Patent Publication Number: US-10773260-B2

Title: Waste processing machine safety device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The subject patent application is the National Stage of International Patent Application No. PCT/US2017/022935, filed on Mar. 17, 2017, which claims priority to and all the benefits of U.S. Provisional Patent Application Ser. No. 62/309,585 which was filed on Mar. 17, 2016, the disclosures of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, generally, to waste processing machines and, more specifically, to a waste processing machine having a safety device for shearing lines. 
     2. Description of the Related Art 
     Conventional waste processing machines are employed to recycle, reduce, or otherwise process waste products or materials, such as bulk wood products, by chipping, cutting, grinding, or otherwise reducing the waste products. To this end, waste processing machines employ an infeed system to receive material to be reduced, such as wood products or tree limbs. A feed system with rotating feed wheels is employed to advance bulk material directed into the infeed system towards a cutting assembly. The cutting assembly, in turn, comprises a rotating disc or drum which is configured to reduce the bulk materials into chips. The chips are subsequently propelled out of a discharge chute arranged downstream of the cutting assembly. 
     In certain applications, one or more lines, cables, ropes, and the like may be used nearby or in connection with the waste processing machine. These lines, cables, or ropes are generally used to gather, secure, drag, lift, etc., the bulk products onto and into the infeed system for capture by the feed system (if provided) of the waste processing machine. By way of non-limiting example, a winch line may be used to drag heavy bulk materials towards the waste processing machine. Tree climber ropes or lines are also typically used nearby the waste processing machine. 
     Waste processing machines, and wood chippers in particular, are regularly utilized in a number of different industries. Those having ordinary skill in the art will appreciate that incorrect operation of waste processing machines can be potentially dangerous. Specifically, it will be appreciated that if proper procedures are not followed, it is possible for lines, cables, or ropes to be captured by one or more of the feed wheels of the feed system and/or by the disk or drum of the cutting assembly. 
     Once captured, the line, cable, or rope can become entangled with or captured by the rotating disc or drum and consequently may be retracted. This retraction of the line, cable, or rope may be too quick for an operator to react to and may cause safety issues. For example, retraction of the line, cable, or rope can cause the line, cable, or rope, and anything attached thereto, to be flung or whipped around, possibly causing damage or injury to nearby objects or operators. Further, if anything becomes entangled in the cable, line, or rope, it may be pulled towards the waste processing machine. 
     Accordingly, while conventional waste processing machines have generally performed well for their intended use, there remains a need in the art for waste processing machines which are, among other things, relatively inexpensive to manufacture and operate, and which provide for increased safety and reliability when used in connection with lines, cables, or ropes. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the disadvantages in the prior art in a waste processing machine for reducing waste material and having a safety device for shearing lines. The waste processing machine includes a housing defining a cutting chamber and an intake opening in communication with the cutting chamber for receiving waste material. A disc is disposed in the cutting chamber and is supported for rotation about an axis. The disc has an axial surface facing the intake opening. A cutting member is fixed to the disc for revolution about the axis concurrent with rotation of the disc for reducing waste material. A cutting anvil is coupled to the housing adjacent to the intake opening and is arranged facing the axial surface of the disc for reducing waste material between the cutting anvil and the cutting member as the cutting member revolves about the axis toward the cutting anvil. A line shear element is operatively attached to the housing, extends into the cutting chamber toward the axial surface of the disc, and is spaced from the cutting anvil for shearing lines caught by the rotating disc. 
     In this way, the waste processing machine safety device of the present invention affords opportunities for improved safety by promoting cutting, shearing, or otherwise breaking of lines, cables, and/or ropes inadvertently captured by the rotating disc that might otherwise pull objects towards the waste processing machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of the present invention will be readily appreciated as the same becomes better understood after reading the subsequent description taken in connection with the accompanying drawings. 
         FIG. 1  is a perspective view of a waste processing machine shown having an infeed system, a feed system, and a cutting assembly with a safety device according to one embodiment of the present invention. 
         FIG. 2  is a left-side plan view of the waste processing machine of  FIG. 1 . 
         FIG. 3  is a front-side plan view of the waste processing machine of  FIGS. 1-2 . 
         FIG. 4  is a partial perspective view of the cutting assembly of  FIGS. 1-3 , depicting a housing defining a cutting chamber and an intake opening, a disc with cutting members, and a cutting anvil coupled to the housing. 
         FIG. 5  is a front-side perspective view of the cutting assembly of  FIG. 4 , depicting a lower housing component spaced from a pair of upper housing components and the disc. 
         FIG. 6  is a front-side exploded perspective view of the cutting assembly of  FIGS. 4-5 . 
         FIG. 7  is an angled perspective view of the lower housing component of  FIGS. 4-6 , depicting a pair of line shear elements disposed within the cutting chamber of the housing according to one embodiment of the present invention. 
         FIG. 8  is a front-side schematic illustration of the housing components, the cutting chamber, the intake opening, the cutting anvil, and the line shear elements of the housing depicted in  FIGS. 4-7 . 
         FIG. 9  is a perspective view of the disc of the cutting assembly of  FIGS. 4-6 , shown having a pair of cutting members, a pair of inner shear blocks, and a pair of outer shear blocks according to one embodiment. 
         FIG. 10  is a front-side schematic illustration of the disc, the cutting members, the inner shear blocks, and the outer shear blocks of the disc depicted in  FIG. 9   
         FIG. 11A  is a first front-side schematic illustration of the disc depicted in  FIG. 10  supported for rotation in the housing depicted in  FIG. 8 , showing a line with a line end positioned adjacent to the intake opening. 
         FIG. 11B  is a second, consecutive front-side schematic illustration of the disc, the housing, the line, and the line end of  FIG. 11A , showing the line end positioned in the intake opening. 
         FIG. 11C  is a third, consecutive front-side schematic illustration of the disc, the housing, the line, and the line end of  FIGS. 11A-11B , showing the line end pulled into the cutting chamber by the rotating disc. 
         FIG. 11D  is a fourth, consecutive front-side schematic illustration of the disc, the housing, the line, and the line end of  FIGS. 11A-11C , showing the line end pulled further into the cutting chamber by the rotating disc. 
         FIG. 11E  is a fifth, consecutive front-side schematic illustration of the disc, the housing, the line, and the line end of  FIGS. 11A-11D , showing the line end pulled even further into the cutting chamber by the rotating disc, with a portion of the line positioned to be cut between one of the line shear elements and one of the inner shear blocks. 
         FIG. 11F  is a sixth, consecutive front-side schematic illustration of the disc, the housing, the line, and the line end of  FIGS. 11A-11E , showing the line end and a portion of the line cut off from the rest of the line outside the housing. 
         FIG. 12  is another schematic illustration of the disc, the housing, the line, and the line end of  FIG. 11A , showing the line end pulled into the cutting chamber by the rotating disc, with a portion of the line positioned to be cut between one of the line shear elements and one of the cutting members. 
         FIG. 13  is another schematic illustration of the disc, the housing, the line, and the line end of  FIG. 12 , showing the line end pulled into the cutting chamber by the rotating disc, with a portion of the line positioned to be cut between another of the line shear elements and one of the cutting members. 
         FIG. 14  is a front-side schematic illustration depicting another embodiment of a disc for use with the cutting assembly of  FIGS. 4-6 , shown having cutting members, inner shear blocks, and outer shear blocks. 
         FIG. 15  is a front-side schematic illustration depicting another embodiment of a disc for use with the cutting assembly of  FIGS. 4-6 , shown having cutting members, inner shear blocks, and outer shear blocks. 
         FIG. 16  is a front-side schematic illustration depicting another embodiment of a disc for use with the cutting assembly of  FIGS. 4-6 , shown having cutting members, inner shear blocks, and outer shear blocks. 
         FIG. 17  is a front-side schematic illustration depicting another embodiment of a disc for use with the cutting assembly of  FIGS. 4-6 , shown having cutting members, inner shear blocks, and outer shear blocks. 
         FIG. 18  is a front-side schematic illustration depicting another embodiment of a housing, cutting chamber, intake opening, and line shear elements for use with the cutting assembly of  FIGS. 4-6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the Figures, where like numerals are used to designate like structure throughout the several views, a waste processing machine according to one embodiment of the present invention is depicted at  30  in  FIG. 1 . The waste processing machine  30  recycles, reduces, or otherwise processes products, such as bulk wood products, by chipping, cutting, grinding, or otherwise reducing the waste products. In the representative embodiment illustrated herein, the waste processing machine  30  is realized as a wood chipper. However, those having ordinary skill in the art will appreciate that the waste processing machine  30  could be of any suitable type or configuration sufficient to chip, grind, cut, or otherwise reduce bulk products or materials, without departing from the scope of the present invention. 
     Conventional waste processing machines  30 , and wood chippers in particular, are regularly utilized in various industries. Those having ordinary skill in the art will appreciate that incorrect operation of waste processing machines  30  can be potentially dangerous. Accordingly, while conventional waste processing machines  30  have generally performed well for their intended use, there remains a need in the art for waste processing machines  30  which are, among other things, relatively inexpensive to manufacture and operate, and which provide for increased safety and reliability. 
     As noted above, the waste processing machine  30  depicted in  FIG. 1  is realized as a mobile, disc-style wood chipper with a frame  32  supported by a pair of wheels  34 . A conventional trailer hitch  36  operatively attached to the frame  32  allows the waste processing machine  30  to be towed by a vehicle (not shown). The frame  32  generally supports a power source  38 , an infeed system  40 , a feed system  42 , a cutting assembly  44 , a winch assembly  46  with a line  48 , and a safety device  50 . Each of these components, systems, and assemblies will be described in greater detail below. 
     As noted above, the waste processing machine  30  depicted in  FIGS. 1-3  is configured so as to be transportable, such as by a vehicle. However, those having ordinary skill in the art will appreciate that the waste processing machine  30  could be configured in a number of different ways without departing from the scope of the present invention. By way of non-limiting example, the waste processing machine  30  could be stationary, could be implemented onto a vehicle, or could be supported on or otherwise moveable along a track. 
     The power source  38  is configured to provide a source of rotational torque which is used to drive the feed system  42  and the cutting assembly  44 . To this end, the power source  38  may be realized as one or more internal combustion engines configured to translate rotational torque to certain components or systems of the waste processing machine  30 , such as to the cutting assembly  44  and also to a hydraulic pump assembly which, in turn, may be used to drive components or systems (not shown). It will be appreciated that the power source  38  could be arranged or otherwise configured in any suitable way without departing from the scope of the present invention. By way of non-limiting example, the power source  38  could utilize or otherwise be realized by one or more electric motors, engines, generators, pump assemblies, hydraulic drives, and the like. 
     The infeed system  40  is employed to facilitate directing material, such as wood products or tree limbs, to the feed system  42  which, in turn, directs the material to the cutting assembly  44  to reduce the material. To this end, the infeed system  40  includes an infeed tray  52  and an infeed hopper  54  arranged to direct material into the feed system  42 . Certain materials, such as relatively small branches or tree limbs, can be inserted directly into the infeed hopper  54  towards the feed system  42 . Other materials, such as relatively larger branches or tree limbs, can be supported first on the infeed tray  52  and then inserted into the infeed hopper  54  towards the feed system  42 . As described in greater detail below, the winch assembly  46  is used to pull particularly large or heavy materials onto the infeed tray  52  and into the infeed hopper  54  under certain operating conditions. 
     The feed system  42  is interposed between the infeed system  40  and the cutting assembly  44  and employs one or more feed wheels  56  (see  FIGS. 1 and 3 ) arranged to pull materials inserted into the infeed hopper  54  towards the cutting assembly  44  to reduce the materials. However, as will be appreciated from the subsequent description below, the waste processing machine  30  could be configured without a feed system  42  for certain applications, whereby the infeed system  40  could be arranged in direct communication with the cutting assembly  44 . 
     Referring now to  FIGS. 1-10 , as noted above, the cutting assembly  44  is arranged in communication with the feed system  42  and reduces waste material directed towards the cutting assembly  44  from the infeed system  40  via the feed system  42  (see  FIG. 2 ). To this end, the cutting assembly includes a housing  58 , a disc  60 , a cutting member  62 , and a cutting anvil  64 . Each of these components will be described in greater detail below. 
     As is best shown in  FIGS. 4-6 , the housing  58  of the cutting assembly  44  defines a cutting chamber  66 , an intake opening  68  in communication with the cutting chamber  66  for receiving waste material, and a discharge opening  70  in communication with the cutting chamber  66  for expelling reduced waste material, as described in greater detail below. The disc  60  is disposed in the cutting chamber  66  and is supported for rotation about a shaft, generally indicated at  72 , along an axis AX. The disc  60  has an axial surface  74  which faces the intake opening  68  defined in the housing  58 . The cutting member  66  is fixed to the disc  60  for revolution about the axis AX concurrent with rotation of the disc  60  for reducing waste material. To this end, the cutting anvil  64  is coupled to the housing  58  adjacent to the intake opening  68  (see  FIG. 7 ) and is arranged facing the axial surface  74  of the disc  60  for reducing waste material between the cutting anvil  64  and the cutting member  62  as the cutting member  62  revolves about the axis AX towards the cutting anvil  64 . The axis AX is depicted by a dash-dash line in  FIGS. 4-6 and 9 , and is depicted as a centerline cross, without a leader or label for the purpose of clarity, in  FIGS. 8 and 11A-17 . 
     Those having ordinary skill in the art will appreciate that the cutting assembly  44  described and illustrated herein forms what is sometimes referred to in the related art as a “disc chipper” style waste processing machine  30 . In the representative embodiment illustrated in  FIGS. 1-10 , and as is shown best in  FIG. 9 , the disc  60  is provided with a first cutting member  62 A and with a second cutting member  62 B spaced from the first cutting member  62 A about the axial surface  74  of the disc  60 . Here, each cutting member  62 A,  62 B is arranged so as to revolve around the axis AX as the disc  60  rotates, and to reduce material passing between the respective, moving cutting member  62 A,  62 B and the stationary cutting anvil  64 . In the representative embodiment illustrated herein, the cutting assembly  44  is arranged at an angle relative to the front of the waste processing machine  30 , with a funnel  76  extending from the intake opening  68  toward the feed system  42  to a funnel inlet  78 , which is generally rectangular and faces the infeed hopper  54 . Other configurations are contemplated herein, such as a disc  60  which is arranged with the axial surface  74  substantially parallel to the infeed system  40 . Moreover, those having ordinary skill in the art will appreciate that the specific configuration, arrangement, size, shape, and the like of the disc  60 , the cutting members  62 A,  62 B, the cutting anvil  64 , and the housing  58  can be adjusted without departing from the scope of the present invention. 
     As noted above, the cutting assembly  44  is driven by the power source  38  which may be throttled or otherwise controlled so as to drive the disc  60  of the cutting assembly  44  at a predetermined rotational speed. Here, a clutch, transmission, and/or geartrain may be interposed between the power source  38  and the cutting assembly  44  to modulate or interrupt torque translation therebetween (not shown, but generally known in the art). The feed system  42  is likewise driven by the power source  38  and is generally controlled independently of the cutting assembly  44  using hydraulics (not shown, but generally known in the art). The disc  60  of the cutting assembly  44  generally rotates at a relatively high velocity, and the feed wheels  56  of the feed system  42  generally rotate relatively slowly. In operation, material directed into the infeed system  40  is captured between the opposed, rotating feed wheels  56  of the feed system  42  which direct, pull, or otherwise cause the materials to move towards the cutting assembly  44  where they encounter the revolving cutting members  62  on the axial surface  74  of the disc  60  of the cutting assembly  44 , and the cutting anvil  64  arranged in the intake opening  68  of the housing  58 , and are reduced into chips which are expelled out of the discharge opening  70  towards a discharge chute  80 . As shown in  FIG. 6 , one or more windage elements  82  may be fixed to the disc  60  to help urge chips towards the discharge opening  70  as the disc  60  rotates about the axis AX in operation. 
     Referring now to  FIGS. 4-8 , as noted above, the housing  58  defines the cutting chamber  66 , the intake opening  68 , and the discharge opening  70 . As is best shown in  FIGS. 5 and 6 , in one embodiment, the housing  58  includes a lower housing portion  58 A, a first upper housing portion  58 B, and a second upper housing portion  58 C. Here, the intake opening  68  is formed in the lower housing portion  58 A, and the discharge opening  70  is formed in the second upper housing portion  58 C. However, those having ordinary skill in the art will appreciate that the housing  58  could be formed from or otherwise be defined by any suitable number of components without departing from the scope of the present invention. 
     As noted above, the winch assembly  46  cooperates with the infeed system  40  to direct materials towards the feed system  42 . To this end, the winch assembly  46  includes a boom  84  through which the line  48  extends to a line end  86 . The line  48  is tensioned using a winch driver, generally indicated at  88 . The winch driver  88  is configured to pull the line end  86  towards the boom  84  and the winch driver  88  and allow the line end  86  to be selectively moved away from the winch driver  88 . Here, the line  48  (also referred to herein as a “cable,” “rope,” or “winch line”) is generally used to gather, secure, drag, lift, etc., large or bulky materials onto the infeed tray  52  and into the infeed system  40  for capture by the feed system  42 . As the winch assembly  46  is utilized, if proper procedures are not followed, it is possible for the line end  86  or another portion of the line  48  to be captured by one or more of the feed wheels  56  of the feed system  42  and/or disc  60  of the cutting assembly  44 , whereby the line  48  could become quickly entangled with or captured by the rotating disc  60  of the cutting assembly  44  and consequently retracted into the cutting assembly  44 . As such, retraction of the line  48  may be too quick for an operator to react to and may cause safety issues. For example, rapid retraction of the line  48  may cause the line end  86 , and anything attached thereto, to be uncontrollably flung or whipped around, possibly causing damage or injury to nearby objects or operators. Further, anything encompassed by the line  48  could be pulled quickly towards the waste processing machine  30  if the line end  86  and/or a portion of the line  48  were to be captured by the disc  60 . Similarly, anything entangled with the line  48  during such a sudden retraction may be rapidly pulled towards the waste processing machine  30 . 
     While the line  48  is described herein as forming part of the winch assembly  46 , those having ordinary skill in the art will appreciate that other types of lines  48 , cables, winch lines, ropes, and the like are frequently used in connection with or nearby waste processing machines  30  (for example, tree-climber ropes), and present similar safety concerns. As such, in the following description, the line  48  and the line end  86  could be of any type or configuration and could form a part of the waste processing machine  30  itself, or could form part of a separate component, system, and the like. 
     As noted above, the cutting members  62  and the cutting anvil  64  are arranged so as to reduce material passing into the intake opening  68  as the disc  60  rotates in operation. Here, the cutting anvil  64  is set to a predetermined position relative to the cutting members  62 , and may be adjustable so as to compensate for wear, to adjust chip size, and the like. While the spacing between the cutting anvil  64  and the cutting members  62  is typically much smaller than the thickness, diameter, and/or size of the line  48 , it is still sometimes possible for a line  48  to become trapped by the rotating disc  60  and become retracted/wound into the cutting chamber  66  without passing between the cutting anvil  64  and the cutting member  62 . Moreover, rotation of the disc  60  tends to pull a trapped line  48  radially inwardly, such as towards the shaft  72 . Here, in certain applications, the relative shape and orientation of the cutting members  62  and the cutting anvil  64  may allow a significant length of trapped line  48  to retract inwardly towards the shaft  72  before passing between the cutting anvil  64  and the cutting member  62 . Nevertheless, because of the speed at which the disc  60  rotates during operation, a single revolution of the disc  60  could potentially result in a length of the line  48  (for example, several feet) being retracted quickly into the cutting chamber  66 . 
     Referring now to  FIGS. 7-13 , the safety device  50  of the present invention is implemented in order to promote safe operation of the waste processing machine  30  and to help prevent damage or injury caused by retraction of the line  48 , as noted above, by shearing lines  84  which may become trapped by the rotating disc  60 . To this end, in one embodiment, the safety device  50  includes a line shear element, generally indicated at  90 , which is operatively attached to the housing  58 , extends into the cutting chamber  66  towards the axial surface  74  of the disc  60 , and is spaced from the cutting anvil  64  for shearing lines  84  caught by the rotating disc  60 . Unlike the cutting anvil  64  disposed in the intake opening  68 , the line shear element  90  is not configured, positioned, or arranged so as to reduce waste materials. Rather, the line shear element  90  is provided to shear, cut, or otherwise break the trapped line  48  as the disc  60  rotates, as noted above. 
     In certain embodiments, such as those depicted in  FIGS. 12 and 13 , the line shear element  90  is configured to shear, cut, or otherwise break lines  84  as one of the cutting members  62  passes by the shear element  90  within the cutting chamber  66  of the housing  58 . In certain embodiments, the safety device  50  further comprises one or more shear blocks, generally indicated at  92 , which are fixed to the disc  60 , are formed separately from the cutting members  62 , and which extend away from the axial surface  74  to shear lines caught by the rotating disc  60  between the shear block  92  and the line shear element  90  (see  FIG. 11E ). In certain embodiments, one or more shear blocks  92  could also be arranged so as to shear lines caught by the rotating disc  60  between the shear block  92  and the cutting anvil  64 . Thus, it will be appreciated that the advantages afforded by the safety device  50  of the present invention can be realized by cooperation between the line shear element  90  and the cutting member  62  to shear the line  48 , and/or by cooperation between the line shear element  90  and the shear block  92  to shear the line  48 . The line shear elements  90  and the shear blocks  92  will each be described in greater detail below. 
     Referring now to  FIGS. 7 and 8 , in one embodiment, the line shear element  90  has a generally rectangular profile and is operatively attached to the lower housing component  58 A of the housing  58 , such as by welding (not shown). In the representative embodiment illustrated in  FIGS. 4-8 , the safety device  50  includes first and second line shear elements  90 A,  90 B which each extend into the cutting chamber  66  towards the axial surface  74  of the disc  60 . Here, the first line shear element  90 A and the second line shear element  90 B are both spaced from the cutting anvil  64  and from each other within the cutting chamber  66 . As shown best in  FIG. 8 , in one embodiment, the first line shear element  90 A and the second line shear element  90 B are each arranged generally transverse to the axis AX and are substantially parallel to each other. 
     As shown in  FIG. 8 , in one embodiment, a first radial distance  94  is defined between the axis AX and the line shear element  90 , and a second radial distance  96 , greater than the first radial distance  94 , is defined between the axis AX and the intake opening  68  defined in the housing  58  (as noted above, the axis AX is depicted in  FIG. 8  as a dash-dash cross without a leader or label for the purpose of clarity). Put differently, the line shear element  90  is arranged so as to be at least partially disposed closer to the axis AX than to the intake opening  68 . However, other arrangements and configurations of the line shear element  90  are contemplated herein. By way of non-limiting example, another embodiment of the housing  58  is schematically depicted in  FIG. 18  with a first line shear element  90 A which extends perpendicularly to the cutting anvil  64 , and with a second line shear element  90 B which is arranged parallel to the cutting anvil  64 . Here in this embodiment, the first line shear element  90 A is longer than the second line shear element  90 B and is arranged perpendicular to the second line shear element  90 B. However, as noted above, any number of line shear elements  90  could be provided and could be shaped and/or arranged in any suitable way sufficient to shear lines  84  trapped by the rotating disc  60  without departing from the scope of the present invention. 
     As noted above, the line shear elements  90  are provided to shear, cut, or otherwise break the trapped line  48  as the disc  60  rotates and are not configured, positioned, or arranged so as to reduce waste materials as the cutting member  62  revolves about the axis AX. Referring to  FIG. 8 , in one embodiment, the cutting chamber  66  of the housing  56  comprises an intake zone  66 A, a discharge zone  66 B, and a dead zone  66 C. The intake zone  66 A is defined by the intake opening  68  for receiving waste material into the cutting chamber  66  to be reduced. The discharge zone  66 B is defined between the intake zone  66 A and the discharge opening  70  for expelling reduced waste material from the intake zone  66 A out of the cutting chamber  66 , such as via windage generated by the windage elements  82  described above in connection with  FIG. 6 . The dead zone  66 C is defined between the discharge zone  66 B and the intake zone  66 A. As shown in  FIG. 8 , in the representative embodiment illustrated herein, the cutting anvil  64  is disposed in the intake zone  66 A, the first line shear element  90 A is disposed in the dead zone  66 C, and the second line shear element  90 B is disposed in the discharge zone  66 B. However, as noted above, other arrangements of the line shear elements  90 A,  90 B are contemplated herein. By way of non-limiting example, a single line shear element  90  could be provided. 
     With continued reference to  FIGS. 7 and 8 , in one embodiment, the cutting anvil  64  has opposing first and second anvil sides  98 A,  98 B defining an anvil length  100  (see  FIG. 8 ) with an anvil edge  102  extending between the anvil sides  98 A,  98 B along the anvil length  100 . Similarly, the line shear element  90  has opposing first and second shear element sides  104 A,  104 B defining a shear element length  106  (see  FIG. 8 ) with a shear element edge  108  extending between the shear element sides  104 A,  104 B along the shear element length  106 . While the shear element length  106  is depicted in connection only with the first line shear element  90 A in  FIG. 8 , those having ordinary skill in the art will appreciate that each line shear element  90  could have respective lengths with separate sides and edges. 
     As shown in  FIG. 8 , in one embodiment, the first anvil side  98 A is arranged radially closer to the axis AX than the second anvil side  98 B, the first shear element side  104 A is arranged radially closer to the axis AX than the second shear element side  104 B, and the first shear element side  104 A is arranged radially closer to the axis AX than the first anvil side  98 A. In one embodiment, the shear element length  106  of the line shear element  90  is greater than the anvil length  100  of the cutting anvil  64 . In one embodiment, the shear element edge  108  of the line shear element  90  is arranged substantially normal to the axial surface  74  of the disc  60 . In one embodiment, the shear element edge  108  of the line shear element  90  is arranged substantially perpendicular to the anvil edge  102  of the cutting anvil  64 . 
     Referring now to  FIGS. 9 and 10 , in one embodiment, the cutting member  62  has opposing first and second cutting member sides  110 A,  110 B defining a cutting member length  112  (see  FIG. 10 ) with a cutting member edge  114  extending between the cutting member sides  110 A,  110 B along the cutting member length  112 . Here too, while the cutting member length  112  is depicted in connection only with the first cutting member  62 A in  FIG. 10 , those having ordinary skill in the art will appreciate that each cutting member  62  could have respective lengths with separate sides and edges. In the representative embodiment illustrated in  FIGS. 4-10 , the shear element length  106  of the line shear element  90  (see  FIG. 8 ) is greater than the cutting member length  112  of the cutting member  62  (see  FIG. 10 ). 
     As noted above, in certain embodiments, the safety device  50  includes one or more shear blocks  92  fixed to the disc  60  and arranged so as to shear trapped lines  84  between the shear block  92  and the line shear element  90 . Here, the shear blocks  92  may be realized as inner shear blocks  116  disposed between the cutting member  62  and the axis AX, or as outer shear blocks  118  disposed between the cutting member  62  and a disc periphery  120  defined by the axial surface  74  of the disc  60 . Here too, both the inner shear blocks  116  and the outer shear blocks  118  are arranged to shear lines  84  trapped by the rotating disc  60 : between the line shear element  90  and the inner shear blocks  116  (see  FIG. 11E ), and between the line shear element  90  and the outer shear blocks  118 . Various arrangements of shear blocks  92  are illustrated throughout the drawings and are described in greater detail below, and it will be appreciated that different arrangements and configurations of inner shear blocks  116  and/or outer shear blocks  118  can be utilized for certain applications. 
     With continued reference to  FIGS. 9 and 10 , in one embodiment, the safety device  50  includes a first inner shear block  116 A disposed between the first cutting member  62 A and the axis AX, and a second inner shear block  116 B disposed between the second cutting member  62 B and the axis AX. Here, both of the inner shear blocks  116 A,  116 B are arranged so as to shear lines  84  trapped by the rotating disc  60  (see  FIG. 11E ). 
     As noted above, different arrangements of inner shear blocks  116  are contemplated herein.  FIGS. 14-17  depict embodiments of inner shear blocks  116  and outer shear blocks  118  with generally rectangular profiles. In the embodiment illustrated in  FIG. 14 , the inner shear blocks  116  extend from the cutting members  62  towards and abutting the shaft  72 . In the embodiment illustrated in  FIG. 15 , the inner shear blocks  116  extend from the cutting members  62  toward but spaced from the shaft  72 . In the embodiment illustrated in  FIG. 16 , the inner shear blocks  116  extend from the shaft  72  toward but spaced from the cutting members  62 . In the embodiment illustrated in  FIG. 17 , the inner shear blocks  116  are disposed between and spaced from both the inner shear blocks  116  and the shaft  72 . As noted above, other inner shear block  116  profiles and arrangements are contemplated herein. 
     As shown in  FIGS. 9 and 10 , in one embodiment, the safety device includes a first outer shear block  118 A disposed between the first cutting member  62 A and the disc periphery  120 , and a second outer shear block  118 B disposed between the second cutting member  62 B and the disc periphery  120 . In the representative embodiment illustrated in  FIGS. 9 and 10 , the outer shear blocks  118  of the safety device  50  each have a generally rectangular profile with a flat or arc-shaped surface  122  disposed adjacent the disc periphery  120 , and are likewise arranged so as to shear lines  84  trapped by the rotating disc  60 . In the embodiments illustrated in  FIGS. 14-17 , the outer shear blocks  118  of the safety device  50  each have a generally rectangular profile, are disposed adjacent the disc periphery  120 , and are likewise arranged so as to shear lines  84  trapped by the rotating disc  60 . It will be appreciated that different arrangements, shapes, and configurations of inner shear blocks  116  and/or outer shear blocks  118  are contemplated herein. 
     Referring now to  FIGS. 11A-11F , the disc  60  depicted in  FIG. 10  is shown supported within the housing  58  depicted in  FIG. 8 . Here, these drawings cooperate to illustrate one way the safety device  50  of the present invention can shear lines  84  trapped by the rotating disc  60 , and each drawing depicts successive rotation of the disc  60  as described below. 
       FIG. 11A  shows the line end  86  of the line  48  positioned adjacent to the intake opening  68  formed in the housing  58 . In  FIG. 11B  the line end  86  of the line  48  has entered the intake opening  68  and has engaged the rotating disc  60  (compare  FIG. 11B  with  FIG. 11A ). In  FIG. 11C , continued rotation of the disc  60  has trapped the line end  86  and has begun to pull the line  48  into the cutting chamber  66  of the housing  58  as the line end  86  approaches one of the line shear elements  90  of the safety device  50  (compare  FIG. 11C  with  FIG. 11B ). Here, because the line end  86  was trapped by the disc  60  between the cutting members  60 , no part of the line  48  has passed by the cutting anvil  64 . In  FIG. 11D , rotation of the disc  60  continues to pull the trapped line  48  into the cutting chamber  66  of the housing  58 , and a portion of the line  48  spaced from the line end  86  has traversed one of the line shear elements  90  of the safety device  50  as the line  48  begins to wrap around the shaft  72  (compare  FIG. 11D  with  FIG. 11C ). In  FIG. 11E , while rotation of the disc  60  has continued to pull the trapped line  48  further into the cutting chamber  66  of the housing, one of the inner shear blocks  116  has come into alignment with the portion of the line  48  traversing the line shear element  90  at a shear point SP (compare  FIG. 11E  with  FIG. 11D ). Here, the line  48  is sheared, cut, or otherwise broken at the shear point SP. In  FIG. 11F , the line end  86  and a portion of the sheared line  48  remains trapped within the cutting chamber  66  of the housing  58 , but the rest of the line  48  is no longer trapped by the rotating disc  60  and, thus, is no longer being retracted into the cutting chamber  66  (compare  FIG. 11F  with  FIG. 11E ). 
     As noted above, the safety device  50  can shear the trapped line  48  against the line shear element  90  in different ways. In  FIG. 11E , the shear point SP is arranged between the second line shear element  90 B and one of the inner shear blocks  116 . In  FIG. 12 , the shear point SP is arranged between the second line shear element  90 B and one of the cutting members  62 . In  FIG. 13 , the shear point SP is arranged between the first line shear element  90 A and one of the cutting members  62 . 
     In this way, the safety device  50  of the present invention significantly reduces potential retraction of lines  48  in connection with disc-chipper type waste processing machines  30  by promoting cutting, shearing, or otherwise breaking of lines  84 , cables, and/or ropes inadvertently captured by the rotating disc  60  that might otherwise pull objects towards the waste processing machine  30 . Specifically, those having ordinary skill in the art will appreciate that trapped lines  84  can be sheared via the line  48  traversing one of the line shear elements  90  as either one of the cutting members  62  or one of the shear blocks  92  revolves into alignment with the line shear element  90  at the shear point SP. Thus, the safety device  50  of the present invention allows the inadvertently trapped line  48  to be sheared quickly and without excessive retraction into the cutting chamber  66 . Moreover, the safety device  50  affords opportunities for shearing trapped lines  84  which are pulled towards the shaft  72  that might otherwise retract significantly into the cutting chamber  66  before coming into alignment between the cutting anvil  64  and the cutting member  62 . Thus, physical injuries to operators and other bystanders, as well as damage to the waste processing machine  30  and other property, may be averted. 
     The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.