Granted Patent
Utility
US 5,970,728 · App. 09/058,632
Multiple compressor heat pump or air conditioner
Inventor:
Thomas H. Hebert
Patented Case
View Patent ↗
Granted: Oct 26, 1999
Filed: Apr 10, 1998
Inventor
Thomas H. Hebert
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.