Granted Patent
Utility
US 4,698,913 · App. 06/779,557
Apparatus and continuous method for the multistage treatment of finely divided solid substances with gases
Inventor:
Manfred Voll
Patented Case
View Patent ↗
Granted: Oct 13, 1987
Filed: Sep 24, 1985
Inventor
Manfred Voll
Assignee (at issue)
Degussa AG
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.