Granted Patent
Utility
US 6,467,541 · App. 09/630,255
Plunger lift method and apparatus
Inventor:
Edward Alexander Wells
Patented Case
View Patent ↗
Granted: Oct 22, 2002
Filed: Aug 1, 2000
Inventor
Edward Alexander Wells
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.