Granted Patent
Utility
US 5,290,498 · App. 07/862,958
Ultra-high molecular weight polyethylene thin-wall pipe, and method of and apparatus for manufacturing the same
Inventors:
Takeshi Shiraki, Iwatosi Suzuki, Kunie Hiroshige
Patented Case
View Patent ↗
Granted: Mar 1, 1994
Filed: Apr 3, 1992
Inventors
Takeshi Shiraki
Iwatosi Suzuki
Kunie Hiroshige
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.