A METHOD ADN FURNITURE ELEMENT FOR MAKING A PIECE OF FURNITURE
The invention relates to a method for making a furniture element by folding of a furniture plate made of a metal plate with at least one layer of veneer fastened to at least one side, and also a furniture element made by means of this method, and a piece of furniture assembled by at least two such furniture elements.
Moulded furniture, furniture components and furniture plates of veneer or laminate are normally made by means of e.g. high- frequency presses, electrically heated multiple daylight presses with standard moulds of e.g. aluminium, and steam- headed multiple daylight plan presses for veneering of e.g. chipboards. The making of a piece of furniture normally require at least one mould. Therefore, it is necessary to make new moulds if the shape and design of the furniture is changed.
Furniture elements are also known that consist of a metal plate with veneer on at least one side. Such a plate can easily be bent to the desired shape using simple means, for example a bending-off press. The problem is that the veneer on the tension face of the bending is likely to be damaged beyond repair because it is subjected to tensile stresses that the veneer cannot stand.
Said problem is tried solved by means of the method described in European Patent Application No. 612609, in which the veneer on the tension side of the bending preliminarily is compressed and applied an adhesive. Thereby, the plate can now be bent to some extent without damaging the structure of the veneer. However, it is in this way not possible to obtain the high quality of the surface finish of the veneer demanded of a piece of furniture which is to form part of a beautiful and tasteful interior in a home or office.
A first aspect of the invention is to provide a method of the kind mentioned in the opening paragraph for by simple means making a furniture element of a veneered metal plate having bends that at least essentially are without flaws or damage to the exterior of the bending.
A second aspect of the invention is to provide a furniture element that is made by means of the method according to the invention.
A third aspect of the invention is to provide a piece of furniture that is assembled by at least two furniture elements according to the invention.
The novel and unique feature according to the invention, whereby this is achieved, is the fact that an intermediary plate is placed on at least one side of the furniture plate during the bending of an area of this plate, said intermediary plate being made of a flexible material and extending at least across said area.
Veneer can optionally be on one or both sides of the metal plate. During a bending operation, the exterior of the bend is extended. The press tools on this side wiill therefore be performing a relative motion along the 'exterior, which simultaneously is stressed by normal forces. The thereby created frictional forces will be inclined to pull the fibres on this side of the veneer away from each other to a greater or smaller extend, whereby the furniture element cannot be used for furniture which has to meet the high demands made today to the quality and finish of furniture.
By placing a flexible intermediate plate between the furniture plate and the tool it is advantageously obtained that the frictional forces instead are created between the tool and the intermediate plate which e.g. can be made of spring steel that
easily can stand being affected by said frictional forces. During the bending' operation, no displacement takes place between the surfaces of the intermediate plate and the veneer. The furniture plate can therefore now be bent in relatively small radii without its surface thereby being damaged and especially if the sides of the elements in each bending area are extending along single-curved faces with generators that are parallel to the fibres of the veneer.
Naturally it is a great advantage that bent furniture elements can be made of prefabricated furniture plates having veneer on one or both sides by means of the above method instead of conventionally having to bend the metal plate and then adhere the veneer to this plate.
To obtain a true joining that can stand being bent, an adhesive can advantageously be used that can be absorbed well into the veneer. The absorbed adhesive furthermore binds the fibres together in a strong bond.
The tool utilized can be traditional folding tools but can in an advantageous embodiment have a die in form of two rotatable, parallel rollers, the I surfaces of which follow during bending whereby the frictional forces are reduced. i
The rollers can furthermore be journaled in such a way that they can be displaced towards each other and thereby overbend the furniture plate so much that it will exactly form the desired angle of e.g. 90° or 180° after elastic recovery.
In a second advantageous embodiment the die can however be made of rubber or a rubbery material that automatically adapts during bending and thereby leaves the furniture plate with a flawless surface.
Furniture elements made by means of the above method can according to the invention be assembled in many different ways to furniture having end edges on two opposite elements adjoining each other and fixed by means of suitable fasteners. These pieces of furniture combine the attractively beautiful appearance of the veneer with the great strength of the metal.
For example two furniture elements can in this way be assembled to a bookcase, which again can be part of a complete shelf system. The furniture elements can also be used as tabletops or for chairs or lamps.
In the last-mentioned case, the furniture plate can be veneered only on the exterior so that the glittering surface of the metal can reflect and spread the light from the bulb.
The invention will be explained in greater details below, describing only exemplary embodiments with reference to the drawing, in which
Fig. 1 is a perspective view of a first embodiment of a tool in starting position for by means of the method according to the invention bending a furniture plate having veneer on one side,
Fig. 2 shows the tool in fig. 1 but in final position,
Fig. 3 is a perspective view of a second embodiment of a tool in starting position for by means of the method according to the invention bending a furniture plate having- veneer on one side,
Fig. 4 is a perspective view of different embodiments of a furniture element according to the invention, and
Fig. 5 is a perspective view of a piece of furniture according to the invention.
Figs. 1 and 2 show a tool 1 for bending a furniture element according to the invention.
The tool comprises a male die 2 and a die 3 that in this case consists of a rubber block fixed in a frame 4. The tool will normally be fixed in a known press (not shown) for imparting a reciprocating motion to the male die and the die in relation to each other during performing of a pressure on the blank to be pressed.
In fig. 1 the tool is in its starting position. On the rubber block an intermediate plate 5 of e.g. spring steel having a smooth surface is placed and on top of the intermediate plate is placed a furniture plate 6 that is to be bent in an area 7.
The furniture plate will typically be an aluminium plate 8 having a layer of veneer 9 and 10 adhered to both sides.
To obtain a strong bond between the veneer and the aluminium plate this plate has first been cleaned of possible oil and other impurities, after which it is applied with a suitable adhesive and the veneer is applied. As adhesive a polyurethane glue can advantageously be used that can penetrate at least partly into the veneer which thereby effectively is secured on the aluminium plate during the bending operation so that the furniture plate can withstand being bent in relatively small radii of curvature without the veneer thereby splitting or breaking.
In the case shown the furniture plate is bent so that its sides will extend along cylinder faces with generators that are at least mainly parallel to the fibres of the veneer.
With an aluminium plate of e.g. 4 mm the furniture plate can thereby be bent with an inside radius of between 32 mm and 48 mm, preferably between 35 mm and 45 mm, and especially between 38 mm and 42 mm.
In fig. 2 the tool is in its final position in which the furniture plate has been bent a little more than 90°. As seen, the rubber block and the air in this block have been compressed during this, whereby a considerable pressure is created between the male die and the die, said pressure pressing the flexible intermediate plate 5 and the furniture plate 8 around the cylindrical lower face of the male die, the frame 4 during this absorbing the horizontal components of the pressure.
As mentioned the furniture plate is in the final position bent a little more than 90°, namely so much that it is bent exactly 90° when the pressure is relieved, the plate springing a little back during this.
During the pressing operation, the surface of the die is sliding on the surface of the intermediate plate, which is smooth and easily can stand being subjected to the frictional forces that are created during sliding. The function of the intermediate plate is thus to "prevent said frictional forces from burdening the veneer with tensile forces that could damage the veneer, for example make it crack.
In figs. 1 and 2 an intermediate plate has only been placed on the outer side of the bending, tensile stresses being created on the inner side opposite the outer side, that are not very likely to damage the veneer on this side. But if necessary an intermediate plate (not shown) can also be placed on the inner side for sparing the veneer from damages that could be done due to the surface of the male die sliding against the surface of the furniture plate.
Fig. 3 shows how a conventional folding tool with fixed die alternatively can be used.
In fig. 4 a number of examples of furniture elements 11a; lib; lie; lid; lie; llf ; llg are shown that are shaped with combinations of 90° and 180° bends.
In fig. 5 is seen how the furniture elements of fig. 4 can be fitted together to a shelf system 12 that can be varied in countless ways as required and desired.
The furniture elements are assembled in pairs with the free end edges adjoining each other so that a smooth transition is created between the elements . The assembling can take place by means of suitable means, for example riveters guided through holes in each their opposite element and pulled together on the inside of the elements with a ring having an inner side compassing the interior end of the riveters and a contour extending obliquely in towards the axis of the ring. This structure is not shown in the drawing.
As mentioned, the furniture elements in fig. 4 can be fitted together into bookcases or used separately as e.g. shelves, stools, tabletops, lampshades, or chairs.