ROTARY DEFLECTING TOOL Russian patent published in 1995 - IPC

FIELD: slant hole directional drilling. SUBSTANCE: rotary deflecting tool consists of body 1 accommodating shaft 2 and circular piston 5 arranged between them. Body 1 has part 8. Installed in piston 5 is articulated extensible member having roller 10. Installed diametrically opposite to extensible member on body 1 are cutters. Eccentric protrusions of upper and lower nipples 14 are located in same plane with cutters. Piston 5 is spring-loaded from one side and has cam 7 from the other side. Cam 7 is located directly near piston internal diameter. Pin 4 is installed on shaft for interaction with cam 7. As drill string moves downward, roller 10 is covered on well wall that increases load onto rock cutting tool and reduces friction forces. Extensible member in the extreme lower position of piston 5 comes fully out of hole of cover plate 11. However, when axle of pusher 9 is broken, pin 13 restricts its falling out to prevent wedging of tool. Stopping of roller 10 by stop protrusion makes it possible to prevent wedging of conjugated surface of body 1 and cover plate 11 when load is exerted on circular piston. EFFECT: higher efficiency. 3 dwg