END AREA INSPECTION TOOL FOR AUTOMATED NONDESTRUCTIVE INSPECTION

摘要

Nondestructive inspection apparatus is mounted on a freestanding housing unit having motorized wheels for driving the housing unit around the circumference of a ferromagnetic pipe. The housing unit includes an electromagnet and pole pieces which are slightly spaced from the surface of the pipe to establish a magnetic circuit with the pipe, thereby producing an attractive force that holds the wheels of the housing unit against the pipe surface, irrespective of the location of the unit on the pipe circumference. The axles for the wheels are canted to produce an axial force tending to move the apparatus away from the end of the pipe as the wheels rotate. Follower means on the apparatus movably engage the end of the pipe and resists said force to hold the apparatus at the end of the pipe as it rotates thereabout. The nondestructive inspection apparatus inspects the end region of the pipe as the housing rotates about the pipe.