Granted Patent
Utility
US 4,063,263 · App. 05/677,269
Manually operated shutter attachment
Inventor:
John Krewalk
Patented Case
View Patent ↗
Granted: Dec 13, 1977
Filed: Apr 15, 1976
Inventor
John Krewalk
Assignee (at issue)
Criterion Manufacturing Limited
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.