Granted Patent
Utility
US 4,835,816 · App. 07/201,502
Twist-off knob
Inventor:
John T. Graef
Patented Case
View Patent ↗
Granted: Jun 6, 1989
Filed: Jun 2, 1988
Inventor
John T. Graef
Assignee (at issue)
Lutron Electronics Co., 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.