Granted Patent
Utility
US 4,726,878 · App. 06/939,181
Chemical milling method for interiors of narrow tubes
Inventor:
Donald W. Gross
Patented Case
View Patent ↗
Granted: Feb 23, 1988
Filed: Dec 8, 1986
Inventor
Donald W. Gross
Assignee (at issue)
Chemtronics 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.