WO1998006302A1

WO1998006302A1 - A sheet of plastically deformable material, a method of assembling an item of furniture, and an item of furniture

Info

Publication number: WO1998006302A1
Application number: PCT/GB1997/002167
Authority: WO
Inventors: Sam Andrew Booth
Original assignee: Sam Andrew Booth
Priority date: 1996-08-13
Filing date: 1997-08-13
Publication date: 1998-02-19
Also published as: GB9616980D0; AU3947197A

Abstract

A single sheet of material is provided with cut lines and fold lines allowing it to be folded along the fold lines to provide a three-dimensional load bearing item of furniture. An item of furniture formed from a sheet of material and a method of assembling an item of furniture are also provided. The material used is preferably sheet steel and the fold lines are preferably formed by providing a row of apertures with relatively small stitches of material between the apertures.

Description

A SHEET OF PLASTICALLY DEFORMABLE MATERIAL, A METHOD OF ASSEMBLING AN ITEM OF FURNITURE, AND AN ITEM OF FURNITURE

This invention relates to folded furniture and especially but not exclusively to furniture which is manufactured in the form of a single sheet of material which can be folded manually by unskilled persons, along predetermined fold lines, in order to provide assembled items.

Self-assembly or flat pack furniture can range in complexity from simple shelving, tables and beds to complete kitchens. At a time when people are cautious about spending, flat pack or self-assembly furniture is regarded as offering value for money and is currently the only growth area in the furniture market. There is no single aesthetic that dictates the look of a self- assembly item of furniture.

Most self-assembly or flat pack furniture is aimed at assembly with the minimum of tools. However, some self-assembly items are highly complex kits requiring both time and skill to put together. Self-assembly furniture is not usually intended to be collapsible but is generally fixed in its final form once assembled. Self-assembly or flat pack furniture can be regarded simply as any furniture un-assembled at the point of sale and assembled by purchasers in their own homes .

Existing self-assembly furniture suffers from a perception that it is difficult to assemble. A study has shown that 59% of buyers in the self-assembly market complain of too many parts, of missing parts or of instructions which are difficult to understand. Market research has shown that self-assembly furniture is bought predominantly by men and that both women and the elderly are less confident about their ability to assemble such furniture.

In some cases the furniture is sold as a kit consisting of the component parts of an otherwise fully formed piece of furniture, with instructions on how to complete assembly. Construction can require both a high level of skill and a comprehensive tool kit. Parts are frequently numerous, difficult to identify or easily lost. Where attempts have been made to simplify the assembly process it is often to the detriment of the finished form. Self-assembly furniture can suffer from a nut and bolt aesthetic and is often considerably less attractive than furniture which is purchased fully assembled. Therefore although it may offer value for money it is rarely bought for its desirability as a finished object.

According to a first aspect of the present invention there is provided a sheet of plastically deformable material which contains at least one fold line comprising a plurality of holes arranged in a line such that the sheet may be folded manually along the fold line, the sheet being foldable along the or each fold line to form an item of furniture. Preferably the sheet also contains at least one cut line comprising an elongated slot such that the sheet may be separated manually along the cut line.

Preferably the plastically deformable material is metal, preferably steel, which may be powder coated, and which is preferably less than 2mm thick.

Preferably the holes are in the form of slots arranged with their longer dimension parallel to the fold line, the slots being separated by uncut sections of sheet of a length less than that of the slots. Preferably the ratio between the length of slot and length of uncut section is greater than 5, more preferably greater than 10, and in a preferred embodiment greater than 15. Preferably the length of each uncut section is of the same order of magnitude as the thickness of the sheet, and most preferably is approximately equal to the thickness of the sheet.

The sheet may have a rectangular area bounded by four fold lines and forming a seat upper panel of a chair when the sheet is folded. The sheet may further have at least three parallel, elongated rectangular areas separated by fold lines and forming a polygonal tubular chair leg when the sheet is folded. Preferably the elongated rectangular areas forming the rear chair leg are of a length such that the rear chair leg extends continuously from the floor to a back rest positioned above the seat when the sheet is folded.

Preferably the sheet is provided with a number of apertures adapted for receiving fixing means therethrough to fix the form of the furniture when the sheet is folded. Preferably the sheet is provided with a number of pairs of apertures positioned so that the two apertures of each pair align when the sheet is folded, such that a fixing member can be inserted through both apertures of each pair.

According to a second aspect of the present invention there is provided a method of assembling an item of furniture, in which a sheet of plastically deformable material is folded manually along at least one fold line comprising a plurality of holes arranged in a line to form an item of furniture.

Preferably the sheet is also separated manually along at least one cut line comprising an elongated slot.

The sheet may be delivered as a flat sheet, and may be sandwiched between two layers of packing material, such as cardboard.

The holes and slots are preferably cut using CNC techniques and may be cut using laser cutting apparatus.

According to a third aspect of the present invention there is provided an item of furniture fabricated from a single sheet of plastically deformable material by folding along at least one fold line comprising a plurality of holes arranged in a line.

Preferably the sheet also contains at least one cut line comprising an elongated slot.

Preferably the plastically deformable material is metal, preferably steel, which may be powder coated, and which is preferably less than 2πurt thick. Preferably the holes are in the form of slots arranged with their longer dimension parallel to the fold line, the slots being separated by uncut sections of sheet of a length less than that of the slots.

The item of furniture may have a plurality of legs, each leg being formed from at least three parallel, elongated rectangular areas folded along fold lines to form a polygonal tubular leg.

The item of furniture may be a chair, with a rectangular area bounded by four fold lines forming the seat of the chair.

The item of furniture may be a shelf unit having integral book ends, with a rectangular area bounded by four fold lines forming the horizontal shelf surface.

The item of furniture may be a bedside cabinet.

The item of furniture may be a stool.

Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings in which:

Fig. la is an schematic plan view of an embodiment of a sheet of material in accordance with the present invention, foldable to form a chair;

Fig. lb is a plan view corresponding to the embodiment of Fig. la showing accurately the layout of the sheet;

Figs. 2 to 9 illustrate the folding of the sheet of Fig. la to form a chair, shown in perspective view in Fig. 9; Figs. 10 to 12, respectively, show side, front and rear elevations of the chair of Fig. 9;

Fig. 13 shows a part-schematic view of an embodiment of a sheet of material in accordance with the present invention, foldable to form a shelf unit;

Figs. 14 to 19 illustrate the folding of the sheet of Fig. 13 to form a shelf unit, shown in perspective view in Fig. 13;

Figs. 20 to 23 respectively show front, plan, side and rear elevations of the shelf unit of Fig. 13;

Fig. 24 shows a plan view of an alternative embodiment of the present invention in the form of a sheet of material foldable to form a bedside cabinet;

Figs. 25 to 28 illustrate the folding of the sheet of material of Fig. 25 to form a bedside cabinet, shown in perspective view in Fig. 28;

Fig. 29 shows a plan view of an alternative embodiment of the present invention in the form of a sheet of material foldable to form a stool; and

Figs. 30 to 33 illustrate the folding of the sheet of material of Fig. 29 to form a stool, shown in perspective view in Fig. 29.

With reference to Figs, la to 9, an embodiment of a sheet of material in accordance with the present invention is in the form of a generally rectangular sheet 1 having fold lines 10 (shown in Fig. lb and designated by the less pronounced lines in Fig. la) and cut lines 11 (shown in Fig. lb and designated by the more pronounced lines in Fig. la).

The sheet of material is preferably a sheet of steel about 1.0 to 1.2 mm thick. The fold lines are preferably "stitch cut" consisting of a number of elongate apertures 12 about 25 mm by 2 mm in size, with the longer dimension of the aperture extending along the fold line 10. Evenly spaced stitches 13 of material are left between the apertures 12, and the length of these stitches 13 is preferably approximately equal to the thickness of the sheet material (about 1.0 to 1.2 mm in this embodiment). Thus, in this embodiment a fold line 400 mm length, to be folded in 1.2 mm steel would have fifteen 25 mm long apertures evenly spaced apart by stitches approximately 1.5 mm long therebetween. Apertures or stitches of other lengths may be provided at the ends of the fold lines in order to ensure that fold lines end with a stich rather that with an aperture, which could create an undesirable sharp corner. This allows for the material to be accurately and easily folded by hand. The folding is intended to be done only once and then fixed in place, as the stitches will fatigue if continually folded. Once the fold is fixed in place it takes on the strength of the cross sectional area of all the stitches combined.

Referring to Fig. la, the sheet 1 includes first and second front leg portions 20, 22 each including first to fourth fold lines 21a to 21d, 23a to 23d respectively, dividing each front leg portion 20, 22 into first to fifth planar panels 20a to 20e, 22a to 22e.

The sheet further includes first and second rear leg portions 24, 26 each including first to third fold lines 25a to 25c, 27a to 27c dividing each rear leg portion 24, 26 into first to fourth planar panels 24a to 24d, 26a to 26d.

A seat bottom portion 28 is formed between the front leg portions 20, 22 and is divided from the innermost panels 20e, 22a of the front leg portions 20, 22 by first and second seat bottom cut lines 29a, 29b. The seat bottom portion 28 includes first and second seat bottom subsidiary panels 28a, 28b formed generally parallel to the front leg panels 20a to 20e, 22a to 22e, and divided from the main part of the seat bottom portion by first and second seat bottom fold lines 28c, 28d.

A seat upper portion 30 is formed between the rear leg portions 24, 26 and is divided from the innermost panels 24d, 26a of the rear leg portions 24, 26 by first and second seat upper cut lines 31a, 31b. The seat upper portion 30 includes first and second seat upper subsidiary panels 30a, 30b formed generally parallel to the rear leg panels 24a to 24d, 26a to 26d, and divided from the main part of the seat upper portion by first and second seat upper fold lines 30c, 30d.

A seat front panel 32 lies between the seat upper portion 30 and the seat bottom portion 28 and is divided from them, respectively, by a seat front upper fold line 32a and a seat front lower fold line 32b. The seat front panel 32 is continuous and co-planar with the innermost panels 20e, 22a of the front leg portions 20, 22.

The seat further includes a back rest front portion 40 in the form of a rectangular portion of the sheet divided on its long sides (which are generally parallel to the short sides of the generally rectangular sheet 1) from first and second subsidiary back rest panels 40a, 40b by respective back rest fold lines 40c, 40d. Surrounding the back rest front portion 40 is a chair back portion 48. Lower part 48a of the chair back portion is adjacent the seat upper portion 30, with a first connection panel 17 therebetween. A first connection panel fold line 17a is provided between the first connection panel 17 and the seat upper portion 30 and a second connection panel fold line 17b is provided between the first connection panel 17 and the lower part 48a of the chair back portion 48. On the other side of the lower part 48a of the chair back portion 48 is a second connection panel 18. A third connection panel fold line 18a is provided between the second connection panel and the lower part 48a of the chair back portion 48.

On either side of the main chair back portion 48 is a respective back post portion 44, 46 each having first to fourth panels 44a to 44d, 46a to 46d which are, respectively, continuous and co-planar with the first to fourth panels 24a to 24d, 26a to 26d of the rear leg portions 24, 26. The second innermost panels 44c, 46b are also continuous and co-planar with respective back rest tabs 44e, 46e which extend outwardly therefrom and are separated from the outer panels 44a, 44b, 46c, 46d by first and second chair back cut lines 49a, 49b. At one end of the sheet 1, and adjacent to the chair back portion 48 is a chair back top panel 50. In order to allow the chair back top panel 50 to be folded relative to the chair back portion 48, a top panel fold line 50a is provided.

Fig. 2 shows the first stage in folding the sheet 1 to form a chair. Each of the fold lines 21a to 2 Id, 23a to 23d of the first and second front leg portions 20, 22 is folded ninety degrees in order that the two front leg portions 20, 22 are formed into two front legs which are tubular and substantially square in cross section. Each of the front leg portions 20, 22 includes five panels, so that one of the sides of the square tube is formed from two thicknesses of material (as is best seen in Fig. 3).

As shown in Fig. 3 the next stage is to move the now tubular front leg portions 20, 22 so that they are perpendicular to the seat upper portion 30, thus creating a fold along the seat front upper fold line 32a. When the front leg portions 20, 22 are perpendicular to the seat upper portion 30, first and second side panel tab portions 34a, 34b which are continuous and co-planar with the first front leg portion fourth panel 20d and second front leg portion second panel 22b (as shown in Fig. la) abut the seat upper portion 30.

Fig. 4 shows the next stage in the assembly, from the other side of the sheet 1, that is to say the whole sheet has been turned over between the views of Fig. 3 and Fig. 4. As the sheet is turned over the seat upper portion 30 is moved relative to the chair back portion 48 to an angle of about 45 degrees and the subsidiary panels 30a, 30b of the seat upper portion 30 are folded to a right angle to the main part of the seat upper portion 30 along the seat upper portion fold lines 30c, 30d until they contact the respective front leg portions 20, 22, and the tabs 34a, 34b.

Figs. 5 to 7 illustrate the next step in assembly, which is to form the rear leg portions 24, 26 into square cross section tubes in a way similar to that in which the front leg portions 20, 22 were formed into square cross section tubes. The rear leg portions 24, 26 each have only four panels 24a to 24d, 26a to 26d so unlike the front leg portions no side of the folded tube will comprise two overlapping panels. However, each of the rear leg portions 24, 26 includes a respective tab portion 24e, 26e which is used instead of a fifth panel to fold over and secure the tubular structure of the rear leg portions 24, 26. It will be appreciated that forming the rear leg portions 24, 26 into tubular form also serves to form the chair back post portions 44, 46 into tubular form.

As shown in Fig. 7 when the back post portions 44, 46 are folded into tubular form the back rest tabs 44e, 46e are set parallel to and spaced apart from the chair back portion 48. The back rest front portion 40 is then folded so that it lies flat against the back rest tabs 44e, 46 and the fold lines 40c and 40d are folded to right angles so that the back rest portion subsidiary panels 40a, 40b each extend between and perpendicular to the back rest front portion 40 and the chair back portion 48. The chair back top panel 50 is then folded over the first subsidiary panel 40a of the back rest front portion 40a.

Fig. 8 shows the final folding required to form the sheet into a functional chair. The seat upper portion 30 is moved from 45 degrees to ninety degrees to the chair back portion 48. The seat bottom portion 28 is folded so that it is spaced apart from and parallel to the seat upper portion 30, with the seat front panel extending therebetween. The lowest part 48a of the chair back portion 48 is parallel to, and at the same height as the seat front panel 3 . The connection panel 17 extends diagonally downwardly from the seat upper portion 30 to the bottom of the lower part 48a of the chair back portion 48. The second connection panel 18 is folded so that it is parallel and substantially co-planar with the seat upper portion 30 and is attached to a tab 30e on the seat upper portion 30. Thus the first connection panel 17, second connection panel 18 and lower part 48a of the chair back portion 48 form a triangular box section part (not shown) to help support the rear of the seat upper portion 30. The seat upper portion may be further strengthened by connection of the seat bottom portion 28 to the lower portion 48a of the chair back portion 48 via connection tabs 48b, 48c provided thereon.

Once the sheet 1 has been folded to form a chair, the assembly can be secured by using simple screws. As shown in Fig. lb a number of pairs of apertures a to t are provided in the sheet 1. When the sheet is folded each of the apertures will match up with the other of the pair, so that a single screw can be inserted through both apertures of a pair. This embodiment of the present invention thus provides an item of furniture which can be easily assembled from one main component in the form of the sheet 1 and then secured with a number of identical screws .

Once folded, the form is designed to be the archetypal chair reduced to the outline of legs, seat and back rest. It is commercially important that the chair is pleasing in appearance and far removed from the image conjured up by the notion of folding from a flat sheet. Design and technical considerations in providing a desirable item of furniture include providing a classic outline, thin legs, a seat and a back rest from a single flat sheet of material. A further consideration is to fit the flat sheet into a 600 mm x 1230 mm blank, allowing 4 chairs per stock steel size. It is also desirable that the pattern of fold lines and cut lines on the sheet should be visually simple with as little waste material as possible.

The preferred embodiment of a chair has a 768 mm high back, the seat is 430 mm high, 354 mm deep and 300 mm wide. All legs and the back posts are 30 mm square. The rear legs are located to the outside of the seat perimeter allowing stacking of a number of similar chairs and allowing the rear legs to extend upwards to form the chair back posts .

It is both structurally and visually desirable that the back legs up to the back rest and across the back of the back rest was continuous with no break in the material.

In order to provide the desired features the parts of the sheet 1 are positioned to some degree as one might expect them to be on the assembled chair. Considering the sheet 1 to have a "bottom" end 3 and a "top" end 5 (as shown in Fig la), the parts forming the chair back are located above those forming the seat which in turn are above those forming the front legs. The panel forming the front profile of the front legs is formed within the width of the seat, while those forming the rear legs are located outside and on either side of the seat upper portion. This arrangement achieves the abovementioned features of clarity and structural integrity. There were, however, certain design criteria to be met in arriving at such a design.

Firstly, in order to have the required strength each structural element must have at least one 90 degree bend, so the seat upper portion 30 must have two edges (the seat upper portion subsidiary panels 30a, 30b in this embodiment) to fold down on either side. This has the effect of pushing the back legs further out. It was therefore necessary to devise a way to allow the rear legs to be locked into their tubular form without having two overlapping panels . This was achieved by providing the tab portions 24e, 26e, and by having the back legs located to the outside of the seat perimeter rather than directly behind the front legs.

Secondly, the front and back legs have to be the same length, 430mm in the preferred embodiment. The profile of the front legs folds along the seat front panel 32. As laid out on the sheet 1, the back legs can come no further down than this point. The point along the rear legs at which the seat upper portion 30 would fold at right angles to the rear leg portions (that is the second connection panel fold line 17b) would be 430mm along the length of the rear leg portions and this would require the length from the back to the front of the seat to also be 430mm, which is longer than the maximum 355mm desirable for comfort. The seat length therefore had to be reduced without reducing the length of the rear leg portions.

This was also achieved by using the only non-right- angle folds in the assembly at the first and second connection panel fold lines 17a, 17b. This allows the seat to move further back, both reducing its length and providing a structural beam across its rear edge.

Thirdly, a way to lock the front and rear legs securely at right angles to the seat upper portion was required. For the front legs this was achieved by the provision of front leg side panel tab portions 34a, 34b attached to the front leg portion panels 20d and 22b. The tab portions 34a, 34b are provided with apertures c, d, e, f (see Fig. lb) for attachment to the seat upper portion subsidiary panels 30a, 30b. For the rear legs this was provided by seat upper side panel tab portions 30e, 30f provided with apertures n, o, p, q, r, s for attachment to panels of the rear legs 44b, 46c.

The preferred embodiment of a sheet 1 for folding into a chair is suitable for sale as a flat sheet and will preferably be sold as a flat sheet of powder coated 1.2mm thick steel sandwiched between a folded sheet of 6mm corrugated card. The card will have a simple image describing the product silk screened onto its outside and instructions as to how to fold the sheet on its inside.

The sheet of material 1 is preferably C.N.C. punched from 1.2mm cold reduced steel. The sheet fits within a rectangle of 1230mm x 588.5mm. Suitable positioning on a standard 1250mm x 2450mm sheet, allows four chairs per standard sheet.

The cutting lines and the fold lines are preferably punched out using a standard 25mm x 2mm punch for the outlines and major folds and a 10mm x 3mm punch for smaller folds at the tabs. In all cases the slots are calculated to be evenly spaced and to line up with any slots on parallel folds. Spaces between slots are an average of 1.5mm to achieve a balance between structural strength and ease of fold. 4mm clearance holes and corresponding 3.5mm thread holes line through once folded allowing the chair to be fixed rigid with M4 self tapping screws.

The embodiment of Figs, la to 12 is a relatively complex item, and has therefore been described in considerable detail. Embodiments of the present invention in form of sheets of material for forming other items of furniture will also be described, but since the principles underlying their construction and assembly are similar to, but in practice simpler than, those for the chair they will not be described in such detail.

Fig. 13 shows a plan view of an alternative embodiment of a sheet of material in accordance with the present invention in the form of a sheet 110 for folding in order to form a shelf unit for mounting on a wall. The left hand side of Fig. 13 shows the stitching forming the fold lines, whereas the right hand side shows the shape only schematically.

Fig. 14 corresponds generally to Fig. 13 but shows the sheet 110 in planar form (i.e. before folding) entirely schematically.

The sheet 110 includes a number of tabs A, for fixing and reinforcement, a shelf rear panel B, two shelf-end inner panels C, a shelf upper panel D, two shelf-end upper panels E, two shelf-end outer panels F, a front panel G which forms a shelf front panel and two shelf- end front panels, and a shelf bottom panel H.

Figs. 15 to 19 show step-by-step how the sheet 110 is folded to form a shelf unit with integral shelf ends, for mounting on a wall. The folding procedure includes only right angle folds along the fold lines and all folding can be performed by hand by someone of average, or even below average, strength.

As shown in Fig. 15, with the sheet laid out on a flat surface, all tabs A are folded up at right angles, seventeen tabs in total . The angle need only be approximate as any inaccuracy will correct itself when the shelf unit is finally fixed. Then the self rear panel B and shelf front panel G are folded at right angles to the shelf bottom panel H.

As shown in Fig. 16, the shelf-end inner panels C are then folded at right angles, relative to the shelf upper panel D, so that they point directly away front the front panel G.

As shown in Fig. 17, the shelf upper panel D is folded back down toward the shelf bottom panel H and is located on top of the horizontal tab A opposite.

As shown in Fig. 18, the shelf-end upper panels E are folded at right angles and located on top of respective tabs A.

Finally, in order to complete the folding procedure the shelf-end outer panels F are folded and the tabs A thereon are located under the shelf-end upper panels E.

Fig.s 20 to 23 show respectively front, plan, side and rear elevations of the shelf unit.

As shown in Fig. 13, a number of apertures are provided in the panels and tabs. Most of these apertures are circular and are provided so that after folding, the shelf unit can be secured by inserting self tapping screws through aligned apertures. Four of the apertures w, as shown in Fig. 23, are apertures of known type for use in hanging the shelf unit on a wall, and will be described in more detail below. The illustrated preferred embodiment of a shelf unit is in the form of a laterally stretched U-shape 556 mm long x 210 mm deep with one 200 mm high upright on either side.

The shelf unit is designed to hang either open end up with the uprights to either side acting as bookends or open end down as a wall table. The width corresponds to a standard telephone book (210 mm wide) or an A4 folder when used as book shelf or a standard telephone when used as wall mounted table although, of course, different sizes could be provided.

It can be used a single unit or as a multiple of units in any format on a wall.

The stitching of the fold lines also acts as a decorative feature once assembled.

As well as acting as book ends the uprights provide the fixing method to the wall. At the top and bottom of each upright are key hole slots w from which the shelf will hang. Two collared screws are fixed horizontally into a wall 500 mm apart. The shelf is simply slotted onto the protruding screw heads, the same screw position allowing the shelf to be fixed either way up. The screw head and key hole slot then become a fulcrum from which the shelf hangs, its own weight and that of any object thereon holding it against the wall.

In a preferred embodiment the shelf unit is sold as a flat sheet 110 of powder coated 1 mm thick steel sandwiched between a folded sheet of 6 mm corrugated card. The card has a simple image describing the product silk screened onto its outside face and instructions as to how to fold it up on its inside. The sheet 110 is preferably C.N.C. punched from 1 mm cold reduced steel. The sheet 110 fits within a rectangle of 980 mm x 659 mm, so that positioning on a standard 1250 mm x 2450 mm sheet allows 4 shelves per sheet.

The sheet is preferably punched out using a standard 25 mm x 2 mm punch for the cut lines and fold lines for major folds and a 10 mm x 3 mm for smaller folds at the tabs. The slots of the fold lines are calculated to be evenly spaced and to line up with any slots on parallel folds. Stitches between slots are 1 mm plus or minus 0.2 mm to achieve a balance between structural strength and ease of fold. 4 mm clearance holes and corresponding 3.5 mm thread holes line through once folded, allowing the shelf to be fixed rigid with M4 self tapping screws.

Fig. 24 shows an alternative embodiment of the present invention in the form of a sheet of material 210 for folding into a bedside cabinet. Figs. 25 to 27 show the folding process culminating in the finished bedside cabinet shown in Fig. 27.

Fig. 28 shows an alternative embodiment of the present invention in the form of a sheet of material 310 for folding into a stool. Figs. 29 to 31 show the folding process culminating in the finished stool shown in Fig. 31.

The structure of the embodiments of Figs. 24 to 31 is similar in principle to the embodiments of Figs, la to 23. Tabs are included in order to help support and strengthen the structure and apertures are provided to enable simple screws to secure the structure once folding is complete. It will be noted that a secure leg structure can be formed from first to third leg panels 322a, 322b, 322c by securing the central panel 322b to the other two panes 322a, 322c using first to third bottom end tabs 325a, 325b, 325c. The second tab 325a is attached to the central panel 322b and the first and third tabs 325a, 325c are adapted to be folded inside the tubular leg and screwed to the first and third panels 322a, 322c respectively. The rigid three sided tubular leg thus formed can be screwed to the main part of the item of furniture (a stool in this embodiment) by using a further tab 326, rigidly attached to one of the leg panels 322c.

It will be appreciated that other items of furniture can be made from sheets of material in accordance with the invention, as determined by the cut lines and fold lines provided on the sheet.

Embodiments of the present invention should fit well into the growing market for flat pack or self-assembly furniture.

Where existing self-assembly furniture suffers from a perception of difficulty in assembly, embodiments of the present invention solve the problem of multiple, lost or difficult to identify parts by providing only one main component part which can be folded and locked in place using only one type and length of self tapping screw.

Only one tool is needed in assembly, and in a preferred embodiment this is an alien key supplied with the product.

Instructions for assembly will be kept simple. In nearly all cases folds will be at right angles. The furniture can only be folded in and locked in only one form.

Small items such as desk top draw units have previously been designed to be made from folded sheets of cardboard, but they are not durable as objects. Embodiments of the present invention, especially those formed in powder coated steel, are as rigid and durable, once assembled, as ready made pieces of furniture. Unlike cardboard folding furniture embodiments of the present invention are load bearing and can include larger items of furniture such as chairs, tables and shelving.

As the product is manufactured using CNC technology a constant quality can be achieved. Also, as the process requires no item specific tooling, production runs of 100 to 10,000 can be tackled with no significant increase in cost. This, coupled with the speed of manufacturing, means production can be effected in response to even small orders.

The product is intended to be aesthetically desirable as a completed piece of contemporary furniture. In addition, it is economical to produce and easy to assemble.

Lack of outlets for contemporary furniture is often sited as a reason for poor sales. The compact size of the un-asseinbled product (less than 10 mm thick including packaging) makes it possible to retail the product in shops specialising in contemporary design but without the space to display or store ready assembled contemporary furniture. It is also intended that the product could pass the conservative furniture retail market and hang alongside clothing in design conscious retail outlets.

It is preferable to provide embodiments which are neither too heavy or unwieldy to carry as a flat sheet.

Whilst powder coated steel is a preferred material for embodiments of the present invention, other sheet materials, for example rigid plastics, and/or other finishes, for example galvanised sheets of metal, may be used without departing from the scope of the present invention.

Further modifications and improvements may be made without departing from the scope of the present invention. In particular, although the fold lines are described as being formed using holes or apertures, these terms should be interpreted broadly and should be considered to include indentations or hollows that do not extend all the way through the sheet.

Claims

1. A sheet of plastically deformable material which contains at least one fold line comprising a plurality of holes arranged in a line such that the sheet may be folded manually along the fold line, the sheet being foldable along the or each fold line to form an item of furniture.

2. A sheet as claimed in Claim 1 wherein the sheet also contains at least one cut line comprising an elongated slot such that the sheet may be separated manually along the cut line.

3. A sheet as claimed in either preceding claim wherein the plastically deformable material is metal.

4. A sheet as claimed in Claim 3 wherein the plastically deformable material is steel.

5. A sheet as claimed in any preceding claim wherein the sheet is powder coated.

6. A sheet as claimed in any preceding claim wherein the sheet is less than 2mm thick.

7. A sheet as claimed in any preceding claim wherein the holes are in the form of slots arranged with their longer dimension parallel to the fold line, the slots being separated by uncut sections of sheet of a length less than that of the slots.

8. A sheet as claimed in Claim 7 wherein the ratio between the length of slot and length of uncut section is greater than 5, more preferably greater than 10, and in a preferred embodiment greater than 15.

2 9. A sheet as claimed in either of Claims 7 or 8 wherein the length of each uncut section is of the same order of magnitude as the thickness of the sheet.

10. A sheet as claimed in Claim 9 wherein the length of each uncut section is approximately equal to the thickness of the sheet.

11. A sheet as claimed in any preceding claim wherein the sheet includes a rectangular area bounded by four fold lines and forming a seat upper panel of a chair when the sheet is folded.

12. A sheet as claimed in any preceding claim wherein the sheet includes at least three parallel, elongated rectangular areas separated by fold lines and forming a polygonal tubular leg when the sheet is folded.

13. A sheet as claimed in Claim 12 wherein the elongated rectangular areas form a rear chair leg and are of a length such that the rear chair leg extends continuously from the floor to a back rest positioned above a seat when the sheet is folded.

14. A sheet as claimed in any preceding claim wherein the sheet is provided with a number of apertures adapted for receiving fixing means therethrough to fix the form of the furniture when the sheet is folded.

15. A sheet as claimed in Claim 14 wherein the sheet is provided with a number of pairs of apertures positioned so that the two apertures of each pair align when the sheet is folded, such that a fixing member can be inserted through both apertures of each pair.

16. A method of assembling an item of furniture, in which a sheet of plastically deformable material is folded manually along at least one fold line comprising a plurality of holes arranged in a line to form an item of furniture.

17. A method as claimed in Claim 16 wherein the sheet is also separated manually along at least one cut line comprising an elongated slot.

18. A method as claimed in either of Claims 16 or 17 wherein the sheet is delivered as a flat sheet to the person who manually folds along the at least one fold line.

19. A method as claimed in any of Claims 16 to 18 wherein the sheet is sandwiched between two layers of packing material, such as cardboard, when it is delivered as a flat sheet.

20. A method as claimed in any of Claims 16 to 19 wherein the holes and slots are cut using CNC techniques.

21. A method as claimed in any of Claims 16 to 20 wherein the holes and slots are cut using laser cutting apparatus.

22. An item of furniture fabricated from a single sheet of plastically deformable material by folding along at least one fold line comprising a plurality of holes arranged in a line.

23. An item of furniture as claimed in Claim 22 wherein the sheet also contains at least one cut line comprising an elongated slot.

24. An item of furniture as claimed in either of Claims 22 or 23 wherein the item of furniture has a plurality of legs, each leg being formed from at least three parallel, elongated rectangular areas folded along fold lines to form a polygonal tubular leg.

25. An item of furniture as claimed in any of Claims 22 to 24 wherein the item of furniture is a chair, with a rectangular area bounded by four fold lines forming the seat of the chair.

26. An item of furniture as claimed in any of Claims 22 to 24 wherein the item of furniture is a shelf unit having integral book ends, with a rectangular area bounded by four fold lines forming the horizontal shelf surface.

27. An item of furniture as claimed in any of Claims 22 to 24 wherein the item of furniture is a bedside cabinet.

28. An item of furniture as claimed in any of Claims 22 to 24 wherein the item of furniture is a stool.

29. An item of furniture as claimed in any of Claims 22 to 28 wherein the sheet is in accordance with any of Claims 1 to 15.