Granted Patent
Utility
US 4,949,474 · App. 07/432,866
Method and apparatus for drying particulate material
Inventor:
Eero Berg
Patented Case
View Patent ↗
Granted: Aug 21, 1990
Filed: Nov 7, 1989
Inventor
Eero Berg
Assignee (at issue)
A. Ahlstrom Corporation
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.