Granted Patent
Utility
US 5,181,659 · App. 07/461,292
Synthetic resin seamless tube with black portion(s) and through-holes therein
Inventor:
Tatsuta Ohe
Patented Case
View Patent ↗
Granted: Jan 26, 1993
Filed: Jan 5, 1990
Inventor
Tatsuta Ohe
Assignee (at issue)
Mitsui Petrochemical 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.