Granted Patent
Utility
US 4,874,975 · App. 07/127,625
Brushless DC motor
Inventor:
Friedrich R. Hertrich
Patented Case
View Patent ↗
Granted: Oct 17, 1989
Filed: Dec 1, 1987
Inventor
Friedrich R. Hertrich
Assignee (at issue)
Digital Equipment 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.