Patent Abstract:
An ocean wave energy device uses large gas filled and surface vented or partially evacuated flexible containers each having rigid movable ends and rigid fixed depth ends connected by flexible bellows, suitably reinforced against external hydrostatic pressure, submerged to a depth below anticipated wave troughs. One or more said containers compress and expand as waves and troughs, respectively, pass overhead driving hydraulic or pneumatic, pumping means producing pressurized fluid flow for a common sea bed motor-generator or for other uses or on-board direct drive generators. Mechanical, hydraulic or pneumatic means re-expand said containers when a wave trough is overhead. Power output is augmented by mechanically connecting said rigid moving surfaces to surface floats, which may also provide said submerged container venting such that as waves lift and troughs lower said floats, said containers are further compressed and re-expanded, respectively. Power output is further augmented by wave kinetic energy capture through focusing, reflection and refraction.

Full Description:
RELATED U.S. APPLICATION DATA 
     Continuation-in-Part of U.S. application Ser. No. 12/454,984 filed on May 27, 2009 now abandoned, incorporated herein by reference. 
    
    
     FIELD OF INVENTION 
     This invention relates to devices for producing electrical power, pressurized water or other useful work from surface waves on a water body. 
     More particularly, this invention relates to wave energy converters wherein either all or a substantial portion of the energy captured or produced is from one or more submerged devices relying on overhead wave induced subsurface differences in hydrostatic pressure and/or enhanced surge or pitch which expand and contract or otherwise deform or deflect one or more gas filled submerged containers, thereby producing useful work. Such expansion and contraction is enhanced or supplemented by wave focusing, reflection or diffraction techniques and/or by overhead surface floating bodies. 
     BACKGROUND OF THE INVENTION 
     Wave energy commercialization lags well behind wind energy despite the fact that water is several hundred times denser than air and waves remain for days and even weeks after the wind which originally produced them has subsided. Waves, therefore, efficiently store wind kinetic energy at much higher energy densities, typically averaging up to 50 to 100 kw/m of wave front in many northern latitudes. 
     Hundreds of uniquely different ocean wave energy converters (OWECs) have been proposed over the last century and are described in the patent and commercial literature. Less than a dozen OWEC designs are currently deployed as “commercial proto-types.” Virtually all of these suffer from high cost per average unit of energy capture. This is primarily due to the use of heavy steel construction necessary for severe sea-state survivability combined with (and in part causing) low wave energy capture efficiency. Only about 10% of currently proposed OWEC designs are deployed subsurface where severe sea-state problems are substantially reduced. Most subsurface OWECs are, unfortunately, designed for near shore sea bed deployment. Ocean waves lose substantial energy as they approach shore (due to breaking or reflected wave and bottom and hydrodynamic friction effects). Near shore submerged sea bed OWECs must be deployed at greater depths relative to average wave trough depths due to severe sea-state considerations to avoid breaking wave turbulence, and depth can not be adjusted for the large tidal depth variations found at the higher latitudes where average annual wave heights are greatest. Wave induced subsurface static pressure oscillations diminish more rapidly in shallow water as the depth below waves or swell troughs increases. 
     Only a few prior art subsurface devices use gas filled or evacuated containers like the present invention, producing container deformation in response to overhead swell and trough induced static pressure changes. None of the prior art subsurface OWECs capture both hydrostatic (heave) and hydrokinetic wave energy (surge or pitch) which represents half of all wave energy. None of these prior art subsurface OWECs enhance or supplement energy capture with overhead floating bodies. All of the prior subsurface deformable container OWECs suffer from high mass (and therefore cost) and low energy capture efficiency (even more cost) usually due to near shore or sea bed deployment and high mass. None of these have the tidal and sea-state depth adjustability of the present invention needed for enhanced energy capture efficiency and severe sea-state survivability. None have the low moving mass (allowing both short wave and long swell energy capture) and the large deformation stroke (relative to wave height) needed for high capture efficiency of the present invention. 
     At least two prior art devices use two variable volume gas filled containers, working in tandem, to drive a hydraulic turbine or motor. Gardner (U.S. Pat. No. 5,909,060) describes two sea bed deployed gas filled submerged inverted cup shaped open bottom containers laterally spaced at the expected average wavelength. The inverted cups are rigidly attached to each other at the tops by a duct. The cups rise and fall as overhead waves create static pressure differences, alternately increasing and decreasing the gas volume and hence buoyancy in each. The rise of one container and concurrent fall of the other (called an “Archemedes Wave Swing”) is converted into hydraulic work by pumps driven by said swing. 
     Similarly, Van Den Berg (WO/1997/037123 and  FIG. 1 ) uses two sea bed deployed submerged average wavelength spaced interconnected pistons, sealed to underlying gas filled cylinders by diaphragms. Submerged gas filled accumulators connected to each cylinder allow greater piston travel and hence work. The reciprocating pistons respond to overhead wave induced hydrostatic pressure differences producing pressurized hydraulic fluid flow for hydraulic turbines or motors. 
     The twin vessel Archemedes Wave Swing (“AWS”) of Gardner (U.S. Pat. No. 5,909,060) later evolved into a single open bottomed vessel ( FIG. 2 ) and then more recently Gardner&#39;s licensee, AWS Ocean Energy has disclosed an enclosed gas filled vessel (an inverted rigid massive steel cup sliding over a second upright steel cup) under partial vacuum ( FIG. 3 ). Partial vacuum, allowing increased stroke, is maintained via an undisclosed proprietary “flexible rolling membrane seal” between the two concentric cups. Power is produced by a linear generator ( FIG. 2  shown) or hydraulic pump driven by the rigid inverted moving upper cup. An elaborate external frame with rails and rollers, subject to fouling from ocean debris, is required to maintain concentricity and preserve the fragile membrane. 
       FIG. 4  (Burns U.S. 2008/0019847A1) shows a submerged sea bed mounted gas filled rigid cylindrical container with a rigid circular disc top connected by a small diaphragm seal. The disc top goes up and down in a very short stroke in response to overhead wave induced static pressure changes and drives a hydraulic pump via stroke reducing, force increasing actuation levers. Burns recognizes the stroke and efficiency limitations of using wave induced hydrostatic pressure variations to compress a gas in a submerged container and attempts to overcome same by arranging multiple gas interconnected containers perpendicular to oncoming wave fronts. North (U.S. Pat. No. 6,700,217) describes a similar device. Both are sea bed and near shore mounted and neither is evacuated or surface vented like the present invention to increase stroke and, therefore, efficiency. 
       FIG. 5  (Meyerand U.S. Pat. No. 4,630,440) uses a pressurized gas filled device which expands and contracts an unreinforced bladder within a fixed volume sea bed deployed rigid container in response to overhead wave induced static pressure changes. Bladder expansion and contraction within the container displaces sea water through a container opening driving a hydraulic turbine as sea water enters and exits the container. Expansion and contraction of the submerged bladder is enhanced via an above surface (shore mounted) diaphragm or bellows. High gas pressure is required to reinflate the submerged bladder against hydrostatic pressure. 
     DISCLOSURE OF THE PRESENT INVENTION 
     According to embodiments of the present invention, one or more gas tight containers are submerged to a depth slightly below anticipated wave and swell troughs. The container(s) have a fixed depth rigid end or surface held at relatively fixed depth relative to the water body mean water level or wave troughs by either a flexible anchoring means, with horizontal depth stabilization discs or drag plates, or by a rigid sea bed attached spar or mast, or the bottom itself. A second movable rigid end or surface opposes said first fixed end or surface. Said fixed and movable ends are separated and connected by and sealed to a flexible, gas tight, reinforced, elastomer or flexible metal bellows, or a diaphragm or accordion pleated skirt also suitably reinforced against collapse from container internal vacuum or external hydrostatic pressure. Overhead waves and troughs produce hydrostatic pressure variations which compress and expand said containers, respectively, bringing said movable end closer to and further from said fixed depth end. Container expansion and contraction (or “stroke”) is enhanced by either partial evacuation of said container or venting of said containers&#39; gas to a floating surface atmospheric vent or to a floating surface expandable bellows or bladder, or reservoir. Without said partial evacuation or atmospheric venting, said stroke and hence energy capture would be reduced several fold. The relative linear motion between said containers&#39; fixed and movable ends is connected to and transferred to a hydraulic or pneumatic pumping means or, mechanical or electrical drive means. The pressurized fluid flow from said hydraulic or pneumatic pumping can drive a motor or turbine with electric generator. Mechanical means can direct drive a generator via rack and pinion gearing, oscillating helical drive or other oscillating linear one or two way rotational motion means. Electrical drive means can be by a linear generator. After compression return and expansion of said containers and its&#39; movable end can be assisted by mechanical (i.e. springs) pneumatic (compressed gas), hydraulic or electric means. Efficiency can be further enhanced by delaying said compression and expansion until hydrostatic pressure is maximized and minimized, respectively via the use of pressure sensors and control valves. Power recovery can occur on either or both strokes. The submerged depth of said containers relative to the sea bed and wave troughs can be hydrostatically sensed and adjusted by a hydrostatic bellows or by hydraulic or electro-mechanical drives for tides to maintain high efficiency by maintaining a relatively shallow submerged depth. The submerged depth can also be increased or the device can be temporarily compressed or locked down during severe sea-states to increase survivability. The stroke or linear motion produced by said container&#39;s compression and expansion and applied to said pumping or drive means can be reduced and its&#39; drive force correspondingly increased by use of leveraged connecting means such as rack and pinion or reduction gears, scissor-jacks, linear helical drivers, or lever and fulcrum actuators. High hydraulic pressure can be produced even in moderate sea states by the sequential use of multiple drive cylinders of different sectional areas or by using multi-stage telescoping cylinders. The linear oscillating motion of said container(s) expansion and contraction can be converted into smooth one way turbine, pump, motor or generator rotation via the use of known methods including accumulator tanks, flow check (one way) valves and circuits or mechanical drives, ratchets and flywheels. Mechanically connecting said moving second surface to any floating overhead device, including said floating vent buoy or a floating wave energy converter further increases stroke, energy capture and efficiency. Suitably shaping, inclining (towards wave fronts) and extending the surfaces of said moving second surface provides major additional energy capture. Wave reflection (off a back wall) and focusing also increase both potential (heave) and kinetic (surge and pitch) wave energy capture. The subject device may have a typical diameter and stroke of 5-10 meters and produce 0.25 MW to 1 MW of electrical power. Elongated or multi-unit devices may have major dimensions and outputs of several times that. 
     Distinguishing Features Over Prior Art 
     The subject invention provides substantial advantages over the prior art. Van Den Berg (WO/1997/037123), shown in  FIG. 1 , requires two shallow water sea bed mounted pistons rather than the one of the present invention, separated by an average wavelength. A gas tight chamber is maintained below each piston by a rolling membrane seal. The rolling membrane seal limits stroke and, therefore, energy capture and is vulnerable to frictional wear between the piston and cylinder and near shore debris caught within the seal. The two chambers are connected to two gas accumulator tanks to slightly increase piston travel and rebound rather than utilize the partial evacuation or surface or atmospheric venting of the present invention. The piston connecting rods drive hydraulic pumps which drive a hydraulic motor and generator. Twin chamber devices spaced one average wavelength apart are inherently inefficient as wavelengths are very seldom at their average value. At 0.5 or 1.5 times average wavelength, such devices produce no energy. Submerged shallow sea bed mounted devices must be placed well below the average wave or swell trough depth to survive breaking waves in severe sea-states. Wave induced static pressure differences diminish rapidly with depth in shallow water. Shallow water sea bed mounted devices must be rugged and therefore costly as well as inefficient. Unlike the present invention, depth of sea bed devices can not be adjusted for tides. 
     Gardner (U.S. Pat. No. 5,909,060) also proposes a twin chamber shallow sea bed device which is essentially two inverted open bottomed cup shaped air entrapped vessels spaced an “average” wavelength apart and rigidly connected by an air duct. One vessel rises as the other falls (like a swing) pumping hydraulic fluid for an hydraulic motor generator. The device is called an “Archemedes Wave Swing.” A single vessel open bottom shallow sea bed mounted variant ( FIG. 2 ) is also described, the upside-down air entrapped cup moves up and down in response to overhead wave induced static pressure variations driving a generator with a mechanical or hydraulic drive. Unlike the present invention, which uses an evacuated or surface or atmospheric vented closed vessel, Gardner&#39;s up and down movement, and therefore output and efficiency, is restricted because the vessel is not evacuated or vented to atmosphere or an accumulator. The entrapped air is, therefore, compressed thus restricting movement, efficiency, and output. The open bottom also presents problems such as weed fouling and air loss (absorption in water) not encountered in the closed vessel of the subject invention. Shallow water or sea bed mounting also raises costs and lowers efficiency as previously described in Van Den Berg above. 
     Gardner licensed U.S. Pat. No. 5,909,060 to AWS Ltd. which published an “improved” evacuated enclosed vessel design in November 2007 (as depicted in  FIG. 3 ). Air under partial vacuum is entrapped between a moving rigid (heavy) inverted cylindrical cup shaped upper vessel ( 11  in down position,  12  in up position) which slides over a similar slightly small diameter stationary up oriented cup shaped vessel affixed to the sea bed. Partial vacuum is maintained by a “flexible rolling membrane seal” ( 14  in down position and  15  in up position). To prevent frictional seal wear and binding between the moving and stationary cup, an elaborate marine foulable “ectoskeleton” or frame  16  with rollers  17  or skids is required. The movable inverted cup drives a hydraulic piston  18  providing pulsed pressurized flow on each down stroke. Unlike several embodiments of the present invention, no power is produced on the upstroke which is used to hydraulically return the piston  18  and movable inverted cup  11  and  12  to its&#39; up position  12 . 
     The present invention differs from the published AWS design of  FIG. 3  in the following major ways:
         1. The flexible elastomer bellows and smaller (plate not cup) light weight (fiberglass) moving surface of the present invention reduces total and moving mass several fold and is, therefore, several fold less costly (light weight flexible (elastomer) sidewalls vs AWS heavy rigid steel overlapping sidewalls). Low moving mass of the present invention greatly increases responsiveness allowing both wave and swell kinetic energy capture vs. the heavy AWS mass for swells only. Low moving mass also allows effective timing, or delayed release, of the compression and expansion strokes until the wave crest and trough, respectively, are overhead preserving precious stroke length until hydrostatic forces are at a maximum (for compression) and minimum (for re-expansion). This “latching” control alone can increase the energy capture efficiency of heaving mode OWECs several fold (see cited references Falnes &amp; McCormick).   2. Certain preferred embodiments of the present invention use direct or indirect atmospheric venting, rather than the partial vacuum used by AWS which may be more difficult to maintain sea water leak free and may compromise hydraulic seals. Partial vacuum also results in some gas compression on the vessel compression stroke which reduces stroke and, therefore, energy capture.   3. Certain preferred embodiments of the present invention utilize overhead surface floating buoys connected to the flexible reinforced bellows container to enhance compression or expansion of said containers or otherwise supplement energy capture.   4. No expensive, heavy, high maintenance, marine debris fouled ectoskeleton/cage with exposed rollers (to maintain concentric cylinder in cylinder movement) is required for the present invention.   5. No “flexible rolling membrane seal” (a fragile high wear, high maintenance item) is required with the present invention. Partial container evacuation combined with hydrostatic seawater pressure draws this seal into the container interior reducing container volume and increasing seal wear.   6. The membrane seal and concentric overlapping cups of the AWS device restricts stroke to less than half that of a present invention device of comparable size, halving cost and doubling energy capture.   7. The “rolling membrane seal” limits the AWS device to a circular horizontal planar section. An oblong section possible with the present invention, may be oriented transverse to the wave front direction (parallel to the waves) and, can capture more energy per unit of horizontal planar area and width. The sides of a circle have very little frontal area and capture.   8. The rigid near shore sea bed attachment post of the AWS device ( 19  in  FIG. 3 ) does not allow depth adjustment for tides or optimized energy capture or protection from severe sea-states like the adjustable depth mooring systems of the present invention.   9. Embodiments of the present invention use a force multiplier or leveraged connecting means and/or multi-staged or multiple sequenced drive cylinders to increase stroke while maintaining higher capture efficiency than the AWS device ( FIG. 3 ).   10. The device of the present invention, unlike the AWS device, can be oriented vertically (with either fixed or moving surface up), horizontally, to also capture lateral wave surge energy, or in any other orientation.       

     Burns (2008/0019847A1, 2007/025384/A1, and 2006/0090463A1) and  FIG. 4  also describes a submerged sea bed mounted pressurized gas filled cylindrical container  11  having a small diaphragm  39  flexibly connecting a rigid movable top  25 ,  28  to the top of cylindrical side walls  17 . The top and attached small diaphragm move slightly in response to overhead swell induced static pressure changes driving a leveraged  63  hydraulic pump  47 . To overcome gas compression stroke limitations, Burns in some embodiments uses multiple adjacent gas interconnected containers, but they are too close to each other to be effective. North U.S. Pat. No. 6,700,217 describes a very similar container and small diaphragm, without gas evacuation, venting or gas interconnection. 
     The present invention overcomes the limitations of Burns and North in like manner to the AWS/Gardner limitations described in 1-10 above. More particularly or in addition:
         1. Neither Burns nor North use surface or atmospheric venting or partial evacuation like the present invention to reduce container gas compressive/resistance and greatly increase stroke and energy capture.   2. Neither Burns nor North or any other submerged vessel prior art use any means before, after on or floating above their vessels to focus or capture any kinetic wave energy representing 50% of all wave energy. Likewise no submerged vessel prior art use a mechanical connection between said submerged vessel and a surface float to increase the stroke and energy capture of said submerged vessel.   3. While Burns and North have less moving mass than AWS, their total mass (and therefore cost) is probably greater due to their heavy walled ( 11  and  17 ) ballasted sea bed mounted containers.   4. Burns&#39; and North&#39;s small unreinforced diaphragms  29  severely limit their power stroke lengths to a small fraction of the overhead wave height and, therefore, a like small fraction of energy capture rather than a substantial or even majority stroke to wave height ratio of the present invention.   5. Burns&#39; power stroke (and, therefore, energy capture efficiency) is limited by his return means, which uses stroke limiting container internal gas pressure.   6. Burns&#39; attempts to improve his poor stroke and energy capture efficiency in his latest application (2008/0019847A1) by aligning a series of pressurized gas interconnected containers into the direction of wave travel in an “arculated” shape is ineffective in overcoming gas compressive resistance because his containers span less than ½ average wave length.   7. Sea bed mounting of Burns&#39; devices further severely reduces potential energy capture efficiency because sea bed mounting places Burns&#39; movable device tops substantially below average wave trough depth due to tides and severe sea-state device protection considerations. Wave induced static pressure fluctuations fall off drastically with increased depth in shallow water as previously stated.       

     Meyerand U.S. Pat. No. 4,630,440 ( FIG. 5 ) shows a submerged sea bed deployed gas filled unreinforced bladder  18  within a larger rigid sea water filled container  26 . Meyerand&#39;s “bladder in a box” differs materially from the “reinforced flexible bellows” with one fixed rigid end surface and an opposing moving rigid end surface of the present invention. Meyerand&#39;s bladder is connected via an air duct to a second shore or surface floating bladder  34 . Sea water enters and exits the rigid container  26 , in response to overhead wave induced pressure changes on the bladder  18 , through a single opening pipe containing a sea water driven turbine-generator. Meyerands &#39;440 suffers the same limitations of near shore sea bed mounted hydrostatic pressure driven devices previously described. The long pneumatic hose  24  between the submerged container  26  with bladder  18  and the shore or surface based bladder  34  produces substantial pneumatic flow efficiency losses. It also reduces the submerged bladder response time limiting energy capture to long swells and not waves. Most significantly, to get Meyerand&#39;s “constant pressure” and “constant volume” two bladder system to reinflate when a trough is overhead (Meyerand&#39;s only “return means”), the operating “constant pressure” must be extremely high to support and lift the water column above it (45 psi per 100 ft. of water depth). This high “constant pressure”, “constant volume” gas needed for submerged bladder inflation severely limits submerged bladder volume changes and energy capture. The present invention does not use high pressure gas within the container and surface vent or bellows as its&#39; return means. The container gas pressure is approximately one (1) atmosphere or lower allowing several times more stroke and energy capture. 
     Margittai (U.S. Pat. Nos. 5,349,819 and 5,473,892) describes a flexible gas (air) filled submerged (sea bed placed) container which expands and contracts in response to overhead wave induced hydrostatic pressure changes. The rigid top surface is rigidly affixed to and drives a vertical  1  stroke sea water open cycle pump. Unlike the present invention, Margittai does not vent or evacuate his container (he actually “inflates” or pressurizes it to hold its shape against submerged hydrostatic pressure and to provide his only return or re-expansion means, thereby limiting his stroke and wave energy absorption several fold. Margittai uses a simple bladder unreinforced against external hydrostatic pressure, unlike the “reinforced bellows” of the present invention (reinforced against both internal vacuum and external hydrostatic pressure). Margittai relies upon severely stroke and efficiency limiting internal air pressurization for his return means rather than the mechanical or hydraulic return means of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a submerged elevation sectional view of the Prior Art by Van Den Berg 1997/037123. 
         FIG. 2  is a submerged elevation sectional view of the Prior Art of Gardner U.S. Pat. No. 5,909,060. 
         FIG. 3  is a submerged elevation sectional view of the Prior Art of AWS Ltd. as described in the published 29 October-11 November “The Engineer” (pgs. 26 and 27). 
         FIG. 4  is a submerged elevation sectional view of the Prior Art by Burns (2008/0019847A1). 
         FIG. 5  is an elevation view of Meyerand U.S. Pat. No. 4,630,440. 
         FIG. 6  shows a submerged elevation sectional view of a preferred embodiment of application Ser. No. 12/454,984 (FIG. 15) incorporated herein by reference. 
         FIG. 7  shows a submerged elevation sectional view of one embodiment of the present invention comprising a vertically oriented partially evacuated or surface vented reinforced flexible bellows container with a said second moving surface extended beyond said bellows top and inclined toward prevailing wave fronts driving a telescoping hydraulic cylinder powering a sea bed hydraulic motor generator. Mooring, tidal depth adjustment, and depth fixing means are also shown. 
         FIG. 8  shows submerged elevation sectional ( 8   a ) and plan view ( 8   b ) of one embodiment of the present invention comprising an expanded partially evacuated or surface vented reinforced flexible bellows container, said bellows being flexibly inclined toward prevailing wave fronts. Said second moving surface is extended both forward and down (towards oncoming waves) and rearward and upwards for increased wave kinetic energy capture. Said bellows extensions having spring loaded vents or flaps reducing hydrodynamic drag when said second moving surface is re-extended. 
         FIG. 9  shows a submerged elevation sectional view of one embodiment of the present invention similar to  FIG. 8 , but comprising a hinged movable surface over said second moving surface, said hinged surface driving a hydraulic cylinder supplementing the hydraulic drive cylinder within said bellows. 
         FIG. 10  shows submerged elevation ( 10   a ) and plan ( 10   b ) views of one embodiment of the present invention comprising a fixed depth inclined shoaling plane in front of said bellows container and a fixed wave reflective wall behind said bellows container, relative to the direction of oncoming waves. Wave funneling and focusing means are also incorporated. 
         FIG. 11  shows an elevation view of a preferred embodiment of the present invention similar to  FIG. 8  except also comprising a floating surface vent buoy mechanically connected through a lever to said submerged container so as to assist in compression and expansion of said container when waves and troughs, respectively pass overhead. 
         FIG. 12  shows an elevation partial (cutaway) sectional view of an embodiment of the present invention comprising a submerged vertically oriented bellows chamber with extended and inclined moving said second surfaces vented to and lever connected to a surface floating bellows. An air turbine generator produces power from alternating gas flow through a duct connecting said bellows. 
         FIG. 13  shows a submerged isometric view of one embodiment of the present invention showing multiple partially evacuated or surface vented elongated flexible bellows containers having common inclined said second moving surface extending both forward (toward oncoming waves) and rearward and common fixed first surface hinged together. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1-5  show prior art previously discussed.  FIG. 6  shows a preferred embodiment of U.S. patent application Ser. No. 12/454,984 (FIG. 15) incorporated herein by reference and of which this application is a Continuation-in-Part. 
       FIG. 7  shows an embodiment of the present invention similar to  FIG. 6 . Stationary surface  1  (sealed to a reinforced flexible bellows  3 ) is part of a molded or fabricated lower hull  100  which may have integral buoyancy chambers  101 . Moving surface  2  is part of upper hull  102  which may also contain buoyancy chambers  101  which may also serve as expansion chambers. Flexible bellows  3  is supported against external hydrostatic pressure and, optionally internal partial vacuum, by (internal only) support rings  6 . Bellows expansion return is via return spring  44  which return can be assisted or replaced by the  3  stage telescoping hydraulic drive cylinder  103 . Bellows internal support rings  66  could be replaced by a helically wound spring (not shown) also serving as said return means. Said bellows  3  and drive cylinder  103  are protected from severe lateral loads and deflection if required by an internal central slide tube or rails sliding within mating tubes or rails  105  in both the top and bottom hulls. Such sliding is facilitated by rollers or bearings  106 . The bellows  3  is further supported against lateral or shear loads by cross members  107  also rolling on said slide tube or rails  104 . The drive cylinder  103  is hydraulically connected to a sea bed mounted “power pod”  110  via hydraulic lines  108  and  109  passing through a rigid mast or spar  111 . Said single “power pod” can service multiple bellows via additional hydraulic lines (not shown). The upper mast  111  houses or supports a tidal depth adjusting jack screw  112  driven by electric or hydraulic jack screw drive  113 . Said power pod is sealed against sea water and houses high pressure hydraulic fluid accumulator tanks  114 , hydraulic motor  115 , electric generator  116 , and controls. The hydraulic circuit contains control valves  117  on high pressure supply and low pressure return lines which may be used to delay or time the drive cylinder  103  power (down) stroke and return stroke until the wave crest  5  or trough (shown), respectively, are overhead, for maximum stroke length and energy capture (per Ref. cited and included “latching” by Falnes and McCormick). Fixed surface  1  is held in deep water at a relatively fixed depth by the buoyance of the gas filled bellows container  4  and any buoyance chambers  101  and drag planes, plates or discs  118 . Said spar  111  and said container can be held in a relatively vertical position by three or more upper cables  119  and three or more lower cables  120  affixed to three or more anchor points  121 . The upper surface  125  of upper hull  102  is inclined toward prevailing waves with the leading extension  126  curving slightly downward creating an “artificial shoal” increasing the wave height above it (and hydrostatic pressure below it) and producing and absorbing supplemental “surge” kinetic energy. The trailing extension  127  curves upward directing waves upward and also reflecting waves back, both also increasing wave height and energy capture. 
       FIG. 8  shows an embodiment of the present invention similar to  FIG. 7 . Like  FIG. 7 , upper said moving surface  125  has leading  126  and trailing  127  extensions as well as lateral extensions  128  to increase wave height and capture horizontal (surge) wave kinetic energy component. To reduce the hydrodynamic drag of these extensions, hinged  130  vents or flap panels ( 131  leading and  132  trailing) are spring loaded  133  about said hinges  130  such that lateral wave particle motion keeps said panels closed when waves move overhead and said bellows containers  4  are compressing and said springs  133  open said panels  131  and  132  when troughs are overhead and said bellows containers  4  are re-expanding reducing return stroke drag losses. Unlike  FIG. 7 , the central axis of movement  134  of said bellows chambers  4  is rotatably inclined forward about hinge  140  preferably from 20 to 120 degrees (from vertical up), and more preferably from 30° to 90°, to capture a larger portion of oncoming wave horizontal (surge) kinetic energy component which both compresses container  4  and rotates it rearward about hinge  140 . Said rotation about hinge  140  compresses supplemental hydraulic drive cylinders  141 . Such rotation is restored after each wave surge by return springs  142  on said drive cylinders  141 , or spring  143  attached to said fixed mast  111 . Such surge component is increased by the “artificial shoal” forward extension  125  which extension should preferably be from 90° to 150° regardless of the orientation angle of said containers central axis of movement  134 . Container extended top moving surface  125  also has vertical “side shields” or vanes  135  to prevent oncoming waves piling up on extended surface  125  from prematurely spilling off before driving surface  125  downward. Said side shields  135  are converging providing a wave funneling or focusing effect. Said side shields  135  also keep said bellows container oriented into oncoming wave fronts. 
       FIG. 9  shows an embodiment of the present invention similar to  FIG. 8  except that a movable upper surface  137  curving or extending upwards and rotatably hinged  138  to said moving second surface  125  drives supplemental hydraulic drive cylinder  139  (with optional return spring). Alternatively, said hinged surface  137  could also drive main drive cylinder  103  if its&#39; shaft were extended (and sealed) through surface  125  (not shown). 
       FIG. 10   a  (elevation) and  10   b  (overhead plan view) show submerged embodiment of the present invention similar to  FIGS. 8 and 9 . Like  FIG. 8  or  9 , said containers axis of compressive movement is inclined forward. Said container is rigidly attached to the fixed depth mast of spar  111  rather than pivoting (like  FIGS. 8 and 9 ). Said inclination angle can be adjusted by compression bolt  155 . Like  FIG. 7 , said mast or spar  111  has a retractable section  145  allowing the devices above it to be raised or lowered in depth to compensate for tides, average wave height, or severe sea states. The bellows container  3  and mooring system can be of construction similar to that described in  FIG. 7 . Said bellows container  3  is shown in the compressed position with wave  5  cresting directly overhead. Like  FIG. 7 , said moving surface  2  has a central section  125 , a downward curved leading section  126  (facing toward oncoming prevailing wave fronts) and an upward curving section  127 . The fully expanded position of said bellows container  3  and said surfaces  125 ,  126 ,  127  are shown as dotted lines. Said moving surface also has vertical side walls  135  as described in  FIGS. 8 and 9 . Said bellows container  3  is preceded by an “artificial shoaling” surface  146  which is inclined or curved downward which surface acts like a shallow sea bed bottom increasing wave height and converting deep water wave particle circular motion (and wave kinetic energy) into horizontal motion (wave surge motion) for enhanced capture by surfaces  125  and  127 . Said shoaling surface  146  has generally vertical converging side shields  147 . Said surface  146  is wider at its entrance  148  than at its exit  149  near said container downward curved leading section  126 . Said shoaling surface entrance  146  also has to relatively flat vertical surfaces  156  or wave refraction surfaces aligned with and extending from shoal entrance  148  all generally parallel to prevailing waves (crests and troughs). Said wave refraction surfaces  156  and shoaling surface converge, focus, or funnel additional wave height and energy on to and in to said bellows moving surface  125 ,  126 ,  127  increasing wave energy capture. Said shoaling surface  146  with side shields  147  and refracting surface  156  are fixably mounted by support arm  150  onto said stationary mast or spar  111 . 
     Behind said bellows container  3  is a generally vertical wave reflecting wall  152  affixed to stationary mast  111  by its&#39; support arm  153 . Wave crests  154  impacting said wall  152  reflect back over said bellows container  3  further increasing wave height  154  available for energy capture by bellows container  3 . Said reflecting wall  152  can be passive (as shown) or “active” if mounted in hinged manner with energy absorbing means (as per  FIG. 11 ). 
       FIG. 11  shows an embodiment of the present invention with forward and rearward extensions of central movable surface  125  like  FIG. 7 ,  8  or  10 . It may also be preceded by a fixed shoaling surface (not shown) like  146  of  FIG. 10  with similar converging and refraction features. Like  FIGS. 8 and 9 , said bellows container may be flexibly attached via hinged joint  140  to fixed mast  111  and have supplemental energy absorption means (cylinder  141 ) with optional mechanical return means (springs  142 ). Compression and expansion of bellows container  4  is supplemented by surface float base  161  with optional surface vent bellows  160  mounted above said base  161  attached at pivot  168  to said submerged bellows central moving surface  125  by multiple lever arms  165  rotating about fulcrum arm  162  hinge or pivot points  163 . The distant end of lever arm  165  is flexibly attached to multiple vertical connecting rods  166  at lower end hinge joint  167 . The flexible upper end joints  168  of said connecting rods  166  is attached to said surface float base  161 . Like  FIG. 10 , a wave reflecting wall  169  can be attached to and span between the upper portions of said vertical connecting rods  166 . Because surface float base  161  with optional vent bellows  160  will have more vertical movement than said bellows moving surface  125 , said fulcrum pivot point  163  will be closer to the bellows pivot point  164  than said connecting rod pivot point  167 . For added travel and shock absorption, said connecting rod  166  can have a (spring  170 ) mounted telescoping section  171 . Said bellows float can be fitted with supplemental wave energy (pitch mode) drive cylinders  172  with return springs  173 . Said connecting rods  166  bases can also be fitted with supplemental drive cylinders  174  and return springs  175 . Reflecting wall  169  is connected to said connecting rods  166 . Alternatively, said reflecting wall could be affixed to the surface float base  161 . If the optional vent bellows  160  is used on top of the surface float  161 , then a flexible gas vent duct  176  is used to allow free gas flow between said submerged bellows container  4  and said floating surface vent bellows  160 . If no surface vent bellows  160  is used, the interior of bellows container  4  is partially evacuated to reduce interior gas compression resistance. 
       FIG. 12  shows a sectional elevation of an embodiment of the present invention utilizing a fixed (shown) submerged inclined bellows container  4  (like  FIG. 11 ) with an adjustable base hinged about pivot  140  with sublemental energy absorption by cylinder  141  and extended and curved bellows top surface ( 125 ,  126 ,  127 ) (also like  FIG. 11 ). Fixed shoaling surfaces (like  FIG. 10 ) or “active” (powered) wave reflective back walls (like  FIG. 11 ), could also optionally be used. The submerged bellows container  4  is shown expanded with a trough overhead with and a vent surface bellows compressed by return springs  185  or weighted top surface  190 . When an ensuing wave crest passes overhead gas from said submerged bellows container  4  flows through duct sections  180 ,  181  and  182  before passing through two-way air turbine generator  184  and through float base  161  expanding surface bellows  160  and tensioning float bellows return springs  185  or lifting weighted top  190 . When the next wave trough passes overhead, the tensioned return springs  185  compress said surface bellows  160  driving gas through said two way turbine generator  184  housed in the base of surface float  161  and then through duct section  180  and back into submerged bellows container  4  re-expanding it and tensioning its&#39; return springs  186 . Internal concentric telescoping glide tubes or rails (as described for  FIG. 7 ) can provide lateral stability if needed. Wave reflecting wall  181  can be at least partially hollow and also serve as gas duct  181  or house air turbine generator  184  (not shown). Like  FIG. 11 , lever arm  165 , hinged about fixed fulcrum  163 , attaches moving submerged bellows surface  125  at pivot point  164  to telescoping spring loaded connecting rod  166  at attachment point  167 . 
       FIG. 13  shows a submerged or semi-submerged embodiment of the present invention utilizing multiple partially evacuated gas tight elongated compressible bellows containers  4  mounted on a common base  190  held at relatively fixed depth by multiple downward masts or spars  111  with depth fixing, adjustment and mooring means as described in  FIG. 7 . Common (shown) or multiple (not shown) moving upper surface  191  has a forward (oncoming wave facing) downward sloped section  192  optionally flexibly connected to said common base  190  by hinges  194 . The rearward upsloping section  193  of said common moving upper surface may also serve as a passive (shown) or active powered (not shown) wave reflector wall increasing wave height, and both hydrostatic and kinetic wave energy capture as previously described. Frontal inclined or downward sloping frontal section  192  acts as a shoaling surface further increasing wave kinetic energy capture as previously described (in  FIGS. 7 ,  8  and  9 ) or it may be preceded by a fixed shoaling surface (as described in  FIG. 10 ). Base  190  can be hinged  140  to stationary masts  111  as previously described (in  FIGS. 8 ,  9 , and  11 ) with supplemental energy capture by cylinders  141  and return springs  142  or rigidly attached (not shown). Primary energy capture as overhead wave crests compress surface  191  towards base  190  is via hydraulic cylinders  103  with return springs  44  as previously described in  FIGS. 7 ,  8 ,  9 ,  11  and  12 . Elongated bellows containers as shown have major advantages over round “point source” wave energy absorbs by spanning more wave front per unit of container (or buoy) area or volume. Large containers arranged in series front to back, span a larger portion of each wave length (25% to 50% of total wave length) increasing wave capture efficiency. The hinged front  194  eliminates the need for lateral supports for drive cylinders  103 . 
     Modifications, improvements, and combinations of the concepts described herein may be made without departing from the scope of the present invention.

Technology Classification (CPC): 5