Granted Patent
Utility
US 6,810,956 · App. 09/806,220
Thread coupling for a drill string for percussive rock drilling
Inventor:
Roger Sandström
Patented Case
View Patent ↗
Granted: Nov 2, 2004
Filed: May 14, 2001
Inventor
Roger Sandström
Assignee (at issue)
Uniroc AB
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.