Granted Patent
Utility
US 4,890,364 · App. 07/297,395
Split ring springs for snap fasteners and method of manufacturing the same
Inventors:
Akira Tanaka, Kenji Hasegawa
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Jan 17, 1989
Inventors
Akira Tanaka
Kenji Hasegawa
Assignee (at issue)
Yoshida Kogyo K.K.
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.