Mechanical locking system for floor panels

1. A set of ceramic or stone tiles comprising a first tile provided with a first edge and a second tile provided with a second edge, wherein the tiles are provided with a locking system for locking the first edge to the second edge in a horizontal direction parallel with a tile surface and in a vertical direction perpendicular to the horizontal direction, the locking system comprising a first tongue and a second tongue and a strip part provided with a first locking element and a second locking element, the first and second tongues each including a respective oblique flexible sliding surface configured to bend and compress inwardly during locking, wherein:

the strip part comprises a first vertically extending tongue body and a second vertically extending tongue body, wherein the second vertically extending tongue body is spaced from the first vertically extending tongue body in a length direction of the first edge and/or in a length direction of the second edge in a locked position of the first edge and the second edge,

the first tongue and the second tongue protruding from opposite sides of the first vertically extending tongue body and the second vertically extending tongue body, respectively,

the first edge is provided with a first horizontal groove and a first vertical groove formed in a body of the first tile, wherein the first locking element is configured to cooperate with the first vertical groove for locking in the horizontal direction and the first tongue is configured to cooperate with the first horizontal groove for locking in the vertical direction,

the second edge is provided with a second horizontal groove and a second vertical groove formed in a body of the second tile, wherein the second locking element is configured to cooperate with the second vertical groove for locking in the horizontal direction and the second tongue is configured to cooperate with the second horizontal groove for locking in the vertical direction,

each of the first horizontal groove and the second horizontal groove comprises an upper lip and a lower lip, and

there is a space between the outer and upper part of the first edge and the outer and upper part of the second edge in a locked position of the first edge and the second edge.

2. The set as claimed in claim 1 , wherein the lower lip of the first horizontal groove extends horizontally to or is within an upper and outer part of the first edge and the lower lip of the second horizontal groove extends horizontally to or is within an upper and outer part of the second edge.

3. The set as claimed in claim 1 , wherein the lower lip of the first horizontal groove extends horizontally essentially to the upper and outer part of the first edge and the lower lip of the second horizontal groove extends horizontally essentially to the upper and outer part of the second edge.

4. A set of ceramic or stone tiles comprising a first tile provided with a first edge and a second tile provided with a second edge, wherein the tiles are provided with a locking system for locking the first edge to the second edge in a horizontal direction parallel with a tile surface and in a vertical direction perpendicular to the horizontal direction, the locking system comprising a first tongue and a second tongue and a strip part provided with a first locking element and a second locking element, the first and second tongues each including a respective oblique flexible sliding surface configured to bend and compress inwardly during locking, wherein:

the first edge is provided with a first horizontal groove and a first vertical groove formed in a body of the first tile, wherein the first locking element is configured to cooperate with the first vertical groove for locking in the horizontal direction and the first tongue is configured to cooperate with the first horizontal groove for locking in the vertical direction,

the second edge is provided with a second horizontal groove and a second vertical groove formed in a body of the second tile, wherein the second locking element is configured to cooperate with the second vertical groove for locking in the horizontal direction and the second tongue is configured to cooperate with the second horizontal groove for locking in the vertical direction,

each of the first horizontal groove and the second horizontal groove comprises an upper lip and a lower lip,

there is a space between the outer and upper part of the first edge and the outer and upper part of the second edge in a locked position of the first edge and the second edge, and

the lower lip of the first horizontal groove extends horizontally beyond an upper and outer part of the first edge and the lower lip of the second horizontal groove extends horizontally beyond an upper and outer part of the second edge.

5. The set as claimed in claim 1 , wherein a depth of the first horizontal groove measured as the horizontal distance from a vertical plane, located at the upper and outer part of the first edge, and to a bottom of the first horizontal groove, varies along the first edge; or

wherein a depth of the second horizontal groove, measured as the horizontal distance from a vertical plane, located at the upper and outer part of the second edge, and to a bottom of the second horizontal groove, varies along the second edge.

6. The set as claimed in claim 5 , wherein the depth varies with at least 0.10 mm.

7. The set as claimed in claim 1 , wherein the locking system is configured to be locked by angling and/or vertical snapping and/or horizontal snapping of the first tile and the second tile.

8. The set as claimed in claim 1 , wherein the ceramic or stone tiles are floor panels with hard surfaces bonded to a sheet shaped material.

9. The set as claimed in claim 1 , wherein a flexible grout material formed as a flexible strip is inserted between the upper part of the first edge and the upper part of the second edge.

10. The set as claimed in claim 9 , wherein the flexible grout material is continuous.

11. The set as claimed in claim 9 , wherein the flexible grout material is bonded to an upper part of the first and/or second vertically extending tongue body.

12. The set as claimed in claim 9 , wherein the flexible grout material is mechanically connected to the first and/or second vertically extending tongue body.

13. The set as claimed in claim 1 , wherein a flexible material is provided between the first edge and the second edge.

14. The set as claimed in claim 13 , wherein the flexible material is provided at least partly in the first horizontal groove and the second horizontal groove.