A DRAWER RUNNER SYSTEM

TECHNICAL FIELD

[0001]The present invention relates to a drawer runner system, and to a chest of drawers comprising such drawer runner system.

BACKGROUND

[0002]Drawer runner systems are commonly used for providing a smooth motion as drawers are pulled out from and pushed into an associated cabinet. Typical requirements for modern drawer runner systems include low friction, robustness, low complexity, and reasonable cost.

[0003]One specific type of drawer runner system comprises a rail being fixed to the interior wall of the cabinet, and a member being fixed to the exterior wall of the drawer at a rear portion. As the drawer is pulled out from the cabinet, the member is allowed to roll or slide, preferably with low friction, against the rail which also functions to limit the lateral motion of the drawer. Runner systems of this type are often referred to as concealed runner systems, as the runner system parts will normally not be visible even when the drawer is pulled out to its maximum extent, i.e. when the member reaches the end position of the rail.

[0004]One drawback of these systems is the required lateral space between the interior cabinet wall and the exterior drawer wall. This space needs to accommodate the rail as well as brackets and fasteners for mounting the member to the exterior drawer side, including tolerances. Available solutions of today are difficult to use if this lateral space is to be less than 14 mm, or even less than 10 mm.

[0005]Especially for small pieces of furniture the lateral space being 10 mm or more will significantly impair the visual appearance of the piece of furniture, as well as reducing the useable volume of the drawer as the total width of the drawer needs to be significantly smaller than the interior width of the cabinet. Hence there is a need for an improved drawer runner system which can be used in concealed applications and which require a reduced lateral space to fit between the interior cabinet wall and the exterior drawer side.

SUMMARY

[0006]Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above-mentioned problems by providing a drawer runner system which can be made more compact in the width-wise direction while still providing the desired functionality, robustness, and cost efficiency.

[0007]According to a first aspect a drawer runner system is provided. The drawer runner system comprises a rail having a mounting plate, a top engagement portion and a bottom engagement portion. Said top and bottom engagement portions are extending in parallel along the rail. The drawer runner system further comprises a runner member having a top sliding surface for sliding engagement with the top engagement portion and a bottom sliding surface for sliding engagement with the bottom engagement portion, wherein the lateral width of at least one of the top and bottom sliding surfaces is greater than the lateral width of the associated top and bottom engagement portion(s). By this configuration the rail can be made with significantly less dimensions, especially in the horizontal direction, compared to what has been suggested by the prior art. Especially with the proposed solution the rail does not need to fully enclose the entire lateral width of the runner member, but only provide a narrow sliding interface while still achieving a robust sliding interface with low friction. In addition, the drawer runner system does not require any use of bearings, such as ball bearings, or any rollers, which is required by many runner systems known in the art.

[0008]Preferably, the top and bottom engagement portions are vertically aligned.

[0009]The lateral width of each one of the top and bottom sliding surfaces may be greater than the lateral width of the associated top and bottom engagement portion(s).

[0010]At least one of the top and bottom engagement portions may be provided with a radius. Preferably the radius is in the range of 0,5-5.0 mm, such as 0,7-4.0 mm, preferably in the range of 0,8-3.0 mm, even more preferably in the range of 1,0-2.5 mm.

[0011]The lateral width of at least one of the top and bottom engagement portions may be in the range of 1 mm or less.

[0012]The rail may comprise a top flange being tilted to extend downwards, and an upper lip arranged outside and extending upwards from said top flange, wherein the interface between the top flange and the upper lip forms the top engagement portion.

[0013]The rail may comprise a bottom flange being tilted to extend upwards, and a bottom lip arranged outside and extending downwards from said bottom flange, wherein the interface between the bottom flange and the bottom lip forms the bottom engagement portion.

[0014]The mounting plate, the top engagement portion, and the bottom engagement portion may be integrally formed.

[0015]The lateral distance between the mounting plate and the top and bottom engagement portions may be greater than half the lateral width of the runner member.

[0016]The runner member may be configured to be capable of being turned in relation to the drawer side wall. Hence, the runner member may be arranged and adapted for being turned in relation to the drawer side wall. The runner member may be designed such that it may be turned in relation to the drawer side wall.

[0017]The runner member may be made of plastic. The rail may be made of metal, preferably coated by a coating, such as a lacquer.

[0018]The runner member may have the shape of a polygon or cylinder, preferably the runner member has the shape of a polygon, such as a rectangular shape or a hexagonal shape.

[0019]At least one of the top sliding surface and the bottom sliding surface may be at least partly concave.

[0020]At least one of the top sliding surface and the bottom sliding surface may comprise an outer end wing, optionally also an inner end wing, and a central sliding portion extending from the outer end wing.

[0021]Preferably, a vertical distance between an outer edge of the top sliding surface and an outer edge of the bottom sliding surface is larger than a vertical opening distance between the top and bottom engagement portion. This prevents the runner member from being laterally displaced out of the rail.

[0022]At least one of the outer edges of the top and bottom sliding surfaces may preferably be defined by an outer end wing, such that the vertical distance between the outer edges of the top and bottom sliding surfaces is defined by the vertical distance between the outer edge of the outer end wing of one sliding surface and the central sliding portion of the other sliding surface, or in case of each sliding surface being provided with a respective outer end wing, the vertical distance between the outer edges of the outer end wings.

[0023]The central sliding portion may at least partly be provided with a radius. The radius of the central sliding portion of the top sliding surface and/or the bottom sliding surface may be equal to or greater than the radius of the top and/or bottom engagement portions.

[0024]The central sliding portion may have a horizontal portion, preferably such horizontal portion being arranged as an intermediate portion between two portions provided with a radius.

[0025]The rail may comprise a horizontal front section, an intermediate retardation section being tilted vertically upwards, and a rear section being tilted vertically downwards.

[0026]The total width of the drawer runner system may be less than 14 mm, such as 3-14 mm, preferably in the range of 6-10 mm.

[0027]According to a second aspect, a chest of drawers is provided. The chest of drawers comprises a cabinet, at least one drawer, and at least one drawer runner system according to the first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]The invention will be described in further detail below with reference to the accompanying drawings, in which

[0029]FIG. 1a is an isometric view of a chest of drawers according to an embodiment;

[0030]FIG. 1b is an isometric view of the chest of drawers shown in FIG. 1a, with one drawer pulled out.

[0031]FIG. 2 is an exploded view of a drawer runner system according to an embodiment;

[0032]FIG. 3 is an isometric view a drawer runner system in an assembled state;

[0033]FIG. 4 is an isometric view of a rail of a drawer runner system according to an embodiment;

[0034]FIG. 5a is a cross-sectional view of a drawer runner system according to an embodiment;

[0035]FIG. 5b is an isometric view of a runner member of a drawer runner system according to an embodiment;

[0036]FIG. 6 is a cross sectional view of a drawer runner system shown in three different positions;

[0037]FIG. 7 is a cross-sectional view of a runner member of a drawer runner system; and

[0038]FIGS. 8a-d are cross-sectional views of rails of a drawer runner system according to different embodiments.

DETAILED DESCRIPTION

[0039]Several embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in order for those skilled in the art to be able to carry out the invention. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The embodiments do not limit the invention, but the invention is only limited by the appended claims. Furthermore, the terminology used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.

[0040]Starting in FIGS. 1a and 1b a chest of drawers 1 is shown. The chest of drawers 1 represents one possible implementation for a drawer runner system as will be described in the following, however other possible applications exist where one part is intended to move relative another part.

[0041]The chest of drawers 1 comprises a cabinet 10. The cabinet 10 is provided with a plurality of drawers 20 which are connected to cabinet 10 in a manner allowing the drawers 20 to move from a closed position, shown in FIG. 1a, to an open position as shown in FIG. 1b. This motion is enabled by means of at least one drawer runner system 30. The drawer runner system 30 is not visible in FIGS. 1a and 1b (only indicated), as it is designed as a concealed drawer runner system meaning that the components of the drawer runner system 30 are normally not visible for a user even when the drawer 20 is pulled out from the cabinet 10. It should however be understood that the herein described drawer runner system 30 may also be used in other types of drawer runner systems being visible or concealed, and operating to pull out the drawer to an extent such as 3/4 extension, full extension, and/or over-travel extension.

[0042]The drawer runner system 30 is, for the purpose of proper function of the chest of drawers 1, forming a moving interface between the cabinet 10 and the drawer 20. One part 40 of the drawer runner system 30 is fixedly attached to the cabinet 10, while another part 50 of the drawer runner system 30 is fixedly attached to the drawer 20 (see FIG. 1b). By engagement between the parts 40, 50 of the drawer runner system 30, the drawer 20 will be allowed to move in and out from the cabinet 10.

[0043]Now turning to FIG. 2 details of a drawer runner system 30 will be further described. The drawer runner system 30 comprises a rail 40 and an associated runner member 50. The rail 40 is securely attached to the interior wall of the cabinet 10, preferably in a substantially horizontal configuration. The rail 40 extends in a longitudinal direction L from a front end 41F to a rear end 41R. Fastening means 42, such as through holes for allowing attachment of the rail 40 to the interior of the cabinet 10 of FIGS. 1a-b by means of screws, dowels, etc., are provided along the length of the rail 40 i.e. somewhere between the front end 41F and the rear end 41R.

[0044]The rail 40 provides a guide for the runner member 50. In operation the runner member 50, which will be described in further detail below, is allowed to run freely along the rail 40, but prevented from unrestricted motion in a direction perpendicular to the longitudinal direction L of the rail 40. The runner member 50 is securely attached to the exterior side of a drawer side panel 21. In the shown embodiment the runner member 50 is pre-mounted to a bracket 51 which in turn is attachable to the exterior side of the drawer side panel 21, e.g. by means of screws, dowels, etc. The runner member 50, which may be provided with a centrally aligned through hole, may e.g. be attached to the bracket 51 by means of a rivet 59 which also forms a shaft for the runner member 50.

[0045]Preferably, the bracket 51 is designed such that the runner member 50, when secured to the drawer side panel 21, is located close to the bottom rear corner of the drawer 20.

[0046]As can be seen in FIG. 2 the drawer runner system 30 may also comprise a bottom guide 60 which is mounted to the bottom side of the drawer side panel 21. Although not further described herein, the bottom guide 60 may be designed to slide relative a fixed sliding member 70 which is arranged at the front end 41F of the rail 40.

[0047]In FIG. 3 the assembled drawer runner system 30 is shown, however the cabinet is excluded for facilitated understanding. The rail 40, in this illustration the right side rail, is shown from its back side which preferably is relatively flat in order to provide a robust contact when mounted to the cabinet wall. In FIG. 3 the runner member 50 (not shown, but indicated by dashed lines) is received by the rail 40 at the bottom rear corner of the drawer side panel 21. The illustration of FIG. 3 corresponds to the situation in FIG. 1a, meaning the drawer is fully inside of the cabinet. When the drawer is pulled out of the cabinet, to the situation illustrated in FIG. 1b, the drawer side panel 21 and the runner member 50 will move to the left in the illustration of FIG. 3.

[0048]In FIG. 4 the rail 40, in this illustration the left side rail, is shown in more detail. As compared to the embodiment shown in FIGS. 2 and 3, in FIG. 4 details of the front end 41F are omitted. The rail 40 comprises an upper engagement portion 43 and a bottom engagement portion 44. The upper and bottom engagement portions 43, 44 are connected by means of a mounting plate 45 and they are vertically aligned and extending in parallel along the rail 40. Preferably, the entire rail 40 is formed from a single piece of material, i.e. the mounting plate 45 is integrally formed with the upper and bottom engagement portions 43, 44. Suitable materials for the rail 40 include metals, such as steel or aluminium, as well as polymeric materials, plastics, alloys, composite materials, etc. The rail may be produced by bending sheet metal, by extrusion, by injection moulding or by other another suitable manufacturing process.

[0049]During operation, the runner member 50 (not shown in FIG. 4) is received in a vertical space formed between the upper and bottom engagement portion 43, 44. Due to the parallelism of the upper and bottom engagement portions 43, 44 this vertical space is constant along the length of the rail 40.

[0050]The rail 40 is preferably comprising three sections. A front section FS has a substantially horizontal extension, which means that the drawer 20 will move essentially horizontally when the runner member 50 is guided by the front section FS. When pushed inwards towards a closed position, the runner member 50 will travel along the front section FS which transitions to an intermediate section IS. The intermediate section is tilted slightly vertically upwards, such as between 1° and 5°, thus forming a retardation zone for the runner member 50 travelling along the intermediate section IS. At the rear end 41R of the rail 40 the intermediate section IS transitions to a rear section RS, being tilted slightly vertically downwards, such as between 3° and 10°, to the same horizontal level as the front section FS. The rear section RS of the rail 40 forms a self-closing zone for the runner member 50, which will be assisted by gravity the last distance of travel. Further, the rear section RS ensures that the drawer 20 will stay in its closed position until a user applies a pulling force to it to pull it out. As indicated in FIG. 4, the rear section RS is provided with a stop member 46, which may be formed by a protrusion of the mounting plate 45 in its normal direction.

[0051]Now turning to FIG. 5a the drawer runner system 30 is shown in cross-section, especially illustrating details of the rail 40, in this illustration the right side rail, same as in FIG. 3, and its engagement with the runner member 50.

[0052]As explained previously the runner member 50 is arranged in the vertical space formed between the top and bottom engagement portions 43, 44 of the rail 40. The runner member 50 comprises a top sliding surface 53 for the top engagement portion 43 and a bottom sliding surface 54 for the bottom engagement portion 44. Hence, when moving the drawer 20 in and out from the cabinet 10 the top sliding surface 53 of the runner member 50 will slide against the top engagement portion 43 of the rail 40, while the bottom sliding surface 54 of the runner member 50 will slide against the bottom engagement portion 44 of the rail 40.

[0053]Typically, the sliding engagement between the rail 40 and the runner member 50 is designed to provide low friction, and various techniques and adaptations can be made in order to accomplish a desired level of the static and the dynamic friction. For example, the runner member 50 may be made of a plastic material while the rail 40, and in particular the top and bottom engagement portions 43, 44, may be made of a metal. Such metal may be coated by a coating, such as a lacquer, such as a lacquer applied by an electrophoretic deposition process. Other suitable techniques known in the art includes applying a lacquer comprising a resin to the rail 40, spray coating the rail 40, etc. Optionally, a lipophilic composition coating, e.g. a lubricant, may be applied to the runner member 50 and/or onto the rail 40, either directly onto the rail 40, or onto the coating, such as the lacquer, applied to the rail 40. Such rail 40 with a lacquer applied thereto is preferably used with a runner member 50 made of plastic.

[0054]As described above, the runner member 50 has a top sliding surface 53, and a bottom sliding surface 54. In addition, the runner member 50 has an outer surface 55a and an inner surface 55d. The inner surface 55d preferably faces the drawer side panel 21. Preferably, the outer surface 55a faces the rail 40. The outer surface 55a and the inner surface 55d are opposite to each other. Further, the runner member 50 has an upper surface 55b and a bottom surface 55c. The upper surface 55b and the bottom surface 55c separate the outer surface 55a from the inner surface 55d.

[0055]In the shown embodiments the runner member 50 has a rectangular shape, thereby defining the top and bottom sliding surfaces 53, 54 as substantially horizontal and planar. Therefore, the shape of the outer and inner surfaces 55a, 55d are rectangular. The outer and inner surfaces 55a, 55d are perpendicular to the top and bottom sliding surfaces 53, 54. However, as is shown in FIG. 5b the corners 50c of the rectangular shape of the runner member 50 may be slightly rounded in order to achieve a smooth motion between the different sections FS, IS, RS of the rail 40. The outer and inner surfaces 55a, 55d may have slightly rounded corners, as shown in FIG. 5b. Since the runner member 50 is designed with top and bottom sliding surfaces 53, 54 being substantially horizontal and planar, and with the outer and inner surfaces 55a, 55d having a rectangular shape, the runner member 50 may be rotated in relation to the drawer side panel 21.

[0056]As described above the runner member 50 may be a rectangular body being fixed in relation to the associated drawer 20, thereby providing a purely sliding interface between the runner member 50 and the rail 40. Other shapes, not necessarily rectangular, for example hexagonal, and octagonal shapes, are also possible for a sliding runner member 50. The outer and inner surfaces 55a, 55d of the runner member 50 may have other shapes, not necessarily rectangular, for example hexagonal, and octagonal shapes.

[0057]As can be seen in FIG. 5a the lateral width LW1 of the top and bottom sliding surfaces 53, 54 of the runner member 50 is substantially greater than the lateral width LW2 of the associated top and bottom engagement portion(s) 43, 44 of the rail. Each one of the top and bottom engagement portions 43, 44 provide a narrow contact point with the associated sliding surface 53, 54. This narrow contact point, being in the range of a width of 1 mm or less, will form a limited contact area assisting in providing the desired low friction between the runner member 50 and the rail 40.

[0058]Generally, the lateral width LW1 of the top and bottom sliding surfaces 53, 54 is defined as the section engaging with the respective top and bottom engagement portions 43, 44 during normal operation of the drawer runner system. The top and bottom sliding surfaces 53, 54 do not necessarily need to be entirely planar, they are in some embodiments provided with a curvature such that they exhibit e.g. a concave shape as is further discussed with reference to FIG. 7. In accordance with this definition, the runner member 50 may extend laterally beyond the top and bottom sliding surfaces 53, 54 as mentioned below with respect to the end wings 56, 57 (see FIG. 6).

[0059]Similarly, the lateral width LW2 of the top and bottom engagement portions 43, 44 is defined as the section of the rail 40 being in contact with the respective top and bottom sliding surfaces 53, 54 during normal operation of the drawer runner system. Preferably the top and bottom engagement portions 43, 44 are each provided with a radius, and the exact lateral width LW2 during use may thus depend on pressure, material deformation, etc.

[0060]The rail 40 has the general shape of a C-profile, where the active parts of the engagement with the runner member 50 are formed by the top and bottom engagement portions 43, 44 defining the vertical gap in which the runner member 50 is disposed. As is clear from FIG. 5a the rail 40 does not extend to cover all sides of the runner member 50. The rail 40 extends along the outer surface 55a of the runner member 50 by means of the mounting plate 45, along a part of the upper surface 55b forming the top sliding surface 53 by means of the top engagement portion 43, along a part of the bottom surface 55c forming the bottom sliding surface 54 by means of the bottom engagement portion 44, but not along the inner surface 55d which faces the drawer side panel 21.

[0061]As is shown in FIG. 5a the rivet 59 being used to fasten the runner member 50 does not protrude beyond the outer surface 55a of the runner member 50. The runner member 50 is fixed in relation to the associated drawer 20, thereby providing a purely sliding interface between the runner member 50 and the rail 40. Hence, the runner member 50 is stationary when the rail 40 slides along the top and bottom sliding surfaces 53, 54.

[0062]Leaving the inner side 55d completely free from coverage of the rail 40 would possibly lead to a risk for the rail to lose its engagement with the runner member 50 by lateral displacement of the rail 40 relative the drawer 20, e.g. as a result of cabinet 10 bulging. However, this is prevented due to the configuration of the runner member 50 as is further illustrated in FIGS. 6 and 7.

[0063]In FIG. 6 the drawer runner system 30 is shown in three different positions, while in FIG. 7 the runner member 50 is shown in more detail. In the rightmost and lowermost position of FIG. 6 the distance between the drawer side panel 21 (schematically indicated in FIG. 6, better shown in FIGS. 3 and 5a) and the rail 40 (i.e. the cabinet 10) is at its minimum. In this position the outer surface 55a of the runner member 50 will be in contact with the mounting plate 45 of the rail 40, which mounting plate 45 blocks any further lateral displacement in this direction of the runner member 50.

[0064]In the middle position the runner member 50 is centrally arranged within the rail 40, i.e. the only contact between the rail 40 and the runner member 50 is the sliding engagement between the top and bottom engagement portions 43, 44 and the respective top and bottom sliding surfaces 53, 54.

[0065]In the leftmost and uppermost position the lateral distance between the drawer side panel 21 and the rail 40 (i.e. the cabinet 10) is increased to a maximum distance. This may for example be due to a bulging of the cabinet, that may be caused by overly high loads in the drawers. This maximum distance is defined by the runner member 50 being provided with end wings 56. The runner member 50 thus has a central sliding portion 58 delimited by an outer end wing 56 and an optional inner end wing 57. These end wings 56, 57 are preferably extending out from the central sliding portion 58 both at the top sliding surface 53 and at the bottom sliding surface 54. Preferably each one of the top and bottom sliding surfaces 53, 54 is curved shaped, such that the vertical height of each one of the top and bottom sliding surfaces 53, 54 varies between a maximum value at the outer end of the runner member 50 corresponding to the outer end wing 56, to a minimum value at the central portion of the runner member 50 corresponding to the central sliding portion 58, and back to the maximum value at the inner end of the runner member 50 corresponding to the inner end wing 57. Hence, the end wings 56, 57 form the lateral end sections of the respective top and bottom sliding surfaces 53, 54 however the end wings 56, 57 are not intended to be in sliding engagement with the top and bottom engagement portions 43, 44. The intended sliding engagement of the top and bottom sliding surfaces 53, 54 is defined by the central sliding portion 58 having a lateral width LW1 (see FIGS. 5a and 7) corresponding to the section being in contact with the respective top and bottom engagement portions 43, 44 of the rail 40 during normal use of the drawer runner system 30.

[0066]With the provision of the end wings 56, 57 the drawer 20 is mounted to the cabinet 10 by inserting the drawer 20 such that the runner member 50, attached at the rear section of the drawer 20, enters into the front end 41F (FIG. 2) of the rail 40, and subsequently pushing the drawer inwards.

[0067]As can be seen in FIG. 6 (leftmost position) the lateral distance LD between the mounting plate 45 and the top and bottom engagement portions 43, 44 is greater than half the lateral width LW of the runner member 50, i.e. the lateral width LW times 0,5. This is indicated by the reference numeral HLW in the leftmost position of FIG. 6.

[0068]The minimum vertical height at the central portion 58 of the runner member 50 is slightly smaller than the vertical distance between the top and bottom engagement portions 43, 44 of the rail 40. The maximum vertical height at the outer end of the runner member 50, i.e. the vertical height of the outer end wing 56, is greater than the vertical distance between the top and bottom engagement portions 43, 44 of the rail 40. This means that the runner member 50 will fit with the rail 40, but it is not allowed to move beyond the rail as the outer end wing 56 will be blocked by the respective engagement portions 43, 44 of the rail 40. Thereby the outer wings 56 will, as illustrated to the left in FIG. 6, prevent the runner member 50 from being laterally disengaged from the rail 40. Thereby, the outer wings 56 will prevent an undue bulging of the cabinet and will prevent the drawer from falling down.

[0069]The geometry of the runner member 50 is further shown in FIG. 7, specifically indicating the vertical height H1 of the runner member 50 at the position of the outer wing end 56, the vertical height H2 of the runner member 50 at the central portion, and the vertical height H3 of the runner member 50 at the position of the inner wing end 57. Preferably, however not necessarily, H1≥H3. Further, H2<H1, H3.

[0070]The central portion 58 is, as indicated in FIG. 7, formed by a flat entirely horizontal part which at both opposite ends transitions to the wing ends 56, 57 by a curved section. However, in other embodiments the central portion 58 is provided with a radius R such that the entire central portion 58 is concave. Such concave configuration is indicated at the top sliding surface 54 in FIG. 7, where the dashed line indicates the top sliding surface 54 for such embodiment. Now turning to FIGS. 8a-d different embodiments of the rail 40 are shown. Starting in FIG. 8a, the rail 40 comprises a top flange 46a tilted downwards, and an upper lip 47a extending outwards and entirely vertically upwards from said top flange 46a. The interface between the top flange 46a and the upper lip 47a forms the top engagement portion 43. The top flange 46a is preferably integrally formed with the upper lip 47b, whereby the different orientations of the top flange 46a and the upper lip 47a are formed by bending a piece of material, such as sheet metal. For this reason, the top engagement portion 43 will be provided with a radius R2. Alternatively, a similar radius may be obtained by producing the rail 40 using other equipment such as extruders or similar.

[0071]The rail 40 further comprises a bottom flange 46b tilted upwards, and a bottom lip 47b extending outwards and entirely vertically downwards from said bottom flange 46b. The interface between the bottom flange 46b and the bottom lip 47b forms the bottom engagement portion 44. The bottom flange 46b is preferably integrally formed with the bottom lip 47b, whereby the different orientations of the bottom flange 46b and the bottom lip 47b are formed by bending the piece of material, such as sheet metal, or by other suitable manufacturing techniques. For this reason, the bottom engagement portion 44 will be provided with a radius R3. Preferably, the rail 40 is symmetrical such that the top engagement portion 43 has the same dimensions as the bottom engagement portion 44, i.e. R2=R3. The radius R2, R3 may be in the range of 0,5-5.0 mm, such as 0,7-4.0 mm, or even in the range of 0,8-3.0 mm. Most preferably the radius R2, R3 is in the range of 1,0-2.5 mm.

[0072]For embodiments where the runner member 50 is provided with one or more end wings 56, 57, the central portion 58 of the runner member 58 is preferably designed to transition to the end wings 56, 57 by a respective radius which is preferably selected to match the radius R2, R3 of the top and bottom engagement portions 43, 44, or the transition has a radius that is slightly larger than the radius R2, R3.

[0073]For the embodiments where the central portion 58 of the runner member 50 is concave by a radius R, this radius R is preferably larger than the radius R2, R3 such that the lateral width of the central portion 58 is greater than the lateral width LW2 of the associated top and bottom engagement portion(s) 43, 44 of the rail.

[0074]The rail 40 of FIG. 8b is identical to the rail 40 of FIG. 8a, except that the mounting plate 45 is provided with a bump 48. The bump 48, which preferably runs along the entire rail 40 or at least along the part of the rail 40 against which the runner member 50 slides, will provide a limited contact area between the runner member 50 and the mounting plate 45 when the drawer 20 is at its minimum distance in relation to the cabinet 10, as explained above with reference to FIG. 6, to the right thereof.

[0075]The rail 40 of FIG. 8c is similar to the rail 40 shown in FIG. 8b, however in this embodiment the upper and bottom lips 47a, 47b are not extending entirely vertically upwards, but they are instead oriented to extend in parallel with the respective top and bottom flanges 46a, 46b, i.e. the transition between the top and bottom flange 46a, 46b to the respective upper and bottom lip 47a, 47b is formed by a 180° fold, which fold forms the respective top and bottom engagement portions 43, 44. In order to keep the radii R2, R3 small the parallel distance between the top flange 46a and the upper lip 47a may be kept at a minimum. Correspondingly, also the parallel distance between the bottom flange 46b and the bottom lip 47b may be kept at a minimum.

[0076]Another possible configuration of the rail 40 is shown in FIG. 8d. In this embodiment the mounting plate 45 is provided with a plurality of bumps 48. Further, the rail 40 has a slightly different configuration of the top and bottom engagement portions 43, 44. In this embodiment the top and bottom flanges 46a, 46b are L-shaped, extending horizontally from the mounting plate 45 and transitioning to a vertical extension, i.e. the top and bottom flanges 46a, 46b are folded by 90°. Each flange 46a, 46b transitions to the respective lip 47a, 47b by a 180° fold which form the respective engagement portion 43, 44. Each lip 47a, 47b is also substantially L-shaped extending vertically from the respective engagement portion 43, 44, and then transitions, by a 90° fold, to a horizontal extension. While this embodiment has a slightly more complex shape than the previous embodiments, it does allow for a more distinct configuration of the end wings 56, 57 of the runner member 50.

[0077]Notably, in all embodiments shown in FIGS. 8a-d the mounting plate 45, the top engagement portion 43, and the bottom engagement portion 44 are integrally formed.

[0078]Also, in case the top sliding surface 53 and/or the bottom sliding surface 54 of the runner member 50 is concave thus exhibiting a radius R, preferably this radius R is greater than the radii R2, R3 of the top and/or bottom engagement portions 43, 44.