Granted Patent
Utility
US 4,462,428 · App. 06/350,924
Three-way needle valve
Inventors:
Kenneth L. Guenther, Edward H. Zemke, Gerald D. Warden
Patented Case
View Patent ↗
Granted: Jul 31, 1984
Filed: Feb 22, 1982
Inventors
Kenneth L. Guenther
Edward H. Zemke
Gerald D. Warden
Assignee (at issue)
Bell and Howell, 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.