Granted Patent
Utility
US 4,374,944 · App. 06/244,855
ABS Composition containing coal tar pitch
Inventors:
Donald G. Ashburn, Glendon T. Steady
Patented Case
View Patent ↗
Granted: Feb 22, 1983
Filed: Mar 18, 1981
Inventors
Donald G. Ashburn
Glendon T. Steady
Assignee (at issue)
United States Steel 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.