Granted Patent
Utility
US 4,953,412 · App. 06/822,755
Pipeline caliper pig
Inventors:
Jeffrey S. Rosenberg, Kevin W. Lockyear
Patented Case
View Patent ↗
Granted: Sep 4, 1990
Filed: Jan 17, 1986
Inventors
Jeffrey S. Rosenberg
Kevin W. Lockyear
Assignee (at issue)
T.D. WILLIAMSON
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.