MACHINE FOR DRIVING AN ELECTRIC GENERATOR

Abstract

A machine for driving an electric generator moves a power module through a DOWN and UP duty cycle along a closed-loop, vertically oriented pathway. In the DOWN portion of the duty cycle, the module falls through air under the influence of gravity and generates kinetic energy for work to drive the electric generator. Upon disengagement of the power module from the electric generator, the kinetic energy of the power module then dives the power module into a bi-level water tank for a subsequent UP portion of the duty cycle. A valve mechanism and a displacement device are submerged in the bi-level tank to cooperate, in combination with each other, to create an unobstructed underwater pathway for the power module through the bi-level tank. The power module then rises under the influence of buoyancy to generate sufficient momentum for exit from the bi-level tank, and a consecutive duty cycle.

Claims

1. A machine for driving an electric generator which comprises: a buoyant power module having a volume V.sub.m and a mass m of weight W, wherein the power module is constructed to establish a buoyancy factor for the power module in a range of 0.6 to 0.75; a bi-level tank including a transfer tank with a lower water surface level, and a return tank with an upper water surface level, wherein the return tank is mounted on and above the transfer tank with a transfer port positioned therebetween, and wherein the transfer tank includes a separate access port; a valve mechanism mounted on the bi-level tank to perform a changeover operation between an open/close access valve at the access port and a close/open transfer valve at the transfer port; a displacement device submerged in the transfer tank, wherein the displacement device has a projected displacement area A.sub.d and includes a drive mechanism for moving the displacement area A.sub.d back and forth through a volume of water V.sub.d in the transfer tank to alternately displace V.sub.d from the transfer tank and recover a same volume of air V.sub.d into the transfer tank to compensate for the passage of the power module through the transfer tank, wherein V.sub.d=V.sub.m; and a control unit for launching the power module to start a duty cycle by dropping the power module from a launch platform into engagement with the electric generator, to generate electric power as the engaged power module continues falling through air by gravity, and for coordinating an operation of the valve mechanism with an operation of the displacement device, when the power module has disengaged from the electric generator and is in the transfer tank, to return the power module through water in the bi-level tank by buoyancy, to start a successive duty cycle.

2. The machine of claim 1 wherein the power module comprises: an upper end, wherein the upper end is engineered to have a coefficient of drag C.sub.D(upper); and a lower end, wherein the lower end is engineered to have a coefficient of drag C.sub.D(lower), and wherein a body for the power module is positioned between the upper end and the lower end of the power module to surround the chamber.

3. The machine of claim 2 wherein the coefficient of drag C.sub.D(upper) for the upper end of the power module is designed to establish a terminal velocity v.sub.t to generate a momentum mv.sub.t for the power module in the return tank with impetus to exit the power module from the return tank at the upper water surface level of the bi-level tank.

4. The machine of claim 2 wherein the power module accelerates to an engagement velocity v.sub.e for an engagement of the power module with the electric generator, where v.sub.e remains constant during engagement to maintain a kinetic energy of ½ mv.sub.e.sup.2 to drive the electric generator, and wherein the kinetic energy of ½ mv.sub.e.sup.2 does work after disengagement of the power module from the electric generator to initiate a dive by the power module into the transfer tank of the bi-level tank, and the coefficient of drag C.sub.D(lower) for the lower end of the power module is designed to effectively decelerate the power module in the transfer tank to zero velocity as soon as practicable.

5. The machine of claim 1 wherein the power module further comprises: a compartment for holding electronic and magnetic components, wherein the electronic and magnetic components interact with the machine and with the electric generator to guide and control movements of the power module on a closed-loop pathway through the machine.

6. The machine of claim 1 wherein the power module follows the closed-loop pathway during a duty cycle and the closed-loop pathway comprises: a power portion for the power module, wherein the power module is dropped onto the power portion for free fall from a start point, to accelerate the power module to an engagement velocity v.sub.e for engagement of the power module with the electric generator, where v.sub.e is held constant, to maintain a constant kinetic energy of ½ mv.sub.e.sup.2; and a return portion extending from within the transfer tank and through the return tank to the start point, whereon the power module attains a terminal velocity v.sub.t in the return tank to generate a momentum mv.sub.t for the power module with impetus to exit the power module from the return tank at the upper water surface level of the bi-level tank, and wherein a deflector/exit chute is incorporated with the return tank and oriented with an exit angle ϕ from vertical to facilitate the exit of the power module from the return tank.

7. The machine of claim 1 wherein the displacement device further comprises: an outside upper surface formed with the projected displacement area A.sub.d submerged in the transfer tank; a piston connected to the outside upper surface of the displacement device, wherein the piston has an inside upper surface distanced from the outside upper surface, and a lower surface formed with an area A, wherein A is less than A.sub.d and is aligned with A.sub.d; a pressure tank for holding compressed air at a predetermined pressure p.sub.1; a concertina skirt connected to the piston and positioned to surround the lower surface area A, wherein the concertina skirt is connected with the pressure tank to place the lower surface area A of the piston in fluid communication with the pressure tank, and to allow relative movement between the displacement device and the pressure tank, wherein the inside upper surface of the piston is positioned in fluid communication with the return tank; and a force actuator connected to the inside upper surface of the piston to periodically exert a force greater than Δp on the piston to move the piston through the volume V.sub.d, wherein Δp is a difference between a water pressure force A.sub.dp.sub.2 acting on the outside upper surface of the displacement device and a bias force acting against the lower surface of the piston.

8. The machine of claim 7 wherein the force actuator comprises: a motorized winch; and a cable connecting the winch to the inside upper surface of the piston, wherein the winch is connected with the control unit to periodically exert a force greater than ΔpA.sub.d on the inside upper surface of the piston to change the displacement device from a deactivated configuration to an activated configuration for displacing a volume of water V.sub.d from the transfer tank and to alternately remove the force from the inside upper surface of the piston to change the displacement device from the activated configuration to the deactivated configuration for recovering a volume of air V.sub.d into the transfer tank.

9. The machine of claim 1 further comprising: a plurality of position velocity sensors connected to the control unit and positioned on the machine for determining the velocity and location of the power module on a closed-loop pathway during a duty cycle; and a plurality of hydrodynamic sensors submerged in the bi-level tank and connected to the control unit for determining respective water pressures in the transfer tank and the return tank during an operation of the machine.

10. A machine for driving an electric generator which comprises: a buoyant power module having a volume V.sub.m and a mass m of weight W, wherein the power module moves in a duty cycle along a closed-loop vertically oriented pathway; a power portion of the pathway for the power module, wherein the power module is dropped onto the power portion for free fall from an elevated start point and accelerated under the influence of gravity to an engagement velocity v.sub.e for engagement with the electric generator, where v.sub.e is held constant during the engagement to maintain a constant kinetic energy of ½ mv.sub.e.sup.2 while driving the electric generator, and after the power module disengages from the electric generator to facilitate a dive of the power module into a bi-level water tank; a return portion of the pathway through the bi-level tank to the start point, whereon the power module attains a terminal velocity v.sub.t during its rise in the bi-level tank to generate a momentum mv.sub.t with sufficient impetus to exit the power module from the bi-level tank; a means mounted on the bi-level tank for performing a changeover operation between an open/close access valve at an access port into the bi-level tank and a close/open transfer valve submerged in the bi-level tank; a means for alternately displacing a volume of water V.sub.d from the bi-level tank and for recovering a same volume of air V.sub.d into the bi-level tank to compensate for the passage of the power module through the bi-level tank, wherein V.sub.d=V.sub.m; and a means for launching the power module from the elevated start point to start a duty cycle, and for coordinating an operation of the changeover performing means with an operation of the displacing/recovering means, when the power module is in the bi-level tank, to return the power module through water in the bi-level tank by buoyancy, to the start point for a successive duty cycle.

11. The machine of claim 10 wherein the power module is constructed to establish a buoyancy factor for the power module in a range of 0.6 to 0.75.

12. The machine of claim 10 wherein the bi-level tank includes a transfer tank with a lower water surface level, and a return tank with an upper water surface level, wherein the return tank is mounted on and above the transfer tank with a transfer port positioned therebetween, and wherein an open/close configuration for the transfer port is determined by the changeover performing means.

13. The machine of claim 10 wherein the displacing/recovering means is a displacement device submerged in the transfer tank, wherein the displacement device has a projected displacement area A.sub.d and includes a drive mechanism for moving the displacement area A.sub.d back and forth through a distance d to alternately displace the volume of water V.sub.d in the bi-level tank and recover a same volume of air V.sub.d into the transfer tank.

14. The machine of claim 13 wherein the drive mechanism is selected from the group consisting of pneumatically activated inflatable bladders and pressurized bellows, mechanically activated pistons, plungers, and plates, and devices requiring both pneumatic and mechanical activation, as well as devices that employ a piston component activated by an electric and/or electromagnetic drive.

15. The machine of claim 13 wherein the changeover performing means is a valve mechanism with valves selected from the group consisting of globe valves, butterfly valves, gate valves, ball valves, check valves, diaphragm valves, plug valves and pinch valves.

16. The machine of claim 10 wherein the power module comprises: an upper end, wherein the upper end is engineered to have a coefficient of drag C.sub.D(upper); and a lower end, wherein the lower end is engineered to have a coefficient of drag C.sub.D(lower), and wherein a body for the power module is positioned between the upper end and the lower end of the power module to surround the chamber.

17. The machine of claim 16 wherein the coefficient of drag C.sub.D(upper) for the upper end of the power module is designed to establish a terminal velocity v.sub.t to generate a momentum mv.sub.t for the power module in the return tank with impetus to exit the power module from the return tank at the upper water surface level of the bi-level tank, and wherein the coefficient of drag C.sub.D(lower) for the lower end of the power module is designed to effectively decelerate the power module in the transfer tank to zero velocity as soon as practicable.

18. The machine of claim 11 wherein the power module further comprises: a compartment for holding electronic and magnetic components, wherein the electronic and magnetic components interact with the machine and with the electric generator to guide and control movements of the power module on the closed-loop pathway.

19. A method for manufacturing a machine for moving a power module through a DOWN and UP duty cycle for driving an electric generator which comprises the steps of: constructing a transfer tank having a cover, wherein the cover is formed with an access port and a transfer port; erecting a return tank on the cover of the transfer tank, wherein the return tank is a hollow tower having an upper end and a lower end, and wherein the lower end is mounted over the transfer port of the transfer tank with a fluid tight seal to establish fluid communication between the transfer tank and the return tank, to create a bi-level tank including the transfer tank with a lower water surface level at the access port, and including a return tank with an exposed upper water surface level; establishing a deflector/exit chute at the upper end of the return tank, wherein the deflector/exit chute is oriented to establish an exit angle ϕ from vertical, wherein the exit angle ϕ will preferably be in a range between 15°-20°; providing a launch platform above the return tank for receiving a power module from the deflector/exit chute; mounting a valve mechanism on the bi-level tank to perform a changeover operation between an open/close access valve at the access port and a close/open transfer valve at the transfer port; positioning a submerged displacement device in the transfer tank, wherein the displacement device has a projected displacement area A.sub.d and includes a drive mechanism for moving the displacement area A.sub.d through a volume of water V.sub.d in the transfer tank to alternately displace a volume of water V.sub.d from the transfer tank and recover a same volume of air V.sub.d into the transfer tank to compensate for the passage of the power module through the transfer tank, wherein V.sub.d=V.sub.m; and incorporating a control unit connected with the bi-level tank for launching the power module from the launch platform to start a duty cycle by dropping the power module into engagement with the electric generator, to generate electric power as the engaged power module continues falling through air by gravity, and for coordinating an operation of the valve mechanism with an operation of the displacement device, when the power module is in the transfer tank, to return the power module through water in the bi-level tank by buoyancy, to start a successive duty cycle.

20. The method of claim 19 further comprising the steps of: creating the power module as a structure having a volume V.sub.m and a mass m of weight W, wherein the power module is formed with a chamber to establish a buoyancy factor for the power module in a range of 0.6 to 0.75; engineering a lower end of the power module to have a coefficient of drag C.sub.D(lower) designed to effectively decelerate the power module in the transfer tank to zero velocity as soon as practicable after the power module enters the transfer tank; engineering an upper end of the power module to have a coefficient of drag C.sub.D(upper) wherein the coefficient of drag C.sub.D(upper) is designed to establish a terminal velocity v.sub.t for generating a momentum mv.sub.t in the return tank with impetus to exit the power module from the return tank; and establishing a compartment in the chamber for holding electronic and magnetic components, wherein the electronic and magnetic components interact with the machine and with the electric generator to guide and control movements of the power module on a closed-loop pathway.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

[0081] FIG. 1 is a perspective view of a machine for the present invention;

[0082] FIG. 2A is a cross-section view of the machine as seen along the line 2-2 in FIG. 1, when the machine is configured to receive a power module;

[0083] FIG. 2B is a view of the machine as shown in FIG. 2A when the machine is configured to reorient the power module in the transfer tank of the present invention;

[0084] FIG. 2C is a view of the machine as shown in FIG. 2A after the power module has passed through the transfer tank and the transfer tank has been reconfigured to receive the next successive power module;

[0085] FIG. 3A is a cross-section view of a displacement device for use with the present invention, with the displacement device shown in a deactivated configuration;

[0086] FIG. 3B is a view of the displacement device as shown in FIG. 3A, with the displacement device in an activated configuration;

[0087] FIG. 4A is a perspective view of a power module in accordance with the present invention;

[0088] FIG. 4B is a cross-section view of the power module as seen along the line 4B-4B in FIG. 4A;

[0089] FIG. 5 is a cross-section view of the machine of the present invention showing a positioning of velocity and hydrodynamic sensors on the machine;

[0090] FIG. 6 is a table showing the correlation between a functional operation of the machine and the changeover operation of the valve mechanism of the present invention;

[0091] FIG. 7 is a velocity profile for a single power module during a duty cycle in accordance with an operation of the machine wherein four power modules are used, with a corresponding reference for each successive three power modules identified relative to the first power module; and

[0092] FIG. 8 is a diagram of interconnected components required for operating and controlling an operation of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0093] Referring initially to FIG. 1, a machine in accordance with the present invention is shown and is generally designated 10. As shown, the machine 10 includes a bi-level tank 12 that has a both a lower transfer tank 14 and an upper return tank 16. The operational purpose of the machine 10 is to move a power module 18 through a duty cycle on a closed-loop pathway 20 which is generally designated by the dashed line 20 in FIG. 1. Further, as shown in FIG. 1, a duty cycle on closed-loop pathway 20 includes a DOWN portion, indicated by the arrow 22, and an UP portion, indicated by the arrow 24. FIG. 1 also shows that the machine 10 includes a deflector/exit chute 26 that is connected to the top of the return tank 16 for directing the power module 18 as it leaves the bi-level tank 12. As will be appreciated with the additional disclosure presented below, an important consideration for the machine 10 is that it requires an external power source 28 for its operation. As envisioned for the present invention, the external power source 28 can be any such source well known in the art, such as a power grid provided by a commercial power company or some other external generator.

[0094] Additional aspects of the bi-level tank 12 will be appreciated with reference to FIG. 2A. In FIG. 2A a launch platform 30 is shown positioned above the transfer tank 14 at a location near the deflector/exit chute 26 of the return tank 16. At this location, the launch platform 30 is positioned to receive a power module 18 as it exits from the return tank 16 through the deflector/exit chute 26 at the end of a duty cycle. Further, it is shown that a rotating mechanism 32 is provided for the launch platform 30. In detail, when a power module 18 is received by the launch platform 30, it will be held on the launch platform 30 until the rotating mechanism 32 is activated to move the launch platform to an orientation indicated for launch platform 30′. The power module 18 will then be dropped from the launch platform 30′. After a power module 18 has been dropped, the orientation for launch platform 30 is reassumed to receive the next power module 18 in sequence. It is to be noted that an operation of the launch platform 30 requires power from the external power source 28.

[0095] Still referring to FIG. 2A, it will be seen that the transfer tank includes an access port 34 which can be closed or opened by an access valve 36. Also, a transfer port 38 is located between the transfer tank 14 and the return tank 16 which can be closed or opened by a transfer valve 40. Because the access valve 36 and the transfer valve 40 must perform a changeover operation with each other, the valves are sometimes referred to, collectively in this disclosure, as a valve mechanism 36/40.

[0096] An operation of the valve mechanism 36/40, and its import for an operation of the machine 10, will be best appreciated with a successive consideration of FIGS. 2A, 2B and 2C. In FIG. 2A, it will be noted that the valve mechanism 36/40 is configured so that the access port 34 is open and the transfer port 38 is closed. With this configuration for the valve mechanism 36/40, the transfer tank 14 is isolated from the return tank 16 and there is no fluid communication between water in the transfer tank 14 and water in the return tank 16. Also, the water surface 42 in the transfer tank 14 is exposed to only the atmosphere. The consequence of this configuration is that a power module 18 can enter the transfer tank 14 through the open access port 34. Moreover, the kinetic energy of the power module 18 (½ mv.sup.2) must only do work against an exposed water surface 42 that experiences a head height h.sub.1, which is directly influenced by only the atmosphere.

[0097] In FIG. 2B the valve mechanism 36/40 is shown configured with the access port 34 closed and the transfer port 38 open. With this configuration for the valve mechanism 36/40, the transfer tank 14 is opened to the return tank 16. This establishes an unobstructed underwater pathway 20 from the transfer tank 14, through the return tank 16, and up to the atmospherically exposed water surface 44 of the return tank 16. At this point however, although water in the transfer tank 14 is subjected to an increased head height h.sub.2, it is to be appreciated there is no adverse operational effect on the power module 18. Note: in their relationship to each other h.sub.2>>h.sub.1.

[0098] For the next successive configuration for the valve mechanism 36/40, FIG. 2C shows that the access port 34 has been reopened and the transfer port 38 has been reclosed. This changeover operation puts the bi-level tank 12 back into a configuration for receiving a next module 18 into the transfer tank 14. In accordance with the present invention, the successive configurations of valve mechanism 36/40 are repeated for each duty cycle of the power module 18.

[0099] As disclosed above, the valve mechanism 36/40 is provided for the purpose of maintaining different levels for the water surface 42 and the water surface 44 in the bi-level tank 12. Insofar as the actual operation of a valve mechanism 36/40 is concerned, this operation merely needs to changeover the open and closed condition of the access port 34 and the transfer port 38 in the bi-level tank 12. For this purpose, the selection of a specific type valve mechanism 36/40 for each machine 10 will depend on the operational requirements of the machine 10 that is being constructed (e.g. structural strength required, size, timing and output power requirements). Thus, although many valve types can be considered for use with the machine 10, the selection of a particular valve type for the valve mechanism 36/40 is a design and engineering consideration that can, and often will, require an evaluation of many different types of valves; to include: globe valves, butterfly valves, gate valves, slide valves, ball valves, check valves, diaphragm valves, plug valves and pinch valves.

[0100] In general, the operation of a displacement device 46 in accordance with the present invention will be best appreciated with reference to FIGS. 2B and 2C. In FIG. 2B, the bi-level tank 12 is shown configured after a power module 18 has entered the transfer tank 14. Specifically, for this configuration the access port 34 is closed and the transfer port 38 is open. At this point in a duty cycle, the water pathway 20 from the transfer tank 14 into the return tank 16 is unobstructed by the transfer valve 40 at the transfer port 38. It is also important to recognize that in FIG. 2B, the displacement device 46′ has been activated while the power module 18 is in the transfer tank 14.

[0101] Structurally, the activated displacement device 46′ occupies a displacement volume V.sub.d in the transfer tank 14 that is equal to the volume V.sub.m of the power module 18 (V.sub.d=V.sub.m). To establish this relationship, a surface 48 of the displacement device 46, having a flat projection displacement area A.sub.d, has been moved into the transfer tank 14 through a displacement distance d (i.e. V.sub.d=A.sub.dd). The result here is that in addition to the presence of a power module 18 of volume V.sub.m in the transfer tank 14, a volume of water equal to A.sub.dd (i.e. V.sub.d) has been displaced from the transfer tank 14 and moved into the return tank 16. Recall V.sub.d=V.sub.m. Therefore, the total water displaced from the transfer tank 14 for the configuration of the bi-level tank 12 shown in FIG. 2B, is V.sub.d+V.sub.m=2V.sub.m.

[0102] In FIG. 2C, it will be seen that the power module 18 has progressed from the transfer tank 14 and into the return tank 16. Also, the displacement device 46 has been deactivated to remove a volume V.sub.d of water from the transfer tank 14. The configuration of the bi-level tank 12 has also been changed to open the access port 34 and close the transfer port 38. The consequence of this is that the power module volume V.sub.m has moved into the return tank 16. Also, the displacement volume V.sub.d has been removed by a deactivated displacement device 46 to recover a volume of air V.sub.d into the transfer tank 14 that is equal to V.sub.m. The result here is that the bi-level tank 12 has been reconfigured to receive the next successive power module 18 (see FIG. 2A).

[0103] As envisioned for the present invention, a displacement device 46 can have any one of several different structures. Accordingly, each structure will have correspondingly different components. It is possible that the displacement device 46 may be either pneumatically activated, mechanically activated or activated by a structure that requires both pneumatic and mechanical activation. For instance, as a pneumatic device, the displacement device 46 may employ compressed air to operate pressurized bellows or an inflatable bladder. On the other hand, for a mechanical device the displacement device 46 may employ a piston component that is activated by an electromagnetic drive, an electric drive or a mechanical drive. Stated differently, the present invention recognizes the possibility that different drive components may be employed to operate a displacement device 46 for the purposes of the present invention. In any case, it is necessary for the displacement device 46 to first displace a volume of water V.sub.d from the transfer tank 14 as disclosed above. Then, the displacement device 46 needs to be timely activated in cooperation with the valve mechanism 36/40 to recover a same volume of air V.sub.d into the transfer tank 14, as also disclosed above.

[0104] With reference to FIGS. 3A and 3B, a displacement device 46 is shown submerged in the transfer tank 14, with a configuration wherein it is deactivated. As shown, the displacement device 46 has an outside upper surface 48, and it includes a piston 49 with a lower surface 50 and an inside upper surface 51. Also, FIG. 3A indicates that the lower surface 50 of the piston 49 has a surface area A that is in fluid communication with a pressure tank 52 which holds compressed air at a pressure p.sub.1. Thus, the lower surface 50 of the piston 49 will continuously be subject to a pressure of approximately p.sub.1 that exerts a force equal to p.sub.1A on the lower surface 50. Further, FIG. 3A indicates that the inside upper surface 51 of the piston 49 is in fluid communication with the return tank 16 and it will thereby be continuously subject to a pressure p.sub.2.

[0105] Still referring to FIG. 3A, it is seen that a concertina skirt 54 surrounds the lower surface 50 of the displacement device 46. The concertina skirt 54 also interconnects the displacement device 46 with the pressure tank 52. Further, the displacement device 46 is shown to be mechanically connected directly to a force actuator 56, that is external to the transfer tank 14.

[0106] At this point in the duty cycle of a power module 18, in order to displace a volume of water V.sub.d from the transfer tank 14, and to move it into the return tank 16, the outside upper surface 48 of the displacement device 46 must act against the water pressure p.sub.2 that is caused by the head height h.sub.2 in the transfer tank 14. In this case, the work required to displace V.sub.d will be equal to the product of the projected displacement area A.sub.d for the upper surface 48 of the displacement device 46, the pressure p.sub.2 in the return tank 14, and the displacement distance d that is required for a movement of the displacement device 46 to create a volume V.sub.d (i.e. A.sub.dp.sub.2d).

[0107] In a preferred embodiment for the displacement device 46, fluid pressure p.sub.1 from pressure tank 52 is established in fluid communication with the lower surface 50 of the piston 49 of the displacement device 46. This pressure p.sub.1 on the lower surface 50 of piston 49 will act directly against the area A of the lower surface 50 and thereby create a biasing force Ap.sub.1. This biasing force Ap.sub.1 will then directly oppose the force A.sub.dp.sub.2 that acts against the upper surface 48 of the displacement device 46. Recall, the inside upper surface 51 of the piston 49 will also be subject to the pressure p.sub.2. Thus, a structure is created where the only pressure forces acting on the displacement device are p.sub.1 and p.sub.2. Within this structural combination, the pressure p.sub.2 that is due to head height h.sub.2 in the return tank 16 and the pressure p.sub.1 from the pressure tank 52 can be respectively used to create a pressure differential Δp=p.sub.2−p.sub.1, wherein p.sub.2>p.sub.1. Thus, a force that is proportional to Δp will always act against the displacement device 46 to urge the displacement device 46 into its deactivated configuration. It is also to be appreciated that other devices can be used to create the bias force. For instance, instead of using compressed air, a spring can be used with an appropriate spring constant to establish Δp. Further, the use of a counteracting water column is possible. For example, water pressure from the return tank 16 can be directed against the lower surface 50 of the piston 49 to create Δp.

[0108] In any event, it is important that the bias force create a Δp that is relatively small, e.g. in a range between 1.5 and 2 psi. Accordingly, an activating force from the force actuator 56 that will raise the displacement device 46 through a distance d, against the force A.sub.dp.sub.2d that is caused by water in the transfer tank 14, need only be greater than A.sub.dΔp. Preferably, the force actuator 56 will be a motorized winch-type motor that is connected by a cable 57 with the inside upper surface 51 of the piston 49.

[0109] The power module 18 shown in FIGS. 4A and 4B is exemplary of a preferred structure for the power module 18 of the present invention. As shown, the power module 18 has an upper end 58, a body 60 and a lower end 62. Further, FIG. 4A shows that the lower end 62 can be modified for hydrodynamic purposes, such as by being slanted as shown by the dashed line for the lower end 62′. Depending on engineering design considerations, the length L of the power module 18 can be varied. Operationally, recall the power module 18 remains upright, i.e. with the upper end 58 remains above the lower end 62, during an entire duty cycle of the power module 18.

[0110] FIG. 4B, shows that the interior of a power module 18 will include an enclosed chamber 64 that is surrounded by a structure 66. This structure 66 will preferably be a strong heavy material, such as a metal, that is formed to create the exterior surface of the power module 18. For purposes of the present invention, the power module 18 will have weight W and a volume V.sub.m.

[0111] As emphasized above, it is an important design consideration for the present invention that the power module 18 be buoyant. For this consideration, the weight W and the volume V.sub.m are constant, and are predetermined. Thus, the buoyancy of the power module 18 must consider the weight that is added by components put into the chamber 64. For instance, it is envisioned that the chamber 64 will include a compartment 68 for holding electronics (e.g. sensors) and possibly magnets (not shown). Also, if necessary, materials including a support grid 70 can be erected in the interior of the chamber 64 for added strength and rigidity. In any event, as disclosed above, the power module 18 must be buoyant, and have a buoyancy factor that is preferably in a range between 0.6 and 0.75.

[0112] In accordance with above disclosure, and with reference to FIG. 5, it will be appreciated that an operation of the present invention requires precise velocity control over each power module 18 during its duty cycle. Preferably, by way of example, the present invention will involve a multi-module machine 10 that simultaneously uses four power modules 18. For purposes of the present invention, a plurality of position/velocity control sensors 72 are variously mounted on the machine 10. Additionally, a plurality of hydrodynamic sensors 74 are submerged in the bi-level tank 12. Further, FIG. 5 shows that an output power gauge 76 is mounted on an electric generator 78 that is connected with a linear drive component 80. As envisioned for the present invention, the linear drive component 80 may be either a mechanical chain drive, as show in FIGS. 2A-C, or it can be an electro-magnetic solenoid 80′, as shown in FIG. 5. With either structure, it is important that the power module 18 be securely engaged with the linear drive component 80/80′ as its kinetic energy is used to drive the electric generator 78.

[0113] The plurality of position/velocity sensors 72 are specifically located on the machine 10 to measure positions and velocities of each power module 18 as it passes selected points in the bi-level tank 12 during its respective duty cycle. Preferably, at least one position/velocity sensor 72 is positioned at the launch platform 30 to determine when a power module 18 is ready for launch. At least one position/velocity sensor 72 is located on the DOWN portion of the closed-loop pathway 20 to monitor the velocity v.sub.e of power modules 18 while they are driving the electric generator 78 by their engagement with a linear drive component 80 for the electric generator 78.

[0114] Also, a plurality of position/velocity sensors 72 are positioned in the bi-level tank 12. More specifically, position/velocity sensors 72 are positioned in the transfer tank 14 to monitor the transfer of a power module 18 from the transfer tank 14 into the return tank 16. Further, position/velocity sensors 72 are positioned in the return tank 16 to ensure appropriate duty cycle locations for power modules 18 on the UP portion of the closed-loop pathway 20 in preparation for a subsequent exit from the return tank 16.

[0115] The plurality of hydrodynamic sensors 74 are submerged in the bi-level tank 12 to measure fluid characteristics of the liquid in the bi-level tank 12. In particular, at least one hydrodynamic sensor 74a records fluid pressure in the transfer tank 14 when the access port 34 is open and the transfer port 38 is closed. At least one other hydrodynamic sensor 74b records fluid pressure in the transfer tank 14 when the access port 34 is closed and the transfer port 38 is open. And, at least one hydrodynamic sensor 74c records fluid pressure in the transfer tank 14 to monitor variations Δ.sub.1 in the lower level water surface 42 of the transfer tank 14. The general purpose here is to provide hydrodynamic values that can affect the velocity of a power module 18 in the bi-level tank 12, and to provide information to a control unit 82 (see FIG. 8) pertaining to the level of the lower water surface 42 and the level of the upper water surface 44 together with their respective variations Δ.sub.1 and Δ.sub.2 that are needed for a timely operation of the valve mechanism 36/40. Additionally, the hydrodynamic sensors 74 in the transfer tank 14 provide important information to the control unit 82 regarding fluid pressure values in the transfer tank 14 that must be accounted for during a proper operation of the displacement device 46.

[0116] With reference to FIG. 6, the required operation of the valve mechanism 36/40 with the operation of the displacement device 46 is provided for reference purposes. Specifically, FIG. 6 correlates a functional operation of the machine 10 with the changeover required for an operation of the valve mechanism 36/40, and the corresponding configurations of the access port 34 and the transfer port 38. As disclosed above, a valve mechanism 36/40 is provided for the purpose of maintaining different liquid surface levels in the bi-level tank 12. On the other hand, the displacement device 46 is required to accommodate the passage of a power module 18 through the transfer tank 14. Also, it is to be recalled that the displacement device 46 is activated when the access port 34 is closed and the transfer port 38 is open. Furthermore, the displacement device 46 is deactivated when the access port 34 is open and the transfer port 38 is closed.

[0117] Operational control for the machine 10 will be best appreciated with reference to FIG. 7, where the velocity profile of an exemplary duty cycle 84 for one power module 18 is presented. FIG. 7, shows this duty cycle 84 in a context with the operation of the valve mechanism 36/40. Recall, when access valve 36 is open, transfer valve 40 will be closed and vice versa. Moreover, in FIG. 7, the duty cycle 84 for a single power module 18 is shown in a relation of its engagement time T.sub.e with the electric generator 78 and the engagement times 2-4 T.sub.e for three additional power modules 18.

[0118] With reference to the timeline in FIG. 7, it is to be appreciated that a duty cycle 84 can be considered as extending from t.sub.0 to t.sub.0. In this case, the engagement time T.sub.e (see FIG. 5) will extend from t.sub.2 to t.sub.3. For a four-module machine 10, as shown in FIG. 5, a complete duty cycle 84 for each power module 18 will have a duration equal to 4T.sub.e.

[0119] With the above in mind, the positions and velocities of each power module 18 as it travels through a duty cycle 84 must necessarily be based on T.sub.e. Also, as discussed above, there are two velocities in a duty cycle 84 that will remain substantially constant. First, the engagement velocity V.sub.e that a power module 18 has during a power phase 86 (see FIG. 1) of the duty cycle 84 needs to be constant during the time T.sub.e. Specifically, V.sub.e is constant while the power module 18 is engaged with the linear drive component 80 of the electric generator 78. Second, the velocity v.sub.t which is the terminal velocity attained by the power module 18 as it rises in the return tank 16, during a return phase 88 of the duty cycle 84, will remain constant. Module velocities other than v.sub.e and v.sub.t are transitional velocities which will either accelerate to v.sub.e or v.sub.t; or decelerate from v.sub.e or v.sub.t to zero.

[0120] FIG. 7 shows that from the time t.sub.0 when a power module 18 is dropped for free fall 90 from the launch platform 30 until it engages with the linear drive component 80 at time t.sub.2, the velocity of a power module 18 increases from zero to v.sub.e. For the present invention, v.sub.e will depend on the weight W of a power module 18, as well as the free fall distance 92 (see FIG. 5). Importantly, v.sub.e for a power module 18 is established so it will generate the voltage and sine wave characteristics that are required by the end user (e.g. a commercial grid). Operationally, v.sub.e can be controlled by control unit 82 using output from power gauge 76 to determine appropriate loading for the linear drive component 80.

[0121] As shown, v.sub.e is held constant between t.sub.2 and t.sub.3 for a time interval T.sub.e. Note: at the time t.sub.3, as a power module 18 disengages from the linear drive component 80, the next successive power module 18 will simultaneously engage with the linear drive component 80. Also, it is important to note that at the time t.sub.3, the access port 34 will be open to allow the disengaged power module 18 to enter the transfer tank 14. At this time, the transfer port 38 will accordingly be closed. As a safety feature, in order to ensure that access port 34 is indeed open, a mechanical trip switch 94 (see FIG. 5) can be provided at a predetermined distance above the access port 34. Shortly after t.sub.3, however, i.e. once the power module 18 has entered the transfer tank 14, access port 34 immediately closes.

[0122] Once the power module 18 is in the transfer tank 14, the displacement device 46 is activated to force a volume of liquid V.sub.d from the transfer tank 14, through the now-open transfer port 38. Specifically, as noted elsewhere herein, this displaced volume V.sub.d of liquid will be equal to the volume V.sub.m of the power module 18 that is in the transfer tank 14 at the time.

[0123] While it is inside the transfer tank 14, the power module 18 will decelerate to zero (v=0). Then, as it is being reoriented in the transfer tank 14, the power module 18 will accelerate to its terminal velocity v.sub.t as it transitions from the transfer tank 14 and into the return tank 16. It is important that the power module 18 leave the transfer tank 14 within the time interval T.sub.e so the next power module 18 will be able to enter the transfer tank 14 during its respective duty cycle 84.

[0124] Still referring to FIG. 7 it will be appreciated that a power module 18 will maintain its terminal velocity v.sub.t in the return tank 16 until it exits from the return tank 16. Before starting its next duty cycle 84, the power module 18 will decelerate from v.sub.t to zero. Deceleration is then complete when the power module 18 is repositioned on the launch platform 30 to begin its next duty cycle 84 with another free fall 90.

[0125] Recall, with reference to FIG. 7, the above disclosure has been described in terms of a duty cycle 84 for only one power module 18. As has been noted, however, for an operation that involves a plurality of power modules 18 (e.g. four), each power module 18 will experience a same duty cycle 84. Moreover, each power module 18 will be engaged with the linear drive component 80 for a same time interval T.sub.e. Thus, in this example the time duration of the duty cycle 84 for each power module 18 will be 4T.sub.e.

[0126] As envisioned for the present invention, it may be desirable for there to be a plurality of power modules 18 concurrently engaged with the linear drive component 80. In this case, the time each power module 18 is reoriented in the transfer tank 14 will necessarily be shortened since there can only be one power module 18 at a time in the transfer tank 14.

[0127] Another consideration for the structure of a machine 10 is the incorporation of internal guides 96 that are referred to in FIG. 8. These guides can be positioned along the closed-loop pathway 20 to establish and maintain a controlled movement of the power module 18 through the machine 10 to include engagement with the electric generator 78 and a reorientation of the power module 18 in the transfer tank 14. For this purpose, internal guides 96 can be positioned along the portion of closed-loop pathway 20 where power modules 18 engage with the linear drive component 80 of electric generator 78. Internal guides 96 can also be appropriately positioned in the bi-level tank 12. The particular structures used for internal guides 96 will depend primarily on engineering design criteria, the size and shape of power modules 18, and the operational requirements for a machine 10. With this in mind, internal guides 96 will typically be rollers, rails, bulkheads, barriers, restraints, magnets, or a combination of these various structures.

[0128] Referring now to FIG. 8, it will be seen that the control unit 82 is connected in electronic communication with a timer 98 and with other electronic and mechanical components of the machine 10. Specifically, the control unit 82 uses the timer 98 to coordinate the operation of the various system components. In particular, these components include the launch platform 30, the displacement device 46 and the valve mechanism 36/40. They also include the internal guides 96 that assist in keeping power modules 18 on the closed-loop pathway 20 during a duty cycle 84.

[0129] While the particular Machine for Driving an Electric Generator as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.