Granted Patent
Utility
US 4,743,480 · App. 06/930,411
Apparatus and method for extruding and expanding polytetrafluoroethylene tubing and the products produced thereby
Inventors:
Michael L. Campbell, Benjamin G. Williams, Rob G. Riffle, Charles E. Biggerstaff
Patented Case
View Patent ↗
Granted: May 10, 1988
Filed: Nov 13, 1986
Inventors
Michael L. Campbell
Benjamin G. Williams
Rob G. Riffle
Charles E. Biggerstaff
Assignee (at issue)
W. L. Gore & Associates, 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.