Abstract:
A watercraft is powered by a user sitting on a sliding seat and using footrests. The user operates a simulated rowing mechanism which includes a handle, cord, and reel. Power is transmitted through the rowing mechanism to a series of paddles, which move in a loop in a horizontal plane through the water underneath the watercraft. The paddles are mounted on a belt that passes around front and rear wheels. The paddles are feathered when moving forwards, by means of followers and/or a cam surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Application No. 61/178,181 filed in the U.S. Patent and Trademark Office on May 14, 2009, the entire contents of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This disclosure relates to a system for the propulsion of watercraft. More particularly, the disclosure concerns a system in which an operator uses manual power to operate a propulsion mechanism. 
       BACKGROUND 
       [0003]    Rowing is a popular method of propelling a boat, in which the rower transmits effort by means of oars. However, it has a number of disadvantages. Skill is required for the successful manipulation of the oars, and considerable skill is required to handle boats designed to travel at higher speeds, such as sculls. Significant training is required before a single scull, for example, can be used effectively. In a conventional rowing boat, the rower does not face the direction of travel, making it necessary to turn round at intervals, which is uncomfortable and can spoil the enjoyment to an extent as well as raising safety issues. It is also difficult to transmit the rower&#39;s muscle power effectively. A trained oarsman can transmit power effectively, and in such cases rowing is one of the healthiest forms of exercise for all the muscle groups. However, an inexperienced rower will find it difficult to exercise effectively when rowing a boat. 
         [0004]    U.S. Pat. No. 6,755,706 of Roger Lin, entitled Sculling Boat Assembly discloses an arrangement in which an operator can sit facing the bow of a boat and power the boat using a simulated rowing mechanism. A pair of simulated oar handles are mounted for pivoting about vertical axes. As the handles are pivoted towards and away from the operator, rearwardly extending paddles move sideways to propel the boat forwards. This is neither an effective way of extracting power from human movements, nor an efficient way of transforming that power into movement of a boat. 
         [0005]    In U.S. Pat. No. 5,833,256 of Roger C. Gilmore, entitled User Powered Vehicle and Propulsion Mechanism it has been proposed to convert simulated rowing movement into propulsion of a vehicle on ice, snow or land. A wheel provided with a tire, for use on land or snow, or provided with studs for use on ice, is rotated to propel the vehicle forwards. 
       SUMMARY 
       [0006]    According to one aspect of the present disclosure, there is provided a watercraft having a bow and a stern, an operator seat facing the bow, and an operator footrest; a simulated rowing mechanism for use by the operator, the simulated rowing mechanism comprising a rotatable reel, a flexible element having one end attached to and wound around the reel, a handle member attached to the other end of the flexible element, movement of the handle in a first direction which is towards the stern from the bow serving to effect rotation of the reel in a first sense by the flexible element, and a return mechanism to rotate the reel in the opposite sense whilst the handle moves in a second direction opposite to said first direction; the watercraft further comprising a rotatable drive member which is driven by the reel at least during rotation of the reel in said first sense, and water engaging propulsion apparatus powered by the drive member. 
         [0007]    According to another aspect of the present disclosure, there is provided a watercraft having a bow and a stern, an operator seat facing the bow, and an operator footrest; a simulated rowing mechanism for use by the operator, the simulated rowing mechanism comprising a handle member; and a series of paddles mounted on a drive element powered by the simulated rowing mechanism; wherein the paddles are positioned underneath the hull of the watercraft and move in a horizontal plane. 
         [0008]    According to another aspect of the present disclosure, there is provided a watercraft having a bow and a stern, an operator seat facing the bow; a series of paddles mounted on a drive element, the paddles being positioned underneath the hull of the watercraft for movement in a horizontal plane; the drive element being a continuous drive loop extending around a pair of wheels spaced longitudinally of the watercraft, the wheels being rotatable about vertical axes, and one of the wheels being driven in rotation by a drive mechanism; each paddle being connected to the drive loop by a feathering mechanism. 
         [0009]    According to another aspect of the present disclosure, there is provided a watercraft having a bow and a stern, a seat and a footrest arranged for an operator to sit facing the bow, a simulated rowing mechanism for use by an operator sitting on the seat and holding at least one member of the simulated rowing mechanism, a rotatable drive member arranged for rotation at least during power strokes in which the operator pulls the member towards the operators body, and water engaging propulsion means connected to the drive member so as to propel the watercraft forwards at least during the power strokes. 
         [0010]    According to another aspect of the present disclosure, there is provided a method of propelling a watercraft through water, the watercraft having a bow, a stern, and a seat, the method comprising the steps of sitting on the seat facing the bow, holding at least one member of a simulated rowing mechanism, and operating the member so as to rotate a drive member at least during power strokes in which the member is pulled towards the body, the drive member being connected to water engaging propulsion means so as to propel the watercraft forwards at least during the power strokes. 
         [0011]    According to another aspect of the present disclosure, there is provided a watercraft having a bow and a stern, a seat and a footrest arranged for an operator to sit facing the bow, a reel, a flexible element attached to and wound around the reel, a handle attached to the flexible element whereby an operator can rotate the reel in a first sense by pulling on the handle in a power stroke, a return mechanism causing the reel to turn in the opposite sense and the flexible element to be re-wound onto the reel whilst the operator causes the handle to move in a return direction in a return stroke, a rotatable drive member coupled to the reel so that the drive member is rotated during the power stroke, and water engaging propulsion means connected to the drive member so as to propel the watercraft forwards during the power stroke. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The disclosure will be better understood by reference to the following detailed description of preferred embodiments by way of example only, in conjunction with the accompanying drawings, in which: 
           [0013]      FIG. 1  is a plan view of a boat embodying an embodiment; 
           [0014]      FIG. 2  is a plan view showing the drive wheels of the propulsion mechanism; 
           [0015]      FIG. 3(   a ) is a plan view of the drive mechanism in greater detail; 
           [0016]      FIG. 3(   b ) is a view of a paddle; 
           [0017]      FIG. 4(   a ) is a plan view of an alternative drive mechanism; 
           [0018]      FIG. 4(   b ) is a front view of a paddle in this alternative arrangement; 
           [0019]      FIG. 4(   c ) is a side view of a paddle in this alternative arrangement; and 
           [0020]      FIG. 5  is a partial section through the boat showing part of the drive mechanism of  FIG. 4(   a ). 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    In use of some embodiments, an operator of a watercraft can sit on a seat facing forwards, position his or her feet on a footrest, grasp a handle, and perform a simulated rowing action with power strokes and return strokes, thus propelling the watercraft forwards. Preferably the seat is a sliding seat on rails, to enhance the rowing action. The footrest may be used for steering, with pressure on the left or right foot causing a rudder to turn the boat in the appropriate direction. The footrest may be a single member, or separate members for each foot. If not used for steering, the footrest may simply be constituted by, for example, a floor of the watercraft. 
         [0022]    Means are provided so that the watercraft is propelled forwards during the power stroke, but is not propelled backwards during the return stroke. Thus, a unidirectional coupling such as a ratchet could be used. This could be positioned between the reel and the drive member, although it could be positioned elsewhere such as between the drive member and the propulsion means. The propulsion means itself could be such that it operates only in one direction. 
         [0023]    The propulsion means may be such that it is “feathered” when it is not driving, i.e. during the return stroke, to reduce friction whilst the watercraft is gliding forwards before the next power stroke. Alternatively, the arrangement could be such that the propulsion means continues to be driven during the power stroke. Thus, the reel could be connected to a flywheel which stores energy which is used to drive the propulsion means. Gearing could be provided so that the speed of rotation of the flywheel is greater than that of the reel. Further gearing could be provided so that the propulsion means is driven at an appropriate speed. In general, whatever configuration is used, gearing may be provided as appropriate. 
         [0024]    The propulsion means could be one or more paddles, propellers or other known arrangement which can convert rotational drive into a propulsive force. 
         [0025]    The reel may be organised in any desired plane, for example horizontal or vertical, and this may depend on the general layout of the watercraft and the means of propulsion. For example, if laterally arranged paddle wheels are provided, rotatable about a horizontal axis, the reel may also be disposed with its axis horizontal. 
         [0026]    In some embodiments, the propulsion means comprises a series of paddles underneath the hull of the watercraft which move in a horizontal plane, and the reel is disposed with its axis extending vertically. 
         [0027]    It will be appreciated that the expressions “vertical” and “horizontal” are not meant to be construed in a strict geometric sense. 
         [0028]    The watercraft may take any suitable form for human propulsion. Whilst the preferred configuration has the general form of a rowing boat, other forms are possible such as a simple board such as a surfboard or sailboard, a pair of floats with a platform or the like—such as in a “pedalo”—a raft and so forth. 
         [0029]    A brake may be provided, which can act on any part of the drive mechanism to prevent the propulsion means from operating. For example, in an arrangement with a flywheel a friction brake could act on that. In the case of propulsion means which can operate in both directions, means may be provided to drive it in the reverse direction. There could, for example, be a coupling or gearing between the reel and the remainder of the drive mechanism, which reverses the direction of drive although of course the power stroke will still rotate the reel in the same direction. Alternatively, there could be an auxiliary arrangement for driving the propulsion means in the reverse direction such as a rotatable handle or the like. 
         [0030]    It will be appreciated that there are other mechanisms for simulating rowing, which could also be used to drive the propulsion means, including arrangements in which the operator moves rigid members to simulate the operation of oars. Such movement can be converted into rotary motion and also used to drive the propulsion means. In some arrangements, the operator could power the propulsion means during both the power stroke and the return stroke. 
         [0031]    Referring now to  FIG. 1 , there is shown a boat  1  having a hull  2 . Within the hull  2 , an operator  3  sits on a sliding seat  4  mounted on longitudinal rails  5 , facing the bow  6  of the boat. The feet of the operator rest on foot rests  7  and  8 , which are movable so as to control a rudder  9  at the stern of the boat by means of cables. 
         [0032]    The operator is holding a transverse handle  10  which is attached to a cord  11 , itself attached to a reel  12  which is mounted for rotation about a vertical axis. A return spring mechanism is provided, as well as a ratchet arrangement. Thus, on the power stroke in which the operator pulls the handle  10 , the reel  12  provides rotary drive. During the return stroke, the cord is wound up on the reel and the ratchet arrangement prevents reverse drive. During the return stroke the seat  4  slides towards the bow of the boat, and during the power stroke the seat  4  slides towards the stern of the boat. 
         [0033]      FIG. 2  shows how a drive shaft  13  which receives rotary drive from the reel  12  is connected to a first pulley or gear wheel  14 , which in turn drives a smaller second pulley or gear wheel  15  by means of a belt or chain  16 . A gear train could be incorporated if desired. The second pulley or gear wheel  15  is mounted coaxially with a first drive wheel  17 , coupled to a second drive wheel, or slave drive wheel,  18  by a belt  19 . Both drive wheels rotate about vertical axes, and the second drive wheel is spaced from the first drive wheel in the longitudinal direction of the boat, towards the stern. 
         [0034]    The belt  19  carries paddles  20  which are described in more detail with reference to  FIGS. 3  ( a ) and ( b ). The paddles are operative along the centre line of the boat, and adopt a feathered state during return when they are towards the outside of the boat. In an alternative arrangement, the paddles could be out of the water in the return phase, and in that arrangement the axes of the various rotatable members would be horizontal rather than vertical. 
         [0035]    With reference to  FIGS. 3  ( a ) and ( b ), each paddle  20  is flat and generally rectangular. The paddles  20  are made of wood, plastic, metal or any other suitable material. The precise number and size depends on the use of the boat, i.e. the force likely to be applied by the operator. They could be flat or curved, to engage the water more effectively. There is a system, described below, so that they only push the water when moving in one direction although the same effect could be obtained in a number of ways. 
         [0036]    As shown in  FIGS. 3(   a ) and ( b ), each paddle  20  is mounted pivotally on the belt  19 , on a vertical, central axis, and is provided with a wheel  21  or like follower element at one end. Extending along the boat are a pair of guide rails  22  and  23 , which are parallel for most of their length and diverge at their ends. As each paddle leaves the region of the first drive wheel  17 , the wheel  21  is received between the lateral guide rails  22  and  23 , and urges the paddle  20  to an orientation which is perpendicular to the intended direction of travel. The paddle then pushes on the water as it moves on the guide rails. Adjacent the second drive wheel  18 , the wheel  21  leave the guide rails  23  and  23 . The paddle  20  is then free to move and will adopt an orientation generally parallel to the direction of travel. The paddle stays in that orientation until it completes its return path to the first drive wheel  17 . 
         [0037]      FIGS. 4  ( a ), ( b ) and ( c ) and  FIG. 5  show an alternative arrangement, in which belt  19  is provided with paddles  24 . Instead of being pivotally attached to the belt for rotation about a vertical axis, the paddles are mounted for rotation about a horizontal axis. A wheel or other follower  25  is provided, but as shown in  FIGS. 4  ( c ) and  5 , this is displaced rearwardly from the blade of the paddle by a member  26  extending perpendicularly from the blade. Instead of the wheel  25  being received between lateral guide rails as in the previous embodiment, it engages a longitudinal cam surface  27  arranged above the paddles, extending from the first drive wheel  17  to the second drive wheel  18 . At its ends this cam surface  27  is curved away from the drive wheels. Thus as the paddles  24  leave the first drive wheel  17 , they are pivoted downwards so as to be perpendicular to the direction of intended travel. As the paddles  24  reach the second drive wheel  18 , they are free to pivot so as to lie in a horizontal orientation parallel to the direction of travel. 
         [0038]    As shown in  FIG. 5 , the cam surface  27  is provided on a bottom portion of the hull  2  of the boat. 
         [0039]    In an alternative arrangement, there could be provided two sets of paddles, mounted by means of respective drive wheels, and arranged symmetrically, on either side of the centre line of the hull. In that case, preferably the arrangement is such that the outer lines of paddles move backwardly and are used to propel the boat, whilst the inner lines of paddles move forwardly and are feathered. In such an arrangement a gearing mechanism can be used to apportion the drive from the reel of the rowing machine. This mechanism may be capable of apportioning the drive between the two sets of paddles in different ratios. This apportionment can thus be varied so that the differing drive forces on different sides of the boat can be used to steer the boat. The mechanism can be controlled by the footrest, so that pushing on one side in preference to the other will cause the boat to turn. 
         [0040]    For reverse movement, there could be an auxiliary propulsion mechanism, such as a paddle wheel or propeller that can moved into position and, with the main propulsion disconnected, driven by the rowing mechanism. A lever or such like could disengage a clutch to disconnect the main propulsion system, and simultaneously to engage drive with the auxiliary propulsion system. 
         [0041]    In the preferred embodiments, there is thus provided an effective method of propelling a boat, in which an operator simulates a rowing action, and the effort of the operator is converted firstly to rotary motion and then to horizontal movement of paddles to drive the boat through the water. 
         [0042]    It will be appreciated that the paddle mechanism per se may be used to propel a watercraft that is powered by an arrangement other than that described specifically with reference to the accompanying drawings, which involves a simulated rowing mechanism. The invention therefore extends to aspects of the paddle mechanism also. Thus, for example, according to a further embodiment, there is provided a paddling mechanism having a first drive wheel coupled to a second drive wheel by a belt or chain or similar wherein both drive wheels lie in substantially the same horizontal plane and pivot about vertical axes; a series of paddles, attached to the belt at intervals; a pivot on each paddle, permitting the primary surface of the paddle to be normal to the direction of motion of the belt or parallel thereto; and a mechanism for moving the paddles between these two orientations, operable such that the paddles moving from the first drive wheel towards the second are substantially in one orientation, and the paddles moving from the second drive wheel towards the first are substantially in the other. 
         [0043]    This paddling mechanism might be attached to a water craft such that only those paddles travelling from the primary drive wheel to the secondary drive wheel engage with the water lying under the craft, so as to propel the craft through the water. It will be understood that any source of rotary force could be used to power such a mechanism. This aspect of the invention is not limited to the rotary force being provided by a simulated rowing action; it could, for example, be powered by an internal combustion engine. 
         [0044]    The description of the above embodiments is by way of example only and is not to be taken as limiting then scope of the invention, which is defined by the appended claims.