Abstract:
A stackable platform assembly has an improved coupler for interconnecting a plurality of stackable platforms. The coupler has projections that are appropriately sized and spaced to facilitate frictional engagement of the coupler with platforms having different dimensions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 11/901,624, which was filed on Sep. 18, 2007. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to coupling elements used to removably secure a plurality of platforms in stackable juxtaposition. More specifically, the invention relates to couplers capable of removably connecting platform sections having different dimensions. 
       BACKGROUND OF THE INVENTION 
       [0003]    In many industrial and commercial work environments, workers are provided with flooring surfaces which provide separation between the underlying flooring and the worker&#39;s feet. Such flooring provides thermal insulation, improves footing, and separates the worker&#39;s feet from contaminants, fluids, or moisture which may be found on the factory or workplace floor. 
         [0004]    Often, this type of flooring is in the form of individual and repositionable panels which may be laid in the tiled fashion, if necessary interlocked. Using these techniques, selected areas in the factory or workplace floor may be covered with panels as needed. 
         [0005]    In addition to the foregoing, it is frequently desirable to provide elevated sections of the flooring. For example, not all persons who operate machinery or other equipment from a standing position are of the same height. To ensure that operators are provided the opportunity to operate equipment at a comfortable working height, it may be desirable to raise or lower a worker&#39;s working position in relation to the machinery to minimize discomfort and fatigue. A wide variety of mats or platform-like devices have been proposed to enable persons of varying heights to be positioned at appropriate elevations during the performance of operations on a machine. 
         [0006]    As taught in U.S. Pat. No. 5,683,004, variable heights of support structures may be constructed from a plurality of platform members which may be removably stacked through the use of coupling members. Preferably, the coupling members are uniform so that any one of them may be accommodated in sockets formed in platform members. 
         [0007]    As known in the prior art, each coupling member comprises a cylindrical body open at one end and closed at the other end by a transverse wall. Fixed to and extending from the wall are extensions of the body section in the form of a pair of projections which are spaced apart from one another. The overall length of each coupling member is such that when the body section is accommodated in a socket, the projections extend beyond the upper surface of the associated platform a distance sufficient to engage the next adjacent platform. 
         [0008]    Each platform has a plurality of spaced apart ribs or partitions which define an open grid construction for each platform. A part of each socket adjacent to the upper surface of each platform is spanned by at least one crossbar, thereby providing a grid configuration across the upper end of each socket. 
         [0009]    In the prior art, the space between the two projections in each coupling member corresponds substantially to the thickness of one of the crossbars which spans the socket, thereby enabling the projections of a coupling to extend beyond the lower surface of an upper platform member and straddle the crossbar which spans the socket of the next adjacent lower platform. Preferably, space between the two projections in each coupling tapers or narrows toward the free ends of the projections, thereby enabling the projections frictionally to grip the crossbar and minimize inadvertent separation of one platform from another. 
         [0010]    The grid configurations in each platform enable any spilled liquids or small or other parts to fall through the platform, thereby avoiding the buildup of liquids and/or contaminants on the upper surface of the platform. Preferably, the transverse wall at the closed end of each of the body sections of the couplings also has openings therein through which liquids may drain. The grid configurations of the platforms in earlier implementations of the invention were uniform, in that the thickness of the crossbars was constant, regardless of the size and shape of the platform sections. However, more recently, platform sections have been developed with higher load capabilities, necessitating thicker grid crossbars on coupling members designed for older designs of platforms that are accordingly improperly sized to engage the grid crossbar of the newer platform sections. While it is possible to solve this problem by substituting coupling members having a larger space between the projections, such coupling members will not provide a suitable friction set when used with older styled platform sections having thinner grid crossbars. 
         [0011]    Additionally, it has been learned that suitable drainage cannot be obtained using prior art devices and that a substantially larger number of drain passageways must be incorporated. 
         [0012]    Prior art devices are also limited in that the structural strength of the cylindrical wall of the coupling member has been shown to be insufficient, and structural changes to the coupling body to improve its strength are required. Moreover, in order to ensure interconnection of adjacent coupling members, it is necessary that the dimensions for strengthening be designed in such a fashion so as to prevent interference between the projections of the coupling and the interior of the cylindrical portion of the adjacent coupling. 
         [0013]    An object of the present invention is, therefore, to provide a coupling member which will effectively interface with platforms having varying grid dimensions. A further object of the invention is to provide a coupling member for platform sections with the improved strength and drainage characteristics. 
         [0014]    These, and other objects of the invention, will be apparent from the detailed description which herein follows. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0015]    The description herein makes reference to the accompanying drawings wherein like referenced numerals refer to like parts throughout several views and wherein: 
           [0016]      FIG. 1  is a perspective view of the critical elements of the prior art shown in exploded relationship; 
           [0017]      FIG. 2  is a perspective view of a coupling found in the prior art; 
           [0018]      FIG. 3  is a side view of the coupling found in the prior art; 
           [0019]      FIG. 3A  is an elevational view of a coupling found in the prior art; 
           [0020]      FIG. 4  is a plan view of a coupling found in the prior art; 
           [0021]      FIG. 5  is a perspective view of the important components of the invention as shown in exploded configuration; 
           [0022]      FIG. 6  is a perspective view of the coupling of the present invention; 
           [0023]      FIG. 7  is a side view of the coupling of the present invention; 
           [0024]      FIG. 8  is an elevational view of a coupling as described in the present invention; and 
           [0025]      FIG. 9  is a plan view of the coupling of the present invention. 
       
    
    
     DESCRIPTION OF THE PRIOR ART 
       [0026]    With reference now to  FIGS. 1 ,  2 ,  3 ,  3 A, and  4 , the prior art over which the present invention improves will be understood. 
         [0027]    In the prior art, a plurality of square, rectangular, or other suitably-shaped platforms  1 , each of which has opposite end walls  2  joined by opposite side walls  3  and a plurality of longitudinal and transversely-extending ribs  4  and  5 , respectively, form a grid having a plurality of spaces  6  therein. Each platform  1  preferably is molded of a suitable plastic having sufficient strength to support a person and which is substantially inert to oils and other liquids to which it may be subjected in the environment of its use. 
         [0028]    At suitably spaced intervals each platform has at its lower side a cylindrical socket  7  having a smooth bore  8  and an annular wall  8   a . The number and spacing of such sockets should be sufficient to enable each platform to be supported in a stable, horizontal position by a support member yet to be described. At its upper end the socket  7  is spanned by continuations of the ribs  4  and  5  to form a grid of crossbars  9  and  10  integrally formed with the remainder of the platform. The crossbars  9  and  10  span the upper end of the socket, but the opposite or lower end of the socket  7  is open. One of the crossbars,  10 , extends diametrically of the socket. 
         [0029]    A single platform  1  may be placed in such position as to support a worker at a machine operated or attended by such worker. Such platform provides adequate support for the worker and the open grid construction of the platform enables any small objects or spilled liquids to pass through the platform, rather than collect on the upper surface thereof. 
         [0030]    Not all workers are of such height as to be able to assume a comfortable, non-tiring position alongside the machine that such worker is operating or attending. Accordingly, provision is made to enable at least one, and preferably more, like platforms to be stacked and retained in overlying relation with one another. It is important that the stacked platforms be immovable relative to one another so as to avoid the possibility that a person stepping onto or leaving the stacked platforms causes the stacked platforms to shift relative to one another. 
         [0031]    The apparatus includes coupling means  11  for connecting adjacent, vertically stacked platforms  1  to one another. Each coupling is identical and comprises a cylindrical body section  12  having a smooth inner bore  13 , the body section  12  being open at its upper end and closed at its lower end by a transverse wall  14 . The inner surface of the wall has integrally formed therewith an upstanding hub  15  from which ribs  16  radiate. The hub and ribs strengthen the wall  14 . To provide drainage through the coupling  11  the wall  14  has one or more drain openings  17  formed therein. 
         [0032]    Secured to and extending from the outer surface of the wall  14  in prolongation of the body section  12  is a pair of projections  18 , each of which terminates in a free end  19 . Each projection  18  preferably is hollow to provide some flexibility of the projections for a purpose presently to be explained. 
         [0033]    Each projection has adjacent its wall  14  an enlarged, outwardly arcuate portion  20  that is joined to a reduced end portion  21 , the portions  20  and  21  being separated by a shoulder  22 . Each side of each projection  18  has a flat surface  23 . 
         [0034]    Preferably, the outer surface of the body section  12  adjacent the free end is reduced in size, as shown at  24 , which facilitates insertion of the body section into a socket  7 . 
         [0035]    To assemble a pair of platforms  1  in overlying relation, the upper platform is raised to enable a coupling  11  to be accommodated in selected sockets  7  of the upper platform. The overall height of the body section  12  preferably corresponds substantially to the height of the socket  7  so that, when the open end of the body section  12  abuts the crossbars  9  and  10 , the projections  18  extend below the lower surface of the platform in which the coupling is mounted. The extent to which the projections  18  extend beyond the lower surface of the upper platform  1  is sufficient to enable the two projections to pass and straddle the diametrical crossbar  10  of the adjacent lower platform  1 , the crossbar  10  being accommodated in a space  25  provided between the two extensions  18 . 
         [0036]    The radius on which the arcuate surface  21  of each projection is formed preferably is less than the radius on which the socket bore  8  is formed, but the radius on which the enlarged portion  20  of each projection is formed corresponds substantially to the radius of the bore  8  of the socket thereby enabling the enlarged portions  20  of the projections to provide lateral stability for the associated coupling when the coupling is assembled with the platform. The flat surfaces of the projections  18  enable the reduced portion of each projection to pass between parallel crossbars  9  at the upper end of the socket  7  of the lower platform. 
         [0037]    The height of the space  25  corresponds to the full length of each projection  18 , thereby enabling the outer surface of the transverse wall  14  at the closed end of the body section  12  to seat on the upper surface of the crossbar  9  and  10  which span each socket  7 . 
         [0038]    Opposite the space  125 , an open-ended recess  130  is formed on the end portion  121  of each projection  118 . The flat surfaces  123  of each projection  118  are spaced by the recess  130 . 
         [0039]    Preferably, the space  25  between the adjacent projections  18  has a width corresponding substantially to the thickness of the crossbar  10 , but tapers toward the free ends  19  of the projections by one or two degrees. The material from which the projections is formed has sufficient resilience to enable the projections to flex, and the flexibility of the projections is enhanced by the hollow construction thereof. The taper enables the diametrical crossbar  10  to deflect the projections away from one another as the crossbar  10  moves into the space  25 , and the resilience of the projections enables the crossbar to be gripped by the projections when the crossbar  10  is accommodated between the projections, thereby minimizing the likelihood of inadvertent separation of the coupling from the lower platform  1 . 
         [0040]    A ground engagable support is provided for each socket  7  of the lower platform  1 . Such support as indicated at  26  and comprises a hollow cylinder  27  open at its upper end and provided at its lower end with a rubbery or other suitable cap  28  which provides an anti-skid surface for the lower end of the cylinder  27 . The overall height of the cylinder  27  is such that the latter may be accommodated in any one of the sockets  7  with its upper end abutting the crossbars  9  and  10  and with its non-skid cap  28  projecting slightly beyond the lower surface of the lower platform  1 . The supports  26  enable the lowermost platform to occupy a horizontal position. 
         [0041]    The length and width of each platform should be sufficient to enable it to provide adequate space in which a person may stand and move to the extent necessary to operate or attend a particular machine. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0042]    The disclosed prior art performs well; however, it has been learned that improved performance of the platform elements can be achieved by making certain dimensional changes to the platform ribs and that the system, as a whole, will benefit from increasing drainage performance in certain industrial environments. 
         [0043]    The improvement of the present invention; therefore, is described in detail below and depicted in  FIGS. 5-9 . 
         [0044]    The presently preferred embodiment of the invention is illustrated in the drawings and comprises a plurality of square, rectangular, or other suitably shaped platforms  101  each of which has opposite end walls  102  joined by opposite side walls  103  and a plurality of longitudinally and transversely extending ribs  104  and  105 , respectively, which form a grid having a plurality of spaces  106  therein. Each platform  101  preferably is molded of a suitable plastic having sufficient strength to support a person and which is substantially inert to oils and other liquids to which it may be subjected in the environment of its use. 
         [0045]    At suitably spaced intervals each platform has at its lower side a cylindrical socket  107  having a bore  108  and an annular wall  108   a . The number and spacing of such sockets should be sufficient to enable each platform to be supported in a stable, horizontal position by a support member yet to be described. At its upper end the socket  107  is spanned by continuations of the ribs  104  and  105  to form a grid of crossbars  109  and  110  integrally formed with the remainder of the platform. The crossbars  109  and  110  span the upper end of the socket, but the opposite or lower end of the socket  107  is open. One of the crossbars,  110 , extends diametrically of the socket. 
         [0046]    A single platform  101  may be placed in such position as to support a worker at a machine operated or attended by such worker. Such platform provides adequate support for the worker and the open grid construction of the platform enables any small objects or spilled liquids to pass through the platform, rather than collect on the upper surface thereof. 
         [0047]    Not all workers are of such height as to be able to assume a comfortable, non-tiring position alongside the machine that such worker is operating or attending. Accordingly, provision is made to enable at least one, and preferably more, like platforms to be stacked and retained in overlying relation with one another. It is important that the stacked platforms be immovable relative to one another so as to avoid the possibility that a person stepping onto or leaving the stacked platforms causes the stacked platforms to shift relative to one another. 
         [0048]    The apparatus includes coupling means  111  for connecting adjacent, vertically stacked platforms  101  to one another. Each coupling is identical and comprises a cylindrical body section  112  having a smooth inner bore  113 , the body section  112  being open at its upper end and closed at its lower end by a transverse wall  114 . The inner surface of the wall has integrally formed therewith an upstanding hub  115  from which ribs  116  radiate. The hub and ribs strengthen the wall  114 . To provide drainage through the coupling  111  the wall  114  has one or more drain openings  117  formed therein. 
         [0049]    Secured to and extending from the outer surface of the wall  114  in prolongation of the body section  112  is a pair of projections  118 , each of which terminates in a free end  119 . Each projection  118  preferably is hollow to provide some flexibility of the projections for a purpose presently to be explained. 
         [0050]    Each projection has adjacent its wall  114  an enlarged, outwardly arcuate portion  120  that is joined to a reduced end portion  121 , the portions  120  and  121  being separated by a shoulder  122 . Each side of each projection  118  has a flat surface  123 . 
         [0051]    Preferably, the outer surface of the body section  112  is tapered, so that the diameter of the body section  112  nearest its upper end  124  is smaller than the diameter near the closed end transverse wall  114 . This configuration facilitates frictional engagement between the outer cylindrical circumference of body section  112  and socket  107 . 
         [0052]    To assemble a pair of platforms  1  in overlying relation, the upper platform is raised to enable a coupling  111  to be accommodated in selected sockets  107  of the upper platform. The overall height of the body section  112  preferably corresponds substantially to the height of the socket  107  so that, when the open end of the body section  112  abuts the crossbars  109  and  110 , the projections  118  extend below the lower surface of the platform in which the coupling is mounted. The extent to which the projections  118  extend beyond the lower surface of the upper platform  101  is sufficient to enable the two projections to pass and straddle the diametrical crossbar  110  of the adjacent lower platform  101 , the crossbar  110  being accommodated in a space  125  provided between the two extensions  118 . 
         [0053]    The height of the space  125  corresponds to the full length of each projection  118 , thereby enabling the outer surface of the transverse wall  114  at the closed end of the body section  112  to seat on the upper surface of the crossbar  109  and  110  which span each socket  107 . 
         [0054]    It will be appreciated that the distance between the projections  118  of the coupling  111  and the dimensions of crossbars  109  and  110  will enable the coupling  111  to remain immovably secured to the platform  101 . Platforms  101 , however, may be manufactured with varying dimensions of grid width and spacing. In some applications, diametrical crossbar  110  is characterized by a maximum width of 0.35 inches of the space  125  between adjacent projections  118  of coupler  111 , accordingly, is designed to have a complimentary dimensions at free end  119 , and a nominally smaller dimension closer to transverse wall  114 . Accordingly, when the projections  118  of the coupling  111  are inserted to spaces  106 , to straddle crossbar  110 , the frictional forces exerted by projections  118  against crossbar  110  increase since dimension “A 1 ” as shown in  FIG. 8  is nominally smaller than the dimension “A” shown in the same figure. As a result, when coupling  111  is fully inserted into platform  101  by engagement of projections  118  against rib  110 , a secure frictional engagement between the coupling and the platform is achieved. In this application the invention, however, flat surfaces  123  of projections  118  are not brought into contact with crossbars  109 . This is because dimension B as shown in  FIG. 7  is specifically selected to ensure that the width of projections  118  between opposing flat surfaces  123  is smaller in dimension than the opening formed between two parallel crossbars  109 . 
         [0055]    Preferably, the space  125  between the adjacent projections  118  has a width corresponding substantially to the thickness of the crossbar  110 , but tapers toward the free ends  119  of the projections by one or two degrees. The material from which the projections is formed has sufficient resilience to enable the projections to flex, and the flexibility of the projections is enhanced by the hollow construction thereof. The taper enables the diametrical crossbar  110  to deflect the projections away from one another as the crossbar  110  moves into the space  125 , and the resilience of the projections enables the crossbar to be gripped by the projections when the crossbar  110  is accommodated between the projections, thereby minimizing the likelihood of inadvertent separation of the coupling from the lower platform  101 . 
         [0056]    A second version of platform  101  incorporates narrower crossbars  109  and  110 . In this version of the platform, crossbars  109  and  110  have a width of approximately 0.325 inches. The dimension between parallel crossbars  109  is nominally 0.85 inches, which is approximately 0.05 inches less than the inter-crossbar dimension of the first type of platform  101 . With reference now to  FIG. 7 , it will be appreciated that by making dimension B .825 inches or slightly less, and tapering the projections  118  so that dimension B 1  is 0.825 inches or slightly larger, that a frictional fit can be achieved between flat surfaces  123  and crossbars  109  when coupling  111  is used with the second style of platform  101 . 
         [0057]    In this fashion, a single coupling is disclosed which serves to couple both styles of platform  101 . It is preferred that a ground engageable support be provided for each socket  107  of the lower platform  101 . Such support as indicated at  126  and comprises a hollow cylinder  127  open at its upper end and provided at its lower end with a rubbery or other suitable cap  128  which provides an anti-skid surface for the lower end of the cylinder  127 . The overall height of the cylinder  127  is such that the latter may be accommodated in any one of the sockets  107  with its upper end abutting the crossbars  109  and  110  and with its non-skid cap  128  projecting slightly beyond the lower surface of the lower platform  101 . The supports  126  enable the lowermost platform to occupy a horizontal position. 
         [0058]    The length and width of each platform should be sufficient to enable it to provide adequate space in which a person may stand and move to the extent necessary to operate or attend a particular machine. It is possible, of course, to have a lowermost platform of relatively great length so that upper platforms of shorter length may be supported atop the lower platform with spaces between the shorter platforms. It also is possible for the areas of upper and lower platforms to be the same. 
         [0059]    It will be appreciated that, in the present invention, the dimension between the outer surfaces of the first stepped sections  120  of projections  118 , being dimension C is selected to be substantially equal to the diameter of the inner bore  113 , thereby permitting one coupling  111  to be nestable within the inner bore  113  of an adjacent coupling  111 . In other words, projections  118  are fully insertable into the inner bore  113  of an identical coupling  111 . Further, diametrical dimension D measured between the outermost surfaces of second step section  121  corresponds substantially to the inner diametrical bore dimension of support  126 . The dimension E of first stepped section  120  is selected to be substantially equal to the thickness of crossbars  109  and  110 , so that when coupling  111  is inserted into socket  107  of platform  101 , only the second step section  121  of legs  118  projects into the bore  108 . In this fashion, the outer circumference of support  126  frictionally engages the bore  108 , while the inner bore of support  126  accommodates second stop section  121  of legs  118 , thereby adding to the security and stability of the assembly. Dimension D is also smaller than the diametrical dimension of the inner bore  113 , thereby permitting coupling  111  to be inserted from the underside of platform  101  into bore  107 , thereby facilitating the stacking of multiple platforms  110  utilizing multiple couplings  111 . 
         [0060]    The disclosed embodiment is representative of the presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.