Granted Patent
Utility
US 4,994,055 · App. 07/330,399
Fluid flow control apparatus
Inventors:
Douglas M. Spranger, Karl D. Kirk, III, Robert K. Cohen, Preston J. Keeler, III, Jeffrey A. Stein
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Mar 29, 1989
Inventors
Douglas M. Spranger
Karl D. Kirk, III
Robert K. Cohen
Preston J. Keeler, III
Jeffrey A. Stein
Assignee (at issue)
Pfizer Hospital Products Group, 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.