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BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to garden ponds and protective grates for them.  
           [0003]    2. Description of the Related Art  
           [0004]    For as long as people have been gardening, landscapers have taken advantage of existing pools or ponds of water, or created new ponds of water, for both decorative and functional purposes in gardening. Such ponds typically are not intended for use for swimming or wading, but are installed for their visual appeal and/or as a holding pond for run-off.  
           [0005]    Unlined garden ponds have the disadvantage that they often leak water into the surrounding ground, requiring constant replacement of the water. It therefore has become common to either line the pond with a water impermeable liner (usually thick, flexible plastic), or to make the pond using a prefabricated insert (usually rigid plastic or metal). Both lined ponds and ponds made with an insert often have irregular shapes, e.g., to enable them to mimic natural ponds.  
           [0006]    Such garden pools or ponds are typically 20-100 cm deep, so they sometimes are deep enough for a small child to drown in. The solution to this problem typically used with swimming pools is to install a tall fence around the pool, but this would entirely defeat the aesthetic purpose of having the garden pond in the first place. Therefore, a garden owner to date simply had to accept the risk of having an open body of water, if they wanted a garden pond.  
           [0007]    In addition, garden ponds often are stocked with expensive decorative fish, such as Japanese koi. Unfortunately, raccoons, herons and other predators find koi in the shallow ponds to be quite attractive prey. Plants provide only limited protection for the fish. Many people do not object to the presence of the predators and do not wish to harm them, but the fish they are preying on can be quite expensive, so some way to better limit predation would be desirable.  
           [0008]    Finally, many dog owners will testify to problems with dogs swimming or rolling around in garden ponds. This often completely disrupts the plants and ecosystem in the pond, in addition to often causing odor problems for the dogs.  
         SUMMARY OF THE INVENTION  
         [0009]    These and other problems have been solved according to the present invention by providing a safety grate for the garden pond positioned slightly below the surface of the pond, so that it does not disturb the aesthetics of the pond, but prevents small children or dogs from falling into or swimming in the pond, and greatly restricts the possibilities for predation on any fish in the pond.  
           [0010]    The grate preferably is formed of a rigid open mesh the perimeter of which is shaped to match the shape of the pond, so that water can flow through it, plants can grow through it and fish can swim through it. The grate is mounted slightly below the surface of the pond, e.g. 2-40 cm, and should be strong enough to support at least a moderate sized child, and preferably a large adult. In addition, one or more supports may be provided in spaced relation to the edges of the grate where the grate is of substantial area to insure that all locations on the grate have adequate support.  
           [0011]    Preferably, the grate is removably mounted, so that it can be removed if work must be done to portions of the pond underneath the grate. This can be done conveniently by mounting the grate to the pond using suitable brackets and bolts, with additional support legs bolted in the middle if the pond has a large expanse. The legs may be provided with broad flat bases, or positioned on stones, to prevent them from poking through the pond liner.  
           [0012]    If the pond has a recirculation pump for circulating water between the pond and a fountain or stream and/or a filter, it may also be desirable to have an access hatch or opening in the grate positioned above the pump and/or filter. This would allow access to the pump or filter without the need to remove the entire grate. Such access hatch may also be useful if the pond has fish in it which may be larger than the size of the openings in the grate.  
           [0013]    The size of the openings in the grate will depend on the application. Smaller openings reduce the likelihood of a small foot or paw slipping through the grate, but very small openings make it difficult for plants or pond fish to grow or swim through the grate, so a balance is preferably struck for the particular application. If necessary, a tight mesh grating can be used, with occasional larger openings cut in the grate to allow plants to grow through the grate or large fish to swim through.  
           [0014]    The grate and mounting structures preferably are coated with a protective coating to reduce the likelihood of corrosion and to cover any sharp edges. They may also be formed of a corrosion resistant material.  
           [0015]    As will be apparent, the present invention provides a substantial reduction in the risk of accidental drowning, predation and animal swimming, while at the same time preserving the desired aesthetics of a garden pond. These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a perspective view of a grate according to the present invention positioned in a pond insert;  
         [0017]    [0017]FIG. 2 is a broken enlarged plan view of the grate of FIG. 1;  
         [0018]    [0018]FIG. 3 is a further broken, cross-sectioned elevation view through the edge of the grate, as viewed substantially along line  3 - 3  of FIG. 2;  
         [0019]    [0019]FIG. 4 is a broken cross-sectioned, side elevation view of the pond insert and grate, as viewed substantially along line  4 - 4  of FIG. 1, and showing fasteners and supports for the mounting of the grate in the pond insert;  
         [0020]    [0020]FIG. 5 is an exploded, perspective view of the grate support shown in FIG. 4;  
         [0021]    [0021]FIG. 6 is a broken, cross-sectioned, side elevation view, as viewed substantially along line  6 - 6  of FIG. 1, and showing a preferred embodiment of access hatch overlying a pond pump and/or filter;  
         [0022]    [0022]FIG. 7 is a plan view of the hatch substantially as viewed in FIG. 6 with a hatch cover;  
         [0023]    [0023]FIG. 8 is a broken cross-sectioned, side elevation view of the hatch as viewed substantially along line  8 - 8  of FIG. 7;  
         [0024]    [0024]FIG. 9 is a broken cross-sectioned, side elevation view through the hatch handle as viewed substantially along line  9 - 9  of FIG. 7; and  
         [0025]    [0025]FIG. 10 is a cross-sectioned, side elevation view similar to FIG. 4, but of a pond having a water impermeable flexible plastic liner and a preferred embodiment of grate in accordance with the principles of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    In FIG. 1 a grate  10  according to a preferred embodiment of the present invention is shown positioned in a garden pond or pond insert  12 . The pond insert  12  is typically pre-shaped in an irregular shape of a relatively rigid metal or plastic. The earth is excavated to receive the insert and is then back filled once the insert  12  has been positioned.  
         [0027]    The grate  10  is shaped to substantially match the shape of the garden pond insert  12 , and is positioned below the anticipated water level W/L of the pond as can be seen in FIGS. 1 and 4. Preferably, the grate is about 2-40 cm below the anticipated water level, more preferably, about 10-30 cm below the water level, and still more preferably about 15 cm below the water level W/L.  
         [0028]    A portion of the grate  10  is shown in more detail in FIG. 2. The grate  10  as shown in FIG. 2, is preferably formed of a welded wire mesh  14  which can be cut and trimmed to match the shape of the garden pond insert  12 . The gauge of the wire should be heavy enough to support the weight of a child and preferably an adult who may step or fall into the pond, and the size of the openings are preferably small enough to prevent the foot of a person or animal from falling through the openings but permit at least smaller fish to pass through if fish are to be present in the pond. By way of example it has been found that a wire gauge of about 12.5 and square openings of about 3.5 cm are generally satisfactory for these purposes.  
         [0029]    An edging  16  preferably surrounds and encloses the edges of the wire mesh. As best seen in FIG. 3, edging  16  preferably is U-shaped in cross-section having an outer covering  17  of for example plastic, and an internal metal spring channel  18 . The covering  17  also preferably has a barbed lip  19  running along one side of its inside surface to hold the irregular edges of the wire mesh  14 , as best seen in FIG. 3.  
         [0030]    A preferred embodiment of Z-shaped bracket  20  for mounting the grate  10  to the garden pond insert  12  is shown in FIG. 4. The bracket  20  has an upper generally horizontal leg  21  which extends outwardly with a bolt  22  extending downwardly from it. The bolt  22  is bolted through hole  23  in the garden pond insert  12 , and held in place by lock washer  24  and nut  25 . The bracket  20  also has a lower generally horizontal leg  26  which extends inwardly and has a pair of spaced bolts  27  and  28  which extend upwardly through wire mesh  14 , and are held in place by a plate  29 , and lock washers  30  and nuts  31 . The upper horizontal leg  21  and lower horizontal leg  26  are preferably formed integrally with and bent from a connector leg  32  to support the grate  10  below the pond waterline W/L.  
         [0031]    If the overall area of the pond is of substantial size and/or if it is desired to support a relatively heavy object on the grate  10  in spaced relation to the perimeter of the pond, it may be desirable to position one or more support stands, generally  34 , in spaced relationship to the pond edge as best shown in FIGS. 1, 4 and  5 . The support stand  34  preferably comprises a pair of plates  36  which may be identical to each other. The plates  36  include a collar  38  extending from one side of the plate. The collar  38  is open in its center  40 , as best seen in FIG. 5, to receive an extension piece  42  in the open center. Any one of several different length extension pieces, such as a longer piece  42  and shorter piece  44 , may be provided to permit selective construction of the support stand  34  to have any one of a number of different custom lengths depending upon the depth of the pond and the depth to which the grate  10  is to be submerged below the waterline W/L. A coupling extension piece  46  is also preferably provided to couple adjacent extension pieces  42  and  44 , as viewed in FIG. 5. Suitable holes  48  are provided in the collars  38  to align with comparable holes in extension pieces  42 ,  44  and  46  to receive bolts  50  to couple the extension pieces and plates  36  together so as to form a strong stationary support for the grate  10  and/or any heavy objects which may fall into the pond or are to be supported in the pond, such as a decorative rock R as shown in FIGS. 1 and 4. Nuts  51  are also preferably threaded onto the bolts  50  to firmly and securely fasten all of the parts together.  
         [0032]    A top plate  52  is also provided in overlying relationship to the grate  10 . Plate  52  preferably has holes  54  in its corners which align with corresponding holes  54  in the plates  36 , as best seen in FIG. 5. Bolts  56 , lock washers  57  and nuts  58  mount plate  52  to the plate  36  immediately beneath the grate  10  to firmly sandwich the grate  10  in between, as seen in FIG. 4.  
         [0033]    In order to assemble the support stand  34 , appropriate length extension pieces  42 ,  44  and  46  are selected which will result in the proper and desired height of the support stand  34  to span the height between the bottom of the pond insert  12  and the grate  10 , as seen in FIG. 4. One of the plates  36  is then positioned to rest on the bottom of the pond insert  12 , as shown in FIG. 4, with its collar facing upwardly. Another plate  36  is arranged on top of the assembled extension pieces with its collar  38  facing downwardly. The extension pieces  42 ,  44  and  46  are then bolted together, and to the collars  38  on the plates  36  with bolts  50  and nuts  51  to form a column, and the support stand  34  is then positioned as shown in FIG. 4. The support stand  34  assembly is completed by bolting a top plate  52  on top of the grate  10  with bolts  56  extending downwardly through the mesh openings in the grate, and the holes  54  in the corner of the top plates  36  and  52 . This assembly results in a very strong and sturdy support which should minimize the possibility of collapse in the event a person, child or large predatory animal falls or steps onto the grate  10 . The support stand  34  is also capable of supporting heavy decorative objects, such as a rather large rock R or heavy potted plant.  
         [0034]    If desired, an access hatch  60  may also be provided in the grate  10  as shown in FIGS. 1 and 6- 8  to permit ready access to a filter and/or pump P. This can be as simple as forming a hinged portion from the grate  10 , as shown in FIGS.  6 - 8 , or can be made of some other material, such as sheet metal. In the alternative, the hatch  60  may be simply an open hole without a cover. Although the latter would permit access through the grate  10  for larger fish, it may not prevent the possibility of someone or something from stepping through the hole. In either case, at least edging  16  as shown in FIGS. 2 and 3 is preferably provided around the inside of the opening in the grate  10  to strengthen the grate  10  and protect against cuts.  
         [0035]    Where the access hatch  60  is relatively large, and/or if it has a door  62 , a more substantial frame is preferred to insure that the grate  10  maintains sufficient strength. In such instance both the edge of the opening in the grate  10  and the edge of the door mesh are preferably framed using an extruded metal stock  64  as seen in FIGS.  6 - 9  of a non-corrosive material, such as aluminum. Such extruded stock typically has channels running the length of its sides which are capable of receiving the mesh  14  of the grate  10  and/or door  60 , as well as bolt assemblies  66  for attaching the channels using suitable retainer plates  68  to the mesh  14 , hinges  70  for pivotly mounting the door  60  on the grate  10  and/or a door handle  72  on the door  60 . The handle  72  is preferably used to support the door  62  in its closed position, as shown in FIGS.  6 - 9 , and open and close the door as shown in FIG. 6.  
         [0036]    A second embodiment of garden pond and grate arrangement is shown in FIG. 10.  
         [0037]    In some instances, a preformed pond insert is not employed. In these instances, the pond is simply excavated to form a hole H in the ground G which is of generally the depth and shape that is desired. Once the hole H has been formed, a simple flexible sheet-like liner  74  is positioned so as to line the hole, as seen in FIG. 10, to prevent the water from seeping into the ground G. Once the pond has been lined, whatever plants or the like are desired are positioned in the pond, the pond is filled and fish, if any, are added to the pond.  
         [0038]    The grate  10  of the present invention may also be employed in such simplified pond constructions which do not have a preformed rigid insert  12  as previously described with respect to FIG. 1. In these simpler installations, as the pond is being excavated, a narrow ledge  76  is formed about the perimeter of the pond at the depth at which it is desired to place the grate  10 . The flexible liner  74  is then positioned in the excavation to cover the bottom, the side walls and the ledge  76 , as well as the walls above the ledge as seen in FIG. 10. Once the liner  74  is positioned and whatever objects are to be placed into the pond have been positioned and located as desired, the grate  10  is then cut to fit the maximum perimeter of the ledge  76 , and the grate  10  with its edging  16  is then simply positioned as shown in FIG. 10 to rest upon the ledge beneath the waterline W/L. If desired, the support stand  34  and hatch  60  as previously described, may also be employed in this embodiment.  
         [0039]    Although the embodiment of FIG. 10 has been described in terms of a flexible liner  74  lining the walls of the hole H, it will be appreciated that the hole H may be lined with concrete or the like which is formed and set in place after the hole has been shaped. In such case either the brackets  20  or the ledge  76  may be employed as desired to support the grate  10 .  
         [0040]    While the grate  10  has been shown as formed of welded wire mesh, it could be formed of any suitable equivalent, such as expanded metal grates, plastic grates, punched sheet metal or plastic sheeting or the like.  
         [0041]    Similarly, any suitable mounting arrangement which will hold the grate in place and provide sufficient support for the grate can be used in place of the Z-shaped bracket  20 .  
         [0042]    Edging piece  16  may also be omitted if the edges of the wire mesh  12  or its equivalent either are not rough, such as a rolled edge on sheet metal, of if they are otherwise protected such as by the design of a shelf support in the garden pond insert.  
         [0043]    Preferably, most of the elements of the grate  10  are coated to protect them from corrosion and/or to cover any rough edges. Any suitable coating may be used, e.g. zinc, zinc alloy or any suitable plastic, such as polyvinyl chloride (PVC). The color of the grate  10 , its mesh  14  and its supports is preferably dark, and more preferably black, so that when the grate  10  is submerged somewhat beneath the water line W/L as herein described, the grate  10  and its components are virtually invisible to an observer viewing the pond.  
         [0044]    A grate  10  according to the present invention may conveniently be manufactured by starting with an outline of the perimeter of the garden pond into which the grate  10  will be installed, at the height the grate  10  will be installed. Wire mesh  14  then is cut to match the shape and size of this perimeter, normally with some tolerance allowed around the edge. Edging  16  then is bent to match this shape and mounted on the edge of the wire mesh  14 . If desired, the opening  60  may be cut through the wire mesh  14  and more edge  16  material mounted around the opening. If desired, the access hatch  60  can be mounted to wire mesh  14  with suitable hinges, latches and/or bolts over the opening as previously described. If the garden pond insert  12  and the grate  10  are being designed at the same time, the garden pond insert can be provided with a shelf around all or part of its periphery to support the grate  10  at the desired depth in a manner similar to that described with respect to FIG. 10.  
         [0045]    It will be understood that these exemplary embodiments in no way limit the scope of the invention. Other modifications of the invention will be apparent to those skilled in the art in view of the foregoing description. These descriptions are intended to provide specific presently preferred examples of elements, dimensions, materials or configurations contained therein. All alternative modifications and variations of the present invention which will fall within the spirit and scope of the appended claims are intended to be covered.

Summary:
A safety grate ( 10 ) is provided for a garden pond by mounting a grate ( 10 ) below the anticipated surface of the water in the pond. This reduces the risk of drowning in the pond, predators catching fish in the pond and animals swimming or rolling in the pond, while preserving the aesthetics of the garden pond. The grate ( 10 ) may have larger openings in it for plants and fish or for access to equipment in the pond. The openings may be covered with an access hatch to allow brackets, a support stand and/or a shelf to support the grate ( 10 ) at the desired depth in the pond.