Granted Patent
Utility
US 4,388,531 · App. 06/241,083
Ionizer having interchangeable ionization chamber
Inventors:
George C. Stafford, David R. Stephens
Patented Case
View Patent ↗
Granted: Jun 14, 1983
Filed: Mar 6, 1981
Inventors
George C. Stafford
David R. Stephens
Assignee (at issue)
Finnigan 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.