Patent ID: 7683611

Claim:
A pipeline inspection device for a pipe comprising: an exciter coil capable of providing an alternating current magnetic field and producing eddy currents; a plurality of sensors capable of sensing a magnetic field produced by said eddy currents, said plurality of sensors engaged with a sensor shoe; said sensor shoe connected to a sensor support arm wherein said support arm is pivotably attached to a fixed hub and to a control arm; a driven hub pivotably attached to said control arm; and a lead screw, said lead screw engaged to and capable of positioning said driven hub along an axial axis of said pipeline inspection device; said sensors capable of being positioned at a first distance D 1 with respect to an inner pipe wall surface and capable of providing coupling to said magnetic field produced by said eddy currents; said sensor shoe capable of retracting to a second distance D 2 , wherein D 1 <D 2 .