Granted Patent
Utility
US 4,807,641 · App. 06/412,227
Pneumotach and components therefore and combined pulmonary function measuring kit containing the same
Inventors:
John R. Boehringer, Jay B. Nelson, John Karpowicz
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Aug 27, 1982
Inventors
John R. Boehringer
Jay B. Nelson
John Karpowicz
Assignee (at issue)
Boehringer Laboratories LLC
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.