Granted Patent
Utility
US 5,163,818 · App. 07/476,131
Automatic constant air flow rate pump unit for sampling air
Inventors:
Harry Edwards Betsill, William A. Cook
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: Feb 5, 1990
Inventors
Harry Edwards Betsill
William A. Cook
Assignee (at issue)
Ametek, 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.