Mechanical locking system for floor panels

1. Building panels including at least a first building panel and a second building panel that are provided with a locking system for vertical locking of the first building panel and the second building panel by a vertical displacement of the first and second building panels relative each other, the locking system comprising a displaceable tongue attached into a sidewardly open displacement groove provided at an edge of the first building panel, said displaceable tongue cooperates with a tongue groove provided at an adjacent edge of the second building panel for locking the edge and the adjacent edge vertically, and the locking system further comprising a strip that protrudes from the edge or the adjacent edge:

below the displacement groove and outwardly beyond an upper part of the edge; or

below the tongue groove and outwardly beyond an upper part of the adjacent edge,

wherein the displaceable tongue comprises a main tongue body extending along the edge of the first building panel and separate flexible spring parts that are detachably attached to the main tongue body, and

the separate spring parts are located in an inner part of the displacement groove and spaced from each other in an length direction of the main tongue body.

2. The building panels as claimed in claim 1 , wherein the spring parts are asymmetric in a direction along the edge.

3. The building panels as claimed in claim 1 , wherein the separate flexible spring parts are mechanically attached to the main tongue body.

4. The building panels as claimed in claim 1 , wherein said main tongue body comprises an upwardly open fixing groove or a downwardly open fixing groove.

5. The building panels as claimed in claim 1 , wherein said separate spring parts comprise an upwardly extending fixing connection part or a downwardly extending fixing connection part.

6. The building panels as claimed in claim 1 , wherein said spring parts during locking are displaced or compressed horizontally beyond a vertical tongue plane that comprises an inner part of the main tongue body before locking of the first and second building panels.

7. The building panels as claimed in claim 1 , wherein said spring parts overlap a part of the tongue body during locking.

8. The building panels as claimed in claim 1 , wherein said spring parts are located in a vertically open flexing cavity formed in the main tongue body.

9. The building panels as claimed in claim 1 , wherein said building panels are floor panels.

10. The building panels as claimed in claim 1 , wherein each of the separate flexible spring parts is detachably attached to the main tongue body via a friction protrusion that presses against an inner wall of the main tongue body.

11. A tongue blank comprising at least two tongues, which are each designed to be inserted into a groove of a building panel and lock the building panel to an adjacent building panel, a part of each tongue is configured to be displaced during locking wherein the tongues are of an elongated shape and wherein each tongue comprises a separate spring part that is configured to be detachably attached to a main body of the tongue.

12. The tongue blank as claimed in claim 11 , wherein the spring part is asymmetric in the length direction of the tongue.

13. The tongue blank as claimed in claim 11 , wherein each tongue comprises two or more spring parts that are spaced from each other in a length direction of the tongue.

14. Building panels including at least a first building panel and a second building panel that are provided with a locking system for vertical locking of the first building panel and the second building panel by a vertical displacement of the first and second building panels relative each other, the locking system comprising a displaceable tongue attached into a sidewardly open displacement groove provided at an edge of the first building panel, said displaceable tongue cooperates with a tongue groove provided at an adjacent edge of the second building panel for locking the edge and the adjacent edge vertically, and the locking system further comprising a strip that protrudes from the edge or the adjacent edge:

below the displacement groove and outwardly beyond an upper part of the edge; or

below the tongue groove and outwardly beyond an upper part of the adjacent edge,

wherein the displaceable tongue comprises a main tongue body extending along the edge of the first building panel and separate flexible spring parts attached to the main tongue body,

the separate spring parts are located in an inner part of the displacement groove and spaced from each other in an length direction of the main tongue body, and

the main tongue body and the spring parts are made of different materials.

15. Building panels including at least a first building panel and a second building panel that are provided with a locking system for vertical locking of the first building panel and the second building panel by a vertical displacement of the first and second building panels relative each other, the locking system comprising a displaceable tongue attached into a sidewardly open displacement groove provided at an edge of the first building panel, said displaceable tongue cooperates with a tongue groove provided at an adjacent edge of the second building panel for locking the edge and the adjacent edge vertically, and the locking system further comprising a strip that protrudes from the edge or the adjacent edge:

below the displacement groove and outwardly beyond an upper part of the edge; or

below the tongue groove and outwardly beyond an upper part of the adjacent edge,

wherein the displaceable tongue comprises a main tongue body extending along the edge of the first building panel and separate flexible spring parts that are adapted to be attached to the main tongue body, and

the separate spring parts are located in an inner part of the displacement groove and spaced from each other in an length direction of the main tongue body.