Mechanical locking system for floor panels

1. Building panels provided with a locking system comprising a tongue at a second edge of a second panel, the tongue being configured to cooperate with a tongue groove at a first edge of a first panel for locking in a vertical direction, the tongue groove comprising an upper lip and a lower lip, the locking system further comprising one or more clips attached to the first edge and a downwardly open locking groove formed at the second edge, each clip comprises an upwardly extending locking element, which is configured to cooperate with the locking groove for locking the first edge and the second edge in a horizontal direction, wherein:

the clip comprises a clip body at a rear side of the first panel, said clip body is provided with an inner part, which extends inwardly from the first edge, and an outer part, which extends outwardly from said first edge,

the inner part comprises a fixing element that cooperates with a downwardly open fixing groove, formed on the rear side of the first panel, for locking the clip to the first edge in a horizontal direction,

the clip comprises a locking protrusion, which protrudes upwardly from the clip body, said locking protrusion is configured to lock the clip to the first edge in a vertical direction,

the tongue comprises a recess, and

the locking protrusion is in a locked position positioned in the recess.

2. The building panels according to claim 1 , wherein a part of the locking protrusion is located in the tongue groove.

3. The building panels according to claim 1 , wherein a part of the locking protrusion is located below the tongue.

4. The building panels according to claim 1 , wherein the locking protrusion is spaced horizontally inwardly in the tongue groove beyond the outer tip of the tongue.

5. The building panels according to claim 1 , wherein the locking protrusion comprises a first part that extends upwardly from the clip body and a second part that extends inwardly into the tongue groove.

6. The building panel according to claim 1 , wherein the locking protrusion is located inwardly and spaced horizontally from the vertical plane.

7. The building panels according to claim 1 , wherein the panel comprises a core of plastic material.

8. The building panels according to claim 1 , wherein the panel comprises a surface of thermoplastic material.

9. The building panels according to claim 1 , wherein the panel comprises a core with an upper core layer and a lower core layer, and wherein the locking protrusion protrudes vertically beyond the lower core layer.

10. The building panels according to claim 1 , wherein the recess is formed in a lower part of the tongue.

11. The building panels according to claim 10 , wherein the recess is configured to accommodate an outer part of the clip that extends beyond an upper edge of the panel.

12. The building panels according to claim 1 , wherein the recess extends from the tongue to the locking groove.

13. The building panels according to claim 1 , wherein the clip is an extruded section.

14. The building panels according to claim 13 , wherein the extruded section is a plastic section or an aluminium section.

15. The building panels according to claim 1 , wherein the recess includes a curved recessed surface extending from an outer tip of the tongue and along a lower surface of the tongue.

16. A flooring system comprising a first panel and a second panel being provided with a locking system comprising clips, said clips being arranged at a first edge of the first panel and at an opposite second edge of the second panel,

wherein the locking system is configured to lock the first edge of the first panel to the second edge of the second panel in a horizontal direction and a vertical direction,

wherein the first edge and the second edge each comprise a horizontal groove comprising a lower lip,

wherein each clip respectively comprises a vertically extending locking protrusion with an upper part that is located essentially above the lower lip of only one of the first panel and the second panel, such that each clip respectively locks directly to only the one of the first panel and the second panel,

wherein an entirety of the lower lip of the first edge is spaced horizontally and inwardly from an upper lateral surface of the first edge, and an entirety of the lower lip of the second edge is spaced horizontally and inwardly from an upper lateral surface of the second edge, and wherein, in a locked state of the first and second panels by each clip, the upper lateral surface of the first edge abuts against the upper lateral surface of the second edge in the horizontal direction, the upper lateral surface of the first edge being the outwardly-most surface of the first edge, and the upper lateral surface of the second edge being the outwardly-most surface of the second edge.

17. A method of locking a first building panel and a second building panel, the first and second panels being provided with a locking system comprising clips, said clips being arranged at a first edge of the first panel and at an opposite second edge of the second panels, the method comprising:

locking the first edge of the first panel to the second edge of the second panel in a horizontal direction and a vertical direction, wherein the first edge and the second edge each comprise a horizontal groove comprising a lower lip, wherein each clip respectively comprises a vertically extending locking protrusion with an upper part that is located essentially above the lower lip of only one of the first panel and the second panel, such that each clip respectively locks directly to only the one of the first panel and the second panel, and wherein an entirety of the lower lip of the first edge is spaced horizontally and inwardly from an upper lateral surface of the first edge, and an entirety of the lower lip of the second edge is spaced horizontally and inwardly from an upper lateral surface of the second edge, such that the upper lateral surface of the first edge abuts against the upper lateral surface of the second edge in the horizontal direction, the upper lateral surface of the first edge being the outwardly-most surface of the first edge, and the upper lateral surface of the second edge being the outwardly-most surface of the second edge.