Abstract:
A remote powered propulsive device having a rudder which carries a propeller or oscillating fins which are powered by pedals alone or with hydraulic assist or by an electric motor.

Description:
Applicants claim the benefit of U.S. Provisional Patent Application 61/207,715 , filed Feb. 12, 2009. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to propulsion system for watercraft. 
     BACKGROUND OF THE INVENTION 
     Small boats commonly use some mechanism to convert energy of the human body into a propulsive force to move the boat. A simple device is a paddle or oar; however, more sophisticated designs use the larger muscles of the lower body and feet to propel the boat and leave the hands free. 
     U.S. Pat. Nos. 2,158,349 and 5,090,928 describe a device that is powered by cables moving back and forth which turns the propeller or fins at the bottom of the rudder to create a propulsive force at the bottom of the rudder, but the steering is limited to angles much less than plus/minus 180 degrees and it can only be retracted about 100 degrees. 
     There are many patents that have pedals and turn a propeller which provide forward and reverse;
         U.S. Pat. Nos. 7,371,138, 6,905,379, 6,210,242, 6,165,030, 6,165,029, 5,643,020, 4,968,274, 4,676,755, 4,648,846.       

     There are a few that have a propeller on the rudder which can provide forward, reverse and be able to turn the rudder about plus or minus 45 degrees. They can not rotate 360 degrees and they can not be stored on the deck. 
     U.S. Pat. No. 4,891,024 describes a design that would have forward, reverse and could steer, but the angle to which it could steer would be limited by the articulation of the universal joint in the shaft. This design has the pedals going in a circular motion which requires the feet to go much higher in their path. And the circular path has the dead zones. 
     U.S. Pat. No. 5,580,288 describes a design that would have similar capabilities but would have the same limitations for the same reasons. 
     There are several patents which are remotely powered with cables or ropes that activate a fin or paddle at the bow or stern: 
     U.S. Pat. Nos. 5,584,732, 5,584,732, 4,960,396, 6,077,134, 5,021,015, 6,997,765 
     SUMMARY OF INVENTION 
     A remotely driven watercraft having a bow and a stern, a deck, a rudder at the stern and a cockpit intermediate the bow and the stern comprising means carried by the watercraft comprising a source of propulsive power, said rudder being freely rotatable in any direction and carried about a vertical axis and having in proximity to its lower extremity a propeller for propelling the watercraft and means connecting said source of propulsive power with the bottom of said rudder to drive said propeller. 
     A remotely driven watercraft having a bow and a stern, a deck, a rudder at the stern and a cockpit intermediate the bow and the stern comprising means carried by the watercraft comprising a source of propulsive power, said rudder being freely rotatable in any direction and carried about a vertical axis and having in proximity to its lower extremity pairs of oppositely oscillating flexible fins for propelling the watercraft and means connecting said source of propulsive power with the bottom of said rudder to drive said pairs of oppositely oscillating flexible fins. 
     A remotely driven watercraft having a bow and a stern, a deck, a rudder at the stern and a cockpit intermediate the bow and the stern comprising means carried by the watercraft comprising a source of propulsive power, said rudder being freely rotatable in any direction and carried about a vertical axis and having in proximity to its lower extremity an electric motor and electrical means connecting said source of propulsive power with the bottom of said rudder to operate said electric motor and drive a propeller or fins. 
     A remotely driven watercraft having a bow and a stern, a deck, a rudder at the stern and a cockpit intermediate the bow and the stern comprising means carried by the watercraft comprising a source of propulsive power comprising a pair of pedals for receiving human input force, a seating area in said cockpit aft of said pedals for carrying a human operator, said rudder being freely rotatable in any direction and carried about a vertical axis and having in proximity to its lower extremity a propeller for propelling the watercraft and means connecting said pedals with said bottom of said rudder for driving said propeller comprising tension means running rearwardly from said pedals to said stern and downwardly to power said propeller. 
     A remotely driven watercraft having a bow and a stern, a deck, a rudder at the stern and a cockpit intermediate the bow and the stern comprising means carried by the watercraft comprising a source of propulsive power, including a pair of pedals for receiving human input force, a seating area in said cockpit aft of said pedals for carrying a human operator, said rudder being freely rotatable in any direction about a vertical axis and having in proximity to its lower extremity a propeller for propelling the watercraft, and means connecting said source of propulsive power with said bottom of said rudder for driving said propeller, said source of propulsive power comprising hydraulic means operatively connected to said pedals to generate fluid pressure, and means conveying said fluid pressure running rearwardly from said hydraulic means to said stern and downwardly to hydraulically power said propeller. 
     In one embodiment of this invention the propulsion device resembles the lower unit of an outboard motor. It looks like a rudder with a propeller near the bottom. At the top there are two pulleys that turn the two power cables 90 degrees down into the rudder. 
     In this embodiment the power cables terminate in a pair of spools which are on clutch bearings which are on the propeller shaft. Before the cables terminate they wrap around the spools several times. One end of a third cable is terminated in the opposite end of the spool. This third cable makes several wraps around the spool and then proceeds deeper down into the rudder where it passes around a pulley which it turns it about 180 degrees. The cable then goes back up and makes several wraps around the other spool and terminates on the spool. 
     When one of the power cables is pulled, the spool turns and the cable unwinds from one of the spools. The third cable winds onto the spool as it moves. This movement causes the second spool to turn in the opposite direction and the second power cable is wrapped around the second spool. Since the power cables are attached to the pedals the pedals will be moving back and forth. 
     When the power cables move back and forth the spools spin back and forth in opposite directions. Since the spools are mounted on the propeller shaft on clutch bearings (the spools are allowed to spin freely in one direction on the shaft) the shaft will turn in just one direction and turn the propeller which creates thrust. 
     In a second embodiment the two power cables come down the rudder and each cable is split into two. The bottom of the rudder has one shaft free to rotate inside a hollow shaft which is free to rotate. The front of each shaft is fitted with a drum. The first power cable splits and one cable winds about 270 degrees around one of the drums and terminates to the drum. The other cable winds about 270 degrees around the other drum in the opposite direction and terminates to the drum. The second power cable splits and the two ends terminate on the drums in the same manner, but in the opposite direction. The final result is that when one cable is pulled the two drums turn in opposite direction. The second power cable is taken up or drawn around the two drums. Again as the two pedals move back and forth the two drums spin back and forth in opposite directions and thus the two concentric shafts spin in opposite directions. 
     On the back of each shaft is mounted a pair of steel rods. On these steel rods is mounted two pairs of flexible fins. The internal shaft extends further aft and the aft pair of fins is mounted on the internal shaft. These flexible fins are free to rotate on the steel rod and fixed to the shaft in such a way that when the shaft turns and the fin is pushed through the water the fins twist and flex in such a way that it assumes the shape of a propeller blade. The flexible fins are able produce forward thrust regardless of which direction the shafts are turning. 
     Since the power cables are relatively thin and flexible they can tolerate a certain amount of twisting as they travel down the rudder. This attribute will allow the cables to transmit power as the rudder is turned up to 270 degrees to the left and right. If the rudder is turned 90 degrees the boat will turn within its own length. If the rudder is turned 180 degrees it will go in reverse. The ability to turn the rudder more than 180 degrees will allow the pilot to steer left or right in reverse. 
     An upper and lower set of ball bearings is provided to allow the rudder to turn about a vertical axis to steer the boat. The upper bearing must be large to create space for the two pulleys that turn the power cables 90 degrees into the rudder. 
     It is important that tension from the power cables or thrust from the propeller or fins do not cause a torque on the rudder which will steer the boat. Thus the power cables pass very near the center of rotation for the rudder. 
     Just above the upper bearing is the quadrant or a groove for the steering lines. There are two lines—one turns the rudder to the right and the other turns the rudder to the left. From the centered position each line can turn the rudder 270 degrees right or left. 
     The rudder is also able to rotate back and out of the water. It can continue for 270 degrees until it lays on the deck of the boat. It can also turn 90 degrees so that it lays flat on the deck. Special accommodations have been made for the power lines and the steering lines. The steering lines pass right through the center of rotation for this movement so the tension in the steering lines does not change as the rudder is rotating up. The power lines will come off of the 90 degree turning blocks and bend around to allow the rudder to rotate through 270 degrees. The propulsion device will work—you can pedal and create thrust while the rudder is rotating up until it reaches 90 degrees and the power cable will begin to rub. This will allow the drive to work in less water depth. 
     There are two lines to control the position of the rudder. One line pulls the rudder down into the normal operating position and locks it there. This line is under considerable pressure in reverse as the drive tries to kick itself up. A second line will raise the rudder and stow it on the deck. 
     The forces of the power cables pass just above the center of rotation for this movement and they cause some torque to raise the rudder, but this torque is easily dealt with. 
     OBJECTS AND ADVANTAGES 
     The main objective of the design is to make a foot operated propulsion device for small watercraft that can be operated remotely. A foot powered craft is better because people tend to have a lot more power in their lower body and it leaves the hand free for other tasks. 
     Power must be transmitted to the drive through a pair of cables or ropes moving in a back and forth motion. This back and forth motion of the cables lends itself well to the back and forth motion of the pedals which is desirable. Pedals that go back and forth can be mounted much lower and are simpler. The resistance you feel on the pedals is smoother. A circular motion can still be used. 
     Also the pilot of the boat should be able to direct the direction of the thrust of the drive in any direction to steer and go in reverse. This will greatly improve the maneuverability of the boat. The pilot should be able to steer the boat with a small tiller. Combining the rudder and the propulsion device into one unit will simplify the boat. 
     Also the pilot should be able to deploy and retract the drive from the seated position. The drive should be able to be stowed flat on the deck of the boat and then the pilot should be able to lock it into the normal operating position. If the drive hits an obstacle in the water, the drive should be released automatically to avoid damage. 
     It is desirable to use a folding propeller because:
         1) The propeller does not produce drag while gliding or while sailing.   2) The propeller is less likely to be damaged if it strikes something.   3) The propeller maybe able to shed sea weed when it folds.       

     Folding props are common in sail boats and are relatively simple unless they are required to work in reverse because the blades will just fold. With the remote drive the propeller is always producing force in the same direction and the drive rotates 180 degrees to go into reverse so the folding propeller will be relatively simple. 
     Relative to a drive that spins the prop in reverse to produce reverse thrust the remote drive has an advantage because the prop is always producing thrust in one direction. The thrust of a prop turning in the reverse direction is compromised because the propeller is designed to be more efficient in the forward direction. 
     Typically the balance of a rudder is completely wrong for a boat going in reverse. Typically a rudder of a boat or plane will have between 85% and 60% of the rudder area behind the pivot line. So if the boat goes in reverse there is too much area ahead of the pivot line and the rudder will be unstable. The pilot will have to actively work to prevent the rudder from turning all the way to the stop. Since the rudder of the remote drive turns 180 degrees to go in reverse the balance of the rudder will always stay the same. This is an advantage for a fisherman who prefers to troll in reverse and watch his line in his wake. 
     A further benefit of the invention is the ability to push the stern of the boat in any direction—forward, reverse or any angle in between which enable the boat to turn at any turning radius. A further benefit is the ability to retract the device and store it flat on the deck of the watercraft. 
    
    
     
       THE DRAWINGS 
         FIG. 1  is a side view of the remote drive in the down position on a kayak. 
         FIG. 2  is a top view of the remote drive in the down position on a kayak. 
         FIG. 3  is an expanded side view of the remote drive with cutaways to show the cables inside. 
         FIG. 4  is an expanded rear view of the remote drive. 
         FIG. 5  is an expanded top view of the remote drive. 
         FIG. 6  is a sectional view of the top of the remote drive from  FIG. 4 . 
         FIG. 7  is a sectional view of the bottom of the remote drive. Sectioned along line C C from  FIG. 3 . 
         FIG. 8  is a sectional view of the top of the remote drive showing the steering line. Sectioned along line B B from  FIG. 4 . 
         FIG. 9  is an exploded isometric view of the remote drive. 
         FIG. 10  is an exploded isometric view of the propeller assembly. 
         FIG. 11  is a detail view of the cable and spool assembly. 
         FIG. 12  shows the remote drive retracted and laying flat on the deck of a kayak. 
         FIG. 13  shows a cross sectional view of the spool and clutch bearing assembly. 
         FIGS. 14 and 15  show an alternative embodiment with the remote drive on a catamaran. 
         FIGS. 16 ,  17 ,  18 , and  19  show other alternative embodiments. 
         FIGS. 20 and 21  show an alternative embodiment where human input power is transferred to the rudder via hydraulic fluid. 
         FIGS. 22 and 23  show an alternative embodiment of the remote drive where power is transfer with a hydraulic fluid. 
         FIG. 24   a  shows details of a hydraulic motor where the forward piston is going down—the power stroke. 
         FIG. 24   b  shows details of a hydraulic motor where the forward piston is going up—the exhaust stroke. 
         FIGS. 25 and 26  show end views of the rotary valve and crankshaft. 
         FIG. 27  shows details of pedals and hydraulic pumps. 
         FIG. 28  shows the remote drive with an electric motor option on a kayak. 
         FIGS. 29 and 30  show an alternative embodiment of the remote drive with electric motor assist. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Considering the drawings  FIGS. 1 to 30  in more detail, the rudder bracket  1  is fastened to hull  2  with four #10 screws. The rudder mount  3  snaps into the rudder bracket  1  and can pivot 270 degrees. A set of ball bearings  5  is captured between the rudder quadrant  4  and the rudder mount  3  and the rudder quadrant  4  can rotate inside the rudder mount  3 . A second set of ball bearings  7  is captured between the lower bearing  6  and the rudder mount  3  and the lower bearing  6  is free to rotate. Lower bearing  6  is fixed to the rudder quadrant  4  with 3 screws. The strut  9  slides into the lower bearing  6  and the rudder quadrant  4 . 
     The rudder  10  slides into the bottom of the strut  9  and is secured. The propeller assembly  11  slides into the rudder  10  and the rear bearing  17  is secured to the rudder  10  with a #10 screw. The pawl  12  slides into the recess in the rudder  10  is secured with a spring. The pawl  12  engages the ratchet in the propeller hub  14  and will prevent the propeller from rotating in a counter clockwise direction when looking at the drive from behind. 
     The propeller shaft  15  is secured in the propeller  11  with a #10 screw. The rear bearing  17  and the spacer  18  are placed onto the shaft. The rear bearing  17  and the spacer  18  are placed onto the shaft. The spacer  18  is secured to the shaft with a ¼-20 set screw. A clutch bearing  19  is pressed into the front spool  21  and the rear spool  20 . A plastic bushing  23  is placed inside the front spool  21  and the rear spool  20  on each side of the clutch bearing  19 . The plastic bushing  23  keeps the spool centered on the propeller shaft  15  to minimize friction. An O ring  22  is placed inside each end of front spool  21  and rear spool  20 . The O rings seal oil inside the spool for the clutch bearing and keep water and dirt out. The direction of the spiral cut in the front spool  21  is opposite from the rear spool  20 . 
     The inside of the clutch bearing  19  has 10 hardened steel rods (0.092″×0.305″)  25 . The inside surface of the clutch bearing  19  has a ramp  27  for each steel rod  25 . A plastic leaf spring  26  pushes the steel rod  25  onto the ramp  27 . When the clutch bearing  19  is rotated clockwise when looking from the rear of the boat the steel rod  25  rides up the ramp  27  and the steel rod  25  is pushed toward the propeller shaft  15  and the clutch bearing  19  is essentially fixed to the propeller shaft  15 . When the propeller shaft  15  is rotated clockwise with respect to the clutch bearing  19  while looking from the rear of the boat the steel rod  25  rides down the ramp  27  away from the propeller shaft  15 . The propeller shaft is free to rotate in a clockwise direction while looking at the boat from the rear. 
     Power from the rider  30  is transmitted to the pedals  31  and  32  by moving the pedals back and forth with a stepping motion of the rider&#39;s  30  feet. Power from the pedals  31  and  32  is transmitted back to the rudder via a pair of power cables  33  and  34 . A loop  52  is formed in the front end of twin pairs of power cables  35  and  36  with a swage  53 . Power cables  33  and  34  are connected to the loop  52  of the twin pairs of power cable  35  and  36 . The twin pairs of power cables  35  and  36  are made up of two smaller cables (nylon coated 1/16″ 7×19 stainless steel) that are better suited for rounding the small diameter of the pulleys  37  and  38  and the front and rear spools  21  and  20 . 
     The twin pairs of power cables  35  and  36  come back and are turned by pulleys  37  and  38  and go down through the strut  9  and into the rudder  10 . Pulleys  37  and  38  are supported by ⅜″ bolt  39 . The ⅜″ bolt  39  is supported by pulley support  40 ,  41  and  42 . Pulley supports  40 ,  41  and  42  are fastened to the rudder mount  3  with 6 #10 screws. Cable capture device  43  is fastened to pulley supports  41  and  42  with 2 #6 screws. The cable capture device prevents the two cables from twisting as they go onto the pulleys  37  and  38 . 
     The twin pairs of power cables  35  and  36  come into the rudder  10  and begin to wrap around the front and rear spools  21  and  20  and are terminated in the front and rear spools  21  and  20  with a swage  46 . Tension in the twin pairs of power cables  35  and  36  will cause the front and rear spools  21  and  20  to rotate in a clockwise direction while viewing the boat from the rear. The idler pulley cable  47  terminates in the front and rear spools  21  and  20  with a swage  51 . The idler pulley cable  47  passes around the idler pulley  48  which is supported by idler pulley axle  49 . Idler pulley door  50  covers the pulley and supports the idler pulley axle  49 . 
     The steering handle  60  is in close proximity to the left hand of the rider  30  who is located in the cockpit  8 . The steering handle  60  is connected to the steering quadrant  61 . The steering lines  62  and  63  are wrapped around the steering quadrant  61  and go aft to the rudder  10 . The steering lines go through the rudder bracket  1  and rudder mount  3  and turn aft and wrap about 270 degrees around the rudder quadrant  4  and terminate with 2 knots  64  and  65  on the inside of the rudder quadrant. The steering handle  60  can be rotated to the right or the left up to 270 degrees which will cause equal amount of rotation of the rudder quadrant  4  in the opposite direction. 
     To retract the remote drive the rider  30  pulls on the up line control handle  70  which is attached to up control line  71 . Pulleys  72 ,  73 , and  74  direct the up control line  71  back to the remote drive. The up control line  71  passes over a line guide  75  on the top of the pulley support  40  and then passes over a line guide  76  on the rudder mount  3  and then it terminates with a knot in the rudder mount  3  at  77 . Tension in the up control line  71  will cause the remote drive to rotate up about 270 degrees until it lays flat on the deck  78 . The remote drive can be steered 90 degrees to the right or left so that it lays flat on the deck  78 . 
     To deploy the remote drive the rider  30  pulls on the down line control handle  80  which is attached to down control line  81 . Pulleys  82 ,  73 , and  74  direct the down control line  81  aft to the remote drive. The down control line  81  passes over the sheaves  83  and  84  and then it terminates with a knot at  86 . 
     As shown in  FIG. 15 , the invention of  FIGS. 1 to 14  is adapted for use on catamarans. 
       FIGS. 16 ,  17 ,  18  and  19  show another embodiment of this invention. The twin pairs of power cables now  35  and  36  come back to the remote drive and are turned down into the rudder  10  with the pulleys  37  and  38 . The left power cable pair  35  is then split and one cable goes around turning block  114  and one goes around turning block  112 . The right drive cable pair  36  splits and one cable goes around the turning block  113  and one goes around turning block  115 . The four cables go around the two drums  116  and  117  in opposite directions so that when drive cable pair  35  is pulled drums  116  and  117  turn in opposite directions and when drive cable pair  36  is pulled the drums  116  and  117  turn in the opposite directions. 
     Drum  117  is connected to hub  111  and drum  116  is connected to hub  110 . Hubs  111  and  110  rotate opposite each other with each stroke of pedals  31  and  32 . Fins  118 ,  119 ,  120 ,  121  are flexible and assume the shape of propeller blade when forced through the water. 
       FIGS. 20 ,  21 ,  22 ,  23 ,  24 ,  25  and  26  show still another alternative embodiment of this invention in which human input power is transferred from the pedals  31  and  32  to the remote drive with hydraulic fluid (water) instead of tension cables. Force on the pedals  31  or  32  causes piston assemblies  91  or  92  to move forward. Movement of piston assemblies  91  or  92  causes increased pressure inside cylinders  93  and  94  and causes the water to move back to the remote drive in hose  95 . 
     When pedal  31  or  32  moves back water is drawn into cylinder  93  or  94  through hose  96  or  97  through the floor of the watercraft  98 . 
     The water travels down the rudder  9  through hose  95  and into the rotary valve  100 . The rotary valve directs the water into the front of the crankshaft  104 . Water passes through the crankshaft  104  and exits through the port  138 . The water goes into the port  106  of the rotary valve  100 . The water is directed to hose  102  which leads to the first of 3 cylinders  102  which is the power stroke. The water pressure forces the piston  103  down and turns crankshaft  104  through connecting rod  135  which turns the propeller  11  in the clockwise direction while viewing from the rear. 
       FIG. 24   b  shows the same section view but the propeller  11  and crankshaft  104  has been rotated 180 degrees and cylinder  102  is exhausting the water out through hose  101 . The water passes back through port  106  of the rotary valve  100  and into the crankshaft  104 . The water exits through port  105  in the crankshaft  104 . 
     Rotary valve  100  has 2 other ports  107  and  108 . These ports direct water to or from cylinders  109  and  130  through hoses  131  and  132  when these ports  107  and  108  line up with the ports  105  or  138  of the crankshaft  104 . Water pressure acts on pistons  133  and  134  and turns the crankshaft  104  through connecting rods  136  and  137 . 
       FIGS. 28 ,  29  and  30  show yet another alternative embodiment of this invention which uses an electric motor and battery for power and thrust. A power cord  90  comes from a battery  140 , which preferably is carried just behind the cockpit  8  and goes forward to the throttle control  141  which is located in convenient location for the rider  30  to operate. The power cord  90  then goes back to the stern and then goes down the rudder  10  and to the electric gearmotor  88 . A clutch bearing  87  allows torque to go from the gearmotor  88  to the propeller assembly  11 , but does not allow the torque to go into the gearmotor  88 . A seal  89  prevents water from entering the gearmotor  88 . 
     The electric motor can also be used in conjunction with the human powered embodiments of  FIGS. 1 to 25 .