Patent ID: 7121059

Claim:
A mechanical locking system for locking a first edge of a first panel to a second edge of an identical second panel that are arranged on a subfloor, the mechanical locking system comprising: a connector system on the first edge and the second edge for 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 panels; and a locking device arranged on an 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, wherein the connector system includes a tongue and a groove, the groove being defined, in part, by a strip that is integrally formed in one piece with and of the same material as the first edge of the first panel and the tongue being integrally formed in one piece with and of the same material as the second edge of the second panel, a thickness of the strip varies as the strip extends from the first panel, an inner part of the tongue adjacent the second panel being thicker than a distal, outer part of the tongue, wherein the tongue and the groove are configured such that, when the first and second edges are joined together, a space exists between an inner part of the groove and the distal, outer part of the tongue, and wherein the tongue and the groove are configured such that when the second edge is pressed against an upper part of the first edge and is then angled down against the subfloor, the tongue can enter the groove to effect the first and second mechanical connections, wherein the strip is substantially coplanar with a bottom surface of the second panel, and.