This application is being filed on 3 October 2013, as a PCT International patent application, and claims priority to U.S. Provisional Patent Application No. 61/710,425, filed October 5, 2012, the disclosure of which is hereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to material reducing machines. In particular, the present disclosure relates to reducing elements for material reducing machines such as grinders and chippers.

BACKGROUND

Material reducing machines are used to reduce waste materials such as trees, brush, stumps, pallets, root balls, railroad ties, peat moss, paper, wet organic materials and the like. Two common types of material reducing machines include grinders and chippers. Grinders (e.g., tub grinders, horizontal grinders, etc.) are typically configured to reduce material through blunt force impactions. Thus, the reduced material product generated by grinders generally has a ground, flattened texture with relatively high fines content. This type of reduced material is typically used as mulch. In contrast to the blunt force action used by grinders, chippers reduce material through a chipping action. The reduced product generated by chippers preferably has a relatively small percentage of fines. This type of chipped reduced product can readily be used as fuel for a burner since the material is more flowable than ground reduced material and can easily be handled by the material processing equipment used to feed fuel to a burner.

Grinders typically include reducing hammers on which replaceable grinding cutters (i.e., grinding tips or grinding elements) are mounted. Grinding cutters generally have relatively blunt ends suitable for reducing material through blunt force impactions. In contrast to the grinding cutters used on grinders, chippers typically include relatively sharp chipping knives configured to reduce material through a cutting/slicing action as opposed to a grinding action. An advantage of grinders is that grinders are generally suited to better tolerate wear than chippers without unduly negatively affecting the performance of the grinders and quality of the product output by the grinders. An advantage of chippers is that the sharpness of the chipping knives allows certain materials (e.g., trees) to be processed more rapidly with less power than would typically be required by a grinder.

SUMMARY

One aspect of the present disclosure relates to reducing elements for material reducing machines such as grinders and chippers. The replaceable reducing element includes a reducing element body having first and second major sides, the first major side being a front side and the second major side being a back side. The reducing element body also includes at least one reducing feature positioned at the front side of the reducing element body and a fastening feature. Furthermore, the reducing element body includes a first and a second rear projection that project rearwardly from the back side of the reducing element body. The first and second rear projections are separated from the fastening feature by intermediate spacings. The fastening feature and the first and second rear projections are aligned along a reference plane that extends through the reducing element body in a front-to-back orientation and the intermediate spacings are measured along the reference plane.

A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a material reducing machine in accordance with the principles of the present disclosure;

Figure 2 is a cross-sectional view taken through a portion of the material reducing machine of Figure 1;

Figure 3 is a perspective view of a rotary component used in the material reducing machine of Figure 1 ;

Figure 4 is a perspective view of a leading/front side of a reducing element in accordance with the principles of the present disclosure, the reducing element is shown aligned with a mounting position on a hammer of the rotary component of Figure 3;

Figure 5 is a perspective view of a trailing/rear side of a reducing element in accordance with the principles of the present disclosure, the reducing element is shown aligned with a mounting position on a hammer of the rotary component of Figure 3;

Figure 6 is a leading/front side view of the reducing element of Figures 4 and

5;

Figure 7 is a top side view of the reducing element of Figures 4 and 5;

Figure 8 is a right side view of the reducing element of Figures 4 and 5; Figure 9 is a cross-sectional view taken through a portion of the reducing element of Figure 8;

Figure 10 is a rear perspective view of the reducing element of Figures 4 and

5;

Figure 1 1 is a rear perspective view of a second embodiment of a reducing element in accordance with the principles of the present disclosure;

Figure 12 is a perspective view of a third embodiment of a reducing element in accordance with the principles of the present disclosure; the reducing element is adapted for use in a stump cutter;

Figure 13 is a side view of the reducing element of Figure 12;

Figure 14 is a rear perspective view of a reducing element with a different design configuration in accordance with the principles of the present disclosure;

Figure 15 is a rear perspective view of a reducing element with a different design configuration in accordance with the principles of the present disclosure;

Figure 16 is a rear perspective view of a reducing element with a different design configuration in accordance with the principles of the present disclosure; and

Figure 17 is a rear perspective view of a reducing element with a different design configuration in accordance with the principles of the present disclosure.

DETAILED DESCRIPTION

Figure 1 shows a material reducing machine 20 in accordance with the principles of the present disclosure. The material reducing machine 20 includes a material reducing chamber 22, a material in-feed arrangement 24 for feeding material desired to be reduced into the material reducing chamber 22, and a material out-feed arrangement 26 for carrying reduced product away from the material reducing chamber 22. The material in-feed arrangement 24 includes a material in- feed trough 28 having a floor 30 and side walls 32 positioned on opposite sides of the floor 30. The floor 30 is defined by a conveying arrangement such as a continuous conveyor (e.g., a belt, chain track or other conveying structure driven in a continuous loop) configured to feed material desired to be reduced into the material reducing chamber 22. The material in-feed arrangement 24 also includes an upper feed roller 34 that cooperates with the conveyor floor 30 to feed material into the material reducing chamber 22. The feed roller 34 can also function to grip material being fed into the material reducing chamber 22 to prevent the material from being pulled too quickly into material reducing chamber 22. The material out- feed arrangement 26 includes a discharge conveyor 36 that typically extends beneath the material reducing chamber 22. When material is reduced within the chamber 22, the material can fall from the material reducing chamber 22 onto the discharge conveyor 36 which carries the reduced product away from the material reducing chamber 22. The discharge conveyor 36 can be used to load the reduced material into a container such as the bed of a truck. While the reducing machine 20 is depicted as a horizontal grinder, it will be appreciated that aspects of the present disclosure are also applicable to chippers, stump cutters, tub grinders or other types of reducing machines.

Referring to Figure 2, the material reducing machine 20 includes a rotary component 40 positioned within the material reducing chamber 22. The rotary component 40 is rotatable about a central longitudinal axis of rotation 42. Power for rotating the rotary component can be provided by an engine 44 (see Figure 1) coupled to the rotary component 40 by a torque transferring arrangement (e.g., an arrangement of sheaves, belts, gears, shafts, chains or other known structures). A plurality of hammers 46 are mounted to the rotary component 40. As shown at Figure 2, a plurality of reducing elements 62 in the form of grinding cutters are mounted to the hammers 46. The material reducing chamber 22 is defined by a surround or enclosure 41 that surrounds at least a portion of the rotary component 40. The enclosure 41 includes an anvil 50 that cooperates with outer portions of the reducing elements 62 of the rotary component 40 to define an in-feed nip or gap 49 for material desired to be reduced to be fed into the material reducing chamber 22. The enclosure 41 also includes a sizing screen 52 that extends around a portion of the rotary component 40. The sizing screen 52 defines a plurality of sizing openings 43 through which material reduced in the material reducing chamber 22. passes before falling onto the discharge conveyor 36. The enclosure 41 further includes a transition plate 54 and a top cover plate 56. The transition plate 54 extends from the anvil 50 to a leading edge 51 of the sizing screen 52. The top cover plate 56 extends from a trailing edge 53 of the sizing screen 52 over a top side of the rotary component 40.

Referring to Figure 3, the rotary component 40 includes a drive shaft 58 that is preferably connected to the frame of the reducing machine via a bearing arrangement. In use, torque from the engine 44 is transferred from the engine to the drive shaft 58 to cause the rotary component 40 to be rotated about the axis of rotation 42. The axis of rotation 42 extends longitudinally through the center of the drive shaft 58.

In use of the material reducing machine 20, material desired to be reduced is loaded into the material in-feed arrangement 24. The material in-feed arrangement 24 then feeds the material against the rotary component 40 while the rotary component 40 is rotated about the axis of rotation 42 in a counterclockwise direction as shown by arrow 60 provided at Figure 3. As the material desired to be reduced is fed against the rotary component 40, the reducing elements 62 mounted on the hammers 46 engage the material initially reducing the material and forcing the material through the in-feed gap 49 between the anvil 50 and the rotary component 40. Once inside the material reducing chamber 22, the material is further reduced by the reducing elements 62 and forced through the sizing holes 43 in the sizing screen 52. From the sizing screen 52, the reduced material falls to the discharge conveyor 36 of the out-feed arrangement 26. The discharge conveyor 36 carries the reduced material to a material collection location.

Referring now to Figures 4-10, the replaceable reducing element 62 is depicted. The replaceable reducing element 62 includes a reducing element body 64 having first major side 66 and a second major side 68. In this example, the first major side 66 is a front side (i.e., a leading side) and the second major side 68 is a back side (i.e., a trailing side). The reducing element body 64 further includes at least one reducing feature 70 positioned at the front side of the reducing element body 64. The at least one reducing feature 70 can be an edge, corner, rounded edge, projection, extension, hook, wing, tab, or the like. 3193

As shown, the reducing element body 64 also includes a fastening feature 72 for use in securing the reducing element body 64 to one of the hammers 46. In one embodiment, the fastening feature 72 is an opening that extends through the reducing element body 64 from the front side 66 to the back side 68 for receiving a fastener 69, such as a bolt. In this way, the fastening feature 72 allows the fastener 69 to be used to secure the reducing element body 64 to a leading side of the hammer 46 as shown in FIGS. 4 and 5. In other embodiments, the fastening feature can include a fastener integrally connected (e.g., welded, unitarily formed, cast, etc.) with the reducing element body 64. In still other embodiments, the fastening feature can include a blind or through-hole, internally threaded opening defined at the back side of the reducing element body 64 into which a fastener can be secured (e.g., threaded). In a preferred embodiment, a single fastener is used to secure the reducing element body 64 to the hammer 46.

The reducing element 62 can also include an anti-rotation feature for preventing the reducing element body 64 from rotating relative to the hammer 46 about an axis defined by the fastening feature 72. For example, the reducing element body 64 can further include a first rear projection 74 and a second rear projection 76 that each project rearwardly from the back side of the reducing element body 64. Projections 74 and 76 are received by apertures 75a and 77a. In other examples, the hammer 46 can be made reversible by having apertures 75b and 77b on the opposite side. In this example, the first and second rear projections 74, 76 have a truncated conical shape. The first and second rear projections 74, 76 can be separated from the fastening feature 72 by intermediate spacings SI . The fastening feature 72 and the first and second rear projections 74, 76 are aligned along a reference plane PI (illustrated in Figure 9) that extends through the reducing element body 64 in a front-to-back orientation. The reference plane PI bisects the reducing element body 64 into left and right sides and cuts through the fastening feature 72. The intermediate spacings SI are measured along the reference plane PL Referring again to Figure 9, the fastening feature 72 defines a first cross- dimension CI and the first and second rear projections 74, 76 each define a second cross-dimension C2. In this example, each of the second cross-dimensions C2 is smaller than the first cross-dimension CI. In some embodiments, each of the second cross-dimensions C2 is no more than 70, 80 or 90 percent of the first cross- dimension CI. In this example, the first and second rear projections 74, 76 have 63193 truncated conical shapes with bases B, and that the second cross-dimensions C2 are measured at the bases B of the truncated conical shapes. As shown, the intermediate spacings SI are each smaller than the first cross-dimension CI . In other

embodiments, the first cross-dimension CI is at least 80, 150, 200, 300 or 500 percent larger than each of the intermediate spacings SI and the second cross- dimensions C2 are at least 70, 150, 200, 300 or 400 percent larger than each of the intermediate spacings S 1.

Referring to Figure 9, center-to-center spacings S2 are defined between a center axis Al of the fastening feature 72 and center axes A2, A3 of the rear projections 74, 76. In this example, the center-to-center spacings S2 are each larger than each of the second cross-dimensions C2. For example, the center-to-center spacings S2 can each be at least 30, 40 or 50 percent larger than each of the second cross-dimensions C2.

In this example, the fastening feature 72 defines the fastening feature axis Al and the first and second rear projections 74, 76 define the projection axes A2, A3 respectively. The rear projections axes A2, A3 are parallel to the fastening feature axis Al. As shown, the fastening feature 72 defines an opening cross-sectional area 96 taken along a cross-sectional plane P2 that is perpendicular to the fastening feature axis Al . The first and second rear projections 74, 76 define projection cross- sectional areas 98, 100 taken along line 9-9 of Figure 8. Each of the projection cross-sectional areas 98, 100 is smaller than the opening cross-sectional area 96. In one example, each of the projection cross-sectional areas 98, 100 is no more than 55, 70 or 80 percent of the opening cross-sectional area 96. In another example, each of the projection cross-sectional areas 98, 100 is larger than the opening cross-sectional area 96.

Figure 11 depicts another embodiment having a first and a second rear projections 174, 176. It also includes a fastening feature 172. As shown, the first and second rear projections 174, 176 each have a cross-dimension that is larger than the cross-dimension of the fastening feature 172. In some embodiments, the first and second rear projections 174, 176 and the fastening feature 172 can have cross- dimensions of the same size. The fastening feature 172 can be a blind or through- hole, internally threaded opening for receiving a threaded end of a fastener.

Figures 12-13 show yet another embodiment having a first rear projection 274 and a second rear projection 276. It also includes a fastening feature 272, where the fastening feature 272 can be a fastener including a shank 278 that is integrated with the reducing element body 264 and projects rearwardly from the reducing element body 264. The shank 278 is fixed to the reducing element body 264 and has a threaded end with a nut 280 attached thereon. This embodiment is adapted to be used in a material reducing machine such as a stump cutter.

Figures 14-17 are examples of other designs for reducing cutting elements according to principles of the present disclosure. Each of the designs have a different cutting feature. Other embodiments may include designs in accordance with principles of the disclosure. As shown, the cutting elements each have a reducing element body 364,464,564,664 having a first rear projection 374, 474, 574, 674 and a second rear projection 376, 476, 576, 676 thereon. The cutting elements also include fastening features 372, 472, 572, and 672 respectively.

The preceding embodiments are intended to illustrate without limitation the utility and scope of the present disclosure. Those skilled in the art will readily recognize various modifications and changes that may be made to the embodiments described above without departing from the true spirit and scope of the disclosure.