Granted Patent
Utility
US 6,221,151 · App. 09/375,093
Gypsum set accelerator and method of making the same
Inventors:
Frank H. Campbell, Robert Piasecki, Larry W. Kingston, Edward A. Burkard
Patented Case
View Patent ↗
Granted: Apr 24, 2001
Filed: Aug 16, 1999
Inventors
Frank H. Campbell
Robert Piasecki
Larry W. Kingston
Edward A. Burkard
Assignee (at issue)
National Gypsum Company
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.