I was browsing a US Patent web site and saw this.

http://patimg1.uspto.gov/.piw?docid=US006357746&PageNum=1&&IDKey=D74BBAC0C47A&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1%2526Sect2=HITOFF%2526d=PALL%2526p=1%2526u=/netahtml/srchnum.htm%2526r=1%2526f=G%2526l=50%2526s1=6,357,746.WKU.%2526OS=PN/6,357,746%2526RS=PN/6,357,746