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GB456570A
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An improved roller cutter and bearing assembly for earth boring drills
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GB458361A
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Improvements in or relating to roller cutter and spindle assemblies for earth boring drills
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GB428648A
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Improvements in or relating to rotary earth boring drills
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|
GB420633A
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Improvements in rotary earth boring drills
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GB418592A
|
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Improvements in rotary earth boring drills
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GB296779A
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Improvements in and relating to deep well drilling apparatus
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GB283514A
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Improvements in and relating to earth boring drills
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GB290314A
|
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Improvements in rotary deep well drilling apparatus
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GB280033A
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Improvements in rotary drill bits
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GB278897A
|
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Improvements in drills of the rolling cutter type
|
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GB265507A
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Rotary deep well drilling apparatus
|
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GB265274A
|
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Rotary deep well drilling apparatus
|
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GB265504A
|
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Improvements in deep well drilling apparatus
|
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GB265505A
|
|
Rotary deep well drilling apparatus
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|
GB265506A
|
|
Rotary deep well drilling apparatus
|
|
GB198087A
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Improvements in or relating to well boring apparatus
|
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GB176048A
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|
Improvements in or relating to well-boring drills
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GB177476A
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Improvements in or relating to well-boring apparatus
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CA237513A
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Lubricator for deep well drills
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