Granted Patent
Utility
US 5,219,208 · App. 07/861,407
Scrubber for dispersing dust generated by longwall shearers
Inventors:
Chung F. Liao, George W. Graham
Patented Case
View Patent ↗
Granted: Jun 15, 1993
Filed: Mar 31, 1992
Inventors
Chung F. Liao
George W. Graham
Assignee (at issue)
Zeigler Coal Holding 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.