Abstract:
The present invention is directed to a water pump that may be easily constructed from inexpensive parts and materials and that is powered by the water source from which the water to be pumped is drawn. In a preferred embodiment, two pairs of lever arms located on opposite sides of the pump are alternately filled with water from the source and then emptied causing the lever arms to alternately ascend and descend. As the lever arms ascend and descend, they alternately fill and then compress a pair of pistons causing water to be pumped to an outlet of the pump. Water from the emptied lever arms may preferably be returned to the source, thus minimizing any impact of the pump on the environment and downstream users of the water source.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to the field of pumps and, more specifically, is directed to a pump that may be constructed of inexpensive materials and uses the kinetic and/or potential energy in a source of water to power the pump. 
       BACKGROUND OF THE INVENTION 
       [0002]    Although there exist a wide variety of water pumping systems for farm irrigation and other purposes, most such systems are complex, expensive, and require electricity or some other form of man-made power for their operation. In many underdeveloped or depressed areas, however, farmers and other persons requiring water for crop irrigation or other purposes cannot afford to install or maintain expensive pumping systems. Moreover, in many contexts, such as relatively small organic farms built to supply produce to local consumers and restaurants, the amount of water needed may not justify a complex pumping system. Furthermore, in remote areas, access to electricity or other man-made power sources may not always be readily available. Accordingly, there exists a need for inexpensive water pumps that are easy to construct and maintain, don&#39;t require access to man-made power sources, and can supply water in volumes needed for relatively small farms and other applications with relatively modest water demands. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention addresses the above need and is directed to a water pump that may be easily constructed from inexpensive parts and materials and that is powered by the water source from which the water to be pumped is drawn. In a preferred embodiment, two pairs of lever arms located on opposite sides of the pump are alternately filled with water from the source and emptied. A relatively small amount of water from the source is separately directed via a first pair of one-way valves to a pair of pistons. As the lever arms fill and empty, they ascend and descend, alternately filling and then compressing each piston. Compression of the pistons causes water to be pumped through a second pair of one-way valves to an outlet of the pump. Water from the emptied lever arms is preferably returned to the source, thus minimizing any impact of the pump on the environment and downstream users of the water source. 
         [0004]    The pump of the present invention provides many advantages, including that it is “self-bleeding” in that it prevents air from collecting in the pump which would reduce pumping efficiency. The structure of the pump of the present invention is preferably relatively “open” to minimize resistance against a flowing water source and minimize any tendency for the water source to push the pump downstream. The pump is also preferably of relatively modest height to minimize the amount of kinetic or potential energy in the water required to drive the pump, particularly where the energy for driving the pump is created by damming the water source since it may not be possible or desirable to increase the height of the dam to provide more energy. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  illustrates a preferred embodiment of the pump of the present invention; 
           [0006]      FIG. 2  illustrates aspects of the pump shown in  FIG. 1  viewed from the front with the pump&#39;s rotating assembly in a first position (rotated clockwise); 
           [0007]      FIG. 3  illustrates aspects of the pump shown in  FIG. 1  viewed from the front with the pump&#39;s rotating assembly in a second position (rotated counterclockwise); 
           [0008]      FIG. 4  illustrates aspects of the pump shown in  FIG. 1  viewed from the front with the pump&#39;s rotating assembly in the first position; 
           [0009]      FIG. 5  illustrates aspects of the pump shown in  FIG. 1  viewed from the front with the pump&#39;s rotating assembly in the second position; 
           [0010]      FIG. 6  illustrates aspects of the pump shown in  FIG. 1  viewed from above; 
           [0011]      FIG. 7  illustrates aspects of the pump shown in  FIG. 1  viewed from underneath; 
           [0012]      FIG. 8  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the brackets and rods that connect the lever arms to the pistons; 
           [0013]      FIG. 9  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the source pipe; 
           [0014]      FIG. 10  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the chamber; 
           [0015]      FIG. 11  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the valve tower; 
           [0016]      FIG. 12  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the valve tower in a partially disassembled state; and 
           [0017]      FIG. 13  illustrates aspects of the pump shown in  FIG. 1  in greater detail with a focus on the base. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    A preferred embodiment of a pump  100  constructed in accordance with the present invention is shown in  FIGS. 1-13 . In a preferred embodiment, pump  100  comprises a base  102 , which may preferably be constructed from concrete or another heavy material to provide a stable platform for the pump and prevent the pump from moving during operation. As shown in  FIG. 13 , bolts or other suitable hardware may be embedded in base  102  to facilitate affixing other components of pump  100  to base  102 . These include a fulcrum  104  that may be rotatably attached to base  102  by a block  106  and pin  108 . 
         [0019]    Pump  100  further preferably comprises a first pair of lever arms  110 , and a second pair of lever arms  112 , each attached to fulcrum  104 . It should be noted that although described herein as separate elements, each lever arm  110  and lever arm  112  may in practice be constructed from a single continuous piece of pipe separated into two parts by a seal or other separator within the pipe. 
         [0020]    Each pair of lever arms  110 , 112  is preferably respectively joined at its distal end by an end piece  114  comprising an outlet  116  through which water from lever arms  110 , 112  may exit the pump, as described in more detail below. In a preferred embodiment, lever arms  110 , 112  and/or end pieces  114  may be structured to include a concave bend or curve so that pump  100  may be more fully rotated during operation without having lever arms  110 , 112  or end pieces  114  contact the ground or surface of the water source. In this connection, it should be noted that the efficiency of pump  100  may decrease if the water level of the source rises sufficiently to cover outlets  116  in whole or in part during the phases of pump operation (described in more detail below) that outlets  116  discharge water back to the water source. 
         [0021]    Pump  100  further comprises a source pipe  118  adapted to receive water (or other liquid) from a stream or other source. Source pipe  118  preferably comprises two outlets, a first outlet  120  adapted to pass most of the water received via source pipe  118  to lever arms  110 , 112  via a partitioned waterbox  122 , and a second outlet  124  adapted to pass a relatively small proportion of the water received via source pipe  118  (which may preferably be approximately 5%) to a pipe  126 . Pipe  126  preferably extends through the top of a chamber  128  so that water flowing out the bottom of pipe  126  fills the chamber. Chamber  128  may preferably be provided with a filter  130  for trapping debris drawn into pump  100  from the water source. An inspection and cleaning port  132  is also provided to permit access to the inside of chamber  128  for cleaning filter  130 . Chamber  128  may further preferably be provided with a stopcock (not shown) near the bottom of the chamber to permit the chamber to be emptied. Periodic emptying of the chamber permits flushing of heavier detritus such as pebbles or sand that may collect and settle at the bottom of chamber  128 . 
         [0022]    Waterbox  122  is preferably affixed to lever arms  110 , 112  so that waterbox  122 , lever arms  110 , 112 , and fulcrum  104  collectively form a rotating assembly  134  adapted to rotate about pin  108 . Waterbox  122  is preferably positioned relative to source pipe  118  so that: (i) when rotating assembly  134  is rotated clockwise of center, water is directed from outlet  122  to the left side of waterbox  122  (when viewed from the front of the pump) and then into lever arms  110  through inlets  136 ; and (ii) when rotating assembly  134  is rotated counterclockwise of center, water is directed to the right side of waterbox  122  (when viewed from the front of the pump) and then into lever arms  112  through inlets  138 . 
         [0023]    Pump  100  further preferably comprises a pair of pistons  140  connected to lever arms  110 , 112  via brackets  142 , rods  144  and blocks  146 . In some embodiments, a pair of rings (not shown) may be positioned along each rod  144  on either side of bracket  142  for additional stability if required. Pistons  140  are preferably connected to base  102  by a block  148  and rod  150  to permit some rotation of piston  140  about rod  150  during operation of pump  100 . In a preferred embodiment, each piston  140  is located between one pair of lever arms  110 , 112  to avoid the creation of twisting forces which may cause unnecessary wear on pump  100 . In addition, in a preferred embodiment, pistons  140  are positioned relatively close to fulcrum  104  which helps prevent the pump stalling. 
         [0024]    Piston size may be adjusted as desired keeping in mind that decreasing piston diameter generates higher pressure (permitting water to be pumped higher or further) but decreases the volume of pumped water. Increasing piston size has the opposite effects. 
         [0025]    Each bracket  142  preferably comprises an upper portion  152  having formed therein an elongated slot  154  adapted to slidably hold rod  144 , and a lower portion  156  for attaching to piston  140 . Lower portion  156  preferably comprises an outlet  158  adapted to receive a hose (described below). Because of elongated slot  154 , rotation of assembly  134  from the fully clockwise-rotated or fully counterclockwise-rotated positions will not immediately apply any force to pistons  140 . Rather, initial rotation of assembly  134  causes rod  144  to slide up or down within slot  154  until it reaches the end of the slot. Only then, once some momentum has been built up in rotating assembly  134 , is force applied to pistons  140  to raise or lower the pistons. This feature of the preferred embodiment helps rotating assembly  134  to drive pistons  140 , which would be more difficult if rotating assembly  134  immediately engaged pistons  140  when first changing its direction of rotation. 
         [0026]    Pump  100  further comprises four one-way valves  160 - 166 . A first valve  160  is connected to chamber  128  via an elbow  168  and to a hose  170  via a T-junction  172  and is oriented to permit water flow only from chamber  128  to hose  170 . A second valve  162  is connected to hose  170  via T-junction  172  and to an outlet pipe  174  via a T-junction  176  and is oriented to permit water flow only from hose  170  to outlet pipe  174 . A third valve  164  is connected to chamber  128  via an elbow  178  and to a hose  180  via a T-junction  182  and is oriented to permit water flow only from chamber  128  to hose  180 . Finally, a fourth valve  166  is connected to hose  180  via T-junction  182  and to outlet pipe  174  via a T-junction  184  and is oriented to permit water flow only from hose  180  to outlet pipe  174 . 
         [0027]    In a preferred embodiment, valves  160 - 166  are attached to T-junctions  172 , 176 , 182 , 184  and elbows  168 , 178  by a friction fit to permit simple service and replacement. O-rings  186  may be provided to facilitate improved sealing at the friction fit junctions. 
         [0028]    In operation, source pipe  118  is preferably placed in contact with a source of water (or other liquid) such as a stream or lake via, for example, a pipe  188 . Water from the source preferably has either kinetic energy (e.g., from stream flow) or potential energy (e.g., from being located higher than the pump), or a combination of the two, which provides the energy used to drive pump  100 , as described in more detail below. Water pumped by pump  100  may preferably be delivered from outlet pipe  174  through a hose  190  to any desired location within the hose&#39;s reach to provide water for irrigation, drinking, or any other purpose. 
         [0029]    The preferred embodiment of pump  100  shown in  FIGS. 1-13  operates in two half-cycles and pumps water during each half-cycle. At the beginning of the first half-cycle, assembly  134  is rotated fully in the clockwise direction. Water entering source pipe  118  is directed from outlet  120  into the left part of waterbox  122  (viewed from the front of the pump) and then through inlets  136  into lever arms  110 . As the amount of weight in lever arms  110  increases, assembly  134  begins to rotate in a counterclockwise direction. At first, this rotation causes rods  144  to slide within slots  154  of brackets  142  without immediately applying any force to pistons  140 . As noted above, this facilitates operation of pump  100  because it permits rotating assembly  134  to build up some momentum before engaging pistons  140 . 
         [0030]    Once rods  144  reach the end of slots  154 , continued rotation of assembly  134  begins driving pistons  140 . In the first half-cycle, this causes the piston  140  on the right side of pump  100  (when viewed from the front) to rise, drawing water into the piston from chamber  128  through one-way valve  160  and hose  170 . Concurrently, the piston  140  on the left side of pump  100  (when viewed from the front) is compressed, pumping water out of the piston through hose  180 , one-way valve  166 , and outlet pipe  174 . 
         [0031]    Counterclockwise rotation of assembly  134  also causes lever arms  112  to rise and lever arms  110  to descend so that the water in lever arms  110  flows toward their distal ends and exits the pump through outlet  116 . In a preferred embodiment, water exiting the pump is delivered back into the river or other water source from which the water was taken. In an alternative preferred embodiment concrete basins may be positioned under outlets  116  to prevent water exiting the pump from eroding the stream bed. Water exiting the pump, lightens the weight of lever arms  110  and facilitates the next half-cycle of pump operation during which lever arms  110  rise, as described below. 
         [0032]    Turning now to the second half-cycle of pump operation, this half-cycle begins with assembly  134  rotated fully in the counterclockwise direction. Water entering source pipe  118  is directed into the right part of waterbox  122  (viewed from the front of the pump), and then through inlets  138  into lever arms  112 . As the amount of weight in lever arms  112  increases, assembly  134  begins to rotate in a clockwise direction. As above, this rotation causes rods  144  to slide within slots  154  of brackets  142  without immediately applying any force to pistons  140 . As noted above, this aids pump operation because it permits rotating assembly  134  to build up some momentum before engaging pistons  140 . 
         [0033]    Once rods  144  reach the end of slots  154 , continued rotation of assembly  134  begins driving pistons  140 . In this second half-cycle, this causes the piston  140  on the left side of pump  100  (when viewed from the front) to rise, drawing water into the piston from chamber  128 , through one-way valve  164  and hose  180 . Concurrently, the piston  140  on the right side of pump  100  (when viewed from the front) is compressed, pumping water out of the piston through hose  170 , one-way valve  162 , and outlet pipe  174 . 
         [0034]    Clockwise rotation of assembly  134  also causes lever arms  110  to rise and lever arms  112  to descend so that the water in lever arms  112  flows toward their distal ends, and exits the pump through outlet  116  preferably back into the river or other water source from which the water was taken. Alternatively, as described above, concrete basins may be positioned under outlets  116  to prevent water exiting the pump from eroding the stream bed. Water exiting the pump lightens the weight of lever arms  112  and facilitates the next half-cycle of pump operation during which lever arms  112  will rise, as described above. 
         [0035]    In a preferred embodiment, pump  100  further comprises an expansion chamber/bladder  192  to smooth out discontinuities in pump output caused by the fact that the pump operates in two distinct half-cycles and allow for a more steady continuous flow from the pump. An exemplary expansion chamber/bladder suitable for this purpose is a two gallon expansion tank available from Utilitech of Charlotte, N.C. Alternatively, a suitable expansion chamber/bladder  192  may be constructed using a chamber housing a bicycle tube that is adapted to form a sealed rubber bladder that can compress and expand as it is exposed to water output by pump  100  to absorb and smooth out the discontinuity in the pump output. If desired, the expansion chamber/bladder need not be affixed to pump  100  and may instead be located several feet away from the pump and connected to the pump by suitable length hoses. 
         [0036]    In a preferred embodiment, non-contaminating lubricants (e.g., Crisco) are used for any components of pump  100  requiring lubrication to avoid contamination of the water source and the water being pumped. 
         [0037]    It should be noted that although  FIGS. 1-13  illustrate a pump constructed using a specific set of materials, including concrete and PVC pipe, the pump of the present invention may in other preferred embodiments be constructed from other materials so long as their physical properties permit them to perform the functions set out above. For example, embodiments of the pump of the present invention could be created by rotomolding the pump elements described herein into two components, one comprising the left half of the pump and the other comprising the right half of the pump. The components may then be shipped to any desired destination where they may be assembled to create the pump of the present invention. 
         [0038]    In addition, although the preferred embodiment illustrated in  FIGS. 1-13  comprises two lever arms on each side of the pump, the pump could be modified to include one lever arm or more than two lever arms on each side. Furthermore, although the preferred embodiment illustrated in  FIGS. 1-13  comprises two pistons, one on each side of the pump, the pump could be modified to include a piston only on one side of the pump or to include more than one piston on one or both sides of the pump. In a preferred embodiment, where the pump is constructed with a single piston, a double action piston that pumps water on both half-cycles of operation may be used. 
         [0039]    It should further be noted that, although in the preferred embodiment shown in  FIGS. 1-13  a single water source is used to provide both the energy for driving the pump and the water to be pumped, construction of the pump of the present invention may be modified so that the pump comprises a first inlet connected to one water source (or other liquid) that is used to drive rotating assembly  134 , and a second inlet connected to a second water source (or other liquid) to provide the water (or other liquid) to be pumped. In this alternative embodiment, the first inlet may feed water to rotating assembly  134  and the second inlet may feed water to chamber  128 . 
         [0040]    More generally, although the present disclosure has been described in relation to particular embodiments, many other variations, modifications, and other use of the present invention will be apparent to those skilled in the art. Accordingly, the scope of the present invention should be limited not by the specific disclosure herein, but only by the appended claims.