Abstract:
A collapsible or compactable hydrofoil device having front and rear foils, a support structure and a steering mechanism that may be collapsed into a compact size for transport and storage. The steering mechanism includes several releasably coupled components that are in turn coupled to a drive platform and drive foil. The drive platform may be configured in a plurality of embodiments that each achieve ready disassembly and reassembly. The drive foil may be configured of multiple releasably couplable sections.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 10/3657,664, filed Sep. 7, 2003, and having the same inventor as above and entitled “Self Propelled Hydrofoil Device.” 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to hydrofoil devices and, more specifically, to hydrofoil devices that may be configured for self propelled operation and are compactable for ease of transport and storage.  
       BACKGROUND OF THE INVENTION  
       [0003]     Relevant prior art hydrofoil devices include the “Trampofoil” device disclosed in Swedish Design Patent no. 98-0088 and a Water Vehicle disclosed in U.S. Pat. No. 6,099,369 issued to Puzey.  
         [0004]     The Trampofoil discloses a basic self-propelled hydrofoil device having a main foil in the rear and a steerable foil in the front. The &#39;369 patent issued to Puzey discloses a related device that has a biased pivot point located substantially above the rear foil, i.e., under the area at which a user stands when in use (FIG. 9, item 82, or FIG. 10, item 72).  
         [0005]     Disadvantageous aspects of the Trampofoil device and the &#39;369 patent include that they may not permit the front edge of the rear or “drive” foil to tilt sufficiently downward in response to a driving leg thrust to adequately propel the craft forward. A significant amount of the downward leg force may thus be impaled upon the foil, rather than shearing through water—wasting significant driving energy. In addition, the steering shaft of the Trampofoil is made of fiberglass which bends not only in the direction of travel, but also laterally, making steering difficult.  
         [0006]     Due to these and other disadvantageous aspects, the arrangement of the Trampofoil and that of the &#39;369 patent are difficult to use, particularly by lay persons.  
         [0007]     A need thus exists for a hydrofoil device that may be configured for self-propelled operation and is relatively easy to use. A need also exists for a hydrofoil device that provides sufficient forward thrust for the energy expended by the downward thrust of an operators leg&#39;s (or other means).  
         [0008]     In addition, the arrangements of the Trampofoil and the &#39;369 patent are bulky and not collapsible. This negatively impacts transport and storage and accessibility for use. For example, either a special large capacity vehicle is required for their transport, or they are assembled in place and remain there. Storage opportunities are also negatively impacted by the large unweilding configuration of these devices.  
         [0009]     A need exist for a hydrofoil device that can be readily collapsed or compacted for easy transport and/or storage.  
       SUMMARY OF THE INVENTION  
       [0010]     Accordingly, the present invention is directed towards providing a hydrofoil device that provides ready forward movement in response to driving thrusts or a related force.  
         [0011]     The present invention is further directed towards providing a hydrofoil device that is collapsible or compactable for ready transport and storage.  
         [0012]     These and related objects of the present invention are achieved by use of a self-propelled hydrofoil device as described herein.  
         [0013]     In one embodiment of the present invention, one or more of the steering mechanism, operator platform and foils are collapsible, and preferably all are to render a compact size.  
         [0014]     The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective view of a hydrofoil device  10  in accordance with the present invention.  
         [0016]      FIG. 2  is a diagram of relative drive foil position during use.  
         [0017]      FIGS. 3-7  are perspective views of other embodiments of a hydrofoil device in accordance with the present invention.  
         [0018]      FIG. 8  is a perspective view of an embodiment of a hydrofoil device in accordance with the present invention that achieves a compact size.  
         [0019]      FIG. 9  is a perspective view of another embodiment of a hydrofoil device in accordance with the present invention that achieves a compact size.  
         [0020]      FIGS. 10-12  are perspective views that illustrate assembly details for the hydrofoil devices of  FIGS. 8 and 9 . 
     
    
     DETAILED DESCRIPTION  
       [0021]     Referring to  FIG. 1 , a perspective view of a hydrofoil device  10  in accordance with the present invention is shown. Hydrofoil device  10  may include a forward located canard arrangement  20  and a rear or aft located drive foil  30 .  
         [0022]     The canard  20  may include a plate or spoon  21  (which tracks the water surface) and a foil member  22 , or be otherwise arranged. The primary function of the canard is finding and locking onto the water surface and canards and like devices are known in the art.  
         [0023]     The principal or drive foil  30  may be one of any suitable hydrofoil “wings” or “foils.” Such foils are known in the art. Drive foil  30  may be fixedly coupled to vertical members  33  which may be fixedly coupled to support bar  34 . Drive platform  60  is preferably configured to receive a standing human and may include two foot placement plates  62  or be otherwise arranged. Plates  62  are preferably fixedly coupled to bar  34  so that a downward thrust on the plates translates to a similar downward force asserted on foil  30 . Note that the plates may be located on the inside edge of support bar  34  such that the substantially downward thrust is first applied to the leading edge  31  of foil  30 .  
         [0024]     The steering mechanism  40  may include a steering handle  41  coupled to a steering shaft  42  that is provided in sleeve  61 . The distal end of the shaft is pivotally coupled to canard  20  at pivot  23 . The steering mechanism is preferably coupled to the drive platform via a support shaft  63  and associated sleeve  61 . The support shaft and sleeve may be securely coupled to the drive platform, for example, to support bar  34 .  
         [0025]     Shaft  42  preferably includes an upper section  44  and a lower section  45  that are coupled in such a manner that they may pivot or otherwise move relative to one another in such a manner as to achieve a downward tilt in the front edge  31  of drive foil  30 .  
         [0026]      FIG. 1  illustrates upper and lower steering shaft sections  44 ,  45  jointed at pivot  46  and bias into a given position by bias spring  47 . The relative movement of the two sections about pivot  46 , indicated as angle α, achieves a similar movement in the angle of attack, β, of leading edge  31  of foil  30 . Increases in α and thus β correspond to a more aggressive cutting of foil  30  into the water, thereby propelling hydrofoil device  10  forward.  
         [0027]     As the thrust of a user is spent, the force of bias spring  47  causes upper and lower sections  44 ,  45  to move towards their “rest position,” i.e., into closer alignment, thereby decreasing both α and β and ultimately causing leading edge  31  of foil  30  to move upward placing foil  30  back in position for another downward, forward propelling thrust.  
         [0028]     Referring to  FIG. 2 , a diagram of relative drive foil position during use is shown. Position A is a glide or “steady-state” position as the foil glides through the water. Prior to a leg thrust a user preferably pushes on steering handle  41 . This causes upper and lower sections  44 ,  45  to move apart, i.e., out of alignment, increasing α (and β) and causing leading edge  31  to tip downward (Position B). The user then asserts a leg thrust on platform  60  causing tip  31  to descend further and causing the entire foil to descend into the fluid medium at an angle, pushing the craft forward against the resistance of the water. The position of foil  30  at this stage is shown in Position C. As the thrust expires, the force of the bias spring begins to reduce α and β, causing the leading edge to begin to rise and the foil to pass through a substantially steady state position, but further submerged than in Position A (Position D). The leading edge then rises slightly (due in part to the surface finding properties of the canard) causing the foil to rise (Position E) and return to its steady-state position (Position F, and Position A), ready for the next thrust.  
         [0029]     Note that while the upper and lower sections  44 ,  45  are preferably moveable in a first dimension to facilitate a desired movement of leading edge  31 , they are sufficiently rigid from side to side or in a “steering dimension” to provide adequate steering.  
         [0030]     Referring to  FIGS. 3-7 , other embodiments of a hydrofoil device in accordance with the present invention are shown. The devices illustrated in these figures are intended to illustrate aspects of the breadth of the present invention and in no way to limit the present invention to the illustrated embodiments.  
         [0031]      FIG. 3  illustrates device  10 , but with a pivot arrangement in steering shaft  42  that is different from that shown in  FIG. 1 . In the embodiment of  FIG. 1 , the upper section  44  extends past pivot  46 . In the embodiment of  FIG. 3 , the lower section  45  extends past pivot  46 . Bias spring  47  in both the embodiments of  FIGS. 1 and 3  may be an expansion spring or other suitable means.  
         [0032]      FIG. 4A  illustrates a perspective view (from below horizontal) of hydrofoil device  10  having a compression spring based pivot mechanism  70  in steering shaft  42 .  FIG. 4B  illustrates a close-up perspective view of the compression spring based pivot mechanism  70 . The embodiment of  FIGS. 4A-4B  provide a coupling member  71  that couples upper section  44  to lower section  45  via pivot  46 . A compression spring  72  is provided between the upper and lower sections  44 ,  45  and adjacent pivot  46  such that it compresses in a manner that increases α and β and expands in a manner that decreases these two angles, such that foil  30  functions as discussed above.  
         [0033]      FIG. 5  illustrates hydrofoil device  10 , albeit with a leaf spring type mechanism  81  coupled to pivotally connected sections  44 ,  45 . The leaf spring  81  may be made of steel or fiberglass or other suitable material. It may be formed with loops at both ends which are then coupled to the respective shaft sections  44 ,  45  by mounting pins. Other mounting mechanisms may be used. Spring  81  functions in a manner similar to compression spring  72 .  
         [0034]      FIG. 6  illustrate hydrofoil device  10 , albeit with a linear coil spring  82  coupled between shaft sections  44 ,  45 . A support shaft  83  is provided internal to the coil spring and the lower end of support shaft  83  descends into lower section  45 . In use, coil spring  82  is compressed when a user pushes down on handle  41  and thrusts his or her leg downward on platform  60 . The leg thrust on platform  60  drives the front end  31  of foil  30  downward propelling the craft forward and subsequent expansion of spring  82  pulls foil front end  31  back up through positions D and E to Position F (see  FIG. 2 ).  
         [0035]      FIG. 7  illustrates hydrofoil device  10 , albeit with a parallelogram or like coupling mechanism  85 . Mechanism  85  may include two cross-coupling members  86 ,  87  and a spring or other bias member  88 . The device of  FIG. 7  operates in a manner similar to that described in  FIG. 6  (with the two steering shaft sections  44 ,  45  toward or away from one another) and as elsewhere described herein.  
         [0036]     Referring to  FIG. 8 , a perspective view of an embodiment of a collapsible hydrofoil device  110  in accordance with the present invention is shown. Hydrofoil device  110  may include a forward located canard arrangement  120  and a rear or aft located drive foil  130 .  
         [0037]     The canard  120  may include a plate or spoon  121  (which tracks the water surface) and a foil member  122 , or be otherwise arranged. The canard preferably functions in a similar manner to canard  20  discussed above.  
         [0038]     A steering mechanism  140  is preferably provided similar to steering mechanism  40  of  FIG. 1 . The steering mechanism  140  may include a steering handle  141  coupled to a steering shaft  142  that is provided in sleeve  161 . The distal end of the shaft is pivotally coupled to canard  120  at pivot  123 . The steering mechanism is preferably coupled to a drive platform  160  via a support shaft or similar structure  163  which is coupled to sleeve  161 .  
         [0039]     Shaft  142  preferably includes an upper section  144  and a lower section  145  that function similar to upper and lower sections  44 ,  45  of shaft  42 . In the embodiment of  FIG. 8 , the lower section  145  is curved and a curved leaf spring  147  is provided for biasing the shaft sections towards a desired position (recovery position).  
         [0040]     A plurality of releasable pins or other releasable fastening mechanism  186 - 189  may be provided at the various joints of steering mechanism  140  to permit releasable attachment of the respective members to one another.  
         [0041]     Drive platform  160  is preferably coupled to the support shaft  163  and the drive foil  30  in a manner that permits collapsibility or ready disassembly of the drive mechanism of hydrofoil device  110 .  
         [0042]     The drive platform includes support bar  134  to which are coupled two foot placement plates  162 . In the embodiment of  FIG. 8 , support bar  134  includes two extension segments  136 ,  137  which are releasably mounted in receive cavities  153 ,  154 , respectively, in center bar segment  138 . The center bar segment may be of a length that is sufficient to securely mount plate  162 . Bar segments  136 ,  137  are respectively coupled through elbows  151 ,  152  to vertical members  133 ,  135 . The distal ends of vertical members  133 ,  135  in turn releasably couple to drive foil  130 . Drive foil  130  may be configured of multiple disassemble pieces such as foil sections  171 ,  172 . By providing extension segments  136 ,  137 , the center segment may be limited in length to that which is needed to support foot plates  162 , thereby rendering this portion of the drive platform compact. While support shaft  163  is releasably coupled in the embodiment of  FIG. 9  (see below), the relatively narrow center segment  138  permits the support shaft to be fixedly coupled while still maintaining a relatively compact footprint.  
         [0043]     Referring to  FIG. 9 , a perspective view of hydrofoil device  110  with another collapsible drive platform assembly in accordance with the present invention is shown. In  FIG. 9 , hydrofoil device  110  may have a canard  120 , steering mechanism  140  and coupling support shaft  163  as discussed above with reference to  FIG. 8 . The drive platform  160 , however, has an alternative configuration. In this embodiment, support bar  134  is formed in an extended configuration having an extended bar member  139  that releasably couples on one end to bar mounting section  155  and on the other end to bar mounting section  156 . The bar mounting sections  155 ,  156  are respectively coupled through elbows  151 ,  152  to vertical members  133 ,  135  and further to foil  130  as discussed above.  
         [0044]      FIG. 9  also illustrates that support shaft  163  may be releasably coupled to the drive platform  160 . In one embodiment, this is achieve by way of a stub  173  extending from support bar  134  and being configured to snuggly fit inside the tubular structure of the support shaft. The stub and shaft may have aligned at holes  174 ,  175  through which a removable fastener  176  may be provided. Alternatively, stub  173  may include a protrusion pin that is biased outward that fits into hole  175 , but may be depressed to release shaft  163 .  
         [0045]     Support shaft  163  is preferably releasably coupled to drive platform  160  in the embodiment of  FIG. 9  because the extended bar member  139  is longer then center segment  138  (of  FIG. 8 ) and, therefore, would be less compact than the embodiment of  FIG. 8  if not decouplable. It should be recognized that while the embodiment of  FIG. 8  illustrates a fixed coupling of shaft  163  to plate  160 , this joint may be decouplable as illustrated in  FIG. 9 , etc.  
         [0046]      FIGS. 10-12  illustrate features of the releasable assembly of hydrofoil device  110 .  FIG. 10  illustrates bar mounting section  155  having a longitudinal key or protrusion  157  that fits into a complementary recess located inside the tubular structure of extended bar member  139 . These components preferably achieve a snug frictional fit. Bar segments  136 ,  137  preferably have a similar key that fits into a complementary recess in the tube structure of receive cavities  153 ,  154 , respectively, or vice versa.  
         [0047]      FIG. 11  illustrates releasable coupling of vertical member  133  to foil section  171 . The end of vertical member  133  may include a mounting tab  181  that fits into a corresponding opening  183  in foil section  171 . Foil section  171  is preferably sealed about opening  183  so that water does not enter the foil. A similar tab  182  and corresponding opening  184  are provided with vertical member  135  and foil section  172 , respectively (see  FIG. 9 ).  
         [0048]     Vertical members  133 ,  135  are preferably made of a material such as aluminum, graphite, fiberglass or other material that has a some inherent elasticity, permitting the openings  183 ,  184  to be positioned inside of the non-flexed ends of the vertical members. The vertical members are then slightly flexed and their tabs respectively inserted into their corresponding openings. The tension or bias in the vertical members serves to positively couple the vertical members in the foil and thereby the keyed protrusions in their corresponding recesses.  
         [0049]      FIG. 12  illustrates the assembly of drive foil  130  from multiple sections  171 ,  172 . Section  172  may include an extension arm  191  having bias protrusions or pins  192  that are biased outward. Section  171  has a sleeve  193  with holes  194  formed therein. Arm  191  is preferably inserted into sleeve  193  such that pins  192  seat into holes  194 , thereby securely holding the two sections of the drive foil together. Alternatively other releasable fastening means including screws and the like may be used to releasably couple the foil sections.  
         [0050]     It should be recognized that the various releasable coupling schemes discussed above may be interchanged where appropriate and that various other releasable coupling mechanisms are known in the art and may be use as appropriate to releasably couple the various components of device  10 .  
         [0051]     Referring to  FIGS. 8 and 9 , it can be seen that the joint between foil section  171 ,  172  is approximately midway between the vertical members  133 ,  135 . It can also be seen that for each half section the vertical member attaches at a location where roughly ⅓ of the foil section extends outward of its vertical member and ⅔ inward. Through empirical evidence it has been determined that this configuration puts low or no pressure on the joint region during driving thrusts, thereby lessening the structural impact on the joint region.  
         [0052]     The embodiments discussed above may be, but are not necessarily, formed of the following materials. The foils may be formed of aluminum or graphite or fiberglass or another suitable material. The frame is preferably formed of aluminum or another suitable material. Frame components may be welded together or otherwise joined as appropriate and known. The bias mechanisms may include metal or composite springs, rubber or other elastic materials, etc. The handles may include rubber. Plastic may be provided on corners, edges and tube ends, etc., to smooth rough edges, provide seals or join components, etc. Various fabrication materials and techniques are known in the art.  
         [0053]     While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention and the limits of the appended claims.