Patent ID: 7543536

Claim:
Apparatus for remotely positioning an inspection device within a walled cavity, comprising: a frame; traction wheels mounted on the frame; a source of motive power operatively coupled to the traction wheels; a positioner for carrying the inspection device through the cavity, said positioner comprising: a central hub assembly coupled with the frame; a plurality of extendable arms pivotally coupled with the central hub assembly, said plurality of extendable arms arranged in a plurality of extendable scissor mechanisms wherein a medial portion of one arm crosses and is pivotally connected to a medial portion of another arm, said extendable scissor mechanisms adapted to expand and collapse to maintain contact with walls of said cavity regardless of a changing dimension along a length of said cavity, including cavities comprising a tapering cross section; wall engaging members mounted on the arms; a biasing means urging the scissor mechanisms outwardly to engage the walls of the cavity.