Abstract:
The present invention relates to an accessory system simulating the biomechanical motion of manual paddling such as with a canoe or small boat. The system comprises: a watercraft attaching portion having width-adjusting members, an array of levers and members, paddle attaching members, a pedal system, and linkage therebetween, all forming a mechanical structure adapted to simulate the biomechanical motion commonly used by manual-propulsion watercraft operators.

Description:
FIELD OF THE INVENTION 
   The present invention relates to an accessory system simulating the biomechanical motion of manual paddling such as with a canoe or small boat. The system comprises: a watercraft attaching frame having a width-adjustable joining portion, an array of levers and members, paddle attaching members, a pedal system, and linkage therebetween, all forming a mechanical structure adapted to simulate the biomechanical motion commonly used by operators paddling a small watercraft. 
   BACKGROUND OF THE INVENTION 
   For illustration purposes, the applicant will illustrate the use of the present invention as used on a conventional canoe. However, it will be understood that the invention, as described, is equally effective on small boats and similar watercrafts, which can commonly be propelled by use of conventional paddles. 
   The inventor sought to provide canoe operators with a system for not only propelling a canoe using pedal power from one&#39;s legs, but also with the ability to easily disable said system when not required, and particularly, simulate the biomechanical motion of canoe paddling thus optimizing water displacement, making the effort of paddling optimally efficient. Furthermore the present invention provides improvement in the art of pedal-propulsion systems designed for small watercraft. Most pedal propulsion systems aim to eliminate the need of manually paddling the watercraft by hand, or to replace electric or gas powered motors, which in turn drive propeller drives or paddle wheel assemblies. Existing pedal powered propulsion devices for small watercraft are usually attached to the watercraft in a fashion so that it could be removed at a later time. However, during the period of use, afloat in the water, the device is always attached in a way that in turn may limit the flexibility of travel for the watercraft. One such case is where the watercraft is required to traverse a narrow waterway or fixed obstacles in its path. 
   There are three basic categories of human-powered propulsion systems for small watercrafts, they are:
     i. propeller driven,   ii. paddle wheel driven, and   iii. row-style driving devices.   

   Devices falling into categories (i) and (ii) develop problems with tangling of aquatic plants, damage to aquatic plants and to equipment. Devices falling into categories (ii) and (iii) are usually of a bulky nature and cumbersome, which take up space outside of the watercraft, in turn limiting the maneuverability of said watercraft. 
   In summary devices of category (i), propeller driven, have the following problems; 
   
       
       Pedal powered propeller drives are complicated and costly, 
       They are heavy, and 
       They can damage and become tangled in aquatic plants.
 
Category (ii) devices, paddle wheels, have the following problems;
 
       Paddle wheels can grab aquatic plants and become tangled, 
       Entry and exit into and out of the water surface by a paddle wheel is not efficient, 
       They are noisy, 
       They waste energy by splashing water outward from the wheel paddles, 
       Splash guards are required to keep the passengers dry, 
       They have a lower energy transfer efficiency, 
       They are heavy, and 
       Have a multiplicity of redundant paddles and structure to support them.
 
Category (iii) devices, rowing-style driving devices, have the following problems;
 
       They are efficient but take up a large space, thus reducing maneuverability, and 
       They are heavy due to the structure required, 
     
  
   Therefore, the applicant intends to overcome a majority of the problems associated with prior art human-powered propulsion system by providing a new improved biomechanically correct pedal powered paddling system for small watercrafts. 
   The applicant is aware of attempts in prior art to provide means of propelling small watercrafts using mechanically powered apparatuses. 
   An example of prior art may be had when referring to U.S. Pat. No. 5,584,732 of Owen, issued Dec. 17, 1996 depicting a part paddle attached to a mechanical linkage device powered by foot pedals. However, the device fails to compare with the present invention in that it propels the watercraft using a fish-tail motion know to be inefficient when adapted to a rigid body since it exerts a large portion of its force in a side to side motion. 
   Another example may be had in referring to U.S. Pat. No. 1,532,990 of Csengery, issued Apr. 7, 1925, which teaches of a boat having a rotary paddle apparatus adapted to propel said boat by hand power. This device fails to compare with the present invention in that it does not simulate the biomechanical motion of human paddling, as does the present invention. 
   Another example may be had in referring to U.S. Pat. No. 5,249,991 of Schinkel, issued Oct. 5, 1993, which depicts a manually operated propulsion device for a canoe comprising generally of a rotary paddle arrangement power by hand, again failing in that it does not simulate the biomechanical motion of human paddling. 
   SUMMARY OF THE INVENTION 
   It is thus the object of the present invention to provide canoe operators with a system for not only propelling a canoe using pedal power from one&#39;s legs, but also with the ability to easily disable said system when not required, and particularly, simulate the biomechanical motion of canoe paddling thus optimizing water displacement and efficiency. 
   In one aspect of the invention, the system synthesizes the natural manual paddle motion commonly used when paddling by hand. 
   In another aspect of the invention, the system&#39;s biomechanically correct simulation enhances the efficiency in power transfer by reducing drag while increasing paddle alignment. 
   In another aspect of the invention, the system of the present invention can easily collapse when use thereof is not desired. 
   In another aspect of the invention, the system can be quickly installed and removed from the watercraft in a matter of minutes without making alterations or modifications to said watercraft. 
   Accordingly, the system of the present invention provides canoe operators with a system for propelling a canoe using pedal power from one&#39;s legs, the ability to easily disable said system when not required, and particularly, simulates the biomechanical motion of canoe paddling thus optimizing water displacement a paddling efficiency. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other advantages of the invention will become apparent upon reading the following brief description and upon referring to the drawings in which: 
       FIG. 1  is a left side elevation view of the orientational path of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention. 
       FIG. 2  is a left side elevation view of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention in use. 
       FIG. 3  is a cross-sectional view taken from  FIG. 4  of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention. 
       FIG. 4  is a partial top plan view of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention. 
       FIG. 5  is a partial rear perspective view from above of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention. 
       FIG. 6  is a side elevation view of a paddle clamp of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention in an opened position. 
       FIG. 7  is a side elevation view of a paddle clamp of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention in an closed position. 
       FIG. 8  is a selected view taken from  FIG. 1  of the frame clamp device of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention. 
       FIG. 9  is a partial side elevation view of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention in a collapsed position. 
   

   While the invention is described in conjunction with preferred illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In the following description, similar features in the drawings have been given similar reference numerals. 
   Turning to the drawings, in particular,  FIG. 1 , which illustrates a left side elevation view of the orientational path of the biomechanically correct pedal-powered paddling system for small watercrafts of the present invention wherein members  12  represent the paddle, and each member  12  is of equal length, numerical  FIGS. 2   x  to  9   x  (where x depict points a, b, and c) represent a fixed point on said paddle, where Xa (where X depicts 2, 3, 4 . . . 9) represents the tip of the paddle, Xb represents the lower pivot clamp fixed to a mid section of the paddle, and Xc represents the upper pivot clamp also fixed to the upper section of said paddle. 
   A paddle crank having a non-rotational female end adapted to receive the male end of a drive shaft, and a rotational end adapted to secure to a linkage attaching portion of the above paddle receiving portion rotates at a drive axis  11 , and a swing lever rotates at a lever axis  10 . 
   Upon following the path as illustrated in this Figure, one can comprehend the compound motion generated by this dual axis-dual pivot method of obtaining the biomechanically correct simulation of natural paddling motion. The system of the present invention therefore promotes optimal paddle entry to and exit from the water body  14  on which a canoe  16  is traveling. 
   Turning now to  FIG. 2 , a left side elevation view of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention in use comprising; a watercraft attaching frame  20 , a frame extension  21 , a vertical arm member  22 , an swing lever  23 , a diagonal support member  24 , a paddle  25 , a drive crank  26 , a lower paddle clamp  27  and an upper paddle clamp  28  wherein, the watercraft attaching frame  20  fixedly attaches to the gunwale portion  17  by means of a turn screw clamp, the frame extension  21  is integral with the watercraft attaching frame  20 , the vertical arm member  22  is pivotally attached to a rear bracket  30  integral with the frame extension  21  and pivotally engaged with the rear portion of the swing lever  23 , the swing lever  23  is also pivotally engaged to the upper paddle clamp  28 , the diagonal support member  24  is pivotally attached to a front bracket  31  and to an upper-mid section of the vertical arm member  22  thereby forming a structural triangle rigidly supporting said vertical arm member  22 , the paddle  25  is held in place by means of the lower paddle clamp  27  and the upper paddle clamp  28 , and one end of the drive crank  26  is non-rotationally engage to the outermost end of the pedal drive assembly, and its other end pivotally engaged to the lower paddle clamp  27 . 
   In reference now to  FIG. 3 , a cross-sectional view taken from  FIG. 4  of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention illustrating, in a different perspective, the assembly components of the system wherein, a watercraft attaching frame  20  is securedly yet releasably attached to the gunwale  17  of a small watercraft such as a canoe  16  as illustrated, using a turn-screw type clamp  40  thereby securing said frame  20  from movement at any axis in relation to the canoe  16 . The watercraft attaching frame  20  is made to adjust to the varied width of conventional watercrafts by means of slotted multi-tongue members  32  adapted to slidably engage to each opposing frame member and secured to each other with bolts  33  thus creating a larger contact surface area thereby preventing displacement between each frame member. The frame  20 , formed in two mirror opposite portions, each have a horizontal central portion, a diagonal portion extending upwardly and outwardly from the central portion, and a horizontal clamp portion, is so formed to allow sufficient clearance for rotational movement of the pedal members of the pedal assembly and said frame  20  is integral in maintaining vertical and horizontal parallel alignment to both left and right sides in respect to the alignment and shape of the watercraft. 
   Two frame extension portions  21  extending rearwardly from each upper outermost portion of said frame  20  integrally include a front bracket  31  and a rear bracket  30  wherein the front bracket  31  serves to rotationally attach the lower portion of a diagonal support  24 , and the rear bracket  30  serves to also rotationally attach the lower portion of a vertical arm  22  on which the upper portion of the diagonal support  24  in turn rotationally attaches to a perforation in the upper-mid section of the vertical member  22  thereby resulting is a triangular structure formed between the frame extension  21 , the vertical member  22  and the diagonal support  24 . Pedal drive extensions  36  having deep female end and a male end wherein the female end having a generally square inner form is adapted to slidably but non-rotationally engage with the outer surface of the pedal drive  37 , and the male end of the pedal drive extension is partly threaded to accept a nut after traversing the crank arm  26  thus preventing rotational freedom of crank arm with pedal drive extension  36 . 
   A swing lever  23  having a perforation near each end, rotationally attaches at one end of said lever  23  to the uppermost perforation of the vertical member  22 , and the opposing end of said lever  23  securedly attached to pivoting member of the upper paddle clamp  28 . 
   The upper paddle clamp  28  and lower paddle clamp  27  frictionally attach to a conventional paddle and said paddle clamps  28  and  27  comprise: a paddle receiving portion, a locking member, an axle member and a linkage attaching portion. 
   Turning now to  FIG. 4 , a partial top plan view of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention illustrating the assembly components of the system comprising: a watercraft attaching frame  20  securedly yet releasably attached to the gunwale  17  of a small watercraft such as a canoe  16  as illustrated. The watercraft attaching frame  20  is made to adjust to the varied width of conventional watercrafts by means of slotted multi-tongue members  32  adapted to slidably engage to each opposing frame member and secured to each other with bolts  33  thus creating a larger contact surface area thereby preventing displacement between each frame member. 
   Two frame extension portions  21  extending rearwardly from each upper outermost portion of said frame  20  integrally include a front bracket  31  and a rear bracket wherein the front bracket  31  serves to rotationally attach the lower portion of a diagonal support  24 , and the rear bracket serves to also rotationally attach the lower portion of a vertical arm  22  on which the upper portion of the diagonal support  24  in turn rotationally attaches to a perforation in the upper-mid section of the vertical member  22  thereby resulting is a triangular structure formed between the frame extension  21 , the vertical member  22  and the diagonal support  24 . 
   A drive crank  26  is non-rotationally engage to the outermost end of the pedal drive assembly, and its other end pivotally engaged to the lower paddle clamp  27  thus, when rotational force is created by a paddler, the pedal assembly thereby rotates the drive crank  26 , which in turn exerts a rotational force at an arm motion on upper paddle clamps  28  rotationally attached to the ends of the drive crank  26 . Said paddle clamps  27 , when frictionally attached to the lower mid portion of a conventional paddle  25 , form a basis of the compound motion of the system of the present invention, which synthesizes to natural motion of arm-powered paddling. 
   The upper paddle clamp  28  and lower paddle clamp  27  frictionally attach to a conventional paddle and said paddle clamps  28  and  27  comprise: a paddle receiving portion, a locking member, an axle member and a linkage attaching portion. The pedal drive extensions  36  having deep female end and a male end wherein the female end having a generally square inner form is adapted to slidably but non-rotationally engage with the outer surface of the pedal drive  37 , and the male end of the pedal drive extension  36  is partly threaded to accept a nut after traversing the crank arm  26  thus preventing rotational freedom of crank arm with pedal drive extension  36 . 
   Therefore, it can be understood that a paddler, seated ( 55 ) within the watercraft  16 , places his feet one on each pedal  34  at the pedal drive assembly  37 , and supports himself by holding the gunwales  17  of said watercraft  16 , pedals as he would a bicycle to drive the attached crank arm  26 , which is rotably engaged to the lower mid section of a conventional canoe paddle  25  by means of a pivotal lower paddle clamps  27 , and said canoe paddle  25  is pivotally engaged to a swing lever  23  by means of a pivotal upper paddle clamp  28 , which said upper paddle clamp  28  being attached to said swing lever  23  and said swing lever  23  opposing end being pivotally attached to a vertical arm  22  supported by a diagonal support  24  thereby, when the drive crank  26  is rotated, the lower paddle clamp  27  simply moves in a continually rotational movement equal in radius to the center to center of both perforations in the drive crank  26 , and the upper paddle clamp  28  movement is thereby limited to an arc of a tangent generally equal to twice the radius of the crank arm  26 . Therefore, the combination of these movements for a compound action at the tip of a paddle  25  closely synthesizes the natural motion of conventional arm-powered paddling but is powered by the user&#39;s legs. 
     FIG. 5 , a partial perspective view from the rear of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention better illustrating the assembly of the present invention onto a canoe  16  wherein, a watercraft attaching frame  20  securedly yet releasably attached to the gunwale  17  of said canoe  16 . The frame  20  comprises two mirror opposite portions, each have a horizontal central portion, a diagonal portion extending upwardly and outwardly from the central portion, and a horizontal clamp portion, is so formed to allow sufficient clearance for rotational movement of the pedal members of the pedal assembly and said frame  20  is integral in maintaining vertical and horizontal parallel alignment to both left and right sides in respect to the alignment and shape of the watercraft. The frame  20  is made to adjust to the varied width of conventional watercrafts by means of slotted multi-tongue members  32  adapted to slidably engage to each opposing frame member and secured to each other with bolts  33  thus creating a larger contact surface area thereby preventing displacement between each frame  20  member. 
   A pedal drive assembly  37  having two foot pedals  34  both offset on the same plane and integrally attached to a drive member, which rotates on a horizontal axis perpendicular to the canoe&#39;s  16  length, a bearing portion  39  at each end distal from the foot pedals  34 , drive extension members  36  having deep female end and a male end wherein the female end having a generally square inner form is adapted to slidably but non-rotationally engage with the outer surface of the pedal drive  37 , and the male end of the pedal drive extension  36  is partly threaded to accept a nut after traversing the crank arm  26  thus preventing rotational freedom of crank arm with pedal drive extension  36 . Two frame extension portions  21  extending rearwardly from each upper outermost portion of said frame  20  integrally include a front bracket  31  and a rear bracket wherein the front bracket  31  serves to rotationally attach the lower portion of a diagonal support  24 , and the rear bracket serves to also rotationally attach the lower portion of a vertical arm  22  on which the upper portion of the diagonal support  24  in turn rotationally attaches to a perforation in the upper-mid section of the vertical member  22  thereby resulting is a triangular structure formed between the frame extension  21 , the vertical member  22  and the diagonal support  24 . 
   A drive crank  26  is non-rotationally engage to the outermost end of the pedal drive assembly, and its other end pivotally engaged to the lower paddle clamp  27  thus, when rotational force is created by a paddler, the pedal assembly thereby rotates the drive crank  26 , which in turn exerts a rotational force at a circumferential motion on paddle clamps  28  rotationally attached to the ends of the drive crank  26 . Said paddle clamps  28 , are frictionally attached to the lower mid portion of a conventional paddle  25 . 
   Turning now to  FIGS. 6 and 7 , both illustrating a paddle clamp  27  or  28  of the biomechanically correct pedal powered paddling system for small watercrafts of the present invention wherein,  FIG. 6  illustrating said clamp in an opened position, and  FIG. 7  in a closed or locked position. The paddle clamps  27  or  28  comprise: a body portion  60  having a generally U-shaped form made of a relatively resilient material, a hinge portion  59 , one or more inner paddle cradles  63  and  64 , and an outer clamp cradle  65 , a two axis hinge  62 , a locking level  61  having an off-center hinge axis  70 , an axle  66 , swivel bearing  67 , and a connecting member  68 . 
   In its opened position, the paddle clamp  27  or  28  is poised to receive a paddle  25  handle between its inner paddle cradles  63  and  64 . Once the paddle  25  is in place, the two-axis hinge  62  is pulled over the body portion  60  and the locking lever&#39;s  61  knuckle placed into the outer clamp cradle  65 , the locking lever  61  is then turned over the body  60  wherein the off-center hinge axis portion  70  applies compression to the paddle handle  25 . The axle  66 , being rotationally engaged within the body portion  60  and fixedly attached to a corresponding swing lever or crank arm allows free rotational motion of the clamps  27  or  28  from the axle  66  and its attached members. 
   Turning to  FIG. 8 , a partial rear elevation view selected from  FIG. 3 , illustrates more closely, the details of watercraft-attaching portion of the frame  20  wherein an outer clamps member  45  abuts the outer surface of a canoe&#39;s  16  gunwale  17  and the lower surface of said frame  20  rests atop said gunwale  17 . A female inner clamp member  43  fixedly attached to the underside of the frame  20  rotationally mated a like-threaded turn screw  40  having a knob  41  and a threaded bolts  42  fixedly attached to said knob  41 . A compression block  44  rotationally engaged to said threaded bolt  42  but not threaded to allow rotational motion and not threadedly engaged to said threaded bolts  42 , compresses against the inner surface of the gunwale  17  thus clamping said frame  20  firmly to the canoe&#39;s  16  gunwale  17 . A taper is provided on the gunwale-contacting portion of the compression block, which prevents slippage of clamp assembly from the gunwale  17 . 
   Turning to  FIG. 9 , which depicts an option of the present invention is so far as, said system can be easily folded down when user wishes to paddle by hand. This is sometimes necessary when paddling in shallow waters or narrow water paths. In order to fold down the system, the user simply disconnects disconnect the upper connector of both diagonal supports  24 , loosens the lower connector of the vertical member  22  and folds down the assembly against the extension portion  21  of the frame  20 . 
   Therefore in resolution of the above specification of the present invention, anyone with a small watercraft such as a canoe with two paddles can quickly and easily adapt said watercraft and benefit from the features and utility of the present invention.