Granted Patent
Utility
US 5,178,171 · App. 07/790,269
Hydrocleaning of the exterior surface of a pipeline to remove coatings
Inventors:
Gordon R. Chapman, Donald R. Andruik
Patented Case
View Patent ↗
Granted: Jan 12, 1993
Filed: Nov 8, 1991
Inventors
Gordon R. Chapman
Donald R. Andruik
Assignee (at issue)
CRC-Evans Rehabilitation Systems, 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.