Granted Patent
Utility
US 6,041,862 · App. 09/087,705
Ground heat exchange system
Inventor:
Thomas R. Amerman
Patented Case
View Patent ↗
Granted: Mar 28, 2000
Filed: Jun 1, 1998
Inventor
Thomas R. Amerman
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.