Granted Patent
Utility
US 4,338,153 · App. 06/243,944
Welding plastic tube lining
Inventor:
Heinz Zimmerman
Patented Case
View Patent ↗
Granted: Jul 6, 1982
Filed: Feb 23, 1981
Inventor
Heinz Zimmerman
Assignee (at issue)
Ameron, 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.