Granted Patent
Utility
US 4,403,561 · App. 06/323,773
Presser bar spring-connection
Inventors:
Henry Schaeflern, Jan Szostak
Patented Case
View Patent ↗
Granted: Sep 13, 1983
Filed: Nov 23, 1981
Inventors
Henry Schaeflern
Jan Szostak
Assignee (at issue)
The Singer Company 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.