DS

David N. Shirley-Fisher

NL Nl Petroleum Products Limited: 2 patents #4 of 9Top 45%
Overall (All Time): #2,324,031 of 4,157,543Top 60%
2
Patents All Time

Issued Patents All Time

Showing 1–2 of 2 patents

Patent #TitleCo-InventorsDate
4928777 Cutting elements for rotary drill bits — 1990-05-29
4705122 Cutter assemblies for rotary drill bits Michael Wardley 1987-11-10