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US2660268A
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Hinged base frame for portable derrick masts
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US2552924A
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Cable anchor for well derrick lines
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US2590362A
|
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Hydraulic adapter
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US2513990A
|
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Spring loaded hydraulic adapter
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US2506767A
|
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Rotary for drilling wells
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US2622846A
|
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Combined traveling block, adapter, and hook
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US2505088A
|
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Well-drilling rig
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US2472061A
|
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Rotary swivel for drilling rigs
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US2580503A
|
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Sectional frame structure
|
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US2424760A
|
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Cable-gripping mechanism
|
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US2431532A
|
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Method of producing jars for well drilling tools
|
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US2505087A
|
|
Portable derrick structure
|
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US2379333A
|
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Portable well-servicing apparatus
|
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US2377705A
|
|
Well derrick substructure
|
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US2223779A
|
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Rotary drilling machine
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US2299208A
|
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Water cooled brake
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US2276561A
|
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Rotary drilling machine
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US2284120A
|
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Spinning line guide
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US2157728A
|
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Speed-up and speed-down for rotaries
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US2195200A
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Brake for drums
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