Patent ID: 6971990

Claim:
A propulsion apparatus for transport of accessory devices within body cavities or canals, sections of pipe, lumens, and other generally tubular spaces and environments, comprising: a toroid, the toroid being a fluid-filled, enclosed ring formed of a flexible material, the enclosed ring defining a central cavity, having an interior volume and presenting an exterior surface and an interior surface which move continuously in opposite directions when the apparatus is in motion; a frame formed of a support structure located within the interior volume of the enclosed ring, a housing structure concentrically and coaxially located relative to the support structure and disposed in the central cavity of the enclosed ring; and a series of at least two sets of interlocking rollers or skids located on the support and housing structures, the rollers or skids being located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon.