Image Number 5 for United States Patent #5293823.
A robotic vehicle (10) for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle (10) comprises forward and rear housings (32 and 12) each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings (32 and 12) are selectively held in a stationary position within the conduit. The vehicle (10) also includes at least three selectively extendable members (46), each of which defines a cavity (56) therein. The forward end portion (50) of each extendable member (46) is secured to the forward housing (32) and the rear end portion (48) of each housing is secured to the rear housing (12). Each of the extendable members (46) is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity (56) of the extendable member such that the distance between the forward housing (32 ) and the rear housing (12) can be selectively increased. Further, each of the extendable members (46) is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity (56) of the extendable member (46) such that the distance between the forward housing (32) and the rear housing (12) can be selectively decreased.