Abstract
Floor panels (1, 1′) are shown, which are provided with a mechanical locking system that may be locked with a vertical displacement of a first panel against a second panel. The locking system includes a flexible strip (6) that during locking bends upwardly or downwardly. The locking system includes a first (7a) and a second (7b) joint edge section with different locking functions. One section provides a horizontal locking and another section provides a vertical locking.
Claims
1. A set of essentially identical floor panels provided with a mechanical locking system comprising a strip extending horizontally from a lower part of a first edge and a downwardly open locking groove formed in an adjacent second edge, wherein the strip comprises an upwardly protruding locking element configured to cooperate with the locking groove and to lock the first and the second edge in a horizontal direction parallel to a main plane of the floor panels and in a vertical direction perpendicularly to the horizontal direction, wherein the locking system is configured to be locked with a vertical displacement of the second edge against the first edge wherein an outer portion of the strip during an initial stage of the vertical displacement is configured to bend upwards towards the second edge and during a final stage of the vertical displacement is configured to bend downwards towards its initial unlocked position.
2. The set of essentially identical floor panels as claimed in claim 1, wherein the mechanical locking system, along the first edge and the second edge, comprises a first edge section and a second edge section, wherein a cross section of the locking groove or a cross section of the locking element varies along the first edge or the second edge, in a locked position.
3. The set of essentially identical floor panels as claimed in claim 1, wherein an upper portion of the locking element is configured to be displaced during locking into a space provided between an outer groove wall of the locking groove and an inner surface of the locking element.
4. A set of essentially identical rectangular floor panels each comprising long edges and a first short edge and a second short edge, the first short edge and the second short edge being provided with a mechanical locking system comprising a strip extending horizontally from a lower part of a first short edge and a downwardly open locking groove formed in the second short edge, the strip comprises an upwardly protruding locking element that is configured to cooperate with the locking groove for locking the first short edge and the second short edge in a horizontal direction parallel to a main plane of the panels and in a vertical direction perpendicularly to the horizontal direction, wherein the locking element comprises an inner surface, an outer surface and a top surface, the inner surface being positioned closer to an upper edge of the first edge than the outer surface, wherein the locking groove comprises an outer groove wall, an inner groove wall and an upper groove wall, the outer groove wall is positioned closer to the upper edge of the second edge than the inner groove wall, the locking element comprising an upper locking surface and the locking groove comprising a lower locking surface, wherein the upper locking surface is spaced vertically above an uppermost surface of an inner portion of the strip, and wherein in a locked position, the first short edge and the second short edge comprise a horizontal plane, a first joint edge section and a second joint edge section located along the first short edge and the second short edge, the first edge section is configured such that the outer groove wall of the locking groove and the inner surface of the locking element along the horizontal plane are in contact with each other and lock the first short edge and the second short edge horizontally and the second edge section is configured such that along the horizontal plane there is a space between the outer groove wall of the locking groove and the inner surface of the locking element, and the upper locking surface of the locking element and the lower locking surface of the locking groove are configured to be in contact with each other and to lock the first short edge and the second short edge vertically.
5. The set of essentially identical rectangular floor panels as claimed in claim 4, wherein the first edge section is located closer to a long edge than the second edge section.
6. The set of floor panels as claimed in claim 4, wherein the locking system is configured to be locked with a vertical displacement of the second short edge against the first short edge.
7. The set of floor panels as claimed in claim 6, wherein the locking system is configured such that a vertical displacement of the second short edge against the first short edge during an initial stage of the vertical displacement bends the strip upwards towards the second edge such that the upper locking surface and lower locking surface overlap each other.
8. The set of floor panels as claimed in claim 4, wherein the lower locking surface is essentially horizontal.
9. The set of floor panels as claimed in claim 4, wherein the upper locking surface is located on the outer surface of the locking element and the lower locking surface is located on the inner groove wall of the locking groove.
10. The set of floor panels as claimed in claim 4, wherein a tangent line to the lower locking surface intersects the outer wall of the locking groove.
11. A set of essentially identical rectangular floor panels each comprising long edges and a first short edge and a second short edge, the first short edge and the second short edge being provided with a mechanical locking system comprising a strip extending horizontally from a lower part of a first short edge and a downwardly open locking groove formed in the second short edge, the strip comprises an upwardly protruding locking element that is configured to cooperate with the locking groove for locking the first short edge and the second short edge in a horizontal direction parallel to a main plane of the panels and in a vertical direction perpendicularly to the horizontal direction, wherein the locking element comprises an inner surface, an outer surface and a top surface, the inner surface being positioned closer to an upper edge of the first edge than the outer surface, wherein the locking groove comprises an outer groove wall, an inner groove wall and an upper groove wall, the outer groove wall is positioned closer to the upper edge of the second edge than the inner groove wall, the locking element comprising an upper locking surface and the locking groove comprising a lower locking surface, wherein in a locked position, the first short edge and the second short edge comprise a horizontal plane, a first joint edge section and a second joint edge section located along the first short edge and the second short edge, the first edge section is configured such that the outer groove wall of the locking groove and the inner surface of the locking element along the horizontal plane are in contact with each other and lock the first short edge and the second short edge horizontally and the second edge section is configured such that along the horizontal plane there is a space between the outer groove wall of the locking groove and the inner surface of the locking element, and the upper locking surface of the locking element and the lower locking surface of the locking groove are configured to be in contact with each other and to lock the first short edge and the second short edge vertically, wherein the locking system is configured to be locked with a vertical displacement of the second short edge against the first short edge, wherein the locking system is configured such that a vertical displacement of the second short edge against the first short edge during an initial stage of the vertical displacement bends the strip upwards towards the second edge such that the upper locking surface and lower locking surface overlap each other.
12. A set of essentially identical rectangular floor panels each comprising long edges and a first short edge and a second short edge, the first short edge and the second short edge being provided with a mechanical locking system comprising a strip extending horizontally from a lower part of a first short edge and a downwardly open locking groove formed in the second short edge, the strip comprises an upwardly protruding locking element that is configured to cooperate with the locking groove for locking the first short edge and the second short edge in a horizontal direction parallel to a main plane of the panels and in a vertical direction perpendicularly to the horizontal direction, wherein the locking element comprises an inner surface, an outer surface and a top surface, the inner surface being positioned closer to an upper edge of the first edge than the outer surface, wherein the locking groove comprises an outer groove wall, an inner groove wall and an upper groove wall, the outer groove wall is positioned closer to the upper edge of the second edge than the inner groove wall, the locking element comprising an upper locking surface and the locking groove comprising a lower locking surface, wherein in a locked position, the first short edge and the second short edge comprise a horizontal plane, a first joint edge section and a second joint edge section located along the first short edge and the second short edge, the first edge section is configured such that the outer groove wall of the locking groove and the inner surface of the locking element along the horizontal plane are in contact with each other and lock the first short edge and the second short edge horizontally and the second edge section is configured such that along the horizontal plane there is a space between the outer groove wall of the locking groove and the inner surface of the locking element, and the upper locking surface of the locking element and the lower locking surface of the locking groove are configured to be in contact with each other and to lock the first short edge and the second short edge vertically, wherein a tangent line to the lower locking surface intersects the outer wall of the locking groove.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The disclosure will in the following be described in connection to exemplary embodiments and in greater detail with reference to the appended exemplary drawings, wherein:
(2) FIGS. 1a-1g illustrate a fold down locking systems according to known principles.
(3) FIGS. 2a-2c illustrate known principles to form locking systems.
(4) FIGS. 3a-3e illustrate vertical folding and edge separation.
(5) FIGS. 4a-4f illustrate bending of protruding parts.
(6) FIGS. 5a-5b illustrate a first and a second edge section of a locking system according to one embodiment.
(7) FIGS. 6a-6b illustrate the first and second edge sections of the locking system in FIGS. 5a-5b in a locked position.
(8) FIGS. 7a-7d illustrate alternative embodiments of the first and second edge sections.
(9) FIGS. 8a-8c illustrate a vertical displacement of a first edge section according to an embodiment.
(10) FIGS. 9a-9e illustrate a vertical displacement of a second edge section according to an embodiment.
(11) FIGS. 10a-10c illustrate jumping tool heads and rotating carving tools according to an embodiment.
(12) FIGS. 11a-11f illustrate forming of an edge section with jumping tool heads according to an embodiment.
(13) FIGS. 12a-12b illustrate forming with carving tools according to different embodiments.
(14) FIGS. 13a-13e illustrate a panel edge comprising a first and a second edge section according to an embodiment.
(15) FIGS. 14a-14e illustrate different embodiments of locking systems and their formation.
(16) FIGS. 15a-15d illustrate a locking system according to a second principle.
(17) FIGS. 16a-16c illustrate a locking system edge section according to the second principle.
(18) FIGS. 17a-17d illustrate a method to strengthen a protruding part according to an embodiment.
(19) FIGS. 18a-18f illustrate an embodiment of a production method to form a locking system.
(20) FIGS. 19a-19f illustrate another embodiment of a production method to form a locking system.
(21) FIGS. 20a-20d illustrate locking of long and short edges according to an embodiment and forming of a locking system according to an embodiment.
(22) FIGS. 21a-21e illustrate a long edge locking system according to an embodiment.
(23) FIGS. 22a-22d illustrate a long edge locking system according to an embodiment.
(24) FIGS. 23a-23d illustrate locking of furniture components according to an embodiment.
(25) FIGS. 24a-24f illustrate a locking system formed according to a third principle.
(26) FIGS. 25a-25d illustrate various embodiments of flex grooves provided in the second floor panel.
(27) FIGS. 26a-26b illustrate various embodiments of slits provided in the first floor panel.
(28) FIGS. 27a-27c illustrate an embodiment with a flexible and a bendable locking element.
DETAILED DESCRIPTION
(29) FIGS. 1a-1f show some examples of known fold down locking systems made in one piece with the core 5 that are intended to lock short edges with a vertical displacement of a second edge of a second panel 1′ against a first edge of a first panel 1. All systems comprise a horizontally protruding strip 6 with a locking element 8 in the first edge of the first panel 1 that cooperates with a locking groove 14 in the second edge of the second panel 1′ and locks the edges of the panels 1, 1′ horizontally. Different methods are used to lock the edges vertically.
(30) FIG. 1a shows that a small tongue 10 that cooperates with a tongue groove 9 may be used for the vertical locking. Compression of the tongue 10 is required to accomplish the locking. The upper edges are, during the vertical displacement, spaced from each other with a space S that corresponds to the horizontal protrusion of the tongue 10. The adjacent edges must be pulled together during the final stage of the locking. The friction between the long edges, that during the final stage of the locking are practically aligned horizontally and are in a locked position, prevents such pulling together and there is a major risk that the edges are locked with a space or that the locking element 8 is damaged. A considerable pressure force is required to press the edges together and thickness tolerances may create further problems, especially if the second panel 1′ is thicker than the first panel 1 and will hit the subfloor before the upper surfaces are aligned horizontally. The locking system is not suitable to lock panels comprising, for example, an HDF core or other non-compressible materials.
(31) FIG. 1b shows a similar locking system with two tongues 10a, 10b and two tongue grooves 9a, 9b. This system requires material compression and creates edge separation during locking. The locking surfaces are almost vertical and have a locking angle LA of about 60 degrees against a horizontal plane H. The protruding tongues are very small and protrude a few tenths of a millimeter and this corresponds to normal production tolerances resulting in locking system that are not possible to lock or without any overlapping locking surfaces.
(32) FIG. 1c shows a locking system with two tongues 10a, 10b. The locking element comprises a locking surface that is inclined upwardly towards the upper edge in order to increase the vertical locking strength. This locking system is even more difficult to lock than the locking systems described above and suffers from the same disadvantages.
(33) FIG. 1d shows an embodiment that is based on downwardly protruding locking elements that are intended to bend inwardly against each other such that two tongues 10a, 10b may be inserted into tongue grooves. The flexibility that may be obtained over the limited vertical extension of the locking elements in an HDF material is not sufficient to obtain a locking force necessary for flooring applications. However, the locking system eliminates separation forces during locking.
(34) FIG. 1e shows a locking system wherein similar flexibility is obtained with a groove formed behind the locking groove 14. Such locking systems suffer from the same disadvantages as the locking system shown in FIG. 1d. Similar locking system may also comprise locking surfaces 10b, 9b that are shortened in regions, for example as described in WO 2010/100046, in order to reduce damages of the locking means during installation when material is compressed. In practice no reduction of damages may be obtained.
(35) FIG. 1f shows a locking system comprising a strip 6 that is bended downwards during the vertical displacement. The locking system is intended to be used together with an installation method wherein the long edges of the first and the second panels are in an angled position such that the friction forces are reduced to a level where the locking element during upward snapping is capable to automatically pull the edges together. The major disadvantage is that the installation must be made with panels in angled position and this is more complicated than the conventional single action fold down installation.
(36) FIG. 1g shows locking systems that may comprise slits 6a in the locking strip, for example as described in US 2010/0037550 or slits 14a behind the locking groove, for example as described in WO 2008/116623. Such slits may increase the flexibility and the horizontal displacement possibilities of the locking elements considerably and a very easy locking may be obtained. The main problem is that such slits also increase the vertical flexibility and flexibility. This will result in a very low locking strength in the vertical direction. Therefore attempts to introduce such locking systems have failed.
(37) FIGS. 2a-2c show that the geometry of the locking systems is restricted in several ways by the production methods wherein double-end tenors comprising a chain 33, a belt 34 and several large rotating tools 17 with a diameter of about 20 cm are used. FIGS. 2a and 2b show that efficient production methods require that grooves and protrusions are formed with rotating tools 17 that rotate vertically or horizontally or that are angled away from the chain 33 and the belt 34. FIG. 2c shows that only essentially vertical locking surfaces may be formed on an inner part of the locking element 8 or on the locking groove 14 and that very small rotating tools with a low milling capacity may be used. Several of the known locking systems are not possible to produce in a cost efficient way.
(38) FIGS. 3a-3e explain the separation forces that may occur during vertical folding when a second panel 1′ is angled against a previously installed panel 1″ in a previous row and wherein this angling action also connects a short edge of the second panel 1′ to a short edge of a first panel 1 as shown in FIG. 3a. The short edges are locked with a scissor like movement wherein the short edges are gradually locked from one long edge to the other long edge. The adjacent short edges of the first and the second panels 1, 1′ have along their edges a start section 30 that becomes active during a first initial step of the folding action, a middle section 31 that becomes active during a second stage of the folding action and an end section 32 that becomes active during a final third step of the folding action.
(39) The shown locking system is based on an embodiment with a strip 6 that during vertical displacement bends downwards and thereafter snaps upwards. FIG. 3b shows that one part of the edge, that is close to the long edge where the angling takes place, is almost in locked position, as shown by the cross section A-A, when the locking element 8 and the locking groove 14 of middle sections B-B are still spaced from each other vertically, as shown in FIG. 3c, and when edge sections C-C that are most distant to the long edge where angling takes place are spaced from each other vertically without any contact between the cross sections C-C as shown in FIG. 3d. FIG. 3e shows the final step of the locking when the edges must be pulled together with a pulling force that is sufficient to overcome the friction between long edges of the first installed panel 1″ and the second panel 1′. The friction may be substantial, especially when the panels are long or when a high friction material is used as a core. The high friction is to a large extent caused by the geometry of the long edge locking system that must be formed with a tight fit between the tongue and the tongue groove in order to avoid squeaking sound.
(40) FIGS. 4a and 4b show a one piece locking system formed in a laminate floor panel comprising an HDF core. The locking system is locked with horizontal snapping. The HDF material comprises wood fibres 24 that during HDF production obtain an essentially horizontal position in the core material. The density profile is such that the upper 5a and the lower 5b parts of the core 5 have a higher density than the middle parts. These outer portions are also reinforced by the melamine resin from the impregnated paper of the surface 2 and in the balancing layers 3 that during lamination penetrates into the core 5. This allows that a strong and flexible strip 6 may be formed that, during locking, bends downwards. The snapping function is supported by the upper lip 9′ that bends slightly upwards and the protruding tongue 10 that bends slightly downwards. The locking element may easily be formed with a high locking angle and with essentially vertical locking surfaces.
(41) As a comparison, bending of vertically protruding locking elements 8 are shown in FIGS. 4c-4f. FIGS. 4c and 4d show a locking element 8 that during vertical displacement is bended outwardly. The bending takes place in the rather soft part of the HDF core and a crack 23 will generally occur in the lower part of the locking element 8. FIGS. 4e and 4f show a locking element 8 that is used to lock against a locking groove 14 in a horizontal H and a vertical direction V. The locking can only take place with material compression and this causes damages and cracks 23, 23′ in the locking system.
(42) FIGS. 5a and 5b show a first embodiment of the disclosure according to a first main principle. A set of similar floor panels 1, 1′ are provided, wherein each floor panel preferably comprises a surface layer 2, a core 5, a balancing layer 3 and a first and a second short edge. A first short edge 4c of a first floor panel 1 may be locked to an adjacent second short edge 4d of a similar second floor panel 1′ with a vertical displacement of the second edge against the first edge. According to the present embodiment, the vertical displacement is a vertical scissor movement caused by the same angling action that is used to connect the long edges of the panels. The first short edge 4c comprises a horizontally protruding strip 6 with a vertically protruding locking element 8 at its outer part that cooperates with a downwardly open locking groove 14 formed in the adjacent second edge 4d.
(43) According to the present embodiment, the locking element 8 is essentially rigid and is not intended to be bended or compressed during locking that contrary to known technology is accomplished essentially with a horizontal displacement of the upper part of the locking element 8 towards the upper first edge 43. By essentially rigid is here meant that during locking the locking element itself is bended and/or compressed in a horizontal direction by a distance HD that is less than 50% of a horizontally protruding upper locking surface 11a located in the upper part of the locking element 8 as shown in FIG. 6b. The displacement of the locking element 8 is mainly accomplished with a bending and/or deformation of the strip 6. The locking element comprises an inner surface 8a, an outer surface 8b and an upper or top surface 8c. The inner surface 8a is closer to an upper edge 43 of the first panel 1 than the outer surface 8b. More specifically, a horizontal distance between the inner surface 8a and the upper edge 43 is smaller than a horizontal distance between the outer surface 8b and the upper edge 43. According to the present embodiment, the upper edge 43 is a portion of the first edge close to the front side of the first panel 1.
(44) Moreover, the upper edge 43 is provided in a side wall 45 of an indentation 44 which is provided in the first edge. The indentation 44 is upwardly open and, in a locked position, an upper support surface 16 of a projection 46 provided in the second edge engages with a lower support surface 15 of the indentation which is a portion of an upper strip surface 6a of the strip 6. The locking groove 14 comprises an outer groove wall 14a, an inner groove wall 14b and an upper groove wall 14c.
(45) The projection 46 is provided outside of the locking groove 14 and share the outer groove wall 14a with the locking groove 14. The outer groove wall 14a is closer to an upper edge 43′ of the second panel 1′ than the inner groove wall 14b. More specifically, a horizontal distance between the outer groove wall 14a and the upper edge 43′ is smaller than a horizontal distance between the inner groove wall 14b and the upper edge 43′. The locking element 8 comprises an upper locking surface 11a formed in the outer surface 8b of the locking element 8 that cooperates with a lower locking surface 11b formed in the inner groove wall 14b and that locks the adjacent edges in a vertical direction. The upper 11a and the lower 11b locking surfaces are spaced vertically upwards from the upper surface 6a of the strip 6. For example, the upper 11a and the lower 11b locking surfaces may be spaced vertically upwards with a vertical locking distance VLD from the entire upper surface 6a or from an uppermost part of the upper surface 6a, e.g. the lower support surface 15 of the indentation 40. In non-limiting examples, VLD may be between 20% and 70%, e.g. 30%, 40% or 50%, of a thickness T of the floor panels in the vertical direction. The locking element 8 comprises a first locking surface 12a formed in the inner surface 8a of the locking element 8 that cooperates with a second locking surface 12b formed in the outer groove wall 14a and that locks the adjacent edges in a horizontal direction.
(46) According to an alternative embodiment, the locking element 8 may be configured to bend during locking.
(47) Adjacent edges comprise in locked position a first edge section 7a and a second edge section 7b. The edge sections are characterized in that a cross section of the locking groove 14 and/or a cross section of the locking element 8 varies along the adjacent edges of the panels 1, 1′ which are formed with a basic geometry that is thereafter modified such that the first 7a and the second 7b cooperating edge sections are formed with different geometries and different locking functions. Here, the geometries and cross sections are specified in a side view of the panels as shown in FIGS. 5a and 5b.
(48) The first edge section 7a is preferably a start section 30 that becomes active during a first initial step of the folding action and the second edge section 7b is preferably a subsequent section 31 or a middle section 31 that becomes active during a second step of the folding action.
(49) It is clear that, according to an alternative embodiment, the second edge section 7b may be a start section 30 that becomes active during a first initial step of the folding action and that the first edge section 7a may be a subsequent section 31 or a middle section 31 that becomes active during a second step of the folding action. This is shown in FIG. 26b.
(50) FIG. 5a shows a first cooperating edge section 7a that is used to prevent edge separation during locking and to lock adjacent edges horizontally in the locked position. The first edge section 7a has no vertical locking function since one of the locking surfaces, in this preferred embodiment the upper locking surface 11a, has been removed. The first 12a and the second 12b locking surfaces are preferably vertical and they are used to guide the second panel 1′ during the vertical displacement along a vertical plane VP that intersects the upper and outer edge 21 of the first panel 1.
(51) The first 12a and the second 12b locking surfaces may be inclined against the vertical plane VP. Such geometry may be used to facilitate unlocking of the short edges with an angling action. A locking system with vertical first 12a and second 12b locking surfaces may be unlocked with a sliding action along the short edges.
(52) FIG. 5b shows the second edge section 7b that is used to lock the adjacent edges vertically. The second edge section 7b cannot prevent edge separation and has no horizontal locking function since a part of the locking element 8 and/or the locking groove 14 has been removed in order to form a space S along a horizontal plane HP that allows a turning or displacement of the locking element 8 inwardly during locking when the second edge 1′ is displaced vertically along the vertical plane VP.
(53) The turning of the locking element 8 is mainly caused by an upward bending of a part of the strip 6 within the second edge section 7b that takes place when a horizontal pressure is applied by a part of the inner groove wall 14b on the outer surface 8b of the locking element 8 during the vertical displacement of the second edge 4d against the first edge 4c. Such locking function provides major advantages. No material compression is required and the material properties of the protruding strip may be used to obtain the necessary flexibility that is needed to displace the upper part of the locking element 8 in order to bring the upper and lower locking surfaces 11a, 11b in a locked position.
(54) According to the present embodiment, the space S has a vertical extension substantially corresponding to a vertical extension of the inner surface 8a so that it extends down to the upper strip surface 6a. It is clear that, according to alternative embodiments (not shown), the space S may have a smaller vertical extension.
(55) Preferably, however, the space S is located at an upper part of the locking element 8. Moreover, the vertical extension is preferably larger than a vertical extension of an upper protruding part 25 formed on an outer and upper part of the locking element 8, e.g. 15, 2 or 3 times larger.
(56) In a first example, the vertical extension of the space S varies along the edge. The vertical extension may vary along the edge from a minimal vertical extension to a maximal vertical extension and then, optionally, back to a minimal vertical extension. The variation may be smooth.
(57) In a second example, the vertical extension of the space S is constant along the edge. A first and a second wall of the space S that are spaced from each other along the edge may be vertical and parallel.
(58) By way of example, the space S may be formed by means of milling, scraping, punching, perforation or cutting.
(59) The strip 6 and the locking element 8 are during locking twisted along the first short edge. In the first edge section 7a, the strip 6 is essentially in a flat horizontal position during locking and in the second edge section 7b the strip 6 is bended upwards and the locking element 8 with its upper locking surface is turned and/or displaced inwardly during locking.
(60) Optionally, or alternatively, at least portions of the strip 6 may be twisted and/or compressed during locking. For example, a portion between a lower part of the strip 6b and the upper strip surface 6a and/or the locking element 8 of the strip 6 may be twisted and/or compressed. The twisting may occur at least around an axis that is perpendicular to the vertical plane VP. The compression may occur at least inwardly in a horizontal direction that is perpendicular to the vertical plane VP. In particular, the strip 6 may be twisted in the transition regions between the first 7a and second 7b edge sections. Moreover, the strip 6 may become compressed in the second edge section 7b and such compression may facilitate a displacement of the locking element 8 even in rather rigid materials since the material content of the strip 6 is much larger than the material content of the locking element 8. As an example it may be mentioned that the locking element 8 may have a horizontal extension of about 4 mm and the strip 6 may protrude horizontally about 8 mm from the side wall 45 and to the inner surface 8a of the locking element. At a compression of 1%, the locking element will contribute with 0.04 mm or with about ⅓ of a total compression and the strip with 0.08 mm or with about ⅔ of the total compression.
(61) Generally, the locking element in an HDF based laminate floor must be displaced horizontally with a distance of at least 0.2 mm in order to provide sufficient locking strength. 0.4 mm is even more preferred. Depending on the joint geometry and material properties about ⅓ of the necessary displacement may be accomplished with material compression and ⅔ with bending and turning or twisting of the strip and the locking element.
(62) The upper 11a and lower 11b locking surfaces are preferably essentially horizontal. The locking surfaces are in the showed embodiment inclined against a horizontal plane HP with a locking angle LA that is about 20 degrees. The locking angle LA is preferably 0-45 degrees. Locking surfaces with low locking angles are preferred since they provide a stronger vertical locking. The most preferred locking angle LA is about 5-25 degrees. However it is possible to reach sufficient locking strength in some applications with locking angles between 45 and 60 degrees. Even higher locking angles may be used but such geometries will decrease the locking strengths considerably.
(63) FIGS. 6a and 6b show the first 7a and the second 7b edge sections in a locked position. The first edge section 7a is configured such that the outer groove wall 14a of the locking groove 14 and the inner surface 8a of the locking element 8 are in contact with each other along a horizontal plane HP and lock the first short edge and the second short edge horizontally and the second edge section 7b is configured such that along the same horizontal plane HP there is a space S between the outer groove wall 14a of the locking groove 14 and the inner surface 8a of the locking element 8. The space S allows that the locking element 8 may be turned and/or displaced inwardly. The first edge section 7a is also preferably configured such that there is no vertical locking and no turning and/or displacement of the locking element 8 since at least one of the locking surfaces 11a, 11b has been removed and the second edge section 7b is configured such that it comprises upper 11a and lower 11b locking surfaces that lock the edges vertically and upper and lower 26 protruding parts that during locking press, displace and/or turn the locking element 8 inwardly. Also compression and/or twisting are possible.
(64) FIG. 6a shows the first edge section 7a in a locked position. The first locking surface 12a formed on the inner surface 8a of the locking element 8 is in contact with the second locking surface 12b formed on the inner groove wall 14a of the locking groove 14. The first 12a and the second 12b locking surfaces lock the adjacent edges horizontally and prevent a horizontal separation of the panels 1, 1′.
(65) FIG. 6b shows the second edge section 7b in a locked position. The upper locking surface 11a formed on the outer surface 8b of the locking element 8 is in contact with the lower locking surface 11b formed on the inner groove wall 14b of the locking groove 14. The upper 11a and lower 11b locking surfaces lock the adjacent edges vertically and prevent a vertical separation of the panels 1, 1′.
(66) According to the present embodiment, there is an intermediate cavity 47 provided between a portion of the upper support surface 16 and a portion of the upper strip surface 6a. Since a thickness of the strip 6 in this area is smaller than at the location of the lower support surface 15, the strip may be bended more easily. The upper support surface 16 preferably is a planar surface and the projection 50 preferably has a constant thickness in a direction perpendicular to the vertical plane VP as measured from its surface layer 2. The thickness is preferably also constant along the edge of the second panel 1′.
(67) According to an alternative embodiment (not shown), however, the thickness of the projection 50 may vary in a direction perpendicular to the vertical plane VP.
(68) Thereby, least a portion of the projection 46 may extend below the lower support surface 15.
(69) The space S is an essential feature in this embodiment of the disclosure. A horizontal extension of the space S along a horizontal plane HP that intersects the upper 11a and lower 11b locking surfaces preferably exceeds a horizontal distance HD of the upper and lower locking surfaces. Here, the horizontal extension of the space S may be a maximal horizontal extension.
(70) FIG. 7a shows a preferred embodiment of the first edge section 7a where a part of the inner groove wall 14b and the lower locking surface 11b have been removed. FIG. 7b shows a preferred embodiment of the second edge section 7b where a part of the outer groove wall 14a has been removed in order to form the space S that allows the locking element 8 to turn inwardly during locking.
(71) According to the present embodiment, the space S has a vertical extension substantially corresponding to a vertical extension of the outer groove wall 14a so that it extends up to the upper groove wall 14c. It is clear that, according to alternative embodiments (not shown), the space S may have a smaller vertical extension. Preferably, however, the space S is located adjacent to the upper groove wall 14c. Moreover, the vertical extension is preferably larger than a vertical extension of the upper protruding part 25, e.g. 1.5, 2 or 3 times larger.
(72) The vertical extension of the space S may vary or may be constant along the edge as explained above in relation to the embodiment in FIGS. 5a-b.
(73) FIGS. 7c and 7d show that the embodiments shown in FIGS. 5a, 5b and 7a, 7b may be combined. As shown in FIG. 7c, the first edge section 7a configured to prevent edge separation and to lock horizontally may be formed according to FIG. 7a and the second edge section 7b comprising the space S and configured to bend and to lock vertically may be formed according to FIGS. 5b and 6b. Alternatively, as shown in FIG. 7d, the first edge 7a section may be formed according to FIG. 5a or 6a and the second edge section 7b may be formed according to FIG. 7b.
(74) It is stressed that any of the additional and/or optional features described above in relation to the embodiments in FIGS. 5a-5b, 6a-6b and 7a-7b also may be combined with the embodiment according to FIGS. 7c and 7d.
(75) In any of the embodiments in the present disclosure, there may also be an upper cavity 48 between the upper groove wall 14c and the upper surface 8c in a locked position of the first 1 and second 1′ panel. The upper cavity 48 may be located in the second edge second 7b and optionally also in the first edge section 7a.
(76) Thereby, there is more space provided in the second edge section 7b for the upwardly bending locking element 8.
(77) Additionally, it is clear that there may be at least one first edge section 7a and at least one second edge section 7b. In particular, there may be a plurality of first 7a and second 7b edge sections along the edge. The first 7a and second 7b edge sections may be arranged alternately. In particular, the edge sections may be arranged in a sequence along the edges such as {7a, 7b, 7a}, {7a, 7b, 7a, 7b, 7a} or {7a, 7b, 7a, 7b, 7a, 7b, 7a} with a first edge section 7a at the corners of the edges.
(78) Alternatively, there may be a second edge section 7b at the corners of the edges so that a sequence such as {7b, 7a, 7b}, {7b, 7a, 7b, 7a, 7b} or {7b, 7a, 7b, 7a, 7b, 7a, 7b} is provided along the edges.
(79) FIGS. 8a-8c show vertical displacement of the first edge section 7a that according to the present embodiment constitutes a start section 30 and that is active from an initial first step of the folding action. The embodiments in FIGS. 8a-8c and 9a-9d may be understood in conjunction with FIG. 13a. The end section 32 that is active during the final step of the folding action is preferably also formed with geometry similar or identical to the first edge section 7a. The start 30 and end 32 sections are arranged at a first and a second corner section, respectively, of the first 1 and second 1′ panels, adjacent to their long edges 4a, 4b. A part of the inner surface 8a of the locking element 8 is formed as a first locking surface 12a that is essentially parallel with a vertical plane VP and a part of the outer groove wall 14a is formed as a cooperating second locking surface 12b that preferably is essentially parallel with the vertical plane VP. The first and the second locking surfaces 12a, 12b guide the edges of the panels 1, 1′ during the folding action and counteract separation forces that are caused by the second edge section 7b that becomes active in a second step of the folding action when the major part of the first section 7a is in a horizontally locked position with the first 12a and the second 12b locking surfaces in contact with each other as shown in FIG. 8b. FIG. 8c shows the adjacent edges in a final locked position.
(80) FIGS. 9a-9d show locking of the second edge section 7b that according to the present embodiment constitutes a middle section 31 and that is active from a second step of the folding action when the guiding and locking surfaces 12a, 12b of the first edge section 7a are active and in contact with each other. FIG. 9a shows that a horizontally extending upper protruding part 25 is formed on the outer and upper part of the locking element 8 and above the upper locking surface 11a and is in initial contact with a sliding surface 27 formed on a lower part of the inner groove wall 14b. The sliding surface 27 extends essentially vertically upwards to a horizontally extending lower protruding part 26 formed below the lower locking surface 11b. The sliding surface 27 will during the vertical displacement create a pressure force F against the upper protruding part 25 and this will press the locking element 8 inwardly towards the upper edge of the first panel 1 and bend the strip 6 upwards as shown in FIG. 9b.
(81) The pressure against the locking element 8 will create separation forces tending to displace the second panel 1′ horizontally away from the first panel 1, but that are counteracted by the first and the second locking surfaces 12a, 12b of the first edge section 7a. The pressure that is needed to lock the edges may be reduced if the sliding surface 27 is essentially vertical and extends over a substantial vertical sliding distance SD, measured vertically over a distance where the inner groove wall 14b is in contact with the outer surface 8b of the locking element during the vertical displacement, and/or if the vertical extension VE of the locking element 8, defined as the vertical distance from the lowest point on the upper surface of the strip 6a and to the upper surface 8c of the locking element 8, is large. Preferably, the inclination of the sliding surface 27 is 10-30 degrees in relation to a vertical plane VP and the vertical sliding distance SD is 0.2-0.6 times the size of floor thickness T. A vertical sliding distance SD of 0.3-0.5 times the size of floor thickness T is even more preferred. Preferably, the vertical extension VE of the locking element 8 is 0.1-0.6 times the size of floor thickness T.0.2*T-0.5*T is even more preferred.
(82) An upward bending of a strip is suitable for wood based cores, such as for example HDF, since the fibres in the upper part of the strip that are sensitive to pulling forces and shear stress will be compressed and the fibres in the lower and stronger part of the strip that are more resistant to pulling forces and shear stress will be stretched.
(83) A considerable amount of bending deflection 29 may be reached and a strip 6 that extends horizontally from the upper edge about 8 mm or with the same distance as the floor thickness T may be bended upwards about 0.05-1.0 mm, e.g. 0.1 mm or 0.5 mm. Here, a bending deflection 29 is defined as a vertical distance, in a direction perpendicular to the horizontal plane HP, from a horizontal plane HR being parallel and essentially coinciding with the rear side 60 of the first panel 1 in an unlocked state to an outermost and lowermost part of the strip 6. Thus, the bending deflection 29 typically varies along the edge of the first panel 1 and also varies during the various stages of the locking. A maximal bending deflection 29 may be located in a middle portion of a second edge section 7b along a length direction of the edges.
(84) FIG. 9c shows an embodiment according to which the upper and lower locking surfaces 11a, 11b will start to overlap each other already when the upper surfaces of panels 1, 1′ are still spaced vertically. This means that the strip 6 will pull the second panel 1′ comprising an upper support surface 16 towards a lower support surface 15 formed on the edge of a first panel 1 to a final locked position and this will reduce the pressure force that is required to lock the panels 1, 1′. An additional advantage is that the vertical locking may be made with a pretension such that the strip 6 is slightly bended upwards in locked position as shown in FIG. 9d. The remaining bending deflection 29 in the locked position may be about 0.05-0.30 mm, e.g. 0.1-0.2 mm, when the lower and upper support surfaces 15, 16 are in contact with each other. According to this embodiment, the locking system is configured such that in the locked position a middle section 31 comprises a strip 6 that is upwardly bended compared to its unlocked position and a start section 30 that comprises a strip which is essentially in a similar locked position than in an unlocked position. It is understood that there may be transition parts between the first 7a and second 7b edge sections wherein the strip is upwardly bended.
(85) According to a different embodiment, the strip of the start section may even be slightly bended backwards in locked position.
(86) Another advantage is that problems related to thickness tolerances of the panels may be avoided since even in the case that the second panel 1′ is thicker than the first panel 1 and normally will hit the sub floor 35 before the upper surfaces are in the same horizontal plane, locking may be made with offset upper edges where the surface of the second edge is above the first edge and the strip will pull the panels to a correct position with horizontally aligned upper surfaces and upper and lower support surfaces 15, 16 in contact with each other. Such locking function is also favorable when the floor panels are installed on a soft underlay, such as foam, and a counter-pressure from the sub floor cannot be used to prevent a downward bending of the strip 6.
(87) A strip formed in soft materials such as an LVT core comprising thermoplastic materials and filler may not snap back towards the initial position after the locking.
(88) This may be solved with a joint geometry where the upper groove wall 14c is formed to be in contact with the upper surface 8c of the locking element 8 during the final stage of the locking action such that the locking element 8 and the strip 6 are pressed downwards. The locking system may also be formed with an outer and lower support surface 15a that cooperates with the projection 46 during locking in order to press the strip 6 downward to or towards its initial position as shown in FIG. 9b.
(89) FIG. 9e shows that the strip 6 may be formed such that an inner part 6c is bended slightly downwards and an outer part 6d is bended slightly upwards. Such strip bending and compression will also bend and displace the locking element 8 inwards toward the first upper edge 43. The upper and lower locking surfaces 11a, 11b may even in this embodiment overlap each other during locking when the first and the second panels are still vertically displaced in relation to the final locked position with the second panel 1′ spaced vertically upward from the first panel 1.
(90) FIGS. 10a and 10b show that rotating jumping tool heads 18 may be displaced horizontally and may be used to form cavities 42, nonlinear grooves 36 or may be displaced vertically and may be used to form grooves 37 with different depths in a panel 1. FIG. 10c shows another cost efficient method to form cavities 42 or grooves 36, 37 with a rotating carving tool 40. A tool rotation of the rotating carving tool 40 is synchronized with a displacement of the panel 1 and each tooth 41 forms one cavity 42 at a predetermined position and with a predetermined horizontal extension along an edge of a panel 1. It is not necessary to displace the carving tool 40 vertically. A carving tool 40 may have several sets of teeth 41 and each set may be used to form one cavity. The cavities 42 may have different cross sections depending on the geometry of the teeth. The panel 1 may be displaced with or against the tool rotation.
(91) This production technology may be used to form the first 7a and the second 7b edge sections.
(92) FIGS. 11a-11f show that a rotating tool 17 may be displaced horizontally along the locking element 8 or the locking groove 14 and a first 7a and a second 7b edge section will be formed when the tool initially removes the upper protruding part 25 of the locking element and then a part of the inner surface 8a of the locking element, or initially removes the lower protruding part 26 of the locking groove 14 and then a part of the outer groove wall 14a of the locking groove 14. This method may be used to form the edge sections in a very efficient way. The horizontal displacement of the rotation tool 17 may be at or less than about 1.0 mm, e.g. 0.5 mm or 0.2 mm.
(93) FIGS. 12a-12b show a fixed carving tool 22 and a part of the edge of the second panel 1′ that is shown with the surface layer 2 pointing downwards. Carving may be used to form an essentially horizontal locking surface 11b in an inner groove wall 14b of the locking groove 14 even when the locking surface 11b comprises a tangent line TL that intersects the outer groove wall 14a. A more detailed description of carving may be found in WO 2013/191632.
(94) FIG. 13a shows a vertical folding of a second panel 1′ against a first panel 1, comprising a locking system according to FIGS. 8a-c and 9a-d. The edges comprise a start section 30 that is formed as a first section 7a, a middle section 31 that is formed as a second section 7b and an end section 32 that is formed as a first section 7a. The first 12a and second 12b locking surfaces are guiding surfaces of the start section that prevent separation and the panels 1, 1′ are folded together with upper edges in contact. FIG. 13b shows an embodiment of a short edge 4c of the first panel 1 comprising a middle section being a second edge section 7b and having an upper protruding part 25 with an upper locking surface 11a and a first edge section 7a on each side of the middle section 7b comprising guiding surfaces 12a. A part of the inner surface 8a of the locking element 8 has been removed at the middle section 7b in order to form a space S that allows an inward turning of the locking element 8, cf. FIG. 5b. FIG. 13c is a top view of the short edge 4c of the first panel 1 as shown in FIGS. 13a and 13b and shows that a part of the strip 6 at a transition part 6c, located between the first 7a and the second 7b edge section, is twisted during the vertical folding since the strip is flat in the first edge section 7a and bended upwards in the second section 7b. The twisting increases the locking pressure that has to be used to lock the edges. Twisting may be reduced or even eliminated if needed with a horizontal cavity 28 formed in the strip 6 between the first 7a and the second 7b edge sections as shown in FIG. 13d.
(95) FIGS. 14a-14e show different embodiments of the disclosure. The embodiments in FIGS. 14a-e may be combined with any of the embodiments of the disclosure. FIG. 14a shows floor panels comprising an HDF core 5 and a strip 6 which is essentially formed in the lower part 5b of the core 5 that has a higher density than the middle part. At least parts of the locking groove 14 and/or the locking element 8 may be coated with a friction reducer 22 in order to reduce friction during locking. For example, the friction reducer 22 may comprise wax. Other exemplary friction reducing substances include oils. Parts of the locking groove 14 and/or the locking element 8 may be impregnated with a reinforcement agent, e.g. resins, in order to reinforce parts adjacent to upper and lower locking surfaces 11a, 11b. Exemplary reinforcement agents include a thermoplastic, a thermosetting resin or a UV curing glue.
(96) FIG. 14b shows a locking system formed in a rather soft core 5. The strip 6 and the locking element 8 have been made larger. A lower essentially horizontal locking surface 11b may be formed by an inclined rotating tool 17 and with a locking angle LA that may be as low as 20 degrees. It is clear that other locking angles LA are equally conceivable. In non-limiting examples, a locking angle LA between 0° and 45° may be formed by the inclined tool 17.
(97) FIG. 14c shows that forming of the lower locking surface 11b may be made with a rotating jumping tool that only removes material mainly within the second edge section 7b. An advantage is that the lower locking surface 11b may be formed with a rotating tool that will not reduce the vertical extension of the second locking surface 12b.
(98) FIG. 14d shows that in some embodiments the first section 7a may comprise locking means 11a, 11b that lock the edges vertically, preferably mainly by material compression. The locking means may be locking surfaces 11a, 11b. In general, the edge sections 7a, 7b may comprise complementary locking means as described in FIGS. 1a-1e, for example a small tongue 10 and groove 9 at the adjacent edges as shown in FIG. 1a.
(99) FIG. 14e shows that panels 1, 1′ with different thicknesses may be produced with the same tool position in relation to the surface layer 2. This means that the strip 6 will be thicker and more rigid in thicker panels. This may be compensated by removal of materials at the lower part 6d of the strip 6 and all panels may comprise a strip 6 with similar flexibility and deflection properties.
(100) FIGS. 15a-15d show a second principle of the disclosure. The locking element 8 comprises an upper locking surface 11a formed at the inner surface 8a and the locking groove 14 comprises a lower locking surface 11b formed in the outer groove wall 14a. A strong vertical locking may be accomplished if the locking surfaces 11a, 11b are essentially horizontal, e.g., within 20 degrees of horizontal. Preferably, a tangent line TL of the upper locking surface 11a intersects an adjacent wall of the upper edge. Moreover, a tangent line TL of the lower locking surface 11b preferably intersects an adjacent wall of the locking groove 14. Locking is accomplished with a downward bending of the strip 6 wherein the locking element 8 is turned outwards as shown in FIG. 15b. A problem is that the strip 6 may still be in a backward bended position and the locking surfaces 11a, 11b may be spaced vertically when the upper edges of the panels 1, 1′ are aligned horizontally as shown in FIG. 15c.
(101) An upper guiding surface 13a is therefore formed as an extension of the upper locking surface 11a and a lower guiding surface 13b is formed as an extension of the lower locking surface 11b. The locking surfaces 11a, 11b and the guiding surfaces 13a, 13b are configured such that the guiding surfaces 13a, 13b overlap each other during locking and during the downward bending of the strip 6 when the upper surface 2 of the second panel 1′ is spaced vertically upwards from the upper surface 2 of the first panel 1.
(102) FIGS. 16a-16b show that a locking system according to the second principle may comprise a first 7a and a second edge section 7b such that the geometry of the locking element 8 and/or the locking groove 14 varies along the edge. Preferably, the first edge section 7a comprises only locking means that lock the edges in a horizontal direction and the second edge section 7b, that according to this embodiment is a middle section 31, comprises horizontal and vertical locking means. According to the present embodiment, a start section 30 and an end section 32 both are first edge sections 7a. An advantage of the present embodiment is that the locking may be made with a lower pressure force that only has to be applied when the second panel 1′ is folded to a rather low locking angle that may be about 5 degrees or lower. The removal of the upper 11a and/or lower 11b locking surfaces within the first edge sections 7a may only have a marginal negative influence on the vertical locking strength since the part of the edges that constitutes a first edge section 7a is locked vertically by the adjacent long edges 4a, 4b as shown in FIG. 16b. FIG. 16c shows that the locking system may be configured such that a controlled crack 23 occurs in the material of the core 5, e.g. a material comprising wood fibres. In non-limiting examples, the material may be HDF material or material from a particle board. Moreover, the crack 23 may be provided parallel to a fibre direction of the material. The crack 23 may extend to a depth of about 1 mm to about 5 mm. The crack 23 may extend along the entire edge of the first panel 1 or, alternatively, only along a part thereof, e.g. in a middle part. The advantage is that the strip 6 will be easier to bend downward during locking than upwards in the locked position. According to the embodiment in FIG. 16c, lower and upper support surfaces 15, 16 are formed in an upper part of the panels 1, 1′.
(103) FIGS. 17a-17d show that a core material 5 may be locally modified such that it becomes more suitable to form a flexible and strong strip 6. Such a modification may be used in all embodiments of the disclosure. FIG. 17a shows that a resin 20, for example a thermosetting resin 20 such as, for example, melamine formaldehyde, urea formaldehyde or phenol formaldehyde resin, may be applied in liquid or dry powder form on a balancing paper 3 or directly on a core material 5.
(104) For example, the balancing paper 3 may be a melamine formaldehyde impregnated balancing paper 3. The resin may also be locally injected into the core 5 with high pressure. FIG. 17b shows that a core material 5, preferably a wood based panel for example an HDF board or a particle board, may be applied on impregnated paper 3 with the added resin 20 prior to lamination. FIG. 17c shows a floor board after lamination when the surface layers 2 and the balancing layer 3 have been laminated to the core 6. The resins 20 have penetrated into the core 5 and cured during lamination under heat and pressure. FIG. 17d shows an edge of a first panel 1 comprising a strip 6 formed in one piece with the core 5. The strip 6 is more flexible and comprises a higher resin content than other parts of the core 5. The increased resin content provides a material that is very suitable to form a strong flexible strip 6 that during locking may be bended.
(105) FIGS. 18a-18f show that the entire edge of the second panel 1′ comprising an essentially horizontal lower locking surface 11b having a tangent line TL that intersects a wall of the locking groove 14 may be formed with rotating tools 17 that are angled away from the chain 33 and the belt 34 and a carving tool 19 that preferably as a last machining step forms the locking surface 11b.
(106) FIGS. 19a-19e show that the edge of the first panel 1 may be formed initially with large rotating tools 17 that are angled away from the chain 33 and the belt 34.
(107) The first and the second edge sections 7a, 7b are formed with a jumping tool 18 as shown in FIG. 19f. A rotating scraping tool may also be used.
(108) FIGS. 20a-20d show a locking system that is particularly suitable and adapted to be used on the long edges of panels 1, 1′ that are locked with a fold down system according to an embodiment of the disclosure. The locking system comprises an upper 10a and a lower tongue 10b that cooperate with an upper 9a and a lower 9b tongue groove and that lock the edges vertically at least in a first direction upwards.
(109) A locking strip 6 with a locking element 8 cooperates with a locking groove 14 in an adjacent panel and locks the panel edges horizontally. A lower protrusion 38 is formed on an edge of the second panel 1′ and an upper part 6a of the strip 6 locks the edges in a second vertical direction downwards. The locking system is configured such that a high friction is obtained between the long edges and along the edges when they are in an almost locked position and when the first and second locking surfaces 12a, 12b of the first edge section 7a of the short edge locking system are in contact with each other and the upper 11a and lower 11b locking surfaces of the second edge section 7b are spaced vertically such that no separation forces are active. This is explained more in detail in FIGS. 21a-21e.
(110) The high friction is mainly obtained with locking surfaces formed on the locking element 8 and the locking groove 14 that are more inclined against a horizontal plane HP and comprises a higher locking angle LA than the so called “free angle” defined by a tangent line TL to a circle with a radius R equal to the distance from the locking surfaces of the locking element and the locking groove to the upper part of the adjacent edges. FIG. 20b shows that the locking system is configured such that in an up angled and locked position there are at least three contact points where the edges are pressed against each other: a first contact point Cp1 between the upper edges, a second contact point Cp2 between the locking element 8 and the locking groove 14, and a third contact point Cp3 between the lower tongue 10b and the lower tongue groove 9b. Alternatively, the contact points may be contact surfaces. It is understood that each of the contact points forms a contact line or a contact surface along the edges. FIGS. 20c and 20d show that the locking system may be formed with a low material waste in connection with the first cutting step comprising large rotating saw blades 17 and carving tools 19 when a large laminated board is separated into individual panels 1, 1′.
(111) FIGS. 21a-21e show the position of the long 4a, 4b and short edges 4c, 4d during the vertical folding. FIG. 21a shows a second panel 1′ that is angled with its long edge 4b against a long edge 4a of previously installed panel 1″ in a previous row and folded with its short edge 4d against a short edge 4c of an installed first panel 1 in the same row. FIG. 21b shows the long edges 4a, 4b of the second 1′ and the previously installed panel 1″ in a partly locked and up angled position when three contact points Cp1, Cp2, Cp3 are pressed against each other in order to create a friction along the long edges in an up angled position. FIG. 21c shows the long edges 4a, 4b of the previously installed panel 1″ and the first panel 1 in a completely locked position. FIG. 21d shows that the first and second locking surfaces 12a, 12b are in contact with each other in the first edge section 7a and FIG. 21e shows that at the same time the locking element 8 and its upper protruding part 25 in the second edge section 7b is spaced from the locking groove 14 and its sliding surface 27 such that no separation forces are active. This means that the separation forces created by the second edge section 7b and the bending of the strip 6 are counteracted by the first and second locking surfaces 12a, 12b of the first edge section 7a and the friction along the long edges 4a, 4b created by a pretension and a contact preferably at three contact points Cp1, Cp2, Cp3 along the long edge locking system. As an example, it may be mentioned the locking system may be formed with a first edge section 7a that extends with an edge distance ED of about 2-8 cm, for example 5 cm, from a long edge 4a as shown in FIG. 21a and with a locking element comprising a vertical extension of about 0.5-6 mm, for example 2, 3 or 4 mm. The second edge section 7b may start at a horizontal distance from a long edge of about 15-35%, e.g. 20%, of the length of the edge.
(112) The long edges may be folded to an angle of about 1-7 degrees, for example 3 degrees, before the locking element 8 is in contact with the locking groove 14 and such a low angle may be used to form a long edge locking system that creates a very high friction along the long edges in a partly locked position where the upper part of the locking element 8 of one long edge overlaps vertically a lower part of the locking groove 14 of an adjacent long edge. Preferably, the long edge locking system is configured such that a locking angle of 3-5 degrees may be reached before the locking element and the locking groove of the second section 7b are in contact with each other.
(113) FIGS. 22a-22d show embodiments of locking systems that may be formed with pretension in a partly locked position as described above. The locking systems according to FIGS. 22a-22d are particularly suitable and adapted to be used on the long edges of panels 1, 1′. The shown locking systems in FIGS. 22a-22d illustrate that the locking systems in FIGS. 21b and 21c may be formed with a fourth contact point Cp4 located at an upper part of a tongue 10 and a tongue groove 9.
(114) FIG. 23a-23d show that all embodiments of the disclosure may be used to lock for example furniture components where a second panel 1′ comprising a locking groove 14 is locked vertically and perpendicularly to a first panel 1 comprising a strip 6 and with a locking element 8. The strip 6 may initially bend upwards or downwards during the vertical displacement of the second panel 1′ against the first panel 1 and the locking element 8 may comprise locking means that lock horizontally parallel to a main plane M1 of the first panel and vertically parallel to the a plane M2 of the second panel 1′. The main plane M1 of the first panel 1 may be defined as a horizontal plane that is essentially parallel with a lower side 80 of the first panel 1. The main plane M2 of the second panel 1′ may be defined as a vertical plane that is essentially parallel with an outer side 82 of the second panel 1′. The panels 1, 1′ may have a first 7a and a second 7b edge section as described above. The first edge section 7a may be formed such that the locking element 8 is in contact with the locking groove 14 when the locking element 8 and the locking groove 14 of the second section 7b are spaced from each other as shown in FIGS. 23a and 23c.
(115) FIGS. 24a-24e show that the locking system of a first 1 and a second 1′ panel may be formed with a first and a second locking element 8, 8′ and a first and a second locking groove 14, 14′. According to the present embodiment, the first 8 and second 8′ locking elements and the first 14 and second 14′ locking grooves extend along the entire edge of the first panel 1 and second panel 1′, respectively.
(116) Alternatively, however, the second locking element 8′ and the second locking groove 14′ may extend along a part of the edge of the first panel 1 and second panel 1′, respectively, wherein an extension of the second locking element 8′ is smaller than or substantially equal to an extension of the second locking groove 14′.
(117) The second locking element 8′ and the second locking groove 14′ may be used to prevent edge separation and to lock the panels horizontally and may replace the first and second locking surfaces 12a, 12b. Preferably, the lower and inner part(s) of the second locking groove 14′ and the upper and outer part(s) of the second locking element 8′ comprise guiding surfaces, for example rounded parts as shown in FIG. 24a, that engage with each other and press the upper edges towards each other such that separation forces are counteracted. As an alternative, the one or both overlapping locking surfaces 11a, 11b may be removed or the entire first locking element 8 may be removed at a corner section of first edge, e.g. between 5% and 20% of a total length of the first edge.
(118) A vertical extension of the second locking element 8′ and/or the second locking groove 14′ may vary along the first and/or second edge, respectively. The vertical extension may vary from a maximal extension to a minimal extension. The variation may be periodic. At the maximal extension, a top surface of the second locking element 8′ may engage with an upper groove wall of the second locking groove 14′.
(119) At the minimal extension, there may be a cavity between the top surface of the second locking element 8′ and the upper groove wall of the second locking groove 14′.
(120) A vertical flex groove 39 may be formed adjacent to and preferably inwardly of the locking groove 14 in all embodiments of the disclosure.
(121) This embodiment offers the advantages that continuous grooves and locking elements without any edge sections may be used and this will simplify the forming of the locking system. A locking system with high vertical and horizontal locking strength may be formed. The space S between the first locking element 8 and the first locking groove 14 allows a turning and/or displacement of the locking element 8 as described in the previous embodiments. The horizontal distance D1 between the inner surfaces 8a of the first locking element 8 and the outer surface 8b′ of the second 8′ locking element is preferably at least about 30% the floor thickness FT in order to provide sufficient flexibility and locking strength. The horizontal distance D1 may be as small as about 20% of the floor thickness. More generally, D1 may be between 20% and 80% of FT. An upper part of the first locking element 8 is preferably located closer to the panel surface than an upper part of the second locking element 8′. Alternatively, however, the upper part of the first locking element 8 may be located closer to the panel surface than the upper part of the second locking element 8′. This may reduce separation forces since the second locking element 8′ will become active before the first element 8 is in contact with the locking groove 14.
(122) FIG. 24f shows a more compact version wherein the first 14 and the second 14′ locking grooves are connected to each other. The second locking groove 14′ forms an outer part of the first locking groove 14. The locking system may have one or a plurality of pairs lower and upper support surfaces that are configured to cooperate in a locked state of the panels. For example, support surfaces 15, 16 may be provided between the inner and lower part of the first panel 1 and the outer and lower part of the second panel 1′, and/or support surfaces 15′, 16′ may be provided between the upper part of the second locking element 8′ and the upper part of the second locking groove 14′. A part of the locking strip 6 and the second locking element 8′ protruding beyond an outer strip portion 50, preferably outside the second locking element 8′, may be removed at a corner section of the first edge in order to eliminate separation forces during the initial stage of the locking when the second panel 1′ is angled down towards the first panel 1.
(123) FIGS. 25a-25e illustrate various embodiments of one or a plurality of flex grooves 39 For simplicity, the second locking element 8′ and the second locking groove 14′ are not shown but may be formed in the edge of the first 1 and second panel 1′ in all embodiments of FIGS. 25a-25d and 26a-26d. FIG. 25a shows a first panel 1 with a plurality of first and second edge sections 7a, 7b and a flex groove 39 that extends along the entire edge of the second panel 1′. FIG. 25a also shows that at least a part of the projection 46 may be removed and this may in some embodiments simplify the forming of second edge section 7b.
(124) The flex groove 39 may also extend along a part of the edge of the second panel 1′.
(125) In the embodiment in FIG. 25b the flex groove 39 has two walls in a direction along the edge and is located in a center portion of the edge in the length direction thereof. Preferably the flex groove is formed in a center portion that corresponds to the location of the second edge portion(s) 7b where the bending of the strip 6 and vertical locking takes place. FIG. 25b shows that the first 7a and the second 7b edge portions may be formed by removal of material in the locking groove 14 only.
(126) An advantage is that only one jumping tool or rotating carving tool is needed at one short edge in order to form the first and second section. In the embodiment in FIG. 25c the flex groove 39 is at least partly open towards one edge side and only has one wall in a direction along the edge so that it is located in a peripheral portion of the edge in the length direction thereof.
(127) Generally, it is noted that each wall of the flex groove may be vertical or, alternatively, have a transition region so that a depth of the flex groove increases along the edge from a minimal depth to a maximal depth.
(128) Moreover, there may be two or more flex grooves 39 arranged along the edge. In the embodiment in FIG. 25d there are two flex grooves 39 which are at least partly open towards a respective side edge, each having one wall in a direction along the edge, and located in opposite peripheral portions of the edge in the length direction thereof.
(129) Preferably, the flex groove 39 does not extend entirely through the second panel 1′.
(130) By way of example, the flex groove 39 may have a vertical extension between 30% and 60% of a maximal thickness of the panel, e.g. 40% or 50%.
(131) As shown in the top views of the first panel 1 in FIGS. 26a-26b, one or a plurality of slits 49 may be formed in the strip 6 along the edge of the first panel 1 in order to increase the flexibility of the strip while still maintaining sufficient locking strength. A cross-sectional shape of the slit 49 may be rectangular, square, circular, oval, triangular, polygon shaped, etc. Preferably, the shapes of the slits 49 are the same along the edge, but varying shapes are also conceivable. The slits may be formed in a cost efficient way with a rotating punching tool. The slits 49 may be provided in all embodiments described in the disclosure. Such slits and the previously described flex grooves 39 may be combined in all embodiments of the disclosure.
(132) The first panel 1 may have a slit 49 and the second panel may have a flex groove 39. The slits 49 are preferably provided inwardly of the locking element 8.
(133) Preferably, the slits 49 extend entirely through the strip 6 to the rear side 60.
(134) Alternatively, however, the slits 49 may not extend through the strip. The slits may have a vertical extension between 30% and 60% of a minimal thickness of the strip.
(135) The slits may be provided in the upper strip surface 6a. In the embodiment in FIGS. 24a-24d the slits 49 may be provided in a strip surface 66 connecting the side wall 45 and the second locking element 8′ or in a strip surface 67 connecting the first locking element 8 and the second locking element 8′. Alternatively, or additionally, the slits may be provided in the rear side 60 of the first panel 1.
(136) In the embodiment in FIG. 26b, the slit 49 is open towards one edge side and has only one wall in a direction along the edge. Such slit offers the advantage that the second section 7b may be used as a start section. The slit 49 will increase the flexibility of the strip and separation forces will be lower during the initial stage of the locking until the first edge section 7a becomes active. A similar slit 49 may be formed in the opposite side edge.
(137) Generally, it is noted that each wall of the slits may be vertical, i.e. parallel with a direction perpendicular to the horizontal plane. For example, in the embodiment in FIG. 26b wherein the slits 49 have a circular shape, the inner surface of the slit 49 may be cylindrical. Alternatively, however, the wall may have a transition region so that a depth of the slit increases from a minimal depth to a maximal depth. For example, in the embodiment in FIG. 26b, the inner surface of the slit 49 may be frustoconical.
(138) FIGS. 27a-27c show an embodiment comprising a flexible locking element 8 that may be bended and/or compressed inwardly during locking. The flexible locking element 8 is provided at an outer part of the strip 6 and is configured to engage with the locking groove 14. An outer, lower part of the locking element 8 engages with a locking surface 11b of the second panel 1′ in the second edge section 7b.
(139) Moreover, an outer part of the locking element 8 is free with respect to the locking surface 11b in the first edge section 7a. Alternative embodiments of the locking surfaces have been described above in relation to other embodiments of the disclosure wherein reference is made thereto. In particular, the outer part of the locking element 8 may be constant along the first edge and the locking surface 11b may be shortened in the first edge sections 7a, cf. the embodiment in FIG. 7a-7b.
(140) Optionally, the flexible locking element may also be bended upwards and/or downwards during locking.
(141) Such embodiments may be used in floor panels with flexible core materials, for example a core comprising thermosetting plastic material, but may also be used in other applications. As already noted, the locking system may be formed according to any previous embodiment of the disclosure. A horizontal extension of the locking element 8 may be larger than a horizontal extension of the upper surface of the strip 6a. Outer parts of the locking element 8 may have a smaller vertical extension than inner parts of the locking element for increasing the flexibility of the locking element.
(142) The major difference as compared to the embodiments disclosed above is that no space S is needed since the locking element 8 may be bended upwards and/or compressed inwardly as shown in FIG. 27b. The first 7a, 7a′ and the second edge sections 7b may be formed with a simple removal of material located at the outer part of the locking element 8, as shown in FIG. 27c, or at the inner part of the locking groove 14 (not shown).
(143) The first edge section 7a′ in FIG. 27c is optional and may be replaced by a second edge section 7b. In other words, the second edge section 7b may extend all the way to one side edge of the first panel 1.
