Granted Patent
Utility
US 4,867,927 · App. 07/152,533
Process of producing thermplastic resin sheet and the like and molding screw therefor
Inventors:
Akira Funaki, Toyokazu Takubo
Patented Case
View Patent ↗
Granted: Sep 19, 1989
Filed: Feb 5, 1988
Inventors
Akira Funaki
Toyokazu Takubo
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.