EP3489431B1 - Panel - Google Patents

Description

The invention relates to a panel with a panel core, a panel surface, a lower panel surface and with at least a first pair of edges of complementary form-fitting retaining profiles on opposite panel edges, one of the retaining profiles having a locking groove with a distally protruding upper groove wall and a lower groove wall that protrudes further distally as the upper groove wall, as well as with a retaining strip, which protrudes at the free end of the lower groove wall in the direction of the panel surface and has a free upper strip end and at least one undercut retaining surface, with this retaining surface facing the panel core and a recess located behind the retaining strip in the limited lower groove wall, wherein the complementary holding profile is provided with a locking spring which has at least one undercut contact surface which is directed to the panel core and in the assembled state with the holding surface of the Haltelei ste cooperates, wherein the locking spring has a spring bottom and a spring top, the spring top having a distal end and a proximal end and being straight or curved and inclined relative to the perpendicular to the panel surface so that the distal end is further away from the panel surface and the proximal end is closer to the panel surface, wherein in the assembled state there is play, which includes vertical play and horizontal play, so that the retaining profiles can be moved perpendicularly to the panel surface and can be moved in a direction that is perpendicular to the panel edges and at the same time parallel to the panel surface, and wherein an inner side of the upper groove wall is straight or curved to match the tongue top side and has an angle of inclination α relative to the perpendicular on the panel surface, which is such that the inclined tongue top side and the inside of the upper groove wall touch flatly when pushed against one another.

A generic prior art is from DE 10 2014 114 250 A1 famous. This proposes a panel which is provided with a spring top which is inclined out of the plumb line and which, when assembled, has play within the positive locking means. Because of the play, mating and locking is somewhat easier than with panels that have positive locking means with no play. The panel is also suitable for a floating floor because of the play. With floating installation, it must be taken into account that the panels are constantly subject to changes in environmental conditions, such as changes in temperature and humidity. Such changes in environmental conditions lead to shrinkage or stretching effects of the panels, which can be compensated for by the play within the mating locking means. This also applies to panels that are intended as wall cladding/wall coverings. The term horizontal play refers to a horizontal application of the panels for a floor. The game referred to as horizontal play may no longer be horizontal on a wall covering, but it is also advantageous here because it can compensate for shrinkage or expansion effects of the panels.

In practice, this becomes the DE 10 2014 114 250 A1 known panels are preferably used for thin floor or wall coverings, with the technology turning away from a panel core made of HDF or MDF, as is usual with laminate panels. Instead, for a thin panel, the panel core is in practice made of a plastic material or a composite consisting of a plastic reinforced with fibers and/or containing other fillers.

In general, the locking means must be manufactured precisely so that they fit together and they must also retain their shape. The material of the panel core is exposed and unprotected at the positive locking means. The thinner the panels are, the more difficult it is to retain their shape. Even small quirks can lead to the locking means no longer fitting into one another.

Because panels with positive locking means are delicate, once removed from a package they must be handled with care. In rough operation on a construction site there is always a risk of damage to the locking means.

As mentioned, the known panel is preferably produced with a panel core made of plastic and generally has a smaller overall thickness than, for example, conventional laminate panels that have a panel core made of MDF or HDF.

The well-known panel with a panel core made of plastic is also produced in large format, for example in the format 40 x 80 cm or even 40x120cm. The thinnest panels are currently produced in such a way that their total thickness is only 3.2 mm. The handling of such large panels is problematic, because a long lever is given when the craftsman lifts the panel at one end from the substructure and at the other end the locking means is to be positively engaged, with the substructure being both a floor and a wall can be. It is difficult to nest the small positive locking means. They can get misjudged into each other, which is difficult for the installer/craftsman to see and hardly notice. This can lead to breaks in the locking means. On the other hand, if the panel is very small, eg 10 x 30 cm, the handling is much easier because the craftsman can grasp the panel with his hands much closer to the locking means and see and feel it. The risk of damage to the locking means is then low.

The invention is based on the object of developing the known panel in such a way that it is less at risk of being damaged, even if the panel is of large format and/or has a small overall thickness.

According to the invention, the object is achieved in that the holding profiles are designed in such a way that the tongue underside of a new panel of the panel type can be placed on the holding strip of a lying panel and the holding profiles can then be moved towards one another by moving this new panel in a direction parallel to the panel plane are, so that the panel edges can be locked almost horizontally, ie lying in the panel plane, that a broken edge is provided between the free upper end of the strip of the retaining strip and its lower retaining surface, wherein the edge breaking forms a relief surface which has a distal end and a proximal end and is straight or curved in shape, and wherein the relief surface has an inclination angle β relative to the perpendicular on the panel surface, with the proviso that in a joining step the spring underside of the locking spring lies horizontally on the Retaining strip of the locking groove can be placed and then the tongue top can be pushed against the inside of the upper groove wall, and that at the end of the said joining step the distal end of the tongue top in the area of the panel core touches the inside of the upper groove wall.

The new panel, which has a spring top that is inclined out of plumb and has play within the positive locking means when assembled, has the advantage that it can be locked almost horizontally, i.e. lying in the plane of the panel.

The locking means are designed in such a way that the underside of the tongue of a new panel can be placed on the holding strip of a lying panel and the holding profiles can then be moved towards one another by moving the panel in a direction parallel to the plane of the panel, with the upper side of the tongue moving closer and closer to the inside of the upper groove wall is movable and finally overlapped by the inside of the upper groove wall without necessarily having come into contact with it.

If a new panel is to be interlocked with a previous panel that is already on a substrate (floor or wall), then the new panel can be laid down or positioned so that its tongue underside rests on the previous panel's retaining bar. The new panel can move slightly towards the opposite panel edge deflected and a deflected part also lying on the ground. The deflection of the new panel is small and the smaller the larger the panel is, ie the farther apart the opposing holding profiles are. The overlap of the tongue top by the inside of the top groove wall is not significantly affected by a small deflection of the new panel.

The new design is very useful for panels with a small overall thickness and for large format panels because it is no longer necessary for locking to start the new panel at an angle, as is the case in the prior art DE 10 2014 114 250 A1 provides (e.g Figure 8a ). Consequently, there is also no longer any need for a pivoting movement down onto the ground, which can lead to damage to the locking means when the panel is handled with a great deal of leverage if they are not inserted into one another exactly but canted. The newly designed panel allows large-format tiles that were previously not possible, with an edge length of 100 x 100 cm and more. Large format square tiles have been tested and surprisingly successfully locked without damaging the retaining profiles.

The new panel is suitable for the floating laying of floors, i.e. without connection to the subsurface, lying loosely on it. Shrinkage and expansion of the panels that can occur in practice are compensated by the built-in play.

On the other hand, the panel is also very favorable if a floor or a wall covering is to be glued to the subsurface. The joining process, which is particularly easy to achieve with the panel proposed here, also favors this type of Laying, because a panel to be locked can only be placed with the underside of the spring on the retaining strip of the previous panel and the lower panel surface can be placed overall on a substrate provided with adhesive. The further joining process can then be done by pushing the panel against the previous panel, whereby the tongue underside of the locking tongue, as described above, is pushed over the retaining strip, then slides down the free surface and the tongue underside finally gets down into the recess of the lower groove wall, where it is stored on its support surface.

The design of the proposed panel also makes it possible, of course, to lift a new panel of this type a little and to attach it at a small angle if this is desired. A high lifting for the purpose of tilting is not necessary. The locking spring is brought into engagement more gently with the locking groove even when the panel is lifted at an angle. In addition, the craftsman needs much less strength to produce a floor. On the one hand, this is because he does not have to lift the panel that high and, on the other hand, because the threading/joining is faster. In addition, with a large format panel, if it has to be lifted high, it will be more difficult to thread the locking tongue into the locking groove. The craftsman needs more time for this. It gets tiring when each panel has to be held up and threaded for longer.

Carrier boards made of HDF, MDF or OSB boards can be used as the starting material for the new panel. But it can also be a support plate made of a wood-plastic composite, for example. Wood Particle Composite (WPC) or a mineral composite, english Mineral Particle Composite (MPC). The plastic used, whether pure or processed with the additives mentioned, can be a thermoplastic, elastomeric or duroplastic plastic. For example, a composition of the MPC comprising talc and polypropylene is well suited for a carrier plate made of an MPC. Furthermore, recycling material can be used, which consists of the aforementioned plastic examples.

Conveniently, a rounded portion is provided at the front distal end of the locking spring, i.e. at its spring tip, which extends between the upper side of the spring and the lower side of the spring. Alternatively, it is possible to provide a flattened surface instead of the rounding, or a surface with a preferably convex curvature.

The design is expedient such that between the underside of the spring and the undercut contact surface there is a broken edge which has a cross-section that is at least 50% smaller than the broken edge of the holding strip. Such an edge break on the locking spring protects the edge from damage. It is then useful to make this edge break relatively small, because then there is more space for the undercut contact surface. The contact surface should be able to extend as far as possible in the direction of the lower panel surface, because the larger the contact surface, the better it counteracts the panels moving apart in the panel plane and perpendicular to the panel edges.

It can also be provided that there is no broken edge on the locking spring in order to thereby maximize the height of the contact surface.

On the other hand, the edge breaking can also have the same purpose as the free surface of the retaining strip, namely to create space so that the locking spring, which is pushed over the retaining strip, can start a downward movement. The desired space can be created by removing material only at the retaining bar, only at the locking spring, or dividing it in the desired proportion and removing material at both locations to create edge breaks.

A further benefit is seen in the fact that the height of the open space is ≥ the height of the holding surface of the holding strip. The larger the free space is, the easier it tends to be to put the holding profiles together.

Preferably, a distal end of the spring top is in the assembled state at a level between the upper free ledge end of the holding ledge and a proximal end of the free space or the distal end of the spring top is an amount corresponding to the height of the free space above the free ledge end. The sliding surface and the sliding zone are intended for the relative movement of the joined panel edges within the limits of the horizontal play.

Favorably, the underside of the tongue provides a sliding surface which is arranged parallel to the panel surface and, in the assembled state, rests on a sliding zone in the recess of the lower groove wall, the sliding zone in turn being arranged parallel to the panel surface.

It is helpful if the retaining strip forms a support surface on which the underside of the spring can be placed during the joining process, and that the locking spring has a bottom panel surface has open recess with a base. In this way, the retaining strip has space in the recess of the locking spring when the panel edges are joined together.

It is also useful if the bearing surface of the retaining strip and the base of the recess are parallel to one another and touch one another when assembled, so that they act as sliding surfaces parallel to the panel surface within the scope of the existing play.

An improvement is seen in the fact that the maximum vertical clearance Q, when the undercut holding surface of the locking groove and the undercut contact surface of the locking spring touch, is in a ratio Q/S to the height S of the holding surface, which is in the range of 0.5-2 0, preferably the ratio Q/S is in the range of 0.8-1.2. The height S of the holding surface is defined as the distance from the upper end of the holding surface perpendicular to the level of the bearing surface of the lower groove wall or the sliding zone. With a ratio ≥ 1.0, the locking spring can be inserted into the locking groove without resistance until the underside of the spring comes into contact with the bearing surface of the lower groove wall. If, on the other hand, a Q/S ratio of <1.0 is chosen, then a certain elastic deformation of the retaining profiles is required in order to assemble them. This can be done by area-wise compression and/or by area-wise bending, for example a downward bending of the lower groove wall. Compression can preferably take place on a rear area of the underside of the spring, which comes into contact with the free surface during the joining movement.

Preferably, the angle of inclination α is the inside of the upper groove wall relative to the perpendicular L on the panel surface in the range of 30° to 60°. The angle of inclination α is particularly preferably 45°. It has been shown that the locking is then easy to produce and the form fit that is produced achieves good strength.

The handling of the panel can be improved if the free surface of the retaining strip is inclined by a free angle β relative to the perpendicular on the panel surface, and that the free angle β is ≥ the inclination angle α of the inside of the upper groove wall. This causes a wedge-shaped narrowing opening of the locking groove to result, which simplifies the insertion of the locking spring.

The clearance angle β is expediently in the range of 1.0 to 1.5 times the angle of inclination α. The clearance angle β is preferably in the range of 1.1 to 1.3 times the angle of inclination α. Alternatively, it is also possible to configure the angle of inclination β<as the angle of inclination α, for example in the range of 0.7 to 1.0 times the angle of inclination α. As a result, effects can be achieved, for example the need for a certain elastic deformation during the joining process.

A second distal holding surface directed towards the panel core can be provided on the holding strip and the locking spring can have a proximal second contact surface matching this. With an uneven ground that has high and low points, it can happen that the holding profiles that are joined together are located at a high point on the ground or at a low point on the ground. Two panels locked together then no longer form a flat surface. Instead it stands between the surface of one panel and the surface of the other panel has an angle > 180° if it is a high part of the base and if it is a low part of the base, the angle is < 180°. The proposed design of the panel with two retaining surfaces on the retaining strip and with two contact surfaces on the locking spring that interact with it provides a remedy because one pair of retaining surface/contact surface always remains in contact, while the other pair of retaining surface/contact surface can lose contact somewhat. However, the positive locking retains its effectiveness.

The second holding surface of the holding bar is expediently arranged at the distal end of the open area.

The panel surface may have a chamfer at least on the locking groove side or on the locking tongue side. Of course, both sides, locking groove and locking tongue, can have a broken edge.

It is useful if the panel is quadrangular and has a second pair of edges, which is provided with complementary holding profiles on opposite panel edges, the holding profiles being designed identically to the holding profiles of the first pair of edges.

Furthermore, a method for laying and locking panels is proposed, which has a pair of edges with complementary holding profiles according to the invention, the tongue underside of a new panel being placed on the holding strip of a panel already lying on a substructure, then the new panel lying vertically in the panel plane is shifted to the panel edge against the lying panel until the spring underside of the new panel has exceeded the retaining bar of the lying panel and sinks down into the recess behind the retaining bar.

Furthermore, a method for laying and locking square panels with two identical pairs of edges is proposed. A new square panel of this type, which has two identical pairs of edges, is locked in a second row of panels with panels of an existing first row of panels and at the same time with an existing panel in the second row by locking the new panel with a spring underside on the retaining strips of the panels first row of panels and with the spring underside of its adjacent locking spring on the retaining ledge of the panel already present in the second row, then the new panel is slid in a diagonal direction, whereby its two adjacent locking springs are simultaneously engaged, namely one locking spring with the locking groove of the panels in the first row of panels and the other locking spring with the locking groove of the panel already present in the second row, with the spring undersides of the two adjacent locking springs of the new panel the retaining strips of the laid panel ü exceeded and lower yourself into the recess located behind the retaining bar. In this way, two panel edges of the new panel are locked almost simultaneously. Its panel edges can of course be of different lengths. This can result in the locking of one panel edge of the new panel being completed earlier and the locking of its other panel edge being completed somewhat later. At least a temporal overlapping of the locking processes of the two panel edges of the new panel is possible.

With the proposed panel, a floor covering can be laid in a herringbone pattern. Two different types of panel are required for this purpose, a type A and a type B. Both panel types A and B have a pair of edges that are identically designed, i. H. the type A locking groove is located on the same panel edge as the type B panel and also the type A locking tongue is located on the same panel edge as the type B panel. H. the panel edge that has the locking tongue in type A has the locking groove in type B and vice versa. In this example, both types have a pair of long panel edges and a pair of short panel edges. The long panel edges are identical in type A to type B. The short panel edges differ. On the panel edge on which type A has the locking tongue, type B has the locking groove. Where type A has the locking groove, type B has the locking spring.

During the production of panels type A and type B, the holding profiles of the long edges are milled first. The panels are then transported further within the production plant in order to mill the short edges, with half of the panels in a batch having to be rotated 180° before the milling operation in order to produce the short edges on this part of the panel in the wrong direction. This laying pattern means that long panel edges and short panel edges can be locked together. Different pairs of edges, for example long edges and short edges, must therefore at least be milled to be compatible with one another. Most simply, the long edges and short edges can be matched with the same or be milled with identical tools. In this way, a herringbone laying pattern can be produced. What is special about it is that the panels can be positively locked on all sides, despite the special laying pattern, whereby a locking effect is achieved in the panel plane (horizontal) and specifically perpendicular to the locked edges, but also a locking effect in a direction perpendicular to the panel plane (vertical). In the case of a rectangular or square panel, the horizontal and vertical interlocking action is therefore possible on both pairs of edges.

Fig. 1a

ein erstes Ausführungsbeispiel eines erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 1b

das Paneel gemäß Fig. 1a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 1c

das Paneel gemäß Fig. 1a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 1d

das Paneel gemäß Fig. 1a im verriegelten Zustand mit Spiel und mit geschlossenem Spalt an der Paneeloberseite,

Fig. 1e

das Paneel gemäß Fig. 1a im verriegelten Zustand in einer mittleren Position im Rahmen des vorhandenen Spiels,

Fig. 1f

das Paneel gemäß Fig. 1a im verriegelten Zustand mit Höhenversatz,

Fig. 2a

ein zweites Ausführungsbeispiel eines erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 2b

das Paneel gemäß Fig. 2a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 2c

das Paneel gemäß Fig. 2a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 2d

das Paneel gemäß Fig. 2a im verriegelten Zustand mit Spiel und mit geschlossenem Spalt an der Paneeloberseite,

Fig. 2e

das Paneel gemäß Fig. 1a im verriegelten Zustand in einer mittleren Position im Rahmen des vorhandenen Spiels,

Fig. 2f

das Paneel gemäß Fig. 2a im verriegelten Zustand mit Höhenversatz,

Fig. 3a

ein drittes Ausführungsbeispiel eines erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 3b

das Paneel gemäß Fig. 3a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 3c

das Paneel gemäß Fig. 3a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 4a

ein viertes Ausführungsbeispiel eines erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 4b

das Paneel gemäß Fig. 4a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 4c

das Paneel gemäß Fig. 4a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 5a

ein fünftes Ausführungsbeispiel eines Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 5b

das Paneel gemäß Fig. 5a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 5c

das Paneel gemäß Fig. 5a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 6a

ein sechstes Ausführungsbeispiel eines Paneels,

Fig. 6b

das Paneel gemäß Fig. 6a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 6c

das Paneel gemäß Fig. 6a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der unteren Paneelfläche,

Fig. 7a

ein siebtes Ausführungsbeispiel eines erfindungsgemäßen Paneels, wobei das Paneel zerteilt dargestellt ist, um dessen komplementäre Halteprofile eines Kantenpaares im Verlauf einer Fügebewegung zu zeigen,

Fig. 7b

das Paneel gemäß Fig. 7a im fortgeschrittenen Verlauf der Fügebewegung,

Fig. 7c

das Paneel gemäß Fig. 7a im verriegelten Zustand mit Spiel und mit maximalem Spalt an der Paneeloberseite,

Fig. 7d

das Paneel gemäß Fig. 7a im verriegelten Zustand mit Spiel und mit geschlossenem Spalt an der Paneeloberseite,

Fig. 8a

ein achtes Ausführungsbeispiel eines erfindungsgemäßen Paneels,

Fig. 8b

das Paneel gemäß Fig. 8a im Verlauf der Fügebewegung,

Fig. 8c

das Paneel gemäß Fig. 8a im zusammengefügten Zustand der komplementären Halteprofile,

Fig. 8d

das Paneel gemäß Fig. 8c mit Vorsprung und Einkerbung im Eingriff,

Fig. 9

ein Verfahren zur Verlegung und Verriegelung eines neuen Paneels mit rechteckigem Format,

Fig. 10

eine weitere Ausführungsform des Paneels,

Fig. 11

eine Draufsicht auf ein Fischgrät-Verlegemuster mit dem erfindungsgemäßen Paneel.

In the following, the invention is illustrated by way of example in a drawing and described in detail on the basis of several exemplary embodiments:

Fig. 1a

a first embodiment of a panel according to the invention, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Fig. 1b

the panel according to Fig. 1a in the advanced course of the joining movement,

1c

the panel according to Fig. 1a in the locked state with play and with maximum gap at the top of the panel,

Fig. 1d

the panel according to Fig. 1a when locked with play and with a closed gap at the top of the panel,

Fig. 1e

the panel according to Fig. 1a in the locked state in an intermediate position within the existing clearance,

1f

the panel according to Fig. 1a when locked with height offset,

Figure 2a

a second embodiment of a panel according to the invention, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Figure 2b

the panel according to Figure 2a in the advanced course of the joining movement,

Figure 2c

the panel according to Figure 2a in the locked state with play and with maximum gap at the top of the panel,

Fig. 2d

the panel according to Figure 2a when locked with play and with a closed gap at the top of the panel,

Figure 2e

the panel according to Fig. 1a in the locked state in an intermediate position within the existing clearance,

Fig. 2f

the panel according to Figure 2a when locked with height offset,

Figure 3a

a third embodiment of a panel according to the invention, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Figure 3b

the panel according to Figure 3a in the advanced course of the joining movement,

3c

the panel according to Figure 3a in the locked state with play and with maximum gap at the top of the panel,

Figure 4a

a fourth exemplary embodiment of a panel according to the invention, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Figure 4b

the panel according to Figure 4a in the advanced course of the joining movement,

Figure 4c

the panel according to Figure 4a in the locked state with play and with maximum gap at the top of the panel,

Figure 5a

a fifth exemplary embodiment of a panel, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Figure 5b

the panel according to Figure 5a in the advanced course of the joining movement,

Figure 5c

the panel according to Figure 5a in the locked state with play and with maximum gap at the top of the panel,

Figure 6a

a sixth embodiment of a panel,

Figure 6b

the panel according to Figure 6a in the advanced course of the joining movement,

Figure 6c

the panel according to Figure 6a when locked with play and with maximum gap at the bottom panel area,

Figure 7a

a seventh embodiment of a panel according to the invention, the panel being shown in sections in order to show its complementary holding profiles of a pair of edges in the course of a joining movement,

Figure 7b

the panel according to Figure 7a in the advanced course of the joining movement,

Figure 7c

the panel according to Figure 7a in the locked state with play and with maximum gap at the top of the panel,

Figure 7d

the panel according to Figure 7a when locked with play and with a closed gap at the top of the panel,

Figure 8a

an eighth embodiment of a panel according to the invention,

Figure 8b

the panel according to Figure 8a in the course of the joining movement,

Figure 8c

the panel according to Figure 8a in the assembled state of the complementary retaining profiles,

Figure 8d

the panel according to Figure 8c with projection and indentation engaged,

9

a procedure for laying and locking a new panel of rectangular format,

10

another embodiment of the panel,

11

a plan view of a herringbone laying pattern with the panel according to the invention.

the Figures 1a-1f show a first exemplary embodiment of a panel 1 according to the invention. The panel is shown in sections in each case in order to illustrate its opposite panel edges 2 and 2' in the course of the joining movement/joining process and to show them in the locked state. Of course, the panel edges shown in sections can also be understood as a representation in sections of two panels which are not severed.

In practice, when the panels have a rectangular format, for example, it is quite common to cut through a panel that is too long at the end of a row of panels in order to shorten it to the required length. A new row of panels can usually be started with the leftover piece that has been cut off. Complementary retaining profiles of a severed panel mate and can be interlocked as illustrated in the examples below.

In Fig. 1a Figure 1 shows panel 1 having a panel core 3, the panel having a panel face 4 and a panel bottom face 5, and a pair of complementary support profiles 6 and 7 at opposite panel edges 2 and 2', the support profiles being of interlocking design.

A holding profile 6 is provided with a locking groove 8 and the holding profile 7 complementary thereto has a locking spring 9 . The locking groove has an upper groove wall 10 and a lower groove wall 11 which projects distally further from the panel core 3 than the upper groove wall. Distally, ie at the free end of the lower groove wall, a retaining strip 12 is provided, which in turn protrudes in the direction of the panel surface 4 and a free upper strip end 12a and has a holding surface 12b, the holding surface being directed towards the panel core 3. Behind this holding surface, ie towards the panel core, a recess 11a is formed in the lower groove wall, which has a bearing surface 11b for the locking spring 9 arranged parallel to the panel surface 4 . The recess 11a is delimited on the outside by the retaining strip 12 or by its retaining surface 12b. A radius 13 is provided between the strip end 12a and the side of the retaining strip 12 that faces outward.

The upper groove wall 10 has an inner side 10a which is inclined, namely inclined relative to the perpendicular L on the panel surface 4 . It has an inclination angle α such that a distal end 10b of the inner side reaches up to the panel surface 4 and the proximal end 10c of the inner side is farther from the panel surface and is oriented close to a median plane of the panel core 3 . Here, the middle level of the panel core can also be slightly exceeded.

Overall, it serves the strength of the locking if essential surfaces of the retaining profiles, such as the tongue upper side and the inside of the upper groove wall, based on the panel thickness, extend into a middle panel thickness area or come close to the area on both sides of the middle plane of the panel core 3 or this cross middle level. This preferably also applies to the holding surface 12b of the holding strip, which in the sense of the invention reaches at least close to the middle plane of the panel core and is arranged in a middle panel thickness area.

The locking spring 9 has a spring underside 9a, the is arranged parallel to the panel surface 4'. Proximally, the locking spring is assigned a downwardly open recess 14, which creates space for the retaining strip 12 when the panel edges 2/2' are assembled. The locking spring is also provided with an undercut contact surface 15, which when assembled with the retaining surface 12b of the and has a tongue top surface 16 which is inclined relative to the perpendicular on the panel surface 4', the angle of inclination being the same as the angle of inclination α of the inner side 10a of the upper groove wall.

In Fig. 1a the spring underside 9a of the locking spring lies on the upper strip end 12a of the holding strip 12, which is arranged parallel to the panel surface 4. This position is a good starting position for the further joining process.

In Fig. 1b the further course of the joining movement is shown. The underside of the spring 9a has now passed the end of the strip 12a and is sliding down an edge break 12c provided on the holding strip 12 . The edge break forms a free surface 12d, which is arranged at an angle of inclination β with respect to the perpendicular L on the panel surface 4. The free surface 12d creates so much free space that a front distal end 9b of the locking spring or the locking spring as a whole can be moved into the locking groove 8 without hindrance.

The joining movement continues in that the underside of the spring 9a passes the free surface 12d and moves further down into the recess 11a of the lower groove wall 11, as in FIG 1c shown. As a result, the spring underside 9a is on the bearing surface 11b of the lower groove wall and the Undercut contact surface 15 of the locking spring is in contact with the associated holding surface 12b of the holding strip 12 of the lower groove wall. A maximum gap W, which is narrower than the amount of clearance P, is formed between the tongue top and the inside 10a of the top groove wall.

In 1c shows a horizontal play P between the spring top 16 and the inside 10a of the upper groove wall. The clearance P allows the locking tongue 9 to be moved further into the locking groove 8, parallel to the panel surface 4/4', until the clearance between the tongue top and the inside of the upper groove wall is zero; latter position is in Fig. 1d shown. For this purpose, the contact surface 15 of the locking spring has moved away from the holding surface 12b of the lower groove wall and horizontal play P' has thus arisen at this point. The underside of the tongue 9a forms a sliding surface and the bearing surface 11b of the recess in the lower groove wall acts as a sliding zone within the framework of the existing horizontal play P/P'.

The holding profiles can take up intermediate positions relative to one another. An intermediate position is in Fig. 1e shown. After that, there is a play component p ₁ of horizontal play between the contact surface 15 and the holding surface 12b, as well as a play component p ₂ of the horizontal play between the upper side of the spring 16 and the inside 10a of the upper groove wall. Both game shares add up to the same amount as the horizontal game P/P' used in the Figures 1c and 1d only exists at one end.

In the Figures 1c and 1e there is vertical play or height play Q, i.e. perpendicular to the panel surface. This vertical play is at its maximum when the undercut contact surface 15 and the holding surface 12b in touch are. If the underside of the tongue 9a then moves upwards and lifts off the bearing surface 11b of the lower groove wall, then, as in 1f shown, a height offset K between the panel surface 4 and that of the panel surface 4'. The higher panel surface 4' forms a small step with an obtuse angle, which has a certain stability because of its obtuse shape.

In the above embodiment, the height clearance Q in relation to the height S of the holding surface is Q/S=1.1. This ratio creates a sort of opening that is wider at the top and narrows towards the bottom of the groove wall. As a result, the locking spring is guided in the narrowing opening during the joining movement.

Two joined panels ideally assume a position relative to one another in which the panel surface 4 of one panel and the panel surface 4' of the other panel enclose an angle of 180°, they then lie exactly in one plane. However, if the substrate is wavy, it can happen that the panel surfaces 4/4' enclose an angle <180° or >180°, with deviations from 180° being approximately ±3°.

In the assembled state, as in the Figures 1d-1f shown, the retaining strip 12 of the lower groove wall 11 protrudes into the recess 14 of the locking spring 9 . In this embodiment, however, there is always a gap 17 between the free end 12a of the retaining strip and the recess 14, which is open at the bottom.

Between the spring underside 9a and the contact surface 15 of In the first exemplary embodiment, the locking spring has been dispensed with in a clear broken edge. Instead, a nearly right-angled corner is formed. At the same time, a right angle is also formed between the bearing surface 11b of the lower groove wall 11 and the holding surface 12b. In practice, this right angle of the lower groove wall will have a very small radius because the tools used to make this geometry do not have sharp angles and such integral corners can only be made/milled with minimal radii/edge breaks. So that the contact surface 15 and the holding surface 12b fit together, the corner on the underside of the spring 9a is also minimally rounded off or has a small chamfer.

The clearance has a height T, which is greater than the height S of the holding surface in the present embodiment. In this case, a proximal end of the free surface coincides with an upper end 12e of the holding surface 12b. The term "height S" means the distance measured from the upper end 12e of the holding surface 12b to perpendicular to the level of the bearing surface 11b of the lower groove wall 11.

The spring top 16 has a distal end 16a, according to the assembled state 1c is at a level that lies between the upper free strip end 12a and an upper end 12e of the holding surface, or in the region of the height T of the free surface 12d.

In the present exemplary embodiment, the angle of inclination α of the inside of the upper groove wall is 45° relative to the perpendicular L on the panel surface 4.

The clearance angle β of the clearance surface of the holding strip is 50° relative to the perpendicular L in the present exemplary embodiment the panel surface 4.

A second embodiment is based on the Figures 2a to 2f shown. It differs in two aspects from the exemplary embodiment of the previous group of figures 1. One aspect is the design of the panel surface 4 on the side of the locking groove 8. Here, an edge break 18 in the form of a chamfer 18a is provided on the upper groove wall 10. As a result, on the one hand, the inside 10a of the upper groove wall 10 is shorter than in the example of the previous group of figures. In addition, a V-joint 19 is formed in the assembled state. The V-joint is often considered more pleasing. It also protects the free end of the upper groove wall 10 from damage. This free end is compared to Fig. 1a duller and lies lower, ie at a certain distance away from the panel surface 4 and is thereby protected.

The second aspect, which differs from the embodiment of the previous group of figures 1, is the relationship of the holding bar 12 to the downwardly open recess 14 of the locking spring 9. Here it is provided that the free end of the bar 12a of the holding bar forms a bearing surface 12f, which Touches and supports recess 14 at its base 14a when the panels are assembled. With a movement within the scope of the horizontal play P/P', the base surface 14a of the recess 14 then slides on the bearing surface 12f. This creates more stability when the panel is loaded from above on the panel surface 4'.

In the position according to Figure 2c is the distal end 16a of the spring top 16 in the assembled state at a level that lies between the upper free strip end 12a and the upper end 12e of the holding surface, or in the region of the height T of the free surface 12d. Between the On the upper side of the spring and the inside 10a of the upper groove wall, a maximum gap W is formed, which is narrower than the amount of play P.

A third embodiment show the Figures 3a to 3c . It largely corresponds to the exemplary embodiment of figure group 2. In the assembled state, it forms a V-joint 19 on the panel surface. The retaining strip 12 provided on the lower groove wall touches the base surface 14a of the recess 14, which is open at the bottom, and supports this area of the locking spring. There is a difference in the design of the spring top 16, which here has a region with a convex curvature 20 (curve). Matching this, the inside 10a of the upper groove wall 10 is provided with a concave curvature 21 (curve). In addition, the free surface 12d has a curvature 22 in this exemplary embodiment. The curve 22 is inclined at a slightly larger angle to the perpendicular L on the panel surface 4 than the inside of the upper groove wall. Between this inner side and the free surface, an opening is formed, so to speak, which has a greater width at the top and becomes narrower and narrower towards the bottom of the groove wall.

A fourth exemplary embodiment is shown in FIG Figures 4a to 4c . This is based on that embodiment of figure group 2 . Like this one, it has a chamfer 18a on the panel surface on the side of the locking groove so that a V-joint 19 is formed when assembled. Furthermore, a downwardly open recess 14 of the locking spring, which is identical in the assembled state as in FIG Figure 2c rests with a base surface 14a on a support surface 12f of the holding strip 12 and is supported thereby.

The exemplary embodiment of figure group 4 differs in that there is a second holding surface 23 provided on the holding strip 12 of the lower groove wall 11 and a second contact surface 24 provided to match this on the locking spring 9. Two pairs of holding surface/contact surface are therefore effective. This doubling of the holding/abutment surface improves the locking effect overall in the assembled state. In the exemplary embodiment shown, the second holding surface 23 starts at the upper end of the free surface 12d and ends at the free end 12a of the strip at the level of the bearing surface 12f of the holding strip. The second contact surface 24 of the locking spring is arranged proximally relative to the first contact surface 15 and, in the assembled state, fits together with the second retaining surface 23 of the retaining strip.

The design with doubled holding surfaces (12b/23) and contact surfaces (15/24) also has an advantage if the base U is uneven, ie if it has a ripple. Waviness means moderate rise/fall of the subsoil, of the order of max. ± 3°. If two interlocked panels are laid and interlocked on such a wavy surface, then the floor surface will no longer be level. An angle of >180° then arises between the panel surface of one panel and the panel surface of the other panel if the retaining profiles are located at an elevated point on the substrate. If they are located at a low point on the subsurface, an angle of < 180° is created between the two panel surfaces. In the proposed embodiment of the figure group 4, there is the advantage that one of the pairs of holding surface / contact surface remains in contact when the panel surfaces of the locked panels in a position <180 ° or > 180° to each other. At all times, one pad/land pair remains in good contact while the other pad/land pair loses contact, but the amount of pad/land contact loss is only tenths of a millimeter or even fractions of a tenth.

A fifth embodiment not belonging to the invention is in turn based on the embodiment of FIG figure group 2 . As in this previous example, an edge break 18 is also provided here on the panel surface 4 on that side of the locking groove 9, on the upper groove wall 10. The edge break is in the form of a chamfer 18a. In addition, in the assembled state there is contact between that recess 14 which is open at the bottom and which is associated with the locking spring 9 and a bearing surface 12f on the strip end 12a of the holding strip. The retaining bar 12 protrudes into the recess 14 and supports its base 14a.

The special feature of the fifth exemplary embodiment consists in the design of the spring top 16, which has a concave curvature 25, while the inside 10a of the upper groove wall 10 has a convex curvature 26 to match. In the position that in Figure 5c is shown, the two curves 25/26 abut one another. On the other hand, horizontal play P′ can be seen between the holding surface 12b of the holding strip and the contact surface 15 of the locking spring. The clearance P' can of course be reduced to zero, thus creating a clearance P between the bends 25 and 26, as well as the clearance P in Figure 2c .

The joining process starts with Figure 5a shown. It starts the same way as in Figure 2a so that the spring underside 9a to be placed on the retaining strip 12 and then to push the locking spring 9 further in the direction of the locking groove 8. According to Figure 5b in this example, the locking spring 9 pushes against the inside 10a of the upper groove wall. In the present example, this requires the panel with the locking spring to be raised/angled by a small angle γ. Alternatively, however, the design could also be changed and, for example, greater play P provided in order to be able to insert the locking spring 9 into the locking groove 8 with less angling or without angling at all.

A sixth embodiment is also based on the group of figures 2. Like this one, it has a chamfer 18a on the panel surface 4 on that side of the locking groove 8, so that a V-joint 19 is formed in the assembled state. Furthermore, a downwardly open recess 14 of the locking spring 9 is jointly provided, which in the assembled state is identical to that in Figure 2c , rests on the retaining strip 12 and the base 14a is supported thereby. Two recesses 27 in the spring underside 9a and two recesses 28 in the contact surface 11b of the lower groove wall 11 are new in the present exemplary embodiment. Two recesses each face one another and together form hollow chambers Y in which, for example, dust or abrasion particles can collect. Alternatively, it is possible to arrange fewer or more such recesses on the spring underside 9a or the bearing surface 11b, or to arrange recesses only on one side on the bearing surface 11b or the spring underside 9a.

The figure group 7 shows an embodiment, which in turn is based on the embodiment of the figure group 2, because here on the panel surface 4 on that Side of the locking groove 8 is a chamfer 18a, so that when assembled, a V-joint 19 is formed and because together with figs 2 a downwardly open recess 14 of the locking spring 9 is provided, which is identical in the assembled state as in Figure 2c , rests on the retaining strip 12 and is supported thereby.

In the present exemplary embodiment, the holding strip 12 of the lower groove wall 11 has a new design. This is because it is also provided with a broken edge on its outer side facing away from the recess 11a. This edge break is designed in such a way that it serves as a sloping contact surface 29 for the locking spring 9, as shown in Figure 7a indicated where the tip of the pen touches the contact surface and is moved upwards along it. In order for this to be possible, its distal end 29a extends down to a level which is deep enough for the locking spring 9 of a new panel to hit the abutment surface when the new panel is placed on the base U. From this position, the new panel can then be pushed further in the direction of the locking groove, as a result of which the locking spring moves upwards along the contact surface 29 until the spring underside 9a comes to rest on top of the retaining strip 12 or on its bearing surface 12f. The further joining process then proceeds as in the embodiment of figure group 2.

An eighth embodiment is in the Figures 8a to 8d shown. It is based on that of figure group 1, compared to which it has been changed in two aspects. The first aspect is the changed relation between the retaining strip 12 provided on the lower groove wall 11 and the recess 14 of the locking spring 9, which is open at the bottom. The design is such that in the assembled state the recess is on the Bearing surface 12f rests, as in Fig. 8c/ 8d shown. The other aspect consists in the special design of the holding surface 12b. As in Figure 8a to see, the holding surface is undercut. It has an indentation 30 . The notch is arranged in such a way that the contact surface 11b of the lower groove wall is extended and merges into the notch. The contact surface 15 of the locking spring is further developed into a projection 31 which faces the panel core 3' and practically forms an extension of the spring underside 9a. According to Figure 8d For example, the protrusion 31 is designed to fit into the notch 30 in the assembled state and position accordingly Figure 8d counteracts a height offset. In this way, a rear form-fitting locking mechanism is provided, so to speak, behind the underside of the spring 9a. Relative to the panel with the locking groove, the rear positive locking is located on that side of the holding strip 12.In that faces the panel core Figure 8b an intermediate position during the joining movement is shown. The underside of the spring is moved down along the free surface 12d, or the projection 31 mentioned slides down the free surface. In Figure 8c the position with play P' is shown in which the tongue top 16 abuts against the inside 10a of the upper groove wall.

9 shows a plan view of a surface of laid panels, panels with a rectangular format being used here, which have retaining profiles on both pairs of edges according to figure group 7. A first panel row of locked panels D1 and a started second panel row D2 can be seen. The new panel has a first pair of edges with a locking tongue 32a and opposite a locking groove 32c and a second pair of edges with a locking tongue 32b opposite one locking groove 32d.

A new panel 32 is to be connected in the second row of panels. For this purpose, it must be interlocked with panels 33 and 34 of the first row of panels D1 and with panel 35 of the second row of panels D2. The new panel 32 is placed on the base U according to the method described here. Next, the new panel is moved in the direction of arrow V (diagonally). It approaches the locking grooves of the panels 33/34 of the first row of panels. At the same time it approaches the locking groove of the panel 35. On both sides of the new panel 32 to be locked, its locking springs 32a and 32b abut contact surfaces 35b and 33b/34b, respectively, which are provided on the outside of the holding strips of the adjacent panels 33, 34 and 35, respectively. As the movement progresses in the direction of arrow V, the undersides of the tongues reach the retaining strips or their contact surfaces and then the undersides of the tongues slide down along the free surfaces and finally move down into the recess of the lower groove wall. This happens both on the panels 33, 34 of the first row of panels D1 and on the panel 35 of the second row of panels D2.

The method steps described above can of course also be carried out if the panels are to be glued to the substrate. When the new panel 32 is laid down, an adhesive must be provided beforehand. The adhesive can be applied to the substrate and/or applied to the bottom panel surface. It must have a sufficient pot life to be able to carry out all installation steps before it hardens. After curing/setting, it creates a material bond with the substrate U.

The locking of the two locking springs 32a, 32b involved in the new panel 32 is generated almost simultaneously. However, due to the flexibility of the panel, it can happen that an interlocking of the locking tongue of the new panel with the locking groove of the already installed panel(s) starts in that panel corner of the new panel in which the arrow V is pointing and starting in this panel corner the creation of the locking zip-like progressively on both panel edges. It may be the case that one panel edge of the new panel is locked faster than the other; This is the case, for example, when the panel edges are of different lengths.

Alternatively, another method of locking can be carried out, which is required for those embodiments of the panel that do not have a contact surface on the outside of the retaining strip, so that the locking spring cannot be automatically moved upwards there via a contact surface. Instead, the new panel is then laid down with its locking springs resting directly on the retaining ledges of the adjacent panels, as in Figs Figures 1a , 2a , 3a , 4a , 6a and 8a shown. Ie for 9 that one locking spring is placed on the retaining ledges of the panels of the first row of panels and the other locking spring is placed on the retaining ledge of the panel that is already present in the second row of panels. It is then pushed diagonally, as indicated by the direction of arrow V, so that the new panel comes into positive engagement with the locking grooves of the adjacent panels at both panel edges to be locked.

10 shows a panel that follows the principle of figure group 8, ie it has a rear positive locking. This is through a notch 30 at the Retaining bar of the locking groove and a matching designed projection 31 can be realized on the locking spring 9, which fits into the notch. When fitted, when the maximum clearance P is present at the panel surface, the protrusion 31 is moved into the notch to the maximum depth, so that the rear positive locking then achieves its best locking action perpendicular to the panel surface. During the joining process, the projection 31 can freely pass the proximal end of the free surface 12d and the underside of the spring 9a can reach the bearing surface 11b of the lower groove wall. An elastic deformation of the holding profiles required during the joining process is not provided in the present exemplary embodiment.

In the embodiment of 10 the notch has a cross-section that is made with the help of a milling tool. A dotted line indicates in 10 the milling tool R and its drive spindle Z, around which the milling tool rotates.

Compared to figure group 8, the locking groove is designed with a larger radius at the bottom of the groove. The distal end 16a of the straight piece of the spring top 16 is at a slightly higher level than the bearing surface 12f of the retaining strip 12, or the strip end 12a. It has the advantage that the risk of a crack can be somewhat reduced in the area of the increased radius, which forms the bottom of the locking groove.

An enlarged radius at the bottom of the groove is not only advantageous for the present exemplary embodiment, but also an expedient option for all previous exemplary embodiments.

When the distal end 16a of the straight length of the spring top 16 overlies the ledge end 12a, as in FIG 10 , then it should suitably be in an area above the end of the strip, the amount of which corresponds to the height T of the free space.

When the projection 31 is moved maximally deep into the indentation 30, that side of the indentation which is closer to the panel surface makes positive contact with an upper side of the projection. In this case, some air can be provided between the free end of the projection and the base of the notch, and a free space can thus be formed. The free space is used to securely produce the form fit and, in addition, any dirt particles can be picked up there.

11 shows an application of the panel according to the invention for the production of a covering surface in a herringbone laying pattern. Two different types of panel are required for this purpose, a type A and a type B. Both panel types A and B have a pair of edges that are identically designed, ie the locking groove of type A is located on the same panel edge as in panel type B and likewise, the locking spring of type A is arranged on the same panel edge as in panel type B. However, the other pair of edges in type B is the reverse of type A, i.e. the panel edge that is provided with the locking spring in type A has in type B the locking groove and vice versa. In this example, both types have a pair of long panel edges and a pair of short panel edges. The long panel edges are identical in type A to type B. The short panel edges differ. On the panel edge where type A has the locking tongue, type B has the locking groove intended. Where type A has the locking groove, type B has the locking spring.

During the production of panels type A and type B, the holding profiles of the long edges are milled first. The panels are then transported further within the production plant in order to mill the short edges, with half of the panels in a batch having to be rotated 180° before the milling operation in order to produce the short edges on this part of the panel in the wrong direction. This laying pattern means that long panel edges and short panel edges can be locked together. Different pairs of edges, e.g. long edge short edge, must therefore be compatible with one another. In this way, a herringbone laying pattern can be produced. What is special is that the panels can be positively locked on all sides, with a locking effect being achieved in the panel plane (horizontal) and specifically perpendicular to the locked edges, but also a locking effect being achieved in a direction perpendicular to the panel plane (vertical). With a rectangular or square panel, this horizontal and vertical interlocking action is possible on both pairs of edges.

With the panel types A and B produced in this way, the herringbone laying pattern can then be implemented. 11 Figure 12 shows schematically an area of interlocked panels laid out in a herringbone pattern. Therein, a panel of type A and a panel of type B are distinguished by different hatching as an example. In this case, (F) indicates where there is a tongue in the respective panel type and (N) indicates where there is a groove.

Due to the advantageous handling of the positive retaining profiles of the panel according to the invention, the locking of the panels to one another is also very simple if two panel types are designed and these are joined together in the herringbone laying pattern shown to form a covering.

Reference List

1

panel

2

panel edge

2'

panel edge

3

panel core

3'

panel core

4

panel surface

4'

panel surface

5

lower panel surface

6

holding profile

7

holding profile

8th

locking groove

9

locking spring

9a

feather bottom

9b

front end

10

upper groove wall

10a

inside

10b

distal end

10c

proximal end

11

lower groove wall

11a

recess

11b

bearing surface

12

retaining bar

12a

last end

12b

holding surface

12c

edge breaking

12d

open space

12e

top end

12f

bearing surface

13

radius

14

recess

14a

Floor space

15

contact surface

16

feather top

16a

distal end

17

gap

18

edge breaking

18a

chamfer

19

V-joint

20

convex curvature

21

concave curvature

22

convex curvature

23

second holding surface

24

second contact surface

25

concave curvature

26

convex curvature

27

recess

28

recess

29

contact surface

29a

distal end

30

notch

31

head Start

32

New panel

32a

locking spring

32b

locking spring

32c

locking groove

32d

locking groove

33

panel

33d

contact surface

34

panel

34d

contact surface

35

panel

35c

contact surface

f

Feather

N

groove

K

height offset

L

Lot

P

Game

P'

Game

p1

game share

p2

game share

Q

height play

R

milling tool

S

Height holding surface

T

Height of open space

u

underground

V

Arrow

W

gap

Y

hollow chamber

Z

drive spindle

a

tilt angle

β

tilt angle

g

angle

Claims (17)

1. A panel (1) comprising a panel core (3, 3'), a panel top surface (4, 4'), a lower panel surface (5) and at least one first edge pair of complementary positively locking holding profiles (6, 7) at mutually opposite panel edges, wherein one of the holding profiles (6) has a locking groove (8) with a distally projecting upper groove wall (10) and a lower groove wall (11) which projects distally further than the upper groove wall (10), and comprising a holding bar (12) which projects at the free end of the lower groove wall (11) in the direction of the panel top surface (4) and has a free upper bar end (12a) and at least one undercut holding surface (12b), wherein said holding surface is directed towards the panel core (3) and delimits in the lower groove wall (11) a recess (11a) which is behind the holding bar, wherein the complementary holding profile (7) is provided with a locking tongue (9) which has at least one undercut contact surface (15) which is directed towards the panel core (3') and in the assembled condition co-operates with the holding surface (12b) of the holding bar (12), wherein the locking tongue (9) has a tongue underside (9a) and a tongue top side (16) of which the tongue top side (16) has a distal end (16a) and a proximal end (16b) and is straight or curved and is arranged inclinedly relative to the perpendicular (L) on the panel top surface (4, 4') so that the distal end (16a) is further away from the panel top surface (4, 4') and the proximal end (16b) reaches closer to the panel top surface (4, 4'), wherein in the assembled state there is a play which includes a vertical play (Q) and a horizontal play (P, P') so that the holding profiles (6, 7) are movable perpendicularly to the panel top surface (4, 4') and are movable in a direction which is perpendicular to the panel edges (2, 2') and at the same time parallel to the panel top surface (4, 4'), and wherein an inside (10a) of the upper groove wall (10) is of a straight or curved shape matching the tongue top side (16) and relative to the perpendicular (L) to the panel surface (4, 4') has an angle of inclination (a) which is such that the inclined tongue top side (16) and the inside (10a) of the upper groove wall (10) are in surface contact in the mutually displaced state, characterised in that in that the holding profiles (6, 7) are designed such that the tongue underside (9a) of a new panel of the type of the panel (1) can be placed on the holding bar (12) of a lying panel, and the holding profiles (6, 7) can then be moved towards one another by displacement of this new panel in a direction parallel to the panel plane, so that the panel edges can be locked almost horizontally, i.e. lying in the panel plane, an edge break (12c) is provided between the free upper bar end (12a) of the holding bar (12) and its lower holding surface (12b), wherein the edge break forms a free surface (12d) which has a distal upper end and a proximal end and is of a straight or curved shape, and wherein the free surface (12d) has an angle of inclination β relative to the perpendicular (L) on the panel top surface (4, 4'), with the proviso that in a joining step the tongue underside (9a) of the locking tongue (9) can be placed horizontally on the holding bar (12) of the locking groove (9) and then the tongue top side (16) is slidable against the inside (10a) of the upper groove wall (10) and that at the end of said joining step the distal end (16a) of the tongue top side (16) contacts the inside (10a) of the upper groove wall (10) in the region of the panel core (3').
2. A panel according to claim 1 characterised in that provided between the tongue under (9a) and the undercut contact surface (15) is an edge break which in relation to the edge break (12c) of the holding bar (12) is of a cross-section which is at least 50% smaller.
3. A panel according to claim 1 or claim 2 characterised in that a height (T) of the free surface is ≥ the height (S) of the holding surface of the holding bar (12).
4. A panel according to one of claims 1 to 3 characterised in that a distal end (16a) of the tongue top side (16) in the assembled state is on a level between the upper free bar end (12a) of the holding bar (12) and a proximal end of the free surface (12d) or is above the free bar end (12a) by an amount corresponding to the height (T) of the free surface.
5. A panel according to one of claims 1 to 4 characterised in that the tongue underside (9a) has a sliding surface which is arranged parallel to the panel top surface (4') and in the assembled state is supported on a sliding zone in the recess (11a) of the upper groove wall (11), the sliding zone being arranged in turn parallel to the panel top surface (4).
6. A panel according to one of claims 1 to 5 characterised in that the holding bar (12) forms a contact surface (12f) on which the tongue underside (9a) can be placed at least during the joining operation and the locking tongue (9) has a recess (14) which is open towards the lower panel surface (5) and has a bottom surface (14a).
7. A panel according to claim 6 characterised in that the contact surface (12f) of the holding bar (12) and the bottom surface (14a) of the recess (14) are in mutually parallel and contacting relationship in the assembled state so that within the present play (P, P') they act as sliding surfaces parallel to the panel top surface (4, 4') .
8. A panel according to one of claims 1 to 7 characterised in that the maximum vertical play (Q), when the undercut holding surface (12b) of the locking groove (11) and the undercut contact surface (15) of the locking tongue (9) are in contact, is in a ratio Q/S relative to the height (S) of the holding surface (12b), that is in the range of 0.5 - 2.0, and preferably the ratio Q/S is in the range of 0.8 - 1.2.
9. A panel according to one of claims 1 to 8 characterised in that the angle of inclination α of the inside (10a) of the upper groove wall (10) relative to the perpendicular (L) on the panel top surface (4, 4') is in the range of 30o to 60o.
10. A panel according to one of claims 1 to 9 characterised in that the free surface (12d) of the holding bar (12) is inclined through a free angle β relative to the perpendicular (L) on the panel top surface (4, 4') and the free angle β ≥ angle of inclination (β).
11. A panel according to claim 10 characterised in that0 the free angle β is in the range of 1.0 to 1.5 times the angle of inclination a.
12. A panel according to one of claims 1 to 11 characterised in that provided on the holding bar (12) is a second distal holding surface (23) directed towards the panel core (3, 3') and the locking tongue (9) in matching relationship therewith has a proximal second contact surface (24).
13. A panel according to claim 12 characterised in that the second distal holding surface (23) of the holding bar (12) is arranged at a distal end of the free surface (12d).
14. A panel according to one of claims 1 to 13 characterised in that the panel top surface (4, 4') has an edge break (18) at least on the side of the locking groove (11) or on the side of the locking tongue (9).
15. A panel according to one of claims 1 to 14 characterised in that the panel (1, 32, 33, 34, 35) is quadrangular and has a second edge pair which is provided at mutually opposite panel edges with complementary holding profiles, said holding profiles being identical to the holding profiles (6, 7) of the first edge pair.
16. A method of laying and locking panels of the type according to one of claims 1 to 14 characterised in that the tongue underside (9a) of a new panel is laid on the holding bar (12) of a panel which is already lying on a support surface so that the new panel is displaced lying in the panel plane perpendicularly to the panel edge (2, 2') against the lying panel until the tongue underside (9a) of the new panel has moved beyond the holding bar (12) of the lying panel and moves downwardly into the recess (11a) behind the holding bar (12).
17. A method of laying and locking panels of the type according to claim 15 characterised in that a new quadrangular panel (32) of said type having two identical edge pairs is locked in a second panel row (D2) with panels (33, 34) of an existing first panel row (D1) and at the same time locked to a panel (35) already present in the second row by the new panel (32) being placed with a tongue underside of a locking tongue (32b) on the holding bars (33d, 34d) of the panels (33, 34) of the first panel row (D1) and with the tongue underside of its adjacent locking tongue (32a) on the holding bar (35c) of the panel (35) already present in the second row, then the new panel (32) is displaced in a diagonal direction whereby its two adjacent locking tongues (32a, 32b) are simultaneously brought into engagement, namely the locking tongue (32b) with the locking groove of the panels (33, 34) in the first panel row (D1) and the other locking tongue (32a) with the locking groove of the panel (35) already present in the second row, wherein the tongue undersides of the two adjacent locking tongues (32a, 32b) of the new panel (32) have moved beyond the holding bars (33d, 34d, 35c) of the laid panel and move downwardly into the respective recess behind the holding bar.

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