Granted Patent
Utility
US 6,518,490 · App. 09/766,931
Drum head with sound attenuating center coating
Inventor:
John J. Good
Patented Case
View Patent ↗
Granted: Feb 11, 2003
Filed: Jan 23, 2001
Inventor
John J. Good
Assignee (at issue)
Drum Workshop, Inc.
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.