Granted Patent
Utility
US 4,545,136 · App. 06/548,396
Isolation valve
Inventors:
Masatsugu Izu, David A. Gattuso
Patented Case
View Patent ↗
Granted: Oct 8, 1985
Filed: Nov 3, 1983
Inventors
Masatsugu Izu
David A. Gattuso
Assignee (at issue)
Sovonics Solar Systems
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.