Granted Patent
Utility
US 5,348,091 · App. 08/107,092
Self-adjusting centralizer
Inventors:
Borislav J. Tchakarov, Leon M. Earl
Patented Case
View Patent ↗
Granted: Sep 20, 1994
Filed: Aug 16, 1993
Inventors
Borislav J. Tchakarov
Leon M. Earl
Assignee (at issue)
The Bob Fournet Company
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.