Source: https://patents.google.com/patent/US10006210B2/en
Timestamp: 2019-04-23 22:36:11+00:00

Document:
The present application is a continuation of U.S. application Ser. No. 14/095,052, filed on Dec. 3, 2013, which is a continuation of U.S. application Ser. No. 12/865,136, filed on Oct. 7, 2010, now U.S. Pat. No. 8,627,862, which is a national stage of International Application No. PCT/SE2009/050103, filed on Jan. 30, 2009, which claims the benefit of U.S. Provisional Application No. 61/050,443, filed on May 5, 2008, the benefit of U.S. Provisional Application No. 61/006,780, filed on Jan. 31, 2008, the benefit of Swedish Application No. 0800995-3, filed on May 5, 2008, and the benefit of Swedish Application No. 0800242-0, filed on Jan. 31, 2008. The entire contents of each of U.S. application Ser. No. 14/095,052, U.S. application Ser. No. 12/865,136, U.S. Pat. No. 8,627,862, International Application No. PCT/SE2009/050103, U.S. Provisional Application No. 61/050,443, U.S. Provisional Application No. 61/006,780, Swedish Application No. 0800995-3, Swedish Application No. 0800242-0 are hereby incorporated herein by reference in their entirety.
The cost structure and production capacity and flexibility to produce and fix a preferably displaceable tongue to an edge of a panel could be improved considerably if tongues could be provided in tongue blanks that comprises multiple rows of tongues. Such a tongue blank could be used in the described embodiments but also in known locking systems for example in systems described in FIGS. 1a-3c . The invention comprises according to a ninth aspect a tongue blank comprising several displaceable tongues arranged in several rows with at least two tongues in each row.
FIGS. 2a-2c show embodiments of prior art locking systems.
FIGS. 3a-3c show embodiments of prior art locking systems.
FIGS. 4a-4c show a locking system according to a basic embodiment of the invention.
FIGS. 5a-5c show locking with side push of a displaceable tongue.
FIGS. 6a-6h show in several steps locking of short edges.
FIGS. 7a-7d show locking of four panels according to one aspect of the invention.
FIGS. 8a-8f show cross sections of panels during installation.
FIGS. 9a-9d show locking systems formed in one piece with the panel.
FIGS. 10a-10c show installation of panels with a one piece locking system combined with a displacement of panels during locking.
FIGS. 11a-11c show an alternative installation method based on connection in angled position.
FIGS. 12a-12f show a locking system on long edges made in one piece with the panel.
FIGS. 13a-13f show a method to lock panels with displacement of long edges and snapping of short edges.
FIGS. 14a-14e show locking of several panels comprising protrusions on long edges.
FIGS. 15a-15e show how panels with protrusions on long and short edges could be locked.
FIGS. 16a-16c show a one piece locking system, which could be connected with a vertical and/or horizontal displacement.
FIGS. 17a-17e show a method to produce protrusions according to a cutter principle.
FIGS. 18a-18e show a method to produce protrusions with a saw blade principle.
FIGS. 19a-19e show a method to produce protrusions according to a screw cutter principle.
FIGS. 20a-20d show an example of a screw cutter tool.
FIGS. 21a-21c show how protrusions could be formed in a wood flooring and forming of protrusions with a specially designed saw blade.
FIGS. 22a-22f show an equipment to connect a separate part to a panel edge.
FIGS. 23a-23e show a method to connect a separate part to an edge by insertion along the joint and a tong blank comprising several tongues.
FIGS. 24a-24c show embodiments of locking systems.
FIGS. 25a-25d show embodiments of displaceable tongues.
FIGS. 26a-26e show wedge formed tongue protrusions and locking systems with vertically extending snapping hooks.
FIGS. 27a-27f show embodiments of locking systems with vertically offset grooves.
FIGS. 28a-28e show embodiments where the side push is replaced by a snapping along the joint.
FIGS. 29a-29e show embodiments where the side push is replaced by a turning action.
FIGS. 30a-30d show embodiments of a displaceable tongue, which locks the adjacent edges vertically (D1) and horizontally (D2).
FIGS. 31a-31e show embodiments of a displaceable tongue, which locks the adjacent edges vertically and horizontally.
FIGS. 32a-32d show embodiments of a displaceable tongue, which locks the adjacent edges vertically and horizontally.
FIGS. 33a-33c show embodiments where a displaceable tongue locks in a groove on an outer part of a locking strip.
FIGS. 34a-34d show a production method to form undercut grooves.
FIGS. 35a-35c show alternative production methods to form undercut grooves.
FIGS. 36a-36d show a method to connect a separate part into an edge with insertion along the joint.
FIGS. 37a-37c show connection of a separate part.
FIGS. 38a-38c show connection of locking systems comprising a separate flexible part.
FIGS. 39a-39d show connection of a separate part with vertical feeding of tongue blanks.
FIGS. 40a-40d show connection of a separate part with turning.
FIGS. 41a-41e show alternative methods to connect a separate part into an edge.
FIGS. 42a-42b show how a displaceable tongue could be formed by punching.
FIGS. 43a-43g show how principles of the invention could be used in prior art locking systems.
FIGS. 44a-44d show how an edge part of a displaceable tongue could be formed in order to reduce friction during locking.
FIGS. 45a-45d show an embodiment with a flexible edge section.
FIGS. 46a-46b show an embodiment with a cavity formed in a locking strip, which could be used to displace a tongue into an adjacent groove.
FIGS. 47a-47c show how cavities could be used to improve prior art locking systems.
FIGS. 48a-48h show several embodiments of flexible and displaceable tongues.
FIGS. 49a-49b show a method to connect separate parts to an edge with two pushers.
FIGS. 50a-50g show an embodiment with displaceable parts that are displaced to a correct position automatically during locking.
FIGS. 51a-51e show unlocking of a locking system with a displaceable tongue and locking with a displaceable tongue comprising only one protrusion.
FIGS. 6a-6h show in four steps locking of a section of the short edges according to the invention. A short edge of a new panel 1′ is in this embodiment moved vertically towards the second panel 1 as shown in FIGS. 6a-6b . The tongue protrusions 31 a match the cavities 33 b, they are offset in relation to the groove protrusions 31 b and located in a plane under the groove protrusions 31 b. Further vertical movement will bring the tongue protrusion 31 a in the groove cavity 33 b and of course also the groove protrusion 31 b in the tongue cavity 33 a. FIGS. 6e-6f show the position when the panels 1, 1′ have been vertically connected and are laying flat in the same plane on the sub floor. FIGS. 6g-6h show finally the vertically locked position where the protrusions 31 a, 31 b overlap each other due to the displacement of the displaceable tongue 30 along the joint edge.
FIG. 10a-10c shows installation of an embodiment with fixed and non-displaceable protrusions 31 a, 31 b. A short edge 4 b of new panel 1′ is connected, preferably with a vertical movement, to an adjacent short edge 4 b of second panel in the same row such that the protrusions 31 a passes the cavities 33 b and that the edges are locked horizontally. The short edges 4 a, 4 b are thereafter displaced in relation to each other and in a horizontally locked position along the adjacent edges such that the long edges 5 a, 5 a′ are aligned along the same straight line as shown in FIG. 10b and locked vertically and horizontally whereby the protrusions 31 a, 31 b overlap each other. The long edges 5 a, 5 a′ of two panels 1, 1′ are thereafter connected to a first panel 1″ with preferably angling as shown in FIG. 10 c.
FIGS. 15a-15e show alternative ways to install panels comprising protrusions on long edges. FIG. 15a shows that adjacent short edges of a second 1 and a new panel 1′ in a second row could be locked vertically and horizontally with for example angling, horizontal snapping or insertion along the joint. The new panel 1′ could thereafter be displaced and connected to the adjacent long edge of a first panel 1″ in a first row, provided that the second panel 1 is not completely locked. This will allow the protrusions to match the cavities on the long edge. The second 1 and the new panels could thereafter be displaced along the connected long edges and locked vertically and horizontally.
FIGS. 15b-15e show an alternative installation method. The short edges of the second 1 and new 1′ panels could be locked by a vertical or horizontal connection of the edges followed by a displacement along the short edges such that the protrusions overlap each other and until the upper parts of the adjacent long edges are in contact, shown in FIGS. 15b-15d . The long edges are finally locked by a displacement of both said panels 1, 1′ along the long edges of panels installed in an adjacent row and this brings the adjacent long edge protrusions in a horizontally overlapping position as shown in FIG. 15 e.
FIGS. 16a-16c shows that the embodiments shown in FIGS. 9a-9d and FIGS. 12a-12f could be combined and that adjacent short edges comprising matching protrusions 31 a, 31 b and cavities 33 a, 33 b could be connected with a vertical and/or horizontal motion and locked vertically and horizontally with a displacement along the adjacent edges such that the protrusions 31 a, 31 b overlap each other and locks the adjacent edges vertically and that the locking element 8 enters into the locking groove 14 and locks the adjacent edge horizontally. Such a locking system could be used to lock the short edges according to FIGS. 15b -15 d.
FIGS. 17a-17e shows a production method to form cavities 33 b and protrusions 31 b according to the cutter principle. Several cutters 70 could be used, one for each cavity. This principle could be used on long and short edges for the tongue and/or the tongue groove side. The forming could take place before or after the profile cut.
FIGS. 18a-18e show that the above mentioned forming could also be made with the saw blade principle where preferably several saw blades 71 preferably on the same axes, forms the protrusions 31 b and cavities 33 b.
FIGS. 19a-19e show a method to form the above mentioned protrusions 31 b and cavities 33 b with a screw cutter principle. Such forming could be produced in a very cost efficient way in a continuous production line and with high accuracy especially if the panel position is synchronized accurately with the tool position and the tool rotation speed. The screw cutter 72 could be used as separate equipment or more preferably as an integrated tool position in a double-end tenoner. It could have a separate control system or more preferably a control system that is integrated with the main control system 65 of the double-end tenoner. The edge is displaced essentially parallel to the axis of rotation AR of the screw cutter tool 72. It is possible to produce any shape, with round or sharp portions. The cutting could take place before, after or in connection with the profile cutting. When forming short edges, it is preferable to use the method as one of the final steps when the long edge and at least the major parts of the short edge locking system have been formed. It is preferable in some embodiments to form the protrusions and cavities on the groove side before the tongue groove 20 is formed. This reduces the amount of lose fibres and chipping on the inner walls of the cavities and protrusions.
FIGS. 20a-20c show an example of a screw cutter 72 which has been designed to form cavities and protrusions in a 6-10 mm thick laminate flooring edge with a core of HDF material. It comprises 32 teeth 56, each with a cutting depth of 0.1 mm which allows forming of cavities with 3.2 mm walls. The pitch is 10 mm and the teeth are positioned in 5 screw rows. The diameter 53 is 80 mm and the length 54 is 50 mm. The rotation speed is about 3000 revolutions per minute, which means that the feeding speed could be 3000*10=30.000 mm/min or 30 meter per minute. The feeding speed could be increased to 40 meter if the rotation speed is increased to 4000 revolutions. The pitch could be increased to 20 mm and this could increase the feeding speed further to 80 meter/minute. The screw cutter could easily meet the conventional feeding speed of 55 meter/minute, which is generally used in production of the short edge locking system. The screw cutter could also be designed to allow a feeding speed of 200 meter/minute if required when forming three-dimensional grooves on short edges.
FIG. 20d shows an edge part 1′ with the surface turned downwards, of an 8 mm laminate flooring, which has been formed with the screw cutter 72 shown in FIGS. 20a-20c . The protrusions 31 b and cavities 33 b are formed on the lower lip 22 of the tong groove 20. The inner part of the cavity 33 b is smaller than the outer part and has the same geometry as the tool tooth. The cavity could be larger than the tooth if the teeth are displaced in the tool or if the tool rotation is not completely adjusted to the feeding of the panel. The intermediate distance will however still be the same.
FIGS. 21a-21b show that forming of the protrusions could be made before the profile cut. A separate material 62 or the panel core with protrusions 31 a and cavities 33 a could be connected to an edge of the floorboard and preferably glued between a surface layer 60 and a balancing layer 61 in a wood or laminate floor. Any of the before mentioned production methods could be used to form the protrusions.
FIGS. 22a-22f show a method and an inserting device 59 to insert and fix a separate part, preferably a displaceable tongue 30 into an edge of a panel, preferably a floor panel. A tongue blank TB comprising several flexible tongues 30 is displaced from a stacking device 58 to a separation device 57 where the displaceable tongue 30 is separated from the tongue blank TB and displaced preferably vertically to a lower plane (FIGS. 22a, 22b ) where a pusher 46 presses the displaceable tongue 30 into a displacement groove 40 on a panel edge (FIG. 22d ) A new tongue could thereafter be separated from the blank as shown in FIGS. 22e-22f . The inserting device 59 should preferably be integrated with the double-end tenoner (not shown), which machines and forms the mechanical locking system. A first advantage of this principle is that the same chain or transportation device could be used to displace and position the edge of the floorboard. A second advantage is that the same control system 65 could be used to control the inserting device and the double-end tenoner. A third advantage is that the chain and the chain dogs could be adapted such that the intermediate distance of the chain dogs is well defined and preferably the same and this will facilitate a precise and easy fixing of the separate part into a groove. A fourth advantage much lower investment cost than in a case when two separate equipments with two separate control systems are used. This equipment and production method could be used in all locking systems comprising a separate part and not only the described embodiments.
FIGS. 23a-23d shows connection of a separate tongue or any similar loose element. A displaceable tongue 30 is connected into a groove 40 at the edge with a pusher according to the above-described method. The pusher could preferably connect the whole tongue or only one edge of the tongue. FIG. 23b shows that a pressure wheel PW could be used to connect the displaceable tongue 30 further into a groove 40. FIG. 23d show that a position device PD could be used to position the tongue in relation to one long edge. This could be made in line in a continuous flow.
FIGS. 24a, 24b shows an embodiments where the lower lip 22 of the groove 20, with its protrusions and cavities, is made of a separate material which is connected to the edge. The locking system could comprise a displaceable tongue 30 and/or a displaceable lower lip 22. It is obvious that the tongue 30 could be made in one piece with protrusions and cavities and that only the lower lip could be displaceable. FIG. 24c shows that all principles that have been described for the vertical locking could be used to lock floorboards horizontally. A separate locking element 8′ with vertically extending protrusions and cavities could be combined with a locking element 8 comprising similar protrusions and cavities. The locking element 8′ or the panel edge could be displaced in order to lock panels horizontally where overlapping protrusions lock behind each other. The figure shows an embodiment with a flexible tongue 30 for vertical locking. It is obvious that a conventional one piece tongue could be used.
FIGS. 26a-26b shows that the tongue protrusions could have a lower contact surface 34, which is inclined upwardly to the horizontal plane. This lower surface could be used to press the groove protrusions 31 b and the edge against the upper part of the strip 6 during displacement in order to lock the edges firmly vertically. The groove protrusions 31 b could also be formed with vertically inclined walls.
FIGS. 26c-26e shows that a separate tongue 30 could comprise hooks 35 that during the vertical snap folding snaps automatically and grip against the upper part of the groove protrusions 31 b. The hooks could extend and flex vertically or horizontally.
Several tests made by the inventor shows that a high vertical or horizontal load could cause a crack C on the strip panel 1, as shown in FIG. 27a . Such a crack occurs mainly between the lower part of the tongue groove 20 and the upper part of the locking groove 14. This problem is mainly related to thin floorings and floorings with a rather soft core with low tensile strength. Generally it is not preferable to solve such problems by just moving the position of the displacement groove 40′ and the tongue groove 20′ upwards since this will create a thin and sensitive upper lip 22 in the strip panel 1.
FIG. 27b shows that this problem could be solved with a locking system comprising a protrusion 7 on the groove side. This geometry allows that several mainly horizontally extending surfaces on the strip side 1, such as the lower contact surface 6 a, and the upper 40 a and lower 40 b displacement groove surfaces, could be formed with the same tool and this could reduce production tolerances.
FIGS. 28a-28e shows another embodiment where a displaceable tongue 30 is displaced automatically during a vertical snap folding such that the displaceable tongue and the tongue groove protrusions overlap each other. The displaceable tongue comprises a flexible edge section 32 a, which during folding is compressed as shown in FIG. 28b . The edge section 32 a will press back the displaceable tongue 30 towards the original position when the panels edges are in the same plane and lock the edges as shown in FIG. 28c . The flexible edge section could also be formed as a flexible link 32 b, which pulls back the displaceable tongue and locks the edges. These principles could be used separately or in combination. FIGS. 28d and 28e shows how a wedge shaped surfaces of the tongue and the tongue groove protrusions 31 a, 31 b cooperate during folding and displace the displaceable tongue such that it can snap back and lock vertically. Such wedge shaped surfaces could also be used to position the tongue during folding and to over bridge production tolerances.
FIGS. 29a-29e shows that as an alternative to the side push a turning action could be used to lock adjacent edges of two panels 1, 1′ when they are in the same plane. Such a locking could be accomplished without any snapping resistance and with limited separation forces. The known turn snap tongue 30 as shown in FIGS. 3a and 29b could comprise a turning extension 38 which could be used to turn the tongue 30 and to lock the edges as shown in FIG. 29c . The locking systems could also comprise two separate parts 39, 30 where one inner part 39 has a cross section such that the width W will increase and push a tongue 30 into an adjacent groove when the turning extension is turned vertically downwards. Displacement of a tongue could also be made with horizontal turning towards the long edge.
FIGS. 30a-30d show a locking system with a displaceable tongue (30) that locks the edges vertically (D1) according to the above-described embodiments but also horizontally (D2) when the displaceable tongue 30 is displaced along the joint such that the protrusions overlap each other. The displaceable tongue has at least two locking elements and each panel edge has at least one locking element preferably formed in one piece with the panel core. The displaceable tongue 30 comprises according to the embodiment shown in FIG. 30a two tongue locking elements 42 a, 42 b. The displacement groove 40 and the tongue groove 20 have also groove locking elements 43 a, 43 b made in one piece with the panel that cooperate with the tongue locking elements and lock the adjacent edges horizontally when the protrusions 31 a, 31 b are displaced in relation to each other such that they overlap each other as shown in FIGS. 8a-8c . FIG. 30a is drawn to scale and shows a 6.0 mm laminate flooring. The locking system is produced with large rotating tools. To facilitate such production, the locking system comprises lower lip edges 48 a, 48 b which have an angled part, adjacent to the displaceable tongue, extending outwardly and downwardly and which are located on a tongue surface which is opposite to a locking element 42 a or 42 b. Due to the fact that this locking system does not have a strip with a locking element and a locking groove in the rear side, it is possible to produce such a vertical push folding system even in very thin floor panels. FIG. 30d shows an embodiment where the locking elements 42 a,b, 43 a,b have essentially vertical locking surfaces 47 which have an angle of about 90 degrees to the horizontal plane. The lower lip edges 48 a,b are essentially vertical. Such a locking system could have a high vertical and horizontal locking strength. The locking surfaces should preferably exceed 30 degrees to the horizontal plane. 45 degrees and more are even more preferable.
The shown one piece locking elements in FIGS. 30a-30d and FIGS. 31a-31e comprises locking elements with inner parts that are formed as an undercut groove. FIGS. 32a-32c shows however that the one piece locking elements 43 a,b could also be formed on a rear side of the panel and not in a groove. This simplifies the production. The inner parts of the tongue locking elements 42 a,b are however in this embodiment formed as an undercut groove. The tongue 30 could be produced by for example machining, injection moulding or extrusion and these production methods could be combined with punching if necessary. The tongue 30 could be formed with many different cross sections, for example with locking elements in lower lips extending beyond the upper lips as shown in FIG. 32d . Such an embodiment is easier to produce since it does not comprise any undercut grooves in the panel edges or in the tongue. Such displaceable tongues 30 could be connected to an edge with angling, snapping or insertion along the edge.
FIGS. 33a-33c show that the displaceable tongue could be arranged on the groove panel 1′ such that it locks in a groove located on an outer part of the strip 6.
FIGS. 34a-34d show a production method to produce a locking element 43 a in a locking system shown in FIGS. 8a-8c . The first tool position T1 could for example form a horizontal groove. Next tool position T2 could form an undercut groove 40 a and finally a fine cutter in a third tool position T3 could form the upper part of the edge.
FIGS. 35a-35c show how a locking system according to FIG. 31b could be produced. A horizontal groove is formed by for example a rotating tool T1. The undercut groove 40 a, which in this case has a vertical locking surface, could have any angle and could be formed by broaching where the panel is displaced relative a fixed tool that cuts like a knife with several small and slightly offset tool blades.
FIGS. 36a-36d show a method to insert a displaceable tongue 30 into a displacement groove 40 such that the tongue is inserted parallel to and along the groove. This method could be used for any tongues but is especially suitable for displaceable tongues with locking elements. The tongue 30 is preferably separated from a tongue blank and moved to a position in line with the displacement groove where it is held in a pre-determined position by one or several tongue holders 44 a,b. The panel 1 is displaced essentially parallel with the displaceable tongue and an edge part is inserted into the displacement groove 40 and preferably pressed further into the groove by one or several guiding unites 45 a,b. The displaceable tongue is released from the tongue holders 44 a,b by preferably a panel edge that cause the holders to for example rotate away from the edge.
FIGS. 37a-37c show a method to insert a tongue into a groove such that the tongue is snapped essentially perpendicularly into a groove. The whole tongue or only a part of the tongue could be inserted with snapping whereby a pusher 46 presses an edge of the tongue 30 into a part of the groove 40. A remaining part of the tongue could be inserted with the above-described method along the joint. The snapping connection could be obtained by flexible lips on the panel edge as shown in FIG. 37b and/or by flexible lips on the tongue 30 as shown in FIG. 37 c.
FIGS. 39a-39d show another method to connect a separate element, preferably a tongue, into a groove. It is an advantage if tongues 30 could be fed vertically towards a panel edge and connected with a horizontal pusher. The problem is that some tongues, especially displaceable and flexible tongues that have a rather complex three dimensional form, could only be produced with a cross section having a main tongue plane TP, defined as a plane in which the tongue is intended to be located horizontally into a groove, that is located in the same plane as the main plane of the tongue blank TB. This problem could be solved as follows. A tongue blank TB is according to the invention positioned and displaced essentially vertically, or essentially perpendicularly to the position of the panel 1, towards a turning unit 50 as shown in FIG. 39a . The tongue is connected to the turning unite 50 and separated from the tongue blank, as shown in FIG. 39b . The turning unit 50 is thereafter turned about 90 degrees in order to bring the tongue 30 with its main tongue plane TP in a horizontal position such that it could be connected into a groove 40 of a panel 1 edge by a pusher 46 that pushes the tongue 30 out from the turning unit and into the groove 40. This is shown in FIGS. 39c and 39d . The panel 1 is shown in a horizontal position with the front face pointing downwards.
FIGS. 41c, 41d, and 41e show that the insertion of a tongue edge 30 a into a groove 40 could be facilitated if a part of the locking element 8 of the strip 6 and/or of the tongue 30 and/or of the groove 40 is removed such that the tongue edge could be inserted into a part of the groove 40 with less or preferably even without any resistance. The remaining part of the tongue 30 could thereafter be inserted along the joint.
FIGS. 44a-44d how a long edge tongue 10 and a pressing edge of the displaceable tongue could be formed in order to reduce vertical friction during locking of the long edges and displacement of the displaceable tongue 30 along the short edge. The first step in a locking is generally a linear displacement in angled position of one long edge 5 a towards a long edge 5 b of a panel laying flat on the sub floor as shown in FIG. 44a . The tongue is preferably pushed an initial distance displacement distance, which could position the short edges in essentially the same plane if for example wedge shaped protrusions are used. The final locking is a turning action as shown in FIG. 44c when the locking element 8 and the locking groove 14 are in contact and facilitate the final locking displacement during which action the displaceable tongue 30 is displaced with a locking distance LD. This final displacement should preferably lock the short edges with a vertical pre tension where the panel edge of the groove pane 1′ is pressed vertically against the upper part of the strip 6 at the strip panel 1 as for example shown in FIG. 27b . The friction between the pressing edge 32 and the tip of the tongue 10 could push the upper part of the edge upwards and create “overwood” at the joint edges in the corner portion between the long end short edges. This could be avoided if the pressing edge 32 is inclined vertically and inwardly against the vertical plane VP and/or rounded. A preferred inclination is 20-40 degrees. It is also an advantage if the tip of the tongue 10 that during locking is in contact with the pressing edge 32 is rounded. The locking distance LD is in the shown embodiment smaller than 0.10 times the floor thickness FT.
FIGS. 45a-45d show that the vertical friction forces could be reduced further with a flexible pressing edge 32 that could be displaced for example vertically during locking. This principle allows that the locking distance LD could be reduced to zero if required.
FIGS. 46a-46b show that the describe methods to form cavities in an edge could be used to displace the known tongue from one groove into an adjacent groove as described in FIG. 1c . One or several cavities 33′ with horizontally extending inclined (FIG. 46b ) or parallel (FIG. 47c ) walls could be formed by cutting through the strip 6 and such an embodiment and production method is more cost efficient than the known methods where thin horizontally cutting saw blades are used to make a cavity.
FIGS. 50a-50g show an embodiment with a displaceable tongue 30 in one edge comprising protrusions 31 a and a displaceable tongue groove lip 22 in the adjacent edges comprising protrusions 31 b. The protrusions are wedge formed with their wedge tips pointing at each other during the initial stage of the vertical folding. The wedge shaped protrusions will during locking automatically adjust the two displaceable parts such that the protrusions could pass each other vertically as shown in FIGS. 50c, 50f, and 50g . This will displace one of the two displaceable parts as shown in FIG. 50g which thereafter could be pushed back in order to lock the adjacent edges vertically and or horizontally. The two displaceable parts 30, 22 could be essentially identical.
FIGS. 51a-51c show a method to unlock two panel edges that have been previously locked with a locking system according to the invention. FIG. 51a shows the unlocked position with tongue protrusions 31 a located in or above the groove cavities 33 b. FIG. 51b shows the locked position with the tongue protrusions 31 a overlapping the groove protrusions 31 b. The displaceable tongue 30 could be displaced one step further into the edge, as shown in FIG. 51c , such that the tongue protrusions 31 a are located over the groove cavities 33 b. It is preferred that the outer end 32′ of the displaceable tongue 30 is designed such that the unlocked position is automatically obtained when this outer end 32′ is in contact with a part of a long edge 41 of a panel installed in a previous row, preferably the inner part of the long edge tongue groove. It is preferred that the tongue initially is positioned such that the distance D1 between the outer end 32′ and the contact point on the adjacent long edge is about the same as the distance D2 between two tongue protrusions 31 a.
FIG. 51e shows an embodiment where the tongue cavities 33 b are formed with thin and horizontally cutting saw blades.
the edges are configured to be locked with a vertical motion.
2. The set of floor panels as claimed in claim 1, wherein the tongue and the tongue groove are configured such that upper parts of the edges can be brought into contact with an essentially vertical motion and that the vertically locked position can be obtained by displacement along one of the edges.
3. The set of floor panels as claimed in claim 1, wherein the protrusions and cavities of the tongue groove are provided at a lower lip and that the lower lip is displaceable in relation to the second panel.
4. The set of floor panels as claimed in claim 1, wherein the width of the tongue varies in the length direction of the tongue.
5. The set of floor panels as claimed in claim 1, wherein at least one protrusion has a wedge shape in the horizontal and/or vertical direction.
6. The set of floor panels as claimed in claim 1, wherein an outer part of at least one protrusion has a width or thickness that is smaller than an inner part.

References: Application No. 61
 Application No. 61
 Application No. 0800995
 Application No. 0800242
 Application No. 61
 Application No. 61
 Application No. 0800995
 Application No. 0800242