Granted Patent
Utility
US 4,432,208 · App. 06/422,287
Cold trap
Inventors:
Osamu Onuki, Toyohiko Kirisawa
Patented Case
View Patent ↗
Granted: Feb 21, 1984
Filed: Sep 23, 1982
Inventors
Osamu Onuki
Toyohiko Kirisawa
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.