|
US1932427A
|
|
Well pipe joint
|
|
US1898067A
|
|
Sand reel
|
|
DE568781C
|
|
Catching tool with grippers guided on inclined surfaces
|
|
GB340292A
|
|
Improvements in or relating to fishing tools for use in well drilling operations
|
|
GB337781A
|
|
Improvements in fishing tools for use in well boring operations
|
|
US1794652A
|
|
Hydraulic trip spear
|
|
US1785152A
|
|
Overshot
|
|
DE528255C
|
|
Safety connection for pipe rods in deep boreholes with detachable locking device
|
|
US1883071A
|
|
Lockable safety joint
|
|
US1797486A
|
|
Work-gripping means for rotary tables and the like
|
|
US1777587A
|
|
Rotary table and pipe-gripping means therefor
|
|
US1883070A
|
|
Well drilling apparatus
|
|
US1883073A
|
|
Work-gripping means for well drilling apparatus
|
|
US1796488A
|
|
Earth-coring machine
|
|
US1720700A
|
|
Core drill
|
