Granted Patent
Utility
US 4,647,772 · App. 06/704,283
Mass spectrometers
Inventors:
Ivor A. S. Lewis, David C. Smith
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Feb 22, 1985
Inventors
Ivor A. S. Lewis
David C. Smith
Assignee (at issue)
VG Instruments Group Limited
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.