Granted Patent
Utility
US 4,729,666 · App. 06/896,902
Screw for molding thermoplastic resin having a stress relaxation section
Inventor:
Toyokazu Takubo
Patented Case
View Patent ↗
Granted: Mar 8, 1988
Filed: Aug 15, 1986
Inventor
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.