author: united states patent office office of search systems and documentation

... 2222 222. U.S. Subclass IPC IPC Subclass Notation Subclass Notation U.S. Subclass IPC U.S. Class 266 - Con . 5/00 Subclass Notation U.S. Class 269 9/36 20 F 27 b 21/00 F 16 f 3/10 Work holders 21 F 27 b 21/02 5/00 22 C 22 b 3/02 ( IPC B ...