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Inventors
Vowles, Alan Keith
Vowles, Gerald John
Application #
013974
Filed
Jan-27-1998
Published
Aug-29-2000
Current US Class
060/398
060/497
060/498
060/502
270/42
290/42
290/53
International Classes
F16D 031/02
Field of Search
60/398 60/495 60/497 60/448 60/502 290/42 290/53 290/54
Examiners
Nguyen; Hoang
US Patent References
| 4717832 |
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Tidal and river tur... |
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| 5461862 |
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System for conversi... |
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| 5710464 |
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Power drive system... |
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Referenced by:
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Citation
Cite This Patent
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Abstract
An apparatus and method as seen in FIG. 2 for converting the motion of waves on a body of fluid 52 into useable energy. This apparatus employs a wave follower 20 to track the rising and falling waves. The reciprocating wave follower interacts with a driven device, such as a pump 202a or generator 202b through an optional lever arm 171 and also through a drive member such as a reciprocating shaft 26. Because the driven device is incorporated into an essentially immovable floating or fixed support member 17, work is accomplished. By increasing the work producing travel distance of the driving member, being the wave follower 20 beyond that of previous art and, in certain embodiments such as that shown in FIG. 2, and by more effectively capturing surge forces that has previous art, this apparatus is intended to produce significantly more work than other similar devices operating in the same waves.
Claims
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. An apparatus for converting the motion of waves on a body of fluid to useable energy comprising:
wave follower means for tracking the rise and fall of waves on a body of fluid, said wave follower means comprising a buoyant upper body portion for tracking the rise of said waves and a ballasted, lower body portion for tracking the fall of said waves;
drive transfer means to power a driven device and actuated by the reciprocating forces exerted by said wave follower means;
load release and re-establish means for eliminating or releasing the load or resistance created by said driven device and for re-establishing said load; for the purpose of increasing travel of said wave follower means thereby increasing apparatus efficiency.
2. A device as defined in claim 1, wherein said load release and re-establish means functions, first by releasing said load, thereby allowing the potential energy stored as buoyant force acting on said buoyant upper body portion, when submerged, to refloat said wave follower means after said load has been released, then by re-establishing said load after said buoyant upper body portion has been re-floated; and second by releasing said load, thereby allowing the potential energy stored as gravitational force acting on said ballasted, lower body portion, when partially suspended in air, to re-submerge said ballasted lower body portion of said wave follower means after said load has been released, then by re-establishing said load after said ballasted, lower body portion of said wave follower means has been re-submerged; for the purpose of increasing the effective, working travel of said wave follower means.
3. A device as defined in claim 2, wherein said apparatus comprises:
rotatable support means which floats in a body of fluid, wherein said rotatable support means may further incorporate a fixedly attached component reaching downward to a point below that which any significant wave action occurs, and wherein said fixedly attached component may be a tube, pipe or cylinder into which components including, a piston rod, piston, accumulator, filters or reverse osmosis membranes may be assembled and wherein said fixedly attached component may be fixedly attached at or near its lower end to a reaction component for the purpose of eliminating or reducing reaction to the heaving of waves;
said drive transfer means linking said wave follower means and said driven device, the drive transfer means being lever arms which can determine mechanical advantage, said lever arm means being pivotally attached at a fulcrum to said rotatable support means;
unequally spaced, horizontal reaction plate means for holding said support means substantially stationary relative to the rise and fall of said wave follower and said waves;
floatation means to render said support means buoyant in order to eliminate the need for said wave follower means to provide buoyancy to said apparatus, said floatation means to move said apparatus up and down with the tides but not with the waves.
4. A device as defined in claim 2, wherein said apparatus comprises:
mechanical advantage modifier means, which allows said apparatus to progressively vary the mechanical advantage to said drive transfer means throughout both strokes in the reciprocating cycle and in a way which reduces the force required, with each change of stroke direction, for said driven device to unlock and thereby function, albeit at reduced output in smaller waves, thereby harnessing energy that would otherwise have been lost.
5. A device as defined in claim 3, wherein said apparatus comprises:
self-furling reaction plate means for holding said support means substantially stationary relative to the rise and fall of said wave follower means and said waves, wherein said self-furling reaction plates means are selectively and progressively more flexible, toward their outer edges, as are some windmill propeller blades; this feature being provided to allow said apparatus to atypically heave or roll rather than break when subjected to extreme forces.
6. A device as defined in claim 3, wherein said apparatus comprises:
linked global positioning system and propulsion system means for the purpose of maintaining the position of said apparatus, if not anchored, or directing said apparatus to move to a specified location or come ashore even when un-manned, or locating said apparatus if forced or otherwise moved away from its expected geographic position.
7. A device as defined in claim 3, wherein said apparatus comprises:
vertically oriented surge reaction plates means positioned both in front of and behind said apparatus and below water level at a depth beyond any significant wave action; said vertically oriented surge reaction plates being buoyed up and anchored and secured to said apparatus by means of cables, for the purpose of stabilizing said apparatus against lateral wave motion.
8. A device as defined in claim 3, wherein said apparatus comprises:
outrigger reactor means, for the purpose of keeping the front of said apparatus aligned with incoming waves, said outrigger reactor means being fixedly attached to said rotatable support means by arms and extending out from the sides of said rotatable support means and wherein alignment occurs due to less force being required to rotate said apparatus than to lift one of said reactor means.
9. A device as defined in claim 3, wherein said apparatus comprises:
dome attached to the top of said wave follower for the following purposes: prevention of pinnipeds or other creatures from resting or establishing habitation on said wave follower; deflecting downward forces; shedding of water from said wave follower, thereby improving device efficiency and protection of maintenance personnel.
10. A device as defined in claim 2, wherein said apparatus comprises:
wave follower means comprising an upper body portion for tracking the rise of said waves and a lower body portion for tracking the fall of said waves, said lower body portion incorporating at least one fluid fillable chamber for holding, static, a volume of fluid, said chamber being enclosed on the top and sides, and with a mouth opening on the bottom of said wave follower, and a one-way valve means between said lower body portion and the atmosphere, allowing air, trapped in said chamber, to be vented to the atmosphere, thereby allowing fluid to freely enter said chamber through said opening during the ascent of waves.
11. A device as defined in claim 2,
wherein said wave follower means may have an outer surface having a plurality of depressions for the purpose of increasing the lifting action of waves on said wave follower and a bottom surface which is formed to incorporate one or a plurality of depressions, which may be concave, in order to maximize the ability of said wave follower to benefit from surface adhesion and suction when a wave is falling away.
12. A device as defined in claim 2, wherein said apparatus comprises:
support means being solidly attached to earth;
said drive transfer means linking said wave follower means and said driven device, the drive transfer means being lever arms which can determine mechanical advantage, said lever arm means being pivotally attached at a fulcrum to said support means;
counterweight means being attached at an opposite end of said lever arm means from said wave follower means, to better balance the weights on either side of said lever arm means;
side wall means to contain the arriving waves in order to focus forces other than buoyant force on said wave follower means;
rear wall means located on the leeward side of said wave follower means and being part of said support means or of said wave follower means and acting as a wave terminating member for the purpose of focusing forces, other than buoyancy and gravity, on said wave follower means;
underwater angled ramp means, being either straight or curved, to increase the height of arriving waves, thus resulting in increased wave follower travel distance, and wherein said underwater angled ramp means may be combined with or integrated into said rear wall means;
funneling panels means to increase the height of arriving waves, thus resulting in increased wave follower travel distance;
floatation means to render said support means buoyant in order to eliminate the need for said wave follower means to provide buoyancy to the apparatus, said floatation means to move said apparatus up and down with the tides but not with the waves.
13. A device as defined in claim 3, wherein said apparatus comprises:
vertically oriented surge reaction plates means positioned both in front of and behind said apparatus and below water level at a depth beyond any significant wave action; said vertically oriented surge reaction plates being buoyed up and anchored and secured to said apparatus by means of cables, for the purpose of stabilizing said apparatus against lateral wave motion;
outrigger reactor means, for the purpose of keeping the front of said apparatus aligned with incoming waves, said outrigger reactor means being fixedly attached to said rotatable support means by arms and extending out from the sides of said rotatable support means and wherein alignment occurs due to less force being required to rotate said apparatus than to lift one of said outrigger reactor means;
counterweight means being attached at an opposite end of said lever arm means from said wave follower means, to better balance the weights on either side of said lever arm means;
side wall means to contain the arriving waves in order to focus forces other than buoyant force on said wave follower means;
rear wall means located on the leeward side of said wave follower means and being part of said support means or of said wave follower means and acting as a wave terminating member for the purpose of focusing forces, other than buoyancy and gravity, on said wave follower means;
underwater angled ramp means, being either straight or curved, to increase the height of arriving waves, thus resulting in increased wave follower travel distance, and wherein said underwater angled ramp means may be combined with or integrated into said rear wall means;
funneling panels means to increase the height of arriving waves, thus resulting in increased wave follower travel distance.
14. A device as defined in claim 2, wherein said load release and re-establish means is utilized for increasing the effective travel distance of any combination of said wave follower means, said lever arm means and said drive transfer means on both the rise and fall of said waves, said load release and re-establish means being connected such that said wave follower means, said lever arm means or said drive transfer means or any combination of them can suddenly change their position in relation to the body of fluid in which said wave follower is floating, without having to overcome the resistance of, or to actuate any attached driven device; said load release and re-establish means being designed to release and then re-establish said load twice per wave cycle, first, when said wave follower is at or near the top of the crest of a wave and second, when said wave follower is at or near the bottom of the trough of a wave, and wherein said load release and re-establish means could function with single acting wave followers which produce work in one direction only, thus eliminating the need for such single acting wave followers to employ springs, weights, elastic members or other means to pull said single acting wave follower back into a wave trough.
15. A device as defined in claim 3, wherein said apparatus includes:
windmill means and solar panels means to increase device output, which may be attached to additional support members passing through or around said wave follower means and connected to said heave reaction plates means but allowing said wave follower to move independently of said heave reaction plates means, said additional support members being used to improve the structural integrity of said apparatus.
Description
This patent application relates to
U.S. Pat. No. 5,405,250 titled Wave Energy Extraction Device (Vowles), and
European Patent No. 0526604 titled Wave Energy Generator (Vowles), and
Canadian Patent application No. 2,081,381-4 (Vowles) wherein all rights previously held by Bruce Vowles of Kitchener, Ontario, Canada have now been assigned to co-inventors Alan K. Vowles of Flin Flon, Manitoba, Canada and Gerald J. Vowles of Belleville, Ontario, Canada.
BACKGROUND OF THE INVENTION
This invention relates generally to devices which are designed to extract energy from the action of waves on a body of fluid. This is achieved by converting the energy in the undulating waves into a useable form for the purpose of powering a variety of devices or processes. More particularly, this invention relates to a double acting device capable of extracting energy from a greater percentage of both the rising and the falling waves than do other similar devices. Numerous other wave energy converter designs have been tested but have failed to reach commercialization. This is primarily because they could not compete economically with existing energy sources such as hydro, nuclear power, and fossil fuels, or because their initial cost was too high. This invention is intended to overcome these and other problems.
With the ever increasing need to be environmentally responsible, more attention is being paid to clean, renewable energy sources. This invention is intended to provide an environmentally benign means by which significant amounts of renewable and sustainable energy can be produced. Furthermore, it is well documented that the need for such basic human needs as fresh water, food, and energy for warmth and development is growing rapidly--as are shortages of these commodities. This invention is intended to offer a means by which these issues and challenges can be addressed more effectively than in the past.
Current research is trending toward the development of smaller devices which may be used as a plurality. Such smaller devices are typically more resistant to storm damage and also offer much lower development and deployment costs. Until now, however, they have been less efficient than their larger counterparts. This invention is intended to provide a means of greatly improving the efficiencies of these smaller devices, thus making them practical. This improved efficiency is not, however, limited to the smaller devices, as it works equally well on larger devices.
SUMMARY OF THE INVENTION
The present invention seeks to provide a more efficient apparatus for the extraction of energy from waves on a body of fluid on both the rise and fall of said waves. Improved efficiency will be achieved by increasing the effective travel of the device's driving component -hereafter called a wave follower- for any given wave height. This is done in a manner which allows any linked driven component or device to accomplish more work than would a similar apparatus without this novel feature.
According to a preferred embodiment of the present invention there is provided an apparatus for converting the motion of waves on a body of fluid to useable energy, said apparatus comprising
rotatable support means being designed to
float in a body of fluid, or
be solidly attached to earth, or
be solidly attached to another floating device, or
be solidly attached to another device which is solidly attached to earth; and wherein said rotatable support means may further incorporate a fixedly attached component reaching downward to a point below that which any normal, significant wave action occurs, and wherein said fixedly attached component may be a tube, pipe or cylinder into which other components such as, but not limited to, a piston rod, piston, accumulator, filters or membranes may be assembled;
one or more lever arm means which determine mechanical advantage, said lever arm means being pivotally attached at a fulcrum to said rotatable support means;
wave follower means for tracking both the rise and fall of said body of fluid, said wave follower means being attached to said lever arm means;
drive transfer means being attached to said lever arm means between said wave follower means and said fulcrum, or
on an opposite side of said fulcrum from said wave follower means, or
such that said wave follower means lies between said fulcrum and said drive transfer means, and is actuated by the reciprocating motion of same lever arm means;
counterweight means being attached at an opposite end of said lever arm means from said wave follower means, to better balance the weights on either side of said pivotally attached lever arm means;
side wall means to enclose the arriving waves in order to focus forces other than buoyant force on the wave follower;
optional underwater angled ramp means, being either straight or curved, to increase the height of the arriving waves, thus resulting in increased wave follower travel distance;
optional funnelling panels means to increase the height of the arriving waves, thus resulting in increased wave follower travel distance;
as well as the following novel features comprising:
modification to said wave follower means incorporating;
an outer surface having a plurality of depressions, which may be concave such as those found on a golf ball, for the purpose of increasing the lifting action of the waves on the wave follower, and
a bottom surface which is formed to incorporate one or a plurality of depressions, which may be concave, in order to maximize the ability of said wave follower to benefit from surface adhesion and/or suction when the wave is falling away;
load release and re-establish means for increasing the effective travel distance of (any combination of) said wave follower means, lever arm means and drive transfer means at a given wave height on both the rise and fall of said waves, said load release and re-establish means being connected such that it will release and allow said drive transfer means or said wave follower means or said lever arm means or a combination of them to suddenly change their position in relation to the body of fluid in which the wave follower is floating, without having to overcome the resistance of, or to actuate, any attached driven device, and
said load release and re-establish means will re-establish said load once said drive transfer means or said wave follower means or said lever arm means or a combination of them has changed its position as needed, and
said release of load resistance and re-establishing of load resistance from said driven device will occur at or near both the highest point of the crest and the lowest point of the trough of said wave, or
will be used as a plurality to accomplish said releasing and re-establishing of said load resistance;
alternate optional load release and re-establish means which can also be used with wave followers designed to work in one direction only, thus eliminating the need for wave followers/floats to employ springs, weighting, elastic members or other means for the purpose of pulling them back down into a wave trough in order to set up for the next oncoming wave crest. This allows such a uni-directional wave follower to increase its efficiency by eliminating a non-productive load and to be dynamically balanced;
optional mechanical advantage modifier means, such as (but not limited to) a cam, which allows the apparatus to progressively vary the mechanical advantage to said drive transfer means as it moves through both strokes in its reciprocating cycle and in a way which reduces the force required, with each change of stroke direction, for said driven device to unlock and thereby function, albeit at reduced output, in smaller waves--energy which would not otherwise be harvested;
optional irregularly spaced, horizontally oriented heave reaction plates means for holding said support structure substantially stationary relative to the rise and fall of said wave follower and said waves; wherein said reaction plates are selectively and progressively flexible such as are the blades of some windmill propellers defined as self-furling. This self-furling feature allows the apparatus to roll with the punches of extreme or unusual wave impacts and then to return to normal operation, rather than to be torn apart, bent or rendered inoperable due to that extreme wave impact;
rear wall means being part of said support structure or of said wave follower and acting as a wave terminating member for the purpose of focusing forces other than buoyancy and gravity on said wave follower; and
optional linked global positioning/locating system and propulsion system for the purpose of either
maintaining the position of said apparatus, if un-anchored, or
directing said apparatus to move to a given point or come ashore even when un-manned, or
locating said apparatus if forced or otherwise moved away from its expected geographic position whereby said propulsion system may or may not be driven by direct or indirect power provided by the action of said waves;
optional vertically oriented surge reaction plates being remote, flexibly attached to said rotatable support means more or less directly behind and in front of said wave energy converter, said surge reaction plates being perpendicular to the surface of the fluid but below the wave effected zone and with their face being parallel to the incoming waves, said surge reaction plates for the purpose of reducing backward and forward lateral movement of the apparatus just as lateral forces in said waves are being redirected to focus on said wave follower.
optional outrigger reactor means, such as but not limited to floats, for the purpose of keeping the front of the apparatus aligned with the incoming waves, said outrigger reactor means being fixedly attached to said rotatable support means by arms and extending to the side(s) of said rotatable support means such that an incoming wave, on encountering one or the other first and not being able to readily lift it will force it back instead until such time as both are under more or less equal pressure from that wave. This design is intended to overcome the effects of local winds or currents running at an angle to the waves, these causing said wave follower to be aligned at an undesirable angle to said waves.
According to a second preferred embodiment of the present invention there is provided an apparatus for converting the motion of waves on a body of fluid to useable energy, said apparatus comprising
rotatable support means being designed to
float in a body of fluid, or
be solidly attached to earth, or
be solidly attached to another floating device, or
be solidly attached to another device which is solidly attached to earth; and wherein said rotatable support means may further incorporate a fixedly attached component reaching downward to a point below that which any normal, significant wave action occurs, and wherein said fixedly attached component may be a tube, pipe or cylinder into which other components such as, but not limited to, a piston rod, piston, accumulator, filters or membranes may be assembled;
one or more optional lever arm means which determine mechanical advantage, said optional lever arm means being pivotally attached at a fulcrum to said rotatable support means;
drive transfer means being attached to said optional lever arm means between said wave follower means and said fulcrum, or
on an opposite side of said fulcrum from said wave follower means, or
such that said wave follower means lies between said fulcrum and said drive transfer means, or
alternately being attached directly to said wave follower means when optional lever arm is not present, said drive transfer means being actuated by the reciprocating motion of said optional lever arm means, when present; as well as the following novel features comprising
wave follower means for tracking the rise and fall of said body of fluid, said wave follower means being attached either to said optional lever arm means or alternately being attached directly to said drive transfer means and incorporating
an outer surface having a plurality of depressions, which may be concave such as those found on a golf ball, for the purpose of increasing the lifting action of the waves on the wave follower, and
a bottom surface which is formed to incorporate one or a plurality of depressions, which may be concave, in order to maximize the ability of said wave follower to benefit from surface adhesion and/or suction when the wave is falling away;
load release and re-establish means for increasing the effective travel distance of (any combination of) said wave follower means, lever arm means and drive transfer means at a given wave height on both the rise and fall of said waves, said load release and re-establish means being connected such that it will release and allow said drive transfer means or said wave follower means or said lever arm means or a combination of them to suddenly change their position in relation to the body of fluid in which the wave follower is floating, without having to overcome the resistance of, or to actuate, any attached driven device, and
said load release and re-establish means will then re-establish said load once said drive transfer means or said wave follower means or said lever arm means or a combination of them has changed its position as needed, and
said release of load resistance as well as re-establishing of load resistance from said driven device will occur at or near both the highest point of the crest and the lowest point of the trough of said wave, or
will be used as a plurality to accomplish said releasing and re-establishing of said load resistance;
alternate optional load release and re-establish means which can also be used with wave followers designed to work in one direction only, thus eliminating the need for wave followers/floats to employ springs, weighting, elastic members or other means for the purpose of pulling them back down into a wave trough in order to set up for the next oncoming wave crest. This allows such a uni-directional wave follower to increase its efficiency by eliminating a non-productive load;
optional mechanical advantage modifier means, such as (but not limited to) a cam, which allows the apparatus to progressively vary the mechanical advantage to said drive transfer means as it moves through both strokes in its reciprocating cycle and in a way which reduces the force required, with each change of stroke direction, for said driven device to unlock and thereby function, albeit at reduced output, in smaller waves energy which would not otherwise be harvested;
optional irregularly spaced, horizontally oriented heave reaction plates means for holding said support structure substantially stationary relative to the rise and fall of said wave follower and said waves; wherein said reaction plates are selectively and progressively flexible such as are the blades of some windmill propellers defined as self-furling. This self-furling feature allows the apparatus to roll with the punches of extreme or unusual wave impacts and then to return to normal operation, rather than to be torn apart, bent or rendered inoperable due to that extreme wave impact;
optional linked global positioning/locating system and propulsion system for the purpose of either
maintaining the position of said apparatus, if un-anchored, or
directing said apparatus to move to a given point or come ashore even when un-manned, or
locating said apparatus if forced or otherwise moved away from its expected geographic position whereby said propulsion system may or may not be driven by direct or indirect power provided by the action of said waves;
optional dome attached to the top of said wave follower for the purpose of
preventing pinnipeds, such as seals, or other creatures from resting or establishing habitation on said wave follower
providing security for service personnel working atop the wave follower
providing protection for various components of the apparatus;
optional load eliminating buoyant component means fixedly attached to said rotatable support means being located such that an upper end breaks the surface of the fluid on which the apparatus is floating and another end extends downward below the surface, said load eliminating buoyant component means exerting a buoyant force sufficient to hold the apparatus at the surface of the fluid on which it is floating without relying on the buoyancy of the wave follower means and thereby not reducing the effectiveness of the wave follower; and
wherein said optional load eliminating buoyant component may protrude up through the wave follower so as not to interfere with or block the advancing waves from making direct or diminished contact with the wave follower from any direction, or
wherein said optional load eliminating buoyant component may partially or fully circumscribe said wave follower means for the purpose of offering protection to the wave follower means in cases where local wave and storm action may be a threat to the ongoing functionality of the wave follower means.
other embodiments may contain a combination of some or all of the above components and features; characterized in that the wave follower means comprises a buoyant upper body portion for tracking the rise of the waves, and a lower body portion incorporating at least one ballast filled or fillable chamber for tracking the fall of the waves. The lower chamber is either enclosed on the top and sides with a mouth opening on the bottom or alternately, it is fully enclosed. In the case of the open bottomed chamber, the ballast is comprised of the portion of that fluid in which the wave follower is floating and which is enclosed by the top and side walls of the chamber. Fluid can freely enter and fill the chamber on the rise of the waves because the air which otherwise occupies the chamber is allowed to escape through a one way valve vented to the external atmosphere. In the case of the fully enclosed chamber the ballast is comprised of some other suitable material or body of fluid and which is held separate from the body of fluid in which the wave follower is floating, and also incorporating an optional angled seaward face to harness the energy of the lateral force of the waves by redirecting that force so as to compliment other forces being harvested by the wave follower;
further characterized in that the load release and re-establish means is comprised, but not limited to, an assembly of known components which may include one or a plurality of; pressure release valves, pressure sensing switches, height sensing switches, clutches, brakes, solenoids or release pins or cams, and which may or may not be further controlled by a programmable logic controller or similar control device in order to optimize the response of the load release and re-establish means to varying wave heights and patterns. Slightly preceding or immediately after a wave reaches its highest point of travel and begins to fall away, the load release and re-establish means momentarily reduces or eliminates the resistive load applied to the wave follower by any driven device, thus allowing the buoyant upper body portion of the wave follower to quickly travel the extra distance needed to refloat itself. Further, slightly preceding or immediately after a wave reaches its lowest point of travel, being in the trough, and begins to rise again, the load release and re-establish means momentarily reduces or eliminates the resistive load applied to the wave follower by the driven device, thus allowing said fluid (ballast) filled lower chamber to quickly fall, travelling the extra distance needed to become re-submerged. The load release and re-establish means is not designed to latch or lock or otherwise prevent the wave follower from moving with the surface of the waves at any time but rather to release the load on the wave follower so that it may move quickly upwards to find it's natural level at the peak of a rising wave in order to reposition itself for a lengthened working stroke on the falling wave and also so that it may move quickly downwards to find it's natural level at the bottom of a falling wave in order to reposition itself for a lengthened working stroke on the subsequent rising wave. Also, the load release and re-establish means will allow the wave follower to respond more efficiently to local storm waves which are superimposed upon the larger wave swells, thereby increasing the effective output of the apparatus. The load release and re-establish means will also allow the wave follower to react to smaller waves than is possible with a similar unit without the feature, thereby increasing the effective output of the apparatus once again;
still further characterized in that the variable mechanical advantage of the apparatus controlled by the optional mechanical advantage modifier means, is at its highest as the wave begins a change of direction immediately after reaching its lowest point and again after reaching its highest point. This mechanical advantage then progressively decreases as the wave follower becomes a) progressively more submerged on the rising wave, and b) progressively held more out of the fluid on the falling wave. This condition of decreasing mechanical advantage continues until such time as the wave changes directions thus activating the load release and re-establish means. Thus the mechanical advantage modifier means allows for earlier unlocking and therefore, travel of the wave follower, rendering it operable in times of smaller than normal wave heights when other devices designed for normal wave patterns would cease to function due to their inability to unlock at smaller wave heights. The mechanical advantage modifier means may be employed as a plurality in order to act sequentially, or cumulatively to power driven devices. In a preferred embodiment, the mechanical advantage modifier means would usually perform its function between the driving and driven components;
still further characterized in that the irregularly spaced, horizontally oriented heave reaction plates means being located below the undulating action of the waves are attached in a plurality of more than two such that the varying distances between the plates will minimize undue vertical movement of the apparatus due to any harmonic movement of the water below normal wave action depth. These unequally spaced reaction plates are solidly attached to the rotatable support means by a connecting component of essentially unchangeable length but with optional lateral flexibility such as, but not limited to, a rod, pole, tube or framework. Further, a plurality of smaller diameter plates will provide greater structural integrity than one single large plate;
still further characterized in that suitable working distance between the wave follower means and rear wall means is maintained in that the centre of the arc of a circle scribed by the rear wall means and the centre of the arc of a circle scribed by the closely adjacent face of the wave follower means and the centre of the fulcrum of the wave follower are common. This design increases the wave follower's capacity to do work by focusing forces other than only floatation and gravity on the wave follower. Further, the rear wall may be formed to enclose the wave follower in such a way as to minimize the flow of fluid past the wave follower as it rises and falls with the waves, this in order to maximize the capture and conversion of said other forces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a modified perspective view of a floating Wave Energy Converter incorporating a wave termination feature, self-alignment feature and off-set heave reaction plates feature in accordance with a first preferred embodiment of the invention.
FIG. 2 is a detailed modified perspective view of the upper portion of the apparatus shown in FIG. 1. wherein a two-way reciprocating pump and an electricity generator are both driven devices and wherein solenoids/release valves/sensors/switches as well as external devices are powered or charged by energy produced by the apparatus itself in accordance with a first preferred embodiment of the invention.
FIG. 3 is a more detailed modified perspective view of the two-way reciprocating pump as shown in FIG. 2 and more specifically of the load release and re-establish means used.
FIG. 4 shows a minor variation of the apparatus shown in FIG. 3 wherein a two-way reciprocating pump is a driven device and wherein solenoids/release valves/sensors/switches do not require electric power.
FIG. 5 is a detailed modified perspective view of a device similar to that in FIG. 4. excepting that the solenoids/release valves/sensors/switches are powered by an externally charged battery or other external source of power.
FIG. 6 is a detailed modified perspective view of a device similar to that in FIG. 4. excepting that the solenoids/release valves/sensors/switches are powered by internally or externally charged power (not shown) and wherein a programmable logic controller (PLC) is used to control the operation of the solenoids/release valves/sensors/switches.
FIG. 7 is a detailed modified perspective view of a device similar to that in FIG. 4. excepting that sensors or senders are located in the wave follower, away from the pump and solenoid/release valve/switches.
FIG. 8 is a modified perspective view of the upper portion of the apparatus shown in FIG. 1. wherein a rotary shaft means and flywheel are driven through a two-way reciprocating arc and wherein a geared cam reduces start-up load.
FIG. 9 is a modified perspective view of a device similar to that in FIG. 8, excepting that a geared cam is not used and a rotary shaft means and flywheel are driven through complete rotations.
FIG. 10 is a modified perspective view of a floating Wave Energy Converter (non-enclosed or "open" style) without wave termination feature, or self-alignment feature but otherwise operationally equivalent to the apparatus shown in FIGS. 1 and 2, in accordance with a second preferred embodiment of the invention.
FIG. 11 is a more detailed, exploded perspective view of the upper portion of a floating "open" Wave Energy Converter described in FIG. 10 and showing the linkage setup for the lever arms as well as the wave follower being assembled from sections.
FIG. 12 is a modified perspective view of a floating Wave Energy Converter similar to the apparatus shown in FIGS. 10, but without lever arm linkages and also incorporating on-board reverse osmosis or mechanical pressure filtration capability (which the apparatus on FIG. 10 could also be rigged with).
FIG. 13 is a modified perspective view of a floating Wave Energy Converter incorporating a wave termination feature, self-alignment feature, unequally spaced heave reaction plates feature as in FIG. 1 and wherein remote, flexibly attached surge reaction plates are utilized.
FIG. 14 is a still more detailed modified perspective view of the submerged unequally spaced, self-furling reaction plates of the floating Wave Energy Converter in accordance with the preferred embodiments of the invention.
FIG. 15 is a still more detailed modified perspective view of the sub-assembly shown in FIG. 9 used to convert two-way reciprocating lateral motion to full rotary motion in one direction in a fashion which overcomes the problem of variable wave frequency working against the apparatus.
FIG. 16 is a detailed perspective view of a mechanical load release and re-establish means which might be used in place of the hydraulic mechanisms more fully described in the specification.
Regarding the numbering associated with the above Figures, the numbers 1 to 19 have been reserved for these drawings, the numbers 20 to 199 and 300 up have been reserved for part, feature and attribute references within the figures and the numbers 200 to 220 have been reserved for varying views of the Wave Energy Converter apparatus.
Further embodiments of a Wave Energy Converter being solidly attached to ground or another immovable body are not shown as they do not differ significantly in operation from those pictured in the included figures other than they do not require the use of reaction plates or damper plates and their means of attachment to any fixed body are much varied and of well known technology.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the floating wave energy converter as seen at 201 is comprised of an enclosure 47 which is designed to trap the energy of incoming waves. The enclosure 47 is made up of a top panel 57, a back panel 48 and two side panels 49. Vertically mounted funnelling panels 50 are fixedly attached to the side panels 49 at an angle such that the waves 67 which enter the apparatus through an open front 53 are amplified in height as the channel established by the funnelling panels 50 becomes narrower. The bottom of the enclosure is open other than for a full or partial ramp 51 (which is described in a subsequent Figure). The apparatus 201 floats in a body of fluid such as an ocean, with an upper portion being above the height of the significant waves on the surface 52 of the fluid. A floatation collar 58, being fixedly attached to the side panels 49, the rear panel 48 and optionally to the funnelling panels 50 but not across the open front 53, provides this floatation. Because the apparatus operates most efficiently when the open front 53 is aligned with the direction of the oncoming waves 67, the apparatus must be capable of realigning itself as wave direction changes. In trying to deal with this problem, others have relied on the local wind direction to align their devices. In practice, this has proven to be less than ideal as very often, local wind direction differs from the direction of the larger, more energy rich swells which have been generated far off by winds blowing in a direction different than the local winds. This problem has been significantly reduced by attaching outrigger float assemblies made up of a buoyant element 54 being fixedly attached to a stiff arm 55 which is solidly affixed at 56 to the side panels 49 of the enclosure 47. These outrigger float assemblies protrude laterally out from the sides of the enclosure 47 on a more or less horizontal plane such that they float in the body of fluid in which the apparatus 201 floats but do not provide additional floatation for the apparatus 201, that being the exclusive function of the floatation collar 58. As the apparatus 201 may, from time to time, begin to rotate it's open front 53 somewhat away from the oncoming waves, one or the other of the outrigger float assemblies will swing frontward toward the oncoming waves 67 while the one on the other side will swing backward away from the oncoming waves 67. The next oncoming rising wave will thus strike the more frontward rotated float first and being a rising or cresting wave will therefore attempt to lift the float 54, it being a buoyant body. However, the reaction plates 60 (which are described in a subsequent Figure) and the stiff arm 55 prevent the apparatus generally and the outrigger float 54 specifically from lifting. Because the floating apparatus 201 is freely rotatable on it's vertical (Y) axis 199, the buoyant energy acting on the frontward outrigger float 54 is then redirected to push the float 54 backward until such time as both outrigger floats 54 are under more or less equal pressure from the oncoming wave front 67. At this point the open front 53 of the apparatus 201 will again be aligned properly with the oncoming waves 67. The length of the arms 55 are determined by the prevailing or significant wave length at the point of installation of the apparatus 201 such that the rearward rotated float 54 will, most often be located in a wave trough when a frontward rotated float 54 is being influenced by a wave crest. Fixedly attached to and extending downward from the enclosure 47 a support member 59 such as a somewhat flexible rod, pole or tube, is also fixedly attached at points 61 to reaction plates 60 which are located at a depth below that effected by motion of the prevailing or significant waves at that site. Reaction plates have been used in other similar applications but have not previously provided a means for lowering their own effectiveness (and related damage) when it would be more beneficial to give way. The unique self-furling reaction plates 60 here described are very stiff toward their centre and become progressively more flexible toward their outer edges--such that they will "give" progressively to the degree required to eliminate or minimize the potential for the apparatus 201 being damaged in the event of sudden, extreme and unusual upward, downward or lateral forces being applied to the apparatus 201, generally due to major storms or tsunami waves. The apparatus 201 is usually held in position by an anchor 62 or other mooring device and an attached cable 63 which is at another end, attached to the support member 59 by an appropriate fastening means 64 but is not limited to use when so anchored.
FIG. 2, provides a more detailed view at 202 of the interior components of the wave energy converter specified in FIG. 1. It is comprised of a full or partial wave ramp 51 which is angled upward until it becomes curved to match the arc scribed by the wave follower 20 rotating on an arc about it's fulcrum 24. At a point lying more or less in line with where the wave follower 20 would float when at rest, the upper end of the curved portion of the wave ramp 51 is fixedly attached to the rear panel 48 of the enclosure 47. The purpose of the wave ramp 51 is twofold. First, it, along with the side panels 49 and the rear panel 48 enclose and focus much of the potential wave energy onto the wave follower 20 making this a wave termination apparatus. Secondly, the wave ramp 51 causes a shoaling effect which is known to increase the height of the waves such as does the narrowing channel established by the angled funnelling panels 50 after the waves 67 enter the enclosure 47 through it's open front 53. The effect of increased wave height is to increase the upward and downward travel distance of the wave follower 20, this being convertible to more foot/pounds or newton/metres of work. Wave follower travel in relation to wave motion becomes apparent in the following text. The wave follower 20 incorporates an upper body portion or flotation unit 21 which is made of any suitable buoyant material, a lower body portion 22 constructed in the form of a hollow chamber and having a complete or partial opening at it's bottom. The lower body portion 22 is attached to the underside of the buoyant upper body portion 21, so that when the wave follower 20 is placed in fluid the upper body portion 21 floats on the surface of the fluid 52, while the lower body 22 remains relatively submerged. A one-way check valve 99 is located in a passage in the buoyant upper body portion 21 for the purpose of allowing air to escape from the lower chamber 22. The operation of the wave follower 20 can be explained as follows. With the absence of waves on the surface of the fluid 52 and with the chamber 22 filled with fluid, the buoyant upper portion 21 of the wave follower floats on the fluid and the lower portion 22 is submerged. However, on the rise of a wave, (an upward stroke with regard to the wave follower), the buoyant upper body portion 21, (after overcoming the resistance of the loads 202a and 202b,) tracks the rise of the wave. Since the fluid in the open bottomed lower chamber 22 is of the same density as the wave and is actually a part of that wave, work is only required to raise the buoyant upper body 21 of the wave follower 20. The fall of the wave starts the downward stroke of the wave follower 20 (again, after overcoming the resistance of the loads 202a and 202b,). As the falling wave trough is tracked by the wave follower, fluid in the chamber 22 will attempt to flow out of the opening at the bottom of the chamber 22. The one-way check valve 99 which is closed at times of pressure equilibrium or pressure drop, prevents the free outflow of fluid from the chamber 22. As the wave falls and the fluid outside the chamber 22 begins to fall away, that fluid in the chamber 22 being now held above the level of that fluid outside the chamber, is pulled down. Also, the suction effect created, and surface adhesion both pull the wave follower 20 down as the wave falls. The force of suction is created as the fluid tries to fall from the lower body portion 22 but cannot because of the now closed one-way check valve 99. The condition of surface adhesion is created as the fluid attempts to break its bond with the roof of the chamber of the lower body portion 22. If the lower body chamber 22 is not entirely filled with fluid because fluid has escaped during the fall of a previous wave (downward stroke with regard to the wave follower) or due to turbulence in the body of fluid, the rise of the next wave 67 causes fluid to attempt to re-enter the chamber 22 through the opening at it's bottom, thereby causing an increase in pressure of the air contained between the fluid and the roof of the chamber 22. The increase in air pressure causes the one-way valve 99 to open, thus allowing air to be exhausted from the lower chamber 22 and, thereby, allowing fluid to freely once again enter and fill the lower chamber 22 through it's open bottom. In accordance with this invention, it is further possible to virtually double the output of the apparatus 202 as described to this point. This capability will become apparent as more detailed drawings of the pump assembly 202a are described in FIG. 3 at 203a and 203b.
Expanding further on FIG. 2, the load release and re-establish means presented at 202c is a hydraulic valving system which is just one of several possible load release and re-establish means configurations. A load release and re-establish means may be any hydraulic, pneumatic, mechanical, electromechanical or other means whose function is to momentarily release the wave follower 20 from the driven and systemic loads of the apparatus 202 such that the wave follower 20 is allowed to find it's own level without the influence of these load resistances. Upon finding it's level, the load is then re-established on the wave follower. This releasing and re-establishing of the load takes place both as a wave 67 reaches the highest point of it's crest and begins to fall and also when a wave 67 reaches the lowest point of its trough and begins to rise. As the wave 67 reaches it's highest point and no more work can be accomplished by the wave follower's 20 moving upward, the load release and re-establish means 202c senses the beginning of a change of direction in the wave (according to adjustable preset parameters) and releases the load on the wave follower 20. Because the force of the load on the wave follower 20 has caused the wave follower 20 to become virtually submerged as it tracked the rising wave, releasing that load allows the wave follower 20 to continue rising in that it "pops" up by a distance equal to the thickness of the buoyant upper portion 21 of the wave follower 20. While no work is accomplished during this "popping up," the wave follower 20 is, nonetheless, now positioned to benefit from extended work producing travel as it tracks the falling wave 67. Once the wave follower 20 has "popped" and the buoyant upper body 21 is floating on the surface of the wave 52, the pressure sensor (185/FIG. 3-203b) detects a preset low pressure condition and the load on the wave follower 20 is re-established by re-closing the valve gates 193 of the sensor/solenoid valves 45 and 43. Likewise, as the wave 67 reaches it's lowest point and no more work can be accomplished by the wave follower's 20 moving downward, the load release and re-establish means senses the beginning of a change of direction in the wave (according to adjustable preset parameters) and again releases the load on the wave follower 20. Because the force of the load on the wave follower 20 has caused it to be held above the body of fluid to a height nearly that of the thickness of chamber 22 as it tracked the falling wave, releasing that load allows the wave follower 20 to continue descending in that it "drops" down (due to gravity pulling on that water in the lower chamber 22 held above the level of the wave) by the thickness of the chamber 22 of the wave follower 20. While no work is accomplished during this "dropping," the wave follower is, nonetheless, now positioned to benefit from extended work producing travel as it tracks the next rising wave 67, to begin the cycle again. Once the wave follower 20 has "dropped" and the chamber 22 is re-submerged below the surface of the wave 52, the pressure sensor 185 detects a preset low pressure condition and the load on the wave follower 20 is re-established by re-closing the valve gates 193 of the sensor/solenoid valves 45 and 43. The load discussed above is made up of that resistance set up by the pump assembly 202a, the linear drive/generator assembly 202b and normal systemic resistances such as friction. In this way the output from a wave energy converter incorporating such a load release and re-establish means can be increased by up to double that of a similar device not so equipped.
In FIG. 3 a still more detailed view of the pump assembly 202a and more particularly the load release and re-establish means 202c are seen. Also, a more detailed view of one of the integrated sensor/switch/valves 45 is seen at 203b. At 202a in FIG. 3, we see the pump assembly previously described being connected to the lever arm extension 172 by a pivotal joint 25. As fluid is pushed ahead of the rising piston 27 in the upper part 192 of cylinder 28, thereby reducing the volumetric capacity in that upper part 192 of the cylinder 28, that same fluid is pressurized to a predictable and measurable pressure range which is hydraulically transmitted through pressure tube 44 to an integrated sensor/solenoid valve 45. As long as the wave follower continues to rise while tracking the rising wave, the sensor/solenoid valve 45 remains closed, hence allowing the piston to force fluid out of the upper cylinder 192, through the check valve 38 and on through the outlet tube 41. As the crest of the wave reaches it's maximum height and then begins to fall, the buoyant force which had been exerted on the wave follower by the rising wave begins to decrease. There is immediately a corresponding drop in fluid pressure applied in the upper cylinder 192. As soon as the pressure sensor 185 in the sensor/solenoid valve 45 (as shown at 203b) determines that this pressure drop exceeds a preset amount it activates the solenoid valve mechanism 187 by means of a linkage 183. (The solenoid switch in this particular embodiment of the invention is electrical, receiving it's power via a power cable 181). This in turn opens a gate 193 in valve body 186. The pressurized fluid, until now being applied against the driven load by the piston 27, is now provided with a path of minimal resistance through the opened valve 186, and on down a bypass tube 184. At the same time that the sensor 185 caused the valve gate 193 in the sensor/solenoid valve 45 to open, it simultaneously caused the valve gate 193 in the sensor/solenoid valve 43 to open as well by transmitting a signal to it via a signal cable 176. These simultaneous valve openings allow for clear passage of the fluid in the upper cylinder 192 into the lower cylinder 192b. In order to adjust for differences of volumetric pressure between the upper cylinder 192 and the lower cylinder 192b as well as for expansion, contraction and other factors, an accumulator or reservoir 182 is installed into the bypass tube 184 such that the fluid 175 will extend into or exit from the accumulator 182. Thus the fluid to be evacuated from the upper cylinder 192 can enter the lower cylinder 192b freely and quickly. In this way the wave follower is suddenly released of it's load resistance. As a result, the buoyant upper body portion of the wave follower which, until now has been virtually submerged as a result of the load resistance (having being designed to be just enough less than the buoyant force acting upon the wave follower to unlock the device and allow the wave follower to track the rising wave,) pops up to float virtually fully on the surface of the fluid because the wave follower has been dynamically balanced by the counterweight as was previously explained. Once the wave follower 20 has "popped" and the buoyant upper body 21 is floating on the surface of the wave 52, the pressure sensor 185 detects a preset low pressure condition and the load on the wave follower 20 is re-established by re-closing the valve gates 193 of the sensor/solenoid valves 45 and 43.
At this point the process is reversed. As fluid is pushed ahead of the falling piston 27 in the lower part 192b of cylinder 28, thereby reducing the volumetric capacity in that lower part 192b of the cylinder 28, that same fluid is pressurized to a predictable and measurable pressure range which is hydraulically transmitted through pressure tube 46 to sensor/solenoid valve 43. As long as the wave follower continues to fall while tracking the descending wave, the sensor/solenoid valve 43 remains closed, hence allowing the piston to force fluid out of the lower cylinder 192b, through the check valve 40 and on through the outlet tube 41. As the trough of the wave reaches it's lowest point and then begins to rise, the gravitational force which had been exerted on the wave follower by the falling wave suddenly begins to decrease. There is immediately a corresponding drop in fluid pressure applied in the lower cylinder 192b. As soon as the pressure sensor 185 in the sensor/solenoid valve 43 (as shown at 203b/45) determines that this pressure drop exceeds a preset amount it activates a solenoid switch mechanism 187 which in turn opens a gate 193 in valve body 186. The pressurized fluid, until now being applied against the driven load by the piston 27, is now provided with a path of minimal resistance through the opened valve 186, and on down a bypass tube 184. At the same time that the sensor 185 in the sensor/solenoid valve 43 caused the valve gate 193 in that sensor/solenoid valve 43 to open, it simultaneously caused the valve gate 193 in the sensor/solenoid valve 45 to open as well, thereby opening a clear passage into the upper cylinder 192. Thus the fluid to be evacuated from the lower cylinder 192b can enter the upper cylinder 192 freely and quickly. In this way, the wave follower is suddenly released of it's load resistance. As a result, the lower body portion of the wave follower which, until now has been held virtually out of and above the surface of the body of fluid as a result of the load resistance (having being designed to be just enough less than the gravitational force acting upon the wave follower to unlock the device and allow the wave follower to track the falling wave,) drops down to a point where the buoyant upper body is floating on top of the surface and the lower chamber is submerged. At this point the process begins over again. Once the wave follower 20 has "dropped" and the chamber 22 is re-submerged below the surface of the wave 52, the pressure sensor 185 detects a preset low pressure condition and the load on the wave follower 20 is re-established by re-closing the valve gates 193 of the sensor/solenoid valves 45 and 43.
The wave follower 20 further incorporates a counterweight 23 at an opposite end of and on another side of the fulcrum 24 of the lever arm 171 of the wave follower 20. This counter weight 23 serves to dynamically balance the wave follower 20 so that none of the buoyancy (potential energy) of the upper body 21 is converted and consumed to support the weight of the wave follower 20. Fixedly incorporated into the lever arm 171 of the wave follower 20 which moves more or less vertically up and down, is a diagonal, vertically oriented extension 172 which therefore, moves more or less horizontally back and forth. The conversion of wave motion to useable energy is accomplished in this embodiment of the invention by attaching a drive shaft 26 to the lever arm extension 172 by a pivotal joint 25 or similar attachment and then connecting the drive shaft 26 to a load, here represented by the pump assembly seen at 202a. and also by attaching a drive shaft 174 to the lever arm extension 172 by a pivotal joint 173 or similar attachment and then connecting the drive shaft 174 to a second load, here represented by the generator assembly seen at 202b. Thus, with the upward and downward movement of the wave follower 20 in reaction to the waves 67, the resulting back and forth motion of the lever arm extension 172, powers the driven devices. What is further illustrated in FIG. 2 is a preferred embodiment of the invention in which the drive shaft is utilized as a piston rod 26 to drive a reciprocating pump 202a. The reciprocating pump is comprised of the piston rod 26, piston 27, cylinder 28, foot valves 37 and 39, check valves 38 and 40, intake 36, outlet 41, pre-filter 35 and various plumbing fittings which will not be numerically identified. The pump is pivotally attached at 30 to the relatively immovable enclosure 47 of the apparatus 202 by mounting bracket 29 which allows the pump to rock backward and forward in order to maintain alignment with the piston rod 26. The piston rod 26, being attached to pivotal joint 25, allows piston rod 26 to stay aligned with the rest of the pump assembly as the lever arm extension 172 rocks back and forth. As the wave follower 20 rises, the piston 27 travels to it's left (toward it's nominal top) within the relatively immovable cylinder 28 creating a suction within the cylinder 28 below the piston 27. This action causes fluid to be pulled into this lower part of the cylinder 28 through the inlet at foot valve 37. As the piston 27 rises, thereby reducing the volumetric capacity in the upper part of the cylinder 28, the fluid contained within the upper part of the cylinder 28 above the piston 27 is pressurized and expelled through the outlet passing through the check valve 38 and through an outlet tube 41. As the wave follower 20 now travels downward, so does the piston 27, thus reversing the action within the cylinder 28. This now creates a suction within the cylinder 28 above the piston 27. This action causes water to be pulled into this upper part of the cylinder 28 through the inlet at foot valve 39. The fluid contained within the lower part of the cylinder 28 below the piston 27 is pressurized as the piston 27 is forced downward, reducing the volumetric capacity in this lower part of the cylinder 28 and is thus expelled through the outlet passing through check valve 40. The expelled, pressurized fluid from both the upward and downward strokes of the piston may then be gathered at 42 to power internal, external or separate and remote devices, systems or processes. In the event of larger than normal waves, the wave follower 20 is prevented from continuing it's upward travel into the pump 202a and the generator 202b and other undesirable areas by a stopper 31 which is fixedly attached at 32 to the enclosure 47 or some other appropriate immovable component of the assembly 202. Further, adequate clearance 33 is available on one or both sides of the stopper 31 to allow the surging fluid lifting the wave follower 20 to escape past the wave follower 20 when it has reached it's maximum allowable height, thus eliminating excessive stress and strains on the apparatus 202. A minimal clearance 34 between the wave follower 20 and the wave ramp 51 eliminates friction and wear to these components while at the same time, minimizing the passage of rising water past the wave follower 20 until such time as the wave follower 20 has reached the stopper 31. This clearance could be effectively eliminated altogether, if deemed worthwhile by the use of a flexible wiper gasket installed along the front and side edges of the wave follower 20.
Also, as with the pump 202a, the reciprocating lever arm extension 172 is linked to another drive shaft 174 by a pivotal joint 173. This joint 173 may be located at a point on the lever arm extension 172 which is either different from or the same as the pivotal joint 25 to which the pump 202a is connected. This drive shaft 174 is rotatably connected by bearings 119 to the threaded shaft 113 of a ball screw linear motion drive being the part of the assembly not i |