Granted Patent
Utility
US 4,915,709 · App. 07/229,911
Knife sharpener
Inventors:
Michael A. Andrew, Thomas G. Siegel, Omer Shifflet, James M. Green, Duane Seaburg
Patented Case
View Patent ↗
Granted: Apr 10, 1990
Filed: Aug 8, 1988
Inventors
Michael A. Andrew
Thomas G. Siegel
Omer Shifflet
James M. Green
Duane Seaburg
Assignee (at issue)
BLACK & DECKER INC.
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.