Mechanical locking system for floor panels
Floor panels are shown, which are provided with a vertical locking system on short edges including a displaceable tongue that is displaced in one direction into a tongue groove during vertical displacement of two panels. Building panels provided with a locking system for vertical locking of a first and a second building panel by a vertical displacement of the panels relative each other, a displaceable tongue is in a sidewardly open displacement groove provided at an edge of a first panel, said tongue cooperates with a tongue groove provided at an adjacent edge of a second panel for locking the edge and the adjacent edge vertically.
1. A displaceable tongue for locking an edge of a first building panel and an adjacent edge of a second building panel vertically, the displaceable tongue being configured to be arranged in a sidewardly open displacement groove provided at an edge of the first building panel,
wherein the displaceable tongue has a longitudinal extent and a transverse extent, said longitudinal extent being larger that said transverse extent,
wherein the displaceable tongue comprises a pulling extension at a transversely outer portion of the displaceable tongue,
the pulling extension being configured to cooperate with a pulling protrusion formed at the adjacent edge of the second building panel such that the displaceable tongue is pulled out from the sidewardly open displacement groove and into a tongue groove provided at the adjacent edge of the second building panel when the edge of the first building panel and the edge of the second building panel are displaced vertically relative to each other; and
wherein the displaceable tongue comprises a locking hook, and further comprises a cavity formed at a tongue section of the displaceable tongue, wherein the locking hook protrudes into the cavity.
2. The displaceable tongue of claim 1 , wherein the locking hook is configured to serve as a friction connection.
3. The displaceable tongue of claim 1 , wherein the locking hook is configured to prevent the displaceable tongue from falling out from the displacement groove after locking of the building panels.
4. The displaceable tongue of claim 1 , wherein the locking hook is configured to prevent the displaceable tongue from sliding back into the displacement groove after locking of the building panels.
5. The displaceable tongue of claim 1 , wherein the locking hook is configured to lock against an upper or lower part of the displacement groove.
6. The displaceable tongue of claim 1 , wherein the locking hook is configured to slide against a bevel formed at the displacement groove.
7. The displaceable tongue of claim 1 , wherein the locking hook is configured to lock against an outer portion of the sidewardly open displacement groove.
8. The displaceable tongue of claim 1 , wherein the locking hook comprises a hook part configured to press the hook connection upwards by rails during an insertion of the displaceable tongue into the displaceable groove.
9. The displaceable tongue of claim 1 , wherein the cavity is formed in the pulling extension.
10. The displaceable tongue of claim 1 , wherein the displaceable tongue comprises a polymer material.
11. The displaceable tongue of claim 1 , wherein the displaceable tongue is formed by injection moulding.
12. The displaceable tongue of claim 1 , wherein the pulling protrusion is inclined in relation to a main horizontal plane of the first and second building panels when the displaceable tongue is arranged in the sidewardly open displacement groove.
13. The displaceable tongue of claim 1 , wherein the pulling extension has a constant thickness.
14. The displaceable tongue of claim 1 , wherein the pulling extension increases in thickness in a direction toward an outermost portion of the pulling extension.
15. The displaceable tongue of claim 1 , comprising a plurality of pulling extensions at the transversely outer portion of the displaceable tongue.
16. The displaceable tongue of claim 1 , wherein displaceable tongue is bendable in a longitudinal direction of the displaceable tongue.
17. The displaceable tongue of claim 1 , wherein the pulling extension extends upwards when the displaceable tongue is arranged in the sidewardly open displacement groove.