CA2545937A1

CA2545937A1 - Flooring and method of manufacturing flooring

Info

Publication number: CA2545937A1
Application number: CA 2545937
Authority: CA
Inventors: Baha-Dean Sanaee; Giuseppe Aprile; David Melbye
Original assignee: MILLWORK BY AMATI Inc
Current assignee: Individual
Priority date: 2005-05-09
Filing date: 2006-05-09
Publication date: 2006-11-09

Abstract

Embodiments relate to flooring and methods of manufacturing flooring.
One particular embodiment relates to tiled flooring including a plurality of tiles connected by at least one connector. Another embodiment relates to flooring planks and methods of forming flooring planks, such planks including a veneer layer and a substrate bonded to the veneer layer. The substrate comprises a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix. The substrate has a thickness sufficient to attenuate at least 60 dB of sound from one face of the plank to an opposite face of the plank. In a further embodiment, the plank is formed by: forming a substrate comprising a solid polyethylene matrix and sawdust immobilized in the matrix;
bonding a wood layer to the substrate; and machining the substrate and wood layer to form the plank. A further embodiment relates to a method of manufacturing wood planks from waste wood.

Description

TITLE: FLOORING AND METHOD OF MANUFACTURING FLOORING
FIELD OF THE INVENTION
[0001] The invention relates generally to flooring and methods of manufacturing flooring. In particular, the invention relates to flooring comprising interlocking flooring tiles and methods of manufacturing such flooring tiles and the mechanisms for interlocking them.
BACKGROUND OF THE INVENTION

[0002] Some kinds of finished flooring consist of a sub-floor and a finished flooring layer supported by the sub-floor. The nature of a sub-floor will vary depending on the flooring surface it needs to support and the environment in which it must function. For example, for linoleum tile or carpet on a main floor of a house, the sub-floor may consist simply of sheets of plywood. For a concrete floor such as commonly found in the basement of a house, sheets of plywood would be inadequate alone as they would often be subjected to moisture rising through the concrete floor of the basement, which would tend to swell and warp the plywood. Accordingly, it may be desirable to space the plywood from the concrete surface supporting the sub-floor in order to allow for air circulation between the sub-floor and the concrete surface to remove moisture that may otherwise swell the plywood.

[0003] Free floating sub-flooring panels that allow for air circulation between the sub-floor and the concrete floor are described in United States Patent Application Serial No. 09/809,307 by Smith, published under U.S.
Patent Publication no. 2002/0139074, the entire contents of which is hereby incorporated by reference. Smith describes floor paneling for use in a sub-floor application. The panels have an upper member made of a sheet floor material, such as plywood, and a lower member made from a waterproof sheet material, such as polyethylene. Smith describes interlocking the flooring panels by mating a tongue on one panel with a groove on another panel to prevent relative vertical movement between the panels. However, Smith does not describe any way of maintaining the relative lateral positions of the tiles, nor does Smith describe any way of laterally and longitudinally aligning the panels. Further, Smith describes panels suitable for establishing a floating sub-floor, but the sub-floor of Smith cannot also act as finished flooring. Rather, the panels of Smith must be overlayed with an insulating or cushioning layer and then overlaid with carpet, hardwood, laminate, vinyl or other flooring in order to achieve finished flooring.

[0004] Another problem encountered in providing flooring relates to sound proofing. Some building codes require that flooring in condominiums, for example, must provide a minimum degree of sound attenuation between different floors of the condominium block. In Ontario Canada, the minimum sound attenuation for hardwood flooring in condominiums is 60 dB.
Traditional hardwood flooring has inadequate attenuation of sound transmission to meet these requirements.

[0005] To address this problem, it has been necessary to provide a further three inches or so thickness of plywood and sound absorbing material under the traditional 3/4 inch hardwood floor. This solution reduces the volume of living space in the condominium. This also often generates problems in matching the difference in heights between two flooring materials, for example where the hardwood meets tiles in the kitchen or bathroom or meets carpeted areas.

[0006] A further problem encountered in manufacturing wood flooring is the waste associated with off-cuts generated by milling long wood planks to a desired size. These off-cuts are commonly gathered into a large disposal bin and the bin is removed by a specialist waste disposal company on a regular basis such as weekly or monthly. The cost of such a waste disposal service is substantial. Also the waste of valuable hardwood represents a further financial loss. These problems are a concern among manufacturers of hardwood flooring.

[0007] It is desired to address or ameliorate one or more of the problems, disadvantages or shortcomings described above, or to at least provide a useful alternative to existing products or techniques. Different aspects of the invention address these problems, disadvantages or shortcomings in separate ways.
SUMMARY OF THE INVENTION

[0008] Aspects of the invention relate generally to flooring and to methods of manufacturing flooring. These aspects relate to flooring comprising interlocking flooring tiles or planks and to manufacturing such interlocking tiles and, in come cases, their interlocking mechanisms.

[0009] In one broad aspect, the invention relates to flooring comprising a plurality of tiles and at least one connector. The tiles each have a plurality of side edges and each side edge has a side face and a groove in the side face extending along the side edge. Each connector has first and second opposed side portions which are receivable in facing grooves of respective tiles so that two tiles can be connected by one connector. Such a connection can be made by having the first side portion of the connector received in the groove of one of the tiles and the second side portion of the connector received in the groove of another of the tiles. The flooring further comprises retention means for retaining the first and second side portions in respective grooves of adjacent tiles so that the adjacent tiles are positioned to have their adjacent side faces substantially abutting and aligned with each other. The retention means acts to substantially hinder removal of the first and second side portions from the groove. The tiles preferably comprise wood.

[0010] The flooring may further comprise, on each tile, a top veneer for providing a walking surface. The top veneer may be, for example, a wood veneer layer or a vinyl layer. The flooring may also comprise a spacing layer on the underside of each tile for spacing the tiles from a support surface, such as a cement floor, underlying the flooring. The spacing layer is configured to allow air to flow between the support surface and the flooring so that moisture coming up from the support surface can be removed by air circulation, rather than by penetrating into the flooring and causing swelling and warping of the flooring.

[0011] Advantageously, the connector may be elongate, for connecting the tiles along a substantial portion of the side edge to an adjacent tile, or may be cross-shaped (like a plus sign) for connecting the tiles at their corner vertices. Such a cross-shaped connector also serves to provide lateral and longitudinal alignment of the tiles, while the retention means, at least partly provided by the connector, maintains the relative position of the tiles in such an aligned state. For increased alignment and retention capability, both elongate and cross-shaped connectors may be used. Alternatively, if an elongate connector is used, a cross-shaped spacer piece may be used to accomplish the alignment function, while the elongate connector serves to maintain the relative positions of the adjacent tiles. In a further alternative, the cross-shaped connector may be used at the corners of the tiles while an elongate spacer is used in place of the elongate connector.

[0012] Advantageously, embodiments of this aspect facilitate easy alignment of the tiles in lateral and longitudinal directions and provide connectors that, in combination with the grooves in the tiles, form retention means such that the connectors grip the wood tiles or otherwise frictionally engage the tiles to prevent or at least substantially hinder removal of the connectors from the tile grooves.

[0013] The retention means may be provided by sizing the connectors and groove so that the connectors are received in the grooves in an interference fit. In such a case, the connectors preferably have angled projections or teeth which press into the internal walls of the grooves because of the interference fit. The angled projections facilitate entry of the side portions of the connectors into the grooves by being angled back towards a central portion of the connector, but resist removal of the connector from the grooves. Other forms of retention means may be employed, however, such as by providing mating recesses within the grooves for receiving projections on the connectors or by providing mating or interlocking contours of the grooves and side portions of the connectors.

[0014] Another broad aspect of the invention relates to flooring planks and methods of manufacturing such flooring planks. In one particular aspect, the invention relates to a flooring plank comprising a wood layer and a substrate bonded to the wood layer. The substrate comprises a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix. The sawdust comprises about 30-35% by volume of the substrate.

[0015] Preferably, the sawdust comprises about 32% by volume of the substrate. The thickness of the flooring plank is preferably about 0.5 inches and the thickness of the substrate is preferably at least 0.375 inches. The thickness of the flooring plank may be greater than 0.5 inches if the substrate is greater then 0.375 inches but it is preferable to maintain the thickness of the wood layer at about 0.125 inches. Preferably, tongue and groove portions are formed in the substrate on opposite lateral sides of the plank.

[0016] In another particular aspect, there is provided a flooring plank comprising a veneer layer and a substrate bonded to the veneer layer. The substrate comprises a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix and the substrate has a thickness sufficient to attenuate a least 60 decibels of sound from one face of the plank to an opposite face of the plank. Preferably, the sawdust comprises between 30%
and 35% by volume of the substrate. More preferably, the sawdust comprises about 32% by volume of the substrate. Preferably, the thickness of the substrate is at least 0.375 inches. Tongue and groove portions are preferably formed in the substrate on opposite lateral sides of the plank. The veneer layer preferably comprises a hardwood veneer of about 0.125 inches in thickness.

[0017] Another particular aspect of the invention relates to a method of manufacturing flooring planks. The method comprises forming a substrate comprising a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix, bonding a wood layer to the substrate and machining the substrate and wood layer to form a plank.

[0018] Preferably, the machining comprises forming tongue and groove portions and a substrate on opposite lateral sides of the plank. The forming step of the method preferably comprises mixing the sawdust with liquid polyethylene and curing the polyethylene and sawdust to provide the solid polyethylene matrix. The liquid polyethylene used to form the polyethylene matrix preferably comprises recycled polyethylene material heated to liquidation. The step of forming the substrate preferably comprises forming the substrate to have a thickness sufficient to attenuate at least 60 decibels of sound from one face of the plank to an opposite face of the plank.

[0019] Advantageously, the substrate of polyethylene mixed with sawdust has been found to provide good sound insulation properties at a relatively small thickness. Additionally, the particular proportions of sawdust to polyethylene have been found to allow the substrate to be milled in a similar manner to normal wood, thus allowing the substrate and wood veneer layer to be milled together after they are bonded. Further, this allows the tongue and groove of the plank to be milled into the thicker substrate portion of the plank so that multiple planks can be fitted together according to normal flooring applications. A further advantage of this aspect is that it can use recycled polyethylene material and sawdust, which are both cheap materials, and only requires a relatively thin layer of hardwood veneer, rather than a hardwood plank of normal 3/4 inch thickness.

[0020] Another broad aspect of the invention relates to a method of manufacturing wood planks from waste wood. The method comprises collecting elongate lengths of waste wood off cuts of at least a predetermined size, applying adhesive to one side of the off-cuts, placing the off-cuts together so that the off cuts are bonded together by the adhesive, pressing the off-cuts vertically and laterally to form a plank and trimming and smoothing the plank.

[0021] Preferably, prior to the step of pressing, the bonded off-cuts are planed to a substantially uniform thickness. The step of placing preferably comprises axially rotating each of the off-cuts so that the adhesive applied to the one side of an off-cut faces an adjacent off-cut and pressing the off-cuts laterally together. The method preferably further comprises forming tongue and groove portions along opposed lateral sides of each plank and forming shallow grooves longitudinally along an underside of the plank. The top surface of the plank is preferably finished as a walking surface. A further aspect of the invention provides a flooring plank manufactured according to the method described above.
BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Aspects of the invention are described in further detail below, by way of example only, with reference to embodiments shown and described in relation to the drawings, in which:

[0023] Figure 1 is an exploded plan view of flooring according to one embodiment;

[0024] Figure 2 is a partial plan view of the flooring of Figure 1 as assembled;

[0025] Figure 3 is a partial cross-sectional view of a flooring tile and connector, shown in assembled form;

[0026] Figure 4 is a partial perspective view of a flooring tile, connectors and a spacer used in the flooring shown in figure 1;

[0027] Figure 5 is an exploded partial side cross-sectional view of flooring according to another embodiment;

[0028] Figure 6 is a perspective view of an elongate connector for use with the flooring of Figure 5;

[0029] Figure 7 illustrates an alternative form of connector and a correspondingly shaped recess in a tile for receiving one side portion of the connector;

[0030] Figure 8 shows a further alternative form of connector and a mating recess formed in a tile for receiving one side portion of the connector;

_ $ _ [0031] Figure 9A is a partial and sectional view illustrating a further form of connector, shown in an interference fit within the grooves of adjacent abutting tiles.

[0032] Figure 9B is an end sectional view of the connector of Figure 9A;

[0033] Figure 10A is a plan view of a further alternative form of connector;

[0034] Figure 10B is an end cross-sectional view of the alternative connector of Figure 10A, taken along line B-B;

[0035] Figure 11A is an end view of a flooring plank according to another embodiment;

[0036] Figure 11 B is a perspective view of the plank of Figure 11A;

[0037] Figure 12 is a process flow diagram of a method of manufacturing the flooring plank of Figures 11A and 11 B;

[0038] Figure 13 is an end view of two pieces of flooring planks manufactured according to a further embodiment;

[0039] Figure 14 is an end view of a flooring plank manufactured according to yet another embodiment; and [0040] Figure 15 is a process flow diagram of a method of manufacturing the flooring planks shown in Figures 13 and 14.
DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] This invention has several separate main aspects. A first main aspect relates to flooring, including tiles and connectors for connecting those tiles, as shown and described in relation to Figures 1-9A, 9B, 10A and 10B. A
second main aspect of the invention relates to flooring planks and a method of forming such flooring planks to include a wood or veneer layer and a substrate, as shown and described in relation to Figures 11A, 11 B and 12. A
third main aspect of the invention relates to a hardwood flooring plank and a method of manufacturing such a plank using waste wood, as shown and _g_ described in relation to Figures 13 to 15. These three main aspects are described in further detail below, separately and in sequence.

[0042] Throughout this specification and in the drawings, like reference numerals are used to indicate like features or functions as between the drawings and/or the elements as shown therein. Where practical, reference numerals are structured so as to use the same number in the hundreds column for like or related embodiments and to use the numbers in the remaining two digit positions to indicate like features or functions as between different embodiments. Thus, for example, connectors are generally designated by reference numerals ending in the number 20 as applied to the first main aspect. For example, the connectors of the different embodiments of the first main aspect shown in Figures 1, 5, 7 and 8 are designated by reference numerals 120, 520, 720 and 820.

[0043] Embodiments of the invention relating to the first main aspect will now be described, with reference to Figures 1-9A, 9B, 10A and 10B.

[0044] Figure 1 is an exploded plan view of flooring 100 according to one embodiment. Flooring 100 comprises a plurality of flooring tiles or panels 110 interconnected by connectors 120. The tiles 110 are designed to be fitted together in substantially the same plane so that their side edges abut the side edges of adjacent tiles. Tiles 110 are preferably about 2 feet by 2 feet square and composed of at least a main wood layer. The wood may be any form of manufactured wood, for example such as random wafer board, oriented strand board, plywood, particleboard or multi-density fiberboard.

[0045] While tiles 110 are shown in Figure 1 as being generally square, it should be understood that they may be formed of other shapes, including generally rectangular shapes, triangular shapes, pentangular shapes, or hexagonal shapes, for example. Alternatively, tiles of more than one shape may be employed together to form visually interesting patterns. Depending on the particular tile shape chosen, the dimensions of tiles 110, connectors 120 and spacers 140 (described below) may vary.

[0046] Tiles 110 preferably have a top veneer layer 115 (shown in Figure 5), which is a finished flooring layer, such as a hardwood veneer, laminate or vinyl bonded by suitable adhesive to the main wood layer. Tiles 110 also include a spacing layer 116 adhered by a suitable adhesive to a lower surface of the main wood layer of tiles 110. Spacing layer 116 is water impermeable and comprises a plurality of projections 177 projecting downwardly from tiles 110 toward the concrete floor underneath the tiles 110 sides to separate the tiles 110 from the concrete floor. An example spacing layer 116 is shown and described in US 09/809,307 by Smith. Projections 117 are spaced apart so as to allow airflow between the spacing layer 116 and the concrete floor. Thus, tiles 110 in conjunction with connectors 120 can be used as sub flooring and finished flooring, thereby providing two functions in one flooring product.

[0047] Tiles 110 have continuous groves 112 formed in their side edges. The grooves 112 are continuous on each side edge of each tile 110 and meet at the corner vertices of each tile 110. Grooves 112 are preferably shaped as channels having a roughly rectangular cross-section and being 1/4 inch across by about 3/4 inches to 19/32 of an inch deep (depending on the lateral width of connector 120). The shape of groove 112 may be varied, depending on the chosen mechanism for retaining connectors in groove 112.
Several such retention mechanisms are contemplated and described herein in relation to certain embodiments.

[0048] Connectors 120 are formed as elongate extruded plastic inserts.
Each connector 120 has a lateral width greater than its thickness but significantly less than its longitudinal length. Connectors 120 are preferably made of a form of polyvinyl chloride (PVC). On each lateral side of each connector 120 there are a plurality of outwardly projecting teeth 124, which are angled back towards the lateral center of the connector 120. These teeth 124 begin at an end face 122 on each lateral side of connector 120 and progress in series back towards the center portion of connector 120 on both the top and bottom faces of connector 120. The thickness of connectors 120 and the degree of projection of teeth 124 are sized to make an interference fit with the inside walls of groove 112. As shown in Figures 3 and 4, three teeth 129 may be provided on each lateral side and on each face. A greater or lesser number of teeth may be used, depending on the particular requirements of the retention means.

[0049] The teeth 124 of connector 120 are swept (angled) back in order to facilitate entry of each lateral side portion into the respective grooves 112 of adjacent tiles 110. The swept back form of teeth 124 in combination with the interference fit also serves to substantially hinder removal of a connector from the groove 112 of a tile 110 once it has been inserted therein. Thus, connectors 120, in combination with grooves 112, serve to provide an effective retention means for retaining tiles 110 in a particular orientation or position, once placed in such an orientation or position.

[0050] As shown in Figure 2, when the flooring tiles 110 are assembled so as to adjacently abut each other using connectors 120, connectors 120 are enclosed within the facing grooves 112 of adjacent tiles 110. Grooves 112 and connectors 120 are preferably sized so that each groove 112 is slightly deeper than half of the lateral width of connector 120.

[0051] Also as shown in Figure 2, a spacer member 140 is used to assist and aligning tiles 110 laterally and longitudinally with respect to other tiles. Spacer member 140 is received in grooves 112 adjacent the corner vertices of each tile 110 and is shaped like a cross a or plus sign. Spacer member 140 can be used to laterally and longitudinally align two, three or four tiles with each other as spacing member 140 has four concave vertices for mating with prespective convex vertices of tiles 110.

[0052] Spacing member 140 is sized so as to be received in grooves 112 in a close fit but not an interference fit as, at least as shown in the embodiment illustrated in Figure 2, spacing member 140 does not provide a positive connection function in the manner of connectors 120. In other embodiments, the spacer member may also provide a connection function, for example such as connector 1020 shown and described in relation to figures 10A and 10B.

[0053] Spacer members 140 also provide a leveling and support function for tiles 110. For a situation where four tiles are connected by connectors 120, an area of reduced tile thickness is formed around the point where all four tiles meet and this area may become weaker as a result. By having a spacer member 140 inserted in the grooves under the area where all four tiles meet, the tiles 110 are supported against any weakness associated with the area of lower tile thickness.

[0054] Figure 2 shows an area marked "A" , which corresponds to the area marked "A" in Figure 4, showing a close up perspective view of a flooring tile 110 with spacer member 140 partially inserted into grooves 112 adjacent the corner vertex of tile 110. Figure 4 also shows connectors 120 inserted into grooves 112 along adjacent side edges of tile 110. As can be seen from Figure 2 and Figure 4, each cross-shaped spacer member 140 has two sets of opposite wings 142 defining concave vertices 144 therebetween. Wings 142 extend partially along facing grooves 112 of adjacent tiles 110 when spacer member 140 is located in position with its concave corner vertices 144 mating with the interior convex corner vertices of tiles 110 (created by the intersection of grooves 112 on adjacent sides). Thus, the lateral width of each wing 142 is preferably the same as the lateral width of connectors 120 so that spacer member 140 fits snugly into all intersecting grooves of all adjacent tiles.

[0055] Although spacer member 140 is described and shown as being cross-shaped, if alternative tile configurations (other than rectangular) are used, for example such as triangular or hexagonal tiles the spacer member may have an alternative shape and a different number of concave vertices. In such instances, for triangular tiles, spacer member 140 may have six or eight evenly spaced concave vertices or, for hexagonal tiles, spacer member 140 may have three equally spaced concave vertices.

[0056] The terms "concave" and "convex" are used herein to indicate any form of recess or projection, respectively, rather than to indicate that there is any particular curvature associated with the relevant feature. Thus "concave" and "convex" as used herein include shapes having sharp angles or corners.

[0057] Figure 3 shows a connector 120 inserted halfway into the groove 112 of a tile 110. The other half of connector 120 would normally be received in a facing groove 112 of an adjacent tile 110, although this is not shown in Figure 3. As is visible in Figure 3, teeth 124 engage the interior walls of groove 112 in an interference fit such that the teeth 124 cannot be easily removed from groove 112. Connector 120 is shown in Figure 3 as having its lateral end face 122 abutting an inner end wall 118 of groove 112.
In alternative forms of retention means, space may be provided between end face 122 and inner and end wall 118. With the connector and groove configuration shown in Figure 3, when the connector 120 is enclosed by facing grooves 112 of adjacent tiles 110, the end faces 111 of the tiles 110 will contact and abut each other.

[0058] Referring now to Figure 5, tiles 110 are shown employing a slightly different form of retention means. In Figure 5, the retention is accomplished by interlocking teeth 524 on connector 520 with corresponding tooth shaped recesses 514 in the sidewalls of grooves 112. Connector 520 is sized to be enclosed by grooves 112 when tiles 110 are brought together so that their side faces 111 abut each other along the full length of each facing side of the adjacent tiles 110.

[0059] Connector 520 is shown in perspective in Figure 6. Connector 520 is shaped like an elongate substantially rectanguloid bar with teeth 524 projecting from the top and bottom faces on each lateral side of the bar.

[0060] Referring now to Figure 7, an alternative form of retention means is shown. In this alternative embodiment, tiles 710 receive one lateral side of a connector 720 in a groove 712. The groove 712 has an internal cross-sectional profile corresponding to projections on the lateral side portion of connector 720. For example, groove 712 has recesses 714 formed to cooperate with projections 724 on connector 720 in a similar manner to the embodiment shown and described in relation to Figures 5 and 6.

[0061] Referring now to Figure 8, a further alternative form of retention means is shown. In Figure 8, a connector 820 has side portions 824 on each lateral side for interlocking with a groove 812 of tile 810. Groove 812 is sized so as to receive side portions 824 in a locking manner when connector 820 is pressed laterally into groove 812. Groove 812 has an internal wall profile that tends to resist removal of side portions 824 from groove 812.

[0062] In the embodiment shown in Figure 8, side portions 824 are generally circular in cross-section and groove 812 is contoured so as to enclose the generally circular side portion 824 by contact with the internal walls of groove 812, while allowing the central portion of connector 820 to extend outwardly from the groove to the opposite lateral side portion 824.
Groove 812 has angled walls adjacent a mouth of the groove which narrow inwardly and which allow side portion 824 to be directed inwardly into the groove 812. Inner angled walls 814 within groove 812 then widen inwardly to create angled walls which serve to contact and hinder removal of the circular side portions of connector 820.

[0063] Referring now to Figures 9A and 9B, there is shown a further form of connector 920, having a reduced number of teeth 924 relative to connector 120. Further, connector 920 is of a reduced lateral width.
Connector 920 may be used for grooves 112 of a lesser depth because of the reduced lateral width of connector 920. In Figure 9B, connector 920 is shown having about an 80 degree angle between the (horizontal) central portion of connector 920 and a centrally directed face of projections 924. Connector 920 is also shown as having an angle of about 77 degrees between the outward face of projections 924 and the vertical. This may be alternatively viewed as being 13 degrees from the horizontal central portion of connector 920. These angles are presently preferred but some variation may be permitted, for example in the order of plus or minus 5 degrees.

[0064] The angular orientation of the outward and centrally directed of projections 924 are also applicable to the angled projections 124 of the embodiment as shown in Figures 3 and 4. The main difference between connector 920 and connector 120 is that connector 920 has fewer angled projections 924. Otherwise, connectors 120 and 920 operate in a similar manner.

[0065] Referring now to Figure 10, there is shown a further alternative connector 1020, which combines the functions of spacer member 140 and connector 920. Connector 1020 is generally cross shaped (like a plus sign) but has angled projections 1024 projecting outwardly from the upper and lower faces of connector 1020. These angled projections 102, when inserted into grooves 112 at the corners of tiles 110, grip the interior walls of grooves 112 to provide a form of retention means in a similar manner to connectors 120. Like spacer member 140, connector 1020 has four concave vertices 1044 for engaging fihe internal corner vertex of grooves 112 on adjacently positioned tiles 110. Wings 1022 extend partially along the grooves 112 of the side of each tile 110 to assist in alignment of the tiles 110 relative to each other, similar to the alignment and spacing function of the wings 144 of spacer member 140.

[0066] Figure 10A shows connector 1020 in plan view while Figure 10B
shows connector 1020 in partial side cross section, taken along line-B-B. The width of wings 1022 as indicated by dimension Q in Figure 10A, while the depth of wings 1022 (i.e. the amount by which they extend along the side of each tile 110) is indicated by dimension R. The width of the central portion of each wing 1022 between angled projections 1024 is given by dimension P.
Connector 1020 is laterally, longitudinally and diagonally symmetrical.

[0067] Embodiments of the invention relating to the second main aspect will now be described, with reference to Figures 11A, 11 B, and 12.
Figures 11A and 11 B show front and perspective views of a plank 1100 for use in flooring applications. Plank 1100 is ideally suited to use in circumstances where it is designed to limit the transmission of noise from one level of a multi-level building to the level below, while providing a flooring that resembles normal hardwood flooring and which is not unduly thick or bulky.

[0068] Planks 1100 have a groove 1112 and a tongue 1114 for interlocking a number of planks 1100 to provide flooring across a substantial area. Planks 1100 have a top veneer layer 1120 resembling a normal hardwood plank and a substrate 1110 bonded to veneer layer 1120 by an adhesive 1130.

[0069] Substrate 1110 has a thickness Z of at least 3/8" in order to provide the desired level of sound attenuation of at least 60 decibels. The thickness X of plank 1100 is preferably about 1/2", with the thickness Y of the veneer layer 1120 being about 1/8". A thickness Z of about 3/8" of substrate 1110 has been found to provide sound attenuation of about 61.5 decibels based on the proportions of polyethylene and sawdust in substrate 1110 described below. A thicker substrate layer 1110 may be provided for even greater sound attenuation.

(0070] Substrate 1110 is formed primarily of polyethylene and sawdust.
While good results have been obtained using only polyethylene and sawdust, where the sawdust comprises 30% to 35% by volume of the substrate, substrate 1110 may comprise small amounts of other materials if they are suitable for enhancing the properties of substrate 1110 (and as long as they do not detract from the properties of the substrate 1110).

[0071] It has been found that a proportion of 32% sawdust by volume is optimal for substrate 1110. The resulting properties of substrate 1110 provide good sound insulation while permitting substrate 1110 to be milled as if it were a solid wood plank and also providing a good bonding strength between veneer layer 1120 and substrate 1110. Pure polyethylene is difficult to bond with a hardwood veneer layer in a lasting fashion. Attempts were made to bond a polyethylene substrate with a wood veneer layer using a number of different adhesives. It was found that, once sawdust was added to the polyethylene before curing it, the bonding characteristics of substrate 1110 improved substantially.

[0072] Referring also to Figure 12, a manufacturing method 1200 for manufacturing planks 1100 is described. Firstly, in order to form the substrate 1110, polyethylene material is heated to its melting point, at step 1210.
Preferably, the polyethylene material is recycled polyethylene. At step 1220, sawdust is added to the liquid polyethylene and mixed in evenly until the mixture is sufficient to provide sawdust at a level of 32% by volume of the solid substrate 1110.

[0073] At step 1230, the polyethylene and sawdust mixture is cooled (or otherwise cured) and formed into sheets of solid material. Wood veneer is then adhered to the sheets of substrate material to formed unmachined panels at step 1240. The adhesion of the wood veneer layer to the substrate may be done by a suitable adhesive, such as a polyvinyl acetate (PVA) glue or other non-toxic, stable adhesive.

[0074] At step 1250, the panels are milled to a predetermined plank size and the tongue and groove is formed in each plank using standard machinery. At step 1260, the wood veneer layer on each plank is finished in order to provide a suitable walking surface for flooring.

[0075] Embodiments of the invention relating to the third main aspect will now be described with reference to Figures 13 to 15.

[0076] Figure 13 shows two wood planks 1300 placed laterally side-by-side in an orientation common for flooring planks. Planks 1300 each have a tongue 1314 and a groove 1312 for mating with an adjacent plank 1300.
Each plank 1300 has a body 1310 formed of a number of longitudinally elongate wood pieces 1305. These wood pieces 1305 are recycled wood offcuts from a milling operation where large wooden planks are cut down to a predetermined size. The offcuts generated from this milling process are often long, thin pieces of wood which can be reused. The offcuts are substantially rectangular in cross-section. Planks 1300 are thus formed of reused hardwood and are finished for use as hardwood flooring so as to have a finished walking surface 1350 on the top face of the planks 1300.

[0077] Figure 14 shows a plank 1400 identical to planks 1300, except for the addition of shallow longitudinal grooves 1460 on an underside of plank 1400. These shallow longitudinal grooves 1460 are provided for stress relief of plank 1400 and are preferably about 2mm to 4mm deep and 6mm to 10 mm wide. Plank 1400 has a finished walking surface 1450 on its top surface and has a tongue 1414 and a groove 1412 for use in fitting the planks together in normal flooring applications. Plank 1400, like planks 1300, is formed a number of long, thin wood pieces 1405 of rectangular cross-section.

[0078] Figure 15 illustrates a method 1500 of manufacturing either of wood planks 1300 or 1400. Method 1500 starts by milling wood to produce offcuts of a predetermined thickness at step 1505. This can be done by placing extra cutting blades at a certain distance outside the normal cutting blades such that, for example, an offcut of 3/4" thickness can be obtained. At step 1510, the offcuts are collected and cut to an appropriate longitudinal length to be formed into a plank 1300 or 1400 of the desired length.

[0079] At step 1515, adhesive is applied to the offcuts on one side, for example, at the top. At step 1520, the offcuts are each rotated by about 90 degrees and butted together to form a plank. The plank is then smoothed with a planer at step 1525 and is pressed in a hot press, at step 1530. The hot press presses the plank from the top and the bottom and the plank is also pressed from its lateral sides while it is under vertical pressure in the hot press.

[0080] At step 1535, the plank is trimmed and smoothed and the tongue and groove is formed on opposite lateral sides. The stress relief grooves are formed on the underside of the plank at step 1540, if plank 1400 is being made. Otherwise, step 1540 is skipped if plank 1300 is being made.
Finally, the top surface of plank 1300 or 1400 is finished as a walking surface at step 1545.

[0081] While embodiments of aspects of the invention have been described and shown in the drawings, it is to be understood that these embodiments are presented by way of example only, without limitation to the principles of the described aspects of the invention.

Claims

1. Flooring, comprising:
a plurality of tiles, each tile having a plurality of side edges, each side edge having a side face and a groove in the side face extending along the side edge;
at least one connector, each connector having first and second opposed side portions receivable in facing grooves of respective tiles so that two tiles can be connected by one connector by having the first side portion of the connector received in the groove of one of the tiles and the second side portion of the connector received in the groove of another of the tiles; and retention means for retaining the first and second side portions in respective grooves of adjacent tiles so that the adjacent tiles are positioned to have their adjacent side faces substantially abutting and aligned with each other, the retention means acting to substantially hinder removal of the first and second side portions from the grooves.

2. The flooring of claim 1, wherein the tiles comprise wood and wherein the wood is selected from the group consisting of: random water board, oriented strand board, plywood, particleboard and multi-density fiberboard.

3. The flooring of claim 1 or 2, further comprising, on each tile, a top veneer for providing a finished walking surface, wherein the top veneer is a hardwood veneer.

4. The flooring of claim 3, further comprising a spacing layer on an underside of each tile for spacing the tiles from a support surface underlying the flooring, the spacing layer being configured to allow air flow between the support surface and the flooring.

5. The flooring of any one of claims 1 to 4, wherein, for each tile, each groove extends along the full length of the respective side edge so that the grooves of adjacent side edges intersect at a vertex of the tile.

6. The flooring of claim 5, wherein each tile has four side edges and is generally rectangular in plan view.

7. The flooring of claim 5 or 6, further comprising at least one spacer member partly receivable in facing grooves of adjacent tiles for laterally and longitudinally aligning the adjacent tiles.

8. The flooring of claim 7, wherein the spacer member is cross-shaped and has four concave vertices for receiving convex vertices of four tiles to laterally and longitudinally align the four tiles with each other.

9. The flooring of any one of claims 1 to 8, wherein the retention means comprises angled projections on each connector which, when the connector is received in the groove, engage internal walls of the grooves to substantially hinder removal of the connector from the groove.

10. The flooring of claim 9, wherein the angled projections are received in the groove in an interference fit.

11. The flooring of any one of the claims 1 to 8 wherein the retention means comprises an interference fit between the first and second side portions and internal walls of the grooves.

12. The flooring of any one of claims 1 to 11, wherein, the grooves and connectors are dimensioned so that when adjacent tiles are abutted and aligned with each other, the connector connecting the adjacent tiles is enclosed within the facing grooves of the adjacent tiles.

13. The flooring of any one of claims 1 to 6 and 8 to 12, wherein the at least one connector is substantially cross-shaped and has respective concave vertices adjacent the first and second side portions for receiving corresponding convex vertices of adjacent tiles to laterally and longitudinally align the adjacent tiles.

14. A flooring plank comprising:

a wood layer; and a substrate bonded to the wood layer, the substrate comprising a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix, the sawdust comprising 30% to 35% by volume of the substrate.

15. The flooring plank of claim 14, wherein the sawdust comprises about 32% by volume of the substrate.

16. The flooring plank of claim 14 or 15, wherein the thickness of the flooring plank is about 0.5 inches.

17. The flooring plank of claim 14, 15 or 16, wherein the thickness of the substrate is at least 0.375 inches.

18. The flooring plank of any one of claims 14 to 17, wherein tongue and groove portions are formed in the substrate on opposite lateral sides of the plank.

19. A flooring plank comprising:
a veneer layer; and a substrate bonded to the veneer layer, the substrate comprising a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix, the substrate having a thickness sufficient to attenuate at least 60 dB of sound from one face of the plank to an opposite face of the plank.

20. The flooring plank of claim 19, wherein the sawdust comprises between 30% and 35% by volume of the substrate.

21. The flooring plank of claim 20, wherein the sawdust comprises about 32% by volume of the substrate.

22. The flooring plank of any one of claims 19 to 21, wherein the thickness of the flooring plank is about 0.5 inches.

23. The flooring plank of any one of claims 19 to 21, wherein the thickness of the substrate is at least 0.375 inches.

24. The flooring plank of any one of claims 19 to 23, wherein tongue and groove portions are formed in the substrate on opposite lateral sides of the plank.

25. The flooring plank of any one of claims 19 to 24, wherein the veneer layer comprises a hardwood veneer.

26. A method of manufacturing flooring planks, comprising:
forming a substrate comprising a solid polyethylene matrix and sawdust immobilized in the polyethylene matrix;
bonding a wood layer to the substrate;
and machining the substrate and wood layer to form a plank.

27. The method of claim 26, wherein the machining comprises forming tongue and groove portions in the substrate on opposite lateral sides of the plank.

28. The method of claim 26 or 27, wherein the forming comprises mixing the sawdust with liquid polyethylene and curing the polyethylene and sawdust to provide the solid polyethylene matrix.

29. The method of claim 28, wherein the liquid polyethylene comprises recycled polyethylene material which has been heated to liquidation.

30. The method of any one of claims 26 to 29, wherein the substrate comprises about 30% to 35% by volume of sawdust.

31. The method of claim 30, wherein the substrate comprises about 32%
by volume of sawdust.

32. The method of any one of claims 26 to 31, wherein the step of forming comprises forming the substrate to have a thickness sufficient to attenuate at least 60dB of sound from one face of the plank to an opposite face of the plank.

33. The method of claim 32, wherein the thickness of the substrate is at least 0.375 inches.

34. A method of manufacturing wood planks from waste wood, comprising:
collecting elongate lengths of waste wood offcuts of at least a predetermined size;
applying adhesive to one side of the offcuts;
placing the offcuts together so that the offcuts are bonded together;
pressing the offcuts vertically and laterally to form a plank; and trimming and smoothing the plank.

35. The method of claim 34, further comprising, prior to the step of pressing, planing the bonded offcuts to a substantially uniform thickness.

36. The method of claim 34 or 35, wherein the step of placing comprises axially rotating each of the offcuts so that the adhesive applied to the one side of an offcut faces an adjacent offcut and pressing the offcuts laterally together.

37. The method of any one of claims 34 to 36, further comprising forming tongue and groove portions along opposed lateral sides of each plank and forming shallow grooves longitudinally along an underside of the plank.

38. The method of claim 37, further comprising finishing a top surface of the planks as a walking surface.

39. A flooring plank manufactured according to the method of any one of claims 34 to 38.