GB2522996A

GB2522996A - An underwater mechanical tool for a remotely operated vehicle

Info

Publication number: GB2522996A
Application number: GB1422529.6A
Authority: GB
Inventors: Keith Stuart Elliot; Rory Mcgarry
Original assignee: Allspeeds Holdings Ltd
Current assignee: Allspeeds Holdings Ltd
Priority date: 2013-12-20
Filing date: 2014-12-17
Publication date: 2015-08-12
Anticipated expiration: 2034-12-17
Also published as: GB2522996B; GB201322687D0

Abstract

An underwater mechanical tool 1 for a remotely operated vehicle (ROV) comprises first and second jaws 3, 4 adapted for gripping and/or cutting a line, such as submarine wire ropes, armoured telecommunication and power cables, and hoses. The jaws are relatively moveable between an open and a closed position by a mechanical linkage located between at least one of the jaws and a rotary torque receptacle 10 adapted for attachment to a rotary torque tool of the ROV. Preferably, the first and second jaws are respectively secured at the ends of first and second pivot arms 16, 17 that are pivotally mounted to a housing 5, 6 of the tool. The other ends of the pivot arms are preferably mounted directly or indirectly to at least one nut 21; 26 adapted to travel along a drive screw 22; 27 such that rotation of the drive screw moves the jaws between their open and closed positions. A third, stationary jaw 19 may be provided with at least one spike 20 adapted to impale the line.

Description

AN UNDERWATER MECHANICAL TOOL

FOR A REMOTELY OPERATED VEHICLE

The present invention relates to an underwater mechanical tool for a remotely operated vehicle (ROV) and in particular to a remotely operated tool for use in submarine conditions on lines such as cables, ropes and hoses.

Underwater powered tools are designed for gripping, lifting and cutting lines such as submarine wire ropes, armoured telecommunication and power cables, and hoses. Conventionally, such tools are attached to an arm of the remotely operated vehicle (ROy) and are hydraulically powered.

This means that a hydraulic hose must be connected between the tool and the vehicle. In the case of tools that are attached to the cable such as gripping tools, the arrangement usually includes an ejection system including a is hydraulic connection ejection system to disconnect the gripping tool and the hydraulic hose from the vehicle once the tool has been attached to the submarine cable or rope so that the tool can be recovered along with the gripped line by a recovery vessel at the surface. Tools such as cutters are also provided with a similar arrangement but can usually be disconnected from the vehicle after the vehicle has been recovered from the sea. In both cases, however, the arrangements are a source of pollution because it is not possible to disconnect the hydraulic hose from the remotely operated vehicle without some escape of hydraulic fluid into the environment. In the case of submarine disconnection, it will be appreciated that this results in the hydraulic fluid being released into the sea.

The object of the present invention is to overcome or substantially mitigate the aforementioned problem by the provision of a mechanical tool that does not operate hydraulically.

According to the present invention there is provided an underwater mechanical tool for a remotely operated vehicle comprising first and second jaws adapted for gripping and/or cutting a line that are relatively moveable between an open and a closed position by a mechanical linkage between at least one of the jaws and a rotary torque receptacle adapted for attachment to a rotary torque tool of the remotely operated vehicle.

Preferably, a third jaw is provided that is stationery relative to the movement of the first and second jaws.

Preferably also, the third jaw is provided with at least one spike that is adapted to impale a line gripped by the first and second jaws as they are moved into the closed position. Alternatively, the third jaw is provided with at least one connector that is adapted to retain an item for attachment around a line gripped by the first and second jaws as they are moved into the closed position. The connector is may be at least one spike and preferably the item is a sleeve, grommet or crimp that is adapted to be secured around the is line when the jaws are closed and detached from the connector when the jaws are subsequently opened.

Preferably also, the first and second jaws are each secured at one end of first and second pivot arms respectively that are pivotally mounted adjacent the jaws to a housing of the tool.

Preferably also, the housing comprises first and second plates between which the mechanical linkage is located.

Preferably also, the other ends of the pivot arms are mounted directly or indirectly to at least one nut adapted to travel along a drive screw such that rotation of the drive screw moves the jaws between their open and closed positions.

In a first embodiment, the pivot arms are mounted respectively on nuts on first and second drive screws such that rotation of the drive screws moves the nuts and thereby the pivot arms along the drive screws to open and close the first and second jaws. Advantageously, the first and second drive screws are rotated via a gear means powered via a drive nut located within the rotary torque receptacle.

In a second embodiment the other ends of the pivot arms are connected to first and second link arms respectively that are pivotally mounted to a nut mounted on a drive screw such that rotation of the drive screw moves the link arms along the drive screw to open and close the first and second jaws. Advantageously, one end of the drive screw is secured to a drive nut located within the rotary torque receptacle.

Other preferred but non-essential features of the invention are described in the dependent claims.

Embodiments of the present invention will now be described by way is of example with reference to the accompanying drawings in which;-Fig. 1 is a perspective view of a first embodiment of underwater mechanical tool in accordance with the present invention and with its first and second jaws in a closed position; Fig. 2 is a view similar to Fig. 1 but with a side plate forming part of a housing for the tool removed to reveal the internal structure of the tool; Figs. 3 and 4 are front elevations of the tool shown in Fig. 2 with the first and second jaws shown in fully open and fully closed positions respectively; Fig. 5 is a view similar to Fig. 2 but of a second embodiment of underwater mechanical tool in accordance with the present invention, a rotary torque receptacle of the tool being shown in longitudinal cross-section; Figs 6 and 7 are front elevations of the tool shown in Fig. 5 with first and second jaws of the tool shown in fully open and fully closed positions respectively; Fig. 8 is a perspective view of the first embodiment of the tool shown in Fig. 1 when in use securing an item such as a sleeve, grommet or crimp around a line; and Fig. 9 is a perspective view of the line shown in Fig. 8 after attachment of the item thereto.

The first and second embodiments of underwater mechanical tools 1 and 2 respectively shown in the drawings are both adapted for gripping submarine lines such as wire ropes, armoured telecommunication and power is cables, and hoses. The tool 1, 2 forms a link between a recovery line from a surface vessel and submarine line when the latter is to be brought to the surface. The tool 1, 2 must therefore grip the line and maintain the grip during the lifting procedure. To this end, the tool 1, 2 is adapted to be attached to the submarine line using a submarine remotely operated vehicle (ROy). After attachment to the submarine line to be recovered, the tool 1, 2 is disconnected from the ROV so that it can be hanied aboard the surface vessel along with the submarine line by the recovery line that is attached to it.

As shown in the drawings, both embodiments of tool 1, 2 comprise first and second jaws 3, 4 that are adapted for gripping and/or cutting a submarine line and that are relatively moveable between open and closed positions, as shown in Figs. 3 and 4 and 6 and 7, by a mechanical linkage.

The mechanical linkage, as is further described below, is mounted in a housing comprising side plates 5 and 6 that are connected together via bolts 7 (not shown in Figs. 5 to 7). Secured to one 5 of the side plates are a pair of connecting loops 8 to which shackles may be attached for securement of a recovery line or similar. Other connecting loops 9 are attached to the bolts 7 and may also be connected to shackles for use in the connection of the tool 1, 2 to the ROy.

The jaws 3, 4 project beneath lower parts of the side plates 5, 6.

Opposite them between upper portions of the side plate 5, 6 is located a rotary torque receptacle 10, sometime termed a "torque bucket" that is adapted for attachment to a rotary torque tool of the ROy. Typically, this rotary torque tool will be located at the end of an operating arm of the ROV to enable the tool 1, 2 of the present invention to be manoeuvred into position when in use. The rotary torque receptacle 10 is defined between guide plates ii that themselves define slots 12 into which projections of the torque tool locate to releasable lock the torque tool into position. At the lower part of the receptacle 10 is a drive nut 13 that forms a part of the mechanical linkage and that is engaged and subsequently rotated by the is torque tool to power the mechanical tool 1, 2.

The jaws 3, 4 comprise inter-meshing gripping plates 14, 15 that are respectively secured at one end of first and second pivot arms t6, 17, which are pivotally mounted by pins 8 between the side plates 5, 6 part way along their length and adjacent the jaws 3, 4. A third jaw comprising a gripping plate 19 is also provided which is fixed between the pivot arms i6, 17 and is stationery relative to the movement of the first and second jaws 3, 4. This third jaw 19 may be provided with one or more spikes 20 that are adapted to impale a line gripped by the first and second jaws 3, 4 as they are moved into the closed position. The spikes 20 are preferably detachably mounted to the third jaw 19 so that they can be deployed as appropriate dependent on the nature of the line to be gripped by the tool 1, 2. Impalement of a line by the spikes 20 reduces the risk of a line being recovered using the tool 1, 2 from pulling free of its grasp during a recovery operation.

The mechanical linkage employed between the jaws 3, 4 and the rotary torque receptacle 10 will now be described.

In the first embodiment of tool i shown in Figs. 1 to 4, the pivot arms i6, 17 each comprise a pair of arms between which is mounted, at their ends opposite the ends attached to the jaws 3, 4, a nut 21 that is adapted to travel along a drive screw 22. Hence, there are two nuts 21 and two drive screws 22, the latter being mounted in-line on opposite sides of gear means 23, such as a bevel gear arrangement, that powers rotation of the screws 22. The gear means 23 is itself powered by the drive nut 13 that is engaged by the rotary torque tool of the ROV.

As shown in Fig. 3, when the jaws 3, 4 are fully open, the nuts 21 and pivot arms i6, 17 are located adjacent the gear means 23 at the inner ends of the drive screws 22. Rotation of the drive screws 22 by the gear means 23 moves the nuts 21 outwards, pivoting the pivot arms i6, 17 around the pins i8 and moving the jaws 3, 4 from an open to a closed position, as shown in is Fig. 4. As the jaws 3, 4 move into their closed position, the gripping plates 14, 15, inter-mesh and force any line disposed between them towards the third jaw 19 to be impaled on the spike or spikes 20 if the latter are present. To release the line, the drive screw 22 are driven in an opposite direction by the gear means 23 to move the nuts 21 back along their drive screws 22.

In contrast, in the second embodiment of tool 2 shown in Figs. 5 to 7, the ends of the pivot arms i6, 17 opposite the jaws 3, 4 are pivotally connected to ends of first and second link arms 24, 25 respectively. The other ends of the link arms 24, 25 are pivotally mounted to a nut 26 that is adapted to travel along a single drive screw 27. The drive screw 27 is connected to the drive nut 13 and disposed between the nut 13 and the third jaw 19. Hence, the drive screw 27 is rotated when the drive nut 13 is engaged and rotated by the rotary torque tool of the ROy.

As shown in Fig. 6, when the jaws 3, 4 are fully open, the nut 26 is located at the top of the drive screw 27 adjacent the drive nut 27. Rotation of the drive nut 13 and thereby the drive screw 27 moves the nut 26 down the drive screw 27 towards the third jaw 19 and the link arms 24, 25 force the pivot arms 16, 17 to rotate around the pins 18 to move the jaws 3, 4 from an open to a closed position, as shown in Fig. 7. As in the first embodiment, as the jaws 3, 4 move into their closed position, the gripping plates 14, 15, again inter-mesh and force any line disposed between them towards the third jaw 19 to be impaled on the spike or spikes 20 if the latter are present. To release the line, the drive screw 27 is rotated in an opposite direction to move the nut 26 back up the drive screw 27.

In a modification of the aforementioned embodiments, the tool 1, 2 may be used to attach an item 28 such as a sleeve, grommet or crimp around a line 29, as shown schematically in Fig. 9. This item 28 may then be used, for example, to connect the line 29 to a hoist or other means for bringing the line to the surface. In this case, the third jaw 19 of the tool 1, 2 is provided with at least one connector that is adapted to retain the item 28 for attachment around the line 29. This connector may be one or more spikes 20 as described above that, for example, frictionally retain the item by locating in appropriately sized apertures in the item 28. When the first and second jaws 3 and 4 are moved into the closed position, as shown in Fig. 8, the item 28 is secured around the line 29, for example by crimping the item 28 into position or by bring ends of the item 28 together so that they fasten together, for example in the manner of a handcuff, appropriate interconnecting devices being provided at the respective ends of the item. When the first and second jaws 3 and 4 are subsequently opened, the item 28 is preferably disconnected or disconnectable from the connector, for example if the tool 1, 2 is withdrawn from the item 28 the spikes 20 may be withdrawn from the apertures leaving the item 28 in position around the line 29.

In other embodiments of underwater mechanical tools according to the invention, the tool can be adapted to cut or sever a submarine line or to sever such a line while remaining attached to one of the severed parts. In some embodiments, this can be achieved by replacing the gripping plates 14, by blades or cutting/gripping blades as required.

It will be appreciated that the mechanical tool of the invention operates without the need for hydraulic fluid. It can, therefore, be connected to and disconnected from an ROV without any leakage of such fluid into the environment.

Claims

CLAIMS1. An underwater mechanical tool for a remotely operated vehicle comprising first and second jaws adapted for gripping and/or cutting a line that are relatively moveable between an open and a closed position by a mechanical linkage between at least one of the jaws and a rotary torque receptacle adapted for attachment to a rotary torque tool of the remotely operated vehicle.
2. A tool as claimed in Claim 1, wherein a third jaw is provided that is stationery relative to the movement of the first and second jaws.
3. A tool as claimed in Claim 2, wherein the third jaw is provided with at least one spike that is adapted to impale a line gripped by the first and second jaws as they are moved into the closed position.
4. A tool as claimed in Claim 2, wherein the third jaw is provided with at least one connector that is adapted to retain an item for attachment around a line gripped by the first and second jaws as they are moved into the closed position.
5. A tool as claimed in Claim 3, wherein the connector is at least one spike.
6. A tool as claimed in Claim 3 or Claim 4, wherein the item is a sleeve, grommet or crimp that is adapted to be secured around the line when the jaws are closed and detached from the connector when the jaws are subsequently opened.
7. A tool as claimed in any of Claims 1 to 6, wherein the first and second jaws are each secured at one end of first and second pivot arms respectively that are pivotally mounted adjacent the jaws to a housing of the tool.

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8. A tool as claimed in Claim y, wherein the housing comprises first and second plates between which the mechanical linkage is located.
9. A tool as claimed in Claim 7 or Claim 8, wherein the other ends of the pivot arms are mounted directly or indirectly to at least one nut adapted to travel along a drive screw such that rotation of the drive screw moves the jaws between their open and closed positions.
10. A tool as claimed in any of Claims 7 to 9, wherein the pivot arms are mounted respectively on nuts on first and second drive screws such that rotation of the drive screws moves the nuts and thereby the pivot arms along the drive screws to open and close the first and second jaws.
ii. A tool as claimed in Claim 10, wherein the first and second drive screws are rotated via a gear means powered via a drive nut located within the rotary torque receptacle.
12. A tool as claimed in any of Claims 7 to 9, wherein the other ends of the pivot arms are connected to first and second link arms respectively that are pivotally mounted to a nut mounted on a drive screw such that rotation of the drive screw moves the link arms along the drive screw to open and close the first and second jaws.
13. A tool as claimed in Claim 12, wherein one end of the drive screw is secured to a drive nut located within the rotary torque receptacle.
14. An underwater mechanical tool for a remotely operated vehicle substantially as described herein with reference to Figs. 1 to 4 or Figs. to 7 of the accompanying drawings.