Human powered hydrofoil vehicle and use method

Abstract

The human powered hydrofoil bicycle includes multiple subsystems integrated together including a structural frame subsystem with associated steering and tiller module, a hydrofoil subsystem to provide vehicle lift, and a powertrain subsystem. The structural frame subsystem may be fitted with buoyancy modules to provide the overall vehicle with a near neutrally buoyant character. The structural frame subsystem also supports a seat for an operator and provides structural support for the steering and tiller module for the hydrofoil subsystem and the drivetrain subsystem. The hydrofoil subsystem includes multiple hydrofoil elements at lowermost portions of the vehicle. These hydrofoil elements generally include in a preferred embodiment a larger rear foil and a smaller front foil. The powertrain subsystem generally includes pedals rotatably supported on the vehicle at a convenient location for engagement and driving by feet of an operator. Power transmission elements extend from the pedals down to a prime mover such as a propeller.

Claims

1. A hydrofoil vehicle, comprising in combination: a substantially rigid frame having a front section and a rear section, said front section being forward of said rear section in a longitudinal direction; a front foil connected beneath said front section of said substantially rigid frame; a rear foil connected beneath said rear section of said substantially rigid frame; said front foil and said rear foil each having an elongate form extending primarily laterally to vehicle motion and primarily horizontally, and with a foil shape and orientation which causes lift when moving forward through water; a prime mover located beneath and supported by said substantially rigid frame, said prime mover powered by a power source carried by said substantially rigid frame; said prime mover coupled to said power source through a drive train therebetween, said prime mover extending forward from portions of said drive train adjacent to said prime mover; said prime mover located at least partially above a lowermost one of said front foil and said rear foil; and wherein at least one buoyancy module is removably attachable to said substantially rigid frame, said at least one buoyancy module adding sufficient buoyancy to the hydrofoil vehicle to cause it to have positive buoyancy.

2. The hydrofoil vehicle of claim 1 wherein said prime mover is located entirely above said lowermost one of said front foil and said rear foil.

3. The hydrofoil vehicle of claim 1 wherein said prime mover is located forward of said rear foil and rearward of said front foil.

4. The hydrofoil vehicle of-claim 1 wherein said rear foil is lower than said front foil, said prime mover located above said rear foil and supported by said rear section of said substantially rigid frame.

5. The hydrofoil vehicle of claim 1 wherein said prime mover is located above a line extending between said rear foil and said front foil.

6. The hydrofoil vehicle of claim 1 wherein said prime mover includes at least one propeller.

7. The hydrofoil vehicle of claim 1 wherein said power source includes pedal cranks rotatably coupled to said prime mover to power said prime mover as said pedal cranks rotate, said pedal cranks adapted to be rotated by a human rider carried upon said substantially rigid frame.

8. The hydrofoil vehicle of claim 1 wherein at least one of said front foil or said rear foil includes a cross-sectional form, when viewed from a right or left side, with a convex upper surface and a recurve lower surface, including a convex forward portion and a concave rearward portion.

9. The hydrofoil vehicle of claim 8 wherein at least one of said front foil or said real foil has an elongate form with a lower central portion coupled to said substantially rigid frame and with elevated left and right extremities, and with said left and right extremities coupled to said lower central portion through diagonal intermediate portions.

10. The hydrofoil vehicle of claim 8 wherein at least one of said front foil or said rear foil has an elongate form with an oval contour when viewed from above, with a longest chord length at a central portion thereof and with rounded left and right extremities.

11. The hydrofoil vehicle of claim 8 wherein said cross-section, when viewed from a left or right side of at least one of said foils has a square trailing edge where said convex upper surface of said foil and said recurve lower surface of said foil come together.

12. The hydrofoil vehicle of claim 8 wherein at least one of said front foil and said rear foil are removably connected beneath said substantially rigid frame, through a joint which facilitates rapid removal and secure re-attachment to said substantially rigid frame.

13. The hydrofoil vehicle of claim 12 wherein a plurality of separate foils are provided, said joint through which said foils are connected to said substantially rigid frame allows said plurality of separate foils to be swapped with each other, with one of said plurality of separate foils connected to said substantially rigid frame through said joint.

14. The hydrofoil vehicle of claim 1 wherein said prime mover is coupled to a drive shaft which causes said prime mover to rotate, said driveshaft coupled to said prime mover through a free wheel linkage which causes said prime mover to rotate when said driveshaft rotates in a first direction, and which does not cause said prime mover to rotate when said driveshaft rotates in a second direction opposite said first direction.

15. The hydrofoil vehicle of claim 1 wherein said at least one buoyancy module includes a frame front section buoyancy module and a frame rear section buoyancy module, said frame front section buoyancy module having a lower density than water and configured to be attached to said front section of said substantially rigid frame, said frame rear section buoyancy module having a lower density than water and configured to be attached to said rear section of said substantially rigid frame.

16. The hydrofoil vehicle of claim 15 wherein at least one of said front section buoyancy module and said rear section buoyancy module include two halves which are removably attachable together and with a contour on portions thereof facing each other which correspond with a contour of said substantially rigid frame front or back sections to which they attach.

17. The hydrofoil vehicle of claim 16 wherein said rear section buoyancy module is sufficiently narrow to avoid interfering with legs of a user when said power source includes pedal cranks rotatably coupled to said prime mover to power said prime mover as said pedal cranks rotate, said pedal cranks adapted to be rotated by a human rider carried upon said substantially rigid frame.

18. A hydrofoil vehicle, comprising in combination: a substantially rigid frame having a front section and a rear section, said front section being forward of said rear section in a longitudinal direction; a front foil connected beneath said front section of said substantially rigid frame; a rear foil connected beneath said rear section of said substantially rigid frame; said front foil and said rear foil each having an elongate form extending primarily laterally to vehicle motion and primarily horizontally, and with a foil shape and orientation which causes lift when moving forward through water; a prime mover located beneath and supported by said substantially rigid frame, said prime mover powered by a power source carried by said substantially rigid frame; said prime mover coupled to said power source through a drive train therebetween, said prime mover extending forward from portions of said drive train adjacent to said prime mover; said prime mover located at least partially above a lowermost one of said front foil and said rear foil; and wherein said cross-section of at least one of said front foil or said rear foil has a highest portion of said upper surface between 30% and 50% of the way from a leading edge to a trailing edge, and wherein said lower surface has a lowest portion between 20% and 40% of the way from said leading edge to said trailing edge, and wherein said lower surface has an inflection point between 40% and 70% of the way from said leading edge to said trailing edge, and wherein said lower surface has a concave portion with a highest portion thereof between 70% and 90% of the way from said leading edge to said trailing edge, and wherein a vertical thickness of said cross-section of said at least one foil has a maximum thickness at a location between 20% and 50% of the way from said leading edge to said trailing edge, which maximum thickness portion is between 10% and 20% of said chord length of said cross-section.

19. A hydrofoil vehicle, comprising in combination: a substantially rigid frame having a front section and a rear section, said front section being forward of said rear section in a longitudinal direction; a front foil connected beneath said front section of said substantially rigid frame; a rear foil connected beneath said rear section of said substantially rigid frame; said front foil and said rear foil each having an elongate form extending primarily laterally to vehicle motion and primarily horizontally, and with a foil shape and orientation which causes lift when moving forward through water; a prime mover located beneath and supported by said substantially rigid frame, said prime mover powered by a power source carried by said substantially rigid frame; said prime mover coupled to said power source through a drive train therebetween, said prime mover extending forward from portions of said drive train adjacent to said prime mover; said prime mover located at least partially above a lowermost one of said front foil and said rear foil; wherein at least one of said front foil or said rear foil includes a cross-sectional form, when viewed from a right or left side, with a convex upper surface and a recurve lower surface, including a convex forward portion and a concave rearward portion; wherein at least one of said front foil and said rear foil are removably connected beneath said substantially rigid frame, through a joint which facilitates rapid removal and secure re-attachment to said substantially rigid frame; and wherein said rear foil is removably connected beneath said substantially rigid frame through a bayonet Interface joint comprising male and female counterparts and with one of said male counterpart or female counterpart affixed to a central portion of said rear foil and with the other of said male counterpart or said female counterpart affixed to a lower portion of said rear section of said substantially rigid frame, said male counterpart and female counterpart arranged so that said bayonet interface is caused to be tightened by force of water acting on said rear foil as the vehicle moves relative to water in a forward direction.

20. A hydrofoil pedal driven vehicle, comprising in combination: a frame having a front section and a rear section; a front foil connected beneath said front section of said frame; a rear foil connected beneath said rear section of said frame; said front foil and said rear foil each having an elongate form extending primarily laterally and with a shape and orientation which causes lift when moving forward through water; a prime mover located beneath and coupled at least indirectly to said frame, said prime mover powered by a power source carried by said frame; said prime mover is located at least partially above a lowermost one of said front foil and said rear foil; said prime mover coupled to said power source through a drive train therebetween, said prime mover extending forward from portions of said drive train adjacent to said prime mover; wherein said prime mover is coupled to a drive shaft which causes said prime mover to rotate, said driveshaft coupled to said prime mover through a free wheel linkage which causes said prime mover to rotate when said driveshaft rotates in a first direction, and which does not cause said prime mover to rotate when said driveshaft rotates in a second direction opposite to said first direction; and wherein said driveshaft includes a ratchet with a series of ratchet teeth extending radially therefrom and which are slanted in one rotational direction, said prime mover having at least one pawl with teeth associated therewith which engage said ratchet teeth of said ratchet when the driveshaft rotates in said first direction, but which allows the prime mover to freewheel and not rotate when said driveshaft rotates in a second direction opposite said first direction.

21. The hydrofoil pedal driven vehicle of claim 20 wherein at least one of said front foil or said rear foil includes a cross-sectional form with a convex upper surface and a recurve lower surface including a convex forward portion and a concave rearward portion.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

(2) FIG. 1 is a perspective view of an exemplary embodiment of a hydrofoil bike;

(3) FIG. 1A is a perspective view of a bare frame depicting the strut extents and the position of their respective hydrofoils exploded therefrom;

(4) FIG. 1B is a perspective drawing of a preferred embodiment of an intermediary bayonet-mount to connect the rear foil to the frame;

(5) FIGS. 2 & 2A are perspective views of an exemplary embodiment of a hydrofoil bike with buoyancy modules;

(6) FIG. 2B is a perspective view depicting an exemplary propeller cowling that provides a streamlined and buoyant covering that encapsulates the rear strut and lower drivetrain;

(7) FIG. 2C is a series of two perspective views depicting an optional protective tail-piece at the rear portion of the streamlined strut cowling.

(8) FIG. 3 is a perspective view of an embodiment depicting the preferred hydrofoil arrangement that is a canard configuration;

(9) FIG. 3A is the cross-section profile of a supercritical-type foil specifically developed for an exemplary embodiment of the present invention;

(10) FIG. 3B is a perspective view depicting an exemplary embodiment of a hydrofoil bi-plane arrangement that utilizes a secondary or auxiliary foil;

(11) FIG. 3C is a perspective view depicting an exemplary embodiment of a hydrofoil arrangement that utilizes an elliptical-style rear foil;

(12) FIG. 3D is a perspective view depicting an exemplary embodiment of a hydrofoil arrangement that utilizes a swept-back rear foil;

(13) FIG. 3E is a perspective view depicting an exemplary embodiment of a hydrofoil arrangement that utilizes a surface-piercing rear foil;

(14) FIGS. 4 & 4A are perspective views of an exemplary embodiment of a steering assembly;

(15) FIG. 5 is a perspective view of an exemplary embodiment of a preferred tiller assembly;

(16) FIG. 5A is an exploded perspective view of FIG. 5;

(17) FIG. 5B are a series of typical perspective views of different tiller arms and tiller heads;

(18) FIG. 6 is a perspective view of an exemplary embodiment of a preferred drivetrain assembly;

(19) FIG. 6A is an exploded perspective view of an exemplary embodiment of a preferred drivetrain assembly, depicting its two main sub-sections; the drive-mechanism and the gearbox units, relative to the placement of the propeller assembly;

(20) FIG. 6B is an exploded perspective view of an embodiment of a drive-mechanism sub-section;

(21) FIG. 6C is an exploded perspective view of an embodiment of a drive-mechanism sub-section, relative to the bike frame and the top gearbox unit;

(22) FIG. 6D is a diagram of typical locations where a singular motor or series of motors can be introduced along the drive-path of the drivetrain assembly;

(23) FIG. 6E is a perspective view of an exemplary embodiment of an alternative drivetrain assembly that incorporates a mid-drive electric motor;

(24) FIG. 6F is a perspective view of a bare frame specifically designed to accept a drivetrain assembly that incorporates a mid-drive electric motor, typically identified by the absence of a bottom bracket tube;

(25) FIG. 6G is a perspective view of a bare frame specifically designed to accept a drivetrain assembly that incorporates a mid-drive electric motor, depicting a bottom bracket module so that the frame can reverted back to a manual non-motorized configuration;

(26) FIG. 7 is a perspective view of an exemplary embodiment of a preferred propeller assembly, relative to the thrust-tube of the frame and the lower gearbox;

(27) FIG. 7A is an exploded perspective view of an exemplary embodiment of a preferred propeller assembly;

(28) FIG. 7B is an exploded perspective view of an exemplary embodiment of a preferred configuration of a ratchet-type propeller drive-block;

(29) FIG. 7C is an exploded perspective view of an exemplary embodiment of a preferred propeller;

(30) FIGS. 7D & 7E are diagrams of typical locations where the propeller can be positioned, relative to the water surface and the rear foil while the bike is in cruise mode;

(31) FIG. 8 is a perspective view depicting a favorable starting position for the hydrofoil bike with an ‘above-water’ jetty launch maneuver;

(32) FIG. 9 is a perspective view depicting a favorable momentary position for the hydrofoil bike and rider, prior to starting a submerged launch maneuver;

(33) FIG. 10 is a perspective view depicting a favorable above-water surface cruising position.

BEST MODES FOR CARRYING OUT THE INVENTION

(34) FIG. 1 depicts an exemplary embodiment of a hydrofoil bike (150) whereby all of its various assemblies and components are attached to its main frame (100). Generally the hydrofoil bike is subdivided into two sections—the front section (100F) wherein the steering and pitch/elevation of the vehicle is controlled; and the rear section (100R) from which the vehicle derives its mode of propulsion and its substantial source of lift.

(35) The various parts of a preferred embodiment of the main frame (100) are depicted in FIGS. 1 and 1A. A horizontal member (101) of the main frame (100) connects the front section (100F) and the rear section (100R) together. The steering fork (401) (also seen in FIG. 4A) derives its orientation from the head tube (102) which also restricts the side to side movement of the fork (401) via a restrictor slot (102a).

(36) A typical bike saddle (103a) is conventionally attached to a typical seat post (103b) which is then inserted into the seat tube (103) that forms an adjustable telescopic interface. The position of the seat post (103b) is secured by a seat clamp (103c) clasping the upper end of the seat tube (103) of the bike frame (100).

(37) The overall configuration of the main frame (100) includes a front strut (104) and a rear strut (106). The front strut (104) is also part of a steering assembly (400) (seen in FIG. 4) and is therefore a reactive structural member with variable orientation in relation to the bike frame (100). The rear strut (106) is a fixed structural member of the bike frame (100) which extends downwards from a bottom bracket tube (107) and the horizontal member (101). The horizontal and transverse orientation of the bottom bracket tube (107) has apertures at both sides, upon which the drive-mechanism (601) (seen in FIG. 6A) is integrated.

(38) A thrust tube (109) is located at or near a bottom end of the rear strut (106). The horizontal and longitudinal orientation of the thrust tube (109) has a front end, upon which the propeller assembly (700) (seen in FIG. 7) is integrated in this exemplary embodiment. A mounting gusset (108) is located behind and adjacent to the bottom bracket tube (107). The mounting gusset (108) and the rear end of the thrust tube (109) are both mounting points, upon which gearbox unit (sub-section (602) seen in FIG. 6A) is integrated.

(39) An intermediary vertical member (110) is located between the bottom of the thrust tube (109) and an upper midsection of a rear foil (302). The top end of the vertical member (110) is integrated securely onto the bottom of the thrust tube (109) via appropriate fasteners (109a) as depicted in FIG. 1B, thereby becoming a unified structural extension of the rear strut (106) of the bike frame (100).

(40) The bottom end of the vertical member (110) is fashioned to have a male bayonet shape which provides a quick-release interface when connected to its female bayonet counterpart or shoe (111) and is locked securely in place by one bolt (111a). This female bayonet shoe (111) is likewise integrated onto the upper midsection of the rear foil (302). Appropriate fasteners (302a) inserted from the bottom of the rear foil (302) midsection are tightened against threaded areas at the bottom of the female bayonet shoe (111). This exemplary rear interface between the frame (100) and rear foil (302) allow for modularity to facilitate disassembly for storage, transport, repair, swapping of parts for performance adjustment, etc.

(41) The bottom end of the front strut (104) has an intermediary flange or front strut shoe (105) that provides a wider footing to allow a more secure connection for a front foil (301). This flange or front strut shoe (105) is clamped in between the bottom of the front strut (104) and the upper midsection of the front foil (301). As shown in FIG. 5A, appropriate fasteners (301a) are inserted from the bottom of the front foil (301) midsection, and are tightened against threaded areas at the bottom end of the front strut (104). This exemplary front interface can similarly allow for removal of the front foil (301) from the frame (100) to facilitate modularity as discussed above.

(42) FIG. 2 depicts a perspective view of an exemplary embodiment of a hydrofoil bike (150) with buoyancy modules (201 and 202). Although the preferred embodiment is separated into a front module section (201) and a rear module section (202), a singular unified buoyancy module (not shown) may also be adopted. The illustration continues to show a streamlined strut cowling (203) that covers a lower half of the gearbox unit subsection (602) (as seen in FIG. 6A), the rear strut (106), the thrust tube (109), and the bayonet upright member (110) below it (as shown in FIG. 1A).

(43) An optional storage module (202a) is preferably located at the front of buoyancy module (202) and below the saddle (103a). This module may be utilised as a storage area, or may house a battery if an electric motor is installed. Alternatively, the area may be allocated for attaching a drinking bottle. However, this is not meant to be limiting as other locations around the hydrofoil bike (150) may be utilised for this purpose.

(44) FIGS. 2A and 2B illustrate how the buoyancy modules (201-202) and the rear strut cowling (203) are split into two halves (201L, 201R; 202L, 202R; and 203L, 203R respectively) along its vertical centerline in this exemplary embodiment. The central portions of the modules and cowling halves have matched cavities that allow them to encapsulate appropriate portions of the bike frame (100) and all drive assemblies, such that vital operational functions and user movements are unimpeded. The buoyancy modules (201, 202, 203) are preferably formed with void space between inner and outer surfaces, either open or filled with a lightweight filler (e.g. closed cell foam) so that the modules (201, 202, 203) are low density and add buoyancy to the bike (150). This buoyancy is preferably enough to give the bike overall slightly positive buoyancy. In this way, the bike (150) cannot sink and allows for deep water starts (as depicted in FIG. 9) without requiring a bulky and high drag hull.

(45) On occasions where the user may want to park the hydrofoil bike to rest on the ground from its rear end, an optional tail-piece (204) may be utilised to protect and reinforce the rear portion of the strut cowling (203) as shown in FIG. 2C (i) and (ii). The tail-piece (204) can be made of resilient material, such as nylon or polyethylene, so that the non load-bearing cowling (203) construction can remain as lightweight as possible. The tail-piece (204) is a replaceable item that also serves as a fastener to secure the rear of the cowling halves (203R and 203L) together.

(46) The preferred hydrofoil canard arrangement in FIG. 3 depicts a rudimentary embodiment of a hydrofoil bike (150a) that utilizes a versatile multi-purpose rear foil (302) and front foil (301) designs—the size and span of which are complementary to each other. The rear foil (302) is designed to be capable of low-speed submerge launching (high lift), but also has very good high-speed cruising characteristics (relatively low drag within the intended cruising speed range). Both the rear foil (302) and the front foil (301) (or at least one of them) utilize a purposely developed supercritical style hydrofoil profile (300). Its cross-sectional detail is depicted in FIG. 3A. The leading end is (300a) and the trailing end (300b) has a butted square trailing edge. The distance between them is the chord length (300c).

(47) The particular supercritical style hydrofoil profile depicted in FIG. 3A has a cross-sectional profile that is generally defined by an upper surface of convex form and a lower surface of recurve form, with a convex forward portion and a concave rearward portion. The upper surface and lower surface come together at a leading edge and also come together at the trailing end (300b). The upper surface has an upper maximum which is slightly closer to the leading edge than to the trailing end (300b). In particular, this upper maximum is preferably between 30% and 50% of the way from the leading edge to the trailing edge, and most preferably at between 40% and 45% of the way from the leading edge to the trailing edge.

(48) The lower surface has a lower minimum which is located in the forward convex portion of the lower surface, and preferably about 30% of the way from the leading edge to the trailing edge, but generally between 20% and 40% of the way from the leading edge to the trailing edge. The lower surface has a recurve contour with an inflection point (where it transitions from being convex to being concave) which is preferably located between 40% and 70% of the way from the leading edge to the trailing edge, and most preferably at about 60% of the way from the leading edge to the trailing edge. The concave rearward portion of the lower surface has a local maximum which is preferably located between 70% and 90% of the way from the leading edge to the trailing edge, and most preferably located at about 82% of the way from the leading edge to the trailing edge.

(49) The supercritical foil profile (300) preferably has a thickness which is about 15% of the chord length at its greatest extent (and generally between 10% and 20%), which is located generally between 20% and 50% of the way from the leading edge to the trailing edge. Other details of the hydrofoil profile (300) can be discerned from careful study of FIG. 3A.

(50) At much higher top cruising speeds, a general purpose rear foil (302) will have excessive lift and drag characteristics. A rear foil with a shorter chord length and narrower wingspan is more suitable for high speed applications. A typical high speed foil (303) as seen in FIG. 3B is depicted in a rudimentary embodiment of a hydrofoil bike (150b). It has lower drag characteristics but it comes at the expense of reduced lift, such that low speed submerged launching may no longer be possible.

(51) FIG. 3B also illustrates a bi-plane configuration whereby an auxiliary rear foil (304) is employed to augment the lift deficiency of a smaller high speed rear foil (303). Both foils (303 and 304) are submerged initially, so that their combined lift output is sufficient to elevate the vehicle from a submerged launch maneuver. However, as soon as the vehicle gathers sufficient speed, the auxiliary foil (304) affixed appropriately onto the rear strut (106), is eventually elevated above the surface of the water. In doing so, the extraneous lift and drag generated by an auxiliary foil (304) at high cruising speeds is eliminated. Other styles of auxiliary foils (304) may be appropriately attached to intermediary structural members extending from the rear strut (106), or the mid-section of the bike frame (101), or from the ends or any portion of the rear foil itself (302). Such an auxiliary foil (304) can also act to guard the propeller (700) (FIG. 6) from contacting a user's foot, should it slip off of the pedals (601).

(52) FIG. 3C depicts a rudimentary embodiment of a hydrofoil bike (150c) which has an elliptical rear foil (305) being employed to achieve enhanced or specialized maneuvering characteristics, where a narrower wingspan combined with a much longer chord length (300c) at the midsection of the rear foil (305) is desirable. FIGS. 3D and 3E depicts rudimentary embodiments of a hydrofoil bike (150d and 150e) equipped with representations of a swept-back wing (306) and a surface-piercing hydrofoil (307), respectively. Both foil types are solutions to manage extraneous lift and drag characteristics at higher cruising speeds.

(53) Although FIGS. 3B, 3C, 3D and 3E illustrate various foil types as alternatives to a preferred multi-purpose rear foil (302) as applied to the rear section of the bike (100R), it is not beyond the scope of the invention to employ any of these foil types as alternatives to a preferred front foil (301) as applied the front section of the bike (100F). The front and rear foils may be a matched pair of any one particular foil type alternative, or may be configured in any mismatched combination.

(54) A preferred embodiment of the steering mechanism (400) of the vehicle is associated with the front section (100F) of the bike frame (100), and is illustrated in FIGS. 4 and 4A. A steering fork (401) is inserted from the bottom end of the head tube (102). Its steerer tube (401a) can rotate along its axis, supported by low-friction bearings or bushings (406) at the top and bottom end of the head tube (102). The steering fork is held securely in place by a locking clamp (405) affixed adjacent to the top steerer bushing (406).

(55) A handlebar (402) with hand grips on either end (403) is attached to an intermediary stem (404) which is then attached to the top end of the steerer tube (401a). A fork horn (401b) extends forward from the base of the steerer tube (401a). The forward end of the fork horn (401b) has a transverse fork horn or pivotal aperture (401c) onto which a pivot junction (501) is attached (see FIG. 5). The rear end of the fork horn (401b) has a structural protrusion (401d) that fits into a restrictor slot (102a) at the base of the head tube (102). The restrictor slot (102a) limits the movement of the fork protrusion (401d), and so therefore restricts the rotational movement of the fork horn (401b) along its steerer tube (401a) axis according to this exemplary embodiment. This restricted fork movement is in direct proportion to the side to side pivotal movement of the front strut (104), see in FIG. 1A, relative to its function as a rudder.

(56) As shown in FIGS. 5 to 5B(iii) a tiller module (500) is provided as a pivoting mechanism that enables an automatic, self-correcting pitch control for the front foil (301). The mechanism is comprised of a pivot junction (501), a tiller arm (502), and a tiller head (503 preferred). The pivot junction (501) is attached to the fork horn aperture (401c) via a transverse pivot pin (501a). The pivot junction (501) has a top cavity (501b) and a bottom cavity (501c). The fork horn (401b) is inserted into the top cavity (501b) which forms a mechanical restrictor that limits the transverse pivotal up/down movement of the tiller module (500). This restricted tiller movement is in direct proportion to the transverse pivotal forward/aft pendulum movement of the front strut (104), because the strut is integrated into the bottom cavity (501c) of the pivot junction (501).

(57) The integration is secured by an appropriate fastener (104a) which is inserted from the top of the pivot junction (501) and tightened against a threaded portion at the top end of the front strut (104). Because the front foil (301) is directly connected to the bottom end of the front strut (104), the strut's transverse pivotal forward/aft pendulum movement changes the pitch (angle of attack) of the front foil (301) accordingly.

(58) The front end of the tiller arm (502) can be fitted with various tiller heads depicted in FIG. 5B(i) to (iii). The tiller head may be a simple skid-plate (505), or a streamlined bulb or nose cone (504), or another miniature pivoting tiller mechanism (503) to constitute a compounded tiller module (500), which is a preferred embodiment.

(59) FIG. 6 is a perspective view of an exemplary embodiment of a preferred drivetrain assembly (600) that delivers power from a power source to the propeller (701) or other prime mover, and a propeller assembly (700) relative to the bike frame (100). The drivetrain assembly (600) has two sub-sections; the drive mechanism sub-section (601), and the gearbox units sub-section (602) as depicted in FIG. 6A. The gearbox sub-section (602) is comprised of an upper gearbox (602a), a lower gearbox (602b), and a vertical driveshaft (602c) which connects them both.

(60) FIGS. 6B and 6C are exploded perspective views showing the various components of the exemplary drive mechanism sub-section (601). A crankset sub-assembly (603) may be installed relative to the bottom bracket tube (107) onto the bike frame (100). The crankset assembly (603) may be similar to a typical bicycle crankset sub-assembly. The drive sprocket-wheel (601a) also referred to as a chainring, transmits rotary motion to the drive sprocket wheel (601b) via a roller chain (601c), which is kept at a correct tension by an idler wheel (601d) held in place by a tensioner arm (601h) which is adjustably fastened to a torque plate (601i). The drive sprocket wheel (601b) is securely held and rotates along the axis of a ball bearing (601j) which is pressed into place at the back end of the torque plate (601i). The ball bearing (601j) supported by the torque plate (601i), bears the majority of the applied torque load being exerted onto the driven sprocket-wheel (601b). This configuration ushers two advantages; the upper gearbox (602a) having bevel gear axles with small internal bearings is therefore insulated from excessive side-thrust loads; and the upper gearbox (602a) may therefore be removed from the gusset plate (108) mount and replaced without having to dismantle the entire drive mechanism sub-section (601).

(61) The chainring (601a) rotates along the axis of the crank axle (601e), which derives its rotational orientation from the bottom bracket tube (107) into which the axle (601e) and the bottom bracket bearings (not shown) are installed. The user applies human energy onto the pedals (601g) (as one form of power source) so that up and down leg motion is converted into rotary motion by the crank arms (601f), which drives the axle (601e), which in turn drives the chainring (601a).

(62) Motorized configurations (fully-powered or pedal-assist modes) can be installed to transmit full or supplementary drive power along any sector of the drivetrain assembly (600) and propeller assembly (700), as depicted in a typical diagram FIG. 6D. A motor in position [A] may be internally integrated with gears to drive the crank axle (601e) directly, or may be externally integrated to drive the crank axle (601e) via an auxiliary set of sprocket-wheels with its own auxiliary roller chain.

(63) FIG. 6E is a perspective view of another exemplary embodiment of a preferred drivetrain assembly (600) that delivers power from a mid-drive motor assembly (601MD) in position [A] (see FIG. 6D) to the propeller (701) or other prime mover, and a propeller assembly (700) relative to a mid-drive bike frame (100MD). The mid-drive bike frame (100MD) is configured to accept a mid-drive motor (604) and a battery unit (606). Motorized mid-drive units (604) may typically incorporate a built-in crank axle (601e) or crankset assembly (603) as shown in FIG. 6F as mid-drive crank assembly 605. In this arrangement the mid-drive bike frame (100MD) is characterized by the absence of a bottom bracket tube (107), as depicted in FIG. 6F. A mid-drive motor (604) may be affixed to a mid-drive bike frame (100MD) using one or more gusset mounts (112), preferably there are a plurality of gusset mounts. Preferably the one or more gusset mounts are removable. One or more of the gusset mounts may function as a gusset mount (108MD) for the upper gearbox (602a). Other variations of mid-drive motor units (604) may be adapted easily to fit the mid-drive bike frame (100MD), by utilizing corresponding gusset mounts (112) that match the bolting pattern of said mid-drive motor unit variation. In some forms the motorized mid-drive unit (604) is electric and may include a self-contained and detachable battery unit (606) to provide the electrical power. A skilled addressee would appreciate that any type of battery may be used including rechargeable or non-rechargeable batteries. FIG. 6E depicts the battery (606) located but not limited to a position directly above the horizontal member (101). In other forms, other types of fuel or energy may be similarly contained and located to be used to power the motor—such as but not limited to petrol, diesel, combustible gaseous fuels or compressed gaseous propellants.

(64) FIG. 6G is a perspective view of an exemplary embodiment of a mid-drive bike frame (100MD) depicting a conversion method to revert the frame configuration back to utilize a manual non-motorized drive train (601). The conversion is achieved by replacing the mid-drive motor (604) with a bottom bracket module (113). The bottom bracket module (113) comprises a bottom bracket tube (107) to allow coupling of a typical crankset assembly. The bottom bracket module (113) is affixed to the mid-drive bike frame (100MD) via the one or more motor gusset mounts (112). After attachment of the bottom bracket module (113) a crankset assembly (603) may be installed to the bottom bracket tube (107) of the bottom bracket module (113).

(65) A motor in position [B] may be integrated to drive the vertical driveshaft (602c) directly. A motor in position [C] which may be placed in front, within, or behind the thrust tube (109) integrated to drive the propeller shaft (707) (as seen in FIG. 7A) directly. A motor in position [D] may be integrated inside the cylindrical boss of the propeller (701a) itself (as seen in FIG. 7C).

(66) Although a single motor may be placed in one location [either A, B, C, or D], it is not beyond the scope of the invention to employ more than one motor in any two or more locations within the drivetrain assembly (600) and propeller assembly (700). Further to this, a completely independent motor (or motors) that is mechanically separated from a pedal-operated drivetrain, may be integrated on one location or multiple locations on the bike to provide full or supplementary sources of propulsion.

(67) FIG. 7 shows that the propeller assembly (700) is located ahead of the rear strut (106) and is directly attached to the front end of the thrust tube (109). When rotational energy is applied to the propeller assembly (700), it produces thrust such that it pulls the thrust tube (109) and all associated structural members along with it, and therefore propels the whole vehicle forward. Generally, the rotation axis of the propeller assembly (700), the longitudinal centerline of the thrust tube (109) and the rotational axis of the forward-facing output shaft of the lower gearbox unit (602b), share a precise commonality.

(68) As seen in FIG. 7A, propeller shaft (707) with a female spline interface protrudes at the rear end of the propeller assembly (700). The lower gearbox unit (602b) is attached to the rear end of the thrust tube (109). Its forward-facing output axle has a male spline interface which couples directly with the rear end of the propeller shaft (707) inside the thrust tube (109). This splined coupling is free to move forward and aft even while drive force is applied, but is axially fixed by the structural association provided by the thrust tube (109). Therefore only the thrust tube (109) and the rear strut (106) connected to it, are subjected to the full thrust load generated by the propeller assembly (700), thus pulling the bike forward. This configuration ushers two advantages; the lower gearbox (602b) having axles with small internal bearings is therefore insulated from excessive frontal-thrust loads; and the lower gearbox (602b) as well as the propeller assembly (700) can therefore be removed from the bike frame and replaced without prior dismantling of either assembly.

(69) FIG. 7A is an exploded perspective view showing the various parts that comprise the propeller assembly (700) in detail. Thrust bearings (706a) are pressed into stepped apertures at the front and rear of the bearing hub (706), with a spacer tube (706b) in between them. The propeller shaft (707) is inserted from behind the bearing hub (706) and passes through the centre of the bearings (706a) and spacer (706b), such that the propeller shaft (707) is allowed to freely rotate along the central axis of the bearing hub (706) but cannot be pulled forward and removed out the front of its hub (706). Low-friction bushings (701d) are pressed into stepped apertures at the front and rear of the cylindrical propeller boss (701a) (as seen in FIG. 7C), such that the propeller (701) freely rotates along the axis of the propeller shaft (707) regardless of whether the shaft is stationary or rotating with drive motion. Without an intermediary hexagonal drive block (703 or 704) installed inside the hexagonal cavity (701c) located at the front of the cylindrical propeller boss (701a), the propeller shaft (707) is incapable of driving the otherwise free-spinning propeller (701).

(70) The drive block (703 or 704) has a hexagonal hole running through the entire length of its central axis. The front end of the propeller shaft (707) has a matching hexagonal spline (707a) which is inserted through the centre of the drive block (703 or 704) which forms an interface whereby the propeller shaft (707) is able to rotate the drive block (703 or 704), which in turn is able to rotate the propeller (701).

(71) A ratchet-type drive block (704) is capable of rotating the propeller (701) only in its thrust direction, but will spin-freely in the opposite direction. Whereas a solid-type drive block (703) is capable of rotating the propeller (701) in either direction, so that it may be used to produce propulsion and a braking effect. A locknut (705) is installed on the threaded portion (707b) of the propeller shaft (707) which then unifies all the various parts of the assembly (700)—with the exception of the propeller nose cone (702) which is a non load-bearing member. An appropriately designed nose cone (702) is held in place either by the threaded portion (707b) protruding past the locknut (705) (as in the case when a solid drive block (703) is used), or the nose cone may be press-fitted into protrusions at the front of a ratchet drive block (704).

(72) FIG. 7B is an exploded perspective view showing the various parts that comprise the preferred embodiment of a ratchet-type drive block (704). A central thimble barrel (704c) has a central hexagonal hole running through its entire length, which is coupled to the matching hexagonal spline (707a) of the propeller shaft (707) resulting in a secure connection capable of bearing the entire thrust load of the propeller (701), as seen in FIG. 7A. The central thimble barrel (704c) has ratchet teeth all along its outer periphery which engage with pawls (704d) that are pivotally encapsulated within a hexagonal housing (704a and 704b combined) that fits inside the propeller cavity (701c). Dedicated flat reed springs (704e) fit between dedicated slits in posts extending rearward from the front half (704a) and forward from the rear half (704b) of the hexagonal housing and also press against cam grooves in the pawls (704d). These springs (704e) ensure that each of the pawls (704d) engage or disengage against the ratchet teeth, depending on direction of rotation of the propeller. Fasteners (704f) in the form of long bolts which thread into threaded bores in the posts of the rearward half (704b), pass through holes in the forward half (704a) of the hexagonal housing to unify the entire ratchet assembly. These bolts (704f) or other fasteners also serve as structural protrusions to press-fit the nose cone (702) into.

(73) A propeller (701) may have any number of blades (701b), typically ranging from 2 to 6 (4 blades illustrated) arising from a central cylindrical boss (701a) with a diameter (701e) ranging from approximately 2 to 4 inches (approximately 50 mm to 100 mm), as shown in FIG. 7C. The circular travel path of the blade ends (701-X) defines the diameter (or size) of the propeller (701-DIA) with a range between approximately 8 to 14 inches (approximately 203 to 355 mm). The depth (701-Y) between the surface of the water [W] and the upper extremity of the circular travel path of the blade ends (701-X) ranges from a minimum of 60 mm and a maximum of 300 mm depending on the operational application, is depicted in FIG. 7D.

(74) FIG. 7D is a diagram where the trust tube (109) and therefore the rotational axis of the propeller (701) is positioned substantially higher than the chord of the rear foil (302) whereby the distance (701-Z) between the bottom of the rear foil (302) and the lower extremity of the circular travel path of the blade ends (701-X) ranges from 0 to 100 mm. It will be apparent to persons skilled in the art that the thrust tube (109) needs to be positioned at an appropriate elevation along the rear strut (106) in order to achieve these ideals.

(75) FIG. 7E is a diagram where the trust tube (109) and therefore the rotational axis of the propeller (701) is positioned at the same level of the rear foil (302). A strake or an arrangement of strakes (708) extending down from the bottom of the rear foil (302) can be utilised in order to protect the propeller blades (701b) from ground strikes, whereby the distance between the bottom end of the strake/s (708) and the lower extremity of the circular travel path of the blade ends (701-X) ranges from 0 to 100 mm.

(76) The scope of the various locations for the propeller (701) can be anywhere in between the ideals specified in FIGS. 7D and 7E. While the rear foil (302) is lower than the front foil (301), an imaginary line between the bottom of these two foils (301, 302) is preferably sufficiently low that the propeller (701) is above this line and hence is elevated above a surface if both foils (301, 302) are resting upon such a surface.

(77) Launching the hydrofoil bike (150) from a structure above the water (W) is illustrated in FIG. 8. The user lowers the rear foil (302) and propeller (701) into the water (W), while standing on an appropriate platform (801). The orientation of the bike (150) is such that the tiller module (500) as well as the front foil (301) remains momentarily above the water (W). While initially holding the saddle (103a) with one hand, and holding the handlebar (402) with the other, the user lunges forward in one fluent motion, by pushing off with one foot while simultaneously placing the preferred foot onto the leading pedal (601g). The user then sits on the saddle (103a) and pedals immediately to generate propulsion and therefore lift.

(78) Launching the hydrofoil bike (150) from a semi-submerged position in deep water (W) is illustrated in FIG. 9. The user swims to the hydrofoil bike (150) and re-orients it to an upright position. Learnt skill is required for the user to be able to mount the bike (150) (not seated but with feet planted on both pedals), while keeping the bike orientation substantially horizontal while stationary—as depicted in the illustration. As the user's weight is shifted above the vehicle, the inherently buoyant bike (150) will sink completely underwater—with the user ending up being chest deep in water when static and momentary equilibrium is achieved.

(79) Until some forward movement is attained by pedaling, the user should refrain from placing too much weight onto the handlebars (402) otherwise static equilibrium is lost. This is because without forward movement, the front foil (301) is not producing any lift to support the weight of the user, should it bear down on the front section (100F) of the bike. As the bike gradually attains adequate speed to be able to produce sufficient lift to elevate the bike out of the water, the user is able to lean forward while pedaling hard off the saddle (standing) and continually adjusts his or her body weight (forward or aft) to achieve the ideal sub-launching pitch (or angle of attack) for the rear foil (302). This is a very satisfying intuitive skill that can only be mastered by practicing and repetition.

(80) Operating the hydrofoil bike (150) from above the water surface at cruising speed is illustrated in FIG. 10. Once the bike (150) has achieved sufficient speed commencing from a launch off a structure (801) substantially above the water (as depicted in FIG. 8), or commencing from a submerged launch (as depicted in FIG. 9)—the rear foil (302) will produce sufficient lift to elevate the rider and the upper portion of the bike (150) above the water (W) surface. The tiller head (503, in this instance a mini tiller) will be able to sustain its propensity to travel along the surface of the water (W). In so doing, the tiller arm (502) will be pivotally and dynamically actuated by the tiller head (503). Because the front strut (104) is unified with the tiller arm (502), the pivotal movements of these members are directly proportionate to each other.

(81) As the front strut (104) swings in its predetermined forward/aft pendulum motion, the front foil (301) which is attached to the bottom end of the front strut (104) will undergo a change in angle of attack depending on the tiller arm (502) orientation. If the bike (150) is cruising too low, the tiller head (503) skimming on the water (W) surface will spontaneously actuate the tiller arm (502) to adopt an upward orientation which will produce a positive angle of attack for the front foil (301). Inversely, if the bike (150) is cruising too high, the tiller head (503) will spontaneously actuate the tiller arm (502) to adopt a downward orientation which will produce a negative angle of attack for the front foil (301). Therefore, the ideal cruising elevation of the bike (150) in relation to the water (W) surface is maintained during speed variations within an acceptable cruising speed range—because the front foil (301) acts as the elevator control in a canard configuration where the rear wing (302) is the main source of lift for the vehicle.

INDUSTRIAL APPLICABILITY

(82) This invention exhibits industrial applicability in that it provides a pedal (or other human) powered water vehicle, using hydrofoil wings and a pedal (or other) driven prime mover, for transportation over a body of water.

(83) Another object of the present invention is to provide a pedal powered hydrofoil water vehicle which can be started from a standstill substantially entirely submerged, and a rider can ride up out of the water until most of the vehicle other than the hydrofoils is above the water's surface.

(84) Another object of the present invention is to provide a hydrofoil human powered vehicle for passing over bodies of water.

(85) Another object of the present invention is to provide a water vehicle which is human powered and efficiently transports a rider over the body of water.

(86) Another object of the present invention is to provide a human powered hydrofoil vehicle which can be fitted with various different hydrofoil wings which are interchangeable to vary performance characteristics of the vehicle.

(87) Another object of the present invention is to provide a human powered vehicle for transportation over a body of water which includes limited buoyancy, such that the vehicle is close to neutrally buoyant and a single user can readily change the orientation of the vehicle in various different ways while in the water with the vehicle, to allow a rider to mount the vehicle before it is moving and to drive the vehicle from a submerged start into a planning orientation with most of the vehicle above a surface of the water, other than hydrofoils thereof.

(88) Another object of the present invention is to provide a hydrofoil vehicle which can be effectively launched from a dock or other platform above a surface of the water while a rider is upon the vehicle.

(89) Another object of the present invention is to provide a method for launching a human powered hydrofoil vehicle from a deep water start position.

(90) Another object of the present invention is to provide a method for launching a human powered hydrofoil vehicle from a dock or other platform elevated above a surface of the water.

(91) Another object of the present invention is to provide a human powered hydrofoil vehicle which can be conveniently disassembled into subparts sufficiently small to allow easy shipping and transportation thereof, such as in a car, for transport to a body of water for use.

(92) Other further objects of this invention which demonstrate its industrial applicability, will become apparent from a careful reading of the included detailed description, from a review of the enclosed drawings and from review of the claims included herein.