Patent ID: 7823359

Claim:
Floorboards with substantially planar and parallel upper top sides and lower undersides and core material located between the upper and lower sides, and a mechanical locking system for locking a first edge of a first floorboard to a second edge of a substantially identical second floorboard, the mechanical locking system comprising: a tongue on the first edge; a groove on the second edge, the groove comprising an upper wall, a lower wall opposing the upper wall, and side wall connecting the upper wall and the lower wall; the tongue and groove forming a first mechanical connection locking the first and second edges to each other in a first direction at right angles to a principal plane of the floor boards, the tongue and groove being formed in the core material which is located between said upper top side and lower underside; and a locking device arranged on the underside of the first and the second edges, the locking device forming a second mechanical connection locking the first and the second edges to each other in a second direction parallel to the principal plane and at right angles to the edges; the locking device includes a locking groove which extends parallel to and spaced from an upper part of the first edge, the locking groove being formed in the core material and being open at the underside of the floorboard and including an internal surface; the locking device further includes a strip extending distally beyond an upper part of the second edge, the strip extending throughout substantially an entire length of the second edge and being provided with a locking element projecting from the strip; wherein the strip, the locking element, and the locking groove are configured such that when the first edge is pressed against an upper part of the second edge and is then angled down, the locking element can enter the locking groove; the locking element has a locking surface which faces the second edge and is configured so as to contact the internal surface of the locking groove to prevent substantial separation of the first and second edges when joined together; an uppermost part of the top surface of the locking element is at a different height than the lower wall of the groove; and wherein, when the first edge and the second edge are locked together, there is a space in the locking system between the first and the second floorboards, wherein there is at least a space between an upper part of the tongue and the upper top side of the floorboard.