Patent ID: 7287607

Claim:
A directional drilling apparatus for use as a serial element of a drilling fluid conducting drill string, the apparatus comprising: a) a housing comprising an upper and a lower portion, each having an independent axis, connected by an actuator bearing pack that permits rotation of said lower portion relative to said upper portion; b) a motor situated in said upper portion, with a drive shaft extending axially into said lower portion; c) a deflection control apparatus, in said housing, comprising said actuator bearing, with an axis of bearing rotation that is non-parallel with said axes of either said portions, and a rotation limiter to limit, between preselected limits, the rotation of said lower portion relative to said upper portion; d) a deflection driving apparatus, in said housing, comprising a rotational linkage between said motor and said lower portion; and e) a clutch, in said housing, responsive to the characteristics of flow of drilling fluid in said housing, to selectively engage and selectively disengage said rotational linkage.