Abstract:
A floating, water current-driven electrical power generation system has a hull supporting one or more paddle wheels. The unit is tethered in a stream or river so that the moving water turns the paddle wheel coupled to an electrical generator. A transmission matches stream flow conditions to the electrical generator. Stabilizing fins on the hull bottom help keep the hull properly aligned in the stream&#39;s current. Built-in leg structures are sized to prevent bottoming of the paddle wheel during periods of low water in the stream or river. Mounts are provided for an outboard motor useful for propelling the unit to a desired location. Larger versions of the system may be equipped with a boat mooring facility allowing a boat to propel the unit to a desired position in a stream or river.

Description:
FIELD OF THE INVENTION 
   The present invention pertains to water-driven electrical generators and, more particularly to a floating, water current-driven electrical power generation system. 
   BACKGROUND OF THE INVENTION 
   Harnessing the potential or kinetic energy of water to provide motive force or, more especially, electrical power is well known. Vast hydroelectric projects take advantage of the potential energy available from water falling from one elevation to a lower elevation. On a smaller scale, water wheels and other similar mechanism have long been utilized to turn mill stones, and to power industrial machinery. In addition, stationary water wheels have, in fact, been used to turn small electrical generators. 
   However, traditional water wheels suffer from many disadvantages. Most importantly, they must be located near an uninterrupted source of water to function. This generally requires construction of a dam to impound sufficient water to overcome seasonal rainfall variations. Dam construction is typically both expensive and environmentally problematic. Obtaining a construction permit for a dam is no small feat. It would, therefore, be advantageous to utilize a “portable” water wheel to capture energy from moving water without need for a permanent structure, especially a dam. 
   DISCUSSION OF THE RELATED ART 
   Attempts to provide portable structures capable of harvesting energy from flowing water may be found in the prior art. For example, U.S. Pat. No. 4,598,210 for WATER CURRENT MOTOR, issued Jul. 1, 1986 to Lloyd I. Biscomb teaches a floating hull having a pair of paddle wheels extending outwardly from the sides thereof. The BISCOMB paddle wheels drive a central rotary load, for example, an air compressor, water pump, or electrical generator. The BISCOMB hull is adapted for tethered mooring in a stream of flowing water. 
   U.S. Pat. No. 3,986,787 for RIVER TURBINE, issued Oct. 19, 1976 to William J. Mouton, Jr. et al. discloses another floating structure adapted for capturing energy from the flowing water of a stream. MOUTON et al. utilize a pair of flow-through turbines supported beneath a floating platform which may be tethered to an anchor in the stream bed. An electrical generator mounted on the deck receives mechanical input from the turbines to produce electrical power therefrom. 
   U.S. Pat. No. 4,725,195 for ADVANCED PIGGYBACK WATER POWER GENERATOR, issued Feb. 16, 1988 to B. Ryland Wiggs provides a pontoon-supported, paddle wheel-driven electrical power generation system adapted to be tethered in a flowing stream. 
   U.S. Pat. No. 4,843,249 for HYDROELECTRIC SYSTEM, issued Jun. 27, 1989 to Jean L. Bussiere, shows a leg-support hydro-powered electrical power generation system. The BUSSIERE system is free to move vertically on its support posts and uses a paddle wheel to capture wave in relatively large bodies of water. 
   None of the forgoing patents, taken individually or in any combination, are seen to describe or suggest the novel floating, water current-driven electrical power generation system of the invention. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, there is provided a floating, water current-driven electrical power generation system. A hull supporting one or more paddle wheels adapted to interact with the water current in a river or stream, is tethered, typically at least two points to help ensure positional stability of the hull relative the stream bed or other fixed location. The paddle wheel (or wheels) turns a shaft thereby producing rotary motion. The shaft&#39;s rotary motion is transmitted to an electrical generator or alternator through a transmission that allows matching stream flow conditions to the electrical generator or alternator. Stabilizing fins on the hull bottom help keep the hull properly aligned in the stream&#39;s current. Built-in leg structures are provided that are useful during construction or for servicing the unit and/or for storing the unit when in dry dock. The legs are sized to prevent bottoming of the paddle wheel during periods of low water in the stream or river. 
   The inventive system may be provided in a variety of sizes depending upon the stream conditions and/or the amount of electrical energy required. Mounts are provided to accommodate an outboard motor useful for propelling the unit to a desired location in a stream or river. Other versions of the inventive electrical power generation system may be equipped with a boat mooring facility which may also be used to interact with a boat whereby a larger unit may be propelled and steered to a desired position in a stream or river. 
   It is, therefore, an object of the invention to provide a floating, water current-powered electrical power generation system. 
   It is another object of the invention to provide a floating, water current-powered electrical power generation system having a buoyant hull supporting a platform. 
   It is a further object of the invention to provide a floating, water current-powered electrical power generation system having one or more water (i.e., paddle) wheels or the like supported on a platform thereof. 
   It is an additional object of the invention to provide a floating, water current-powered electrical power generation system having an electrical generator or alternator mounted on a platfrom thereof. 
   It is an object of the invention to provide a floating, water current-powered electrical power generation system having a variable speed drive, transmission, or gearbox between the paddle wheel and the generator. 
   It is a further object of the invention to provide a floating, water current-powered electrical power generation system wherein the hull is made from or treated with a rustproof material. 
   It is an additional object of the invention to provide a floating, water current-powered electrical power generation system having a catamaran hull for stability. 
   It is yet another object of the invention to provide a floating, water current-powered electrical power generation system having legs attached to the hull to facilitate service and storage, and to prevent bottoming of the paddle wheel. 
   It is a further object of the invention to provide a floating, water current-powered electrical power generation system having a protective structure to keep debris away from the paddle wheel. 
   It is a still further object of the invention to provide a floating, water current-powered electrical power generation system having an included step-up transformer. 
   It is another object of the invention to provide a floating, water current-powered electrical power generation system having at least one outboard motor mount on the hull. 
   It is yet another object of the invention to provide a floating, water current-powered electrical power generation system having a buoyant hull including a boat mooring facility. 
   It is another object of the invention to provide a floating, water current-powered electrical power generation system having a weather-proof covering over the generator, alternator and/or other system components. 
   It is an additional object of the invention to provide a floating, water current-powered electrical power generation system adapted for ganged deployment. 
   It is a still further object of the invention to provide a floating, water current-powered electrical power generation system having one or more structures adapted to direct water towards the paddle wheel. 
   It is an object of the invention to provide a floating, water current-powered electrical power generation system having emergency systems such as a drag anchor and a paddle wheel lock. 
   It is another object of the invention to provide a floating, water current-powered electrical power generation system having warning lights for installation on systems deployed in navigable waters. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A complete understanding of the present invention may be obtained by reference to the accompanying drawings when considered in conjunction with the subsequent detailed description, in which: 
       FIG. 1  is a schematic, top plan view of the floating, water current-driven electrical power generation system of the invention; 
       FIG. 2  is a schematic, side view of the power generation system of  FIG. 1 ; 
       FIG. 3  is a partial schematic front elevational view of the power generation system of  FIG. 1 ; 
       FIG. 4  is detailed view of the debris guard portion of the electrical power generation system of  FIG. 1 ; and 
       FIG. 5  is a partial top plan schematic view of a portion of the deck of the electrical power generation system of  FIG. 1  showing a boat mooring feature thereof. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The present invention features a floating electrical power generation system for deployment in flowing streams, rivers, and other such bodies of water. The term river or stream is used hereinafter to describe any suitable body of water in which the electrical power generation system of the invention can be successfully operated. 
   Referring first to  FIG. 1 , there is shown a schematic, top plan view of one embodiment of the floating electrical power generation system of the invention, generally at reference number  100 . A pair of pontoons, port pontoon  102  and starboard pontoon  104 , forms a catamaran-style hull  105 . A planar platform  106  is affixed to an upper surface of pontoons  102 ,  104 . While a catamaran-style hull  105  has been chosen for purposes of disclosure, it will be recognized that other hull styles and types may also be used to implement the inventive electrical generation system  100 . Consequently, the invention is not considered limited to any particular hull style or type but covers any and all suitable hull types. 
   A paddle wheel  108  is supported on a central shaft  110 , disposed between pontoons  102 ,  104  through an opening  114  in platform  106 . Central shaft  110  is supported in bearing housings  112 . Central shaft  110  has a pulley, bull gear, or other suitable power take off  116  affixed thereto. 
   A transmission or gearbox  118  is mounted adjacent paddle wheel  108  and is operatively connected to power take off  116  by a suitable power transfer arrangement  120 . Such a power transfer arrangement  120  may be one or more V-belts, poly V-belts, gog belts, a gear train, or any other suitable arrangement whereby rotary motion at power take off  116  is transferred to an input of transmission or gearbox  118 . Such coupling arrangements are known to those of skill in the rotating machinery arts and are not further described herein. The invention is not considered limited to the V-belt drive chosen for purposes of disclosure. Rather, the invention encompasses any and all suitable power transfer mechanisms. 
   One or more generators  122  are connected to transmission or gearbox  118  by a second power transfer arrangement  124 . Like power transfer arrangement  120 , any suitable mechanism including, but not limited to, V-belts, poly V-belts, cog belts, or a gear train, etc. may be used to perform the necessary power transfer function. Generator  122  is used to represent any useful rotating machine which may be powered by application of rotary motion to an input thereof. Examples of such rotary machines, in addition to generators or alternators, include air compressors and pumps. While generator  122  has been chosen for purposes of disclosure, it is intended to represent any such rotary machine. It will be recognized that multiple generators  122  may be driven by transmission or gearbox  118  using any suitable coupling arrangement. 
   The use of the term generator herein encompasses alternators as well as generators. The term generator is used generically for purposes of simplicity. 
   A pair of outboard motor mounts  126  is disposed at a stern region of platform  106  and adapted to mount an outboard motor, not shown, or similar motive device to system  100 . Tandem outboard motors, not shown, of course, may also be used. 
   Mooring attachment points  128  are typically disposed near the forward port and starboard corners of platform  106  and are adapted for attachment of a mooring cable, rods or rope  130 . 
   A debris guard  132  having debris guard fingers  134  is disposed at the forward edge of platform  106 . Fingers  134  may best be seen in  FIGS. 2 and 4 . It will be recognized that other arrangements may be provided to prevent water-borne debris from jamming or injuring paddle wheel  108 . The invention is not considered limited to the particular debris guard arrangement chosen for purposes of disclosure. It will further be recognized that additional debris guards not mechanically affixed to electrical power generation system  100  may also be placed upstream therefrom when required. 
   Referring now also to  FIG. 2 , there is shown a schematic, side elevational view of the inventive floating, water current-driven electrical power generation system  100 . A weatherproof housing  136  may be provided to protect components such as generator  122 , transmission or gearbox  118 , etc. from weather and/or spray from the stream or river. In addition, housing  136  is useful for protecting system  100  from vandalism or other unauthorized access. Housing  136  may be made from fiberglass, aluminum, or other thermoplastic resins or metals. Housing  136  may be attached to platfrom  106  using any suitable attachment system, not shown. In alternate embodiments, housing  136  may be hingedly attached to platform  106 . One or more suitable locks, not shown, may be provided to prevent unauthorized removal of housing  136  from platform  106 . 
   Legs  138  are provided, typically around the periphery of platform  106 . Legs  138  have a minimum length extending below fins  140  and also corresponding to the radius of paddle wheel  108  projecting beneath platform  106 . Legs  138  have several functions, notably to prevent the bottoming of paddle wheel  108  during periods of low water. In addition, legs  138  are potentially useful during the construction of system  100  and/or for dry docking system  100  during winter months. Legs  138  may be rigidly or slidably and adjustably attached to platform  106  using mounting or height-adjusting mechanisms known to those skilled in the art. Typically, at least four legs  138  are provided. Legs  138  are typically disposed near the four corners of the rectangular portion of platform  106 . It will be recognized that other numbers of legs may be chosen to meet a particular operating circumstance or environment. Consequently, the invention is not considered limited to any particular number, style, attachment point, or attachment modality of legs  138  but covers any number of legs attached to platform  106  in any manner. 
   Port and starboard pontoons  102 ,  104  may be equipped with downward-projecting fins  140  disposed along a longitudinal major axis thereof. Fins  140  provide a stabilizing force to keep pontoons  102 ,  104  aligned with the current of the stream or river in which system  100  is deployed. 
   A waterproof housing  142  may optionally be provided to keep power take (i.e., pulley or bull gear  116 ) dry. Housing  142  allows pulley or gear to have a relatively large diameter without exposing it or any encircling belts  120  to water. 
   It is anticipated that electrical power generation system  100  may be provided in a range of different physical sizes with corresponding generation capacities. On small versions of system  100 , a single or tandem outboard motor attached to outboard motor mounts  126  will be sufficient to propel and steer system  100  to a desired position in a river or stream. Larger versions of system  100  may be too large and/or unmaneuverable to be placed in a desired location using only one or more outboard motors. 
   Referring now to  FIG. 5 , there is shown a top, plan view of a portion of system  100  showing a boat mooring facility  144  formed in platform  106  and a boat  146  moored thereat. Boat  146  forms no part of the instant invention and is shown only to illustrate the intended function of boat mooring facility  144 . Boat  146  may be used as a tug boat to push system  100  to a desired position in a stream or river. It will be recognized that boat mooring facility  144  may be disposed in positions other than the starboard position chosen for purposes of disclosure, the exact position forming no part of the invention. Mooring facility  144  also provides a convenient docking facility for a boat used to transport service personnel to the platform  106  of the electrical power generation system  100 . 
   If the inventive floating, water current-driven electrical power generation system  100  of the invention is to be used in navigable waters, it is imperative that appropriate navigational lights be provided in accordance with United States Coast Guard regulations, local regulations, or any other authority having such a requirement. Lights may be disposed on masts or directly attached to platform  106  as required. An exemplary stern navigation light  148  may be seen in  FIG. 2 . The selection and placement of navigational lights for watercraft is well known to those of skill in the art and is not further described herein. 
   In operation, the inventive electrical power generation system  100  may be constructed in a dry dock where legs  138  elevate paddle wheel  108  above a deck or other surface. When desired, system  100  may be placed into a flowing body of water and navigated to a desired location thereupon by an outboard motor, not shown, attached to platfrom  106  at outboard motor mounts  126 . Alternatively, if platform  106  is equipped with a boat mooring facility  144 , boat  146  may be used as a tugboat to navigate the system  100  to its desired location. 
   Once in position, cables, rods or ropes  130  or the like may be used to tether the system  100  in the river or stream. In small streams, shore based attachment points, not shown, are preferable as such fixed attachment points are not subject to movement by water currents in the stream or river. If shore attachment is not possible, anchor blocks, not shown, or other types of mooring may be provided. Anchor blocks and the like are well known to those of skill in the marine construction arts and are not further described herein. Mooring attachment points  128  are typically provided at or near the outer corners of platform  106  to allow a two-point anchoring system to be used thereby optimizing alignment of the hull of system  100  with the water current. 
   Paddle wheel  108  extends beneath platform  106  and is rotated by the action of water against the blades thereof. The rotation of paddle wheel  108  turns power take off device  116  (e.g., a pulley or bull gear). Rotary motion of power take off  116  is transferred to an input of transmission or gearbox  118  by belts  120 . The output of transmission or gearbox  118  is, likewise, coupled to generator  122  by belt  124 . Transmission or gearbox  118  is used to manually, semi-automatically, or fully automatically control the rotational speed of generator  122  as water current conditions in the stream or river change. Such control of transmission or gearbox  118  is well understood by those of skill in the art; a more complete description of the operation thereof is not included herein. As previously stated, transmission or gearbox  118  may be a gearless transmission using one or more conical pulleys to maintain a substantially constant speed of generator  122  regardless of the rotational speed of paddle wheel  108 . 
   Electrical power from generator may be used to charge an on-vessel battery to power navigational lights, etc. A step-up transformer, not shown, may raise the generator voltage to minimize transmission losses to shore. Power transmission to shore may be by an underwater or an overhead cable, not shown. 
   Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
   Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.