Granted Patent
Utility
US 6,250,478 · App. 09/246,999
Stepped disc screens of unequal inclination angles for conveying and grading recycling materials
Inventor:
Robert M. Davis
Patented Case
View Patent ↗
Granted: Jun 26, 2001
Filed: Feb 8, 1999
Inventor
Robert M. Davis
Assignee (at issue)
CP MANUFACTURING, 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.