Granted Patent
Utility
US 4,413,677 · App. 06/372,138
Dual string well packer
Inventor:
Donald H. Perkins
Patented Case
View Patent ↗
Granted: Nov 8, 1983
Filed: Apr 27, 1982
Inventor
Donald H. Perkins
Assignee (at issue)
Otis Engineering 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.