Granted Patent
Utility
US 5,287,889 · App. 07/949,459
Low-noise rotary control valve
Inventor:
Christopher M. Leinen
Patented Case
View Patent ↗
Granted: Feb 22, 1994
Filed: Sep 22, 1992
Inventor
Christopher M. Leinen
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.