Patent Document

BACKGROUND 
   This invention relates generally to modular conveyor belts hingedly linked by hinge pins and, more particularly, to removable attachments to those conveyor belts. 
   Conveyor belts are widely used in many industries to transport articles. In the food and beverage industries, modular plastic belts, or chains, are often used because of their cleanability and their ability to operate with little lubrication. The modular belts are generally constructed of a plurality of belt modules arranged side by side to form a belt row. The modules include hinge elements at each end. The hinge elements of consecutive rows are interleaved and interconnected by hinge rods to construct a conveyor belt of any desired length and width. 
   Usually, these belts form generally flat article-conveying surfaces. But some applications require accessories that deviate from a flat article-conveying surface. Sideguards, flights, rollers, holddown tabs, guides, and various inserts are examples of accessories added to belts to perform various functions. Some accessories are detachable from the belt and others are integrally molded with or permanently bonded to the belt. Examples of integral accessories include integrally molded flights and bonded high-friction elastomeric layers. In some cases, integral accessories give the belt a complex geometry that requires an expensive mold that is difficult to operate properly; in others, co-molding different materials requires special processes and careful process control. 
   One shortcoming associated with integral accessories is that the belt modules including them must be made in a separate mold and represented by a separate part number from standard belt modules without accessories with which they are interconnected to form a conveyor belt. Another shortcoming is that, once an integral accessory is damaged, the entire module must be replaced. 
   To solve these problems, detachable accessories have been used. But these usually require attachment to a specially designed base module with a specially designed receptacle for the accessory or to a standard base module that has been specially machined or otherwise modified to receive the accessory. Or the accessory must be attached to a special-purpose retainer, such as fastener hardware that could come loose and contaminate the conveyed product. 
   To overcome these shortcomings, there is a need for a conveyor belt that accepts accessory attachments of various configurations, including complicated topographies, without necessarily requiring special receptacle modules, additional fastening hardware, or special belt modifications. 
   SUMMARY 
   This need and other needs are satisfied by a modular plastic conveyor belt and an attachment member embodying features of the invention. One version of such a conveyor belt comprises a series of rows of belt modules, in which each row has an intermediate portion that extends longitudinally from a first end to a second end and laterally from a first edge to a second edge. A first set of laterally spaced hinge elements extends longitudinally outward at the first end of the intermediate portion; a second set extends longitudinally outward at the second end of the intermediate portion. Gaps separate consecutive hinge elements of each set. The hinge elements of the first and second sets each have a first side toward the first edge of the row and an opposite second side toward the second edge and an aperture extending laterally from the first side to the second side. The series of rows are connected end to end with the first set of hinge elements of a row interleaved with the second set of hinge elements of an adjacent row so that the apertures of interleaved hinge elements are aligned to form a lateral passageway for receiving one of a plurality of hinge rods to connect adjacent rows together into a conveyor belt having a conveying surface and an opposite surface. An attachment member includes a body having an outer surface and a base surface, an interaction element connected to the outer surface, and a first leg and a second leg extending from the base surface. The legs each have a foot at a distal end. The attachment member is installed in the conveyor belt with the base surface contacting the conveying surface or the opposite surface. The first and second legs extend directly from the conveying surface or the outer surface into one or more of the gaps between hinge elements of the first set. The first and second legs are spaced apart so that the first leg contacts the first side of one of the hinge elements of the first set while the second leg contacts the second side of one of the hinge elements of the first set. The feet are retained by the hinge rod extending through the first set of hinge elements. 
   In another aspect of the invention, an attachment member for installation in a modular plastic conveyor belt comprises a body having an outer surface and a base surface. An interaction element is connected to the outer surface. Laterally spaced legs extend from the base surface. The lateral spacing between laterally consecutive legs alternates between a first wide spacing and a second narrow spacing. 
   In yet another aspect of the invention, an attachment member for installation in a modular plastic conveyor belt comprises a body having an outer surface and an opposite base surface, an elastomeric surface layer bonded to the outer surface, and a plurality of laterally spaced legs extending from the base surface for attaching to a conveyor belt. 

   
     DETAILED DESCRIPTION OF THE DRAWINGS 
     These features and aspects of the invention, as well as its advantages, are better understood by reference to the following description, appended claims, and accompanying drawings, in which: 
       FIG. 1  is a top plan view of a portion of a modular plastic conveyor belt embodying features of the invention including a high-friction attachment member; 
       FIG. 2  is an exploded view of a portion of the belt of  FIG. 1 ; 
       FIG. 3  is a bottom plan view of a portion of the belt of  FIG. 1 ; 
       FIG. 4  is an exploded view of a portion of a belt as in  FIG. 1  with another version of attachment member for holding the belt down in turns; 
       FIG. 5  is a front elevation view of a portion of the belt of  FIG. 4 ; 
       FIG. 6  is an exploded view of a portion of a belt as in  FIG. 1  with yet another version of attachment member for forming lanes on the belt&#39;s conveying surface; and 
       FIG. 7  is another view of the conveying surface of a belt as in  FIG. 6 . 
   

   DETAILED DESCRIPTION 
   A portion of the conveyor belt embodying features of the invention is shown in  FIG. 1 . The belt  10  is constructed of a series of rows  12  of one or more belt modules  14 , such as a short edge module  14 ′ and a long edge module  14 ″. The edge modules have edge structure  16  that gives the belt relatively flat-surfaced side edges  18 ,  19  and serves to restrain a hinge rod  20  from migrating past the belt edge. One or more internal modules similar in structure to the edge modules, but without edge structure may be positioned between the two edge modules in each row to construct a wider belt. For belts constructed of more than one module per row, the modules are preferably arranged in a bricklay pattern with laterally offset seams  22  from row to row for strength. 
   Each row includes an intermediate portion  24 , in this case, a lateral strip. A first set of hinge elements  26  extends from the intermediate portion longitudinally in the direction of belt travel  28 . A second set  27  extends longitudinally in the opposite direction. The first and second sets of hinge elements define first and second ends of the rows. As shown in  FIG. 2 , apertures  30 ,  31  through the first and second sets of hinge elements receive the hinge rod  20 . The apertures  30  along the first end are preferably circular with a diameter just greater than that of the hinge rod. The apertures  31  through the second set of hinge elements are longitudinally elongated to allow the belt to negotiate turns. But both sets of apertures could be circular for a straight-running belt or shaped otherwise for other hinge rod cross sections or special purposes. The first set of hinge elements of a row are interleaved with the second set of hinge elements of an adjacent row. The aligned apertures of the interleaved hinge elements form a lateral passageway for the hinge rod, which connects adjacent rows together at a hinge joint  32 . The belt is able to articulate at its joints about sprockets or drums that drive the belt. 
   A high-friction attachment member  34  is shown in  FIG. 1  attached at a conveying surface  36 , of the belt. As shown in  FIG. 2 , the attachment member includes a body  38  having an outer surface  40  and a base surface  41 . An interaction element in the form of a high-friction element  42  is attached, preferably by bonding, to the outer surface of the attachment body. (An interaction element means an element that interacts with an external object not part of the belt. A conveyed article and conveyor frame structure are examples of external objects.) A T-shaped beam  44  upstanding from the outer surface provides the wide attachment member with beam strength to prevent the attachment member from warping under molded-in stresses and also adds more surface area to improve the attachment of the high-friction element to the attachment body. 
   First legs  46  and second legs  47  extend from the base surface  41  of the attachment element. Each leg is much narrower than the lateral dimension of gaps  48  formed between consecutive hinge elements that accommodate interleaved hinge elements of an adjacent row. As shown in  FIG. 3 , the narrow legs leave enough space in the gap to accommodate the interleaved hinge elements. At the distal end of each leg is a foot  50  that extends from the leg. The foot is a slight projection that hooks under a hinge rod in the lateral passageway. A narrow neck  52  of each hinge element extends longitudinally from the intermediate portion of each belt module to a wide distal head  54 . Each hinge element extends in thickness from a first side  56  nearer the first edge  18  of the belt to a second side  57  nearer the opposite second edge. The first leg  46  is separated laterally from the second leg  47  so that, when the attachment member is installed in the belt, the first leg contacts the first side of a hinge element, e.g., hinge element  26 ′ in  FIG. 3 , and the second leg contacts the second side of a hinge element, e.g., hinge element  26 ″. This spacing registers the attachment member in position with its base surface  41  supported a top the conveying surface of the belt. The hinge rod hooked under the feet of the legs resides between the feet and the base surface of the attachment member. 
   The attachment member shown in  FIGS. 2 and 3  has three pairs of legs. The lateral spacing between adjacent legs alternates between wide spacings and narrow spacings. In this example, the narrow spacing corresponds to the lateral thickness of the neck of a hinge element. It can also be seen that the legs&#39; longitudinal extent generally matches the longitudinal extent of the neck of the hinge elements. The wide attachment element can span a seam, such as seam  22 ′ in  FIG. 1 , and thereby provide additional beam strength to the row. 
   The belt is preferably a modular plastic conveyor belt constructed of modules made of a thermoplastic polymer such as polypropylene, polyethylene, acetal, or a composite polymer in an injection-molding process. The hinge rod may be stainless steel, but is preferably a thermoplastic rod molded or extruded. The attachment member body may likewise be molded out of a thermoplastic polymer. Belts and hinge rods of this kind are manufactured and sold by Intralox, L.L.C., of Harahan, La., USA. The high-friction material may be a rubber or elastomer that is bonded to the outer surface of the attachment body by co-molding, welding, adhesives, or mechanical connection. 
   Another version of attachment member is shown in  FIGS. 4 and 5  connected into a similar belt. The attachment member  60  includes a body having an outer surface  62  and an opposite base surface  63 . An interaction element in the form of holddown wing  64  with a lateral wingspan extends from the base surface via a central post  66 . First and second legs  46 ,  47  extend from the base surface. Each leg has a foot  50  protruding at its distal end. The holddown attachment member  60  is inserted into a single gap  48  between adjacent hinge elements. The first leg  46  contacts the first side of the hinge element  26 ′, and the second leg  47  contacts the second side  57  of hinge element  26 ″ to register the holddown member in place. A hinge rod inserted in the lateral passageway through the interleaved hinge elements retains the attachment member in place. The base surface of the attachment member is flush with the opposite surface  37  of the belt from the conveying surface  36 . In operation, the wing  64  hooks under a horizontal ledge of a conveyor guide  68  to hold the belt down in turns. The wing shown in the figures is two-sided, but a one-sided wing is also possible. 
   Yet another version of an attachment member is shown in  FIGS. 6 and 7 . In this version the attachment member  70  is a lane divider. The attachment member has a body with an outer surface  72  and an opposite base surface  73 . An interactive element in the form of an upstanding plate  74  extends from the outer surface of the body. First and second legs  46 ,  47  extend from the base surface. Feet  50  project outward from the legs. The legs slip directly into the gaps  48  between adjacent hinge elements with the base surface supported on the conveying surface  36  of the belt. In this version, the first and second legs fit into adjacent gaps separated by a hinge element  26 ′. The first leg  46  contacts the first side  36  of the hinge element, and the second leg  47  contacts the second side of the same hinge element. A hinge rod inserted into the lateral passageway at the hinge joint  32  between the base surface and the feet  50  straddling the hinge element retains the attachment member firmly in position. Like the legs of the other attachment members, these legs have a flat wall  76  that does not contact the hinge element and an opposite contoured wall  77  that matches the shape of and contacts the side of the hinge element. As shown in  FIG. 7 , a series of sideguards or lane dividers  70  along the length of the belt can divide the belt into longitudinal lanes, such as an edge lane  78  at each edge and one or more interior lanes  79 . The edge lanes can serve as product-free belt regions, while multiple interior lanes can separate product laterally into individual flows. 
   Although the invention has been described with respect to a few preferred versions, other versions are possible. For example, the attachment member could include an interaction element consisting of a lateral plate to form a flight. As another example, a variety of surfaces could be attached to a bas surface as on the body of  FIG. 2 . Rollers and other elements could be attached in an assembly to a belt using the attachment scheme shown. So, as these few examples suggest, the scope of the claims is not meant to be limited to the preferred exemplary versions described.

Technology Category: 7