Abstract:
An improved system for draining bunkers on golf courses. A receptacle is positioned below the bunker surface and can have an aperture for receiving drain water and an outlet for discharging the water through a conduit. A perforated pipe water collection system can be attached to the receptacle to direct water to the receptacle interior space. A receptacle cover is removable to permit access to the receptacle interior space. The cover is sufficiently strong to support the overlying weight of people and equipment and can have apertures for permitting water entry while resisting sand entry into the receptacle interior space.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The invention relates to the field of golf. More particularly, the invention relates to sand bunkers and an improved water drain system for removing excess water.  
           [0002]    The field of golf imposes unique design requirements on turf systems and sand bunkers disposed near greens. Bunkers are deliberately positioned to create artificial hazards to errant golf balls. The bunkers are typically constructed as depressions having a clay base with sloped sidewalls rising upward to turf. The bunkers have specific peripheral configurations, depth, and sloped sides. Sand overlays the clay base to provide the playing surface for golf balls. The sand is typically groomed daily by hand or with motorized equipment to present an even surface to the golfers. Rakes and other equipment “fluff” the top surface of the sand to present the desired surface.  
           [0003]    In wet climates, rainwater compacts the sand and mixes the sand with the underlying clay base. Clay particles or “fines” discolor the overlying sand and also alter the playing qualities of the bunker. Various efforts have been made to reduce the commingling of sand and clay particles and to prevent other contamination of the sand. Cement is mixed with the clay base to harden and stabilize such base. However, mechanized equipment in the bunkers tends to crack the cement stabilized liner, leading to further deterioration. As shown in U.S. Pat. No. 5,746,546 to Hubbs et al. (1998), fiber strands and water absorbent particles such as psyllium are added to soil to improve the soil shear strength.  
           [0004]    Other bunker systems use geotextile fabrics underlying the sand. Fabric liners do not easily retain the sand on the sloped sides and are subject to rupture and other failure. Such liners do not independently correct the problems associated with rainwater accumulation in the bunkers.  
           [0005]    Because the bunkers comprise depressions in the soil, rainwater collects in the bunkers and must be drained to another location. Perforated pipe is installed in the bottom of bunkers to drain excess water to a water discharge line. Gravel is packed around the exterior surface of the perforated drain pipe to form a French drain. Such systems eventually fail in wet climates because the clay linings are susceptible to erosion. Clay particles and other contaminants such as grass clippings pack around the perforated pipe to lower the fluid transmissivity of the gravel, and such particles further enter the pipe interior. Over time the accumulated intrusion clogs the pipe, requiring reconstruction of the entire bunker. Such construction is not only expensive to accomplish but also disrupts the utility of the golf course during construction.  
           [0006]    Drain systems have been developed for other applications such as large playing fields. For example, U.S. Pat. No. 5,848,856 to Bohnhoff (1998) disclosed a thermoplastic mat underlying the surface which facilitated capture of water within an inflatable container for redistribution to the turf surface. Bohnhoff further described conventional perforated pipe networks and the problems associated with poor drainage.  
           [0007]    In bunkers having perforated pipe drains, clay fines inevitably pack off the pipe at the lowest point in the bunker. This occurrence causes excess water to pond at this position within the bunker, further accelerating deterioration of the bunker drain system. A need exists for an improved bunker drain system which facilitates water drainage from bunkers and facilitates maintenance operations.  
         SUMMARY OF THE INVENTION  
         [0008]    The invention provides a system for draining water from a bunker having a surface covered with sand. The system comprises a receptacle having an interior space for collecting water and for discharging the water through an outlet in the receptacle, wherein the receptacle is capable of being positioned in the bunker surface at an elevation below the sand, an aperture in the receptacle for permitting water entry into the receptacle interior space, and a cover detachably engaged with the receptacle, wherein the cover resists entry of sand into the receptacle interior space, and wherein the cover is moveable to permit entry into the receptacle interior space.  
           [0009]    In another embodiment of the invention, a perforated pipe connected to the receptacle collects water and directs the water toward the receptacle. The perforated pipe can be divided into two or more branches for covering a larger surface area of the bunker. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 illustrates an elevation view of a receptacle installed in a bunker.  
         [0011]    [0011]FIG. 2 illustrates an elevation view of a pipe connected to a receptacle aperture.  
         [0012]    [0012]FIG. 3 illustrates a screen in cooperation with an aperture for permitting entry of water while resisting sand entry into the receptacle interior space.  
         [0013]    [0013]FIG. 4 illustrates a plan view of a perforated pipe collection system draining water to a single receptacle.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    The invention provides a unique method and apparatus for draining water from a bunker having a surface covered with sand. FIG. 1 illustrates receptacle  10  positioned within bunker  12  comprising soil  14  and sand  16 . Bunker  12  is irregularly shaped and is sloped toward one or more ends so that excess water collects toward the low end of bunker  12 . Soil  14  can comprises existing soil conditions, imported material such as clay, stabilized soil material, or other conventional bunker base material. Bunker  12  has steeply sloped sides terminating at ground elevation  18  so that bunker  12  forms a golf play hazard depressed below ground elevation  18 .  
         [0015]    Receptacle  10  comprises a substantially hollow box having interior space  20  and is formed with a material resistant to degradation such as plastic, metal, composite, or cemetitious product. Cover  22  is engaged with receptacle  10  and is movable to permit entry into interior space  20 . Cover  22  resists entry of sand and other contaminants into interior space  20  and can be positioned on the upper portion of receptacle  10  as shown in FIG. 1 of on a side of receptacle  10  as shown in FIG. 2. One or more apertures  24  are located in receptacle  10 , in cover  22 , or both to permit water entry into interior space  20 . As shown in FIG. 1, one or more apertures  24  can be incorporated within cover  22  to permit water entry. As shown in FIG. 2, aperture  24  can be connected to pipe  26  for the purposes described below. Although apertures  24  are illustrated in the side of receptacle  10 , apertures  24  can be located in cover  22  as shown in FIG. 3.  
         [0016]    In one embodiment of the invention, apertures  24  can be smaller than the particle size of sand  16  and other contaminants to resist entry into interior space  20 . In another embodiment, screen  28  can be integrated with one or more larger apertures to provide the function of resisting sand entry as shown in FIG. 3. Screen  28  can be formed with a rigid or flexible material resistant to degradation and can comprise expanded metal, plastic, composites, fibreglass, filter cloth, or other material. Screen  28  can be removable to facilitate damage repairs or to adjust the screen  28  mesh size. Screen  28  can be formed with a single material or a combination of materials.  
         [0017]    In one embodiment of the invention as shown in FIG. 2, aperture  24  can be positioned in a side of receptacle  10  for connection with pipe  26 . Multiple pipes  26  can be connected with receptacle  10  instead of the single pipe shown. Pipe  26  can comprise a perforated pipe having one or multiple branches  30  for installation in different portions of bunker  12 . FIG. 4 illustrates a plan view of bunker  12  wherein multiple branches  30  of perforated pipe  26  are positioned in bunker  12  to resist surface movement of water and to facilitate water drainage from the bottom surface of bunker  12 . One or more branches  30  can connect directly to receptacle  10  or such branches can be combined into a single trunk branch  32  connected to receptacle  10  as shown. Depending upon the configuration and various elevations of bunker  12 , more than one receptacle  10  can be installed at various low points within bunker  12 , and such receptacles  10  can be connected together with pipe  16  or each can separately drain to an outside location. Although pipe  26  is not essential to the operation of the invention, pipe  26  removes water from the surface of bunker  12  at different locations and reduces the horizontal migration of water within bunker  12 . This feature reduces the impact of erosion on sand  16  during moderate rainfall. For events of heavy rain, excess water can flow along the surface of bunker  12  or through sand  16  and enter receptacle through one or more apertures  24 .  
         [0018]    Referring to FIG. 2, receptacle  10  has one or more outlets  34  for discharging water from interior space  20 . Outlet  34  can be connected to conduit  36  for transporting water to another location by gravity fall or by a pump mechanism (not shown). Outlet  34  can be positioned flush with the bottom of interior space  20  or can be elevated above such bottom as illustrated to trap sediments within receptacle  10  for subsequent removal. If desired, filter  38  can be positioned proximate to outlet  34  to restrict sediment particles from outflow into conduit  36 .  
         [0019]    As shown in FIG. 1, handle  40  can be attached to cover  22  to facilitate removal of cover  22  from engagement with receptacle  10 . Handle  40  can be attached to the top of cover  22  as shown or to the sides of cover  22 . In one embodiment of the invention, one or more hinges  42  can connect cover  22  to receptacle  22 . If cover  22  is located on the upper portion of receptacle  10 , cover  22  is preferable strong enough to withstand impacts from persons or equipment or other animate or inanimate object travelling over or stepping onto cover  22 . The size and configuration of apertures  24  located in cover  22  can be smaller than a person&#39;s foot to resist damage caused by overlying foot traffic.  
         [0020]    By positioning sand on top of receptacle  10  or cover  22 , the presence and function of cover  22  is not readily apparent to golfers, leading to relatively uninterrupted golf play. This feature of the invention is particularly significant because a golf ball resting on top of receptacle  10  or cover  22  can be played from the overlying sand  16  surface, therefore providing uninterrupted play regardless of location.  
         [0021]    The invention provides superior benefits regarding the installation cost, operability, and maintenance costs associated with sand bunkers on golf courses and other applications. Costly replacement of perforated drain pipe systems is essentially eliminated, since cover  22  provides access to interior space  20  within receptacle  10  to facilitate routine sediment removal. Sediment is easily removed from interior space  20 , from upstream pipe  26 , and from downstream conduit  36 . Pipe cleaning tools can be operated through cover  22  and moved upstream through pipe  26  (or downstream through conduit  36 ) to remove sediments intruding into pipe  26  without requiring upstream location of pipe  26  ends, and without requiring removal of pipe  26  from soil  14  or sand  16 . Underground maintenance can be performed through cover  22  and receptacle  10  without interfering with golf play, and without significantly disrupting the sand surface of bunker  12 . These features of the invention permit ongoing maintenance of golf bunkers without causing expensive cessation of golf play opportunities.  
         [0022]    By providing cover  22  independent from receptacle  10 , the configuration of apertures  24  or the size and composition of screen  28  can be adjusted to adapt to field conditions or to permit change in the composition of materials such as a change in the bunker sand  16 . Screen  28  can comprise a single material or a composition of different materials or layers and can include screen and embedded strength components.  
         [0023]    To enter interior space  20 , the position of receptacle  10  can be mapped regarding its location and sand  16  is removed from the relatively small region overlying cover  22 . After cover  22  is located, cover  22  can be completely detached from receptacle or otherwise moved relative to receptacle  10  to permit inspection or maintenance entry into interior space  20 . When finished, cover  22  is reinstalled relative to receptacle  10  and sand  16  is replaced over cover  22  to restore bunker  12  to the original playing surface.  
         [0024]    Although the invention has been described in terms of certain preferred embodiments, it will become apparent to those of ordinary skill in the art that modifications and improvements can be made to the inventive concepts herein without departing from the scope of the invention. The embodiments shown herein are merely illustrative of the inventive concepts and should not be interpreted as limiting the scope of the invention.