Pneumatically operated pipe crawler

A pneumatically operated pipe crawler for transporting inspection equipment along the interior of a pipe, comprising:

• an elongate cylindrical tube of flexible resilient material, the tube having a leading end and a trailing end,
• support means extending from the leading end of the tube for supporting the inspection equipment ahead of the tube,
• a plurality of longitudinally spaced partition members located within the tube, said members being hermetically sealed to the wall of the tube and defining therein first, second and third longitudinally separated chambers each having a radially and axially extensible wall portion,
• first, second and third flexible gas supply tubes extending from the trailing end of the tube and communicating respectively with said chambers for inflating and deflating the chambers,
• flexible electrical signalling means extending interiorly of the tube, said signalling means extending from the leading end of the tube for connection to the inspection equipment and extending from the trailing end of the tube for connection to a signal receiver,
• said gas supply tubes and signalling means being hermetically sealed to the partition members through which they pass, and
• means for supplying gas to said chambers and exhausting gas therefrom in repeated cyclic sequence for sequentially expanding said chamber wall portions into clamping relation with the pipe, each wall portion recovering to its original axial length upon deflation of the chamber, thereby to propel the tube step by step along the pipe.