Granted Patent
Utility
US 6,529,544 · App. 09/988,927
Vacuum heat treating furnace
Inventor:
Lennie L. Ashburn
Patented Case
View Patent ↗
Granted: Mar 4, 2003
Filed: Nov 19, 2001
Inventor
Lennie L. Ashburn
Assignee (at issue)
Lennie L. Ashburn
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.