Abstract:
A mobile injection device including a peristaltic pump assembly configured to be installed in a device for placing material on or beneath the soil surface. The device delivers material into the soil subsurface as a fluid or a suspension. The peristaltic pump has a rotor assembly that urges a fluid additive in precision amounts through flexible tubes into a manifold. A pressurized fluid is introduced to the manifold to mix the additive in the pressurized fluid and inject the mixture into the ground through an injection nozzle. A computer control system monitors the ground speed of the device and determines the amount of additive to be pumped into the manifold to provide a uniform distribution of the additive to the soil.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. patent application No. 61/931,448 filed on Jan. 24, 2014 which is incorporated by reference as if fully set forth. 
     
    
     INCORPORATION BY REFERENCE 
       [0002]    U.S. Pat. No. 7,581,684 filed Sep. 1, 2009 is incorporated by reference as if fully set forth herein. 
       FIELD OF INVENTION 
       [0003]    This application is generally related to displacement pump systems and more particularly related to a peristaltic pump injection system used in turf maintenance equipment for placing granular or liquid substances below the surface of the ground at a precision depth. 
       BACKGROUND 
       [0004]    Turf and soil maintenance, for those involved in the golfing industry and turf grass management, plays a critical role in the success of a business. The greens and fairways provide the surface where golfers spend the majority of their time. Proper treatment and maintenance of that surface creates a higher quality product, and provides for a more aesthetically appealing landscape, which creates a highly attractive and desirable field for play. 
         [0005]    The introduction of various materials, such as soil amendments, fertilizers, insecticides, and aeration improves the properties of the soil and the growth it supports. Aeration may be used to control compaction, soil temperature, regulate soil moisture, and improve drainage. Timely aeration improves soil texture and the incorporation of certain physical or biological additives prevents the soil from becoming compacted, which impedes overall plant health, germination, root growth, and water transmission. 
         [0006]    Historically, the introduction of materials to the soil surface or subsurface was accomplished through use of tillage tools. These tillage tools cut or plow the surface of the soil and release additives into the openings created. The amount of soil eruption and surface disturbance caused by tillage on golf courses results in decreased play by advanced golfers and increased labor costs for cleanup, spreading of soil amendments, and topdressing. 
         [0007]    Other methods of introducing materials into the soil have also been used. Techniques such as injection of liquid substances into the subsurface using high pressure water jets, may not be as disruptive to the ground surface, but are generally limited to use of liquid or wet additive materials. These and other methods may involve machinery that is more expensive and require more time. 
         [0008]    Thus, a need exists for a faster, more mobile, cost effective system for treating and maintaining a ground surface, while maximizing the number and types of materials usable as additives and the manner these materials are placed below the surface of the soil. 
       SUMMARY 
       [0009]    A peristaltic pump injection system used in turf maintenance equipment for placing additives, such as liquid materials, into the soil at a precision depth is disclosed. Fluid jets, for example using water or air blasts, carry the materials through the peristaltic pump injection system and into the soil and leave no eruption on the surface to interfere with any immediately following activities or other treatments. This is particularly beneficial where the materials are being added to lawns, putting greens and fairways on golf courses, sports fields and the like. 
         [0010]    The additives delivered in a blast can be used to effectively drill a hole in the soil. The hole may have a diameter in the range of 0.1 to 2.0 inches. Substantially simultaneously, the created hole may be filled with a soil additive or amendment. Once the hole has been filled, the surface of the soil is left smooth, with minimal soil disruption and displacement. 
         [0011]    The additives are injected into the injection manifold through an upstream valve and high pressure water is injected through a poppet valve assembly, downstream of the valve where the additive materials are injected. The fluid/additives are injected between high pressure blasts into the injection manifold and are mixed in the injection manifold with the high pressure water. In some instances, the fluid/additives may be injected into the dosing material. This results in injected materials that are not damaged by high pressure and allows for complete defusing of the additives into the soil. This mixture is urged through tubes of the peristaltic pump assemblies, at a precision amount, to nozzles and manifolds of the device. 
         [0012]    The device fires its nozzles as a function of the distance traveled by the device along its path of travel, e.g. as ground speed sensed over a period of time. A ground speed sensor generates a signal that is calculated as a ground speed by the central controller and used to calculate the distance traveled, or the instantaneous speed. The central controller can adjust the injector rates for the peristaltic pumps, on the go, and for systems using multiple peristaltic pumps, the pumps can be adjusted both individually and together. 
         [0013]    Thus, until the device travels its pre-set distance, the next blast from the nozzles may not occur, regardless of whether the device travels quickly or slowly over such distance. In other words, although the spacing between holes may be adjusted by the operator, once a selection is made, that spacing from the beginning of the hole to the beginning of the next hole, remains substantially fixed. 
         [0014]    The device may provide deep penetration of additives into the soil, as great as 10 inches in depth and be used to punch through sod. The device may also punch through fiber or stabilized sports turf to allow better root proliferation below a mesh; aerate, amend, and top-dress in one pass, and allow for play on a smooth surface in approximately one hour. 
         [0015]    For sake of brevity, this summary does not list all aspects of the present invention, which is described in further detailed below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The foregoing summary, as well as the following detailed description of the preferred embodiments, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements shown. 
           [0017]      FIG. 1  is a schematic view of a system for injecting an additive into the soil in accordance with a disclosed embodiment. 
           [0018]      FIG. 2  is a perspective view of a rotating carriage with an encoder disc in accordance with a disclosed embodiment. 
           [0019]      FIG. 3  is a schematic side view of the system of  FIG. 1  on a movable platform in accordance with a disclosed embodiment. 
           [0020]      FIG. 4  is a flow diagram if a method in accordance with a disclosed embodiment. 
       
    
    
       [0021]    To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common in the figures. The figures are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. 
         [0022]    While described in reference to a system for injecting liquid additives to soil, the present invention may be modified for a variety of applications while remaining within the spirit and scope of the claimed invention, since the range of the potential applications is great, and because it is intended that the present invention be adaptable to many such variations. For example, the system could be used for application if stabilizers to a ground cover other than soil, for example asphalt or macadam. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “back,” “forward,” “backwards,” “inner,” and “outer” designate directions in the drawings to which reference is made. Additionally, the terms “a” and “one” are defined as including one or more of the referenced item unless specifically noted otherwise. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. A recitation of “into the soil” or the like means to the surface of the soil as well as beneath the surface of the soil unless the context clearly indicated otherwise. The terminology includes the words specifically noted above, derivatives thereof, and words of similar import. 
         [0024]      FIG. 1  schematically shows an embodiment of a system  100  for injecting an additive into the soil including a peristaltic pump assembly  102 . The peristaltic pump assembly  102  is configured for placing material on or beneath the surface S of a soil system or soil. The device delivers wet material at least to the surface S of the soil and preferably into the soil subsurface to a desired depth D. The peristaltic pump assembly  102  is generally known to include a plurality of rollers  103  supported rotation on a rotating carriage assembly  104 . As the carriage  104  rotates as indicated by arrow  105  under the influence of a variable voltage motor  208  ( FIGS. 1 and 2 ), rollers  103  successively compress a resilient tube  106  to urge a material within the tube  106  in the direction of rotation (i.e., corresponding with arrow  105 ). An axial face of the rotating carriage assembly  104  may include an encoder disc  202 . The encoder disc  202  has features  204 , for example holes  204 , formed around a perimeter of the disc  202  as illustrated in  FIG. 2 . A sensor  206  ( FIG. 1 ) is positioned to read, or sense, data from the encoder disc  202 , for example the number of features  204  passing in a given period of time, and provide that data to a computer control system or controller  108 . 
         [0025]    A first end  106   a  of the resilient tube  106  is fluidly coupled to an additive reservoir  110  containing an additive  111 . The first end  106   a  resilient tube  106  may be directly coupled to the reservoir  110  or may have one or more intermediate fluid conduits forming inlet line  124 . The additive reservoir  110  contains a liquid additive  111  that may comprise one or more miscible or immiscible liquids or one or more solids suspended in one or more liquids, as in a slurry, or other fluid compositions, such as a gel, suitable for pumping via a peristaltic pump. 
         [0026]    A second end  106   b  of the resilient tube  106  is fluidly coupled to the manifold  112  either directly or through one or more intermediate fluid conduits forming outlet line  126 . A check valve  120  is placed in the outlet line  126  between the peristaltic pump  102  and the manifold  112 . The check valve  120  is configured to allow flow from the peristaltic pump  102  to the manifold  112  but to prevent or block flow from the manifold to the peristaltic pump  102 . The peristaltic pump is controlled to constantly provide an amount of additive to the manifold  112 , except for during an injection, discussed below. As the additive  111  flows into the manifold  112 , the pressure within the manifold is at or near atmospheric pressure (i.e., 0 pounds per square inch gage) allowing a free flow of the additive. In a preferred embodiment as illustrated, the second end  106   b  of the resilient tube  106  is coupled with the manifold at a midpoint L/ 2  of the length L of the manifold via outlet line  126 . 
         [0027]    The manifold  112  includes a plurality of nozzles  114 . In the non-limiting embodiment illustrated schematically in  FIG. 1 , eight nozzles  114  are shown evenly spaced along the length L, although spacing need not be even. In other embodiments, a greater or lesser number of nozzles  114  may be used with even or uneven spacing. The nozzles  114  are in direct fluid communication with the interior of the manifold  112  as illustrated. In an embodiment, one or more nozzles  114  may have a valved connection with the manifold  112 . 
         [0028]    A source of pressurized fluid  116  is in fluid communication with the manifold  112  via pressure line  128 . In a preferred embodiment, the point of attachment between the manifold  112  and the source of pressurized fluid  116  is at a midpoint L/ 2  of the length L of the manifold  112  via pressure line  128 . In a preferred embodiment, the source of pressurized fluid  116  is attached to the manifold  112  adjacent to the second end of the resilient tube  106 . 
         [0029]    The source of pressurized fluid  116  may be an accumulator or other device or structure configured to supply a fluid  117  at a substantially constant pressure. As used herein, a pressurized fluid  117  is a fluid at a pressure greater than the surrounding atmospheric pressure. This pressure is sometimes referred to a gage pressure to distinguish it from the total, or absolute, pressure which includes atmospheric pressure. In some embodiments, the pressurized fluid  117  may be at a pressure of up to 4,000 pounds per square inch, for example the pressure of the pressurized fluid  117  may range from about 2,000 pounds per square inch to about 4,000 pounds per square inch. 
         [0030]    A valve, for example a poppet valve  118 , is placed in the pressure line  128  between the source of pressurized fluid  116  and the manifold  112 , preferably adjacent to the manifold  112 . The poppet valve  118  is configured to provide a blast or a jet of pressurized fluid  117  to the manifold. Advantageously, the blast or jet of pressurized fluid  117  interacts with the additive  111  delivered to the manifold by the second end of the resilient tube  106   b.  The interaction of the pressurized fluid  117  and the additive  111  in the manifold evenly, or substantially evenly disperses the additive  111  in the pressurized fluid  117 . 
         [0031]    The (gage) pressure within the manifold  112  varies from atmospheric pressure to approximately the pressure of the pressurized fluid source  116 . Accordingly, a check valve is not included, as the contents of the manifold will not flow in the direction of the pressurized fluid source  116 . However, a check valve may be placed in the pressure line to insure the contents of the manifold do not enter the high pressure source  116 . 
         [0032]    In an embodiment, a hopper  132  containing a dry filler material  134  may be coupled via line  136  to the nozzles  114  (only shown connected to one nozzle  114  in  FIG. 1  for clarity). As the injected material travels through the nozzles  114 , the velocity of flow causes a vacuum in the nozzles  114  behind the flow. This vacuum can be used to draw the dry material  134  into the nozzle  114  and flow into any void caused in the soil surface S or ground G by the injection. The flow of the dry material  134  into the nozzles  114  can be controlled by a valve at the hopper  132  or individually by valves at the nozzles  114 . 
         [0033]    The system  100  can be supported on a platform  302  movable with respect to the surface S of the soil or soil system as illustrated in  FIG. 3 . The platform  302  can be designed to be pulled or towed and may be attached to, at a hitch  304 , a tractor or other vehicle suitable for towing (not shown). The system  100  has wheels  306  that operate as a free-wheel as the system  100  is towed along the surface S. The platform  304  could also be self-propelled with at least one wheel  306  as a drive wheel. 
         [0034]    A sensor  308  may be attached to a wheel  306 , either free-wheel or drive wheel, for selectively sensing data corresponding to ground speed. In an embodiment, the data relates to angular displacement corresponding to rotations of a wheel  306  of a known diameter. Between the sensor  308  and the controller  108  is a communication link  310  to facilitate communication of ground speed data between the sensor  308  and the controller  108 . 
         [0035]    In the non-limiting embodiment illustrated in  FIG. 3 , the entire system  100  is supported on the platform  302  for ease of illustration only. Some components may be supported for movement over the surface S in a separate vehicle. The communication link  310  may be a wired link, or may be a wireless link connection. 
         [0036]    When the output motor  208  rotates the carriage assembly  104 , rollers  103  compress the resilient tube  106  within a cavity peristaltic pump  102  to draw the additive  111  from the additive reservoir  110  through the first end portion  106   a  and force the additive  111  through the second end  106   b  of the resilient tube. In an embodiment, the he carriage assembly  104  can rotate in a clockwise (as illustrated) or counter-clockwise direction and additives in the resilient tube  106  can be urged within the flexible tube in the direction of travel of the rollers  103  (i.e., corresponding with arrow  105  in  FIG. 1 ). 
         [0037]    The additives  111  are provided or metered out by the peristaltic pump  102  in precision amounts to the injection manifold  112 . This is accomplished by mounting an encoder disc  202  on the carriage assembly  104  ( FIG. 2 ). The encoder disc  202  may be formed from a metal, for example stainless steel, with features, such as holes  204  that are sensed by a sensor  206 , for example a Hall Effect proximity sensor. As shown in  FIG. 2 , the sensor  206 , for example a proximity sensor, is mounted to the peristaltic pump housing and detects the absence or presence of metal directly in front of it. In an embodiment the proximity sensor  50  reads the revolutions of the encoder disc  202  per a period of time and reports the revolutions to a computer control system, controller  108  via communication link  130 . The communication link  130  may be a wired link or a wireless link to facilitate transmission of at least a control signal from the controller  108  to the motor  208 . As illustrated in the non-limiting embodiment of  FIG. 4 , each through hole  204  in the encoder disc  202  represents 1/40 of the peristaltic pump&#39;s  102  volume per 1 revolution. For example, if the peristaltic pump&#39;s  102  volume per revolution is 0.16 ounces, each hole would be equal to 0.0036 ounce. As illustrated in  FIG. 1 , the computer sends a control signal, for example a variable output voltage, to the motor  208  to pump the additive material  111  at a given revolution per period of time. In other words, the controller  108  controls the amount of material that is output from the peristaltic pump  102 . The desired amount of material output can be pre-set at the controller  108  and may vary from approximately 3 oz. per 1,000 sq. ft. to approximately 365 oz. per 1,000 sq. ft. The peristaltic pump  102  output is controlled by the controller  108  based on data provided by the sensor  206  and the sensor  308 . The sensor  308  provides ground speed data to central controller  108 . 
         [0038]    As shown in  FIG. 1 , the additives  111  of the peristaltic pump  102  are provided to the injection manifold  112  through valve, check valve  120 , and high pressure fluid, for example water, is injected through a poppet valve assembly  118 , adjacent to the valve  120  where the additive materials  111  of the peristaltic pump  102  are provided. When high pressure fluid (e.g., water) is injected into the injection manifold  112 , the injection causes the pressure in the manifold  112  to rise. The pressure in the manifold  112  can rise to the same, or substantially the same, pressure as the pressurized fluid source  116 . This increase in pressure closes the check valve  120  that allows the additive  111  to flow into the manifold. The pressure within the manifold  112  causes the fluid  117  and the additive  111 , mixed under the influence of the fluid  117  jet in the manifold  112 , to exit the manifold through the nozzles  114 . The nozzles  114  may be in free and open fluid communication with the atmosphere as illustrated, or may include one or more valves to restrict the flow out of the manifold  112 . 
         [0039]    As the pressure drops in the manifold  112 , the check valve moves into an open position and the additives  111  again enter the mixing chamber. Injection of the high pressure fluid  117  into the injection manifold  112  stops the movement of the additive into the injection manifold for duration of approximately 0.05 to 0.30 seconds. During this time period, the pressure in the mixing chamber increases from approximately 0 p.s.i. (gage, therefore corresponding to atmospheric pressure) to approximately 4,000 p.s.i. (gage). After each injection of high pressure fluid  117  into the manifold  112 , the pressure in the manifold  112  decreases to approximately 0 p.s.i.; during this period, between high pressure injections, the additives move into the injection manifold  112 . The mixture of additives and high pressure water is pumped into the soil as noted below. 
         [0040]    During the period when the check valve  120  is closed and the pressure in the manifold  112  is elevated, the carriage assembly  104  of peristaltic pump  102  continues to turn as controlled by the variable voltage motor  208 . The second end portion  106   b  of the resilient tube  106  or the outlet line  126 , or both the resilient tube  106  and the outlet line  126 , acts as an accumulator for the additive materials  111  pumped during that time period. 
         [0041]    The mixture of additives  111  and high pressure fluid  117  is injected into the ground G under high pressure through nozzles  114 . The velocity of the high pressure fluid  117  moving through the nozzles  114  allows the mixture to be forced into the soil profile from depths D of approximately 1 to 12 inches. Movement of the high pressure fluid  117  and mixture into the soil creates fractures in the soil. The mixture is then drawn into micro pores in the soil through capillary action. 
         [0042]      FIG. 4  is a flow diagram representing a method  400  for injecting an additive to the soil according to a disclosed embodiment. At  402  data related to ground speed of the system  100  is sensed by a sensor, for example sensor  308 , which may include an encoder disc mounted to a wheel  306  and a proximity sensor fixed to the movable platform  302 . The data is communicated to the controller  108  where the data may be stored. 
         [0043]    At  404 , the ground speed of the system  100  including at least the manifold  112  and nozzles  114  is calculated at the controller  108  from the data received. 
         [0044]    At  406 , an area per unit time covered by the nozzle assembly  114  at the calculated ground speed is calculated at the controller  108 . 
         [0045]    The controller  108  determines at  408  the amount of additive  111  required at the nozzles  114  in order to apply a predetermined amount of additive per unit area to the soil. 
         [0046]    At  410 , the controller  108  provides a control signal, for example a variable voltage, via the communications link  130  to the peristaltic pump  102  to deliver the determined amount of an additive  111  to the manifold  112 . Under the pressure generated by the peristaltic pump  102  in outlet line  106   b,  the check valve  120  is caused to open, allowing the determined amount of additive  111  to be delivered to the manifold  112 . 
         [0047]    At  412 , poppet valve  118  opens and a pressurized fluid  117  is introduced to the manifold  112 . As the pressurized fluid  117  enters the manifold, the check valve  120  is urged to close and the manifold become pressurized to the same, or substantially the same, pressure as the pressurized fluid  117 . The pressurized fluid  117  enters the manifold  112  as a jet or a blast and distributed the additive within the manifold  112 . 
         [0048]    At  414 , the pressurized manifold forces the mixture of pressurized fluid and additive through the nozzles  114  and injects the mixture of pressurized fluid and additive into the soil. The sequence can be repeated for a set number of cycles programmed into the controller  108 . 
         [0049]    Having thus described various methods, configurations, and features of the present poppet valve in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description above, could be made in the apparatus and method without altering the inventive concepts and principles embodied therein. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.