Granted Patent
Utility
US 6,488,461 · App. 09/892,113
Interlocking two-piece washer
Inventors:
Darwin L. Zacharias, Dick Edward Friesen
Patented Case
View Patent ↗
Granted: Dec 3, 2002
Filed: Jun 26, 2001
Inventors
Darwin L. Zacharias
Dick Edward Friesen
Assignee (at issue)
Flexi-Coil Ltd.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.