Granted Patent
Utility
US 4,302,903 · App. 06/129,178
Stepping device
Inventor:
Kwok Wah Pun
Patented Case
View Patent ↗
Granted: Dec 1, 1981
Filed: Mar 10, 1980
Inventor
Kwok Wah Pun
Assignee (at issue)
Kusan, 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.