Granted Patent
Utility
US 5,180,447 · App. 07/572,003
Grain refiner for aluminum containing silicon
Inventors:
Geoffrey K. Sigworth, Matthew M. Guzowski
Patented Case
View Patent ↗
Granted: Jan 19, 1993
Filed: Aug 24, 1990
Inventors
Geoffrey K. Sigworth
Matthew M. Guzowski
Assignee (at issue)
KB Alloys
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.