Abstract:
A material reduction apparatus for reducing materials having an admixture that resists reduction. The mechanism incorporated into the apparatus to provide a bypass of such admixture while avoiding shut down interruption of the materials reduction operation.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a machine or apparatus for use in reducing material, e.g., for reducing material resulting from structural demolition to enable a more convenient transportation and disposal of such materials.  
       BACKGROUND OF THE INVENTION  
       [0002]     A similar type of machine used for reducing wood and green waste material is disclosed in the commonly owned U.S. Ser. No. 10/225,714. The machine of that patent utilizes a rotor with projections referred to as hammers. Wood materials are conveyed along a path toward the rotating rotor and are first compressed by a compression roller which directs the material against the rotor. The rotor rotates to direct the material up and over the rotor into an overlying fixed anvil or anvil bar located in close proximity to the hammers and thereby to break the materials into smaller sized chunks of material. The thereby reduced material is forced along and through a series of screens which further reduce the material size. The material is deposited on a conveyor and conveyed to a staging area for recycling, e.g., as groundcover.  
         [0003]     One further aspect of note for the machine as described is the provision of a safety release. In the event that a non-wood material, such as a chunk of iron, gets mixed in with the wood and is directed into the rotor and thereafter against the anvil, the anvil is designed to pivot open upon the breaking of a shear pin resulting from the increased impact of the iron mass against the anvil. The operation is closed down and the shear pin is replaced. While the operation is thus interrupted, such occurrences are not frequent and the major components of the apparatus are safeguarded as a result of the shear pin breakage and pivotal mounting of the anvil.  
         [0004]     Use of the same machine is not satisfactory for reducing materials, e.g., resulting from structural demolition. Whereas a non-reducible item is but a rare occurrence for reducing wood materials, it is a common occurrence among structural demolition, and operation interruptions of the kind where replacing shear pins for such occurrences is undesirable.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0005]     Whereas reduction of demolition materials is desirable, it is not required that there be substantially no remaining large items amongst the resulting reduced product of the apparatus. Thus, those items that are not readily reduced can be permitted to bypass the reduction process and still achieve the objective of the reduction operation. Accordingly, the present invention provides a bypass feature whereby a large percentage of the items that resist reduction to the point where damage to the machine may occur, are diverted from the reduction process thus enabling the reduction operation to continue without the otherwise frequent shutdown of the operation. Hereafter such items are referred to as reduction resistant items of material.  
         [0006]     In a preferred embodiment of the invention, the anvil is provided with a release mechanism whereby an oversized and reduction-resistant item causes retraction of the anvil when impacted by the item which opens a bypass route for the item followed by automatic return of the anvil to thereby instantly reestablish the reduction processing of the material.  
         [0007]     The invention will be more fully appreciated and understood upon reference to the following detailed description of a preferred embodiment of the invention having reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]      FIG. 1  is a schematic illustration of a materials reduction machine in accordance with present invention;  
         [0009]      FIG. 1A  is a front view of the rotor and anvil as used in the machine of  FIG. 1 ;  
         [0010]      FIG. 2  is a pictorial view of certain of the components of the machine of  FIG. 1 ;  
         [0011]      FIG. 3  is a side view of the components of  FIG. 2 ;  
         [0012]      FIGS. 3A and 3B  show in detail the breakaway features of the components in  FIG. 3 ;  
         [0013]      FIGS. 4, 5  and  5 A show in greater detail certain of the release features of the machine of  FIGS. 1-3 ; and  
         [0014]      FIG. 6  illustrates an alternate embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0015]      FIG. 1  schematically illustrates an embodiment of the present invention which includes a receiving bin  10  for receiving, e.g., structural demolition material  12 . A conveyor  14  moves the material  12  toward a rotor  16  including radial projections referred to as hammers  18 . A compression roller  20  includes ribs  22  mounted on a pivotal arm  24 . A biasing member  26  between the arm  24  and the frame of the bin  10  urges the arm  24  and thus the roller  20  downward about shaft  28 . The material  12  is thus urged downward and inward toward rotor  16  (arrows  30 ,  32 ).  
         [0016]     As will be apparent from  FIG. 1 , the material  12  is forced against the rotating rotor (arrow  34 ) and carried upwardly and into engagement with stationary anvil  36 . (See also  FIG. 1A ). Material that is too large to fit between the spacing provided between the hammers  18  and the anvil  36  are broken into pieces upon impacting anvil  36 .  
         [0017]     Following anvil  36  clockwise (as viewed in  FIG. 1 ) around rotor  16  are three screen sections  38 ,  40 , and  42 . Material chunks  12 , as reduced by anvil  36  and hammers  18 , are then urged by the hammers against screens  38 ,  40  and  42  and further reduced. Material passing through the screens is deposited onto conveyor  44  and conveyed (arrow  46 ) to a staging site not shown. The materials not passed through the screens are recycled through the process as described, e.g., into the anvil and against the screens.  
         [0018]     As described in the Brief Description above, the invention is directed to the inclusion of a bypass for material  12  that resists reduction. The mechanism for: providing the bypass will be explained, having reference to further drawings and in general as viewed in  FIG. 1  is enabled by mounting of the anvil  36  and screen  38  on a pivotal member pivoted about shaft  28  and which resistively permits pivoting as indicated by the dash line position of anvil  36  and screen  38  to create the bypass  50 .  
         [0019]     Reference is now made to  FIGS. 2, 3  and  4  which illustrate the general relationship as between the compression roller  20  and the pivotal anvil  36 /screen  38 . Both mechanisms are pivotally mounted to pivot shaft  28  and pivot independently about shaft  28 . It will be appreciated that shield  52  captures material  12  being directed into the rotor  16  to force the material against anvil  36 . In prior wood reducing versions, the two mechanisms were independently pivoted and pivoting of the anvil  36 /screen  38  would open a gap to allow materials to flow between the mechanisms. In the illustrated embodiment of  FIG. 3 , the shield  52  is extended as shown in dash line in the form of a curve that coincides with the pivoting of the anvil  36 /screen  38  mechanism. A wiper  54  maintains engagement with the curve to prevent material from passing between the anvil and shield during relative pivoting.  
         [0020]     Seated above the shaft  28  is a compression pad  56  that permits limited upward movement of shaft  28  as a stress relief, e.g., when overloaded. Also observed in  FIG. 3  is a shear pin  58  that is a safety provision in the rare occasion when a reduction-resistant material  12  item exceeds the capability of the bypass feature of the invention, causing breakage of the shear pin and thus shut down and shear pin replacement.  
         [0021]     Reference is now made to the relatchable relief mechanism shown in  FIGS. 2, 3  and  5 .  FIGS. 5 and 5 A illustrate the anvil  36 /screen  38  mechanism only. As shown, the mechanism includes a retractable roller  60  that is mounted to a slide  62  that slides in and out of a pocket formed under plate  64 . A strong spring  72  seated in the pocket (see  FIG. 5A ) urges the roller  60  to its extended position.  
         [0022]     Referring now to  FIGS. 2, 3A  and  3 B where a latch  66  is shown. Latch  66  is secured to the frame of the apparatus and, except for the retractable relatch mechanism, is fixed. As seen in  FIGS. 3 and 3 A, the roller  60  is seated during normal operation in the cradle formed by the latch slide  68  and the latch body  70 . In order for the anvil  36 /screen  38  mechanism to pivot upwardly about pivot shaft  28 , the roller has to retract. Note from  FIG. 3A  that the retractable latch slide is not urged upwardly as the upward force component is normal to the movement of the slide. In any event, it is prevented from upward movement by stop  71 . Thus, the strong spring  72  ( FIG. 5A ) has to be retracted in order for the latch mechanism to release. The spring  72  is provided with a desired force resistance to allow retraction only for severe reduction-resistive materials which can often be encountered when reducing demolition type materials.  
         [0023]     It has been explained that the strong spring  72  does not readily accommodate relatching even though the weight of the machine is substantial and produces a significant relatching force. Thus, relatching is assisted by the provision of the latch slide  68 . With reference to  FIG. 3B , it will be observed that the relatching force indicated by arrow  74  forces inward sliding of latch slide  68  (see arrow  75 ) designed to accommodate the relatching force  74  to thereby allow the roller  60  to slide past the slide  68  and return to the status of  FIGS. 3 and 3 A.  
       Operation  
       [0024]     It will thus be apparent from the above that demolition materials are fed into the rotor  16  and reduced upon impact generated between the movement of the hammers  18  and the stationary anvil  36 , the material then forced through any of the screens  38 ,  40  and  42  or recycled to repeat the reduction process. When a substantial/severe reduction/resistant component is encountered, the force impacted against the anvil  36  will result in forced retraction of latch roller  60  and permit pivotal opening of the anvil  36  and screen  38  as illustrated in  FIG. 1  in dash lines. Once the component passes through the bypass as thus provided (over the top of screens  40  and  42 ), the weight of the mechanism will urge the screen and anvil back to the latched position as permitted by the latch spring  76 . It will be observed from  FIG. 2  that stop members  78  mounted to the frame of the apparatus limits the pivoting of anvil  36  and screen  38 .  
       Alternative Embodiment  
       [0025]      FIG. 6  illustrates an alternative embodiment. Rigid frame members are indicated at reference numbers  80 ,  82 . An upper support beam  84  is rigidly connected to the frame member  80 ,  82 . A lower support  86  is secured to the top of screen section  38 ′. Airbag  88  (or other spring like member) fits between supports  84 ,  86  and resistively permits pivoting of screen section  38 ′ and anvil  36 ′ about shaft  28 ′.  
         [0026]     The embodiment of  FIGS. 1-5  operate to unlatch, permit free bypass and then relatches and is considered desirable for certain applications of demolition reduction.  FIG. 6  allows pivoting while maintaining resistance. As the reduction resistant force increases, the airbag responds with increased resistance but allowing increased bypass of the material  12 . It is envisioned that the airbag version (or other spring like member) may be more desirable for certain operations of demolition reduction, and the latch type mechanism for other certain types of demolition reduction. It will be apparent that the shear pin release of  FIGS. 1-5  may readily be incorporated into the shaft  28 ′ of this alternate version. It will also be appreciated that the resistive forces can be varied through various adjustments or replacement of the spring members (items  65 ,  76 ,  88 ).  
         [0027]     The invention as herein disclosed is considered to be subject to numerous other modifications, improvements and variations as may occur to those skilled in the art. Accordingly, the invention as claimed is intended to be interpreted broadly and is not limited to the specific embodiments or features as adopted for the illustration of the embodiments herein disclosed.