Granted Patent
Utility
US 4,207,283 · App. 05/922,947
Method of post thickening one end section of a plastic pipe
Inventors:
David W. French, Richard C. Faber, Wayne D. Weger
Patented Case
View Patent ↗
Granted: Jun 10, 1980
Filed: Jul 10, 1978
Inventors
David W. French
Richard C. Faber
Wayne D. Weger
Assignee (at issue)
Johns Manville
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.