Abstract:
A turf sprayer has a truss shaped center boom and a pair of pivotal truss shaped wing booms within which spaced spray nozzles are supported. A drift shroud system comprises three integral and one-piece drift shrouds comprising a center shroud for the center boom and a pair of side shrouds for the wing booms. Each shroud is attached to an underside of the corresponding boom in a manner such that the shrouds project below the booms and not substantially above the booms to leave the truss-shapes of the booms open and unobscured to provide access to the spray nozzles within the booms. The shrouds each have openings in a top wall thereof for receiving the spray exiting from the nozzles with the spray passing downwardly between spaced front and rear walls of the shrouds.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a turf sprayer for spraying a liquid on a turf surface and, more particularly, to drift shrouds used on such a sprayer for minimizing undesired drift of the liquid. 
       BACKGROUND OF THE INVENTION 
       [0002]    U.S. Pat. No. 7,364,096 to Sosnowski et al., which is assigned to The Toro Company, the assignee of this invention, discloses a sprayer for applying a liquid, such as a fertilizer, insecticide or herbicide, to a turf surface. The sprayer includes a fixed center boom and a pair of pivotal wing booms that carry spaced spray nozzles along their lengths. In a spray position, the center and wing booms are substantially horizontal and aligned end-to-end along a substantially straight lateral axis with respect to the vehicle that carries the spray booms. In a transport position, the wing booms are folded upwardly and inwardly relative to the center boom until the wing booms become disposed in an X-shaped orientation when they reach the transport position. 
         [0003]    It would be desirable for many reasons to minimize drift of the liquid being sprayed from the spray nozzles during operation of the sprayer. While various types of shrouds or shields have been disclosed for use with sprayers to attempt to solve the problem of spray drift, previously known shrouds or shields have been expensive to manufacture as well as bulky, cumbersome, difficult and time consuming to assemble or install. 
         [0004]    For example, many known sprayers include two sets of booms that can be installed on a given sprayer, namely a first set comprising a plurality of open booms with no shrouds or shields and a second set comprising a plurality of shrouded booms. The sprayer is typically sold by the manufacturer with the set of open booms as standard equipment. The set of shrouded booms is typically offered as an option for purchase at an additional cost by the user. The user typically will purchase one or the other of these sets of booms and use the sprayer with just the purchased set of booms. Obviously, this limits use of the sprayer in some situations. For example, if the user purchases the set of open booms and installs this set of the sprayer, the user may have to wait until there is no or little wind to operate the sprayer in order to avoid undesired spray drift. 
         [0005]    If the user wishes to address the problem of spray drift while maintaining the ability to use open booms, the user theoretically could purchase both sets of booms and then use whatever set of booms is dictated by the conditions at the time the liquid is being sprayed. However, as a practical matter, this is not often done. For one thing, it necessitates the purchase of two different sets of booms which is expensive. It also requires at least several hours of time and effort to change or swap out one set of booms for another to switch back and forth between an open boom style and a shrouded boom style. In addition, it requires the operator of the sprayer to have sufficient storage space to store the unused set of booms. For all these reasons, having two sets of booms, one open and one shrouded, and swapping the shrouded set for the open set when one wants to contain spray drift is not a cost effective practice. 
         [0006]    Therefore, it would be an advance in the art to be able to convert a sprayer to a shrouded boom configuration in a simpler, faster and less expensive manner. 
       SUMMARY OF THE INVENTION 
       [0007]    One aspect of this invention relates to a sprayer for spraying a liquid onto a turf surface. The sprayer comprises a mobile frame having ground engaging wheels for rolling over the ground to traverse the turf surface. At least one spray boom is carried on the frame and extends laterally relative to a fore-and-aft direction of motion of the frame. The boom has a plurality of liquid spray nozzles carried thereon which nozzles are spaced apart along a length of the boom with tips of the spray nozzles being directed vertically downwardly during a spraying operation towards the turf surface. The boom is made as a sufficiently rigid structure to carry the weight of the spray nozzles and to support various hoses and fittings that supply the spray nozzles with liquid. A drift shroud is provided having a top wall and downwardly extending front and rear walls that form a downwardly facing U-shaped spray confining channel. The drift shroud has a plurality of holes in the top wall thereof for receiving at least the tips of the spray nozzles carried on the boom such that the tips of the spray nozzles are located at or below the top wall of the drift shroud when the drift shroud is installed on the boom. The drift shroud is installed on the boom by releasably fastening the top wall of the drift shroud to an underside of the boom such that the drift shroud hangs below the boom but does not extend substantially above the boom. 
         [0008]    Another aspect of this invention relates to a turf sprayer which comprises a truss shaped center boom and a pair of pivotal truss shaped wing booms within which spaced spray nozzles are supported. A drift shroud system is provided comprising three integral and one-piece drift shrouds comprising a center shroud for the center boom and a pair of side shrouds for the wing booms. Each shroud is attached to the corresponding boom in a manner such that the shrouds project below the booms and not substantially above the booms to leave the truss-shapes of the booms open and unobscured to provide easy viewing of or access to the spray nozzles within the booms. The shrouds each have openings in a top thereof for receiving the spray exiting from the nozzles with the spray passing downwardly between spaced front and rear walls of the shrouds. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    This invention will be described more completely in the following Detailed Description, when taken in conjunction with the following drawings, in which like reference numerals refer to like elements throughout. 
           [0010]      FIG. 1  is a perspective view of a portion of a prior art sprayer for spraying liquids onto a turf surface; 
           [0011]      FIG. 2  is a perspective view similar to  FIG. 1 , but showing the sprayer equipped with the drift shroud system of this invention; 
           [0012]      FIG. 3  is an enlarged perspective view of the drift shroud system of this invention, particularly illustrating one of the side shrouds, one of the boots, and the center shroud in an exploded form having been removed from one of the wing booms and the center boom; and 
           [0013]      FIG. 4  is an enlarged perspective view similar to  FIG. 3 , but showing the exploded portions of the drift shroud system from a different angle to illustrate the open inner end of the side shroud. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]      FIG. 1  depicts a portion of the rear of a sprayer  2  previously manufactured and sold by The Toro Company, the assignee of this invention. Sprayer  2  is of the type disclosed in U.S. Pat. No. 7,364,096, also assigned to Toro, which is hereby incorporated by reference.  FIG. 1  depicts sprayer  2  in an open boom configuration as known in the prior art without sprayer  2  having the drift shroud system of this invention.  FIG. 2  depicts sprayer  2  with the drift shroud system of this invention installed thereon. 
         [0015]    Referring to  FIG. 1  and by way of background, sprayer  2  includes a fixed center boom  4   c  and a pair of wing booms  4   w  that are pivotally connected to opposite ends of center boom  4   c.  Center boom  4   c  has a square or rectangular cross-section and each wing boom  4   w  has a triangular cross-section. Each boom  4  comprises a relatively open truss like structure formed from a plurality of interconnected or joined structural members. 
         [0016]    Each boom  4  carries a plurality of spray nozzles  6  spaced across the length thereof for spraying a liquid, such as a fertilizer, herbicide, pesticide or the like, onto a turf surface.  FIG. 1  illustrates booms  4  in a horizontal spray position in which wing booms  4   w  are unfolded and are aligned end-to-end with center boom  4   c  such that booms  4  spray liquid over a swath having a width defined by the aggregate length of all booms  4 . In the spray position, wing booms  4   w  extend substantially beyond the side sides of a self-propelled vehicle which carries booms  4 . To reduce the width of sprayer  2  for transport purposes, wing booms  4   w  can be pivotally folded up into a compact X-shape (not shown) in which wing booms  4   w  are behind the vehicle and are disposed above center boom  4   c.    
         [0017]    Referring now to  FIGS. 2-4 , the drift shroud system  8  of this invention comprises three drift shrouds  10 , i.e. a center shroud  10   c  mounted to the underside of center boom  4   c  and a pair of wing or side shrouds  10   w  mounted to the undersides of wing booms  4   w.  Shrouds  10  all substantially conform to the length of boom  4  on which they are mounted with center shroud  10   c  being shorter than either of side shrouds  10   w  due to the shorter length of center boom  4   c  relative to wing booms  4   w.  Each shroud  10  is a one-piece, integrally molded plastic member that is simply bolted or otherwise fastened by suitable fasteners as an integral piece to the underside of its corresponding boom. Shrouds  10  need not supply any structural strength and need not support any of spray nozzles  6  or the hoses for supplying spray nozzles  6  as all that is already done by booms  4  themselves, thereby allowing shrouds  10  to be light weight. Thus, sprayer  2  can be quickly converted to a shrouded boom configuration through the simple attachment of just three shrouds  10  to the undersides of booms  4  without having to disconnect hoses, remove spray nozzles, or the like. 
         [0018]    Side shrouds  10   w  are identical to one another and, in fact, are the same molded piece. The only difference is how side shrouds  10   w  are mounted. As shown in  FIG. 2 , side shroud  10   w  at the left of  FIG. 2  is mounted to the left wing boom with its rounded and enclosed outer end  12  being inclined and extending outwardly beyond the free end of the left wing boom. Side shroud  10   w  at the right of  FIG. 2  is the same molded piece as that used at the left of  FIG. 2 , but spun or rotated 180° around in a horizontal plane, in order to locate the same rounded outer end  12  at the free end of the right wing boom. In fact, center shroud  10   c  is also made from the same molded piece as side shrouds  10   w  with the only change being that various portions of each end of the molded piece are trimmed off to form the shorter length of center shroud  10   c.  This use of a single molded piece to derive all three shrouds  10  reduces the cost and complexity of drift shroud system  8 . 
         [0019]    Referring to  FIG. 3 , each shroud  10  is in the form of a downwardly facing, generally U-shaped channel having a top wall  14  and downwardly extending front and rear walls  16 . Front and rear walls  16  taper or incline slightly outwardly as they extend downwardly from top wall  10  at an angle a in the range of from 10°-30° and preferably about 20° relative to vertical. Front and rear walls  16  of shrouds  10  are molded with a plurality of inverted, truncated, trapezoidal shaped recesses  18  separated by upright, truncated, trapezoidal shaped ridges or lands  20  spaced along the lengths of shrouds  10  to provide increased strength to shrouds  10 . 
         [0020]    Side shrouds  10   w  are enclosed at their outer ends by the rounded outer end  12  referred to previously. Center shroud  10   c  has no such enclosed end as the rounded and enclosed outer end  12  is severed and discarded when center shroud  10   c  is being formed by cutting or trimming off the unneeded ends of one of the side shrouds  10   w.  Thus, center shroud  10   c  is open at each end thereof. While the inner end of each side shroud  10   w  has a rounded upper side  21 , the inner end of each side shroud  10   w  is open as shown in  FIG. 4 . Only the outer end  12  of side shrouds  10   w  is substantially enclosed. 
         [0021]    Top wall  14  of each side shroud  10   w  is provided with a plurality of spaced nozzle receiving openings  22  that are wide enough along the length of the shroud to allow one spray nozzle  6  carried on a rotatable nozzle turret  7  to be rotated into place with a lower end or tip of spray nozzle  6  extending slightly beneath top wall  10  of the shroud. Nozzle turret  7  carries three spray nozzles  6  with the nozzle that is being used extending straight downwardly with the lower end of the in use nozzle  6  extending down through one nozzle receiving opening  22  in top wall  10 . Opening  22  has to be sufficiently laterally elongated along the length of top wall  10  to allow the rotary motion of nozzle turret  7  to take place. As shown in  FIG. 3 , there are four such nozzle receiving openings  22  in each side shroud  10   w,  but only three such nozzle receiving openings  22  in center shroud  10   c,  to accommodate the different numbers of nozzle turrets  7  used on the different booms. 
         [0022]    In addition to nozzle receiving openings  22  in side shrouds  10   w,  a clearance hole  24  is provided in top wall  14  at the inner end of each side shroud  10   w.  Clearance hole  24  is needed to receive therein the bottom of a portion of the pivot structure  26  that mounts each wing boom  4   w  to center boom  4   c.  Hole  24  is not needed on center shroud  10   c  and will be discarded when the shroud structure is trimmed to create center shroud  10   c.  Top wall  10  of each shroud  10  also includes a plurality of spaced fastener openings  26  for receiving the fasteners (not shown) that releasably attach each shroud  10  to the underside of the corresponding boom. 
         [0023]    Drift shroud system  8  also includes a pair of flexible gaskets or boots  28  attached to the ends of center shroud  10   c  at the interfaces between the ends of center shroud  10   c  and side shrouds  10   w.  Each flexible boot  28  comprises a sheet of flexible material that is formed with or is bent into a generally U-shaped configuration that corresponds to but is slightly larger than the cross-sectional shapes of shrouds  10  to allow boot  28  to nest around the inner end of one side shroud  10   w.  A mounting flange  30  wraps around one end of boot  28  to help maintain the U-shape of boot  28  with mounting flange  30  also being used to secure boot  28  to one end of center boom  4   c  in any suitable manner, such as by bolts or rivets used at spaced locations along mounting flange  30 . 
         [0024]    When boots  28  are installed, there is one boot  28  on each end of center boom  4   c  with each boot  28  facing laterally outwardly to engage against and nest around the exterior of the inner end of each side shroud  10   w  when wing booms  4   w  are folded down into the spray position. When wing booms  4   w  are pivoted up into their transport position, the inner ends of wing booms  4   w  will disengage from boots  28 . However, as wing booms  4   w  pivot back down from their transport positions to their spray positions, the rounded upper sides  21  of the inner ends of wing booms  4   w  help guide the inner ends of wing booms  4   w  back into boots  28  and the flexibility of boots  28  assists in receiving wing booms  4   w  without causing any damage. Boots  28  ensure that the spray confining channels formed by front and rear walls  16  of shrouds  10  are substantially unbroken across the collective span of booms  4 . No spray can escape through gaps between the inner ends of wing booms  4   w  and the ends of center boom  4   c  because such gaps are closed or sealed off by boots  28 . 
         [0025]    Shrouds  10  extend down a substantial distance from the undersides of booms  4 , e.g. approximately 12″ or so, but terminate above the ground by approximately 8″ or so. No gauge or support wheels are thus needed or used on the bottom of shrouds  10  to allow shrouds  10  to roll on the ground. When in use, shrouds  10  are simply held above the ground by their connection to the undersides of booms  4 . 
         [0026]    The size and position of shrouds  10  and their simple bolt on connection to the underside of booms  4  do not in any way hamper the ability of booms  4  to function in the manner taught by the 096 patent which is incorporated by reference herein. The shroud equipped wing booms  4   w  can still fold vertically upwardly into their X-shaped transport position relative to center boom  4   c  as taught in the 096 patent. Similarly, wing booms  4   w  can pivotally breakaway fore and aft in a horizontal plane should wing booms  4   w  hit any obstructions during movement of sprayer  10  as further taught in the 096 patent. No boom functionality is lost through use of shrouds  10 . 
         [0027]    When a low drift spray nozzle such as a TeeJet® Air Induction nozzle, manufactured and sold by TeeJet Technologies of Wheaton, Illinois, is used as each spray nozzle  6 , the Applicants have found that the drift shrouds  10  of this invention can reduce drift by up to 90% over unshrouded booms  4  using conventional flat fan spray nozzles. 
         [0028]    Various modification of this invention will be apparent to those skilled in the art. Accordingly, the scope of this invention is to be limited only by the appended claims.