Granted Patent
Utility
US 4,377,545 · App. 06/274,119
Method of making corrugated reinforced thermoplastic pipe
Inventor:
Robert L. Hornbeck
Patented Case
View Patent ↗
Granted: Mar 22, 1983
Filed: Jun 16, 1981
Inventor
Robert L. Hornbeck
Assignee (at issue)
Borg-Warner Chemicals, Inc.
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.