Abstract:
The present invention is directed to a method and a vehicle designed for cleaning beaches that have been contaminated with substances such as tar balls. The device utilizes an inclined screen assembly on a vehicle and a pivoted hopper supported below the lower end of the inclined screen. As the trailer is on or moved along the beach, contaminated sand is placed on an upper portion of the screen. Sand falls through the screen back down to the beach surface but larger contaminants such as tar balls roll or slide down the screen into a collection hopper. The inclination of the screen assembly may be adjustable.

Description:
[0001]    BACKGROUND OF INVENTION 
         [0002]    1. Field of the Invention 
         [0003]    The invention described in this application relates to a mobile beach sand sifting device that is designed to remove waste material from beach sand and deposit the waste material in a suitable receptacle, while returning the sand to the beach surface. The device may also be used in any environment where it is necessary to separate coarse material from a mass of finer particulate material. A method of removing contaminants from sand on a beach is also disclosed. 
         [0004]    2. Description of Related Art 
         [0005]    Recent events have demonstrated the need for mobile beach-cleaning apparatus in the situation where an oil spill has occurred at sea. Semi-solid accumulations of oil known as tar balls wash up on beaches and need to be picked up and separated from the sand in an efficient manner. 
         [0006]    Known devices for cleaning sand on beaches tend to be large self-propelled vehicles such as that disclosed in U.S. Pat. No. 5,197,211. These units are very expensive, tend to require frequent maintenance and are not very maneuverable. Smaller units such as disclosed in U.S. Pat. No. 7,156,236 are more portable but are also far more complex and consequently more expensive than the current invention. They are also more prone to maintenance issues because they include complex mechanical subassemblies. They are also not particularly effective in picking up tar balls due to the nature of the sifting mechanisms. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The invention disclosed and claimed in this application overcomes the above noted deficiencies by utilizing a compact, maneuverable, and far less complex design. It includes a mobile frame supported by wheels. A towing arm is positioned at a front portion of the frame to form a trailer for attachment to a motorized vehicle. An inclined screen is supported on the frame. A hinged hopper is provided at the lower portion of the screen to collect larger bodies such as tar balls that have been separated out. The hopper can then be tilted to direct tar balls or other bodies into plastic bags for transportation to a treating facility. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0008]      FIG. 1  is a perspective view of the sifter according to an embodiment of the invention. 
           [0009]      FIG. 2  is a side view of the sifter shown in  FIG. 1 . 
           [0010]      FIG. 3  is a top view of the sifter shown in  FIG. 1 . 
           [0011]      FIG. 4  is a perspective view of a record embodiment of the invention. 
           [0012]      FIG. 5  is a side view of the embodiment of  FIG. 4 . 
           [0013]      FIG. 6  is a top view of the embodiment of  FIG. 4 . 
           [0014]      FIG. 7  is a partial perspective view of the L-shaped frame members. 
       
    
    
       [0015]      FIGS. 1-3  illustrate an embodiment of the invention. However it should be understood that this embodiment is one of many constructions that would occur to one with ordinary skill in the art. The particular frame structure and hopper construction can be varied as is known in the art. Similarly, the manner of attaching the sifter to a four wheel utility vehicle is not critical but can be accomplished in any one of the several known hitch arrangements for trailers. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring to  FIG. 1 , an embodiment of sifter  10  of the invention includes a first generally horizontal frame member  5 , a second generally vertical frame member  6  extending upwardly from the front portion of frame member  5  and a slanted or inclined frame member  12  sloping from the top of vertical frame member to the rear end portion of frame member  5 . Inclined frame member  12  supports a rectangular screen  35  secured to a frame in a known manner. The framed screen may be replaced by providing suitable releasable securing means between the inclined frame  12  and the screen frame. 
         [0017]    Sifter  10  may include side rails  14 ,  13  and transverse rails  15 ,  16 , and  17 . Referring to  FIG. 2 , at the rear portion of sifter  10  two L-shaped brackets  30  are provided to pivotably support a hopper  27  positioned slightly below the rear portion of screen  35 . Hopper  27  is hinged at its rear portion on both sides to member  31  of the L-shaped brackets  30 . Handle  28  is attached to hopper  27  so that hopper  27  can be pivoted about pivot  29  to discharge its contents. Supports (not shown) extending between the brackets  30  and  31  may be provided for supporting hopper  27 . 
         [0018]    Sifter  10  also includes two wheels  46  that are pivotably mounted to the frame in any known manner such as an axle or spindle  45  supported by the frame. Towing arm  21  is secured to the front portion of horizontal frame  10  as shown in  FIG. 1 . Coupling device  25  of any known design is positioned on the towing arm for allowing the sifter to be releasably connected to a suitable towing vehicle. The front end of the tow bar may also be provided with a height adjustable wheel assembly  26  that is connected to the draw bar in a known fashion. 
         [0019]    Vertical frame  11  includes a plurality of upright rails  49  and cross rail  19 . Inclined frame member  12  includes two side rails  22  and  23  and upper cross member  18  that form a frame for supporting screen assembly  35 . Intermediate cross member may also extend between rails  22  and  23  to support the screen assembly. A twelve volt vibrator  24  is attached to the overall frame structure at any suitable location so as to vibrate screen assembly  35 , thereby facilitating separation of the material placed on the top of the screen. A power cable  20  extends from vibrator  24  and may be connected to a twelve volt power source on the towing vehicle. Supporting rails  31 ,  33 ,  34  and  41  may further be provided to support the inclined frame  12  on the horizontal frame  10 . The various rail components as described above can be welded to each other to form a rigid assembly, or otherwise secured to each other in any known fashion.  FIGS. 4-6  illustrate a second embodiment of the invention which includes structure for adjusting the inclination of the screen. The same reference numbers have been used for similar elements in the drawings. 
         [0020]    In this embodiment lower frame  5  includes longitudinal beams  13 ,  14  and cross beams  15 ,  16  and  17 . A towing bar  21  extends between cross beams  15  and  17  and has a suitable coupling  25  for attachment to a power vehicle. Vertically adjustable wheel assembly  26  is attached to a forward portion of the towing bar  21 . Two vertical posts  9  and  11  are pivotally mounted at their lower end to longitudinal beams  13  and  14  by pivot assemblies  13   a ,  13   b  and  14   a ,  14   b  respectively. Inclined frame assembly  12  includes 2 L-shaped longitudinal members  22  and  23  and a front L-shaped cross member  18 . 
         [0021]    Members  22 ,  23  and  18  form a frame that is adapted to hold the screen and screen frame assembly in place. The screen frame may be releasably secured to the inwardly extending portion of the L-shaped frame members  22  and  23  by any suitable means such as a nut and bolt assembly passing through apertures in the L-shaped member and the screen frame as shown in  FIG. 7 . 
         [0022]    A pair of bracket members  22   c  and  23   c  are pivotably connected to the forward ends of longitudal frame members  23 ,  22  at  22   b  and  23   c . Bracket members  22   c  and  23   c  include a rectangular collar that slidably receives vertical frame members  9  and  11  and are perforated to receive locking pins  22   a  and  23   a . The rear portions of members  22  and  23  are pivoted to base frame members  13 ,  14  at  13   d  and  14   d.    
         [0023]    The inclination of the screen assembly can be adjusted by removing pins  22   a  and  23   a  and sliding brackets  22   c  and  23   c  up or down on the support posts  9  and  11 . Support posts  9  and  11  include a plurality of holes  9   a  and  11   a  that can receive pin  22   a.    
         [0024]      FIG. 7  illustrates the L-shaped frame members  18  and  23  including the vertical section  18   a  and  23   a  and the horizontal sections  18   b  and  23   b  that support screen and screen frame  35  and  35   a . Screen frame  35   a  is removably attached to L-shaped members  23  and  23  by any suitable means such as a plurality of nuts  51  and bolts  52 . 
         [0025]    The above described apparatus may be used to clean up any contaminants that are present on beaches, but is particularly useful for cleanup of tar balls that are deposited on beaches as a result of oil spills. In use, the sifter is attached to the towing vehicle at coupling  25 . The sifter is positioned on the beach or is slowly driven on the beach as contaminated sand is placed on the top portion of the screen assembly, either by workers (walking alongside the sifter) or by a front loader that has scooped up the sand and contaminants. As shown in  FIG. 3  the sand moves down the screen assembly and due to gravity it falls through the screen back onto the beach  36  but the tar balls  37  roll or slide down the screen into the hopper  27 . The hopper can then be tilted so that the tar balls can be transferred to plastic bags for easy collection. The apparatus increases the productivity of manual cleanup crews because instead of bagging the sand for disposal in a dumpster, the sand placed on the screen returns directly to the beach and only the tar balls need to be hauled away. 
         [0026]    Various modifications to the device can be made as would be apparent to one with ordinary skill in the art. More than one screen assembly with screens of varying mesh size can be utilized. Also, in lieu of a screen, a perforated thin metal sheet may serve as the filtering element. 
         [0027]    It is understood that modifications to the invention may be made as might occur to one skilled in the field of the invention within the scope of the appended claims. All embodiments contemplated hereunder which achieve the objects of the invention have not been shown in complete detail. Other embodiments may be developed without departing from the spirit of the invention or from the scope of the appended claims. Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.