Patent ID: 8513559

Claim:
An apparatus for servicing an interior surface of a conduit having a nadir, comprising: a support frame positioned externally of the conduit; a drive cart mounted on said support frame for movement along said support frame; an application member operable to service the interior surface of the conduit, said application member including a pair of side engagement members engaging side portions of the interior surface of the conduit to provide a uniform path of movement of the application member through the conduit; a linkage apparatus interconnecting the drive cart and the application member to transfer movement of the drive cart to the application member to affect movement of the application member through the interior of the conduit, said linkage apparatus including a plurality of tubular linkage elements pivotally interconnected in an end-to-end relationship by vertically oriented pivot pins defining a pivot axis between adjacent said linkage elements to allow said linkage elements to follow a curved conduit.