Patent Publication Number: US-2006016670-A1

Title: Prefabricated conveyor belt patch apparatus

Description:
This application claims benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 60/589,420, filed on Jul. 20, 2004. 
    
    
     FIELD OF THE INVENTION  
      This invention relates to conveyor belts, in particular to repairing same in the field.  
     BACKGROUND OF THE INVENTION  
      Transporting materials from one to another is the heart of enabling an assembly line to function. Since the assembly line was invented by Eli Whitney and used to make muskets for the U.S. military, the key to making products less expensively has frequently been the use of conveyor belts as at least part of the assembly line process.  
      Whether it is moving raw materials, the mail, and even people, conveyors play a vital role in a modern industrialized society and are so ubiquitous, they are often unnoticed in the industrial landscape. Further, the basic technology is changed little over the years. A continuous loop of conveyor material rotates over two axles. The axles are powered to cause the belt to move around, either clockwise or counterclockwise, so that anything that is to be placed thereon will be moved in a linear fashion. The conveyor surface can be horizontal, vertical or at an angle in between. Conveyor belts with regular spaced partitions are often called elevators. Conveyor belts can be used to load or unload materials such as cement, coal, grain, ore and so on. They can range in axle to axle length of several feet to more  60  miles long used in the phosphate mines in Bu Craa in the Western Sahara to carry the ore to the coast south of Laayoune.  
      While the invention has applications to virtually all such conveyor systems, the use in rock crushing conveyor belts will be used as an example.  
      The belts used on such systems such as manufactured by Metso Minerals of Milwaukee, Wis., are typically tough multi-ply rubber belts, built to withstand the harsh working environment. Despite the sturdiness of the construction of the belts, eventually one or more holes will develop. If allowed to go un-repaired, the repairable hole will eventually cause the belt to be broken, perhaps needing total replacement. Operators are then faced with the cost of shutting down the conveyor with the resultant loss of production time necessary to effectuate the repair or risk to continued operation until the time when the machine is stopped for the day. Of course, if crushing operations are run in three shifts, the down time condition will never be reached until the belt finally breaks and the machine must be stopped.  
      Present methods of fixing holes or severely worn spots in the conveyor belt involve cutting out the bad spot and then cutting a patch to fix it. The matching of a patch to repair a hole is difficult as it must be done accurately or the patch will not fit properly. If the hole that is cut into the belt is too small relative to the patch, the patch will not stay flush with the conveyor and more damage to the belt is inevitable. If the hole is too large relative to the patch, the patch is liable to leak, again resulting in further wear or breakage to the conveyor belt or other components of the system.  
      There is presently no method of quickly and efficiently repairing conveyor belts, especially when the repair must be conducted in an awkward to reach place. In order to minimize production down time, the method of repair must be able to be accomplished quickly and accurately in belts that can have varying sizes of holes and worn regions.  
     SUMMARY OF THE INVENTION  
      It is an aspect of the invention to provide a prefabricated conveyor belt patch apparatus that is available in various sizes and thicknesses in order to meet the repair requirements for a variety of conveyor belts and repair situations.  
      Another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus that is packaged with a corresponding template for cutting a precise hole in the damaged belt so that the patch fits perfectly without the need for guessing or measuring.  
      Still another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus such that the apparatus serves as its own template for drilling fastening holes through the belt whereby the patch can be firmly anchored to the conveyor belt that is being repaired.  
      It is an aspect of the invention to provide a prefabricated conveyor belt patch apparatus that has a plurality of spacers that hold the patch firmly during the drilling process as well as holding the patch centered within the hole that is to be patched.  
      Another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus that has gap tape fastened to the patch to ensure that the patch will not leak.  
      Still another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus that has a skive which will help keep the gap tape flush to the top of the patch and provide the proper overhang to overlap the patch onto the conveyor belt that is being repaired.  
      Still another aspect of the invention is to provide pre-attached clips for attaching the patch to the conveyor belt.  
      Another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus that is adapted for edge repair of a damaged conveyor belt.  
      Still another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus for edge repair that has a tapered edge so that the repaired belt is less likely to have the patch catching and tearing on any parts that the belt may encounter while traveling around the axles.  
      Another aspect of the invention is to provide a prefabricated conveyor belt patch apparatus that includes double wide clips that will match the same spacing pattern of the conveyor belt splice clips. This will enable the patch to be used adjacent to conveyor belt splices such that the gaps between the patch and conveyor belt are eliminated.  
      These and other aspects of the invention will become apparent in light of the detailed description of the invention which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side of the prefabricated conveyor belt patch apparatus in accordance with the invention.  
       FIG. 2  is top view.  
       FIG. 3  is a bottom view.  
       FIG. 4  is top view of an alternative embodiment of the invention.  
       FIG. 5  is a bottom view of the alternative embodiment.  
       FIG. 6  is a view of the double wide fastener.  
       FIG. 7  is a top view of a second alternative embodiment of the invention using double wide fasteners.  
       FIG. 8  is a bottom view of the alternative embodiment shown in  FIG. 7 .  
       FIG. 9  is top view of a third alternative embodiment of the invention.  
       FIG. 10  is a bottom view of the third alternative embodiment shown in  FIG. 9 .  
       FIG. 11  is a side view of another alternative embodiment of the invention.  
       FIG. 12  is a detailed view of the skive indicated in  FIG. 11 .  
       FIG. 13  is a detailed view of the spacers indicated in  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to  FIGS. 1-3 , invention  30  is illustrated. The invention is a kit which includes prefabricated patches of at least one size and thickness as well as a cutting template (not shown) that is used to cut a hole in the conveyor belt that is larger than the defect such that the patch selected will fit properly. The cutting template could be disposable such as might be made from poster board. The cutting template could also be made to be used over and over again such as might be made from thin metal. Each sized patch must have a corresponding template.  
      Patch  10  is preferably made from eurethane or from the same materials as the conveyor belt that is to be repaired. However, materials that are more or less durable would also suffice. Further, the patch  10  should be substantially the same thickness as the thickness of the conveyor belt being repaired. As noted above, the main patch  10  is slightly smaller that the hole made in the conveyor so that the thin skirt integral with and surrounding patch  10  seals the area between the larger hole made in the conveyor belt so that when patch  10  is secured into place it will be flat relative to the surface of the conveyor belt.  
      As shown in  FIG. 11 , an alternative embodiment, gap tape  13  is attached at the perimeter of patch  10  which seals the gap between the conveyor belt and patch  10  to ensure that material being conveyed will not leak through. Gap tape  13  is preferably the type of tape that is sold by Flexco of Downers Grove, Ill. under the brand name FLEXCO-LOK tape. As shown in detail in  FIG. 11 , Skive  14  is cut into patch  10  so that gap tape  13  is flush with the top surface of patch  10  as shown, Thus, the depth of skive  14  is preferably the thickness of gap tape  13 . Optionally, skive  14 ′ could also be cut so that both gap tape  13  and fastener  18  would be recessed thus fastener  18  would be flush with the surface of patch  10  even prior to when the invention is tightened into place. Thus, the depth of skive  14 ′ under the fastener  18  would correspond to the thickness of fastener  18  and the depth of skive  14 ′ under gap tape  13  would correspond the thickness of fastener  18  plus the thickness of gap tape  13 .  
      Fasteners  18  are pre-attached to patch  10  via glue or other attachment means well known in the art. Bolt openings  22  first serve as a template by which holes are drilled through the conveyor belt and then invention  10  can be fastened to patch  10  via a clip and bolts (not shown) which are fed through openings  22  and  21 . The bolts are then tightened into position via specialized nuts (not shown). The specialized bolts and nuts are well known in the art and are manufactured and sold by Flexco.  
      As shown in  FIG. 3 , spacers  16  are used to make invention  30  self centering thus ensuring proper installation. Spacers  16  are a plurality of tabs that are designed to position patch  10  properly within hole  40 . Spacers  16  provide the proper gap  42  between patch  10  and conveyor belt hole  40  so that invention  30  can be tightened without wrinkling or puckering. This undesirable situation would occur if the patch was too large for the hole or was off center within the perimeter of the hole that has been cut using the hole template discussed above.  
      As shown in  FIGS. 3 and 4 , another alternative embodiment is illustrated. This prefabricated patch  31  is used for left and right edge repair. The only difference is that one edge has a taper  20  that helps keep the invention from catching or tearing on any part that the moving conveyor belt passes through during its travel around the axles.  
       FIG. 4  illustrates a double wide fastener  30  that is used in two other embodiments of the invention. Fastener  30  is preferably metal that is sufficiently durable to withstand the rigors of the task. Fastener  30  enables the invention to be used along conveyor belt splices as well as other locations on the belt. Fasteners  30  permit the repair to maintain strength in the splices  35  shown in  FIG. 7  and  8  for example, along with eliminating gaps between patch  10  and the conveyor belt.  
       FIGS. 7 and 8  show the use of fasteners  30  for a center splice repair of conveyor belt  37 . Clips  34  are used to attach conveyor belt  37  together at splice  35 . Each fastener  30  replaces a clip  34  so that splice strength is maintained.  
       FIGS. 9 and 10  show the use of fasteners  30  for an edge splice. The edge of invention  10  is provided with taper  20  so that, as the embodiment doesn&#39;t use double wide fastener  30 , helps keep the invention from catching or tearing on any part that the moving conveyor belt passes during its travel around the axles.  
      In operation, a properly sized hole is made in the belt to remove the defect as has been discussed. Then, patch  10  is aligned within this opening as shown in  FIG. 3  and as discussed above. The next step is to drill mounting holes in the conveyor belt that correspond to bolt holes  22  using these holes as the template. The holes in the conveyor belt are made using a specialized boring tools, well known in the art, such as those tools made by Flexco for drilling holes in a conveyor belt. Finally, the bolts and the mating fastener clip are inserted up through the bottom of the conveyor belt into the holes  21  and  22  and tightened with nuts until fastener  18  is substantially flush with the top surface of the conveyor belt and patch  10 . The bolts are then broken off flush with the top of the nut and the repair is completed quickly and efficiently.  
      While certain representative embodiments of the invention have been described herein for the purposes of illustration, it will be apparent to those skilled in the art that modification therein may be made without departure from the spirit and scope of the invention.