A CARRIAGE WHICH IS MOUNTABLE TO ELONGATE MEMBERS FOR PASSAGE THEREALONG

Abstract: A carriage which is receivable over an elongate member for movement therealong which comprises a base (11), a pair of arms (13) which extend divergently from the base. At least one arm (13) is extendable. The base (11) and arms (13) support roller-like members (12 and 19) which are engageable with the surface of the elongate member to be able to retain the elongate member between them.

Description: "A CARRIAGE WHICH IS MOUNTABLE TO ELONGATE MEMBERS FOR PASSAGE THEREALONG" THIS INVENTION relates to a carriage which is mountable to elongate members for passage therealong. A particular application of the invention relates to a carriage which may be used in association with underwater structures such as pylons or oil drilling platforms to facilitate the inspection and/or cleaning of such structures. In one form the invention resides in a carriage receivable over an elongate member for passage therealong comprising a base and a pair of arms extending divergently from the base, at least one of said arms being extendable, the base and end portion of said arms supporting a roller-like member on their opposed faces which are intended to engage the external faces of an elongate member to retain the elongate member between them. According to a preferred feature of the invention at least one roller-like members is associated with a drive means to cause movement of the carriage along the elongate member. According to a preferred feature of the invention wherein said roller-like member are able to effect movement of the carriage along and around the elongate member. According to a preferred feature of the invention the end portion of said at least one arm is slidably supported on the inner portion of the arm and a drive means is provided to cause controlled movement of the end portion along the arm and hold said end portion at a desired position on the portion. A ccording to a preferred feature of the invention each arm is extendable and the drive means causes corresponding movement of the end portions on the arms. According to a preferred feature of the invention the base pivotally supports an articulated arm having a grasping means capable of grasping an elongate member and drive means provided to effect controlled articulation and movement of the arm with respect to the base and opening and closing of the grasping means. The invention will be more fully understood in the light of the following description of two specific embodiments. The description is made with reference to the accompany¬ ing drawings of which: Figure 1 is an isometric view of a cleaning machine according to the first embodiment; Figure 2 is an end elevation of the second embodiment; and Figure 3 is a side elevation of the second embodiment. Both embodiments are directed towards an apparatus for cleaning marine growth and encrustations from underwater pylons and platforms. The first embodiment is directed to a cleaning device which is able to propel itself along a marine structure and is able to transfer itself between frame members of the structure and move through the air-water interface. As a result the device may be placed in position at the top of the structure or removed from that position at the commencement or completion of a cleaning function respectively and effect the desired cleaning function underwater without the need of a diver or remotely operated vehicle to assist. The first embodiment comprises a carriage comprising a base 11 which supports a pair of transversely spaced wheels 12 which extend inwardly from the base 11. The base 11 further supports a pair of arms 13 which extend divergently with respect to each other from each side of the base. The base 11 and arms 13 support between themselves a cleaning head 14 comprising a plurality of rotary cleaning elements 15 supported from an articulated support (not shown). Each cleaning element 15 is associated with a drive motor supported on the cleaning head 14 which effect rotation of the cleaning elements 15. The cleaning head 14 is also provided with a drive means which causes movement of the cleaning head 14 towards and away from the support pylon upon which the embodiment is mounted. Each side of each arm is formed with a groove 22 and each arm 13 slidably supports a carrier 16 which is movable along the length of the arm and has a pair of rollers (not shown) to each side which are received in the grooves 22. The movement of the carrier 16 on each arm 13 is effected through a pair of endless chains 17 to each side of the carriage and which each extend from the base and down each arm 13. The chains are associated with a drive motor 18 whereby on activation of the drive motor 18 each carrier 16 is moved simultaneously along the arm in a corresponding manner. Each carrier 16 supports a pair of transversely spaced inwardly directed wheels 19. To mount the cleaning carriage to a pylon each carrier 16 is moved along the respective arm 13 towards its outer¬ most position until the spacing between the wheels. 19 on the carriers 16 exceeds the width of the pylon. The base is then moved into engagement with the pylon such that the wheels 12 thereof engage the surface of the pylon and the carriers move inwardly along the arms 13 such that t h e w h eels 19 thereon also engage the pylon to retain the cleaning carriage in position on the pylon. The wheels 12 associated with the base 11 at least are associated with a hydraulic drive to effect rotation of the wheels 12 and thus movement of the cleaning carriage along the pylon. In addition the wheels 12 on the base 11 at least are capable of being steered to facilitate movement of the carriage along and/or around the pylon. During such movement the brushes 15 may be engaged with the external surface of the pylon to effect cleaning thereof. Such engagement is effected by the drive means associated with the cleaning head. In use the cleaning carriage is moved along the length of the pylon to clean axial strips of marine growth and encrustations therefrom. On completion of one length the cleaning carriage is then indexed around the circumference of the pylon. This is accomplished by steering at least the main drive wheels through 90 such that when driven the machine rotates around the member. The wheels are then pivotted to be directed axially on the pylons and the carriage is driven towards the other end and to clean axial strips of growth and encrustation from the pylon. The cleaning carriage supports an articulated arm 20 having an inner portion 20a which is pivotally mounted to the base 11 about an axis normal to the central axis of the pylon to be cleaned and a second axis 21 which is perpendicular to the first axis and substantially co-planar with the central axes of the arms 13. The outer end of the inner portion 20a is associated with a substantially U-shaped outer portion 20b each arm of which extends to each side of the outer end of the inner portion 20a and is pivotally supported from the inner portion 20a to pivot about an axis parallel to the second axis 21. A hydraulic drive means is provided between the arm and base and the inner and outer portions of the arm to effect controlled articulation of the arm. A pair of claw members 23 are pivotally mounted to the outer end of the outer portion 20b and each is associated with a hydraulic cylinder 24 between the outer portion 20b and the respective claw 23. The internal configuration of the claws 23 facilitates engagement of the claws with pylons. The function of the articulated arm 20 and claws 23 is to facilitate the transfer of the cleaning carriage from one pylon to another. This transfer is effected by moving the cleaning carriage to a position adjacent a junction between two pylon or to a position closest to an adjacent pylon as shown and pivotting the arm 20 and support 20b such that the claws 23 are brought into embracing engagement with an adjacent pylon and releasing the cleaning carriage from the pylon to which it is engaged by moving the carriers 16 outwardly along the arms 13. By operation of hydraulic cylinders (not shown) between the arm 20 and the base 11 and between the inner and outer portions of the arm 20 the cleaning carriage may be moved from its position on one pylon to the adjacent pylon. When the carriage is in position on the adjacent pylon the carriers 16 are moved inwardly along the arms 13 to bring the wheels 19 thereof into engagement with the adjacent pylon. Once the cleaning carriage is in position the claws 23 may then be disengaged from the adjacent pylon and cleaning operation commenced or alternatively the cleaning carriage may be transferred to another adjacent pylon by a similar operation. Hydraulic fluid to effect operation of the brushes, movement of the cleaning carriage along a pylon, extension and retraction of the carriers 16 on the arms 13 articulation of the arm 20 and operation of the claws 23 is supplied through an umbilical cord 25 which supports the required number of fluid lines. If the cleaning carriage is to be used in association with pylons having a dimension greater than the maximum spacing available between the wheels 19 of opposed carriers 16 when at their outermost positions on the arms 13 each of the arms may be extended. Such extension is effected by means of extension pieces 26 (shown in broken lines) which are mountable to the ends of existing arms to increase the degree of travel available for the carriers 16 on the arms. As a result of the embodiment a cleaning carriage is provided which is capable of self propulsion along the length of a pylon and which has a capacity to accommodate a variety of pylon diameters. In addition the cleaning carriage is capable of transferring itself between the pylons without the need to utilise a remotely operated vehicle or divers to install the cleaning carriage on the pylon or to effect transfer of the cleaning carriage from one pylon to another. The second embodiment as shown at Figures 2 and 3 is also a cleaning device which is intended for use with underwater structures and which requires a diver or a remotely operated vehicle to effect at least its placement and removal. The second embodiment comprises a base 111 which supports a pair of transversely spaced wheels 112 which extend inwardly from the base 111. The base 111 further supports two pairs of arms 113 wherein the arms of each pair are parallel and the pairs of arms extend divergently from the base. The arms are tubular and have the same circular cross-section. The interior of the arms are hollow and are sealed in order that the cleaning device has a substantially zero buoyancy in water. If desired the buoyancy can be varied by any suitable means. The pairs of arms each support between themselves a carrier 116 which forms the end portion of the arms. The carrier 116 comprises two pairs of parallel struts 130 where each strut of each pair lie to each side of the arms of each pair of arms 113. The inner most end of each pair of struts 130 support a first roller 131 between them which is intended to be received on the exterior face of the respective arm 113. At an intermediate location a second roller 132 extends between each strut and is intended to be received on the internal face of the respective arm 113. The function of the first and second rollers 131 and 132 is to provide for free movement of the carrier 116 along the arms. To restrain the carrier 116 from inward pivotal movement with respect to the arms each pair of struts 130 support a brace member 133 which extends over the outer face of the respective arm to be spaced slightly therefrom when both the first and second rollers 131 and 132 are engaged with the arms 113. Movement of the carriers 116 along the arms 113 is controlled by an endless belt 117 which extends from the base 111 and down each arm 113 and is associated with a drive winch 118 whereby the length of belt on each arm is simultaneously varied in corresponding manner to effect corresponding movement of the carrier 116 along the arms 113. Each carrier 116 supports a pair of transversely spaced wheels 119. Each of the wheels 112 and 119 on the base and carriers are pivotable about an axis perpendicular to the axle and at least the wheels 112 on the base are associated with a drive to effect rotation of the wheels about the perpendicular axis to steer the cleaning device in its movement along an elongate tubular member. In addition at least the wheels 112 on the base are rotatably driven to effect movement of the cleaning device on the elongate member. A cleaning head 115 is pivotally supported from one pair of arms by a yoke 134 and is pivotally supported from the free- end of the yoke 134. A hydraulic ram 135 between the base- 111: and the cleaning head 114 causes the desired movement of the cleaning head 114 towards and away from the base 111. The cleaning head comprises a central member and a ' pair of lateral members each rotatably supporting at least one cleaning element 135 and drive motor 136 for each cleaning element 135. Hydraulic drive members between the central member and lateral members causes movement of the members such that each of the cleaning elements bear equally against the surface of the elongate member. In mounting the cleaning device to an elongate member each carrier 116 is moved along the arm 113 until the spacing between the opposed wheels 119 thereon is greater than the width of the elongate element. The carriers 116 are then retracted on the arms to bring each of the wheels 112 and 119 into engagement with the elongate member. The cleaning head 114 is then engaged with the surface of the elongate member while the cleaning device is moved axially along the elongate member and sequentially indexed around the elongate member after each axial pass therealong. If desired the cleaning device of the second embodiment may be associated with an articulated arm of the same form as that described in relation to the' first embodiment. While the embodiments have been described as a device for effecting cleaning of pylons it should be appreciated that the embodiments and invention may be readily modified to a carriage movable along the pylon for the purposes of testing, inspection, repair or construction of pylons and/or the carriage of items along the length of a pylon and between pylons.

Claims: THE CLAIMS defining the invention are as follows: 1. A carriage receivable over an elongate member for passage therealong comprising a base and a pair of arms extending divergently from the base, at least one of said arms being extendable, the base and end portion of said arms supporting roller-like members on their opposed faces which are intended to engage the external faces of an elongate member to retain the elongate member between them. 2. A carriage as claimed at claim 1 wherein at least one roller-like member is associated with a drive means to cause movement of the carriage along the elongate member. 3. A carriage as claimed at claim 1 or 2 wherein the roller-like members are able to effect movement of the carriage along and around the elongate member. 4. A carriage as claimed at any one of the preceeding claims wherein the end portion of said at least one arm is slidably supported on the inner portion of the arm and a drive means is provided to cause movement of the end portion along the arm and retain the end portion at a desired position along the arm. 5. A carriage as claimed at any one of the preceeding claims wherein each arm is extendable and said drive means causes corresponding movement of the end portions on the arms. 6. A carriage as claimed at any one of the preceeding claims wherein the base supports an articulated arm having a grasping means capable of grasping an elongate member and having drive means to effect controlled articulation and movement of the arm with respect to the base and opening and closing of the grasping means. 7. A carriage as claimed at any one of the preceeding claims wherein the base and/or arms support cleaning elements which are movable inwardly for engagement with the surface of the elongate member. 8. A carriage as claimed at any one of the preceeding claims wherein the buoyancy of the carriage may be varied. 9. A carriage as claimed at any one of claims 1 to 7 wherein the carriage has substantially zero buoyancy. 10. A carriage substantially as herein described.

Inventors: FIELDER NICHOLAS ALBERT WILLIA, FIELDER, NICHOLAS, ALBERT, WILLIAM
Applicants: DAWSON OFFSHORE PTY LTD, DAWSON OFFSHORE PTY. LTD.
Application year: 1986
Main classification: B63C11
IPC codes: B08B9, B25J5, E02B17, E21B41