Granted Patent
Utility
US 4,958,658 · App. 07/066,801
Mass flow stabilized
Inventor:
John Zajac
Patented Case
View Patent ↗
Granted: Sep 25, 1990
Filed: Jun 25, 1987
Inventor
John Zajac
Assignee (at issue)
TEGAL 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.