Hydrofoil assembly

Abstract

A hydrofoil assembly (20, 30) comprising a wing (3), a strut (5) carrying the wing (3), and a housing (11) supporting the strut (5) The strut and the wing are vertically movable with respect to the housing (11) between an employed position and a retracted position. The wing (3) is pivotable with respect to the strut (5) about a wing pivot axis (33).

Description

HYDROFOIL ASSEMBLYTechnical Field

[0001] The present invention relates to a hydrofoil assembly configured to be used with a boat hull. In particular, the hydrofoil assembly is of the type that is retractable, such that the wings (or hydrofoils) can be pulled upwards. Furthermore, the angle of the wing with respect to the strut carrying it, is adjustable.Background Art

[0002] The idea of using hydrofoils for elevating boat hulls above the sea surface when traveling at high speeds have been known for a long time. With the current state of computing power, using a control unit for steering the boat by adjusting the angle of the hydrofoil wings during travel is facilitated. Thus, instead of having fixed hydrofoil wings for elevation of the hull and other means (rudder) for steering, one can steer the boat by manipulating the wing angles.

[0003] Also known is the idea of moving the wings up and down with respect to the boat hull by moving the struts to which they are attached. This is necessary to enable slow travel in shallow waters.

[0004] An example of a hydrofoil boat is disclosed in publication EP4124559A1 . In this solution, a rear hydrofoil assembly comprises a combination of wings / hydrofoil and propulsion means. The assembly can be lowered and raised with respect to the boat hull.Summary of invention

[0005] According to the present invention there is provided a hydrofoil assembly comprising a wing, a strut carrying the wing, and a housing supporting the strut. The strut and the wing are vertically movable with respect to the housing, between an employed position and a retracted position. Moreover, the wing is pivotable with respect to the strut about a wing pivot axis.

[0006] Herein, with the term housing is meant any device or arrangement that supports the strut in such manner that the strut is vertically movable between theemployed and retracted positions. Hence, when installed to a boat hull, the housing will constitute a mechanical connection between the boat hull and the strut.

[0007] Advantageously, the entire wing can be pivotable with respect to the strut. This contrasts with fixed wings and wings that have one fixed portion and an attached, pivoting flap portion.

[0008] In some embodiments, the hydrofoil assembly can further comprise a winch assembly comprising a winch motor and a winch drum, a retraction wire extending between the winch drum and the wing, and an employment wire extending between the winch drum and the wing, via a strut pulley assembly attached to the strut.

[0009] By operation of the winch assembly, a pull in the retraction wire can then retract the strut and the wing upwardly, while a pull in the employment wire can move the strut and wing downwards to the employed position.

[0010] In some such embodiments, one of the retraction wire and the employment wire can be attached to the wing at a forward connection point in front of the wing pivot axis, and the other can be attached to the wing at a rear connection point behind the wing pivot axis.

[0011] The hydrofoil assembly can further comprise a latching arrangement to latch the strut with respect to the housing.

[0012] This enables use of the winch assembly to adjust the angle of the wing about the wing pivot axis, since operation of the winch assembly will not lower or retract the strut. Hence, the solution provides vertical movement of the wing and strut, as well as angle adjustment of the wing with only one actuator (i.e. the winch assembly). This results in a less costly hydrofoil assembly which requires less maintenance.

[0013] Advantageously, the latching arrangement can be configured to latch the strut in different vertical positions.

[0014] The hydrofoil assembly may further comprise a wire protection means that extends in front of whichever of the retraction wire or the employment wire that is connected to the wing at the forward connection point. The wire protection means is connected to the strut or to the wing.

[0015] In some embodiments, the one of the retraction wire or the employment wire which is connected to the wing at the forward connection point may comprise a rigid rod that bridges the distance between the wing and the lower part of the strut. This will protect against debris that may hit the wire during travel.

[0016] In embodiments including the said winch assembly, the winch drum can comprise a first drum and a second drum, of which one is connected to (or holds) the retraction wire and the other is connected to the employment wire. The winch assembly can further comprise an uncoupling lever for temporary disconnection of the first or second drum from the winch motor.

[0017] This will facilitate tensioning of the two wires.

[0018] In some embodiments, the hydrofoil assembly can further comprise a pivot shaft embedded in the wing, between an upper wing surface and a lower wing surface. The pivot shaft can be attached to the wing and extend through a pivot aperture in the lower end of the strut.

[0019] The hydrofoil assembly may further comprise two wing attachment elements attached to the wing, of which one is located on respective sides of the pivot aperture, each comprising a shaft-receiving groove that receives a portion of the pivot shaft.

[0020] In some embodiments of the hydrofoil assembly, the strut can comprise a weakened breaking means located below the housing when the strut is in the employed position. This will protect the housing and the boat hull from excessive forces if the lower part of the strut collides with an object in the water, since the strut will break at the intended location before excessive forces are distributed to the housing.

[0021] An advantage of the hydrofoil assembly according to the invention is that it is suited for retrofitting to existing boat hulls. Moreover, the hydrofoil assembly can be disconnected from the propulsion means, such that it easily can be retrofitted irrespective of the used propulsion means.

[0022] Advantageously, three hydrofoil assemblies according to the invention can be installed on a boat hull, typically two rear hydrofoil assemblies and one forward hydrofoil assembly.

[0023] The hydrofoil assembly may typically be connected to or comprise a control unit (e.g. a CPU) for operation of the wing during use. I.e. the control unit will adjust the mutual angle between the strut and the wing during flight or hydrofoiling mode. Moreover, the control unit can advantageously control both the winch assembly and the latching arrangement. The latching arrangement could in such embodiments typically be electrically operated, such as with an electric motor.Detailed description of the invention

[0024] While various features of the present invention have been presented in general terms above, a more detailed and non-limiting example of embodiment will be given in the following with reference to the drawings, in whichFig. 1 is a schematic top view of a boat hull provided with three hydrofoil assemblies according to the invention;Fig. 2 is a side view of the boat hull shown in Fig. 1 , wherein the wings of the hydrofoil assemblies are in an upper, retracted position;Fig. 3 is a side view corresponding to Fig. 2, however wherein the wings are in a lower, employed position;Fig. 3a is a side view showing the aft portion of the boat hull, with an outboard motor attached to a motor lift carrying the outboard motor in a lowered position;Fig. 4 is a side-view of a hydrofoil assembly, in the form of an aft wing assembly, according to the invention;Fig. 4a is a schematic top view depicting a cross section through a strut and illustrating its connection to a wing;Fig. 4b is a schematic top view illustrating a strut extending through a housing;Fig. 5 and Fig. 6 are side views of the assembly shown in Fig. 4 in a retracted and employed position, with the strut removed for illustrational purpose;Fig. 7 is an enlarged side view illustrating an alternative embodiment of the hydrofoil assembly;Fig. 8 is a perspective view of the lower part of a strut and a wing connected to it; andFig. 9 is an enlarged portion of a strut and a wing, illustrating a solution for attachment of the wing to the strut.

[0025] Fig. 1 depicts the hull 1 of a boat that is equipped three hydrofoil assemblies, in the form of one bow wing assembly 20 and two aft wing assemblies 30.

[0026] Each of the bow wing assembly 20 and aft wing assemblies 30 comprises a wing 3. The wing 3 is pivotably attached to a strut 5 that can be moved vertically, thus into and out of the water. The side views of Fig. 2 and Fig. 3 depict the wings 3 and struts 5 in a retracted and an employed position, respectively. In the retracted position, as shown in Fig. 2, the wings 3 are retracted to a position above the waterline (not shown). In the employed position, as shown in Fig. 3, the wings 3 are deployed into the water, below the waterline. This position can also be termed a flying position or hydrofoiling position, as it is the position of the wings 3 when used for hydrofoil mode, i.e. when the boat is driven such that the hull 1 is above the waterline while the wings 3 are below the waterline.

[0027] Also shown in the present embodiment is an outboard motor 7 arranged on a motor lift 9 configured to adjust the vertical position of the outboard motor 7 with respect to the hull 1 . Thus, when the wings 3 are in the employed position, the outboard motor 7 will be lowered, while it will be elevated to a higher position when the wings 3 are in the retracted position. Intermediate vertical positions are also possible, both for the outboard motor 7 and the wings 3.

[0028] The struts 5 are supported in a housing 11 . The housing 11 is attached to the hull 1 of the boat.

[0029] The housing 11 of the bow wing assembly 20 is in the present embodiment attached to the hull 1 by means of attachment bars 13 that extend between the hull 1 and the housing 11 .

[0030] The housing 11 of the aft wing assemblies 30 is attached to a hull transom, for instance with bolts (not shown).

[0031] The housings 11 of the bow wing assembly 20 and the aft wing assemblies 30 can be attached to the hull 1 in other ways. For instance, they can be integrated with the hull 1 , in such way that the hull is designed for instance with apertures that receive the respective housings 11 .

[0032] Fig. 3a depicts the outboard motor 7 lowered by the motor lift 9 with the aft wing assemblies 30 removed for illustrational purpose.

[0033] Fig. 4 depicts one of the aft wing assemblies 30 with a side view. It shall be noted that the image of Fig. 4 also could relate to the bow wing assembly 20.

[0034] The housing 11 is shown with its housing wall removed for illustrational purpose. Inside the housing 11 there is arranged a winch assembly 15. The winch assembly 15 comprises a winch motor 17, such as an electric motor. The winch assembly 15 further comprises a winch drum 19 that rotates upon operation of the winch motor 17.

[0035] Still referring to Fig. 4, in the shown embodiment, the strut 5 advantageously comprises a weakened breaking means 16. The weakened breaking means 16 is a part of the strut 5 intended to break before any other part of the strut 5 in case of a collision, for instance with an underwater rock or an object in the water. This may protect the housing 11 and other parts from harm upon an impact, and thus facilitate repair. The weakened breaking means 16 can be provided in different ways. For instance, a dent may be formed in the strut 5.

[0036] Also shown in Fig. 4 is a wire protection means 18, attached to the strut 5. The wire protection means 18 is, in the shown embodiment, shaped like a forward and downwardly extending fin, such that a portion of it is arranged in front of an employment wire 21 b (to be discussed further below). The wire protection means 18 will thus hit possible debris (not shown) suspended in the water, instead of the employment wire 21 b. As shown in Fig. 4, while being arranged in front of the employment wire 21 b, it still allows for the wing 3 to be pivoted about a horizontal axis (as will be discussed further below). In alternative embodiments, the wire protection means 18 can be attached to the wing 3 and extend upwards.

[0037] A retraction wire 21 a and the employment wire 21 b is connected to the winch drum 19. As will be explained in further detail with reference to Fig. 5 and Fig. 6, thewinch assembly 15 is used for lowering and elevating the strut 5. While a wire is used as an example herein, it shall be understood that alternatives may be used, for instance a rope, a cable, a chain or similar flexible string. Moreover, wile a wire is used herein as an example of a flexible string, it shall be understood that it does not need to be flexible along its entire length. For instance, a portion of the wire that is not bent or flexed, can be replaced with a rigid rod.

[0038] Still referring to Fig. 4, two the retraction wire 21 a and the employment wire 21 b extend out from the winch drum 19. The retraction and employment wires 21 a, 21 b further connect to the wing 3 at two locations.

[0039] At the elevation of the winch assembly 15, the retraction and employment wires 21 a, 21 b extend into the strut 5 through a strut slit 23. The strut slit 23 is depicted in Fig. 4a, which shows the strut 5 from above. It is also visible in Fig. 9. The strut slit 23 extends along a vertical portion of the strut 5, such that the strut 5 may be moved vertically while the retraction and employment wires 21 a, 21 b extend into the body of the strut 5.

[0040] Fig. 4b depicts the housing 11 and the strut 5 from above.

[0041] Reference is now made to Fig. 5 and Fig. 6, which illustrate the functions of the retraction and employment wires 21 a, 21 b. Fig. 5 depicts the wing 3 in the employed position (i.e. lowered down into the water), while Fig. 6 depicts the wing 3 in its retracted position. The images of Fig. 5 and Fig. 6 are shown without the strut 5 for illustrational purpose. It shall be clear, however, that the strut 5 is connected to the wing 3 and extends through the housing 11 .

[0042] The retraction wire 21 a extends out from the winch drum 19 to a retraction pulley 25. As shown in Fig. 5, the retraction wire 21 a is attached to the wing 3, such that when the winch assembly 15 pulls in the retraction wire 21 a, the wing 3 and the strut 5 will be elevated and thus moved towards and into the retracted position. The winch assembly 15 and the retraction pulley 25 are fixed to the housing 11 .

[0043] The employment wire 21 b extends out from the winch drum 19 and towards an employment pulley 27. The employment pulley 27 is attached to the housing 11 . From the employment pulley 27, the employment wire 21 b extends to a strut pulley assembly 28. The strut pulley assembly 28 comprises a first strut pulley 28a and asecond strut pulley 28b. The first and second strut pulleys 28a, 28b are fixed to the strut 5. Instead of the first and second strut pulleys 28a, 28b, the strut pulley assembly 28 could instead comprise one larger pulley (not shown) with a diameter corresponding to the distance between the first and second strut pulleys 28a, 28b.

[0044] As the skilled reader now will appreciate, when the winch assembly 15 retracts the employment wire 21 b that is guided with the employment pulley 27, the strut 5 (see Fig. 4) will be moved downwards towards the employed position. The employed position is shown in Fig. 5, while the retracted position is shown in Fig. 6.

[0045] Although not shown in the figures, there will always be a certain amount of wire reeled onto the winch drum 19. For instance, in the employed situation shown in Fig. 5, a length of the employment wire 21 b will be stored on the winch drum 19. Correspondingly, in the retracted position shown in Fig. 6, a length of the retraction wire 21 a will be stored on the winch drum 19. In the shown embodiment, since the retraction and employment wires 21a, 21 b share the same winch drum 19, they will be reeled onto the winch drum 19 in different directions (i.e. clockwise and counterclockwise).

[0046] Notably, in both the retracted position and the employed position, two parallel portions of the retraction and employment wires 21 a, 21 b extend upwards from its connection to the wing 3. At the wing 3, the employment wire 21 b and the retraction wire 21 a connect to the wing 3 at a forward connection point 29a and a rear connection point 29b, respectively. The distance between the forward connection point 29a and the rear connection point 29b is equal to the distance between the two portions of the employment wire 21 b that extend downwards at the first and second strut pulleys 28a, 28b. In other words, the retraction wire 21 a and the employment wire 12b exhibit a distance with parallel configuration.

[0047] While the present embodiment comprises the retraction pulley 25 and the employment pulley 27, other embodiments may be without these pulleys. In such embodiments, one may for instance orient the winch drum 19 orthogonally with respect to the orientation shown in the present embodiment.

[0048] Although not shown, the strut 5 will typically comprise strength members arranged between the two vertical parts of the retraction and employment wires 21a, 21 b.

[0049] The part of the employment wire 21 b that bridges the distance between the lower portion of the strut 5 and the wing 3, and which thus will be exposed to collision with objects in the water, may comprise a rigid rod. This part of the employment wire 21 b will not be flexed and can thus either be in form of a rigid rod along this distance, or it may extend through a rigid tube for wire protection. As the skilled reader will appreciate, other embodiments may have the retraction wire 21 a connected to the forward connection point 29a and may thus comprise the rigid rod or rigid tube instead of the employment wire 21 b. In some embodiments, both the employment wire 21 b and the retraction wire 21 a may comprise a rigid rod or extend through a rigid tube for wire protection.

[0050] When the strut 5 has been moved into the employed position, as shown in Fig. 4 and Fig. 5, a latching arrangement 32 (Fig. 4) may be used to fixate the vertical position of the strut 5 with respect to the housing 11 . The latching arrangement may for instance comprise a latch lever 32a that can be moved into and out of engagement with a latching groove 32b. This will prevent excessive force on the retraction and employment wires 21a, 21 b during use (i.e. during flying mode I hydrofoiling mode of the boat). It also enables use of the winch assembly 15 for adjusting the angle of the wing 3, as will be discussed below. In the shown embodiment, three latching grooves 32b are shown, at different vertical positions. The latching arrangement 32 may also be of other designs, for instance a tightening screw or bolt that is forced against a portion of the strut 5.

[0051] Also shown in Fig. 5 and Fig. 6 is a pivot shaft 31 . The pivot shaft 31 connects the wing 3 to the strut 5 in a pivotable manner about a wing pivot axis 33. Instead of a pivot shaft 31 , other means, such as a hinge, could be used.

[0052] When the strut 5 is latched or locked in the employed position, as shown in Fig. 4 and Fig. 5, the winch assembly 15 is used to rotate the wing 3 about the axis of the wing pivot axis 33. In this manner, the winch assembly 15 is used both for moving the strut 5 vertically and for adjusting the angle of the wing 3 during flight mode (i.e. when hydrofoiling).

[0053] Notably, in the shown embodiment, the wing pivot axis 33 is arranged centrally (i.e. with equal distances to) between the forward and rear connection points 29a, 29b.

[0054] Reference is now made to Fig. 7, which depicts the housing 1 1 , the wing 3 in the retracted position, and a particular embodiment of the winch assembly 15. For illustrational purpose, the strut 5 is not shown in Fig. 7.

[0055] Instead of the single winch drum 19 shown in Fig. 5 and Fig. 6, in the embodiment shown in Fig. 7, the winch assembly 15 has a two-part winch drum 19. The retraction and employment wires 21 a, 21 b, guided via the retraction pulley 25 and the employment pulley 27, are wound onto a first drum 19a and a second drum 19b. The first and second drums 19a, 19b both connect to the winch motor 17 and are rotated simultaneously. However, by means of an uncoupling lever 35, one of the first and second drums 19a, 19b can be disconnected from the winch motor 17. In this way, one is enabled to adjust the engagement between one of the retraction and employment wires 21 a, 21 b and the winch assembly 15. For instance, by disconnecting the first drum 19a, the employment wire 21 b can be tightened and then, by actuation of the uncoupling lever 35, the first drum 19a can be re-coupled to the winch motor 17 (and to the second drum 19b). This can be achieved for instance with a ratcheting mechanism.

[0056] As shown in Fig. 7, the pivot shaft 31 is embedded in the wing 3, between an upper wing surface 3a and a lower wing surface 3b.

[0057] Fig. 8 depicts the wing 3 attached to the lower part of the strut 5. Fig. 9 depicts the same strut 5 and wing 3 with an enlarged view. Also shown is the pivot shaft 31 embedded between the upper and lower wing surfaces 3a, 3b.

[0058] The pivot shaft 31 extends through a pivot aperture 39 arranged in the lower end of the strut 5. To fixate the pivot shaft 31 to the wing 3, a pair of wing attachment elements 37 are used, one at respective sides of the pivot aperture 39. Fig. 9 depicts one of the wing attachment elements 37 in a detached mode. It comprises a shaftreceiving groove 41 . When attached to the wing 3, a portion of the pivot shaft 31 will be received in the shaft-receiving groove 41 .

[0059] Furthermore, for attachment of the attachment elements 37 to the wing 3, they comprise screw apertures 43, through which screws or bolts (not shown) will extend for connection to the wing 3.

[0060] This solution enables a reliable, easy and quick solution for detaching and attaching the wing 3 to the strut 5.

[0061] Also shown in Fig. 9 are the forward and rear connection points 29a, 29b, where the employment wires 21 b and the retraction wire 21 a (not shown in Fig. 9) connects to the wing 3.

[0062] The strut 5 can advantageously comprise several parts that are mounted together to form a complete strut.

[0063] It shall be noted that although the term “vertical” has been used herein to describe the extension of a portion of the retraction wire 21 a and retraction wire 21 b, these portions can also exhibit an inclined orientation. This can typically be the case in embodiments where the strut 5 have an inclined orientation.

Claims

Claims1 . A hydrofoil assembly (20, 30) comprising- a wing (3),- a strut (5) carrying the wing (3),- a housing (1 1 ) supporting the strut (5), wherein the strut and the wing are vertically movable with respect to the housing (1 1 ) between an employed position and a retracted position, wherein the wing (3) is pivotable with respect to the strut (5) about a wing pivot axis (33).

2. A hydrofoil assembly (20, 30) according to claim 1 , further comprising- a winch assembly (15) comprising a winch motor (17) and a winch drum (19);- a retraction wire (21 a) extending between the winch drum (19) and the wing (3);- an employment wire (21 b) extending between the winch drum (19) and the wing (3), via a strut pulley assembly (28) attached to the strut (5).

3. A hydrofoil assembly (20, 30) according to claim 2, wherein one of the retraction wire (21 a) and the employment wire (21 b) is attached to the wing (3) at a forward connection point (29a) in front of the wing pivot axis (33), and the other is attached to the wing (3) at a rear connection point (29b) behind the wing pivot axis (33).

4. A hydrofoil assembly (20, 30) according to one of the preceding claims, wherein it further comprises a latching arrangement (32) to latch the strut (5) with respect to the housing (1 1 ).

5. A hydrofoil assembly (20, 30) according to claim 3, wherein it further comprises a wire protection means (18) that extends in front of whichever of the retraction wire (21 a) or the employment wire (21 b) that is connected to the wing (3) at the forward connection point (29a), wherein the wire protection means (18) is connected to the strut (5) or to the wing (3).

6. A hydrofoil assembly (20, 30) according to claim 2, or according to claim 2 and any other of the preceding claims, wherein the winch drum (19) comprises a first drum (19a) and a second drum (19b), of which one is connected to the retraction wire (21 a) and the other to the employment wire (21 b), and wherein the winch assembly (15) further comprises an uncoupling lever (35) for temporary disconnection of the first or second drum (19a, 19b) from the winch motor (17).

7. A hydrofoil assembly (20, 30) according to any one of the preceding claims, wherein it further comprises a pivot shaft (31 ) embedded in the wing (3), between an upper wing surface (3a) and a lower wing surface (3b), wherein the pivot shaft (31 ) is attached to the wing (3) and extends through a pivot aperture (39) in the lower end of the strut (5).

8. A hydrofoil assembly (20, 30) according to claim 7, further comprising two wing attachment elements (37) attached to the wing (3), of which one is located on respective sides of the pivot aperture (39), each comprising a shaft-receiving grove (41 ) that receives a portion of the pivot shaft (31).

9. A hydrofoil assembly (20, 30) according to any one of the preceding claims, wherein the strut (5) comprises a weakened breaking means (16) located below the housing (11 ) when the strut is in the employed position.

Images