Patent Publication Number: US-2023160217-A1

Title: Panel

Description:
The invention relates to a panel comprising coupling parts. The panel is rectangular. The panel comprises a plurality of coupling parts which enables the panels to be installed in complex installation patterns, such as herringbone patterns, without it being required to have more than one type of panels. 
     It is state of the art that all four edges of rectangular panels are provided with grooves; or that the long edges are provided with standard tongue and groove and that both short edges are provided with grooves. Via insertion of separate inserts two different types of panels can be obtained. This allows easy stockkeeping but installation involves high costs. Herringbone patterns can only be installed by modifying the edge profiles during installation of the panels, and therefore involves expensive installation. 
     DE69817781 shows a herringbone installation using only one type of panels, wherein the panel is provided at the opposite long edges with standard tongue profiles. The tongue profiles are removed at certain distances from each other and replaced by grooves, such that a mirror image of the coupling parts is obtained. Both short edges are provided with a standard groove profile. The production of such panel is rather complex. The productivity is rather low, as no large production speed is possible due to the complex structure of the coupling parts. 
     In U.S. Pat. No. 2,187,672A, three layers are glued onto each other, such that at half of the long edge a groove is provided and that at the other half of the long edge a tongue is provided. The two long edges are provided in mirror image. The short edges are provided with a standard tongue and groove profile. The production of such panels is difficult, and the productivity is low. It is possible to install the panels in herringbone pattern or parallel to each other using only one type of panels. 
     EP3128102A1 discloses a panel wherein one long edge comprises a continuous standard groove profile and the other long edge comprises a standard tongue profile which is interrupted at both ends of the panel. The standard tongue profile is replaced by a groove profile at the interruptions. Both short edges are provided with a standard tongue profile. A herringbone installation can be made with only one type of panels. The production of such panels is difficult, and the productivity is low. 
     U.S. Ser. No. 17/870,27A discloses a standard tongue and groove coupling. The groove profile is provided at one long edge and at one short edge; whereas the tongue profile is provided at the opposite long and short edges. A herringbone installation is only possible using two different types of panels. These panels have a number of drawbacks: the production of two different types of panels requires double stock keeping, the risk of taking the wrong panel, increased complexity of installation of the panels and increased costs. 
     DE20208058U1 also discloses a herringbone installation pattern. However, distinct right hand side and left hand side panels are required. These panels also have as drawbacks: the production of two different types of panels requires double stock keeping, the risk of taking the wrong panel, increased complexity of installation of the panels and increased costs. 
     WO2005/098163A1 discloses a panel comprising coupling parts with locking elements enabling a herringbone installation pattern with only one type of panels. 
     It is an objective of the invention to provide panels that are easy to manufacture and that can be installed in complex and different installation patterns, including herringbone patterns, requiring only one type of panels. It is an objective of at least embodiments of the invention that a stable installation can be obtained. It is a further objective of at least embodiments of the invention that the panels can be installed easily. 
     It is a specific objective of the invention to provide panels with tongue and groove coupling means such that complex installation patterns—e.g. installation patterns wherein the panels are installed in a 90° angle configuration such as in herringbone patterns—are possible using only one type of panels. It is an objective of the invention to provide such panels that can be easily manufactured with a minimum of manufacturing operations. 
     The invention is described by the independent claims. The dependent claims provide preferred embodiments of the invention. 
     The first aspect of the invention relates to a panel, wherein the panel is rectangular, wherein the panel comprises a first edge and a third edge, wherein the first edge and the third edges are provided opposite to each other, wherein the panel comprises a second edge and a fourth edge wherein the second edge and the fourth edge are provided opposite to each other, wherein each of the first edge, the second edge, the third edge and the fourth edge comprise a profile selected from a first profile, a second profile and a third profile. The first profile comprises or consists of a groove-tongue profile, wherein the tongue-groove profile comprises a continuous groove having a groove width and a groove depth, and a continuous tongue having different tongue thicknesses and tongue lengths. 
     The second profile comprises or consists of a groove profile comprising a continuous groove having different groove widths and different groove depths. 
     The third profile comprises or consists of a groove-double tongue profile, wherein the groove-double tongue profile comprises a continuous groove having a groove width, wherein the groove-double tongue profile comprises a continuous double tongue having different tongue thicknesses and having different tongue lengths. 
     Two opposite edges comprise the same profile selected from the first profile, the second profile or the third profile. 
     It is a benefit of the invention that complex installation patterns—e.g. herringbone patterns—can be made using only one type of panels. 
     The first profile (which is a groove-double tongue profile) has a double function, the function of a tongue and the function of a groove, as it fits in second profile as well as in the third profile. The first profile, the second profile and the third profile show in the direction perpendicular to the panel surface three levels. 
     The manufacturing of the panels is facilitated as a minimum amount of tooling is required and no complex machinery is required for milling the panel edges. Using continuous profiles along the full length of the panel edges—with a constant cross section of the profiles—facilitates manufacturing as the milling machines do not need special control mechanisms to vary the profile along the length of the panel edge. The cross section of each of the three profiles is rather simple, facilitating the manufacturing process; and making it possible that the profiles can be milled in rather thin panels, as the more complex the profile cross section, the thicker the panel must be for providing the profiles with good quality. Therefore, the invention allows to provide panels with limited thickness, that are easy to produce and that only require one type of panels for installing herringbone profiles. 
     According to the first aspect of the invention, two opposite edges comprise the same profile selected from the first profile, the second profile or the third profile. It means that two opposite edges comprise or the first profile or the second profile or the third profile. It does not mean that the profiles at these two opposite edges must be identical—which however is not excluded—but that the profiles at both opposite edge both fulfill the features of the first profile, or both fulfill the features of the second profile, or both fulfill the features of the third profile. 
     In a preferred embodiment of the first aspect of the invention, each of the first profile, the second profile and the third profile are configured such that they can be realized by milling operations with milling axis perpendicular to the surface of the panel. This further facilitates the production process of the panels. 
     In a preferred embodiment of the first aspect of the invention, the continuous tongue of the groove-tongue profile comprises two different end faces, preferably wherein the two different end faces are provided at different distances from the panel edge where the first profile is provided, more preferably wherein the two end face comprise an end surface substantially perpendicular to or perpendicular to the panel surface. 
     Such embodiments provide improved locking in vertical direction, whereas the panels can be manufactured easily. 
     In a preferred embodiment of the first aspect of the invention, the continuous groove of the third profile has different groove depths. 
     In a preferred embodiment of the first aspect of the invention, the continuous double tongue of the groove-double tongue profile has different tongue thicknesses and/or has different tongue lengths. 
     In a preferred embodiment of the first aspect of the invention, the groove widths of the grooves of the groove-tongue profile, the groove-double tongue profile and the groove profile are configured; and the corresponding tongues of a to be coupled groove-tongue profile and/or a to be coupled groove-double tongue profile are configured such that the panels can be coupled at the upper side and/or at the bottom side of the panel in a form fitting manner. This way the panels are coupled and the panels lie with their edges flush to each other and locked against shifting. The coupled edges are locking in the direction perpendicular to the panel surface, preferably the coupled edges are not mechanically locked in the direction perpendicular to the coupled panel edges and parallel to the panel surface. 
     In a preferred embodiment of the first aspect of the invention, the width of the groove of the groove profile corresponds to the full thickness of the groove-double tongue profile, preferably such that the groove-double tongue profile can be inserted in a form fitting manner in the groove of the groove profile. This way, a coupling of second profile with the third profile is possible, wherein the grooves and the tongues are contacting at the 
     In a preferred embodiment of the first aspect of the invention, the tongues and grooves of the first profile, the second profile and the third profile are configured such that the panel edge or edges provided with the first profile can be coupled onto the panel edge or panel edges provided with the second profile as well as onto the panel edge or panel edges provided with the third profile of another such panel; and such that the panel edge or edges provided with the second profile can be coupled onto the panel edge or panel edges provided with the third profile of another such panel. 
     A preferred panel is rectangular, oblong or square. 
     In a preferred embodiment of the first aspect of the invention, the panel is oblong and both short edges are provided with the same profile selected from the first profile, the second profile or the third profile. 
     In such embodiment, both short edges comprise the same profile selected from the first profile, the second profile or the third profile. It means that both short edges comprise or the first profile or the second profile or the third profile. It does not mean that the profiles at both short edges must be identical—which however is not excluded—but that the profiles at both short edges both fulfill the features of the first profile, or both fulfill the features of the second profile, or both fulfill the features of the third profile. 
     In a preferred embodiment of the first aspect of the invention, each of the first profile, the second profile and the third profile extend continuously and without interruption along the full length of the panel edge where they are provided. 
     This facilitates the production of the panels. 
     In a preferred embodiment of the first aspect of the invention, the first profile, the second profile and the third profile have a constant cross section along the full length of the panel edge where they are provided. This facilitates the production of the panels. 
     In a preferred embodiment of the first aspect of the invention, the continuous groove of the groove profile comprises a bottom lip, wherein the bottom lip extends beyond the closing plane provided closer to the surface of the panel than the location of the continuous groove, wherein the closing plane is provided for making contact with or for being located close to the closing plane of another such panel in coupled condition of the panel with the another such panel 
     Such embodiment provides increased stability of installed panels. 
     In a preferred embodiment of the first aspect of the invention, none of the first profile, the second profile and the third profile are provided with mechanical locking parts that in coupled condition of any one of the edges of the panel to any edge of another such panel would result in a locking in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels. 
     Such panels have less complex coupling profiles and are therefore more easy to manufacture as less complex milling equipment is required. Furthermore, thinner panels can be made. 
     Although there is no mechanical locking in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels, there can be some frictional forces between contact surfaces of contacting tongues and grooves of the coupled edges. 
     In a preferred embodiment of the first aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge are provided closer to the panel surface than the first profile, the second profile and the third profile with a closing plane, wherein the closing planes are provided perpendicularly to the panel surface. In coupled condition of two panels the closing planes of the panel edges coupled to each other contact each other or are positioned close to each other. 
     It is the intention that closing planes of coupled panels contact each other. However, due to manufacturing tolerance it cannot be excluded that a small gap occurs between the closing planes of coupled panels. 
     In a preferred embodiment of the first aspect of the invention, the continuous groove of the second profile relates to a segmented groove, wherein the segmented groove comprises an upper section closest to the surface of the panel, a middle section and a bottom section, wherein the middle section extends more proximal into the panel than the upper section and the bottom section. 
     Such panels are easy to manufacture and provide a very stable locking in the direction perpendicular to the surface of the panels. 
     In a more preferred embodiment of the first aspect of the invention, the middle section comprises an upper lip and a bottom lip, wherein the upper section comprises an upper lip, wherein the upper section extends at its bottom over part of its depth into the middle section, wherein the bottom section comprises a bottom lip and extends at its upper side over part of its depth into the middle section. 
     Such panels are easy to manufacture and provide a very stable locking in the direction perpendicular to the surface of the panels. 
     In a preferred embodiment of the first aspect of the invention, the bottom section extends more distal into the panel than the upper section. 
     Such panels are easy to manufacture and provide a very stable locking in the direction perpendicular to the surface of the panels. 
     In a preferred embodiment of the first aspect of the invention, the panel comprises a decorative layer, wherein the decorative layer is a veneer layer—preferably a wood veneer layer—or wherein the decorative layer is a layer of wood, preferably wherein the layer of wood is thicker than a wood veneer layer. 
     In a preferred embodiment of the first aspect of the invention, the panel comprises a plurality of wood layers, preferably including a decorative wood layer; more preferably wherein the decorative wood layer comprises of consists of a wood veneer or comprises or consists of a layer of wood thicker than a wood veneer layer. 
     In a preferred embodiment of the first aspect of the invention, the panel comprises at least three layers of wood, wherein the layers of wood comprise a first layer of wood, a second layer of wood and a third layer of wood, wherein the second layer of wood is provided between the first layer of wood and the third layer of wood; and wherein the continuous tongue of the first profile is provided in the second layer of wood. 
     Such embodiments have the advantage that the wood layers can be selected for optimum performance of coupling of the edges. 
     In a preferred embodiment of the first aspect of the invention, the first edges comprises the third profile, the third edge comprises the second profile, the second edge and the fourth edge both comprise the first profile. 
     The second edge and the fourth edge comprise the first profile. It means that both edges comprise a profile that comprising the claimed features of the first profile. It does not mean that the profiles at these two edges must be identical—which however is not excluded—but that the profiles at both edges both fulfill the claimed features of the first profile. 
     Such embodiment allows an installation in herringbone pattern without requiring a modification of the panel edges. 
     In a preferred embodiment of the first aspect of the invention, the first edge comprises the first profile, the third edge comprises the second profile, the second edge and the fourth edge both comprise the third profile. 
     The second edge and the fourth edge comprise the third profile. It means that both edges comprise a profile that comprising the claimed features of the third profile. It does not mean that the profiles at these two edges must be identical—which however is not excluded—but that the profiles at both edges both fulfill the claimed features of the third profile. 
     Such embodiment allows an installation in herringbone pattern without requiring a modification of the panel edges. 
     In a preferred embodiment of the first aspect of the invention, the first edge comprises the first profile, the third edge comprises the third profile, and the second edge and the fourth edge both comprise the second profile. 
     The second edge and the fourth edge comprise the second profile. It means that both edges comprise a profile that comprising the claimed features of the second profile. It does not mean that the profiles at these two edges must be identical—which however is not excluded—but that the profiles at both edges both fulfill the claimed features of the second profile. 
     Such embodiment allows an installation in herringbone pattern without requiring a modification of the panel edges. 
     In a more preferred such embodiment, a bottom cheek of the groove of the groove profile of the second profile is removed at the second edge and at the fourth edge of the panel, such that the bottom section of the groove of the groove profile of the second profile ends at the vertical plane comprising the closing plane at the surface of the floor panel or ends more proximal than the vertical plane comprising the closing plane at the surface of the floor panel. 
     This way, the panels can be installed in linear patterns also, besides the installation in herringbone patterns. This enables installation in patterns combining panels installed parallel to each other and panels installed in a 90° angle. 
     With installation is linear pattern is meant that rectangular and oblong panels can be coupled at their short edges to each other. 
     The second aspect of the invention relates to a laying pattern comprising a plurality of panels as in any embodiment of the first aspect of the invention, wherein the panels are coupled to each other at a 90° angle, preferably in a herringbone configuration. 
     The third aspect of the invention relates to a laying pattern comprising a plurality of panels, wherein the panels are panels as in any embodiment of the first aspect of the invention wherein the first edge comprises the first profile, the third edge comprises the third profile, and the second edge and the fourth edge both comprise the second profile, wherein the second edge and the fourth edge comprise the second profile. It means that both edges comprise a profile that comprising the claimed features of the second profile. It does not mean that the profiles at these two edges must be identical—which however is not excluded—but that the profiles at both edges both fulfill the claimed features of the second profile. A bottom cheek of the groove of the groove profile is removed at the second edge and at the fourth edge of the panel, such that the bottom section of the groove of the groove profile ends at the vertical plane comprising the closing plane at the surface of the floor panel or ends more proximal than the vertical plane comprising the closing plane at the surface of the floor panel. In the laying pattern of the third aspect of the invention, the panels are installed in parallel rows, preferably wherein an insert is provided between two coupled edges that each comprise the second profile, wherein the insert is configured for realizing a locking of the coupled panels at these edges in the direction perpendicular to the panel surface. 
     The fourth aspect of the invention relates to a laying pattern comprising a combination of any embodiment of the laying pattern of the second aspect of the invention and any embodiment of the laying pattern of the third aspect of the invention. 
     The fifth aspect of the invention relates to a set of panels, wherein the set of panels comprises and preferably consists of panels as in any embodiment of the first aspect of the invention. 
     The sixth aspect of the invention relates to a panel, wherein the panel is rectangular, square or oblong, wherein the panel comprises a first edge and a third edge, wherein the first edge and the third edges are provided opposite to each other, wherein the panel comprises a second edge and a fourth edge wherein the second edge and the fourth edge are provided opposite to each other, wherein each of the first edge, the second edge, the third edge and the fourth edge comprise a profile selected from a first profile, a second profile and a third profile, wherein the first profile, the second profile and the third profile are configured such that a panel edge comprising the first profile can be coupled to the edge of another such panel wherein the edge of the another such panel comprises any one of the second profile or the third profile, wherein in the coupled condition a locking of the coupled edges is provided in the direction perpendicular to the coupled panels as well as in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels; 
     and such that a panel edge comprising the second profile can be coupled to the edge of another such panel wherein the edge of the another such panel comprises the third profile, wherein in the coupled condition a locking of the coupled edges is provided in the direction perpendicular to the coupled panels as well as in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels. 
     It is a benefit that only one type of panel is required for making installations in herringbone pattern, while a locking of the coupled panels is obtained in the direction perpendicular to the panel surface as well as in the direction perpendicular to the coupled edges and parallel with the panel surface. 
     According to the sixth aspect of the invention, two opposite edges comprise the same profile selected from the first profile, the second profile or the third profile. It means that two opposite edges comprise or the first profile or the second profile or the third profile. It does not mean that the profiles at these two opposite edges must be identical—which however is not excluded—but that the profiles at both opposite edge both fulfill the features of the first profile, or both fulfill the features of the second profile, or both fulfill the features of the third profile 
     In a preferred embodiment of the sixth aspect of the invention, the first profile comprises a groove, wherein the groove is bordered by a lower lip and by an upper lip, wherein the lower lip extends distally to beyond the upper lip; wherein the lower lip comprises a locking element, preferably at its distal end, wherein the locking element is provided for realizing a locking in the direction perpendicular to the coupled edges and parallel with the panel surface when a panel edge comprising the first profile is coupled to the edge of another such panel when said edge of the another such panel comprises any one of the second profile or the third profile. 
     The upper lip comprises a locking surface—preferably wherein the locking surface is parallel to or inclined with respect to the surface of the panel—for establishing a locking in the direction perpendicular to the panel surface when a panel edge comprising the first profile is coupled to the edge of another such panel when said edge of the another such panel comprises the third profile. 
     The second profile comprises a tongue; wherein the tongue is configured for insertion in the groove of the first profile of an edge of another such panel, thereby establishing a locking in the direction perpendicular to the surface of the so coupled panels. 
     The tongue comprises a first recess, wherein the first recess is suited for cooperation with the locking element of the first profile of an edge of another such panel thereby establishing a locking of the so-coupled panels in the direction perpendicular to the coupled edges and parallel with the panel surface. 
     The tongue comprises a second recess, wherein the second recess is suited for cooperation with the locking element of the third profile of an edge of another such panel thereby establishing a locking of the so-coupled panels in the direction perpendicular to the coupled edges and parallel with the panel surface. 
     The second profile comprises closer to the panel surface than the location of the tongue, a locking surface—preferably wherein the locking surface is parallel to or inclined with respect to the surface of the panel—for establishing a locking in the direction perpendicular to the panel surface when a panel edge comprising the second profile is coupled to the edge of another such panel when said edge of the another such panel comprises the third profile. 
     The third profile comprises a first tongue and a second tongue; wherein the second tongue is provided closer to the panel surface than the first tongue; wherein a second groove is provided between the first tongue and the second tongue; wherein the first tongue comprises at its bottom a recess, wherein the recess is provided for establishing, in cooperation with the locking element of the lower lip of the first profile, a locking in the direction perpendicular to the coupled edges and parallel with the surface of the panel when a panel edge comprising the third profile is coupled onto the edge comprising the first profile of another such panel. 
     The second tongue comprises a locking surface for establishing a locking in the direction perpendicular to the surface of the panels in combination with the locking surface of the first profile or the locking surface of the second profile, when a panel edge comprising the third profile is coupled to an edge of another such panel comprising the first profile respectively the second profile. 
     The first tongue or the second tongue comprise a locking element, wherein the locking element is provided for establishing in combination with the second recess of the second profile a locking in the direction perpendicular to the coupled edges and parallel with the panel surface when a panel edge comprising the third profile is coupled to the edge comprising the second profile of another such panel. 
     In a preferred embodiment of the sixth aspect of the invention, the locking element of the lower lip of the first profile is directed upwards. 
     In a preferred embodiment of the sixth aspect of the invention, the first recess and the second recess are provided at different sides of the tongue, preferably wherein the first recess is provided at the bottom of the tongue. 
     Such embodiments ensure efficient locking and facilitate the milling of the profiles. 
     In a preferred embodiment of the sixth aspect of the invention, the first recess and the second recess are provided at the same side of the tongue, preferably wherein the first recess and the second recess are provided at the bottom of the tongue. 
     Such embodiments ensure efficient locking and facilitate the milling of the profiles. 
     In a preferred embodiment of the sixth aspect of the invention, the locking surface of the upper lip of the first profile is provided at the upper surface of an additional groove closer to the panel surface than the groove of the first profile. 
     Such embodiments ensure that a sufficiently large locking surface can be provided for efficient locking of coupled panels in the direction perpendicular to the panel surface. 
     In a preferred embodiment of the sixth aspect of the invention, the locking surface of the upper lip of the first profile is provided as an inclined surface at the distal edge of the upper lip. 
     In a preferred embodiment of the sixth aspect of the invention, the locking surface of the second profile is provided at the upper side of an undercut in the second profile. 
     Such embodiments allow to provide a locking surface with a sufficiently large surface area for efficient locking of coupled panels in the direction perpendicular to the surface of the panels. 
     In a preferred embodiment of the sixth aspect of the invention, an upper surface of the second tongue provides the locking surface of the third profile. 
     This is an efficient way to provide the locking in the direction perpendicular to the surface of the panel, and facilitates the milling operation of the third profile. 
     In a preferred embodiment of the sixth aspect of the invention, the locking surface of the second tongue is provided by a separate insert inserted in the second tongue, The insert is configured such that the displacement of the locking surface by a displacement or—preferably elastic—deformation of at least part of the insert during the coupling of the panel edges provides for the locking in the direction perpendicular to the surface of the panel. Such embodiments provide an efficient way for realizing the vertical locking, especially for panels comprising layers of wood. 
     In a preferred embodiment of the sixth aspect of the invention, in coupled condition of an edge comprising the first profile to an edge comprising the second profile of another such panel, a gap is provided between the upper surface of the locking element of the first profile and the edge of the another panel. 
     Such embodiments allow that milling tolerances can be reduced while still obtaining a good locking of the coupled panels. 
     In a preferred embodiment of the sixth aspect of the invention, in coupled condition of an edge comprising the first profile to an edge comprising the third profile of another such panel, a gap is provided between the upper surface of the locking element of the first profile and the edge of the another panel. 
     Such embodiments allow that milling tolerances can be reduced while still obtaining a good locking of the coupled panels. 
     In a preferred embodiment of the sixth aspect of the invention, in coupled condition of an edge comprising the first profile to an edge comprising the second profile of another such panel, the lower lip of the first profile contacts the second profile of the edge of the another such panel in two distinct zones, wherein a gap is provided between said two distinct zones. 
     Such embodiments allow that milling tolerances can be reduced while still obtaining a good locking of the coupled panels. 
     In a preferred embodiment of the sixth aspect of the invention, in coupled condition of an edge comprising the first profile to an edge comprising the third profile of another such panel, the lower lip of the first profile contacts the bottom of the first tongue of the second profile of the edge of the another such panel in two distinct zones, wherein a gap is provided between said two distinct zones. 
     Such embodiments allow that milling tolerances can be reduced while still obtaining a good locking of the coupled panels. 
     In a preferred embodiment of the sixth aspect of the invention, the first profile, the second profile and the third profile extend continuously and without interruption along the edge(s) where they are provided. 
     Such embodiments facilitate the milling of the profiles at the panel edges. 
     In a preferred embodiment of the sixth aspect of the invention, the first profile, the second profile and the third profile have a constant cross section perpendicularly to the edge where they are provided, over the full length of the edge where they are provided. 
     Such embodiments facilitate the milling of the profiles at the panel edges. 
     In a preferred embodiment of the sixth aspect of the invention, the first profile, the second profile and the third profile extend along the full length of the panel edge(s) where they are provided. 
     Such embodiments facilitate the milling of the profiles at the panel edges. 
     In a preferred embodiment of the sixth aspect of the invention, the panel is oblong and both short edges are provided with the same profile, preferably wherein both short edges are provided with the second profile. 
     In a preferred embodiment of the sixth aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge are provided closer to the panel surface than the first profile, the second profile and the third profile with a closing plane, wherein the closing planes are provided perpendicularly to the panel surface, and wherein in coupled condition of two panels the closing planes of the panel edges coupled to each other contact each other or are positioned closely to each other. 
     It is the intention that closing planes of coupled panels contact each other. However, due to manufacturing tolerance it cannot be excluded that a small gap occurs between the closing planes of coupled panels. 
     In a preferred embodiment of the sixth aspect of the invention, the panel comprises a decorative layer, wherein the decorative layer is a veneer layer—preferably a wood veneer layer—or wherein the decorative layer is a layer of wood, preferably wherein the layer of wood is thicker than a wood veneer layer. 
     In a preferred embodiment of the sixth aspect of the invention, the panel comprises a plurality of wood layers, preferably including a decorative wood layer; more preferably wherein the decorative wood layer comprises of consists of a wood veneer or comprises or consists of a layer of wood thicker than a wood veneer layer. 
     In a preferred embodiment of the sixth aspect of the invention, the panel comprises at least three layers of wood, wherein the layers of wood comprise a first layer of wood, a second layer of wood and a third layer of wood, wherein the second layer of wood is provided between the first layer of wood and the third layer of wood; and wherein the tongue of the second profile is provided in the second layer of wood. 
     This way, the layers of wood can be selected taking the required properties into account, including to obtain optimum performance of the continuous tongue of the first profile. 
     In a preferred embodiment of the sixth aspect of the invention, two opposite panel edges each comprise the first profile, the second profile or the third profile. 
     More preferably, the panel is oblong and the two opposite panel edges comprising each the first profile, the second profile or the third profile are the short edges. 
     In a preferred embodiment of the sixth aspect of the invention, the two panel edges that both comprise the same profile selected from the first profile, the second profile or the third profile, comprise profiles that have the same cross section perpendicular to the panel edge where the profiles are provided. 
     In a preferred embodiment of the sixth aspect of the invention, the two panel edges that both comprise the same profile selected from the first profile, the second profile or the third profile, comprise profiles selected from the first profile or the second profile or the third profile that differ in cross section perpendicular to the panel edge where the profiles are provided. 
     It is meant that the two panel edges comprise both a profile—however with differences between the profiles—that comprises the features of the first profile, or that comprises the features of the second profile, or that comprises the features of the third profile. 
     It is a benefit of such embodiment that the production process of the panel edges can be optimized. 
     In a more preferred such embodiment, two panel edges—preferably opposite panel edges and more preferably the short panel edges—both comprise the third profile, wherein both of these panel edges comprise a configuration of the third profile that differ in cross section perpendicular to the panel edge where the profiles are provided. 
     More preferably, at one of these two panel edges comprising a third profile an upper surface of the second tongue provides the locking surface of the third profile; and wherein at the other one of these two panel edges comprising a third profile the locking surface of the second tongue is provided by a separate insert inserted in the second tongue, wherein the insert is configured such that the displacement of the locking surface by a displacement or—preferably elastic—deformation of at least part of the insert during the coupling of the panel edges provides for said locking in the direction perpendicular to the surface of the panel. 
     It is a particular benefit of such embodiment that excellent locking is obtained, especially at edges comprising the third profile comprising an insert. It is a further benefit that existing production lines can be used, as it is known in the art to position an insert in one of the four panel edges of rectangular panels. It is general practice that opposing edges are milled in one and the same milling operation. Companies having installed such equipment can use it for positioning the insert in this preferred embodiment. No additional investment is required in additional equipment for positioning an insert in the opposing edges, additional investment which would be required if both opposite edges would be provided with an insert. Therefore, such embodiments are especially interesting because of their ease of manufacturing. 
     The seventh aspect of the invention relates to a laying pattern comprising a plurality of panels as in any embodiment of the sixth aspect of the invention, wherein the panels are coupled to each other under a 90° angle, preferably in a herringbone configuration. 
     The eighth aspect of the invention relates to a set of panels, wherein the set of panels comprises and preferably consists of panels as in any embodiment of the sixth aspect of the invention. 
     The ninth aspect of the invention relates to a panel, wherein the panel is rectangular, wherein the panel comprises a first edge, a second edge, a third edge and a fourth edge, wherein the first edge is provided with a first coupling profile, wherein the second edge is provided with a second coupling profile, wherein the third edge is provided with a third coupling profile, and wherein the fourth edge is provided with a fourth coupling profile. 
     The first coupling profile, the second coupling profile, the third coupling profile and the fourth coupling profile are configured such that the panel can be coupled at its first edge to anyone one of the first edge, the second edge or the third edge of another such panel; and such that the panel can be coupled at its second edge to anyone of the third edge or the fourth edge of another such panel, and such that the panel can be coupled at its third edge to the fourth edge of another such panel. 
     The panels according to the ninth aspect of the invention have the benefit that they can be installed in 90° angle configurations of the panels—e.g. in herringbone laying patterns—as well as linearly in rows, and in combinations of such laying patterns. The panels can be manufactured in an easy way and with high productivity. 
     In a preferred embodiment of the ninth aspect of the invention, the first coupling profile, the second coupling profile, the third coupling profile and the fourth coupling profile extend continuously along the edge where they are provided. 
     Such panels can be manufactured in an easy way, without expensive milling machines. 
     In a preferred embodiment of the ninth aspect of the invention, the first coupling profile, the second coupling profile, the third coupling profile and the fourth coupling profile extend along the full length of the edge where they are provided. 
     Such panels can be manufactured in an easy way, without expensive milling machines. 
     In a preferred embodiment of the ninth aspect of the invention, the first coupling profile, the second coupling profile, the third coupling profile and the fourth coupling profile each have along the length of the edge where they are provided a constant cross section perpendicular to the edge where they are provided. 
     Such panels can be manufactured in an easy way, without expensive milling machines. 
     In a preferred embodiment of the ninth aspect of the invention, in each of said coupled configurations of two such panels a locking is provided in the direction perpendicular to the surface of the coupled panels. 
     In a preferred embodiment of the ninth aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge comprises a closing plane, wherein the closing planes are provided substantially perpendicular to the surface of the panel, wherein the closing planes are provided for approaching and preferably for contacting the closing plane of any one of the four edges of another such plane. 
     In a preferred embodiment of the ninth aspect of the invention, the panel comprises a decorative layer, wherein the decorative layer is a veneer layer—preferably a wood veneer layer—or wherein the decorative layer is a layer of wood, preferably wherein the layer of wood is thicker than a wood veneer layer. 
     In a preferred embodiment of the ninth aspect of the invention, the panel comprises a plurality of wood layers, preferably including a decorative wood layer; more preferably wherein the decorative wood layer comprises of consists of a wood veneer or comprises or consists of a layer of wood thicker than a wood veneer layer. 
     In a preferred embodiment of the ninth aspect of the invention, the first coupling profile comprises a first groove at a first distance from the panel surface, a second groove at a second distance from the panel surface and a third groove at a third distance from the panel surface. The second coupling profile comprises a first tongue. The third coupling profile comprises a second tongue, a fourth groove and a fifth groove. The fourth coupling profile comprises a third tongue, a sixth groove and a seventh groove. 
     The first groove is configured for receiving the first tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The second groove is configured for receiving the second tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The third groove is configured for receiving the third tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The fourth groove is configured for receiving the first tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The fifth groove is configured for receiving the third tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The sixth groove is configured for receiving the first tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The seventh groove is configured for receiving the second tongue of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. 
     In a preferred embodiment of the ninth aspect of the invention, the third distance is smaller than the second distance; and the second distance is smaller than the first distance. 
     In a preferred embodiment of the ninth aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge comprise a closing plane, wherein the closing planes are provided substantially perpendicular to the surface of the panel, wherein the closing planes are provided for approaching and preferably for contacting the closing plane of one of the four edges of another such plane. The first coupling profile comprises a bottom lip extending distally to beyond the closing plane of the first edge, wherein the bottom lip is provided with an upper surface wherein the second coupling profile, the third coupling profile and the fourth coupling profile and the upper surface are configured for establishing a locking—preferably with contact—of the first edge of the panel in the direction perpendicular to the panel surface when the first edge is coupled respectively to the second edge, the third edge or the fourth edge of another such panel. 
     In a preferred embodiment of the ninth aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge comprise a closing plane, wherein the closing planes are provided substantially perpendicular to the surface of the panel, wherein the closing planes are provided for approaching and preferably for contacting the closing plane of one of the four edges of another such plane. The second coupling profile comprises proximally from the closing plane of the second edge an upper surface. The third coupling profile and said upper surface are configured for establishing a locking—preferably with contact—of the second edge of the panel in the direction perpendicular to the panel surface when the second edge is coupled to the third edge of another such panel. 
     In a preferred embodiment of the ninth aspect of the invention, each of the first edge, the second edge, the third edge and the fourth edge comprise a closing plane, wherein the closing planes are provided substantially perpendicular to the surface of the panel, wherein the closing planes are provided for approaching and preferably for contacting the closing plane of one of the four edges of another such plane. The second locking profile comprises a contact surface, preferably substantially parallel with the panel surface, wherein said contact surface is provided proximally from the closing plane of the second locking profile. The second coupling profile and the fourth coupling profile are configured for establishing a locking in the direction perpendicular to the panel surface—preferably with contact—of the panel edge comprising the second coupling profile when coupled to the edge comprising the fourth coupling profile of another such panel by means of the upper surface of the third tongue and the contact surface of the second locking profile. 
     In a preferred embodiment of the ninth aspect of the invention, the panel is rectangular and oblong, and the first coupling profile and the fourth coupling profile are provided at the long edges of the panel; and the second coupling profile and the third coupling profile are provided at the short edges of the panel. 
     Such embodiments are easy to manufacture and provide easy of installation with excellent locking in the direction perpendicular to the panel surface. 
     In a preferred embodiment of the ninth aspect of the invention, in none of the coupled configurations of two such panels, a mechanical locking is provided in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels. 
     In a preferred embodiment of the ninth aspect of the invention, each of the first coupling profile, the second coupling profile, the third coupling profile and the fourth coupling profile are configured such that they can be milled exclusively by milling with milling tools having an axis perpendicular to the panel surface. 
     It is a benefit of such embodiment that no expensive machinery is required to produce the coupling profiles of the panels. 
     The tenth aspect of the invention relates to a laying pattern, wherein the laying pattern comprises a plurality of panels as in any embodiment of the ninth aspect of the invention, wherein at least part of the panels is installed in a 90° angle configuration and/or wherein at least part of the panels are installed in linear configuration. 
     The panels of the ninth aspect of the invention allow to install the panels in complex configurations. 
     The panels according to the different aspects of the invention can be made in all kinds of materials, e.g. in laminate, in parquet, in polyvinylchloride (e.g. Luxury Vinyl Tiles, Solid Plastic Composite or Water Proof Composites) and made in different thicknesses. 
     It is possible to make all kind of installation patterns with the panels according to the invention, in particular installation patterns wherein the panels are installed with a 90° angle in between them, e.g. herringbone configurations. 
     The profiles of the panels according to the invention can be made with simple machinery and with high speeds. The installation of the panels in complex patterns is facilitated—and therefore faster—as only one single type of panels is required. 
    
    
     
       With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, several preferred embodiments are described, with reference to the accompanying drawings, wherein: 
         FIG.  1    shows a panel A according to an embodiment of the invention. 
         FIG.  2    shows a top view of panel A of  FIG.  1   . 
         FIG.  3    shows a cross section of a groove-tongue profile  1  according to an embodiment of the invention. 
         FIG.  4    shows a cross section of a groove-double tongue profile  3  according to an embodiment of the invention. 
         FIG.  5    shows a cross section of a groove profile  2  according to an embodiment of the invention. 
         FIG.  6    shows a cross section of a coupling of a groove-tongue profile  1  with a groove-double tongue profile  3  according to an embodiment of the invention. 
         FIG.  7    shows a cross section of a coupling of a groove profile  2  with a groove-double tongue profile  3  according to an embodiment of the invention. 
         FIG.  8    shows a cross section of a coupling of a groove profile  2  with a groove-tongue profile  1  according to an embodiment of the invention. 
         FIG.  9    shows a top view of a plurality of panels A according to the invention, installed such that a 90° angle is established between panels. 
         FIG.  10    shows a top view of panel A of  FIG.  1   . 
         FIG.  11    shows a top view of a panel B according to an embodiment of the invention. 
         FIG.  12    shows a top view of a panel C according to an embodiment of the invention. 
         FIG.  13    shows the groove profile  2  of  FIG.  5   . 
         FIG.  14    shows the groove profile  2  of  FIG.  5    wherein a bottom cheek of the groove of the groove profile  2  is removed. 
         FIG.  15    shows the coupling of two profiles as shown in  FIG.  14    with an insert. 
         FIG.  16    shows an example of an installation of panels A installed parallel to each other, panels A according to an embodiment of the invention, panels A which comprise the profiles shown in  FIGS.  3 ,  4  and  14   . 
         FIG.  17    shows a cross section of a groove-tongue profile according to an embodiment of the invention in a panel comprising three layers of wood. 
         FIG.  18    shows a panel according to the sixth aspect of the invention. 
         FIGS.  19   a - c    show an example of profiles of edges of the panel of  FIG.  18   . 
         FIGS.  20   a - c    show the edge profiles of  FIGS.  19   a - c    in coupled condition. 
         FIGS.  21   a - c    show an example of profiles of edges of the panel of  FIG.  18   . 
         FIGS.  22   a - c    show the edge profiles of  FIGS.  21   a - c    in coupled condition. 
         FIGS.  23   a - c    show an example of profiles of edges of the panel of  FIG.  18   . 
         FIGS.  24   a - c    show the edge profiles of  FIGS.  23   a - c    in coupled condition. 
         FIGS.  25   a - c    show the edge profiles in coupled condition of another example of the sixth aspect of the invention. 
         FIG.  26   a - d    show an example of the profiles of edges of another example of a panel according to  FIG.  18   . 
         FIGS.  27   a - e    show the edge profiles in coupled condition of the profile edges shown in  FIG.  26   . 
         FIG.  28   a - e    show the edge profiles in coupled condition of another embodiment of sixth aspect of the invention. 
         FIG.  29    shows a panel according to the ninth aspect of the invention. 
         FIGS.  30   a - d    shows an example of the coupling profiles of the panel according to the ninth aspect of the invention shown in  FIG.  29   . 
         FIGS.  31   a - f    shows the coupling profiles of  FIGS.  30   a - d    in coupled condition. 
     
    
    
       FIGS.  1 - 17    illustrate the first aspect of the invention, and laying patterns realized with panels according to the first aspect of the invention. 
     The objective of the first aspect of the invention is to provide panels that can be installed in different laying patterns, including herringbone, wherein only one type of panels are required, and without the need to have provide additional inserts such as separate tongues for making the herringbone installation. Panels according to the first aspect of the invention are illustrated in  FIGS.  1 - 17   , in which three different panel embodiments A, B and C are illustrated. 
     The panels of the first aspect of the invention are rectangular, and thus have a first pair of opposing edges and a second pair of opposing edges (the first edge and the third edge are parallel to each other; and the second edge and the fourth edge are parallel to each other). The rectangular panel can be square or oblong. 
     Each of the panels A, B, C comprise a closing plane  101 , which extends from the upper panel surface O perpendicularly in the direction of the panel bottom U up to the start of the profile  1 ,  2 ,  3 . 
     The closing plane  101  is provided for making contact with or for being located close to the closing plane  101  of another such panel in coupled condition of the panel with the another such panel. The objective of the closing plane  101  is to provide a closed visible joint between coupled panels. 
     The basic principle as well as the three profiles (the first profile, the second profile and the third profile); wherein the first profile comprises or consists of a groove-tongue profile  1 , wherein the second profile comprises or consists of a groove profile  2  comprising a continuous groove  109 , and wherein the third profile comprises or consists of a groove-double tongue profile  3 , are first described for an exemplary panel A.  FIG.  1    shows a panel A according to an embodiment of the invention.  FIG.  2    shows a top view of panel A of  FIG.  1   . Both figures show that in this example both short edges (edges  2  and  4 ) of the rectangular panel comprise the same profile, more particularly the groove profile  2 . The two other edges (edges  1  and  3 ) comprise respectively a groove-tongue profile  1  and a a groove-double tongue profile  3 . 
     Examples of these three profiles are described in  FIGS.  3 - 5   .  FIG.  3    shows a cross section of a groove-tongue profile  1  according to an embodiment of the invention.  FIG.  4    shows a cross section of a groove-double tongue profile  3  according to an embodiment of the invention.  FIG.  5    shows a cross section of a groove profile  2  according to an embodiment of the invention. 
       FIG.  3    shows a panel edge comprising a first profile. The panel edge has a closing plane  101 . The first profile comprises a groove-tongue profile  1 . The tongue-groove profile comprises a continuous groove  102  which follows the closing plane  101 . The continuous groove  102  has a groove width N 5  and a groove depth n 4 . The groove  102  is provided for receiving the upper tongue  105  of the groove-double tongue profile  3 , when the first profile and the third profile are coupled to each other, as is shown in  FIG.  6   . 
     Following the continuous groove  102 , the groove-tongue profile  101  comprises a continuous tongue  104  having a total thickness F 2  and a total length f 2 . The nose  103  of the tongue  104  which extends to beyond the vertical plane comprising the closing plane  101  has a thickness F 3  and a length f 2 . The upper side of the tongue nose  103  (from the back end of the groove  102  up to the front end of the tongue nose  103 ) has a tongue length f 5 . The tongue nose  103  is provided for fitting in the groove  160  of the groove-double tongue profile  3 , when the first profile and the third profile are coupled to each other, as is shown in  FIG.  6   . At its bottom, the thickness of the continues tongue  104  increase from F 3  to F 2 , in order to be able to receive the bottom tongue  107  of the groove-double tongue profile  3 , when the first profile is coupled to the third profile, as is shown in  FIG.  6   . The bottom of the continuous tongue  104  has the function to receive a bottom cheek  111  of a groove of the groove profile  2 , when the first profile is coupled to a second profile as is shown in  FIG.  8   . 
     In the example shown, the continuous tongue  104  of the groove-tongue profile  1  comprises two different end faces  113 ,  114 . The two different end faces  113 ,  114  are provided at different distances from the panel edge where the first profile is provided. The two end face comprise an end surface substantially perpendicular to or perpendicular to the panel surface. 
       FIG.  4    shows a panel edge comprising a second profile. The panel edge has a closing plane  101  followed by the groove-double tongue profile  3 . The groove-double tongue profile comprises a continuous groove  106 , having a groove width N 4 . The groove-double tongue profile  3  comprises a continuous double tongue  105 ,  107 , having different tongue thicknesses F 1 , F 4 , F 5  and different tongue lengths f 3 , f 4 . The double tongue comprises an upper tongue  105  and a lower tongue  107 . The upper tongue has thickness F 5  and a length f 3 , it is meant that the upper tongue extends from the closing plane over a distance f 3 . A continuous groove  106  having a width N 4  is provided between the upper tongue  105  and the lower tongue  107 . The continuous groove  106  is configured such that it can receive the tongue  103  of the groove-tongue profile  1 , as is shown in  FIG.  6   . The lower tongue  107  has a thickness F 4  and a length f 4 . The total thickness F 1  of the groove-double tongue  3  is provided by the combination of the thickness F 4  and F 5  of the upper tongue and the lower tongue and the thickness N 4  of the groove  106 , which at least is larger than the thickness F 3  of the tongue  103  of the first profile. The second profile can be coupled to the third profile, as is shown in  FIG.  7   . In the example shown, the groove-double tongue  3  functions as a single tongue with tongue thickness F 1 . It is meant that the upper side of the upper tongue  105  and the bottom side of the lower tongue  107  are to be considered the upper side and the lower side of a single tongue which is inserted in the continuous groove  109  of the groove profile  2  of the second profile, and coupled therewith. 
       FIG.  5    shows a panel edge comprising a second profile. The panel edge has a closing plane  101 . Following to the closing plane, a groove profile is provided comprising a continuous groove  109  having different groove widths N 1 , N 2 , N 3  and different groove depths n 1 , n 2 , n 3 . The continuous groove  109  follows the closing plane  101 . The groove  109  has a tot depth n 1  and a total width N 1 . The continuous groove  109  is a segmented groove. The segmented groove comprises an upper section  110 ,  116  closest to the surface of the panel, a middle section  108 ,  117  and a bottom section  118 . The middle section extends more proximal into the panel than the upper section and the bottom section. 
     The middle section  117  comprises an upper lip  120  and a bottom lip  121  and the upper section  116  comprises an upper lip  122 . The upper section  116  extends at its bottom over part of its depth into the middle section  117 . The bottom section  118  comprises a bottom lip  123 ,  115  and extends at its upper side over part of its depth into the middle section  117 . The bottom section  118  extends more distal into the panel than the upper section  116 . 
     The upper section  116 ,  110  is provided for locking the upper tongue  105  of the groove-double tongue  3 , when the second profile is coupled to third profile as shown in  FIG.  7   . 
     The middle section  117  is an inner groove  108 , the upper side of which end in the groove width n 2  and which bottom side ends in the groove width n 3 . The middle section has a groove width N 3 , configured for receiving the tongue nose  103  of the groove-tongue profile, when the second profile and the first profile are coupled to each other, as is shown in  FIG.  8   . The bottom section has a groove width N 2 -N 3 . The bottom section borders a bottom cheek  111 . The horizontal distance between the between the most proximal end of the middle section and the distal end of the bottom cheek  111  equals n 1 . This distance is larger than the groove depth n 2  between the most proximal end of the middle section and the closing plane  101 . The combined width of the middle section and the bottom section is N 2 . the bottom cheek  111  functions to support the bottom of tongue  107  of the third profile, but also, to be pushed under the bottom of tongue  104  of the first profile, such that a locking is provided in the direction perpendicular to the panel surface. 
     Each of the first profile, the second profile and the third profile illustrated in  FIGS.  3 ,  4  and  5    respectively are configured such that they can be realized by milling operations with milling axis perpendicular to the surface of the panel. 
     In the examples shown, each of the first profile, the second profile and the third profile extend continuously and without interruption along the full length of the panel edge where they are provided; and have a constant cross section along the full length of the panel edge where they are provided. 
     As is clear from the description of the examples shown in  FIGS.  3 - 5   , none of the first profile, the second profile and the third profile are provided with mechanical locking parts that in coupled condition of any one of the edges of the panel to any edge of another such panel would result in a locking in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels. 
     From the description provided for the profiles of  FIGS.  3 - 5   , it will be clear that the groove widths N 3 , N 4 , N 5  of the grooves  102 ,  106 ,  108  of the groove-tongue profile  1 , the groove-double tongue profile  3  and the groove profile  2  are configured; and that the corresponding tongues  103 ,  105 ,  107  of a to be coupled groove-tongue profile  1  and/or a to be coupled groove-double tongue profile  3  are configured such that the panels can be coupled at the upper side U and/or at the bottom side U of the panel in a form fitting manner. 
     From the description provided for the profiles of  FIGS.  3 - 5   , it will be clear that the width N 1  of the groove  109  of the groove profile  2  corresponds to the full thickness F 1  of the groove-double tongue profile  3 , such that the groove-double tongue profile  3  can be inserted in a form fitting manner in the groove  109  of the groove profile  2 . 
     From the description provided for the profiles of  FIGS.  3 - 5   , it will be clear that the tongues  104 ,  105 ,  107  and grooves  102 ,  109 ,  106  of the first profile, the second profile and the third profile are configured such that the panel edge or edges provided with the first profile can be coupled onto the panel edge or panel edges provided with the second profile as well as onto the panel edge or panel edges provided with the third profile of another such panel; and such that the panel edge or edges provided with the second profile can be coupled onto the panel edge or panel edges provided with the third profile of another such panel. 
     The panel comprises a decorative layer  125 , e.g. a veneer layer—preferably a wood veneer layer—or a layer of wood, preferably wherein the layer of wood is thicker than a wood veneer layer. 
     As already indicated,  FIG.  6    shows a cross section of a coupling of a groove-tongue profile  1  with a groove-double tongue profile  3  according to an embodiment of the invention.  FIG.  7    shows a cross section of a coupling of a groove profile  2  with a groove-double tongue profile  3  according to an embodiment of the invention.  FIG.  8    shows a cross section of a coupling of a groove profile  2  with a groove-tongue profile  1  according to an embodiment of the invention. 
       FIG.  9    shows a top view of a plurality of panels A according to the invention, installed such that a 90° angle is established between panels.  FIG.  9    shows a herringbone configuration of panels. No additional parts, such as additional tongues, nor additional post forming of panel edges is required for laying the panels A of  FIGS.  1  and  2    (and provided with the profiles as shown in  FIGS.  3 - 5   ) in herringbone configuration. 
     By using the first profile, the second profile and the third profile on a panel A, B, C; a herringbone installation only using panels A, or only using panels B or only using panels C is possible. It means that it is not required to have two different panels types (left hand side and right hand side panels) available, only one type is sufficient. 
       FIGS.  10 - 12    show three embodiments of panels A, B and C according to the first aspect of the invention. The embodiments differ in which the edges where the first profile  1 , the second profile  2  and the third profile  3  are provided.  FIG.  10    shows a top view of panel A of  FIG.  1   .  FIG.  11    shows a top view of a panel B according to an embodiment of the invention.  FIG.  12    shows a top view of a panel C according to an embodiment of the invention. 
     The edges of panel A ( FIG.  10   ) are provided as follows:
     the first edge comprises the groove-tongue profile  1 ,   the third edge comprises the groove-double tongue profile  3 ; and   the second and the fourth edge both comprise the groove profile  2 .   

     The edges of panel B ( FIG.  11   ) are provided as follows:
     the first edge comprises the groove-double tongue profile  3 ,   the third edge comprises the groove profile  2 ; and   the second and the fourth edge both comprise the groove-tongue profile  1 .   

     The edges of panel C ( FIG.  12   ) are provided as follows:
     the first edge comprises the groove-tongue profile  1 ,   the third edge comprises the groove profile  2 ; and   the second and the fourth edge both comprise the groove-double tongue profile  3 .   

     The second and the fourth edge comprise in each of the three examples (panels A, B and C) the same profile selected from the first profile, the second profile or the third profile. 
     In case of rectangular panel A, B, C with two long edges and two short edges, the second and the fourth edge provide the short edges. 
     The groove-tongue profile  1  of the first profile, the groove profile  2  of the second profile and the groove-double tongue profile  3  of the third profile show in the direction perpendicular to the panel surface three levels. The groove-tongue profile  1  is divided in three levels by the tongue thickness F 2  and F 3  and by the groove thickness N 5 . The groove profile  2  is divided in three levels by the groove thicknesses N 1 , N 2  and N 3 . The groove-double tongue profile  3  is divided in three levels by the groove width N 4  and by the tongue thickness F 4  and F 5 . 
     The first profile, the second profile and the third profile have been established by horizontal profiling. This differs from panels for glueless installation which comprise coupling parts that are profiled in horizontal and in vertical direction. 
     The three embodiments shown (panel A, panel B, panel C) allow to install the panels in different laying patterns, including herringbone, double herringbone, chessfield, braided, association, irregular association and cassette. The laying patterns involve that panels are installed including a 90° angle between the panels. No left and right hand side panels are required to make the laying patterns. 
     An embodiment of the first aspect of the invention according to panel A also allows an installation of the panels in linear rows, as is shown in  FIG.  16   , when the bottom cheek  111  of the groove profile  2  is cut, such that the distal end of the bottom cheek  111  extends up to the vertical plane comprising the closing plane  101  or ends more proximal than the vertical plane comprising the closing plane  101 .  FIGS.  13  and  14    illustrate the cutting of the bottom cheek  111  ( FIG.  13    shows the groove profile  2  in uncut condition,  FIG.  14    shows a groove profile  4  with shortened bottom cheek). 
       FIG.  15    shows the coupling of two profiles  4  as shown in  FIG.  14    with an insert FF. The closing planes contact each other, the coupling of two panel edges with profile  4  is performed by means of an insert FF. The insert FF being shown has a T-shape cross section. The thickness of the insert FF corresponds with the groove width, such that the insert can be used for coupling the panel edges provided with profile  4 . 
     By changing the nut profile into a profile  4  as shown in  FIG.  14   , the linear installation of panels shown in  FIG.  16    can be realized. This allows to realize more and more complex laying patterns. 
       FIG.  17    shows a panel edge comprising a groove-tongue profile as in the first aspect of the invention. The groove-tongue profile is similar to the groove-tongue profile  1  shown in  FIG.  3   ; the reference numbers in  FIG.  17    have the same meaning as in  FIG.  3   . The panel of the example of  FIG.  17    comprises three layers of wood  125 ,  126 ,  127 . The layers of wood comprise a first layer of wood  125 , a second layer  126  of wood and a third layer  127  of wood. The second layer of wood is provided between the first layer of wood and the third layer of wood. The continuous tongue  104  of the first groove-tongue profile  1  is provided in the second layer  126  of wood. 
       FIGS.  18 - 28    illustrate embodiments of panels according to the sixth aspect of the invention. 
       FIG.  18    shows a panel  201  according to the sixth aspect of the invention. The panel  201  is rectangular, square or oblong. The panel comprises a first edge  202  and a third edge  204 . The first edge and the third edges are provided opposite to each other. The panel comprises a second edge  203  and a fourth edge  205 , wherein the second edge and the fourth edge are provided opposite to each other. Each of the first edge, the second edge, the third edge and the fourth edge comprise a profile selected from a first profile, a second profile and a third profile. Both short edges can e.g. be provided with the second profile. 
       FIGS.  19   a - c    show a first example of a set of a first profile  207 , a second profile  208  and a third profile  209  that can be used in the panel according to the sixth aspect of the invention shown in  FIG.  18   .  FIGS.  21   a - c    show a first example of a set of a first profile  207 , a second profile  208  and a third profile  209  that can be used in the panel according to the sixth aspect of the invention shown in  FIG.  18   .  FIGS.  23   a - c    show a first example of a set of a first profile  207 , a second profile  208  and a third profile  209  that can be used in the panel according to the sixth aspect of the invention shown in  FIG.  18   . The reference numbers in these drawings have the same meaning. 
     The first profile  207 , the second profile  208  and the third profile  209  are configured such that a panel edge comprising the first profile can be coupled to the edge of another such panel wherein the edge of the another such panel comprises any one of the second profile or the third profile, wherein in the coupled condition a locking of the coupled edges is provided in the direction perpendicular to the coupled panels as well as in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels;
     and such that a panel edge comprising the second profile can be coupled to the edge of another such panel wherein the edge of the another such panel comprises the third profile, wherein in the coupled condition a locking of the coupled edges is provided in the direction perpendicular to the coupled panels as well as in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels.   

     In the examples shown, each of the first profile  207 , the second profile  208  and the third profile  209  extend continuously and without interruption along the edge(s) where they are provided. In the examples shown, each of the first profile  207 , the second profile  208  and the third profile  209  have a constant cross section perpendicularly to the edge where they are provided, over the full length of the edge where they are provided. In the examples shown, each of the first profile  207 , the second profile  208  and the third profile  209  extend along the full length of the panel edge(s) where they are provided. 
       FIGS.  20   a - c    show the edge profiles of  FIGS.  19   a - c    in coupled condition.  FIGS.  22   a - c    show the edge profiles of  FIGS.  21   a - c    in coupled condition.  FIGS.  24   a - c    show the edge profiles of  FIGS.  23   a - c    in coupled condition. 
     In the examples shown in  FIGS.  19 - 25   , the first profile  207  comprises a groove  211 . The groove is bordered by a lower lip  212  and by an upper lip. The lower lip extends distally to beyond the upper lip. The lower lip comprises at its distal end a locking element  214 . The locking element  214  of the lower lip  212  of the first profile  207  is directed upwards. The locking element  214  is provided for realizing a locking in the direction perpendicular to the coupled edges and parallel with the panel surface when a panel edge comprising the first profile  207  is coupled to the edge of another such panel when said edge of the another such panel comprises any one of the second profile  208  or the third profile  209 . The upper lip  213  comprises a locking surface  215 . The locking surface  215  can be provided parallel to (as is shown in the embodiments shown in  FIG.  19   a    and in  FIG.  25   ) or inclined (as is shown in the embodiments shown in  FIGS.  21   a  and  23   a   ) with respect to the surface of the panel. 
     The locking surface  215  is provided for establishing a locking in the direction perpendicular to the panel surface when a panel edge comprising the first profile is coupled to the edge of another such panel when said edge of the another such panel comprises the third profile. 
     The second profile  208  comprises a tongue  216 . The tongue  216  is configured for insertion in the groove  211  of the first profile  207  of an edge of another such panel, thereby establishing a locking in the direction perpendicular to the surface of the so coupled panels. 
     The tongue  216  comprises a first recess  217 . The first recess is suited for cooperation with the locking element  214  of the first profile  207  of an edge of another such panel thereby establishing a locking of the so-coupled panels in the direction perpendicular to the coupled edges and parallel with the panel surface. The tongue  216  comprises a second recess  218 . The second recess is suited for cooperation with the locking element  219  of the third profile  209  of an edge of another such panel thereby establishing a locking of the so-coupled panels in the direction perpendicular to the coupled edges and parallel with the panel surface. The first recess  217  and the second recess  218  can be provided at different sides of the tongue  216 , as is shown in the embodiments represented in  FIGS.  21   b ,  23   b    and  25 , in these embodiments, the first recess  217  is provided at the bottom of the tongue. In the embodiment shown in  FIG.  19   b   , the first recess  217  and the second recess  218  are both provided at the bottom of the tongue  216 . 
     The second profile  208  comprises closer to the panel surface than the location of the tongue  216 , a locking surface  220 . This locking surface  220  can be provided parallel to (as is shown in the embodiments shown in  FIG.  19   b    and in  FIG.  25   ) or inclined (as is shown in the embodiments shown in  FIGS.  21   b  and  23   b   ) with respect to the surface of the panel. In the examples shown, the locking surface  220  of the second profile  208  is provided at the upper side of an undercut  227  in the second profile. This locking surface  220  is provided for establishing a locking in the direction perpendicular to the panel surface when a panel edge comprising the second profile is coupled to the edge of another such panel when said edge of the another such panel comprises the third profile  209 . 
     The third profile  209  comprises a first tongue  221  and a second tongue  222 . The second tongue  222  is provided closer to the panel surface than the first tongue  221 . A second groove  223  is provided between the first tongue and the second tongue. The first tongue comprises at its bottom a recess  224 . This recess  224  is provided for establishing, in cooperation with the locking element  214  of the lower lip of the first profile, a locking in the direction perpendicular to the coupled edges and parallel with the surface of the panel when a panel edge comprising the third profile is coupled onto the edge comprising the first profile of another such panel. The second tongue  222  comprises a locking surface  225  for establishing a locking in the direction perpendicular to the surface of the panels in combination with the locking surface of the first profile or the locking surface of the second profile, when a panel edge comprising the third profile is coupled to an edge of another such panel comprising the first profile respectively the second profile. The first tongue  221  or the second tongue  222  comprises a locking element  219 , which is provided for establishing in combination with the second recess  218  of the second profile a locking in the direction perpendicular to the coupled edges and parallel with the panel surface when a panel edge comprising the third profile is coupled to the edge comprising the second profile of another such panel. 
     In each of the examples shown in  FIGS.  19 - 28   , the profiles are configured such that in coupled condition of an edge comprising the first profile  207  to an edge comprising the second profile  208  of another such panel, a gap  229  is provided between the upper surface of the locking element  214  of the first profile and the edge of the another panel. This is e.g. illustrated in  FIGS.  20   a ,  22   a ,  24   b   , and  25   b.    
     In each of the examples shown in  FIGS.  19 - 28   , the profiles are configured such that in coupled condition of an edge comprising the first profile  207  to an edge comprising the third profile  209  of another such panel, a gap  230  is provided between the upper surface of the locking element  214  of the first profile and the edge of the another panel. This is e.g. illustrated in  FIGS.  20   b ,  22   b ,  24   a   , and  25   a.    
     In each of the examples shown in  FIGS.  19 - 28   , the profiles are configured such that in coupled condition of an edge comprising the first profile  207  to an edge comprising the second profile  208  of another such panel, the lower lip  212  of the first profile contacts the second profile  208  of the edge of the another such panel in two distinct zones  231 ,  232 , wherein a gap  233  is provided between said two distinct zones. This is e.g. illustrated in  FIGS.  20   a ,  22   a ,  24   b   , and  25   b.    
     In each of the examples shown in  FIGS.  19 - 28   , the profiles are configured such that in coupled condition of an edge comprising the first profile  207  to an edge comprising the third profile  209  of another such panel, the lower lip  212  of the first profile contacts the bottom of the first tongue of the second profile of the edge of the another such panel in two distinct zones  234 ,  235 , wherein a gap  236  is provided between said two distinct zones. This is e.g. illustrated in  FIGS.  20   b ,  22   b ,  24   a   , and  25   a.    
     In each of the examples shown in  FIGS.  19 - 28   , each of the first edge, the second edge, the third edge and the fourth edge are provided closer to the panel surface than the first profile, the second profile and the third profile with a closing plane  101 . The closing planes  101  are provided perpendicularly to the panel surface. In coupled condition of two panels the closing planes of the panel edges coupled to each other contact each other or are positioned closely to each other. 
     In the example shown in  FIG.  19    (and in  FIG.  20    in coupled condition), the locking surface  215  of the upper lip  215  of the first profile is provided at the upper surface of an additional groove  226  closer to the panel surface than the groove  211  of the first profile. 
     In the examples shown in  FIGS.  21    (and in coupled condition in  FIG.  22   ),  23  (and in coupled condition in  FIG.  24   ) and  25  the locking surface  215  of the upper lip  213  of the first profile  207  is provided as an inclined surface at the distal edge of the upper lip. 
     In the examples shown in  FIGS.  19    (and in  FIG.  20    in coupled condition) and  21  (and in  FIG.  22    in coupled condition) an upper surface of the second tongue  222  provides the locking surface  225  of the third profile. 
     In the examples shown in  FIGS.  23    (and in  FIG.  24    in coupled condition) and  25  (showing the edge profiles in coupled condition) the locking surface  225  of the second tongue  222  is provided by a separate insert  228  inserted in the second tongue  222 . A displacement of the locking surface  225 —caused by a displacement or deformation (e.g. an elastic deformation) of at least part of the insert  228  during the coupling of the panel edges provides for the locking in the direction perpendicular to the surface of the panel caused by a sliding or a rotational movement and/or an elastic bending of the insert when coupling the panel edges results in the locking in the direction perpendicular to the surface of the panel.  FIG.  23   c    (and  FIG.  24    in coupled condition) shows an example of insert  228  that can be used.  FIG.  25    show another example of an insert  228  that can be used, which provided the coupling by a sliding movement of at least part of the insert. 
     The examples of the first profile  207 , second profile  208  and the third profile  209  shown in  FIGS.  19 - 25    are such that the two panel edges that—according to the sixth aspect of the invention—both comprise the same profile selected from the first profile  207 , the second profile  208  or the third profile  209 , comprise profiles that have the same cross section perpendicular to the panel edge where the profiles are provided. 
     The panel example of  FIG.  18    is described can e.g. at both short edges  203 ,  205  comprise the second profile  208 . 
     The sixth aspect of the invention also provides that the two edges comprising the same profile selected from the first profile, the second profile and the third profile, comprise profiles selected from the first profile or the second profile or the third profile that differ in cross section perpendicular to the panel edge where the profiles are provided. Examples of such embodiments are illustrated in  FIGS.  26 - 28   . The reference numbers in  FIGS.  26 - 28    have the same meaning as in the  FIGS.  19 - 25   . 
       FIG.  26   a - d    show an example of the profiles at the four edges of a rectangular and oblong panel.  FIGS.  27   a - e    show the edge profiles in coupled condition of the profile edges shown in  FIG.  26   .  FIG.  28   a - e    show the edge profiles in coupled condition of another such embodiment.  FIGS.  26   a - d    illustrate the four profiles, one provided at each of the four panel edges of a rectangular and oblong panel. The first profile  207  is provided at one of the panel edges. The first profile  207  shown in  FIG.  26   a    corresponds to a large extent to the first profile shown in  FIG.  19     a.    
     The second profile  208  shown in  FIG.  26   b    is provided at one of the panel edges. 
     Two—preferably opposite—panel edges (e.g. both short edges) are each provided with a different configuration of a third profile  209   a,    209   b.  The two configurations of the third profile  209   a,    209   b  differ in cross section perpendicular to the panel edge where the profiles are provided. 
     In the example shown in  FIGS.  26  and  27    (which show the edges in coupled condition), in the first configuration of the third profile  209   a  the locking surface of the second tongue  222  is provided by a separate insert  225  inserted in the second tongue. The insert is elastically deformable such that the coupling with locking of the coupled edges in the direction perpendicular to the panel surface can be realized. In the second configuration of the third profile  209   b  an upper surface of the second tongue  222  provides the locking surface  225  of the third profile  209   b.    
       FIG.  28    show—in coupled condition—an alternative for the embodiment shown in  FIGS.  26  and  27   . The profiles (the first profile  207 , the second profile  208 , and both third profiles  209   a,    209   b ) are to a large extent similar to the ones shown is  FIGS.  26  and  27   , major difference being the different type of insert  228  being inserted in the first configuration of the third profile  209   a.  In this example, the locking is obtained via a sliding movement of the locking surface  225  during coupling. To this end, an elastic movement during the coupling of the related panel edges is possible of at least part of the insert  228  in the slot in the second tongue  222  in which the inert  228  is provided. 
     The panels of the sixth aspect of the invention can be installed in laying patterns wherein the panels are coupled to each other under a 90° angle, e.g. as in the herringbone configuration shown in  FIG.  9   . 
       FIGS.  29 ,  30     a - d  and  31   a - f  illustrate in combination an embodiment of the ninth aspect of the invention. 
       FIG.  29    shows a panel  301  according to the ninth aspect of the invention. The panel  301  is rectangular and oblong. The panel  301  comprises a first edge  302 , a second edge  303 , a third edge  304 , and a fourth edge  305 . In the example shown, the first and the fourth edge are provided at the long edges of the panel and the second and the third edge are provide at the short edges of the panel. 
       FIGS.  30   a - d    show an example of the coupling profiles of the panel according to the ninth aspect of the invention shown in  FIG.  29   . The first edge  302  of the panel of  FIG.  29    is provided with a first coupling profile  306  shown in  FIG.  30   a   . The second edge  303  is provided with a second coupling profile  307  shown in  FIG.  30   b   . The third edge  304  is provided with a third coupling profile  308  shown in  FIG.  30   c   . The fourth edge  305  is provided with a fourth coupling profile  309  shown in  FIG.  30     d.    
     Each of the first coupling profile  306 , the second coupling profile  307 , the third coupling profile  308  and the fourth coupling profile  309  extend along the full length of the panel edge where they are provided. 
     Each of the first coupling profile  306 , the second coupling profile  307 , the third coupling profile  308  and the fourth coupling profile  309  have along the length of the panel edge where they are provided a constant cross section perpendicular to the panel edge where they are provided. 
     Each of the first coupling profile  306 , the second coupling profile  307 , the third coupling profile  308  and the fourth coupling  309  profile extend continuously along the edge where they are provided. 
     The first coupling profile  306  comprises a first groove  311  at a first distance D 1  from the panel surface, a second groove  312  at a second distance D 2  from the panel surface and a third groove  313  at a third distance D 3  from the panel surface. The third distance D 3  is smaller than the second distance D 2  and wherein the second distance D 2  is smaller than the first distance D 1 . 
     The second coupling profile  307  comprises a first tongue  333 . The third coupling profile  308  comprises a second tongue  314 , a fourth groove  315  and a fifth groove  316 . The fourth coupling profile  309  comprises a third tongue  317 , a sixth groove  318  and a seventh groove  319 . 
     The first groove  311  is configured for receiving the first tongue  333  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The second groove  312  is configured for receiving the second tongue  314  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The third groove  313  is configured for receiving the third tongue  317  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The fourth groove  315  is configured for receiving the first tongue  333  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The fifth groove  316  is configured for receiving the third tongue  317  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The sixth groove  318  is configured for receiving the first tongue  333  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. The seventh groove  319  is configured for receiving the second tongue  314  of another such panel, wherein a locking is provided in the direction perpendicular to the panel surface. 
     Each of the first edge  302 , the second edge  303 , the third edge  304  and the fourth edge  305  comprises a closing plane  310 . The closing planes  310  are provided substantially perpendicular to the surface of the panel, wherein the closing planes are provided for approaching and preferably for contacting the closing plane of any one of the four edges of another such plane when the panels are in coupled condition. 
     The first coupling profile  306  comprises a bottom lip  320  extending distally to beyond the closing plane  310  of the first edge. The bottom lip  320  is provided with an upper surface  321  wherein the second coupling profile  307 , the third coupling profile  308  and the fourth coupling profile  309  and the upper surface of the bottom lip  321  are configured for establishing a locking—preferably with contact—of the first edge of the panel in the direction perpendicular to the panel surface when the first edge is coupled respectively to the second edge, the third edge or the fourth edge of another such panel. 
     The second coupling profile  307  comprises proximally from the closing plane of the second edge an upper surface  322 . The third coupling profile and the upper surface  322  of the second coupling profile are configured for establishing a locking—preferably with contact—of the second edge of the panel in the direction perpendicular to the panel surface when the second edge is coupled to the third edge of another such panel. 
     The second locking profile  307  comprises a contact surface  323 , substantially parallel with the panel surface. This contact surface  323  is provided proximally from the closing plane of the second locking profile. The second coupling profile  307  and the fourth coupling profile  309  are configured for establishing a locking in the direction perpendicular to the panel surface—preferably with contact—of the panel edge comprising the second coupling profile when coupled to the edge comprising the fourth coupling profile of another such panel by means of the upper surface of the third tongue and the contact surface  323  of the second locking profile. 
     The four coupling profiles  306 ,  307 ,  308 ,  309  are configured such that they can be milled exclusively by milling with milling tools having an axis perpendicular to the panel surface. 
       FIGS.  31   a - f    shows the coupling profiles of  FIGS.  30   a - d    in coupled condition. 
     The first coupling profile  306 , the second coupling profile  307 , the third coupling profile  308  and the fourth coupling profile  309  are configured such that the panel can be coupled at its first edge to anyone one of the first edge, the second edge or the third edge of another such panel; and such that the panel can be coupled at its second edge to anyone of the third edge or the fourth edge of another such panel, and such that the panel can be coupled at its third edge to the fourth edge of another such panel. 
       FIG.  31   a    shows the coupling of the panel edge comprising the first coupling profile  306  to the panel edge comprising the second coupling profile  307 .  FIG.  31   b    shows the coupling of the panel edge comprising the first coupling profile  306  to the panel edge comprising the third coupling profile  308 .  FIG.  31   c    shows the coupling of the panel edge comprising the first coupling profile  306  to a panel edge comprising the fourth coupling profile  309 .  FIG.  31   d    shows the coupling of the panel edge comprising the second coupling profile  307  to a panel edge comprising the third coupling profile  308 .  FIG.  31   e    shows the coupling of the panel edge comprising the third coupling profile  308  to a panel edge comprising the fourth coupling profile  309 .  FIG.  37   f    shows the coupling of the panel edge comprising the second coupling profile  307  to a panel edge comprising the fourth coupling profile  309 . 
     A locking is provided in the direction perpendicular to the surface of the coupled panels in each of the coupled configurations of two such panels. 
     In none of the coupled configurations of two such panels, a mechanical locking is provided in the direction perpendicular to the coupled edges and parallel with the surface of the coupled panels. 
     Thanks to the configuration of the four coupling profiles, the panels according to the ninth aspect of the invention can be installed in laying patterns wherein part of the panels is installed in a 90° angle configuration and wherein part of the panels are installed in linear configuration. Such panels provide a large freedom to select complex installation patterns.