Mechanical locking of floor panels with a flexible bristle tongue

1. A building panel having an edge portion provided with a groove, in which a tongue formed as a separate part is received, wherein the tongue comprises at least two bow shaped protrusions at a first long edge of the tongue and a bow shaped recess at each protrusion, and wherein the protrusions are arranged bendable in the groove.

2. The building panel as claimed claim 1 , wherein the tongue has a second long edge, which extends outside the groove.

3. The building panel as claimed claim 2 , wherein the second long edge is essentially straight over substantially the whole length of the tongue.

4. The building panel as claimed in claim 3 , wherein the second long edge of the tongue is continuous.

5. The building panel as claimed in claim 2 , wherein the groove is made of a different material than the core of the panel.

6. A building panel as claimed in claim 1 , wherein a space is formed by each recess and a bottom of the groove, and wherein a portion of the tongue is bendable into said space.

7. A building panel as claimed in claim 1 , wherein the tongue presents a sliding surface, which is inclined relative to a main plane of the building panel.

8. A building panel as claimed in claim 1 , wherein said tongue is of an elongated shape and made of moulded plastic, and

wherein the protrusions are bendable in a plane parallel to the upper surface of the tongue and extending essentially in the plane and,

wherein the tongue has a second long edge, which is essentially straight over substantially the whole length of the tongue.

9. The building panel as claimed in claim 8 , wherein there is an angle between the at least two protrusions and a longitudinal direction of the tongue.

10. The building panel as claimed in claim 8 , wherein the tongue is arranged displaceable in the groove.

11. The building panel as claimed in claim 10 , wherein the at least two protrusions are configured to extend into the groove of the building panel.

12. The building panel as claimed in claim 1 , wherein the size of the recess is adapted to the size of a respective protrusion.

13. The building panel as claimed in claim 1 , wherein an upper surface and a lower surface of the tongue are displacement surfaces.

14. The building panel as claimed in claim 13 , wherein the upper surface and/or the lower surface has/have a bevelled edge, presenting a sliding surface and an inclined locking surface, respectively.

15. The building panel as claimed in claim 1 , wherein a vertical protrusion is arranged at the upper side and/or at the lower side of at least one of the protrusions.

16. The building panel as claimed in claim 15 , wherein the vertical protrusion is arranged close to or at the tip of the at least one of the protrusions.

17. The building panel as claimed in claim 1 , wherein tongue is made PP or POM, and reinforced with fibres.

18. The building panel as claimed in claim 17 , wherein the fibres are glass fibres.

19. A building panel having an edge portion provided with a groove, in which a tongue formed as a separate part is received, wherein the tongue comprises at least two bow shaped protrusions at a first long edge of the tongue, wherein the protrusions are arranged bendable in the groove, and wherein a part of the protrusions extends outside the groove.

20. A building panel having an edge portion provided with a groove, in which a tongue formed as a separate part is received, wherein the tongue comprises at least two bow shaped protrusions at a first long edge of the tongue, wherein the protrusions are arranged bendable in the groove, and wherein the length of each protrusion is larger than the total width of the tongue, whereby the total width is the width of the tongue plus the distance, perpendicular to a length direction of the tongue, from a tongue body to a tip of the protrusion.

21. The building panel as claimed in claim 20 , wherein the length of each protrusion is larger than two times the total width.

22. A building panel having an edge portion provided with a groove, in which a tongue formed as a separate part is received, wherein the tongue comprises at least two bow shaped protrusions at a first long edge of the tongue, wherein the protrusions are arranged bendable in the groove, and wherein a force to compress the tongue 1 mm in a width direction per 100 mm length of the tongue is about 20 to about 30 N.

23. A building panel having an edge portion provided with a groove, in which a tongue formed as a separate part is received, wherein the tongue comprises at least two bow shaped protrusions at a first long edge of the tongue, the protrusions are arranged bendable in the groove, and wherein a vertical protrusion is arranged at the upper side and/or at the lower side of at least one of the protrusions.