Abstract:
An anchoring device for a self-propelled irrigation system includes a screw pile and drive assembly that drives the screw pile into the ground to anchor a drive tower of the irrigation system to the ground. The screw pile is rotatably driven about a vertical axis and movable vertically relative to the drive tower. The drive assembly can include an electric motor with a suitable gear reduction that causes the screw pile to be rotated slowly with a large amount of torque. The drive assembly can be mounted stationary to the drive tower, or it can be mounted on tracks so as to move vertically together with the screw pile. A low voltage electrical system with one or more batteries can be used to power the electric motor. A solar battery charger or other charging system can be used to maintain an electrical charge in the batteries. A controller is provided to activate the drive assembly when adverse weather conditions are detected, or upon receiving a remote command from the operator.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/888,590 filed on Oct. 9, 2013, and U.S. Provisional Patent Application No. 62/046,780 filed on Sep. 5, 2014. The entire contents of these priority applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to self-propelled irrigation systems, and in particular, to methods and devices for preventing self-propelled irrigation systems from overturning in high wind situations. 
         [0004]    2. Description of the Related Art 
         [0005]    Self-propelled irrigation systems are used to provide water for agricultural purposes in arid regions. Typically, such systems include a series of spaced drive towers connected by truss sections that support an elongated water distribution pipeline between the towers. In center pivot systems, the water distribution pipe extends radially from a central pivot connected to a water supply. In linear move irrigation systems, the water distribution pipe extends laterally from a canal feed or hose drag system that provides the water supply. 
         [0006]    Water passing through the distribution pipeline is forced out through a number of sprinkler heads, spray guns, drop nozzles, or the like spaced along the length of the pipe. Each drive tower in the system is supported on wheels or other structures that are driven at slow speeds to move the tower in a circular path about the central pivot, or a linear path in the case of linear move systems, to irrigate an agricultural field. 
         [0007]    Such irrigation systems are prone to being damaged during severe weather by high winds that cause one or more towers of the irrigation system to overturn. When a tower overturns, major damage to the pipeline, truss sections, and other components typically occurs, resulting in significant downtime and expense. 
         [0008]    Screw piles are known in the prior art and are used, for example, in ground anchoring systems for building foundations. Screw piles can be wound into the ground much like a screw into wood. Screw piles are sometimes referred to as screw-in foundations, screw piers, helical piles, helical anchors, screw anchors, screw foundations and helical piers. 
         [0009]    A need exists in the agricultural industry for a system that prevents sprinkler systems from overturning and becoming damaged during windstorms. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the present invention is to provide an anchoring device for preventing a self-propelled irrigation system from overturning in high winds. 
         [0011]    A further object of the present invention is to provide a self-propelled irrigation system that resists overturning in high winds. 
         [0012]    A further object of the present invention is to provide an anchoring device for use on a self-propelled irrigation system that uses a screw pile and a drive motor mounted on the irrigation system to anchor the irrigation system to the ground during high wind conditions. 
         [0013]    A still further object of the present invention is to provide an anchoring device for a self-propelled irrigation system with a control system to automatically activate the anchoring device upon detecting a wind speed exceeding a predetermined threshold speed. 
         [0014]    A still further object of the present invention is to provide an anchoring device that can be adapted to and used on a variety of different brands and types of self-propelled irrigation systems. 
         [0015]    To accomplish these and other objects of the present invention, an anchoring device for a self-propelled irrigation system is provided. The anchoring device includes a screw pile and a drive assembly that drives the screw pile into the ground to anchor a drive tower of the irrigation system to the ground. The screw pile is rotatably driven about a vertical axis and movable vertically relative to the drive tower. The drive assembly can include an electric motor with a suitable gear reduction that causes the screw pile to be rotated slowly with a large amount of torque. The drive assembly can be mounted stationary to the drive tower, or it can be mounted on tracks so as to move vertically together with the screw pile. A low voltage electrical system with one or more batteries can be used to power the electric motor. A solar battery charger or other charging system can be used to maintain an electrical charge in the batteries. A controller is provided to activate the drive assembly when adverse weather conditions are detected, or upon receiving a remote command from the operator. 
         [0016]    According to one aspect of the present invention, an anchoring device for a self-propelled irrigation system is provided, comprising: a screw pile supported on the irrigation system and arranged to be raised and lowered relative to the irrigation system; and a drive motor arranged to rotate the screw pile to wind the screw pile into the ground to anchor the irrigation system to prevent overturning during severe weather. 
         [0017]    According to another aspect of the present invention, a self-propelled irrigation system that resists overturning in high winds is provided, comprising: an elongated pipeline supported above a field by at least one drive tower, the drive tower comprising a base beam assembly, a tower structure supported by and extending above the base beam assembly for supporting the elongated water pipeline above the base beam assembly, and a plurality of drive assemblies for supporting and propelling the base beam assembly over a field; and an anchoring device for anchoring the drive tower to the ground. The anchoring device comprises: a screw pile supported on the drive tower and arranged to be raised and lowered relative to the irrigation system; and a drive motor arranged to rotate the screw pile to wind the screw pile into the ground to anchor the irrigation system to the ground to prevent overturning during severe weather. 
         [0018]    Numerous other objects of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described an embodiment of the present invention, simply by way of illustration of one of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The present invention will become more clearly appreciated as the disclosure of the present invention is made with reference to the accompanying drawings. In the drawings: 
           [0020]      FIG. 1  is a perspective view of a center pivot-type self-propelled irrigation system equipped with anchoring devices according to the present invention. 
           [0021]      FIG. 2  is a detail perspective view of the area D 2  shown in  FIG. 1 . 
           [0022]      FIG. 3  is a perspective view of an anchoring device for self-propelled irrigation systems according to the present invention. 
           [0023]      FIG. 4  is an elevation view of a screw pile used in the anchoring device. 
           [0024]      FIG. 5  is a detail view of a lower portion of the screw pile shown in  FIG. 4 . 
           [0025]      FIG. 6  is a perspective view of a pile engaging and guiding member used in the anchoring device. 
           [0026]      FIG. 7  is a top plan view of the pile engaging and guiding member shown in  FIG. 6 . 
           [0027]      FIG. 8  is a perspective view of a center pivot-type self-propelled irrigation system equipped with anchoring devices according to another embodiment of the present invention. 
           [0028]      FIG. 9  is a detail perspective view of the area D 9  shown in  FIG. 8 . 
           [0029]      FIG. 10  is a perspective view of a screw pile driving system in which the drive motor is mounted stationary relative to the irrigation system. 
           [0030]      FIG. 11  is a perspective view of another screw pile driving system that allows the drive motor to be mounted stationary relative to the irrigation system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    A self-propelled irrigation system  10  equipped with anchoring devices  20  according to the present invention will now be described with reference to  FIGS. 1 to 11  of the accompanying drawings. 
         [0032]    The self-propelled irrigation system  10  includes a center pivot structure  11 , an elongated water pipeline  12 , and a plurality of drive towers  13  for supporting the water pipeline  12  above a field. The drive towers  13  and water pipeline  12  are arranged to move around the center pivot structure  11 , which remains at a fixed location. However, it should be appreciated that the present invention can also be used with other types of self-propelled irrigation systems, such as lateral move irrigation systems and corner pivot irrigation systems, which are well known in the art. 
         [0033]    The drive towers  13  each include a frame assembly comprising a base beam  14  and a tower structure  15  that extends upwardly from opposite ends  16 ,  17  of the base beam  14 . The water pipeline  12  is supported by the tower structure  15  above the base beam  14  in a conventional fashion. First and second drive assemblies  18 ,  19  are mounted to respective ends  16 ,  17  of the base beam  14  for supporting and propelling the frame assembly over a field. For example, each drive assembly  18 ,  19  may comprise a gear box and a hub and wheel assembly. An electric motor or hydraulic drive is typically used to provide power to the drive assemblies  18 ,  19 . 
         [0034]    In the illustrated embodiment, the wheel assemblies  18 ,  19  positioned at each end of the base beam  14  are sufficiently far apart to provide a stable support for the system during normal weather conditions. However, in high wind conditions, the drive tower  13  will tend to tip about the wheel assembly  18 ,  19  on the downwind side of the system  10 . The present invention provides a solution to the overturning tendency by using a powered anchoring device  20  to anchor the drive tower  13  to the ground. 
         [0035]    The anchoring device  20  includes a screw pile  21  supported on the drive tower  13  and arranged to be raised and lowered relative to the drive tower  13 . A drive motor  22  is provided to rotate the screw pile  21  in a first direction to wind the screw pile  21  into the ground to anchor the drive tower  13  to the ground. The drive motor  22  will also rotate the screw pile  21  in a second direction to unwind the screw pile  21  to retract the screw pile  21  from the ground after the high wind conditions subside. 
         [0036]    In the embodiment shown in  FIGS. 1 to 7 , a slide mounting assembly  23  is used to mount the screw pile  21  and drive motor  22  to the drive tower  13 . The mounting assembly  23  has a lower end  24  connected to the base beam  14  and an upper end  25  connected to a support member  26  attached to the tower structure  13 . For example, the support member  26  may comprise a length of angle iron extending between the upright support structures  15  of the drive tower  13 . 
         [0037]    The mounting assembly  23  has a pair of vertically extending tracks  27  that extend between the base beam  14  and the support member  26  to support the drive motor  22  while allowing vertical movement thereof relative to the drive tower  13 . A follower member  28  protrudes from opposite sides of the drive motor  22  and is guided for vertical movement by the vertically extending tracks  27  as the drive motor  22  is raised and lowered relative to the drive tower  13 . The following member  28  can be, for example, a length of angle iron that spans between the tracks  27  with flat ends  28 A that protrude outwardly through the tracks  27 . A pin  28 B or other suitable structure can be provided in each of the flat ends  28 A of the following member  28  to keep the flat ends  28 A of the following member  28  within the tracks  27 . The following member  28  can also be provided with inner shoulders  28 C near its outer ends that engage inner sides of the tracks  27  to limit the amount of side-to-side movement of the following member  28  between the tracks  27 . 
         [0038]    The mounting assembly  23  also includes a pile engaging member  29  that engages and guides the screw pile  21  and restricts movement of the screw pile  21  in a vertical direction relative to the base beam  14  of the drive tower  13 . The pile engaging member  29  includes a lower bracket  30  attached to the base beam  14  with a hole through which the screw pile  21  passes. The pile engaging member  29  also includes a tube segment  31  attached to the lower bracket  30  and aligned with the hole in the lower bracket  30 . The tube segment  31  has a projection  32  that extends radially inward from a side wall of the tube segment  31  to engage the helical structure on the screw pile  21  and prevent the screw pile  21  from passing through the tube segment  21  in a vertical direction unless the screw pile  21  is being rotated. Alternatively, a female thread or helical flighting can be provided within the tube segment  31  to provide a similar function to the projection  32  in the illustrated embodiment. 
         [0039]    An upper/lower limit switch  32  is provided for sensing when the screw pile  21  reaches its upper and lower limits of movement. The limit switch  32  can be positioned on the following member  28  or other structure that moves vertically up and down with the screw pile  21 . The limit switch  32  is positioned so that it engages a first stationary stop as the screw pile  21  reaches its upper limit of movement, and engages a second stationary stop as the screw pile  22  reaches its lower limit of movement. The limit switch  32  functions to stop the drive motor  22  to prevent the drive motor  22  from continuing to rotate upon the screw pile  21  reaching its upper or lower limits of movement. Alternatively, stationary upper and lower limit switches can be mounted near the respective upper and lower ends of the slide mounting assembly  23  to provide the same function as the upper/lower limit switch  32 . 
         [0040]    An anchoring device  120  according to another embodiment of the invention is illustrated in  FIGS. 8 to 11 . In this embodiment, a drive motor  122  is mounted stationary to the base beam assembly  14 , and a screw pile  121  is raised and lowered relative to the drive motor  122  and the drive tower  13  during operation. The drive motor  122  is operably connected to the screw pile  121  using a suitable gear reduction and drive assembly  123  that allows the screw pile  121  to be rotatably driven by the motor  122  while moving vertically into and out of contact with the ground. 
         [0041]    A pile guide structure  127  is provided above the drive motor  122  for maintaining the screw pile  121  in a vertical orientation. The pile guide structure  127  can be, for example, front and rear sheets of metal that are bowed to accommodate the diameter of the screw pile  121  and attached along their side edges to form a tubular structure. Alternatively, a tubular member, such as a plastic or metal tube, can be used for the pile guide structure  127 . 
         [0042]      FIG. 10  illustrates one embodiment of a drive motor  122  and drive assembly  123  for rotating the screw pile  121  and causing the screw pile  121  to move vertically relative to the drive motor  122 . In this embodiment, a first gear  128  is mounted on the drive shaft  129  of the motor  122 , a second gear  130  is rotatably driven by the first gear  128 , and a third gear  131  is driven by the second gear  130 . The second gear  130  is larger than the first gear  128  to provide a suitable gear reduction for the drive motor  122 . The third gear  131  is fixed on a shaft  132  with a pile engaging structure  133  that rotates together with the third gear  131  to engage and rotate the screw pile  121 . The pile engaging structure  133  has at least one, and preferably multiple, engaging wheels  134  that fit between the adjacent helical rings  121 R of the screw pile  121  to engage and drive the inner shaft  121 S of the screw pile  121 . 
         [0043]    In operation, as the motor  122  rotates in one direction, the screw pile  121  rotates and moves vertically downward until it augers into the soil. As the motor  122  turns in the other direction, the screw pile  121  rotates and moves vertically upward out of the soil and into its raised position. Upper and lower limit switches can be used in this embodiment to ensure that the drive motor  122  stops when the screw pile  121  reaches its upper and lower limits. 
         [0044]      FIG. 11  illustrates another embodiment of a drive motor  122  and drive assembly  123 ′ for rotating the screw pile  121  and causing the screw pile  121  to move vertically relative to the drive motor  122 . This embodiment is similar to the embodiment illustrated in  FIG. 10 , except that the pile engaging structure  133 ′ engages an outer surface of the helical rings  121 R of the screw pile  121  to rotate the screw pile  121 . 
         [0045]    As illustrated in  FIGS. 2 and 9 , an anemometer  40  can be placed on the irrigation system  10  to determine when wind speeds exceed a predetermined threshold. A controller  41  can be connected to the anemometer  40  to automatically activate the drive motor  22 ,  122  to deploy the screw pile anchoring device  21 ,  121  into the ground whenever wind speeds exceed the threshold wind speed. For example, the threshold wind speed can be set at 60 mph by programming the controller  41 , so that whenever the measured wind speed meets or exceeds 60 mph, the controller  41  causes the screw pile  21 ,  121  of the anchoring device to be automatically screwed into the ground. The controller  41  can also be used to energize the drive motor  22 ,  122  remotely using a cell phone, or to allow a user to manually start and stop the drive motor  22 ,  122 . 
         [0046]    The drive motor  22 ,  122  can be powered by a high voltage electricity source that is typically available on the sprinkler, or the drive motor  22 ,  122  can be powered by one or more low voltage DC batteries dedicated to that purpose.  FIGS. 2 and 9  illustrate the use of a pair of 12V automotive batteries  42 ,  43  to supply low voltage power (e.g., 12V or 24V) to the drive motor  22 ,  122 . A solar charger  44  can be mounted on the irrigation system to keep the batteries  42 ,  43  charged. In same cases, a single battery will provide sufficient power, while in other cases multiple batteries may be needed. 
         [0047]    The drive motor  22 ,  122  of the anchoring device of the present invention can be powered by high or low voltage electric systems, as explained above, or alternatively by hydraulic or pneumatic systems. For example, a self-propelled irrigation system with hydraulically driven support towers can be equipped with an anchoring device with a hydraulic drive motor so that the existing hydraulic system be used to power the anchoring device. 
         [0048]    While the invention has been specifically described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.