Granted Patent
Utility
US 6,481,451 · App. 09/607,036
Vertically stacked collapsible structures
Inventor:
Yu Zheng
Patented Case
View Patent ↗
Granted: Nov 19, 2002
Filed: Jun 29, 2000
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.