Granted Patent
Utility
US 4,882,557 · App. 07/120,479
Multipole circuit breaker system with differential pole operation
Inventor:
George S. Harper
Patented Case
View Patent ↗
Granted: Nov 21, 1989
Filed: Nov 13, 1987
Inventor
George S. Harper
Assignee (at issue)
Airpax Corporation
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.