Granted Patent
Utility
US 4,869,863 · App. 07/238,922
Method of and apparatus for tubularly drawing thermoplastic resin
Inventors:
Teruyuki Iwai, Masao Takashige, Hidenobu Takeichi, Yasuo Takai, Yoshinori Sasaki
Patented Case
View Patent ↗
Granted: Sep 26, 1989
Filed: Aug 31, 1988
Inventors
Teruyuki Iwai
Masao Takashige
Hidenobu Takeichi
Yasuo Takai
Yoshinori Sasaki
Assignee (at issue)
Idemitsu Petrochemical Co., 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.