Granted Patent
Utility
US 6,461,257 · App. 09/877,949
Collapsible structures
Inventor:
Yu Zheng
Patented Case
View Patent ↗
Granted: Oct 8, 2002
Filed: Jun 8, 2001
Inventor
Yu Zheng
Assignee (at issue)
Patent Category Corp.
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.