Abstract:
A floating pond skimmer is coupled by a fluid conduit to a remote filter/aerating apparatus. The skimmer sucks a mixture of solids and water, grinds/chops the solids, and pumps the reduced solids and water through the conduit to the filter/aerating apparatus which separates the solids from the mixture and aerates the water from the mixture. The floating skimmer preferably includes a vortex chamber, an on-board pump with a grinding impeller, an adjustable ballast, and an anchor. The filter/aerating apparatus includes an inclined screen and a drain tray beneath the inclined screen coupled to a water discharge conduit. Optionally, an aeration pump is coupled to the discharge conduit. Also optionally, a removable solid waste hopper is located at the lower end of the inclined screen. Otherwise the solid waste simply falls into a compost pile at the bottom of the inclined screen.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to skimmers for ponds and the like. More particularly, the invention relates to a combined skimmer, filter, and aeration apparatus as well as methods for its use.  
         [0003]     2. State of the Art  
         [0004]     Backyard ponds are very popular in many parts of the country. Ponds may vary in size from only a few square feet of surface area to one or more acres. The larger ponds are usually naturally formed whereas the smaller ponds are typically man-made. Solid waste invariably accumulates on the surface of a pond. Leaves, weeds, and other organic matter are among the most common solid waste found on the surface of ponds. In cases where the pond contains nutrients, such as fertilizers which run off surrounding land into the pond, different kinds of organic growth can live on the surface of the pond. The most common kinds of organic growth are watermeal and duck weed. In the case of small ponds, floating waste is easily removed with a hand skimmer or strainer. The larger ponds are not so easily cleaned. Eventually, the wind will blow most of the floating waste to an edge of the pond where it can be collected with hand skimmers or strainers. But the volume of waste in a larger pond calls for an automated solution.  
         [0005]     Electrically operated pond skimmers are well known. Typical of the known pond skimmers are those sold by PondSweep Manufacturing, Co., 1204 Deer Street, Yorkville, Ill. 60560 and described in U.S. Pat. No. 5,584,991. These skimmers generally consist of an enclosure having side walls defining an internal chamber, typically two to three feet deep, which is permanently installed in a hole adjacent to the pond. A water inlet is formed near the top of the chamber adjacent to the surface of the pond water. Filter media such as various nets, screens, and/or baskets, depending on the particular model, are placed beneath the water inlet. A pump or a pump chamber is disposed beneath the filter media. The pump pumps water out of the chamber thereby causing a void which is filled by water from the surface of the pond. Debris which is floating near the water inlet is entrained by the water into the chamber and is captured by the filter media. Over time, the skimmer fills with debris and must be emptied. This involves removing the top of the enclosure and reaching down into the below ground container to remove the debris and clean the filter media. One might consider this periodic cleaning a disadvantage. However, it is generally accepted that all existing pond skimmers require some sort of periodic cleaning.  
         [0006]     Existing pond skimmers are fixed in position and admit water and debris through a floating weir door. The floating weir door will automatically adjust for some changes in the water level of the pond. However, most natural ponds exhibit changes in water level which are beyond the range of the floating weir door. When the water level moves beyond the range of the floating weir door, the skimmer is inoperable.  
         [0007]     It is apparent that a pond skimmer will only skim debris which is close enough to the water inlet. Depending on the size of the pond, and the prevailing winds, some debris may never reach the water inlet of the skimmer. The only solution to this problem is to install additional skimmers around the pond perimeter or to provide some way of generating a water current flowing towards the skimmer. Most people prefer the second option and this is typically accomplished with an artificial waterfall, a fountain, or a deep water aerator. Waterfalls and fountains are desirable, because, in addition to their aeration function which is good for the ecology of the pond, they are aesthetically pleasing. Waterfalls work well in man-made ponds which are designed for a waterfall and skimmer cooperation but may be impractical in natural ponds, depending on their size and shape. If a waterfall is not used, some sort of aeration device is desirable.  
       SUMMARY OF THE INVENTION  
       [0008]     A system according to the present invention includes a floating pond skimmer coupled by a fluid conduit to a remote filter apparatus. Although the invention is described with reference to ponds, it is intended that the invention be applicable to any suitable watercourse including lakes and streams, etc. The floating skimmer preferably includes a vortex chamber and an on-board pump with a grinding/chopping impeller or similar apparatus for reducing solids to pieces. The filter apparatus includes an inclined screen and a drain tray beneath the inclined screen coupled to a water discharge conduit. The skimmer sucks a mixture of solids and water, reduces the solids, and pumps the reduced solids and water through the conduit to the filter apparatus which separates the solids from the mixture. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is an exploded view of a first embodiment of a floating skimmer unit according to the invention;  
         [0010]      FIG. 2  is a partially transparent top view of the skimmer unit of  FIG. 1 ;  
         [0011]      FIG. 3  is a partially transparent side elevation view of the skimmer unit of  FIGS. 1 and 2 ;  
         [0012]      FIG. 4  is a partially transparent side elevation view of a filter apparatus according to the invention;  
         [0013]      FIG. 5  is a schematic illustration of the system shown in a pond;  
         [0014]      FIG. 6  is a transparent top view of a second embodiment of a skimmer according to the invention;  
         [0015]      FIG. 7  is a transparent side view of the second embodiment of the skimmer according to the invention;  
         [0016]      FIG. 8  is a transparent top view of a third embodiment of a skimmer according to the invention;  
         [0017]      FIG. 9  is a transparent side view of the third embodiment of the skimmer according to the invention;  
         [0018]      FIG. 10  is a transparent top view of a fourth embodiment of a skimmer according to the invention;  
         [0019]      FIG. 11  is a transparent side view of the fourth embodiment of the skimmer according to the invention;  
         [0020]      FIG. 12  is an exploded perspective view of a fifth embodiment of the skimmer  
         [0021]      FIG. 12   a  is a transparent side elevational view of the skimmer of  FIG. 12  assembled;  
         [0022]      FIG. 13  is an exploded perspective view of a second embodiment of the filter apparatus;  
         [0023]      FIG. 13   a  is a transparent side elevational view of the filter of  FIG. 13  assembled with the removable tray;  
         [0024]      FIG. 13   b  is a transparent side elevational view of the filter of  FIG. 13  assembled with the removable chute;  
         [0025]      FIG. 14  is a plan view of a skimmer unit according to the invention illustrating the water inlets;  
         [0026]      FIG. 15  is a perspective view of an impeller;  
         [0027]      FIG. 16  is a plan view of the impeller of  FIG. 15 ;  
         [0028]      FIG. 17  is a schematic view of a skimmer system equipped with an oscillating travel feature; and  
         [0029]      FIGS. 18   a - 18   c  illustrate the operation of the spring suspension when the skimmer is powered up. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     Referring now to  FIGS. 1 through 3 , a floating skimmer  10  according to the invention includes a floatbody base  12 , a float body  14 , and a removable lid  16 .  
         [0031]     The floatbody base  12  includes a pump well  18  having cooling holes  20  and an outlet hole  22 , and four mounting holes  24 ,  26 ,  28 ,  30 . The pump well  18  is dimensioned to receive the pump  32 . According to the illustrated embodiment, the pump  32  has a three inch inlet  34  and a two inch outlet  36  and a waterproof power cord  37 . As mentioned above, the pump is preferably provided with a grinding or chopping impeller (not shown). A suitable pump has a capacity of approximately 4,000 to 6,000 gallons per hour.  
         [0032]     The floatbody  14  has a central vortex chamber  38  having a lower outlet  39 . The vortex chamber  38  is surrounded by four mounting holes  40 ,  42 ,  44 ,  46 . Spaces  48 ,  50  on either side of the vortex chamber  38  are adapted to receive respective ballast containers  52 ,  54  which are held in place with poured polyurethane foam  56 .  
         [0033]     The floatbody base  12  and the floatbody  14  are coupled to each other by threaded rods  58 ,  59 ,  60 ,  62 . The rods  58 ,  59  fit into holes  42 ,  46   26 , and  30 , and are provided with “combs”  61 ,  63  which prevent large objects (including small animals) from being sucked into the vortex chamber  38 . The rods  60 ,  62  fit into holes  24 ,  28 ,  40 , and  44 . The bottoms of the rods  60 ,  62  are fastened to L-shaped brackets  68 ,  70  with nuts  64 ,  66 . The brackets  68 ,  70  form anchor points for connecting the skimmer  10  to one or more anchors (not shown). The tops of the rods  60 ,  62  are fastened to the floatbody  14  with nuts  72 ,  74  and washers  76 ,  78 . The removable lid  16  is fastened to the rods  60 ,  62  with threaded knobs  80 ,  82 . As seen in  FIGS. 1-3 , the removable lid allows access to the adjustable ballast containers  52 ,  54  and the vortex chamber  38  for cleaning. The ballast containers are said to be “adjustable” because the amount of ballast contained by them can be adjusted by adding or removing ballast.  
         [0034]     The skimmer  10  is preferably made from thermoformed ABS plastic and has overall dimensions of approximately 22 inches by approximately 32 inches by approximately 15 inches deep. The horizontal distance between the rods  60 ,  62  is approximately 20 inches. Floatation is achieved with approximately 1.25 cubic feet of foam ( 56  in  FIG. 1 ). The ballast containers  52 ,  54  are, according to this embodiment, filled with sufficient ballast so that the water inlets of the skimmer remain about 1.5 inches below the water surface. The pump  32  is preferably a ½ HP sump pump (manufactured by Barnes Pumps, Inc., Mansfield, Ohio) modified to have a chopping or cutting and/or grinding impeller ( FIGS. 15, 16 ) or a ½ HP sewage cutter pump model SC-50 manufactured by Stancor, Inc. Monroe, Conn. With either of these pumps and using a two inch flexible conduit, the filter apparatus may be located several hundred feet from the skimmer.  
         [0035]     As mentioned above, the outlet  36  of the skimmer pump  32  is coupled by a flexible conduit  84  (shown partially in  FIG. 2 ) to a remote filter apparatus  100  ( FIG. 4 ). Turning now to  FIG. 4 , the filter apparatus  100  has an inclined screen  102  and a drain tray  104  disposed beneath the screen. The inlet  106  to the filter  100  is disposed above the screen  102 . A deflector  108  is preferably provided above the screen  102  to deflect water through the screen  102 . The drain tray  104  is provided with a water outlet  110  which is optionally coupled to an aerator before returning to the pond. According to one embodiment, a removable tray  112  is located at the lower end of the inclined screen  102  and the entire filter assembly  100  is provided with a hinged cover  114 . According to another embodiment, the filter assembly is provided with a chute for emptying onto a compost heap.  
         [0036]     The filter apparatus  100  is preferably made from a frame of PVC pipe and thermoformed ABS plastic members. The overall dimensions are approximately 46 inches long by approximately 20 inches wide by approximately 18 inches tall. The screen  102  is approximately twelve inches long and is inclined at approximately 14 degrees.  
         [0037]     Referring now to schematic  FIG. 5 , according to the invention, the floating skimmer  10  is located in an appropriate location on the pond surface PS and anchored in place with anchors  90 ,  92 . The remote filter apparatus  100  is also located in an appropriate location, and the skimmer is coupled to the filter apparatus with a flexible conduit  84 . After the units are located, power is applied to the pump in the skimmer and water and solid debris are sucked into the vortex chamber of the skimmer. The solid debris is ground or chopped fine by the pump and the water and reduced solids mixture is pumped through the conduit to the filter apparatus. The reduced debris is separated from the water by the screen in the filter and is either deposited in the removable tray or allowed to fall onto a compost heap. The water from the filter is optionally aerated and returned to the pond.  FIG. 5  illustrates an optional aerator  200  which is coupled by a conduit  184  to the water outlet  110  of the filter apparatus  100 . As conditions change, e.g. wind changes, seasonal changes, the skimmer and/or the filter apparatus may be moved to a different location.  
         [0038]     The appropriate location of the skimmer is typically close to the debris or where it is likely to catch the most debris. The appropriate location of the filter is governed primarily by the length of the conduit connecting the skimmer and the filter. Aesthetic considerations may also be important in choosing the appropriate locations for the skimmer and the filter.  
         [0039]     Turning now to  FIGS. 6 and 7 , a second embodiment of a skimmer  210  is illustrated schematically. The reference numerals in  FIGS. 6 and 7  are similar to those in  FIGS. 1-3 , increased by 200, and refer to similar parts of the skimmer  210 . As seen best in  FIG. 6 , the floatbody  214  is generally elliptical. In this embodiment, the vortex chamber  238  is hemispherical or nearly hemispherical. It is generally preferred that the vortex chamber be as close to hemispherical as possible and at least closer to hemispherical than elliptical. In any case, it is preferred that the vortex chamber be symmetrical about all three axes. In this embodiment, the pump  232  is mounted horizontally as in the first embodiment. The center of the vortex chamber is slightly off center of the floatbody. Floatation material  256 ,  257  is placed in the spaces  248 ,  250  on either side of the vortex chamber. As seen best in  FIG. 7 , the floatation material is less dense at the low end than at the upper end. The decrease in density at the lower end of the floatation is effected by forming ridges in the foam material.  
         [0040]      FIGS. 8 and 9  illustrate a third embodiment of a skimmer  310  according to the invention. In these Figures similar reference numerals (increased by 300) refer to similar parts as those in  FIGS. 1-3 . This embodiment differs from the second embodiment in that the vortex chamber  338  is located substantially to one side of the floatbody  314  and thus, all or substantially all of the floatation material  356  is located in the space  348  on one side of the vortex chamber.  
         [0041]      FIGS. 10 and 11  illustrate a fourth embodiment of a skimmer  410  according to the invention. The reference numerals in these Figures are similar to the reference numerals in  FIGS. 1-3  (increased by 400 and refer to similar parts of the skimmer. In this embodiment, the vortex chamber  438  is centrally located relative to the floatbody  414  and the pump  432  is mounted vertically. Substantially equal amounts of floatation material  456 ,  457  are placed in the spaces  448 ,  450  on opposite sides of the vortex chamber  438 .  
         [0042]      FIG. 12  illustrates the components of the fifth embodiment of the skimmer  510  and  FIG. 12   a  illustrates those components assembled. This embodiment includes a lower pump housing  512 , an upper housing cover  514 , and a removable lid  516 . The lower pump housing  512  is substantially elliptical and includes mounting holes  524 ,  528  at opposite ends of the housing  512 . A pump  532  has an inlet  534  coupled to the drain  539  of a substantially hemispherical vortex chamber  538 . The pump  532  has an outlet (not shown) and a waterproof electrical cord  537 .  
         [0043]     The upper housing cover  514  has mounting holes  540 ,  544  which align with the mounting holes  524 ,  528  in the lower pump housing  512  when assembled. The upper housing  514  provides spaces  548 ,  550  for floatation material  556 ,  557 , preferably polyurethane foam, and has side openings  561 ,  563  which allow water and debris to enter the vortex chamber  538  when the upper and lower housing parts are assembled.  
         [0044]     Threaded rods  558 ,  560  enter the mounting holes  524 ,  528 ,  540 ,  544  and are used to hold the upper and lower housings  514 ,  512  together with the floatation members  556 ,  557  in the spaces  548 ,  550 . More particularly, the lower end of rod  560  is provided with a threaded anchor plate  568  which is coupled to a larger anchor plate by  570  by screws  572 . A similar arrangement (not shown) exists between rod  558  and anchor plate  571 . The upper ends of the rods  558 ,  560  are engaged by nut and washer assemblies  576 ,  578 ,  580 ,  582 .  
         [0045]     The floatation material and the threaded rod assemblies are arranged so that the water inlet of the skimmer remains approximately 1.5 inches below the water surface.  
         [0046]     The skimmer  510  is also preferably provided with handles  584 ,  586  which allow the skimmer to be easily lifted out of the water and placed into the water.  
         [0047]     The outlet (not shown) of the pump  532  is coupled via a two inch male adapter  588  to a length of ABS pipe  590  which is coupled via a two inch female adapter to a hose (not shown). Two U-brackets  594 ,  596  are used to secure the pump  532  to the anchor plate  571 . The open ends of the U-brackets are closed by rods  598 ,  600  and nuts, e.g.  602 , with the pump then secured in the brackets. The upper closed ends of the brackets are secured to the plate  571  with screws, e.g.  604 .  
         [0048]     According to the illustrated embodiment each rod  558 ,  560  is covered with a coaxial spring assembly, e.g.  610 , which acts as a shock absorber. The spring assembly includes three washers, a PVC spacer and a spring all placed over a threaded rod. According to the illustrated embodiment, from top to bottom, the arrangement is washer, spring, washer, spacer, and washer.  
         [0049]     As seen best in  FIG. 12   a,  the unit has a main pump housing and vortex chamber portion, which has slight negative (but weight balanced) buoyancy and a cover/floatation/suspension portion which provides overall positive buoyancy and is adjustable for different skimming depths. Notable features of this arrangement are:  
         [0050]     a) The main portion contains foam  555  around the pump  532 , which is offset from the center, designed to allow the main portion to be slightly negatively buoyant but even—that is, not overly heavy on either side.  
         [0051]     b) The cover portion has foam  556 ,  557  for floatation but also for suspension. This foam is fixed to the “ceiling” or top of the cover, and may use either a solid or a triangular finger configuration, with the fingers pointing downward. A significant amount of the foam is designed to be above water level, so that if a bird lands on the unit its weight will not submerge the unit. In operation, the main portion is suspended from the cover unit, held in place by the threaded rods, and its depth adjusted by the threaded knobs.  
         [0052]     c) The two portions are joined by the threaded rods with coaxial springs, washers and spacers. The springs operate during start up to stabilize the unit. After the unit has been placed in the water and has filled with water, it may be powered up. At that time, the pump will immediately pull a large amount of water from the vortex chamber, making the main portion more buoyant. As the main portion begins to rise up in the water, the springs compress and lift the top unit further out of the water, thereby reducing overall system buoyancy. As more water rushes into the vortex chamber, the system settles and stabilizes.  
         [0053]     d) Use of the springs, spacers and threaded rods allows variation of the skimming depth for different applications (for example, small particle skimming would be done at a very shallow depth, skimming ponds with walnuts in them would be done at a greater depth). The skimming depth is adjusted by rotating the threaded knobs to tighten or loosen the spring, or by substituting different springs or spacers in the suspension before installation.  
         [0054]      FIGS. 18   a,    18   b,  and  18   c  clarify the operation of the suspension and the interaction between the floating upper portion and the lower portion after the skimmer is placed in the water ( FIG. 18   a ), during start-up ( FIG. 18   b ), and during normal steady-state operation ( FIG. 18   c ).  
         [0055]      FIG. 18   a  shows the skimmer after it has been placed in a body of water  1100 , but before the pump  1150  has been turned on. The floating upper portion  1110  provides buoyancy to keep the skimmer afloat. The lower portion  1120  is suspended from the floating upper portion  1110  by threaded rods  1170 . Preferably, the lower portion  1120  is negatively buoyant when it is filled with water so that it hangs down from the floating upper portion  1110 , suspended by the threaded rods  1170 .  
         [0056]     The lower portion  1120  includes a vortex chamber  1140  that is connected to a pump  1150  via a suitable conduit. The lower portion  1120  also includes one or more water inlets  1130  and a water outlet  1160 . Once the skimmer is placed in the water  1100 , water  1100  will enter via the water inlets  1130  and fill up the vortex chamber  1140 . In the illustrated embodiment, the top of the floating upper portion  1110  floats at a height H 1  above the surface  1101  of the water  1100  during this state.  
         [0057]     When the pump  1150  is turned on, the pump sucks most of the water out of the vortex chamber  1140  and directs it out of the skimmer via the water outlet  1160 . As the water leaves, air rushes into the vortex chamber  1140 . As a result, the buoyancy of the lower portion  1120  increases, and the lower portion  1120  rises upwards. As the lower portion  1120  rises upwards, it presses up on the lower end of the springs  1175 . The springs  1175 , in turn, exert an upward force on the floating upper portion  1110 . This lifts the floating upper portion  1110  to the position shown in  FIG. 18   b,  where the top of the upper portion  1110  is momentarily at a height H 2  (H 2 &gt;H 1 ) above the surface  1101 . As the skimmer rises, the springs  1175  will also compress, absorbing some of the energy.  
         [0058]     Eventually, the springs  1175  decompress and push the lower portion  1120  away from the floating upper portion  1110 . The skimmer settles down in the water  1100  to a position where the water level  1101  is higher than the lower lip of the water inlets  1130 , as seen in  FIG. 18   c.  The springs  1175  operate to stabilize the skimmer by damping the up and down motion of the lower portion  1120  during start up, thereby reducing the shock to the system. This prevents the skimmer from popping in and out of the water, or at least reduces such popping. In this state, the top of the floating upper portion  1110  is at a height H 3  (H 2 &gt;H 3 &gt;H 1 ) above the surface  1101 , and water  1100  pours into the vortex chamber  1140  through the water inlets  1130 . The lower portion  1120  may be negatively buoyant in this state so that it hangs down from the floating upper portion  1110 , suspended by the threaded rods  1170 . Alternatively, the lower portion  1120  could be slightly positively buoyant in this state so that it presses up lightly against the springs  1175 .  
         [0059]     Due to the shape of the vortex chamber, the position of the water inlet  1130  and the operation of the pump  1150 , a water vortex  1105  forms in the vortex chamber, and the inpouring water is pumped by the pump  1150  out through the water outlet  1160 . Forming a vortex is advantageous because it draws floating debris into the pump  1150  and out through the water outlet  1160 . The skimmer may be operated in this state indefinitely (i.e. for the operational lifetime of the pump) as long as power is applied. Water  1100  will continue to flow in via the water inlets  1130 , form a vortex  1105  in the vortex chamber  1140  and be pumped out of the water outlet  1160  by the pump  1150 .  
         [0060]     During the steady-state operation, the lower lip of the water inlets  1130  is below the surface  1101  of the water. The depths of the lower lip of the water inlets  1130  below the surface  1101  can be adjusted by turning the threaded knobs  1172  so as to raise or lower the lower portion  1120  with respect to the floating upper portion  1110 , so as to provide the skimming depth desired by the user (depending on, for example, the type of debris that is being skimmed). For a sample skimmer, the heights H 1 , H 2 , and H 3  shown in  FIGS. 18   a,    18   b,  and  18   c  were measured as 2.0 inches, 3.28 inches, and 2.75 inches, respectively.  
         [0061]      FIG. 13  illustrates the second embodiment of filter apparatus  700 . Like the filter apparatus  100  shown in  FIG. 4 , the apparatus  700  includes an inclined screen  702  and a drain tray  704 . The inlet  706  is disposed above the screen  702  and a flexible skirt deflector  708  is provided downstream above the screen  702 . The drain tray  704  is provided with a pair of water outlets  710  and a removable tray  712  is located at the lower end of the inclined screen. A removable cover  714  is provided over substantially all of the assembly.  
         [0062]     The inclined screen  702  is preferably a stainless steel mesh supported by a stainless steel rod support  716  in an aluminum frame  718 ,  720 . Screens of different mesh size may be provided for different applications. For example, 1,000 micron mesh (normal window screen material) may be suitable for some applications, such as those often treated with a “lake rake”. Five hundred micron mesh may be more suitable for duck weed and the like. One hundred eighty micron is probably most suitable for watermeal.  
         [0063]     The drain tray  704  is provided with a rubber cross stop  703  for stability.  
         [0064]     The outlet  706  is coupled by an aluminum collar  707  to a pivot hinge  705 . The pivot hinge  705  is coupled to the cover  714  and to a tube frame  742  by a pivot bolt  744 .  
         [0065]     The flexible skirt  708  is coupled to a plastic screen housing  726  having an upper LEXAN window  728  via an aluminum screen frame  730 ,  732 . The window  728  allows inspection of the screen  702  and the skirt  708  helps direct the water through the screen  702 .  
         [0066]     The removable tray  712  has a bottom stainless steel screen  722  supported by a stainless steel rod support mesh  724 .  
         [0067]     According to the embodiment shown in  FIGS. 13, 13   a,  and  13   b,  the filter apparatus  700  includes a removable chute  734  which can be placed in the drain tray  704  in place of the removable tray  712 . The chute  734  is provided with a bottom opening  736  covered by a screen support mesh  738  and a stainless steel screen  740 . It will be appreciated that both the removable tray  712  and the chute  734  allow water to pass through their bottoms into the drain tray  704 . The removable tray  712  collects filtered debris which may then be carried to another location. The chute  734  allows debris to exit its open end  735  into a compost heap, for example.  
         [0068]     The filter apparatus  700  is preferably built on an aluminum tube frame  742  which is provided with extension legs  748 ,  750  which are locked in place by, e.g. cross bolts such as cross bolt  746 . This allows the overall height of the apparatus to be adjusted. It also allows the unit to be located on uneven ground. These legs and the chute allow the unit to be positioned to dump solid waste into a wheelbarrow or garden cart.  
         [0069]      FIG. 14  illustrates the configuration for the inlets to the vortex chamber  238 . In particular, one wall ( 802 ,  806 ) of each inlet is nearly straight and the other wall ( 804 ,  808 ) is curved. In this embodiment, no “combs” ( 61 ,  63  in  FIG. 1 ) are used.  
         [0070]      FIGS. 15 and 16  illustrate a chopping or cutting and/or grinding impeller which can be used in any of the embodiments. The impeller has a substantially circular base  902  with a central mounting hole  904  and two upstanding curved walls  906 ,  908 . The walls spiral inward toward the mounting hole and terminate with sharp edges. As seen in  FIGS. 15 and 16 , the sharp edges include teeth and taper from bottom to top. It will be appreciated that other means for reducing solids could be provided. For example, grinding or chopping blades could be provided separate from the pump impeller.  
         [0071]      FIG. 17  is a schematic illustration of a skimmer head having an oscillating jet which causes it to “sweep”. This arrangement  1000  includes a skimmer head  1002  according to the invention. The pump outlet of the skimmer head  1002  is coupled to a short T connector  1004 , one outlet of which supplies an oscillating sprinkler head  1006 . A filter screen (not shown) may be placed between the T connector and the sprinkler head. The other outlet of the T connector is coupled to a first conduit  1008 . The first conduit  1008  is coupled to a second conduit  1012  via an anchor point  1010 . In operation, the oscillating sprinkler head causes the skimmer head to sweep back and forth in an arc about the anchor point  1010 . More particularly, some of the water pumped from the skimmer  1002  is directed through the filter screen (not shown) to the sprinkler head  1006  while the remainder of the water and entrained reduced debris is directed through the conduits  1008 ,  1012 . The water which is directed to the sprinkler head causes the sprinkler head to oscillate back and forth, e.g. through an arc of 180° or so. The water exiting the sprinkler head exerts a lateral force on the T connector which causes the skimmer, sprinkler head, and the T connector to all move in the direction opposite to the direction of the water flowing from the sprinkler head. As the sprinkler head oscillates, the direction changes, thus causing the skimmer to sweep back and forth in an arc. It will also be appreciated that the water exiting the sprinkler head is aerated and returned to the pond.  
         [0072]     The embodiments described above provide one or more of the following advantages:  
         [0073]     systems for removing solid waste from the surface of a pond or similar watercourse;  
         [0074]     a system for removing solid waste from the surface of a watercourse whereby collected solid waste is very easily removed from the system;  
         [0075]     a system for removing solid waste from the surface of a watercourse whereby the system is essentially self-cleaning;  
         [0076]     a system for removing solid waste from the surface of a watercourse which is easily movable from one location to another in the pond;  
         [0077]     a system for removing solid waste from the surface of a watercourse which can be used in cooperation with an aeration device;  
         [0078]     a system for removing solid waste from the surface of a watercourse which automatically adjusts for wide variation in the water level;  
         [0079]     a system for removing solid waste from the surface of a watercourse wherein the solid waste is reduced to prevent clogging; and  
         [0080]     a movable solid waste filter which is adjustable to reside on uneven surfaces.  
         [0081]     There have been described and illustrated herein methods and apparatus for removing floating solid waste from the surface of a pond. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular materials were described, it will be appreciated that the apparatus of the invention can be implemented utilizing different materials. Also, while particular sizes were described with respect to the pond skimmer and filter, it will be appreciated that both the pond skimmer and filter may be implemented in different sizes. Further, while particular hardware was described, it will be appreciated that different hardware could be utilized with respect to the pond skimmer and filter. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed.