurring loads For example, could be based on carbon-based Wälzkörperkäfige (so-called. PEEK cages) can not withstand.

From a manufacturing point of view, it is preferred if the intermediate rail is completely connected to the Lubricant is coated. Compared to a partial coating of the intermediate rail Thus, the coating process can be significantly simplified.

Plays the manufacturing effort to apply the lubricant layer on the rail only a minor role, so it is conceivable, several lubricant layers with different Apply properties. In this case, a lowest layer layer have a large proportion of binders and correspondingly less solid lubricant. As a result, an abrasion-resistant mounting of the lubricant is secured to the rail. On the other hand, a top layer can have little binder and a high proportion of it Have solid lubricant. As a result, the lubricating property of the intermediate rail elevated.

In addition, the layer containing the lubricant further fillers, such as made of ceramic to adjust its coating quality or abrasion resistance.

According to a further embodiment, the extension system can be removed in the cooking appliance to be held. In this case, on the one hand, a simple cleaning of the Extraction system outside the cooking appliance reached. On the other hand, for example, at In a pyrolysis operation in the cooking appliance, the pull-out system is taken out to it not to be exposed to the high temperatures in pyrolysis operation.

Preferably, the extraction system can be designed such that the with the lubricant layer coated rail is protected from contamination. For example the retaining rail and / or the drawer rail can define a cavity in which the coated with the lubricant layer intermediate rail is arranged. In this Case is the intermediate rail at least in the cooking mode in the through the support rail / pull-out rail inserted cavity inserted. A pollution of the intermediate rail By Garflüssigkeit or by Wrasen is thereby substantially reduced. This makes it possible that the lubricant layer is an inorganic solid lubricant having. Such a lubricant layer has excellent lubricating properties but it is difficult to clean. This is due to the physical properties of inorganic solid lubricants. The poor cleanability, however, plays only a minor role, if, having the lubricant layer Rail is largely protected from contamination.

Figur 1

gemäß dem ersten Ausführungsbeispiel ein Auszugssystem in einem Gargerät;

Figur 2

in einer Schnittdarstellung das Auszugssystem des Gargeräts;

Figur 3

einen Kugelkäfig des Auszugssystems; und

Figur 4

gemäß einem zweiten Ausführungsbeispiel ein Auszugssystem in einem Gargerät.

In the following, two embodiments of the invention will be described with reference to the attached figures. Show it:

FIG. 1

according to the first embodiment, an extension system in a cooking appliance;

FIG. 2

in a sectional view of the extension system of the cooking appliance;

FIG. 3

a ball cage of the extension system; and

FIG. 4

according to a second embodiment, an extension system in a cooking appliance.

In the figure 1 is according to the first embodiment, a cooking appliance with a cooking appliance muffle 1, which limits a cooking space. The cooking appliance has a hinged door 3 for closing a front muffle opening 5. In the figure 1 is the swing door 3 shown in an open state. On opposite side walls 9 of the Gargerätemuffel 1 are corresponding lateral guide rods 11 and a pull-out system, consisting of two opposite telescopic extensions 13, held. The telescopic extensions 13 are in a topmost of four horizontal Garraumebenen removably supported. In the underlying three Garraumebenen are each the corresponding guide rods 11 removably supported. On the two corresponding bottom guide rods 11 is supported by a baking sheet 13, which partially has been pushed out of the cooking appliance muffle 1. The guide rods 11 are mufflefrontseitig each inserted in a bearing bush 15. This is in a mounting hole of the Muffle side wall 9 mounted. The telescopic extensions 13 are formed with a holding plate 14, each mounted in an annular groove 16 of the bearing bush 15. In the area a muffle back wall 17, the guide rods 11 and the telescopic extensions 13 each stored in a mounting opening 19. Both the guide rods 11 and the Telescopic extensions 13 are tool-free by a user from the muffle 1 to solve.

In the present case, the extension system 13 is designed as a telescopic extension. The telescopic extension 13 is in cross-section according to FIG. 2 in a viewing direction I shown in FIG shown. The telescopic extension 13 has a lower holding rail 23, the is held stationary on the muffle side wall 9 via the holding plate 14.

Both the holding plate 14 and the bearing bush 15 are shown in dashed lines in FIG Lines shown. In addition to the stationary support rail 23 is the telescopic extension 13 from a movable intermediate rail 25 and a likewise movable extension rail 27. The intermediate rail 25 is connected via balls 29 between the pull-out rail 27 and the stationary support rail 23 stored.

The configuration of the rails 23, 25, 27 is not on the present embodiment limited. Thus, the support rail 23 may also be formed like a round rod 11 be. On the support rail 23, the pull-out rail sliding or other rolling elements be guided stored. The design of the pull-out rail 27 is not on the present embodiment is limited. Rather, the pull-out rail 27 be designed as a sled, a runner or other extract element. Between the pullout element 27 and the support rail 23 can also on the arrangement the intermediate rail 25 are dispensed with.

The retaining rail 23 and the pull-out rail 27 consist according to the figure 2 from each other identically formed U-profile parts of an uncoated sheet steel. The two rails 23, 27 are arranged facing each other with their open sides. They define a substantially closed cavity 31, in which the intermediate rail 25 is arranged. This means that at least in the inserted state of the Telescopic extension 13, the intermediate rail 25 almost completely from the pull-out rail 27 and the support rail 23 is enclosed. Fat spills, dirt or the like are therefore kept away from the balls 29 and from the intermediate rail 25.

To a smooth pulling out and pushing together of the extension system permit, the intermediate rail 25 is coated with a lubricant layer 33. The Lubricant layer 33 is shown in FIG. 2 in an exaggerated layer thickness. The Layer thickness is realistically in a range between 10 and 20 microns. In contrast to the intermediate rail 33, both the balls 29 and the support rail 23 and the drawer rail 27 is not coated with the lubricant layer 33, but uncoated. As a result, the balls 29 run on the one hand on the lubricant layer 33 of the Between rail 25 and on the other hand on the uncoated running surfaces of the retaining rail 23 and the pull-out rail 27.

The surface properties of the metal surface of the balls 29, the support rail 23rd and the pull-out rail 27 on the one hand and the lubricant layer 33 on the other are different. Due to these different surface properties results a particularly good rolling behavior of the balls 29 and thus good running properties of the pull-out system.

Alternatively, the retaining rail 23 and / or the pull-out rail 27 with a second Be coated layer, as shown in Figure 2 by the reference numeral 34 with dashed Line is indicated. The two different layers 33 and 34 have different Surface properties on. In particular, at a different Surface hardness of the rolling behavior of the ball 29 can be improved. The second layer 34 may be formed as a corrosion resistant layer.

In the present case, the lubricant layer 33 comprises particles of an inorganic solid lubricant, such as graphite. For the preparation of the lubricant layer 33 is first a powder of the inorganic solid lubricant suspended in a paint solution and then subsequently coated the intermediate rail 25. In a further step the paint solution is baked in the intermediate rail 25. This results an extremely high mechanical abrasion resistance of the coating 33 and a good chemical resistance to aggressive media, such as detergents. In addition to this cost-effective painting process, other methods, such as a PVD coating (Physical Vapor Deposition) or a CVD coating (Chemical Vapor Deposition) for the preparation of the lubricant layer 33 conceivable.

The lubricant layer 33 of the intermediate rail 25 is sufficient to also between the Balls 29 and the drawer rail 27 and the support rail 23 enough lubricant contribute. The U-shaped rails 23, 27 shown in FIG. 2 are suitable It is particularly good to protect the intermediate rail 33 from contamination. at the rails shown in Figure 2, it is sufficient, the lubricant layer 33 only with respect to adapt to their lubrication properties. Of subordinate importance is in this Case the cleaning ability of the lubricant layer 33. The protection against contamination the lubricant layer 33 is namely of the U-shaped retaining rail 23 and taken from the pull-out rail 27. These act at least in the inserted state like cover elements with respect to the intermediate rail 25 Intermediate rail 25 is therefore largely reduced.

Only such a protection of the intermediate rail 25 from contamination therefore allows meaningfully, a coating of the intermediate rail 25 with the inorganic solid lubricant layer 33. Such a layer is in fact - compared with, say, one PTFE based coating - very difficult to clean.

According to FIG. 2, the balls 29 are arranged in two opposing ball cages 37. The balls 29 are rotatably supported in the ball cages 37. One of the ball cages 37 is shown in FIG. The ball cage 37 consists of a thin sheet steel, formed into an angular part with three trapezoidally arranged in profile sides 39 is. In each of the sides 39 recesses 41 are cut out. The recesses 41 are arranged on each side 39 in two consecutive rows. The two rows are spaced apart via a central portion 43 of the ball cage 37. Every recess 41 is partially bounded by an angled embossing edge 45, the ball 29 in the Recess 41 holds.

The ball cages 37 shown in FIGS. 2 and 3 are additionally provided with the lubricant layer 33 coated. In Figure 2, the applied on the ball cage 37 Lubricant layer 33 indicated by dashed line. In the figure 3 is the on the Ball cage 37 applied lubricant layer 33 indicated in hatching. Thereby can due to the rotation of the balls 29 at the angled embossing edge 45 a minor Lubricant abrasion can be generated. The abrasion is caused by the adjustment movement of the telescopic extension 13 along the running surfaces of the rails 25, 23, 27 distributed. As a result, the pull-out behavior of the extension system is permanently improved. Further be squeaking noises or a stiffness when operating the telescopic extension effectively reduced. The application of the lubricant layer 33 on the ball cage 37 takes place as the application of the lubricant layer 33 to the respective Rail.

The ball cages 37 are freely movable between the rails 23, 25, 27 in the longitudinal direction. The end faces 47 of each ball cage 37 serve in the telescopic extension shown in FIG 13 as stops, which limit a longitudinal movement of the rails 23, 25, 27. The telescopic extension 13 can therefore be pulled apart until the End faces 47 of the ball cage 37 in abutment with corresponding rail stops, not shown come.

In the figure 4, a cooking appliance is shown according to the second embodiment, the Cooking appliance of the first embodiment corresponds. The only difference to the first Embodiment consist in that the telescopic rails 13 of the extension system from the stationary support rail 23 and the directly mounted there extract rail 25 exists. On the intermediate rail 25 is omitted. Here is the pull-out rail 25 as in the first embodiment mounted on balls 29 in the ball cages 37 are held.

According to FIG. 4, the movable pull-out rail 27 is provided with the lubricant layer 33 coated. By an adjusting movement of the pull-out rail 27 of the lubricant distributed in sufficient quantity in the extraction system. In contrast, the stationary retaining rail 23 uncoated. The balls 29 therefore roll between rolling surfaces with different Surface properties, resulting in a particularly good rolling behavior of the Balls 29 and thus good running properties of the extension system results.

Claims (27)

Pull-out system for a household appliance, in particular cooking appliance, which has at least one stationary holding rail (23) and a movable pull-out rail (27) for holding a food support (13), of which at least one first rail (25; 27) is provided with a first layer (33) coated, which has a lubricant, characterized in that at least one second rail (23, 27, 23) is coated with a second layer (34) or is uncoated. Pull-out system according to Claim 1, characterized in that the first rail coated with the first layer (33) is the movable pull-out rail (27). Pull-out system according to claim 1 or 2, characterized in that between the pull-out rail (27) and the stationary holding rail (23) at least one movable intermediate rail (25) is mounted. Pull-out system according to Claim 1, 2 or 3, characterized in that the first rail coated with the first layer (33) is the intermediate rail (25). Pull-out system according to Claim 1, 3 or 4, characterized in that the second rail (23, 27) coated or uncoated with the second layer (34) is the holding rail (23) and / or the pull-out rail (27). Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises an inorganic solid lubricant. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) is formed chemically resistant. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) is designed to withstand high temperatures. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises graphite. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises molybdenum disulfide. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises boron nitride. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises tungsten disulfide. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) comprises a binder which holds the lubricant to the first rail (33). Pull-out system according to claim 13, characterized in that the binder is a lacquer. Pull-out system according to claim 14, characterized in that the paint with the lubricant in the intermediate rail (25) is baked. Pull-out system according to one of the preceding claims, characterized in that the rails (23, 25, 27) are mounted in the pull-out system via rolling elements (29). Pull-out system according to claim 16, characterized in that the rolling bodies (29) are arranged in a rolling body cage (37). Pull-out system according to claim 17, characterized in that the rolling element cage (37) is designed as a stop for limiting a movement of the rail (25, 27). Pull-out system according to one of claims 17 or 18, characterized in that the rolling element cage (37) is coated with the lubricant layer (33). Pull-out system according to one of the preceding claims, characterized in that the first rail (25; 27) is completely coated with the lubricant layer (33). Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) is at least partially multi-layered. Pull-out system according to one of the preceding claims, characterized in that the lubricant layer (33) further fillers, such as ceramic, contains. Pull-out system according to one of the preceding claims, characterized in that the pull-out system (13) is removably mounted in the household appliance. Pull-out system according to one of claims 3 to 27, characterized in that the retaining rail (23) and / or the pull-out rail (27) protects the intermediate rail (25) from contamination. Pull-out system according to one of claims 3 to 27, characterized in that the holding rail (23) and / or the pull-out rail (27) surrounds the intermediate rail (25). Pull-out system according to one of claims 3 to 27, characterized in that the holding rail (23) and / or the pull-out rail (27) define a cavity (31) in which the intermediate rail (25) is arranged. Domestic appliance with a pull-out system according to one of the preceding claims.

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