Abstract:
The present invention relates to an apparatus, suitable for generating energy in an aquatic environment. A preferred embodiment has at least two water piston assemblies connected to a power transfer system, such as a crankshaft or a rack and pinion drive. Each water piston assembly has a water container that slides within a casing. The casing controls the presence of water within the piston assemblies though a system of doors that opens and closes to assist with water intake and expulsion within the water container. Furthermore, the water container has ports which allow water to drain from the water container onto a water exit assembly. The water is then preferably channeled toward a generator or a turbine that converts the kinetic energy of the water flow into an electrical energy.

Description:
CLAIM OF PRIORITY 
     This application claims the priority of U.S. Ser. No. 61/270,983 filed on Jul. 15, 2009, the contents of which are fully incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a device capable of generating energy by transferring a quantity of water between chambers with a reciprocating motion piston device. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a device capable of harnessing hydropower and gravity to drive a power transfer system. The flow of water is then channeled through the device which will spin an axis connected to a turbine, or directly to a generator, to convert the kinetic energy of the moving water into electric energy. Hydropower is the most abundant and oldest known source of renewable energy in the world and experiencing resurgence in popularity as humanity struggles to find alternative sources of energy. 
     The most prevalent contemporary use of hydropower today is in the production of electricity. The present invention is a novel improvement in this field of art, as it presents a device capable of channeling water from a water container or piston into a shoot or piston cylinder that is connected to a pinion drive or a crankshaft, which are then connected to a generator or a turbine. The water itself is channeled away from the invention into another body of water or into drainage. 
     There are many advantages to hydroelectric power, some have already been mentioned. It is abundant and relatively easy to tap. However, the present means to generate hydroelectric power also have many disadvantages. Most of the negative impact is attributed to dams. Reservoirs associated with large dams can cover dry land and river habitat with water, drastically alter appearance of a landscape, decimate native ecosystems and displace human populations. Naturally, dams have had a particular negative impact on fish species that need to continue using the now dammed body of water for breeding, feeding and other migratory activity. Additionally, the stagnant water attributed to reservoirs contributes to the spread of undesirable algae infestation and to growth of a variety of aquatic vegetation that was previously not existent. 
     A number of devices were introduced in the past to resolve the problems associated with large scale damming. However, these devices introduce a number of problems of their own. Overall, these tend to be overly intricate and difficult to implement, requiring complex and expensive setups. These replacement devices do not necessarily prevent damage to the environment and otherwise tend to be extremely bulky and intrusive. On the contrary, the present invention is located toward the bottom of a water filled chamber, with the rest of the assembly located beneath the floor of the chamber. Also unlike existing devices, the present invention may be driven solely on the weight of the water and on natural force of gravity. Additionally, the present invention is very scalable and is effective in small and large embodiments. 
     DESCRIPTION OF THE RELATED ART 
     U.S. Pat. No. 4,599,857 discloses The present invention relates to an apparatus for the generation of power and its method comprising two cylinders, and pistons disposed in the cylinders, and a lever arm containing weighted balls disposed therein and connected to the pistons, whereby the balls are transferred from one end portion of the lever arm to the other end portion thereof and the lever arm, moves up and down about its axis by the force of floats or pistons and the weighted balls. 
     U.S. Pat. No. 6,445,078 teaches a system for gravity generation of electricity which includes upper and lower water reservoirs with a conduit between the reservoirs and a pump to continuously pump water from the lower reservoir to the upper reservoir. A number of water containers are positioned side-by-side and mounted for up and down travel between the upper and lower reservoirs. When the containers have attained their upper most position at the upper reservoir, they are engaged by limit switch mechanisms to fill the containers with water from the upper reservoir. Upon being filled the containers travel by gravity to their lower most position to the lower reservoir wherein additional limit switch mechanisms are employed to drain the containers into the bottom reservoir. As the containers travel downwardly, they engage and drive an electric generator for generating large quantities of electricity. Once the containers are at their lower most position and have been fully drained they are driven back up to the upper reservoir for refill by independent geared motors. 
     U.S. Patent Application Publication No. 2006/0130475 discloses A power generator has a reservoir, a tube, a drive assembly, and multiple floats. The reservoir is filled with a liquid and has a top opening and a side opening. The tube protrudes into the reservoir through the side opening. The drive assembly has four pedestals, four shafts, four sprockets and a chain. The shafts are rotatably mounted respectively in the pedestals. The sprockets are mounted on and rotate the shafts. The chain is mounted around and engages the sprockets in a loop. Each float has a buoyant body and multiple annular seals. The floats are attached to the chain so at least one float is in the tube at all times and are forced up in the reservoir by buoyancy when the floats are submerged in the reservoir. The annular seals are mounted around the floats to prevent liquid from leaking out of the tube. 
     U.S. Patent Application Publication No. 2005/0052028 relates to a hydraulic power generation system employs a plurality of buckets carried by an endless chain to receive water falling from height and drive the chain, which in turn drives a water pumping device to raise water to the height for automatic and continuous generation of power. 
     Various implements are known in the art, but fail to address all the problem solved by the invention described herein. One embodiment of this invention is illustrated in the accompanying drawings and will be described in more detail herein below. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an apparatus, suitable for generating energy in an aquatic environment. A preferred embodiment has at least two water piston assemblies connected to a power transfer system, such as a crankshaft or a rack and pinion drive. Each water piston assembly has a water container that slides within a casing. The casing controls the presence of water within the piston assemblies through a system of doors or valves that open and close to assist with water intake and expulsion within the water container. Furthermore, the water container or cylinder has ports which allow water to drain into a water exit assembly. These ports are preferably lined-up in such a way that the only time the water can exit is when the water container is at the bottom of its stroke or bottom dead center. The water may then be channeled toward a generator or a turbine that converts the kinetic energy of the water flow into an electrical energy. This conversion may take place instead of, or in addition to, the electrical energy generation that is likely to be produced by the spinning components of a power transfer system of the present invention. The water may also simply flow away from the device. 
     It is an object of the present invention to provide an apparatus for generating energy in an aquatic environment. 
     It is another object of the present invention to provide an apparatus that harnesses hydro power coupled with the earth&#39;s force of gravity. 
     Yet another object of the present invention is to provide an apparatus that is simple and relatively inexpensive to implement. 
     Still another object of the present invention is to provide an apparatus that has limited impact on the environment 
     Still another object of the present invention is to provide an apparatus that is capable of sustain sufficient water flow to power mechanical components that drive a turbine or a generator. 
     Yet another object of the present invention is to provide an apparatus that limits waste of kinetic energy by avoiding overflow and spillage associated with traditional paddle wheel devices. 
     Still another object of the present invention is to provide an apparatus that is able to provide a controllable flow of water. 
     Yet another object of the present invention is to provide an apparatus needing little maintenance, due to the small number of moving parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side view of the preferred embodiment of the present invention with the water container in a dead center low position. 
         FIG. 1A  shows a side view of an alternative embodiment of the water container section of the present invention. 
         FIG. 1B  shows a side view of the preferred embodiment of the present invention, with the container having reached the dead center high position within its casing. 
         FIG. 2  shows a top view of an alternative embodiment of the present invention. 
         FIG. 3  teaches a side view of the preferred embodiment of the piston assembly. 
         FIG. 4  shows a front view of the preferred embodiment of the present invention, disclosing the reciprocal operation of the containers within the piston assembly. 
         FIG. 5  shows a perspective view of the preferred embodiment of the present invention, showing the operation of the cylinder casing and the water exit assembly. 
         FIG. 6  shows an alternative embodiment of the present invention with the water container being supported by a rocker arm and pinion wheel combination. 
         FIG. 7  shows a bottom of one of the water containers used in the preferred embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified with the same reference numerals. 
     Reference will now be made in detail to embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto. 
       FIG. 1  presents a side view of the preferred embodiment of the present invention that is installed in a preferred location. Shown are a reservoir  5 , a water piston assembly  10 , a water container  20 , a container top  30 , a container bottom  40 , a sidewall  50 , a casing  60 , a piston opening  65 , an inner wall  70 , an outer wall  80 , a hollow space  90 , a casing bottom  92 , a casing top  94 , doors  100 , an upper surface of the doors  110 , a lower surface of the doors  120 , exit ports  130 , a power transfer system  140 , a connecting rod  150 , a pivot  155 , a first end  160 , a second end  170 , a crank shaft  180 , crankpin  190 , main shaft  195 , crank rod  200 , a retaining wall  240 , a water exit assembly  250 , and a base  260 . 
     The reservoir  5  is preferably between 15 and 20 feet deep between the surface of the water and the casing top  94 , which is the entry point for the water. However, as long as the water level is above the piston opening  65 , it will probably not matter how much higher the water is. Alternatively, the ratio of depth of water to the volume of the piston assembly  10  should be preferably 2:1. It is preferable to install the present invention near the bottom where the volume of the water and the water pressure is the greatest. However the device may also be placed substantially close to the top of the water line, as long as the water line is high enough to flow into the piston opening  65  of the casing  60 . It is also preferable to dispose the piston assembly  10  near a retaining wall  240  as shown, where it can serve as drainage or as a supplemental drainage system, to prevent water from wastefully splashing over the retaining wall  240 . One skilled in the art will understand that this  FIG. 1  and subsequent FIGS present a cross sectional cutout, where one of the sidewalls  50  and inner and outer walls  70  and  80  respectively, have been cut away to reveal the inner workings of the water piston assembly  10 . 
     In the preferred embodiment, the water container  20  is the movable portion of the water piston assembly  10 , whereas the casing  60  is the part that is securely immobilized within the base  260 . There is no preferred means of immobilizing the casing  60  within the base  260 , but some of the conventional examples are riveting, crimping, welding, soldering, brazing, taping, gluing, cementing, or through the use of various adhesives. The preferred volume of the casing  60  is between 2,000 and 4,000 cubic feet, with the preferred volume of the water container  20  is less than or greater then the volume of the casing  60 . Additionally, the casing  60  is shown as mounted on top of the base  260 . In an alternative embodiment, the casing top  94  is flush with the surface of the base  260  with only the piston assembly openings  65  visible at the top. The piston opening  65  is preferably between 10 and 20 feet/inches wide and between 15 and 30 feet/inches long, and may additionally contain a semi-permeable wire mesh that, depending on the grid density, can function to prevent the cylinder assembly from getting clogged up or to even serve as a filtering system. If the environment has the water flow to support it, the casing  60  really has no limit in the size, which in turn can create an unlimited amount of renewable energy. 
     Clearly visible in  FIG. 1  is the inner wall  70  and the outer wall  80  which are linked at the casing top  92  and form a hollow gap  90  that is sized to fit the water container side wall  50 . The water container or piston will fit perfectly between this space at top dead center. The water container  20  slides up and down or back and forth within the hollow gap  90 . It is understood that the relief of the side wall  50  of the container  20  and of the outer wall  80  and the inner wall  70  of the casing  60  should be similar enough to permit an unobstructed sliding movement of the sidewall  50  within the hollow gap  90 . It is preferred that material for the water piston assembly  10  is durable, inflexible and rust proof, and may be made out of stainless steel, aluminum, polyvinyl chloride a metallic alloy, wood ceramic, painted metal, steel alloy or concrete. All components may be manufactured out of the same material, but may be manufactured out of different materials. 
     Still referring to  FIG. 1 , the power transfer system  140  is composed of a connecting rod  150 , which connects to the water container  20  via a pivot  155  at the first end  160 , and to the crankshaft  180  at the second end  170 . The crankshaft  180  is formed out of a plurality of crankpins  190  connecting a plurality of crank rods  200 . The pivot  155  is essentially a bracket formed around a pin (not shown) that is commonly referred to in the art as the gudgeon pin that is attached to the crank rod  200 . Either the pin or the bracket may be disposed at the bottom  40  of the water container  20 . Using a connecting rod  150  that is pivotally connected to a water container  20  is well known and is easily enabled by one skilled in the art. The connecting rod  150  is preferably a solid segment of material with openings to connect to pins at first end  160  and second end  170 . The preferred length of the connecting rod  150  is long enough to have the piston move freely, keeping in mind the greater the cam shaft throw, the greater the horsepower of the device and the more energy is being generated. The length will be dictated by a specific implementation or water body utilizing the present invention. One skilled in the art will appreciate that the capacity or the power of the present invention is directly proportional to the length or the throw of the connecting rod  150  and to the displacement of the water piston assembly  10 . The connecting rod  150  will most likely endure a great deal of stress, particularly at the second end  170 , where the connecting rod  150  connects to the crankpin  190 . For that matter, it is imperative that connecting rod  150  be made of a strong but rust resistant material, such as, but not limited to, stainless steel, tungsten, or a steel alloy. The rust resistance is essential due to a perpetual exposure to water. 
     Still referring to  FIG. 1 , as the water container  20  begins its downward journey, the vents which may be cut outs in the piston may be about 18 inches in height and about 80% of the width of the piston. As the piston is coming down it will be engineered that no water flows out until bottom dead center when the exit ports  130  open and begin to drain. In an alternative embodiment the exit ports are placed on the side of the piston. Preferably, the exit ports  130  are calibrated in such a way that by the time the water container reaches the dead center low position, as shown, it is completely drained, and thus begins its upward stroke. The exit ports  130  preferably contain covers (not shown) that are opened with enough gravitational pressure from the water inside the water container  20 . The exit ports  130  can also have a powered synchronized opening means and are used to drain the piston assembly  10 . The water issuing from the exit ports  130  lands on the water exit facility  250 , which is a sloping shoot or a shelf that then channels the water away from the invention. In one embodiment the water is channeled at speed toward an electricity producing turbine or to a transmission system that provides a mechanical enablement to various other apparatuses. At the dead center low position as shown, all the water has drained, and the container will begin its upward journey into the casing  60 . 
       FIGS. 1A and 1B  show an embodiment of the water piston assembly  10 , with  FIG. 1A  showing an alternative embodiment of the connecting rod  150 . Shown in these FIGS. are a single water piston assembly  10 , a water container  20 , a container top  30 , a container bottom  40 , a sidewall  50 , a casing  60 , a piston opening  65 , an inner wall  70 , an outer wall  80 , a hollow space  90 , a casing bottom  92 , a casing top  94 , a location of the exit ports  130 , a power transfer system  140 , a connecting rod  150 , a pivot  155 , a first end  160 , a second end  170 , a crank shaft  180 , a crankpin  190 , a main shaft  195 , and a crank rod  200 . 
       FIG. 1A  shows an alternative embodiment of the connecting rod  150 , appearing to have a substantially equal width as the container bottom  40  at the first end  160 . This width may remain constant until terminating in a downward facing isosceles triangle, or substantially a 90° downward facing wedge, at the second end  170 . The sloping section  157  of the connecting rod  150  can accommodate a greater number of exit openings  130 , equally notable is the fact that discharging water at the bottom of the connecting rod  150 , rather than at through the container bottom  40  reduces the splash effect due to the close proximity of the connecting rod  150  with the water&#39;s landing point on the water exit assembly  250 . This is more efficient since less water gets splashed on the surrounding surfaces thus enhancing the velocity of the flow of water down the water exit assembly  250 . 
     In  FIG. 1A  the pivot  155 , preferably found on the first end  160  of the preferred embodiment, is not present. Therefore, the connector rod  150  will pivot together with the water container  20 , which will now tilt to accommodate the throw motion of the connecting rod  150 . Therefore, the hollow gap  90  should be made especially wide to permit a substantially free movement for the container top  30 , as this component may need to also be able to tilt in either direction as water container  20  rises and falls in response to the through motions dictated by the crankshaft  180 . 
     Another alternative embodiment of the present invention is to have a water container  20  that is capable of tipping over when full. Given the current diagramed configuration, such a tipping water container  20  would only be tipping partially with the container top  30  remaining within the hollow space  90  even during the tipping stage (not shown). Although this embodiment would call for a more elaborate water container  20 , it would also cause the water to discharge more rapidly. This in turn would lead to a quicker water flow down the water exit assembly  250 . 
       FIG. 1B  shows the preferred embodiment of the connecting rod  150 , with the water container  20  at the dead center high position. It is apparent from this diagram that the sidewall  50  has slidably advanced up the hollow space  90  until the container top  30  is immediately beneath the casing top  94 . The next step would be for the doors  100  ( FIG. 3 ) to open, which in this embodiment occurs with the help of an electrical motor (not shown). The doors  100  move in the upward direction either mechanically through the use of levers or pulleys ( FIG. 4 ) or electronically, as when the sensor at the container bottom  40  or on the container sidewall  50  is activated when it comes in contact with the casing bottom  92 , or whenever a sensor of this type is able to detect a dead center top location of the position of the doors  100 . Once a sensor (not shown) is set off, an electrical motor (not shown) lifts the doors  100  into an open position against the inner wall  70 . The power of such electric motor would depend on the water pressure inside the casing  60 , which depends on the water depth of the water reservoir  5  and on the volume of water present within the casing  60 . 
       FIG. 2  shows the top view of an alternative embodiment of the present invention, in particular, visible is the top of the two reciprocating water piston assemblies  10 . Shown are a container top  30 , a casing top  94 , inner walls  70 , outer walls  80 , and doors  100 . This alternative embodiment shows a set of doors  100 , disposed at the casing top  94 . The doors are diagramed in a closed position, in a preferred twin section embodiment. A twin section embodiment of the doors  100  constitutes the claimed door system, which is the preferred embodiment since this makes the doors  100  smaller, lighter and more maneuverable. Additionally a twin section door  100  can admit and expel water at a greater rate than a single section embodiment. This diagram shows the outer wall  80  surrounding both of the water assemblies as well as in between them. 
     Alternatively  FIG. 2  is a representation of a casing top  94  of a single water piston assembly  10 . In this embodiment the doors  100  form a dual pair of twin panel doors  100 . Note that the strip of outer wall  80  running in between the two pairs of doors  100 , now becomes a cross beam across a piston opening  65 . This segment of the outer wall  80  provides an additional support for the doors  100  as well as enhanced integrity for the rest of the water piston assembly  10 . A dual pair door  100  configuration is applicable when the piston opening  65  is especially large, such as when the width is between 10 and 30 feet and the length is between 20 and 80 feet. A large opening  65  creates the need for bigger doors  100 . However, to keep the doors maneuverable and the water flow rapid, the doors  100  should preferably remain small. Therefore utilizing several pairs of doors  100  for a single piston opening  65 , as shown, is a viable compromise. A wide opening is also preferable when a certain capacity water piston assembly is required, while only a relatively shallow casing  60  and water container  20  may be used. In such a situation, a wider water piston assembly  10 , with a larger opening  65  is preferable. An option may be to not have doors  100  at all, and for the entire water piston assembly  10  to move in reciprocal strokes, meaning, that doors  100  at the piston opening  65  are closed, the entire piston simply drops. 
       FIG. 3  is another side view of the preferred embodiment of the present invention, with the water piston assembly in the dead center low position. Shown are a water piston assembly  10 , a water container  20 , a container top  30 , a container bottom  40 , a sidewall  50 , a casing  60 , a piston opening  65 , an inner wall  70 , an outer wall  80 , a hollow space  90 , a casing bottom  92 , a casing top  94 , a plurality of doors  100 , an upper surface of the doors  110 , a lower surface of the doors  120 , the location of the exit ports  130 , a power transfer system  140 , a connecting rod  150 , a pivot  155 , a first end  160 , a second end  170 , a crank shaft  180 , a crankpin  190 , a main shaft  195 , and a crank rod  200 . The water has just discharged out of the exit ports  130  since the doors  100  are closed, the water container  20  is empty and the casing  65  is again filled with water. The preferable setup of water piston assembly is shown, with doors  100  disposed at the casing bottom  92 . In this embodiment the hinges  125  of the doors  100  could contain an electric motor, which could be activated when a sensor or a system of sensors detects that the water container  20  has advanced upward within the hollow gap  90  to an optimal position for a given operation. Alternatively, the doors could be activated by a mechanical mechanism. 
     The detection mechanism can be accomplished with a simple circuit breaker wire connector, where the container top  30  has a metal plate that completes a circuit when the water container  20  is at a predetermined desired position for such operation. This may be accomplished by having a section of current conducting material disposed on the sidewall  50 . The current conducting material is engaged as the water connector  20  advances upward within the hollow gap  90 , causing the current conducting segment to come in contact with two ends of exposed wiring that are connected in a circuit to a power supply (not shown). The power supply may be a battery, a current feed from a generator or from a conventional power supply grid. The location of the current conducting material is calibrated so that when the water container  20  is an optimal position, the current conducting segment is linking the two wires, thus completing an electric circuit and enabling the flow of current. The same circuit that enables the detection mechanism can also supply power to the electric motor (not shown) within the hinges  125 , either directly or through a safety switch, or a circuit breaker. Once the doors  100  open, the water container  20  gradually becomes heavier due to an influx of water and begins to move downward. The current conducting segment eventually moves away from the two ends of a wire and breaks the circuit, thus cutting power to the electric motors power the doors  100 . This forces the doors  100  to close under the weight of new water that has entered the casing  60  and under the weight of the water above the piston opening  65  that is exerting pressure on the upper surface of the doors  110 . 
     Alternatively, the doors  100  can be enabled through mechanical means by a system of pulleys and levers. The same motion of the sidewall  50  of the water container  20  within a hollow gap  90  would engage the hinges  125  for the doors  100  by means of a pinion gear, cable around a pulley or worm drive. 
     A probable pinion mechanism would work by having a segment of an annular gear (not shown) disposed on the sidewall  50 , on the side facing the hinges  125 . The annular gear would engage a pinion gear (not shown), which would in turn engage the pinion mechanism on the hinges  125 . In this configuration when an annular gear moves upward and engages a pinion gear, the pinion gear will turn in a clockwise direction. The pinion gear on the hinge  125 , that is engaged by the pinion gear presently turning in a clockwise direction, will be begin turning in a counter clockwise direction, thus opening the doors  100 . The process of closing the doors is precisely the same, except that now the annular gear is moving downwards, a pinion gear is turning counter clockwise, and the pinion gear on the hinge  125  is turning clockwise, closing the doors. One skilled in the art will understand that this pinion mechanism description is true, if the pinion gear is engaged by the annular gear on the left side, to operate a left side section of door  100 . When the annular gear engages the pinion gear on the right side the process is the same but in a reverse order to that of the left, namely, as annular gear moves upward, the right side engaged pinion gear turns counter-clockwise, turning the pinion gear on the hinges  125  in a clockwise direction to open the right side section of the door  100 , and in reverse order to close. 
     A similar setup of worm gears would enable the operation the doors  100 . The worm gears tend to be less efficient than spur gears, but are also more compact and self-locking. Due to this difference, a larger embodiment of the present invention will likely use spur gearing, whereas, a worm wheel mechanism will be preferred in more compact embodiments, or when the water pressure inside the casing  60  is especially high. 
     Alternatively, a “cable around a pulley” mechanism may be used to enable the operation of doors  100 . The likely function will be similar to the gear drive described above. A cable (not shown) is connected to the sidewall  50 . This cable is turned around the lower pulley (not shown), and then around the top of the upper pulley (not shown), which may be the hinge  25  or a separate pulley. The second pulley may be slightly offset from the vertical axis of the lower pulley, but does not need to be. Due to the potential size of this mechanism, the cable and pulley arrangement may need to be implemented outside the outer wall  80 . As the sidewall  50  slides upward, the cable is pulled downwards between the pulleys, thereby forcing the doors  100  to open. As the water container  20  sinks, the sidewall  50  slides downwards, the cable between the pulleys slackens. At some point the force of gravity coupled with the weight of the water on the upper surface of the doors  110  is greater than the pulling force of the cable, thereby forcing the doors  100  to close. 
     As an aside, it needs to be mentioned that the outer wall  80  is not strictly necessary, and the sidewall  50  can alternatively form an advancing and retreating jacket around the inner wall  70 , which will also function as guide for the sidewall  50 . 
     Another alternative embodiment compatible with  FIG. 3  is for the water container  20  to have a second set of doors (not shown) disposed at the casing top  94 . In this embodiment both the doors  100  at the casing top  94 , and the doors  100  at the casing bottom  92  will be swinging downward in the direction of the water container  20 . The doors  100  at the casing top  94  would have a lever mechanism (not shown), similar to a gear mechanism that was described above, and which would be engaged within the hollow space  90  by the rising container top  30  and would gradually force the doors at casing top  94  into a shut position. An important enabling feature is that the water container  20  is moving upward at a substantially rapid rate, as will be seen in  FIGS. 4 and 5 , since it is being propelled by the motion of another water container assembly  10  that is disposed on the same crankshaft  180  at 180° angle from the water piston assembly diagramed in the present figure; and as that other water piston assembly  10  is filled with water, it is moving downwards to discharge the water, propelling the water container assembly  10  in present FIG upwards. The rapid rate of motion of the container top  30  provides sufficient velocity to shut the doors  100  at the casing top  94 . Additionally, the torque generated by the closing of the upper doors  100  creates pressure within the casing  60 . This pressure is also exerted on the upper surface of the doors  110 , thereby forcing the second set of doors  100  at the casing bottom  92  to open, releasing the water into the water container  20 . This flow of water forces the water container  20  to sink under the increased weight of the entering water. As the container top  30  moves downward the lower doors  100  close and the upper doors  100  reopen, either with the motion of the sidewall  50  that is engaging a pinion gear, worm drive or pulleys with the workings of an electrical motor (not shown). Alternatively, the lower and the upper doors  100  may both be opening upwards, towards the piston opening  65  or each in a separate direction. 
       FIG. 4  is a diagram of the preferred assembly of the present invention. Shown are a reservoir  5 , a pair of water piston assemblies  10 ; which for clarity are shown as a water piston assembly  10 A and a water piston assembly  10 B; a water container  20 , a container top  30 , a container bottom  40 , sidewalls  50 , a pair of casings  60 , a pair of piston openings  65 , inner walls  70 , outer walls  80 , hollow spaces  90 , a casing bottom  92 , a casing top  94 , a plurality of doors  100 , an upper surface of the doors  110 , a lower surface of the doors  120 , a preferred location of the exit ports  130 , a pair of power transfer systems  140 , connecting rods  150 , pivots  155 , a pair first ends  160 , a pair of second ends  170 , a crankshaft  180 , crankpins  190 , a main shaft  195 , crank rods  200 , bearing ends  205 , a retaining wall  240 , and a base  260 . In an alternate form of the invention, the water container  20  may have vents (not shown) disposed near the top of container top  30  and container bottom  40 , as well as cone shaped cover not shown. Water can pour into the top vents, then exit at the vents located near container bottom  40 . 
     The crankshaft  180  of the power transfer system  140  is responsible for linking the two water piston assemblies  10 A and  10 B, which are exactly alike and shown in a reciprocal configuration that is phased apart at 180° due to the arrangement of the crank rods  200 , also known in the art as crank throws. Each connecting rod  150  is connected via pivot  155 , which may be a piston pin, gudgeon pin or a wrist pin (none shown), to the container bottom  40  on the first end  160 . The second end  170  connects to the crankpin  190 , also known in the art as a crank journal. Water tight bearing or lubrication rings will likely be used in both the first end  160  and in second end  170 . The greatest strain is borne by the second end  170  and the crankpin  190 , so that a bearing ring is most preferable to be disposed on that end. The crank rods  200  create the pulling and the pushing force that is powered by the weight of water inside the water containers  20 , coupled with a force of gravity. Each pair of crank rods  200  frames a crankpin  190 , and each crank rod  200  and crankpin  190  combination is connected to the main shaft  195 . The bearing ends  205  of the main shaft  195  rotate inside bearing rings (not shown) of a fixating structure (not shown). Such a structure would immobilize the crankshaft  180  and only permit axial rotational movement of the main shaft  195 . The main shaft  195  is not a single shaft that runs the length of the crankshaft  180 , but is rather a series of segments that link the crank rods  200  together. 
     Alternatively, the bearing ends  205  may be connected through a series of gears to supplemental shafts, thus forming a transmission of hydropower into a mechanical power to enable mechanized processes to occur (not shown), or to a be converted into electrical power by a direct connection to an electrical generator (not shown). 
     It should be noted that the emphasis is on an efficient and powerful device. Therefore, it may be preferred to limit the maximum size of the present invention only by the space available within a body of water where the present invention is installed, and by the volume and depth of water within this body. One skilled in the art will understand that some components of the power transfer system  140  may become impractical or unnecessary based on size, the overall concept of reciprocating water piston assemblies  10  will always remain true. 
     Depending on the size of the crankshaft  180  and on its revolutions, there may be a need to add counterweights to the crank rods  200 , to limit the stress on the crankpins  190  and on the bearing ends  205 . A crankshaft needs to be especially strong and is therefore commonly made out of metal, stainless steal, vanadium, micro-alloyed steel or any strong but rust resistant material. A crankshaft  180  may be assembled from several components as shown, or may be monolithic segment that is either forged or machined from a single steel bar or cast from a mold. 
     An alternative power transfer system  140  may be in the form of pinion gear, cable around a pulley or worm drive. The pinion gear embodiment is described in  FIG. 6 . One embodiment of a system employing a cable around a pulley is to have an upper pulley block (not shown) disposed above the casing top  94 , which a lower pulley block (not shown) disposed at a distance below the base  260 . The upper and lower pulley blocks will be located between the two water piston assemblies  10 . A cable is then threaded over the top of the upper pulley block, and into an opening in the casing top  94 , and then connected to the container top  30 . The cable is then threaded around the bottom of the lower pulley and up to the container top  30  of the second water piston assembly  10  and finally terminate at the top of the upper pulley block. It is preferred that such a cable is a continuous loop, but may in form of separate segments connecting the water container  20  to the lower or upper pulley block. Yet another alternative is to use just the upper pulley. Regardless of the number of pulleys used, the water container  20  of two water neighboring water piston assemblies  10  will necessarily need to be connected together, so that when one water container  20  sinks when filled, it will pull the other empty water container  20  upwards to be refilled, which will in turn sink, pulling the now drained first water container  20  upwards, thus completing the see-saw motion of the present invention, which will continue until all the water is drained below the enabling volume. Note that some stopping mechanism will need to be implemented to prevent the water containers  20  from sinking below a desired point. 
     One worm drive alternative embodiment of the power transfer system  140  would have two water piston assemblies  10  that are disposed next to one another, have one connecting rod  150 , and each connecting rod  150  have an annular gear that engages a single or a combination of spur or worm gears disposed on a support structure (not shown) in between the two piston assemblies. The reciprocating motion of the water piston assemblies  10  would be communicated through gear communication and the operation of the water cylinders would otherwise function as described above or in  FIG. 4   
     The entire present invention is set into motion by the presence of sufficient amount of water in the reservoir  5 . In  FIG. 4  the invention is shown with one set of doors  100  as opened in the water piston assembly  10 A and the other set of doors  100  closed in the water piston assembly  10 B. The water container  20  of the water piston assembly  10 A is filled with water, making it heavier than the water container  20  of the water piston assembly  10 B. It is obvious to one skilled in the art that the full water container  20  presses downwards on the crankpin  190  with greater force than the empty water container  20 , causing the crank rod  200  to swing or throw in the direction parallel to the axis of the pressure. This swinging or throwing motion also causes the crankpin  190  beneath the empty water container  20  of the water piston assembly  10 B to swing in the opposite direction due to the 180° offset of the crank rods  200 . This swing propels the water container  20  that is on top of the connecting rod  150 , of the water piston assembly  10 B, upwards into the hollow gap  90 . When a water container  20  of the water piston assembly  10 A reaches substantially dead center low position, the exit ports  135  are opened, and the doors  100  are closed. This causes the water piston assembly  10 B to drain completely. At the same time, the doors  100  in the water piston assembly  10 B open, and exit ports  130  close. As the water container  20  of the water piston assembly  10 B swings fills up, and the water container  20  of the water container assembly  10 A empties, the downward pressure becomes greater beneath the water container  20  of the water piston assembly  10 B. Thus the cycle is reversed. 
     It should be noted that the present invention will continue to function as long as the water inside the reservoir  5  remains above a certain volume, preferably between 75 cfps and 100 cfps. Alternatively, the reciprocal motion of the present invention can be supplement by a separate motor (not shown), connected to one or both of the bearing ends  205 . As such, the present invention will also function as a drain, since it will be able to channel water out of the reservoir  5  as long as the water level remains above the casing top  94 , which may be at the base  260  of the reservoir  5 , if the casing  60  is submerged (not shown) as in an alternative embodiment. 
     Still referring to  FIG. 4  the water ports  130  are apertures that remain covered until opened at or close to the dead center low point of the motion of the water container  20 . The covering may be opened and closed through an electrical motor. The motor can be activated when a segment of an electrical current conducting material disposed on the sidewall  50 . The segment of an electrical current conducting material would come in contact with exposed ends of wires at the casing bottom  92 , which completes a circuit, as the water container  20  moves downward toward the dead center low position. The exposed wires at casing bottom  92  are connected to a power source. Therefore, as soon as the circuit is complete, the current begins providing power to motors operating the coverings (not shown) of the exit ports  130 . Alternatively, the crankshaft  180  may be connected to the covers that cover the exit port  130  through a pulley and a belt drive mechanism (not shown) or a series of spur gears that would synchronize the opening and the closing of the exit port covers (not shown) to the motion of the crankshaft  180 . 
     Still referring to  FIG. 4 , the water piston assembly  10 B is positioned at the base  260 , and right next to the retaining wall  240 . Close positioning to the retaining wall  240  is preferable as the invention may serve as a supplemental drainage device to prevent water from pilling over the retaining wall  240 . Additionally, the retaining wall functions as a fixating structure for the bearing end  205 , as shown in  FIG. 5 . The exact proximity of a water piston assembly  10  with respect to the retaining wall  240  is not critical for the enablement of the present invention. 
     It is worth noting that one skilled in the art will appreciate that the reciprocating force of the water piston assemblies  10 A and  10 B is converted into rotational mechanical energy by the crankshaft  180  which itself can be connected to an electrical energy when connected directly to an electric generator. 
       FIG. 5  is a perspective diagram of the preferred assembly of the present invention. Shown are a reservoir  5 ; a water piston assembly  10 A and a water piston assembly  10 B, which are mirror images of each other; a water container  20 ; a container top  30 ; a container bottom  40 ; a sidewall  50 ; a casing  60 ; a piston opening  65 ; an inner wall  70 ; an outer wall  80 ; a casing bottom  92 ; a casing top  94 ; a power transfer system  140 , a connecting rod  150 , a first end  160 , a second end  170 , a crank shaft  180 , several crankpins  190 , a main shaft  195 , crank rods  200 , bearing ends  205 , a retaining wall  240 , a water exit assembly  250 , and a base  260 . One skilled in the art will understand that the retaining wall  240 , the base  260  and the water exit assembly  250  can be manufactured out of metal, concrete, asphalt, rock, ceramic, polymer or wood, or any other construction material commonly used in the art for this purpose. The base  260  can be any kind of a bottom surface, such as, but not limited to, a man-made material of a reservoir  5 , or a river bed. The water exit assembly  250  is preferably wider than the overall width of the water piston assemblies  10 A and  10 B, to ensure that all water captured by the water piston assemblies remains within the confines of the water exit assembly  250  instead of washing of its sides. The casing  60  and the water container  20  are shown as preferably substantially square, but may be in any shape, such as elliptical or circular. 
     The water exit assembly  250  is shown as substantially flat, preferably having grooves or channels to direct water to an electric generator, a paddle wheel or an impulse turbine all of which convert the kinetic energy of the water flow to a of a paddle or a turbine, which is then converted to an electrical energy by an electrical generator. The water exit assembly  250  may be in the shape of a gutter, a water shoot, a pipe or a flat surface that may or may not contain directional elements. 
     The present invention may be installed into the bed of a natural or existing man-made waterway. If that is the case, the area below the base  260 , which represents a river bed or a bed of the man-made waterway, may be excavated to provide sufficient height and width clearance for the motion of the water cylinder  20 , the power transfer system  140 , and the water exit assembly  250 . Once the device is installed into the excavated pit, the excavated area may be sealed to water from the reservoir  5 . Alternatively, if possible, the entire assembly, having a retaining wall  260 , a base  260  and water exist system  250 , along with all the other preferred components may be installed onto an existent river bed or bottom of a reservoir  5 . However, the area below the base  260  may be made free of water and the retaining wall  240  should preferably be above the existing surface of the water. 
       FIG. 6  is an alternative embodiment of the present invention, which uses a piston slidably moving within a cylinder instead of the preferred water container and casing. Shown are a reservoir  5 ; for clarity a water piston assembly  10  is shown as a water piston assembly  10 A and a water piston assembly  10 B, which are mirror images of each other; a piston  55 ; a first door system  100 A; a second door system  100 B; a power transfer system  140 , a rocker arm  210 , a pinion wheel  220 , a annular support  230 , a retaining wall  240 , a base  260 , a cylinder  270 , a cylinder top  280 , a cylinder bottom  290 , a cylinder sidewall  300 , and a cylinder opening  310 . 
     In this embodiment the cylinder  270  has been immobilized within the base  260 , essentially becoming a conventional cylinder. The motion inducement is still being supplied by the gravitational force coupled with the weight of a particular volume of water that is situated above the opening  310  of this alternative embodiment of the present invention. The volume of water may be somewhat less then the required volume of water in the preferred embodiment, since the piston  55  is often, but not always, lighter than the water container  20 . The water enters the cylinder  270  of the empty water piston assembly  10 A through the first door system  100 A, which is currently open. The water begins to exert downward pressure on the piston  55 , which begins to retreat in a downward direction. This downward motion of the piston generates suction forces, further inducing an inflow of water into the cylinder  270 . 
       FIG. 6  shows an alternative embodiment of a power transfer system  140 . The piston  55  is attached to the rocker arm  210  with a pivot  155 , which may be a piston pin, a gudgeon pin or a wrist pin (none shown) as in the preferred embodiment. The rocker arm  210  is attached to an axle (not shown) having a pinion wheel  220  on both ends. The pinion wheels  220  travel laterally along an annular support  230 . A second rocker arm  210  is attached to the pivot  155  that is attached to the piston  55  of the water piston assembly  10 B via the pivot  155 . The preferred length of the rocker arms  210  is between 30 and 100 feet, while its preferred thickness is between 6 inches and 18 inches. Note that depending on the embodiment implemented, the rocker arms  210  may be of a different length; a concept referred to in the art as master and slave rocker arm configuration. Preferably, however, the power transfer system  140  is a standard crankshaft  180 , crankpins  190 , a main shaft  195 , crank rods  200 , and bearing ends  205  as is disclosed in the previous Figures. One skilled in the art will also be able to appreciate that the rocker arm alternative embodiment disclosed in  FIG. 6 , may also be used with the preferred embodiment of the present invention. 
     The power transfer system  140  is preferably linked to an energy generation device or like a generator or a turbine, or to an energy dispersion device such as a transmission system that may have a gear mechanism or a cable and pulley mechanism, or a shaft and belt mechanism. It is preferable that in the present invention the power transfer system  140  is linked to a generator that generates electricity. The likely means by which electricity may be produced by some of the simpler generators may be for a bearing end  205  to be coupled, either directly or indirectly, to an armature loop located between two magnets (not shown). The rotation of the armature loop within a constant magnetic field would cause an electromagnetic force to be present in a circuit connected to such generator. Alternatively, the power transfer system may provide the mechanical energy to a turbine, which may be part of an electrical energy generator device. Those skilled in the art will appreciate the fact that the present invention provides a steady and reliable source of mechanical energy and that there are multiple ways in which the mechanical energy may into electrical energy. 
     Alternatively the mechanical energy created by the present invention, in particular, by the power transfer system  140 , may be dispersed, and used to drive various mechanical devices. This dispersion may be accomplished by connecting one or both of the bearing ends  205  of the present invention to a transfer mechanism having a series of interconnecting spur or worm gears, which then connect to a device needing power, such as factory equipment, conveyer belts, air pumps an any other similar adaptation. As the crankshaft  180  would spin, it would also set in motion any gears connecting to it and any equipment connecting it directly or to gears. 
     A pulley and cable system or a shaft and belt system, will most likely work in substantially similar fashion, except that the gears would be replaced by a pulley wheel or wheels, or by a shaft. The spinning of the crankshaft  180  of the power system  140  would cause the spinning of a pulley system or a shaft system, which in turn would pull belts or cabling attached to such systems and would also provide mechanical power to devices connecting to such belts or cabling. Alternatively, the mechanical energy produced by the power transfer system  140  of the present invention may be embodied within a spinning pinion wheel  220  with the rocker arm  210  or within a mechanism of cable with pulleys or a combination of interconnected gears. 
     Still referring to  FIG. 6 , the second door system  100 B is located in the sidewall  300  of the cylinder  270 . Exit ports  130  are not used in this embodiment since they would be blocked and rendered useless by the piston  55 . A small exit port  130  may be included however, but solely for draining access moisture out of the cylinder  270  that may collect below the piston  55 . 
     Once the piston  55  passes the second door system  100 B, it causes the second door system  100 B to open and the first door system  100 A to close, thus expelling the water within the cylinder  270 . Once the cylinder  270  of the water piston assembly  10  is empty the pressure exerted on the power transfer system  140  by the piston  55  in the water piston assembly  10 B becomes greater, causing piston  55  in the water piston assembly  10 B to fall and the piston in the water piston assembly  10 A to rise. Thus the process repeats itself until the water level falls below the required amount necessary to create sufficient pressure within the cylinders  270  to drive the power transfer system  140 . The second door system  100 B discharges water unto a water exit assembly (not shown) that is similar to the water exit assembly  250  disclosed in the preferred embodiment of the present invention. All other components not altered in this embodiment also remain the same. The water may be channeled into a turbine or a generator to create an electrical current. 
     The first door system  100 A and the second door system  100 B are enabled through motion of the piston  55 . One simple device to control the first and second door systems  100 A and  100 B can be two independent or interlinked levers that either open or close as the piston  55  moves along the cylinder  270 . As the piston  55  moves up, it engages a lever controlling the second door system  100 B, causing it to close. As the piston  55  continues to rise, it trips a second lever to open the first door system  100 A. This second lever may have a part that can only be engaged when the piston  55  gets closer to the bottom  290 , to prevent the first door system  100 A from closing too early. Alternatively, a lever at the bottom of the cylinder  270  may contain a single lever that is engaged with the downward pressure of the cylinder and causes the first door system  100 A to close and the second door system  100 B to open. This lever is released, when the piston  55  begins to move upward, closing the second door system  100 B and opening the first door system  100 A. However, to enable such a lever, the first door system  100 A will additionally need to be spring-loaded to remain in a shut position when a the lever is released and the first door system  100 A will need to spring-loaded to remain in an open position when this lever is release. These are just several enabling structures and there may other ways to enable the coordinated operation of the first and second door systems  100 A and  100 B. 
       FIG. 7  is a diagram of the container bottom  40 . Shown in this figure is a water container  20 , a container bottom  40 , exit ports  130 , a pivot recess  153 , a pivot  155 , a pair of covers  320 , cover rails  330 , a plurality of cover fasteners  340 , and a plurality of cover cables  350 . Shown is a square container bottom  40 , which may also be round, oval, or shaped as a wedge. The shape of the container bottom  40  dictates the shape of the covers  320 . The covers  320  are shown as curtain covers that cover the exit ports  130  like a blanket. Alternatively, each exit port  130  will have it own cover  320 . The cover  320  is preferably thin to reduce weight and water tight to prevent wasteful leakage. The cover  320  slides within the cover rails  330 . The cover  320  is moves apart when pulled by cover cables  350  that are fastened to cover fasteners  340 . The cover cables  350  may be wires that power an electric motor (not shown), which operates the cover  320 . in the embodiment shown, the covers  320  are spring loaded (not shown), the spring will prevent the cover  320  from detaching from the container bottom  40 , and will also force the covers back into place over the exit ports  130  once the cover cables  350  slacken. The cover cables  350  are made from a strong but elastic material that is rust resistant, such as, but not limited to, steel alloys, or synthetic fiber made of polymer or grass. One skilled in the art will appreciate that the exit ports  130 , shown as a series of portals or openings, may instead form one large opening or a many slits or openings forming a grill like structure. The recess  153 , houses the pivot  155 , shown here as a pin. The cover  320  contains a cutout to accommodate the connecting rod  150  (not shown in this figure). 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.