Granted Patent
Utility
US 5,226,870 · App. 07/749,943
Vacuum drum purge method and apparatus
Inventors:
David A. Smith, James LaCombe
Patented Case
View Patent ↗
Granted: Jul 13, 1993
Filed: Aug 26, 1991
Inventors
David A. Smith
James LaCombe
Assignee (at issue)
Dowbrands L.P.
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.