Abstract:
A modular multi-disc assembly for use in material separation screens and a method of application to those screens are provided. The modular multi-disc assembly includes an inner securing hub that clamps onto the drive shaft of a material separation screen. The modular multi-disc assembly further includes an outer multi-disc module split into halves with each half mounting separately onto the inner securing hub. Multiple discs can be replaced at one time as opposed to replacing each individual disc in a typical screen. The inner securing hub spaces the outer multi-disc module away from the drive shaft so that the primary wear concern reduces to the resilient discs on the outer multi-disc module, allowing for multiple outer multi-disc module replacements before needing to replace the inner securing hub.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to an apparatus and method for separating various materials. In particular, this invention relates improvements in a disc screen.  
       BACKGROUND OF THE INVENTION  
       [0002]     Disc or roll screens are used in the materials handling industry for screening flows of materials to remove certain items of desired dimensions. Disc screens are particularly suitable for classifying what is normally considered debris or residual materials. This debris may consist of soil, aggregate, asphalt, concrete, wood, biomass, ferrous and nonferrous metal, plastic, ceramic, paper, cardboard, paper products or other materials recognized as debris throughout consumer, commercial and industrial markets. The function of the disc screen is to separate the materials fed into it by size or type of material. The size classification may be adjusted to meet virtually any application.  
         [0003]     Material separating screens, and more specifically the discs in those screens, have been modified to improve the efficiency of separating out material from flows of debris introduced to the screen. Examples of those modifications are found in U.S. Pat. No. 5,960,964 to Austin et al., U.S. Pat. No. 6,149,018 to Austin et al., and U.S. Pat. No. 6,371,305 to Austin et al., which are incorporated by reference herein.  
         [0004]     Discs must be routinely replaced on material separating screens when the discs wear down due to the normal operation of the screen. Replacing each individual disc involves removing the worn discs by disassembling each disc into its two halves. New discs are then installed on the drive shafts, with each new half disc fastened to that half disc&#39;s corresponding other half.  
         [0005]     A typical screen will employ around 600 individual discs. Removal and replacement of all these discs is time-consuming. The process also requires at least two workers to perform the removal and replacement because a first disc half is held in place on the drive shaft by one worker while a second worker attaches or removes the second disc half that attaches to the first disc half.  
         [0006]     What is needed is a material separating screen that requires less time to perform replacement of discs and reduces the man-power required to perform the replacement.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view of a modular multi-disc assembly mounted on a material separating screen drive shaft according to an embodiment of the invention.  
         [0008]      FIG. 2  is an exploded perspective view of the modular multi-disc assembly of  FIG. 1 .  
         [0009]     FIG. 3  is an exploded perspective view of an outer multi-disc module of the modular multi-disc assembly of  FIG. 1 .  
         [0010]      FIG. 4  is an exploded perspective view of a securing hub of the modular multi-disc assembly of  FIG. 1 .  
         [0011]      FIG. 5  is a simplified perspective view of a material separating screen utilizing modular multi-disc assemblies according to another embodiment of the invention.  
         [0012]      FIG. 6  is a top plan view of the simplified material separating screen of  FIG. 5 . 
     
    
     DETAILED DESCRIPTION  
       [0013]      FIG. 1  shows a perspective view of the modular multi-disc assembly  20  assembled on material separating screen drive shaft  26  (shown in phantom).  FIG. 2  shows an exploded perspective view of the multi-disc assembly  20  and the drive shaft  26  (shown in phantom).  
         [0014]     The modular multi-disc assembly  20  includes inner securing hub  22 , which includes two securing hub halves  28  and  30 , and outer multi-disc module  24 , which includes two mounting plate halves  32  and  34  and two resilient molded surface multi-disc halves  36  and  38 .  
         [0015]     The inner securing hub  22  is sized and shaped to clamp around the square drive shaft  26 . The outer multi-disc module  24  mounts onto the inner securing hub  22 . The halves of the outer multi-disc module  24  are oriented around the longitudinal axis of the assembly  20  about ninety degrees to the inner securing hub halves  28  and  30 . Mounting the outer multi-disc module  24  in this manner provides additional structural support and stability to the assembly  20 .  
         [0016]      FIG. 3  shows an exploded perspective view of the outer multi-disc module  24 . The mounting plate halves  32  and  34  are formed to fit around the outer radius of the inner securing hub  22 . The mounting plate halves  32  and  34  are preferably formed from a metal such as aluminum or steel.  
         [0017]     The resilient molded surface multi-disc halves  36  and  38  are corresponding halves of multiple compound discs  39 . Each compound disc  39  includes a major profile  41  and a minor profile  43 . Alternatively, each multi-disc half  36  and  38  can include more than one major profile  41  and at least one minor profile  43 . Most preferable, as shown in  FIG. 3 , four compound disc halves  39  are formed together to make a modular 4-disc assembly. However, modules of varying number of compound discs  39  are contemplated to be within the scope of the multi-disc assembly  20 .  
         [0018]     Each major profile  41  includes a wear indicator hole  62 . When major profile  41  is worn down, wear indicator hole  62  becomes exposed alerting an operator of a material separating screen that the outer multi-disc module  24 , or at least a half of the outer multi-disc module  24 , on that part of the screen should be replaced.  
         [0019]     Each resilient molded surface multi-disc half  36  and  38  is further molded onto the corresponding mounting plate halves  32  and  34 .  
         [0020]      FIG. 4  shows an exploded perspective view of the inner securing hub  22  with the drive shaft  26  shown in phantom. The inner securing hub  22  includes first and second securing hub halves  28  and  30 , respectively.  
         [0021]     Each inner securing hub half  28  and  30  includes disc module mounting portions  42 . Preferably, each hub half  28  and  30  has two disc module mounting portions  42  positioned correspondingly at first and second longitudinal ends of each hub half  28  and  30 . The mounting portions  42  are shaped to have an outer diameter spaced outwardly apart from an inner clamping portion  51  that is shaped to clamp around the drive shaft  26 . Each mounting portion  42  has a length  45  less than the overall length  47  of the inner securing hub  22 .  
         [0022]     Each securing hub half  28  and  30  further includes an outer longitudinal portion  44  that extends between the mounting portions  42  and has an outer diameter matching the outer diameter of the mounting portions  42 .  
         [0023]     The inner securing hub  22  is preferably made from a metal material and is most preferably made from aluminum.  
         [0024]     Each inner securing hub half  28  and  30  has mounting holes  46  and  48  used for clamping to each other and onto the drive shaft  26 . Preferably, mounting holes  46  in the first hub half  28  are counter-sunk to receive fasteners  50 , and mounting holes  48  in the second hub half  30  are tapped to threadingly receive fasteners  50  to clamp the inner securing hub  22  securely onto the drive shaft  26 .  
         [0025]     Each inner securing hub half  28  and  30  also includes disc mounting holes  53  that correspond to mounting holes  52  in the outer multi-disc module  24 . Disc mounting holes  53  are preferably tapped to threadingly receive fasteners (not shown) that attach each half of the outer multi-disc module  24  to the inner securing hub  22 . The disc mounting holes  53  are arranged on the inner securing hub half  28  and  30  to orient the halves of the outer multi-disc module  24  about ninety degrees to the inner securing hub halves  28  and  30  around the longitudinal axis of the assembly  20 . Each half of the outer multi-disc module  24  can then be independently mounted onto the inner securing hub  22 .  
         [0026]      FIG. 5  is a simplified perspective view of a material separating screen  60  using the modular multi-disc assemblies  20  described above.  FIG. 6  is a top plan view of the simplified screen  60 . On typical screens, many modular multi-disc assemblies would be mounted on each drive shaft  26 . In  FIGS. 5 and 6 , for illustration purposes, only two modular multi-disc assemblies  20  are shown mounted on each separate screen drive shaft  26 . When the resilient discs wear down and require replacement, each half of each outer multi-disc module  24  can be removed from the inner securing hubs  22 . Contrastingly, current screens require removal of each complete individual compound disc, with each individual disc comprising two half discs attached to the drive shaft  26  by clamping to each other.  
         [0027]     In  FIGS. 5 and 6 , a single worker can remove an outer multi-disc half  36  or  38  by unfastening the disc half  36  or  38  from the inner securing hub  22 , then rotating the drive shaft  26  and removing the other disc half in the same manner. Replacement of disc halves is similarly easily performed.  
         [0028]     A method for mounting modular multi-disc assemblies on a material separation screen will now be described by referring to  FIGS. 1 and 2 .  
         [0029]     Two inner securing hub halves  28  and  30  are mounted onto a material separation screen drive shaft  26 . Then a first half of the outer multi-disc module  24  including a mounting plate half  32  and resilient multi-disc half  36  is mounted onto one side of the inner securing hub  22 . Finally, a second half of the outer multi-disc module  24  including a mounting half plate  34  and resilient multi-disc half  38  is mounted onto the other side of the inner securing hub  22 .  
         [0030]     In allowing for mounting a first half of the outer multi-disc module  24  and then mounting a second half of the outer multi-disc module, an operator can also replace the first or second half of the outer multi-disc module  24  when one half of the module  24  wears more than the other half.  
         [0031]     Mounting the halves of the outer multi-disc module  24  preferably includes fastening the halves to the inner securing hub  22  using mounting holes  52  on the outer multi-disc module  24  and corresponding disc mounting holes  53  on the inner securing hub  22 . The disc mounting holes  53  are tapped to threadingly receive fasteners fastening the outer multi-disc module  24  onto the inner securing hub  22 .  
         [0032]     By mounting the outer disc module  24  on the inner securing hub  22 , less structural material is wasted when the outer disc module  24  is replaced as compared to replacing a whole single disc, as is typically done. On typical screens using individual discs, the discs have a solid core beneath the resilient disc portion. When an individual disc wears out, the entire disc including the solid core is thrown away. In the embodiments presented above, initially only the resilient outer disc module  24  is replaced, leaving the inner securing hub  22  intact clamped to the drive shaft  26 .  
         [0033]     Further, less material is used in the inner securing hub  22  to transfer the rotational force of the drive shaft  26  to the outer disc module  24 . As mentioned above, a typical single disc construction has a solid core of material between the resilient disc and the drive shaft. The inner securing hub  22  reduces the amount of material by mounting the outer disc module  24  on the disc module mounting portions  42  (shown in  FIG. 4 ) located at the ends of the inner securing hub  22  that have a length  45  that is less than the overall length  47  of the inner securing hub  22 .  
         [0034]     It should be appreciated that reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the invention.  
         [0035]     Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.