Granted Patent
Utility
US 6,309,149 · App. 09/471,768
Twist drill for dry drilling
Inventors:
Bernhard Borschert, Jürgen Seidel
Patented Case
View Patent ↗
Granted: Oct 30, 2001
Filed: Dec 23, 1999
Inventors
Bernhard Borschert
Jürgen Seidel
Assignee (at issue)
Kennametal PC 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.