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US2519501A
|
|
Crankshaft bearing
|
|
US2559659A
|
|
Pump valve
|
|
US2544997A
|
|
Actuating system for air-brake mechanism
|
|
US2511729A
|
|
Traveling block
|
|
US2491747A
|
|
Lubricating means for well-drilling rotaries
|
|
GB643618A
|
|
Pumping unit
|
|
US2537683A
|
|
Rotary swivel
|
|
GB626108A
|
|
Improvement in well drilling draworks
|
|
GB642317A
|
|
Improved oil well drawworks
|
|
US2539585A
|
|
Pumping unit
|
|
US2533597A
|
|
Master bushing for rotary oil well drilling machines
|
|
US2517841A
|
|
Unloading valve for oil well pumps and the like
|
|
US2443744A
|
|
Locking mechanism for well drilling rotaries
|
|
US2507256A
|
|
Well drilling apparatus
|
|
US2465164A
|
|
Hoist brake with equalizer and power booster
|
|
US2544327A
|
|
Well-drilling drawworks
|
|
US2450895A
|
|
Stuffing box
|
|
US2447185A
|
|
Detachable fluid line manifold
|
|
US2510697A
|
|
Clutch shifter
|
|
US2560233A
|
|
Lubrication system
|
