Granted Patent
Utility
US 5,539,638 · App. 08/149,216
Virtual emissions monitor for automobile
Inventors:
James D. Keeler, John P. Havener, Devendra Godbole, Ralph Bruce Ferguson
Patented Case
View Patent ↗
Granted: Jul 23, 1996
Filed: Nov 5, 1993
Inventors
James D. Keeler
John P. Havener
Devendra Godbole
Ralph Bruce Ferguson
Assignee (at issue)
Pavilion Technologies, Inc.
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.