Granted Patent
Utility
US 4,646,644 · App. 06/597,943
Pneumatic time delay valve
Inventors:
Martin R. Richmond, Mark A. Hayner
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Apr 9, 1984
Inventors
Martin R. Richmond
Mark A. Hayner
Assignee (at issue)
Sanders GmbH
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.