Abstract:
An automatic solar powered flush valve by which sand or gravel may be quickly and efficiently flushed from piping associated with a center pivot irrigation system. The valve, when moved to an open position, provides a fully open port which enables rapid discharge water flow to flush sand and gravel from the piping in a very short time thus enabling the valve to be closed quickly in order to save irrigation water. The valve includes a movable ball valve combined with a rotatably driven eccentric which moves the ball to a closed position on a valve seat and permits the ball to move away from the valve seat when the eccentric is rotated to a position to permit such movement of the ball valve. The eccentric is driven by an electric motor powered by a battery charged by a solar panel and a timer controls the frequency and duration of each cycle of opening and closing of the valve.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to flush valves by which sand or gravel may be quickly and efficiently removed from piping associated with a center pivot irrigation system. Such flush valves, when moved to an open position, provide a fully open port which enables rapid discharge of water for flushing all sand and gravel from the irrigation piping in a very short period of time. 
     2. Description of the Prior Art 
     Center pivot irrigation systems are well known and include an elongated elevated water supply pipe rotatably connected at one end to a well and pump unit to supply pressurized water into the pipe. The pipe is supported by a plurality of spaced, ground engaging driven elements, such as wheels, which transport the pipe in a generally horizontal position around a circular path about a center pivot formed by the well and pump unit. A plurality of generally vertical spray pipes depend from the supply pipe, and nozzles at the lower ends of the spray pipes discharge irrigation water adjacent crop level. The elevated supply pipe usually includes a manually operated, elevated end valve which can be opened to enable sand or gravel to be flushed out of the elevated pipe when in open position. Depending upon the quantity of sand and gravel entrained in the irrigation water, the end valve is either left open continuously or manually opened periodically to flush sand and gravel out of the elevated pipe. 
     The following United States patents relate to various types of valve structures: 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
                 521,350 
                 1,538,404 
                 3,014,688 
               
               
                 582,911 
                 1,763,942 
                 4,314,592 
               
               
                 877,063 
                 2,066,112 
                 4,461,453 
               
               
                 995,903 
                 2,344,304 
                 4,535,813 
               
               
                 1,479,724 
                 2,366,693 
                 4,637,426 
               
               
                 1,496,317 
                 2,946,343 
                 5,109,887 
               
               
                   
               
             
          
         
       
     
     While the above patents disclose various types of ball valves, including cam operated ball valves, none disclose a flush valve especially suited for flushing sand and gravel from the piping associated with center pivot irrigation systems. These prior patents also do not disclose an automatic timer controlled, solar powered flush valve located at the lower end of a vertical pipe for connection to an outer end portion of a center pivot elevated irrigation water supply pipe. Further, the prior patents do not disclose a valve that provides a fully opened port and is cam operated between a closed and open position to enable rapid discharge of the water and any entrained sand or gravel which enables the valve to be left open only for a short time, thus saving irrigation water while still enabling sand and gravel to be efficiently flushed from the irrigation system. 
     SUMMARY OF THE INVENTION 
     The present invention is a timer controlled, solar energy powered, cam operated ball valve which can quickly and efficiently flush sand and gravel from an elevated center pivot irrigation water supply pipe when the ball valve is moved to open position and quickly terminate the discharge of flushing water when the valve is moved to closed position. The automatic ball valve of the present invention is preferably located vertically at the lower end of a down pipe which is connected at its top adjacent the outer end of the irrigation water supply pipe. 
     The ball valve of the present invention includes a vertical housing which is connected to the lower end of the down pipe preferably by screw threading or the like. The ball valve and ball valve seat are oriented so that gravity and water pressure in the irrigation system will bias the ball valve towards open position. A rotatably driven cam engages the ball valve in opposed relation to the force exerted by gravity and water pressure to retain the ball valve;closed. Rotation of the cam permits the ball valve to move downwardly to open position and upwardly to close position, all in response to an automatic timer control. The cam engaging the ball valve is driven by a solar power unit which includes an electric motor powered from a battery that is charged by an upwardly facing solar power panel. The solar power unit is preferably located in spaced relation to the discharge port for the valve. The discharge port has a cross-sectional area at least generally equal to the cross-sectional area of the down pipe to enable rapid flow of irrigation water out of the down pipe to efficiently and quickly flush sand and gravel from the irrigation system. 
     An object of the present invention is to provide an automatic solar powered flush valve for center pivot irrigation systems which is timer controlled. 
     A further object of the present invention is to provide a solar powered flush valve for center pivot irrigation systems which includes a rapidly opening and closing ball valve oriented below a downwardly facing ball valve seat with an operating cam engaging the ball valve for opening and closing the valve. 
     A still further object of the present invention is to provide an automatic flush valve for center pivot irrigation systems which is driven by an electric motor powered by a rechargeable battery that is recharged by an upwardly facing solar panel located adjacent the discharge port of the valve. 
     Another object of the present invention is to provide a flush valve for center pivot irrigation systems which is located at the lower end of a down pipe adjacent the outer end of the elevated supply pipe of the center pivot irrigation system. 
     Yet another object of the present invention is to provide a solar powered flush valve for center pivot irrigation systems which includes a sealed housing to assure maintenance free operation for extended time periods with the flush valve including a ball valve moved vertically in response to rotation of an eccentric powered by a gear motor with the motor being powered by a battery that is charged by a solar panel. 
     Still another object of the invention is to provide a flush valve for center pivot irrigation systems which is timer controlled with the valve open and valve closed time cycles being selected from a preset large number of available cycles. 
     A still further object of the present invention is to provide a solar powered flush valve which includes a vertical valve housing provided with a discharge port having a cross-sectional discharge area generally equal to the cross-sectional area of the down pipe supporting the valve and connected to the elevated water supply pipe of the center pivot irrigation system. 
     Yet another object of this invention to be specifically enumerated herein is to provide a solar powered flush valve for center pivot irrigation systems in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation. 
     These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic elevational view of a portion of a center pivot irrigation system illustrating the flush valve of the present invention installed at the lower end of a down pipe adjacent the outer end of an elevated water supply pipe. 
     FIG. 2 is a perspective view of the flush valve of the present invention with the outer guard member removed. 
     FIG. 3 is a side elevational view of the flush valve shown in FIG.  2 . 
     FIG. 4 is an end elevational view of the flush valve shown in FIGS. 2 and 3, illustrating the positions of the ball valve in broken lines. 
     FIG. 5 is a vertical sectional view taken along section line  5 — 5  on FIG. 4 illustrating specific structural details of the valve. 
     FIG. 6 is an elevational view of the timer control panel and flush cycle chart. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Although only one preferred embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the preferred embodiment, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     The flush valve of the present invention is generally designated by reference numeral  10 . As shown in FIG. 1, the flush valve  10  is supported at the lower end of a down pipe  12 . The upper end of the down pipe  12  is connected to an elevated irrigation water supply pipe  14  adjacent its outer end on the underside of the pipe  14  as at  15 . The irrigation pipe  14  generally extends horizontally and is supported by a plurality of depending drive units, generally designated by reference numeral  16 , with ground engaging wheels  17 . The drive units  16  move the elevated pipe  14  in a circular path about a center pivot (not shown) which includers a pump and well assembly with a vertical water supply pipe rotatably supporting the inner end of the elevated pipe  14  in a manner well known in this art. 
     The water supply pipe  14  is provided with a plurality of depending spray pipes  18  which have their upper ends  19  extending above the pipe  14 . The upper ends  19  are connected to the elevated pipe  14  along the upper surface of the pipe  14  as indicated by reference numeral  20  so that any sand or gravel in the water will not enter the spray pipes  18 . Thus, the sprinkler nozzles  22  at the lower ends of the spray pipes  18  will not become clogged with sand or gravel. If sand or gravel or other debris is present, it will accumulate along the lower surface of the interior of the generally horizontal pipe  14  to which the down pipe  12  is connected. The sprinkler nozzles  22  are oriented in a position above crops  24  but adjacent to the crops in order to reduce evaporation and reduce the possibility of winds causing the water to be discharged in an area that is not beneficial to the plants. An outermost spray pipe  26  may be provided with a pressure gauge  28  for observation to determine whether the irrigation system is properly operating. 
     The flush valve  10  includes a vertical inlet pipe  30  having an upper end which is preferably screw threaded externally at  32  for threaded connection with the down pipe  12 . The lower end of the inlet pipe  30  includes a circular flange  34  extending peripherally thereof which is mounted on flange  76  projecting laterally from a housing  38 . The flange  76  has a circular raised portion  36  on its upper surface which generally matches and mates with flange  34  on the inlet pipe  30 . Laterally extending flange  76  is preferable integral with the body of housing  38 , formed as a single structure, preferably of metal, such as aluminum or the like, and gussets  78  serve to reinforce the connection of the flange  76  to the housing  38 . 
     Attached to the side of the housing  38  below flange  76 , is an L-shaped bracket  43  having a bottom flange  42  generally parallel with and spaced from the flange  76  at the upper end of the housing  38 . The bracket  43  includes a vertical portion  44  secured to a side wall of the housing  38  as by welding, gluing or the like. 
     A plurality of vertically oriented cylindrical metal spacer rods  46  are positioned in a generally circular arrangement and extend between flanges  76  and  42 . Fastening cap bolts  40  extend through the flanges  34  and  76  and are screw threaded into the upper ends of the spacer rods  46 , as illustrated in FIG.  5 . The lower ends of the spacer rods  46  are secured to flange  42  by cap bolts  41  which are screw threaded into the bottom end of the rods  46 . The upper end portion of each spacer rod  46  is provided with a sleeve  48  having a smooth outer surface, preferably a suitable plastic material, which has a lower end abutting a shoulder  49  on spacer rods  46 . 
     A spherical ball valve  50  is positioned within the spacer rods  46  and engages the surfaces of the sleeves  48  on the upper end portions of the spacer rods  46 . There are preferably three spacer rods  46  which are arranged in an equally spaced relationship at about  1200  apart to form a cage for controlling the vertical movement of ball valve  50  in a direction toward and away from an O-ring valve seat  52  received in recess  53  in flange  36 . The valve seat  52  is clamped between the flanges  34  and  76  and is exposed to the interior of the passageway  33  through the inlet pipe  30  and flanges  34  and  76 . The diameter of the valve seat is preferably sized to receive a substantial portion of the periphery of the ball valve  50  when in its closed position as illustrated by broken line in FIG.  3 . The ball valve  50  is preferably constructed of a hard plastic or elastomeric material although it could be metal such as stainless steel or the like. The surfaces of the ball valve  50  are prevented from being marred by contact with the metal spacer rods  46  inasmuch as during vertical movement of the ball valve  50 , it is always in contact with the plastic sleeves  48  on the spacer rods  46 . 
     Positioned below the ball valve  50  is a cam structure or eccentric generally designated by reference numeral  54 . The cam structure  54  is in the form of a cylindrical member  55 , preferably of a plastic or elastomeric material, mounted on a cylindrical member  56 , preferably of metal. The cylindrical member  56  is rotatably supported and driven by a shaft  57  oriented in eccentric relation to the center of the cylindrical members  55  and  56  so that rotation of the cylindrical members  55  and  56  by the shaft  57  causes the cylindrical members  55  and  56  to move in an eccentric path about shaft  57 . The eccentric path of cylindrical members  55  and  56  causes the cam structure  54  to move the ball valve  50  between open and closed positions as illustrated in FIGS. 3-5. The position of the cam structure  54  when the ball valve  50  is in closed position is illustrated in broken lines in FIGS. 3 and 4 and when the valve  50  is in the open position, in solid lines in FIGS. 4 and 5. 
     The shaft  57  has an outer end journalled in a bore  66  extending through the spacer rod  46  which is positioned in remote relation to the housing  38  with the bore  66  preferably including a suitable sleeve-type bearing or bushing  67  to support the outer end of the shaft  57 . A cylindrical spacer  68  is journalled on the shaft  57  and positioned between the axial surface of the eccentrically rotating cylindrical members  55  and  56  and the interior surface of the spacer rod  46 . The spacer  68  positions the cam structure  54  in properly oriented relation so that the radial surface of the cam structure  54  is correctly aligned with the peripheral surface of the ball valve  50 . The portion of the shaft  57  inwardly of the cam structure  54  is also provided with a spacer  70  which extends between the axial surface of the cam structure  54  and the surface of the flange or bracket  44  secured to the housing  38 . The spacer  70  thus maintains the cam structure  54  properly  11  oriented and shields the shaft  57  where it extends through the bracket  44  and into the housing  38 . 
     As illustrated in FIGS. 3-5, the ball valve  50  is oriented for movement within the interior of the sleeves  48  on the three spacer rods  46  so that the ball valve  50  will engage the O-ring valve seat  52  when in its elevated, broken line, closed position. The ball valve  50  loosely engages the sleeves  48  on the upper end portions of the spacer rods  46  when in its closed or elevated position as shown in dotted lines in FIGS. 4 and 5 and when in its open or lowered position illustrated in solid line in FIGS. 3-5. The cam structure  54  and ball valve  50  may be constructed of stainless steel or hard plastic material and the spacers  68  and  70  may be constructed of the same material as the eccentrically rotating cylindrical member  55 . 
     A perforated rigid guard  72 , preferably made of metal, surrounds the spacer rods  46 , cam structure  54  and ball valve  50 , as shown in FIG.  2 . The guard  12  protects the valve mechanism from damage and also prevents unauthorized access to the cam structure  54  and ball valve  50  thus avoiding possible injury to a person or animal engaging an appendage between the moving cam structure  54  and ball valve  50 . The guard  72  includes a plurality of large openings  74  and its top is spaced approximately one inch below the flange  76  in order to permit free flow of water, sand and gravel outwardly from beneath the flange  76  when the valve is opened. The guard is generally U-shaped in configuration and of rigid construction with free side edges abuttingly engaging the outer surface of the bracket vertical portion  44  while surrounding the spacer rods  46  and cam mechanism  54 . The guard rests on the upper surface of the flange  42 , and a short threaded cap bolt  73  secures the central outer portion of the guard  72  to the spacer rod  46  which supports the outer end of the shaft  57 . The cap bolt  73  enables removal of the guard  72  when necessary or desired to clean the valve  50  and cam structure  54  or replace the components of the valve and cam structure. 
     As illustrated schematically in FIGS. 3 and 5, the shaft  57  extends into the interior of the housing  38  and is driven by a reversible electric motor  59  that is battery powered by a battery  58 . The motor  59  is timer controlled by a timer  60 , and the battery  58  is recharged by a solar panel  62  to provide electrical energy to the motor  59 . 
     As illustrated in FIG. 6, the timer  60  includes a control panel  80  secured to housing  38  by fasteners  81  to provide access to the interior of the housing. The panel  80  includes a timer cycle chart  82  preferably printed on or painted on one end area thereof, a three position selector switch  84  mounted at the other end area thereof and a rotary valve timer switch  86  mounted in a central area thereof. 
     The selector switch  84  includes an “off” position, a “timer A” position and “timer B” position which correlates to the “timer A” columns  88  on chart  82  and the “timer B” columns  90  on chart  82 . The valve timer switch  86  includes positions “A”-“O” and “test” which correlate with the “switch position” column  92  on chart  82 . The control panel  8 d also includes an area  94  for instruction indicia and an area  96  for identification indicia. The switches  84  and  86  enable the valve  10  to be closed for a relatively long period of time and opened for a relatively short period of time during which the water, sand, gravel and other debris are flushed from the elevated supply pipe  14 . For example, the closed cycle could be set for one to forty-eight hours and the open cycle for one to thirty minutes. By setting switch  84  in position “timer A”, the valve timer switch  86  can be set in any position “A”-“O” to set the “off” (valve closed) time and the “on” (valve open) time in a cycle of operation to effectively flush sand and gravel from the center pivot irrigation system in a period of time that can be adjusted to be as short as possible depending upon the requirements in each installation. This enables the use of a minimum quantity of irrigation water to be used in flushing the irrigation system. One of the positions for the valve timer switch  86  is “test”, thus providing different test cycles when switch  84  is in “timer A” or “timer B” position. By having a multitude of different time cycles, the operator is provided with the capability of selecting the appropriate timer cycle for flushing the sand and gravel from the supply pipe of the center pivot irrigation system on which the valve is installed. 
     In operation, the flush valve  10  of the present invention is installed on the lower end of a down pipe  12  which is connected at its upper end to the elevated generally horizontally extending irrigation water supply pipe  14 . When assembled on the down pipe  12 , the solar panel  62  of the valve  10  faces upwardly towards the sun for capturing the solar energy to power the valve unit. The operator then selects the desired timer cycle by positioning the valve timer switch  86  and selector switch  84 , and the valve  10  is then in operation. If desired, a “test” cycle can be initiated first by positioning switch  86  in “test” position and switch  84  in “timer A” or “timer B” position. 
     As the center pivot irrigation system operates with water supplied through the irrigation water supply pipe  14  to the depending spray pipes  18 , the timer periodically causes the battery  58  to energize motor  59  to rotate shaft  57  and cam structure  54  which allows ball valve  50  to move away from the O-ring valve seat  52  to an open position, where the cam structure  54  and ball valve  50  remain for a preselected time in accordance with the selected timer cycle. Upon opening of the ball valve  50 , the water in down pipe  12  and supply pipe  14  are caused to exit the valve  10  and carry with it the sand, gravel and other debris which may have collected along the interior bottom surface of the supply pipe  14  while the valve  10  was in the closed position. Upon completion of the flushing cycle, the motor  59  is energized and the shaft  57  and cam structure  54  continue rotation in the same direction which causes the ball valve  50  to move back up into seated engagement with the O-ring valve seat  52 . This closes the valve and prevents further water from exiting the down pipe  12  for a predetermined time in accordance with the selected timer cycle. In the event the cam structure or ball valve becomes stuck or jammed because of debris or for any other reason, the motor  59  will be driven in reverse direction by a microprocessor in an effort to flush out or dislodge the debris. Operation of the motor can be automatically stopped if the cam structure or ball valve become jammed such that they cannot move in either direction. 
     The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.