Human Powered Hydrofoil Vehicle

The present invention relates to a device for use for transport over water and a method for using same. The invention has particular application to hydrofoil vehicles or hydrofoil bikes, although it could be applied to other vehicles as appropriate.

Hydrofoil vehicles are those which are provided with hydrodynamic foils (which, for ease of reference, will now be referred to as “foils”) in a manner similar to aerofoils, such as those found on fixed-wing aircraft.

PCT Publication No. WO 2018/162962 (WO '962), the contents of which is included herein by reference, describes a pedal-powered hydrofoil vehicle. The vehicle has a similar configuration to a bicycle, with foils (or groups of foils) in place of the wheels, and with the pedals and/or a motor driving a propeller. Such a vehicle is referred to herein as a “hydrofoil bike” or simply a “bike”.

Such hydrofoil bikes often lack a genuine hull, and so may be only marginally buoyant. When launching such a bike from standstill in open water (i.e., when no jetty, dock or other structure is available for support), the majority of the bike may be submerged. The user must correctly orientate the bike before attempting to launch the bike into a foiling condition. However, the bike may not be inherently stable when in the necessary submerged, upright position. This may make launching difficult, particularly for inexperienced riders.

Control of the pitch of the vehicle may be automated when foiling. For example, WO '962 describes a hydrofoil bike with a front foil which acts as an elevator control in a canard configuration. The angle of attack of the front foil is automatically controlled by a forward mounted pitch control mechanism (referred to in WO '962 as a “tiller mechanism”) which comprises a skid plate connected to a further small foil. Such an arrangement may work well once the bike is up to speed and is foiling. However, when launching the bike, the front foil may inadvertently be orientated at an inconvenient angle. Control of the angle of the front foil is possible by movement of the user's body weight, but this may be difficult, particularly for inexperienced users. This may also increase the difficulty in launching the bike.

It is an object of the technology to provide a human powered hydrofoil vehicle which is easier to operate than similar vehicles of the prior art. Alternatively, it is an object of the technology to provide a human powered hydrofoil vehicle which is easier to launch than similar vehicles of the prior art. Alternatively, it is an object of the technology to provide a hydrofoil vehicle which will overcome or ameliorate at least one problem with the hydrofoil vehicles of the prior art.

Alternatively, it is an object of the technology to at least provide the public with a useful choice.

According to one aspect of the technology there is provided 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.

Preferably, the locking mechanism activates automatically when the hydrofoil vehicle is not foiling. Alternatively, the locking mechanism can be manually activated by a user.

Preferably, 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.

Preferably, the moveable control surface comprises one of the at least one foils.

Preferably, the moveable control surface comprises an elevator foil.

Preferably, the elevator foil forms part of a self-adjusting pitch control mechanism.

Preferably the self-adjusting pitch control mechanism comprises a control foil which is connected to the elevator foil by a control arm.

Preferably, the locking mechanism is provided within the control arm.

Preferably the frame comprises a front strut, and the control arm is rotatably connected to the front strut.

Preferably, 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.

Preferably, 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.

According to another aspect of the present technology there is provided 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,

Preferably, the locking mechanism comprises a buoyant member configured to actuate the locking mechanism when the buoyant member is immersed in water.

According to another aspect of the technology, there is provided a human powered hydrofoil vehicle comprising a buoyant frame,

the vehicle further comprising:

the hydrofoil vehicle further comprising a prime mover mounted to the rear strut above the main foil, and a motor mounted to the rear strut, wherein the pedal and crank formation are connected to the prime mover by a drivetrain,

wherein, when floating in an upright orientation, a centre of mass of the hydrofoil vehicle is below the centre of buoyancy.

Preferably, the frame further comprises a front strut, and the stabiliser foil is connected to the front strut.

Preferably, the prime mover comprises a propeller.

Preferably, the motor is substantially in line with the propeller.

According to another aspect of the technology there is provided a human powered hydrofoil vehicle comprising a frame, a main foil and a stabiliser foil, wherein the main foil is provided in front of the stabiliser foil, the vehicle further comprising a pedal and crank formation for use by the user, and a prime mover for converting energy from the pedal and crank formation into thrust.

Preferably, the vehicle further comprises an electric motor for driving the prime mover.

Preferably, the prime mover comprises a propeller.

According to another aspect of the present invention there is provided a battery assembly for a watercraft, the battery assembly comprising a battery comprising a waterproof casing and an enclosure for the battery, wherein the enclosure is also waterproof, the wherein an electrical connector is provided in a wall of the enclosure to allow a component external of the enclosure to be electrically connected to the battery.

Preferably, the enclosure comprises a transparent or translucent portion to allow a user to determine if water has entered the enclosure.

Further aspects of the technology, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading of the following description which provides at least one example of a practical application of the technology.

Referring first to, a hydrofoil bikeis shown. Inthe frameof the bikeis shown in the normal orientation when foiling.

The bikecomprises a frameor chassis comprising a substantially horizontal main memberand a rear strutwhich extends generally downwardly and rearward from the aft end of the main member. A main foilis attached to a lower end of the rear strutand a propelleris provided above, for example immediately above, the main foil.

A front strutis provided at the front of the bike. The front strutextends generally downward and forward from the main member. The front strutis rotatably mounted to the main member such that it can rotate around its longitudinal axis. In the example shown, handlebarsare operatively connected to the front strutto allow the user to steer. A seat, for example a typical bicycle saddle, is mounted to the frameabove the rear strutvia a seat post. The seat postmay be slideably connected to the frameto allow adjustment of the seat height relative to a pedal/crank mechanismwhich is provided below the seat. The pedals/crankare connected to the propelleror other prime mover by a drivetrain which is described further below.

A pitch control mechanismis connected to the front strut. The pitch control mechanismcomprises an elevator foilwhich is mounted such that the angle of attack of the elevator foilcan be varied relative to the frame. In the example shown inthe pitch control mechanismis self-adjusting and comprises a control foilwhich is rotatably connected to a control arm. The control armis rotatably connected to the lower end of the front strutand is rigidly connected to the elevator foil. The angle of attack of the control foilis controlled by a skid platewhich is configured to ride on the surface of the water when the bikeis moving. Movement up or down of the control foiladjusts the angle of attack of the elevator foiland hence the pitch of the bike. The elevator foilalso provides lift to hold the bike clear of the water.

Referring next to, in examples, the pitch control mechanismis provided with a locking mechanismfor locking the pivotal movement of the control armrelative to the front strut(and hence the angle of attack of the elevator foil) when the mechanism is submerged, for example, when the user is performing launching of the hydrofoil bikefrom a submerged or semi-submerged position.

As best seen in, the control armis rotatably connected to the front strut(shown in part only in), e.g. by an axleprovided to the front strutwhich runs in bearingswhich are mounted to the control arm. In examples, the control armis connected to a mounting portionof the front strutwhich is configured to be releasably attachable to the remainder of the front strut, e.g. to allow for disassembly of the pitch control mechanismfrom the frameduring transportation.

As shown in, in examples a locking mechanismis provided within the control arm. In one example the locking mechanismcomprises a buoyant member, referred to herein as a “float”, connected to a bell crank. The bell crankis rotatable around a pivotwhich is connected to, or is at least fixed relative to, the control arm. The axis of rotation of the bell crankmay be substantially parallel to the rotational axis of the control armrelative to the front strut.

The lower portion of the front strut(e.g. mounting portion) may comprise a formationwhich comprises an opening. In the example shown the formationcomprises a pair of transverse pinswhich are spaced apart in the fore-aft direction to define the opening. 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.

A catchis provided at the opposite end of the bell crankto the float. The catchcomprises a latch projectionwhich is configured to be inserted into the openingwhen the control armis to be locked, and which can be moved clear of the openingwhen the control armis allowed to move over its normal range. In examples, the latch projection extends perpendicular to the bell crank.

The floatis exposed to the environment surrounding the hydrofoil bikein use. In examples the control armmay comprise openingsin its upper and lower surfaces,to allow ingress of water and escape of air when the bikecontrol armis submerged and to allow draining of the water when the bikeis operating on the foils,.

When the bikeis correctly orientated for a launch, the submerged control armfills with water. The buoyancy of the floatlifts the float side of the bell crankand thereby causes the projectionto enter the openingbetween the pins. With the projectionin this position, the rotation of the control armis limited by the interference of the projectionwith the pins, and the elevator foilis held in the correct position for launching.

Once the portion of the control armcontaining the floatis clear of the waterline, the water quickly drains from the control arm(via the openings) and the floatdrops, thereby lifting the projectionout of the space between the pinsand allowing the control armits normal range of rotational movement. In examples, the full range of rotational movement of the control armmay be defined by stopsprovided to the control armin front of, and behind, the lower portion of the forward strut.

Those skilled in the art will appreciate that in examples of the technology the weight distribution of the locking mechanismabout the pivotmay be configured such that the mechanismautomatically returns to the “unlocked” position when the water drains from the control arm. However, in other examples biasing means (e.g. torsion springs) may be provided to ensure that the mechanismoperates as intended.

In examples, the width of the openingin the forward-aft direction is greater than the width of the latch projection, such that the latch can engage the openingwhen the control armis positioned in any one of a range of angles (albeit a limited range, such as, for example 6 degrees), rather than the control armneeding to be held at a precise angle before locking can occur. In examples, the formationdefining the openingdoes not allow rotation of the bell crankif the angle of the control armis outside the required range, in order to prevent jamming of the control armin an incorrect position. In the example shown, the diameter of the pinsis selected to prevent the catch from rotating to the locked position in when the control armis orientated such that the latch projectionwill not engage the opening, as well as ensuring that the bearing stress between the catch and pins does not exceed a maximum allowable stress.

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

Referring next to, in another example the lower portion of the front strut, e.g. mounting portion, may have an opening or depressionin a side face thereof. A latch projectionmay engage the openingupon activation of a bell crankby a cable (not shown) which is operated by the user. In this example the bell crankrotates around a pivothaving an axis which is substantially parallel to a longitudinal axis of the front strut.

In another example (not shown) a locking mechanism, for example one similar to that shown in, 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.