Home appliances

Abstract

The present invention relates to a household appliance, comprising: an article support arranged in the household appliance; and a device for extracting and retracting the article support from the household appliance, the extraction and retracting device comprising: a first guide rail unit and a second guide rail unit extending parallel to each other, which are arranged to be movable in a longitudinal direction relative to each other; and a first group of roller elements and a second group of roller elements, longitudinally distributed between the first guide rail unit and the second guide rail unit along the first and second relative outer surfaces of the first guide rail unit to facilitate the relative movement. The first guide rail unit is provided with a support material in an area extending between and between the first and second relative outer surfaces at least along one or more sections of its length, so as to allow absorption of compressive forces in the support material and resist compression deformation of the first guide rail unit when one or more roller elements exert a force on either of the first and second relative outer surfaces.

Description

Technical Field

[0001] The present invention relates to a household appliance, such as a dishwasher. In particular, the present invention relates to a device for extracting and retracting a support for items, such as a basket or a rack, from a household appliance. Background Art

[0002] Dishwashers are usually provided with a device for extracting and retracting a basket or rack arranged between opposite side walls of the machine. Such a device may comprise two metal rails arranged on each inner side wall of the machine, one rail fixed to the wall and the other rail slidably arranged on the other wall, and a set of plastic wheels arranged on each side of the basket and fitting into the slidable rails. The basket can then be extracted by a combination of extracting the slidable rails and rolling the basket outwards using the wheels.

[0003] More recently, extraction / retraction devices have been proposed in which the wheels have been replaced by roller bearings or similar structures which are intended to provide smoother extraction / retraction of baskets or other item supports. However, these devices are generally quite expensive and in some cases appear to exhibit questionable properties at least in terms of durability.

[0004] EP2891447A1 discloses an example of a dishwasher provided with a basket extraction / retraction device comprising three rails and two ball bearings on each side of the dishwasher. This device may be durable, but it is more expensive than conventional devices comprising wheels attached to the basket.

[0005] Thus, there remains a need for improvement in the area of ​​basket or article support extraction / retrieval arrangements for dishwashers and other household appliances. Summary of the invention

[0006] An object of the present invention is to provide a household appliance with a basket or object support extraction / retraction device which exhibits a reliable and user-friendly function and provides improved cost efficiency.

[0007] The invention relates to a household appliance, such as a dishwasher, wherein the household appliance comprises: a support for articles, such as a basket or a rack, arranged in the household appliance; and a device for extracting and retracting the article support from and into the household appliance, wherein the extraction and retraction device comprises: a first and a second guide rail unit extending substantially parallel to each other, wherein the first and the second guide rail unit are arranged to be movable in a longitudinal direction relative to each other. The extraction and retraction device also comprises a first and a second set of roller elements, which are longitudinally distributed between the first and the second guide rail unit along first and second opposing outer surfaces of the first guide rail unit to facilitate the relative movement.

[0008] The present invention is characterized in that the first guide rail unit is provided with supporting material in an area extending between and between the first and second relative outer surfaces at least along one or more sections of its length, so as to allow absorption of compressive forces in the supporting material and resist compressive deformation of the first guide rail unit when one or more roller elements exert a force on any of the outer surfaces.

[0009] This means that the supporting material is arranged in the area extending between the first and second outer surfaces, i.e. between the roller elements, and that the material is able to prevent compression of the first guide rail unit when subjected to compressive forces exerted by the roller elements. This therefore means that the first guide rail unit is designed so that the material itself will absorb the compressive forces internally. This is due to the feature that the material is present between the first and second outer surfaces and is located in between them. Therefore, the material is not only present on one or both sides of the area located between these surfaces, which will cause a bending moment when a force presses one of the outer surfaces towards the other.

[0010] The material is supported and the first rail unit can withstand compression deformation, which means that the material itself is basically incompressible, that is, it is not flexible and porous, and the material is arranged in a structure that can handle the force (within reasonable limits) directed to another outer surface from one of the outer surfaces and not significantly compressed. As described below, the material is preferably plastic or polymer material (to avoid more expensive steel rails). As for structure, there are multiple possible solutions. An example is to make the first rail unit completely solid between the outer surfaces and along some parts / sections of its length. Another example of typically saving weight and material is to provide a plurality of relatively thin wall members for the first rail unit, which pass through and / or extend along the rail in the (compression) load absorbing frame. Due to the wall member extending through the first rail unit provides a solid cross section between the outer surfaces for the first rail unit, so this wall actually forms a modification of the aforementioned example, i.e., the first rail unit is only between the outer surfaces along the modification of the very short completely solid part / section of its length. The combination of wall members and other supporting structures is also possible.

[0011] Applying a particular design "at least along one or more sections of its length" means that the design does not necessarily apply to the entire length of the first guide rail unit. For example, during use, one or more components of the first guide rail unit may not be located between the roller elements and will not be subject to the above-mentioned compressive forces.

[0012] The expression "at least along one or more sections of its length" also means that there can be some longitudinal distances between different sections to which this design is applied. The reason is that a specific section can provide compression resistance not only to its precise longitudinal position, but also to some parts of the first guide rail unit that are close enough to this specific section. Therefore, as mentioned above, an example of such a section is a thin-walled member extending through the first guide rail unit. Therefore, an example of a design according to the present disclosure is to distribute a plurality of wall members along (a part of) the first guide rail unit, wherein each wall member forms a "section" and extends between the first and second outer surfaces and passes through the first guide rail unit. Such wall members can extend laterally through the first guide rail unit, or present a certain angle relative to the transverse direction. The selection of the longitudinal distance between such wall members depends on, for example, the thickness of the wall member, the overall size of the first guide rail unit, and the material thickness of other components of the first guide rail unit.

[0013] The design as described above is significantly different from the design of steel rails commonly used in the extraction and retraction devices of dishwashers. Such steel rails have a substantially C-shaped cross section, wherein the wheel is mounted between two substantially horizontal parts of the C-shape, or two C-shaped rails of different sizes (i.e. different heights or widths) cooperate with each other via (upper and lower) ball bearing elements arranged between the horizontal parts of the C-shape of the two rails, as exemplified in the device disclosed in EP2891447A1. In such ordinary steel rails, there is no material at all in the "area extending between and located in the middle of the opposite outer surfaces (i.e. the two substantially horizontal parts of the C-shape)" that is subjected to compressive forces. On the contrary, such rails are made of steel of sufficient quality and thickness so that the horizontal part of the C-shaped cross section that is subjected to compressive forces can withstand bending moments, and in this way prevent the rails from deforming due to compression.

[0014] It may be noted that the cross-section of ordinary steel guide rails is rarely formed precisely into a typical C-shape, but they are usually made of an elongated steel plate and, after pressing / bending, present a cross-section having two opposite, mirror-symmetrical flanges, each flange usually having a recessed portion to accommodate, for example, a portion of a ball, and a main portion extending generally substantially perpendicular to the flanges (except for the area between the "outer surfaces") and connecting the end portions of the flanges, resulting in a substantially C-shaped cross-section.

[0015] The effect of providing support material between the first relative outer surface and the second relative outer surface is that the first rail unit will not deform (within reasonable limits) when subjected to compressive forces (because the compressive forces will not subject the first rail unit to bending moments), even if made of a material having lower strength or higher flexibility than the steel used for conventional C-shaped rails. As a result of this effect, the first rail unit can be made of a plastic or polymer material, such as polypropylene, which significantly reduces the cost of the first rail unit, not only because of material costs, but also because it is more cost-effective to manufacture a plastic rail by, for example, injection molding than to form a C-shaped cross-section by stamping a flat steel sheet. In addition, injection molding of plastic has the potential to reduce tolerances compared to stamping of steel.

[0016] For example, the compressive force from the roller element may increase when the item support is secured to the first rail unit and the weight of the item support presses the first rail unit toward the roller element located below the first rail unit, or when the items are unevenly distributed on the item support, for example, all of the items are located at the front (outer) end of the dishwasher basket, thereby generating a torque that presses the front (outer) component of the first rail unit downward and the rear (inner) component upward.

[0017] The roller elements can be balls, but also cylindrical roller elements.

[0018] In one embodiment, the first rail unit comprises a plurality of wall members extending through the first rail unit, wherein the wall members constitute at least a portion of the support material between the first and second relative outer surfaces. As mentioned above, this reduces cost and weight compared to a more solid design. The wall members are preferably distributed along the first rail unit, at least distributed along a portion of its length. A single wall member can extend laterally or present a certain angle relative to a transverse direction. In addition, a single wall member can extend in a plane or a curved plane. The wall member can also be arranged in the longitudinal direction of the first rail member.

[0019] In one embodiment, the first rail unit is fixed to the article support so as to allow the article support to be withdrawn in a direction away from the household appliance and retracted in a direction into the household appliance when the first rail unit is moved relative to the second rail unit. The first rail unit may be connected directly or indirectly to the article support.

[0020] In one embodiment, the first rail unit is provided with a first stop element, which is configured to interact with a corresponding second stop element arranged at a fixed position relative to the second rail unit when the extraction and retraction device is fully extracted, thereby preventing further extraction of the first rail unit when the first and second stop elements interact, thereby setting a maximum extraction position of the first rail unit relative to the second rail unit. This prevents the first rail unit from being extracted too far relative to the second rail unit.

[0021] In one embodiment, the article support is directly or indirectly connected to the first rail unit along a connection length extending in the longitudinal direction of the first rail unit, and wherein when the first rail unit is in its maximum withdrawal position relative to the second rail unit, less than half of the connection length is located outside the second rail unit. The connection length relates to the length of the connection at the first rail unit, wherein the weight of the article support is transferred to the first rail unit. If the first rail unit is allowed to be withdrawn from the second rail unit until the entire connection length is withdrawn to the extent outside the second rail unit, the first rail unit will be subjected to a considerable bending moment, at least when the article support is loaded with heavy items. This bending moment may be acceptable for conventional steel rails with a C-shaped cross-section, but in order to allow the first rail unit to be made of plastic or polymer material, and still allow the first rail unit to be thin and "weak" enough to take advantage of the potential for cost-effectiveness, the embodiment is designed to only allow the first rail to be withdrawn so that less than half of the connection length is located outside the second rail unit. The less the connection length allowed to be withdrawn from the second rail unit, the less the bending moment the first rail unit is subjected to. In order to completely avoid exposing the first rail unit to the bending moment caused by protruding the connection length from the second rail unit, the maximum withdrawal position of the first rail unit relative to the second rail unit can be set so that the connection length is not allowed to be located outside the second rail unit at all. If the weight load of the article support is only partially (or not at all) carried by the first rail unit, the remaining part (or all of the load) can be carried by the second rail unit. In this case, the second rail unit can be designed to carry the load and withstand the resulting bending moment, for example, by having or including a traditional type of steel rail with a substantially C-shaped cross-section. The advantage is that it can be avoided that the first rail unit needs to be a steel rail, but can be made of a plastic material and designed to mainly withstand compression forces.

[0022] In one embodiment, when the first rail unit is in its maximum extended position relative to the second rail unit, less than 20% of the connection length is located outside the second rail unit. Preferably, as described above, when the first rail unit is in its maximum extended position relative to the second rail unit, the connection length is not located outside the second rail unit at all.

[0023] In one embodiment, the first and second groups of roller elements are arranged between the first surface and the second opposing outer surface of the first track unit and the corresponding opposing first and second inner surfaces of the second track unit. Thus there are (at least) two rows of roller elements, one row between the first inner surface and the first outer surface, and another row between the second inner surface and the second outer surface. Typically, there is one row below the first track unit and one row above the first track unit.

[0024] In one embodiment, the second guide rail unit comprises an outer frame made of a metal material and a guide rail insert made of a plastic or polymer material, wherein the guide rail insert is arranged within the outer frame and fixed to the outer frame. Thus, the outer frame can be a conventional steel guide rail with a substantially C-shaped cross section, i.e. a type of steel guide rail having high strength and capable of withstanding the above-mentioned bending moments. The outer shape of the plastic guide rail insert is preferably adapted to the inner shape of the metal frame, while the inner shape of the plastic guide rail insert can be given various designs depending on the application, in particular adapted to the design of the first guide rail unit and the roller element.

[0025] A particular advantage of using an outer metal frame and a plastic insert is that an already available second rail outer frame (or even a second rail outer frame already installed in a domestic appliance) comprising wheels connected to the article support and adapted to fit into the outer metal frame can be adapted to a conventional extraction and retraction device, the second rail outer frame being easily converted into an extraction and retraction device using roller elements instead of wheels by adapting the plastic rail insert to the existing second rail outer frame and the first rail unit to be used, etc. The existing outer frame of the second rail can still be used for a wheel solution, for example for a less expensive variant of the domestic appliance in question. The plastic rail insert can be produced cost-effectively, for example by injection molding.

[0026] In one embodiment, the first and second opposing inner surfaces of the second guide rail unit are arranged in a guide rail insert. This means that, in this embodiment, the outer metal frame of the second guide rail unit (which may be a conventional type of steel guide rail with a generally C-shaped cross-section that is already available and may have been originally designed for a wheel solution) is converted into a composite second guide rail unit by introducing a plastic guide rail insert inside the frame and the guide rail insert is adapted to receive the roller elements and the first guide rail unit, which is preferably also made of plastic as described above. This is a more cost-effective solution than redesigning the second steel guide rail unit and adding another steel guide rail (i.e. the first steel guide rail) of the same type and material as the second guide rail.

[0027] In one embodiment, the extraction and retraction device comprises a roller element carrier which holds the first and second sets of roller elements in position at the first and second opposing outer surfaces of the first guide rail unit.

[0028] In one embodiment, the roller element carrier is longitudinally movable relative to each of the first and second track units.

[0029] In one embodiment, the second stop element is arranged on the roller element carrier.

[0030] In one embodiment, the roller element carrier is provided with a third stop element, which is configured to interact with a corresponding fourth stop element arranged on the second guide rail unit so that when the third and fourth stop elements interact, further extraction of the roller element carrier is prevented, thereby setting a maximum extraction position of the roller element carrier relative to the second guide rail unit.

[0031] Therefore, when the second stop element is arranged on the roller element carrier (not on the second guide rail unit), when the extension and retraction device is fully extended and the third and fourth stop elements interact with each other, the second stop element is arranged in a fixed position relative to the second guide rail unit, i.e. further extension of the roller element carrier is prevented and the maximum extension position of the roller element carrier relative to the second guide rail unit is thereby set.

[0032] In one embodiment, the first rail unit is made of plastic or polymer material. As mentioned above, this is more cost-effective than using traditional steel rails.

[0033] In one embodiment, the first track unit comprises a track component extending along the roller element and a connecting component fixed to the track component and directly or indirectly connected to the article support. The connecting component can be connected to the track component, or the two components can form an integral assembly. The connection between the first track unit and the article support can include other components.

[0034] In one embodiment, the extraction and retraction device comprises a third rail unit fixed to the inner wall of the household appliance. The third rail may be a conventional steel rail having a substantially C-shaped cross section. The device may comprise one or more further rails.

[0035] The household appliance preferably comprises similar extraction and retraction means on the opposite side of the object support.A corresponding third guide rail can therefore be fixed to the opposite inner wall of the household appliance.

[0036] In one embodiment, the second guide rail unit is movably connected to the third guide rail via a third group of roller elements and a fourth group of roller elements longitudinally distributed between the second guide rail unit and the third guide rail unit. Therefore, in this case, the device includes three guide rails. As described above, the third guide rail unit and the second guide rail unit, or at least the outer frame of the third guide rail and the second guide rail unit, can also be adapted to another design of the first guide rail including rollers or another type.

[0037] In one embodiment, the guide rail insert is provided with a flexible braking member for slowly decelerating the roller element carrier during extension before the third stop element and the fourth stop element interact and the roller element carrier reaches its maximum extension position, wherein the roller element carrier is provided with a brake activation member, which is arranged to interact with the flexible braking member before the roller element carrier reaches its maximum extension position, and wherein the flexible braking member is made of a flexible material, has a closed loop shape, and is oriented in a plane substantially parallel to the longitudinal direction of the guide rail insert.

[0038] Thus, the flexible brake member has a circular or oval or similar shape and is oriented such that the roller element carrier will move in a direction substantially parallel to the orientation plane of the flexible brake member when moving along the second track unit and the track insert. When the roller element carrier is extracted, the brake activation member will therefore interact with the flexible brake member and deform the ring. Before the third and fourth stop elements interact, the energy used to deform the ring decelerates the roller element carrier, thereby providing a smooth deceleration of the roller element carrier when extracted.

[0039] The flexible brake member may form an integral part of the (plastic) guide rail insert.

[0040] Preferably, corresponding braking means are provided on the other side of the guide rail insert for providing a smooth deceleration when the roller element carrier is retracted into the household appliance.

[0041] In one embodiment, the household appliance is a dishwasher. In this case, the item support is typically a basket or wire rack for supporting bowls, glasses, etc. Alternatively, the household appliance may be, for example, a refrigerator or freezer. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the description of the embodiments of the present invention given below, reference is made to the following drawings, in which:

[0043] Figure 1 An embodiment of a household appliance in the form of a dishwasher is shown;

[0044] Figure 2 Shows Figure 1The internal parts of a dishwasher of the type described herein comprise a dishwasher basket, means for withdrawing the basket from the dishwasher and retracting the basket into the dishwasher, one such means being provided on each side of the basket, and an internal frame supporting the withdrawal and retraction means;

[0045] Figure 3 Shows Figure 2 An exploded view of the overall components of the

[0046] Figure 4 An exploded view of one of the extraction and retraction devices is shown;

[0047] Figure 5A An outer facing side of a component connecting the basket to one of the extraction and retrieval devices is shown;

[0048] Figure 5B Shows Figure 5A The inner surface of the component;

[0049] Figure 6 A first rail unit of the extraction and retraction device is shown;

[0050] Figure 7 A cross-sectional view showing the extraction and retraction device;

[0051] Figure 8 a perspective view showing the extraction and retraction device in a retracted position;

[0052] Fig. 9 Shows Figure 8 A longitudinal cross-sectional view of the extraction and retraction device;

[0053] Fig.10 a perspective view showing the withdrawal and retraction device in the withdrawn position;

[0054] Fig.11 Shows Fig.10 A longitudinal cross-sectional view of the extraction and retraction device;

[0055] Fig.12 shows the roller element carrier in a position close to a maximum extended position relative to the second guide rail unit of the extension and retraction device; and

[0056] Fig.13 The second rail unit is shown in the maximum extended position. Fig.12 Roller element carrier. DETAILED DESCRIPTION

[0057] Figure 1 An embodiment of a household appliance in the form of a dishwasher 1 is shown. The interior washing chamber of the dishwasher 1 is defined by walls 2, a top 3, a bottom 4 and a door 5, which is located at Figure 1The dishwasher 1 is open in the middle. A removable and retractable basket / wire holder 6 for supporting items such as glasses is arranged between the side walls 2 of the dishwasher 1. The dishwasher 1 is usually provided with additional components, such as one or more spray arms and one or more additional baskets. These components are well known and are not shown here.

[0058] Figure 2 Shows Figure 1 The inner parts of the dishwasher 1 include a dishwasher basket 6, a first device 10 and a second device 11 (left and right) for extracting and retracting the basket 6 from and into the dishwasher 1, and an inner wall frame 7 supporting the extraction and retraction devices 10, 11. Figure 2 As shown, the first extraction and retraction device 10 and the second extraction and retraction device 11 are arranged on opposite sides of the horizontally oriented basket 6 and are connected to the respective sides of the wall frame 7. In this example, the first extraction and retraction device 10 and the second extraction and retraction device 11 have the same but mirror-symmetrical design. The detailed description below focuses on the first (left) extraction and retraction device 10.

[0059] Figure 3 Shows Figure 2 Exploded view of the components shown.First and second connection assemblies 12,13 connect the basket 6 to the respective extraction and retrieval devices 10,11.

[0060] For example Figure 4 , Figure 7 , Figure 8 and Fig.10 As shown, the first (left side) extraction and retraction device 10 (and the second device 11) comprises a first rail unit 15, a second rail unit 17 / 18 and a third rail unit 20, which extend substantially parallel to each other. The first rail unit 15 and the second rail unit 17 / 18 are arranged to be movable in the longitudinal direction relative to each other. Similarly, the second rail unit 17 / 18 and the third rail unit 20 are arranged to be movable in the longitudinal direction relative to each other. The third rail unit 20 is fixed to the wall frame 7 by brackets 21, 22.

[0061] In this example, the third rail unit 20 is a conventional steel rail with a generally C-shaped cross section. In this example, the second rail unit 17 / 18 comprises two main elongated parts combined into one rail unit: an outer steel frame 18 and a rail insert 17 made of a plastic or polymer material, wherein the rail insert 17 is arranged inside along the outer frame 18 and fixed to the outer frame. The outer steel frame 18 is also a conventional steel rail with a generally C-shaped cross section, but has slightly smaller dimensions in order to allow the second rail unit 17 / 18 to be arranged inside it along the third rail unit 20.

[0062] Like the rail insert 17, the first rail unit 15 is made of a plastic or polymeric material. The first rail unit 15 is fixed to the basket 6 via the connection assembly 12 so as to allow the basket 6 to be withdrawn in a direction out of the dishwasher 1 and retracted in a direction into the dishwasher when the first rail unit 15 moves relative to at least one of the second rail unit 17 / 18 and the third rail unit 20 (and relative to both of the second rail unit 17 / 18 and the third rail unit 20 if moving between the maximum withdrawn position and the maximum retracted position).

[0063] The device 10 also includes first and second sets of roller elements in the form of balls 16a, 16b (see, e.g. Fig. 9 and Fig.11 ), the balls are longitudinally distributed along the first and second opposing outer surfaces 15a, 15b of the first guide rail unit 15 between the first and second guide rail units 15, 17 / 18 (actually between the guide rail inserts 17 of the first and second guide rail units 15, 17 / 18, see below) to facilitate relative movement between the first and second guide rail units 15, 17 / 18. More specifically, the first and second groups of balls 16a, 16b are arranged between the first and second opposing outer surfaces 15a, 15b of the first guide rail unit 15 and the corresponding first and second opposing inner surfaces 17a, 17b of the second guide rail unit 17 / 18, in which case the first and second inner surfaces 17a, 17b are formed in the guide rail insert 17, which is fixed and arranged in the frame 18 of the second guide rail unit 17 / 18 (for example, refer to Figure 7 ).

[0064] The first roller element carrier 16 holds the balls 16a, 16b in position at a distance from each other in the longitudinal direction of the first and second guide rail units 15, 17 / 18.The first roller element carrier 16 is longitudinally movable relative to each of the first and second guide rail units 15, 17 / 18.

[0065] In order to facilitate the relative movement between the second and third guide rail units 17 / 18, 20, an additional and similarly structured ball bearing device is also provided between the two guide rail units. This additional ball bearing device includes a longitudinally distributed between the second guide rail unit 17 / 18 and the third guide rail unit 20 (actually between the outer frame 18 of the second guide rail unit 17 / 18 and the third guide rail unit 20, for example, refer to Figure 7 ) of the third and fourth groups of balls 19a, 19b, wherein the balls 19a, 19b are carried by a second roller element carrier 19, which can be longitudinally moved relative to each of the second guide rail unit 17 / 18 and the third guide rail unit 20.

[0066] like Figure 6As shown, the first rail unit 15 comprises a rail part 15c extending along the other rails (and, for example, along the row of balls 16a, 16b) and a connecting part 15d fixed to the rail part 15c. In this case, the rail part 15c and the connecting part 15d form an integral part, which can be made by injection molding, for example. The first rail unit 15 is indirectly connected to the basket 6 via the connecting part 15d, in this example via the connecting assembly 12. The connecting assembly 12 is arranged on the connecting part 15d (by sliding the connecting assembly down along the connecting part 15d so that the ridge fits into the groove), so that the weight of the basket 6 (i.e. the load carried by the first rail unit 15) is distributed to the first rail unit 15 along a connecting length 25 corresponding to the length of the connecting part 15d, as shown in FIG. Figure 6 The load transfer connection between the basket 6 and the first rail unit 15 may be arranged in different ways, but the length and position of the connection are of particular interest in the present disclosure, as further explained below.

[0067] In this example, the connection assembly 12 has a specific design related to the function of lifting and lowering the basket 6, which also involves Figure 4 and Figure 7 This lifting / lowering function is not particularly important for the present disclosure, but it should be noted that the part 14 can be considered to form part of the first guide rail unit 15, as further explained below.

[0068] Compared with conventional steel rails such as the third rail unit 20, the first rail unit 15 has a special design, that is, the first rail unit 15 is provided with support materials 30, 14 between the first opposing outer surface 15a and the second opposing outer surface 15b so as to withstand compression deformation when one or more balls 16a, 16b apply force to any one of the outer surfaces 15a, 15b, for example, referring to Figure 4 , Figure 6 , Figure 7 and Fig.11 When the first rail unit 15 is compressed between the outer surfaces 15a, 15b, the supporting material therebetween is subjected to compressive forces which are relatively easy for most building materials, including for example plastic materials, to withstand, compared to bending forces and the like to which the end flanges of conventional steel rails are subjected under similar circumstances. Thus, this design enables the first rail unit 15 to be made of a plastic or polymer material, rather than of steel, which is typically more expensive.

[0069] In the example shown herein, the first rail unit 15 includes a plurality of wall members 30 extending through (in this case laterally through) the first rail unit 15, wherein the wall members 30 constitute at least a portion of the support material between the first and second opposing outer surfaces 15a, 15b. Figure 6 and Fig.11 It is shown or at least indicated that the first guide rail unit 15 is also provided with a wall member ( Fig.11 The cross section is taken along the longitudinally extending wall member. Figure 7 As shown, the part 14 also forms part of the support material arranged between and intermediate the first opposing outer surface 15a and the second opposing outer surface 15b. For another type of connection between the first rail unit 15 and the basket 6, i.e. a connection not involving a specific connection assembly 12, a further cross wall member 30 may alternatively be arranged in the area where the part 14 is located.

[0070] The first rail unit 15 is also provided with a first stop element 41, which is configured to stop when the extraction and retraction device 10 is fully extracted (see Fig.11 ), interacting with a corresponding second stop element 42 arranged at a fixed position relative to the second guide rail unit 17 / 18. Therefore, when the first stop element 41 and the second stop element 42 interact, further extraction of the first guide rail unit 15 is prevented, and the maximum extraction position of the first guide rail unit 15 relative to the second guide rail unit 17 / 18 is thereby set.

[0071] In this example, the second stop element 42 is arranged on the first roller element carrier 16. The first roller element carrier 16 is in turn provided with a third stop element 43 which is configured to interact with a corresponding fourth stop element 44 arranged on the second guide rail unit 17 / 18, or more specifically with the guide rail insert 17 arranged fixed to the metal outer frame 18 (see Fig.11 ). Thus, when the third stop element 43 and the fourth stop element 44 interact, further extraction of the first roller element carrier 16 is prevented and the maximum extraction position of the first roller element carrier 16 relative to the second guide rail unit 17 / 18 is thereby set. When the extraction and retraction device 10 is fully extracted, this in turn sets the fixed position of the second stop element 42 relative to the second guide rail unit 17 / 18 (see Fig.11 ).

[0072] As described above, the basket 6 is connected to the first rail unit 15 along a connection length 25 extending in the longitudinal direction of the first rail unit 15. The embodiment shown herein is configured so that when the first rail unit 15 is in its maximum extracted position relative to the second rail unit 17 / 18 (see e.g. Figure 10-11), no connection length 25 or only a small part (i.e. significantly less than half of the connection length 25) is located outside the second rail unit 17 / 18, in particular relative to the outer frame 18. Therefore, when the extraction and retraction device 10 is fully extracted, the weight of the basket 6 can also be carried by the outer steel frame 18 of the second rail unit 17 / 18. In this way, the first rail unit 15 does not have to withstand any significant bending moment, which also allows the first rail unit 15 to be made of plastic or polymer material instead of steel.

[0073] The extraction and retraction device 10 is configured such that the outer steel frame 18 of the second rail unit 17 / 18 carries the weight and handles the bending moments when the extraction and retraction device 10 is fully retracted, and when in positions between fully extracted and fully retracted.

[0074] The guide rail insert 17 is provided with a flexible brake member 50 for slowly decelerating the first roller element carrier 16 during the extraction process before the third stop element 43 and the fourth stop element 44 interact and the first roller element carrier 16 reaches its maximum extraction position, with reference to Figure 12-13 .

[0075] The first roller element carrier 16 is provided with a brake activating member 51 which is arranged to interact with the flexible brake member 50 before the first roller element carrier 16 reaches its maximum extracted position.

[0076] The flexible brake member 50 is made of a flexible material, has a closed loop shape, and is oriented in a plane substantially parallel to the longitudinal direction of the guide rail insert 17. Figure 12-13 As shown, the flexible brake member has an oval shape and is oriented vertically.

[0077] Fig.12 The first roller element carrier 16 is shown in an approximately maximally extended position relative to the second guide rail unit 17 / 18 . Fig.13 FIG. 4 shows the first roller element carrier 16 in a maximum extended position, wherein the third stop element 43 and the fourth stop element 44 interact with each other. Fig.13 As shown, before the third stop element 43 and the fourth stop element 44 interact, the oval flexible brake member 50 is already slightly deformed, thereby causing the first roller element carrier 16 to slowly decelerate during the extraction process.

[0078] As mentioned above, Figure 4-13 Various views of the extraction and retrieval device 10 are provided.

[0079] The invention is not limited to the above-described embodiments, but may be modified in various ways within the scope of the claims. For example, the support material may be distributed continuously between the opposing outer surfaces along the first rail unit, or distributed in relatively long sections, rather than forming thin-walled members (forming very short longitudinal sections when extending across the rail). However, the distribution of the wall members can withstand compression deformation and is conducive to saving weight and material costs.

[0080] Furthermore, the connection between the first rail unit and the basket / article support may be arranged in different ways, for example by using a plurality of brackets or connecting rods distributed over a certain longitudinal distance that will form the connection length.

[0081] Furthermore, the extraction and retraction device does not necessarily have to comprise three guide rail units, and for example the second guide rail unit may have a different design.

Claims

1. A household appliance, in, The household appliances include: an article support arranged in the household appliance, and means for extracting and retracting the object support from the household appliance, The extraction and retraction device includes: a first guide rail unit (15) and a second guide rail unit, the first guide rail unit (15) and the second guide rail unit extending parallel to each other, wherein the first guide rail unit (15) and the second guide rail unit are arranged to be movable relative to each other in a longitudinal direction; a first group of roller elements and a second group of roller elements, the first group of roller elements and the second group of roller elements being longitudinally distributed between the first guide rail unit (15) and the second guide rail unit along a first relative outer surface (15a) and a second relative outer surface (15b) of the first guide rail unit (15) to facilitate the relative movement, Features The first guide rail unit (15) is provided with a support material in a region extending between and intermediate the first relative outer surface (15a) and the second relative outer surface (15b) at least along one or more sections of its length, so as to allow absorption of compressive forces in the support material and resist compression deformation of the first guide rail unit (15) when one or more roller elements exert a force on either the first relative outer surface (15a) or the second relative outer surface (15b), wherein the first group of roller elements and the second group of roller elements are arranged between the first relative outer surface (15a) and the second relative outer surface (15b) of the first guide rail unit and the corresponding first relative inner surface (17a) and the second relative inner surface (17b) of the second guide rail unit, wherein the second guide rail unit comprises an outer frame (18) made of a metal material and a guide rail insert (17) made of a plastic or polymer material, and wherein the guide rail insert (17) is arranged inside the outer frame (18) and fixed to the outer frame (18), and Wherein, the first relative inner surface (17a) and the second relative inner surface (17b) of the second guide rail unit are arranged in the guide rail insert (17).

2. The household appliance according to claim 1, wherein: The first rail unit (15) comprises a plurality of wall members (30) extending through the first rail unit (15), wherein the wall members (30) constitute at least a portion of a support material between the first opposing outer surface (15a) and the second opposing outer surface (15b).

3. The household appliance according to claim 1, wherein: The first rail unit (15) is fixed to the article support so as to allow the article support to be withdrawn in a direction away from the household appliance and retracted in a direction into the household appliance when the first rail unit (15) is moved relative to the second rail unit.

4. The household appliance according to claim 1, wherein: The first guide rail unit (15) is provided with a first stop element (41), and the first stop element is configured to interact with a corresponding second stop element (42) set at a fixed position relative to the second guide rail unit when the withdrawal and retraction device is fully withdrawn, so that when the first stop element (41) and the second stop element (42) interact with each other, further withdrawal of the first guide rail unit (15) is prevented, and the maximum withdrawal position of the first guide rail unit (15) relative to the second guide rail unit is set.

5. The household appliance according to claim 4, wherein: The article support is directly or indirectly connected to the first guide rail unit (15) along a connection length (25) extending in the longitudinal direction of the first guide rail unit (15), and wherein, when the first guide rail unit (15) is in its maximum extended position relative to the second guide rail unit, less than half of the connection length (25) is located outside the second guide rail unit.

6. The household appliance according to claim 5, wherein: When the first guide rail unit (15) is in its most extended position relative to the second guide rail unit, less than 20% of the connection length (25) is located outside the second guide rail unit.

7. The household appliance according to claim 4, wherein: The extraction and retraction device comprises a first roller element carrier (16) which holds the first and second groups of roller elements in place at first and second opposing outer surfaces (15a and 15b) of the first rail unit (15).

8. The household appliance according to claim 7, wherein: The first roller element carrier (16) is longitudinally movable relative to each of the first guide rail unit (15) and the second guide rail unit.

9. The household appliance according to claim 7, wherein: The second stop element (42) is arranged on the first roller element carrier (16).

10. The household appliance according to claim 7, wherein: The first roller element carrier (16) is provided with a third stop element (43), and the third stop element is configured to interact with a corresponding fourth stop element (44) arranged on the second guide rail unit, so as to prevent the first roller element carrier (16) from being further withdrawn when the third stop element (43) and the fourth stop element (44) interact with each other, thereby setting the maximum withdrawal position of the first roller element carrier (16) relative to the second guide rail unit.

11. A household appliance according to any one of the preceding claims, wherein: The first guide rail unit (15) is made of plastic or polymer material.

12. The household appliance according to any one of claims 1 to 10, wherein: The first rail unit (15) comprises a rail member (15c) extending along the first and second groups of roller elements and a connecting member (15d) fixed to the rail member (15c) and directly or indirectly connected to the article support.

13. The household appliance according to any one of claims 1 to 10, wherein: The withdrawing and retracting device comprises a third rail unit (20) fixed to the inner wall frame (7) of the household appliance.

14. The household appliance according to claim 13, wherein: The second guide rail unit is movably connected to the third guide rail unit (20) via a third set of roller elements and a fourth set of roller elements longitudinally distributed between the second guide rail unit and the third guide rail unit (20).

15. The household appliance according to claim 10, wherein: The guide rail insert (17) is provided with a flexible braking member (50) to slowly decelerate the first roller element carrier (16) during extraction before the third stop element (43) and the fourth stop element (44) interact and the first roller element carrier (16) reaches its maximum extraction position, and wherein the first roller element carrier (16) is provided with a brake activation member (51) which is arranged to interact with the flexible braking member (50) before the first roller element carrier (16) reaches its maximum extraction position.

16. The household appliance according to claim 15, wherein: The flexible braking member (50) is made of a flexible material, has a closed loop shape, and is oriented in a plane parallel to the longitudinal direction of the guide rail insert (17).

17. The household appliance according to any one of claims 1 to 10, wherein: The household appliance is a dishwasher.

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