Abstract:
The various embodiments disclosed and pictured illustrate a multi-connector hammer for comminuting various materials. The illustrative embodiments pictured and described herein are primarily for use with a rotatable hammermill assembly. The multi-connector hammer includes a connection portion having a rod hole therein, a contact portion for delivery of energy to the material to be comminuted, and a multi-connector neck portion affixing the connection portion to the contact portion. In other embodiments, a shoulder is positioned around the periphery of the rod hole for added strength. In still other embodiments, a neck reinforcement is positioned along a portion of the neck for increased strength. A weld or plurality of welds may be affixed to various surfaces of the contact portion to aide in comminuting and/or longevity of the multi-connector hammer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Applicant states that the present application is a continuation of and claims priority from U.S. patent application Ser. No. 13/566,967 filed on Aug. 3, 2012 (now U.S. Pat. No. 8,800,903), which application claimed priority from provisional U.S. Pat. App. No. 61/514,644 filed on Aug. 3, 2011, both of which applications are incorporated by reference herein in their entireties. 
    
    
     FIELD OF INVENTION 
     This invention relates generally to a device for comminuting or grinding material. More specifically, the invention is especially useful for use as a hammer in a rotatable hammermill assembly. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     No federal funds were used to develop or create the invention disclosed and described in the patent application. 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
     Not Applicable 
     BACKGROUND 
     A number of different industries rely on impact grinders or hammermills to reduce materials to a smaller size. For example, hammermills are often used to process forestry and agricultural products as well as to process minerals, and for recycling materials. Specific examples of materials processed by hammermills include grains, animal food, pet food, food ingredients, mulch and even bark. This invention although not limited to grains, has been specifically developed for use in the grain industry. Whole grain corn essentially must be cracked before it can be processed further. Dependent upon the process, whole corn may be cracked after tempering yet before conditioning. A common way to carry out particle size reduction is to use a hammermill where successive rows of rotating hammer like devices spinning on a common rotor next to one another comminute the grain product. For example, methods for size reduction as applied to grain and animal products are described in Watson, S. A. &amp; P. E. Ramstad, ed. (1987, Corn: Chemistry and Technology, Chapter 11, American Association of Cereal Chemist, Inc., St. Paul, Minn.), the disclosure of which is hereby incorporated by reference in its entirety. The application of the invention as disclosed and herein claimed, however, is not limited to grain products or animal products. 
     Hammermills are generally constructed around a rotating shaft that has a plurality of disks provided thereon. A plurality of free-swinging hammers are typically attached to the periphery of each disk using hammer rods extending the length of the rotor. With this structure, a portion of the kinetic energy stored in the rotating disks is transferred to the product to be comminuted through the rotating hammers. The hammers strike the product, driving into a sized screen, in order to reduce the material. Once the comminuted product is reduced to the desired size, the material passes out of the housing of the hammermill for subsequent use and further processing. A hammer mill will break up grain, pallets, paper products, construction materials, and small tree branches. Because the swinging hammers do not use a sharp edge to cut the waste material, the hammer mill is more suited for processing products which may contain metal or stone contamination wherein the product the may be commonly referred to as “dirty”. A hammer mill has the advantage that the rotatable hammers will recoil backwardly if the hammer cannot break the material on impact. One significant problem with hammer mills is the wear of the hammers over a relatively short period of operation in reducing “dirty” products which include materials such as nails, dirt, sand, metal, and the like. As found in the prior art, even though a hammermill is designed to better handle the entry of a “dirty” object, the possibility exists for catastrophic failure of a hammer causing severe damage to the hammermill and requiring immediate maintenance and repairs. 
     Hammermills may also be generally referred to as crushers—which typically include a steel housing or chamber containing a plurality of hammers mounted on a rotor and a suitable drive train for rotating the rotor. As the rotor turns, the correspondingly rotating hammers come into engagement with the material to be comminuted or reduced in size. Hammermills typically use screens formed into and circumscribing a portion of the interior surface of the housing. The size of the particulate material is controlled by the size of the screen apertures against which the rotating hammers force the material. Exemplary embodiments of hammermills are disclosed in U.S. Pat. Nos. 5,904,306; 5,842,653; 5,377,919; and 3,627,212. 
     The four metrics of strength, capacity, run time and the amount of force delivered are typically considered by users of hammermill hammers to evaluate any hammer to be installed in a hammermill. A hammer to be installed is first evaluated on its strength. Typically, hammermill machines employing hammers of this type are operated twenty-four hours a day, seven days a week. This punishing environment requires strong and resilient material that will not prematurely or unexpectedly deteriorate. Next, the hammer is evaluated for capacity, or more specifically, how the weight of the hammer affects the capacity of the hammermill. The heavier the hammer, the fewer hammers that may be used in the hammermill by the available horsepower. A lighter hammer then increases the number of hammers that may be mounted within the hammermill for the same available horsepower. The more force that can be delivered by the hammer to the material to be comminuted against the screen increases effective comminution (i.e. cracking or breaking down of the material) and thus the efficiency of the entire comminution process is increased. In the prior art, the amount of force delivered is evaluated with respect to the weight of the hammer. 
     Finally, the length of run time for the hammer is also considered. The longer the hammer lasts, the longer the machine run time, the larger profits presented by continuous processing of the material in the hammermill through reduced maintenance costs and lower necessary capital inputs. The four metrics are interrelated and typically tradeoffs are necessary to improve performance. For example, to increase the amount of force delivered, the weight of the hammer could be increased. However, because the weight of the hammer increased, the capacity of the unit typically will be decreased because of horsepower limitations. There is a need to improve upon the design of hammermill hammers available in the prior art for optimization of the four (4) metrics listed above. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limited of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.  FIGS. 7B, 8B, 10B, 18B, 21A, 22A, 23A, 24A , and  25 A are shown to scale. 
         FIG. 1  provides a perspective view of the internal configuration of a hammer mill at rest as commonly found in the prior art. 
         FIG. 2  provides a perspective view of the internal configuration of a hammermill during operation as commonly found in the prior art. 
         FIG. 3  provides an exploded perspective view of a hammermill as found in the prior art as shown in  FIG. 1 . 
         FIG. 4  provides an enlarged perspective view of the attachment methods and apparatus as found in the prior art and illustrated in  FIG. 3 . 
         FIG. 5  provides a perspective view of a first embodiment of a multi-connector hammer. 
         FIG. 6A  provides top view of the first embodiment of a multi-connector hammer with illustrative dimensions included therein. 
         FIG. 6B  provides side view of the first embodiment of a multi-connector hammer with illustrative dimensions included therein. 
         FIG. 7A  provides a top view of two multi-connector hammers according to the first embodiment thereof positioned vertically with respect to one another. 
         FIG. 7B  provides a perspective view of the multi-connector hammers shown in  FIG. 7A . 
         FIG. 7C  provides a top view of two multi-connector hammers according to the first embodiment thereof positioned horizontally with respect to one another. 
         FIG. 7D  provides a perspective view of two multi-connector hammers according to the first embodiment thereof positioned horizontally with respect to one another. 
         FIG. 8A  provides a perspective view of a second embodiment of a multi-connector hammer. 
         FIG. 8B  provides a top view of a second embodiment of a multi-connector hammer. 
         FIG. 9A  provides top view of two multi-connector hammers according to the second embodiment thereof positioned vertically with respect to one another. 
         FIG. 9B  provides a perspective view of the multi-connector hammers shown in  FIG. 9A . 
         FIG. 9C  provides a top view of two multi-connector hammers according to the second embodiment thereof positioned horizontally with respect to one another. 
         FIG. 9D  provides a perspective view of the multi-connector hammers shown in  FIG. 9C . 
         FIG. 10A  provides a perspective view of a third embodiment of a multi-connector hammer. 
         FIG. 10B  provides a top view of the third embodiment of a multi-connector hammer with illustrative dimensions included therein. 
         FIG. 10C  provides a side view of the third embodiment of a multi-connector hammer. 
         FIG. 11  provides a perspective view of a first embodiment of a protective arm and a fourth embodiment of a multi-connector hammer engaged with a hammer rod. 
         FIG. 12  provides a detailed view of the embodiment of the protective arm and multi-connector hammer shown in  FIG. 11 . 
         FIG. 13  provides a detailed view of one side of the first embodiment of the protective arm. 
         FIG. 14  provides a detailed view of the first embodiment of the protective arm and the attachment thereof to the hammer rod. 
         FIG. 15  provides a detailed view of another side of the first embodiment of the protective arm. 
         FIG. 16  provides another detailed view of the first embodiment of the protective arm and fourth embodiment of a multi-connector hammer. 
         FIG. 17  provides another detailed view of the first embodiment of the protective arm and the attachment thereof to the hammer rod. 
         FIG. 18A  provides yet another detailed view of the first embodiment of the protective arm and the attachment thereof to the hammer rod. 
         FIG. 18B  provides a perspective view of the first embodiment of the protective arm. 
         FIG. 18C  provides a top view of the first embodiment of the protective arm. 
         FIG. 18D  provides a side view of the first embodiment of the protective arm. 
         FIG. 19A  provides a perspective view ofa fifth embodiment of a multi-connector hammer. 
         FIG. 19B  provides a side view of the embodiment of a multi-connector hammer shown in  FIG. 19A . 
         FIG. 19C  provides a top view of the embodiment of a multi-connector hammer shown in  FIG. 19A . 
         FIG. 20A  provides a perspective view of a sixth embodiment of a multi-connector hammer. 
         FIG. 20B  provides a side view of the embodiment of a multi-connector hammer shown in  FIG. 20A . 
         FIG. 20C  provides a top view of the embodiment of a multi-connector hammer shown in  FIG. 20A . 
         FIG. 2  IA provides a perspective view of a second embodiment of a protective arm in relation to a fourth embodiment of a multi-connector hammer. 
         FIG. 21B  provides a top view of the protective arm and multi-connector hammer from  FIG. 21A . 
         FIG. 21C  provides a side view of the protective arm and multi-connector hammer from  FIG. 21A   
         FIG. 22A  provides perspective view of the embodiment of the multi-connector hammer shown in  FIG. 21A . 
         FIG. 22B  provides a top view of a half member of the multi-connector hammer shown in  FIG. 21 . 
         FIG. 22C  provides a side view of the multi-connector hammer shown  FIG. 22A   
         FIG. 23A  provides a perspective view of a second embodiment of a protective arm. 
         FIG. 23B  provides a top view of the second embodiment of a protective arm. 
         FIG. 23C  provides a side view of the second embodiment of a protective arm. 
         FIG. 24A  provides a perspective view of a seventh embodiment of a multi-connector hammer. 
         FIG. 24B  provides a top view of the embodiment of a multi-connector hammer shown in  FIG. 24A . 
         FIG. 24C  provides a side view of the embodiment of a multi-connector hammer shown in  FIG. 24A . 
         FIG. 25A  provides a perspective view of a half member of the multi-connector hammer shown in  FIG. 24A . 
         FIG. 25B  provides a top view of the half member shown in  FIG. 25A . 
         FIG. 25C  provides a side view of the half member shown in  FIG. 25C . 
     
    
    
     DETAILED DESCRIPTION 
     Listing of Elements 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Element 
                 Element # 
               
               
                   
                   
               
             
             
               
                   
                 Hammermill assembly 
                 2 
               
               
                   
                 Hammermill drive shaft 
                 3 
               
               
                   
                 End plate 
                 4 
               
               
                   
                 End plate drive shaft hole 
                 5a 
               
               
                   
                 End plate hammer rod hole 
                 5b 
               
               
                   
                 Interior plate 
                 6 
               
               
                   
                 Interior plate drive shaft hole 
                 7a 
               
               
                   
                 Interior plate hammer rod hole  
                 7b 
               
               
                   
                 Hammer rod 
                 8 
               
               
                   
                 Spacer 
                 8a 
               
               
                   
                 Hammer (prior art) 
                 9 
               
               
                   
                 Hammer body (prior art) 
                 9a 
               
               
                   
                 Hammer contact edge (prior art)  
                 9b 
               
               
                   
                 Hammer rod hole (prior art) 
                 9c 
               
               
                   
                 Multi-connector hammer 
                 10 
               
               
                   
                 Seam 
                 12 
               
               
                   
                 Half member 
                 14 
               
               
                   
                 Connection portion 
                 20 
               
               
                   
                 Connector 
                 22 
               
               
                   
                 Rod hole 
                 24 
               
               
                   
                 Connector interstitial area 
                 26 
               
               
                   
                 Neck 
                 30 
               
               
                   
                 Neck first end 
                 32 
               
               
                   
                 Neck second end 
                 34 
               
               
                   
                 Neck interstitial area 
                 36 
               
               
                   
                 Contact portion 
                 40 
               
               
                   
                 Contact member 
                 42 
               
               
                   
                 Primary contact surface 
                 44 
               
               
                   
                 Contact interstitial area 
                 46 
               
               
                   
                 Protective arm 
                 50 
               
               
                   
                 Arm connection portion 
                 52 
               
               
                   
                 Arm rod hole 
                 52a 
               
               
                   
                 Arm spacer portion 
                 54 
               
               
                   
                 Arm distal end 
                 56 
               
               
                   
                   
               
             
          
         
       
     
     ILLUSTRATIVE EMBODIMENTS 
     Before the various embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first”, “second”, and “third” are used herein and in the appended claims for purposes of description and are not intended to indicate or imply relative importance or significance. Furthermore, any dimensions recited or called out herein are for exemplary purposes only and are not meant to limit the scope of the invention in any way unless so recited in the claims. 
     1. Free-Swinging Hammermill Assemblies 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIGS. 1-3  show a hammermill assembly  2  as found in the prior art. The hammermill assembly  2  includes two end plates  4  on each end with at least one interior plate  6  positioned between the two end plates  4 . The end plates  4  include an end plate drive shaft hole  5   a  and the interior plates  6  include an interior plate drive shaft hole  7   a . A hammermill drive shaft  3  passes through the end plate drive shaft holes  5   a  and the interior plate drive shaft holes  7   a . The end plates  4  and interior plates  6  are affixed to the hammermill drive shaft and rotatable therewith. 
     Each end plate  4  also includes a plurality of end plate hammer rod holes  5   b , and each interior plate  6  includes a plurality of interior plate hammer rod holes  7   b . A hammer rod  8  passes through corresponding end plate hammer rod holes  5   b  and interior plate hammer rod holes  7   b . A plurality of hammers  9  are pivotally mounted to each hammer rod  8 , which is shown in detail in  FIG. 4 . The hammers  9  are typically oriented in rows along each hammer rod  8 , and each hammer rod  8  is typically oriented parallel to one another and to the hammermill drive shaft  3 . 
     Each hammer  9  includes a hammer body  9   a , hammer contact edge  9   b , and a hammer rod hole  9   c  passing through the hammer body  9   a , which is shown in detail in  FIG. 4 . Each hammer rod  8  passes through the hammer rod hole  9   c  of at least one hammer  9 . Accordingly, the hammers  9  pivot with respect to the hammer rod  8  to which they are attached about the center of the hammer rod hole  9   c . A spacer  8   a  may be positioned around the hammer rod  8  and between adjacent hammers  9  or adjacent hammers  9  and plates  4 ,  6  to better align the hammers  9  and/or plates  4 ,  6 , which is best shown in  FIGS. 3-4 . As is well known to those of skill in the art, a lock collar (not shown) would typically be placed on the end of the hammer rod  8  to compress and hold the spacers  8   a  and the hammers  9  in alignment. All these parts require careful and precise alignment relative to one another. This type of hammer  9 , which is shown affixed to the hammermill assembly  2  shown in  FIGS. 1-3  and separately in  FIG. 4 , is commonly referred to as free-swinging hammers  9 . Free-swinging hammers  9  are hammers  9  that are pivotally mounted to the hammermill assembly  9  in a manner as described above and are oriented outwardly from the center of the hammermill assembly  2  by centrifugal force as the hammermill assembly  2  rotates. 
     The hammermill assembly  2  and various elements thereof rotate about the longitudinal axis of the hammermill drive shaft  3 . As the hammermill assembly  2  rotates, centrifugal force causes the hammers  9  to rotate about the hammer rod  8  to which each hammer  9  is mounted. The hammermill assembly  2  is shown at rest in  FIG. 1  and in a dynamic state in  FIG. 2 , as in operation. Free-swinging hammers  9  are often used instead of rigidly connected hammers in case tramped metal, foreign objects, or other non-crushable material enters the housing with the particulate material to be reduced, such as grain. 
     For effective comminution in hammermill assemblies  2  using free-swinging hammers  9 , the rotational speed of the hammermill assembly  2  must produce sufficient centrifugal force to hold the hammers  9  as close to the fully extended position as possible when material is being communited. Depending on the type of material being processed, the minimum hammer tip speeds of the hammers are usually 5,000 to 11,000 feet per minute (“FPM”). In comparison, the maximum speeds depend on shaft and bearing design, but usually do not exceed 30,000 FPM. In special high-speed applications, the hammermill assemblies  2  may be configured to operate up to 60,000 FPM. 
     In the case of disassembly for the purposes of repair and replacement of worn or damaged parts, the wear and tear causes considerable difficulty in realigning and reassembling the various elements of the hammermill assembly  2 . Moreover, the elements of the hammermill assembly  2  are typically keyed to one another, or at least to the hammermill drive shaft  3 , which further complicates the assembly and disassembly process. For example, the replacement of a single hammer  9  may require disassembly of the entire hammermill assembly  2 . Given the frequency at which wear parts require replacement, replacement and repairs constitute an extremely difficult and time consuming task that considerably reduces the operating time of the size reducing machine. Removing a single damaged hammer  9  may take in excess of five (5) hours due to both the hammermill assembly  2  design and the realignment difficulties related to the problems caused by impact of debris with the non-impact surfaces of the hammermill assembly  2 . 
     Another problem found in the prior art hammermill assemblies  2  shown in  FIGS. 1-3  is exposure of a great deal of the surface area of the hammermill assembly  2  elements to debris. The end plates  4  and interior plates  6 , spacers  8   a , and hammers  9  are all subjected to considerable contact with the debris and material within the hammermill assembly  2 . This not only creates excessive wear, but contributes to realignment difficulties by bending and damaging of the various elements of the hammermill assembly  2 , which may be caused by residual impact. Thus, after a period of operation, prior art hammermill assemblies  2  become even more difficult to disassemble and reassemble. The problems related to comminution service and maintenance of hammermill assemblies  2  provides abundant incentive for improvement of hammers  9  to lengthen operational run times. 
     2. Illustrative Embodiments of a Multi-Connector Hammer 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIG. 5  provides a perspective view of a first embodiment of a multi-connector hammer  10 , and  FIGS. 6A and 6B  provide top and side views thereof, respectively. 
     As shown herein, the multi-connector hammer  10  generally includes a connection portion  20  and contact portion  40  connected to one another by a neck  30 . The embodiment shown in  FIGS. 5-7D  includes at least two necks  30 , whereas the embodiments shown in  FIGS. 8A-10C  include at least one neck  30 . In both embodiments a neck first end  32  may be affixed to the connection portion  20 , and a neck second end  34  may be connected to the contact portion  40 . The embodiment shown in  FIGS. 5-7D  may also include a neck interstitial area  36  positioned between the two necks  30 . 
     The connection portion  20  generally may be configured for attachment to a hammer rod  8  and may include at least two connectors  22 . A rod hole  24  may be fashioned in each connector  22  through which the hammer rod  8  may pass. A connector interstitial area  26  may be positioned between adjacent connectors  22 . Among other advantages, including but not limited to increased turbulence within the hammermill assembly  2  in certain applications, spacing connectors  22  apart from one another dispenses with the need for spacers  8   a , as required by the prior art. 
     The contact portion  40  generally may be configured for contact with a material to be comminuted within the hammermill assembly  2  and includes at least one contact member  42 . The embodiment in  FIGS. 5-7D  may include four contact members  4 , wherein a contact interstitial area  46  may be positioned between adjacent contact members  42 . At the distal end of each contact member  42  may be a primary contact surface  44 , which may have a hardened edge. The hardened edge may be applied via heat treating, welding, infusion, or any other method known or unknown without limiting the scope of the multi-connector hammer  10 . Additionally, the primary contact surface  44  may be composed of any suitable material, known or unknown. 
     As shown in  FIG. 6A , the necks  30  in the first embodiment of the multi-connector hammer  10  may be asymmetrical with respect to the connection portion  20  and/or contact portion  40 . Furthermore, as shown in  FIG. 8B , the neck  30  in the second embodiment of the multi-connector hammer  10  also may be asymmetrical with respect to the connection portion  20  and/or contact portion  40 . The optimal configuration/orientation of the neck(s)  30  with respect to the connection portion  20  and/or contact portion  40  may vary depending on at least the material to be comminuted. Certain configurations/orientations may allow for more or less turbulence within the hammermill assembly  2 . Additionally, asymmetrical configurations such as those shown in  FIGS. 5-9D  allow for offsetting the necks  30  of adjacent multi-connector hammers  10  as best shown in  FIGS. 7A &amp; 9A . 
     A third embodiment of a multi-connector hammer  10  is shown in  FIGS. 19A-19C . As best shown in  FIGS. 19A &amp; 19C , this embodiment includes three connectors  22  and three contact members  42 . It is contemplated that this embodiment of the multi-connector hammer  10  will be relatively easy and inexpensive to manufacture. As clearly shown in  FIGS. 19A and 19C , each connector  22  and corresponding contact member  42  and neck  32  may be formed as a unitary piece, wherein three unitary pieces are affixed to one another to produce the multi-connector hammer  10  shown in  FIGS. 19A-19C . A seam  12  may be positioned between the unitary pieces. Each unitary piece may be stamped from a sheet of material and then joined together at a seam  12 . The rod hole  24  in each connector  22  may be heat treated for hardness. As with the previous embodiments, the third embodiment dispenses with the need for spacers  8   a  in most applications. 
     A fourth embodiment of a multi-connector hammer  10  is shown in  FIGS. 20A-20C . The fourth embodiment includes two connectors  22  and two contact members  42 . As a corollary to the third embodiment, it is contemplated that each connector  22  and corresponding contact member  42  and neck may be formed as a unitary piece, wherein two unitary pieces are affixed to one another to produce the fourth embodiment of the multi-connector hammer  10 . A seam  12  may be positioned between the unitary pieces. Each unitary piece may be stamped from a sheet of material and then joined together at a seam  12 . The rod hole  24  in each connector  22  may be heat treated for hardness. As with the previous embodiments, the fourth embodiment dispenses with the need for spacers  8   a  in most applications. 
     Both the third and fourth embodiments of the multi-connector hammer  10  may be formed from unitary pieces having different thicknesses. For example, the material may be ¼ inches thick for one application and ⅜ inches thick for another. Typically, the narrower the thickness of the material used in the multi-connector hammer  10 , the finer the grind of the material. Accordingly, the optimal thickness of each unitary piece will vary from one application of the multi-connector hammer  10  to the next, and is in no way limited to the scope thereof. 
     3. Illustrative Embodiment of a Protective Arm 
       FIGS. 11-18  show various view of an illustrative embodiment of a protective arm  50 , which may be used with various different hammermill assemblies  2 . It is contemplated that the illustrative embodiment of the protective arm  50  will be especially useful in rotating hammermill assemblies  2 , but it may be used in other applications as well. Furthermore, different embodiments of the protective arm  50  may be used with equipment other than rotating hammermill assemblies  2 . 
     As shown, the protective arm  50  may be engaged with a hammer rod  8  via an arm rod hole  52   a , which may be positioned in an arm connection portion  52 . The arm connection portion  52  is formed as a loop in the embodiment of the protective arm  50  shown herein, but may be differently configured in other embodiments. An arm spacer portion  54  may be connected to an integrally formed with the arm connection portion  52 . The protective arm  50  may terminate at an arm distal end  56 . 
     As best shown in  FIG. 14 , the protective arm  50  may be pivotally mounted to a hammer rod  8  on which a multi-connector hammer  10  is also mounted. The arm connection portion  52  may be positioned on the hammer rod  8  between two connectors  22  of the multi-connector hammer  10 . 
     The dimensions of the arm connection portion  52 , arm spacer portion  54 , and arm distal end  56  may be chosen such that the protective arm  50  prevents one surface of the multi-connector hammer  10  from contacting the adjacent hammer rod  8 , as best shown in  FIG. 11 . Accordingly, if the multi-connector hammer  10  contacts an object during operation that causes the multi-connector hammer  10  to recoil, the protective arm  50  prevents damage to the trailing edge of the multi-connector hammer  10  by shielding it from direct contact with the hammer rod  8 . 
     The arm spacer portion  54  and arm distal end  56  may be offset from the arm rod hole  52   a , as best shown in  FIG. 15 . This allows the multi-connector hammer  10  to function normally under typical conditions. Furthermore, this allows the multi-connector hammer  10  to recoil almost as far when used in conjunction with the protective arm  50  as when not, which is best shown in  FIG. 11 . Furthermore, this configuration of the protective arm  50  allows the protective arm  50  to be situated immediately adjacent the multi-connector hammer  10  during normal operation of the hammermill assembly  2 , as best shown in  FIG. 12 . However, in other embodiments of the protective arm  50 , the arm spacer portion  54  and arm distal end  56  may be oriented differently with respect to the arm connection portion  52 . 
     A second embodiment of a protective arm  50  that may be used with a hammermill assembly  2  is shown adjacent a multi-connector hammer  10  in  FIG. 21  and alone in  FIG. 23 . The second embodiment of the protective arm  50  includes two arm connection portions  52  at either end thereof, wherein each arm connection portion  52  is formed with an arm rod hole  52   a  therein. An arm spacer portion  54  is positioned between the two arm connection portions  52 . Adjacent hammer rods  8  in a hammermill assembly  2  may be positioned in the two arm rod holes  52   a  of the second embodiment of the protective arm  52 . Accordingly, it is estimated that the second embodiment of the protective arm  50  will require less material and/or horsepower than the first embodiment thereof. 
     During use, the multi-connector hammer  10  engaged with the hammer rod  8  adjacent a first arm connection portion  52  (as shown in  FIG. 21 ) may pivot counterclockwise as shown in  FIG. 21  when the multi-connector hammer  10  encounters an obstruction of sufficient magnitude. The neck  30  of the multi-connector hammer  10  may then contact the protective arm  50  at the arm spacer portion  54 , which prevents damage to the non-leading edge of the contact portion  40 . 
     The materials used to construct the connection portion  20 , neck  30 , and contact portion  40  will vary depending on the specific application for the multi-connector hammer  10 . Certain applications will require a high tensile strength material, such as steel, while others may require different materials, such as carbide-containing alloys. Accordingly, the above-referenced elements may be constructed of any material known to those skilled in the art, which material is appropriate for the specific application of the multi-connector hammer  10 , without departing from the spirit and scope of the multi-connector hammer  10  as disclosed and claimed herein. 
     Other methods of using the multi-connector hammer  10  and embodiments thereof will become apparent to those skilled in the art in light of the present disclosure. Accordingly, the methods and embodiments pictured and described herein are for illustrative purposes only. The multi-connector hammer  10  also may be used in other manners, and therefore the specific hammermill assembly  2  in which the multi-connector hammer  10  is used in no way limits the scope of the multi-connector hammer  10 . 
     It should be noted that the multi-connector hammer  10  is not limited to the specific embodiments pictured and described herein, but is intended to apply to all similar multi-connector hammers  10 . Modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the multi-connector hammer  10 . 
     The materials used to construct the arm connection portion  52 , arm spacer portion  54 , and arm distal end  56  will vary depending on the specific application for the protective arm  50 . Certain applications will require a high tensile strength material, such as steel, while others may require different materials, such as carbide-containing alloys. Accordingly, the above-referenced elements may be constructed of any material known to those skilled in the art, which material is appropriate for the specific application of the protective arm  50 , without departing from the spirit and scope of the protective arm  50  as disclosed and claimed herein. 
     Other methods of using the protective arm  50  and embodiments thereof will become apparent to those skilled in the art in light of the present disclosure. Accordingly, the methods and embodiments pictured and described herein are for illustrative purposes only. The protective arm  50  also may be used in other manners, and therefore the specific hammermill assembly  2  in which the protective arm  50  is used in no way limits the scope of the protective arm  50 . 
     It should be noted that the protective arm  50  is not limited to the specific embodiments pictured and described herein, but is intended to apply to all similar protective arms  10  designed to extend the working life of a hammer. Modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the protective arm  50 .