Granted Patent
Utility
US 4,847,712 · App. 07/046,234
Disc drive spindle motor with log cogging torque
Inventor:
Allan D. Crapo
Patented Case
View Patent ↗
Granted: Jul 11, 1989
Filed: May 4, 1987
Inventor
Allan D. Crapo
Assignee (at issue)
Seagate Technology LLC
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.