Mechanical locking of floor panels with a flexible tongue

1. A set of floor panels adapted to be locked to other panels mechanically, each panel having an edge portion with a sidewardly open groove, in which groove a tongue formed as a separate part is received, wherein the tongue is an extruded section and is bendable in a plane substantially parallel with a front face of the floor panel such that a part of the tongue is bent and resiliently displaced inside said groove in said plane during locking of one panel with another panel, and wherein

the tongue includes an upper surface and a lower surface and an inclined sliding surface extending between the upper and lower surfaces, and

the another panel has an inclined sliding surface which cooperates with the inclined sliding surface of the tongue, and the inclined sliding surface of the another panel is configured to be initially above the sliding surface of the tongue during locking and then to be below the tongue when locking is completed.

2. A set of floor panels adapted to be locked to other panels mechanically, each panel having an edge portion with a sidewardly open groove, in which groove a tongue formed as a separate part is received, wherein the tongue is an extruded section and is bendable in a plane substantially parallel with a front face of the floor panel such that a part of the tongue is bent and resiliently displaced inside said groove in said plane during locking of one panel with another panel, and wherein

the tongue includes an upper surface and a lower surface and an inclined sliding surface extending between the upper and lower surfaces,

the another panel has an inclined sliding surface which cooperates with the inclined sliding surface of the tongue, and the inclined sliding surface of the another panel is configured to be initially above the sliding surface of the tongue during locking and then to be below the tongue when locking is completed, and

wherein the floor panels are essentially identical, the floor panels comprising connectors which are integrated with the floor panels and adapted to connect a new floor panel to a first and a second floor panel, so that upper joint edges of said new and second floor panels in the connected state define a vertical plane

a first connector being designed to connect said new floor panel with said second floor panel in a horizontal direction perpendicular to said vertical plane and a second connector being designed to connect said new floor panel with said second floor panel in a vertical direction parallel to the vertical plane,

the second connector comprises the tongue which is a flexible tongue and which is received in the sidewardly open groove in one of the new or the second floor panel,

the sidewardly open groove is formed in an edge of the panel and is open towards the vertical plane,

the flexible tongue has a length direction along the joint edges, a width in the horizontal plane perpendicular to the length and a thickness in the vertical direction, the flexible tongue is designed to cooperate, in a connected state with a tongue groove in the other of the new or the second floor panel,

the first connector comprises a locking strip which projects from said vertical plane in the second panel and carries a locking element,

said locking strip is designed to cooperate, in a connected state, with a downward open locking groove of the new floor panel, and

the new floor panel is adapted to be locked to the first and second floor panels with vertical folding along the vertical plane, vertical folding being where a side edge of the new floorboard is pressed against an upper part of a second side edge of the first floorboard and when the new floorboard is angled down the flexible tongue side edge is folded down into a connection with the side edge of the second floorboard.

3. The set of floor panel as claimed in claim 2 , wherein a vertical protrusion, serving as a friction connection between the flexible tongue and the sidewardly open grove, is arranged at an upper or lower part of the tongue.

4. The set of floor panels as claimed in claim 3 , wherein two or more protrusions are arranged along the longitudinal direction of the flexible tongue.

5. The set of floors panel as claimed in claim 3 , wherein the flexible tongue is on the same edge as the locking strip.

6. The set of floor panels as claimed in claim 2 , wherein the flexible tongue comprises a projecting portion which is displaceable by 0.1 mm or more.

7. The set of floor panels as claimed in claim 6 , wherein the displacement is only about 0.1 mm and wherein the floor panel has a core of High Density Fibreboard material.

8. The set of floor panels as claimed in claim 2 , wherein the new panel has a vertical locking surface, which is closer to a rear side than the tongue groove and that the vertical locking surface cooperates with the locking strip and locks the joint edges in a vertical direction.

9. The set of floor panels as claimed in claim 5 , wherein the extruded section is V- or U-shaped.

10. The set of floor panels as claimed in claim 9 , wherein the extruded V- or U-shaped section comprises an outer or inner part which is flexible and which causes at least a part of the section to move essentially horizontally during locking.

11. The set of floor panels as claimed in claim 2 , wherein the upper joint edges of the new and the second floor panels comprise a bevel.

12. The set of floor panels as claimed in claim 2 , wherein there are spaces of 0.1 mm or more between an inner and upper part of the tongue groove and the flexible tongue.

13. The set of floor panels as claimed in claim 2 , wherein the new panel has a sliding surface which cooperates during locking with a sliding surface of the flexible tongue.

14. The set of floor panels as claimed in claim 13 , wherein in the sliding surfaces are formed like a bevel.

15. The set of floor panels as claimed in claim 1 , wherein at least a part of the tongue is bent in the length direction and parallel with the width.

16. The set of floor panels as claimed in claim 3 , wherein said flexible tongue has a total horizontal width which is limited outwardly by a projecting portion which in a connected state is located outside the sidewardly open groove and cooperates with the tongue groove and limited inwardly by a groove portion located in the sidewardly open groove.

17. The set of floor panels as claimed in claim 1 , wherein the tongue is made of plastic and reinforced with fibres.

18. The set of floor panels as claimed in claim 17 , wherein the plastic is Polypropylene or polyoxymethylene and wherein the fibres are glassfibre.

19. The set of floor panels as claimed in claim 2 , wherein the locking strip is made in one piece with the panel.

20. The set of floor panels as claimed in claim 2 , wherein the sidewardly open groove or the tongue groove is formed in a separate material, which is connected as an edge portion to a core of the panel.

21. The set of floor panels as claimed in claim 20 , wherein the edge portion is made of High Density Fibreboard, plywood, plastic or special hard wood.

22. The set of floor panels as claimed in claim 21 , wherein the separate edge portion is fixed between a top layer and the balancing layer of the floor panel.

23. The set of floor panels as claimed in claim 1 , wherein at least a part of the tongue is fixed in the sidewardly open grove with a pretension.

24. The set of floor panels as claimed in claim 2 , wherein the locking systems that locks the new panel to the first panel is produced to have a pretension.

25. The set of floor panels as claimed in claim 1 , wherein the sidewardly open groove is a displacement groove and wherein a part of the tongue is displaced in the displacement groove.

26. The set of floor panels as claimed in claim 2 , wherein the whole tongue is located in a horizontal plane which is spaced vertically from the upper part of the locking element.

27. The set of floor panels as claimed in claim 1 , wherein the inclined sliding surface of the another panel is configured to be vertically below all portions of the tongue when locking is completed.

28. The set of floor panels as claimed in claim 1 , wherein cooperation of the inclined sliding surface of the another panel with the inclined sliding surface of the tongue during locking of one panel with the another panel causes the part of the tongue to be bent and resiliently displaced inside the groove in said plane.

29. The set of floor panels as claimed in claim 1 , wherein the sidewardly open groove comprises a top wall, a bottom wall and a side wall between the top wall and the bottom wall, and the part of the tongue that is bent and resiliently displaced inside the groove during locking is at least a side of the tongue between the upper and lower surfaces that faces the side wall of the groove.