Granted Patent
Utility
US 4,409,172 · App. 06/234,120
Device and method for fabricating multi-layer tubing using a freely suspended mandrel
Inventors:
Robert S. Ward, Donald R. Beckham
Patented Case
View Patent ↗
Granted: Oct 11, 1983
Filed: Feb 13, 1981
Inventors
Robert S. Ward
Donald R. Beckham
Assignee (at issue)
Thoratec Laboratories 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.