GB2495784A - Clamping device for remote connectors - Google Patents

Abstract

The invention relates to a subsea connection device and comprises a first assembly including a first stab plate 1 carrying or adapted to carry a multiplicity of coupling halves 3 and a second assembly including a second stab plate 2 carrying or adapted to carry a multiplicity of coupling halves 4 each mateable with a respective coupling half 3 on the first stab plate when the stab plates are brought together. The first stab plate assembly comprises an engagement profile 6 and the second assembly comprises pawls 13 carried on a carrier 25, which is moveable to allow the pawls to engage the engagement profile. A locking member 9, (58 figure 5) is moveable coaxially with the carrier to a position wherein the locking member locks the pawls into the engagement profile, to allow a force acting on the second stab plate to move the second stab plate 2 towards the first stab plate 1. The plates 1 & 2 may be forced apart, when the pawls are released, by means of the locking member 9, (58 figure 5).

Description

Clamping device for Remote Connectors.

The invention relates to an improved technique of coupling subsea stab plates. These plates contain an array of equipment, typically self-sealing hydraulic couplings and electrical connections. There is typically a fixed stab plate which is attached to a subsea structure to which hydraulic or electrical lines are mn to an array of fixed hatf couplings on this stab plate.

The free stab plate has a corresponding array of the free halves of the electrical and hydraulic couplings from which hydraulic tubes or electric cables connected to surface equipment are attached. A so-called umbilical connection often many kilometres long takes the supply lines from the surface equipment to the free stab plate.

Initially the free stab plate would be at the surface awaiting deployment. The free stab plate would then be transported (flown in' by remote operated subsea vehicle ROV) to the subsea structure.

The device has preferably both hydraulic and mechanical means of separating the two plates Description of the coupling clamping mechanism (external type).

The device comprises two separate plates or Units (refer to figl). Plate 1 termed the fixed plate contains the male halves (3) of the couplings. Plate 2 the free plate' contains all the female halves (4) of the couplings.

A cylinder attached to plate 1 has a face 7 and a smaller dia. with a groove 6 which may be of semi-circular or faceted shape.

The free plate2 has a body S attached, Sliding within body S is a tubular hydraulic cylinder 9. This tubular cylinder 9 defines a sleeve which includes a key profile 10.

The tubular cylinder is spring 11 energised forwards (towards D) but may be pulled backwards (towards A) by lever 12.

Within the tubular cylinder 9 there is a pawl rod 25 carrying pawls 13. The pawls may be spherical but will carry increased load if faceted to avoid indenting. These pawis act as detents. The many balls or pawis may be equi-spaced in pockets 33 around the paw! rod circumference. The balls (pawis cannot fall through the pawl pockets 33 because of a slight ridge at the inner edge of the paw! rod. The action of spring 11 would cause the pawl to move and be held radially inwards locked by the key profile.

There is a key 16 on the pawl carrier 25 which runs in a straight axial track 17 in body 8 which maintains the orientation of the rod and the body.

One preferred use of this feature would require the spring!! to be unable to move the tubular cylinder beyond the locked position. This is shown on fig2 where the spring washer 34 strikes shoulder 35 preventing fi.irther motion by the spring. The tubular cylinder can be further moved to separate the Units 1&" by thrusting the leverl2 towards D or pressurising chamber 22 by hydraulic fluid.

Pulling back wards on the lever 12 to the stop 14 frees the pawls to move outwards to the restraining diameter 15. When the free unit 2 is in this position it may be placed on the spigot 6a.

Releasing the lever 12 permits the spring to move the tube to hold the pawls in the locked position. In this position the male and female units are clamped together.

In the locked together position clockwise rotation of the rotary nut 18 on thread 19 moves plate 2 towards plate I until the male and female coupling parts are all connected together in their desired functioning position. This position will be termed the Home' position.

To demate the couplings the rotary nut 18 may be rotated anticlockwise to return the units to their initial position.

When in the Home position forward force towards D on lever 12 moves tubular cylinder 10 forwards releasing the pawlsl3 into the clearance chamber 20. The movable unit 2 has been freed from unit 1. Further forward motion of the lever 12 thrusts the tubular cylinder against face 7 of unit 1 and pushes unit 2 away from unit I giving complete separation.

The above has described a simple manual operation of the device. With this manual control the lever 12+12a projects thai the tubular cylinder into a straight track 21 in the pawl rod as shown on fig2.

A simple hydraulic separation can be achieved. With the units made up in the Home' position supply of hydraulic pressure through port 23 into chamber 22 would thrust the plates apart as shol%11 in fig 2 giving complete separation.

In the deep marine environments where this could be used it may be desirable to positively lock the pawis into the groove 6. This is achieved by a shaped track 24 in the pawl rod 25 as shown in figi. Fig 1 shows the leverl2 pulled back into notch A of track 24 freeing the Pawls to assemble Unit 2 onto Unit 1. Releasing the lever spring 11 pushes the tubular cylinder forwards until the lever 12 strikes the track 24 at X. The pawls are now locked in track 6 and the 2 Units locked together. The next motion of the lever has to be sideways towards either B or C. A sleeve 26 slides on body 8 (fig 1), it carries a piston 27 which acts at right angles to the axis of the pawl rod. A spring in chamber 29 ensures that piston 27 pushes lever 12 into notch B. This ensures that the pawls cannot be accidentally released. A hydraulic pressure through port 30 into chamber 29 acts as further means of ensuring that the pawls cannot be released.

When it is required to separate units 2 &1 either moving the lever 12 to the right against the spring28, or applying pressure into chamber 31 through port 32, reaches point C of the track 24. At this point either manual movement of the lever 12 towards the stab plate or pressurising chamber 22 will firstly unlock the pawis and release the units then permit the tubular cylinder to thrust the units apart.

The units as described above are shown on fig 3 in various positions: Fig3a Prepared to engage. Lever 12 central, pulled towards A. Pawis freed to permit mounting.

Fig3b Unit2 assembled. Lever 12 central, pulled towards A. Pawls still free.

Fig3c Unit2 locked on Uniti. Lever 12 spring energised towards B. Pawls locked.

Fig3d Plates screwed together. Lever 12 spring energised towards B. Pawis locked.

Fig3e Plates thrust apart. Lever 12 to side C and thrust towards D. Pawis are freed by first movement then plates are thrust apart.

Hydraulic control The units may achieve the positions shown in fig 3 in entirely by hydraulic control means: Fig3a Prepared to engage. Lever 12 central, pressurised by cylinder towards A. Pawls freed to permit mounting.

Fig3b Unit2 assembled. Lever 12 central, pressurised by cylinder towards A. Pawis still free. Unit2 is flown onto Unit I Fig3c Unit2 locked on Uniti. Lever 12 pressure energised towards B (pressure in port 36). Pawls locked.

Fig3d Plates screwed together. Lever 12 pressure energised towards B (pressure in port 36). Pawls locked.

Fig3e Plates thrust apart. Lever 12 pressure energised towards C (pressure in port 38) and pressure thrust by pressure in port 23 towards D. Pawls are freed by first movement then plates are thrust apart.

The pawl locking device may also be internal. Figs 4 show the Free Unit 2 locking internally within Unit 1.

This version of the design (shown larger in Fig. 5) requires the locking probe 58 with key ring 60 to be inside the pawl tube 59. The separation member is the central rod or locking probe 58. The locking probe has a piston 68 which can be acted upon by a spring 64 or pressure applied to pan 58 which can assist the spring to release the pawls and separate the units. If pressure is applied to port 55 this opposes the spring putting the unit in the assembly position. On this design the track 63 in which lever 12 can be locked is in the paw! tube 59. An advantage of this design is the guidance that body 66 gives to body 65 at point 67.

An additional feature shown in Fig 5 is gear teeth 50 added around the nut 51. The additional gear wheel 52 is arranged to mesh with wheel 50/51 forming a gear pump.

Application of pressure to port 56 and venting from port 57 will cause the nut 51 to rotate clockwise which will make up the stab plates. Reversing the ports to which pressure is applied i.e. to 57 and venting from 56 reverses the direction of rotation of the nut which causes the stab plates to demate, An advantage of this clamping mechanism is the ability to hydraulically force the units apart when the units are deep subsea. This mechanism need not be flown to place by an ROV but lowered by a crane, Unit2 being latched to Unit!; then the various operations described can be performed remotely by hydraulics. The lever and track enables function of the units manually during manufacture or if used at small depths by a diver.

Claims (1)

1. <claim-text>Claims 1. A subsea connection device comprising a first assembly including a first stab plate (1) carrying or adapted to carry a multiplicity of coupling halves (3) and a second assembly including a second stab plate (2) carrying or adapted to carry a multiplicity of coupling halves (4) each mateable with a respective coupling half (3) on the first stab plate when the stab plates are brought together, wherein the first stab plate assembly comprises an engagement profile (6) and the second assembly comprises at least one pawl (13) carried on a carrier (25) which is moveable to allow the pawl to engage the engagement profile, and a lacking member (9, 58) which is moveable coaxially with the carrier to a position wherein the locking member locks the pawl into the engagement profile, whereby to allow a force acting on the second stab plate to move the second stab plate (2) towards the first stab plate (I).</claim-text> <claim-text>2. A device according to claim 1 in which the pawl (13) comprises a detent ball.</claim-text> <claim-text>3. A device according to claim 2 in which the ball is faceted.</claim-text> <claim-text>4. A device according to any of claims I -3 in which the carrier carries a multiplicity of circumferentially spaced pawls (13) each engageable with the engagement profile.</claim-text> <claim-text>5. A device according to claim 4 in which the engagement profile (6) comprises an annular groove in a member extending from the first stab plate.</claim-text> <claim-text>6. A device according to any of claims I -5 in which the said locking member (9) has a sleeve portion outside the carrier (25) for engagement with the pawl or pawls.</claim-text> <claim-text>7. A device according to any of claims 1 -5 in which the said locking member (58) extends within the carrier to engage the pawl or pawis from the inside.</claim-text> <claim-text>8. A device according to any of claims I -7 and including an operating lever (12) for moving the said locking member relative to the carrier.</claim-text> <claim-text>9. A device according to claim 8 in which the lever has a control track or slot (24) shaped to allow and prevent movement of the locking member according to the position of the lever within the track or slot (24).</claim-text> <claim-text>10. A device according to any of claims 1 -9 in which means are provided for urging the locking member (9) to engage the pawl or pawis.</claim-text> <claim-text>11. A device according to any of claims I -10 and including means (18, 19) for driving the second stab plate (2) relatively to the carrier whereby to move the second stab plate (2) towards the first stab plate (1).</claim-text> <claim-text>12. A device according to any of claims 1 -11 and including separating means operable to release the pawl or pawls from the engagement profile and to cause the locking member (9, 58) to force the stab plates apart when the pawl or pawis are released.</claim-text>