Granted Patent
Utility
US 4,523,897 · App. 06/630,351
Two stage vacuum pump
Inventors:
Ralph C. Lower, Gary P. Murray
Patented Case
View Patent ↗
Granted: Jun 18, 1985
Filed: Jul 16, 1984
Inventors
Ralph C. Lower
Gary P. Murray
Assignee (at issue)
Robinair Division
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.