WO2013166017A1

WO2013166017A1 - Apparatus for reduced fluid-flow fish passage

Info

Publication number: WO2013166017A1
Application number: PCT/US2013/038871
Authority: WO
Inventors: Norman NEUFELD
Original assignee: Neufeld Norman
Priority date: 2012-04-30
Filing date: 2013-04-30
Publication date: 2013-11-07

Abstract

The present invention teaches a fish passage unit for providing a reduced flow rate of water having a chain drive system that is powered by the flow of water in the stream or river in which the unit is placed. In some embodiments, the chain drive system may be driven by the rotation of a waterwheel that is rotated by water from the stream flowing against the waterwheel. The chain drive system includes one or more catches that periodically contact a physical projection attached to each of the gates of the fish passage unit, thereby alternately and sequentially opening and closing the gates of the fish passage unit in order to control the flow of water through a passageway of the unit.

Description

[0001] TITLE: APPARATUS FOR REDUCED FLUID-FLOW FISH PASSAGE

[0002] CROSS REFERENCE TO RELATED APPLICATION(S)

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 61/640,344, filed on April 30, 2012 and entitled "APPARATUS FOR REDUCED FLUID- FLOW FISH PASSAGE," the entire contents of which are incorporated herein by reference as if fully set forth.

[0004] FIELD OF INVENTION

[0005] The present invention relates to the field of fish passageways, and more particularly to an apparatus that reduces the flow of water through a passageway so that migrating fish can travel through the passageway while minimizing the risk of injury to the fish.

[0006] BACKGROUND

[0007] Dams, pollution, deforestation, and urban sprawl have all taken their toll on streams used by migrating fish, such as salmon and steelhead trout. Many migrating fish species are now endangered.

[0008] Impediments or obstructions, such as dams and culverts, effectively block or greatly hinder upstream migration for many returning fish. Prior attempts to remedy this include fish ladders and complex and costly underground piping systems that run the length of migrating streams. Most of these systems or apparatuses are costly and cannot be readily removed. Additionally, with most of these systems, the migrating fish generally must jump to avoid swimming against great fluid pressure created by the differential of the head of the fluid level between the after-impediment water level and the pre-impediment water level. Typically, a series of height-staggered concrete boxes are used to allow the fish to jump to the next height level. Use of these devices causes the fish to be injured or, at least, greatly exhausted during the migration process. It is believed that the condition of the fish at the spawning location greatly impacts the long-term viability of the particular fish species. Therefore, it is important to protect the vitality of the fish during the migration process.

[0009] Because fish migration is generally seasonal, depending on the species of the fish, it is also desirable to have a portable, relatively inexpensive apparatus for transporting migrating fish past river or stream impediments that also reduces the flow rate on the migrating fish during differential fluid level acclimation.

[0010] Attempts have been made to provide a solution to these drawbacks. For example, U.S. Patent No. 6,394,699, entitled Apparatus for Reduced Flow Fish Passage, which is owned by the applicant of the present application and incorporated herein by reference as if set forth in its entirety, teaches an apparatus for reduced flow rate fish passage that uses a pair of pneumatically-driven gates or valves located within a passageway that open alternately in order to control the flow rate of water passing through the passageway. A drawback to this solution is that it requires an external power source to be located at or near the apparatus in order to drive the compressor that supplies pressure to the pneumatically-driven gates. These external power sources are expensive to operate and often prove difficult to provide, since the fish passageway apparatus may be located in a woodland area far from accessible power lines.

[0011] Therefore, it is desirable to provide an independently-powered apparatus that addresses these and other known disadvantages of the prior art. [0012] SUMMARY OF THE INVENTION

[0013] Briefly, the present invention teaches a fish passage unit for providing a reduced flow rate of water having a chain drive system that is powered by the flow of water in the stream or river in which the unit is placed. In some embodiments, the chain drive system may be driven by the rotation of a waterwheel that is rotated by water from the stream flowing against the waterwheel. The chain drive system includes a plurality of catches that periodically grab a physical projection attached to each of the gates of the fish passage unit, thereby alternately and sequentially opening and closing the gates of the fish passage unit in order to control the flow of water through a passageway of the unit.

[0014] In some embodiments, each gate is a single, solid unit. In alternate embodiments, each gate may be comprised of a plurality of small pipes or bars which are independently rotatable so that stronger-swimming fish may manually push through the gate even when it is not in its open position.

[0015] In alternate embodiments, the waterwheel may be omitted, and the fish passage unit according to the present invention may be externally powered.

[0016] In another respect, the present invention is a method for controlling the rate of passage of a fluid through a passageway, the passageway comprising a first gate and a second gate therein, a first projection attached to the first gate and located external to the passageway, and a second projection attached to the second gate and located external to the passageway, each of the first and second gates being adjustable between open and closed positions, the first gate having a first gate body and the second gate having a second gate body, the method comprising: using the fluid to operate a chain drive system such that a catch located at a fixed point along a length of a chain of the chain drive system presses against the first proj ection, thereby changing a position of the first gate from its closed position to its open position during a first period of time; using the fluid to continue to operate the chain drive system such that the catch continues to press against the first projection for a second period of time during which the first gate is maintained in its open position; using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the first projection, thereby permitting the first gate to return to its closed position during a third period of time via a first spring that biases the first gate into its closed position; using the fluid to operate the chain drive system such that the catch presses against the second projection, thereby changing a position of the second gate from its closed position to its open position during a fourth period of time; using the fluid to continue to operate the chain drive system such that the catch continues to press against the second projection for a fifth period of time during which the second gate is maintained in its open position; and using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the second projection, thereby permitting the second gate to return to its closed position during a sixth period of time via a second spring that biases the second gate into its closed position.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention disclosed herein, certain embodiments in accordance with the herein disclosed invention are shown in the drawings. It should be understood, however, that the herein disclosed invention is not limited to the precise arrangement(s) shown. The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals denote like elements. In the drawings:

[0019] FIG. 1 is a schematic view of a prior art system showing an externally-powered fish passage unit deployed within a body of water in the vicinity of an obstruction;

[0020] FIGS. 2A-2C are schematic views of a simplified sequence of operation of a series of externally-powered gates in a fish passage unit according to the prior art; [0021] FIGS. 3 and 4 are side views of a fish passage unit according to the present invention;

[0022] FIG. 5 is a close-up view of the area marked 5-5 in FIG. 4;

[0023] FIG. 6 is a close-up view of the area marked 6-6 in FIG. 4;

[0024] FIG. 7 is a top perspective view of a gate mechanism of the fish passage unit according to the present invention, with the gate in a closed position;

[0025] FIG. 8 is a top perspective view of the gate mechanism of FIG. 7 in an open position;

[0026] FIGS. 9-12 are schematic views of the gate cycling stages of the fish passage unit according to the present invention; and

[0027] FIG. 13 is a schematic view of an alternative gate design according to the present invention.

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The ensuing detailed description provides preferred exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the herein disclosed invention. Rather, the ensuing detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments in accordance with the herein disclosed invention. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention, as set forth in the appended claims.

[0030] To aid in describing the invention, directional terms may be used in the specification and claims to describe portions of the present invention (e.g., upper, lower, left, right, etc.). These directional definitions are merely intended to assist in describing and claiming the invention and are not intended to limit the invention in any way. In addition, reference numerals that are introduced in the specification in association with a drawing figure may be repeated in one or more subsequent figures without additional description in the specification in order to provide context for other features.

[0031] In the specification and accompanying claims, two parts are said to be "approximately parallel" when their respective axes are no more than 5 degrees from parallel with each other. In the specification and accompanying claims, two parts are said to be "approximately perpendicular" or "approximately orthogonal" when their respective axes are no more than 5 degrees from perpendicular or orthogonal with each other. In the specification and accompanying claims, an angle is said to be "approximately X" degrees when it has a value of X plus or minus 5 degrees.

[0032] FIG. 1 shows a schematic view of a prior art system of a fish passage unit 10 that is located just below the surface 2 of a body of water 1 on a downstream side of an obstruction 4. The fish passage unit 10 has an attraction flow device 12 that creates a high-velocity area in the vicinity of the attraction flow device 12 that helps to aid in directing the fish 5 into the fish passage unit 10. For example, the attraction flow device 12 may be a concrete bucket that provides downstream spillover typically used in conventional fish ladders. Because migratory fish are instinctively attracted to the fastest parts of a stream, fish 5 are guided into attraction flow device 12 and enter the access pipe 14 which is connected to the fish passage unit 10. The fish passage unit 10 is comprised of a pair of gates 16a, 16b which, in this embodiment, are pneumatically driven by a compressor 25 coupled to a control unit 24, which feeds fluid through a pneumatic line 23 to control opening and closing of the gates 16a, 16b. The gates 16a, 16b control the rate of flow of water in the passageway 20 and thereby permit the fish 5 to travel against the water flow direction 3 without exhausting themselves or becoming injured. Once the fish pass by the gates 16a, 16b and exit the fish passage unit 10, they are able to travel upwardly through a passageway 18 which passes over or through the obstruction 4, so that the fish 5 can exit safely on the upstream side of the obstruction 4.

[0033] The control unit 24 can be programmed to cycle the gates 16a, 16b to open and close at different intervals according to the type and quantity of fish that are expected to be migrating through the fish passage unit 10. The cycling times can be manually adjusted at the control unit 24 or remotely controlled. For example, during peak migration of the Pacific Northwest salmon, the cycling time between the two stages may be approximately 20 minutes.

[0034] FIGS. 2A-2C show schematic views of a simplified sequence of operation of a series of externally-powered gates 116a, 1 16b deployed within a fish passage unit 1 10 according to the prior art. In this embodiment, the gates 1 16a, 1 16b are electrically powered to open and close according to a pre-selected schedule. At a first stage, as shown in FIG. 2A, the fish 105 are located within the fish passage unit 110 on a downstream side of gate 1 16a. At this stage, both gates 1 16a, 1 16b are closed. It should be understood that, even when the gates are in their closed positions, some limited quantity of water is permitted to flow through the passageway 120 so that the fish located between the gates 116a, 1 16b can become acclimated to the fluid flow differential between the water located on the upstream side of the obstruction 4 and the water located on the downstream side of the obstruction 4. At a second stage, as shown in FIG. 2B, gate 1 16a is open and fish 105 are attracted into passageway 120 against the water flow direction 103 towards gate 116b, which is closed at this time. At a third stage, as shown in FIG. 2C, the gate 116a is closed and the gate 116b is open, which permits the fish 105 to travel out of the fish passage unit 1 10 and continue their migration.

[0035] With reference to FIGS. 3-8, an improved fish passage unit 210 according to the present invention will now be described in detail. When deployed in a body of water, the unit 210 is placed such that a fish entry location 21 1 is placed towards the downstream end of the body of water and a fish exit pipe 213 is placed towards the upstream end of the body of water (i.e., towards the obstruction 4). In other words, the direction of water flow travels in a direction from the fish exit pipe 213 towards the fish entry location 21 1. Between the ends of the unit 210 is located a passageway 220 comprising a pair of gates 216a,216b, which will be described in greater detail below. In this embodiment, the unit 210 is in the general shape of a rectangular prism and includes a top wall 214, a bottom wall 215 (see FIG. 7), a pair of sidewalls 219a,219b (see FIGS. 3 and 4, respectively), and a pair of endwalls (not labeled, but located respectively at the fish entry location 21 1 end and fish exit pipe 213 end ofthe unit 210). In this embodiment, the top wall 214 is comprised of a transparent plastic material, for example Poly(methyl methacrylate) (PMMA). It should be understood that, in alternate embodiments, the top wall 214 may be comprised of a solid material and/or the bottom wall 215, sidewalls 219a,219b, and/or endwalls could be made of a transparent material.

[0036] It should be understood that the fish passage unit 210 of the present application can replace the fish passage units 10, 110 of the prior art, mutatis mutandis. It should further be understood that the principles of controlling water flow dynamics as disclosed in U. S. Patent No. 6,394,699, which is incorporated herein by reference, are equally applicable and relevant to the present invention.

[0037] When deployed in the body of water, the natural flow direction ofthe stream or river will route water through a hose 230 and out of a water outlet pipe 232, which is located above a waterwheel 226. In this embodiment, the waterwheel 226 is supported above the top surface of the passageway 220 via a waterwheel support brace 228. In this embodiment, some portion of the same water source— e.g., the flow of a river or stream— that is flowing through the fish passage unit 210 is the sole power source used to power the sequential opening and closing ofthe gates 216a,216b. In alternative embodiments, the waterwheel 226 may be omitted entirely and the chain drive system 234, as detailed below, can be powered by some alternative hydrodynamic or external power source, such as solar or wind-powered sources.

[0038] As best seen in FIGS. 4 and 5, the waterwheel 226 is connected to a chain drive system 234 which turns a plurality of chains 236, 240 that, in connection with a plurality of catches 244a, 244b, interact with the gates 216a,216b in order to open and close the gates 216a,216b according to a pre-determined schedule, as further discussed below. The waterwheel 226 is attached to a first chain 236 that is attached to a gear cassette 238. Rotation of the waterwheel 226 in a waterwheel rotation direction 227 turns the first chain 236 in a first chain rotation direction 237, thereby rotating the gear cassette 238. The gear cassette 238 is also connected to the second chain 240. Rotation of the gear cassette 238 causes the second chain 240 to rotate in a second chain rotation direction 241. A plurality of sprockets 242 are included on the body of the unit 210 in order to assist rotation of the second chain 240 in the second chain rotation direction 241. The size and arrangement of the waterwheel 226, chains 236,240, and the gear rings on the gear cassette 238 can be modified in order to provide a desired rotational speed of the second chain 240.

[0039] In alternate embodiments, the chain drive system 234 could be replaced with a belt- driven system that functions in a similar manner to the chain drive system 234. In further alternative embodiments, one or both of the first chain 236 and the second chain 240 could be replaced by a belt that functions in a similar manner to the respective chain, as would be understood by one of ordinary skill in the art.

[0040] As best seen in FIGS. 4 and 8, located at fixed positions along the length of the second chain 240 are a pair of catches 244a,244b, which in this embodiment each have a respective slot 245a,245b located therein for accommodation of rods or projections 252a,252b. In this embodiment, the catches 244a,244b are located at opposing points along the length of the second chain 240 (in other words, the catches 244a,244b are spaced a maximum distance apart along the length of the second chain 240), though this could be varied in other embodiments in order to change the sequence of opening and closing of the gates 216a,216b. While in this embodiment two catches 244a,244b are located along the length of the second chain 240, in alternate embodiments a different number of catches could be supplied along the length of the second chain 240 so that the gates 216a,216b are opened more or less frequently.

[0041] The following discussion will make reference to the parts and operation of one of the gates, i. e. , gate 216a. It should be understood that this discussion applies equally to the parts and operation of the other gate, i.e., gate 216b. Gate 216a has a gate center mount 248a which is attached to the body 218a of the gate 216a along a central axis thereof (the central axis is not labeled in the drawings but should be understood to be located generally through the middle of the gate center mount 248a and the gate body 218 and oriented in a direction that extends approximately orthogonal to the page in FIGS. 7 and 8). In this embodiment, the gate body 218a is of solid, single-piece construction. As best seen in FIGS. 7 and 8, the rod 252a is comprised of a first portion 255a and a second portion 256a that is separated from the first portion 255a by a bend 253a. The first portion 255a extends from the gate center mount 248a at an angle 251a measured between the first portion 255a and a transverse axis 250a of the gate body 218a. In this embodiment, the second portion 256a extends from the bend 253a at an angle 254a with respect to the first portion 255a. In this embodiment, both the angle 251a and the angle 254a are approximately 45 degrees, though other values for one or both of the angles are possible within the scope of this invention.

[0042] As the second chain 240 moves the catch 244a around in the second chain rotation direction 241, the slot 245a of the catch 244a will come into contact with the rod 252a in the vicinity of the bend 253a. The rod 252a, being of a generally-circular cross-sectional shape in this embodiment, will fit into the generally arcuate-shaped slot 245a in the catch 244a and be pushed by the catch 244a in the direction of the second chain rotation direction 241. As the rod 252a is pushed, the gate 216a will rotate via the gate center mount 248a about its central axis so that the gate 216a transitions from its closed position (as generally shown in FIG. 7, in which the second portion 256a of the rod 252a is approximately perpendicular to the sidewall 219b) to its open position (as generally shown in FIG. 8). Due to the approximate 45 degree angle of the first portion 255a of the rod 252a with respect to the gate body 218a and the approximate 45 degree angle of the second portion 256a of the rod 252a with respect to the first portion 255a, the catch 244a will push (and thereby rotate) the rod 252a in the vicinity of the bend 253 a through a range of approximately 90 degrees, thereby changing the orientation of the gate body 218a by approximately 90 degrees and affecting the transition between closed and open positions of the gate 216a. Once the rod 252a has been rotated through a range of approximately 90 degrees, owing to the orientation of the second portion 256a vis-a-vis the first portion 255a, the catch 244a will then ride along the length of the second portion 256a until the end of the second portion 256a has been reached and the catch 244a no longer makes contact with any portion of the rod 252a. During this period of time, the second portion 256a is approximately parallel with the second chain 240 (i.e., approximately parallel with sidewall 219b) and the gate 216a is held in its open position (as approximately shown in FIG. 8). In this embodiment, the catches 244a,244b contact the rods 252a,252b of the gates 216a,216b along an upper portion of the path of the second chain 240 (in other words, along that portion of the path of the second chain 240 located nearest to the top wall 214). In alternate embodiments, the fish passage unit could be designed such that the catches come into contact with the rods of the gates only or also along some other portion of the path of the second chain.

[0043] Once the catch 244a comes out of contact with the rod 252a, the gate is automatically returned to a closed position via the restorative force supplied to the rod 252a by a return spring 257a. The return spring 257a is attached at one end to a connection point 264a located along the first portion 255a of the rod 252 and at a second end to a return spring attachment point 258a located on the top of the unit 210. A support chain 260a is attached at a first end to the connection point 264a and at a second end to a support chain attachment point 261a located on the top of the unit 210. The support chain 260a helps to limit the return action of the return spring 257a, so that the rod 252a is not pulled too far in the opposite direction by the return spring 257a. In this way, the return spring 257a and support chain 260a act to return the rod 252a to its proper starting position when it is not in contact with the catch 244a, which ensures that the gate 216a returns to its proper closed position.

[0044] It should be understood that, in alternative embodiments, the "closed" position of the gate 216a could be such that the gate body 218a is not orthogonal or approximately orthogonal to the sidewalls 219a,219b of the passageway 220. In other words, the closed or "home" position of the gate 216a could be such that the gate body 218a is angled with respect to one of the sidewalls 219a,219b of the passageway 220 at an angle that is less than 90 degrees or 85 degrees, respectively. For example, in a closed position of the gate 216a, the gate body 218a could be angled at approximately 45 degrees from one of the sidewalls 219a,219b ofthe unit 210, so that the gate 216a need only be rotated through an additional 45 degrees to be placed in its open position. In another embodiment, the gate body 218a could be angled approximately 15 degrees with respect to a sidewall 219a,219b of the passageway 220 in its "closed" position. This could be accomplished, for example, by varying the angle 25 la, the tension of the return spring 257a, or the length of the support chain 260a. In this way, the user can vary the quantity of water flow through the passageway 220, e.g., to provide a period of relatively low water flow that enables smaller fish to pass through the passageway 220. [0045] FIGS. 9-12 are top schematic views of the gate cycling stages of the fish passage unit 210 according to the present invention, with the return springs 257a,257b, support chains 260a,260b, and other components of the unit 210 removed from view for purposes of simplicity. In these FIGS., the direction of movement of the catch 244a as it comes into contact with the rods 252a,252b is in the same general direction as the water flow direction 203 (see FIG. 3) that is moving through the unit 210. In these embodiments, migratory fish would travel through the unit 210 in the opposite direction thereto. In FIG. 9, in a first stage of upstream fish passage, both gates 216a,216b are in their closed position, and catch 244a is just about to come into contact with rod 252b. In the closed position of the gates 216a,216b, the low flow rate of water that is travelling through the passageway 220 acclimates any fish that are located between the gates 216a,216b to the normal flow rate, which is higher than the acclimation fluid flow at the upstream side of the obstruction 4. In FIG. 10, at a second stage of upstream fish passage, catch 244a is in contact with the second portion 256b of rod 252b such that gate 216b is being held in its open position, while gate 216a remains in a closed position. In this stage, just enough water flows past the closed gate 216a to create a substantially constant acclimation flow rate. Any fish that had been located between the gates 216a,216b in the previous stage may now swim upstream with minimal exertion and with no anticipated injuries resulting therefrom. In FIG. 1 1 , at a third stage of upstream fish passage, catch 244a is located between the two gates 216a,216b but not in contact with either of the two rods 252a,252b. Therefore, both gates 216a,216b return to their closed positions. In FIG. 12, at a fourth stage of upstream fish passage, catch 244a is in contact with the second portion 256a of rod 252a such that gate 216a is being held in its open position, while gate 216b remains in a closed position. In this stage, the fish that have collected prior to the fish passage unit 10 downstream of gate 216a are now allowed to enter the passageway 220. The low flow rate in the passageway 220 acclimates the fish to the normal flow rate, which is higher than the acclimation fluid flow at the upstream side of the obstruction 4. The cycle then repeats beginning at the first stage, as shown in FIG. 9, until all of the migrating fish have passed through the unit 210.

[0046] FIG. 13 shows a front schematic view of an alternative design for a gate 316. In this embodiment, the gate body 318 is comprised of a plurality of individual, separately -rotatable pipes or panels 366a-366i, which are each separately attached to the gate center mount 348 along a central axis 368. In this embodiment, the gate 316 may generally function in the same fashion as gates 216a,216b, except that the individual pipes 366a-366i are individually rotatable about the central axis 368 such that stronger swimming fish, who may not need or desire to wait for the gate 316 to open entirely through rotation of the rod 352, may push through one or more of the individual pipes 366a-366i— thereby causing the one or more individual pipes 366a-366i to rotate so that the gate is partially "open"— in order to move through the fish passage unit 210. As described above with respect to the gate 216a, in the "closed" position of the gate 316, the individual pipes 366a-366i need not extend orthogonally or approximately orthogonally with respect to the sidewalls of the passageway of the fish passage unit.

[0047] In this embodiment, the individual pipes 366a-366i are horizontally arranged and center-supported, i.e., supported at a central portion of their respective length that defines the rotation point of the individual pipe. In alternative embodiments, the individual pipes could be vertically arranged within the fish passage unit 210 and/or could be end-supported, i.e., mounted at or near one end about which the individual pipes rotate. In a further alternative embodiment, the individual pipes could be supported from an upper portion of the passageway 220 of the unit 210 but not orthogonally-arranged or approximately orthogonally-arranged with respect to the top or bottom surface of the passageway 220. In other words, the individual pipes could be angled when in their rest (closed) position such that they do not extend precisely vertically or within plus or minus 5 degrees from vertical within the passageway 220.

[0048] It will be appreciated that the foregoing is presented by way of illustration only, and not by way of any limitation, and that various alternatives and modifications may be made to the illustrated embodiments without departing from the spirit and scope of the present invention.

[0049] ASPECTS OF THE INVENTION

[0050] Additional aspects of the invention include:

[0051] Aspect 1 : An apparatus for controlling the rate of passage of a fluid therethrough, the apparatus comprising a passageway through which the fluid is permitted to pass, the passageway comprising a first gate and a second gate therein, each of the first and second gates being adjustable between open and closed positions, the first gate having a first gate body and the second gate having a second gate body; a first projection attached to the first gate and located external to the passageway; a second projection attached to the second gate and located external to the passageway; and a chain drive system located external to the passageway, the chain drive system comprising at least one catch that sequentially comes into contact with the first rod in order to temporarily move the first gate to its open position and the second rod in order to temporarily move the second gate to its open position.

[0052] Aspect 2: An apparatus according to any one of Aspects 1 and 3-14, wherein the chain drive system is operatively connected to a waterwheel and the chain drive system is powered by movement of a portion of the fluid into contact with the waterwheel.

[0053] Aspect 3 : An apparatus according to any one of Aspects 1, 2, and 4-14, wherein the chain drive system further comprises a pair of chains.

[0054] Aspect 4: An apparatus according to any one of Aspects 1-3 and 5-14, wherein the chain drive system further comprises a pair of catches located at opposing points along a length of one of the chains of the pair of chains .

[0055] Aspect 5: An apparatus according to any one of Aspects 1-4 and 6-14, wherein in its respective open position, the respective gate body of at least one of the first gate and the second gate is oriented approximately parallel with a sidewall of the passageway.

[0056] Aspect 6: An apparatus according to any one of Aspects 1-5 and 7-14, wherein in its respective closed position, the respective gate body of at least one of the first gate and the second gate is oriented approximately perpendicular to a sidewall of the passageway.

[0057] Aspect 7: An apparatus according to any one of Aspects 1-6 and 8-14, wherein at least one of the first projection and the second projection has a bend in it, the bend having an angle that measures approximately 45 degrees.

[0058] Aspect 8 : An apparatus according to Aspect 7, wherein the bend separates a first portion of the respective proj ection from a second portion of the respective projection, wherein when the respective gate is in its open position, the second portion is approximately parallel with a sidewall of the passageway and when the respective gate is in its closed position, the second portion is approximately perpendicular with the sidewall of the passageway.

[0059] Aspect 9: An apparatus according to any one of Aspects 1-8 and 10-14, wherein at least one of the first gate body and the second gate body is of solid, single-piece construction.

[0060] Aspect 10: An apparatus according to any one of Aspects 1-9 and 11-14, wherein at least one of the first gate body and the second gate body is comprised of a plurality of individual, separately -rotatable pipes. [0061] Aspect 11 : An apparatus according to any one of Aspects 1-10 and 12-14, wherein at least one of the first gate body and the second gate body is rotatable about a central axis of the gate.

[0062] Aspect 12: An apparatus according to any one of Aspects 1-1 1, 13, and 14, wherein at least one of the first gate body and the second gate body is rotatable about a central axis of the gate.

[0063] Aspect 13 : An apparatus according to any one of Aspects 1-12 and 14, wherein at least one of the first gate body and the second gate body is rotatable about a central axis of the gate.

[0064] Aspect 14: An apparatus according to any one of Aspects 1-13, wherein the first gate has a first spring attached thereto that biases it into its closed position and the second gate has a second spring attached thereto that biases it into its closed position.

[0065] Aspect 15: A method for controlling the rate of passage of a fluid through a passageway, the passageway comprising a first gate and a second gate therein, a first projection attached to the first gate and located external to the passageway, and a second projection attached to the second gate and located external to the passageway, each of the first and second gates being adjustable between open and closed positions, the first gate having a first gate body and the second gate having a second gate body, the method comprising: using the fluid to operate a chain drive system such that a catch located at a fixed point along a length of a chain of the chain drive system presses against the first projection, thereby changing a position of the first gate from its closed position to its open position during a first period of time; using the fluid to continue to operate the chain drive system such that the catch continues to press against the first projection for a second period of time during which the first gate is maintained in its open position; using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the first projection, thereby permitting the first gate to return to its closed position during a third period of time via a first spring that biases the first gate into its closed position; using the fluid to operate the chain drive system such that the catch presses against the second projection, thereby changing a position of the second gate from its closed position to its open position during a fourth period of time; using the fluid to continue to operate the chain drive system such that the catch continues to press against the second projection for a fifth period of time during which the second gate is maintained in its open position; and using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the second projection, thereby permitting the second gate to return to its closed position during a sixth period of time via a second spring that biases the second gate into its closed position.

* * *

Claims

1. An apparatus for controlling the rate of passage of a fluid therethrough, the apparatus comprising:

a passageway through which the fluid is permitted to pass, the passageway comprising a first gate and a second gate therein, each of the first and second gates being adjustable between open and closed positions, the first gate having a first gate body and the second gate having a second gate body;

a first projection attached to the first gate and located external to the passageway;

a second projection attached to the second gate and located external to the passageway; and a chain drive system located external to the passageway, the chain drive system comprising at least one catch that sequentially comes into contact with the first rod in order to temporarily move the first gate to its open position and the second rod in order to temporarily move the second gate to its open position.

2. The apparatus of claim 1, wherein the chain drive system is operatively connected to a waterwheel and the chain drive system is powered by movement of a portion of the fluid into contact with the waterwheel.

3. The apparatus of claim 1, wherein the chain drive system further comprises a pair of chains.

4. The apparatus of claim 3, wherein the chain drive system further comprises a pair of catches located at opposing points along a length of one of the chains of the pair of chains.

5. The apparatus of claim 1, wherein in its respective open position, the respective gate body of at least one of the first gate and the second gate is oriented approximately parallel with a sidewall of the passageway.

6. The apparatus of claim 1, wherein in its respective closed position, the respective gate body of at least one of the first gate and the second gate is oriented approximately perpendicular to a sidewall of the passageway.

7. The apparatus of claim 1, wherein at least one of the first projection and the second projection has a bend in it, the bend having an angle that measures approximately 45 degrees.

8. The apparatus of claim 7, wherein the bend separates a first portion of the respective projection from a second portion of the respective projection, wherein when the respective gate is in its open position, the second portion is approximately parallel with a sidewall of the passageway and when the respective gate is in its closed position, the second portion is approximately perpendicular with the sidewall of the passageway.

9. The apparatus of claim 1, wherein at least one of the first gate body and the second gate body is of solid, single-piece construction.

10. The apparatus of claim 1, wherein at least one of the first gate body and the second gate body is comprised of a plurality of individual, separately-rotatable pipes.

1 1. The apparatus of claim 1, wherein at least one of the first gate body and the second gate body is rotatable about a central axis of the gate.

12. The apparatus of claim 9, wherein at least one of the first gate body and the second gate body is rotatable about a central axis of the gate.

13. The apparatus of claim 10, wherein at least one ofthe first gate body and the second gate body is rotatable about a central axis ofthe gate.

14. The apparatus of claim 1, wherein the first gate has a first spring attached thereto that biases it into its closed position and the second gate has a second spring attached thereto that biases it into its closed position.

15. A method for controlling the rate of passage of a fluid through a passageway, the passageway comprising a first gate and a second gate therein, a first projection attached to the first gate and located external to the passageway, and a second projection attached to the second gate and located external to the passageway, each ofthe first and second gates being adjustable between open and closed positions, the first gate having a first gate body and the second gate having a second gate body, the method comprising: using the fluid to operate a chain drive system such that a catch located at a fixed point along a length of a chain of the chain drive system presses against the first projection, thereby changing a position of the first gate from its closed position to its open position during a first period of time;

using the fluid to continue to operate the chain drive system such that the catch continues to press against the first projection for a second period of time during which the first gate is maintained in its open position;

using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the first projection, thereby permitting the first gate to return to its closed position during a third period of time via a first spring that biases the first gate into its closed position; using the fluid to operate the chain drive system such that the catch presses against the second projection, thereby changing a position of the second gate from its closed position to its open position during a fourth period of time;

using the fluid to continue to operate the chain drive system such that the catch continues to press against the second projection for a fifth period of time during which the second gate is maintained in its open position; and

using the fluid to continue to operate the chain drive system such that the catch comes out of contact with the second projection, thereby permitting the second gate to return to its closed position during a sixth period of time via a second spring that biases the second gate into its closed position.