Granted Patent
Utility
US 6,719,074 · App. 10/105,012
Insert chip of oil-drilling tricone bit, manufacturing method thereof and oil-drilling tricone bit
Inventors:
Keiichi Tsuda, Nobuyuki Mori, Hideki Moriguchi
Patented Case
View Patent ↗
Granted: Apr 13, 2004
Filed: Mar 20, 2002
Inventors
Keiichi Tsuda
Nobuyuki Mori
Hideki Moriguchi
Assignees (at issue)
Japan National Oil Corporation
SUMITOMO ELECTRIC INDUSTRIES, 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.