The present invention relates to a building panel such as a floor panel, a wall panel, a ceiling panel, a furniture component or the like, which is provided with a mechanical locking system, and a method for producing said building panel with said locking system.

Building panels provided with a mechanical locking system comprising a displaceable and resilient tongue cooperating with a tongue groove for vertical locking is known and disclosed in, e.g., WO2006/043893. The tongue is a separate part and is made of, e.g., plastic, and positioned in an insertion groove at an edge of a panel. The tongue is pushed into the insertion groove during a vertical assembling of the panels and springs back into the tongue groove of an adjacent panel when the panels have reached a locked position.

Also known is a locking system for panels comprising a tongue, which is slightly longer than the width of a panel, see, e.g., WO2008/004960, and cooperates with a tongue groove for vertical locking. The tongue is a separate part and is inserted in a displacement groove. The panels may be assembled by a vertical movement and the tongue is pressed between long edges of two adjacent panels and bent along its length direction. WO2008/116623 discloses a locking system comprising a displaceable tongue which is integrally formed with the body of the panel.

Although the description relates to floor panel, the description of techniques and problems thereof is applicable also for other applications, such as panels for other purposes, for example wall panels, ceiling panels, furniture etc.

A drawback with the known system is that a separate tongue must be produced and special inserting machines are required to position the tongue in the insertion groove with high precision.

The above description of various known aspects is the applicant's characterization of such, and is not an admission that any of the above description is considered as prior art.

It is an object of certain embodiments of the present invention to provide an improvement over the above described techniques and known art.

A further object is to provide a locking system and a method to produce a locking system, which comprises a tongue that may be formed out of the edge of the building panel. Such a system simplifies the production since no loose and additional parts are necessary to produce and to position at the correct position in the locking system.

Another object is to provide a more efficient production method, which requires a less complicated production equipment.

At least some of these and other objects and advantages that will be apparent from the description have been achieved by a method for producing a locking system at edges of building panels. The locking system may comprise a tongue, at first edge of a first building panel, cooperating with a tongue groove, at a second edge of an adjacent second building panel, for vertical locking of the building panels. The method, which is a first aspect of the invention, may comprise the steps of:

• forming material of the first edge to obtain at least parts of the outer shape of the tongue; in a production line comprising mechanical cutting devices ;
• forming an insertion groove at the first edge, in said production line, wherein said insertion groove is sidewardly open and extends in the horizontal direction; and
• displacing the tongue in said production line at least partly into the insertion groove.

The forming of the insertion groove and the tongue is preferably made in a production line comprising mechanical cutting devices, such as milling tools. The displacement of the tongue into the insertion groove is preferably made in the same production line. The tongue may be displaced by a device, which in a first step displaces the tongue in a vertical direction and in a second step displaces the tongue in a horizontal direction and into the insertion groove.

The parts of the outer shape of the tongue may be formed at an upper part of the first edge, preferably above the insertion groove.

The insertion groove may be formed below the upper part of the first edge and the tongue may be displaced downwards and into the insertion groove.

The method may furthermore comprise the step of forming a connection part between the tongue and an upper edge of the first edge.

The method may comprise the step of forming a connection part by forming a groove between an upper edge of the first edge and outer parts of the tongue. The connection part may have the advantage that the tongue is in fixed position until the tongue is displaced.

The method may comprise the step of breaking the connection part by the displacement of the tongue. The connection part may also be cut off, preferably in connection with the displacement of the tongue.

The method may comprise the step of forming the tongue groove, at the second edge.

An inner groove may be formed throughout the tongue, between the tongue and the first edge of the building panel, in order to obtain a resilient tongue part. The inner groove may extend in the longitudinal direction of the tongue and between a first and a second protruding part of the tongue, at the third and the fourth edge of the building panel respectively. The resilient tongue part may extend from the first to the second protruding part. Before the tongue is displaced into the insertion groove the protruding parts may function as connection parts as described above.

The method may comprise the step of forming a sidewall in the insertion groove at a third edge of the first building panel, which is adjacent the first edge, and forming an opening of the insertion groove at a fourth edge at, which is opposite the third edge and adjacent the first edge. The tongue may be displaced to a position in which a pressing part of the tongue protrudes through the opening of the insertion groove. This position has also a displacement of the tongue in a direction along the first edge of the building panel.

The tongue may, in a locked position of the first and second edge, be pressed between the sidewall and an edge of an adjacent building panel, such that the tongue bends and a part of the tongue is pushed into the tongue groove.

The tongue may essentially have the same length as the length of the first edge.

The method may comprise the step of forming a locking element at the first edge and a locking groove at the second edge or a locking element at the second edge and a locking groove at the first edge, wherein said locking element and locking groove are configured to cooperate for locking of the first and the second edge in the horizontal direction.

The production steps above may be performed in any order. The building panel may also be positioned upside down in the production line.

The locking system is preferably formed by mechanical cutting, such as milling, drilling, cutting by knife and/or sawing, of the edges of the building panels.

A second aspect of the invention is building panels, which preferably are produced according to an embodiment of the first aspect, provided with a mechanical locking system. The locking system may comprise a tongue, at first edge of a first building panel, cooperating with a tongue groove, at a second edge of an adjacent second building panel, for vertical locking of the building panels. The tongue is preferably produced of material of the first edge. The tongue may be at least partly positioned in an insertion groove at the first edge.

The tongue may be displaceable in the insertion groove to enable a vertical assembling of the first and the second edge. An embodiment may have a resilient part between the displaceable tongue and a bottom wall of the insertion groove. The resilient part makes it possible to push the displaceable tongue into insertion groove, by an edge of the second edge, during a vertical assembling of the first and the second edge. The tongue springs back and into the tongue groove when the first and the second building panel have reached a locked position. The embodiment with the resilient part is particularly useful for building panels with edges comprising a rigid material, such as solid wood. A resilient part may not be necessary for building panels with edges comprising a resilient material, such as plastic and vinyl. For such building panels it may be possible to configure a tongue, which is compressible enough to be pushed into insertion groove during the vertical assembling.

The displaceable tongue may, in another embodiment, be configured such that when pressed between a sidewall in the insertion groove and an edge of an adjacent third building panel the tongue bends and a part of the tongue is pushed into the tongue groove. This solution is particularly useful for building panels with edges comprising wood, such as HDF or MDF.

The sidewall may be arranged in the insertion groove at a third edge of the first building panel, which is adjacent the first edge and the insertion groove may have an opening at a fourth edge, which is opposite the third edge and adjacent the first edge. The displaceable tongue may be positioned such that a press part of the displaceable tongue protrudes through the opening. Such a position improves the possibilities to apply a force on the press part.

Another embodiment comprises a fixed tongue, which preferably is arranged firmly in the insertion groove. The fixed tongue comprises a protruding part, which protrudes outside the upper edge of the first edge and cooperates with the tongue groove for the vertical locking. A first and a second edge provided with a locking system comprising the fixed tongue may be assembled by an angular movement. This embodiment is particularly advantageous for thin building panels, preferably with a thickness in the range of about 3-7 mm or more preferably in the range of about 4-6 mm. A reason is that it's easier to produce a locking system, which comprises a displaceable tongue, at the edge of a thicker building panel than at the edge of a thinner building panel. The tools for forming a locking system with a displaceable tongue require more space and material than the tools for forming a locking system with a fixed tongue. This embodiment is particularly useful for plastic and vinyl tiles, which normally have a thin thickness.

Embodiments of the locking system and the building panels in the above first and the second aspect may comprise the features described below.

A contact surface of the tongue groove may cooperate, for the vertical locking, with a contact surface of the tongue.

The contact surface may be positioned such that when the displaceable tongue springs back and into the tongue groove, during a vertical assembling of the building panels, the tongue is prevented to reach its original position. The contact surface of the tongue asserts a force against the contact surface of the tongue groove in order to avoid a play between the panels.

The contact surface may be positioned such that when the displaceable tongue is pushed into the tongue groove the contact surface of the tongue asserts a force against the contact surface of the tongue groove in order to avoid a play between the panels.

The locking system may comprise a locking element, preferably arranged on a locking strip, at the first edge of the first panel and a locking groove at the second edge of the second panel or locking groove at the first edge of the first panel and a locking element at the second edge of the second panel. Said locking element and locking groove cooperate, for locking the panels horizontally.

The first and the second building panel are preferably essentially equal, thus an edge opposite said first edge of the first panel is provided with the same parts of the locking system as said second edge of the second panel.

The panels may be square-shaped and the edges between said first and said opposite edge are preferably provided with a locking system, which enables assembling to an adjacent panel by an angling movement.

The insertion groove may be filled with a resilient material or part, such as plastic or rubber, to improve the resilient properties of the displaceable part and/or to make the locking system stronger.

The building panel may be a floor panel, a wall panel, a ceiling panel, a furniture component or the like.

The core of the building panels may be a wood-based core, preferably made of MDF, HDF, OSB, WPC, or particleboard or of plastic, e.g., vinyl or PVC.

The edge of the panels, of which the locking system may be made, may comprise the core material.

The present invention will by way of example be described in more detail with reference to the appended schematic drawings, which shows embodiments of the present invention.

• FIG. 1 shows a known locking system with a separate and resilient tongue.
• FIGS. 2A-C show a known locking system with a separate and displaceable tongue.
• FIGS. 3A-C show cross-sections of known locking systems with a separate and displaceable tongue.
• FIGS. 4A-C show cross-sections and top views of known locking systems with a separate and displaceable tongue.
• FIGS. 5A-C show an embodiment of the building panels.
• FIGS. 6A-C show top views of an embodiment of the building panels.
• FIGS. 7A-C show an embodiment of an assembling of an embodiment of the building panels.
• FIGS. 8A-C show an embodiment of an assembling of an embodiment of the building panels.
• FIGS. 9A-C show top views of an embodiment of the building panels.

Detailed description

A known locking system for building panels, which comprises a displaceable and resilient tongue 30, at a first edge 4a of a first panel 1, cooperating with a tongue groove 20, at a second edge 4b of a second panel 1', for vertical locking of the first and a second edge 4a, 4b, is shown in FIG. 1. The tongue 30 is a separate part and is made of, e.g., plastic, and is arranged in an insertion groove at the first edge 4a. The tongue 30 is pushed into the insertion groove during a vertical assembling of the short edges 4a, 4b of the panels and springs back into the tongue groove 20, when the panels have reached a locked position. The locking system comprises at the first edge a locking strip 8 with a protruding locking element 6, which cooperates with a locking groove 14 at the second edge. A third and a fourth edge 5a, 5b of the panels 1', 1', 1" are provided with a locking system, which enables assembling to of panels in a first and second row R1, R2 by an angling movement, to obtain a simultaneous locking of adjacent edges 5a, 5b, 4a, 4b.

FIGS. 2A-C show simultaneously assembling of adjacent long and short edges 5a, 5b, 4a, 4b in three steps from FIG. 2A to FIG. 2C. The second panel 1' is angled down along its first long edge 5a, at a second long edge 5b of a third panel 1", and the second edge 4b of the second panel 1' is simultaneous lowered vertically to be connected to the first edge 4a of the first panel 1. The tongue 30 is gradually pushed into the insertion groove, see FIG. 2B, and spring back into the tongue groove 20 when the first, the second and the third panels 1, 1', 1" have reached a locked position, see FIG. 2C.

FIGS. 3A-C show cross sections of different embodiments of the known displaceable and resilient tongue 30 during assembling of two adjacent short edges. The panel with the tongue groove is lowered in relation to the panel with tongue 30, which is pushed into the insertion groove 40 by the lowered panel. The tongue springs back, and into the tongue groove, when the panels has reached a locked position, and locks the panels vertically.

FIGS. 4A-F discloses another known embodiment, comprising a displaceable and resilient tongue 30, during assembling of a first and a second edge 4a, 4b of a first and a second panels 1, 1'. This embodiment is similar to the locking system shown in FIGS. 1-3, but the displaceable and resilient tongue 30 that locks automatically by a spring effect during the vertical movement is replaced by a displaceable and resilient tongue 30 that locks the first and the second edge 4a, 4b, when a third 1 "and a forth 1"' building panel are assembled at the third and the forth edge respectively of the first panel 1. The displaceable and resilient tongue 30 is, in this embodiment, longer than the width of the front face of the first and the second panel 1, 1'. A third and fourth edge 5a, 5b of the third and fourth building panel 1", 1"' respectively, apply a force at outer parts E1, E2 of the displaceable and resilient tongue 30. The force bends the displaceable and resilient tongue 30 and a part is pushed into the tongue groove 20 at the second edge of the second panel 1'.

Embodiments of the invention are shown in FIGS. 5-9. A locking system is formed at a first and a second edge 4a, 4b of a first and second panel 1, 1' for locking the first and the second edge 4a, 4b in a vertical and/or horizontal direction. Embodiments of the locking system comprise a displaceable or compressible tongue that enables assembling of the first and the second edge 4a, 4b by a vertical movement, see FIGS. 5A-C, 6A-C and 7A-C. Another embodiment, which may comprise a fixed tongue, enables assembling of building panels at the adjacent edges by an angular movement, see FIGS. 8A-8C. The locking system is preferably formed by mechanical cutting, such as milling, drilling, cutting by knife and/or sawing, of the edges of the building panels.

FIGS. 5A discloses a tongue 30, which is formed of material of a first edge of first building panel 1 and at an upper part of the first edge. A tongue groove is formed at a second edge of a second building panel 1'. The tongue 30 is configured to cooperate, in a locked position of the first edge and the second edge see FIG. 5C, with the tongue groove 20 for vertical locking of the first and the second edge.

A connection part 50 may be formed between outer part of the tongue 30 and an upper edge of the first edge. The connection part 50 is preferably formed by making a groove 51, e.g., by cutting, between the outer part of the tongue 30 and an upper edge of the first edge. The connection part keeps the tongue in the correct position before the tongue is displaced.

An insertion groove 40 is formed below the upper part and the tongue 30 is displaced into the insertion groove 40, see FIGS. 5B.

The tongue 30 is displaced into the tongue groove 20 during assembling of the first and the second edge, see FIGS. 5C. A contact surface of the tongue is pressed against a contact surface 52 of the tongue groove 20.

An embodiment may have a resilient part (not shown) between the tongue 30 and a bottom wall of the insertion groove 40. The resilient part makes it possible to push the tongue 30 into insertion groove, by an edge of the second edge, during a vertical assembling of the first and the second edge. The tongue springs back and into the tongue groove when the first and the second building panel have reached a locked position.

A locking strip 8 with a vertically protruding locking element 6 is formed at the edge of the first building panel. The locking element 6 cooperates with a locking groove 14, formed at the edge of the second building panel 1', for horizontal locking of the first and second edge.

Another embodiment is shown in top views in FIGS. 6A-C. The embodiment comprises an insertion groove 40 with a sidewall 60 formed at a third edge, which is adjacent the first edge, of the first building panel 1. An opening of the insertion groove 60 is formed at the forth edge, which is opposite the third edge and adjacent the first edge, of the first building panel 1. A pressing part E2 may protrude through the opening of the insertion groove. When the first and the second edge are in a locked position a force is applied at the pressing part E2. The force presses an inner part E1 of the tongue 30 against the sidewall 60. The force bends the tongue 30 and a part of the tongue is pushed into the tongue groove 20 at the second edge of the second building panel 1'.

Further embodiments are shown in cross sections in FIGS. 7A-C and 8A-C. The tongue 30 and the insertion groove 40 are formed of material of the first edge. The width of tongue 30 is greater than the depth of the insertion groove 40 to obtain a tongue with protruding part that protrudes outside the upper edge of the first edge when inserted into the insertion groove 40. If the edge material is an elastic material, such as plastic or vinyl, the tongue may be compressed, such that the protruding part is pushed into the insertion groove, and thereby enable a vertical assembling as shown in FIGS. 7B-C.

If the tongue is not compressible and enables a vertical assembling as shown in FIGS. 7B-C, the first and the second edge may be assembled by an angular movement as is shown in FIGS. 8A-C. The tongue 30, which may be a fixed tongue, which may be arranged firmly in the insertion groove 4, if the first and the second edge are intended to be assembled by an angular movement.

FIGS. 9A-C show a top view of an embodiment of the invention in which an inner groove 90 is formed throughout the tongue 30, between the tongue and the first edge of the building panel, in order to obtain an embodiment of a resilient tongue part. The inner groove extends in the longitudinal direction of the tongue and between a first and a second protruding part 91 of the tongue 30, at the third and the fourth edge of the building panel respectively. The resilient tongue part extends from the first to the second protruding part. Before the tongue is displaced into the insertion groove the protruding parts function as connection parts as described above. A part of the tongue extends outside the insertion groove when the tongue is displaced into the insertion groove. The second building panel 1' is provided with recesses 92 in the lower lip of the tongue groove at positions that correspond to the first and the second protruding part 60, as is shown in FIG. 9A. The recess enables the second building panel to be assembled to the first building panel by a vertical motion. The resilient part is pushed into the insertion groove during the vertical motion. When the first and the second building panel are in a common horizontal plane, the resilient part springs back and into the tongue groove and provides for vertical locking of the first and the second building panel. As is shown in FIGS. 9B-C, if the insertion groove is provided with the side wall 60 and the opening as described for the embodiment shown in FIGS. 6A-C this embodiment may comprise a further locking step comprising applying a force at the pressing part E2. The force presses an inner part E1 of the tongue 30 against the sidewall 60. The force bends the tongue 30 and a part of the tongue is pushed into the tongue groove 20 at the second edge of the second building panel 1'.