Patent ID: 7389830

Claim:
A system for rotating and guiding a drill bit in an underground bore, comprising: a drilling motor comprising a housing, and a rotor mounted in the housing so that the rotor rotates in relation of the housing; a drive shaft coupled to the rotor and the drill bit so that drill bit rotates in response to rotation of the rotor; and a guidance module comprising a housing coupled to the housing of the drilling motor so that the housing of the guidance module rotates with the housing of the drilling motor and the drive shaft extends through the housing of the guidance module, and an actuating arm mounted on the housing of the guidance module, the actuating arm being movable in relation to the housing of the guidance module between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position, wherein the guidance module further comprises (i) a piston movably disposed in a cylinder formed in the housing so that the piston can extend from the cylinder and contact an underside of the actuating arm and (ii) a hydraulic pump for pressurizing a fluid, and wherein the housing of the guidance module has a hole formed therein for placing the pump in fluid communication with the cylinder.