Granted Patent
Utility
US 6,543,444 · App. 09/546,292
System and method for air time remaining calculations in a self-contained breathing apparatus
Inventor:
John E. Lewis
Patented Case
View Patent ↗
Granted: Apr 8, 2003
Filed: Apr 10, 2000
Inventor
John E. Lewis
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.