Abstract:
The present invention addresses the need for a water pump that may be constructed from inexpensive materials available even in impoverished areas. The pump uses a simple rocking motion to pump water and can pump significant amounts of water from sources that otherwise could not be reached. In a preferred embodiment, the pump comprises three concrete chambers, a pumping platform adapted to rock in a see-saw fashion, and a plurality of valves to control the flow of water. The first two chambers contain diaphragms that, as a result of rocking the pumping platform, draw liquid into the chambers and force liquid from those chambers into the third chamber. Two valves selectively permit liquid to be drawn into the first and second chambers, and prevent the liquid from exiting the chambers and returning to the source. Third and fourth valves allow liquid to flow from the first and second chambers into the third chamber, and prevent the liquid in the third chamber from flowing back into the first or second chambers.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to the field of pumps and, more specifically, is directed to a water pump that is easy to construct and may be built from inexpensive and commonly available materials. 
     BACKGROUND OF THE INVENTION 
     Farmers in developing nations and other impoverished areas often lack the financial resources to invest in technologies that simplify the farming process and make it more profitable. In particular, many such farmers do not have access to inexpensive yet effective irrigation and water pumping technologies. 
     One pump intended to address this issue is a foot-powered pump called the MoneyMaker manufactured by KickStart Technologies. This pump, however, requires users to employ a relatively taxing “step climber” motion to pump water in which the user stands and alternately presses down on a pair of pedals. Additionally, because the pump is made primarily of machined metal parts, it is relatively expensive and cannot be manufactured by farmers themselves. Also, since the pump is not manufactured from parts that are easily replicable or available to farmers, it is relatively difficult and expensive to repair the pump in the event of a malfunction or to replace worn out parts. 
     Accordingly, there continues to exist a need for an inexpensive water pump that is easy to construct form materials commonly available even in impoverished areas of the world. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the above need and provides an easy to construct water pump that may be constructed from inexpensive materials available even in impoverished areas. The pump uses a simple rocking motion to draw and pump water that can be performed by almost any person from child to senior and can pump significant amounts of water per unit time from a given source. It can also make water available from sources that otherwise could not be reached because, e.g., of their depth below the ground surface. 
     In a preferred embodiment, the pump comprises three concrete chambers, a pumping platform adapted to rock in a see-saw fashion, and a plurality of valves to control the flow of water. The first two chambers contain diaphragms that, as a result of rocking the pumping platform, draw liquid into the chambers and force liquid from those chambers into the third chamber. Two valves selectively permit liquid to be drawn into the first and second chambers, and prevent the liquid from exiting the chambers and returning to the source. Third and fourth valves allow liquid to flow from the first and second chambers into the third chamber, and prevent the liquid in the third chamber from flowing back into the first or second chambers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one preferred embodiment of the present invention; 
         FIG. 2  is a top plan view of the preferred embodiment of  FIG. 1  with the platform, upper cylinders, diaphragms and disks removed; 
         FIG. 3  is a top plan view of the preferred embodiment of  FIG. 1 ; 
         FIG. 4  is a front elevation view of the preferred embodiment of  FIG. 1 ; 
         FIG. 5  is a top plan view of the preferred embodiment of  FIG. 1  with the platform and upper cylinders removed; 
         FIG. 6  is a top plan view of a second preferred embodiment of the present invention; 
         FIG. 7  is a front elevation view of the preferred embodiment of  FIG. 6 ; 
         FIG. 8  is an exploded perspective view showing a preferred embodiment of the components of the first two pump chambers of the present invention; 
         FIG. 9  is an exploded perspective view showing a preferred embodiment of the components of the third pump chamber of the present invention; 
         FIG. 10  is a perspective view of a third preferred embodiment of the present invention; and 
         FIG. 11  is a second perspective view of the third preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A preferred embodiment of a pump constructed in accordance with the present invention is shown in  FIGS. 1-5  and  8 - 9 . As shown in  FIG. 1 , a pump  100  comprises a base  102  having a generally three-sided footprint. As best seen in  FIG. 2 , base  102  has formed therein a plurality of cavities  202 - 206 . Cavities  202 - 204  may have a depth of approximately 1 inch, and a diameter of approximately 5.25 inches at the top of each cavity and tapering to approximately 5 inches at the bottom of each cavity. Cavity  206  may have a depth of approximately 0.25 inches, and a diameter of approximately 5.25 inches at the top of the cavity and tapering to approximately 5 inches at the bottom of the cavity. The height of base  102  may be approximately 2.5 inches. 
     The floor of each cavity  202 - 206  comprises two openings ( 208 - 210  in cavity  202 ;  212 - 214  in cavity  204 ; and  216 - 218  in cavity  206 ) each of which connects to a channel formed within base  102  and lined with PVC pipe, as described in more detail below. The shoulders of cavities  202 - 206  have embedded therein a plurality of securing bolts  220  with their threaded ends extending upward. 
     Returning to  FIG. 1 , pump  100  further comprises a plurality of cylinders  106 - 110  securely fastened to the concrete base  102  by securing bolts  220  by washers and nuts. A diaphragm assembly  112  is secured between concrete base  102  and cylinders  106 - 108 , as described in more detail below. The overall length of bolts  220  may be approximately 3.5 inches for embodiments where the cylinders are concrete and approximately 1.5 inches for embodiments where the cylinders are made of PVC as in the embodiment shown in  FIGS. 10-11  below. The bolt size or diameter of bolts  220  may be approximately ¼ inches or 6 millimeters. 
     Pump  100  further comprises a pumping platform  114  having a pivot  116  adapted to engage a depression in a fulcrum  104 . Pumping platform  114  is connected to diaphragm assemblies  112  by driving rods  118 - 120  secured by washers and nuts. Driving rods  118 - 120  may be bolts having a length of approximately 10-11 inches and a bolt size or diameter of approximately ⅜ inches or 10 millimeters. A handle  130  attached to the base  102  by a bracket  132  may be provided to help a user maintain his or her balance while standing on the pumping platform. 
     Also shown in  FIG. 1 , are hoses  122 ,  124 . A first end of hose  122  is preferably placed in contact with a source of water (or other liquid) to be pumped such as a stream, well, or lake (not shown). The second end of hose  122  attaches to an inlet  126  in concrete base  102 . 
     Hose  124  is attached at one end to an outlet  128  in the top of cylinder  110 . Water (or other liquid) pumped by pump  100  is delivered to hose  124  via outlet  128  and may then be further carried through hose  124  to any desired location within the hose&#39;s reach to provide water for drinking, irrigation, or any other purpose. 
     As noted, a plurality of channels that connect to openings  208 - 218  of cavities  202 - 206  are formed in base  102 . More specifically, as best shown in  FIG. 2 , a first channel  222  formed in base  102  connects inlet  126  to opening  208  of cavity  202  and opening  212  of cavity  204 . In an alternative preferred embodiment best shown in  FIG. 10 , inlet  126  may be located along the flat side of base  102  between cavities  202 ,  204 . In this alternative preferred embodiment, channel  222  is preferably formed in a “T”-shape with the “vertical” stroke of the “T” extending from the inlet to a point between cavities  202 ,  204  under fulcrum  104 , and the “horizontal” stroke of the “T” extending into cavity  202  at one end and cavity  204  at the other end. 
     A second channel  224  connects opening  210  of cavity  202  to opening  218  of cavity  206 . A third channel  226 , connects opening  214  of cavity  204  to opening  216  of cavity  206 . Each channel may be lined with PVC pipe or other suitable pipe material. The PVC or other pipe may have a diameter of approximately 1¼ inches. The height of the foundation of base  102  is preferably sufficient to permit the pipe that lines channels  222 - 226  to be fully embedded within base  102  so as to avoid the potential for puncturing or other damage to the pipe. 
     As further shown in  FIG. 2 , cavities  202 - 206  are provided with respective valve assemblies  228 - 232 . Valve assemblies  228 ,  230  are the same in structure and operation and will be described jointly. In particular, each of valve assemblies  228 ,  230  comprises a half-circle rubber flap  234  secured to the floor of its respective cavity  202 ,  204  by bolts  236  embedded in base  102  and running through holes in rubber flap  234 , and fastened respectively by a washer and nut. Rubber flaps  234  are positioned so as to respectively cover openings  208 ,  212  of cavities  202 ,  204 . 
     By contrast, valve assembly  232  comprises a full-circle rubber flap  238  secured to the floor of its respective cavity  206  by bolts  240  embedded in base  102  and running through holes in rubber flap  238 , and fastened respectively by a washer and nut. Rubber flap  238  is positioned so that a first portion of the flap covers opening  216  of cavity  206 , and a second portion of the flap covers opening  218  of cavity  206 . 
       FIG. 8  is an exploded view illustrating components of diaphragm assembly  112  secured between cylinders  106 - 108  and the shoulders of cavities  202 - 206 . As shown in  FIG. 8 , each diaphragm assembly  112  comprises a first metal disk  502 , a rubber diaphragm  504 , and a second metal disk  506 . Rubber diaphragm  504  may be a round piece of rubber with a center hole and a plurality of perimeter holes spaced so as to interact with securing bolts  220 . Metal disks  502 ,  506  may also be round and have a diameter smaller than the inner diameter of cavities  202 ,  204 . Each is also provided with a center hole. Rubber diaphragm  504  is held between metal disks  502 ,  506  by a driving rod  118 ,  120  fastened with a washer and nut. 
     Each diaphragm assembly  112  also comprises a seal  512  and preferably two such seals. Each seal  512  may be a round ring of rubber having a width approximately the same as that of the shoulders of cavities  202 ,  204  and a plurality of perimeter holes spaced so as to interact with securing bolts  220 . When assembled, securing bolts  220  pass through seals  512 , rubber diaphragm  504 , and a cylinder  106 ,  108  and fastened with washers and nuts. 
       FIG. 9  is an exploded view illustrating the manner in which cylinder  110  is secured to the shoulder of cavity  206 . As shown in  FIG. 9 , at least one and preferably two seals  512  are secured between cylinder  110  and the shoulder of cavity  206  by securing bolts  220 , washers and nuts. 
     In operation, a user stands on platform  114  and rocks from side to side causing driving rods  118 ,  120  to alternately raise and lower diaphragm assemblies  112  in cavities  202 ,  204 . During the period that driving rod  118  is raising the diaphragm assembly of cavity  202 , a vacuum is created within the cavity beneath the diaphragm thus causing water to be drawn through inlet  126  and channel  222 . This causes the flap of valve assembly  234  to lift permitting the drawn water into the cavity. 
     While driving rod  118  is being raised, driving rod  120  is simultaneously being lowered, thus depressing diaphragm assembly  112  of cavity  204 . During the period that diaphragm assembly  112  is being lowered by driving rod  120 , valve assembly  234  is forced closed and seals opening  212 , and water in the cavity is forced through channel  226 . Pressure from this water causes one flap of valve assembly  238  to open, exposing opening  216  and forcing water from channel  226  into cavity  206 . 
     Conversely, during the period that driving rod  120  is raising diaphragm assembly  112  of cavity  204 , a vacuum is created within the cavity beneath the diaphragm thus causing water to be drawn through inlet  126  and channel  222 . The pressure from this water flow lifts the flap of valve assembly  234  permitting the drawn water into cavity  204 . 
     While driving rod  120  is being raised, driving rod  118  is simultaneously lowered, thus depressing diaphragm assembly  112  of cavity  202 . During the period that diaphragm assembly  112  is being lowered by driving rod  118 , valve assembly  234  is forced closed and seals opening  208 , and water in the cavity is forced through channel  224 . Pressure from this water causes a flap of valve assembly  238  to open, exposing opening  218  and forcing water from channel  224  into cavity  206 . 
     As the process continues and more water is forced into cavity  206  than it can hold, the water collecting in cavity  206  is forced out the top of cylinder  110  through outlet  128  and into hose  124 . As will be recognized, water may not exit through outlet  140  immediately when the user begins rocking on platform  118  because it may take several cycles of operation to prime the pump and draw enough water to fill cavity  206 . 
     In a preferred embodiment, pump  100  is constructed completely or as completely as possible from easily available materials and does not require any machining or metal working in its construction. In particular, base  102  of pump  100  may be formed of molded concrete. Channels  222 - 226  may be created by placing PVC pipe of an appropriate diameter within the mold. The pipe is preferably secured while the concrete is set because it will otherwise float to the surface of the concrete during setting. In one preferred embodiment, the pipe may be secured by placing a wooden frame on top of the mold with wood screws pointing down out of the bottom of the frame and positioned to hold down the pipe while the concrete is setting. Bolts  220 ,  236 ,  240  are also secured within the mold such that they will be embedded in base  102  when the concrete poured into the mold hardens. In an alternative embodiment, the base of the pump may be formed from PVC or other suitable material, as shown in  FIGS. 10-11 . 
     Cylinders  106 - 110  may similarly be created from molded concrete using an appropriate mold. Hollow rods may be placed in the mold to form the passages through the cylinders through which securing bolts  220  and driving rods  118 ,  120  will pass. Alternatively, cylinders  106 - 110  may be formed of PVC material, as shown in  FIGS. 10-11 . 
     It should be noted that although  FIGS. 1-9  illustrate a pump constructed using a concrete base and concrete cylinders and  FIGS. 10-11  illustrate a pump constructed using a PVC base and PVC cylinders, the pump of the present invention may in a preferred embodiment be constructed from mixed materials, e.g., using a concrete base such as shown in  FIGS. 1-9 , and PVC cylinders, such as shown in  FIGS. 10-11 . Furthermore, although illustrated as having cylinder like shape in the preferred embodiments of  FIGS. 1-9  and having a cylinder like shape with a flat rim in the embodiment shown in  FIGS. 10-11 , components  106 - 110  may be formed in other shapes if desired. 
     Diaphragm  504 , seals  512 , and valve flaps  234 ,  238  may all be constructed from rubber material and preferably from the inner tubes of tires, a commonly available source of rubber in many underdeveloped areas of the world. PVC pipe and the various bolts, washers, nuts, rectangular brackets, and circular disks used to construct pump  100  are all common hardware items typically available even in underdeveloped areas. Platform  114  may be constructed from any type of available wood. 
     An alternative embodiment of the present invention is shown in  FIGS. 6-7  in which the base  1102  is generally rectangular in shape and chambers  1104 - 1108  are oriented generally in a straight line. In this alternative embodiment, chamber  1104  performs the role of chamber  202  of  FIG. 2  and is provided with an appropriate valve assembly  234  and diaphragm assembly  112 . Chamber  1106  performs the role of chamber  204  of  FIG. 2  and is provided with an appropriate valve assembly  234  and diaphragm assembly  112 . Chamber  1108  performs the role of chamber  206  of  FIG. 2  and is provided with an appropriate valve  238  and seal  512 . 
     As shown in  FIG. 6 , in this alternative embodiment, chambers  1104 - 1108  are connected via channels formed in base  1102  analogous to those described above in connection with the embodiment of  FIG. 2 . As above, each channel may be lined with PVC pipe or other suitable pipe material. 
     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.