Abstract:
A rotational molded plastic refuse container having side walls defining downwardly facing shoulders. A pair of metal side fork pockets each having outwardly extending flanges abutting one of said shoulders and being affixed thereto. The shoulders and the flanges functioning to bear the weight of the container and its contents when the container is being manipulated to empty its contents. A lid pivotally attached to the open upper end of the container and casters removably attached to the bottom of the container. ARFID tag disposed internally of at least one of the side walls.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to refuse containers and more particularly to an improved trash or refuse containers of the relatively large commercial sizes handled by mechanical refuse collecting trucks. More specifically, the invention is directed to such a container which is rotationally molded and includes two external side fork pockets secured to the outer walls of the container in such a manner to facilitate the lifting of the container with the forks of a refuse truck without damage to the container. 
         [0003]    2. Prior Art 
         [0004]    Refuse bins or containers of the type with which the present invention is concerned are generally fabricated of steel and provided with hinged steel lids. Such containers are relatively expensive to fabricate and have the disadvantage that they are subject to deterioration due to rusting caused by their outside storage. They also have a disadvantage that they are heavy and therefore difficult to handle. In addition because these metal containers are hollow they generate a great deal of noise when the refuse trucks handle them to empty the refuse from the container into the trucks. Recently attempts have been made to overcome the disadvantages of the prior art of metal containers by manufacturing such containers from plastic material. Such plastic containers have been formed in essentially the same shape as the prior art metal containers. In order to provide a lifting mechanism for the refuse trucks, metal sleeves, channels and skids have been bolted or otherwise attached to the outside surfaces of the plastic containers for receiving the forks of the typical refuse trucks. 
         [0005]    Because the forks of the refuse trucks have become substantially standardized in spacing, the prior art plastic and steel bins have been about the same capacity in size because the sleeves through which the forks are inserted are typically on the outside of the container such that the container must fit between the forks. In addition the mounting techniques for attaching the sleeves to the container have resulted in numerous occasions wherein the sleeves are pulled from the container destroying the ability of the refuse truck to lift and unload the container. Depending upon the degree of the damage done when the sleeves are pulled from the containers such damage may result in replacement of the plastic refuse containers. 
         [0006]    To overcome these problems a refuse container is known in which the sleeves or side fork pockets are secured to the container in such a manner that the plastic container rim supports the weight of the container when the container is lifted with the forks of a front load refuse truck. Such a structure places a great deal of stress on the molded plastic rim and in many instances causes a failure thereof. 
         [0007]    In further refuse containers of the type of which the present invention is concerned utilize a metal lift tube sleeve which is incorporated in the container during the rotational molding process. Such a structure is difficult to manufacture and adds additional expense. 
         [0008]    In many applications it becomes desirable to be able to maintain an accounting of the refuse containers including the weight of the contents thereof, the location thereof, the time when the refuse truck empties the contents of the container into the truck and the like. If such accounting was accomplished in the prior art, such was done by making manual entries either by hand or through the utilization of APDA or the like. 
         [0009]    There is therefore a need for a rotationally molded plastic refuse bin or container which is provided with metal sleeves or side fork pockets adapted to receive the forks of a refuse truck and which are attached to the outside of the refuse bin or container in such a manner that the weight of the container and the trash contained therein are supported by the container walls in such a manner that damage to the rotationally molded plastic container or the container rim is eliminated. There is also a need for providing apparatus for automatically accounting for the refuse container and the operational processes with regard thereto as the refuse container is being emptied by the refuse truck operators. 
       SUMMARY OF THE INVENTION 
       [0010]    A plastic container having a molded plastic body including a floor, a front wall, a rear wall, a first end wall, and a second end wall with the combination defining an open top plastic container which further comprises a downwardly directed shoulder on each of the first and second end walls, first and second metal side fork pockets secured to said first and second end walls respectively, each of said side fork pockets comprises means for abutting said shoulder, each of said side fork pockets including a lift tube for receiving a fork on a refuse truck and the combination of the abutting means and the shoulder supporting the weight of the container and its contents for manipulation and emptying. 
         [0011]    In accordance with the more specific aspect of the present invention there is also provided metal caster plates which are affixed to the bottom wall of the container. Casters are affixed to the caster plates in such a manner that the casters may be easily removed and replaced in the field thereby eliminating the necessity of returning the container for repair and replacement of casters. 
         [0012]    In accordance with the added further specific aspect of the present invention there is provided a molded plastic lid which is attached to a hinge which includes a metal bar affixed to the back of the container molded rim and includes a plurality of hinge plates secured thereto to allow the lid to hang freely behind the container without any binding. 
         [0013]    In accordance with yet a further added specific aspect of the present invention, there is provided an RFID tag which is insitu molded into a wall of the molded plastic container during the time that it is being molded. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a perspective view of a molded plastic refuse container constructed in accordance with the principles of the present invention; 
           [0015]      FIG. 2  is a perspective bottom view of the container as shown in  FIG. 1  with an unattached side fork and caster plates; 
           [0016]      FIG. 3  is a bottom perspective view similar to that of  FIG. 2  but with a side fork and caster plate attached; 
           [0017]      FIG. 4  is a front perspective view of a refuse container of the present invention with side forks and casters attached; 
           [0018]      FIG. 5  is a perspective view of a side fork attached to a side wall of the refuse container; 
           [0019]      FIG. 6  is a perspective view of a caster plate; 
           [0020]      FIG. 7  is a bottom perspective view showing a caster plate attached to the bottom of the refuse container with a caster attached thereto; 
           [0021]      FIG. 8  is a perspective view showing a back bar with hinge plates affixed thereto to which the lid for the refuse container is pivotally attached; 
           [0022]      FIG. 9  is a rear perspective view of an assembled refuse container constructed in accordance with the principles of the present invention with the lid open; 
           [0023]      FIG. 10  is a partial cross-sectional view of a portion of the front wall  12  of the container taken about the lines  10 - 10  of  FIG. 3 ; and 
           [0024]      FIG. 11  is a partial cross-sectional view of the wall of a rotational mold illustrating the positioning of an RFID tag prior to formation of the container. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    The plastic refuse container of the present invention is designed to be manufactured by rotational molding. However, the container may be manufactured by other manufacturing techniques without departing from the spirit or scope of the invention as defined by the claims. A plastic refuse container of this invention may have a volume of two, three, four, six, seven or eight cubic yards in interior volume and preferably is manufactured utilizing a medium density polyethylene plastic material or any other plastic material suitable for rotational molding 
         [0026]    Rotational molding takes places by melting thermoplastic resin in powder or pellet form in a biaxially-rotating, heated mold. The interior shape of the mold corresponds generally to the shape of the product to be molded. The particles of thermoplastic resin melt and puddle in the bottom of the mold. As the mold is rotated simultaneously through a vertical and horizontal axis all parts of the mold rotate through this puddle of thermoplastic material causing a thin layer of the material to coat the inner surface of the hot mold and fuse to the mold in layers. The process continues with the fused layers becoming progressively thicker until the desired product thickness is achieved and the layers have taken on the shape of the mold being used to form the product. A principal characteristic of a typical rotationally molded product is that it is hollow. The thickness of the walls of the molded product is controlled by the amount of powder or pellets with which the mold is charged before the biaxial rotation of the mold begins. 
         [0027]    After all of the plastic material has melted and fused to the interior walls of the mold the mold is moved to a cooling chamber where the mold is typically cooled by air and water or a mist of the two. The part in the mold cools to a point where the mold can be opened and the part removed. 
         [0028]    Referring now to the drawings and more particularly to  FIG. 1  there is illustrated a perspective view of a rotational molded plastic refuse container constructed in accordance with the principles of the present invention. The container  10  includes a front wall  12 , a first side wall  14 , a second side wall  16 , a rear wall  18  and a bottom wall  20 . The front wall  12  includes a plurality of reinforcing ribs as shown at  22  and  24 . The rear wail  18  is constructed in similar fashion having such reinforcing ribs formed therein. A pair of side fork pockets  26  and  28  are affixed to the side walls  14  and  16  respectively. A lid  30  is pivotally secured to the upper rear rim  32  of the rear wall  18  in a manner to be more fully described below. The plastic rotational molded refuse container as thus generally described and shown in  FIG. 1  provides a container having a hollow interior covered by a lid which may be in sections and when opened provides access to the interior of the container to allow it to receive refuse. The side fork pockets are secured to the side walls of the container in a manner to readily receive the lift forks on a fork bearing lifting apparatus of the type normally used on refuse collecting vehicles. 
         [0029]    Referring now more particularly to  FIGS. 2 ,  3 , and  4  a refuse container constructed in accordance with the principles of the present invention is further illustrated. As is therein shown, the bottom wall  20  of the container is also constructed with a plurality of reinforcing ribs such as shown at  34 ,  36 , and  38  to provide additional strength to the bottom of the container. It is of particular importance to note that the side wall  16  is constructed so that there is provided a downwardly facing shoulder  40  that extends completely across the width of the side wall  16 . As shown in  FIGS. 2 ,  3 , and  4  the distance between the side walls  14  and  16  is reduced at approximately one-third (⅓) the distance from the top of the container to form the downwardly facing shoulder  40 . The shoulder  40  has a width sufficient to support the weight of the container and refuse that is contained therein when the container is lifted as will be described more fully below. Also illustrated in  FIG. 2  is a side fork pocket  28  which is unattached and a pair of caster plates  42  and  44  which are unattached to the container. 
         [0030]    In  FIG. 3  the caster plate  42  is shown attached to the bottom  20  of the container through utilization of fasteners such as bolts and nuts illustrated at  46  through  52 . The side fork pocket  28  is also shown attached to the side wall  16 . As is illustrated, the side fork pocket  28  includes a means for abutting the shoulder  40  such as a flange  54  extending therefrom. The flange  54  mates with and abuts the downwardly facing shoulder  40 . A plurality of fasteners such as bolts and nuts  56  through  62  pass through the flange  54  and the downwardly facing shoulder  40  to affix the side fork pocket  28  to the side wall  16  of the container. An additional flange (not shown in  FIG. 3 ) extends upwardly from the side fork pocket along the upper portion of the side wall  16  and is also affixed to the side wall by fasteners to stabilize the side fork pocket. The opening  64  in the side fork pocket is adapted to receive the lifting fork of a refuse collecting vehicle. A protective plate  66  extends from the front opening  64  of the side fork pocket  28  and curves around to shield the edge of the front wall  12  of the container adjacent the side fork pocket. The purpose of the curved shield  66  is to accommodate the lifting forks on the refuse collecting vehicle. It will be recognized by those skilled in the art that the drivers of such vehicles will not always precisely align the lifting forks with the openings in the side fork pockets and will rely on the fact that the lifting forks are connected to the fork lifting vehicle in a manner to allow some lateral movement to accommodate misalignment. Without the protective plate  66  the lifting fork distal ends could possibly strike and damage the front wall  12  of the container. 
         [0031]      FIG. 4  illustrates the container  10  and shows side fork pockets  26  and  28  affixed thereto and in addition shows casters  68  and  70  which are affixed to caster plates attached to the bottom  20  of the container as illustrated in  FIG. 3 . As shown, the container is hollow and includes a hollow plastic molded rim  72  which completely encircles the open upper end of the container. It should be noted that the hollow rim  72  extends completely around the upper edge of the body of the container and is formed in such a manner that there are no vent holes provided therein. Through the utilization of such a hollow non-vented rim, air which is trapped internally of the hollow molded rim during the molding process creates a pressure as the air tries to expand which functions to maintain the rim and the upper edge of the containers rigid and straight during the molding process. Obviously, when the plastic is allowed to cool subsequent to the completion of the rotational molding process, the pressure returns to ambient. However, at this point, the hollow plastic molded rim  72  is formed and has sufficient strength to maintain its shape and to assist in maintaining the shape of the upper edge of the rotational molded plastic container body. 
         [0032]    By reference now more particularly to  FIG. 5  there is illustrated in greater detail the side fork pocket apparatus  28 . As is therein shown, the side fork pocket apparatus  28  includes upper and lower walls  74  and  76  and side walls  78  and  80 . The protective curved member  66  is an extension of the side wall  80  and as illustrated extends forwardly and curves around the edge  82  of the container where the front wall  12  and the side wall  16  come together. Extending upwardly from the top wall  74  there is provided an additional flange  84  which is affixed by a plurality of fasteners  86 ,  88 , and  90  to the side wall  16  of the container. A plurality of reinforcing gussets  92 ,  94 , and  96  are rigidly secured between the flange  84  and the top wall  74  of the side fork pocket  28 . It will be recognized by those skilled in the art that by having the flange  54  abutting the downwardly facing shoulder  40  and secured thereto by the fasteners  56  through  62  and by having the flange  84  secured to the side wall  16  by the fasteners  86 ,  88 , and  90 , that when a lifting fork is inserted into the opening provided by the lifting fork pocket  28  and is activated to lift the refuse container the weight of the container and the refuse contained therein is supported by the flange  54  abutting the downwardly facing shoulder  40 . With the fasteners securing the side fork pocket in the manner as described there will be little or no shearing forces or tension forces placed on the fasteners securing the side fork pocket apparatus to the container therefore substantially precluding any damage to the container. 
         [0033]    Although the flanges  54  and  84  are described as being used to receive the fasteners to attach the side fork pockets to the container  10  it will be recognized that such may be accomplished in other ways. For example, the additional flange may be eliminated and the top wall  74  of the side fork pocket may be positioned to abut the downwardly facing shoulder  40  with fasteners passing through the shoulder and the top wall  74 . A stabilizing flange could extend downwardly from the rear wall  80  and be affixed to the side wall  16 . In any event it will be recognized by those skilled in the art that the load of the container and refuse is supported by the vertical structure of the side walls  14  and  16  having the downwardly facing shoulder formed by under cutting or in setting the side walls. 
         [0034]    By referring now more particularly to  FIG. 6  a caster plate such as that shown at  42  and  44  is illustrated at  98  in greater detail. As is therein shown, there is a U-shaped plate  100  having disposed at each end thereof caster receiving brackets  102  and  104 . The plate is attached to the bottom of the container as illustrated in  FIG. 3  with fasteners passing through the openings  106  through  116 . As is shown in  FIG. 7  a caster  118  is affixed to an axel support bracket  120  by way of an axel  122  retained by a nut  124  threadably secured thereon: A bolt  126  passes through the caster receiving bracket arms to provide integrity to the caster receiving bracket when forces are applied thereto by movement of the container on the casters. Although only one caster is shown in  FIG. 7  it will be appreciated by those skilled in the art that casters are attached to each end of the two caster receiving brackets or plates as shown at  42  and  44  in  FIG. 2  with each of these plates being affixed with fasteners to each end of the container. As will be recognized by those skilled in the art should a caster become damaged or otherwise inoperative through operation in the field it can easily be replaced simply by removing the nut  124  from the threaded end of the axel  122  removing the axel and then replacing the caster with a new one after which the axel and nut are replaced. 
         [0035]    By referring now more particularly to  FIGS. 8 and 9  the manner in which the lid  30  is attached to the container is illustrated in greater detail. As is shown there is a bar or bracket  130  secured by fasteners  132 ,  134 ,  136 , and  138  to the molded plastic rim  72  at the upper end of the rear wall  18  of the container. As is illustrated the fasteners take the form of a bolt and nut which pass through upper and lower arms of the bar  130  to secure it in place on the rim  72 . The bar  130  thus provides added rigidity and strength to the molded plastic rim  72  along the rear surface thereof. Affixed to the bar  130  are a plurality of hinge plates  140 ,  142 , and  144 , each of which defines an opening therethrough. As is illustrated more clearly in  FIG. 9 , a rod  146  passes through the openings in the hinge plates  140 ,  142 , and  144  and also through protrusions  148  through  158  extending from the two sections  160  and  162  of the lid  30 . Such construction allows the lids, which may or may not be constructed in sections as illustrated in  FIG. 9 , to hang freely down the back of the refuse container  10 . 
         [0036]    Throughout the description of the molded plastic container formed in accordance with the principles of the present invention as above set forth, various references are made to a plurality of metal components. Such metal components include the side fork pockets, caster plates, axels, brackets, fasteners, and the like. In accordance with the principles of the present invention all of these metal parts are formed from stainless steel. By utilization of stainless steel for these various metallic parts, the deterioration of the container as a result of rust is precluded thereby extending the useful life of the plastic containers. 
         [0037]    As was indicated above, under certain applications and circumstances, it is desirable to provide a detailed accounting of the containers and their use. Such may be done for billing purposes, as well as to maintain control of the location of the containers and to track maintenance activity with regard thereto. To provide a ready means for automatically maintaining such accounting information a radio frequency identification tag (RFID) is insitu molded into the front wall  12  of the refuse container. Such is illustrated schematically in  FIG. 10  to which reference is hereby made. As is therein shown, an RFID tag  170  is disposed between the outer surface  172  and the inner surface  174  of the front wall  12  of the container. Since the RFID tag is disposed internally of the wall  12  it is not visible by visual inspection of the outer surface of the container. This provides additional security to preclude tampering with the RFID tag. The RFID tag is coded with appropriate accounting information such as an identification number for the container, the size and capacity of the container, the date of manufacture, the location of the container, and other appropriate information as may be desired in accordance with a particular application. The RFID tag may also be provided with the ability to receive and transmit information generated during the emptying of the refuse container such as the weight of the contents of the container. Such information would be generated by appropriate sensors located in the refuse truck. This information would then be transmitted to the RFID tag which in turn by way of its activation would further transmit the information to a receiver in the refuse truck which would receive the information previously recorded on the RFID tag as well as the weight of the contents of the container at the time it was being emptied. At the same time additional information such as the date and time of day could also be transmitted by the RFID tag. This activity would provide detailed accounting would could be utilized for billing a customer or the like as may be desired. 
         [0038]    To obtain an insitu disposition of the RFID tag  170  between the surfaces  172  and  174  of the wall  12  such must be accomplished during the container molding process. Shown schematically in  FIG. 11  is one means by which such can be accomplished. As is therein illustrated, the RFID tag  170  is affixed to the interior wall  176  of the mold  178  which is used to accomplish the rotational molding of the container. The RFID tag is so affixed through the utilization of an adhesive material  180  which is compatible with the plastic material from which the container is manufactured. In accordance with the preferred embodiment of the present invention such material  180  would be a strip of the same plastic material from which the plastic container is molded. The RFID tag  170  is affixed to one surface of the strip  180  so that it is maintained securely in place and the opposite surface of the strip  180  of the plastic material is then affixed to the surface  176  of the wall of the mold  178 . The strip  180  of plastic material thus maintains the RFID tag displaced slightly (approximately one-eighth of an inch) from the interior surface  176  of the wall  178  of the mold. As the mold is then bi-axially rotated as above described, the plastic material which forms the rotationally molded plastic container covers the RFID tag  170  and the strip of plastic material  180  becomes an integral portion of the wall  12  of the plastic container. 
         [0039]    There has thus been disclosed a rotationally molded plastic refuse container which includes a support structure for side fork pockets affixed to the container which provides for substantial and sufficient weight bearing support for the weight of the container and the refuse deposited therein to preclude separation of the side fork pockets from the container during lifting and emptying thereof. There is also provided an attachment structure for the casters so that they may be easily and rapidly exchanged or replaced in the field should such be required.