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Toggle actuated underreamer
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Patent number 4,023,629
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Issue date May 17, 1977
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Watson, Incorporated
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David L. Watson
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E21 - EARTH DRILLING MINING
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Core barrel
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Patent number 3,999,619
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Issue date Dec 28, 1976
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Watson, Incorporated
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John V. Watson
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B28 - WORKING CEMENT, CLAY, OR STONE
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Core barrel
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Patent number 3,999,620
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Issue date Dec 28, 1976
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Watson, Incorporated
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John V. Watson
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B28 - WORKING CEMENT, CLAY, OR STONE