Patent Publication Number: US-2015064995-A1

Title: Weight steerable self-propelled personal watercraft

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 14/011,654 titled “A Self Propelled Personal Watercraft” filed Aug. 27, 2013, and claims the benefit of U.S. Provisional Application No. 50/437,511 filed Aug. 29, 2012, both in the name of the same inventor as this application. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
     Not Applicable 
     BACKGROUND 
     The present disclosure generally relates to a self-propelled personal watercraft that may be steered by a rider shifting his or her weight. The watercraft preferably does not include or use a rudder, steering bucket (thrust vectoring), or skegs for steering. 
     SUMMARY 
     Aspects of the subject technology include a self-propelled personal watercraft. The watercraft includes a hull with a middle narrower than a bow and a stern of the watercraft and with a bottom of the bow being raised with respect to the middle and the stern, and a propulsion device within the hull. While the watercraft is propelled through water by the propulsion device with a rider on board, shifting of the rider&#39;s weight to either side of the watercraft increases contact of the bow with the water on that side, the increased contact resulting in increased drag and turning the watercraft to that side. 
     In some aspects, while the watercraft is propelled through water by the propulsion device with the rider on board and the watercraft is not turning, the bottom of the bow makes contact with the water across a narrower distance than the bottom of the middle. In addition or alternatively, when not turning, the bottom of the middle makes contact with the water across a narrower distance than the bottom of the stern. 
     The watercraft may also include a hinged bow area with a hatch to an internal storage compartment accessible when the hinged bow area is raised. The hatch preferably is located on a bottom side of the hinged bow area when the bow area is not raised. 
     In some aspects, the watercraft includes chest support, recessed forearm supports, elbow stops, and/or recessed knee pockets for the rider while laying prone on the watercraft. 
     Some aspects of the subject technology may include an internal chassis support within the hull. The watercraft may further include a removable chassis installed in the chassis support, with the removable chassis including at least a power source for the propulsion device. The propulsion device may be an electric water jet and the power source may be one or more batteries, for example in the form of a swappable sealed battery module. The removable chassis may include a mount or tray for the battery module. 
     In some aspects, the watercraft may include a remote throttle system for the propulsion device such as a potentiometer protected in a waterproof housing. Other control systems may also be included, for example for remote throttle limitation and/or control and remote steering via one or more servo-motor shifted weights inside the hull. 
     The hull of the watercraft may be made from any suitable material. A translucent material may be used, for example to enable a light to shine through the hull in a waterproof manner for night operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. 
         FIG. 1  illustrates a perspective view of a self-propelled personal watercraft according to aspects of the subject technology. 
         FIG. 2  illustrates another perspective view of a self-propelled personal watercraft according to aspects of the subject technology. 
         FIG. 3  illustrates a translucent perspective view of a self-propelled personal watercraft showing interior elements according to aspects of the subject technology. 
         FIG. 4  illustrates a bottom view of a self-propelled personal watercraft according to aspects of the subject technology. 
         FIG. 5  illustrates a translucent side perspective view of a self-propelled personal watercraft showing interior elements according to aspects of the subject technology. 
         FIG. 6  illustrates another translucent side perspective view of a self-propelled personal watercraft showing interior elements according to aspects of the subject technology. 
         FIG. 7  illustrates translucency of the hull of a self-propelled personal watercraft with lighting according to aspects of the subject technology. 
         FIG. 8  illustrates a control system for a self-propelled personal watercraft according to aspects of the subject technology. 
     
    
    
     DETAILED DESCRIPTION 
     U.S. patent application Ser. No. 14/011,654 titled “A Self Propelled Personal Watercraft” filed Aug. 27, 2013, and U.S. Provisional Application No. 50/437,511 filed Aug. 29, 2012, both in the name of the same inventor as this application, are hereby incorporated by reference as if fully set forth herein. 
     In some aspects, a unique hull design of a self-propelled personal watercraft according to aspects of the subject technology allows steering without a need for a rudder, steering bucket (thrust vectoring), or skegs. Steering is instead achieved by changing drag characteristics of the watercraft by a rider shifting his or her weight. One possible benefit of the technology is a reduction in both the complexity and weight of the watercraft. 
     Some concepts from the unrelated technology of skiing may help to understand the subject technology. Modern skis often have curved edges that are narrower under a skier&#39;s foot than at the ski&#39;s tip and tail. When a skier tilts such a ski onto its edge, the ski will bend under the weight of the skier. The further the ski is tipped, the more the ski will bend. As the ski moves forward, the ski will tend to follow the curve of the edge meeting the snow and turn in a smooth arc. This action is often referred to as “carving.” The amount of the arc achieved by carving is controlled by the shape of the ski, the amount of pressure that the skier applies, and how much the ski bends under that pressure. 
     The hull of a watercraft according to aspects of the subject technology also effectively “carves” into water when a rider shifts his or her weight. However, instead the hull of the watercraft substantially flexing or otherwise changing shape to facilitate a turn, the shape of the watercraft&#39;s hull allows a rider to change the shape of contact of the hull with water by shifting his or her weight. In particular, the shape enables control of drag by either side of the hull while moving through water. (It should be noted that some flexing of the hull may occur, but this flexing preferably is not part of the steering mechanism for the watercraft.) 
     In addition, the hull&#39;s shape preferably has a narrower middle as compared to the hull&#39;s stern and bow. This shape facilitates sitting up on the watercraft with the rider&#39;s legs straddling either side of the hull. The narrower middle also facilitates carrying of the watercraft under a person&#39;s arm. 
       FIG. 1  illustrates a perspective view of a self-propelled personal watercraft having the foregoing characteristics according to aspects of the subject technology. Watercraft  10  includes hull  12 . Middle  14  of hull  12  is narrower than bow  16  and stern  18  of the watercraft. (In this document, the bow is considered to be the front third of the watercraft, the middle is considered to be the middle third of the watercraft, and the stern is considered to be the back third of the watercraft. The width for comparing which portion is narrower is considered to be the lateral distance across a middle of each portion.) As also shown in at least  FIG. 1 , the top of bow  16  of the hull is raised compared to the top of middle  14  and the top of stern  18 . 
     As a result of the illustrated hull shape, shifting of the rider&#39;s weight to either side of the watercraft while moving through water increases contact of the bow with the water on that side. The increased contact results in increased drag and turns the watercraft to that side. 
       FIG. 2  illustrates another perspective view of a self-propelled personal watercraft according to aspects of the subject technology. Aspects of the subject technology that facilitate steering via weight shifting, comfort while riding, and other features are discussed with respect to this figure. 
     Watercraft  10  in  FIG. 2  includes chest support  20 , recessed forearm supports  22 , elbow stops  24 , and recessed knee pockets  26  for the rider while laying prone on the watercraft. Handholds  28  are also illustrated. A throttle may be disposed on or near one or both of the handholds for controlling the watercraft&#39;s speed. 
     Hatch  30  in hinged bow area  32  is also illustrated. Bow area  32  may be raised as illustrated, and a storage area in the bow area may be accessed via preferably water-tight hatch  30 . The hatch preferably is located on a bottom side of the hinged bow area when the bow area is not raised. This arrangement facilitates access to the interior of the storage area with limited water ingress while the watercraft is in water. One or more interior dry storage areas may be included within the storage area. 
     D-Ring mounts  36  may be included to provide versatile mounting options, for example to allow a person to affix a carry strap bridging the narrowed middle of the hull for easier carrying. Two of the D-Ring mounts are labeled in  FIG. 2 . Two other D-Rings mounts are also shown opposite the labeled mounts. 
     The watercraft shown in  FIGS. 1 and 2  according to aspects of the subject technology does not include any rudder or skegs. As a result, the watercraft has a reduced draft, is lighter, and can be more easily carried than other personal watercraft such as jet skis and wave runners. In addition, the watercraft can be more easily stacked for transport and/or storage. Rudders and/or skegs may be included without departing from the invention; however, any such rudders and/or skegs should be small and may detract from the advantages of the present technology. 
       FIG. 3  illustrates a translucent perspective view of a self-propelled personal watercraft showing interior elements according to aspects of the subject technology. Watercraft  10  includes propulsion device  38  inside hull  12 . The illustrated propulsion device is a battery powered electric water jet. Other types of propulsion devices may be used. Also shown in  FIG. 3  is access port  40  with a watertight cover for accessing the propulsion device and other elements of the watercraft within the hull. 
       FIG. 4  illustrates a bottom view of a self-propelled personal watercraft according to aspects of the subject technology. This view shows an area of contact of the watercraft&#39;s hull with water when being ridden without turning. In this case, the bottom of bow  16  makes contact with the water across a narrower distance than the bottom of middle  14 , which in turn preferably makes contact with the water across a narrower distance than the bottom of stern  18 . 
     As discussed above with respect to  FIG. 1 , the middle is narrower than the bow. Thus, in order for the bow to make contact with the water across a narrower distance than the middle, the bottom of the bow is raised with respect to the bottom of the middle and preferably the stern. The stern also may tail off toward the rear of the watercraft. Depending on the amount of tailing, the area of contact of the middle with water may be narrower than the area of contact of the stern, as shown, or the area of contact of the middle may be wider. In either event, the area of contact of the bow with the water while not turning preferably is narrower than the area of contact of both the middle and stern. 
     As a result of the hull shape illustrated by  FIGS. 1 to 4 , when a rider shifts his or her weight to one side of the watercraft, the bow on that side of the watercraft will “dig” into the water, causing the drag on that side to increase. This drag in turn causes the watercraft to turn without a need to use a rudder or skegs. 
     Also shown in  FIG. 4  are lifting strakes  42  on the bottom of hull  12 . The strakes may enhance turning efficiency as well as providing protection for the hull when placed or moved along a surface. 
       FIGS. 5 and 6  illustrates translucent side perspective views of a self-propelled personal watercraft showing interior elements according to aspects of the subject technology. Chassis support system  44  permits some internal components of watercraft  10  to be assembled outside of hull  12  in chassis  46 . The chassis may then be slid into place inside the hull. After installation, the chassis may be removed for maintenance. The combination of the chassis support system and the chassis may also provide internal structural support for the watercraft&#39;s drivetrain assembly and strength for the hull. 
     One component that may be carried by the chassis is a battery tray for swappable sealed battery module  48  that includes one or more batteries for powering the watercraft. Other components that may be carried by chassis  46  include but are not limited to electronics, a remote throttle assembly such as a potentiometer in a waterproof case for electronic throttle control, circuit breaker(s) or fuse(s), an integrated master power switch, a battery shutoff device that renders the battery module inert when not installed, and the like. 
     As shown in  FIGS. 5 and 6 , the top of hull  12  preferably tapers at the back of the stern. This tapering may provide a more comfortable angle for a rider reducing neck fatigue. Additionally the main chassis  50  include the propulsion device preferably has a matching tapering toward its rear. This arrangement provides a “shoe horn effect” for the main chassis in the hull, which tends to provide good structural integrity and stability. 
       FIG. 7  illustrates translucency of the hull of a self-propelled personal watercraft with lighting according to aspects of the subject technology. The material of hull  12  preferably is a suitably durable material such as HDPE. Other materials may be used. In preferred aspects, the material is translucent such that internal lights may show through for aesthetic reasons and to permit use at night without an exposed external light. 
       FIG. 8  illustrates a possible control system for a self-propelled personal watercraft according to aspects of the subject technology. This control system may permit various different types of control for the watercraft, including but not limited to the following:
     RF Radio Fencing—automatic limiting of board throttle potential outside of a given area. A transmitter placed on shore or on another watercraft may sends a radio frequency signal to the board. Range from the transmitter may be determined by the controller, for example by detecting signal strength. Full throttle may be permitted within a predetermined range of the transmitter, while throttle potential may be limited outside of the predetermined range.   Remote Control. A remote control signal may be received by the controller, which may then actuate one or more servo-motor(s) to shift one or more weight(s) inside the board. The shifting weights may be used to steer the board.   Automatic Reserve Power Limiting. The controller may detect when the power supply for the propulsion device has reached a certain threshold and then limit throttle potential. Thus, a rider would feel the watercraft slow down when power is low, giving the rider warning that he or she should return.   Mobile Application Connectivity. The controller may enable cell phones through the use of mobile applications to connect to the watercraft and designate minimum and maximum speed perimeters, shut the board off, and create a lock feature. Examples of the speed perimeters include but are not limited to a parent setting a maximum speed for their children to ride the watercraft, compliance with speed limits on lakes, and the like. The lock feature would permit the controller to disable the remote throttle if the board was stolen.   

       FIG. 8  shows various elements that may be used to enable these types of control. Controller  80  includes one or more processors and memory for instructions executed by the processor. Controller  80  may interface with various other elements shown in  FIG. 8 . These elements include one or more receivers  82 , for example for radio frequency or wireless phone signals. Mobile device  84  may interface directly with controller  80 , for example via a USB cable, or remotely with controller  80 , for example via a wireless phone network. Controller  80  may receive battery power information from battery power sensor  85 . The information from these and other sources may be used by controller  80  to control the watercraft, for example via remote throttle control  86  in the form of a potentiometer, steering mechanism  88 , or other devices included in the watercraft. 
     The invention is in no way limited to the specifics of any particular embodiments and examples disclosed herein. For example, the terms “aspect,” “example,” “preferably,” “alternatively” and the like denote features that may be preferable but not essential to include in some embodiments of the invention. In addition, details illustrated or disclosed with respect to any one aspect of the invention may be used with other aspects of the invention. Additional elements may be added to various aspects of the invention and/or some disclosed elements may be subtracted from various aspects of the invention without departing from the scope of the invention. Singular elements imply plural elements and vice versa. Many other variations are possible which remain within the content, scope and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.