A Drawer Runner System

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

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.

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.

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.

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.

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.

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.

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

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).

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.

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

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.

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.

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

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.

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.

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

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.

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

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.

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.

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.

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.

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.

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

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.

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.

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.

Starting ina chest of drawersis shown. The chest of drawersrepresents 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.

The chest of drawerscomprises a cabinet. The cabinetis provided with a plurality of drawerswhich are connected to cabinetin a manner allowing the drawersto move from a closed position, shown in, to an open position as shown in. This motion is enabled by means of at least one drawer runner system. The drawer runner systemis not visible in(only indicated), as it is designed as a concealed drawer runner system meaning that the components of the drawer runner systemare normally not visible for a user even when the draweris pulled out from the cabinet. It should however be understood that the herein described drawer runner systemmay 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.

The drawer runner systemis, for the purpose of proper function of the chest of drawers, forming a moving interface between the cabinetand the drawer. One partof the drawer runner systemis fixedly attached to the cabinet, while another partof the drawer runner systemis fixedly attached to the drawer(see). By engagement between the parts,of the drawer runner system, the drawerwill be allowed to move in and out from the cabinet.

Now turning todetails of a drawer runner systemwill be further described. The drawer runner systemcomprises a railand an associated runner member. The railis securely attached to the interior wall of the cabinet, preferably in a substantially horizontal configuration. The railextends in a longitudinal direction L from a front endF to a rear endR. Fastening means, such as through holes for allowing attachment of the railto the interior of the cabinetofby means of screws, dowels, etc., are provided along the length of the raili.e. somewhere between the front endF and the rear endR.

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

Preferably, the bracketis designed such that the runner member, when secured to the drawer side panel, is located close to the bottom rear corner of the drawer.

As can be seen inthe drawer runner systemmay also comprise a bottom guidewhich is mounted to the bottom side of the drawer side panel. Although not further described herein, the bottom guidemay be designed to slide relative a fixed sliding memberwhich is arranged at the front endF of the rail.

Inthe assembled drawer runner systemis shown, however the cabinet is excluded for facilitated understanding. The rail, 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. Inthe runner member(not shown, but indicated by dashed lines) is received by the railat the bottom rear corner of the drawer side panel. The illustration ofcorresponds to the situation in, meaning the drawer is fully inside of the cabinet. When the drawer is pulled out of the cabinet, to the situation illustrated in, the drawer side paneland the runner memberwill move to the left in the illustration of.

Inthe rail, in this illustration the left side rail, is shown in more detail. As compared to the embodiment shown in, indetails of the front endF are omitted. The railcomprises an upper engagement portionand a bottom engagement portion. The upper and bottom engagement portions,are connected by means of a mounting plateand they are vertically aligned and extending in parallel along the rail. Preferably, the entire railis formed from a single piece of material, i.e. the mounting plateis integrally formed with the upper and bottom engagement portions,. Suitable materials for the railinclude 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.

During operation, the runner member(not shown in) is received in a vertical space formed between the upper and bottom engagement portion,. Due to the parallelism of the upper and bottom engagement portions,this vertical space is constant along the length of the rail.

The railis preferably comprising three sections. A front section FS has a substantially horizontal extension, which means that the drawerwill move essentially horizontally when the runner memberis guided by the front section FS. When pushed inwards towards a closed position, the runner memberwill 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 membertravelling along the intermediate section IS. At the rear endR of the railthe 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 railforms a self-closing zone for the runner member, which will be assisted by gravity the last distance of travel. Further, the rear section RS ensures that the drawerwill stay in its closed position until a user applies a pulling force to it to pull it out. As indicated in, the rear section RS is provided with a stop member, which may be formed by a protrusion of the mounting platein its normal direction.

Now turning tothe drawer runner systemis shown in cross-section, especially illustrating details of the rail, in this illustration the right side rail, same as in, and its engagement with the runner member.

As explained previously the runner memberis arranged in the vertical space formed between the top and bottom engagement portions,of the rail. The runner membercomprises a top sliding surfacefor the top engagement portionand a bottom sliding surfacefor the bottom engagement portion. Hence, when moving the drawerin and out from the cabinetthe top sliding surfaceof the runner memberwill slide against the top engagement portionof the rail, while the bottom sliding surfaceof the runner memberwill slide against the bottom engagement portionof the rail.

Typically, the sliding engagement between the railand the runner memberis 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 membermay be made of a plastic material while the rail, and in particular the top and bottom engagement portions,, 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, spray coating the rail, etc. Optionally, a lipophilic composition coating, e.g. a lubricant, may be applied to the runner memberand/or onto the rail, either directly onto the rail, or onto the coating, such as the lacquer, applied to the rail. Such railwith a lacquer applied thereto is preferably used with a runner membermade of plastic.

As described above, the runner memberhas a top sliding surface, and a bottom sliding surface. In addition, the runner memberhas an outer surfaceand an inner surface. The inner surfacepreferably faces the drawer side panel. Preferably, the outer surfacefaces the rail. The outer surfaceand the inner surfaceare opposite to each other. Further, the runner memberhas an upper surfaceand a bottom surface. The upper surfaceand the bottom surfaceseparate the outer surfacefrom the inner surface

In the shown embodiments the runner memberhas a rectangular shape, thereby defining the top and bottom sliding surfaces,as substantially horizontal and planar. Therefore, the shape of the outer and inner surfaces,are rectangular. The outer and inner surfaces,are perpendicular to the top and bottom sliding surfaces,. However, as is shown inthe cornersof the rectangular shape of the runner membermay be slightly rounded in order to achieve a smooth motion between the different sections FS, IS, RS of the rail. The outer and inner surfaces,may have slightly rounded corners, as shown in. Since the runner memberis designed with top and bottom sliding surfaces,being substantially horizontal and planar, and with the outer and inner surfaces,having a rectangular shape, the runner membermay be rotated in relation to the drawer side panel.

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

As can be seen inthe lateral width LWof the top and bottom sliding surfaces,of the runner memberis substantially greater than the lateral width LWof the associated top and bottom engagement portion(s),of the rail. Each one of the top and bottom engagement portions,provide a narrow contact point with the associated sliding surface,. 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 memberand the rail.

Generally, the lateral width LWof the top and bottom sliding surfaces,is defined as the section engaging with the respective top and bottom engagement portions,during normal operation of the drawer runner system. The top and bottom sliding surfaces,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. In accordance with this definition, the runner membermay extend laterally beyond the top and bottom sliding surfaces,as mentioned below with respect to the end wings,(see).

Similarly, the lateral width LWof the top and bottom engagement portions,is defined as the section of the railbeing in contact with the respective top and bottom sliding surfaces,during normal operation of the drawer runner system. Preferably the top and bottom engagement portions,are each provided with a radius, and the exact lateral width LWduring use may thus depend on pressure, material deformation, etc.

The railhas the general shape of a C-profile, where the active parts of the engagement with the runner memberare formed by the top and bottom engagement portions,defining the vertical gap in which the runner memberis disposed. As is clear fromthe raildoes not extend to cover all sides of the runner member. The railextends along the outer surfaceof the runner memberby means of the mounting plate, along a part of the upper surfaceforming the top sliding surfaceby means of the top engagement portion, along a part of the bottom surfaceforming the bottom sliding surfaceby means of the bottom engagement portion, but not along the inner surfacewhich faces the drawer side panel.

As is shown inthe rivetbeing used to fasten the runner memberdoes not protrude beyond the outer surfaceof the runner member. The runner memberis fixed in relation to the associated drawer, thereby providing a purely sliding interface between the runner memberand the rail. Hence, the runner memberis stationary when the railslides along the top and bottom sliding surfaces,.