Granted Patent
Utility
US 6,158,818 · App. 08/964,893
Rock cutting head
Inventors:
Hans Schaeff, Ian Webster
Patented Case
View Patent ↗
Granted: Dec 12, 2000
Filed: Nov 5, 1997
Inventors
Hans Schaeff
Ian Webster
Assignee (at issue)
Webster Schaeff & Co.
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.