Abstract:
A conveyor module includes a plurality of first projections extending in a first direction. Each of the first projections include a hinge hole for receiving a first hinge pin. A plurality of second projections extends in a second direction substantially opposed to the first direction. Each of the second projections include a hinge hole for receiving a second hinge pin. A reinforcement bracket nests with at least a portion of one of the second projections. The reinforcement bracket includes a first hinge hole aligned with the hinge holes in each of the first projections for receiving the first hinge pin. The reinforcement bracket further includes a second hinge hole aligned with the hinge holes in the one of second projections for receiving the second hinge pin.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 10/572,773 filed on Nov. 10, 2006, which claims priority to International Application No. PCT/NL04/00659 filed on Sep. 23, 2004, which claims priority to Dutch Patent Application No. 1024361 filed on Sep. 23, 2003, all of which are fully incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0003]    The invention relates to a conveyor mat comprising a number of plastic modules successive in a conveying direction, each provided at a front and rear side with a row of projections extending transversely to the conveying direction, provided with hinge holes with recesses located therebetween, the projections cooperating with recesses of successive modules, the hinge loops of adjoining modules being coupled with the aid of hinge pins, reaching through the hinge holes transversely to the transport direction, while hinge pins are included with clearance in oversized hinge holes of projections at the front and/or the rear side. 
         [0004]    Such a conveyor mat is generally known and is indicated by the skilled person as modular bend mat or flexmat. As the hinge pins are included with clearance in the hinge holes, the projections can slide into and out of the recesses so that the conveying path to be traveled by the modules of the conveyor mat can make a bend in the conveying plane. 
         [0005]    Often, the modules are laid side by side transversely to the conveying direction, so that the width of the mat can be varied in steps. The modules of the mat can be guided along a conveying path. The mat can then negotiate a bend transversely to the conveying plane in that successive modules can pivot about the hinge pins. 
         [0006]    When traveling a straight length of the conveying path, the tensile force in the mat is transmitted via the hinge pins over the entire width of the mat from the projections on the edge of one module to the projections on the adjoining edge of the successive module. 
         [0007]    A problem that occurs with such modular bend mats is the absorption of the forces during negotiation of the bend. 
         [0008]    As the projections and recesses of the modules slide into each other when a bend is negotiated, it is impossible without further measures to transmit the tensile force in the mat via the hinge pin over the entire width of the mat from the projections on one side of the module to the projections on the adjoining side of a successive module. In theory, in the bend, all force will be transmitted via the outermost projections while the projections in the center and the inside transmit no forces. In practice, the flexibility of the modules and the material of the hinge pins can provide for a number of outer projections to contribute to the transmission of forces but still, when the bend is negotiated, an increased load is formed on the outer edge of the mat. This may lead to the mat giving way, which, in practice, often forms a restriction on the usability of the mat. 
         [0009]    It has already been suggested to reinforce the projections on the edges of the conveyor mat, for instance by designing them to be thicker and/or by coupling successive hinge pins on the edge of the conveyor mat with the aid of steel links. A disadvantage of the first solution is, inter alia, that this adversely affects the sliding in and sliding out of the mat and adversely affects the manufacture of the modules as injection molding product. A disadvantage of the second solution is, inter alia, that, when negotiating a bend, the contact surfaces of the hinge pin and link slide over each other, so that relatively much wear occurs, for instance in that the links dig into the pin. 
       SUMMARY OF THE INVENTION 
       [0010]    The object of the invention is a modular bend mat of the type indicated in the opening paragraph, which, while maintaining the advantages, avoids the disadvantages mentioned. To that end, the conveyor mat according to the invention includes modules having a plurality of first projections extending in a first direction. Each of the first projections include a hinge hole for receiving a first hinge pin. A plurality of second projections extends in a second direction substantially opposed to the first direction. Each of the second projections include a hinge hole for receiving a second hinge pin. A reinforcement bracket nests with at least a portion of one of the second projections. The reinforcement bracket includes a first hinge hole aligned with the hinge holes in each of the first projections for receiving the first hinge pin. The reinforcement bracket further includes a second hinge hole aligned with the hinge holes in the one of second projections for receiving the second hinge pin. 
         [0011]    The foregoing and other objects and advantages of the invention will appear from the following detailed description. In the description, reference is made to the accompanying drawings which illustrate a preferred embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will presently be further elucidated with reference to an exemplary embodiment represented in a drawing. In the drawing: 
           [0013]      FIG. 1  shows a schematic perspective view of a length of conveyor mat in a first embodiment; 
           [0014]      FIG. 2  shows a schematic top plan view of a part of a second embodiment of the conveyor mat; 
           [0015]      FIG. 3  shows a schematic perspective view of the underside of a module of the conveyor mat of  FIG. 1  in taken apart condition; 
           [0016]      FIG. 4  shows a schematic perspective view of the module of  FIG. 3  in composed condition; and 
           [0017]      FIG. 5  shows a schematic perspective view of the top side of the module of  FIG. 4 . 
       
    
    
       [0018]    The Figures only relate to schematic embodiments of preferred embodiments of the invention and therefore only serve as non-limitative exemplary embodiment. In the Figures, identical or corresponding parts are indicated with the same reference numerals. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    In  FIGS. 1 and 2 , two exemplary embodiments of modular bend mats according to the invention are represented. Referring to  FIG. 1 , an assembled conveyor mat  1  is shown, comprising a number of plastic modules  3  successive in a conveying direction indicated with an arrow  2 . The plastic modules have been manufactured by means of injection molding and, as can be seen in  FIGS. 3-5 , are each provided at a front side  4  with a row of forward reaching projections  5  extending transversely to the conveying direction, with recesses  6  located therebetween. Further, at their rear side  7 , the modules  3  are provided with a row of backward reaching projections  8  extending transversely to the conveying direction, with recesses  9  located therebetween. As can be seen well in  FIG. 1 , the projections  5 ,  8  cooperate with corresponding recesses  6 ,  9  of successive modules  3 . Successive modules  3  are coupled with the aid of hinge pins  11  proceeding transversely to the conveying direction  2 . The projections  5 ,  8  are provided with hinge holes  10 , formed by bores extending through the rows of projections, transversely to the conveying direction. 
         [0020]    The hinge pins  11  are included with clearance in the hinge holes  10  in the forward reaching projections  5 . In this exemplary embodiment, the projections  5  reaching forward are provided with slotted holes  10   a  as hinge holes, orientated with their longitudinal axis in conveying direction, while the backward reaching projections  8  are provided with cylindrical hinge holes. The outermost central axes through the hinge holes  10   a ,  10   b  are in a straight line, extending transversely to the conveying direction. The central axes through hinge holes  10   a ,  10   b  run parallel. In this exemplary embodiment, the projections  5 ,  8  are formed by hinge loops reaching outwards relative to a body part designed as a central carrier  17 . 
         [0021]    As the hinge pins  11  are included with clearance in the front hinge holes  10 A, the projections  5 ,  8  can slide into and out of the recesses  6 ,  9 , so that the conveying path followed by the modules  3  of the conveyor mat  1  can negotiate a bend in the conveying plane T formed by the top surfaces of the body parts of the modules. 
         [0022]    In this exemplary embodiment, the conveyor mat forms an endless belt running on a sprocket wheel. Here, the modules of the mat are guided along a conveying path (not shown). Driving takes place in that the teeth of a number of the sprocket wheels engage drive surfaces provided on the modules. When traveling, the conveyor mat  1  negotiates a bend transversely to the conveying plane in that successive modules can pivot about the hinge pins  11 . When traveling a straight part of the conveyor path, the tensile force in the mat is guided through, via hinge pins, over the entire width of the mat from the projections on the edge of one module to the projections on the adjoining edge of the successive module. The mat can then negotiate a bend transversely to the conveying plane as successive modules can pivot about the hinge pins. 
         [0023]    Referring to  FIG. 3 , it is shown in detail that at least one of the hinge pins  11 , in this case a short hinge pin  11 A, bears an intermediate element  12 . The intermediate element  12  is bearing mounted so as to be pivotal relative to a pivot A placed transversely to the hinge pin, in a bearing opening  13  formed in the module  3 . The intermediate element  12  is provided with a cylindrical casing surface  14  which cooperates with a correspondingly formed bearing surface  15  of the bearing opening  13  formed in the module  3 . 
         [0024]    The bearing opening  13  is located at least partly in a forward reaching hinge loop  5 A. The bearing opening  13  is enclosed between two hinge holes  10 A 1 ,  10 A 2  of the forward reaching hinge loop  5 A which are located on both sides of the bearing opening  13 . The short hinge pin  11 A is included, secured against rotation, in the hinge holes  10 B  31 ,  10 B 2  of the rearward reaching projections  8 B 1 ,  8 B 2  bounding the recess  9 B which cooperates with the forward reaching projection in which the bearing opening  13  is formed. This can for instance be designed with the aid of serrated edges at the ends of the hinge pin  11 A. Optionally, the pin  11 , when this is of long design, can be fixed in a different hinge hole  10 , for instance of a hinge loop which, upon negotiation of a bend in the conveying plane, is located at the inside radius of the mat. 
         [0025]    In addition to one of the hinge holes enclosing the bearing opening, a number of further projections provided with hinge holes are provided which complete the row. Advantageously, the bores forming the hinge holes provide a cylindrical abutting surface for cooperation with the cylinder surface of the hinge pin  11 . 
         [0026]    The intermediate element  12  is provided with a guide cam  20  extending downward relative to the module  3 . As shown in  FIG. 3 , the guide cam can be provided with a beveled guide surface  21 . Alternatively, the guide cam  20  can be provided with an idler wheel  22 , shown here as a conical wheel bearing mounted about a rotation axis extending substantially downward relative to the module  3 . 
         [0027]    In  FIG. 1  it is shown that the successive modules  3  of the mat are interconnected by the pins  11  via intermediate elements  12  and form a chain extending in conveying direction. The bearing openings  13  and intermediate elements  12  are located adjacent a side edge  18  of the mat. 
         [0028]    In  FIG. 2 , a part of a variant of the conveyor mat is shown in which several modules can be included in the mat transversely to the conveying direction. Here, the modules shown in  FIG. 2  are designed as end modules. The modules are further provided with a substantially U-shaped reinforcement bracket  23  surrounding the bearing opening. The free ends  24 A,  24 B of the reinforcement bracket are provided with holes for cooperation with a hinge pin  11 A reaching through the holes  25 A,  25 B. The holes of the bracket are therefore included in a row of hinge holes  10 . In this exemplary embodiment, this is the row of hinge holes  10 B of the backward extending projections  8 . As shown in  FIG. 2 , a plurality of modules are assembled forming a partial mat with forward projections  5  extending into recesses  9 . Further shown in  FIG. 2  are a plurality of reinforcement brackets  23  nesting with portions of backward projections  8 . 
         [0029]    During assembly, the short hinge pin  11 A is fitted through the holes  25  at the free ends  24  of the reinforcement bracket  23 , so that during use, the hinge pin  11 A and the reinforcement bracket  23  cannot rotate relative to each other. Adjacent the closed end  26  enclosing the bearing opening  13 , the reinforcement bracket is provided with oversized holes  27 A,  27 B. These holes  27  correspond with the oversized holes  10 A of the row of forward reaching projections  5  and serve for contactlessly guiding the short hinge pin  11 A bearing the intermediate element. The purpose of these holes is to provide space to the hinge pin when it pivots about the pivot A via the intermediate element  2 . 
         [0030]    The projections are formed by hinge loops reaching outwards relative to a central carrier extending transversely to the conveying direction. In the row of forward reaching hinge loops, oversized hinge holes have been provided, in this exemplary embodiment designed as slotted holes oriented in conveying direction. The backward reaching hinge holes are cylindrical. The hinge holes of both the forward reaching and the backward reaching hinge loops are each in a straight line. The outermost central axes are parallel and therefore have a constant intermediate distance defining the pitch of the module. 
         [0031]    In this exemplary embodiment, the body  17  of the module is designed from plastic and the reinforcement bracket  23  is designed from metal. Here, the intermediate element  12  is designed from plastic material, the hinge pin  11 A is designed from steel, and the hinge pin  11 B is designed from plastic material. It will be clear that the choice of these materials can be different and that the hinge pins  11 A,  11 B can also be manufactured from one whole, for instance entirely from plastic or entirely from steel. 
         [0032]    In this exemplary embodiment, the choice is made to use the closed end of the U-shaped bracket  23  as bearing surface  15  for the intermediate element  12 . It will be clear that to this end also, a plastic part of the body  17  of the module  3  can be used, for instance a plastic back surrounded by die bracket  23  or only an opening, recessed in the body  17  while no reinforcement bracket is present. 
         [0033]    As is represented in  FIG. 2 , the mat  1  can be composed by, for instance, alternately interconnecting a series of short and long end modules through insertion of a short pin  11   a . Then, by arranging modules  3  brick-wise, a mat  1  of desired width can be made. By including at the other edge a row of short and long customary end modules, i.e. without intermediate elements and bearing openings, the mat can be completed. Naturally, as is represented in  FIG. 1 , it is also possible to construct a mat comprising only one row of modules transversely to the conveying direction. 
         [0034]    When negotiating a bend, the hinge loops and the recesses located at the inside of the bend slide into each other, to then slide out of each other after having negotiated the bend. In the embodiment shown, the modules cannot slide into each other at the location of the outside radius of the conveying mat. Depending on the driving direction of the mat, the conveying direction of the mat proceeds in a direction indicated with the double arrows  2  and the conveying mat can negotiate a bend to the left or to the right in the conveying direction. In this connection it is noted that the terms front and back as used in this application can be exchanged. 
         [0035]    When it is desired that the mat can negotiate bends in two directions in the conveying plane in a conveying direction, the chain of intermediate elements can be provided in the center of the mat, for instance by providing a special center module. Such a module can for instance be made by designing the modules represented so as to be double, through mirroring about the pivot of the bearing opening and having the pitch between the hinge holes increase from the intermediate element when the modules travel transversely to the conveying direction. 
         [0036]    It is noted that the invention is not limited to the embodiments described here, but that many variants are possible within the range of the invention as outlined by the following claims.