Membership
Tour
Register
Log in
Siegfried Starke
Follow
Person
Grob Ilsede, DE
People
Overview
Industries
Organizations
People
Information
Impact
Patents Grants
last 30 patents
Information
Patent Grant
Drill bit
Patent number
4,635,738
Issue date
Jan 13, 1987
Norton Christensen, Inc.
Hans Schillinger
E21 - EARTH DRILLING MINING