Arch-ribbed tile system

Abstract

A tile for forming a floor covering includes a perimeter support wall, a top surface, interconnecting structure for releasably connecting with adjacent tiles, and intermediate upstanding grid structure. The intermediate upstanding grid structure comprises a repeating pattern of polygonal units, such as hexagons, having sidewalls extending from a bottom of the tile to the underside of the top surface. An arched support structure is disposed within each polygonal unit, connecting an upper portion of the sidewalls of each polygonal unit with the underside of the top surface. The arched configuration reduces stress concentrations at the junction of the arched support structure and the sidewalls.

Description

PRIORITY CLAIM

This application claims priority from U.S. provisional patent application Ser. No. 60/482,104, filed on Jun. 24, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to floor tile systems. More particularly, the present invention relates to an interlocking floor tile system having a support system of hexagonal cells and arched support ribs disposed below the top surface of the tile to improve the dispersion of forces applied to the tile and to reduce irregularities in the top surface.

2. Related Art

Numerous types of flooring have been used to create multi-use surfaces for sports, as well as for other purposes. In recent years, the use of modular flooring assemblies made of synthetic materials has grown in popularity. Modular flooring systems generally comprise a series of interlocking tiles that can be permanently installed over a subfloor, such as concrete or wood, or temporarily laid down upon another surface from time to time when needed.

Such synthetic floors are advantageous for several reasons. One reason for the popularity of these types of systems is that they are typically formed of materials that are generally inexpensive and lightweight. Additionally, if one tile becomes damaged, it can be removed and replaced quickly and easily. If the flooring needs to be temporarily removed, the individual tiles making up the floor can easily be detached and stored for subsequent use. Another reason for the popularity of these types of flooring assemblies is that the durable plastics from which they are formed are long-lasting. Also, unlike some other long-lasting alternatives, such as asphalt and concrete, interlocking tiles of polymer material are generally better at absorbing impact, and there is less risk of injury if a person falls on the plastic material, as opposed to concrete or asphalt. Moreover, the connections for modular flooring assemblies can be specially engineered to absorb lateral force to reduce injuries, as is described in U.S. Pat. No. 4,930,286. Additionally, these flooring assemblies generally require little maintenance as compared to other flooring, such as wood.

One problem that has plagued modular floor covering systems is uneven point load distribution. Uneven load distribution can make the floor feel unnatural to those using it, and can result in premature failure of the flooring tiles. These problems have limited the use of these flooring systems. If the floor feels unnatural, those using the facility will often object to the flooring tiles and/or return to more conventional floor materials, such as wood or concrete. Premature failure of the flooring tiles also increases the likelihood that the modular flooring will be replaced by other alternatives.

Attempts to create improved flooring assemblies have lead to numerous different designs. One improvement provides an “isogrid” tile having equilateral sides in triangular configuration, as disclosed in U.S. Pat. No. 5,787,654. Such flooring assemblies help improve load distribution and appear to enhance tile performance over prior systems. However, a substantial cost is involved with the quantity of materials needed for the equilateral wall structure of an isogrid tile.

An alternative design which reduces the amount of material required for an individual tile is disclosed in U.S. Pat. No. 5,992,106. This design provides a tile with a bottom support structure comprising a repeating pattern of hexagon units. Disposed against the underside of the top surface of the tile within each hexagon unit are a series of cross ribs extending between the vertices of the sidewalls of the hexagon. These ribs act as beams that help distribute loads from the center of each hexagon to the sidewalls thereof. One problem with this hexagon tile is that it experiences stress concentrations at the juncture of each cross rib with the walls of the hexagon. This is a particular problem when point loads are imposed on a tile. The stress concentration contributes to cracking and failure of the tile where the cross ribs meet the corresponding hexagon wall. Warping and dimpling of the top surface are also common problems with injection molded polymer floor tiles. The prior art has not adequately addressed these problems.

SUMMARY OF THE INVENTION

It has been recognized that it would be advantageous to develop an improved floor tile that provides more even distribution of loads, and eliminates stress concentrations that can lead to premature failure of the tile.

It would also be advantageous to develop a floor tile design that reduces the risk of warping and other distortions, while at the same time reducing the amount of plastic material needed to produce a single tile.

The invention advantageously provides a tile for forming a floor covering, comprising a perimeter support wall, a top surface connected atop the perimeter support wall, and intermediate upstanding grid structure. The perimeter support wall defines an outer boundary of the tile, and includes interconnecting structure for releasably connecting with interconnecting structure of adjacent tiles to form a continuous floor surface. The intermediate upstanding grid structure is internally coupled to the perimeter support wall and within the outer boundary, and comprises a repeating pattern of hexagon units extending in parallel orientation substantially across an entire area of the tile within the outer boundary, the hexagon units having sidewalls extending from a bottom of the tile to the underside of the top surface. A support structure, connecting an upper portion of the sidewalls of each hexagon unit with the underside of the top surface, is disposed within each hexagon unit. The support structure has an arched configuration so as to reduce stress concentrations at the junction of the support structure and the sidewalls.

In accordance with a more detailed aspect of the present invention, the support structure comprises a plurality of continuously curved arched ribs extending across the hexagon unit, connecting opposing sidewalls thereof. The arched ribs may be circularly or otherwise curved, and may vary in their proportions.

In accordance with another more detailed aspect of the present invention, the support structure comprises a substantially solid dome structure disposed within the upper portion of each hexagon unit, having a downwardly open concave surface, the dome extending between all opposing portions of the hexagon unit.

Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a polymeric floor tile having loop and pin interlocking structure.

FIG. 2 is a bottom perspective view of one embodiment of the floor tile of FIG. 1, having a bottom support structure comprising hexagonal cells with arched ribs.

FIG. 3 is a top plan view of the floor tile of FIG. 1.

FIG. 4 is a bottom plan view of the bottom support structure of FIG. 2.

FIG. 5 is a bottom, perspective view of a portion of a hexagon support grid having arched support ribs according to the present invention.

FIG. 6 is a close-up partial bottom plan view of the hexagon support grid with arched support ribs.

FIG. 7A is a partial sectional view of FIG. 6 showing support ribs having a circularly arched shape.

FIG. 7B is a partial sectional view of a hexagon unit similar to that of FIG. 7A, wherein the support ribs have a non-circularly curved shape.

FIG. 8A is a partial sectional view of a hexagon unit wherein the arched support structure comprises an integrally formed dome structure.

FIG. 8B is a partial sectional view of a hexagon unit wherein the arched support structure comprises an insert defining a dome structure.

FIG. 9 is a top partially cut-away perspective view of a prior art polymeric floor tile having loop and pin interlocking structure.

FIG. 10 is bottom, perspective view of a prior art floor tile having a hexagon support grid.

DETAILED DESCRIPTION

Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

Modular interlocking floor tiles come in a variety of configurations. Shown in FIG. 9 is one prior art polymeric floor tile 210 that is approximately square in plan, with a thickness T that is substantially less than the plan dimension L. Tile dimensions and composition will depend upon the specific application to which the tile will be applied. Sport uses, for example, frequently use tiles having a square configuration with a side dimension L of either 9.8425 inches (metric tile) or 12.00 inches. The thickness T frequently ranges from about ¼″ to ½″, though other thicknesses are possible. The tiles can be made of many suitable materials, including polyolefins such as polyurethane and polyethylene, and other polymers including nylon.

As shown, the top 212 of the tile is a smooth solid surface, whereas the bottom 214 is comprised of a lattice-type structure 220, which gives strength to the tile while keeping its weight low. The solid top and lattice-type bottom structure are integrally formed of the same material so as to be structurally strong. It will be apparent, however, that the invention described herein is not necessarily limited to floor tiles with a smooth, solid top surface. Tiles having a grid or lattice-type top surface of various configurations have also been produced, as disclosed in some of the prior patents referenced above.

The floor tile 210 includes loops 216 on two adjacent sides, and pins 218 on the two other adjacent sides, as shown. To install a floor, a tile is placed with its top 212 facing up, and its bottom 214 on any suitable subfloor, such as concrete. A second tile is then placed parallel to and alongside the first tile, oriented such that the pins of one side of the second tile are adjacent the loops of a corresponding side of the second tile. The pins of the second tile are then snapped into the loops of the first tile, such that the sides of the two tiles are fitted snugly together. This process is continued to enable a plurality of tiles to be joined together in a single floor assembly, such as a tennis court or basketball court. The loop and pin configuration advantageously allows lateral give between the tiles, and allows for improved absorption of sudden forces that are common in games such as basketball and tennis, which involve sudden acceleration and deceleration. One embodiment of this sort of loop and pin attachment system is explained in detail in U.S. Pat. No. 4,930,286.

Referring to FIG. 10, there is shown an enlarged bottom perspective view of a corner of the prior floor tile 210 having a hexagon support structure. The tile has an outer perimeter defined by a wall 224. As described above, the tile includes interlocking attachments, including positioning loops 216 and resilient insert pins 218 for connecting to an adjacent tile. Disposed inside the exterior wall are repeating groups of hexagon support structures 226 having sidewalls 228 that meet at vertices 229. The hexagon pattern is identified by dashed line 230. It will be noted that each side of the hexagon defines a common side with an adjacent hexagon unit in a recurring pattern.

The size of the hexagon units 226 may be defined by the side-to-side dimension 232 between opposing parallel sidewalls of the hexagon, and may range between 0.3 to 1.0 inches. Such hexagon tiles have been constructed with a hexagon cell diameter of 0.625 inches and a height of approximately 0.5 inches.

The hexagon support structure of FIG. 10 includes a plurality of elongate ribs 234 disposed across the diagonal of the polygon to form contiguous equilateral triangles having a common axis at the center of each hexagon. These cross ribs constitute reinforcing beams that provide support similar to the equilateral ribs of the isogrid tile disclosed in U.S. Pat. No. 5,787,654. The ribs help distribute loads in the tile. This is especially true for rolling and point loads. The ribs help distribute the load, and reduce the risk of damage when heavy loads are rolled over the tile.

While these prior art reinforcing ribs 234 help retain stiffness and strength while reducing the total amount of material in the tile and providing other benefits, it has been found that cracks are likely to form at the junction of the ribs with the sidewalls 228 of the hexagon cells or units 226. Such cracks can lead to premature mechanical failure of an individual tile.

Advantageously, the inventors have developed an improved tile having a polygonal support grid with arched support ribs. Provided in FIGS. 2 and 5 are bottom, perspective views of a hexagon support grid 20 with an arched support structure 26 according to the present invention. FIGS. 4 and 6 provide bottom plan views of the hexagon support grid. For purposes of illustration, FIG. 5 shows a close-up view of a portion of a hexagonal support grid that is not part of a floor tile. However, it is to be understood that this improved support structure is designed to form a part of a floor tile in a similar manner to the prior art hexagonal support structure (shown in FIG. 10).

The floor tile 10 has a top surface 12 connected atop a perimeter support wall 24 (that when incorporated into a floor tile defines an outer boundary of the tile), and intermediate upstanding grid structure 26 internally coupled to and within the perimeter support wall. The tile also includes interconnecting structure of loops 16 and pins 18 for releasably connecting with interconnecting structure of an adjacent tile to form a continuous floor surface. As noted above, interlocking polymeric floor tiles can have a variety of configurations. The tile shown in FIGS. 1-4 has a length L that is about 24 inches, and a width W that is about 3 inches, so as to resemble the typical shape of a natural wood floorboard. The thickness T of the tile is about ⅜″. Alternatively, a tile according to the present invention could have a square shape, like that shown in FIG. 9.

The tile of FIGS. 1-4 retains many of the improvements in material quantity reduction, and ease of mold release provided by the prior art hexagon tile shown in FIGS. 9 and 10, but increases the tile's resistance to cracking at the intersection of the support ribs and hexagon walls. The upstanding grid support structure 26 comprises a repeating pattern of polygon units or cells 30 extending in parallel orientation substantially across an entire area of the tile within the outer boundary. As shown, the polygonal cells are hexagonal in shape. However, other shapes may be used. Each sidewall 28 of a hexagon unit defines a common side with an adjacent hexagon unit, and the sidewalls of the hexagons have a height common with a height of the perimeter wall 24, extending from the bottom of the tile to the underside of the top surface 12, for providing support for loads imposed on the top surface of the tile.

Disposed within each hexagon unit 30 is a support structure 32 having an arched configuration. This support structure connects an upper portion of the sidewalls 28 of each hexagon unit with the underside of the top surface 12, in a manner similar to the elongate support ribs (234 in FIG. 10) of the prior hexagon tile. Advantageously, the arched configuration reduces stress concentrations at the junction of the support structure 32 and the sidewalls of the hexagon unit, while still adequately distributing loads from the top surface of the tile to the sidewalls of the hexagon units.

In one embodiment, the support structure 32 comprises continuously curved, arched ribs 34 extending transversely between opposing sidewalls 28 of the hexagon unit 30. The arched ribs may define a circular curve 36, as shown in FIG. 7A, or a non-circular curve 38, as shown in FIG. 7B. Non-circular arches may define a portion of a parabola, a hyperbola, an ellipse, or some other continuously curved geometric shape. The curve shown in FIG. 7B is elliptical. The configuration and proportions of the arched ribs may vary. For example, the arched ribs may extend to the base of the tile, having a first arch base 40 at the bottom of one wall of a hexagon unit, and a second arch base 42 at the bottom of the opposing wall of the hexagon unit, as shown in FIGS. 7A and 7B. Alternatively, the arches may begin some distance above the bottom of the tile, as shown in FIGS. 8A and 8B. As yet another alternative, the arched ribs may be discontinuous, not extending entirely across a cell, as shown in cells 52 in FIG. 4.

Referring back to FIG. 7A, the ratio of height H to width W of the arches may also be varied for both circular and non-circular arches. Where the arches are semi-circular, in one embodiment each arch has a radius R that is equal to or greater than one half the width W between opposing sidewalls 28 of the hexagon unit 30, as shown in FIG. 7A. In an embodiment with non-circular arches, such as in FIG. 7B, the arched ribs 34 have a minimum radius R_min that is at least about 60% of a maximum radius R_max thereof.

The number of ribs 34 may also vary. The embodiments shown in FIGS. 3 and 4 depict three ribs, each extending between two opposing sidewalls 28 of a hexagon. However, a greater or lesser number of ribs may be provided. As shown in FIGS. 4 and 6, the arched ribs 34 may extend between sides of the hexagon units 30, unlike the non-arched cross ribs 234 of the prior hexagon tile (shown in FIG. 10), which extend between opposing vertices 229 of the hexagon units. However, the arch-ribbed support structure of the present invention may also be configured to provide continuously curved arched ribs extending transversely between opposing vertices of a respective hexagon unit in a similar manner.

As an alternative to the cross rib structure, a floor tile in accordance with the present invention may provide an arched support structure comprising a substantially solid dome structure 44 disposed within the upper portion of each hexagon unit 30. Such a structure is shown in cross-section in FIGS. 8A and 8B. The dome provides a downwardly facing concave surface 46, and extends between opposing sides of the hexagon unit. As with the arched ribs 34 shown in FIGS. 7A and 7B, the dome structure may extend to the bottom of the hexagon unit, or may simply occupy an upper portion of the hexagon unit as shown in FIGS. 8A and 8B. Likewise, the dome may be circularly or non-circularly curved.

As shown in FIG. 8A, a tile 10′ may have a dome structure comprising a hexagonal insert 48 with a flat top surface 50, and a concave, domed lower surface 46, which is configured to be inserted into hexagon units 30′ having no integrally formed cross ribs. The insert may be secured in place by a variety of means, such as with an adhesive. Alternatively, as shown in FIG. 8B, a dome structure 44″ may be integrally formed with the material of a floor tile 10″. In this embodiment, the concave surface 46 is integrally formed with the material of the top surface 12″ and the sidewalls 28″ of the hexagonal units 30″.

It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the claims.

Claims

1. A polymer tile for forming a floor covering, comprising:

a top surface;

a perimeter wall supporting the top surface and enclosing a perimeter boundary for the tile;

a honeycomb support structure, interconnected between inner portions of the perimeter wall and supporting the top surface, comprising recurring polygonal cells divided by upright support walls of common dimension, the support walls having a height common with a height of the perimeter wall for providing support for a load imposed on the top surface; and

a top surface support structure connecting an upper portion of the polygonal cells to an underside of the top surface, the top surface support structure having an arch configuration so as to reduce stress concentrations at the connection of the top surface support structure to the support walls of the honeycomb support structure.

2. A floor tile in accordance with claim 1, wherein the arch configuration comprises a plurality of continuously curved arched ribs disposed in traversing orientation between opposing support walls of the polygonal cells.

3. A floor tile in accordance with claim 2, wherein the arched ribs define a circular curve.

4. A floor tile in accordance with claim 3, wherein the circular curve has a radius at least as great as one half the distance between opposing support walls of the polygonal cell.

5. A floor tile in accordance with claim 2, wherein the arched ribs include a first arch base at the bottom of one wall of a polygonal cell, and a second arch base at the bottom of an opposing wall of the polygonal cell.

6. A floor tile in accordance with claim 2, wherein the arched ribs define a non-circular curve.

7. A floor tile in accordance with claim 6, wherein the arched ribs have a minimum radius that is at least about 60% of a maximum radius thereof.

8. A floor tile in accordance with claim 1, wherein the support structure comprises a substantially solid dome structure disposed within the upper portion of each polygonal cell, having a downwardly open concave surface, the dome extending between all opposing portions of the polygonal cell.

9. A floor tile in accordance with claim 8, wherein the dome structure comprises an insert configured to be inserted into a polygonal cell.

10. A floor tile in accordance with claim 8, wherein the dome structure is integrally formed with the material of the floor tile.

11. A tile for forming a floor covering, comprising:

a perimeter support wall defining an outer boundary of the tile and including interconnecting structure for releasably connecting with interconnecting structure of adjacent tiles to form a continuous floor surface;

a top surface connected atop the perimeter support wall, the top surface having an underside; and

intermediate upstanding grid structure internally coupled to the perimeter support wall and within the outer boundary, said grid structure comprising: (i) a repeating pattern of polygonal units extending in parallel orientation substantially across an entire area of the tile within the outer boundary, the polygonal units having sidewalls extending from a bottom of the tile to the underside of the top surface; and (ii) a support structure, connecting an upper portion of the sidewalls of each polygonal unit with the underside of the top surface, the support structure having an arched configuration so as to reduce stress concentrations at the junction of the support structure and the sidewalls.

12. A floor tile in accordance with claim 11, wherein the support structure comprises continuously curved, arched ribs extending transversely between opposing sidewalls of a respective polygonal unit.

13. A floor tile in accordance with claim 12, wherein the arched ribs define a circular curve.

14. A floor tile in accordance with claim 13, wherein the circular arch has a radius greater than one half the distance between opposing sidewalls of the polygonal unit.

15. A floor tile in accordance with claim 12, wherein the arched ribs include a first arch base at the bottom of one wall of a polygonal unit, and a second arch base at the bottom of an opposing wall of the polygonal unit.

16. A floor tile in accordance with claim 12, wherein the arched ribs define a non-circular curve.

17. A floor tile in accordance with claim 16, wherein the arched ribs have a minimum radius that is at least about 60% of a maximum radius thereof.

18. A floor tile in accordance with claim 16, wherein the curvature of the arched ribs defines at least a portion of a shape selected from the group consisting of a parabola, a hyperbola, and an ellipse.

19. A floor tile system in accordance with claim 11, wherein the support structure comprises continuously curved, arched ribs extending transversely between opposing vertices of a respective polygonal unit.

20. A floor tile system in accordance with claim 11, wherein the support structure comprises a substantially solid dome structure disposed within the upper portion of each polygonal unit, having a downwardly open concave surface, the dome extending between all opposing portions of the polygonal unit.

21. A floor tile system in accordance with claim 20, wherein the dome structure comprises an insert configured to be inserted into a polygonal unit.

22. A floor tile system in accordance with claim 20, wherein the dome comprises base portions that extend to the bottom of the polygonal unit.

23. A floor tile system in accordance with claim 20, wherein the dome structure is integrally formed with the material of the floor tile.

24. A floor tile system in accordance with claim 20, wherein the concave surface is non-circularly curved.