Granted Patent
Utility
US 4,983,079 · App. 07/283,916
Twist drill
Inventors:
Koujiro Imanaga, Shinichi Nakamura, Hideji Hosono, Yoshiyuki Yanase
Patented Case
View Patent ↗
Granted: Jan 8, 1991
Filed: Dec 13, 1988
Inventors
Koujiro Imanaga
Shinichi Nakamura
Hideji Hosono
Yoshiyuki Yanase
Assignee (at issue)
Mitsubishi Kinzoku Kabushiki Kaisha
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.