NO20131645A1 - CLUTCHING SYSTEM FOR CONNECTING A ROB TO A TMS - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a coupling system for coupling a submarine remote controlled vehicle or a load (13) to a fastening rope handling system (1) from below, in operational use, wherein the coupling system comprises a locking mechanism and a cable termination (2) for a fastening rope (20), the locking mechanism is coupled between the attachment rope handling system (1) and the vehicle or load (13), where the cable termination is configured to receive and lock into the locking mechanism and the locking mechanism is configured to receive and form a two-dimensional enclosure (11) for cable termination (2), and further configured such that a size of said enclosure (11) is gradually reduced as the cable termination (2) moves into the enclosure (11).

Description

COUPLING SYSTEM FOR CONNECTING A ROV TO A TMS

The invention relates to a coupling system for coupling an underwater remotely operated vehicle (ROV) or a load to a tether management system (Tether Management System, TMS) from below.

An ROV is an unmanned vessel used for various underwater operations. As an ROV has an approximately neutral weight in the water, it is a challenge to lower the ROV to the position where the work/operations are carried out, possibly within a depth of several kilometres. To increase the speed of the vertical transport, a TMS is used, which is a kind of ROV elevator. The TMS is heavier than water and therefore sinks easily. The TMS is connected to the surface through a cable called an umbilical, which both carries the weight as well as transmitting electricity and communications. The umbilical cord is wound on a drum (or spool) located on a boat or platform. A handling system, typically an A-frame, lifts the TMS off the deck and overboard.

Another coil is located inside the TMS with a cable (mooring rope) that transfers electricity and communication between the TMS and the ROV. The TMS can be obtained in two main variants; one where the ROV is parked inside the TMS and one where the ROV or a corresponding load is connected under the TMS. The invention is related to this second variant. There is a coupling mechanism to lock/connect the end of the tether to the underside of the TMS where the ROV hangs below the TMS. This end of the mooring rope is attached to the top of the ROV, and is terminated with a steel device that connects the TMS and the ROV together, without applying any load to the mooring rope. In the case of a TMS where the ROV hangs below, the mooring rope passes through a trumpet-shaped opening in the bottom of the TMS. A locking system (blocking) is placed directly above the opening and catches the end of the lashing rope when the lashing rope is pulled in. The connection of the TMS and the ROV underwater requires the TMS drum to wind up the mooring rope, as the ROV cannot push the mooring rope into the TMS through the opening. The mooring rope must therefore be wrapped faster than the speed at which the ROV and the TMS approach each other. As mentioned above, the TMS "hangs" from the surface. This means that it moves up and down in time with the waves even though it is several kilometers below the surface. This movement of the TMS does not occur when the TMS is hanging from a platform. When the TMS hangs from a ship, the motion can be canceled out if the ship actually compensates for the wave motion by unwinding/rewinding from the drum. In some cases, the ROV and TMS must be connected when the TMS is moving. If the ROV and TMS approach each other faster than the mooring line is retracted, the mooring line may be damaged and, in the worst case, severed when the cable termination enters the opening in the TMS before the mooring line is fully retracted, or if the cable termination hits the underside of the TMS.

WO02/06146A1 discloses a lashing rope handling system comprising a drum of lashing rope, which includes a pivoted guide roller revolving around a lashing rope outlet hole provided below the drum. The system guides the lashing rope vertically into the exit hole.

US 6,276,1625B1 discloses a method for storing ROV mooring lines without the use of electric rotating drag rings, and a mooring line storage drum. The heart of this Tether Storage System (TSS) involves the rotating beam with a driven tether sheave and guide plate on a circular track. The concept of the rotating beam with a driven mooring pulley and beam drive motors in a single unit differs from previous mooring rope storage and handling systems. It publishes rotation of the disc about a TSS frame's vertical axis. To achieve this, a drive motor is preferably mounted at each end of the beam. A drive wheel on each motor reacts against the channel track to rotate the beam. Rollers at each end of the beam support and guide it. The lashing rope is stored in a large circular basket below the disc in the cylindrical frame. A guide plate attached to the disc beam rests on top of the lashing rope in the storage basket. This plate rotates with the beam and moves vertically to remain on top of the mooring rope, to facilitate feeding during deployment and storage. The mooring rope passes from the basket through the guide plate feed gap, to the mooring rope wedge, then through the guide tube and docking assembly, from the TSS to the ROV. The lashing rope's path is simple and direct with a minimum of bending, stretching and twisting. The overall configuration is a cylindrical tubular frame that houses the rotating sheave beam assembly, mooring rope guide plate, storage basket and other operational components. The system captures and deploys the ROV for launch and recovery from the surface to the working depth. A docking pin on top of the ROV mates with the TSS docking assembly to provide this steering. The TSS expands the operational parameters of submersible ROVs by freeing it from surface effects, plume currents, and main umbilical drag.

One of the problems with the known systems is thus that when the ROV returns to the TMS, the mooring rope can become strangled if it is not unwound quickly enough. Furthermore, docking the ROV can be cumbersome.

The purpose of the invention is to remedy or reduce at least one of the disadvantages of the known technique, or at least to provide an important alternative to the known technique.

The purpose is achieved through the features indicated in the description below and in the following requirements.

In a first aspect, the invention relates more specifically to a coupling system for coupling an underwater remotely controlled vehicle or a load to a mooring rope handling system from below, in operational use, where the coupling system comprises a locking mechanism and a cable termination for a mooring rope, where the locking mechanism is connected between the mooring rope the handling system and the vehicle or cargo, wherein the cable termination is configured to be received and locked into the locking mechanism, and wherein the locking mechanism is configured to receive and form a two-dimensional enclosure for the cable termination, and is further configured such that a size of said enclosure gradually decreases as the cable termination moves into the enclosure. An important aspect of the invention is thus that the coupling system comprises two parts, namely a locking mechanism and a cable termination which is received in the locking mechanism, and that the enclosure formed by the locking mechanism is gradually reduced as the cable termination is moved further into the locking mechanism. In a variant, the cable termination can be implemented on top of the ROV, while the locking mechanism is mounted on the bottom of the TMS. However, this can also be the other way around, with the locking mechanism arranged on top of the ROV and the cable termination on the bottom of the TMS. Although the first variant has a clear advantage over the second, as will become clear in the discussion of some of the embodiments, both variants are considered to fall within the scope of the invention as it is claimed to be protected.

The drawn "cable termination" shall be interpreted as a projecting element for carrying a mooring rope that enters from a hole in an upper end thereof, and for guiding said mooring rope further to the vessel/1 a stone or the TMS. In fact, it may form part of the cable and be permanently connected to it, but it may also be connected to an upper part of an undersea remotely operated vehicle or cargo, in operational use.

The wording "two-dimensional enclosure for the cable termination" shall be interpreted as an opening for insertion of the cable termination, where the opening in projection in the direction of the cable termination on a virtual plane cutting said cable termination encloses the cable termination.

In one embodiment of the coupling system, the locking mechanism has been attached to a lower part of the lanyard handling system, and the cable termination has been attached to an upper part of the vessel or cargo. This embodiment constitutes the previously mentioned first main variant of the invention. Primarily, this embodiment is advantageous because the ROV can be held more easily and smaller, as it does not require the locking mechanism to be arranged on its top. Further advantages will be explained in light of the different embodiments of this variant.

In one embodiment of the coupling system, said locking mechanism comprises two pairs of oppositely placed gates, each pair delimiting a long opening, where the pairs of gates are preferably mounted perpendicularly, so that the elongated openings between said pair of gates together form the enclosure by projecting in one direction of said cable termination, where the enclosure is square or square-shaped, rectangle-shaped or parallelogram-shaped. The use of two pairs of oppositely placed gates, each pair forming a respective oblong opening, provides a practical way of forming a two-dimensional enclosure which is gradually reduced in size for locking. Such pairs of ports are preferably positioned substantially orthogonally, but this is not essential. Orthogonally placed ports make the design of the locking mechanism a little easier.

In one embodiment of the coupling system, said ports are mounted in a rotating manner in said locking mechanism, so that a simultaneous rotating movement of all ports together either increases or decreases a size of said enclosure depending on a direction of said rotating movement. The advantage of using pivoting gates is that it allows the design to be made so that pushing against the gates to make them move inwards also results in a reduction in the size of the enclosure, i.e. it promotes a very simple and practical mechanism .

In one embodiment of the coupling system, an inward movement of said gates reduces the size of said enclosure, where, in operational use, either the upper part of the vessel or cargo or the lower part of the mooring rope handling system is used to push said gates inwards and close the locking mechanism, as it moves towards the mooring rope handling system, and where an outward movement of said gates increases the size of said enclosure, where, preferably, in operational use, after unlocking, said locking mechanism is opened and/or held in an open position by the weight of said gates or by spring force. Depending on the main variant selected, either the weight of the gates can be used to open (after unlocking) the locking mechanism, or spring force can be used.

In one embodiment of the coupling system, each of said gates comprises a rolling element at its edge which delimits said oblong openings, and/or each of which comprises wheels at its ends for rolling on the upper part of said vehicle or cargo. The use of rollers has the advantage that the locking of the cable termination in the locking mechanism is smoother as the ports can roll on the surface of the cable termination. A further advantage is that the lashing rope is protected when it is pulled in or out.

In an embodiment of the coupling system, the system further comprises locking means for keeping the gates in a locked position after receiving and locking said cable termination, and preferably comprises release means for releasing said gates for uncoupling the underwater remote-controlled vehicle or a load from the mooring rope handling system. It is practical to keep the locking mechanism locked until the moment when the ROV is to be released again. Various techniques are available to achieve this effect, one of which has been described in the following detailed description.

In another aspect, the invention relates more specifically to the locking mechanism for use in the coupling system according to the invention. In fact, both the locking mechanism as well as the cable termination have been adapted to achieve the locking effect according to the invention, and both are characterized over the prior art. Both parts act together as a plug and socket. The inventor is therefore entitled to a claim against the locking mechanism as well as devices comprising such a locking mechanism.

In a third aspect, the invention relates more specifically to a lashing rope handling system comprising the locking mechanism according to the invention.

In a fourth aspect, the invention relates to a more specific cable termination for use in the connection system according to the invention. In fact, both the locking mechanism as well as the cable termination have been adapted to achieve the locking effect according to the invention, and both are characterized over the prior art. Both parts act together as a plug and socket. The inventor is therefore entitled to claims directed to the cable termination as well as units comprising such cable termination.

In a fifth aspect of the invention, more specifically, an underwater remote-controlled vehicle or cargo that is provided with the cable termination according to the invention, where the cable termination is arranged on an upper part of the remote-controlled vehicle or cargo.

In the following, an example of a preferred embodiment is described which is illustrated in the accompanying drawings, where: Fig. 1 shows a front view of an embodiment of the locking mechanism according to the invention when it is in an open position; Fig. 2 shows a side view of the embodiment in fig. 1; Fig. 3 shows a view from below of the embodiment of fig. 1; Fig. 4 shows a front view of an embodiment of the locking mechanism according to the invention when it is in a closed position; Fig. 5 shows a side view of the embodiment in fig. 4; Fig. 6 shows a view from below of the embodiment of fig. 4; Fig. 7 shows on a larger scale the coupling system according to the invention, part of the locking mechanism, as well as the cable termination; Fig. 8 shows on a larger scale a gate in accordance with an embodiment of the invention; Fig. 9 shows a further gate in accordance with an embodiment of the invention; Fig. 10 shows part of the locking mechanism when it is in an open position;

Fig. 11 shows the part in fig. 10 when in a closed position, and

Fig. 12 shows on a smaller scale a complete TMS and ROV system in operation

use.

The invention will now be discussed in more detail, particularly in relation to an advantageous embodiment. However, it must be noted that other embodiments are also possible, and do not deviate from the scope of the invention as it is required to be protected. To support this statement, some of the possible variants and alternatives will be discussed after the mention of the advantageous embodiment.

Fig. 12 shows a complete TMS and ROV system in operational use. The figure shows the TMS (1) connected to a boat or ship (99) via an umbilical cord (25). The TMS is connected to an ROV (15) via a tether (20). The figure further illustrates that the ROV (15) is attached to a cable termination (2) on its upper side, and the TMS (1) is provided with a locking mechanism (30) on its underside for receiving the cable termination (2).

The TMS coupling system (more precisely the locking mechanism (30) of the coupling system, which comment is also valid for the remaining discussion of the figures) is illustrated in the drawings, in which figures 1 to 3 show a TMS (1) with a coupling system in the open position, and figures 4 to 6 show the system in a closed position. Figures 1 and 4 show the front, figures 2 and 5 show the side and figures 3 and 6 show the bottom. Fig. 7 shows a cable termination on top of a load (13) which is caught between the rollers of the coupling system (3a, 4a).

An H-structure (3b, 4b) constitutes the frame for each port (3, 4) shown in Figures 8 and 9. One of the ends of the ports is hinged (5) below the TMS (1). At the other end of the frame there are rollers (3a, 4a) which are mounted on the ends (3b, 4b) of the frames via bearings (3c, 4c). (12) are wheels made of soft material. The stoppers (3d, 4d, shown in Figures 1, 2, 10 and 11) secure the gates to prevent them from tipping upwards. The buffer (3e, 4e) is a "soft" tube with a D profile to protect the top of the load when the TMS and ROV are connected. The fastening device (7) shown in figures 10 and 11 is hinged from the frame (4b) and closed against the pins (8) at the bottom of the TMS (la). The fastening device (7) has at least two positions, one for closed gate, shown in fig. 11, and one for open gate, shown in fig. 10. A third position can be identified as the closed but freely movable position. A spring (9) pushes the fastening device against the pin (8), so that it can easily be moved from position a (PA) to position b (PB) along a track 7b. However, it is locked in position b (PB). A cylinder (10) pulls the fastening device (7) to bring the pin (8) from position b (PB) into the slot (7b) to release the fastening device (7). A piston rod (10a) extends through the spring (9) and is connected to a hole (7a) in the fastening device (7), which makes it possible to only pull, not push, the fastening device (7). At the same time, the piston rod holds the spring (9) in a correct position.

The ports (3, 4) are located below the TMS (1) in two pairs which are shown perpendicularly positioned. This is shown in figures 3 and 6. From the front view in fig. 4 and the side view in fig. 5 it can be seen that the pairs of gates (3, 4) are positioned on top of each other, with a height difference between the hinges (5) which is equal to the diameter of the rollers. Both pairs of gates (3, 4) hang horizontally when the gates (3, 4) are closed. This is important to achieve an underside that is even and coherent.

The pairs of ports (3, 4) are not exactly the same. The pairs of gates (3, 4) in the upper position are slightly narrower, otherwise the side beams (4f) would have collided with the side beams (3f) of the pairs of gates (3) in the lower position. Furthermore, a locking mechanism (7-10) at one of the ports (3) is only necessary to lock the system. However, it is an advantage that both of the underlying ports (3) can be locked in place. The upper ports (4) are caught between the stopper (3d) in the lower ports (3) and the bottom of the TMS (la). The load that the cable termination (2) applies to the rollers (3a and 4a) is thus more evenly distributed, and for transport on land it may be desirable to fix all the ports (3, 4) in the closed position.

Fig. 7 shows the cable termination (2) which is equipped with 1 or 2 circular edge parts (2a) which have a larger external diameter than the width of the funnel (11) which is formed between the rollers (3a and 4a) when the ports (3, 4) are closed (Fig. 6). Although the use of a circular edge part (2a) may be sufficient - the use of 2 circular edge parts (2a) will better distribute the load and wear. Fig. 7 further shows part of a fastening rope (20) which enters the cable termination (2) through an opening at an upper end thereof.

So, in summary, the embodiment of the coupling system illustrated in Figures 1 to 12 comprises two pairs of ports (3, 4) which are hinged below the TMS (1), and a cable termination (2) with a profile to fit the enclosure (11) which is formed between the gates (3, 4) when all the gates are closed. The gates (3, 4) are held in place both in the open and closed position by a fastening device (7) which is hinged on each of the stop beams (3f) of the lower gates (3). A piston rod (10a) passes through a hole in the fastening device (7a) from a cylinder (10b) which is hinged on the same stop beam (3f, 4f). A spring (9) is placed around the piston rod (10a) between the cylinder housing (10b) and the fastening device (7), and pushes the fastening device against a pin (8) in the constructions of the TMS. A wheel of soft material (12) is mounted in each corner of the gates (3, 4). Each of the edges of the respective ports (3, 4) forming the respective elongated opening (11a, 11b) comprises a roller (4a, 3a).

The invention also relates to a coupling system as indicated in the following points:

1. Coupling system for TMS where an ROV or a corresponding load to be attached from below to a TMS using a locking mechanism of a cable termination at the end of a cable, which supplies the load with electricity and communication, characterized by two pairs of ports (3, 4 ) perpendicularly mounted under the TMS (1), so that the elongated openings (lia and 11b) between all the ports (3, 4) form a square-shaped or square-shaped clamp (11). 2. Coupling system for TMS according to point 1, characterized in that the gates (3, 4) are locked in the closed position using spring-loaded hooks (7) which only need a power supply to open the gates (3, 4), not to close them . 3. Connection system for TMS according to points 1-2, characterized in that the gate (3, 4) is pushed in and closed by the top of the load (13a) when the ROV or a corresponding load (13) and the TMS (1) pushed against each other. 4. Coupling system for TMS according to points 1-3, characterized in that the gates (3, 4) are opened and held in an open position using their own weight when the hooks (7) are released and the TMS (1) and the load ( 13) are separated from each other. 5. Connection system for TMS according to points 1-4, characterized in that the edges of the gates consist of rollers (3a, 4a) and form the elongated openings (lia, 11b). 6. Coupling system for TMS according to points 1-5, characterized in that the corners of the gates (12) consist of wheels made of a soft material.

As can be deduced from the description of the preferred embodiment with regard to the drawings, the core of the invention lies in the provision of a coupling system for coupling an underwater remote-controlled vessel or cargo (13) to a mooring rope handling system (1) from below, in operational use. Further, that the coupling system comprises a locking mechanism and a cable termination (2) for a mooring rope (20), where the locking mechanism is connected between the mooring rope handling system (1) and the vessel or load (13), where the termination (2) is configured to be received and locked into the locking mechanism. And further that the locking mechanism is configured to receive and form a two-dimensional enclosure (11) for the cable termination (2), and is further configured so that a size of said enclosure (11) is gradually reduced as the cable termination (2) moves into the enclosure (11).

It must be pointed out that the use of "pivoting" ports is one way of achieving this effect, but that there are also other ways, such as the use of a diaphragm construction where the size of the diaphragm is gradually reduced as the cable termination is moved into the hole in the diaphragm. Additional mechanical means may be provided to ensure that the diaphragm is gradually reduced to opening as the cable termination moves into this hole. For example, a spring-loaded, extendable pressable element that is pressed in when a top of the ROV or the bottom of the TMS is very close.

It must also be pointed out that kinematic reversals can also be considered, i.e. that the locking mechanism is arranged on the ROV and the cable termination is arranged on a bottom of the TMS.

It should be noted that the above embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, all reference characters placed between brackets shall not be interpreted as limiting the claim. The use of the verb "comprises" and its conjugations does not exclude the presence of elements or steps other than those set forth in a claim. The article "a" or "an" before an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several separate elements, and by means of a suitably programmed computer. In the device requirement that lists several means, several of these means can be given concrete form by one and the same item of hardware. The mere fact that certain measures are listed in different interdependent claims does not indicate that a combination of these features cannot be advantageously used. In the figures, similar or corresponding features are indicated throughout with the same reference number or marks.

Claims (11)

1. Coupling system for coupling an underwater remotely controlled vehicle or a load (13) to a mooring rope handling system (1) from below, in operational use, where the coupling system comprises a locking mechanism (30) and a cable termination (2) for a mooring rope (20) , wherein the locking mechanism (30) is coupled between the lashing rope handling system (1) and the vessel or cargo (13), wherein the cable termination (2) is configured to be received and locked in the locking mechanism (30), and wherein the locking mechanism (30) is configured to receiving and forming a two-dimensional enclosure (11) for the cable termination (2), and further configured so that a size of said enclosure (11) is gradually reduced as the cable termination (2) moves into the enclosure (11). 2. Coupling system as set forth in claim 1, characterized in that the locking mechanism (30) has been attached to a lower part of the lashing rope handling system (1), and the cable termination (2) has been attached to an upper part (13a) of the vessel or load ( 13). 3. Coupling system as specified in claim 1 or 2, characterized in that said locking mechanism (30) comprises two pairs of oppositely placed gates (3, 4), each pair delimits an elongated opening (lia, 11b), where the pairs of gates (3, 4) is preferably mounted perpendicularly so that the openings (lia, 11b) between said pair of ports (3, 4) together form the enclosure (11) by projecting in one direction of said cable termination (2), where the enclosure (11) is square or square-shaped, rectangle-shaped or parallelogram-shaped. 4. Coupling system as stated in claim 3, characterized in that said ports (3, 4) are mounted in a rotating manner in said locking mechanism, so that a simultaneous rotating movement of all ports (3, 4) together either increases or decreases a size of said enclosure (11) depending on a direction of said rotating movement. 5. Coupling system as stated in claim 3 or 4, characterized in that an inward movement of said gates (3, 4) reduces the size of said enclosure (11), where, in operational use, either the upper part (13a) of the vehicle or the load (13) or the lower part (la) of the mooring rope handling system (1) is used to push said gates inwards and close the locking mechanism (30), when it moves towards the mooring rope handling system (1), and where an outward movement of said gates (3, 4) increase the size of said enclosure (11), where, preferably, in operational use, after unlocking, said locking mechanism (30) is opened and/or held in an open position by the weight of said gates (3, 4 ) or by spring force. 6. Coupling system as stated in any one of claims 3 to 5, characterized in that each of said gates (3, 4) comprises a rolling element (3a, 4a) at its edge which delimits said oblong openings, and/or each comprises wheels (12) at the ends thereof for rolling on the upper part (13a) of said vessel or load (13). 7. Coupling system as stated in any one of claims 3 to 6, characterized in that the system further comprises locking means (7, 7a, 7b, 8, 9) to keep said gates (3, 4) in a locked position after receiving and locking of said cable termination (2), and preferably comprises release means (10, 10a, 10b) for releasing said ports (3, 4) for disconnection of the underwater remote-controlled vehicle or a load (13) from the anchorage te ri n g syste m et (1). 8. Locking mechanism (30) for use in the coupling system according to any one of the preceding claims. 9. Tie-down rope handling system (1) comprising the locking mechanism (30) according to claim 8. 10. Cable termination (2) for use in the coupling system according to any one of claims 1 to 7. 11. Underwater remotely controlled vehicle or load (13) which is provided with the cable termination (2) according to claim 10, which is arranged on an upper part (139) thereof.