Granted Patent
Utility
US 6,135,216 · App. 09/292,516
Venting and sealing system for down-hole drills
Inventors:
Leland H. Lyon, Richard K. Smith
Patented Case
View Patent ↗
Granted: Oct 24, 2000
Filed: Apr 15, 1999
Inventors
Leland H. Lyon
Richard K. Smith
Assignee (at issue)
Ingersoll-Rand 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.