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.

Description

TECHNICAL FIELD

[0001] The invention relates generally to self-propelled vehicles for use in conduits, typically remote-controlled vehicles with apparatus for cleaning conduits. In particular it addresses issues of rotation of the apparatus as it travels along a conduit.BACKGROUND ART

[0002] The applicant has previously filed patent applications (WO 2005 / 061944 A1—PCT / NZ2004 / 000330) for self propelled apparatus which travels along a pipe. In summary this apparatus comprises a forward section, and a rearward section, connected in a manner in which the two sections can be forced apart or drawn together. Movement along a conduit is achieved by extending clamping elements on the rearward section to engage the inner surface of the conduit. Clamps present on the forward section are released and the connection between the sections is extended so the forward section moves forward. The clamps on the forward section are then engaged against the inner surface of the conduit, whilst those of the re...

Examples

second embodiment

[0075]the vehicle is illustrated in FIGS. 4-8 and like numerals are used to refer to like components. The wall-engaging arrangement 50a on the rearward body portion 3 is also arranged generally symmetrically about the central elongate axis A of the vehicle, the feet being angularly spaced at 120°. The mechanism 50a extends and retracts the feet 5a generally radially and includes control links 66 for maintaining the wall-engaging face of each foot 5a generally parallel to the wall of the pipe. The wall-engaging arrangement 50a includes three rear legs 10a angularly spaced, each of the legs 10a being fixed between a pair of control links 66 connecting each foot 5a to the rearward body portion 3.

[0076]Each leg 10a is pivotally attached to the foot 5a at an outer end by a first pivot 61 and to a mount 62 fixed to the rearward body portion 3 by a second pivot 63. A roller 64 fixed to an inner end of the leg 10a and the three rollers 64 are received between two radially-extending flanges ...

first embodiment

[0078]Hydraulic fluid supply and return hoses 75 are connected between the valve block 38 and the double-acting actuator 13. The hoses 75 pass around a wheel 76 and are tensioned by the gas spring 77. As in the first embodiment, in the extended position the force applied to the rearward body portion 3 (e.g. when the forward body portion 1 is being driven forward) provides a self-servo action increasing the frictional engagement between each foot 5 and the conduit 14.

[0079]Like the mechanism 50a, the wall-engaging arrangement 20a on the forward body portion 1 in the second embodiment of the vehicle extends and retracts the feet 5a′ generally radially while employing control links 66a for maintaining the wall-engaging face of feet 5a′ generally parallel to the wall of the pipe. The wheel bracket 19a is pivotably fixed to the mount 62a and resiliently connected to the pivoting legs 18a by means of compression spring 70 and bar 71. In this manner the wheels 17a are firmly pressed agains...

TECHNICAL FIELD

[0001] The invention relates generally to self-propelled vehicles for use in conduits, typically remote-controlled vehicles with apparatus for cleaning conduits. In particular it addresses issues of rotation of the apparatus as it travels along a conduit.BACKGROUND ART

[0002] The applicant has previously filed patent applications (WO 2005 / 061944 A1—PCT / NZ2004 / 000330) for self propelled apparatus which travels along a pipe. In summary this apparatus comprises a forward section, and a rearward section, connected in a manner in which the two sections can be forced apart or drawn together. Movement along a conduit is achieved by extending clamping elements on the rearward section to engage the inner surface of the conduit. Clamps present on the forward section are released and the connection between the sections is extended so the forward section moves forward. The clamps on the forward section are then engaged against the inner surface of the conduit, whilst those of the re...

Examples

second embodiment

[0075]the vehicle is illustrated in FIGS. 4-8 and like numerals are used to refer to like components. The wall-engaging arrangement 50a on the rearward body portion 3 is also arranged generally symmetrically about the central elongate axis A of the vehicle, the feet being angularly spaced at 120°. The mechanism 50a extends and retracts the feet 5a generally radially and includes control links 66 for maintaining the wall-engaging face of each foot 5a generally parallel to the wall of the pipe. The wall-engaging arrangement 50a includes three rear legs 10a angularly spaced, each of the legs 10a being fixed between a pair of control links 66 connecting each foot 5a to the rearward body portion 3.

[0076]Each leg 10a is pivotally attached to the foot 5a at an outer end by a first pivot 61 and to a mount 62 fixed to the rearward body portion 3 by a second pivot 63. A roller 64 fixed to an inner end of the leg 10a and the three rollers 64 are received between two radially-extending flanges ...

first embodiment

[0078]Hydraulic fluid supply and return hoses 75 are connected between the valve block 38 and the double-acting actuator 13. The hoses 75 pass around a wheel 76 and are tensioned by the gas spring 77. As in the first embodiment, in the extended position the force applied to the rearward body portion 3 (e.g. when the forward body portion 1 is being driven forward) provides a self-servo action increasing the frictional engagement between each foot 5 and the conduit 14.

[0079]Like the mechanism 50a, the wall-engaging arrangement 20a on the forward body portion 1 in the second embodiment of the vehicle extends and retracts the feet 5a′ generally radially while employing control links 66a for maintaining the wall-engaging face of feet 5a′ generally parallel to the wall of the pipe. The wheel bracket 19a is pivotably fixed to the mount 62a and resiliently connected to the pivoting legs 18a by means of compression spring 70 and bar 71. In this manner the wheels 17a are firmly pressed agains...

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