Patent ID: 7597048

Claim:
A conduit travelling vehicle, comprising: an extensible body comprising a forward body portion and a rearward body portion, the forward body portion and the rearward body portion being separated by a powered telescoping connection of variable and controllable length, wherein the powered telescoping connection controllably alters a distance between said forward and rearward body portions; each of said forward body portion and rearward body portion including a wall-engaging mechanism; each wall engaging mechanism comprising a plurality of radially pivotable legs, each radially pivotable leg connected to one of said forward and rearward body portions at one end and having a wall-engaging foot at a distal end; for each wall engaging mechanism, all of the radially pivotable legs comprising wall engaging feet connecting to a common actuator, said common actuator controlling the radially extended position of said radially pivotable legs between retracted and extended positions; at least one of the wall engaging mechanism including at least one retractable wheel arrangement, said retractable wheel arrangement comprising a plurality of wall engageable wheel assemblies each coupled to a radially pivoting wheel bracket; said radially pivotable legs and said radially pivoting wheel brackets of said one wall engaging mechanism coupled with a coupling, the coupling preventing both of i) said radially pivotable legs and ii) said radially pivoting wheel brackets from being simultaneously in a fully radially extended position.