Granted Patent
Utility
US 5,538,261 · App. 08/284,814
Mechanical heat-exchange tube sealing system
Inventors:
Wallace G. Murray, Janek Porowski
Patented Case
View Patent ↗
Granted: Jul 23, 1996
Filed: Aug 2, 1994
Inventors
Wallace G. Murray
Janek Porowski
Assignee (at issue)
Columbian Chemicals Company
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.