James N. Preston

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Phoenix, AZ, US

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Patents Grantslast 30 patents

Information Patent Grant
Gravity and velocity-change differentiator
- Patent number 4,022,064
- Issue date May 10, 1977
- James N. Preston
- G01 - MEASURING TESTING
Information Patent Grant
Gravity-measuring device for water and mineral detection
- Patent number 3,991,625
- Issue date Nov 16, 1976
- James N. Preston
- G01 - MEASURING TESTING