Granted Patent
Utility
US 5,617,691 · App. 08/422,308
Fitting structure of rectangular parallelopipedal blocks
Inventor:
Ken Yamamoto
Patented Case
View Patent ↗
Granted: Apr 8, 1997
Filed: Apr 13, 1995
Inventor
Ken Yamamoto
Assignee (at issue)
Doryokuro Kakunenryo Kaihatsu Jigyodan
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.