BACKGROUND OF INVENTION Man-made materials provide many opportunities for reviewing established construction techniques and extending known techniques to provide improved products.

This invention utilizes the edgewise crushable properties of corrugated board and related board products to provide an improved and simplified method of manufacturing and constructing knockdown storage systems and furniture.

Corrugated cardboard or its plastic equivalent coreboard comprises a corrugated inner core of cardboard sandwiched between two liner boards to produce a flat board of a certain thickness. The board can be readily cut to expose the inner corrugations or the edges of the liner boards.

Corrugated board is readily available in a range of flute sizes and range of laminate layers to provide a wide range of strengths and thicknesses.

While the use of corrugated board for the manufacture of furniture and the like is known, the construction techniques used tend to closely reflect the standard techniques used when conventional board materials are utilized-for example particle board or MDF. When corrugated board materials are used as a substitute for MDF etc., often a satisfactory result can be obtained due to the very rigid nature of the available corrugated and multiple layered materials.

However, the standard construction techniques used to join and fix MDF are not always applicable to corrugated board. Furthermore, such techniques involve the use of hardware and do not fully utilize the distinctive properties of corrugated board.

OBJECT AND STATEMENT OF INVENTION One object of this invention is to provide an improved method of constructing storage and furniture items made from corrugated board materials or formed in part from such materials.

Accordingly, in one aspect the invention provides an improved technique for assembly of preformed component parts of a given item characterized in that said preformed component parts are formed from corrugated board and are fitted to a tolerance requiring crushable distortion of one or more edges of said component parts so as to form a cooperative engagement by a press fit between two or more adjacent component parts.

In another aspect, the invention provides an item of furniture or the like comprising a plurality of interconnecting parts wherein at least one of said parts is formed from corrugated board characterized in that one or more of said board parts are dimensioned so as to require crushable distortion of one or more edges thereof during interconnection with an adjacent part so as to form a self-locking interconnection.

The crushable distortion preferably occurs only at the interface of an interconnection between two parts and does not result in any distortion other that at the edge region of said parts.

The component parts are preferably substantially flat and made from single or multi-layered board. The corrugated board is preferably twin or triple board with greatest preference for triple corrugated board being a composite laminate of three layers of core of differing flute dimensions to provide high performance/weight benefits.

The item of furniture may be a storage system including a plurality of five sided boxes forming a nest of shelves. The nest may comprise a plurality of vertical and horizontal panels. Each vertical and horizontal panel having a plurality of transverse half slots formed from the front or rear respectively to allow the mutual interconnection of the vertical and horizontal panels into a web. The web may be provided with a back in the form of a rear panel dimensioned for a tight fit into the so formed web openings requiring edgewise

distortion of said rear panel. The rear panel may traverse a plurality of web openings and most preferably has a plurality of transverse slots adapted to engage rearward projections of said vertical or horizontal panels.

The item of furniture preferably has forward slots formed in the vertical panels and rearward slots formed in the horizontal panels, so as to provide integral forward vertical support for the shelves so formed, and a rear panel adapted to traverse a vertical column of web openings. The rear panel may be dimensioned to fit between two vertical panels and have mating pairs of partial transverse slots formed to correspond with the position of the rearward horizontal panels, said rearward horizontal parts having an indentation formed therein to receive that section of said rear panel remaining between said mating pair of partial transverse slots such that said rear panel can be pressed into co-operative engagement with said vertical and horizontal panels.

The invention will be described in greater detail with reference to the following examples of a particularly preferred embodiment.

Figure 1 shows a full exploded view of a storage unit.

Figure 2 shows a partially assembled view of a storage unit.

Figure 3 shows the horizontal panel of the storage unit.

Figure 4 shows the vertical panel of the storage unit.

Figure 5 shows the rear panel of the storage unit.

Figure 6 shows the assembled storage unit.

The invention will now be described in more detail with particular reference to one example of a storage system constructed in accordance with the improved construction technique of the invention.

Referring firstly to Figures 1 and 2, the construction technique of the current invention uses multi-layered corrugated cardboard planar material to form the component parts or panels thereof in the form of vertical panels 1, horizontal panels 2 and rear panels 6 which form interconnecting components adapted to be assembled into a finished item of furniture without the need for fixing means, glues or other securing means to hold the various component parts together. Of

course, such fixing means may be used if further reinforcement is deemed necessary.

The board material used in the manufacture of the component parts, provides at the various cut edges, a deformable interface in the form of a crushable region of the component parts which can allow the preparation of close tolerance fitting of the various component parts relying on the crushable distortion of the edges of said component parts so as to allow the interconnection of component parts. A tight press fit between two or more adjacent component parts is desirable where the tightness is sufficient to require the crushable distortion of one or more of the edges to effect the aforesaid press fit. It is the very act of crushing the edges that affects the tight press fit and avoids the need for any additional fixing or fastening methods whatsoever as the assembled unit is secured together by cooperation of the component parts.

The particular item of furniture detailed in the example, is a nest of shelves comprising a plurality of interconnecting parts formed from multi- layered board, preferably of triple laminate construction of the type readily available under various brand names including Tri-wall@, Triple maux@, Twin maxt) or Twin wall@. The various component parts are preferably formed of a substantially flat or planar section of the board in order to provide a ready means of pre-packaging the various component parts for storage, transport or sale.

Referring again to Figure 1, the storage system is shown with a selection of the representative component parts in exploded form and can be seen to comprise a plurality of vertical panels 1 and horizontal panels 2 where each of the vertical and horizontal panels have a plurality of transverse half slots 3 formed therein with the vertical panels having forward slots 9 formed from the front edge 4 and the horizontal panels 2 have rearward slots 10 formed from the rear edge 5. In this manner, the vertical and horizontal panels can be mutually interconnected to form a web.

Referring now to Figure 2, the partially assembled storage unit can be seen with the vertical and horizontal panels press fitted together and in so

forming a plurality of web openings 7. The web openings function as shelves 11. The web is reinforced by the provision of a back in the form of a rear panel 6. The rear panel is dimensioned for a tight fit into the so formed web openings 7 in a manner requiring the edge wise distortion of said rear panel as the rear panel is press fitted into the web opening 7.

The rear panel preferably traverses a plurality of web openings and dependant on the size of the storage unit, may traverse a whole vertical column of web openings.

The rear panel 6 is dimensioned to fit tightly between two vertical panels and is provided with a series of mating pairs of partial transverse slots 8 which are formed to correspond with the position of the rearward horizontal panels 5 as they align with the rear edge of the vertical panels.

The rearward edge 5 or the horizontal panels 2 are provided with indentations 12 therein which are adapted to receive the remaining section of the rear panel remaining after removal of the transverse slots 8.

Once the vertical and horizontal panels are respectively assembled into the web, the rear panels 6 are press fitted in between the vertical panels and the transverse slots 8 form a snug fit in between the rear edges of the corresponding horizontal panels 2 such that once the rear panel 6 are press fitted into the available vertical columns in the web, the rear panel 6 is fully fitted within the confines of the web and therein provides substantial torsional support for the rear side of the assembled web in addition to providing vertical support for the rear edge 5 of the horizontal panels 2 when assembled into the shelving unit.

The formation of forward slots in the vertical panels 1 and the integral nature of the front edge of the horizontal panel 2, provides strong vertical support for the front of the horizontal panel 2 of the shelf 11 and accordingly, the interconnecting nature of the storage unit provides a very rigid self- contained, self-locking assembly without the requirement for any additional or auxiliary fixing or fastening means whatsoever.

Referring now to Figure 3, the horizontal panel can be seen in isolation as an example of a selected length and similarly, Figures 4 and 5 provide views

of the separate vertical panels 1 and rear panels 6. Figure 6 provides a front view of the assembled shelving unit where the open web can be seen to comprise a plurality of shelves 11 in the free-standing unit.

The current invention provides for the first time a readily assemble, free- standing storage unit or other item of furniture without the requirement for any reliance on fastening or fixing means whatsoever which makes full use of the inherent strength of corrugated board in addition to making particular use of the edge feature of cut corrugated board which provides for an element of crushable distortion which is used in the current invention as the fastening means to hold the whole of an assembled piece of furniture together without any auxiliary means whatsoever.

The scope of the current invention covers a vast range of furniture, storage items and other assemblies using various grades of corrugated board manufactured out of cardboard, plastic or any other available material and the invention is not to be construed as limiting in any way to the particular embodiment as detailed in the foregoing example.