Mechanical locking system for building panels

Panels are shown, which are provided with a mechanical locking system comprising a separate and flexible tongue allowing connection with a snap action. An outer edge part of the separate flexible tongue comprises a guiding protrusion that facilitates easy disassembly of the panels and that is deformed during locking and/or unlocking.

TECHNICAL FIELD

The disclosure relates to the field of mechanical locking systems for building panels, especially furniture components with mechanical locking systems, which are intended to lock perpendicularly or in parallel to each other.

FIELD OF APPLICATION OF THE INVENTION

Embodiments of the present invention are particularly suitable for use in furniture components, which are preferably formed of sheet shaped panels and which are joined mechanically with a locking system integrated with the panel, i.e. mounted at the factory, The following description of known technology, problems of known systems and objects and features of the invention will therefore, as a non restrictive example, be aimed above all at this field of application and in particular at furniture components formed as rectangular or square panels intended to be mechanically joined on one pair of opposite edges perpendicularly or parallel to other adjacent panels.

It should be emphasised that the invention can be applied to any type of sheet shaped panel such as for example wood based HDF, particle board and plywood, plastic sheet shaped materials, mineral fibre and metal based materials, stone and ceramics and similar. It may be used to assemble and disassemble furniture components, floor panels and elements for packaging boxes and similar. It may also be used to lock and unlock components, which for example have a cylinder form such as table legs.

BACKGROUND OF THE INVENTION

Furniture such as kitchen cabinets, bookshelves, drawers, tables and similar are generally supplied as flat components in order to save transportation costs. The customer must assemble them. Several methods are used to assemble such furniture components for example glue, spikes, screws and similar. Snapping connections comprising plastic components are widely used to connect for example drawers. It is an advantage if assembled furniture components may be disassembled partly or completely again in a simple way. Mistakes during assembly may be corrected and furniture may be dissembled again to flat components in connection with transportation from one apartment to another. A simple and easy disassembly is an advantage even in the case when furniture components are factory assembled.

Known Technology and Problems Thereof

It is known from WO 2012/154113 that furniture components may be locked mechanically with a perpendicular snap action.FIG. 1ashows a first1and a second2panel. The first panel1comprises a groove6, formed in the panel core7. An insertion groove4formed in one of the groove walls comprises a flexible tongue3that locks into a tongue groove5when an edge of the second panel2is displaced into the groove6.FIG. 1bshows a known flexible bristle tongue3, which is used to connect floor panels. Such a tongue is also used to connect furniture components. The tongue3comprises flexible protrusions8that bend in the length direction of the tongue and that displace the tongue in the insertion groove4during the snap action.FIG. 1bshows the tongue3in the outer locked position.

FIGS. 1cand 1dshow that the locking system may be disassembled. A rod shaped stick9is inserted into the tongue groove3sideways. The flexible tongue3is pushed back into the insertion groove4and the second panel2may be released from the first panel1.

The main problem with such disassembly is that the rod shaped stick9must be turned in a correct position and must be inserted precisely into the tongue groove5. A disassembly is not possible if the rod shaped stick is inserted into the insertion groove4.

SUMMARY OF THE INVENTION

A basic objective of embodiments of the present invention is to simplify disassembly of panels that are locked perpendicularly to each other with a flexible tongue.

The above objects of embodiments of the invention are achieved wholly or partly by a mechanical locking system and panels, according to the independent claims that provide a stronger and easier locking and unlocking. Embodiments of the invention are evident from the dependent claims and from the description and drawings.

A first aspect of the invention is a set of panels comprising a first and a second panel. A panel edge of the second panel is insertable into a core groove of the first panel to obtain a mechanical connection between the first and the second panel. The panel edge is insertable into the core groove by an essentially linear relative displacement of the first and second panel when the first and second panel are arranged essentially perpendicularly to each other. The panel edge comprising a separate and flexible tongue and the core groove comprising a tongue groove, or the panel edge comprising a tongue groove and the core groove comprising a separate and flexible tongue. The separate and flexible tongue is insertable into the tongue groove for connecting the panels to each other in a first direction, which is perpendicular to a main plane (MP-1) of the first panel. The panel edge of the second panel is configured to cooperate with the core groove of the first panel for connecting the panels to each other in a second direction, which is perpendicular to a main plane (MP-2) of the second panel. A longitudinal direction of the separate and flexible tongue extends parallel with the panel edge and/or core groove. The separate and flexible tongue is arranged in an insertion groove and the separate and flexible tongue being displaceable inwardly towards a bottom of the insertion grove and outwardly into the tongue groove during a locking of the first and second panel. The separate and flexible tongue comprises a guiding protrusion at a short edge of the separate and flexible tongue and the guiding protrusion is configured such that its shape changes during the locking and/or unlocking of the first and second panel.

By means of the inventive concept, the panels may be disassembled in an improved and simple manner.

Preferably, the panels in the set of panels are essentially formed as parallelepipeds or, more specifically, as rectangular parallelepipeds.

Each of the panels, in particular the first and the second panel, may comprise a lower side and an upper side. Preferably, the lower and upper sides are shaped as rectangles or squares and are planar. The lower side and the upper side may be parallel. In one example, the panel has a uniform thickness. In another example, the panel has a non-uniform thickness. In yet another example, the panel comprises two or more sections, each having a uniform thickness. The lower side and the upper side of the panel may be parallel with the main plane of the panel. In particular, the main plane of the panel may coincide with the lower or the upper side of the panel. Moreover, each panel may comprise side edges which may connect the upper and lower sides. In the case of a panel formed as a parallelepiped, there may be two pairs of side edges. Preferably, at least portions of the two side edges in each pair of side edges are parallel.

In one example, a density of the panel is uniform. In another example, the density of the panel is higher closer to the upper and/or lower sides than in a center part of the panel.

The first direction may be parallel to the main plane of the second panel. Moreover, the second direction may be parallel to the main plane of the first panel.

The panel edge of a panel may comprise at least a portion of a side edge of the panel. Additionally, the panel edge may comprise a portion of the lower side and a portion of the upper side of the panel close to the side edge. A shape of the panel edge may substantially correspond to a shape of the core groove. Thereby, the second panel may engage with the first panel in a tightly fit manner. In particular, the panel edge and the core groove may be essentially U-shaped. Optionally, corners of the panel edge and/or the core groove may be bevelled.

By a short edge of the separate and flexible tongue is here meant an edge of the tongue in a longitudinal direction of the separate and flexible tongue.

The separate and flexible tongue may comprise an outer edge part that is formed as a guiding protrusion.

The guiding protrusion may be in contact with an inner part of the insertion groove during the locking.

In particular, in a locked position of the first and the second panel, the guiding protrusion may be in contact with the inner part of the insertion groove.

Alternatively, there may be a space between the inner part of the insertion groove and the guiding protrusion in a locked position of the first and the second panel. The space is preferably smaller than the displacement of the separate and flexible tongue during locking along a direction towards the inner part of the insertion groove.

The guiding protrusion may be curve shaped and configured to guide a rod shaped tool into the tongue groove when the rod shaped tool is inserted into the insertion groove. By curve shaped is here meant that at least a portion of the guiding protrusion is shaped as a curve. The curve may have a non-zero curvature. In particular, as seen from a top view, an outer side of the guiding protrusion may be shaped as a curve. The curvature is preferably such that an angle formed between a tangential direction of the outer side of the guiding protrusion and a longitudinal direction of the rod shaped tool is acute. In particular, the angle may be between 1° and 89°. Since the guiding protrusion is curve shaped, the acute angle may vary along the guiding protrusion in a direction towards a tip of the guiding protrusion. For example, the acute angle may increase towards the tip of the guiding protrusion.

According to an alternative embodiment, the guiding protrusion comprises at least one straight portion. As seen from a top view, each straight portion may be inclined with respect to a longitudinal direction of the tongue. In one example, the guiding protrusion comprises one straight portion. In another example, the guiding protrusion comprises at least two straight portions. In the latter example, the straight portions are preferably juxtaposed. The angle with respect to the longitudinal direction of the tongue may be different between the different straight portions. For example, the angle may increase by each straight portion towards the tip of the guiding protrusion.

In one example, a cross section of the guiding protrusion along a direction towards the tip of the guiding protrusion is constant. In another example, the cross section of the guiding protrusion is tapering. Moreover, in non-limiting examples, the cross section of the guiding protrusion along a direction towards its tip may be shaped as a circle, an oval, a polygon, a rectangle, a square, or a triangle.

The guiding protrusion may be flexible. More generally, at least portions of the guiding protrusion may be flexible.

The rod shaped tool may comprise an essentially round cross section. In particular, the cross-section may be shaped as a circle or an oval. By having a rotationally symmetric cross-section, such as a circle, the precise orientation of the rod shaped tool when inserting it into the insertion groove may become immaterial, which may further simplify the disassembly of the panels.

The separate and flexible tongue may comprise several flexible protrusions extending in the length direction of the tongue.

The insertion groove may be formed in the core groove of the first panel.

When the panel edge comprises the tongue groove and the core groove comprises the separate and flexible tongue, the tongue groove may be arranged in the lower side or in the upper side of the second panel. In particular, the tongue groove may be arranged in the lower side or in the upper side of the second panel, close to a side edge of the second panel.

Moreover, when the panel edge comprises the tongue groove and the core groove comprises the separate and flexible tongue, the insertion groove may be formed in the core groove. The core groove may comprise two side walls and a bottom wall. The two side walls of the core groove may be parallel. According to one embodiment, the insertion groove may be arranged in a side wall of the core groove. A shape of at least a part of the flexible tongue may substantially correspond to a shape of the insertion groove. In particular, the flexible tongue and the insertion groove may be essentially U-shaped. The insertion groove may comprise two side walls and a bottom wall. The side walls of the insertion groove may be parallel. In a first example, the bottom wall of the insertion groove is planar. In a second example, the bottom wall of the insertion groove is rounded. The insertion groove may be inclined with respect to the lower side and/or the upper side of the first panel. In a non-limiting example, the angle between a side wall of the insertion groove and the lower side and/or the upper side of the first panel may be between 5° and 45°.

The tongue groove may comprise two side walls and a bottom wall. The side walls of the tongue groove may be parallel. In a first example, the bottom wall of the tongue groove is planar. In a second example, the bottom wall of the tongue groove is rounded. The tongue groove may be inclined with respect to the lower side and/or the upper side of the second panel. In a non-limiting example, the angle between a side wall of the tongue groove and the lower side and/or the upper side of the second panel may be between 45° and 85°. The inclination of the tongue groove may correspond to an inclination of the insertion groove so that in a connected state of the first and second panel, parallel side walls of the tongue groove and parallel side walls of the insertion groove are essentially aligned with each other.

A second aspect of the invention is a locking system for locking of panels comprising a first and a second panel. A panel edge of the second panel is insertable into a core groove of the first panel to obtain a mechanical connection between the first and the second panel. The panel edge is insertable into the core groove by an essentially linear relative displacement of the first and second panel when the first and second panel are arranged essentially perpendicularly to each other. The locking system comprises a separate and flexible tongue arranged in an insertion groove which is formed in the core groove and a tongue groove at the panel edge. The tongue groove is adapted to accommodate a part of the separate and flexible tongue. The separate and flexible tongue comprises a guiding protrusion at a short edge of the separate and flexible tongue. The guiding protrusion is configured such that its shape changes when a rod shaped tool is inserted into at least a part of the tongue groove.

The rod shaped tool may comprise an essentially round cross section.

The invention provides the advantages that a rod shaped tool may be inserted sideways into the insertion groove that generally is larger than the tongue groove and the tool will be automatically guided by the guiding protrusion into the tongue groove. The rod shaped tool may have a simple round cross section and a precise orientation of the tool during insertion into the groove may be avoided. This facilitates an easy and simple disassembly of locked panels.

According to a third aspect of the invention, there is provided a set of panels comprising a first and a second panel. A panel edge of the second panel is insertable into a core groove of the first panel to obtain a mechanical connection between the first and the second panel, the panel edge being insertable into the core groove by an essentially linear relative displacement of the first and second panel when the first and second panel are arranged essentially perpendicularly to each other. Moreover, the panel edge comprises a separate and flexible tongue and the core groove comprises a tongue groove, wherein the separate and flexible tongue is insertable into the tongue groove for connecting the panels to each other in a first direction, which is perpendicular to a main plane of the first panel. The panel edge of the second panel is configured to cooperate with the core groove of the first panel for connecting the panels to each other in a second direction, which is perpendicular to a main plane of the second panel. A longitudinal direction of the separate and flexible tongue extends parallel with the panel edge and/or core groove. The separate and flexible tongue is arranged in an insertion groove and is displaceable inwardly towards a bottom of the insertion groove and outwardly into the tongue groove during a locking of the first and second panel. An engagement portion of the core groove is arranged to engage with the separate and flexible tongue during locking of the first and second panel for displacing the separate and flexible tongue inwardly towards the bottom of the insertion groove, wherein the engagement portion is bevelled.

The bevelled engagement portion may be an upper bevelled engagement portion, provided close to, or at, an upper or lower side of the second panel.

The bevelled engagement portion may be provided in an upper part of the first panel, the upper part having a higher density than a center part of the first panel.

The bevelled engagement portion may be provided between a side wall of the core groove and a lower or upper side of the first panel. In particular, the bevelled engagement portion may join the side wall of the core groove and the upper or lower side of the first panel.

The second panel may comprise an overlapping portion, which engages with the bevelled engagement portion in a locked position of the first and second panel.

A thickness of the second panel may be smaller at the panel edge than in a visible part of the second panel which is visible in a locked position of the first and the second panel.

A distance between a lower edge side and a parallel upper edge side of the panel edge may be smaller than a distance between a lower side and a parallel upper side, the lower and upper edge sides being located closer to a side edge of the second panel than the lower and upper sides.

The insertion groove may be provided in the lower edge side or in the upper edge side of the panel edge. Alternatively, the insertion groove may be provided in the lower side or in the upper side of the second panel.

According to a fourth aspect of the invention, there is provided a set of panels comprising a first and a second panel. A panel edge of the second panel is insertable into a core groove of the first panel to obtain a mechanical connection between the first and the second panel, and the panel edge is insertable into the core groove by an essentially linear relative displacement of the first and second panel when the first and second panel are arranged essentially in the same plane MP-1. Moreover, the panel edge comprises a separate and flexible tongue and the core groove comprises a tongue groove, or the panel edge comprises a tongue groove and the core groove comprises a separate and flexible tongue. The separate and flexible tongue is insertable into the tongue groove for connecting the panels to each other in a first direction, which is parallel to a main plane of the first panel. The panel edge of the second panel is configured to cooperate with the core groove of the first panel for connecting the panels to each other in a second direction, which is perpendicular to the main plane of the panels. A longitudinal direction of the separate and flexible tongue extends parallel with the panel edge and/or core groove. Moreover, the separate and flexible tongue is arranged in an insertion groove and is displaceable inwardly towards a bottom of the insertion groove and outwardly into the tongue groove during a locking of the first and second panel. The separate and flexible tongue comprises a guiding protrusion at a short edge of the separate and flexible tongue, and the guiding protrusion is configured such that its shape changes during the locking and/or unlocking of the first and second panel.

The guiding protrusion may be further configured to be in contact with an inner part of the insertion groove during the locking.

The guiding protrusion may be curve shaped and configured to guide a rod shaped tool into the tongue groove when the rod shaped tool is inserted into the insertion groove.

The rod shaped tool may comprise an essentially round cross section.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

To facilitate understanding, several locking systems in the figures are shown schematically. It should be emphasised that improved or different functions can be achieved using combinations of the preferred embodiments.

FIGS. 2a-dillustrate a first panel1and a second panel2which are connected to each other in accordance with an embodiment. The first panel1comprises a core groove6which is arranged in an upper side1bof the first panel1. The core groove6comprises two opposing side walls6a,6band a bottom wall6c. The opposing side walls6a,6bare parallel. The second panel2comprises a panel edge12which in a locked position of the panels1,2is arranged in the core groove6. More specifically, a portion of a lower side2a, a portion of an upper side2b, and a side edge2cof the second panel2are arranged in the core groove6. The panels1,2may be locked to each other by means of a separate and flexible tongue3.

FIG. 2ashows a top view of the flexible tongue3in a locked position. A part of the flexible tongue3comprising flexible protrusions8is located in an insertion groove4. An opposite part is located in the tongue groove5according to known technology. The flexible tongue3comprises an outer edge part3athat is formed as a guiding protrusion10that automatically guides a rod shaped tool9into a tongue groove5when the tool9is inserted sideways into the insertion groove4. The guiding protrusion10is arranged at a short edge of the tongue3. It is understood that there may be a corresponding guiding protrusion10arranged at the other short edge of the tongue3(not shown).

FIG. 2bshows that the flexible guiding protrusion is deformed when the rod shaped tool9is displaced sideways parallel to the length direction of the tongue3such that the tongue3is pressed into the insertion groove4. It is an advantage if the flexible guiding protrusion10is in contact with an inner part of the insertion groove4during locking and when the tongue is pressed into the insertion groove. The guiding protrusion10is preferably flexible and is preferably also formed as a curved edge part.

FIG. 2cshows a side view of the locking system. According to the present embodiment, a main plane MP-1of the first panel1coincides with the upper side1bof the first panel1. Moreover, a main plane MP-2of the second panel2coincides with the lower side2aof the first panel2, which is situated to the left, as shown inFIG. 2c. The rod shaped tool9preferably comprises an essentially round cross section. According to the present embodiment, the cross section of the rod shaped tool9is circular. Moreover, a width of the rod shaped tool9corresponds to a width of the tongue groove5between two parallel side walls5a,5bthereof. According to the present embodiment, a bottom wall5cof the tongue groove5, connecting the two side walls, is rounded. The curvature of the rounded bottom wall5csubstantially corresponds to the curvature of the rod shaped tool9. Thereby, an improved guiding of the rod shaped tool9may be provided. In the present embodiment, the rod shaped tool9is adapted to be fitted inside the tongue groove5so that essentially no portion of the rod shaped tool9extends outside the lower side2aof the second panel2. Thereby, the panels1,2may be easily disassembled, since the rod shaped tool9may be fitted inside the tongue groove5while the tongue3is displaced into the insertion groove4, thereby releasing the mechanical connection between the first1and the second panel2.FIG. 2dshows disassembly of the first1and the second panel2according to the present embodiment.

It is clear that other shapes of the rod shaped tool9and the tongue groove5are equally conceivable. For example, the cross-section of the rod shaped tool9may be shaped as a polygon, a rectangle, a square, an oval, a triangle or a star. Additionally, according to alternative embodiments, the shape of the bottom wall may not correspond to the shape of the rod shaped tool9. For example, the cross-section of the rod shaped tool9may be circular and the cross-section of the tongue groove5may be U-shaped, for example comprising a planar bottom wall.

The insertion groove4may also be formed in the second panel2and the tongue groove5may be formed in the core groove6of the first panel1. This will be described in more detail below.

The above-described embodiment provides the advantages that the insertion of the tool9may be made into the whole cross section comprising the insertion groove4and the tongue grooves5. A symmetric tool cross section may be used that eliminates a precise orientation of the tool9prior to insertion into the grooves.

The guiding of the rod shaped tool9is illustrated inFIG. 2aandFIG. 2c. The broken lines illustrate the position of the rod shaped tool9when inserted into the insertion groove4and the arrows indicate that the rod shaped tool9is guided into the tongue groove5in the shown direction.

FIG. 3ashows a tongue blank11comprising several thermoplastic injection-moulded flexible tongues3. The tongues are preferably separated from the blank11at a separation portion S located inwardly and at a distance from the outer edge of the tongue3.

FIG. 3bshows that the guiding protrusion10may replace one of the flexible protrusions8such that all flexible protrusions8are located along the tongue in the length direction of the tongue and spaced in the length direction from the guiding protrusion10.

FIG. 3cshows that the principles of the invention may be used to improve disassembly when other types of tongues are used for example flexible tongues comprising a snap tab13at the outer part. The locking system comprising a flexible snap tab13may be formed such that a tool9with an essentially round cross section may be used to release the first1and the second2panels.

FIG. 3dshows that such tongue3comprising a snap tab13may comprise a symmetric cross section in inner parts and an edge portion that may be cut or formed to a wedge shaped edge part14. The flexible tongue may comprise a flexible snap tab and an asymmetric cross section along its length direction.

In particular, the flexible tongue3may be tapering towards an edge of the flexible tongue3in a longitudinal direction. Thereby, an area of the cross section of the flexible tongue3may decrease towards the edge. Additionally, a maximal horizontal distance from an inner part of the cross section to an outer part of the cross section may decrease towards the edge. Here, the horizontal distance is measured in a direction along which the flexible tongue3is adapted to contract and expand. For example, the horizontal distance may be measured in a direction along which the flexible snap tab13is adapted to contract and expand. As shown in the embodiment according toFIG. 3d, the cross section of the flexible snap tab13decreases towards the edge. A portion13aof the flexible snap tab13has been cut out from the flexible tongue3for providing the tapering edge.

Next, an alternative embodiment will be described with respect toFIGS. 4a-c.FIGS. 4aand 4bshow a side view of a first panel1and a second panel2which are being assembled. It is understood that, inFIGS. 4a-c, the first panel1extends horizontally and that the second panel2extends vertically and that only a connecting region of the first1and second2panel is shown. The first1and second2panels are arranged essentially perpendicularly to each other.

According to the present embodiment, the first panel1comprises three parts: an upper part30, a center part32, and a lower part34. The upper part30and the lower part34are located close to the upper1band lower1asides, respectively, and have a higher density than the center part32.

The core groove6comprises two opposing side walls6a,6band a bottom wall6c. The core groove6comprises a tongue groove5. The tongue groove5is provided in the side wall6aof the tongue groove5. Thus, the tongue groove5is provided in a left part21aof the first panel1which is located to the left of core groove6. Moreover, the tongue groove5comprises two parallel side walls5a,5band a bottom wall5c. As seen from the side view inFIGS. 4a-c, a linear extension E of the lower side wall5ais located at or above a right part21bof the first panel1, which is located to the right of core groove6. Thereby, a tool, such as a cutting tool, may easily provide the tongue groove5by means of a linear displacement of the tool.

An engagement portion20of the core groove6is bevelled. The bevelled engagement portion20is provided between an upper part of the side wall6aand the upper side1bof the first panel1, thereby joining them. Alternatively, the engagement portion20of the core groove6may be rounded off.

Moreover, the panel edge12of the second panel2has a smaller thickness than an inner part of the second panel2, wherein the inner part is located farther from a side edge2cof the second panel2than the panel edge12. More specifically, the panel edge12comprises a lower edge side22aand an upper side edge22bwhich are parallel to each other and are located closer to the side edge2cof the second panel2than a lower side2aand an upper side2bof the second panel2. As displayed inFIG. 4c, the distance d1between the lower edge side22aand the upper side edge22bis smaller than the distance d2between the lower side2aand the upper side2b.

The lower edge side22ais joined to the lower side2aby means of an overlapping portion24. According to the present embodiment, there is a corresponding upper edge side22bwhich is joined to the upper side2bof the second panel2by means of an overlapping portion25. By means of the overlapping portions24,25, which in an assembled state, or locked position, of the first1and second2panels engage with the bevelled engagement portion20and a bevelled surface27of the core groove6, respectively, the panel edge12and/or the core groove6may be concealed in an improved manner.

The panel edge12comprises a separate and flexible tongue3. The separate and flexible tongue3may assume a contracted state and an expanded state and has a tendency to assume the expanded state when no forces are acting on it. The separate and flexible tongue3is arranged in an insertion groove4which is provided in lower edge side22aof the panel edge12. The separate and flexible tongue3comprises a chamfered portion23which is pointing downwards when the separate and flexible tongue3is inserted into the insertion groove4.

When the first1and second2panels are assembled, the panel edge12of the second panel2is inserted into the core groove6of the first panel1by a relative vertical displacement of the first1and second2panels. The displacement is linear. The separate and flexible tongue3is partly inserted into the insertion groove4and is further displaced into the insertion groove4when the chamfered portion23engages with the bevelled engagement portion20during the vertical displacement. By means of the bevelled engagement portion20, the chamfered portion23engages with a smooth surface during the assembly. Thereby, the chamfered portion23may avoid engaging with any sharp edges during assembly. When displaced further into the insertion groove4, the separate and flexible tongue3may become contracted. When the side walls4a,4bof the insertion groove4are aligned with the side walls5a,5bof the tongue groove5, the separate and flexible tongue3may expand and may be displaced out from the insertion groove4and into the tongue groove5for obtaining a locking of the first1and second2panels in a direction which is perpendicular to the main plane MP-1of the first panel.

The core groove6comprises an inclined portion16between the side wall6aand the bottom wall6cas well as between the side wall6band the bottom wall6c. Moreover, the panel edge12comprises a bevel26between the lower edge side22aand the side edge2cof the second panel2and a bevel26between the upper edge side22band the side edge2cof the second panel2. A shape of the inclined portion16may substantially correspond to a shape of the bevel26. For example, the inclination of the inclined portion16and the bevel26may be substantially the same. The bevels26may remove sharp corners between the edge sides22a,22band the side edge2c. Moreover, the bevels26may guide the second panel2into a proper locking position.

In a locked position of the panels1,2, the panel edge12cooperates with the core groove6for connecting the panels to each other in a second direction, which is perpendicular to a main plane MP-2of the second panel2.

FromFIG. 4bit is clear that the visible outer parts of the first1and second2panels have a uniform thickness in a locked position of the first1and second2panel.

It is understood that according to an alternative embodiment, the second panel2may have a uniform thickness.

FIG. 4cshows a side view of a first panel1and a second panel2which are being disassembled. This is analogous to the disassembly described above in relation toFIGS. 2a-d. In particular, when disassembling, the rod shaped tool9is inserted sideways into the insertion groove4and is guided into a proper position in the tongue groove5by means of a guiding protrusion10which is provided at a short edge of the separate and flexible tongue3. When the rod shaped tool9is inserted into the tongue groove5, the separate and flexible tongue3is displaced into insertion groove4. Thereby, the second panel2becomes unlocked and the panel edge12may be removed from the core groove6by a relative linear vertical displacement of the first1and second2panel.

FIGS. 5a-5dshow a locking system that may be used to lock and unlock a first1and a second2panel that, in a locked position, are located in the same main plane MP-1. In other words, the panels are arranged essentially in parallel with each other. Such a locking system may be used to lock two or several furniture components with, for example, a length of 0.6 m and that after locking form a part of a book shelf with a length of, for example, 1.2 or 1.8 m. An advantage of providing this type of locking system is that smaller components are easier to transport, assemble and disassemble. It is clear than other lengths of the furniture components are equally conceivable. In non-limiting examples, the length may be between 0.1 m and 1.0 m.

In the present embodiment, the first panel1and the second panel2have a uniform thickness.

The first panel1comprises a core groove6and a tongue groove5and the second panel2comprises a panel edge12that is insertable into the core groove6with a displacement parallel with the main plane MP-1of the first and the second panel. The panel edge12comprises a separate and flexible tongue3which is provided in an insertion groove4. In a locked position of the panels, the separate and flexible tongue3locks into the tongue groove5.

According to an alternative embodiment (not shown), the tongue groove5may be provided in the second panel2and the separate and flexible tongue3may be provided in the first panel1.

It is essential that the locking system is strong in order to provide sufficient rigidity to the locked components. Preferably, an upper edge30aand a lower edge31aof the first panel1and an upper edge31band a lower edge31bof the second panel2are in contact with each other when the panels1,2are locked.

According to the present embodiment, a side face of the panel edge12engages with a bottom wall of the core groove6in a locked position of the first1and second2panel. This may be seen inFIG. 5c. In addition, in a locked position, an upper and a lower face of the panel edge12engage with a respective one of two opposing side walls of the core groove6. According to an alternative embodiment (not shown), however, the side face of the panel edge12may be separated from the bottom wall of the core groove6in a locked position of the first1and second2panel.

The first panel1comprises an engagement portion40which is arranged to engage with the separate and flexible tongue3during locking of the first1and second2panel for displacing the separate and flexible tongue3inwardly towards the bottom of the insertion groove4. The engagement portion40is inclined with respect to the main plane MP-1of the first1and second2panel. Moreover, the engagement portion40is bevelled at a portion42which is adjacent to the tongue groove5.

FIG. 5dshows unlocking of the first1and second2panels with a rod shaped tool9according to the above-described methods. The separate and flexible tongue3comprises an outer edge part3athat is formed as a guiding protrusion10that automatically guides the rod shaped tool9into the tongue groove5when the tool9is inserted sideways into the insertion groove4.