Patent ID: 8544233

Claim:
A system of surface elements forming a surface comprising: a first surface element comprising: an upper surface; a lower surface; a first edge and a second edge, opposite said first edge, joining said upper surface to said lower surface; and a third edge and a fourth edge, opposite said third edge, joining said upper surface to said lower surface; wherein said third edge comprises a separate locking part positioned in a cavity of the third edge, said separate locking part being formed from at least one member selected from the group consisting of a thermoplastic, a thermosetting resin, and a metal; a second surface element, comprising an edge sized and shaped to join with said first edge of said first surface element through relative rotational movement, wherein said first edge of said first surface element and said edge of said second surface element lock said first surface element to said second surface element to limit relative vertical movement; and a third surface element, comprising an edge sized and shaped to join with said third edge of said first surface element only through relative vertical movement, wherein said third edge of said first surface element and said edge of said third surface element lock said first surface element to said third surface element to limit relative vertical movement, and wherein the locking part is disposed along a joint face between the third edge of the first surface element and the edge of the third surface element.