Granted Patent
Utility
US 4,990,057 · App. 07/346,749
Electronic control for monitoring status of a compressor
Inventor:
Douglas J. Rollins
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: May 3, 1989
Inventor
Douglas J. Rollins
Assignee (at issue)
Johnson Service Company
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.