Technical field

The present disclosure relates to structural element, for instance for furnishing. By furnishing is here generally meant furniture and furniture-like elements suitable for the interior of a building such as a residential or office building, for instance.

Background

A general problem with such structural elements is how they can be provided at a reasonable cost for a given strength or other quality.

Summary

One object of the present disclosure is therefore to provide a structural element and a method for producing such a structural element with good properties and at a low cost.

This object is achieved by means of a structural element as defined in claim 1. More particularly, a structural element of the initially mentioned kind comprises a core element in a first material and at least one end element in a second material being different from said first material, wherein the core element and the at least one end element are joined to form a composite element with at least one joint, the composite element having at least one cross section with an outer contour where any corners have an outer angle smaller than 270 degrees, and a veneer layer in a veneer material, attached to the composite element in such a way that it at least partially covers said at least one joint. In this way it is possible to provide a structural element with a uniform outer surface optimized for one property, while the inner core is optimized for another property. The veneer layer may be applied smoothly thanks to the absence of sharp corners.

All cross sections along the composite element length may have an outer contour where any corners have an outer angle smaller than 270 degrees.

For instance, the core element may be made in beech wood while the veneer and end elements may be made in oak wood. This provides the appearance of an oak element, while the product is comparatively cheaper thanks to the lower price of the core element, which may constitute the larger proportion of the structural element. At the same time, the product is lighter and easier to process, e.g. to apply screws, than a solid oak structural element.

The core element may be elongated, and preferably one end element is provided at each end surface of the core element.

The veneer layer may cover a major part of, or even all of, the core element.

The second material may be a solid wood of a second species, such as selected from a group comprising oak, hickory, mahogany, and teak.

The second material may be harder than the first material.

The veneer may be made of the same species of solid wood as the second material.

The first material may be solid wood of a first species, such as selected from a group comprising beech, birch, cedar, aspen, maple, spruce and pine.

The core element may otherwise be made of a material selected from a group comprising particle boards, MDF- and HDF-boards, and/or the core element can be made as a hollow construction, such as a hollow tube of solid wood, plywood, metal, plastic or similar.

The joint may be selected among finger joints and butt joints, for instance.

The structural element may be a furniture pole, and/or the structural element may typically have a cross-section being circular, oval, or elliptical. This cross-section may be the same along the entire length of the structural element and/or the furniture pole.

The veneer layer may be applied as one single sheet of veneer covering the entire periphery of the composite element, and the single sheet of veneer may comprise two or more joined pieces.

Any corners of the cross section of the structural element may have an outer angle being 252 degrees (pentagon) or smaller, more preferred 240 degrees (hexagon) or smaller, more preferred 232 degrees (heptagon) or smaller, and more preferred 225 degrees (octagon) or smaller.

The present disclosure further considers a piece of furniture comprising a structural element as defined above. Such a piece of furniture may be a table, a bed frame, a cupboard, a bookcase, a shelf unit, a shelf, a chair or a sofa.

Typically, the structural element may form part of a leg structure of such a piece of furniture.

The present disclosure further considers a method for producing a structural element, for instance for furnishing. The method includes providing a core element in a first material and at least one end element in a second material being different from said first material, joining the core element and the at least one end element to form a composite element with at least one joint, shaping the composite element, into a shape with a cross section having an outer contour where any corners, if present, have an outer angle smaller than 270 degrees, and providing, on the composite element, a veneer layer in a veneer material, such that it at least partially covers said at least one joint. This provides the same advantages as in the above defined device.

The core element may be elongated, and preferably one end element may be provided at each end surface of the core element.

The veneer layer may cover the major part of, or even all of, the core element.

The second material may be a solid wood of a second species, such as selected from a group comprising oak, hickory, mahogany, and teak.

The second material may be harder than the first material.

The veneer may be made of the same species of solid wood as the second material.

The first material may be solid wood of a first species, such as selected from a group comprising beech, birch, cedar, aspen, maple, spruce and pine.

The first and second materials may comprise solid wood, and wood fibers of the first and second materials may substantially extend in the elongate direction in which said core element is elongated.

The at least one joint may extend substantially in a joint plane, and the elongate direction may form a normal to the joint plane.

The veneer material may be the same as the second material.

The veneer may cover the core element along the entire length thereof. The veneer material may even extend from a first to a second end of the structural element.

The fibers of the veneer may extend in the same direction as a fiber direction of the end element.

The veneer layer may be provided, at its peripheral end regions, with reduced thickness, thereby providing an overlapping peripheral joint having the same thickness as the veneer outside of the end regions.

The joint may be selected among finger joints and butt joints, for instance.

Prior to attaching the veneer, the composite element may be turned, such as by means of a lathe, into a shape with circular cross section.

Brief description of the drawings Figs 1-3 illustrate basic steps for providing a composite element.

Fig 4 shows a composite element which has been processed by turning.

Fig 5 illustrates the application of veneer.

Fig 6 shows a finished furniture pole.

Figs 7-8 illustrate two possible applications for a structural element produced according to the present disclosure.

Fig 9 illustrates a high-volume manufacturing method.

Fig 10 illustrates an example of a composite element with a polygonal cross section.

The present disclosure relates to furnishing the interior of a building. By furnishing is here meant the provision of furniture, but also other decorative and/or functional items such as for instance balusters and handrails for stairs, architraves, etc.

Throughout the history of mankind, solid wood has been a highly appreciated material for furnishing, although initially few alternatives were available. At present, other materials such as reinforced plastic, fiber boards, and metal offer structurally competitive and certainly cheaper alternatives, but solid wood remains high in demand. Not only does solid wood possess beauty, but also considerable technical advantages, especially as its fibers by nature mostly extend along an almost uniform main direction, which gives a high elastic modulus against bending about an axis perpendicular to that main direction.

In the following, an improved method for providing a structural element comprising solid wood is outlined. Generally, this method provides a structural element whose outer surface can be optimized with regard to one parameter, while its inner core is optimized with regard to another.

In this method, there is provided a core element in a first material and at least one end element in a second material being different from said first material. The core element and the at least one end element are joined to form a composite element with at least one joint. Finally, there is provided, on the composite element, a veneer layer, such that the veneer layer at least partially covers the joint.

Figs 1-3 illustrate basic steps for providing a composite element. Fig 1 shows a core element 1 and first and second end elements 3. Selection of material will be discussed later, but in one example, the core element 1 may be made in beech while the end elements 3 may be made in oak. The core element 1 is illustrated as elongated in a main direction 5, and typically this is aligned with the wood main fiber direction of the core element 1. The core element 1 as well as the end elements 3 are illustrated as parallelepiped shaped although this is not necessary. Further, it is not necessary in all applications to use one end element 3 at each end of the core element 1. In many cases, one end element 3 at one end of the core element 1 may be enough.

In fig 2 those end surfaces 7 of the core element 1 and of the end elements 3 that are facing another one of the elements have been machined to prepare for joining by means of finger joints.

Fig 3 shows the core element 1 and the end elements 3 being joined by finger joints 9, usually by means of a glue, to form a composite element 11. The finger joints 9 generally extend in a plane 12 that is perpendicular to the main direction 5 of the core element 1 , although this is not necessary.

It is possible to process the finished composite element 11 in different ways before further steps of the method are carried out. Fig 4 shows a core element 1 T which has been processed, by means of turning, into an elongated cylindrical shape. Other possible processing steps include for instance grinding or cutting off corners to obtain an octagonal shape, rounding corners, etc. Further, the core element may be turned to be tapering, e.g. towards one end thereof.

In general, the composite element may preferably have a cross section along its length which is free from sharp corners, which may be defined as right angle corners or sharper, for instance.

This facilitates the application of a continuous layer of veneer that may be wrapped around the outer contour of the composite element 11 as will be described.

Free from sharp corners may be defined as having an outer contour where any corners all have an outer angle smaller than 270 degrees. This can be accomplished for instance by a polygonal shape with five or more equal corners, but of course also by a wholly or partly circular, elliptical, or oval shape, for instance.

Fig 5 illustrates the application of a veneer layer 13 on the core element 1 T. Veneer application as such is well known, typically a layer with a thickness ranging from 0.2- 2.0 mm is applied with a glue layer and is wrapped around the composite core element 1 T. It may be preferred to provide the veneer layer 13 as a single sheet wrapping the entire outer contour of the core element 1 T thereby requiring only one veneer seam along the length of the element. As is shown in the cross section of fig 5, an overlap 14 may be provided, and the peripheral end regions 15 of the veneer 13 at this overlap 14 may have a tapering thickness so as to achieve a uniform thickness of the veneer layer around the periphery of the composite core element 11

Fig 6 shows a finished furniture pole 17 obtained by the application of veneer in fig 5. The seam 19 of the veneer is indicated in the drawing although this may only be visible as a change of pattern in the veneer surface.

Figs 7-8 illustrates two possible applications for a structural element produced according to the present disclosure. Fig 7 shows a bed frame 21 where a furniture pole 17 as shown in fig 6 may be used as an upright in each corner, and fig 8 shows a chair 23, where such furniture poles 17 may be used in each leg as well as uprights for the backrest.

Fig 9 illustrates schematically a high-volume production method, where a number of composite elements are formed at the same time. First a number of elements of the first material, intended to form core elements 1, are joined with intervening elements of the second material, intended to form end elements 3. Then, the intervening elements of the second material are cut off, such as by means of a saw, at cutting lines schematically illustrated in fig. 9, such that each cutting position form one end element 3 for one composite element 11 and one end element 3 for another composite element.

As mentioned, the second material, making up the end element 3, and possibly also the veneer layer 13, of the structural element can be optimized with regard to one parameter, while the first material, making up the core element 1 , is optimized with regard to another. Those materials may be selected according to a range of different parameters.

The first material, of the core element 1 , may be solid wood of a first species and the second material, of end elements 3 and/or veneer 13, may be solid wood of a second species. Typically, the first material may then be a cheaper type of wood that makes up the bulk of the final product, while the second material is a more expensive type of wood with a desired visual appearance. In addition to more expensive types of wood, the second material could in principle include wood species whose use should be limited due to being rare.

Typically, the first material may be selected from a group comprising beech, birch, cedar, aspen, maple, spruce and pine, and the second material may be selected from a group comprising oak, hickory, mahogany, and teak.

In another example, the second material is a solid wood of a harder species than the first material. For instance, in the above example, beech is softer than oak and may more easily be machined, e.g. by drilling, for instance to attach screws or the like that are used to connect the structural element, for instance a furniture pole, to other elements in a piece of furniture. By a softer solid wood material is here meant one that has a lower Janka hardness rating.

In addition to finger joints, butt joints or other types of joints may be considered to joining the core elements to the end elements.

According to other embodiments the first material making up the core element could be other types of materials, such as particle boards, MDF and HDF, that provide mechanical strength and low price. Still further, the first material making up the core element could be a hollow construction, such as a hollow tube of solid wood or a hollow tube of plywood or other material, e.g. plastic or metal.

As mentioned, it is not necessary to use one end element at each end of the core element. In many cases one end of a structural element may be concealed, e.g. pointing downwards towards a floor, and it may be acceptable to allow the core element to proceed to the outer element surface at that end.

As mentioned, a composite element may have a polygonal cross section which is illustrated in Fig. 10 with an octagonal cross-section which has eight outer corners all with the outer angle 225 degrees. Such a cross section with relatively non-sharp corners is well suited for being wrapped with a thin veneer being glued thereto.

The present disclosure is not limited to the above-described may be varied and altered in different ways within the scope of the appended claims.

The present disclosure thus relates to a structural element and a method for producing a structural element for furnishing, e.g. for furniture. There is provided a core element in a first material and at least one end element in a second material, which are joined to form a composite element with at least one joint. A veneer layer in a veneer material is provided on the composite element, such that it at least partially covers said at least one joint. This allows a structural element to be provided which has a full outer surface in the second material to provide a second material finish, although the core is provided in another material which may have other preferred properties.