Abstract
The invention relates to an excavation installation, comprising excavation means (1,2) in which more than one excavation means (1,2) is positioned offset next to another in a row (34,35) of excavation means (1,2). In use the excavation installation may excavate a horizontal bottom of water (102) in a direction that is perpendicular to the direction of the rows (34,35) of excavation means (1,2). The excavation means (1,2) are connected to a rigid construction, in which the rigid construction (3) is positioned vertically above the excavation means (1,2). The rigid construction (3) is resiliency connected to a bridge (5) that is positioned vertically above the rigid construction (3) and connected by means of actuators (7).
Claims
1. Excavation installation, comprising excavation means in which more than one excavation means is positioned next to another in a row of excavation means, in which multiples of such rows of excavation means are positioned behind one another, and in which the excavation means of a particular row are offset with regard to the excavation means of an adjacent row, such that in use the excavation installation may excavate a horizontal bottom of water in a direction that is perpendicular to the direction of the rows of excavation means, in which the excavation means are connected to a rigid construction positioned vertically above the excavation means by means of a resilient connection in order to absorb the vertical impact loads on the excavation means and to transmit these impacts to the rigid construction, and in which the rigid construction is resiliently connected to a bridge that is positioned vertically above the rigid construction, in which the bridge is connected to the rigid construction by means of linear actuators, in such a way that, during use, the linear actuators exert an adjustable and vertical pressing force onto the excavation means.
2. Excavation installation according to claim 1, in which the bridge comprises a box construction.
3. Excavation installation according to claim 1, in which the bridge is movable along parallel framework beams that are positioned in a longitudinal direction, that together with two transverse beams form a framework.
4. Excavation installation according to claim 3, in which the movable bridge is connected to the two transverse beams by means of winch cables, in which the winch cables permit a longitudinal movement of the movable bridge along the two parallel positioned framework beams.
5. Excavation installation according to claim 3, in which the movable bridge at each of its extremities comprises a guiding tube, in which through the opening of each of these tubes passes one of the two parallel positioned framework beams, such that the movable bridge can move in the longitudinal direction of the framework beams.
6. Excavation installation according to claim 5, in which the guiding tubes at their inner sides comprise resilient wheel sets and/or resilient rollers that, during use, can give the framework beams six kinematic degrees of freedom relative to the guiding tube.
7. Excavation installation according to claim 3, in which the corners of the framework comprise means for anchoring the rectangular frame to the water bottom.
8. Excavation installation according to claim 7, in which the corners of the rectangular frame comprise a supporting means.
9. Excavation installation according to claim 3, comprising one or more means for moving the rectangular frame.
10. Excavation installation according to claim 3, in which the extremities of the framework beams and the extremities of the transverse beams are resiliently and by means of a ball joint connected to a corner in each of the four corners of the rectangular frame, in which the means to anchor the rectangular frame are resiliently connected to the corners, and in which the optional supporting means are resiliently connected to the corners.
11. Excavation installation according to claim 3, in which the excavation installation is submersible.
12. Excavation installation according to claim 11, in which the framework beams, the transverse beams, the corners and/or the movable bridge comprise compartments that can be filled with gas and/or water in order to float or submerse the excavation installation.
13. Excavation installation according to claim 1, in which the bridge is resiliently connected to a floating vessel by means of multiple linear actuators that extend from the floating vessel in a downward direction towards the bridge, and in which the ends of the actuators are connected to the bridge and to the floating vessel by means of ball joints.
14. Excavation installation according to claim 1, in which the excavation means are positioned in two or three rows behind one another.
15. Excavation installation according to claim 1, in which a row with excavation means comprises 3 to 30 excavation means.
16. Excavation installation according to claim 1, in which the excavation means are excavation wheels, drum cutters, drag heads, cutters and/or ploughs.
17. Excavation installation according to claim 1, in which the excavation means comprise wheels that rotate around a substantially horizontal axis, in which the excavation means are positioned in pairs in a row, and in which the rotating wheel of the first excavation means of a pair, during use, rotates in a direction that is contrary to the rotating direction of the rotating wheel of the second excavation means of the pair.
18. Excavation installation according to claim 17, in which the rotating wheel of the first excavation means of a pair is an overcutting wheel and the rotating wheel of the second excavation means of the pair is an undercutting wheel.
19. Excavation installation according to claim 17, in which the excavation means are connected to a rigid construction in pairs, in which the rigid construction is positioned vertically above the excavation means and is connected by means of a resilient connection to the pairs of excavation means in order to absorb the impact loads and the continuously varying and fluctuating loads on the pair of excavation means and to transmit these impact loads to the rigid construction.
20. Excavation installation according to claim 1, in which each of the excavation means is connected to a suction tube for discharging the mixture of soil and water that has been excavated by the excavation means.
21-26. (canceled)
Description
[0041] The excavation installation shall now be described in further detail, referring to the attached drawings.
[0042] FIG. 1 shows a side view of a possible embodiment of the excavation installation according to the invention, with two rows (34,35) of excavation wheels as excavation means (1, 2). The excavation wheels can optionally comprise teeth. The excavation means (1, 2) are connected to a lattice construction (3) as the rigid construction by means of a resilient construction comprising columns (43) resiliently connected to rigid lattice construction (3) by means of springs (45) as can be seen in greater detail in FIG. 5. The lattice construction (3) is positioned vertically above the excavation means (1, 2). The excavation means (1, 2) are connected to a suction tube (4) that is used to discharge the mixture of soil and water that is being excavated by the excavation means (1, 2). The lattice construction (3) is connected to a boxlike bridge (5). The boxlike bridge (5) is positioned vertically above the lattice construction (3) and connected by means of columns (6) and hydraulic cylinders (7).
[0043] The hydraulic cylinders (7) and the thereto attached columns (6) permit a vertical displacement of the lattice construction (3). Therefore, the columns (6) are connected at the bottom side to the lattice construction (3), and the columns (6) are vertically displaceable relative to the boxlike bridge (5) by guiding them through openings (8) in the bridge (5). The hydraulic cylinders (7) are fixed to the bridge (5). The upper end of the column (6) is connected to the upper ends of the hydraulic cylinders (7) by means of a spring construction (10). The spring construction (10) is interesting for absorbing possible impact loads on the excavation means (1, 2). This spring construction (10) can be seen in further detail in FIG. 1a, and comprises an upper plate (11) that is connected to the upper end of the column (6), and also comprises two springs (12) that are connected to the upper ends of hydraulic cylinders (7). The hydraulic cylinders (7) are at their lower parts connected to the boxlike bridge (5). By means of the hydraulic cylinders (7) the rows of excavation means (1, 2) and the thereto connected lattice construction (3) can be vertically moved as can be seen in FIGS. 5a and 5b. The length of the hydraulic cylinders (7) is chosen in such a way that the desired vertical movement of the excavation means (1, 2) and the lattice construction (3) is feasible.
[0044] The construction shown in FIG. 1 has the advantage that lateral forces and bending moments, initiated by the forces originating from the soil on the excavation means (1, 2), are being transferred via the lattice construction (3) and the thereto connected vertical columns (6) to the bridge (5) that in this case has a boxlike construction. Because the bending stiffness of the columns (6) is much larger than the bending stiffness of the hydraulic cylinder rods (7), the lateral forces and moments shall be absorbed more or less completely by the columns (6).
[0045] FIG. 2 shows the construction of FIG. 1 in combination with a submersible and rectangular framework (15). The framework (15) consists of two parallel framework beams (16,17) positioned in the longitudinal direction and two transverse beams (18, 19). The bridge (5) is movably connected to the framework (15) by means of a bridge part (22) comprising two guiding tubes (20, 21) as well as a partially shielded space (22a) in which the excavation means (1, 2) and the lattice construction (3) can move vertically. The bridge part (22) is connected to the two transverse beams (18, 19) by means of winch cables (23) that permit a horizontal movement of the bridge part (22) and thus of the bridge (5) along the two parallel framework beams (16, 17). The framework beams (16, 17) pass through the guiding tubes (20, 21), as can be seen in further detail in FIGS. 7a-c. By means of four hydraulic cylinders (5b) the bridge (5) can be moved vertically upwards relative to the bridge part (22). By doing this the excavation wheels can be moved upwards, for example for carrying out maintenance work.
[0046] FIG. 2 also shows that the four corners (24-27) of the framework (15) comprise screw anchors (33a) for anchoring the framework (15) to the bottom of the water. Each corner (24, 25, 26, 27) also comprises a sled (33) as supporting means, as well as thrusters (28) that can be used to help move the framework (15). The screw anchors (33a) are driven by an engine (not represented), and are connected to the framework (15) by means of a column (29). The column (29) is at its upper extremity connected to hydraulic cylinders (30) by means of a plate (31). The column (29) passes movably through an opening (32) in the corner (24). Hydraulic cylinders (30) are at their lower part connected to the corner (24).
[0047] FIG. 3 shows the excavation installation of FIG. 2, seen from the bottom upwards. The reference numbers refer to the same parts as in FIG. 2. The two rows (34, 35) of excavation means (1, 2) each consist of nine drum cutters. The two rows (34, 35) are positioned adjacently. In other words the rows (34, 35) are parallel and positioned next to one another. One can see that the nine excavation wheels of a row (34) of excavation means are offset relative to the nine excavation wheels of an adjacent row (35). By doing this a continuous surface of the bottom of water will be excavated during use when the bridge (5) is moved by means of winches (23) from a position at the transverse beam (18) in the direction of the transverse beam (19) (or vice versa).
[0048] FIG. 4 shows the bridge (5) of FIG. 1. The reference numbers refer to the same parts as in FIG. 1. This figure shows how the gaps between the excavation means (1) in the row (34) are filled up with the offset excavation means (2) of the adjacent row (35). A continuous row of drum cutters can be seen, formed by the row (34) and by parts of the row (35). This figure also shows how the different suction tubes (36) are integrated into the lattice construction (3) and connected to the lattice construction (3). The suction tubes (36) are resiliently connected to the individual excavation means (1). The suction tubes (36) converge in suction tubes (4) then in turn converge in a central suction tube (37a). These suction tubes (4 and/or 36) are preferably completely or partially flexible, such that, when the rows (34, 35) of excavation means (1, 2) and the lattice construction (3) are hoisted up to the bridge (5) or are being lowered, the suction tubes (4) can be shortened or extended. This can be done by the suction tubes (4 and 36) comprising two telescopically sliding parts, in such a way that the suction tubes are in possession of an adjustable length . An alternative is to have the suction tubes comprise a flexible part, for example a part with a U-form, that can absorb the vertical displacement of the suction tube.
[0049] FIG. 4 also shows a freestanding cutter wheel (34a, 35a) at both extremities of the rows (34, 35), meant to avoid the excavation installation seizing up in its own excavated trench. Moreover, there are two horizontally extendable excavation means (36a) at the top side of the lattice construction (3), which can be moved outwardly and inwardly by means of hydraulic cylinders (36b), in order to realise a plane downwardly sloping surface.
[0050] The mixture of water and solid material that is discharged via the suction tube can be transported directly to the water surface or via a tube, for example to be collected in a vessel. The mixture can also be transported to a storage tank that is positioned on the bottom of water. The thus stored mixture can then be transported from this tank or possibly in this tank to the surface.
[0051] FIG. 5a shows how the excavation wheel (38) is resiliently connected to the lattice construction (3) and also shows the integrated suction tube (36). FIG. 5b is a cross-section along line A-A of FIG. 5a. As each excavation wheel (38) is resiliently connected to the complete lattice construction (3) it is possible that the excavation wheels (38) can move independently of one another in a vertical direction relative to the lattice construction (3). FIG. 5b is a cross-section through the excavation wheel (38) from FIG. 5a. The suction tube (36) comprises a part (37) with a smaller diameter, a part that extends right up to the excavation wheel (38). The part (37) of the suction tube can move vertically in the opening of the suction tube (36). The part (37) of the suction tube passes through and is connected to a boxlike construction (39). A hood (40) enhances the flow of the soil/water mixture, limits the pressure losses, and can be controlled and turned at the required angle by means of hydraulic cylinders (41) that comprise biasing springs (42). The construction is such that the hood (40) can be turned in the direction that is opposite to the direction of movement of the row of excavation means. In other words, this is when the bridge arrives at one side of the frame and subsequently returns to the opposite transverse beam. Moreover, a plunger (47) is foreseen that is used to adjust the excavation depth of the excavation wheels (38).
[0052] On top of the boxlike construction (39) four columns (43) are foreseen per excavation wheel (38) that extend upwardly. The columns (43) pass movably through a tube like opening (44) in the lattice construction (3). Above and below the tube like opening (44) a column (43), comprising springs (45), is clamped between flanges (46). By removing the upper flanges (46) that are positioned above the lattice construction (3) and that are connected to the columns (43), the excavation wheel (38), the part (37) of the suction tube, the box like construction (39), and the columns (43) can be easily dismantled, for example to be replaced by another type of excavation means, such as the already mentioned draghead, cutter, drum cutter, or plough.
[0053] FIG. 5c shows a cross-section of a possible drive of a rotating excavation wheel or drum cutter (1), in which the excavation wheel is driven by two driving shafts (139) that are suspended on both extremities by means of bearings (133) and are connected to synchronously rotating engines (131), in which the engines (131) as well as the bearings (133) are fixed to the water permeable box like construction (39) by means of plate elements (130). The wheels (1) can be replaced in a very simple way by loosening the bolts of the fixed flanged connections (136, 135). This way, the engine and/or the bearings do not need to be replaced. A problem with this construction is that the relatively large space remains present between the excavation wheels (1). Thanks to the configuration with the offset, as can be seen in FIG. 6b, this problem is solved and the excavation means can be assembled in such a way as to allow it to excavate a rectangular surface of the bottom of water. The part of the bottom of water that is not excavated by row 34 shall then be excavated by row 35.
[0054] FIG. 6a shows a cluster of four excavation wheels (50), in which two excavation wheels (51, 52) are connected as a pair (50a, 50b) to a water permeable box like construction (53), whereas the two remaining excavation wheels (54, 55) are connected as a pair to a separate water permeable box like construction (56) via plates (58). For wheel (55) a motor (57) is shown. The excavation wheels are in possession of a horizontal rotating axis. The boxlike constructions (53, 56) are in turn connected to the lattice construction (3) via a resilient connection (43) in order to absorb the impact loads and the continuously varying and fluctuating loads on the pair of excavation means and to transmit these impact loads to the rigid construction (3). Such a connection is comparable to those of FIGS. 1-5. Per pair one of the excavation wheels is overcutting, whereas the other excavation wheel is undercutting with angular velocities in opposite directions but preferably with the same magnitude. With the exception of the over- and undercutting form of the cutting elements, the geometry and the positions of the cutting elements of the excavation wheels (51, 52, 54, 55) are preferably identical. The velocity V is the velocity with which the row of excavation wheels is moved and is directed in the same longitudinal x-direction for the whole lattice construction and thus for all excavation wheels. The resulting tangential forces (soil reaction), respectively Ft1 and Ft4, are supposed to be substantially identical with regard to magnitude and direction. In the same way the tangential forces Ft2 and Ft3 are supposed to be substantially identical with regard to magnitude and direction. All the resulting radial forces (soil reaction), respectively Fr1, Fr2, Fr3, and Fr4, are supposed to be substantially identical with regard to magnitude and direction.
[0055] The resulting forces and moments that are being exerted onto the lattice construction (3) are as follows: [0056] the moment in the XZ-plane: Mxz=Ft1*Y0=Ft2*Y0, in which Y0 is the distance in the Y-direction from the centrelines of the respective excavation wheels 51, 52 (or between the excavation wheels 54 and 55) [0057] the resulting force in the radial direction, Fr=2*Fr1=2*Fr2=2*Fr3=2*Fr4 [0058] the resulting bending moment around the Y-axis: My=(Fr1+Fr2+Fr3+Fr4)*Zgv=4*Fr1*Zgv, in which Zgv is the distance in Z-direction from the centreline in Y-direction of the excavation wheels (51,52,54 and 55) and the centreline of the bottom part of the lattice construction (3).
[0059] The resulting forces and moments that are being exerted onto the lattice construction (3) are identical with regard to magnitude and direction, with the exception of the moment Mxz in the XZ-plane, which works in opposite directions via the boxlike constructions (53, 56).
[0060] The resulting bending moment that is exerted onto the associated boxlike constructions via the excavation wheels by the resulting soil reaction Ft1=Ft2=Ft3=Ft4 is reduced with regard to the order of magnitude to a value of My=Ft1*Zgd*sin =Ft4*Zgd* sin , and the oppositely oriented bending moments My=Ft2*Zgd*sin =Ft3*Zgd*sin (see FIG. 6). The distance Zgd is equal to the vertical distance between the centre line of the excavation wheels (51, 52, 54, 55) and the centre line of the boxlike constructions (53, 56). The angle is equal to the angle between the tangential soil reaction force Ft_1 and the vertical.
[0061] The resulting bending moment on the lattice construction due to the tangential soil reaction forces (Ft1, Ft2, Ft3, Ft4) is negligibly small. The resulting horizontal force upon the lattice construction (3) and upon the bridge part (22) that has to be exerted onto the bridge part (22) by the winch cables (23) due to the forces on the excavation wheels is equal to Fx=4*Fr1* sin 60 , which represents a relatively small value.
[0062] FIG. 6b shows a pair of excavation means of row (34), as well as a pair of excavation means of row (35), seen from beneath. The reference numbers have the same meaning as in the foregoing figures. The beam (3e) is a protective construction. The figure shows how parts of the bottom of water that are situated between the excavation means of row (34), and therefore cannot be excavated efficiently by the row (34), can then be excavated by the excavation means of the adjacent row (35).
[0063] FIG. 7a shows a guiding tube (20) of the bridge part (22) through which the framework beam (16) passes, as can be seen in FIG. 2. In the figure the framework beam (16) is represented somewhat withdrawn, in such a way that the inner side of the guiding tube (20) is visible. The inner side of the guiding tube (20) comprises resilient wheel sets (60) that permit a displacement of the bridge part (22) along the framework beam (16) in the longitudinal direction. The wheel sets (60, 64) are implemented in such a way that they also, during use, permit six kinematic degrees of freedom from the guiding tube (20) in the radial, tangential, and rotational (around the vertical axis) direction relative to the framework beam (16). Such a degree of freedom for the guiding tube (20) with regard to the framework beam (16) is important and avoids clamping forces when the bridge part (22) that can be seen in FIG. 2 is moved along the framework beams (18, 19) by the winches (23). The framework beam (16) is composed of three parallel tubes (61) that form a triangular cross-section and a rigid entity. The outside of these combined tubes (61) comprises a flat plate (62) that comprises a rail (59) on which the wheel sets (60) can roll. The three tubes (61) and the flat plate (62) together form a cross-section that resembles the triangle of the framework beams (16).
[0064] FIG. 7b shows a cross-section of the framework beam (16) and of the guiding tube (20), in which the interaction between the guiding tracks/rails (59) that are uniformly distributed along the circumference of the framework beam (16) and connected thereto, and the resilient wheel sets (60, 64) can be seen. The flat plates on which the point load of the guiding wheels is being exerted can be strengthened by using radial plate elements (59a) or tubes (59b) that fit in the open spaces of the circumference of the framework beam (16) and the combined tubes (61).
[0065] FIG. 7c shows a cross-section of the framework beam (16) and of the guiding tube (20). The resilient wheel sets are in this case resilient rollers (69a) that are resiliently suspended from a wheelset, as can be seen from FIG. 8c.
[0066] FIG. 8a shows the wheel sets (60, 64) of FIG. 7 in further detail. The wheelset (60) comprises a U-form baseplate (62). The baseplate (62) is fixed by its bottom side to the inner side of the guiding tube (20), in such a way that the raised extremities of the U-form baseplate are directed towards the inner sides of the guiding tube (20). Between the raised extremities of the U-form baseplate (62) a system (63) with four wheels is resiliently clamped by means of springs (65). The system (63) with four wheels in turn forms the basis of a wheelset (64) of which the wheels (67) are perpendicular to the direction of the wheels of the system (63) with four wheels. The wheelset (64) of which a wheel (67) is part, is fixed onto the stationary axes (66) of the system (63) with four wheels, and is, thanks to the vertical springs (65a) of the wheelset (64), capable of absorbing a movement in the radial direction. The wheel (67) of the wheelset (64) makes contact with the guiding rails (59) that are fixed to the outside of the framework beam (16), as can be seen from FIG. 7a, and permits, during use, a passage in the X-direction. Thanks to the resilient suspension of the system with four wheels upon which the wheelset (64) is positioned, the wheelset (64) can carry out a small displacement in a substantially tangential direction (Y-direction in FIG. 8a) relative to the inner side of the guiding tube (20) on which the wheelset (60, 64) is mounted.
[0067] FIG. 8b shows in further detail how the wheelset (64) from FIG. 8a can undergo an angular displacement in the radial direction, in such a way that the forces on the wheels (67) and on the guiding rails (59) of the framework beam (16) are strongly reduced.
[0068] FIG. 8c shows a roller (69a) that is resiliently connected to two wheel sets (60) by means of springs (65a), as discussed with regard to FIG. 8a.
[0069] FIG. 9 schematically shows how the extremities of the framework beams (16, 17) and the extremities of the transverse beams (18, 19) are resiliently connected to a corner in each of the four corners (24,25,26,27) of the rectangular frame (15). The sleds (33) are resiliently (73) connected to the corners (24,25,26,27), in such a way that, when the rectangular frame (15) is anchored to the bottom of water, the rectangular frame (15) comprises a resilient geometry with six kinematic degrees of freedom. The resilient connection of the framework beams and the transverse beams with the corners is realised by means of a ball joint (70), a connector (71), and a spring (72). The ball joints (70) permit limited angular displacements (2, 2, 2) of the framework beams (16, 17) and of the transverse beams (18, 19) relative to the corners (24,25,26,27). The displacements of the corners (24,25,26,27) in the horizontal XY-plane are made possible by compressing or extending spring elements (72) and by the angular displacements of the ball joints (70). In order to permit the sleds (33) to follow the contours of the bottom of water properly, the sleds have kinematic degrees of freedom (x, y, z, , , ) that can be realised by means of a spring (73), a hydraulic cylinder (74), ball joints (70), and the springs (72) of the corners (24, 25, 26, 27). Because of the kinematic degrees of freedom (x, y, z, , , ) of the sleds (33) the sleds are capable of, in case of horizontal displacements of the framework (15), following the contours of the bottom of water properly. Moreover, the moments at the corners (24, 25, 26, 27) will be strongly reduced by the flexibility of the framework (15). The displacements (Y7, Z7) and the angular displacements (7, 7, 7) of the bridge part (22) are realised by the translating and rotating resilient wheel sets (60, 64) that can be seen in FIG. 7a-c, and a longitudinal displacement (X7) by means of the winches (23). The applicant has found that, when such a framework (15) is anchored to the bottom of water, a very rigid and form stable framework is obtained that permits an unhindered displacement of the bridge part (22) along the framework beams (16, 17).
[0070] FIG. 10-13 shows a possible embodiment of a bridge (84). In order to realise a large vertical displacement of the rows of excavation means relative to the framework (15), the rows of excavation means (34, 35), the lattice construction (3), and the boxlike construction (5) are part of a telescopic construction. FIG. 10 shows this construction, in which the rows (34, 35) are completely lifted by means of the winch cables (80), the hydraulic cylinders (81), the hydraulic cylinders (82), and the hydraulic cylinders (7). The winch cables (80) can move the lattice construction (3) and the therewith connected rows of excavation means (34, 35) in a vertical direction relative to a bridge part (84). The winch cables (80) also provide a rotational stability for the boxlike construction (5) around the axis that passes through the boxlike construction, from the framework beam (16) to the framework beam (17) (see FIGS. 1 and 2).
[0071] The bridge part (84) is a modified bridge part (22) and also comprises guiding tubes (not represented) to be able to move along the framework beams. The bridge part (84) comprises hydraulic cylinders (81) that can vertically move a boxlike construction (85). The boxlike construction (85) is open at its top side and at its bottom side. The boxlike construction (5) comprises four upright walls (86) that in turn comprise resilient guiding wheels (87) for guiding the inner wall of the open boxlike construction (85). The inner walls (88) of the rectangular opening in the bridge part (84) also comprise resilient guiding wheels (89) for guiding the external wall of the open boxlike construction (85).
[0072] FIG. 11 shows the open boxlike construction (85), which has been moved downwardly by retracting the hydraulic cylinders (81).
[0073] FIG. 12 shows the boxlike construction (5), which has been moved downwardly by extending the hydraulic cylinders (82).
[0074] FIG. 13 shows the lattice construction (3) and the therewith connected rows (34, 35) of excavation means that have been moved downwardly by retracting the hydraulic cylinders (7). Such a bridge, as can be found in FIGS. 10-13, can be part of a submersible framework (15) as a movable bridge part. The framework beams and the transverse beams can be filled with air in order to move the framework (15) from the bottom of water to the water surface.
[0075] FIGS. 14a-d show an excavation installation according to the invention in which the bridge (5) is resiliently connected to a floating vessel (90) by means of four hydraulic cylinders (91), at the top side comprising springs that extend downwardly from the floating vessel (90) to the bridge (5). FIGS. 14a-d show a single row (34) of excavation means. The excavation means shown in FIGS. 14a-b are trailing dredging head (34c). The bridge (5) can also be a telescopic bridge, as can be seen in FIGS. 10-13. Each of the four hydraulic cylinders (91) is at the top side connected to the vessel (90) by means of a ball joint (92), and at the bottom side connected to the bridge (5) by means of a ball joint (93). A lattice framework (100) is connected to the vessel (90).
[0076] The ball joints (92) can, via the lattice framework (100) by means of a cylinder (101), move in a parallel way to the direction of the row of excavation means. Thus, the direction of the cylinder (91) relative to the bridge (5) can be kept substantially in a vertical position when the floating vessel rolls due to swell. The length of the cylinders (101 and 91) shall be adjusted in response to or anticipation of the movement of the floating vessel in such a way that the excavation means can be pressed onto the bottom of water with a substantially constant vertical force. The spring at the top of the cylinder (91) is preferably in possession of a smaller spring constant than that of the hydraulic cylinder. Using this construction, one obtains a complete decoupling of the movements of the floating vessel (90) from the bridge (5), but the necessary vertical pressing force on the excavation means is maintained. The other extremity of hydraulic cylinders (91) is connected to the bridge (5) by means of ball joints (93). By means of the cylinders (91) the aforementioned bridge (5), the therein integrated hydraulic cylinders (7), the columns (6), and one or two rows of excavation means (34 and/or 35) can be lifted off the bottom of water (102) or positioned on the bottom of water (102). The water surface (103) is also drawn in the figures. The bridge (5) comprises four upright walls (104) that, using multiple springs (107, 109) and roll bearings (105, 108), are enclosed along the walls in an opening (106) of the floating vessel (90). Thanks to this resilient suspension of the bridge (5) small rolling and pitching movements of the vessel (90) due to the swell can be absorbed.
[0077] FIGS. 14e-f show an excavation installation according to the invention in which the bridge (5) is resiliently connected to a floating vessel (90) by means of four hydraulic cylinders (91), from which each hydraulic cylinder (91) is connected to a horizontal plate (91b), which is connected to three hydraulic cylinders (91a). For decoupling the motions of the vessel (90) and the bridge (5) the three cylinders (91b) at each corner of the bridge (5) are connected to both the horizontal plates (91b) and the portal of the vessel (100a) by means of ball joints (93a). The three hydraulic cylinders (91a) preferably will be in a vertical direction and will be controlled in such a way that the position of the horizontal plate (91b) in the horizontal x-y plane, within a narrow deviation, is equal to the position in the x-y plane of the bottom of the hydraulic cylinder (91), which is connected to the bridge (5). The hydraulic cylinders (91) are connected to the horizontal plates (91b) and the bridge (5) by means of ball joints (93b). All hydraulic cylinders (91a) and the hydraulic cylinders (91) should be able to withstand the resulting vertical force initiated by the excavating means (1,2) in rows (34,35) and the vessel (90) motions related to the bridge (5) position. The propulsion propellers (145) of the vessel (90) are synchronized with the propulsion propellers (146) connected to the lattice (3) in such a way that the velocity of the vessel (90) equals the velocity of the lattice (3). Connected to both sides of the bridge (5) are excavating means (34a, 35a), which are connected to lattices (3a) and can be displaced vertically using columns (6a) which are connected to hydraulic cylinders (7a). The function of both excavating means (34a, 35a) is to stabilize the excavated trench on both sides in transverse y-direction. Such means (34a,35a) may also be used in combination with a frame (15) as in FIG. 2.
[0078] The suction of the soil/water mixture of the excavation means (1,2) in rows (34,35), especially in shallow waters, is realized using centrifugal pumps (144) which are connected to the lattice (3). Also the flow of the soil/water mixture of side excavation means (34a, 35a) is realized using centrifugal pumps (not presented in the figure), which are connected to the lattices (34a) and are connected to a vertical displaceable suction tube (4a), in a way similar to the suction tubes (4) of the excavation means (1,2).
[0079] FIG. 15 shows how the submersible and rectangular framework (15) of FIG. 2 is anchored by means of screw anchors (33a) to the bottom of water (102) and at a large depth below the water surface (103). In FIG. 15a one can see how the bridge part (22) is moved from right to left by means of winch cables (23). In doing this, the rows (34, 35) of excavation means create a trench (104). In FIG. 15b one sees the bridge part (22) in its uttermost left position after which, from a stationary position, the excavation means are given a small vertical initial movement by the force of the hydraulic cylinders on the lattice construction (3), after which the direction is reversed and the excavation means, the hydraulic cylinders, the columns, and the bridge part (22) are moved to the right by means of the winch cables (23). The next layer of the bottom of water is then excavated and a deeper trench (104) is created, as can be seen in FIG. 15c. The dashed lines in FIG. 15 indicate which compartments are filled with water, in which the fine dashed lines in the framework beam (16) indicate that air is present in the two upper tubes (61) and water in the bottom tube (16).
[0080] FIG. 16 shows how the rectangular framework (15) from FIG. 2 can be connected to a floating vessel (110) by means of a framework (111) and four cylinders (112). The four cylinders are connected to the corners (24, 25, 26, 27) and to the framework (111) in the same way as can be seen in FIG. 2. In the figure the anchors and the supporting means are represented. It should be absolutely clear that these anchors and supporting means in this embodiment have no function. However, it is not impossible for the framework (15) to be alternatively used in the embodiment according to FIG. 16 and in the embodiment according to FIG. 15. By decoupling the cylinders (112) in the corners (24, 25, 26, 27) the framework can be easily submersed and moved away and positioned under the floating vessel (110).
[0081] FIG. 16 also shows two floating barges (114) in which the excavated soil can be collected. By means of pipes and tubing (113) the excavated soil can be transported to these barges by means of pumps (not represented) in the framework (15) or fixed to the lattice construction (3).
[0082] FIG. 17 shows an excavation wheel (1) that comprises a bottom compensator that is made up of two spherical hoods (121) that are pivotably connected to the rotation axis of the wheel (1). If the excavation wheel encounters an obstacle on the bottom of water, as is represented in FIG. 17 by means of the force Fg, the spherical configuration of the hood (121) shall impart an upwardly directed force onto the excavation wheel. Part of this force will be absorbed by springs (120) with which the hood at its upper end is connected to the box like construction (39).
[0083] FIG. 18a shows how an excavation wheel (1) is connected to the lattice construction (3), rotatable around the axis in the transverse direction. For this, the lattice construction (3) comprises a rigid part (3a) and a pivotable part (3b). The pivotable part (3b) is in turn connected to the excavation wheel (38), as can also be seen in FIG. 5a. The rotatable axis (141) comprises rigid torsion springs (140).
[0084] FIG. 18b shows how an excavation wheel (38) is connected to the lattice construction (3) by means of a cardan joint. The excavation wheel is now rotatable around an axis (141) in the transverse direction, and also rotatable around an axis (143) in the longitudinal direction, and is connected to the lattice construction (3). The axes (141, 143) comprise rigid torsion springs (respectively 140 and 142), in such a way that the pivotable parts (3b and 3c) of the lattice construction are returned to their horizontal position, for example after an impact on the excavation wheel (1).
