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US1956188A
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Hydraulic brake and cooling means for hoisting drums
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US1941734A
|
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Air conditioner
|
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US1893487A
|
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Bottom hole choke for oil wells
|
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US1899922A
|
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Blow-out preventing attachment for casing heads
|
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US1932685A
|
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Brake appplying means
|
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US1885675A
|
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Walking beam
|
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US1872105A
|
|
Pressure control head
|
|
US1897108A
|
|
Pump operating mechanism
|
|
US1821788A
|
|
Crown block sheave assembly
|
|
US1893486A
|
|
Shock absorber for rotatable elements
|
|
US1932570A
|
|
Well apparatus
|
|
US1932684A
|
|
Draw works for rotary drilling machines
|
|
US1893485A
|
|
Quick detachable pitman
|
|
US1796500A
|
|
Pipe-gripping means for rotary well-drilling rigs
|
|
US1794273A
|
|
Double-tapered slip for rotaries
|
|
US1872104A
|
|
Control head for oil or gas wells
|
|
US1879049A
|
|
Water cooled winding drum
|
|
US1821135A
|
|
Circulating system for brake flanges
|
|
US1758426A
|
|
Locking device for drive bushings
|
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US1851799A
|
|
Oil bath construction for rotaries
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