Abstract:
An assembled product, such as an assembled product, such as a furniture component or a furniture, such as a drawer, a cupboard, bookshelves, a wardrobe, a kitchen fixture, or a box for storing or transporting including at least three panels arranged in three different planes. Also, a set of panels for an assembled product and a method of assembling the product.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of Swedish Application No. SE 1351060-7, filed on Sep. 16, 2013, Swedish Application No. SE 1450022-7, filed on Jan. 10, 2014, Swedish Application No. SE 1450018-5, filed on Jan. 10, 2014, and Swedish Application No. SE 1450034-2, filed on Jan. 15, 2014. The entire contents of Swedish Application No. SE 1351060-7, Swedish Application No. SE 1450022-7, Swedish Application No. SE 1450018-5, and Swedish Application No. SE 1450034-2 are hereby incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to an assembled product, such as a box or a drawer, a furniture component or a furniture, and a method of assembling the product. The assembled product is provided with a locking device comprising a flexible tongue. 
     TECHNICAL BACKGROUND 
     A furniture provided with a mechanical locking system is known in, e.g., WO 2012/154113 (A1). The furniture comprises a first panel connected perpendicular to a second panel by a mechanical locking system comprising a flexible tongue in an insertion groove. 
     SUMMARY 
     It is an object of certain embodiments of the present disclosure to provide an improvement over the above described techniques and known art. A specific objective is to improve the method for assembling a furniture product. 
     A further object of embodiments of the disclosure is to provide a set of panels for an assembled product, such as a so-called flat-pack furniture product, that are configured to be assembled without tools and a method of assembling the product. 
     At least some of these and other objects and advantages that will be apparent from the description have been achieved by a set of panels for an assembled product. The set of panels are provided with one or more locking devices. Each locking device comprises a flexible tongue arranged in an insertion groove at an edge of a panel, said flexible tongue cooperates with a tongue groove, at an adjacent edge of an adjacent panel, for locking the panel and the adjacent panel together. The locking device is configured such that the edge and the adjacent edge may be connected by hand. The set of panels comprises at least four frame panels that are configured to be connected together at adjacent edges by at least one of said locking devices to obtain a frame, preferably of a rectangular shape. The set of panels comprises a fifth panel, such as a back or bottom panel, which is configured to be connected to a back or bottom edge of the frame by at least one of said locking devices. 
     The fifth panel is preferably configured be connected to a back or a bottom edge of two of the frame panels, by at least one of said locking devices at each of said back or bottom edge. 
     The locking devices may comprise an edge section groove at the panel or at the adjacent panel. An edge section of the other of the panel or the adjacent panel may cooperate with said edge groove for locking the panel and the adjacent panel together. The flexible tongue and the tongue groove cooperate for locking the panel and the adjacent panel together in a first direction and the edge section and the edge section groove cooperate for locking the panel and the adjacent panel together in a second direction, perpendicular to the first direction. 
     The edge section may be provided with a calibrating groove. 
     The panels may be of plastic or wood fiber. For example, the panels may be plastic panels or wood fibre based boards, e.g. HDF boards, particleboard or solid wood board. The panels may be provided with a decorative layer. 
     The assembled product may be a furniture component or a furniture, such as a drawer, a cupboard, bookshelves, a wardrobe, a kitchen fixture, or a box for storing or transporting. 
     The insertion groove, of at least one of said locking devices, may extend along essentially the entire length of the edge of the panel (e.g., at least 80% of the length of the panel). 
     The tongue groove, of at least one of said locking devices, may extend along essentially the entire length of the adjacent edge of the adjacent panel (e.g., at least 80% of the length of the adjacent panel). 
     A tongue groove and an insertion groove that extend along essentially the entire width of the panel and the adjacent panel (e.g., at least 80% of the width of the adjacent panel), respectively, may facilitate the production of the tongue groove and the insertion groove. The tongue groove and the insertion groove may be produced by displacing the panel and the adjacent panel, respectively, pass a mechanical cutting tool, such as a fixed milling head. 
     Any of the panels may be provide with a dismantling groove at any of the locking devices, said dismantling groove or recess is preferably adapted for insertion of a dismantling tool. The dismantling tool may be inserted into the dismantling groove or recess to un-lock the locking device. 
     A second aspect of the disclosure is a method of assembling a set of panels to obtain an assembled product, the method comprising:
         arranging a first panel, with a first main plane, perpendicular to a second panel with a second main plane, wherein the first main plane is perpendicular to the second main plane;   connecting by hand a first edge of the first panel to a first edge of the second panel, by linearly displacing the first panel and/or the second panel;   arranging a third panel, with a third main plane, perpendicular to the first and the second panel, wherein the third main plane is perpendicular to the first and the second main plane; and   connecting by hand a second edge of the third panel to a second edge of the second panel, by linearly displacing the third panel and/or second panel.       

     The method may further comprise the step of connecting by hand a first edge of the third panel to a second edge of the first panel, by linearly displacing the third panel and/or the first panel. 
     The method may further comprise the steps of arranging a fourth panel, with a fourth main plane, perpendicular to the first and the third panel, wherein the fourth main plane is parallel to the second main plane, and connecting by hand a first edge of a fourth panel to a third edge of the first panel, by linearly displacing the fourth panel and/or the first panel. 
     The method may further comprise the step of connecting by hand a third edge of the third panel to a second edge of the fourth panel, by linearly displacing the third panel and/or the fourth panel. 
     The method may further comprise the steps of arranging a fifth panel, with a fifth main plane, perpendicular to the third and the fourth panel, wherein the fifth main plane is parallel to the first main plane, and connecting by hand a first edge of the fifth panel to a third edge of the second panel, and a third edge of a fifth panel to a third edge of the fourth panel, by linearly displacing the fifth panel and/or the second and the fourth panel. 
     The set of panels may comprise at least five panels, wherein each connecting step comprises linearly displacing of one of the five panels. 
     The set of panels under the second aspect may comprise embodiments of the locking device described for use with the first aspect. 
     Each linear displacement may be executed in a direction parallel to the third main plane. 
     Each connecting step may comprise a displacement of a part of a flexible tongue of a locking device, wherein a part of the flexible tongue is displaced into a tongue groove for locking an edge to an adjacent edge. 
     Each connecting step may comprise connecting two panels such that the mechanically locked together in directions perpendicular to the main plane of each of the two connected panels. 
     The panels may be of plastic or wood fiber. For example, the panels may be wood fibre based boards, e.g. HDF boards, particleboard or solid wood board, or plastic panels. The panels may be provided with a decorative layer. 
     The assembled product may be a furniture component or a furniture, such as a drawer, a cupboard, bookshelves, a wardrobe, a kitchen fixture, or a box for storing or transporting. 
     A third aspect of the disclosure is an assembled product comprising at least three panels arranged in three different planes, a first panel is connected essentially perpendicular to a second panel, and a third panel is connected essentially perpendicular to the second panel. The assembled product comprises one or more locking devices, each comprising a flexible tongue arranged in an insertion groove at a panel, said flexible tongue cooperates with a tongue groove, at an adjacent panel, for locking the panel and the adjacent panel together. The second edge of the second panel is connected to a second edge of the third panel by a first of said locking devices. 
     The panels may be of plastic or wood fiber. For example, the panels may be wood fibre based boards, e.g. HDF boards, particleboard or solid wood board, or plastic panels. The panels may be provided with a decorative layer. 
     The assembled product may be a furniture component or a furniture, such as a drawer, a cupboard, bookshelves, a wardrobe, a kitchen fixture, or a box for storing or transporting. 
     The three planes are preferably essentially perpendicular planes. 
     A first edge of the third panel may be connected to a first edge of the first panel by a second of said locking devices. The first panel and the second panel may be a first and a second board, respectively, of a frame, and the third panel may be the back piece, of a bookshelves or a wardrobe. The third panel, such as a back piece, connected by the first and the second of said locking devices, may increase the strength of the assembled product. The angle between first and the second panel may be guided by the angle between the first and the second edge of the third panel. A bookshelves or a wardrobe with perpendicular corners may be obtained easily by embodiments of the disclosure. The first edge of the third panel may be connected slideable along the first edge of the first panel in order to simplify assembling and disassembling. 
     A first edge of a sixth panel may be connected essentially perpendicular to the first panel, between the second and fourth panel. The sixth panel may be essentially parallel to the second and fourth panel. The first edge of the sixth panel may be connected by a seventh of said locking devices. The flexible tongue of the seventh of said locking devices is preferably arranged in an insertion groove at the first edge of the sixth panel. The sixth panel may be a fixed shelf of the assembled product, e.g. a bookshelves. 
     A fourth panel may be connected essentially perpendicular to the first panel, wherein a third edge of the third panel may be connected to a second edge of the fourth panel by a third of said locking devices. 
     The second and the fourth panel may be arranged essentially parallel and the third panel may be connected slideable to the second and the fourth panel in order to facilitate disassembling. 
     A fourth edge of the third panel may be arranged in a groove at a second edge of a fifth panel. The fifth panel may be connected essentially perpendicular to the second and fourth panel. 
     The assembled product may be a semi product for a drawer, without the fifth panel that may be a front panel, and the first, second and fourth panels may be boards of the frame and the third panel may be the bottom board. The front panel may be connected essentially perpendicular to the second and fourth panel in the same factory as the semi product, in another factory or carpentry or by a carpenter at a construction site. 
     A first edge of the fifth panel may be connected to a third edge of the second panel by a fourth of said locking devices, and a third edge of the fifth panel may be connected to a third edge of the fourth panel by a fifth of said locking devices. 
     A first edge of the first panel may be connected to a first edge of the second panel by a sixth of said locking devices. 
     A first edge of a fourth panel may be connected to a third edge of the first panels by a seventh of said locking devices. 
     The insertion groove, in at least one of said locking devices, may extend along essentially the entire length of the panel (e.g., at least 80% of the length of the panel). 
     The tongue groove, in at least one of said locking devices, may extend along essentially the entire length of the adjacent panel (e.g., at least 80% of the length of the adjacent panel). 
     A tongue groove and an insertion groove that extend along essentially the entire width of the panel and the adjacent panel (e.g., at least 80% of the width of the adjacent panel), respectively, may facilitate the production of the tongue groove and the insertion groove. The tongue groove and the insertion groove may be produced by displacing the panel and the adjacent panel, respectively, pass a fixed milling head. 
     The flexible tongue, in at least one of said locking devices, may be displaceable in the insertion groove during locking and un-locking of the locking device. 
     The locking devices may comprise an edge section groove at the panel or at the adjacent panel. An edge section of the other of the panel or the adjacent panel may cooperate with said edge groove for locking the panel and the adjacent panel together. The flexible tongue and the tongue groove cooperate for locking the panel and the adjacent panel together in a first direction and the edge section and the edge section groove cooperate for locking the panel and the adjacent panel together in a second direction, perpendicular to the first direction. 
     The edge section may be provided with a calibrating groove. 
     The third panel may be provided with a dismantling groove or recess at one or more of said locking devices, said dismantling groove or recess is preferably adapted for insertion of a dismantling tool. The dismantling tool may be inserted into the dismantling groove or recess to un-lock the locking device. 
     Any of the first, the second, the fourth or the fifth panel may be provide with a dismantling groove at any of the locking devices, said dismantling groove or recess is preferably adapted for insertion of a dismantling tool. The dismantling tool may be inserted into the dismantling groove or recess to un-lock the locking device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will by way of example be described in more detail with reference to the appended schematic drawings, which shows embodiments of the present disclosure. 
         FIGS. 1A-B  show embodiments of a locking device for a furniture according to embodiments of the disclosure. 
         FIGS. 2A-C  show a furniture component or a furniture according to embodiments of the disclosure. 
         FIGS. 3A-B  show a furniture component or a furniture according to an embodiment of the disclosure. 
         FIG. 4A  shows a method of assembling a furniture component or a furniture according to an embodiment of the disclosure. 
         FIG. 4B  shows a corner section of a furniture component or a furniture according to an embodiment of the disclosure. 
         FIG. 5  shows a partly assembled furniture or furniture component according to an embodiment of the disclosure. 
         FIGS. 6A-D  show embodiments of a locking device for a furniture according to embodiments of the disclosure. 
         FIG. 7A  shows an embodiment of a locking device for a furniture according to an embodiment of the disclosure. 
         FIGS. 7B-C  show embodiments of a locking device for a furniture and a disassembling tool according to embodiments of the disclosure. 
         FIGS. 7D-E  show embodiments of a locking device provided with a disassembling recess and a disassembling tool 
         FIG. 8A-C  show embodiments of a mechanical locking system for a back or a bottom panel according to an embodiment of the disclosure. 
         FIG. 9  shows a locking device for an assembled product according to an embodiment of the disclosure. 
         FIG. 10A  shows a locking device for locking a back or a bottom panel to a frame according to an embodiment of the disclosure. 
         FIG. 10B  shows a locking device for locking a shelf to a frame according to an embodiment of the disclosure. 
         FIG. 11A-H  show flexible tongues according to embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment of a locking device for locking a panel  4  to an adjacent panel  2  is shown in  FIGS. 1A-B . The panel and the adjacent panel may be panels of a furniture that are connected perpendicular to each other, i.e. with a main surface of the panel perpendicular to a main surface of the adjacent panel. An edge section  22  of the panel  4  is arranged in an edge section groove  21  of the adjacent panel  2  for locking the panel and the adjacent panel together in a first direction. The embodiment in  FIG. 1A  comprises a flexible tongue  30  arranged in an insertion groove  20  in the edge section groove  21  and a tongue groove  10  at the edge section  22 . The embodiment in  FIG. 1B  comprises a flexible tongue  30  arranged in an insertion groove  20  at the edge section  22  and a tongue groove in the edge section groove. The flexible tongue  30  and the tongue groove  10  cooperate for locking the panel and the adjacent panel together in a second direction, which is essentially perpendicular to the first direction. The flexible tongue is during assembling, of the panel and the adjacent panel, pushed into the insertion groove when the edge section is inserted into the edge section groove. The flexible tongue springs back and into the tongue groove when the panel and the adjacent panel have reached a connected state. 
     The panel may be a back piece of a bookshelves or a wardrobe and the adjacent panel may be a board of the frame. The panel may also be a bottom panel of a drawer and the adjacent panel a board of the frame. Furthermore the panel and the adjacent panel may be a first and a second board respectively of a frame of a bookshelves, a wardrobe or a drawer. The back piece and the bottom may be a HDF board or a particleboard with a thickness of about 2-4 mm. Embodiments of the disclosure may comprise one or more of the locking devices described above. 
       FIG. 2A  shows a furniture, such as a bookshelves, comprising eight of the locking devices, arranged with a side of the frame facing downwards. The furniture comprises a first panel  1 , e.g. a side of the bookshelves, connected at a first edge to a first edge of a second panel  2 , e.g. the top of the bookshelves, by one of the locking devices. A first edge of a third panel  4 , e.g. a rectangular back piece of the bookshelves, is connected to a second edge of the second panel by another of the locking devices. A second edge of the third panel  4  is connected to second edge of the first panel by another of said locking devices. A first edge of a fourth panel  5 , e.g. a bottom of the bookshelves, is connected to a third edge of the first panel by another of said locking devices. An edge section of a third edge of the third panel  4  may be arranged in an edge section groove at a second edge of the fourth panel  5 . A first edge of a fifth panel  6 , e.g. a side of the bookshelves, is connected to a third edge of the fourth panel  5 , by another of said locking devices, and a third edge of the fifth panel is connected to a third edge of the second panel, by another of said locking devices. An edge section of a fourth edge of the third panel  4  may be arranged in an edge section groove at a second edge of the fifth panel  5 . The locking device at the first and the second edge respectively of the third panel may each comprise two or more flexible tongues  30 . A sixth panel  3 , e.g. a shelf of the bookshelves, which is arranged parallel to the first and the fourth panel, is connected, by another of the locking devices, at a first edge to the first to the first panel, and a third edge is connected, by another of the locking devices, to the fifth panel. The flexible tongue of the locking device at the first and third edge, respectively, of the sixth panel is preferably arranged at the edge section  22 . 
       FIG. 2B  shows a cross section CS  2 B of the first panel  1 , the third panel  4  and the fifth panel  6 . The figure shows that an edge section of the fourth edge of the third panel may be arranged in edge section groove at the second edge of the fifth panel  6 . The third panel  4  may comprise two or more boards  4   a - 4   d  locked by a mechanical locking system. Embodiments of the mechanical locking system are shown in  FIGS. 8A-C . A second edge of the fifth panel may be provided with another of the locking devices (not shown) for connecting adjacent edges of adjacent boards. 
       FIG. 2C  shows a cross section CS  2 C of the second and third panel  2 ,  4 . The third panel is in this embodiment provided with a dismantling groove  33  adapted for insertion of a dismantling tool, which pushes the flexible tongue into the insertion groove, which facilitates dismantling of the second and third panel. 
       FIG. 3A  shows a furniture, such as a bookshelves, comprising eight of the locking devices, arranged with a side of the frame facing downwards. The furniture comprises a first panel  1 , e.g. a side of the bookshelves, connected at a first edge to a first edge of a second panel  2 , e.g. the top of the bookshelves, by one of the locking devices. A first edge of a third panel  4 , e.g. a rectangular back piece of the bookshelves, is connected to a second edge of the second panel by another of the locking devices. An edge section of a second edge of the third panel  4  may be inserted into an edge section groove of a second edge of the first panel. A first edge of a fourth panel  5 , e.g. a bottom of the bookshelves, is connected to a third edge of the first panel by another of said locking devices. A third edge of the third panel  4  is connected to a second edge of the fourth panel  5  by another of said locking devices. A first edge of a fifth panel  6 , e.g. a side of the bookshelves, is connected to a third edge of the fourth panel  5 , by another of said locking devices, and a third edge of the fifth panel is connected to a third edge of the second panel, by another of said locking devices. An edge section of a fourth edge of the third panel  4  may be arranged in an edge section groove at a second edge of the fifth panel  5 . The locking device at the first and the third edge respectively of the third panel may each comprise two or more flexible tongues  30 . A sixth panel  3 , e.g. a shelf of the bookshelves, which is arranged parallel to the first and the fourth panel, is connected, by another of the locking devices, at a first edge to the first to the first panel, and a third edge is connected, by another of the locking devices, to the fifth panel. The flexible tongue of the locking device at the first and third edge, respectively, of the sixth panel is preferably arranged at the edge section  22 . The third panel is preferably connected slideable at the first and the third edge in order to facilitate disassembling. 
       FIG. 3B  shows a cross section CS  3 B of the first panel  1 , the third panel  4  and the fifth panel  6 . The third panel  4  may comprise two or more boards  4   a - b  locked by the mechanical locking system described above. 
       FIG. 4A  shows an embodiment of a method for assembling the assembled product described under  FIG. 2A-C . The first, second and sixth panel  1 ,  2 ,  3  are preferably connected to each other before the third panel is connected. The third panel may be displaced in a diagonal direction  41  such that the first and the second edge of the third panel is connected at the same time to the second edge of the first panel and to the second edge of the second panel. A preferred alternative for assembling the panels comprises:
         arranging a first panel  1 , with a first main plane, perpendicular to a second panel  2  with a second main plane, wherein the first main plane is perpendicular to the second main plane;   connecting by hand a first edge of the first panel  1  to a first edge of the second panel, by linearly displacing the first panel and/or the second panel;   arranging a third panel  4 , with a third main plane, perpendicular to the second and the third panel, wherein the third main plane is perpendicular to the first and the second main plane;   connecting by hand a second edge of the third panel  4  to a second edge of the second panel, by linearly displacing  43  the third panel  4  and/or second panel;   connecting by hand a first edge of the third panel  4  to a second edge of the first panel  1 , by linearly displacing  42  the third panel and/or the first panel  1 ;   arranging a fourth panel  5 , with a fourth main plane, perpendicular to the first and the third panel, wherein the fourth main plane is parallel to the second main plane, and connecting by hand a first edge of a fourth panel  5  to a third edge of the first panel  1 , by linearly displacing the fourth panel  5  and/or the first panel  1 ; and   arranging a fifth panel  6 , with a fifth main plane, perpendicular to the third and the fourth panel, wherein the fifth main plane is parallel to the first main plane, and connecting by hand a first edge of the fifth panel to a third edge of the second panel, and a third edge of a fifth panel to a third edge of the fourth panel, by linearly displacing the fifth panel  6  and/or the second and the fourth panel.       

     Each linear displacement is preferably executed in a direction parallel to the third main plane. 
     The first edge of the third panel  4  is in this alternative connected displaceable at the first edge. Another alternative is to displace the third panel in the second direction  43  perpendicular to the second panel and subsequently displace the third panel in the first direction  43  perpendicular to the first panel. The second edge of the third panel  4  is in this embodiment connected displaceable at the second edge. 
       FIG. 4B  shows that a corner section between e.g. the first and the second panel may be provided with a cover plate, in order to hide the locking device. 
       FIG. 5  shows a furniture, such as a drawer, comprising six of the locking devices, arranged with a side of the frame facing downwards. The furniture comprises a first panel  1 , e.g. an inner side of the drawer, connected at a first edge to a first edge of a second panel  2 , e.g. a side of the drawer, by one of the locking devices. A first edge of a third panel  4 , e.g. a rectangular bottom of the drawer, is connected to a second edge of the second panel by another of the locking devices. An edge section of a second edge of the third panel  4  may be inserted into an edge section groove of a second edge of the first panel. A first edge of a fourth panel  5 , e.g. a side of the drawer, is connected to a third edge of the first panel by another of said locking devices. A third edge of the third panel  4  is connected to a second edge of the fourth panel  5  by another of said locking devices. A first edge of a fifth panel  6 , e.g. a front panel of the drawer, is subsequently connected to a third edge of the fourth panel  5 , by another of said locking devices, and a third edge of the fifth panel is connected to a third edge of the second panel, by another of said locking devices. An edge section of a fourth edge of the third panel  4  may be arranged in an edge section groove at a second edge of the fifth panel  5 . The locking device at the first and the third edge respectively of the third panel may each comprise two or more flexible tongues  30 . The third panel is preferably connected slideable at the first and the third edge in order to facilitate disassembling. A preferred alternative for assembling the panels comprises:
         arranging a first panel  1 , with a first main plane, perpendicular to a second panel  2  with a second main plane, wherein the first main plane is perpendicular to the second main plane;   connecting by hand a first edge of the first panel  1  to a first edge of the second panel, by linearly displacing the first panel and/or the second panel;   arranging a third panel  4 , with a third main plane, perpendicular to the second and the third panel, wherein the third main plane is perpendicular to the first and the second main plane;   connecting by hand a second edge of the third panel  4  to a second edge of the second panel, by linearly displacing  43  the third panel  4  and/or second panel;   arranging a fourth panel  5 , with a fourth main plane, perpendicular to the first and the third panel, wherein the fourth main plane is parallel to the second main plane, and simultaneous connecting by hand, by linearly displacing the fourth panel  5 , a first edge of a fourth panel  5  to a third edge of the first panel  1  and a third edge of the third panel  3  to a second edge of the fourth panel  5 ; and   arranging a fifth panel  6 , with a fifth main plane, perpendicular to the third and the fourth panel, wherein the fifth main plane is parallel to the first main plane, and connecting by hand a first edge of the fifth panel to a third edge of the second panel, and a third edge of a fifth panel to a third edge of the fourth panel, by linearly displacing  44  the fifth panel  6 .       

       FIGS. 6A-B  show alternative embodiments of the locking device. Embodiments are shown with a calibrating groove  40  at one or two sides of the edge section. The tongue groove  10  may be symmetric such that the same dismantling tool can be used at opposite positions of the locking device, i.e. mirror inverted locking devices. The edge section groove may be provided with a guiding surface  32  that facilitates insertion of the edge section into the edge section groove. The edge section groove may be provided with two opposite tongue grooves  10 . Two opposite tongue grooves may be easily made by an end cutter, by e.g. a craftsman on site. 
       FIG. 7A  shows that the embodiment with two opposite tongue grooves  10  may be provided with two flexible tongues  30 . 
       FIG. 7B-C  show disassembling of the locking device by inserting a symmetric dismantling tool  90  into a symmetric tongue groove  10 . 
       FIG. 7D-E  show alternative embodiments provided with a dismantling recess  34 . These embodiments may be an alternative to the embodiment shown in  FIG. 2C , if for example it is desired to un-lock the locking device from the inside of a furniture, such as a drawer, a box or a book. These embodiments may also be used to connect the fifth panel to the second and fourth panel in the embodiment shown in  FIG. 5A . The tongue  30  is arranged in the edges section groove in  FIG. 7B  and at the edge section in  FIG. 7E . The edge section is provided with a dismantling groove  34  which adapted to a dismantling tool  90 . The tongue  30  is pushed back into the displacement groove  20 , and un-lock the locking device, when the dismantling tool is inserted into the dismantling recess. The dismantling recess may be covered by a covering plate (not shown). The embodiments with the dismantling groove or recess are particular advantageous for embodiment which do not have tongue groove which is accessible from an outer end of the tongue groove for insertion of a dismantling tool. However, the embodiments with the dismantling groove or recess may be used to connect any adjacent panels in order to facilitate disassembling. 
       FIG. 8A  shows an embodiment of the mechanical locking system comprising a tongue  64  at a first edge of a first board that cooperates with a tongue groove  50  at a second edge of a second board for locking the first and the second board in a first direction. Furthermore, the locking system comprises a protruding strip  70  with a locking panel  71  at the second edge. The locking panel  71  cooperates with a locking groove  80  at the first edge for locking the first and the second board in a second direction, which is perpendicular to the first direction. The boards and the locking system is preferably arranged in the assembled product, with the locking strip facing the direction that is to be loaded. The locking system may remain locked if arranged in this way. 
       FIG. 8B  shows another embodiment of a panel, such as a back or bottom panel, comprising a first  8   a  and a second board  8   b  provided with a mechanical locking system configured to lock the first  4   a  and the second board  4   b  together. 
     The first main plane of the first board is essentially parallel to a second main plane of the second board, wherein the panel comprises a first face  85  and an opposite second face  86  which are parallel to a main plane of the panel, The mechanical locking system comprising: 
     a first tongue  64  provided at a first edge of the first board  8   a , wherein the first tongue is configured to cooperate with a first tongue groove  50  provided at a second edge of the second board  8   b  for locking together the first and the second panel in a first vertical direction V1; 
     a second tongue  72  at the second edge of the second board  8   b , wherein the second tongue is configured to cooperate with a second tongue groove  73  at the first edge of the first panel  8   a  for locking together the first and the second panel in a second vertical direction V2; 
     a first pair of locking surfaces  83  provided at the first face for locking together the first board  8   a  and the second board  8   b  in a first horizontal direction H1; and second pair of locking surfaces  84  provided at the second face for locking together the first board  8   a  and the second board ( 8   b  in a second horizontal direction (H2). 
     The first pair of locking surfaces ( 83 ) are preferably essentially vertical. The second pair of locking surfaces  84  are also preferably essentially vertical. 
     The first tongue  64  and the first tongue groove  50  cooperate at a third pair of locking surfaces  87  that are preferably arranged essentially horizontally. 
     The second tongue  72  and the second tongue groove  73  cooperate at a fourth pair of locking surfaces  74  that are preferably arranged at an angle  88  to the main plane of the panel that is greater than zero. The angle  88  is elected to allow the first board to be locked to the second board by an angling motion of the first panel, wherein the first tongue  64  is inserted in the first tongue groove  50 , as is shown in  FIG. 8C . 
     The first face  85  is arranged upwards, or in the direction were the greatest load F1 is likely to be applied, to prevent that the first and the second board are unlocked by a reversed angling motion. 
     The second face  86  is arranged downwards, or in the direction were the smallest load F2 is likely to be applied on the panel. The second tongue and the tongue groove may provide a resistance for unlocking of the first and the second board by a reversed angling motion. 
     The angle  88  may be in the range of about 30° to about 60°. The angle is preferably about 45°. 
       FIG. 9  shows a preferred embodiment of the locking device for locking together a panel and an adjacent panel of the frame panels  1 ,  2 ,  4 ,  5 . The locking device comprises a first thickness  55  of a core material, between an edge section groove  21  and a first edge. The first thickness is greater than a minimum second thickness  54  of a core material of an edge section  22 . The ratio between the first thickness  55  and the minimum second thickness  54  may be at least about 1.25; preferably at least about 1.5; and more preferably at least about 2. A preferred ratio between the first thickness  55  and the minimum second thickness  54  is in the range of about 1.1 to about 3. 
     An embodiment comprises an edge section groove  21  that comprises a first wall  56  and a second wall  57 , wherein the first wall is closer to the an edge of the panel than the second wall. The first thickness  55  is preferably measured between the first wall  56  and the first edge  53 . The first and the second walls  56 ,  57  are preferably connected by a bottom wall  58 . 
     The edge section  22  may comprise a first wall and an opposite second wall, wherein the tongue groove  10  is provided in the first wall. The minimum second thickness  54  may be measured between a bottom of the tongue groove and the second wall. 
     An embodiment of the insertion groove  20  that extends along essentially the entire length of the edge section groove of first edge may lead to an easier production. An embodiment of the tongue groove  10  that extends along essentially the entire length of the edge section of the second edge may also lead to an easier production. 
     The edge  53  of the panel  2  is in a preferred embodiment provided essentially in the same plane as an outer face  63  of the adjacent second panel  4 . The panel  2  may have a decorative layer  61 . 
     An edge of the opening of the edge section groove may be provided with a bevel  59  or rounding in order to facilitate the insertion of a flexible tongue  30  into the insertion groove  20 . 
       FIG. 10A  shows an embodiment of a locking device for locking the third panel  4 , such as a back piece or a bottom panel, to any back or bottom edge  81  of the frame. An embodiment of the frame is shown in  FIGS. 2A, 3A and 5 . 
       FIG. 10B  shows an embodiment of a locking device for locking the sixth panel  3 , such as a shelf, to any panel  82  of the frame. A first edge of the sixth panel may be connected to the frame by linearly displacement and/or an angling motion. An embodiment of the frame is shown in  FIG. 2A  and  FIG. 3A . 
     An embodiment of the flexible tongue  30 , which is displaceable in an insertion groove  20 , is shown in  FIGS. 11A-11D .  FIGS. 11A-B  show the flexible tongue in a locked potion and  FIGS. 11C-D  show the flexible tongue during assembling of the a panel and an adjacent panel.  FIG. 11B  shows a cross section of the flexible tongue in  FIG. 11A .  FIG. 11D  shows a cross section of the flexile tongue in  FIG. 11C . The flexible tongue comprises bendable protruding parts  24 . A space  23  is provided between the tongue and a bottom wall of the insertion groove  20 .  FIG. 11C  shows that the flexible tongue is pushed into the insertion groove  20  and towards the bottom wall during the assembling of the panel. The tongue springs back when the first and the second panel have reached a locked position. A recess  25  is preferably arranged at each bendable protruding part. 
     The flexible tongue may have a first displacement surface  26  and a opposite second displacement surface  27 , configured to be displaced along a third and a fourth displacement surface  28 ,  29 , respectively, of the insertion groove  20 . 
     An alternative embodiment of the flexible tongue  30 , without the protruding bendable parts, is shown in  FIG. 11E-F .  FIG. 11F  shows a cross section of the tongue in  FIG. 11E . The alternative embodiment is bendable in its length direction in order to accomplish the same function as the embodiment shown in  FIG. 11A-D . 
     A further embodiment of the flexible tongue  30  is shown in  FIG. 11G-H .  FIG. 11G  shows the flexible tongue  30  before the panel and the adjacent panel are locked together by the flexible tongue. The flexible tongue comprises an inner part  31  provided with wedge elements and an outer part for the locking together the panel and the adjacent panel by the flexible tongue. The locking is obtained by applying a force P, in a direction parallel to the first edge, at a short edge of the outer part. The force displaces the outer tongue part in the direction parallel to the edge of the panel and the wedges force the outer tongue part in a perpendicular direction, out of the insertion groove  20 . The resulting displacement  32  of the outer part of the flexible tongue is therefore in a direction between the direction parallel to the first edge and the perpendicular direction. 
     While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g. of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during prosecution of the application, which examples are to be construed as non-exclusive.