Granted Patent
Utility
US 6,752,163 · App. 10/438,679
Collapsible play structures
Inventor:
Yu Zheng
Patented Case
View Patent ↗
Granted: Jun 22, 2004
Filed: May 15, 2003
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.