Alfred E. W. Fletcher

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Pretoria, ZA

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Patents Grantslast 30 patents

Information Patent Grant
Device for steering a drilling tool and/or drill string
- Patent number 4,947,944
- Issue date Aug 14, 1990
- Preussag Aktiengesellschaft
- Trevellyn M. Coltman
- E21 - EARTH DRILLING MINING