TECHNICAL FIELD

The present invention relates to a rectangular plate for forming a hollow furniture structure as well as a furniture part comprising a rectangular plate.

BACKGROUND

A piece of furniture, both in homes and in public, is exposed to large loads and wear. It needs to be well constructed and robust. Additionally, it should be easy to assemble at a factory. Further, the furniture should be aesthetically pleasing and comfortable. This can e.g. be accomplished by rounded shapes.

It is known, e.g. from GB2010173A, to provide a plank with grooves such that it can be bent in order to form a columnar article. A drawback with this product is that a core material to be inserted into the hollow part of the column is described. This suggests that the wood structure in itself is not strong enough to make the columnar structure robust.

A method of producing curved wood surfaces by grooves or notches in the face of a wooden plate is also described in FR2553023. Also this structure requires reinforcement in the form of a stiffening framework which holds the curvature in its desired state.

A strengthening framework or core material adds to the costs of the product, as well as the weight. It would therefore be desirable to produce a curved shape of furniture that does not need a supportive backing. SUMMARY

An object of the present invention is to provide a new type of furniture part which is improved over prior art and which eliminates or at least mitigates the drawbacks discussed above. More specifically, an object of the invention is to provide a furniture part that is lightweight, robust and easy to assemble. These objects are achieved by the technique set forth in the appended independent claims with preferred embodiments defined in the dependent claims related thereto. In a first aspect of the invention, a rectangular plate for forming a hollow furniture structure is provided. The plate comprises a first surface, a second surface, and a first and a second edge portion provided at a first and a second end portion of the plate respectively. The first surface is provided with at least two parallel elongate slots by which the plate is arranged to be folded to form the hollow furniture structure. This furniture structure is advantageous since it is made out of one piece of material. It is also light weight since it is a hollow structure.

In one embodiment, the hollow furniture structure is provided with at least one curved portion. A curved portion is aesthetically appealing, and a vault like construction is also robust.

In another embodiment, the second surface comprises a recess configured to receive the second edge portion. Thereby the construction locks itself in that no additional locking or clamping elements are needed.

Preferably, the recess is rectangular. This is advantageous since the second edge portion in most embodiments is rectangular. Thus, the second end portion fits well into the recess.

The plate may be a wooden plate or a chipboard plate. An advantage with a wooden plate is that is robust. An advantage with a chipboard plate is that it is light weight.

In one embodiment, the first surface is further provided with a number of parallel elongate grooves. The grooves may be V-shaped. Further, the grooves are configured to form the at least one curved portion. This is an advantageous way to form a curved portion, by removing wedge shaped portions of the plate, such that the plate may be bent.

The grooves may be parallel with the short sides of the rectangular plate and the grooves may have a length corresponding to the width of the rectangular plate. This is advantageous if a curvature with equal curvature diameter along the whole extension of the curved portion.

In one embodiment, the grooves are provided in the first end portion of the plate such that the at least one curved portion is obtained by folding of the plate. In another embodiment, a rectangular recess is provided between two of the V- shaped grooves and which is configured to receive the first edge portion. Glue is provided in the recess. This is advantageous since locks the furniture structure. Glue is provided in order to further increaser the robustness of the structure.

The slots may be V-shaped and surfaces of the slots may be provided with a

45° slope relative a normal plane of the first surface of the rectangular plate. This provides the finished structure with 90° corners.

In a second aspect, a furniture part comprising a rectangular plate is provided. The plate comprises a first inner surface provided with at least two slots by which the plate is folded to form a boxlike shape, and a second outer surface. The plate further comprises a first and a second end portion configured to meet each other to form the box-like shape. This is an advantageous way to form a furniture part since it involves only one piece of material and no splicing is required.

The inner surface may further be provided with at least one groove, the at least one groove may be V-shaped. The grooves may be provided in parallel with the short ends of the plate and may have a length corresponding to the width of the rectangular plate. The grooves may provide the furniture part with a curved portion when the plate is folded. V-shaped grooves are advantageous when the plate is supposed to be folded into a curved shape.

Preferably, the outer surface comprises a rectangular recess in which the second edge portion is provided to lock the furniture part, and wherein glue is provided in the recess. By securing the furniture structure in a self-securing manner, no need for additional clamping or securing organs are required. Glue is provided for extra robustness of the attachment.

The slots may be V-shaped and sloping surfaces of the slots may be provided with a 45° angle relative a normal plane of the first surface of the plate such that the furniture part may be provided with corners of 90° when the plate is folded.

The first surface of the plate is in one embodiment provided with a recess in which the first end portion is provided. This provides for additional stability of the furniture part.

The furniture part is in one embodiment an armrest for a piece of furniture. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described in the following; reference being made to the appended diagrammatical drawings which illustrate non-limiting examples of how the inventive concept can be reduced into practice.

Fig. 1 is a perspective view of a sofa comprising rounded armrests,

Fig. 2a is a perspective view of a plate with grooves,

Fig. 2b is a perspective view of the plate with one end portion raised,

Fig. 2c is a perspective view of the plate with two end portions raised,

Fig. 2d is a perspective view of the plate with a curved portion, and

Fig. 2e is a perspective view of a curved armrest.

DETAILED DESCRIPTION

Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. 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 by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention, such as it is defined in the appended claims, to those skilled in the art.

In Fig. 1 a sofa 100 is shown, which comprises curved armrests 101a, 101b formed from a rectangular plate. In other embodiments, the armrests 101a, 101b may form part of an armchair, a chair, a couch, or any other piece of furniture that may benefit from an armrest. In another embodiment the rectangular plate may form another furniture part, or a structure not associated with a piece of furniture.

The armrests 101a, 101b are hollow, thus, no large weight is added to the sofa 100. The rounded shape of the armrests 101a, 101b contribute to a comfortable and aesthetically appealing piece of furniture 100. It is obvious that a seating area 102 of the sofa 100 needs to withstand the load of a number of people sitting in the sofa 100, but also the armrests 101a, 101b need to withstand a load larger than just of an arm resting on it. It is not unusual that people sit down on the armrest 101a, 101b. If that happens, the armrest 101a, 101b must not collapse or get damaged. The armrest 101a and the assembly thereof will be further described below.

Fig. 2a shows a rectangular plate or board 103 which comprises a first surface 104 and an opposite second surface 105. The plate 103 may be made of wood, chipboard or any other suitable material. The plate 103 may be a homogenous plate. The plate may alternatively be inhomogeneous, such as a chipboard with different densities at different locations of the chipboard. This plate 103 will form the armrest 101a. In the first surface 104 a number of grooves 108 and a recess 109 are milled in a direction parallel with the short sides of the rectangular wooden plate 103. Both the grooves 108 and the recess 109 extend over the whole width of the plate 103. The grooves may be milled in a continuous production line such that all or several grooves are milled simultaneously giving a very high production speed.

In a first end portion 106 of the plate 103 a grooved section 115 is provided comprising eleven V-shaped grooves 108 which are provided close to each other. See also the enlarged section for a closer view of one of the V-shaped grooves 108. Each groove 108 comprises two sloping surfaces 108a, 108b. The number of V-shaped grooves 108 may of course vary between applications. Eleven is not a fixed number. The V-shaped grooves 108 do not extend all the way through the wooden plate 13, see the enlarged section of Fig. 2a. A thin strip of material 110 is left such that the wooden plate 103 is kept in one piece. To additionally strengthen the plate 103, a foil or film

(not shown) may be provided on the second surface 105 such that the plate 103 does not come apart due to the grooves 108 or slots 112, 113. The film or foil can be made of plastic, metal or any other suitable material. The film is glued to the second surface 105. Alternatively the grooves may be made all the way through the board and plastic strips, or foil, or tape, may be attached to keep the board together.

In addition it is possible, however not shown herein, to mill the grooves on both sides of the board to achieve a smoother folding surface. The general technique of milling a board from two directions and using a foil as a hinge member is described in WO2010/049418 Al and will thus not be described in more detail herein. The technique of milling and folding shown in WO2010/049418 Al may be used for the grooves 108 as wells as for the slots 112, 113. Further, among the V-shaped grooves 108 the rectangular recess 109 is provided.

In an area located between the middle of the rectangular plate 103 and a second end portion 107 of the plate 103 two additional V-shaped slots 112, 113 are provided parallel with the short sides of the rectangular plate 103. The sloping surfaces 112a, 112b, 113a, 113b of these V-shaped slots 112 do not descend as steeply as the sloping surfaces 108a, 108b of the grooves 108. The sloping surfaces 112a, 112b, 113a, 113b are provided with an angle of 45° to a normal plane of the first surface 104. Thus each V-shaped slot 112, 113 have a larger width than each groove 108.

In the second surface 105 a rectangular recess 114 is provided in the second end portion 107, also extending in parallel with the short side of the rectangular plate 103.

In the following the process of forming a rounded armrest 101a, 101b of the plate 103 is described. In Fig. 2b the second end portion 107 is raised according to the arrow. The plate 103 is thus bent along the V-shaped slot 112. Thus, the second end portion 107 comprises the part of the plate 103 extending from the slot 112 to an edge portion 117. Since the sloping surfaces 112a, 112b of the slot 112 are provided with such an angle, 45°, the second end portion 107 forms a 90° angle relative the rest of the plate 103 when the surfaces 112a, 112b meet.

In Fig. 2c also the first end portion 106 is raised according to the arrow. The plate 103 is bent along the V-shaped slot 113 such that the surfaces 113a, 113b contact each other forming a 90° angle. Thus, the first end portion 106 comprises the part of the plate 103 extending from the slot 113 to an edge portion 118. The first surface 104 becomes an inner surface of the assembly and the second surface 105 becomes an outer surface.

Further to Fig. 2d, the rounded portion of the armrest 101a is formed. The grooved section 115 is rolled up such that it assumes a curved shape and becomes a curved portion 116. This is achieved by the grooves 108. Each pair of sloping surfaces 108a, 108b of each groove 108 is brought into contact with each other such that a curved or rounded shape is formed of the first end portion 106. To stabilize the armrest 101a the edge portion 117 of the end portion 107 is received by the rectangular recess 109 and locked in place (see arrow). To lock the curved portion 116 the edge portion 118 of the first end portion 106 is received by the rectangular recess 114 (see arrow). Glue is provided in the recess 114 to secure the edge portion 118. Thus, the structure is self-locking and no additional support or locking means are required.

The finished armrest 101a is shown in Fig. 2e. This will be mounted to the other components of the sofa 100 and lined with padding and fabric in order to finish the sofa 100. The other armrest 101b is formed according to the same procedure, but it is mirrored.

In summary, the method for forming the armrest 101a, 101b from the flat plate 103 comprises the steps of folding the first end portion 106 90°, folding the second end portion 107 90°, curving the grooved section 115 such that the first edge portion 117 is fitted in the recess 109 and the second end portion 118 fits in the recess 114. Thus, the finished armrest 101a, 101b comprises both 90° bends and a curved shape, all of them formed by means of grooves or recesses.

The finished armrest 101a is a stable and robust structure thanks to its vaultlike construction. The wooden pieces between the grooves 108 form wedges which, when they are pressed together maintains the rounded shape. In order to further secure the first edge portion 117 in the recess 109, and the second edge portion 118 in the recess 114, glue is applied in both recesses 109, 118 prior to inserting the edge portions 117, 118.

The armrest 101a, 101b does not necessarily comprise a rounded shape. In an alternative embodiment the first 117 and second 118 edge portions contact each other in a 90° angle such that the armrest 101a, 101b form a rectangular shape. This is not shown in the drawings. The edge portions 117, 118 may for example be secured to each other by a surface strip.

It should be appreciated that the inventive concept is not limited to the embodiments described herein, and many modifications are feasible within the scope of the invention set forth in the appended claims. For instance the distance between the first 112 and second 113 V-shaped slots may vary, with the result that the width of the armrest 101a, 101b becomes larger or smaller. Further, the distance between the first V- shaped slot 112 and the first edge portion 117 can vary, such that the height of the armrest 101a, 101b becomes higher or lower. The number of grooves 108 in the grooved section 115 may vary in order to achieve a curvature with a larger or smaller diameter. The angle of the surfaces 112a, 112b, 113a, 113b need not be 45°. A larger or smaller angle would provide the finished structure with a different appearance, not having corners of 90°. The technique for forming a curved portion from a flat plate is of course not limited to armrests for sofas. The method could be applied to other armrests, as well as other parts of furniture, and also in applications not relating to furniture, where a curved outline is desired. In addition it is possible to use the technique described herein to achieve a piece of furniture which does not have any curved outlines, for instance an armrest for a sofa which does not have a curved upper surface but instead have a rather straight upper surface, or another part of a sofa such as the backrest.