HUMAN POWERED HYDROFOIL VEHICLE

Abstract

A hydrofoil vehicle comprises a frame and at least one foil. The vehicle comprises a moveable control surface configured to control a pitch of the vehicle, in use. A locking mechanism is provided for restricting movement of the control surface when the vehicle is not foiling, for example during launching. In examples, the locking mechanism activates automatically when the hydrofoil vehicle is not foiling. In examples, the vehicle is human powered.

Claims

1. A hydrofoil vehicle comprising a frame and at least one foil, the vehicle comprising a moveable control surface configured to control a pitch of the vehicle, in use, the vehicle further comprising a locking mechanism for restricting movement of the control surface when the vehicle is not foiling.

2. The hydrofoil vehicle of claim 1, wherein the locking mechanism activates automatically when the hydrofoil vehicle is not foiling.

3. The hydrofoil vehicle of claim 1, wherein the locking mechanism comprises a buoyant element, wherein the locking mechanism is configured to restrict movement of the control surface when the buoyant element is immersed in water and to allow greater movement when the buoyant element is not immersed.

4. The hydrofoil vehicle of claim 3, wherein the moveable control surface comprises one of the at least one foils.

5. The hydrofoil vehicle of claim 4, wherein the moveable control surface comprises an elevator foil.

6. The hydrofoil vehicle of claim 5, wherein the elevator foil forms part of a self-adjusting pitch control mechanism.

7. The hydrofoil vehicle of claim 6, wherein the self-adjusting pitch control mechanism comprises a control foil which is connected to the elevator foil by a control arm.

8. The hydrofoil vehicle of claim 7, wherein the locking mechanism is provided within the control arm.

9. The hydrofoil vehicle of claim 7, wherein the frame comprises a front strut, and the control arm is rotatably connected to the front strut.

10. The hydrofoil vehicle of claim 7, wherein the locking mechanism comprises a bell crank which is rotatably engaged with the control arm, wherein the buoyant element is connected to one side of the bell crank and a latch projection is provided to the opposite side.

11. The hydrofoil vehicle of claim 9, wherein the front strut comprises a formation which defines an opening, wherein the latch projection is configured to enter the opening when the buoyant element is immersed in water, to thereby limit rotation of the control arm relative to the front strut.

12. The hydrofoil vehicle of claim 1, wherein the locking mechanism can be manually activated by a user.

13. A hydrofoil vehicle comprising a frame, a front foil connected to the frame and a rear foil connected to the frame, wherein one of the foils is pivotable relative to the frame about a transverse axis, wherein the angle of the pivotable foil is controllable by a hydrodynamic self-adjusting pitch control mechanism, the vehicle further comprising a locking mechanism configured to limit angular movement of the pivotable foil relative to the frame when the vehicle is being launched.

14. The hydrofoil vehicle of claim 13, wherein the locking mechanism comprises a buoyant member configured to actuate the locking mechanism when the buoyant member is immersed in water.

15.-23. (canceled)

Description

5. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] One or more embodiments of the technology will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which:

[0040] FIG. 1 is a side view of a hydrofoil bike according to one form of the technology.

[0041] FIG. 2 is a front perspective view of the hydrofoil bike of FIG. 1.

[0042] FIG. 3 is an enlarged view of the control arm and front strut mounting portion of the hydrofoil bike of FIG. 1, with an outer surface of the arm removed to show a foil locking mechanism.

[0043] FIG. 4 is an enlarged front perspective view of the control arm with the outer surface removed and the front strut not shown.

[0044] FIG. 5 is an enlarged rear perspective view of the control arm with the outer surface removed.

[0045] FIG. 6 is a side perspective view of an alternative front strut mounting portion and foil locking mechanism, with the control arm shown in outline.

[0046] FIG. 7 is a side view of the rear strut of the hydrofoil bike of FIG. 1, with the outer surface removed to show the drivetrain.

[0047] FIG. 8 is an enlarged cross-section view of the lower end of the rear strut.

[0048] FIG. 9 is a perspective view of the battery enclosure of the hydrofoil bike of FIG. 1.

[0049] FIG. 10 is a perspective view of the battery enclosure with a top cover removed.

[0050] FIG. 11 is an exploded view of the battery enclosure and battery.

[0051] FIG. 12 is a rear perspective view of a hydrofoil bike according to one form of the technology.

6. BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0052] Referring first to FIG. 1, a hydrofoil bike 100 is shown. In FIG. 1 the frame 1 of the bike 100 is shown in the normal orientation when foiling.

[0053] The bike 100 comprises a frame 1 or chassis comprising a substantially horizontal main member 2 and a rear strut 3 which extends generally downwardly and rearward from the aft end of the main member 2. A main foil 4 is attached to a lower end of the rear strut 3 and a propeller 10 is provided above, for example immediately above, the main foil 4.

[0054] A front strut 5 is provided at the front of the bike 100. The front strut 5 extends generally downward and forward from the main member 2. The front strut 5 is rotatably mounted to the main member such that it can rotate around its longitudinal axis. In the example shown, handlebars 6 are operatively connected to the front strut 5 to allow the user to steer. A seat 7, for example a typical bicycle saddle, is mounted to the frame 1 above the rear strut 3 via a seat post 8. The seat post 8 may be slideably connected to the frame 1 to allow adjustment of the seat height relative to a pedal/crank mechanism 9 which is provided below the seat 7. The pedals/crank 9 are connected to the propeller 10 or other prime mover by a drivetrain which is described further below.

[0055] A pitch control mechanism 20 is connected to the front strut 5. The pitch control mechanism 20 comprises an elevator foil 21 which is mounted such that the angle of attack of the elevator foil 21 can be varied relative to the frame 1. In the example shown in FIG. 1 the pitch control mechanism 20 is self-adjusting and comprises a control foil 22 which is rotatably connected to a control arm 23. The control arm 23 is rotatably connected to the lower end of the front strut 5 and is rigidly connected to the elevator foil 21. The angle of attack of the control foil 22 is controlled by a skid plate 24 which is configured to ride on the surface of the water when the bike 100 is moving. Movement up or down of the control foil 22 adjusts the angle of attack of the elevator foil 21 and hence the pitch of the bike 100. The elevator foil 21 also provides lift to hold the bike clear of the water.

6.1. Foil Lock

[0056] Referring next to FIGS. 3-5, in examples, the pitch control mechanism 20 is provided with a locking mechanism 30 for locking the pivotal movement of the control arm 23 relative to the front strut 5 (and hence the angle of attack of the elevator foil 21) when the mechanism is submerged, for example, when the user is performing launching of the hydrofoil bike 100 from a submerged or semi-submerged position.

[0057] As best seen in FIG. 3, the control arm 23 is rotatably connected to the front strut 5 (shown in part only in FIG. 3), e.g. by an axle 31 provided to the front strut 5 which runs in bearings 32 which are mounted to the control arm 23. In examples, the control arm 23 is connected to a mounting portion 5a of the front strut 5 which is configured to be releasably attachable to the remainder of the front strut 5, e.g. to allow for disassembly of the pitch control mechanism 20 from the frame 1 during transportation.

[0058] As shown in FIGS. 3-5, in examples a locking mechanism 30 is provided within the control arm 23. In one example the locking mechanism 30 comprises a buoyant member 33, referred to herein as a float, connected to a bell crank 34. The bell crank 34 is rotatable around a pivot 35 which is connected to, or is at least fixed relative to, the control arm 23. The axis of rotation of the bell crank 34 may be substantially parallel to the rotational axis of the control arm 23 relative to the front strut 5.

[0059] The lower portion of the front strut 5 (e.g. mounting portion 5a) may comprise a formation 36 which comprises an opening 37. In the example shown the formation 36 comprises a pair of transverse pins 38 which are spaced apart in the fore-aft direction to define the opening 37. However, other formations which define a suitable opening may be used, for example a suitable U-shaped formation or a suitably orientated plate with an opening therein.

[0060] A catch 39 is provided at the opposite end of the bell crank 34 to the float 33. The catch 39 comprises a latch projection 40 which is configured to be inserted into the opening 37 when the control arm 23 is to be locked, and which can be moved clear of the opening 37 when the control arm 23 is allowed to move over its normal range. In examples, the latch projection extends perpendicular to the bell crank 34.

[0061] The float 33 is exposed to the environment surrounding the hydrofoil bike 100 in use. In examples the control arm 23 may comprise openings 41 in its upper and lower surfaces 42, 43 to allow ingress of water and escape of air when the bike 100 control arm 23 is submerged and to allow draining of the water when the bike 100 is operating on the foils 4, 21.

[0062] When the bike 100 is correctly orientated for a launch, the submerged control arm 23 fills with water. The buoyancy of the float 33 lifts the float side of the bell crank 34 and thereby causes the projection 40 to enter the opening 37 between the pins 38. With the projection 40 in this position, the rotation of the control arm 23 is limited by the interference of the projection 40 with the pins 38, and the elevator foil 21 is held in the correct position for launching.

[0063] Once the portion of the control arm 23 containing the float 33 is clear of the waterline, the water quickly drains from the control arm 23 (via the openings 41) and the float 33 drops, thereby lifting the projection 40 out of the space between the pins 38 and allowing the control arm 23 its normal range of rotational movement. In examples, the full range of rotational movement of the control arm 23 may be defined by stops 44 provided to the control arm 23 in front of, and behind, the lower portion of the forward strut 5.

[0064] Those skilled in the art will appreciate that in examples of the technology the weight distribution of the locking mechanism 30 about the pivot 35 may be configured such that the mechanism 30 automatically returns to the unlocked position when the water drains from the control arm 23. However, in other examples biasing means (e.g. torsion springs) may be provided to ensure that the mechanism 30 operates as intended.

[0065] In examples, the width of the opening 37 in the forward-aft direction is greater than the width of the latch projection 40, such that the latch can engage the opening 37 when the control arm 23 is positioned in any one of a range of angles (albeit a limited range, such as, for example 6 degrees), rather than the control arm 23 needing to be held at a precise angle before locking can occur. In examples, the formation 36 defining the opening 37 does not allow rotation of the bell crank 34 if the angle of the control arm 23 is outside the required range, in order to prevent jamming of the control arm 23 in an incorrect position. In the example shown, the diameter of the pins 38 is selected to prevent the catch from rotating to the locked position in when the control arm 23 is orientated such that the latch projection 40 will not engage the opening 37, as well as ensuring that the bearing stress between the catch and pins does not exceed a maximum allowable stress.

[0066] In examples, an indicator or indicating means for indicating to a person riding the bike when the locking mechanism 30 is engaged may be provided (not shown). For example, an upper surface of the control arm 23 may be provided with an aperture or window (e.g. a transparent portion) through which the float 33, or part of the float (e.g. an indicator portion) can be seen when the locking mechanism 30 is engaged, but which cannot be seen when the mechanism is not engaged.

[0067] Referring next to FIG. 6, in another example the lower portion of the front strut 5, e.g. mounting portion 5a, may have an opening or depression 37 in a side face thereof. A latch projection 40 may engage the opening 37 upon activation of a bell crank 34 by a cable (not shown) which is operated by the user. In this example the bell crank 34 rotates around a pivot 35 having an axis which is substantially parallel to a longitudinal axis of the front strut 5.

[0068] In another example (not shown) a locking mechanism, for example one similar to that shown in FIGS. 3-5, may be manually operated by the user. In examples a locking mechanism may be actuated by handlebar mounted lever or button via a Bowden cable. An electrically powered locking mechanism may also be used. In such examples the user may manually unlock the locking mechanism at the preferred time, or the electrically powered lock may operate based on the position of a float.

[0069] While the locking mechanism 30 is described above with reference to locking a front foil 21, it may be adapted to lock any other control surface while the bike 100 is being launched, for example the angle of attack of a main foil 4, an elevator tab provided to a main foil 4 and/or the angle of attack of a trailing foil 70.

6.2. Chassis

[0070] As shown in FIGS. 1 and 2, in one form of the technology the frame or chassis 1 comprises a substantially horizontal main member 2 and front and rear struts 5, 3 extending downwardly from the main member 2.

[0071] In examples, the main member 2 of the frame 1 is a monocoque design, such that the external surface of the main member 2 is load bearing. In examples, the frame 1 may be formed from a fibre composite such as fibreglass or carbon fibre. At least a portion of the volume between the frame 1 and the components contained within the frame 1 (e.g. the drivetrain) may be filled with a structural foam to improve the strength of the frame 1 and to prevent water ingress.

[0072] In examples, the components of the bike are arranged so that the centre of mass of the bike 100 is lower than the centre of buoyancy when the bike 100 is floating in an upright orientation. In order to locate the centre of buoyancy as high as possible, the main member 2 may be located above the rotational axis of the pedals 9, that is, such that the lower surface 2a of the main member 2 is above the rotational axis of the pedals 9 when the bike 100 is foiling stably. In order to move the centre of mass as low as possible, the motor 50 may be located substantially in line with the propeller 10 (e.g. such that the output shaft 51 of the motor 50 is substantially collinear with the propeller shaft 52), near the base of the rear strut 3. This may mean that the bike 100 naturally adopts a substantially upright orientation (e.g. with seat 7 and handlebars 6 located above the foils 21, 4) when floating but substantially submerged, which may assist the rider to correctly orientate the bike 100 before performing a water launch.

6.3. Drive Train

[0073] The bike 100 includes a drivetrain assembly which transfers the energy of the user and/or some other power source (e.g. electric motor 50) to a propeller 10 (or other prime mover) to create propulsion.

[0074] The drivetrain assembly begins with a typical bicycle pedal/crank mechanism 9 which may be utilised to harness pedalling motion in order to rotate a propeller 10 to produce thrust.

[0075] Referring next to FIGS. 7 and 8 in particular, in one example the drive mechanism comprises a series of spur gears 53 to increase the rotational speed from the pedals 9. The spur gears 53 are connected to a bevel gear (not visible) which drives a drive shaft 54 which extends along the rear strut 3. A sensor 55, for example a torque sensor, cadence sensor, or combined torque and cadence sensor, is also provided to provide information on the effort being exerted by the user, so that the speed of the electric motor 50 can be adjusted accordingly.

[0076] At the lower end of the drive shaft 54 a second bevel gear 56 drives the propeller shaft 52. The drive shaft may also be provided with a one-way clutch to allow the propeller to be driven by the motor without also driving the pedals.

[0077] The motor 50 is provided in line with the propeller shaft 52. The motor 50 drives an epicyclic gearbox 57 which is connected to the propeller shaft 52 via a one-way clutch 58 which allows the motor 50 to be disconnected from the propeller shaft 52 if the user wishes to pedal without assistance.

6.4. Battery Assembly

[0078] Referring next to FIGS. 1, 2 and 9-11, the battery 60 may be provided with a casing 61 which conforms to the IP67 standard for protection against water ingress. The battery casing 61 may contain the battery cells and battery management system. In examples the battery casing may be made from aluminium.

[0079] The battery 60 may be placed in a watertight enclosure 62, in use. The watertight enclosure 62 may also conform to the IP67 standard for protection against water ingress. In examples, the watertight enclosure 62 may be made from, or may comprise, a transparent or translucent material, such that the user can visually confirm that no water has entered the enclosure 62. The battery 60 is electrically connected to a waterproof connector 63 which extends through the wall of the enclosure 62 and allows connection of an external power cable 64.

[0080] The combination of watertight enclosure 62 and water-resistant battery casing 61 ensures that the battery cells and battery management system are not subject to water damage.

[0081] In one form of the technology the battery 60 is located, in use, in the main member 2 of the frame 1. In use, a top cover 65 of the battery box forms a portion of the top surface of the main member 2. While locating a relatively dense component such as the battery relatively high in the frame may appear to run counter to the goal of locating the centre of mass as low as possible, this location for the battery allows other, even heavier components (e.g. the electric motor) to be mounted in a lower position. Mounting the battery in this position also allows easy access by the user.

[0082] The battery box is held within the frame 1 by an engagement mechanism 66 which moves to a locked position when a handle 67 of the battery enclosure 62 is pushed downward, and which moves to an unlocked position when the handle 67 is lifted.

6.5. Alternative Foil Configuration

[0083] Referring next to FIG. 12, in another form of the technology, the entire front mounted pitch control mechanism 20 may be omitted. Instead, the bike 100 may comprise a stabiliser foil 70 provided behind the main foil 4. The main foil 4 may provide a greater amount of lift than the stabiliser foil 70, for example the main foil 4 may be larger (e.g. wider and/or longer) than the stabiliser foil 70. In such examples, the main foil 4 may need to be positioned in a more forward position to offset the lack of lift which would be provided by the front mounted pitch control mechanism 20, in particular from the elevator foil 21.

[0084] In examples, there may be no foil positioned further forward than a mid-point of the bike, for example mid-section of the main member 2.

[0085] In examples, the position the main foil 4 may be adjustable, e.g. in forward-aft direction, to allow the adjustment of the centre of lift.

[0086] In examples, the stabiliser foil 70 may be rigidly mounted to a mounting strut 71, such that no adjustment of the angle of attack of the stabiliser foil 70 (relative to the frame 1) is possible (or at least, such that no movement is possible when the bike is in use). In such examples, maintenance of the pitch of the bike 100 during foiling depends on the user moving their weight forward and aft. However, in other examples, the angle of attack of the elevator foil 21 (or a smaller control surface provided to the elevator foil 21) may be adjustable e.g. by the user via a cable connected to a handlebar mounted lever or similar, or automatically. In examples with an adjustable elevator foil (or other control surface) a mechanism for locking the angle of attack, e.g. one of those described herein, may be provided, to assist in holding the control surface at the correct angle when launching the bike 100.

[0087] In one example, both the main foil 4 and the stabiliser foil 70 may be connected to a common mounting strut 71 which is slideably (but lockably) connected to the rear strut 3, such that the position of the foils 4, 71 can be adjusted in the forward-aft direction.

[0088] In some examples with this foil configuration, the handlebars 6 may be rigidly mounted (rather than rotatably mounted) to the frame 1. Control of the direction of the bike 100 may be achieved by leaning the bike 100 in the desired direction. However, in other examples the handlebars 6 may be attached to a rudder, for example a front strut 5 as described above.

[0089] While FIG. 12 shows a hydrofoil bike with a different main member and rear strut to the example shown in FIGS. 1 and 2, the alternative foil configurations described above may also be used with the frame configuration shown in FIGS. 1 and 2 and described above.

[0090] In examples at least one of the foils 4, 21, 70 may have a substantially constant cross-section along its length, and may be manufactured by a pultrusion process, e.g. from fibreglass, carbon fibre or the like.

6.6. Other Remarks

[0091] Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of including, but not limited to.

[0092] The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

[0093] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[0094] The technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0095] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0096] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the technology and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present technology.