Granted Patent
Utility
US 4,002,891 · App. 05/604,241
Mixer control system
Inventor:
John Porter
Patented Case
View Patent ↗
Granted: Jan 11, 1977
Filed: Aug 13, 1975
Inventor
John Porter
Assignee (at issue)
B. F. Goodrich 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.