# Patent

## Title
Set of floorboards having a resilient groove

## Abstract

A set of essentially identical floorboards each including a front face and a rear face extending in the horizontal plane, a core, and a surface layer, a mechanical locking system is arranged at least at two opposite edges for connecting a floorboard with an adjacent floorboard in a horizontal and a vertical direction, said mechanical locking system being configured for connecting the floorboard with the adjacent floorboard by vertical folding, wherein one of said opposite edges is provided with a horizontally extending protrusion at an upper edge, and wherein said protrusion is configured to overlap a surface groove at an upper edge of the other of said opposite edges, such that two connected and adjacent floorboards have upper overlapping edges.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. application Ser. No. 13/552,357, filed on Jul. 18, 2012, which is a continuation of U.S. application Ser. No. 13/046,011, filed Mar. 11, 2011, which is a continuation of U.S. application Ser. No. 11/649,837, filed on Jan. 5, 2007, and claims the benefit of U.S. Provisional Application No. 60/758,213, filed on Jan. 12, 2006 and the benefit of Swedish Application No. 0600055-8, filed on Jan. 12, 2006. The entire contents of each of U.S. application Ser. No. 13/522,357, U.S. application Ser. No. 13/046,011, U.S. application Ser. No. 11/649,837, U.S. Provisional Application No. 60/758,213 and Swedish Application No. 0600055-8 are hereby incorporated herein by reference.


AREA OF INVENTION
Embodiments of the present invention relate to a set of moisture proof floorboards and flooring with a resilient surface layer comprising a decorative groove and/or a sealing means.
BACKGROUND OF INVENTION
Embodiments of the invention may concern a floorboard comprising a mechanical locking system, formed at least at two opposite edges and a resilient surface layer provided with a decorative groove. The following description of known techniques, problems of known systems and objects and features of embodiments of the invention will above all, as a non-restrictive example, be aimed as the field of the application. It should be emphasized that embodiments of the invention may be used in any floorboard and it could be combined with all types of known locking systems, for example, where the floorboards are intended to be joined using a mechanical locking system connecting the panels in the horizontal and vertical directions on at least two adjacent sides.
It is known that a floorboard with a resilient surface layer can be provided with a decorative joint portion, in the form of a bevel, for example as described in WO 03/012224.
OBJECTS AND SUMMARY
The floorboards with a resilient surface layer with a decorative joint portion known up to now have several disadvantages. It is only possible to provide the edge with a bevel, which is smaller than the thickness of the resilient surface layer. If the bevel is made larger, the bevel extends down to the moisture sensitive core. The resilient layer is normally thin, and therefore it is only possible to produce small bevels, which are barely visible. Another disadvantage is that both joined and adjacent edges of two floorboards have to be provided with the bevel, in order to look attractive and to increase the total width of the decorative joint portion. Known joints between two floorboards with a resilient surface layer also have the problem of penetration of moisture into the joint, which destroys the moisture sensitive core or sub-floor. The problem increases if the floorboards at the joint are provided with bevels, due to accumulating of dirt and moisture at the bottom of the V-shaped grove, formed by the two adjacent bevels, and a remaining thin barrier part of resilient material.
Embodiments of the present invention relate to a moisture proof flooring and a set of moisture proof floorboards with a resilient surface layer comprising a decorative groove, which provides for embodiments offering advantages. A useful area for the floorboards is public flooring, e.g., in stores, restaurants, ships, hotels, airports, or at home in rooms which are heavily exposed to dirt and therefore often cleaned by mopping. Another useful area is wet-rooms. “Moisture proof floorboard” means that the front face of the floorboard is provided with a moisture proof material and that connecting means and edges of the floorboard are configured to obtain a joint between the floorboard and another adjacent floorboard which is moisture proof.
According to a first aspect, embodiments of the invention provide a set of moisture proof floorboards, comprising a front face, a rear face, a core, connecting means arranged at least at two opposite edges for connecting the floorboard with a similar floorboard, a resilient surface layer at the front face, preferably of rubber or plastic. The resilient surface layer comprises a decorative groove at an edge of the floorboard. The bottom of the decorative groove is essentially flat and parallel to the front face.
An advantage of embodiments of the invention is that there is no limitation of the width of the decorative groove. Even a large decorative groove may be watertight and protect the core or the sub-floor. A second advantage is that only half the amount of edges has to be worked, since it is possible to replace two narrow grooves with one wide groove.
Preferably the edge with the decorative groove comprises, in the resilient layer, a sealing means configured to cooperate with another sealing means in the resilient layer at an edge of another adjacent floorboard, to obtain a sealing. In one embodiment, the sealing means comprises a horizontally extending protrusion and the other sealing means comprises a sideways open groove. In the most preferred embodiment one or both of the sealing means are also provided with a sealing agent.
In another preferred embodiment both of the sealing means comprise a sideways open groove provided with a sealing agent.
Preferably, the connecting means comprise a mechanical locking system formed at least at two opposite edges of the floorboard, which facilitates the joining of a similar floorboard. Mechanical locking systems joined by angling are for instance known from WO 94/26999, which is especially advantageous at the long sides of a rectangular floor, and another locking system especially advantageous at the short sides, particularly when combined with an angling locking system like the one described in WO 94/26999, are described in PCT/SE2005/001586, owner Välinge Innovation AB. Other shapes of floorboards are also possible. The above mentioned combination of locking systems makes it possible to join floor panels by several methods preferably with a single action method, where the long edge is installed with angling and the short edge, which is provided with a flexible tongue, with vertical folding. This combination is also very easy to disassemble. Other mechanical locking systems are also known, and possible to use, including, for example, systems joined by Angling-Angling, Angling-Snapping or Snapping-Snapping. Floorboards with a mechanical locking system are generally laid floating, i.e. without gluing, on an existing subfloor.
It is also possible to use a tongue and a groove joint, usually combined with gluing or nailing or other fastening means.
According to an embodiment of the first aspect the wood based core may be made of MDF or HDF, preferably of a thickness of 6-9 mm. The thickness of the resilient surface layer is preferably 1-3 mm.
According to an embodiment, the resilient surface layer comprises three layers, a transparent wear layer at the top, a decorative intermediate layer and reinforcement layer closest to the core. It is also possible to print a pattern directly at the rear side of the transparent wear layer or at the top of the reinforcement layer. Preferably, the decorative groove is only in the transparent layer and optionally colored, but it is also possible to extend the groove down to the decorative layer or the reinforcement layer. Different colors of the layers create a visual effect by extending the groove down to other layers and no coloring may be needed. Another embodiment is a resilient layer comprising only a transparent layer and a reinforcement layer of, for example, a colored plastic or a cork layer. An alternative is that the decorative layer is a wood veneer or a cork layer or that the resilient surface layer has two layers, a transparent wear layer and reinforcement layer of, for example, cork.
According to a second aspect, embodiments of the invention provide a set of moisture proof floorboards, comprising a front face a rear face, a core, connecting means arranged at least at two opposite edges for connecting the floorboard with a similar floorboard, a resilient surface layer at the front face, preferably of rubber or plastic. A moisture proof floorboard being provided at an edge and in the resilient layer with a sealing means configured to cooperate with a another sealing means in the resilient layer at an edge of another adjacent floorboard, to obtain a sealing.
Preferably the sealing means comprises a horizontally extending protrusion and the other sealing means comprises a sideways open groove. In the most preferred embodiment one or both of the sealing means are provided with a sealing agent.
In another preferred embodiment both of the sealing means comprise a sideways open groove provided with a sealing agent.
The sealing means and the sealing agent increase the resistance of moisture and water penetration into the joint and the core and the aim is to completely seal the joint.
According to a second object, embodiments of the invention provide for a flooring comprising at least two of the floorboards above in the first object, joined along adjacent edges, preferably mechanically.
In view of the above, an objective of embodiments of the invention is to solve or at least reduce the problems discussed above.
In particular, an objective of embodiments of this invention is to provide a flooring and floorboard comprising a resilient surface layer with a decorative groove in the resilient surface layer, wherein the groove is clearly visible. Further, the floorboard is moisture proof and preferably shows great acoustic properties.
All references to “a/an/the [element, device, component, means, step, etc.]” are to be interpreted openly as referring to at least one instance of said element, device, component, means, step, etc., unless explicitly stated otherwise.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1a shows a floorboard with a resilient surface layer and decorative groove known in the art.
FIG. 1b shows a floorboard according to an embodiment of the invention.
FIGS. 2a-d show alternative embodiments of the invention.
FIG. 3 shows three joined floorboards according to an embodiment of the invention.
FIGS. 4a-c show a floorboard and joined floorboards in different views according to an embodiment of the invention.
FIGS. 5a, 5c and 6a-6c show joined floorboards according to embodiments of the second aspect of the invention.
FIG. 5b shows an embodiment of a floorboard, according to the first aspect provided with a sealing means according to the second aspect.



DETAILED DESCRIPTION OF EMBODIMENTS
As represented in FIGS. 1b-4, the first aspect of the invention relates to a set of moisture proof floorboards and flooring, provided with a resilient surface layer with a decorative groove.
FIG. 1a show floorboards with decorative joint portions known in the art and described in WO 03/012224. The floorboard 1 comprises a front face 2 and a rear face 3 extending in the direction of the horizontal plane HP, a wood-based core 5 and a resilient surface layer 4 at the front face. The resilient surface layer 4 comprises three different surface layers having different functions. The upper most layer is a transparent, hard and durable wear layer 16 of plastic material, the intermediate layer is a decorative layer 17 of plastic film and the lowest layer is a reinforcement layer 18 which is made of an elastic material and which can be both moisture-proof and sound-absorbing. The decorative layer 17 of plastic film can be replaced with decorative patterns, which are printed directly on the underside of the transparent wear layer 16 or on the upper side of the elastic reinforcement layer 18. The floorboard is provided with a mechanical locking system for locking the floorboards horizontally and vertically at its long and short edges (12a, 13a, 12b, 13b) through angling and/or snapping.
According to a first aspect of the invention, as represented in FIG. 1b-4c, a floorboard 1 is to be joined with a similar floorboard 1′ at adjacent joint edges at a joint plane extending in the vertical plane VP, comprising a front face 2 and a rear face 3 extending in the horizontal plane HP, a core 5, a connecting means arranged at least at two opposite edges for connecting the floorboard with a similar floorboard 1′ in a vertical and/or horizontal direction and a resilient surface layer 4, characterized in that at least one edge of the floorboard 1 comprising a decorative groove 6 in the resilient surface layer 4 with a bottom 7 which is essentially parallel to the front face 2. If the floorboard is rectangular, preferably only one of the long edges is provided with the decorative groove; certainly it is also possible to provide one of the long and one of the short edges with the groove 7. Other shapes of the board are also possible, e.g. 3, 5, 6, 7 and 8 edges. The resilient surface layer comprises preferably a transparent wear layer 16 at the top, preferably of a plastic material, an intermediate decorative layer 17 and an elastic reinforcement layer 18 closest to the core 5. The decorative layer 17, preferably of a plastic film can be replaced with decorative patterns, which are printed directly on the underside of the transparent wear layer 16 or on the upper side of the elastic reinforcement layer 18. An alternative is that the decorative layer is a wood veneer or cork layer. According to the embodiment represented in FIG. 1b, the groove 7 is only in the transparent layer and optionally the groove is colored.
Preferably the connecting means is a mechanical locking system formed at least at two opposite edges 12a, 13a, 12b, 13b. The shown mechanical locking system comprising a locking strip 15 with a locking element 9, a tongue 8 and a tongue groove 10. Other known mechanical locking systems for floorboards are also possible to use such as the tongue lock in FIG. 4a-c or the flexible tongue described in described in PCT/SE2005/001586. The tongue may also be replaced by a displaceable tongue 8′ arranged in a displacement grove 54, as shown in FIGS. 5b to 6c, of the type disclosed in PCT/SE2005/001586 or PCT/SE2006/001218.
There are many alternatives for the number of layers in the resilient layer, the material of the layers and into which layer the groove extends. Some of the alternatives are represented in FIG. 1b-2d. 
The resilient surface layer 4, illustrated in FIG. 2a, comprising a transparent surface layer 16, an intermediate decorative layer 17 and a reinforcement layer 18 closest to the core. The groove 6 extends down to the reinforcement layer and is preferably colored. If one of the layers in the resilient layer, represented in FIG. 1b-bd is of a non-water proof or moisture sensitive material, it is preferred that the groove does not extend into this layer.
The resilient surface layer 4, illustrated in FIG. 2b, is substantially a transparent surface layer 16 and a reinforcement layer closest to the core 18. The groove 6 extends down to the reinforcement layer, preferably of plastic and is preferably colored.
The resilient surface layer 4 illustrated in FIG. 2c, is substantially a transparent surface layer 16 and a reinforcement layer closest to the core 18. The groove 6 is only in the transparent layer and is preferably colored. The reinforcement layer is preferably of a colored plastic or a cork layer.
The resilient surface layer 4 in FIG. 2d, is substantially only one layer. The groove is preferably colored.
In FIG. 4b an embodiment of the invention is represented, comprising a rectangular floorboard 1 with a mechanical locking system at long 13a, 13b and short edges 12a, 12b and a decorative groove 6 along only one of the long edges and along only one of the short edges. Additional grooves 41 in the resilient surface layer, between the short edges, are provided. FIG. 4a is a cross section of the floorboard in FIG. 6b, perpendicular to the long edges, joined to similar floorboards 1′ and 1′′. FIG. 4c is a cross section of the floorboard in FIG. 4b, perpendicular to the short edges, joined to similar floorboards 1′ and 1′′.
The wood-based core material is preferably a particle, MDF, HDF or plywood board.
As non-limiting example, materials that can be used in a resilient surface layer are acrylic plastic-based materials, elastomers of synthetic rubber, urethane rubber, silicone rubber or the like, polyurethane-based hot-melt adhesive, PVC or polyethylene.
The decorative groove may be made by chemical or mechanical working, preferably cutting or grinding. It is also possible to color the groove. If grinding is used it is possible to make a very shallow groove or even just change the roughness and the brightness of the surface. The grinding method is applicable also to a laminate flooring with a surface layer of resin-impregnated sheets. Another technique is to cut off a part of the resilient surface layer, or cut it to the desirable shape before attaching it to the core, and replace it with another resilient layer of different color or structure.
A second aspect of the invention, as illustrated in FIG. 5a-6c, is a set of essentially identical moisture proof floorboards 1 each comprising a sealing means at an edge. Each floorboard comprises a front face and a rear face extending in the horizontal plane HP, a core, a connecting means 8, 9, 10, 11, 15, 8′, 54 arranged at least at two opposite edges for connecting a floorboard with a another floorboard 1′ in a vertical and/or horizontal direction and a resilient surface layer 4. A moisture proof floorboard comprising, at an edge and in the resilient layer 4, a sealing means 51 configured to cooperate with another sealing means 52 in the resilient layer at an edge of another adjacent floorboard, to obtain a sealing.
The sealing means may comprise a horizontally extending protrusion and the other sealing means may comprise a sideways open groove, as shown in FIG. 5a. In the most preferred embodiment one or both of the sealing means are provided with a sealing agent 53.
In another embodiment, shown in FIG. 6a, both the sealing means 51, 52 comprise a sideways open groove provided with a sealing agent 53.
In FIG. 5c an embodiment of the sealing means is illustrated comprising overlapping edges, preferably provided with a hook shaped connection 51, 52. A sealing agent 53 may also be provided.
The sealing agent may comprise wax, grease, oil or bitumen. A preferred sealing agent comprises a mix of paraffin wax and paraffin oil. Another example is a micro wax and a natural or synthetic rubber strip.
In FIG. 6b an embodiment of the sealing means is illustrated comprising an expandable sealing agent 53′, arranged at a sideways open groove 51 in the resilient layer 4. The sealing agent is configured to expand into a sideways open groove 52 in the resilient layer of an adjacent floor panel, as illustrated in FIG. 6c, after that the two panels are connected to each other by the connecting means. An example of an expandable sealing agent 53′ is a strip, preferably of polyurethane, provided with tape, which is removed just before the connection of the two adjacent floorboards. Other examples are materials, which expand when exposed to moisture.
The first aspect of the invention, comprising a decorative groove 7, may be combined with the second aspect, comprising sealing means 51, 52, as illustrated in 5b. 
A second object of the invention, represented by FIGS. 3 and 4, is a flooring comprising a set of the floorboards 1, 1′, according to the first and/or second aspect, joined along adjacent edges, preferably mechanically.
In the most preferred embodiment, only one of the edges 12a, 13a, 12b, 13b of the two joined and adjacent edges is provided with the decorative groove.
Embodiments of the invention have mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein.

## Claims

1. A set of essentially identical moisture proof floorboards, each floorboard comprising a front face and a rear face extending in a horizontal plane, a core, a connector arranged at least at two opposite edges for connecting one of the floorboards with another floorboard in a vertical or horizontal direction, and a resilient surface layer,
wherein at least one edge of each of the floorboards comprises a decorative groove in the resilient surface layer, wherein the decorative groove has a roughness and a brightness that differs from the remaining front face,
wherein the resilient surface layer comprises a transparent wear layer of a moisture proof material, and
wherein a bottom of the decorative groove is in the transparent wear layer.

2. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the edge with the decorative groove comprises a sealing arrangement configured to cooperate with another sealing arrangement in the resilient layer at an edge of another adjacent floorboard to obtain a sealing.

3. The set of essentially identical moisture proof floorboards as claimed in claim 2, wherein one of the sealing arrangements is a horizontally extending protrusion and the other sealing arrangement is a sideways open groove.

4. The set of essentially identical moisture proof floorboards as claimed in claim 3, wherein one or both of the sealing arrangements comprises a sealing agent.

5. The set of essentially identical moisture proof floorboards as claimed in claim 2, wherein both of the sealing arrangements are a sideways open groove comprising a sealing agent.

6. The set of essentially identical moisture proof floorboards as claimed in claim 4, wherein the sealing agent comprises paraffin wax or paraffin oil.

7. The set of essentially identical moisture proof floorboards as claimed in claim 5, wherein the sealing agent comprises paraffin wax or paraffin oil.

8. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein a width of the decorative groove is larger than a thickness of the resilient surface layer.

9. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein a width of the decorative groove is at least twice as large as a thickness of the resilient surface layer.

10. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein each floorboard is provided with the decorative groove only at one of the two opposite edges.

11. The set of essentially identical moisture proof floorboards as claimed in claim 10, wherein each floorboard is quadrilateral and has a decorative joint portion only at one edge.

12. The set of essentially identical moisture proof floorboards as claimed in claim 10, wherein each floorboard is quadrilateral and has a decorative joint portion only at two adjacent edges.

13. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein each floorboard comprises a core of a wood-based material.

14. The set of essentially identical moisture proof floorboards as claimed in claim 13, wherein the core comprises HDF, MDF, particleboard or plywood.

15. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the connector is a mechanical locking system.

16. The set of essentially identical moisture proof floorboards as claimed in claim 15, wherein the mechanical locking system is formed in the edge of each floorboard.

17. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the resilient surface layer comprises a plastic material.

18. The set of essentially identical moisture proof floorboards as claimed in claim 17, wherein the plastic is PVC or polyethylene.

19. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the resilient surface layer comprises a decorative layer.

20. The set of essentially identical moisture proof floorboards as claimed in claim 19, wherein the decorative layer is a plastic film, a wood veneer, a cork layer or a print.

21. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the resilient surface layer comprises a reinforcement layer, wherein the reinforcement layer is the layer of the resilient surface layer positioned closest to the core of each floorboard.

22. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the resilient surface layer comprises a decorative layer and a reinforcement layer, wherein the reinforcement layer is the layer of the resilient surface layer positioned closest to the core of each floorboard.

23. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the resilient surface layer comprises substantially only one layer of a moisture proof material.

24. The set of essentially identical moisture proof floorboards as claimed in claim 1, wherein the decorative groove is at an edge of the floorboards which comprises the connector.