Abstract:
An improved bulk material conveyor belt scraper comprises a skirt that shields mounting surfaces from the bulk material dust. By shielding the mounting surfaces from bulk material dust, such dust does not interfere with the replacement of the scraper blade. The belt scraper also comprises an improved securing mechanism for attaching belt scrapers to belt scraper mounts. The improved securing mechanism comprises pegs that have an elongate transverse cross-section that more evenly distributes bearing loads between the belt scrapers and their respective mounts. This eliminates local yielding that can cause belt scrapers to become loose over time.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       APPENDIX 
       [0003]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention pertains generally to bulk material conveyor belt assemblies. More specifically, this invention pertains to a conveyor belt scraper comprising a skirt that prevents bulk material that is removed from the conveyor belt by the belt scraper from migrating to mating surfaces between the belt scraper and the mounting member that holds the scraper blade. By preventing bulk material removed from the conveyor belt from migrating to the mating surfaces between the belt scraper and the mounting member, such material does not interfere with the replacement of worn belt scrapers. The belt scraper assembly also utilizes securing pegs that have an elongate transverse cross-section that distribute bearing loads more evenly than would securing pegs having circular transverse cross-sections. 
         [0006]    2. General Background 
         [0007]    Bulk material conveyor belt systems often comprise belt scraper assemblies that are configured to remove bulk material carryback from the belt. Due to the function they serve, belt scrapers necessarily become covered with dust and fine particles removed from the conveyor belt. This is especially the case on the leading side of a belt scraper, since the leading side is the side that engages and redirects the bulk material removed from the conveyor belt. Unfortunately, the dust and fine particles can make the task of replacing worn belt scrapers difficult since the dust and fine particles often interfere with mating surfaces between the belt scrapers and the mounts that hold the belt scrapers. For example, belt scrapers are often formed of polymeric material, which can make it difficult to rigidly attach such belt scrapers to belt scraper mounts. As such, in some cases, the belt scraper comprises a tapered mounting portion that mates with, and is inserted into, a correspondingly tapered rigid pocket of the mount that supports the belt scraper. This provides the belt scraper with good fixation relative to the mount. However, during use, dust from the bulk material scraped from the conveyor belt can work its way into the pocket of the mount. While this doesn&#39;t necessarily interfere with the operation of the belt scraper, it does make it difficult to replace the belt scraper when worn and, more particularly, to attach a replacement belt scraper to the mount. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention helps prevent bulk material dust removed from the conveyor belt from interfering with the process of replacing worn belt scrapers. The invention is achieved by providing a belt scraper with a skirt that shields mounting surfaces from the bulk material dust. The invention also pertains to an improved securing mechanism for attaching belt scrapers to belt scraper mounts. The improved securing mechanism more evenly distributes bearing loads between the belt scrapers and their respective mounts. This eliminates local yielding that can cause belt scrapers to become loose over time. 
         [0009]    In a first aspect of the invention, a bulk material conveyor belt scraper has a leading side and a trailing side and comprising a scraper portion, a mounting portion, and a skirt portion. The scraper portion has a scraping edge that lies on the leading side of the belt scraper. The scraping edge is configured and adapted to engage a moving conveyor belt in a manner such that the scraper portion removes bulk material from the conveyor belt, with the leading side of the belt scraper leading the trailing side relative to the movement of the belt. The mounting portion of the belt scraper is integrally formed with the scraper portion as a monolithic part. The mounting portion is opposite the scraper portion and protrudes therefrom in a manner such that the mounting portion tapers in a narrowing manner as it extends away from the scraper portion. The skirt portion is integrally formed with the scraper portion and the mounting portion as a portion of the monolithic part, and forms a portion of the leading side of the belt scraper. The skirt portion protrudes from the scraper portion and is adjacent to and spaced from the mounting portion in a manner such that the skirt portion lies between the mounting portion and the leading side of the belt scraper and such that a slot extends through the belt scraper parallel to the scraping edge. 
         [0010]    In another aspect of the invention, a method comprises operating a bulk material conveyor belt system. The conveyor belt system comprises a belt moving in an endless loop. The method includes engaging the belt with a belt scraper assembly in a manner removing material from the conveyor belt. The belt scraper assembly comprises a belt scraper and a mounting member. The belt scraper has a leading side and a trailing side. The belt scraper is in contact with the belt in a manner such that there is relative movement therebetween with the leading side of the belt scraper leading the trailing side. The belt scraper also comprises a scraper portion, a mounting portion, and a skirt portion. The scraper portion is engaged with the belt. The mounting portion is integrally formed with the scraper portion as a monolithic part and protrudes from the scraper portion. The skirt portion is integrally formed with the scraper portion and the mounting portion as a portion of the monolithic part and forms a portion of the leading side of the belt scraper. The skirt portion protrudes from the scraper portion and is adjacent to and spaced from the mounting portion in a manner such that the skirt portion lies between the mounting portion and the leading side of the belt scraper. The mounting member comprises a pocket. The mounting portion of the belt scraper is positioned in the pocket of the mounting member. The skirt portion is outside of and adjacent the pocket, and shields the pocket in a manner preventing at least some the material from entering the pocket. 
         [0011]    Further features and advantages of the present invention, as well as the operation of the invention, are described in detail below with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  depicts an exploded perspective view of a belt scraper assembly in accordance with the invention. 
           [0013]      FIG. 2  depicts another exploded perspective view of the belt scraper assembly shown in  FIG. 1 . 
           [0014]      FIG. 3  is a perspective view of the belt scraper assembly shown in  FIGS. 1 and 2  and is shown with the components assembled to each other. 
           [0015]      FIG. 4  is another perspective view of the belt scraper assembly from a different point of view. 
           [0016]      FIG. 5  is a side view of the belt scraper by itself. 
           [0017]      FIG. 6  is an elevation view of the leading side of the belt scraper. 
           [0018]      FIG. 7  is an elevation view of the trailing side of the belt scraper. 
           [0019]      FIG. 8  is a perspective view of the belt scraper. 
       
    
    
       [0020]    Reference numerals in the written specification and in the drawing figures indicate corresponding items. 
       DETAILED DESCRIPTION 
       [0021]    A belt scraper assembly  10  in accordance with the invention is shown in  FIGS. 1-4 . The belt scraper assembly  10  comprises a belt scraper  12 , a mounting member  14 , and two securing pegs  16 . 
         [0022]    The belt scraper  12  itself has a leading side  18  and a trailing side  20  and is preferably symmetric about a plane. The leading side  18  of the belt scraper  12  is preferably convex. The trailing side  20  is preferably concave. The belt scraper  12  comprises a scraper portion  22 , a mounting portion  24  and a skirt portion  26 . The scraper portion  22 , the mounting portion  24 , and the skirt portion  26  are preferably formed as a monolithic integral part of polymeric material. The scraper portion  22  comprises a scraping edge  28  on the leading side  18  of the belt scraper  12  that is configured and adapted to engage a moving conveyor belt. 
         [0023]    The mounting portion  24  of the belt scraper  12  protrudes from the scraper portion  22  and tapers in a narrowing manner as it extends away from the scraper portion. This tapering aspect of the mounting portion  24  is most notable in  FIG. 5  and is shown as the angle α (a being greater than zero) between the front face  30  and the rear face  32  of the mounting portion. The mounting portion  24  comprises a primary slot  34  that is parallel to and centered about the plane of symmetry of the belt scraper  12 . The primary slot  34  divides and separates the mounting portion  24  into two mounting protrusions  36  that are mirror images of each other. Each of the mounting protrusions  36  comprises a relief slot  38  and a peg opening  40 . Each of the peg openings  40  has an elongate transverse cross-section (i.e. the cross-section perpendicular to its longitudinal direction) oriented with its larger dimension perpendicular to the plane of symmetry of the belt scraper  12 . The peg openings  40  extend completely through the mounting portion  24  of the belt scraper  12 . Each relief slot  38  bisects its respective mounting protrusion  36  and intersects the respective peg opening  40 . The relief slots  38  are parallel to the plane of symmetry of the belt scraper  12 . The mounting portion  24  of the belt scraper  12  further comprises guide notches  42  that serve as visual and tactile guides when the belt scraper is being inserted into the mounting member  14  of the belt scraper assembly  10  (discussed below). 
         [0024]    The skirt portion  26  of the belt scraper  12  forms a portion of the leading side  18  of the belt scraper and extends from the scraper portion  22 . The skirt portion  26  is adjacent to and spaced from the mounting portion  24  in a manner such that a slot  44  is formed between the skirt portion and the mounting portion. The peg openings  40  that extend through the mounting portion  24  also extend through the skirt portion  26  of the belt scraper  12 . 
         [0025]    The mounting member  14  is configured and adapted to receive the mounting portion  24  of the belt scraper  12 . The mounting member  14  is preferably formed of metal and comprises two pockets  46 , with each being adapted to receive one of the mounting protrusions  36  of the mounting portion  24  of the belt scraper  12 . Similar to the mounting portion  24  of the belt scraper  12 , each pocket  46  of the mounting member  14  tapers in a narrowing manner as it extends into the mounting member. The longitudinal walls  48  of the mounting member  14  comprise two peg openings  50 , with each extending into a respective one of the pockets  46 . The lateral walls  52  of the mounting member  14  comprise guide protrusions  54  that protrude slightly into the pockets  46 . 
         [0026]    The securing pegs  16  each comprise a tapered lead-in section  56  and a main body portion  58 . The main body portion  58  of each securing peg  16  preferably has an elongate transverse cross-section that is slightly larger than the transverse cross-section of the peg openings  40  of the belt scraper  12 . The main body portion  58  of each securing peg  16  also preferably has length sufficient to extend through both of the longitudinal walls  48  of the mounting member  14 . 
         [0027]    The belt scraper assembly  10  is assembled by inserting the mounting protrusions  36  of the belt scraper  12  into the pockets  46  of the mounting member  14 . The tapered nature of the mounting protrusions  36  and of the pockets  46  ensures that the two parts rigidly engage each other when they are assembled to each other. As the mounting protrusions  36  are being inserted into the pockets  46  of the mounting member  14 , the guide protrusions  54  on the lateral walls  52  of the mounting member push inward on the mounting protrusions  36 . The relief slots  38  of the mounting portion  24  of the belt scraper  12  allow the mounting protrusions  36  to resiliently deform as this occurs. Once the mounting protrusions  36  of the belt scraper  12  are fully seated in the pockets  46  of the mounting member  14 , the guide notches  42  of the belt scraper become aligned with the guide protrusions  54  of the mounting member. This provides tactile confirmation that the parts are fully engaged with each other. To prevent the belt scraper  12  from being dislodged from the mounting member  14 , the securing pegs  16  are inserted through the peg openings  40  of the belt scraper and through the peg openings  50  of the mounting member. The lead-in portions  56  of the securing pegs  16  facilitate initial alignment of the pegs with the openings. The securing pegs  16  have a slight interference fit in the peg openings  40  of the belt scraper  12  and therefore must be forcibly driven into or out of the belt scrapers  12 . This prevents the securing pegs  16  from inadvertently separating from the belt scraper assembly  10 . As assembled, the skirt portion  26  of the belt scraper  12  covers the exterior of one of the longitudinal walls  48  of the mounting member  14 , and that longitudinal wall extends into the slot  44  that is formed between the skirt portion and the mounting portion  24  of the belt scraper. 
         [0028]    Once assembled as described above, the belt scraper assembly  10  can be brought into contact with a moving conveyor belt for the purpose of removing bulk material from the conveyor belt. As this is done, the scraping edge  28  of the scraper portion  22  of the belt scraper  12  engages the conveyor belt and bulk material is forced onto the leading side  18  of the belt scraper  12 . It should be appreciated that the skirt portion  26  of the belt scraper  12  protects and shields the pockets  46  of the mounting member  14 . As such, bulk material is not able to migrate from the leading side  18  of the belt scraper  12  into the pockets  46  of the mounting member  14 . This prevents the bulk material from interfering with the replacement of the belt scraper  12  after its useful life is exhausted. It should also be appreciated that the elongate transverse cross-sections of the securing pegs  16  and peg openings  40 ,  50 , is configured to distribute pull-out bearing loads evenly across the width of the pegs and openings. This is an improvement over the use of securing pegs and peg openings having circular transverse cross-sections, which tend to focus bearing loads over small portions of the bearing surfaces. Thus, the elongated transverse cross-sections of the securing pegs  16  and peg openings  40 ,  50  helps prevent the peg openings  40  of the belt scraper  12  from yielding during the useful life of the belt scraper. 
         [0029]    In view of the foregoing, it should be appreciated that the invention achieves the several advantages over prior art conveyor belt scrapers and belt scraper assemblies. 
         [0030]    As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. 
         [0031]    It should also be understood that when introducing elements of the present invention in the claims or in the above description of exemplary embodiments of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed unless such order is necessary.