Abstract:
Disclosed is an apparatus and method for generating energy, and in particular electrical energy, using fluid supported bodies, each disposed in one of a plurality of chambers filled with a fluid. The fluid, which issues from a fluid source, has a density which is greater than the body so that the bodies are all buoyant, and therefore float, in the fluid. A rotatable shaft is supported above the chambers, with each of said bodies being coupled to the shaft through a clutch mechanism for driving the shaft in rotation. An electrical energy-generating device may be coupled to the shaft for generating electrical energy when the shaft rotates. Conduits interconnect the chambers with the fluid source, and fluid level sensors and valve means communicating with the conduit means and the chambers for regulating ingress and egress of fluid from the chambers. The fluid in each of the chambers is selectively evacuated whenever the body in the respective chamber has been lifted to a preselected height within the chamber. The rate of evacuation of the fluid is greater than the rate of descent of the body so that after the fluid has been evacuated from the chamber, the body experiences “controlled” free fall and in so doing it turns the rotatable shaft. The series of bodies falling in the chambers is timed so that at any time, there is at least one body experiencing “controlled” free fall in free space.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to the production of energy, and more particularly to a method and apparatus for producing energy, such as electricity, in which kinetic energy is converted to useful, energy producing, work. The apparatus of the invention provides for utilization of a natural energy source, preferably a renewable natural energy source, to rotatably drive shafts coupled to one or more generators so that electricity is produced on a continuous basis. 
     2. Description of the Related Art 
     The prior art is replete with teachings of devices and methods for producing power using renewable natural energy sources, such as solar power, geothermal power, tidal wave energy, and wind. Also, there are many teachings of machines that will convert gravitational potential energy into kinetic energy, as by using objects that fall onto and move receptacles attached to a rotatable shaft. 
     The prior art also teaches that it is well known to provide floatation devices, such as buoys or floats, to take advantage of fluid displacement and then to convert into work the upward thrust realized upon release of a submerged body (see for example U.S. Pat. No. 3,668,412 to Vrana et al., U.S. Pat. No. 4,425,510 to Jury, and U.S. Pat. No. 4,260,901 to Woodbridge all of which disclose apparatus for harnessing ocean tides in such a manner as to convert the energy associated with the rising and falling motion of the tides to useful power. 
     There is therefore a great and long-felt need for an electricity generating apparatus which converts the kinetic energy of bodies falling under the influence of gravity into useful work. 
     Against this background of known similar technology, the applicant has developed an electricity generating apparatus which converts the kinetic energy of falling bodies into useful energy. The energy generating apparatus of the invention further includes a plurality of modular units containing a multitude of fluid supported bodies possessing potential energy which are connected to a common generator shaft so that kinetic energy of the bodies created when the bodies are released for “free-fall” can be converted to rotational energy to drive the generator shaft in rotation. Additionally, it is contemplated that the modular units of the invention can be arranged in an array in such a manner that they are all connected through the common shaft to one or more generators. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus and method for extracting energy through the generation of work from kinetic energy of bodies that are constrained for “controlled” (i.e., tethered) free-fall motion. In addition, the invention provides an apparatus and method for converting extracted energy into useful work, and in particular converting useful work into generated electricity. 
     As used herein, “controlled” free-fall motion refers to the falling motion of a body that is attached to a rotatable shaft via a tether which, while under tension, exerts no appreciable force on the falling body to prevent the falling motion of the body. Further, as used herein, “controlled” free-fall motion refers to the motion of the body falling solely under the force of gravity while being tethered to and causing rotation of the rotatable shaft located above the falling body. The weight of the tether is so negligible relative to the weight of the body that, even though the tether is constantly maintained in tension between the falling body and its point of connection to the rotatable overhead shaft, the body essentially experiences no restraining force other than a virtually miniscule tension in the tether as the body falls downwardly. Thus, the falling body essentially experiences free-fall motion. 
     In one aspect of the present invention, there is provided a modular unit having a plurality of outer containers, each of which houses an inner container capable of exhibiting buoyancy in a column of fluid, preferably water. The fluid in the outer containers is introduced thereinto and removed therefrom in accordance with preselected parameters and in such a manner that, when the level of fluid in a first one of the outer containers is substantially at the top of the container, the level of fluid in a second outer container is substantially smaller, e.g., at the bottom of thereof, and the level of fluid in the remaining outer containers is at levels other than and between the substantially filled top level and the substantially smaller “bottom” level. In accordance with programmable instructions carried out by electronic controls, at preselected times, valves located in conduits connecting the outer containers are actuated to cause the fluid in the outer containers to be redistributed, and as a result, the inner containers are allowed to undergo “controlled” free-fall in a specified sequence. Insofar as each inner container is connected to the overhead rotatable shaft via a tether, as the body falls, it causes rotation of the shaft, which in turn causes rotation of electrical current generating device. 
     In another aspect of the present invention, a method of generating electricity includes the steps of providing a plurality of containers, disposing a floating body in each of the containers, sequentially moving an amount of fluid into the containers in a predetermined manner such that the floating bodies are sequentially supported at predetermined levels on the surface of the fluid via pressure, timing and valve sensors and actuating mechanisms. The method entails attaching each of the bodies to an overhead rotatable shaft via a tether of negligible weight that allows downward motion of the body in the respective container which results in rotation of the shaft. The method further entails evacuating the fluid from sequential ones of the containers at a rate greater than the fall of the bodies so that the bodies then experience “controlled” free fall, that is, free fall motion that is unrestrained, yet tethered. With the shaft coupled to a power generator, the fluid in the containers is redistributed, resulting in the continuous generation of power output. 
     These and other aspects, advantages, and features of the present invention will become more apparent and better understood, as will equivalent structures which are intended to be covered herein, with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments thereof in the specification, claims and drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates, in side sectional view, the power generating apparatus of the present invention in accordance with a first embodiment of the apparatus, 
     FIG. 2 illustrates, in side sectional view, the power generating apparatus of the present invention in accordance with a second embodiment of the apparatus. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a novel construction and method for generating electrical power by converting the kinetic energy of bodies experiencing “controlled” free fall into useful work. 
     Referring now to FIGS. 1 and 2 of the drawings, where like or similar reference numerals indicate the same or similar components in the two Figures, the invention is seen to include a plurality of outer containers or tanks  10   a ,  10   b ,  10   c  arranged in an array and capable of being filled with fluid, preferably water, from a source of fluid. The tanks may be situated relative to the source so that a head pressure head is developed before the fluid enters the tanks (FIG.  1 ), or alternatively, a pump may be used to fill the tanks from an available naturally-occurring fluid source (FIG.  2 ), such as a river or the sluice of a dam. 
     Each of the tanks is preferably substantially identical to one another, and may be formed from metal, concrete or plastic, depending on the application, and/or the site conditions, of the energy generating apparatus. 
     Positioned within each outer cylinder  10   a ,  10   b ,  10   c  is an inner container or tank  20   a ,  20   b ,  20   c  having its interior filled with a liquid, preferably water. Inner tanks  20   a ,  20   b ,  20   c  have a volume greater than the volume of liquid within the inner tank  20   a ,  20   b ,  20   c  to yield positive buoyancy. The invention contemplates that this substance can be air, air filled foam, or any other material that would allow positive buoyancy. While the tanks are shown in the Figures possessing a cylindrical shape, the tanks can also possess other shapes. In any event, it would be anticipated that due to hydrodynamic considerations, complimentary shapes for the tanks would be chosen to prevent any excessive water turbulence between the outer tanks  10   a ,  10   b ,  10   c  and the inner tanks  20   a ,  20   b ,  20   c  which could adversely affect the efficiency of the operation of the electrical generator. 
     Attached to the upper end of each inner tank  20   a ,  20   b ,  20   c  is an elongated tether member  22   a ,  22   b ,  22   c  which can be a chain, a rod, a cable, an articulated element, or any other mechanical attachment to the shaft  30 . Each elongated member  22   a ,  22   b ,  22   c  is attached between the upper end of a respective inner tank  20   a ,  20   b ,  20   c  and a clutch mechanism  32   a ,  32   b ,  32   c  positioned on and mounted to the shaft  30  which extends substantially horizontally across the top of tanks  10   a ,  10   b ,  10   c . The clutch mechanisms  32   a ,  32   b ,  32   c  are coupled to the tether members to convert the downward motion of the inner tanks  20   a ,  20   b ,  20   c  into a rotary motion of the shaft  30 . 
     Fluid transfer pipes  34   a ,  34   b ,  34   c  extend from the lower end regions of adjacent tanks  10   a ,  10   b ,  10   c  to interconnecting pipes  36  extending between and coupling the fluid transfer pipes  34   a ,  34   b ,  34   c . Valves  38  are positioned within each of the fluid transfer pipes  34   a ,  34   b ,  34   c  for starting and stopping the flow of fluid from and into the respective tanks  10   a ,  10   b ,  10   c.    
     All of the fluid transfer pipes  34   a ,  34   b ,  34   c  are fluidly coupled via the interconnecting pipes  36  with a fluid source, which can be a natural source of fluid, a pressure tank, or a combination of both. 
     Where the fluid source comprises a pressure tank (shown at  40  in FIG.  1 ), a pressure supply conduit  42  and cut-off valve  50  will be provided to allow the interior of the pressure tank to be coupled to a pressure generating apparatus, such as a pump or compressor (designated with the reference symbol PGA in FIG.  1 ). The pressure tank  40  is also provided with a pressure release conduit  44  and a valve  48 . Valves  48  and  50  are located outside the pressure tank  40  for a purpose to be described below in connection with the operation of the apparatus. 
     Where the fluid source comprises a natural source of fluid (shown at NS in FIG.  2 ), an inlet pipe  102  is fluidly coupled with the source NS, which by means of take-off conduits  104   a ,  104   b ,  104   c  is also fluidly coupled with the fluid transfer pipes  34   a ,  34   b ,  34   d . A discharge pipe  106  is fluidly coupled with the inlet pipes  104   a ,  104   b ,  104   c . Valve  56  is provided in the inlet pipe for selectively cutting the flow of fluid off to the outer containers when repair or maintenance is required. Valves  46   a ,  46   b ,  46   c  are provided in the conduits  104   a ,  104   b ,  104   c  upstream of the fluid transfer pipes  34   a ,  34   b ,  34   c , respectively, and valves  38   a ,  38   b ,  38   c  are provided in the conduits  104   a ,  104   b ,  104   c  downstream of the fluid transfer pipes  34   a ,  34   b ,  34   c , respectively to allow selective cut-off of the flow of fluid from the outer containers  10   a ,  10   b ,  10   c  throughout the cycles of operation as described below. A cut-off valve  158  is provided at the discharge end of the conduit  108 . 
     Various elements similar to those detailed above, that is any elements composed of an outer tank and a buoyant inner tank, may be arranged in a battery configuration, with all of them acting in concert on the rotating shaft through a respective clutch mechanism associated with each tank. While FIG. 1 shows a configuration with three tanks situated in a row or array  80 , it is to be understood that a principal aim of this invention is to provide continuous generation of electricity using any number of tank assemblies (it is to be understood that each tank assembly includes an inner tank and an outer tank, with associated pipes and valves) in an array  80 , as long as there are at least two tank assemblies. Further, two or more tank assembly arrays  80  may be arranged in series or in parallel and can be operated all as an electricity generating system to increase the operating efficiency of the generating system, or to increase the generating capacity of the system. 
     The shaft  30  may be connected to an electricity generating apparatus  60  or any other energy conversion device. A gearbox  52  may be connected via the shaft  30  disposed on opposite sides of the gearbox  52  to apparatus  60  to step up or step down the number of rotations of the shaft  30 , depending on the intended use of the output of the system. 
     The opening and closing of valves for the intake and output of fluid into and from the respective outer tanks  10   a    10   b ,  10   c , . . . is automatically achieved using fluid detecting sensors electronically coupled to the valves, with the sensors being located along the outer surface of the outer tanks. 
     The fluid in the outer tanks of the apparatus of the present invention can be replenished from a source of freely obtainable fluid capable of generating a head pressure (e.g., from a reservoir, lake, or other naturally occurring source of fluid such as a geyser). Alternatively, the fluid in the outer tanks can be replenished from a container of the fluid which is pressurized. Using water as the fluid, in the first case, replenishment can be accomplished by directing the fluid from a source of free flowing water having a head pressure greater than that needed to raise the level of fluid in the outer tanks to the upper extremity of the outer tanks, while in the second case, a pressure vessel is used to cause the fluid to refill the outer tanks to requisite levels. 
     Operation of the apparatus of the present invention is now described with reference to FIGS. 1 and 2 as noted below. The following description is based on an array of three outer tanks  10   a ,  10   b ,  10   c  and will, for ease of description, be described in terms of three cycles of operation (cycle I, cycle II, and cycle III) which are repeated over and over, ad finitem, from the start of operation of the apparatus until termination of operation of the apparatus which may occur when maintenance or replacement of components is required. 
     Referring now to FIG. 1, the operation of the inventive apparatus is described where the water comes from free flowing water having a head pressure greater than the pressure at the top of the tanks  10   a ,  10   b ,  10   c.    
     Prior to initiation of cycle I, the outer tank  10   a  is filled with water to a level near the top of the tank so that the buoyant tank  20   a  floats at that level within the outer tank  10   a . The outer tank  10   b  is partially filled with water and the buoyant tank  20   b  floats within the tank at the level of water in outer tank  10   b . Outer tank  10   c  at this time is empty with the buoyant inner tank  20   c  resting on the bottom of the outer tank  10   c.    
     Following setup of the apparatus, cycle I of operation of the apparatus is started by simultaneously opening valves  38   a  and  38   b  to allow water within outer tanks  10   a  and  10   b  to equalize. Allowing the water to evacuate from tank  10   a  faster than the rate at which the inner tank  20   a  can fall allows the full use of the kinetic energy descent y means of the connecting tether  22   a  to the clutch  32   a  and the rotating shaft  30 . Shaft  30  rotates by means of the tethered descending weight allowing shaft  30  to be connected to an energy-using device, such as an electrical generator. 
     Upon equalization of tanks  10   a  and  10   b , valve  38   b  is closed and valve  38   c  is opened simultaneously with the closing of valve  38   b . This allows water within tanks  10   a  and  10   c  respective tanks to equalize. As the equalization takes place, valve  56  and valve  46   b  open simultaneously to permit free water to fill outer tank  10   b  to the top, carrying with the liquid the inner buoyant tank  20   b  to the top of the inner tank  10   b . When the inner tank  20   b  reaches the top of the outer tank  10   b , valves  46   b  and  56  close simultaneously. At this topmost position, the inner tank  20   b  is poised for initiation of cycle II of the operation of the three tank array, while the remainder of the inner tanks continue to proceed through cycle I of the operation of the array. Upon equalization of the water in outer tanks  10   a  and  10   c , valve  38   c  closes simultaneously with the opening of valve  54  so that the remaining water from the outer tank  10   a  drains to the discharge outlet associated with outer tank  10   a.    
     When the outer tank  10   a  is fully drained, valve  38   a  and valve  54  close simultaneously. When the inner tank  20   a  reaches the bottom of the outer tank  10   a , cycle II of the process begins. This prevents the rotating shaft  30  from stopping its rotation, thereby allowing for continuous power generation. 
     Cycle II starts with the simultaneous opening of valves  38   b  and  38   c . This permits water in outer tank  10   b  to be evacuated therefrom, while permitting the water in the two tanks  10   b  and  10   c  to become equalized. The evacuation of water from outer tank  10   b  at a rate faster than the inner tank  20   b  can fall permits the tethered inner tank  20   b  to cause rotation of the rotatable shaft  30 . Upon equalization of the water in tanks  10   b  and  10   c , valve  38   c  closes simultaneously with the opening of valve  38   a.    
     As this equalization occurs, valve  56  and valve  46   c  open simultaneously allowing free water to fill tank  10   c  to the top carrying with it the inner tank  20   c  to the top of outer tank  10   c . Upon arrival of the inner tank  20   c  to the top, valve  46   c  and valve  56  close simultaneously. This position now sets the inner tank  20   c  for the beginning of cycle III while continuing to completion of cycle II. Upon equalization of tanks  10   c  and  10   a , valve  38   a  closes with the simultaneously opening of valve  54  to allow the remaining water in tank  10   b  to drain to the discharge outlet. When the tank  10   b  is fully drained, valve  38   a  and valve  54  close simultaneously. When the inner tank  20   b  reaches nearly to the bottom of outer tank  10   b , then cycle III begins, and the rotating shaft  30  continues to be driven in rotation, thereby allowing continuous power generation. 
     Upon starting cycle III, valves  38   a  and  38   c  open simultaneously to permit water within their respective tanks to equalize. Allowing water to evacuate from tank  10   c  causes the tethered bouyand tank  20   c  to transfer the power stroke from near to the bottom buoyant/weighted tank  20   b  uninterrupted allowing continuous rotation of shaft  30 . 
     Upon equalization of tanks  10   a  and  10   c , valve  36   a  closes and valve  36   b  opens simultaneously allowing water to flow into their respective tanks and equalize. As this equalization occurs, valve  56  and valve  46   a  open simultaneously to allow free water to fill tank  10   a  to the top carrying with it the buoyant/weighted inner tank  20   a  to the top of the outer tank  10   a . This position now sets the stage for the beginning of cycle I, as previously described, while continuing through the end of cycle III. 
     Upon equalization of tanks  10   c  and  10   b , valve  38   b  closes and valve  54  opens simultaneously allowing the remaining water in tank  10   c  to drain into the discharge outlet. When tank  10   c  is fully drained, valve  38   c  and  54  close simultaneously. 
     When the falling inner tank  20   c  reaches the bottom of its outer tank  10   c , cycle I will again be started so as to prevent the rotating shaft  30  from stopping, thereby facilitating continuous rotation of the shaft. 
     Referring now to FIG. 2, in which the water is provided by a pressurized source, operation of the apparatus entails first preparing the tanks by filling the outer tank  10   a  with water almost to the top of the tank so that the buoyant inner tank  20   a  floats on the water within the outer tank  10   a , filling the second outer tank  10   b  partly with water so that the buoyant tank  20   b  floats within tank  10   b  at that level, and leaving the outer tank  10   c  substantially empty with the buoyant tank  20   c  resting on the bottom of outer tank  10   c.    
     Upon initiating operation of the apparatus (i.e., at the start of cycle I), valves  38   a  and  38   b  are opened simultaneously to allow water within tanks  10   a  and  10   b  to equalize (i.e., to reach the same level). By allowing the water to be evacuated from tank  10   a  at a rate of speed greater than the falling buoyant tank  20   a , the full effect of the kinetic energy associated with the inner tank  20   a  as it descends can be harnessed to drive the rotatable shaft  30  in rotation. This is accomplished through the tether  22   a  which rotatably connects the tank  20   a  to the clutch  32   a  and hence the shaft  30 . The shaft  30  rotates and in turn causes the transfer of energy from the rotating shaft to an energy-using device such as an electrical generator. 
     When the level of the water in the outer tanks  10   a  and  10   b  are equal, valve  38   b  closes simultaneously with the opening of valve  38   c , thereby allowing water, remaining in tank  10   a  after equalization of the level of water in tanks  10   a  and  10   b , to continue to drain out of tank  10   a . When the level of water in tank  10   a  reaches the level of water in tank  10   c , valve  38   c  is closed and valve  46  is opened to allow the water remaining in the outer tank  10   a  to drain into the pressure vessel  40 . 
     When outer tank  10   a  is fully drained valve  38   a  closes, and valve  38   b  opens, while valve  48  closes simultaneously with the opening of valve  50 , the latter two valves cooperating to allow pressure vessel  40  to be subjected to pressurize from a source (not shown) thereby forcing water from pressure vessel  40  to the outer tank  10   b  to fill that outer tank to the top carrying with it the buoyant inner tank  20   b . When the inner buoyant tank  20   b  reaches the top of the outer tank  20   a , valve  38   b  closes, valve  46  closes, valve  48  opens and valve  50  closes simultaneously. This now sets the apparatus of the invention up for initiation of cycle II of the process. When the falling inner tank  20   a  reaches very nearly the bottom of tank  10   a , then cycle II begins so as to prevent the cessation of rotation of the shaft  30 , thereby facilitating continuous power generation. 
     Upon starting cycle II, valves  38   b  and  38   c  are opened simultaneously to allow water within tanks  10   b  and  10   c  to equalize, that is reach the same level. By allowing the water to be evacuated from tank  10   b  at a rate of speed greater than the falling buoyant/inner tank  20   b , the kinetic energy of inner tank  20   b  as it descends is effectively harnessed to drive the rotatable shaft  30  in rotation. This effect is accomplished through the connection of the inner tank  20   b  to the clutch  32   b  via tether  22   b . The shaft  30  is caused to rotate and in turn causes the transfer of energy from the rotating shaft  30  to an energy-using device, such as the electrical generator referred to above in connection with the description of cycle I. 
     When the level of the water in the outer tanks  10   b  and  10   c  are equal, valve  38   c  closes simultaneously with the opening of valve  38   a , thereby allowing water, remaining in outer tank  10   b  after equalization of the level of water in tanks  10   b  and  10   c , to continue to drain out of tank  10   b . When the level of water in tank  10   b  reaches the level of water in tank  10   a , valve  38   a  is closed and valve  46  is opened to permit the water remaining in the outer tank  10   b  to drain into the pressure vessel  40 . 
     When tank  10   b  is fully drained, valve  38   b  closes, valve  38   c  opens simultaneously with the closing of valve  48 . Further, valve  50  opens to allow pressure vessel  40  to be pressurized thereby forcing water from the pressure vessel  40  to tank  10   c  filling the tank to the top and carrying the buoyant inner tank  20   c  to the top of the outer tank  10   c . When tank  20   c  reaches the top of tank  10   c , valve  38   c  and valve  46  close, and valve  48  opens simultaneously with the closure of valve  50 . This sequence of steps now sets the apparatus of the invention up for cycle III of the process. When the falling inner tank  20   b  reaches very nearly the bottom of tank  10   b , then cycle III begins so as to prevent the rotating shaft  30  from stopping, thereby facilitating continuous power generation. 
     Upon starting cycle III, valves  38   a  and  38   c  are opened simultaneously to allow water within tanks  10   a  and  10   c  to equalize. By allowing the water to be evacuated from tank  10   c  at a rate of speed greater than the falling buoyant inner tank  20   c , the kinetic energy of inner tank  20   c  as it descends is effectively harnessed to drive the rotatable shaft  30  in rotation This is accomplished through the connection of the inner tank  20   c  to the clutch  32   c  via tether  22   c . The shaft  30  is caused to rotate and in turn causes the transfer of energy from the rotating shaft  30  to the electrical generator referred to above. 
     Upon equalization of the level of water in tanks  10   a  and  10   c , valve  38   a  closes simultaneously with the opening of valve  38   b  to allow the level of water within tanks  10   c  and  10   b  to equalize. Once equalization has been achieved, valve  38   b  is closed, and valve  46  opens simultaneously with the opening of valve  48  allowing the remaining water within tank  10   c  to drain into the pressure vessel  40 . When tank  10   c  is fully drained, valve  38   c  closes, valve  38   a  opens, valve  48  closes and valve  50  opens, all simultaneously, allowing pressure vessel  40  to be pressurized forcing water from pressure vessel  40  into tank  10   a  filling tank  10   a  to the top while carrying with it inner tank  20   a  to the top of tank  10   a.    
     Upon arrival of buoyant tank  20   a  to the top of tank  10   a , valve  38   a  closes, simultaneously with the closing of valve  46 , the opening of valve  48  and the closing of valve  50 . This position now stages the apparatus for the beginning of cycle I again as previously described above. 
     Those skilled in the art will appreciate that various adoptions and modifications of the invention as described above can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.