EP3705659B1 - Panel with a hook-like locking system - Google Patents

Description

The invention relates to a panel according to the preamble of claim 1. Such panels comprise a panel upper side and a panel lower side as well as at least four panel edges, which are opposite one another in pairs, with complementary retaining profiles provided in pairs on the panel edges, which fit one another in such a way that panels of the same type can be fastened to one another, wherein at least one of the retaining profile pairs is provided with hook profiles, namely on one panel edge with a receiving hook and on the opposite panel edge with a locking hook. Such panels are made of DE 102011 086846 A known. Further similar panels are in DE 102011 121348 A , WO 2012/001503 A , and WO 03/016654 A disclosed.

Such panels are used to produce floor coverings, for example; such panels are particularly suitable for floating floor coverings. The panels usually have decorative surfaces.

The panel to be proposed should be suitable for locking using the "fold-down method". For this method, a type of panel is used in which one of the retaining profile pairs is provided with a modified tongue and groove profile, while the other retaining profile pair is provided with the hook profiles according to the invention. For the fold-down method, a new panel is angled and preferably brought with its tongue profile edge to the groove profile edge of a horizontal panel or a row of panels. The new panel is then swiveled down into the plane of the mounted panels, thereby locking the tongue profile with the groove profile in a form-fitting manner. During the above-mentioned pivoting movement, a form-fitting locking of the hook profiles is generated at the same time, because one of the hook profiles moves like scissors towards the other hook profile and hooks it with a form fit. A locking takes place.

The proposed hook profiles are also suitable for push-down locking. For a push-down locking, all retaining profile pairs of a panel must be able to be connected by a vertical movement, i.e. for example by a lowering movement of a panel, namely in a direction perpendicular to the top of the panel (vertical). The fold-down method cannot then be used.

In practice it happens that a panel cannot be locked at the end of a row of panels because a wall is in the way and the panel is too long. So that the gap in the floor can be closed, it is common to cut through a panel, e.g. with a saw, in order to shorten it to the required length. A new row of panels can usually be started with the cut off remainder of the panel. In principle, the complementary retaining profiles of a severed panel always fit into one another. In principle, therefore, complementary retaining profile edges of a severed panel can be locked together.

the WO 01/02670 suggests different pairs of hook profiles. The hook profiles are intended to prevent the panels from being pulled apart horizontally, ie in the plane of the panel and perpendicular to the locked panel edges. It turns out, however, with a load in the mentioned horizontal direction that the strength of the hook profiles is unsatisfactory.

Further panels with pairs of hook profiles are from the WO 2010/143962 A1 known. The various exemplary embodiments of this prior art suffer from the fact that the pairs of hook profiles can burst when they are pulled apart in the plane of the panel and perpendicular to the locked panel edges. This happens especially when the panels are made of artificial Made of wood-based material, which consist of wood particles or fibers that are bound with a binder to form a plate material.

Therefore, the applicant is looking for a panel with an improved pair of hook profiles.

The invention proposes a panel according to claim 1 for this purpose.

According to the invention, at least a portion of the top of the receiving edge runs downwardly inclined in the direction of the outside of the receiving edge, with at least a portion of the groove bottom of the locking groove being adapted in a complementary manner to the inclination of the top of the receiving edge, and with a gap between the outside of the receiving edge and in the locked state Groove flank of the locking groove is provided.

In the context of the invention, the normal vector is directed vertically outward from the corresponding locking surface (not directed into the panel material). The normal vector forms an angle with the respective panel side that it intersects, which is the same size as the angle by which the locking surfaces are inclined relative to the perpendicular on the top of the panel (alternating angle).

The inclination of the locking surfaces with respect to the perpendicular on the top of the panel can be in an angular range α of 4 ° to 50 °. The angle α is preferably in a range from 5 ° to 30 ° and particularly preferably in a range from 5 ° to 15 °.

The panel is preferably made of a wood material, such as HDF, MDF or OSB, which in a broader sense also includes WPC materials (wood plastic composite). Since the locking mechanism requires a certain elasticity, in particular in the area of the first and corresponding second latching means, the materials mentioned are suitable because of their certain elasticity. Alternatively, the panel material can also be a plastic, for example in the case of LVT (luxury vinyl tiles) products, because this plastic also has a certain elasticity.

If the body of the panel consists at least partially of a plastic, then a configuration can consist of a body made of a plastic or a wood-plastic composite material (WPC). The carrier plate respectively the fuselage is formed, for example, from a thermoplastic, elastomeric or thermosetting plastic. Furthermore, recycling materials made from the materials mentioned can be used within the scope of the invention. Plate material is preferably used, in particular made of thermoplastic material such as polyvinyl chloride, polyolefins (e.g. polyethylene (PE), polypropylene (PP), polyamides (PA), polyurethanes (PU), polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) , Polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyetheretherketone (PEEK) or mixtures or co-polymers. Independent of the base material of the carrier plate, for example, plasticizers can be provided, which are approximately in a range of ≥0 wt. -% to 20% by weight, in particular 10% by weight, preferably 7% by weight, for example in a range from 5% by weight to 10% by weight includes, for example, the plasticizer sold by the company BASF under the trade name “Dinsch.” Furthermore, copolymers such as acrylates or methacrylates can be provided as a substitute for conventional plasticizers.

Thermoplastics in particular also offer the advantage that the products made from them can be recycled very easily. Recycled materials from other sources can also be used. This results in a further possibility for reducing the manufacturing costs.

Such carrier plates are very elastic or resilient, which allows a comfortable impression when walking and can also reduce the noises occurring when walking in comparison to conventional materials, thus improving footfall sound insulation can be realized.

In addition, the aforementioned carrier plates offer the advantage of good water resistance, since they have a swelling of 1% or less. In addition to pure plastic carriers, this surprisingly also applies to WPC materials, as these are explained in detail below.

In a particularly advantageous manner, the material of the carrier plate can comprise or consist of wood-polymer materials (wood plastic composite, WPC). Here, for example, a wood and a polymer can be suitable, which can be present in a ratio of 40/60 to 70/30, for example 50/50. Polypropylene, polyethylene or a copolymer of the two aforementioned materials can be used as polymeric constituents. Such materials offer the advantage that they can be formed into a carrier plate even at low temperatures, such as in a range of ≥180 ° C to ≤200 ° C in the above-described method, so that a particularly effective process control, for example with exemplary line speeds in a range of 6m / min. For example, for a WPC product with a 50/50 distribution of wood and polymer components with an exemplary product thickness of 4.1 mm, this can enable a particularly effective manufacturing process.

Furthermore, very stable panels can be produced in this way, which furthermore have a high elasticity, which can be advantageous in particular for an effective and inexpensive design of connecting elements on the edge region of the carrier plate and also with regard to footfall sound insulation. Furthermore, the aforementioned good water compatibility with a swelling of less than 1% can also be made possible with WPC materials of this type. WPC materials can have stabilizers and / or other additives, for example, which can preferably be present in the plastic component.

Furthermore, it can be particularly advantageous that the carrier plate comprises or consists of a PVC-based material. Such materials can also be used in a particularly advantageous manner for high-quality panels, which can also be used without problems in damp rooms, for example. Furthermore, PVC-based materials are also suitable for the carrier plate for a particularly effective manufacturing process, since here, for example, line speeds of 8 m / min with an exemplary product thickness of 4.1 mm can be possible, which can enable a particularly effective manufacturing process. Furthermore, such carrier plates also have advantageous elasticity and water compatibility, which can lead to the aforementioned advantages.

In the case of plastic-based panels as well as WPC-based panels, mineral fillers can be advantageous. Talc or calcium carbonate (chalk), aluminum oxide, silica gel, quartz flour, wood flour, plaster of paris are particularly suitable here. For example, chalk can be provided in a range from 30% by weight to 70% by weight, the slip of the carrier plate in particular being able to be improved by the fillers, in particular by the chalk. They can also be colored in a known manner. In particular, it can be provided that the material of the carrier plates has a flame retardant.

According to a particularly preferred embodiment, the material of the carrier plate consists of a mixture of a PE / PP block copolymer with wood. The proportion of PE / PP block copolymer and the proportion of wood can be between 45% by weight and 55% by weight. Furthermore, the material of the carrier plate can contain between 0% by weight and 10% by weight of further additives, such as flow aids, thermal stabilizers or UV stabilizers. The particle size of the wood is between> 0 µm and ≤600 µm with a preferred particle size distribution D50 of ≥400 µm. In particular, the material of the carrier plate can comprise wood with a particle size distribution D10 of 400 μm. The particle size distribution is related to the volumetric diameter and relates to the volume of the particles. The material of the carrier plate is particularly preferably provided as a granulated or pelletized, pre-extruded mixture of a PE / PP block copolymer with wood particles of the specified particle size distribution. The granulate and / or the pellets can preferably have a grain size in a range from 400 μm to 10 mm, preferably 600 μm to 10 mm, in particular 800 μm to 10 mm.

According to a further preferred embodiment, the carrier plate consists of a mixture of a PE / PP polymer blend with wood. The proportion of the PE / PP polymer blend and the proportion of wood can be between 45% by weight and 55% by weight. Furthermore, the material of the carrier plate can contain between 0% by weight and 10% by weight of further additives, such as flow aids, thermal stabilizers or UV stabilizers. The particle size of the wood is between> 0 µm and ≤600 µm with a preferred particle size distribution D50 of ≥400 µm. In particular, the carrier board can have wood with a particle size distribution D10 of 400 μm. The particle size distribution is related to the volumetric diameter and relates to the volume of the particles. The material of the carrier plate is particularly preferably provided as a granulated or pelletized, pre-extruded mixture of a PE / PP polymer blend with wood particles of the specified particle size distribution. The granulate and / or the pellets can preferably have a grain size in a range from 400 μm to 10 mm, preferably 600 μm to 10 mm, in particular 800 μm to 10 mm.

In a further embodiment, the material of the carrier plate consists of a mixture of a PP homopolymer with wood. The proportion of PP homopolymer and the proportion of wood can be between 45% by weight and 55% by weight. Furthermore, the material of the carrier plate can contain between 0% by weight and 10% by weight of further additives, such as flow aids, thermal stabilizers or UV stabilizers. The particle size of the wood is between> 0 µm and ≤600 µm with a preferred particle size distribution D50 of ≥400 µm. In particular, the carrier board can have wood with a particle size distribution D10 of 400 μm. The particle size distribution is related to the volumetric diameter and relates to the volume of the particles. The material of the carrier plate is particularly preferably provided as a granulated or pelletized, pre-extruded mixture of a PP homopolymer with wood particles of the specified particle size distribution. The granulate and / or the pellets can preferably have a grain size in a range from 400 μm to 10 mm, preferably 600 μm to 10 mm, in particular 800 μm to 10 mm. In a further embodiment of the invention, the material of the carrier plate consists of a mixture of a PVC polymer with chalk. The proportion of PVC polymer and the proportion of chalk can be between 45% by weight and 55% by weight. Furthermore, the material of the carrier plate can contain between 0% by weight and 10% by weight of further additives, such as flow aids, thermal stabilizers or UV stabilizers. The particle size of the chalk is between> 0 µm and ≤600 µm with a preferred particle size distribution D50 of ≥400 µm. In particular, the material of the carrier plate can include chalk with a particle size distribution D10 of 400 μm. The particle size distribution is related to the volumetric diameter and relates to the volume of the particles. The material of the carrier plate is particularly preferred as granulated or Pelletized, pre-extruded mixture of a PVC polymer with chalk of the specified particle size distribution provided. The granulate and / or the pellets can preferably have a grain size in a range from 400 μm to 10 mm, preferably 600 μm to 10 mm, in particular 800 μm to 10 mm.

In a further embodiment, the material of the carrier plate consists of a mixture of a PVC polymer with wood. The proportion of PVC polymer and the proportion of wood can be between 45% by weight and 55% by weight. Furthermore, the material of the carrier plate can contain between 0% by weight and 10% by weight of further additives, such as flow aids, thermal stabilizers or UV stabilizers. The particle size of the wood is between> 0 µm and ≤600 µm with a preferred particle size distribution D50 of ≥400 µm. In particular, the material of the carrier plate can have wood with a particle size distribution D10 of 400 μm. The particle size distribution is related to the volumetric diameter and relates to the volume of the particles. The material of the carrier plate is particularly preferably provided as a granulated or pelletized, pre-extruded mixture of a PVC polymer with wood particles of the specified particle size distribution. The granulate and / or the pellets can preferably have a grain size in a range from 400 μm to 10 mm, preferably 600 μm to 10 mm, in particular 800 μm to 10 mm.

To determine the particle size distribution, the generally known methods, such as laser diffractometry, can be used. With this method, particle sizes in the range from a few nanometers up to several millimeters can be determined. It can also be used to determine D50 or D10 values which are 50% or 10% of the measured particles smaller than the specified one Value.

According to a further embodiment, the material of the carrier plate has a matrix material comprising a plastic and a solid material, the solid material being at least 50% by weight, in particular at least 80% by weight, particularly preferably at least 95% by weight on the solid material, formed by talc. The matrix material is present in an amount, based on the material of the carrier, of 30% by weight to 70% by weight, in particular from 40% by weight to 60% by weight, and is that Solid material, based on the material of the carrier, in an amount, based on the material of the carrier plate, from 30% by weight to 70% by weight, in particular from 40% by weight to 60% by weight , for example less than or equal to 50% by weight. Furthermore, it is provided that the material of the carrier plate and the solid material are present together, based on the material of the carrier plate, in an amount of 95% by weight, in particular 99% by weight. In such an embodiment of the invention, at least 50% by weight, in particular at least 80% by weight, for example 100%, based on the solid material, of the solid material can be formed by talc. In this context, talc is understood in a manner known per se to be a magnesium silicate hydrate which, for example, can have the chemical empirical formula Mg3 [Si4O10 (OH) 2]. Thus, the solid content is advantageously formed at least by a large part of the mineral substance talc, which substance can be used in powder form or can be present in the material of the carrier plate in the form of particles. In principle, the solid material can consist of a powdery solid. It can be advantageous if the specific surface density according to BET, ISO 4652 of the talc particles is in a range from 4 m 2 / g to 8 m 2 / g, roughly in a range from ≥ 5 m2 / g to ≤ 7 m2 / g.

Furthermore, it can be advantageous if the talc is present at a bulk density according to DIN 53468 in a range from 0.15 g / cm3 to 0.45 g / cm3, for example in a range from 0.25 g / cm3 to 0.35 g / cm3.

The matrix material in such a configuration serves in particular to receive or embed the solid material in the finished carrier. The matrix material has a plastic or a plastic mixture. In particular with regard to the production method, as is described in detail below, it can be advantageous that the matrix material comprises a thermoplastic material. This enables the material of the carrier plate or a component of the material of the carrier plate to have a melting point or a softening point in order to shape the material of the carrier plate in a further process step by the action of heat, as is described in detail below with reference to the process . The matrix material can in particular consist of a plastic or a plastic mixture and optionally an adhesion promoter. These components can preferably make up at least 90% by weight, particularly preferably at least 95% by weight, in particular at least 99% by weight of the matrix material.

Furthermore, it can be provided that the matrix material, based on the material of the carrier plate, is from 30% by weight to 70% by weight, in particular from 40% by weight to 60% by weight is present. Furthermore, it is provided that the solid material, based on the material of the carrier plate, in an amount, based on the material of the carrier plate, of 30% by weight to 70% by weight, in particular of 40% by weight up to 60% by weight.

Polypropylene is particularly suitable as a matrix material because, on the one hand, it can be obtained inexpensively and, as a thermoplastic synthetic material, also has good properties as a matrix material for embedding the solid material. In particular, a mixture of a homopolymer and a copolymer can enable particularly advantageous properties for the matrix material. Such materials also offer the advantage that they can be shaped into a carrier even at low temperatures, such as in a range from 180 ° C. to 200 ° C. in the method described above, so that a particularly effective process management, for example with exemplary Line speeds in a range of 6m / min, can be made possible.

Furthermore, it can be advantageous if the homopolymer has a tensile strength according to ISO 527-2 which is in a range from 30 MPa to 45 MPa, for example in a range from 35 MPa to 40 MPa, in order to achieve good stability reach.

Furthermore, it can be particularly advantageous for good stability if the homopolymer has a flexural modulus according to ISO 178 in a range from 1000 MPa to 2200 MPa, for example in a range from 1300 MPa to 1900 MPa, for example in one range from ≥ 1500 MPa to ≤ 1700 MPa.

With regard to the tensile deformation of the homopolymer according to ISO 527-2, it can also be advantageous if this is in a range from 5% to 13%, for example in a range from 8% MPa to 10%.

For a particularly advantageous producibility it can be provided that the Vicat softening temperature according to ISO 306 / A for an injection molded component is in a range from 130 ° C MPa to 170 ° C, for example in a range of 145 ° C up to ≤ 158 ° C.

It can furthermore be advantageous for the solid material to have at least one further solid in addition to talc. This configuration can in particular enable the weight of the material of the carrier plate or of a panel formed with the material of the carrier plate to be significantly reduced compared to a material of the carrier plate or panel in which the solid material consists of talc. Thus, the solid added to the solid material can in particular have a density that is reduced compared to talc. For example, the added substance can have a bulk density which is in a range of 2000 kg / m3, in particular 1500 kg / m3, for example 1000 kg / m3, particularly preferably 500 kg / m3. Depending on the added solid, further adaptability to the desired, in particular mechanical, properties can be made possible.

For example, the further solid can be selected from the group consisting of wood, for example in the form of wood flour, expanded clay, volcanic ash, pumice, aerated concrete, in particular inorganic foams, cellulose. With regard to aerated concrete, this can be, for example, the solid material used by the Xella company under the brand name YTONG, which essentially consists of quartz sand, lime and cement, or the aerated concrete can have the aforementioned components. With regard to the added solid, it can be composed, for example, of particles which have the same particle size or particle size distribution as the particle sizes or particle size distributions described above for talc. The further solids can in particular be present in the solid material in a proportion which is in a range of <50% by weight, in particular <20% by weight, for example <10% by weight, further for example <5% by weight, lies.

Alternatively, it can be provided, for example for wood, in particular for wood flour, that its particle size is between> 0 μm and 600 μm with a preferred particle size distribution D50 of 400 μm.

According to a further embodiment, the material of the carrier plate can have hollow microspheres. Such additives can in particular have the effect that the density of the carrier plate and thus of the panel produced can be significantly reduced, so that particularly simple and inexpensive transport and, furthermore, particularly convenient laying can be ensured. In particular, by inserting hollow microspheres, a stability of the panel produced can be ensured, which is not significantly reduced in comparison to a material without hollow microspheres. Thus, the stability is completely sufficient for a large part of the applications. In this context, hollow microspheres can in particular be understood to mean structures which have a hollow base body and a size or a maximum diameter which is in the micrometer range. For example, hollow spheres that can be used can have a diameter which is in the range from 5 μm to 100 μm, for example 20 μm to 50 μm. In principle, any material, such as glass or ceramic, can be used as the material for the hollow microspheres. Furthermore, due to their weight, plastics, such as those also used in the material of the carrier plate, for example PVC, PE or PP, can be advantageous, whereby these can be prevented from deforming during the manufacturing process, for example by suitable additives.

The hardness of the material of the carrier plate can have values in a range of 30-90 N / mm ² (measured according to Brinell). The modulus of elasticity can be in a range from 3,000 to 7,000 N / mm ² .

The section of the bottom of the locking groove and the section of the top of the receiving edge can be aligned parallel to one another in the locked state.

The receiving groove of one hook profile is such that the locking edge of the complementary hook profile fits into the receiving groove and the locking groove of the complementary hook profile is such that the receiving edge of one hook profile fits into the locking groove.

A further development provides that the first latching means of the lower latching has a latching projection, and that the second latching means of the lower latching has a matching latching recess.

Alternatively, the first latching means of the lower latching mechanism can have a latching recess and the second latching means of the lower latching mechanism can have a latching projection that matches this. It can also be useful if an upper latching is provided which has a first latching means on an outside of the locking edge, and a corresponding second latching means is provided on a set back groove flank of the receiving groove.

The first latching means of the upper latching arrangement expediently has a latching projection and the second latching means of the upper latching arrangement has a latching recess that matches this.

Alternatively, the first latching means of the upper latching mechanism can have a latching recess and the second latching means of the upper latching mechanism can have a latching projection that matches this.

Another benefit results from the at least one free space between the underside of the locking edge and the groove base of the receiving groove.

The free space can hold dirt particles or other loose particles. In the case of panels made of wood-based materials, for example, particles can settle from the edge of the panel peel off, which should not get stuck between the joining surfaces of the hook profiles. Otherwise, you could prevent the hook profiles from locking in the correct position.

In addition, in the locked state, a gap is provided between the outside of the receiving edge and the groove flank of the locking groove.

In the locked state, an underside of the locking edge advantageously touches the groove base of the receiving groove, at least in some areas. If a load presses on the upper side of the panel in the area of the locking edge, the locking edge can bear this load because its underside is supported on the groove bottom of the receiving groove of the receiving hook.

The receiving edge expediently has a transition to the inside of the receiving groove, the transition being provided with a curvature. The curvature provides edge protection. It can also serve to guide the locking edge when it comes into contact with the curvature. So the locking edge is moved down along the curvature into the receiving groove.

Fig. 1

fold-down-Methode rechtsgängig

Fig. 2

fold-down-Methode linksgängig

Fig. 3

ein erstes Ausführungsbeispiel eines nicht erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen gegenüberliegende Hakenprofile im noch nicht verriegelten Zustand darzustellen,

Fig. 4

die Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

Fig. 4a

ein vergrößertes Detail gemäß Ausschnitt IVa in Fig. 4

Fig. 4b

eine Alternative für Fig. 4a

Fig. 5

ein nicht erfindungsgemäßes Ausführungsbeispiel für Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

Fig. 5a

ein vergrößertes Detail gemäß Ausschnitt Va in Fig. 5

Fig. 5b

eine alternative für Fig. 5a

Fig. 6

ein nicht erfindungsgemäßes Ausführungsbeispiel für Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

Fig. 7

ein nicht erfindungsgemäßes Ausführungsbeispiel für Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

Fig. 8

ein erfindungsgemäßes Ausführungsbeispiel für Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

Fig. 8a

ein vergrößertes Detail gemäß Ausschnitt VIIIa in Fig. 8

Fig. 8b

eine alternative für Fig. 8a

Fig. 9

ein weiteres erfindungsgemäßes Ausführungsbeispiel für Hakenprofile des Paneels gemäß Fig. 3 im verriegelten Zustand,

In the following, the concepts on which the invention is based are illustrated by way of example in a drawing and described in detail using several exemplary embodiments. Show it:

Fig. 1

right-hand fold-down method

Fig. 2

left-handed fold-down method

Fig. 3

a first embodiment of a panel not according to the invention, wherein the panel is shown divided in order to show its opposite hook profiles in the not yet locked state,

Fig. 4

the hook profiles of the panel according to Fig. 3 in the locked state,

Figure 4a

an enlarged detail according to section IVa in Fig. 4

Figure 4b

an alternative for Figure 4a

Fig. 5

an embodiment not according to the invention for hook profiles of the panel according to FIG Fig. 3 in the locked state,

Figure 5a

an enlarged detail according to section Va in Fig. 5

Figure 5b

an alternative for Figure 5a

Fig. 6

an embodiment not according to the invention for hook profiles of the panel according to FIG Fig. 3 in the locked state,

Fig. 7

an embodiment not according to the invention for hook profiles of the panel according to FIG Fig. 3 in the locked state,

Fig. 8

an inventive embodiment for hook profiles of the panel according to Fig. 3 in the locked state,

Figure 8a

an enlarged detail according to section VIIIa in Fig. 8

Figure 8b

an alternative for Figure 8a

Fig. 9

according to another embodiment of the invention for hook profiles of the panel Fig. 3 in the locked state,

Fig. 1 shows a perspective fold-down method for locking panels according to the prior art. A new panel 1 is angled at an angle with a tongue profile edge 2 in front of a groove profile edge 3 of a horizontal panel 4 of a previous row of panels. The new panel 1 is then pivoted down into the plane of the mounted panels, with an identical panel 5 already lying in the same row of panels. Due to the pivoting joining movement, the tongue and groove profile edges lock together. The new panel 1 also has a pair of hook profiles, namely a receiving hook (not shown) and a locking hook 6. During the downward pivoting joining movement, the locking hook 6 of the new panel 1 is moved like scissors in the direction of the complementary receiving hook 7 of the identical panel 5. The locking hook 6 hooks with the receiving hook 7 and, at the same time as the tongue and groove profile edge is locked, the hook profiles are locked in a form-fitting manner.

According to Fig. 1 the structure of a floor area is indicated. In this example, a new panel is always created continuously to the left.

Fig. 2 shows a second example of a fold-down method known in the prior art for locking panels. It differs from the method of Fig. 1 only in that a new panel has to be placed continuously to the right, ie the panel edges that have the receiving hook or the locking hook are opposite to the example of Fig. 1 been swapped.

Tongue and groove profiles that are suitable for positive locking by means of the fold-down method are well known in the prior art, for example from US Pat WO 97/47834 A1 or off WO 00/63510 .

Fig. 3 shows a first embodiment of a panel 1 not according to the invention with a panel top side 1a and a panel bottom side 1b, with only a pair of retaining profiles of the panel being shown in simplified form. The pair of retaining profiles shown here has complementary hook profiles, namely a locking hook 6 (above) and a receiving hook 7 (below). In order to explain the mode of operation, the panel 1 can be imagined as being cut into two parts, so that the two hook profiles (6 and 7) of the panel can be hooked together. Hook profiles of identical panels are of course locked in the same way.

The receiving hook 6 has a receiving edge 8 facing the panel top 1a and a receiving groove 9 open to the panel top. The locking hook 7 is provided with a locking edge 10 facing the panel bottom 1b and with a locking groove 11 open to the panel bottom 1b.

An inner side of the receiving edge 8 faces the receiving groove 9 and this inner side serves as a lower locking surface 12. Matching this, the locking hook 7 forms an upper locking surface 13 on an inner side of its locking edge 10 facing the locking groove 11, which interacts with the lower locking surface 12 of the receiving edge 8 .

Both the lower locking surface 12 and the upper locking surface 13 are inclined by an angle α with respect to the perpendicular L on the upper side of the panel. The inclinations are matched to one another so that the corresponding locking surfaces 12 and 13 are aligned parallel to one another in the locked state and can touch one another.

In addition, the inclination of the lower locking surface 12 is selected such that the normal vector N ₁₂ , which is directed perpendicularly outward from the lower locking surface 12, intersects the panel top side 1a. Correspondingly conversely, the normal vector N ₁₃ on the upper locking surface 13 is directed vertically outwards, so that this normal vector N ₁₃ intersects the opposite panel underside 1b. In general, it is true that the panel top side 1a and the normal vector N ₁₂ enclose an angle which is just as large as the above-mentioned angle α (alternating angle). The same applies to the underside of the panel, which forms an equally large angle (alternating angle) _{with the normal vector N 13.}

The locking hook is seated with an underside 10a of the locking edge 10 7 firmly on a groove base 9a of the receiving groove 9 of the receiving hook 6. If a load presses on the panel top 1a in the area of the locking edge 10, the locking edge 10 can bear this load because its underside 10a is supported on the groove bottom 9a of the receiving groove 9.

Another function of the hook profiles is to counteract a height offset of the locked panel edges. A lower catch 14 is provided for this purpose. This comprises a first latching means in the form of a protruding latching projection 15 on the receiving hook 7. The latching projection 15 is arranged on an outer side 8 a of the receiving edge 8. Corresponding to this, a second latching means in the form of a latching recess 16 is provided on the locking hook 7. The latching recess 16 is arranged on a groove flank 11 a of the locking groove 11 that is set back.

On the receiving hook 6, a section 8b of the upper side of the receiving edge 8 has a downward slope, namely falling in the direction of the outside 8a of the receiving edge. To this end, a section 11b of the bottom of the locking groove 11 on the locking hook 7 is matched in a complementary manner to the inclination of the section 8b of the upper side of the receiving edge 8. In the locked state, the inclined sections 8b and 11b of the upper side of the receiving edge and the bottom of the locking groove are aligned parallel to one another.

In addition, a transition from the upper side 8b of the receiving edge 8 to the lower locking surface 12 is provided on the receiving hook 6. The transition is designed as a curvature 17. The curvature 17 is a radius in the present example. A transition with a curvature 18 between the section 11b of the groove base of the locking groove 11 and the upper locking surface 13 is also provided on the locking hook 7. The curvature 17 on the receiving edge offers edge protection and a guide surface. The edge protection is stronger than the protective effect one phase which is the same Has width and height, as the curvature 17. The curvature 18 forms a groove. In the present example, it has a radius and is used for stability in the transition area from the upper locking surface 13 to the groove base of the locking groove 11.

According to Fig. 4 the hook profiles are off Fig. 3 shown in the locked state. The latching projection 15 of the receiving hook 6, which is arranged on the outside 8a of the receiving edge 8, engages positively in the latching recess 16, which is arranged on the set back groove flank 11a of the locking groove 11. The lower latching 14 counteracts a height offset of the two panel tops 1a, that is, a movement of the panel edges perpendicular to the panel surface is counteracted. A closed joint F is also formed in the horizontal direction on the panel surface 1a. At this joint, an outer side 10b of the locking edge 10 is in contact with a set-back groove flank 9b of the receiving groove 9.

A gap 19 is present between the inclined section 11b of the bottom of the locking groove and the inclined section 8b of the top of the receiving edge 8. This favors avoiding a height offset at the joint F of the panel top 1a. In addition, the gap 19 grants a certain resilience of the locking hook 7. It has a point with its smallest thickness, which is located where the locking groove 11 is deepest. The flexibility obtained in this way can be used because the gap 19 creates space into which a deformation can take place.

Figure 4a shows a detail that enlarges a section that is shown in Fig. 4 is noted with IVa. In Figure 4a the locking projection 15 is provided on the receiving hook 6, namely on the outside 8a of the receiving edge 8. The locking recess is provided on the locking hook 7 and is set back there on one Groove flank 11a of locking groove 11.

In the case of an alternative, which is shown in the section according to Figure 4b is shown, the positions of the locking recess and locking projection are interchanged. Here a locking recess 15a is arranged on the receiving hook 6, namely on the outside 8a of the receiving edge 8. A locking projection 16a is then provided on the locking hook 7, namely the locking groove 11 is provided on its set-back groove flank 11a.

Another embodiment not according to the invention for a panel with special hook profiles suggests Fig. 5 before. This is based on the embodiment of FIG Figures 3 and 4 the end. It differs from this by an additional upper latching 20. The upper latching 20 has a first latching means in the form of a latching projection 21 on the locking hook 7, which is arranged on the outside 10b of the locking edge 10. It works together with a corresponding second latching means on the receiving hook 6, which is provided on the set back groove flank 9b of the receiving groove 9. The second latching means forms a latching recess 22, as best shown in the cutout according to FIG Figure 5a can be seen. Figure 5a enlarges the detail shown in Fig. 5 is denoted by Va. In the case of an alternative that is shown in the section according to Figure 5b is shown, the positions of the locking recess and locking projection are interchanged. Here, a latching recess 21a is arranged on the locking hook, namely on the outside of the locking edge 10. A latching projection 22a is provided on the receiving hook, specifically on the set-back groove flank 9b of the receiving groove 9.

The embodiment not according to the invention of Fig. 6 shows hook profiles based on the Figures 3 and 4 have a change, namely in the shown locked state of the hook profiles a free space 23 is formed, which is between the groove base 9a of the receiving groove 9 of the receiving hook 6 and a Underside 10a of the locking edge 10 of the locking hook 7 extends. The free space 23 extends as far as the outside 10b of the locking edge 10 or as far as the set-back groove flank 9b of the receiving groove 9. The free space 23 can accommodate dirt particles or other loose particles. In the case of panels made of wood-based materials, for example, particles can detach from the panel edge. Detached items should not get between the joining surfaces of the hook profiles and get stuck there, because otherwise they would prevent the hook profiles from being locked in the correct position. Between the bottom 10a of the locking edge 10 and the groove bottom 9a of the receiving groove 9 is the in Fig. 6 proposed free space 23 formed in a gap shape. The gap-shaped free space 23 continues towards the groove base 9a and in this way creates the desired space for receiving undesired particles.

The embodiment not according to the invention of Fig. 7 shows hook profiles, which are also based on the Figures 3 and 4 have a change in such a way that, in the locked state of the hook profiles, a free space 24 is formed which extends between the groove base 9a of the receiving groove 9 of the receiving hook 6 and an underside 10a of the locking edge 10 of the locking hook 7. The free space 24 extends up to the lower locking surface 12 of the receiving hook 6 or up to the upper locking surface 13 of the locking hook 7. In order to create the free space 24, the underside 10a of the locking edge 10 is provided with a flat shoulder 24a which protrudes from the underside 10a of the locking edge 10. The free space 24 can also take up dirt particles or other loose particles and, in the case of panels made of wood-based materials, take up any detached wood particles that would otherwise get stuck between the joining surfaces of the hook profiles and prevent the hook profiles from locking in the correct position. The remaining area of the underside 10a is in the locked state with the groove base 9a of the receiving groove 9 in contact and thereby supported.

The inventive embodiment of the Fig. 8 also shows hook profiles created by the Figures 3 and 4 go out. Compared to these figures, only the lower catch 14 has been modified. According to Fig. 8 the locking projection 15 of the receiving hook 6 protrudes further from the outside 8a of the receiving edge 8 than in FIG Fig. 4 . The depth of the locking recess 16 is opposite Fig. 4 unchanged. This creates a gap 25 between the outside 8a and the set back groove flank 11a of the locking groove 11 of the locking hook 7. The gap 25 improves the ability of the lower latching mechanism 14 to snap into place.

In Figure 8a the lower latching 14 is enlarged as a section. An alternative to Figure 8a shows the section according to Figure 8b . Then the position of the locking recess and locking projection is reversed. A latching recess 15a is now arranged on the receiving hook 6, specifically on the outside 8a of the receiving edge 8. For this purpose, a latching projection 16a is provided on the locking hook 7 on its set back groove flank 11a of the locking groove 11.

Another embodiment according to the invention for hook profiles of the panel is shown in FIG Fig. 9 shown. This is also based on that Figures 3 and 4 and also integrates all changes made in the examples of Fig. 5, Fig. 6 , Figures 7 and 8 were proposed.

List of reference symbols

1

new panel

1a

Panel top

1b

Panel underside

2

Spring profile edge

3

Groove profile edge

4th

horizontal panel previous row

5

Panel from the same row of panels

6th

Mounting hook

7th

Locking hook

8th

Recording edge

8a

Outside

8b

Section top

9

Receiving groove

9a

Groove base

9b

recessed groove flank

10

Locking edge

10a

bottom

10b

Outside

11

Locking groove

11a

recessed groove flank

11b

Part of the groove base

12th

lower locking surface

13th

upper locking surface

14th

lower latch

15th

Locking projection

15a

Locking recess

16

Locking recess

16a

Locking projection

17th

curvature

18th

curvature

19th

gap

20th

upper latching

21

Locking projection

21a

Locking recess

22nd

Locking recess

22a

Locking projection

23

free space

24

free space

25th

gap

α

angle

F.

Gap

Claims (12)

1. Panels (1, 4, 5) comprising a panel top side (1a) and a panel underside (1b) and comprising at least four panel margins which are situated opposite one another in pairwise fashion, having complementary holding profiles which are provided in pairwise fashion on the panel margins and which fit together such that identical panels are fastenable to one another, wherein at least one of the holding profile pairs is equipped with hook profiles, specifically with a receiving hook (6) on one panel margin and with an arresting hook (7) on the opposite panel margin, wherein the receiving hook (6) has a receiving edge (8) directed towards the panel top side (1a) and a receiving groove (9) open towards the panel top side, and the arresting hook (7) is provided with an arresting edge (10) which is directed towards the panel underside (1b) and with an arresting groove (11) which is open towards the panel underside (1b), wherein the receiving edge (8) has an inner side which faces towards the receiving groove (9), and said inner side serves as lower locking surface (12), and in a manner adapted to this, the arresting edge (10) has an inner side which faces towards the arresting groove (11), and said inner side serves as corresponding upper locking surface (13), with the condition that both the lower locking surface (12) and the upper locking surface (13) are each inclined relative to the perpendicular (L) to the panel top side (1a) such that, in the locked state, said lower locking surface and upper locking surface are oriented parallel to one another and can make contact, wherein the inclination of the locking surfaces (12, 13) is selected such that the normal vector (N₁₂) with respect to the lower locking surface (12) intersects the panel top side (1a) and the normal vector (N₁₃) with respect to the upper locking surface (13) intersects the panel underside (1b), wherein a lower detent engagement point (14) is provided which comprises a first detent means (15, 15a) which is arranged on an outer side (8a) of the receiving edge (8), and the lower detent engagement point (14) comprises a second detent means (16, 16a) which corresponds to said first detent means and which is arranged on a recessed groove flank (11a) of the arresting groove (11), and wherein at least one free space (23, 24) is provided between the underside (10a) of the arresting edge (10) and the groove base (9a) of the receiving groove (9), characterized in that at least a partial section (8b) of the top side of the receiving edge (8) runs downwards in an inclined manner in the direction of the outer side (8a) of the receiving edge (8), wherein at least a partial section (11b) of the groove base of the arresting groove (11) is adapted in complementary fashion to the inclination of the partial section (8b) of the top side of the receiving edge (8), and wherein, in the locked state, a gap (25) is provided between the outer side (8a) of the receiving edge (8) and the groove flank (11a) of the arresting groove (11) .
2. Panel according to Claim 1, characterized in that the first detent means of the lower detent engagement point (14) has a detent projection (15), and in that the second detent means of the lower detent engagement point (14) has a detent depression (16) adapted to said detent projection.
3. Panel according to Claim 1, characterized in that the first detent means of the lower detent engagement point (14) has a detent depression (15a), and in that the second detent means of the lower detent engagement point (14) has a detent projection (16a) adapted to said detent depression.
4. Panel according to one of Claims 1 to 3, characterized in that an upper detent engagement point (20) is provided which has a first detent means (21, 21a) on an outer side (10b) of the arresting edge (10), and a second detent means (22, 22a) corresponding to said first detent means is provided on a recessed groove flank (9b) of the receiving groove (9).
5. Panel according to Claim 4, characterized in that the first detent means of the upper detent engagement point (20) has a detent projection (21), and in that the second detent means of the upper detent engagement point (20) has a detent depression (21a) adapted to said detent projection.
6. Panel according to Claim 4, characterized in that the first detent means of the upper detent engagement point (20) has a detent depression (21a), and in that the second detent means of the upper detent engagement point (20) has a detent projection (22a) adapted to said detent depression.
7. Panel according to one of Claims 1 to 6, characterized in that the underside (10a) of the arresting edge (10) makes contact at least in regions with the groove base (9a) of the receiving groove (9) in the locked state.
8. Panel according to one of Claims 1 to 7, characterized in that the receiving edge has a transition to the inner side of the receiving groove (9), and in that the transition is provided with a curvature (17).
9. Panel according to one of Claims 1 to 8, characterized in that there is a gap (19) between the inclined partial section (11b) of the groove base of the arresting groove (11) and the inclined partial section (8b) of the top side of the receiving edge (8) .
10. Panel according to one of Claims 1 to 9, characterized in that the arresting hook (7) has a position of lowest thickness at the point at which the arresting groove 11 is at its deepest.
11. Panel according to one of Claims 1 to 10, characterized in that the free space (23) is in the form of a gap and widens in the direction of the groove base (9a).
12. Panel according to one of Claims 1 to 11, characterized in that the first detent means (15) is spaced apart from the inclined partial section (8b) of the top side of the receiving edge (8).

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