John Hirst Walker

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Cheltenham, EN

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Patents Grantslast 30 patents

Information Patent Grant
Mine roof support
- Patent number 4,027,489
- Issue date Jun 7, 1977
- Dowty Mining Equipment Limited
- John Hirst Walker
- E21 - EARTH DRILLING MINING
Information Patent Grant
Mine roof support
- Patent number 4,010,618
- Issue date Mar 8, 1977
- Dowty Mining Equipment Limited
- John Hirst Walker
- E21 - EARTH DRILLING MINING
Information Patent Grant
Mine roof support
- Patent number 3,952,525
- Issue date Apr 27, 1976
- Dowty Mining Equipment Limited
- John Hirst Walker
- E21 - EARTH DRILLING MINING