Granted Patent
Utility
US 5,234,331 · App. 07/729,476
Automated pipe making machine
Inventor:
Ronald D. Schmidgall
Patented Case
View Patent ↗
Granted: Aug 10, 1993
Filed: Jul 12, 1991
Inventor
Ronald D. Schmidgall
Assignee (at issue)
Hawkeye Concrete Products Co.
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.