Abstract:
A dual propulsion steering and control system for a watercraft which utilizes simple movement of an operator&#39;s feet to independently vary thrust from a pair of propulsion units, each mounted on opposite sides of the centerline of a watercraft. By varying the amount and direction of thrust on each side, the watercraft may be steered in a multitude of directions, propelled at varying speeds, and turned completely around in a short distance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a preliminary amendment to application number 12/214,779, filed Jun. 23, 2008. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    This invention is generally directed to propulsion, steering, and control devices for watercraft and, more specifically, to such devices which utilize a pair of independently operable engines or motors with propellers or other drives to provide both the thrust and steering capability for the craft and which includes separate foot controls to independently vary an amount and direction of thrust from the propellers or drives, each mounted on opposite sides of the watercraft&#39;s centerline, for the purpose of controlling the forward/rearward direction, speed, and steering of the watercraft. The invention is also directed to various other power converters and propulsion means. 
         [0004]    2. History of the Related Art 
         [0005]    Over the years there have been a number of innovations directed to enabling watercraft to be powered and steered by propulsion systems. Many of these systems are specifically designed to facilitate the use of watercraft for specific outdoor activities and thus utilize controls which are manipulated by an operator&#39;s feet so that the operator&#39;s hands remain free for the use of fishing or other equipment. 
         [0006]    Most of these systems control the speed and/or direction of common trolling motors with standard propellers which perform reasonably well if the propellers are located at least a propeller diameter distance under the water&#39;s surface. Any less depth creates cavitation and/or ventilation of the propeller (lots of noise, little or no performance). Propellers (or props) usually consist of a set of two or more twisted, airfoil-shaped blades mounted around a shaft. Each face of the blade has surface area which is less than the total surface area within the diameter of the propeller. Most propellers are approximately three times more efficient in forward motion than in reverse. 
         [0007]    Only a few of these systems are designed to control power driven augers (Archimedes Screws). It should be noted that augers, as opposed to propellers, have one or more helical flanges, also known as flighting, normally mounted around a shaft. Each face of flange has surface area which is more than the total surface area within the diameter of the auger. Simple augers perform equally well in forward and reverse motions and are less susceptible to cavitation and ventilation. Prior art is limited in addressing other alternative propulsion means, including but not limited to, pumps, jets, and turbines whereby foot controls are utilized for differential steering. 
         [0008]    In 1956, U.S. Pat. No. 2,764,117 to Persia discloses a vehicle propelled by 2 auger type rotors, but the boat is human powered through foot pedals, the augers cannot operate individually, and steering is done by rudder attached to a steering wheel. 
         [0009]    In 1964, U.S. Pat. No. 3,116,602 to Dahle describes a single hydro jet operating in one direction with a clamshell thrust diverter to accomplish reverse motion. 
         [0010]    U.S. Pat. No. 2,213,520 to Gentry discloses a foot control system which incorporates two separate electrical motors which are mounted to the two opposite sides of a boat or watercraft. Wherein, it is possible to use reverse propulsion of one motor relative to the other in order to assist in turning the boat about itself. Unfortunately, only the direction, not the speed, may be controlled. Therefore, precise control is limited. 
         [0011]    U.S. Pat. Nos. 2,804,838 to Moser and 6,758,705 to Bechtel disclose systems utilizing a foot control but are limited to a single propulsion unit. 
         [0012]    U.S. Pat. No. 4,537,144 to Horton describes a propelled watercraft using two trolling motors and on-off pressure switches mounted on a portable support, but not foot controlled. 
         [0013]    Yet another device, U.S. Pat. No. 3,995,579 to Childre, discloses a pair of reversible electric motors mounted in a fixed angle relationship to each other on a single shaft. Unfortunately, the foot plate is operated by one foot and rockers to each of four corners to actuate forward right motor, reverse right motor, forward left motor, or reverse left motor. To change speed, the foot must be lifted from the plate and moved to the speed control wheel. Again, precise control is limited. 
         [0014]    In 1986, U.S. Pat. No. 4,631,033 to Meene describes a foot control whose rocker pedal controls the rotation of the shaft of a single early model trolling motor and thus the steering of the boat. This invention is not intuitive and controls only one motor. A separate toe wheel controls speed. 
         [0015]    In 1987, U.S. Pat. No. 4,702,713 to Bruce Lee recognized that a commonly available foot pedal control could be mounted on a plate that slides on a track to keep the pedal in proximity with an operator&#39;s foot when the operator is swiveling in a chair. It did not address multiple pedals or multiple motors. 
         [0016]    In 1988, U.S. Pat. No. 4,722,706 to Young revealed that Bruce Lee&#39;s sliding plate could be put on wheels to function better, but still did not address multiple controls or motors. 
         [0017]    In 1990, U.S. Pat. No. 4,950,187 to Smith used a motor and screw to rotate the shaft on a single trolling motor. Again this did not use foot controls to differentially steer multiple motors. 
         [0018]    More relative and in 1992, U.S. Pat. No. 5,131,875 to Warren D. Lee discloses a propulsion and steering system for dual motors, especially of the trolling motor type, which incorporates a pair of foot pedals which are electrically connected between a battery and the motors and which are operable to independently control the direction of thrust and speed of the motors so that the motors are used to both propel and steer the boat. Lee&#39;s foot control means includes a foot pedal that has toe and heel portions and pivots about a single axis generally perpendicular to the elongated axis extending between said toe and heel portions (under the foot). Lee missed the opportunity to pivot the pedal about an axis closer to an operator&#39;s ankle for a more ergonomic and significantly longer sweep for more precise control. Lee also missed the opportunity to use a forward and rearward movement of the foot allowing longer travel resulting in a more precise speed control and comfortable operation. 
       SUMMARY OF THE INVENTION 
       [0019]    This invention is directed to a dual propulsion steering and control system for watercraft and especially to such a system which incorporates a power source, a pair of power conversion means, a pair of propulsion means each located on either side of the centerline of the watercraft, and a pair of foot control means each connected to a power regulating means for independently varying the output of each power conversion means resulting in controlled thrust from each propulsion means. By positioning the foot control means, an operator may control forward and reverse direction, speed, and steering of the watercraft. 
         [0020]    In a further embodiment of the present invention two basic variations of foot controls are described, one uses a pivoting motion, the other uses a forward and reverse motion. 
         [0021]    It is a primary object of the present invention to provide a dual propulsion steering and control system for watercraft which enables the independent control of a pair of power conversion means and thus the connected propulsion means through individual foot control means which are connected to separate power regulating means which not only initiates activation of each power converter means independently of one another but also controls the direction of propulsion and the amount of thrust from each propulsion means whereby the speed, direction, and steering of the watercraft is positively controlled through the operation of the foot control means. 
         [0022]    It is also an embodiment of the present invention to provide a control system for watercraft wherein a pair of power converting means, and thus, a pair of propulsion means are individually controlled through an operator&#39;s positioning of the foot control means with the thrust of each propulsion means being related to the independent amount of movement of the operator&#39;s feet 
         [0023]    It is further an object of the present invention to present alternatives for power sources, power converting means, foot control means, power regulating means, and propulsion means. Power sources may include, but are not limited to, batteries, compressed gases or liquids, fuels, and other stored energy. Power converting means may include, but are not limited to, trolling motors, electric motors, valves, engines, and hydraulic equipment. Foot control means may include, but are not limited to, heel pockets, foot plates, receptacles, pedals, rocker pedals, pivot assemblies, tracks, potentiometers, and switch means. Power regulating means may include, but are not limited to, switches, resistance wiring, relays, potentiometers, valves, and/or readily available electronic speed control components. Propulsion means may include, but are not limited to, propellers, augers, screws, power transmissions, impellers, jet drives, turbines, and pumps. 
         [0024]    It is further an object of the present invention to provide a differential thrust steering system using a pair of individually controlled augers or Archimedes screws, each mounted on opposite sides of the centerline of a watercraft. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0025]      FIG. 1  is a perspective and exploded view of a typical watercraft with dual propulsion means showing power conversion means, propulsion means, power source, and foot receptacles of the present invention mounted thereto. It also depicts three possible modules of a watercraft. 
           [0026]      FIG. 2  is a side elevation of the typical watercraft of  FIG. 1  showing foot receptacle, power conversion means, and propulsion means of the present invention mounted thereto. 
           [0027]      FIG. 3  is an enlarged view of a foot control means utilizing a forward/rearward motion of an operator&#39;s feet to provide input to a linear potentiometer mounted thereto. 
           [0028]      FIG. 4  is an enlarged view of a foot control means converting a forward/rearward motion to a rotary motion required to operate a typical power regulating means which is mounted thereto. 
           [0029]      FIG. 5  shows the uncomfortable movement of an operator&#39;s foot using the foot pedal claimed in Lee&#39;s Pat. No. 5,131,875 which pivots under the foot. 
           [0030]      FIG. 6  shows the (claimed) ergonomically preferred pivotation of the foot control means near the operator&#39;s ankle which is superior to Lee&#39;s design (U.S. Pat. No. 5,131,875) in both comfort and range of motion and is included in this patent. Though not shown, a typical rotary power regulating means would be attached at pivot point  605  near the operator&#39;s ankle. 
           [0031]      FIG. 7  shows operator&#39;s seat with attached casting seat in normal low seating position as well as with seat back flipped forward exposing casting seat for higher seating position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    With continued reference to the drawings, the dual propulsion steering and control system of the present invention is shown in  FIG. 1  as being utilized with a small boat or watercraft which is shown as, but not limited to, a one person watercraft. Said watercraft is shown as three possible modules, a mid-section  110 , a bow  111 , and a stern  112 . Also shown is an auger as a propulsion means  102 , an electric motor as a power conversion means  103 , a foot receptacle  106 , an electrical battery as a power source  120 , and an operator&#39;s seat  108 . 
         [0033]    The basic operation of the steering and control system is shown in  FIG. 2 . At rest, an operator&#39;s leg is relaxed and his foot rests in a foot receptacle  106 , a portion of a foot control means not fully shown for simplicity, which is in a neutral position  208 . At this position  208 , no power is transmitted from the power source  120  through a power regulating means  401 , shown in  FIG. 4 , to the power conversion means  103 . As the operator pushes a left or right foot forward to position  209  and beyond, the corresponding power regulating means progressively delivers power from the source  120  to the corresponding power conversion means  103  to activate the connected propulsion means  102 . The propulsion means delivers force in the proper direction  203  to move the corresponding side of the watercraft  201  forward at a progressive rate. A similar process takes place when the operator pulls back on a foot receptacle  106  with the operator&#39;s heel to position  210 . As the receptacle  106  progressively moves rearward, the power regulating means receives power from the source  120  and progressively delivers the power to the corresponding power conversion means  103  activating propulsion means  102  which directs progressively more force in direction  204  which moves and increases speed of the corresponding side of the watercraft  201  in a rearward motion. 
         [0034]    In  FIG. 3 , the dual propulsion steering and control system of the present invention includes another variation of left or right foot receptacle  306 , which pivots in bracket  302 . This assembly glides forward and rearward along tracks  304  between the front and rear stops of potentiometer housing  303 . Tracks  304  are fastened to a floor or deck of the watercraft  101 . A linear potentiometer  301  is attached to housing  303 . A transfer means  308  on bracket  302  makes contact with linear potentiometer  301 , which in turn, alters input to a power regulating means, varying the power to the power conversion means and resulting in varying the thrust from the propulsion means. The pivoting ability of foot receptacle  306  within bracket  302  allows forward and rearward pivoting of the foot lessening the tendency for the heel to depart from the receptacle, even when the operator changes seating height and/or leg angle. 
         [0035]    Alternately,  FIG. 4  shows a spur gear  405  attached to the shaft of a common power regulating means  401  which is fastened to the floor or deck of watercraft  201 . A multi-toothed rack  407  is attached to the surface  403  which glides along track  404 . As the operator&#39;s foot, resting in a variation of foot receptacle  406 , moves forward or rearward, the rack  407  rotates spur gear  405  which controls power regulating means  401 . The foot receptacle  406  combined with parts  403 ,  404 ,  405 , and  407  may also be considered a foot control means. An elastic material  409  is attached at fixed positions near each end of the track  404  and also attached approximately at the midpoint of the sliding surface  403  to bias the foot control means to a neutral position. 
         [0036]    It should be noted that commonly available motors come in a variety of voltages, multiple fixed speeds, variable speeds, and controls. Trolling motors with rotating tiller handles adapt well to this invention when the manufacturer&#39;s rotary power regulating means  401  is retained and the invention&#39;s foot control means converts its forward/rearward foot motion or pivotation to the rotary motion required. 
         [0037]    In  FIG. 5 , an operator&#39;s foot  501  and foot pedal  503  are shown in solid line form to indicate the forward-most achievable pivotation from an operator&#39;s foot. The same foot  501  and foot pedal  503  are shown in broken line form to indicate the rearward-most achievable pivotation from an operator&#39;s foot. Note the uncomfortable travel of the operator&#39;s ankle  502  and the limited angle of rotation  506  resulting about axis  505 . 
         [0038]    In  FIG. 6 , the operator&#39;s foot  501  rests on a more ergonomically designed foot pedal  603  which pivots about the more logical axis  605  which is generally aligned with operator&#39;s ankle  502 . This arrangement provides approximately 60% more angle of rotation, shown as  606 , than the arrangement shown in  FIG. 5 , and is significantly more comfortable for the operator. This arrangement also demonstrates sufficient difference from previous patents, especially Pat. No. 5,131,875. Note that the power regulating means is omitted from  FIG. 5  and  FIG. 6  for clarity of foot and leg positions. A power regulating means  401  of  FIG. 4  may easily be attached and controlled by the pivoting motion of the operator&#39;s foot about axis  605 . 
         [0039]      FIG. 7  shows seat  108  in normal low seating position and also with seat back flipped forward to expose casting seat  701  for higher operator&#39;s seating position. In this higher position, the operator&#39;s legs and feet are in different angles from the low seating position. The pivoting foot receptacle in  FIG. 3  enhances the operator&#39;s comfort in this higher position. 
       Conclusions, Ramifications, and Scope 
       [0040]    It should also be noted that this dual propulsion steering and control system could be utilized on a variety of watercraft equipped with two propulsion units, each located on either side of the watercraft&#39;s centerline. The system is compatible with, but not limited to, electrically powered trolling motors, power converters, ducted propellers, impellers, centrifugal and axial pumps, paddles, screw drives, augers, and surface propellers. The system also functions well with potentiometers and other metering means attached to the foot control means for input to electronic variable speed controllers which vary the power from a power source to the power conversion means and propulsion means. 
         [0041]    While the above description of a simple intuitive dual propulsion steering and control system contains many specificities, these should not be construed as limitations on the scope of the invention. Materials, sizes, shapes, and methods are merely demonstrations of a workable model.