Granted Patent
Utility
US 4,573,398 · App. 06/668,001
Pressure control device and method of making the same
Inventors:
Carl N. Johnson, Hemant Phadke, Roger L. Sieling
Patented Case
View Patent ↗
Granted: Mar 4, 1986
Filed: Nov 5, 1984
Inventors
Carl N. Johnson
Hemant Phadke
Roger L. Sieling
Assignee (at issue)
RANCO CO., Ltd.
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.