Granted Patent
Utility
US 5,639,188 · App. 08/662,074
Clean air bulk material handling system
Inventors:
John W. Howanski, Clifford B. Richardson
Patented Case
View Patent ↗
Granted: Jun 17, 1997
Filed: Jun 12, 1996
Inventors
John W. Howanski
Clifford B. Richardson
Assignee (at issue)
Conductron Corporation
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.