Method for selectively coupling or uncoupling a coupling, and a coupling therefor

A method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit. The method includes providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof and providing an uncoupling pressure prevailing in the supply conduit for the purpose of activating shut-off valves in the supply conduit and on the cylinder and activating a release which uncouples the coupling. A coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly including a pump, a cylinder, a supply conduit between the pump and the cylinder, and such a coupling.

“This application is a national stage filing under 35 U.S.C. 371 of pending International Application No. PCT/NL2020/050508, filed Aug. 12, 2020, which claims priority to Netherlands Patent Application No. 2023701, filed Aug. 23, 2019, and also claims priority to Netherlands Patent Application No. 2024977, filed Feb. 24, 2020, the entirety of which applications are incorporated by reference herein.”

The invention relates to a method for selectively coupling or uncoupling a coupling, and more particularly to a method for selectively coupling or uncoupling on the basis of pressure in a supply conduit a coupling with a release, which is arranged between the supply conduit and a cylinder.

The invention further relates to a coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly comprising such a coupling, and to a control for such an assembly.

Many constructions, which are placed offshore, consist of a foundation and an upper part. Sometimes a transition piece is also present therebetween. It is often necessary to form a temporary connection between parts of the construction when they are being placed. The use of hydraulic cylinders for this application is generally accepted. After the definitive connection has been made, the cylinders are relieved again so that the definitive connection transmits the forces between the parts of the construction.

When prior art couplings are uncoupled, it is common for a limited amount of hydraulic liquid to run from the cylinder into the sea after the coupling has been uncoupled from a hydraulic cylinder. The cylinder generally remains behind, and only the coupling and the supply conduit are lifted from the sea. Operating of the uncoupling generally takes place via a hydraulic conduit configured for this purpose, whereby in a conventional system a second hydraulic conduit is also provided for the purpose of operating the coupling, this in addition to a hydraulic supply conduit for feeding a hydraulic medium to the cylinder under pressure.

It is an object of the present invention to provide a method and coupling, wherein the stated drawbacks do not occur, or at least do so to lesser extent.

The stated object is achieved according to the invention with a method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit, comprising the steps of:providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof; andproviding an uncoupling pressure prevailing in the supply conduit for the purpose of:activating shut-off valves in the supply conduit and on the cylinder; andactivating a release which uncouples the coupling.

Because according to the invention a pressure prevailing in the supply conduit can be used to allow the coupling to switch between different positions, it is possible, even with a single hydraulic conduit, to bring about an uncoupling, wherein hydraulic liquid is moreover prevented from leaking to the surrounding area. This also creates the option of evacuating hydraulic liquid from a cylinder which remains behind from the cylinder to the supply hose prior to uncoupling of the supply hose and the cylinder.

The invention further relates to a coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, comprising:a hydraulically controllable release; anda hydraulic control which is connected at least to the release and is configured to:provide hydraulic liquid to the cylinder when an operating pressure prevails in the supply conduit; andactivate the release and uncouple the coupling when an uncoupling pressure prevails in the supply conduit.

Particularly advantageous preferred embodiments form the subject of the dependent claims.

In the placing of foundations for wind turbines the foundation is referred to as monopile or MP. The transition part between the foundation and the mast is referred to as transition piece or TP. When the transition piece is placed on the monopile, there is a function for hydraulic cylinders at two locations in the construction (FIGS. 1A and 1B).

FIG. 1Ashows the hydraulic adjustment of the transition piece TP to a levelled/vertical orientation by means of using cylinders77. These cylinders77are generally mounted in the TP and, from there, also operated by an operator by means of a hydraulic pump. When the orientation of the TP has been set, the TP is temporarily fixed relative to the MP. The monopile MP is in the seabed78, and the transition piece TP carries a turbine79.

FIG. 1Bshows the hydraulic fixing of the TP relative to the MP by means of using hydraulic cylinders77. This ensures that the parts do not move relative to each other during arranging of the definitive connection. In this case this is grout71, a type of cement. After grout71has cured, cylinders77must be relieved in order to ensure that the force that must be transmitted between the two parts of the construction is transmitted purely via the grouted connection.

In the above the challenge lies in the fact that fixation cylinders77are mounted under the water surface76. Because of this, the cylinders77have to be remote-controlled. An additional problem is that all hydraulic conduits to fixation cylinders77must be removed after the installation process, and that no hydraulic liquid, or at least as little hydraulic liquid as possible, should be released therein.

In the present prior art there are roughly two ways of solving the described problem.

The first solution can be seen inFIGS. 2A and 2B. A non-return valve80is placed in the supply conduit to cylinder77. This ensures that oil can get into but not out of cylinder77. This ensures that cylinder77is load-bearing. A hose cutter81is mounted on the short length of hose between cylinder77and the non-return valve. This cutter has its own supply conduit82. When the grout71in the foundation has cured sufficiently, hose cutter81is activated. This causes the hose between cylinder77and non-return valve80to be cut. Cylinder77will return by means of a spring mounted in cylinder77. The medium present in cylinder77runs into the sea, which is undesirable, but perhaps acceptable under some circumstances, since it is only a limited amount of medium. Both the hose running to cylinder77and the hose with the hose cutter81can then be pulled upward and above water surface76. Cylinder77remains behind in the construction but can no longer bear load.

A further prior art development (not shown) is a valve which is mounted on the cylinder. The valve is provided with two supply conduits. The one is used to operate the cylinder. The cylinder is brought to pressure and, after curing of the grout, is relieved of pressure again. The cylinder will return by means of a spring mounted in the cylinder. The medium present in the cylinder is collected on top of the TP, in a tank. The second hose is then used to transmit a control pressure to the uncoupling mechanism. This causes the valve to be uncoupled from the cylinder after the grouting process. The valve is then pulled upward to a position above the water surface by the two hoses.

The invention relates to a method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit, comprising the steps of:providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof; andproviding an uncoupling pressure prevailing in the supply conduit for the purpose of:activating shut-off valves in the supply conduit and on the cylinder; andactivating a release which uncouples the coupling.

In order to be able to perform this method a coupling is according to the invention further provided for the purpose of respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, comprising:a hydraulically controllable release; anda hydraulic control which is connected at least to the release and is configured to:provide hydraulic liquid to the cylinder when an operating pressure prevails in the supply conduit; andactivate the release and uncoupling the coupling when an uncoupling pressure prevails in the supply conduit.

The embodiment described below comprises at least one spring return pressure cylinder1, at least one hydraulic coupling2consisting of a female coupling half6and a male coupling half7, an release mechanism5and only one liquid supply conduit3in which the liquid can be supplied and brought to pressure remotely, by a pump4.

According to the present invention, at least two of the following three functions are activated sequentially in at least three pressure steps, including for instance:a first function, also referred to hereafter as “operative function”; wherein the cylinder is extended and brought to the required operating pressure (500 bar) in order to fulfil the function for which the cylinder is intended;a second function, also referred to hereafter as “evacuating function”; wherein the cylinder is relieved and is retracted at least partially; anda third function, also referred to hereafter as “uncoupling function”; wherein the release mechanism is actuated and the coupling halves are uncoupled.

The release mechanism is an embodiment of a controllable coupling. In a first preferred embodiment (FIGS. 3-5) cylinder assembly1acomprises internally a retracting pin8a(shown inFIGS. 4 and 5) which is pivotally connected to a seesaw member9. Plunger12ais urged into a retracted position by a draw spring13a. Prior to installation plunger12amust be partially extended, such that seesaw member9is given space to pivot around a pivot point11and retracting pin8acan take up an extended position (FIG. 4). In this extended position already connected coupling halves6aand7aare fixed by retracting pin8a. The force necessary to extend plunger12asuch that retracting pin8acan take up the extended position is realized by means of applying an operating pressure of 5 bar in supply conduit3aby means of the pump4ashown inFIG. 3. Coupling halves6aand7aeach have a non-return valve32aand33awhich, when the two coupling halves6a,7aare coupled, press each other open. When coupling halves6a,7aare however uncoupled, the non-return valves fall shut and thus prevent oil leakage.

After installation, the above-described operative function can be carried out, wherein an operating pressure of 500 bar is applied by pump4ain supply conduit3aand therefore in cylinder chamber15a. Cylinder assembly1awill thus fulfil the function for which it is intended in normal operation, i.e. applying a clamping force.

The above mentioned evacuating function is activated by opening the valve16a, which is shown inFIG. 3and is positioned at the position of pump4a, and reducing the operating pressure from 500 bar to 5 bar. Plunger12awill retract using draw spring13a, and the hydraulic liquid from cylinder chamber15awill flow via coupling halves6aand7a, supply conduit3aand valve16aback into reservoir17a. Cylinder1ais hereby retracted at least partially.

The above mentioned uncoupling function is then activated. When the operating pressure becomes lower than 5 bar, draw spring13awill retract plunger12afurther still. Plunger12awill hereby make contact at the position of pivot point10with seesaw element9which, when plunger12ais retracted further, pivots around pivot point11and thus urges retracting pin8ainto a retracted position (FIG. 5). Coupling halves6aand7aare hereby no longer mechanically fixed. Compression spring14awill then urge the two coupling halves6aand7aapart. The non-return valves in the two coupling halves6aand7aclose, whereby the remaining liquid from cylinder chamber15aor supply conduit3acannot leak out. This prevents the release from shooting into this state (with all the consequences this entails), on the one hand during pressureless mounting of the cylinder on the TP or on the other hand if the pressure is raised to 5 bar (and then higher), up to the operating pressure, by means of a temporary mechanical locking which must be manually removed after installation.

In a second preferred embodiment (FIGS. 6-18) a cylinder assembly1bis connected to a female coupling half6band a valve assembly18is connected to a male coupling half7band to a supply conduit3b. Positioned between the two coupling halves6band7bis a compression spring14b. During installation of the cylinder assembly1brelative to the valve assembly18a compression spring14bis compressed and the two coupling halves6band7bare mechanically fixed by at least one retracting pin8bwhich is forced into a groove30of a sleeve29by a compression spring31. Coupling halves6band7beach comprise a non-return valve32,33which, when the two coupling halves6b,7bare coupled, press each other open. When coupling halves6b,7bare however uncoupled, non-return valves32,33fall shut and thus prevent oil leakage.

Sequence valves20and21(FIG. 9) both comprise an adjusting screw28, a compression spring24, a cone27, a seat22, a radial seal23, a feed opening25and a discharge opening26, wherein the diameter of seat22is substantially smaller than the diameter of radial seal23. Cone27is pressed with a determined force into seat22by adjusting compression spring24by means of tightening adjusting screw28. When a pressurized liquid is applied to feed opening25, a force is created on cone27in the direction of compression spring24. When the pressure rises to a predetermined or pre-set threshold value, which differs for the sequence valves20and21, the cone will be pressed out of seat22. The pressure value necessary for this purpose is adjustable by pressing compression spring24against cone27with more or less force by means of tightening adjusting screw28. When cone27is pressed out of seat22, the pressurized liquid will press against radial seal23. Due to a difference in diameter between seat22and radial seal23, cone27will then fall back onto seat22again at a substantially lower pressure. The pressure drop between feed opening25and discharge opening26is hereby minimized.

Compression spring24of first sequence valve20is set such that cone27of first sequence valve20opens at an operating pressure of 600 bar and closes at an operating pressure of 90 bar.

Compression spring24of second sequence valve21is set such that cone27of second sequence valve21opens at an operating pressure of 700 bar and closes at an operating pressure of 100 bar.

A first control valve19(FIG. 10) comprises a ball35, a seat36, a control plunger39, a first compression spring40, a second compression spring43, a radial seal41, a first feed opening38, a second feed opening42and a discharge opening37, wherein the diameter of seat36is smaller than the diameter of radial seal41and wherein compression spring40is configured to urge control plunger39into a blocking position. When control plunger39is in the blocking position, ball35will be pressed against seat36by compression spring43. An oil coming from discharge opening37will hereby be blocked. Oil coming from feed opening38will cause compression spring43to be compressed and ball35to be lifted off seat36. An oil flow will thus only be admitted when it comes from feed opening38. When a control pressure coming from discharge opening26of first sequence valve20however presses via feed opening42on control plunger39, this will be urged into a position allowing passage. In this position allowing passage control plunger39also urges ball35off seat36, whereby an oil flow between feed opening38and discharge opening37is admitted in both directions. When the control pressure on control plunger39has dropped below a determined value, control plunger39is once again urged into the blocking position by compression spring40.

A second control valve34(FIG. 11) comprises a ball44, a compression spring47, a seat46, a control plunger52, a first radial seal51, a second radial seal50, a first feed opening45, a second feed opening53, a third feed opening49and a discharge opening48. Seat46has a smaller diameter than first radial seal51, and first radial seal51has a smaller diameter than second radial seal50. When control plunger52is in a blocking position, ball44will be pressed against seat46by compression spring47. Oil coming from feed opening45is hereby blocked. Oil coming from discharge opening48will ensure that compression spring47is compressed and ball44is lifted off seat46. As such, an oil flow will only be admitted when it comes from discharge opening48. Feed opening53is in contact with supply conduit3b. When a control pressure presses via feed opening53on control plunger52, this will be urged into a position allowing passage. In this position allowing passage control plunger52also urges ball44off seat46, whereby an oil flow between feed opening45and discharge opening48is admitted in both directions. Because radial seal50has a greater diameter than radial seal51, and because the difference in pressure on the two seals can be no greater than 90 bar due to the minimum drop in pressure between feed opening25and discharge opening26in first sequence valve20, control plunger52will be urged back into its blocking position when a control pressure coming from discharge opening26of first sequence valve20presses via feed opening49on control plunger52.

Retracting pin8b(FIG. 12) comprises a first radial seal54and a second radial seal55having a greater diameter. Compression spring31forces retracting pin8ainto a coupling position. When a control pressure coming from discharge channel26of valve21presses via feed channel56on retracting pin8b, this will take up a retracted position which defines an uncoupling position. The protruding part of retracting pin8bis here pulled from groove30of sleeve29, and the mechanical connection between coupling halves6band7bis broken.

FIG. 13shows a schematic representation of a hydraulic diagram of the coupling according to the second preferred embodiment. The operation of the coupling will now be further elucidated with reference toFIGS. 14-17.FIGS. 14-17correspond toFIG. 13, but are further elucidated by showing therein the respective valves, i.e. the first control valve19, the first sequence valve20, the second sequence valve21and the second control valve34, as well as the retracting pins8b, as physical components.

After installation, the above mentioned operative function (FIG. 14) can be carried out. An operating pressure of 500 bar is applied by pump4bin supply conduit3band therefore in cylinder chamber15b. Cylinder1bwill thus fulfil the function for which it is intended in normal operation. Control plunger52of valve34will be urged into its second position due to the pressure in supply conduit3b. The oil flow through valve34will hereby be admitted in both directions. Control plunger39of valve19is urged into its first position by compression spring40, whereby valve19will admit only an oil flow in the direction of cylinder1b. If desired, the pressure can hereby be relieved from feed conduit3bby means of valve16bwithout cylinder chamber15bbeing relieved. This reduces the risk of a broken conduit.

The above mentioned and optional evacuating function (FIG. 15) is activated when pump4bincreases the pressure in conduit3b, valve assembly18and cylinder assembly1bto 600 bar. Cone27of first sequence valve20opens hereby, after which the pressurized liquid flows via discharge opening26of first sequence valve20to feed opening42of first control valve19and to feed opening49of second control valve34. Control plunger39of first control valve19hereby moves to its second position, whereby first control valve19admits an oil flow in both directions. Control plunger52of second control valve34moves back to its first position, and second control valve34will thereby allow only an oil flow from cylinder assembly1bto pump4b. When the pressure of supply conduit3bis relieved by means of valve16b, the oil will flow from cylinder chamber15bback into tank17b. Cylinder assembly1bwill hereby be relieved and be retracted at least partially. When cylinder assembly1bhas been retracted to sufficient extent, the above mentioned uncoupling function can be activated. Pump4bonce again builds up pressure in supply conduit3band valve assembly18. Because the second control valve34blocks oil flow in the direction of cylinder assembly1b, the oil will not flow into cylinder chamber15b. The pressure is built up further to 700 bar, after which the second sequence valve21opens. Retracting pin8bis retracted via discharge opening26of second sequence valve21such that coupling halves6band7bare no longer mechanically fixed and are pressed apart by compression spring14b. Non-return valves32and33in the two coupling halves6band7bfall shut, whereby the remaining oil from cylinder chamber15bor supply conduit3bcannot leak out.

After the described functions have been performed, valve assembly18can be retrieved by the user. Control valves19and34must be reset in order to be used again. Control pin27of both valve20and valve21are pushed in simultaneously by means of pressing push button57(FIG. 18). All remaining residual pressure can hereby disappear, and all valves hereby move to their original starting position.

A third preferred embodiment is shown inFIGS. 19-24.FIG. 20shows that cylinder assembly1cis connected to female coupling half6cand male coupling half59is connected to supply conduit3b. Positioned between the two coupling halves6cand59is compression spring14c. During installation of cylinder assembly1crelative to coupling half59compression spring14bis compressed and the two coupling halves6cand59are mechanically fixed by at least one retracting pin8cwhich is urged by compression spring31cinto groove30cof sleeve29c. Coupling half6ccomprises a non-return valve32cwhich allows an oil flow in the direction of cylinder assembly1cand blocks it in the other direction. Coupling half59comprises an adjusting screw60, a first compression spring61, a second compression spring65, a third compression spring67, a control plunger62, a blocking pin66, a ball63, a first seat68, a second seat69, a radial seal70, at least one retracting pin8cand a switch-over valve64which opens at 700 bar. Using adjusting screw60, compression spring61can be set such that control plunger62opens at an operating pressure of 600 bar in a first position in which it rests on seat69. Because radial seal70has a greater diameter than seat69, control plunger62takes up a second, retracted position after opening. This second position of control plunger62is mechanically secured by blocking pin66which is pressed in front of control plunger62by compression spring65(FIGS. 21A and 21B).

When control plunger62is in its first position, ball63is pressed off seat68, and when control plunger62is in its second position, ball63is pressed by compression spring67back onto its seat68. Non-return valve32cof coupling half6cis then pressed open by control plunger62. When the switch-over valve64, set to 700 bar, is opened, the oil therebehind presses retracting pin8cinto a retracted position, whereby it no longer protrudes into groove30cof sleeve29c. At that moment coupling halves6cand59are no longer mechanically fixed and compression spring14cpresses the two coupling halves apart.

After installation, the above mentioned operative function can be carried out. An operating pressure of 500 bar is applied by pump4cin supply conduit3cand therefore in cylinder chamber15c. As such, cylinder1cwill fulfil the function for which it is intended in normal operation. Control plunger62is in its first position, whereby the oil flow through non-return valve32cwill only be admitted in the direction of cylinder assembly1c. If desired, the pressure from feed conduit3ccan hereby be relieved by means of valve16c, without cylinder chamber15cbeing relieved. This reduces the risk of a broken conduit.

The above mentioned and optional evacuating function is activated when pump4cincreases the pressure in conduit3c, coupling half59and cylinder assembly1to 600 bar. Control plunger62hereby moves to its second position, after which non-return valve32cis opened, ball63falls onto seat68, and hereby allows only an oil flow from cylinder assembly1cto pump4c. When the pressure of supply conduit3cis relieved by means of valve16c, the oil will flow from cylinder chamber15cback into tank17c. Cylinder assembly1cwill hereby be relieved and be retracted at least partially. When cylinder assembly1chas been retracted to sufficient extent, the above mentioned uncoupling function can be activated. Pump4conce again builds up pressure in supply conduit3cand coupling half59. Because ball63blocks oil flow in the direction of cylinder assembly1c, the oil will not flow into cylinder chamber15c. The pressure is built up further to 700 bar, after which switch-over valve64opens. Retracting pin8cis retracted such that coupling halves6cand59are no longer mechanically fixed and are pressed apart by compression spring14c. The non-return valve32cin coupling half6cfalls shut, ball63was already shut, whereby the remaining oil from cylinder chamber15cor supply conduit3ccannot leak out.

After the described functions have been performed, coupling half59must be reset manually. This is done by urging blocking pin66back into its retracted position.

Finally, it should be noted that the solution provided by the present disclosure to the problem of oil leakage can also be realized in other ways, within the scope of the present disclosure.

A fourth preferred embodiment of a controllable coupling is shown inFIGS. 23-34. This fourth preferred embodiment has many similarities to the second preferred embodiment shown inFIGS. 7-18, but differs therefrom in that the fourth preferred embodiment is able with a single control valve119to fulfil the functionality of control valves19and34of the second preferred embodiment. Another addition relative to the second preferred embodiment is that the fourth preferred embodiment comprises a mechanical blocking, which is a similarity to the third preferred embodiment shown inFIGS. 19-22B.

In the fourth preferred embodiment a cylinder assembly1dis connected to a female coupling half6dand a valve assembly18dis connected to a male coupling half7dand to a supply conduit3d. Positioned between the two coupling halves6dand7dis a compression spring14d. During installation of the cylinder assembly1drelative to the valve assembly18dthe compression spring14dis compressed and the two coupling halves6dand7dare mechanically fixed by at least one retracting pin8dwhich is forced into a groove130of a sleeve129by a compression spring131. Coupling halves6dand7deach comprise a non-return valve132,133which, when the two coupling halves6d,7dare coupled, press each other open. When coupling halves6d,7dare however uncoupled, non-return valves132,133fall shut and thus prevent oil leakage.

Sequence valves120and121(FIG. 33) both comprise an adjusting screw128, a compression spring124, a cone127, a seat122, a radial seal123, a feed opening125and a discharge opening126, wherein the diameter of seat122is substantially smaller than the diameter of radial seal123. Cone127is pressed with a determined force into seat122by adjusting compression spring124by means of tightening adjusting screw128. When a pressurized liquid is applied to feed opening125, a force is created on cone127in the direction of compression spring124. When the pressure rises to a predetermined or pre-set threshold value, which differs for the sequence valves120and121, the cone will be pressed out of seat122. The pressure value necessary for this purpose is adjustable by pressing compression spring124against cone127with more or less force by means of tightening adjusting screw128. When cone127is pressed out of seat122, the pressurized liquid will press against radial seal123. Due to a difference in diameter between seat122and radial seal123, cone127will then fall back onto seat122again at a substantially lower pressure. The pressure drop between feed opening125and discharge opening126is hereby minimized Compression spring124of first sequence valve120is set such that cone127of first sequence valve120opens at an operating pressure of 600 bar and closes at an operating pressure of 90 bar. Compression spring124of second sequence valve121is set such that cone127of second sequence valve121opens at an operating pressure of 700 bar and closes at an operating pressure of 100 bar.

A control valve119(FIGS. 26 and 27) comprises a first ball135, a second ball144, a first seat136, a second seat146, a control plunger152, a first compression spring140, a second compression spring143, a third compression spring147, a fourth compression spring165, a locking pin166, a radial seal150, a first feed opening138, a second feed opening145, a third feed opening149, a first discharge opening137and a second discharge opening148, wherein the diameter of seat136is smaller than the diameter of radial seal150and wherein compression spring140is configured to urge control plunger152into a first position. When control plunger152is in a first position (FIG. 26), ball135will be pressed by compression spring143against seat136. Ball144will then be lifted off seat146by control plunger152, counter to the spring force of compression spring147. Oil coming from discharge opening137is hereby blocked, and oil coming from feed opening145is admitted. Oil pressure in feed opening149, this coming from discharge opening126of sequence valve120, will ensure that compression spring140is compressed and that control plunger152is urged into a second position. When control plunger152is in a second position, locking pin166moves by means of compression spring165to an extended position and locks control plunger152in the second position. When control plunger152is in a second position (FIG. 27), ball144will be pressed against seat146by compression spring147. Ball135will then be lifted off seat136by control plunger152, counter to the spring force of compression spring143. Oil coming from discharge opening145is hereby blocked, and oil coming from feed opening137is admitted. Irrespective of the position of control plunger152, oil coming from discharge opening148and flowing toward feed opening145and coming from discharge opening138and flowing toward feed opening137is admitted.

Retracting pin8d(FIG. 34) comprises a first radial seal154and a second radial seal155. The second radial seal155has a larger diameter than the first radial seal154. Compression spring131forces retracting pin8dinto a coupling position. When a control pressure coming from discharge channel126of valve121presses via feed channel156on retracting pin8d, this will take up a retracted position which defines uncoupling position. The protruding part of retracting pin8dis here pulled from groove130of sleeve129and the mechanical connection between coupling halves6dand7dis broken.

The operation of the coupling will now be further elucidated with reference toFIGS. 28-31. After installation, the above mentioned operative function (FIG. 28) can be carried out. An operating pressure of up to 500 bar is applied by pump4din supply conduit3dand therefore in cylinder chamber15d. In this state cylinder1dwill thus fulfil the function for which it is intended in normal operation. Control plunger152is urged into its first position by compression spring140of control valve119. The oil flow along ball144will hereby be admitted in both directions, and an oil flow along ball135is only admitted in the direction of cylinder1d. If desired, the pressure from feed conduit3dcan be relieved by means of valve16dwithout cylinder chamber15dbeing relieved. This reduces the impact of a broken conduit and eliminates dynamic phenomena as a result of the flexible conduits. The above mentioned and optional evacuating function (FIG. 29) is activated when pump4draises the pressure in conduit3b, valve assembly18dand cylinder assembly1dto 600 bar. Cone127of first sequence valve120opens hereby, after which the pressurized liquid flows via discharge opening126of first sequence valve120to feed opening149of control valve119. Control plunger152of control valve119hereby moves to its second position and is locked therein by means of locking pin166. In this second position control valve119admits oil flow along ball135in both directions and oil flow along ball144is admitted only from cylinder1d. When the pressure of supply conduit3dis relieved by means of valve16d, the oil will flow from cylinder chamber15dback into tank17d. Cylinder assembly1dwill hereby be relieved and be retracted at least partially. When cylinder assembly1dhas been retracted to sufficient extent, the above mentioned uncoupling function can be activated. Pump4donce again builds up pressure in supply conduit3dand valve assembly18d, but because ball144of control valve119blocks an oil flow in the direction of cylinder assembly1d, the oil will not flow into cylinder chamber15d. The pressure is built up further to 700 bar, after which second sequence valve121opens. Via discharge opening126of second sequence valve121retracting pin8dis retracted such that coupling halves6dand7dare no longer mechanically fixed and are pressed apart by compression spring14d. Non-return valves132and133in the two coupling halves6dand7dfall shut, whereby the remaining oil from cylinder chamber15dor supply conduit3dcannot leak out.

After the described functions have been performed, valve assembly18dcan be retrieved by the user. Control valve119must be reset in order to be used again. Control pins127of both valve120and valve121are pushed in simultaneously by means of screwing reset screw157in and out (FIG. 32). Provided that valve16dis in the return position, all remaining residual pressure will disappear hereby. Locking pin166of control valve119must be pulled out manually in order to return control plunger152of control valve119to its first position. After this, all valves are in their original starting position.

FIG. 35shows a release between the transition piece (TP) and the cylinder, where supply conduit3runs to the coupling with release8therein, and then a further conduit from the coupling to the cylinder. When grout71has cured, wherein cylinders1which function as fixation cylinders72during curing engage the monopile (MP) from the TP in order to immobilize the TP relative to the MP in a dead straight position brought about with the adjusting cylinders73in order to compensate for any incline of the MP, the coupling can be controlled in order to release, after which fixation cylinders1,72detach from the TP and are thus recoverable. Oil leakage can thus be prevented with certainty. The recoverable fixation cylinder1,72should however ideally be made reliable enough to still function properly under water after a considerable time, for instance two weeks, and be usable for a subsequent project, which could increase costs. To this day, project managers in the offshore wind industry are assessed on the results of the project, in terms of speed and costs. This is why these project managers currently generally still seek out the cheapest solution for their project and, for the time being, are less focused on the long term.

For the embodiment inFIG. 36it is also the case that the cylinders1applied therein as fixation cylinders72are recoverable because they are arranged in the interior of an MP and TP assembly. This can be an additional/alternative development, separate from controlling of the operation of the release with pressure in a single supply conduit, as in the above described embodiments. Holes or passages74are here arranged in the wall of the MP and a piston rod75of a fixation cylinder1,72is inserted through each hole or opening74. If the fixation cylinders1,72are actuated with pressurized hydraulic liquid, the TP is immobilized relative to the MP, which thus does not take place until the adjusting cylinders73have at least made a start with aligning the TP dead straight with the MP. Fixation cylinders1,72can be attached to the MP with interposing of a support or trestle welded onto the MP, or can be welded directly onto the MP. After curing of grout71the fixation cylinders1,72can be removed from the inside. Because fixation cylinders1,72can here be arranged above the waterline76, simplifications of fixation cylinders1,72can even be envisaged relative to the fixation cylinders1,72outside the TP and MP assembly, as in the above described embodiments, and it is expected that they can be reused more easily and at lower cost. Placing the fixation cylinders1,72at the position of adjusting cylinders73can prevent holes from having to be arranged in the MP. The dead straight alignment may then however be more difficult to achieve, and holes in the MP can moreover be filled after curing of grout71and removal of fixation cylinders1,72and spaces between the holes or openings74and the piston rods75protruding therein can be filled, so that during pouring or curing thereof, grout71cannot flow along piston rods75into the interior space of the assembled MP and TP.

The invention relates to a method for selectively coupling or uncoupling a coupling with a release8,8a,8b,8c,8d, arranged between the supply conduit3,3a,3b,3c,3dand a cylinder1,1a,1b,1c,1d, on the basis of pressure in a supply conduit3,3a,3b,3c,3d, comprising the steps of:providing an operating pressure prevailing in the supply conduit3,3a,3b,3c,3din order to provide hydraulic liquid to the cylinder1,1a,1b,1c,1don the basis thereof; andproviding an uncoupling pressure prevailing in the supply conduit3,3a,3b,3c,3dfor the purpose of:activating shut-off valves32,33,132,133in the supply conduit3,3a,3b,3c,3dand on the cylinder1,1a,1b,1c,1d; andactivating a release8,8a,8b,8c,8dwhich uncouples the coupling.

According to the preferred embodiment shown inFIGS. 3-34, the method further comprises the step, after the uncoupling of the coupling and the cylinder1,1a,1b,1c,1d, of removing the supply conduit3,3a,3b,3c,3dwith the coupling connected thereto and, preferably, the step of leaving behind the cylinder1,1a,1b,1c,1don a foundation construction MP.

It is however possible to envisage that, as shown inFIGS. 36 and 39, the cylinder1is uncoupled from foundation construction MP, wherein the coupling and cylinder1are removable together with the supply conduit3.

According to the preferred embodiment shown inFIGS. 3-34, the cylinder1,1a,1b,1c,1dis left behind on the foundation construction MP. In order to prevent hydraulic liquid from being able to leak to the surrounding area as soon as the coupling uncouples the supply conduit3,3a,3b,3c,3dfrom the cylinder1,1a,1b,1c,1dthe method preferably further comprises the step of evacuating the hydraulic liquid from the cylinder prior to the uncoupling of the coupling when an evacuation pressure prevails in the supply conduit3,3a,3b,3c,3d.

According to a preferred embodiment of the method, it comprises the step of providing in the supply conduit3,3a,3b,3c,3dthe evacuation pressure with a pressure level lower than the pressure level of the operating pressure. In the cylinder1,1a,1b,1c,1da compression spring13bcan be provided which presses a cylinder chamber15bempty, whereby an evacuation of the hydraulic liquid from the cylinder1,1a,1b,1c,1dcan take place.

According to a further preferred embodiment, the method comprises of providing an evacuation position setting pressure prior to setting the evacuation pressure. At this evacuation position setting pressure the coupling can be set for a subsequent evacuation of the hydraulic liquid from the cylinder1,1a,1b,1c,1d.

According to yet another preferred embodiment, providing the evacuation position setting pressure comprises of raising the pressure prevailing in the supply conduit3,3a,3b,3c,3dfrom the level of the operating pressure to a pressure higher than the pressure level of the evacuation position setting pressure. The evacuation position setting pressure of the embodiment shown inFIGS. 6-18is shown as a pressure level at 600 bar inFIG. 37.

According to yet another preferred embodiment, providing the uncoupling pressure prevailing in the supply conduit3,3a,3b,3c,3dcomprises of providing an uncoupling pressure with a pressure higher than the pressure level of the evacuation pressure. The uncoupling pressure of the embodiment shown inFIGS. 6-18is shown as a pressure level at 700 bar inFIG. 37.

According to yet another preferred embodiment, providing the uncoupling pressure prevailing in the supply conduit3,3a,3b,3c,3dcomprises of providing an uncoupling pressure with a pressure higher than the pressure level of the operating pressure. The operating pressure of the embodiment shown inFIGS. 6-18is shown as a pressure level at 500 bar inFIG. 37. According to yet another preferred embodiment, providing the uncoupling pressure prevailing in the supply conduit3,3a,3b,3c,3dcomprises of providing an uncoupling pressure with a pressure higher than the pressure level of the evacuation position setting pressure.FIG. 38shows the evacuation setting pressure at 600 bar and the uncoupling pressure at 700 bar.

According to yet another preferred embodiment, when an evacuation pressure prevails in the supply conduit3,3a,3b,3c, at least one control valve19,34,119functions selectively as a non-return valve which admits flow of hydraulic liquid away from the cylinder1,1a,1b,1cand blocks flow of hydraulic liquid to the cylinder1,1a,1b,1c. In the second embodiment, shown inFIGS. 7-18, a first control valve19and a second control valve34are provided, while the fourth embodiment shown inFIGS. 23-34provides the same functionality with one control valve119. According to an alternative preferred embodiment, providing the evacuation pressure comprises of reducing the pressure prevailing in the supply conduit3,3afrom the level of the operating pressure to a lower pressure level of the evacuation pressure. Of the embodiment shown inFIGS. 3-5, the evacuation pressure is shown inFIG. 38as a pressure level at 5 bar, which is lower than the operating pressure of 500 bar.

According to a further alternative preferred embodiment, providing the uncoupling pressure prevailing in the supply conduit3,3acomprises of providing an uncoupling pressure with a pressure lower than the pressure level of the evacuation pressure. The uncoupling pressure of the embodiment shown inFIGS. 3-5is shown as a pressure lower than 5 bar inFIG. 38.

The shown preferred embodiments show a coupling for respectively coupling and uncoupling a supply conduit3,3a,3b,3c,3dwhich is connected to the coupling to/from a cylinder1,1a,1b,1c,1d, comprising:a hydraulically controllable release; anda hydraulic control which is connected at least to the release and is configured to:provide hydraulic liquid to the cylinder1,1a,1b,1c,1dwhen an operating pressure prevails in the supply conduit3,3a,3b,3c,3d; andactivate the release and uncoupling the coupling when an uncoupling pressure prevails in the supply conduit3,3a,3b,3c,3d.

According to a preferred embodiment of the coupling, this coupling is configured to remain connected to the supply conduit3,3a,3b,3cafter uncoupling from the cylinder1,1a,1b,1c,1d.

According to a further preferred embodiment of the coupling, the hydraulic control is configured to evacuate the hydraulic liquid from the cylinder1,1a,1b,1c,1dwhen an evacuation pressure prevails in the supply conduit3,3a,3b,3c,3d.

According to yet another preferred embodiment of the coupling, it further comprises shut-off valves32,33on the cylinder1,1a,1b,1cand on the supply conduit3,3a,3b,3c, wherein shut-off valves32,33can be activated by activating the release.

According to yet another preferred embodiment of the coupling, it further comprises at least one control valve19,34,119which is configured to admit at least flow of hydraulic liquid to the cylinder1,1a,1b,1cwhen an operating pressure prevails in the supply conduit3,3a,3b,3c. In practice, each of the at least one control valve19,34,119is configured to admit at least flow of hydraulic liquid to the cylinder1,1a,1b,1c,1dwhen an operating pressure prevails in the supply conduit3,3a,3b,3c.

According to yet another preferred embodiment of the coupling, the at least one control valve19,34,119is configured to block flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dwhen an operating pressure prevails in the supply conduit3,3a,3b,3c. In a preferred embodiment with a first control valve19and a second control valve34both control valves19,34are preferably configured to block flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dwhen an operating pressure prevails in the supply conduit3,3a,3b,3c.

According to yet another preferred embodiment of the coupling, one of the at least one control valve19,34,119is configured to function as non-return valve which blocks flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dwhen an operating pressure prevails in the supply conduit3,3a,3b,3c. In the shown second embodiment with two control valves19,34the second control valve34fulfils this function.

According to yet another preferred embodiment of the coupling, each of the at least one control valve19,34,119is configured to admit flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dafter an evacuation position setting pressure has been reached and when an evacuation pressure prevails in the supply conduit3,3a,3b,3c,3d.

According to yet another preferred embodiment of the coupling, at least one of the at least one control valve19,34,119is configured to selectively function as a non-return valve configured to admit flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dand to block flow of hydraulic liquid to the cylinder1,1a,1b,1c,1dwhen the evacuation pressure prevails in the supply conduit3,3a,3b,3c,3d. In the shown second embodiment with two control valves19,34the second control valve34fulfils this function.

According to yet another preferred embodiment of the coupling, at least one of the at least one control valve19,34,119is configured to selectively function as a non-return valve configured to block flow of hydraulic liquid to the cylinder1,1a,1b,1cwhen an uncoupling pressure prevails in the supply conduit3,3a,3b,3c. In the shown second embodiment with two control valves19,34the second control valve34fulfils this function.

According to yet another preferred embodiment of the coupling, it comprises a sequence valve20configured to admit flow to the at least one control valve19,34,119when the evacuation position setting pressure or the uncoupling pressure prevails in the supply conduit3,3a,3b,3c,3d, wherein this at least one control valve19,34,119is configured, on the basis of this admitted flow, to be:released from a setting as non-return valve which is configured to admit flow of hydraulic liquid to the cylinder1,1a,1b,1c,1dand to block flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1d; andset as a non-return valve which is configured to admit flow of hydraulic liquid away from the cylinder1,1a,1b,1c,1dand to block flow of hydraulic liquid to the cylinder1,1a,1b,1c,1d.

According to yet another preferred embodiment of the coupling, the at least one control valve19,34,119comprises the first control valve19and the second control valve34, wherein:first control valve19is configured to be released from a setting as non-return valve on the basis of this admitted flow; andsecond control valve34is configured to be set on the basis of this admitted flow as a non-return valve which is configured to admit flow of hydraulic liquid away from the cylinder1,1a,1b,1cand to block flow of hydraulic liquid to the cylinder1,1a,1b,1c.

According to yet another preferred embodiment of the coupling, it comprises a further sequence valve21configured to admit flow to the release when an uncoupling pressure prevails in the supply conduit3,3a,3b,3c,3d, wherein the release is configured to release and to uncouple the coupling on the basis of this admitted flow.

According to yet another preferred embodiment, the coupling further comprises a mechanical locking which is configured to lock control valve119in a position corresponding to the evacuation position setting pressure. A mechanical locking is more reliable and can be controlled better than a hydraulic locking.

FIGS. 3, 6, 8, 13-17, 19, 20, 23, 28-31 and 39in particular show an assembly, comprising: a pump4,4a,4b,4c,4d, a cylinder1,1a,1b,1c,1d, a supply conduit3,3a,3b,3c,3dbetween the pump and the cylinder; and a coupling according to the invention.

In a preferred embodiment this assembly further comprises a control (not shown) which controls the pump4,4a,4b,4c,4dand is configured to control the pump4,4a,4b,4c,4din order to selectively generate a pressure in the supply conduit3,3a,3b,3c,3dfrom a group comprising at least: operating pressure or uncoupling pressure.

In a further preferred embodiment the control (not shown) which controls the pump is further configured to control the pump4,4a,4b,4c,4din order to selectively generate an evacuation pressure in the supply conduit3,3a,3b,3c,3d. The invention also relates to such a control.

Although they show preferred embodiments of the invention, the above described embodiments are intended only to illustrate the present invention and not to limit the scope of the invention in any way. It is thus noted that a connection between a foundation construction, more particularly a monopile MP, and a transition part, more particularly a transition piece TP, is described as possible application of the invention, but that the invention is not limited thereto. The invention is particularly suitable for locations that are difficult to access, such as typically below a water surface. Other applications are for instance under the ground, such as in mining.

When measures in the claims are followed by reference numerals, such reference numerals serve only to contribute toward understanding of the claims, but are in no way limitative of the scope of protection. It is particularly noted that the skilled person can combine technical measures of the different embodiments.

The rights described are defined by the following claims, within the scope of which many modifications can be envisaged.