Abstract:
A partially releasable disc for processing recycling materials in general. More specifically a disc that is sufficiently flexible to function in heavy machinery without excessive wear while maintaining sufficient stiffness to avoid excessive fluctuations, wobbling, or other undesired excess deflection in the disc. An outer flexible portion may be wrapped around a less flexible core. A disc may comprise a plurality of outer impacting elements configured for engaging materials to be classified and propelling the materials in a conveying direction when a core is rotated. For ease of replacement, when the flexible portion is worn or damaged, the flexible portion may be removed without necessarily removing the inner core, saving labor and equipment expense when maintain a screen, such as the separation screens used for sorting recycled materials.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The application claims priority from U.S. Provisional Patent Application No. 61/534,886, filed on Sep. 14, 2011, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     A disc screen typically includes a frame in which a plurality of rotatable shafts are mounted in parallel relationship. A plurality of discs is mounted on each shaft and a chain drive rotates the shafts in the same direction. The discs on one shaft interleave with the discs on each adjacent shaft to form screen openings between the peripheral edges of the discs. The size of the openings determines the dimension (and thus the type) of material that will fall through the screen. Rotation of the discs, which have an irregular outer contour, agitates the mixed recyclable materials to enhance classification. The rotating discs also propel the larger articles which are too big to fall between the discs across the screen. The general flow direction extends from an input area where the stream of material pours onto the disc screen to an output where the larger articles pour off of the disc screen. The smaller articles fall between the discs onto another disc screen or a conveyor, or into a collection bin. 
     The discs of a disc screen normally have a central opening or bore that permits the discs to be slid over an end of a shaft which may have a round or square cross-section. See for example U.S. Pat. No. 4,836,388 of Bielagus. Eventually, discs wear out and must be replaced. It is not practical to refurbish or repair damaged or worn discs without removing them from the shafts of the disc screen. However, it is tedious to dismount the ends of the shafts of a disc screen from their respective bearings so that the old discs may be removed and replaced by sliding the discs off the ends of the shafts. If only a single disc is worn or broken, it is usually necessary to remove several discs before the damaged or broken disc may be slid off the shaft for replacement. 
     Previous attempts have been made to develop spot discs as manufactured by CP Manufacturing, Inc. of National City, Calif. See U.S. Pat. No. 6,318,560 of Robert M. Davis. The split disc is comprised of two identical halves which are assembled around a shaft and tightly held together by a pair of bolt assemblies which clamp the disc to the shaft. Each disc half is made of an outer rubber portion which is stiffened with a rigid internal metal frame embedded inside the rubber portion. While the aforementioned patented two-piece disc construction has been commercially successful, it would be desirable to provide a disc construction that is even more convenient to remove and install while offering a lower part cost for replacement of worn or damaged discs in a disc screen. 
     Past inventions have attempted to provide useful discs comprising rigid, metal frames embedded within a flexible material, such as urethane, such that the rigid, metal frame extends substantially in a radial direction within the flexible material to provide stiffness to the disc. A disadvantage with these past inventions is that excessively rigid metal frames can be expensive and heavy. A load of discs may be shipped long distances at rated depending upon the freight weight. A load of discs laden with heavy, rigid, metal frames can be excessively costly to transport. A lighter disc would offer substantial savings when multiplied by the number of discs shipped at a lighter freight weight. Additionally, using less metal (or even no metal) may reduce material costs, machining time, other factors to provide an improved disc. 
     Thus it would be advantageous to use a disc that minimizes manufacturing costs, comfortably operates, saves freight costs, reduces weight of the device, and provides stability in rotation, and offers a flexible outer surface, optionally with a tongue-and-groove feature, particular clamping features, and other beneficial features. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a disc for attachment to a shaft in a disc screen apparatus may comprise an outer flexible material, the outer flexible material consisting of one piece, without a hinge or interconnecting flap, and a disc core connected to the outer flexible material with a mating connection. 
     In another aspect of the present invention, a disc for a recycling apparatus may comprise a disc core configured to engage a shaft member to locate the disc core on the shaft member, and an outer flexible portion removably mounted to the disc core to project beyond the disc core to contact waste material being processed by a recycling apparatus as the shaft member rotates, wherein the outer flexible portion comprises of one piece, without a hinge or interconnecting flap. 
     In a further aspect of the present invention, a disc for releasable attachment to a shaft in a disc screen apparatus for classifying mixed recyclable materials may comprise: an inner frame; an outer material partially covering the inner frame and defining an outer impacting surface with a generally square shape for engaging and propelling mixed recyclable materials in a conveying direction along a disc screen; the inner frame and the outer material covering the frame being separable into a plurality of portions, the portions being configured to provide an opening for receiving a shaft of the disc screen apparatus; and means for releasably clamping the portions around the shaft, wherein the inner frame is situated less than 50% of the radial distance between an inner diameter of the disc and the outer perimeter of the disc. The inner frame may be situated less than 25% of the radial distance between an inner diameter of the disc and the outer perimeter of the disc. Additionally, another frame may be situated, in addition to a first inner frame, over 59% of the radial distance between an inner diameter of the disc and the outer perimeter of the disc. 
     In a still further aspect of the present invention, a disc and shaft assembly for a disc screen of a recycling apparatus configured to separate mixed recyclable materials according to size may comprise a shaft having opposite ends configured to be rotatably supported in a frame of a recycling apparatus, a plurality of discs mounted at spaced intervals along the shaft to rotate with the shaft and configured for classifying a stream of mixed recyclable materials, each disc comprising an outer flexible portion, the outer flexible portion consisting of one piece, without a hinge or interconnecting flap and a disc core connected to the outer flexible portion with a mating connection, the shaft extending transversely through bores within the plurality of discs, and each outer flexible portion material is shaped for engaging materials to be classified and propelling the materials in a conveying direction when the disc core is rotated. 
     These and other aspects, objects, features and advantages of the present invention, are specifically set forth in, or will become apparent from, the following detailed description of an exemplary embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects of the present invention will become more apparent by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which: 
         FIG. 1A  illustrates a disc, according to an embodiment of the present invention; 
         FIG. 1B  illustrates the flexible portion from  FIG. 1A  seen along section B-B, according to an embodiment of the present invention; 
         FIG. 2  illustrates the disc from  FIG. 1A  secured in a closed manner according to an embodiment of the present invention; 
         FIG. 3  is side view of a disc core according to another embodiment of the present invention; 
         FIG. 4  is an elevation view of the disc core from  FIG. 3 , viewed along section A-A according to yet another embodiment of the present invention; 
         FIG. 5  is a perspective view of a disc core, according to a further embodiment of the present invention; 
         FIG. 6  is a perspective view of a flexible portion of a disc, according to a yet further embodiment of the present invention; 
         FIG. 7  is a cross-section view of a flexible portion of a disc, according to an additional embodiment of the present invention; 
         FIG. 8  is a perspective view of an assembled disc, according to a still yet further embodiment of the present invention; and 
         FIG. 9  is a plan view of a disc screen apparatus, according to further embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     The present invention relates generally to discs for processing recycling materials in general. More specifically to a disc that is sufficiently flexible to function in heavy machinery without excessive wear while maintaining sufficient stiffness to avoid excessive fluctuations, wobbling, or other undesired excess deflection in the disc. The present invention relates to machines used to separate particulate materials or mixed recyclable materials into different fractions, and more particularly, to a disc construction for a disc screen that allows discs to be more easily separated, removed, and replaced. 
     The invention may be useful in the recycling industry. For example, the invention&#39;s disc may be used in a disc screen for classifying material by size, shape, or other features with discs mounted in rows. The present invention may be used for recycling, sorting, grading, measuring, treating, and other similar uses for various materials. 
     Referring now to the drawings in detail, wherein like reference characters refer to like elements, there is shown in  FIG. 1A  a disc  10  according to one embodiment of the present invention. A disc core  12  comprising a durable material, such as steel, or other suitable materials, may be wrapped alongside a circumference by an outer flexible material or portion  14 . The outer flexible material  14  may be comprised of a polymer, such as polyurethane, rubber, rubber-like materials, or other suitable material. The disc core  12  may comprise a protuberance, such as an outer tongue or ridge  16  extending radially outward from the center of the disc core  12 . A lip  18  may be located at a circumference of the disc core  12 , such as at a location between the center of the disc core  12  and an outer circumference of the ridge  16 . 
     The outer flexible material  14  may contain protuberances, such as a plurality of fingers  20  integrally formed as an appendage to a radial perimeter  30  of the outer flexible material  14 . The outer flexible material  14  may be wrapped around a perimeter of the disc core  12 . The outer flexible material  14  may comprise two ends,  22 ,  24 , which may mesh in a mating arrangement. The outer flexible material  14  is constructed without a hinge or interconnecting flap and a disc core (as described below) may be connected to the outer flexible portion  14  with a mating connection. The mating connection may comprise a tongue-and-groove connection or other suitable connection for joining the outer flexible material  14  to a disc core  12 . The disc core  12  may comprise a passage  26  for engagement with a shaft in a disc screen apparatus. Although  FIG. 1A  depicts a passage  26  with a square shape, it is to be understood that the passage  26  may be of any suitable shape to effectively engage with a shaft. Also, the ridge  16  and lip  18  may comprise a convex, concave, or other form to engage in a mating arrangement with the outer flexible material  14 , as later described regarding  FIG. 6 . The outer flexible material  14  may be further secured to the disc core  12  by one or more bolts  28 . 
     In  FIG. 1B  a portion  40  of the outer flexible material  14  may be viewed along section BB such that ridges  42  may mate with the lip  18  and the disc core ridge  16  may fit in between ridges  42 . 
       FIG. 2  shows an exemplary method of securing the outer flexible material  14  to the disc core  12 . Bolts  28  are inserted into bores  44  at various distances through the disc  10  to secure portions of the disc core  12  (if the disc core  12  comprises more than one portion) and to secure the outer flexible material  14  to the disc core  12 . One or more studs  50  may be used to secure the outer flexible material  14  to the disc core  12 . 
     A side view of a disc core  12  is shown in  FIG. 3 , showing the bores  44  arranged along the perimeter of the disc core  12 . 
       FIG. 4  shows the disc core  12  of  FIG. 3 , viewed along section A-A. As can be seen in  FIG. 4 , the disc core  12  may be separable into a plurality of portions  52 ,  54  that may be assembled around a shaft. 
     A disc core  60  according to another embodiment of the present invention is shown in  FIG. 5 . An outer ridge  62  may extend radially from the center passage  72 . The outer ridge  62  may comprise concave portions  64  and convex portions  66 . Lip  68  may extend radially between lip  70  and outer ridge  62  for engagement with mating portions of an outer flexible portion. The center passage  72  may comprise concave portions  74  and convex portions  76  for engagement with a shaft to rotate the disc core  60 . 
     An outer flexible material  80 , which may be suitable for a disc core  60  (as shown in  FIG. 5 ), is shown in  FIG. 6 . The outer perimeter  82  of the outer flexible material  80  may comprise a plurality of fingers  86  integrally formed as appendages. Ranges  84  and  94  may be integrally formed within the inner aperture  96  of the outer flexible material  80 . Convex portions  90  and concave portions  92  may be situated within the interior or the outer flexible material  80  to engage with an outer perimeter of a disc core  80  (as discussed above regarding  FIG. 5 ). At least one bore  88  may guide bolts (such as bolts  28  shown in  FIG. 2 ) to secure the outer flexible material  80  to a disc core (such as disc core  60  described above regarding  FIG. 5 ). 
       FIG. 7  shows a cross-sectional view of an outer flexible material  100 . An inner aperture  102  and an outer perimeter, such as contoured outer surface  104 , may be considered to reference various components. The contoured outer surface  104  comprises various shapes to contact waste material being processed by a recycling apparatus. Long fingers  106  and short fingers  108  may be integral protuberances for engaging mixed recyclable materials. A lip  116  may be separated from the inner aperture  102  with at least one concave portion  110  and at least one convex portion  112  to engage with an outer perimeter of a disc core  80  (as discussed above regarding  FIG. 5 ). One or more bores  114  may be placed along the span of the outer flexible portion  100  for attachment to a disc core. 
       FIG. 8  shows an assembled disc  150 , such as a disc assembled from the disc core  60  from  FIG. 5  and the outer flexible portion  80  from  FIG. 6 . The contoured outer surface  104  of the outer flexible material  80  may comprise a series of step regions  154  formed about the periphery thereof. The varied nature of the contoured outer surface  104 , such as features long fingers  106 , short fingers  108 , and step regions  154  support separation of mixed recyclables as each feature acts differently on materials of various sizes, flexibilities, rigidness, and other aspects. 
     Referring to  FIG. 9 , a top view of disc screen section  200  comprises discs  202  mounted on shafts  204 . The shafts  204  are mounted between two end portions of the frame  208 . A drive mechanism  206  engages with an end of shafts  204  to cause the shafts  204  to rotate about the central axis of the discs  202  in a controlled manner. The disc screen section  200  may be a disc and shaft assembly for a disc screen of a recycling apparatus configured to separate mixed recyclable materials according to size. A shaft  204  may have opposite ends configured to be rotatably supported in a frame  208  of the recycling apparatus. A plurality of discs  202  may be mounted at spaced intervals along the shaft  204  to rotate with the shaft  204  and configured for classifying a stream of mixed recyclable materials. Each disc  202  may comprise an outer flexible portion  80 , the outer flexible portion  80  consisting of one piece, without a hinge or interconnecting flap and a disc core  60  connected to the outer flexible portion  80  with a mating connection. The shaft  204  extending transversely through bores  72  within the plurality of discs  202 . Each outer flexible portion (material)  80  is shaped for engaging materials to be classified and propelling the materials in a conveying direction when the disc core  80  is rotated. 
     The foregoing description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. 
     Furthermore, a method may be performed in one or more sequences other than the sequence presented expressly herein.