LE East Jr, TW Cavender, DJ Attaway - US Patent 7,273,099, 2007 - Google Patents
3,857,444 A 12/1974 Copeland-166/276 4,848,470 A 7/1989 Korpics...................... 166/312
3,863,709 A 2/1975 Fitch............. 165/1 4,850,430 A 7/1989 Copeland et 31 ' 166/276 …