Granted Patent
Utility
US 4,313,496 · App. 06/142,689
Wellhead shearing apparatus
Inventors:
Eric G. Childs, Friedrich E. Just
Patented Case
View Patent ↗
Granted: Feb 2, 1982
Filed: Apr 22, 1980
Inventors
Eric G. Childs
Friedrich E. Just
Assignee (at issue)
Cameron Iron Works, Inc.
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.