Patent Description:
The present application claims priority from <CIT>.

A recent development in surfboard technology is the attachment of a motor to a hydrofoil surfboard. The hydrofoil motor is typically an electric motor mounted close to the hydrofoil. The hydrofoil elevates the board clear of the water when under power from the motor, which reduces drag and provides high speed travel over the water.

The hydrofoil motor is positioned at a lower end of a mast while an upper end of the mast is bolted to an underside of the board. A housing is fixed into a top side of the board to accommodate batteries. External wires connect to the batteries and circuitry within the housing. The wires pass through a hole in the board and internally down the mast in order to connect to the electric motor.

<CIT> shows a personal watercraft having a board, with a hydrofoil and motor connected to the board by a strut. A battery, motor speed controller, and throttle interface are located in a watertight compartment in the board. The strut is attached to the board using a fitting.

Document <CIT> discloses introducing air from the atmosphere to an upper surface of a hydrofoil, where air is introduced from the atmosphere to the upper surface of the foil and that a valve <NUM> this flow optionally using a controller.

The references in this specification to any prior publication (or information derived from it), or to any matter which is known, are not, and should not be taken as, an acknowledgement or admission or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

According to one aspect of the invention, there is provided a module according to claim <NUM>.

In one example form, the thermal bridge also thermally connects the internal control circuitry to a plurality of external cooling fins. In another form, the module further includes an attachment plate that secures the mast to the module, wherein the attachment plate forms at least part of the thermal bridge. In yet another form, the cooling fins extend from the attachment plate such that they are located adjacent the mast on an underside of the board when the module is attached to the board.

In other particular, but non-limiting, example forms: the mast is made substantially from aluminium or an aluminium alloy; the module further includes a connector for data communication; and the internal control circuitry includes electronic speed control for the electric motor.

In still further particular, but non-limiting, example forms: the module further includes fittings to releasably fix the module to the board; and the fittings include lateral flanges with apertures to receive fasteners that fix the module to the board.

According to another aspect of the invention, there is provided a mast, including: a motor and a hydrofoil coupled to a lower end; and a module fitted to an upper end; wherein the module is substantially as defined herein.

According to yet another aspect of the invention, there is provided a board with a mounting section including a frame that defines a through hole from an underside of the board to a connection bay, wherein the mounting section is configured to receive a module that is substantially as defined herein, the module being fixed relative to the frame so that the module projects into the bay for the connector to be connected to a power source.

In one example form, the frame is an insert fixed into the board, the insert having attachment holes configured to match fittings on the module. In another form, the board further includes a compartment for a power source and a below deck space between the compartment and the bay for connection between the power source and the connector of the module. In yet another form, the board further includes a tray embedded in a body of the board, the tray being an integral unit which defines the bay, the compartment and the below deck space.

It will be appreciated that the broad forms of the invention and their respective features can be used in conjunction, interchangeably and/or independently, and reference to separate broad forms is not intended to be limiting.

Example embodiments should become apparent from the following description, which is given by way of example only, of at least one preferred but non-limiting embodiment, described in connection with the accompanying figures, wherein:.

The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments.

In the Figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the Figures.

An embodiment of a module <NUM> according to the invention is shown in <FIG>. The module <NUM> is configured for removable attachment to a board. While not shown in this figure, the module <NUM> is attached to an end of a mast, the mast supporting a hydrofoil and a motor to drive the board. The module includes a connector, in this case leads <NUM>, for connecting the module <NUM> to a power source located in the board <NUM>. Internal control circuitry is provided in the module <NUM>, such as Electronic Speed Control (ESC) block <NUM>.

A thermal bridge thermally connects the ESC block <NUM> to the mast. In the embodiment shown, the thermal bridge includes a plate <NUM> and a base <NUM>, but it will be appreciated that the thermal bridge may take many other forms in alternative embodiments. For example, the plate <NUM> may be omitted in some alternative embodiments, thereby further reducing the thermal resistance between the internal control circuitry and the mast.

The module <NUM> is advantageous because it allows the mast and associated components to be quickly and easily removed and reattached to the board. Removal of the mast from the board is typically necessary for transporting the board, so it is desirable for the mast to be easily reattached. This is particularly important for this type of product, as this task must be performed away from a workshop, such as on a beach or other outdoor space.

The module <NUM> greatly simplifies this attachment of the mast to the board, as the connection of the leads to the power source is relatively simple. Importantly, no liquid connections for cooling to the internal circuitry or any other components are necessary, thanks to the thermal bridge connecting the circuitry to the mast.

A number of other example features will now be described, which are included in the embodiment shown in the Figures, but may not be provided in some alternative embodiments or may be provided in a different form in various other alternative embodiments.

Referring to <FIG>, a hydrofoil motor <NUM> is shown at a lower end <NUM> of a mast <NUM>. The hydrofoil motor <NUM> includes an electric motor <NUM> with a propeller <NUM> and integral front hydrofoil <NUM> and rear hydrofoil <NUM>. A board <NUM> is attached at an opposite end of the mast <NUM> to the motor <NUM>. These Figures all show the system in an assembled configuration ready for use.

Referring now to <FIG>, the motor <NUM> and mast <NUM> are shown separated from the board <NUM>. A module <NUM> is attached to an upper end <NUM> of the mast <NUM>. The module <NUM> includes a housing <NUM> and an attachment plate <NUM>. Removing the module <NUM> from the board <NUM> in this manner is convenient for transporting the board, for example, as described previously.

<FIG> show the module <NUM> in more detail. As shown in <FIG>, for example, the attachment plate <NUM> has fittings <NUM> in the form of lateral flanges <NUM> with apertures <NUM>. These fittings <NUM> are used for securing the module <NUM> to the board <NUM>, as will be described in more detail below. The module <NUM> is shown in these Figures without the mast <NUM> for clarity, however typically the module <NUM> is not designed to be easily removed from the mast <NUM>.

<FIG> show an underside of a board <NUM>. A frame <NUM> with an opening <NUM> is embedded in the board <NUM>. The opening <NUM> is bordered by a lip <NUM> adjacent a channel <NUM> that extends around a periphery of the hole <NUM>.

Rebates <NUM> are formed in a face of the frame <NUM>. The rebates <NUM> are configured to match the flanges <NUM> of the module <NUM>. Attachment holes <NUM> are positioned align with the holes <NUM> of the module <NUM> when it is fitted. In this way, the attachment holes <NUM> receive fasteners that, in use, fix the module <NUM> to the frame <NUM>. These fasteners are preferably bolts or screws that screw fix the module <NUM> to the board <NUM>, however it will be appreciated that many other forms of fasteners may be used in alternative embodiments.

To connect the mast <NUM> and module <NUM> to the board <NUM>, the housing <NUM> is inserted through the opening <NUM> on the underside of the board <NUM> until the flanges <NUM> are seated in the rebates <NUM>. Fasteners can then be used to secure the module <NUM> in place.

With reference to <FIG>, the mast <NUM> and module <NUM> are shown connected into the frame <NUM>. A tray <NUM> is embedded in a body <NUM> of the board <NUM>, forming a compartment <NUM> and a connection bay <NUM>. An end <NUM> of the module <NUM> projects into the board <NUM> so that it is close to the connection bay <NUM> when the mast <NUM> is assembled into the tray <NUM>.

A power source in the form of a battery can be housed in the compartment <NUM>. A space <NUM> is provided between the connection bay <NUM> and the portion of the compartment <NUM> where the power source is housed. A deck <NUM> of the board <NUM> is removable to allow access to the compartment <NUM>, connection bay <NUM> and power source. The space <NUM>, together with the connection bay <NUM>, allows external leads <NUM> of the module <NUM> to connect with the power source.

In an alternative arrangement, the tray <NUM> may be dispensed with and the compartment <NUM> and bay <NUM> can instead be formed or moulded directly into the body <NUM> of the board <NUM>. In yet another alternative embodiment, the frame <NUM> may also be integrally formed with the compartment <NUM> and/or body <NUM> of the board <NUM>.

Referring to <FIG>, the construction of the module <NUM> is shown in more detail. An Electronic Speed Control (ESC) block <NUM> with control circuitry is housed within the module <NUM>. When the module <NUM> is assembled, the ESC block <NUM> is connected to a base <NUM> of the attachment plate <NUM>. In some alternative embodiments this mounting may be direct, however in the present embodiment the ESC block <NUM> is mounted to a plate <NUM>, with the plate then being mounted to the base <NUM>. A seal <NUM> is positioned between the base <NUM> and the plate <NUM>.

The ESC block <NUM> is held securely to the plate <NUM> by a bracket <NUM>. Fasteners can extend through the holes <NUM> in the bracket, holes <NUM> in the plate <NUM> and into holes <NUM> in the base <NUM>. A thermal paste or thermal adhesive may be used to maximise the thermal conductivity between the ESC block <NUM>, plate <NUM> and base <NUM>.

The ESC block <NUM> typically generates a large amount of heat during use, and one of the main challenges in designing a system such as this involves providing sufficient cooling to this component. The direct connection between the ESC block <NUM> and the base <NUM> acts as a thermal bridge between the control circuitry of the ESC block <NUM> and the mast <NUM>, thereby dissipating the heat generated into the mast <NUM>.

The thermal bridge <NUM> connecting the control circuitry of the ESC block <NUM> to the mast <NUM> removes the need for active cooling, such as a liquid coolant circuit or similar, as is typically seen in the prior art. This is advantageous for a number of reasons, including reducing complexity and also reducing the risk of leaks that would cause damage to sensitive components. Importantly, removing the need for a liquid cooling circuit also removes the need for connecting and disconnecting liquid supply lines when the mast is separated from the board, greatly simplifying this assembly process.

In the embodiment currently being described, the internal control circuitry includes electronic speed control for the electric motor. Containing this circuitry in the module <NUM>, rather than closer to the motor <NUM> for example, is advantageous because it allows the underwater components to be reduced in size as much as possible. This in turn reduces drag and improves the performance of the board.

Placing this circuitry closer to the motor may otherwise be desirable for assisting with cooling, however the present invention removes this need. Of course, it will be appreciated that in some alternative embodiments of the invention the motor speed control may be placed outside of the module, with the module containing other control circuitry components.

Referring still to <FIG>, the plate <NUM> includes a number of tapered openings <NUM>, into which cable gland inserts <NUM> are fitted and held in place by a cable gland plate <NUM>. The cable gland plate <NUM> is held in place by a fastener which can be tightened to compress the inserts <NUM>. This sealing system allows cables to pass from the ESC block <NUM> into the base of the attachment plate <NUM> and into the mast <NUM>, but prevents any water that may leak in from the base of the attachment plate <NUM> from reaching the ESC block <NUM> or other internal parts of the module <NUM>.

This sealing system is advantageous over other systems as it accommodates the significant thermal stress and expansion due to thermal loads without compromising the seal. It will still be appreciated, however, that alternative sealing methods may also be used in some alternative embodiments.

The leads <NUM> from the battery enter the module <NUM> through holes <NUM> near the top of the housing <NUM> and are sealed by cable glands <NUM>. Power is provided to the ESC block <NUM> through lower leads <NUM>.

A motor control printed circuit board (PCB) <NUM> is positioned above the ESC block <NUM> and can be configured and/or programmed to provide more sophisticated control functions based on a range of operational conditions and/or inputs from various internal and/or external sensors. A socket <NUM> is also provided that allows simple connection via a quick disconnect <NUM> to enable data transfer between the motor control PCB <NUM> and external devices or components, such as a receiver and/or other sensors.

A seal <NUM> is positioned between the base <NUM> and the housing <NUM> which are fastened together at corners by screws <NUM> or other suitable fasteners. The connection of the housing <NUM> to the attachment plate <NUM> in this way encloses the other components to form the complete module as shown in <FIG>.

It will be appreciated that the control circuitry is located in a watertight cavity once the module <NUM> is assembled. This is achieved by various components, including the various seals as discussed previously. Advantageously, however, the present invention through the thermal bridge effectively allows heat transfer from inside this watertight cavity to the outside, without the need for any physical transfer of material, such as a liquid cooling circuit. This thereby helps to maintain the watertight cavity intact over time as components wear, due to the reduced complexity of this setup.

Otherwise stated, the module <NUM> includes a watertight cavity in which the internal control circuitry is contained. That is, the attachment plate <NUM>, plate <NUM> and housing <NUM> together create a cavity that contains the ESC block <NUM>, motor control PCB <NUM> and various other components that may be sensitive to moisture.

During use, even with the thermal bridge connecting the ESC block <NUM> to the mast <NUM>, the temperature inside the module <NUM> can increase significantly. This temperature can also reduce quite rapidly when use is stopped, particularly if the mast <NUM> and attachment plate <NUM> remain in contact with cool water. To help maintain this watertight cavity despite the thermal cycling, a vent <NUM> is provided in the housing <NUM>.

Referring to <FIG>, the attachment plate <NUM> includes external cooling fins <NUM>. The thermal bridge thermally connects the internal control circuitry of the ESC block <NUM> to these fins <NUM>. That is, the fins <NUM> extend from the base <NUM> of the attachment plate <NUM>, which in turn is connected to the plate <NUM> that connects to the base of the ESC block <NUM>.

The fins <NUM> in the embodiment shown are located adjacent a mast connection flange <NUM>. The flange <NUM> ensures a strong connection between the mast <NUM> and the attachment plate <NUM> and also assists in maximising heat transfer between the base <NUM> of the attachment plate <NUM> and the mast <NUM>.

The fins <NUM> on the attachment plate <NUM> are located on the underside of the board <NUM> when the module <NUM> is fitted to the board <NUM>. These fins <NUM>, being part of the attachment plate <NUM>, are connected by the thermal bridge to the ESC module <NUM>.

The fins <NUM> can thereby provide additional cooling for the control circuitry of the ESC module <NUM>, as they may transfer heat to the air when the board is above the surface of the water or they may transfer heat to the water when the board is on the surface or if water is splashed onto the fins <NUM>.

It should be appreciated, however, that the fins are an optional feature that may not be included in some alternative embodiments of the invention, or may be provided in different locations in yet other embodiments.

The module <NUM> and mast <NUM> thereby form an integral unit that is effectively plugged into the board <NUM> and fixed in place. A gasket <NUM> on the outside of the attachment plate <NUM> helps to seal the module <NUM> with the board <NUM> when fitted, in conjunction with the channel <NUM>.

In an alternative embodiment of the invention, instead of attaching directly to the frame <NUM>, the module <NUM> and mast <NUM> can instead be fixed directly to an underside <NUM> of the board <NUM> using appropriate bolts or the like.

In any case, the module <NUM> accommodates control circuitry that can be used to either modulate motor speed and/or, in various alternative embodiments of the invention, perform other functions such as controlling the hydrofoils <NUM>, <NUM> to adjust the aspect of the board <NUM>.

The control circuitry generates heat which can be readily dissipated into the water via the mast <NUM>, which is preferably formed of a high heat transmissive material such as aluminium or an aluminium alloy.

Since the control circuitry is contained within the module <NUM> fitted directly to the upper end <NUM> of the mast <NUM>, the only wired connection outside of the module <NUM> is to the power source via the external leads and a single data connection. As such, there is no requirement for the many wires and liquid connections of the prior art boards.

While the connector provided for the module <NUM> to connect to the power source in the preferred embodiment takes the form of two leads <NUM>, it will be appreciated that many other forms of connector may be provided in alternative forms of the invention. For example, the connector may be a single lead, a socket or multiple sockets. Similarly, the socket <NUM> may also be provided in many other forms. In still yet other forms of the invention, the data and power connections may be combined or arranged in a different configuration of leads, sockets or other forms of connector.

The thermal bridge described in this specification relates to thermal conduction by solid components that are in physical contact. It will be appreciated, however, that a thermal bridge can be any form of connection that provides low thermal resistivity, and many other configurations of thermal bridge will be possible and are considered to fall within the scope of the present invention.

The invention has been described with reference to a board specifically in the context of a surfboard with a mast mounted motor. However, reference to 'board' should be taken as a reference to any form of water craft.

As may be appreciated, many modifications and variations may be made without departing from the scope of the invention described, which is defined by the claims. For example, the module can be connected to a mast with a motor other than a hydrofoil motor and the motor itself need not be an electric motor driving a propeller but could instead be a jet nozzle, turbine or the like.

In the foregoing description of preferred embodiments, specific terminology has been resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "front" and "rear", "inner" and "outer", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

Whilst the present invention has been described with reference to particular embodiments, it will be understood that many modifications will be apparent to those skilled in the art. All such variations and modifications should be considered to fall within the scope of the invention as claimed below.

Claim 1:
An assembly, comprising:
a mast (<NUM>);
a hydrofoil (<NUM>) coupled to a lower end of the mast (<NUM>);
a module (<NUM>) fitted to an upper end of the mast (<NUM>), the module (<NUM>) configured for allowing the mast and associated components to be quickly and easily removed and reattached to a board (<NUM>); and
a motor (<NUM>) coupled to a lower end of the mast (<NUM>) and configured to drive the board (<NUM>);
the module (<NUM>) comprising:
a connector (<NUM>) for connecting the module (<NUM>) to a power source located in the board (<NUM>);
internal control circuitry (<NUM>) contained in a watertight cavity comprised in the module (<NUM>); and
a thermal bridge (<NUM>) to thermally connect the control circuitry (<NUM>) to the mast (<NUM>).