Hard floor panel for floating installation forming a floor panel assembly

Abstract

The present invention relates to a hard floor panel (1) with a core made of a wood-based panel, a wood-based plastic panel, or a plastic panel, having a top (2) and a bottom (3) and side edges (10, 20; 30, 40) with complementary tongue-and-groove profiles along the panel sides for floating installation to form a floor panel assembly, wherein at least two floor panels are joined together, wherein each of the two opposite side edges of the at least two floor panels, relative to the thickness of the floor panel, has an (upper) section A and a (lower) section B, wherein a tongue (11, 31) is provided in section B of the first side edge (10, 30, 50, 70) and a groove (21, 41) is provided in section B of the second opposite side edge (20, 40), wherein a first joining surface (16,36) and in section A of the second opposite side edge (20, 40) a second joining surface (26, 46) is provided, wherein the first joining surface (16, 36) of the first side edge (10, 30) and the second joining surface (26, 46) of the second side edge are each inclined away from the perpendicular to the top of the panel at an angle α, wherein the angle of inclination α is between 1 and 10°, preferably between 2 and 5°, particularly preferably between 2 and 3°.

Description

[0001] The present invention relates to a hard floor panel for floating installation to form a floor panel composite, in particular a laminate floor. Description

[0002] Floor panels with tongue-and-groove profiles on the side edges for installation in panel assemblies, such as laminate flooring, are widely used and conventionally known. The tongue-and-groove profiles enable easy installation of floor panels into floor coverings. Such floor coverings can be made of wood fiberboard or plastic panels, for example. The floor panels are usually provided with a decorative layer and an abrasion-resistant surface layer.

[0003] However, the conventionally used tongue-and-groove profiles have the disadvantage of creating gaps of varying sizes between adjacent panels. Dirt and moisture can penetrate these gaps and cause the floor panel's core board to expand or swell, especially when using wood-based panels as the core board. This expansion or swelling of the wood-based core board causes the surface layer to lift, exposing it to increased abrasion.

[0004] Accordingly, various alternative tongue-and-groove profiles have been developed in the past to reduce the gap size. For example, EP 1026341 B1 discloses a floor panel for creating a floor covering, wherein coupling parts in the form of a tongue and groove are provided on the edges of two opposite sides of the panels. The tongue and groove are designed such that, when two or more floor panels are joined together, a tension force is exerted on them, forcing the floor panels together. The tension force is created by an elastically bendable lip in the groove, which is at least partially bent when joined together and thus provides the aforementioned tension force.

[0005] However, this approach also creates a gap on the top side of the joined panels, particularly at the contact points of the joining surfaces of the two opposite side edges of two joined floor panels, through which moisture and dirt can penetrate between the floor panels.

[0006] Laminate flooring with so-called V-joints has also proven very popular. A V-joint is created when the edges of the wood panels are beveled or chamfered. Bevels are slanted milled cuts on the side edges that create a V-shaped joint when the floor panels are joined together. The purpose of the joint is to enhance the visual impression of individual panels and create a visual separation between the boards. Another problem with the V-joint is that moisture can accumulate in the joint and penetrate the gap between the panels.

[0007] To reduce moisture penetration into V-joints, it is known, for example, from WO 2020 / 200988 A1, to provide the side edges with chamfers of different lengths. When joined together, the chamfers of different lengths overlap, with the longer chamfer partially covered by the shorter chamfer. The shorter chamfer forms an overhang or undercut, which serves as a contact surface with the longer chamfer of the opposite side edge. A wedge-shaped gap can be formed between the joining surfaces of the side edges when joined together, with the tip of the wedge-shaped gap pointing upwards toward the panel surface.

[0008] A disadvantage of the approach described in WO 2020 / 200988 A1 is that the side edges of the panels must be provided with bevels of different lengths, which requires additional production effort and thus results in higher costs. Installation of floor panels designed in this way is also more problematic, as the overhang or undercut of the shorter bevel represents a predetermined breaking point, resulting in more frequent scrap.

[0009] The object of the present invention was therefore to further develop the tongue-and-groove profiles known from the prior art in such a way that, on the one hand, gap formation at the joining surfaces, especially at V-joints, of the floor panels is avoided, thus preventing the penetration of moisture and dirt and the associated disadvantages. On the other hand, production should be possible in existing production lines without additional technical effort.

[0010] This object is achieved with a floor panel having the features of claim 1.

[0011] Accordingly, a hard floor panel with a core made of a wood-based panel, a wood-based plastic panel or a plastic panel with a top and a bottom and with side edges with complementary tongue and groove profiles along the panel sides (i.e. along the long sides and short sides) is provided for floating installation to form a floor panel assembly, wherein in each case at least two floor panels are joined together or connected to one another, wherein in each case two opposite side edges of the at least two floor panels each have an (upper) section A and a (lower) section B based on the thickness of the floor panel, wherein a first joining surface is provided in section A of the first side edge and a second joining surface is provided in section A of the second opposite side edge, wherein a tongue is provided in section B of the first side edge and a groove is provided in section B of the second opposite side edge, wherein the first joining surface of the first side edge and the second joining surface of the second side edge are each inclined concurrently away from the vertical line to the top side of the panel at an angle of inclination α, wherein the angle of inclination α is between 1 and 10°, preferably between 2 and 5°, particularly preferably between 2 and 3°.

[0012] For the purposes of the present invention, joining surfaces are understood to be the pair of surfaces on which the joined panels rest against each other to form a flat, closed upper surface of the connected and locked panels. Accordingly, the technical term "joining surface" encompasses the section of the side edges that are actually pressed together. The joining surfaces lie directly against each other to close the surface. The first joining surface and the second joining surface run parallel to each other, so that when the floor panels are joined together, the joining surfaces rest against each other and are in contact with each other along their entire surface.

[0013] As already indicated, the chamfering of the joining surfaces or joining edges in the sense of the present invention is to be understood as a bevel or inclination of the joining surfaces or joining edges from the top side of the panel away from the perpendicular or vertical (relative to the top side of the panel).

[0014] Typically, the panel top and the respective joining surfaces of the side edges form a right angle (β = 90°). The panel top and joining surfaces are arranged at right angles to each other, i.e., the first and second joining surfaces usually run parallel at a perpendicular angle β to the panel top.

[0015] In the panel according to the invention, however, the first and second joining surfaces are inclined at an angle α from the vertical. Since the inclined joining surfaces are concurrent, i.e., parallel to each other, this means that the first joining surface and second joining surface are inclined in the same direction away from the vertical, so that the angle of inclination α of both joining surfaces is equal.

[0016] Due to the inclination of the joining surfaces, the angle β between the panel top and the respective joining surface is no longer 90°, but greater than 90° for the first joining surface and less than 90° for the second joining surface. Thus, an angle β' between the panel surface and the first joining surface can take values ​​of 90° plus the inclination angle α, and an angle β" between the panel surface and the second joining surface can take values ​​of 90° minus the inclination angle α; angle β' is thus greater than angle β".

[0017] Thus, the β' can be between 91° and 100°, preferably between 92° and 95°, particularly preferably between 92° and 93°. The angle β" can be between 80° and 89°, preferably between 85° and 88°, particularly preferably between 87° and 88°.

[0018] When the inclined joining surface of the first side edge of the tongue profile and the inclined joining surface of the second side edge of the groove profile are aligned, a linear pressure occurs at the contact points of the joining surfaces when at least two floor panels are joined together. This makes it possible to prevent the formation of gaps between adjacent floor panels and thus reduce the ingress of moisture and dirt into the floor covering. The linear pressure results from the profile geometry and the applied pressure. In this case, the term "linear pressure" refers to a linear pressure along the joining surfaces or locking surface, or a pressure that is essentially linear.In this case, the joining surfaces (along the entire or almost the entire surface) press against each other in a practically linear manner.

[0019] Due to the concurrent bevel or inclination of the joining surfaces, the angle between the line pressure of the joining surfaces and the panel top side in the assembled state of the floor panels is 90° minus the inclination angle α (corresponding to the angle β" defined above). Thus, the angle between the line pressure and the panel top side can be between 80° and 89°, preferably between 85° and 88°, particularly preferably between 87° and 88°.

[0020] Furthermore, there are advantages during installation and surface pressure of panels with the inclination angle of 2-10° defined according to the invention compared to flatter angles (i.e. inclination angles of, for example, more than 20° as in CN 107938992). Due to prestressing in the profile connection of floor panels, a certain amount of pressure must be built up during installation to prevent the penetration of liquids. The flatter the angle, the less pressure can be built up. In contrast, the side edge or joining edge according to the invention (at an angle parallel to one another) allows the side edges to be closed under pressure, thus preventing the penetration of water into the gap and the profile.

[0021] In a preferred embodiment of the present panel, the first side edge and second side edge on the panel top side (in section A) each have a chamfer to form a V-joint. A chamfer or bevel (also referred to as edge refraction) is thus provided at the transition between the panel top side and the joining surface.

[0022] The (opposite) chamfers of the first side edge and the second side edge preferably have the same length, so that in the joined state there is no overlap of the chamfers.

[0023] The angles γ', γ" between the bevel (or edge break) and the panel surface are between 20 and 50°, preferably 30 to 40°, i.e. the bevel is angled or broken off by this angle in relation to the panel surface. The angles γ', γ" can be the same or different. In one embodiment, the angle γ' can, for example, be between 20 and 30°, while the angle γ" is between 30 and 40°. However, the angles γ', γ" are preferably the same.

[0024] When the floor panels are joined together, the opposing bevels form a V-joint, with the V-joint having an opening angle of 90 to 130°, preferably 100 to 120°.

[0025] In a preferred embodiment, the floor panels thus form a V-joint when joined together, with the contact point of the opposing bevels representing the tip of the V-shaped joint. From this contact point or tip of the V-joint, the joining surfaces of the opposing side edges run parallel to one another in the line pressure away from the vertical plumb line in the direction of the panel surface with an inclination angle α of between 1 and 10°, preferably between 2 and 5°, particularly preferably between 2 and 3°. The parallel, inclined joining surfaces run over the entire first section A of the opposing side edges up to the second section B of the opposing side edges, i.e. up to the tongue and groove profiling.

[0026] The distance between the base of the bevel on the panel's top side and the tip of the V-joint is between 0.2 and 0.8 mm, preferably between 0.35 and 0.7 mm. The bevel length can be determined trigonometrically.

[0027] The thickness of the panels can be between 4 and 12 mm, preferably between 4 and 10 mm, particularly preferably between 5 and 7 mm, e.g. 5.5 mm or 6.4 mm.

[0028] In one embodiment of the present floor panel, the section A with the first and second joining surfaces has a width or thickness of 1 to 3 mm, preferably 1 to 2 mm, particularly preferably 1 to 1.5 mm, ie the length of the first and second joining surfaces is in a range between 1 to 3 mm, preferably 1 to 2 mm, particularly preferably 1 to 1.5 mm, e.g. 1.2 mm.

[0029] The design of the tongue and groove profiling is described in more detail below.

[0030] The tongue and groove profiles provided in the present floor panel as coupling parts between two panels are preferably formed in one piece.

[0031] In one embodiment, the tongue of the first side edge has an upper side and a lower side; wherein the first joining surface of the first side edge extends from the upper side of the floor panel to the upper tongue side.

[0032] The groove in the second side edge has a top surface and a bottom surface, the top surface of the groove being defined by an upper lip and the bottom surface of the groove being defined by a lower lip; the second joining surface of the second side edge extending from the top surface of the floor panel along the upper lip.

[0033] In a further embodiment of the floor panel, a projection with a contact surface is provided on the lower side of the tongue of the first side edge; and a recess with a contact surface is provided in the lower lip of the groove of the second side edge. When at least two floor panels are joined together, the projection of the tongue engages the recess of the lower lip of the groove, so that the contact surfaces of the projection of the tongue and the recess of the lower lip of the groove exert a clamping force on each other.

[0034] The tongue and groove preferably have shapes that are complementary to each other. The projection on the lower side of the tongue extends along the lower lip of the groove and engages in the recess of the lower lip of the groove when two panels are coupled. The contact surfaces of the projection, the tongue and the recess lie against each other. When the floor panels are joined together, the tongue sits precisely against the upper side and the lower side of the groove, exerting a pressure P on the upper lip of the groove. This pressure is absorbed not only by the upper lip, but by the entire structure, since the pressure can be transmitted through the tongue and the lower lip. The pressure P creates the clamping force that joins and holds the panels together.

[0035] The distance of the top of the spring from the top of the panel and the bottom of the spring from the bottom of the panel can vary depending on the panel thickness.

[0036] The thickness of the tongue is preferably equal to the width of the groove, so that the upper lip of the groove is supported by the tongue, and the tongue is in turn supported by the lower lip of the groove.

[0037] The upper side of the tongue is flat and horizontal relative to the panel's upper surface. The upper side of the groove (or the lower side of the upper lip of the groove) is also flat and horizontal, allowing the tongue and groove to mesh or slide into each other without resistance. The upper side of the tongue and the lower side of the upper lip form contact surfaces that run essentially parallel to the plane defined by the floor panel.

[0038] In a further embodiment of the present floor panel, a recess is provided between the joining surface of the tongue profile and the top side of the tongue.

[0039] The underside of the spring is also intended to have a bevel at its edge. This bevel can also be described as a chamfer with an angle between 45 and 55°.

[0040] As described above, the protrusion on the underside of the tongue extends along the lower lip of the groove. The protrusion engages with the recess of the lower lip of the groove when two panels are coupled. The angle of the contact surfaces of the tongue protrusion and the recess of the lower lip is between 30 and 70° with respect to the horizontal plane. This angle is ideal for achieving optimal compression of the floor panels while allowing for easy engagement and assembly of the floor panels.

[0041] When the tongue and groove are joined or coupled, an additional space can form between the projection of the lower tongue side and the recess in the lower lip of the groove, which can function as a dust chamber, for example. The size of the dust chamber can vary, for example, between the profiles on the long sides of the panel (longitudinal profile) and the transverse sides of the panel (transverse profile).

[0042] It is also intended that the lower lip of the groove extends beyond the upper lip of the groove. In this case, the recess in the lower lip of the groove is located in the portion of the lower lip that extends beyond the upper lip of the groove.

[0043] In one embodiment of the present floor panel, at least one saddle is provided in the recess of the lower lip of the groove. This saddle can be of varying thickness in the transverse and longitudinal profiles.

[0044] The thickness of the upper lip of the groove can be greater than or equal to the thickness of the lower lip. In the case of unequal thicknesses of the upper and lower lips, the center line is positioned below the center line of the panel by the tongue and groove. In this arrangement, the lower lip of the groove is bent when joining two floor panels, preventing the top surface of the floor panel from being subjected to any changes or deformation.

[0045] The upper and lower lips also have rounded edges, which simplifies joining the panels. For example, the joining surface of the upper lip can have a rounded edge or chamfer. The chamfer is provided at the contact point between the upper lip of the groove and the top of the tongue and allows for easy joining of the floor panels.

[0046] In another embodiment, an inclined surface or chamfer (or ramp surface) is also provided at the free end of the lower lip of the groove, which allows the tongue-and-groove profiles to be easily pushed into one another.

[0047] At the transition from the tongue and groove profile to the underside of the panel, a 0.6 mm bevel or chamfer is provided at an angle between 20 and 30°, preferably 25°. The bevel is provided in particular in a counter-beam on the underside of the panel and enables better installation without splintering.

[0048] In further embodiments of the present floor panel, the tongue-and-groove profiles have one of the following properties or a combination thereof: rounded corners (or edges) of the tongue-and-groove profiles; dust chambers between all sides of the interlocked floor panels; in particular, the above-mentioned dust chamber between the recess of the lower lip of the groove and the projection of the tongue;

[0049] The tongue-and-groove profiles allow two floor panels to interlock by applying a rotating or pivoting movement ("angle-angle"). This involves first placing a first floor panel at an angle against a horizontally arranged second floor panel, followed by pivoting the first floor panel toward the installation plane so that the joined floor panels are aligned. To allow the two floor panels to interlock with a rotating movement, the edges or curves are preferably rounded or circular.

[0050] The present floor panel preferably has a rectangular shape, with tongue and groove profiles being provided on the longitudinal side edges and on the transverse side edges.

[0051] The longitudinal profile used to connect the panels along the longitudinal side edges may have the same or a different tongue-and-groove profile than the transverse profile used to connect the panels along the transverse side edges.

[0052] Key differences between the longitudinal and transverse profiles include the formation of a saddle in the recess of the lower lip, which also requires a larger space or chamber between the tongue projection and the groove recess when the floor panels are assembled. In the case of the transverse profile, the lower lip of the groove also has a ramp surface at the end of the groove, which is not provided for in the longitudinal profile.

[0053] The present panels preferably have a core made of a wood-based panel, preferably an HDF or MDF panel, a wood-based plastic panel, preferably a WPC panel, or a plastic carrier panel, preferably a PVC carrier panel or SPC carrier panel. If plastic is used, the core can contain at least one filler in an amount of up to 70% of the total weight of the core of the carrier panel, preferably calcium carbonate or materials with comparable properties. In a preferred embodiment, a panel or board made of a core made of a wood fiberboard or particleboard with an increased adhesive content (12-60%) is used.

[0054] As mentioned above, these floor panels are used for floating installation. The installation procedure includes the following steps: Laying a first floor panel, and attaching a second floor panel to the first floor panel, wherein the tongue of the second floor panel is inserted into the groove of the first floor panel, wherein the lower lip of the groove profiling is bent outwards in the assembled state, so that the lower lip provides a force by which the panels are permanently forced towards each other.

[0055] The prestress caused by the interaction of tongue and groove is optimally transferred to the upper side of the floor panel, whereby in the engagement direction the joining surfaces of the tongue and groove profiles are pressed against each other in such a way that at the contact point of the joining surfaces a linear pressure occurs, forming an angle between the joining surfaces.

[0056] The present invention will be explained in detail below using the following exemplary embodiments with reference to the figures. They show: Figure 1A shows a schematic cross-section of a floor panel with a thickness of 6.4 mm having a tongue profile according to a first embodiment (cross profile); Figure 1B shows a schematic cross-section of a floor panel with a thickness of 6.4 mm having a groove profile according to a first embodiment (cross profile); Figure 1C shows a schematic cross-section of two joined floor panels with the profile shown in Figure 1A spring profiling shown and the one in Figure 1Bshown groove profiling; Figure 2A a schematic cross-section of a floor panel with a thickness of 6.4 mm with a tongue profiling according to a second embodiment (longitudinal profile); Figure 2B a schematic cross-section of a floor panel with a thickness of 6.4 mm with a groove profiling according to a second embodiment (longitudinal profile); Figure 2C a schematic cross-section of 2 joined floor panels with the Figure 2A spring profiling shown and the one in Figure 2B shown groove profiling; Figure 3A a floor panel according to Figure 1A with a bevel; Figure 3Leg floor panel according to Figure 1B with a bevel; Figure 3Ctwo joined floor panels according to Figure 1C with a V-joint; Figure 4A floor panel according to Figure 2A with a bevel; Figure 4Leg floor panel according to Figure 4B with a bevel; Figure 4Ctwo joined floor panels according to Figure 2C with a V-joint.

[0057] The invention is explained for rectangular floor panels that can be connected to each other along their long sides as well as along their short sides or even just along one side.

[0058] So the ones in the Figures 1A , 3A spring profiling shown and the Figure 1B , 3B The groove profiling shown in the first embodiment is provided in the transverse sides of the floor panels, ie in the shorter sides, while the groove profiling shown in the Figures 2A , 4A and 2B , 4B shown profiles according to the second embodiment are inserted into the long sides of the floor panels.

[0059] The side edges shown in the figures each have an (upper) section A and a (lower) section B, based on the thickness of the floor panel. Section A of the side edges includes first joining surfaces 16, 36 and second joining surfaces 26, 46. Section B of the side edges includes tongues 11, 31 and grooves 21, 41.

[0060] The present floor panels have a rectangular shape with side edges 10,20 extending along the long and short sides of the panel and are suitable for floating installation to form a floor panel.

[0061] The floor panels are typically one to two meters long. The thickness of the panels can also vary, but is Figures 1A-C and 2A-C described embodiments 6.4 mm.

[0062] Each floor panel has the tongue-and-groove profiles described in detail below on the opposite edges 10, 20, which allow two adjacent floor panels to be joined together. A tongue 11 is provided in a first side edge 10, and a groove 21 is provided in the second, opposite side edge 20.

[0063] Figure 1A shows a first tongue profile intended for a transverse side of the floor panel. The tongue 11 of the tongue profile of the first side edge 10 has an upper side 12 and a lower side 13.

[0064] The distance of the spring top 12 from the panel top or panel surface 2 and the distance of the spring bottom 13 from the panel bottom 3 can vary depending on the panel thickness.

[0065] The upper side 12 of the tongue 11 has a flat surface 19, which is arranged horizontally with respect to the panel top. The length of the tongue top can be measured in the cross section ( Figure 1A ) and longitudinal profile ( Figure 2A ) must be equal, while the length of the lower spring side in the transverse profile must be greater than the length of the lower spring side in the longitudinal profile.

[0066] The lower side of the spring 11 has a bevel or chamfer 17 on its edge with an angle between 45-55°.

[0067] On the lower side 13 of the spring, a projection 14 is provided with a contact surface 15. The projection 14 has an inclination of between 10° (transverse profile) and 44° (longitudinal profile) with respect to the flat, horizontal section of the underside 13 of the spring.

[0068] The length and height of the projection 14 also vary depending on the design of the spring as a transverse profile or longitudinal profile.

[0069] The spring profile of the Figure 1A has a joining surface 16 on the side edge, which runs from the top side 2 of the floor panel toward the upper tongue side 12 and has a bevel or inclination from the top side of the floor panel toward the upper tongue side. The bevel or inclination of the joining surface 16 runs at an angle α of 3° away from the vertical or perpendicular (relative to the panel top side). The angle β' between the panel top side and the inclined first joining surface 16 is 93°.

[0070] with respect to the perpendicular to the top of the floor panel. Thus, the joining surface 16 has a bevel toward the vertical line.

[0071] A recess 16a is provided at the transition of the joining surface 16 of the spring profile to the upper side 12 of the spring.

[0072] According to the presentation of the Figure 1BThe groove 21 provided in the second side edge 20 of the floor panel 1 has a top side and a bottom side, wherein the top side of the groove 21 is defined by an upper lip 22 and the bottom side of the groove is defined by a lower lip 23. The width of the groove formed by the upper lip 22 and the lower lip 23 corresponds to the thickness of the tongue 11, so that the tongue 11 can be inserted into the groove 21.

[0073] The lower side of the upper lip 23 of the groove with surface 29, like surface 19 of the tongue top side, is flat and horizontally arranged, so that the tongue and groove can interlock or slide into each other without resistance. Surface 19 of the tongue top side and surface 29 of the underside of the upper lip 23 form contact surfaces that run essentially parallel to the plane defined by the floor panel.

[0074] The thickness of the upper lip 22 and the lower lip 23 differ, whereby the upper lip 22 can be thicker than the lower lip 23. Due to a smaller thickness of the lower lip 23, this serves as an elastically bendable projection.

[0075] In the lower lip 23 of the groove, a recess 24 with a contact surface 25 is provided, wherein the recess 24 interacts with the contact surface 25 in a complementary manner to the tongue 11 with the contact surface 15. A saddle 27 is formed in the recess 24. The formation of the saddle 27 in the transverse profile ( Fig. 1B ) and the saddle 47 longitudinal profile ( Fig. 2B ) varies in intensity, which is due to the technical profile geometry and the associated pre-tensioning effect.

[0076] The groove profiling of the Figure 1Bhas a joining surface 26 on the side edge, which runs along the upper lip 22. The joining surface 26 is beveled, like the joining surface 16 of the tongue, whereby the bevel of the joining surface 26 also runs at an angle α of 3° away from the vertical or perpendicular (relative to the panel top). The angle β' between the panel top and the inclined second joining surface 26 is 87°.

[0077] Joining surface 16 and joining surface 26 are therefore inclined at an angle α of 3° away from the vertical or perpendicular (relative to the top of the panel).

[0078] A bevel or chamfer 26a is provided at the transition of the joining surface 26 to the underside of the upper lip 23 with the surface 29.

[0079] At the free end of the lower lip 23 of the groove, a ramp surface 28 is provided, which simplifies the engagement of the short transverse sides. The corresponding ramp surface 48 in the longitudinal profile ( Fig. 2B ), on the other hand, is less pronounced and is intended to be more of a curve. This geometric difference is due to the different behavior of the cross and longitudinal profiles when angling the profiles during installation. The ramp surface 28 allows for easier placement of the cross profiles. It also ensures installation with tapping wood without damaging the profiles.

[0080] When assembled (see Figure 1C ) the projection 14 of the spring 11 engages in the recess 24 of the lower lip 23 of the groove, so that the contact surface 15 of the projection 14 and the contact surface 25 of the recess 24 of the lower lip exert a clamping force or preload on each other.

[0081] When the beveled joining surface 16 of the tongue profile and the beveled joining surface 26 of the groove profile are applied in the assembled state of two floor panels, a linear pressure occurs at the contact of the joining surfaces 16, 26 along the beveled, parallel joining surfaces 16, 26. The joining surfaces 16, 26 are thus pressed together, forming an almost continuous surface.

[0082] Due to the geometric design of the tongue-and-groove profiles, dust chambers are formed between all sides of the interlocking floor panels. Special attention should be paid to the chamber that is visible in the cross-section between the recess 24 of the lower lip 23 of the groove 20 and the projection 14 of the tongue 11 ( Figure 1C ).

[0083] In the longitudinal profile (see Figure 2C), this cavity or dust chamber between the recess 44 and the projection 34 is smaller. This is due to the selected spring mechanism of the groove profiles in the transverse profile and longitudinal profile, whereby the spring deflection in the transverse profile is greater than in the longitudinal profile. In addition, the transverse profile also has a greater profile spacing compared to the longitudinal profile (i.e. lower lip 23 of the transverse profile is longer than the lower lip 43 of the longitudinal profile). This allows the groove cheek of the transverse profile to spring out, which, in combination with the ramp surface 28 and the cavity, enables easier installation in the transverse profile. The slightly varying profile dimensions and geometry of the transverse profile and longitudinal profile is due in particular to the different behavior of the transverse profile and longitudinal profile when the profiles are angled during installation using different lever arms.

[0084] When assembled, the Figure 1CIn the floor panels shown, a gap can also be seen between the lower lip 23 and the lower tongue edge at the transition to the underside of the panel, which occurs particularly when HDF panels are installed.

[0085] The Figures 2A to 2C The second embodiment of the tongue and groove profiling shown is, as already mentioned, provided as a longitudinal profile in the long sides of the floor panel.

[0086] The spring profiling of the Figure 2A essentially corresponds to the spring profiling of the Figure 1A , whereby the length of the lower spring side 13 in the transverse profile differs from the length of the lower spring side 33 in the longitudinal profile. In particular, the length of the lower spring side 13 in the transverse profile is longer than in the longitudinal profile of the Figure 2 A .

[0087] Furthermore, the geometry of projection 14 in the transverse profile differs from the geometry of projection 34 in the longitudinal profile. Thus, projection 14 in the transverse profile is less pronounced than projection 34 in the longitudinal profile, i.e., the height of projection 14 in the transverse profile is smaller than the height of projection 34 in the longitudinal profile. This geometric difference is also due to the different behavior of the transverse profile and the longitudinal profile when angling the profiles during installation, due to different lever arms.

[0088] When assembled (see Figure 2C ), a linear pressure occurs along the beveled joining surfaces 36, 46. The joining surfaces 36, 46 are thus pressed together along the longitudinal edges, forming an almost continuous surface.

[0089] The length of the lower lip 23 of the transverse profile also differs from the length of the lower lip 43 of the longitudinal profile, with the lower lip 23 of the transverse profile being longer than the lower lip 43 of the longitudinal profile.

[0090] The Figures 3A-C and 4A-C The embodiments shown differ from the embodiments of the Figures 1A-C and 2A-C in that the first side edge 10, 30 and second side edge 20, 40 each have a chamfer at the transition from the top of the panel to the joining surface, which results in a V-joint when joined together.

[0091] The angles γ', γ" between the bevel (or edge refraction) and the panel surface are the same in these embodiments and are each between 30 and 40°.

[0092] The opening angle of the V-joint in the joined panels of the Figures 3C and 4Cis between 100-120°. The distance between the apex or tip of the V-joint and the beginning of the bevel on the panel's top side is between 0.35-0.7 mm. The bevel length can be calculated trigonometrically using sin (opening angle / 2). Accordingly, a bevel length of between 0.46-0.91 mm results for an opening angle of 100° and a distance of 0.35 mm, and a bevel length of 0.4-0.8 mm for an opening angle of 120° and a distance of 0.35 mm. NALFA test and ISO 4760

[0093] Test surfaces were prepared according to ISO 4760 from the planks manufactured according to the design variants described in the figures. Reference samples were also provided from planks without any inclination angle.

[0094] The assembled panels were subjected to a NALFA test, which examines water penetration into the profile.

[0095] 100 ml of colored water was poured into the ring adhered to the surface. The water remained on the surface for 24 hours. Afterward, an assessment was performed according to the standard. This included not only determining the amount of residual water in the ring but also determining the swelling of the test specimens in the test area.

[0096] It was found that only 36% of the comparison samples passed the Nalfa test, while the success rate for the samples according to the invention was 90%. Thus, an inclination angle of the joining surfaces leads to a significant improvement in the Nalfa test. List of reference symbols

[0097] 1Floor panel 2Top of the floor panel 3Bottom of the floor panel 10, 30 First side edge of a 4.5 mm thick panel with tongue profile 11, 31 Tongue 12, 32 Top of the tongue 13, 33 Bottom of the tongue 14, 34 Projection 15, 35 Contact surface of the projection 14, 34 16, 36 Beveled joining surface 16a, 36a Recess in joining surface 16, 36 17, 37 Chamfer 19, 39 Contact surface on the top side 12, 32 20, 40 Second side edge with a thickness of 4.5 mm with groove profiling 21, 41 Groove 22, 42 Upper lip 23, 43 Lower lip 24, 44 Recess in the lower lip 23, 43 25, 45 Contact surface of the recess 24, 44 26, 46 Chamfered joining surface 26a, 46a Chamfer 27, 47 Saddle in the recess 24, 44 28, 48 Ramp surface 29, 49 Contact surface on the underside of the upper lip 22, 42 αInclination angle of the first joining surface 16, 36 and the second joining surface 26, 46 away from the vertical β'Angle β' between panel top 2 and the inclined first joining surface 16, 36 β"Angle between panel top 2 and the inclined second joining surface 26, 46

Claims

1. Hard floor panel (1) with a core made of a wood-based panel, a wood-based plastic panel or a plastic panel with a top side (2) and a bottom side (3) and with side edges (10, 20;30, 40) with complementary tongue and groove profiles along the panel sides for floating installation to form a floor panel assembly, wherein at least two floor panels are joined together, wherein two opposite side edges of the at least two floor panels each have an (upper) section A and a (lower) section B based on the thickness of the floor panel, wherein a tongue (11, 31) is provided in section B of the first side edge (10, 30, 50, 70) and a groove (21, 41) is provided in section B of the second opposite side edge (20, 40), wherein a first joining surface (16, 36) is provided in section A of the first side edge and a second joining surface (26, 46) is provided in section A of the second opposite side edge (20, 40), ; characterized in thatthe first joining surface (16, 36) of the first side edge (10, 30) and the second joining surface (26, 46) of the second side edge are each inclined away from the vertical perpendicular to the panel top side at an angle α, wherein the angle of inclination α is between 1 and 10°, preferably between 2 and 5°, particularly preferably between 2 and 3°.

2. Floor panel according to claim 1, characterized in that the first and second side edges in section A on the top side of the panel each have a chamfer to form a V-joint.

3. Floor panel according to claim 2, characterized in that the respective bevel has an angle γ', γ" between bevel (or edge refraction) and panel surface between 20 to 50°, preferably 30 to 40°.

4. Floor panel according to one of the preceding claims, characterized in thatthe section A with the first joining surface (16, 36) and second joining surface (26, 46) has a width or thickness of 1 to 3 mm, preferably 1 to 2 mm, particularly preferably 1 to 1.5 mm.

5. Floor panel according to one of the preceding claims, characterized in that the tongue (11, 31) of the first side edge (10, 30) has an upper side (12, 32) and a lower side (13, 33); wherein the first joining surface (16, 36) of the first side edge (10, 30) extends from the upper side (2) of the floor panel (1) towards the upper tongue side (12, 32).

6. Floor panel according to one of the preceding claims, characterized in thatthe groove (21, 41) in the second side edge (20, 40) has an upper side and a lower side, wherein the upper side of the groove (21, 41) is delimited by an upper lip (22, 42) and the lower side of the groove is delimited by a lower lip (23, 43); wherein the second joining surface (26, 46) of the second side edge (20, 40) extends from the upper side (2) of the floor panel (1) along the upper lip (22, 42).

7. Floor panel according to one of the preceding claims, characterized in thata projection (14, 34, 54, 74) with a contact surface (15, 35, 55, 75) is provided on the lower side (13, 33, 53, 73) of the tongue of the first side edge; and a recess (24, 44, 64, 84) with a contact surface (25, 45, 65, 85) is provided in the lower lip (23, 43, 63, 83) of the groove (21, 41, 61, 81) of the second side edge; wherein, in the assembled state of at least two floor panels, the projection (14, 34) of the tongue (11, 31) engages in the recess (24, 44) of the lower lip (23, 43) of the groove (21, 41), so that the contact surfaces (15, 35; 25, 45) of the projection (14, 34) of the tongue (11, 31) and the recess (24, 44) of the lower lip (23, 43) of the groove (21, 41) exert a clamping force on one another.

8. Floor panel according to claim 7, characterized in thatthe recess (24, 44) in the lower lip (23, 43) of the groove (21, 41) is provided in the section which is located in the part of the lower lip (23, 43) of the groove (21, 41) extending beyond the upper lip (22, 42) of the groove (21, 41).

9. Floor panel according to one of claims 7 or 8, characterized in that at least one saddle (27, 47) is provided in the recess (24, 44) of the lower lip (23, 43) of the groove (21, 41).

10. Floor panel according to one of the preceding claims, characterized in thatthe tongue-and-groove profiles have one of the following properties or a combination thereof: - roundings at the corners (or edges) of the tongue-and-groove profiles; - dust chambers between all sides of the interlocked floor panels; in particular a dust chamber between the recess (24, 44) of the lower lip (23, 43) of the groove (21, 41) and the projection (14, 34) of the tongue (11, 31); - ramp surface (28, 48) at the free end of the lower lip (23, 43) of the groove (21, 41); - contact surfaces (19, 29; 39, 49) formed by the upper side (12, 32) of the tongue (11, 31) and the underside of the upper lip (22, 42), which run essentially parallel to the plane defined by the floor panels (1).

11. Floor panel according to one of the preceding claims characterized by a rectangular shape, with tongue and groove profiles provided on the longitudinal side edges and on the transverse side edges.

12. Floor panel according to claim 11, characterized in that the tongue and groove profiles in the longitudinal side edges and in the transverse side edges are the same or different from each other.

13. Floor panel according to one of the preceding claims, characterized in that the panels consist of a wood fibre or chipboard with an adhesive content of 12 to 60%, a WPC board, a PVC core board or an SPC core board.

14. A method for floating installation of floor panels according to one of the preceding claims to form a floor panel assembly comprising the following steps: - laying a first floor panel, - attaching a second floor panel to the first floor panel, wherein the tongue of the second floor panel is inserted into the groove of the first floor panel, wherein the lower lip of the groove profiling is bent outwards in the assembled state, so that the lower lip provides a force by which the panels are permanently forced towards one another.

15. Floor panel composite producible by a process according to claim 14.

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