U.S. patent 6,516,579 (issued Feb. 11, 2003) is based on the original ALLOC patent application dating back to the mid-'90s, and is directed to laminate floor panels where two edges are locked together by angling.
U.S. patent 6,510,665 (issued Jan. 28, 2003) protects a mechanical locking system for laminate panels, focusing on the flexibility of laminate and its ability to be machined.
For more information on the patents, visit www.valingealuminium.se.