Granted Patent
Utility
US 5,639,285 · App. 08/440,773
Polycrystallline cubic boron nitride cutting tool
Inventors:
Xian Yao, Matthew W. Collier, Madapusi K. Keshavan, Ghanshyam Rai
Patented Case
View Patent ↗
Granted: Jun 17, 1997
Filed: May 15, 1995
Inventors
Xian Yao
Matthew W. Collier
Madapusi K. Keshavan
Ghanshyam Rai
Assignee (at issue)
SMITH INTERNATIONAL, 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.