Granted Patent
Utility
US 4,569,638 · App. 06/445,676
Pump with resiliently mounted impeller
Inventors:
John H. Harker, Thomas Boesen
Patented Case
View Patent ↗
Granted: Feb 11, 1986
Filed: Nov 30, 1982
Inventors
John H. Harker
Thomas Boesen
Assignee (at issue)
International Telephone and Telegraph Corporation
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.