Pipe travelling apparatus with alignment control

Abstract

A conduit travelling apparatus is capable of crawling through a conduit for performing certain operation by a stepwise sequence of alternating sequences of expanding and contracting the length of the body while bracing each end alternately. The apparatus provides a self aligning element for correcting rotation of such apparatus due to powered operations it may perform, or any natural tendency to twist as it progresses. The self aligning element includes steering elements overseen by a control system which helps return the travelling apparatus to a preferred alignment during its forward or rearward travel.

1 - 17 . (canceled) 
     
     
         18 . Conduit travelling apparatus for travelling through a conduit, said conduit travelling apparatus comprising two travelling body portions, each with associated wall engaging clamping means, and said travelling body portions connected by extensible drive means capable of moving said travelling body portions towards and away from each other;
 at least one said travelling body portion including at least one steerable contact portion which can be brought to bear against the inside of a conduit as the travelling body portion moves with respect to the conduit;   a said steerable contact portion including at least one conduit engaging element for contacting an inner surface of said conduit;   
       the arrangement being such that said conduit engaging element can exert a steering force against said inner surface of the conduit when its carriage portion bears against and travels along same;
 the conduit travelling apparatus including and/or communicable with inclination and orientation control means comprising inclination determining means, for determining the rotational inclination of the conduit travelling apparatus; 
 said inclination and orientation control means consequently controlling one or more said steerable contact portions associated with the conduit travelling apparatus. 
 
     
     
         19 . A conduit travelling vehicle as claimed in  claim 18  having an extensible body in which:
 said two travelling body portions comprise a forward body portion and a rearward body portion separated by a powered telescoping connection of variable and controllable length, the powered telescoping connection characterized that the distance between said forward and rearward body portions is controllably alterable; 
 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 connected to a said body portion at one end and having a wall-engaging foot at the distal end; 
 for each wall engaging mechanism, all of the radially pivotable legs with 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; 
 the wall engaging mechanism on either or both of said forward and rearward body portions including at least one retractable wheel arrangement, a 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 a wall engaging mechanism coupled, the coupling preventing both of i) said radially pivotable legs and ii) said radially pivoting wheel brackets being simultaneously in a fully radially extended position. 
 
     
     
         20 . Conduit travelling apparatus as claimed in  claim 18  in which there is inclination determining means associated with each said travelling body portion. 
     
     
         21 . Conduit travelling apparatus as claimed in  claim 18  in which the inclination and orientation control means determines the rotational inclination of the conduit travelling apparatus relative to one or more preferred reference orientations. 
     
     
         22 . Conduit travelling apparatus as claimed in  claim 21  in which a preferred reference orientation comprises either or both a true horizontal, or a true vertical. 
     
     
         23 . Conduit travelling apparatus as claimed in  claim 18  in which the inclination and orientation control means determines the steering action required to correct the rotational inclination of the conduit travelling apparatus towards a preferred rotational inclination. 
     
     
         24 . Conduit travelling apparatus as claimed in  claim 18  in which there is controllable steering drive means associated with a said steerable contact portion. 
     
     
         25 . Conduit travelling apparatus as claimed in  claim 24  in which a said controllable steering drive means is driven by one or methods in the following list: hydraulically powered, electrically powered, and pneumatically powered. 
     
     
         26 . Conduit travelling apparatus as claimed in  claim 18  in which a conduit engaging element is pivotably connected to a steerable contact portion, to provide a steering action. 
     
     
         27 . Conduit travelling apparatus as claimed in  claim 18  in which a steerable contact portion comprises a carriage. 
     
     
         28 . Conduit travelling apparatus as claimed in  claim 18  in which a steerable contact portion is pivotably connected to a travelling body portion so as to provide a steering action. 
     
     
         29 . Conduit travelling apparatus as claimed in  claim 18  in which a conduit engaging element comprises one or more members for the following list of engaging elements:
 wheels, rollers, rotating track assemblies, and skids. 
 
     
     
         30 . Conduit travelling apparatus as claimed in  claim 18  in which the inclination and orientation control means either or both continuously or repetitively adjusts the degree of steering of a steerable contact portion during motion of a travelling body portion. 
     
     
         31 . Conduit travelling apparatus as claimed in  claim 18  in which either or both of a steerable contact portion and conduit engaging element is retractable so as to not engage an inner surface of said conduit. 
     
     
         32 . Conduit travelling apparatus as claimed in  claim 18  in which the pressure by which a conduit engaging element bears against an inner surface of the conduit can be varied. 
     
     
         33 . Conduit travelling apparatus as claimed in  claim 18  in which the inclination and orientation control means adjusts the pressure by which a conduit engaging element bears against an inner surface of the conduit as part of its control over the steering and changing of the inclination of a travelling body portion.