Granted Patent
Utility
US 4,201,365 · App. 05/887,180
Lined gate valve having improved seat
Inventors:
George J. Paptzun, Collin C. Hall, Benjamin B. Bullwinkle
Patented Case
View Patent ↗
Granted: May 6, 1980
Filed: Mar 16, 1978
Inventors
George J. Paptzun
Collin C. Hall
Benjamin B. Bullwinkle
Assignee (at issue)
International Telephone and Telegraph Corporation
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.