Granted Patent
Utility
US 5,169,281 · App. 07/642,658
Detachable crane- or boom-operated heat exchanger tube bundle extractor
Inventor:
Thomas B. Boisture
Patented Case
View Patent ↗
Granted: Dec 8, 1992
Filed: Jan 17, 1991
Inventor
Thomas B. Boisture
Assignee (at issue)
Ohmstede Mechanical Services, 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.