Panels comprising a mechanical locking device and an assembled product comprising the panels

1. A set of panels comprising a first panel having a first main plane and a second panel having a second main plane, wherein the first panel and the second panel comprise a locking device for locking a first edge of the first panel to a second edge of the second panel, wherein the first main plane is essentially perpendicular to the second main plane in a locked position of the first panel and the second panel, the locking device comprising an edge groove at the first edge and a tongue groove at the second edge, the edge groove comprising an insertion groove at a first side of the edge groove,

wherein the insertion groove comprises a flexible tongue which is configured to cooperate with the tongue groove for locking together the first edge and the second edge in a first direction which is perpendicular to the first main plane, said first side of the edge groove comprising a first groove surface at a first side of the insertion groove and a second groove surface at a second side of the insertion groove, and a first side of said second edge comprising a first edge surface at a first side of the tongue groove and a second edge surface at a second side of the tongue groove,

wherein the first groove surface and the first edge surface are configured to cooperate for locking the first edge and the second edge in a second direction, which is perpendicular to the second main plane,

wherein the second groove surface and the second edge surface are configured to cooperate for locking the first edge and the second edge in the second direction,

wherein the first groove surface is closer to an opening of the edge groove than the second groove surface,

wherein said locking device is configured to be unlocked by inserting a tool in the tongue groove, whereby the flexible tongue moves out of the tongue groove and the flexible tongue is pushed back into the insertion groove,

wherein the first groove surface is arranged offset in the second direction, in a direction away from a centre of the edge groove, relative to the second groove surface by a first distance in a state where the first groove surface is in contact with the first edge surface,

wherein the first edge surface is arranged offset in the second direction relative the second edge surface by a second distance, and

wherein the first groove surface is, in the locked position, configured to extend partly over the tongue groove.

2. The set of panels as claimed in claim 1 , wherein the second distance is essentially equal the first distance in the state where the first groove surface is in contact with the first edge surface.

3. The set of panels as claimed in claim 1 , wherein the first distance is in the range of about 0.1 mm to about 0.4 mm.

4. The set of panels as claimed in claim 1 , wherein the first groove surface and the first edge surface are parallel.

5. The set of panels as claimed in claim 4 , wherein the first groove surface and the first edge surface extend parallel to the second main plane.

6. The set of panels as claimed in claim 1 , wherein the second groove surface and the second edge surface are parallel.

7. The set of panels as claimed in claim 6 , wherein the second groove surface and the second edge surface extend parallel to the second main plane.

8. The set of panels as claimed in claim 1 , wherein the edge groove comprises, at a second side that is opposite to the first side, a third groove surface, which is configured to cooperate with a third edge surface of the second edge for locking the first edge and the second edge in the second direction.

9. The set of panels as claimed in claim 1 , wherein the first edge surface is a bottom surface of a recess at the second edge, and is positioned in the locked position adjacent a first side of an opening of the edge groove.

10. The set of panels as claimed in claim 9 , wherein a side surface of the recess is configured to cooperate with a first main surface of the first panel.

11. The set of panels as claimed in claim 1 , wherein the first edge surface is at a first main surface of the second panel.

12. The set of panels as claimed in claim 11 , wherein a bottom surface of the edge groove is configured to cooperate with an outer edge surface of the second edge for locking in the first direction.

13. The set of panels as claimed in claim 1 , wherein the locking device comprises cooperating surfaces at a second side of an opening of the edge groove.

14. The set of panels as claimed in claim 13 , wherein the cooperating surfaces are adjacent an outer edge surface of the first panel and an outer corner of the first panel and the second panel in the locked position.

15. The set of panels as claimed in claim 1 , wherein the locking device comprises a bevel or rounding at an opening of the tongue groove.

16. The set of panels as claimed in claim 1 , wherein the locking device is configured such that a play is obtained between an outer surface of the tool and the first groove surface when the tool is inserted in the tongue groove.

17. The set of panels as claimed in claim 1 , wherein the play is essentially equal the first distance.

18. The set of panels as claimed in claim 1 , wherein a cross section of the tool has essentially the same shape as a cross section of the tongue groove.

19. A combination comprising a set of panels comprising a first panel having a first main plane and a second panel having a second main plane and a tool, wherein the first panel and the second panel comprise a locking device for locking a first edge of the first panel to a second edge of the second panel, wherein the first main plane is essentially perpendicular to the second main plane in a locked position of the first panel and the second panel, the locking device comprising an edge groove at the first edge and a tongue groove at the second edge, the edge groove comprising an insertion groove at a first side of the edge groove,

wherein the insertion groove comprises a flexible tongue which is configured to cooperate with the tongue groove for locking together the first edge and the second edge in a first direction which is perpendicular to the first main plane, said first side of the edge groove comprising a first groove surface at a first side of the insertion groove and a second groove surface at a second side of the insertion groove, and a first side of said second edge comprising a first edge surface at a first side of the tongue groove and a second edge surface at a second side of the tongue groove,

wherein the first groove surface and the first edge surface are configured to cooperate for locking the first edge and the second edge in a second direction, which is perpendicular to the second main plane,

wherein the second groove surface and the second edge surface are configured to cooperate for locking the first edge and the second edge in the second direction,

wherein the first groove surface is closer to an opening of the edge groove than the second groove surface,

wherein said locking device is configured to be unlocked by inserting the tool in the tongue groove, whereby the flexible tongue moves out of the tongue groove and the flexible tongue is pushed back into the insertion groove,

wherein the first groove surface is arranged offset in the second direction, in a direction away from a centre of the edge groove, relative to the second groove surface by a first distance in a state where the first groove surface is in contact with the first edge surface,

wherein the first edge surface is arranged offset in the second direction relative the second edge surface by a second distance, and

wherein the first groove surface is, in the locked position, configured to extend partly over the tongue groove.

20. The combination comprising a set of panels and a tool as claimed in claim 19 , wherein the second distance is essentially equal the first distance in the state where the first groove surface is in contact with the first edge surface.