Steering arm for a floating vessel

Abstract

A steering arm for a floating vessel includes an arm with a first end rotatably connected to the vessel and a second end; a connection part connected to the second end of the arm, the connection part comprising a steering mechanism; drive means connected to the connection part; a second arm structure extending between the vessel and the connection part for controlling the position and / or orientation of the connection part; and a movement system for controlling the position of the arm.

Description

[0001] STEERING ARM FOR A FLOATING VESSEL

[0002] BACKGROUND

[0003] Wet salt harvesting typically involves a floating vessel which is propelled through a pond by tracks mounted to telescopic legs, usually four legs with a track on the end of each leg. A typical prior art wet salt harvesting vessel 1 is shown in Fig. 1. Each leg 2 uses a track suspension box which slides up and down rails, and a telescopic leg slides up and down in the track suspension box. A cylinder moves the box, and a second cylinder extends the leg. If needed (e.g., a track is starting to slip), extra force can be added to the tracks by means of a spring system mounted at the top of each suspension leg, allowing for a doubling of the force on the track and a proportionate increase in traction.

[0004] In operation, the hull of the vessel typically floats in the brine, and the tracks rest on their own weight at the bottom of the pond. The harvesters typically work in a pattern of long straight lanes where an auger or other removal device 3 scrapes the top layer of salt off the bottom of the pond, first sending it to a suction mouth and then through a pipeline to a processing plant. At the end of one lane in the pond, the vessel makes a 180 degree turn. The turn is made by lifting two tracks off the bottom (e.g., the front tracks or back tracks); blocking one track by cutting off the hydraulic supply, and then skid steering with the last track. This results in a relatively slow turn, with limited force to make the turn. Additionally, this creates substantial friction between the floor of the salt basin and the track used for turning, which can cause damage to the floor of the basin and potential leakage.

[0005] SUMMARY

[0006] According to a first aspect, a steering arm for a floating vessel comprises an arm with a first end rotatably connected to the vessel and a second end; a connection part connected to the second end of the arm, the connection part comprising a steering mechanism; drive means connected to the connection part; a second arm structure extending between the vessel and the connection part for controlling the position and / or orientation of the connection part; and a movement system for controlling the position of the arm. Such a steering arm provides a simple yet effective method for propelling and controlling the movement of a floating vessel, which is particularly useful in systems directed toward harvesting minerals or other deposits from a seabed. The movement system and second arm structure provide for effective control of the positioning of the arm from a lifted to a use position (and vice versa) while maintaining the proper orientation of the drive means and with minimal parts above deck in use, providing for a safe, light and aesthetically pleasing system.

[0007] According to an embodiment, the second arm structure comprises a parallel arm arrangement with the arm. Optionally, the parallel arm arrangement comprises a first parallel arm, a pivot piece and a second parallel arm. The first parallel arm can connect between the vessel and the pivot piece, and the second parallel arm can connect between the connection part and the pivot piece. The pivot piece can also rotatingly connect to the arm, for example, at a central bend. Such a parallel arm arrangement provides a simple yet effective way of ensuring the connection part and therefore steering mechanism to remain at the proper orientation (e.g., with a substantially vertical axis) for proper placement and control of the drive means.

[0008] According to an embodiment, the movement system extends between the vessel and the arm for moving the steering arm between a use position and a lifted (e.g., nonuse) position. The connections can be rotatable or pivoting connections. Such a movement system provides a simple connection between the vessel and arm for safely and controllably moving the steering arm between a use position where the drive means contact another surface (e.g., lower surface of the pond or sea) and lifted position (fully or partially lifted), allowing for simple control and effective steering and propelling of the vessel through the steering arm.

[0009] According to an embodiment, the movement system is a hydraulic system, for example one or more hydraulic cylinders. Optionally, the hydraulic system further comprises pressure means for applying additional pressure to the drive means when in a use position. In some embodiments, the pressure means comprise one or more springs and / or one or more hydraulic accumulators. Optionally, the springs extend from the hydraulic or other movement system and connect to the second arm structure. Such springs or other pressure means can help to provide additional force on the drive means, thereby helping to provide additional traction when needed. Such an ability to provide additional force and therefore traction is useful as the use of steering arms can result in a system which is lighter in weight than prior art steering legs (and associated systems) and thus have less natural (gravitational) force acting on the drive means for providing and maintaining traction. Thus, the ability to provide additional traction through other pressure means is useful for propulsion, traction and proper movement.

[0010] According to an embodiment, the drive means is a track, wheels and / or an Archimedes screw. Optionally, the connection part connects to the drive means with a pivoting connection. Such drive means can provide for controllable movement of the vessel by the steering arm and allow for turning, even very sharply, as needed when harvesting in a grid-like pattern. Connecting the drive means with a pivoting connection helps to allow for steering with minimal disturbing of the bed and any minerals or other deposits on the top of the bed where the drive means connect. Alternatively, the connection could be stiff (not pivotal). Such a stiff connection could allow for intentional tilting or providing additional pressure on the front or the back of the drive means as desired. Further this is useful for creating more contact pressure over the entire length of the drive means (instead of the typical higher pressure at the back of the track when driving torque is applied).

[0011] According to an embodiment, the arm has a bent configuration from the first end to the second end, for example a bend of about 90 degrees at a center position. Such a configuration provides for an arm easily able to connect the drive means to a liquid body bed while taking up minimal space in the vessel.

[0012] According to an embodiment, the steering mechanism is one or more of a slew drive, cylinder and spindle drive. Optionally, the steering mechanism is a slew drive with an axis of rotation substantially vertical. Such a steering mechanism allows for full steering movements, providing for using all arms (and drive means) simultaneously during operations, and even during turning. This can result in sharper turn radiuses than past systems, faster turning, less load on the steering and suspension and less damage to the seabed during a turn.

[0013] According to a further aspect, a floating vessel comprises one or more steering arms as previously described, for example, 3-4 steering arms. Such a configuration provides for precise steering and therefore more precise harvesting of a mineral or deposit on a bed. The configuration of steering arms, each with a connection part with steering mechanism, an arm controlled by a movement system and a second arm structure allows for effective use of all steering arms simultaneously, allowing for an overall more precise and efficient system. This is particularly useful in grid-like harvesting systems where many sharp turns are needed.

[0014] According to an embodiment, each of the one or more steering arms rotates from a use position where the drive means is positioned to contact a bed of a liquid body to a raised position where the drive means does not contact the bed. Such rotation allows for easy placement for controlling the movement of a floating vessel as well as a simple way to turn the vessel by lifting one or more arms and rotating the drive means through the steering mechanism.

[0015] According to an embodiment, a rotation axis of each of the one or more steering arms is perpendicular to a longitudinal or movement direction of the vessel. Such a configuration results in less space needed for the steering arms on the vessel as they rotate to and from a use position.

[0016] According to an embodiment, a rotation axis of each of the one or more steering arms is parallel to a longitudinal or movement direction of the vessel. Such a configuration with the rotation axis of the arm perpendicular to the rotation axis of the track results in a mechanical decoupling of the ground pressure applied by the springs from the driving forces, meaning the ground pressure is constant regardless the applied drive torque.

[0017] According to an embodiment, the vessel further comprises a collection system for collecting a mineral or other deposit from the bed. Such a collection system can be, for example, an auger with a suction mouth and suction tube which can scrape minerals or other deposits from a seabed and suction them into the suction tube and eventually to a pipeline for transporting to a location for processing. The collection system could be, for example, connected to a front end of the vessel or at another location.

[0018] According to a further aspect, a method for steering a floating vessel in a liquid body comprising a bed is provided. The vessel comprises at least one steering arm as previously described and the method comprises rotating the at least one steering arm to a use position where the drive means of each of the at least one steering arm contacts the bed. Such a method provides a simple yet effective way to move and precisely steer the floating vessel.

[0019] According to an embodiment, the method further comprises lifting the at least one steering arm such that the drive means does not contact the bed; rotating the drive means of the lifted steering arm(s); and lowering the rotated drive means of the at least one steering arm such that each rotated drive means contacts the bed. Such a method of lifting to rotate the steering arm allows for very sharp turns without damaging the bed which the drive means contacts. Lifting to steer avoids the skid steering of past systems, and consequent potential damage to the bed from such skid steering.

[0020] According to an embodiment, the method further comprises increasing the downward force applied to the drive means contacting the bed. Optionally, this is done by using one or more hydraulic accumulators, an overpressure valve and / or springs. Such a method of increasing the downward force can allow for better traction on the bed for gripping the seabed to propel and steer the vessel.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 shows a prior art vessel with salt harvesting system.

[0023] FIG. 2A shows a steering arm connected to a floating vessel in a lifted position;

[0024] FIG. 2B is a close-up view of a part of Fig. 2A, with a cross-sectional view of the arm and hydraulic cylinder connection;

[0025] FIG. 2C shows the steering arm of FIG. 2 A in a use position;

[0026] FIG. 2D is a back view of a part of the steering arm;

[0027] FIG. 3 shows a second embodiment of a steering arm in a use position; and

[0028] FIG. 4 shows a steering arm connected to a floating vessel in a transverse direction.

[0029] DETAILED DESCRIPTION

[0030] FIG. 2 A shows a steering arm 10 with track 12 connected to a floating vessel 14 in a lifted position; FIG. 2B is a close-up view of part of steering arm 10, with a cross- sectional view of a hydraulic cylinder connection; FIG. 2C shows steering arm 10 in a use position; and FIG. 2D is a back view of a part of the steering arm 10.

[0031] Steering arm 10 includes arm 16, which in this embodiment bends at a center point, approximately 90 degrees, to extend from first end 18 which is rotatably connected to vessel 14 to second end 20. Steering arm 10 has a rotation axis which is perpendicular to a longitudinal or movement direction of the vessel. Steering arm 10 further includes connection part 22 which connects second end 20 of arm 16 to track 12 (e.g., through a fork or other connection means). Connection part 22 can include various components or features depending on the configuration of steering arm 10, arm 16, steering mechanism 26, and track 12 (or other drive means such as wheels, Archimedes screw, etc.). In the embodiment shown, connection part 22 provides for a pivotal connection between arm 16 and track 12, and includes frame 24 which extends over the top of and on each side of track 12 to connect on the sides of track 12.

[0032] Alternatively, connection part 22 could provide a stiff (non-pivoting) connection to track 12. Such a stiff connection configuration allows for placing more or less pressure on the front or the back of track 12, which can allow for reducing or eliminating damage to the bottom of the basin, for example, by slightly tilting the front of track upwards. Particularly when operating in liquid bodies with a soft bed (e.g., lake beds), being able to control the pressure placed on the front or back of track 12 helps to reduce or avoid damaging and scarring areas of the bed, which can happen if the base layer is pierced through, allowing for washing out of mud.

[0033] Connection part 22 also includes steering mechanism 26, which in this case is a slew drive but in other embodiments could be a cylinder, spindle drive, etc. Slew drive 26 can be driven by two hydraulic motors through gear boxes, giving substantial steering force. The axis of the slew drive 26 is configured to remain substantially vertical throughout movement of steering arm 10 through second arm structure 28. Slew drive also allows for full rotational turning as well as tilting of track 12, enabling very tight turns, and for traversing uneven terrain. Track 12 is typically driven by a hydraulic motor (not shown).

[0034] Steering arm 10 further comprises second arm structure 28 which in this case is a parallel arm arrangement with arm 16, and extends from vessel 14 to connection part 22, with rotating or pivoting connections on either side. Second arm structure 28 shown in Figs. 2A-2D includes first parallel arm 30, pivot piece 32 and second parallel arm 34. First parallel arm 30 connects from vessel 14 to pivot piece 32, and second parallel arm 34 connects between connection part 22 and pivot piece 32. Pivot piece 32 rotatingly connects to arm 16 at the bend, as can be seen in Figs. 2B and 2D. Second parallel arm structure 28 guides the position and / or orientation of connection part 22 and therefore steering mechanism 26, ensuring that connection part 22 with steering mechanism 26 maintains a substantially vertical axis no matter the orientation of arm 16.

[0035] Movement system 36 is formed of two hydraulic cylinders 38, one extending on each side of arm 16. Each hydraulic cylinder 38 extends from vessel 14 to arm 16, in this case connecting at the bend of arm 16, rotatably connecting to arm 16 and vessel 14. Cylinders 38 are able to extend and retract to control the position of steering arm 10 with respect to vessel 14. As shown in cross-section in Fig. 2B, movement system 36 can also include pressure means 40 for applying additional pressure to track 12 (or other drive means). In the embodiment shown, pressure means 40 are springs extending from the connections between hydraulic cylinders 38 and arm 16, but could be other pressure means 40 (e.g., a hydraulic accumulator) and / or positioned differently for applying additional pressure to track 12 or other movement system in this or other embodiments.

[0036] In operation, steering arm 10 can start from a raised position as shown in Fig. 2A, where hydraulic cylinders 38 are in an extended state, raising track 12. This can be in a fully raised position (shown in Fig. 2A) or a partially raised position. Typically a vessel 14 would have a number of steering arms 10 (e.g., 2-4) and if all steering arms 10 are in a raised position, vessel 14 would simply be floating.

[0037] Movement system 36 can then lower steering arm(s) 10 to the position shown in Fig. 2C where track 12 contacts the bed 50. This movement is through hydraulic cylinders 38 retracting to rotate and lower steering arm 10 to the use position shown in Figure 2C. In the embodiment shown in Figs. 2A-2D, steering arm 10 has an axis of rotation substantially perpendicular to the movement direction of vessel 14.

[0038] As hydraulic cylinders 38 rotate arm 16 to lower track 14 to contact bed 50, second arm structure 28 also moves with this movement. Specifically, the connections at pivot piece 32 and connection part 22 ensure that second arm structure 28 moves with the movement of arm 16, and also maintains a substantially vertical axis of connection part 22 and steering mechanism 26, thereby keeping track 12 substantially horizontal throughout the movement up or down. This both helps to ensure that track 12 does not come into contact with other steering arm 10 components when raised (and thereby avoid potential damage from such contact), and that track 12 is appropriately oriented for contacting bed 50 when lowered.

[0039] When steering arms 10 are lowered, as shown in Fig. 2C, they can be used for propelling vessel 14 in the liquid body. Track 12 contacts bed 50 and then propels the vessel in the direction in which track 12 extends. When it is desired to turn, for example, when vessel 14 reaches the end of a liquid body, one or more steering arms 10 can be lifted off bed 50, rotated by slew drive (or other driving mechanism), and then placed back in contact with bed 50 to propel vessel 14 in a new direction. This allows for a faster turn, with less load on the steering and suspension. Such a system can result in being able to perform very tight turns, which is especially useful when collecting or mining a substance or deposit (e.g., salt) from bed 50. With one or more such steering arms 10, vessel 14 is able to perform wet mining or harvesting operations precisely, and more efficiently by faster turning and with little to no damage to the bed 50.

[0040] As mentioned in the background, prior art telescoping leg systems for salt harvesters were slow to turn and maneuver, and had the potential of damaging the floor as they typically used skid steering. Additionally, the telescoping system resulted in a lot of moving parts and hoses within the reach of walkways and personnel, causing potential safety issues and being aesthetically unpleasant.

[0041] Steering arm 10, with rotatable arm 16, second arm structure 28, connection part 22 (with steering mechanism 26) and movement system 36, allows for a lighter, faster, less complex system which is more easily able to turn and allow for all tracks 12 to be used in a turn. Additionally, all parts are below deck when in use, reducing possible safety issues and being aesthetically more pleasing. Configuring steering arm 10 such that the rotation axis is perpendicular to a longitudinal or movement direction of the vessel results in a relatively small footprint, allowing more space in vessel 14 for other systems. Additionally, pressure means 40 allows for applying additional pressure to tracks 12 when needed, for example, to gain better traction for propelling vessel 14 on uneven terrain. Second arm structure 28 helps to ensure that track 12 stays correctly oriented whether in a lifted or use position, and connection part 22 with steering mechanism 26 provides a simple but effective way to enable effective steering and tight turns when needed, making for an overall very effective system for use in harvesting minerals or other deposits on a seabed.

[0042] FIG. 3 shows a second embodiment of a steering arm 10’ in a use position. Steering arm 10’ is similar to and operates similarly to steering arm 10 shown and described in Figs. 2A-2D so only differences will be discussed. In steering arm 10’, second arm structure 28’ is formed by a single arm 60 connecting directly between vessel 14 and the steering mechanism 26 of connection part 22. Directly connecting arm 60 allows for providing the stabilizing and orienting guidance for connection part 22 and track 12 while reducing the number of parts and connections needed overall in steering arm 10’.

[0043] The embodiment of Fig. 3 additionally uses hydraulic accumulators in hydraulic cylinders 38. Alternatively, an overpressure valve could be used. This provides the ability to apply downward pressure on track 12 while eliminating the need for additional springs or other pressure means.

[0044] FIG. 4 shows a steering arm connected to a floating vessel in a transverse direction. Specifically, an axis of rotation of arm 10” extends in or parallel to a movement or longitudinal direction of vessel 14.

[0045] Such a configuration results in a mechanical decoupling of the ground pressure applied by the springs 40 (or other pressure means) from the driving forces. This results in the ground pressure being constant regardless of the applied drive torque. As such, configuring arm 10” such that the rotation axis of each of the one or more steering arms is parallel to a longitudinal or movement direction of the vessel can result in better traction and less damage to the seabed due to the constant ground pressure.

[0046] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

CLAIMS:

1. A steering arm for a floating vessel, the steering arm comprising: an arm with a first end rotatably connected to the vessel and a second end; a connection part connected to the second end of the arm, the connection part comprising a steering mechanism; drive means connected to the connection part; a second arm structure extending between the vessel and the connection part for controlling the position and / or orientation of the connection part; and a movement system for controlling the position of the arm, wherein the second arm structure comprises a parallel arm arrangement with the arm.

2. The steering arm of claim 1, wherein the parallel arm arrangement comprises a first parallel arm, a pivot piece and a second parallel arm.

3. The steering arm of any of the preceding claims, wherein the movement system extends between the vessel and the arm for moving the steering arm between a use position and a lifted position.

4. The steering arm of any of the preceding claims, wherein the movement system is a hydraulic system.

5. The steering arm of any of the preceding claims, wherein the movement system comprises one or more hydraulic cylinders.

6. The steering arm of any of claims 4-5, wherein the hydraulic system further comprises pressure means for applying additional pressure to the drive means when in a use position, preferably wherein the pressure means are springs and / or one or more hydraulic accumulators.

7. The steering arm of claim 6, wherein the pressure means comprises springs extending from the hydraulic system and connected to the second arm structure.

8. The steering arm of any of the preceding claims, where the drive means is a track, wheels and / or an Archimedes screw; preferably wherein the connection part connects to the drive means with a pivoting connection.

9. The steering arm of any of the preceding claims, wherein the arm has a bent configuration from the first end to the second end.

10. The steering arm of any of the preceding claims, wherein the steering mechanism is one or more of a slew drive, cylinder and spindle drive.

11. The steering arm of claim 10, wherein the steering mechanism is a slew drive and an axis of the slew drive is substantially vertical.

12. A floating vessel comprising one or more steering arms according to any of the preceding claims.

13. The floating vessel of claim 12, comprising 3-4 steering arms.

14. The floating vessel of any of claims 12-13, wherein each of the one or more steering arms rotates from a use position where the drive means is positioned to contact a bed of a liquid body to a raised position where the drive means does not contact the bed.

15. The floating vessel of any of claims 12-14, wherein a rotation axis of each of the one or more steering arms is perpendicular to a longitudinal or movement direction of the vessel.

16. The floating vessel of any of claims 12-14, wherein a rotation axis of each of the one or more steering arms is parallel to a longitudinal or movement direction of the vessel.

17. The floating vessel of any of claims 12-16, and further comprising a collection system for collecting a substance or deposit from the bed.

18. Method for steering a floating vessel in a liquid body comprising a bed, the vessel comprising at least one steering arm according to any of claims 1-11, the method comprising: rotating the at least one steering arm to a use position where the drive means of each of the at least one steering arm contacts the bed.

19. The method of claim 18, and further comprising: lifting the at least one steering arm such that the drive means does not contact the bed; rotating the drive means of the lifted steering arm(s); and lowering the rotated drive means of the at least one steering arm such that each rotated drive means contacts the bed.

20. The method of any of claims 18-19 and further comprising: increasing the downward force applied to the drive means contacting the bed, preferably using one or more hydraulic systems and / or springs.

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