U.S. PATENT# 6,488,913 U.S. PATENT# 6,365,134 U.S. PATENT# 4,396,378 U.S. PATENT# 5,965,632 U.S. PATENT# 6,284,030 U.S. PATENT# 5,925,689 U.S. PATENT# 6,981,875 U.S. PATENT# 6,696,043 U.S. PATENT# 6,365,134 U.S. PATENT# 5,141436 U.S. PATENT# 7,067,115 U.S. PATENT# 4,383,826 U.S. PATENT# 4,380,432 U....