Abstract:
A rolling herbicide applicator contains an herbicide nozzle fastened to a rigid shaft and axle at the center of a rolling disc for selectively applying herbicide to undesirable plants, while shielding desirable plants from herbicide overspray. The rolling applicator allows a user to trace a flowing outline through landscape arrangements of any shape with a steady movement as the rolling disc proceeds along the outline. The open design simultaneously provides the operator a direct and continuous view of the sprayer in operation.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an apparatus and method for applying herbicide to select areas and, more specifically, to a rolling herbicide applicator for selectively applying herbicide to undesirable plants, while simultaneously shielding desirable plants from unintended overspray. 
       BACKGROUND OF THE INVENTION 
       [0002]    Landscaping and garden arrangements are becoming increasingly complex. Modern lawns often use a variety of plants alongside grass arranged in flowing lines so that it is frequently difficult to maintain the boundaries between different types of vegetation. It is even more difficult to apply herbicide to selected plants without inadvertently spraying desirable plants. 
         [0003]    The system disclosed in U.S. Pat. No. 7,581,350 to Ram, for example, attempts to overcome the problem of overspray by disclosing an apparatus designed to encircle individual plants so as to protect those plants when applying herbicide. While useful in protecting specific plants, Ram does not provide a system for rapidly applying herbicide to select areas of vegetation arranged in flowing lines; nor does Ram provide a system for applying an herbicide while tracing a specific pattern as the operator walks along that pattern. 
         [0004]    U.S. Patent Publication No. 2009/0294555 discloses a rolling herbicide applicator that uses a cylinder-shaped shroud to apply herbicide within the shroud as the operator proceeds along a given area. This design attempts to overcome some of the deficiencies in Ram, but still does not allow the operator to view the sprayer in operation. That is an important deficiency because the sprayer should be viewable while in use to allow the operator to view the area being sprayed in order to adjust the sprayer as needed during use. It is also important that the sprayer be viewable so that the operator knows, for example, when the sprayer is not working properly or when the herbicide level is low. 
         [0005]    What is needed is a system that allows an operator to apply herbicide in a defined pattern as he walks along that pattern, but that simultaneously protects selected vegetation from overspray. What is also needed is a system that allows an operator to view operation of the herbicide nozzle as he walks along a variable pattern. What is also needed is a system that allows the operator to adjust the friction of a rolling applicator for applying herbicide. 
         [0006]    Accordingly, an object of the present invention is to provide a rolling herbicide applicator that allows an operator to apply herbicide in a flowing or irregular pattern as he walks along that pattern, but that simultaneously protects selected vegetation from overspray. 
         [0007]    Another object of the present invention is to provide a rolling herbicide applicator that allows an operator to view operation of the herbicide nozzle as he walks along a variable pattern. 
         [0008]    Yet another object of the present invention is to provide a rolling applicator that allows the operator to adjust the friction of a rolling applicator for applying herbicide 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0009]    The present invention accomplishes the foregoing objections by providing a rolling herbicide applicator for selectively applying herbicide to undesirable vegetation, while shielding desirable vegetation. The rolling herbicide applicator comprises: an L-shaped rigid shaft comprising an upright length designed for use substantially perpendicular to a ground surface and a parallel length designed for use substantially parallel to a ground surface; a disc carried by the shaft, wherein a rounded opening is provided at the center of the disc and wherein the distal end of the parallel length is inserted through the opening and held in place by a first connection means thereby allowing the disc to rotate about the parallel length; and a second connection means for attaching an herbicide sprayer substantially parallel to the perpendicular length, wherein herbicide may be delivered to a selected area adjacent to a corresponding side of the disc while the disc operates as a shield to prevent delivery of the herbicide to the opposing side of the disc. 
         [0010]    The applicator may include a first connection means comprising a member at the distal end of the parallel length, whereby the member is compressible to facilitate insertion through the rounded opening of the disc. 
         [0011]    The applicator may also include a first connection means comprising a threaded portion at the distal end of the parallel length and one or more threaded nuts, whereby the one or more threaded nuts are attached to the threaded portion. 
         [0012]    The applicator may also include a first connection means adjustable to provide a variable amount of friction between the shaft and the disc. 
         [0013]    The applicator may also include a first connection means adjustable to provide a variable distance between the disc and the upright length. 
         [0014]    The applicator may also include a second connection means comprising adjustable fittings to attach varying sizes of herbicide sprayer nozzles. 
         [0015]    The present invention also includes a method of using the rolling herbicide applicator comprising the steps of securing an herbicide sprayer to a rolling shield; placing said rolling shield in contact with a ground surface having undesirable vegetation; operating said herbicide sprayer to begin application of herbicide to said undesirable vegetation; proceeding along said ground surface, while maintaining said rolling shield in contact with said ground surface so that said rolling shield rotates about a shaft, whereby said herbicide is applied to said undesirable vegetation on a first side of said disc, while said rolling shield simultaneously shields desirable vegetation on a second side of said disc from said herbicide. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  illustrates a rolling herbicide applicator system according to the present invention. 
           [0017]      FIG. 2A  illustrates an herbicide applicator with a threaded shaft and two nuts to affix a rolling disc. 
           [0018]      FIG. 2B  illustrates an herbicide applicator with compressible attachment means to affix a rolling disc. 
           [0019]      FIG. 2C  illustrates an herbicide applicator with a threaded shaft and two nuts to affix a rolling disc and a small spray nozzle affixed to the sprayer shaft. 
           [0020]      FIG. 2D  illustrates an herbicide applicator with compressible attachment means to affix a rolling disc and a large spray nozzle affixed to the sprayer shaft. 
           [0021]      FIG. 3  illustrates a rolling herbicide applicator in use to treat weed encroachment along a flowing path. 
           [0022]      FIG. 4  illustrates a method of using a rolling herbicide applicator according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The present invention is directed to an apparatus and method of using a rolling herbicide applicator with integrated shield for selectively applying herbicide to undesirable vegetation, while shielding desirable vegetation. Referring now to  FIG. 1 , a rolling herbicide applicator system  100  according to the present invention is illustrated. System  100  allows an operator, such as a gardener or landscaping employee, to apply herbicide such as Roundup® to a designated area along a flowing or varied path in a manner that simultaneously protects desirable vegetation adjacent to the flowing path. 
         [0024]    A standard herbicide spray nozzle  102  is affixed to shaft  104  using attachment means  106 . The flow of herbicide is controllable through control valve  110  to apply herbicide in a desired spray pattern  108 . Attachment means  106  is used to connect spray nozzle  102  to the shaft  104 , which is preferably an L-shaped member. Preferably two or more adjustable clamps are used for attachment means  106  so that spray nozzle  102  may be accommodated in various sizes, such as the standard ¼ inch and ⅝ inch diameters nozzles. 
         [0025]    Liquid herbicide is stored in reservoir  112 , which is preferably maintained in a back-pack-style reservoir and worn on an operator&#39;s back using straps  114 . An operator fills the herbicide reservoir  112  through filler cap  116 . During use, liquid herbicide flows from reservoir  112 , through delivery tube  118 , through control valve  110 , and ultimately out of the distal end of sprayer nozzle  102 . 
         [0026]    In a preferred embodiment, an operator (not shown) walks along a specified path  122  and rolls disc  120  along an edge parallel to that path so that herbicide may be delivered in an appropriate width  126 . In this manner herbicide is delivered in an intended spray pattern  108  along spray path  124  so that proper application of the liquid herbicide will eliminate unwanted vegetation growing along spray path  124 . At the same time, desirable plants  128  growing in area  130  on the opposite side of disc  120  are shielded from liquid herbicide overspray by disc  120 . Spray path  124  is treated in this manner with a desired placement of herbicide, while area  130  is protected from inadvertent herbicide spray as desired. 
         [0027]    Referring now to  FIG. 2A , an L-shaped shaft  202  is illustrated with a parallel length and perpendicular length. The parallel length is illustrated with a distal end threaded portion  204  designed for insertion through round opening  206  in the center of disc  208 . In this embodiment, nut  210   a  is first placed along threaded portion  204  at the proper inside location. Distal end  204  is then inserted through opening  206  until disc  208  comes into contact with nut  210   a.  Nut  210   b  is then threaded onto the opposite side of disc  208  to hold disc  208  in the proper position along the parallel length. In a preferred embodiment, nut  210   a  and nut  210   b  are lock nuts to prevent loosening as disc  208  rotates about shaft  202  during use. Triangular reinforcement  212  may also be used to provide further reinforcement to shaft  202  in the  90  degree elbow portion thereof. 
         [0028]    Referring now to  FIG. 2B , L-shaped shaft  220  is provided with an alternate connection means  222  along a distal end of its parallel length. In this embodiment, a cone-shaped and slotted compressible member forms connection means  222  to hold disc  208  in the proper position along shaft  220 . Connection means  222  is inserted through opening  206  in the direction indicated. The two ends of the compressible member in connection means  222  squeeze together to allow insertion through  206 . When disc  208  is forced along shaft  220  to the proper position, where disc  208  comes into contact with tapered sleeve  224  located on the parallel length, the two ends of the compressible member in connection means  222  decompress and hold disc  208  in the proper position on shaft  220 . 
         [0029]    Referring now to  FIG. 2C , L-shaped shaft  202  is illustrated securely fastened by nut  210   a  and nut  210   b,  which hold disc  208  substantially parallel to the perpendicular (generally upright) length of shaft  202 . Herbicide nozzle  230  is affixed to the perpendicular length of shaft  202  by a second connection means  232 . In this embodiment, second connection means  232  is provided by two metal or plastic bands fastened by butterfly screws  234   a  and  234   b . Use of butterfly screws  234   a  and  234   b  provide a simple connection means that is also easily adjustable to accommodate different diameter nozzles  230 . Once nozzle  230  is placed along the perpendicular length of shaft  202  as illustrated, butterfly lock nuts  234   a  and  234   b  are tightened to hold nozzle  230  securely in place along shaft  202 . 
         [0030]    The second connection means  232  can also be any number of other well known devices, such as pipe clamps. It is even possible that the second connection means may be disposable tie wraps that incorporate the needed holding strength, variable length, and ease of use. This variable mode of attachment allows the invention to accommodate multiple nozzle sizes and diameters. For example, the herbicide nozzle  240  illustrated in  FIG. 2D  is substantially larger than nozzle  230  in  FIG. 2C , but both are connected using the same type of second connection means  232 . Preferably, second connection means  232  offers the flexibility of accommodating a wide range of herbicide nozzles as needed. This flexibility is important because gardeners and other intended users generally keep multiple types of herbicide in multiple containers that employ multiple types and sizes of nozzles. 
         [0031]    The first connection means illustrated as nuts  210   a  and  201   b  in  FIG. 2A  and compressible member  222  in  FIG. 2B , respectively, may also be configured to provide adjustability of friction in the turning of disc  208 , as well as the distance disc  208  is set from the perpendicular portion of shaft  202 . In the embodiment illustrated in  FIG. 2C , nuts  210   a  and  210   b  are provided to incorporate these important aspects of the invention. More specifically, nut  210   a  may be tightened or loosened in conjunction with nut  210   b  to increase or decrease the rolling resistance of disc  208 . This may be desirable to increase or decrease the required downward force applied to shaft  202  in order to hold disc  208  in place along a desired pathway. If the surface of the desired pathway is slippery, for example, it may be desirable to decrease the rolling resistance of disc  208  by loosening nut  210   a  or  210   b.    
         [0032]    The placement of nuts  210   a  and  210   b  along threaded portion  204  of the parallel length is also adjustable to increase or decrease the width of a desired herbicide spray pattern. The spray pattern width  126  illustrated in  FIG. 1 , for example, may be easily varied by moving nuts  210   a  and  210   b  closer to or further from spray nozzle  230  as illustrated in  FIG. 2C . The distance of rolling disc  208  from nozzle  230  is varied in this manner so that the simultaneous shield effect provided by disc  208  can be widened or narrowed. 
         [0033]    By contrast, the first connection means of  FIG. 2D  does not provide the same adjustability, but instead provides a quicker connection and disconnection means for disc  208 . This embodiment may be more desirable if the operator intends to use different sizes or types of disc  208  for different applications. 
         [0034]    Referring now to  FIG. 3 , operator  300  is illustrated using a rolling herbicide applicator system  100  according to an embodiment of the present invention. Area  312  is illustrated with a mulch covering that is suffering from unwanted encroachment of grass  310  past boundary  304 . Operator  300  is illustrated using rolling herbicide applicator  100  to apply herbicide directly to the encroaching grass  310 . 
         [0035]    Operator  300  begins the process by placing disk  120  of applicator  100  directly onto pathway  308  at starting point  302 . Operator  300  then operates control valve  110  to begin the flow of herbicide as he simultaneously proceeds along pathway  306 , which pathway is roughly parallel to boundary  304 . As operator  300  walks along pathway  306 , he endeavors to follow boundary  304  by maintaining direct contact of disc  120  on pathway  308 , which is directly parallel to boundary  304 , so that disc  120  rolls along parallel pathway  308 . Herbicide flows as illustrated into a designated area just inside boundary  304 . In this manner the weed encroachment  310  indicated just inside of boundary  304  is sprayed with herbicide, while desirable vegetation in area  312  is shielded from overspray by disc  120 . 
         [0036]    The above is possible for many reasons related to the design of the invention. For example, the design of rolling disc  120  allows operator  300  to follow a flowing path with precision. Rolling disc  120  also simultaneously prevents overspray because its round shape provides a sufficient physical barrier. 
         [0037]    Referring now to  FIG. 4 , a method is illustrated for using an embodiment of the invention to apply herbicide to undesirable vegetation while simultaneously shielding desirable vegetation. An operator, such as operator  300 , secures an herbicide sprayer to a rolling shield at step  402 . A standard herbicide sprayer, such as those illustrated in  FIGS. 1 and 3  is preferable. 
         [0038]    The operator at step  404  then places the rolling shield in contact with a ground surface having undesirable vegetation. Once properly placed, the herbicide sprayer is operated at step  406  to begin application of herbicide to undesirable vegetation, which should be directly beneath the herbicide sprayer. This is illustrated in perhaps more detail with respect to  FIG. 3 . 
         [0039]    The operator then proceeds along the ground surface at step  408 , while maintaining the rolling shield in direct contact with the ground surface so that the rolling shield rotates about a shaft. Herbicide is applied as desired in step  410 , whereby the herbicide is applied to the undesirable vegetation on one side of the disc, while the rolling shield simultaneously shields desirable vegetation on the other side of the disc from herbicide overspray. 
         [0040]    These illustrated examples are, however, offered by way of illustration of the invention&#39;s versatility and not meant to limit the invention in any way. The present invention may be embodied in other specific forms without departing from its spirit of essential characteristics. The described embodiments are to be considered in all respects only illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and scope of equivalency of the claims are to be embraced within their scope.