Device for the connection of a spud guide to a vessel

Abstract

 A device for the connection of a spud guide to a vessel (9), in particular a dredger vessel, comprising a guide mechanism (1) in which the spud (2) is mounted for movement in the lengthwise direction, said mechanism being attached relative to the vessel by means of two hinged constructions (3, 6, 7), where each construction is pivotally connected at one end at a fixed point to the vessel (8, 9) and at the other end is pivotaly connected to the mechanism (1), and at least one of these constructions (3) can swing, in an essentially vertical plane extending parallel to the lengthwise direction of said vessel, while provision is made for at least one displacement device (7) which is connected at one side to the mechanism and at the other side to the vessel, and retaining means preferably formed by at least one hinged elongated element (5′) for holding the side edges of the mechanism, during the displacement of the mechanism, in paths running essentially in the lengthwise direction of the vessel.

Description

[0001] The invention relates to a device for the connec­tion of a spud guide to a vessel, in particular a dredger vessel, comprising a guide mechanism in which the spud is mounted essentially in a vertical position so that it can move in the lengthwise direction, said mechanism being supported by the vessel so that it can be moved relative to the vessel essentially in the lengthwise direction thereof, while provision is made for at least one displacement device which is connected at one side to the mechanism and at the other side to the vessel, and retaining means for holding the side edges of the mechanism, during the displacement of the mechanism, in paths running essentially in the length­wise direction of the vessel. Such a device is known from Dutch Patent 162164.

[0002] A device of this type serves to permit displacement of the vessel and the spud in the horizontal direction relative to each other. In the working position the pointed lower end of the spud is in the bottom lying un­der water, so that this point is affected not only by the vertical reaction force due to the weight of the spud, but also by horizontal reaction forces due to the anchoring effect, which produce a bending moment and transverse forces in the spud. These forces and moments, and also the forces and moments occuring during the guiding of the guide mechanism along the spud and rota­tion of the guide mechanism about said spud, must be transferred to the vessel by the guide mechanism.

[0003] In the known device the guide mechanism is sup­ported relative to the vessel by means of at least two wheels which are attached to the mechanism, rotate about coinciding horizontal axes and rest on horizontal runner rails attached to the vessel.

[0004] The runner rails or guides for the guide mechanism must meet high standards of strength and accuracy, par­ticularly in relatively large vessels where great forces occur, especially since these forces are not absorbed at one fixed point by the guides, but at a point which is movable over the entire length of the guides. The con­struction of the guides thus constitutes a great problem, both as regards their design and as regards the resulting costs.

[0005] The object of the invention is to produce a device of the type mentioned in the preamble where there are no guides or guides which are simple to design.

[0006] This object is achieved in that in the device ac­cording to the invention the guide mechanism is attached relative to the vessel by means of two hinged construc­tions, where each construction is hingedly connected at one end at a fixed point to the vessel and at the other end is hingedly connected to the mechanism, and at least one of these constructions can swing, in an essentially vertical plane running parallel to the lengthwise direc­tion, from a vertical central position from and to the centre of the vessel.

[0007] In a device designed in this way some of the mo­ments and forces acting upon the guide mechanism are transferred by means of these hinged constructions to the vessel and are thus absorbed at fixed points by hinge points.

[0008] The hinged construction which can swing in the said vertical plane can comprise at least one hinged bar-­shaped member, but can also be of at least two hinged bar-shaped members always running parallel to each other.

[0009] In the latter case the two above-mentioned bar-­shaped members may be connected to each other to give a torsionally rigid box-type construction, so that there is then no need for the above-mentioned retaining means.

[0010] In an advantageous manner the bar-shaped members are formed by piston-cylinder assemblies, in which means are present for controlling these piston-cylinder as­semblies in conjunction with the displacement device in such a way that during the displacement of the guide mechanism its centre of gravity moves in a horizontal plane, and not according to a circular arc, which will be the case in bar-shaped members of invariable length.

[0011] In a device in which the displacement device comprises an operable piston-cylinder assembly or similar device, the second hinged construction is advan­tageously formed by at least one operable piston-­cylinder assembly which extends in a horizontal plane, in the same direction as and parallel to the displace­ment device, while means are present for ensuring synchronism of all these piston-cylinder assemblies during sliding in and out thereof.

[0012] This embodiment has the advantage that the piston-­cylinder assemblies can also act as buffers for the prevention of overloading, by the absorption of energy, to which end the piston-cylinder assemblies are provided with an overflow facility and with a device for return­ing the piston-cylinder assemblies to their initial position after the buffering.

[0013] The retaining means are preferably formed by at least two hinged elongated elements which run parallel to each other and are swivellable in a substantial horizontal plane, and which are hinged at one of their ends to the vessel and at the other end are hingedly connected to the guide mechanism, while these elements in their centre positions stand al­most perpendicular to the vertical plane through the longitudinal axis of the vessel.

[0014] In a device in which the displacement device com­prises an operable piston-cylinder assembly or similar device the retaining means can in an advantageous manner be formed by at least one hinged elongated element which can be swung in a horizontal plane, and which is hingedly connected at one end to the vessel and hingedly connected at the other end to the guide mechanism, while this element in its centre position stands essentially perpendicular to the vertical plane through the lon­gitudinal axis of the vessel, and by at least one operable piston-cylinder assembly which extends in a horizontal plane, in the same direction as and parallel to the displacement device, while means are present for ensuring synchronism of all piston-cylinder assemblies during sliding in and out thereof.

[0015] This design of the retaining means ensures that the remaining part of the moments and forces acting upon the guide mechanism is also transferred by means of hinged constructions and the displacement device to the vessel and thus absorbed at fixed points by hinge points.

[0016] The elongated elements can be formed by bars, but advantageously consist of piston-cylinder assemblies, by means of which the guide mechanism is displaced along a path in a vertical plane parallel to the longitudinal direction of the vessel, which path is in the form of a circular arc if the elements are formed by bars. In ad­dition, energy can be absorbed also in the crosswise direction by the piston-cylinder assemblies for the pur­pose of preventing overloading, in the same manner as described above.

[0017] If the fitting of the horizontally running elon­gated elements constitutes a problem on account of the available space in the vessel, then the retaining means can be made of at least one pair of guide elements which are provided on the guide mechanism on the side edges thereof running parallel to the longitudinal direction of the vessel, and which are guided along a pair of guide elements disposed on the vessel, one of these pairs of guide elements consisting of guide tracks.

[0018] The guide tracks need in principle only be capable of transmitting transverse forces, so that they can be of a relatively simple design. Moreover, the guide ele­ments may be pretensioned in the direction towards the guide tracks, so that there is never space between the guide elements and the guide tracks and the standards for alignment of the guide tracks relative to each other can be made much less rigid.

[0019] The guide elements can consist of elements made of an elastic material e.g. rubber but they are advantageously each formed by an end part of the slidable part of a piston-cylinder assembly whose non-slidable part is connected to the guide mechanism, while a space inside the cylinder closed off by the piston is connected to a source of a pressure fluid.

[0020] It is also possible to have a measuring instrument for continuous measurement of the position in the transverse direction of the guide mechanism relative to the vessel, and a device which in response to a measured deviation from the desired position of the guide mechanism can take pressure fluid to or discharge it from the enclosed space inside the cylinder, as a result of which the above-mentioned deviation is corrected.

[0021] The invention is explained in greater detail with reference to the drawing, in which:

Figs. 1 to 8 show schematically different embodi­ments of the device according to the invention;

Fig. 9 shows the embodiment according to Fig. 1 in greater detail, in a front view (Fig. 9a), in a side view (Fig. 9b), and in a top view (Fig. 9c);

Fig. 10 shows the embodiment according to Fig. 2 in greater detail, in a front view (Fig. 10a), in a side view (Fig. 10b), and in a top view (Fig. 10c); and

Fig. 11 shows schematically the control device used in the embodiment according to Fig. 10.

[0022] As shown in Fig. 1, the device comprises a guide mechanism 1, in which the spud 2 is slidably mounted. The mechanism 1 is suspended relative to the vessel (not shown) by means of a first hinge construction comprising the hinged bars 3 and a second hinge construction com­prising the piston-cylinder unit 4. The bars 3 can also be disposed in the manner shown by dotted lines for one of these bars at 3′. Also present are retaining means in the form of a hinged bar 5 which can be swung in a horizontal plane, and a piston-cylinder unit 6 lying in a horizontal plane, and a displacement device also in the form of a piston-cylinder unit 7. By means of devices which are not shown, the piston-cylinder units 4, 6 and 7 are connected to each other in such a way that synchronism of these assemblies is ensured during the sliding in and out thereof. During the sliding in and out of the said piston-cylinder units the guide mechanism 1 will thus be moved in a virtually horizontal direction relative to the vessel, while the bars 3 will swing in a vertical plane in the direction of the arrow A.

[0023] In the embodiment shown in Fig. 2 there is again a guide mechanism 11 for guiding the spud 12, said mechanism 11 being suspended relative to the vessel by means of the hinged bars 13 and the piston-cylinder unit 14. The piston-cylinder units 16 and 17 are further dis­posed in the same way. The hinged bar 5 in the embodi­ment shown in Fig. 1 is, however, replaced here by the guide elements 18 which are disposed on the mechanism 11 and are guided along guide tracks 19 on the vessel, which is not shown.

[0024] According to Fig. 3, the guide mechanism 21 for the spud 22 is again suspended relative to the vessel from a hinged construction consisting of two hinged bars 23, but here the second hinged construction is formed by a hinged bar 24 which can be swung in a vertical plane, and which runs parallel to the bars 23 and has the same length as these bars. The retaining means are here formed by two hinged bars 25 which can be swung in a horizontal plane. Finally, there is a displacement device in the form of a piston-cylinder unit 27.

[0025] In the embodiment shown in Fig. 4 the guide mechanism 31 for the spud 32 is suspended in the same way as in Fig. 3 by the bars 33 and 34, but here the hinged bars 25 are replaced by a single hinged bar 35 and a piston-cylinder unit 36 which runs parallel to the displacement device comprising a piston-cylinder unit 37. The piston-cylinder units 36 and 37 are connected together, for synchronism, by means not shown.

[0026] The embodiment shown in Fig. 5 corresponds largely to that of Fig. 1 as regards the suspension of the guide mechanism 41 for the spud 42 which is formed by the hinged bars 43 and the piston-cylinder unit 44. However, the bar 5 and the piston-cylinder 6 in the embodiment of Fig. 1 are replaced here by two hinged bars 45 which can be swung in a horizontal plane. The displacement device, comprising the piston-cylinder unit 47, is again con­nected to the piston-cylinder unit 44 for purposes of synchronism.

[0027] The embodiment shown in Fig. 6 largely corresponds to that of Fig. 2, but instead of one pair of guide ele­ments 18 there are here two pairs of guide elements 58 and 58′ which are disposed on the guide mechanism 51 and which are guided along the guide tracks 59 and 59′ mounted on the vessel. The piston-cylinder unit 16 shown in Fig. 2 may consequently be left out. The displacement device comprising a piston-cylinder unit 57 is again coupled to the piston-cylinder unit 54 for purposes of synchronism, so that during the sliding in and out of these units the guide mechanism 51 with the spud 52 run­ning through it can be displaced in a horizontal direc­tion relative to the vessel, while the hinged bars 53 swing in a vertical plane in the direction of the arrow A.

[0028] In the embodiment shown in Fig. 7 the guide mechanism 61 for the spud 62 is suspended relative to the vessel (not shown) on one side by means of the bars 63, which are joined together to form a torsionally rigid box 68, and on the other side by means of the piston-cylinder assembly 64. The displacement device, comprising the piston-cylinder unit 67, is again con­nected to the piston-cylinder unit 64 for purposes of synchronism.

[0029] The embodiment shown in Fig. 8 corresponds largely to that of Fig. 7 as regards the suspension of the guide mechanism 71 for the spud 72, by means of the tor­sionally rigid box 78. However, the guide mechanism 71 is suspended relative to the vessel on the other side by means of the hinged bar 74. So here a single piston-­cylinder assembly 77 forming the displacement device is present.

[0030] In the embodiments shown in Figs. 2 to 8 the bars 13...., 73 can be designed in the same way as shown by 3′ in Fig. 1.

[0031] It will be clear that in the case of the embodi­ments shown in Figs. 1 to 8 the centre of gravity of the guide mechanism 1, 21 ....., 71 during the displacement thereof will describe a circular arc in a vertical plane, and in the embodiments shown in Figs. 1, 3, 4 and 5 will also describe a circular arc in a horizontal plane, as a result of the bars 5, 25, 35, 45. If, however, it is desired that the guide mechanism should be displaced purely in a straight line, this can be achieved by replacing the bars 3, 13 ...., 73 and the bars 5, 25, 35, 45 by piston-cylinder assemblies, in which case means are then present for controlling these piston-cylinder assemblies in such a way in conjunction with the displacement device that on displacement of the guide mechanism this mechanism describes a purely rec­tilinear path.

[0032] Fig. 9 shows the embodiment of Fig. 1 in greater detail, with the horizontal hinged bar 5 being replaced by a piston-cylinder unit 5′. The guide mechanism 1 for the spud 2 is suspended by means of the hinged bars 3 from a derrick construction 8 mounted on the vessel 9 above the well 10. Also shown are the piston-cylinder assemblies 4, 6 and 7 which are hingedly connected on one side to the vessel 9 and at the other side are hingedly connected to the mechanism 1. The spud 2 is retained in the mechanism 1 by means of the brace 1′.

[0033] When the guide mechanism 1 is displaced, this mechanism will move parallel to the initial position as a result of the piston and piston rods moving to the same extent inside the piston-cylinder assemblies 4, 6 and 7. The bottom hinge points, where the bars 3 are at­tached to the guide mechanism 1, will thereby describe a circular arc about the top hinge points of these bars. It can be determined mathematically what position the piston and piston rod of the piston-cylinder unit 5′ must assume in order to make the centre of the spud describe a pure straight line inside the well 10 in any position of the pistons inside the piston-cylinder as­semblies 4, 6 and 7. For this, the positions of the pis­tons inside the piston-cylinder units 4, 6 and 7 and 5′ are measured and compared, following which the position of the piston inside the assembly 5′ is corrected if there is a difference between the actual and the desired position.

[0034] The hinged bars 3 can be replaced by piston-­cylinder assemblies, where in the same way as described for the piston-cylinder assembly 5′ the positions of the cylinders inside these piston-cylinder assemblies can be corrected for a purely rectilinear running of the guide mechanism 1, seen in Fig. 9b.

[0035] The piston-cylinder assemblies 5′ and 4, 6 and 7 can be designed in such a way that they can overblow via safety devices in the operating system and destroy energy if forces in the transverse or longitudinal direction become too great.

[0036] A force on the tip of the spud will result in a mo­ment about horizontal axes in the longitudinal and transverse direction. The transverse moment will be ab­sorbed in the bars 3, while a moment will occur about a vertical axis. This moment and any further moments of rotation in consequence of the rotation of the spud in­side the braces 1′ will be absorbed by the piston-­cylinder assemblies 6 and 7. The longitudinal moment is absorbed by the piston-cylinder assemblies 6, 7 and 4. If the piston-cylinder assembly 5′ is not perpendicular to the piston-cylinder assemblies 4, 6 and 7, it will also absorb part of the moment of rotation and the lon­gitudinal moment. A transverse force will be absorbed practically entirely by the piston-cylinder assembly 5′, and will result in a force on the piston-cylinder as­semblies 4, 6 and 7 and the bars 3. The piston-cylinder assemblies 4, 6 and 7 will essentially absorb lon­gitudinal forces, but the assembly 5′ will also absorb some of these forces if this assembly is not perpen­dicular to the other piston-cylinder assemblies 4, 6, 7. The vertical forces on the guide mechanism 1 will essen­tially be absorbed by the bars 3, which causes a resul­tant which is absorbed by the piston-cylinder assemblies 4, 6, 7.

[0037] Fig. 10 shows the embodiment of Fig. 2 in greater detail. The guide mechanism 11, in which the spud 12 is slidably mounted by means of the braces 11′, is suspended by means of the hinged bars 13 from a derrick construction 18 mounted on the vessel 19. There are also the piston-cylinder assemblies 14, 16 and 17, which are designed in the same way as the assemblies 4, 6, 7 of Fig. 9.

[0038] The guide mechanism 11 is provided with guide ele­ments 18, 18′ which are guided along guide tracks 19, 19′ on either side of the well 20.

[0039] As shown in Fig. 11, the guide elements 18, 18′ are formed by end parts of the cylinder casings 80, 80′ which are slidable within the guide bushes 81, 81′ dis­posed on the guide mechanism 12 and along the pistons 82, 82′ which are mounted by means of the bars 82˝, 82˝ on the mechanism 12. A pressurized feed fluid is pumped at 83 through the non-return valves 84, 84′ into the spaces of the cylinders 80, 80′ closed off by the pis­tons 82, 82′, as a result of which the cylinder casings 80, 80′ and thereby the guide elements 18, 18′ are pressed outwards until the elements 18, 18′ rest with slight pretensioning against the guide tracks 19, 19′. The cylinder casings 80, 80′ are protected against ex­cessive pressures by means of the overflow valves 85, 85′.

[0040] The controlled non-return valves 86, 86′ will open when a particular set pressure is exceeded on the high pressure side of the system, i.e. the side to which the force on the guide mechanism 12 is directed, as a result of which the pressure is reduced on the low pressure side to the pressure set with the pressure limiting valve 87 or the said feed pressure at 83. As a result, the forces on the guide elements and guide track are limited and the wear on the guide systems 18, 19 thereby reduced.

[0041] The overflow valves 88 and 89 serve to absorb energy. If the force on the guide mechanism 12 rises too high, the pressure difference over one of the valves 88, 89 will become so great that this valve will overflow; the mechanism 12 will then displace while exerting a maximum force, and will destroy energy.

[0042] A displacement from the centre position of the guide mechanism 12 can be measured continuously, for ex­ample by constantly measuring the distance between this mechanism and the vessel, following which the deviation from the desired position is used to correct the position. The slide 90 and the pump unit 91 are provided for this. The pump unit 91 causes fluid to circulate under pressure in a closed circuit. If a deviation is measured in the position of the mechanism 12, the slide 90 is operated and fluid will flow in the desired direction to and from the cylinder casings 80 and thus correct the position.

[0043] The valves 92 and 93 are provided as a safety device to prevent fluid from being pumped away on one side while the other side is pressureless. The valves 94, 94′ supply feed fluid for the purpose of protecting pump 31.

Claims

1. Device for the connection of a spud guide to a vessel, in particular a dredger vessel, comprising a guide mechanism in which the spud is mounted essentially in a vertical position so that it can move in the lengthwise direction, said mechanism being supported by the vessel so that it can be moved relative to the ves­sel in the lengthwise direction thereof, while provision is made for at least one displacement device which is connected at one side to the mechanism and at the other side to the vessel, and retaining means for holding the side edges of the mechanism, during the displacement of the mechanism, in paths running essentially in the lengthwise direction of the vessel, characterized in that the guide mechanism is attached relative to the vessel by means of two hinged constructions, where each construction is hingedly connected at one end at a fixed point to the vessel and at the other end is hingedly connected to the mechanism, and at least one of these constructions can swing, in an essentially vertical plane running parallel to the lengthwise direction, from a vertical central position from and to the centre of the vessel.

2. Device according to Claim 1, characterized in that the hinged construction which can swing in the said vertical plane comprises at least one hinged bar-shaped element.

3. Device according to Claim 2, characterized in that the said hinged construction comprises at least two bar-shaped elements always running parallel to each other.

4. Device according to Claim 3, characterized in that the said bar-shaped elements are connected together to form a torsionally rigid box-shaped construction.

5. Device according to Claim 2-4, characterized in that the bar-shaped elements are formed by piston-­cylinder assemblies, in which means are present for con­trolling these piston-cylinder assemblies in conjunction with the displacement device in such a way that during the displacement of the guide mechanism its centre of gravity moves in a horizontal plane.

6. Device according to Claims 1-5, in which the displacement device comprises an operable piston-­cylinder assembly or similar device, characterized in that the second hinged construction is formed by at least one operable piston-cylinder assembly which ex­tends in a horizontal plane, in the same direction as and parallel to the displacement device, while means are present for ensuring synchronism of all these piston-­cylinder assemblies during sliding in and out thereof.

7. Device according to Claims 1-6, characterized in that the retaining means are formed by at least two hinged elongated elements which run parallel to each other and are swivellable, and which are hinged at one of their ends to the vessel and at the other end are hingedly connected to the guide mechanism, while these elements in their centre positions stand almost perpen­dicular to the vertical plane through the longitudinal axis of the vessel.

8. Device according to Claims 1-6, in which the displacement device comprises an operable piston-­cylinder assembly or similar device, characterized in that the retaining means are formed by at least one hinged elongated element which can be swung in a horizontal plane, and which is hingedly connected at one end to the vessel and hingedly connected at the other end to the guide mechanism, while this element in its centre position stands essentially perpendicular to the vertical plane through the longitudinal axis of the ves­sel, and by at least one operable piston-cylinder as­sembly which extends in a horizontal plane, in the same direction as and parallel to the displacement device, while means are present for ensuring synchronism of all these piston-cylinder assemblies during sliding in and out thereof.

9. Device according to Claims 7 or 8, characterized in that the said elements consist of bars.

10. Device according to Claims 7 or 8, charac­terized in that the said elements comprise piston-­cylinder assemblies, where means are present for controlling these piston-cylinder assemblies in conjunction with the displacement device in such a way that during the displacement of the guide mechanism this mechanism moves in a vertical plane.

11. Device according to Claims 1-6, characterized in that the retaining means are formed by at least one pair of guide elements which are provided on the guide mechanism on the side edges thereof running parallel to the lon­gitudinal direction of the vessel, and which are guided along a pair of guide elements disposed on the vessel, one of these pairs of guide elements consisting of guide tracks.

12. Device according to Claim 11, characterized in that the guide elements are pretensioned in the direc­tion of the guide tracks.

13. Device according to Claim 12, characterized in that the guide elements are each formed by an end part of the slidable part of a piston-cylinder assembly whose non-slidable part is connected to the guide mechanism, while a space inside the cylinder closed off by the pis­ton is connected to a source of a pressure fluid.

14. Device according to Claim 13, characterized in that the said closed-off spaces inside the cylinders are connected to each other by means of controlled non-­return valves which can open if a particular pressure is exceeded in one of the spaces.

15. Device according to Claims 13 or 14, charac­terized in that a measuring instrument is provided for con­tinuous measurement of the position in the transverse direction of the guide mechanism relative to the vessel, and a device which in response to a measured deviation from the desired position of the guide mechanism can take additional pressure fluid to or discharge it from the enclosed space within the cylinder, as a result of which the above-mentioned deviation is corrected.

Drawing