Patent Publication Number: US-2015082594-A1

Title: Tooth Assembly for Excavating Apparatus with Rare Earth Material

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/549,509, filed Oct. 20, 2011, the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates generally to replaceable machine parts that are exposed to high wear, and more specifically to a tooth assembly for an excavating apparatus with rare earth material. 
     BACKGROUND OF THE INVENTION 
     Digging and leveling apparatuses such as draglines, backhoes, front-end loaders, and the like often use replaceable tooth assemblies that are mounted on tooth horns, excavator lips, edges, or the like to provide sacrificial parts that are exposed to repeated shock loading and high wear occasioned by a digging operation. In such systems, each tooth assembly typically includes a wedge-shaped adapter that mounts directly on the tooth horn of the bucket, shovel, or alternative digging or scraping mechanism of the equipment. A wedge-shaped tooth point for engaging the material to be excavated is frontally seated on and securely pinned to the adapter. 
     Attachment of the tooth point is typically accomplished by means of one or more inserts that are inserted into insert cavities in the adapter. The inserts are internally threaded to accommodate a bolt that secures the tooth point to the adapter. Installation and removal of tooth points secured using such a system requires substantial time and effort because the bolts that secure the tooth points must be screwed in and unscrewed when the tooth is to be replaced. Such screwing and unscrewing operations typically require the use of a powered impact wrench. Moreover, the use of such a tool presents the danger of over-torquing, which results in damage to the threads and possible personal injury to the operator. 
     SUMMARY OF THE INVENTION 
     In accordance with particular configurations of the present disclosure, the disadvantages and problems associated with tooth assemblies for excavating apparatuses may be substantially reduced or eliminated. 
     In accordance with particular configurations of the present disclosure, a system for coupling equipment components may include a magnetic coupling assembly. The magnetic coupling assembly may couple a tooth point to an adapter. The magnetic coupling assembly may be received at least partially within a recess formed in the adapter. The magnetic coupling assembly may include an insert and a magnetic coupler. The insert may be placed within the recess of the adapter, and the insert may include an internal recess. The magnetic coupler may be received within the internal recess of the insert. 
     Technical advantages provided by particular configurations of the present disclosure may include allowing operators of excavation equipment or other replaceable machine parts to quickly and efficiently install and remove replaceable parts. For example, a tooth point may be coupled to or removed from an adapter using a magnetic coupler. The magnetic coupler may be removed quickly and efficiently utilizing one or more of a mechanical replacement tool and a heating element as the tooth point degrades or wears out during use. By substantially reducing replacement time of replaceable parts, such a magnetic coupler may allow operators to utilize excavating equipment and other machine parts longer and with less idle time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of an attachment system in accordance with particular configurations of the present disclosure. 
         FIG. 2A  shows an exploded top sectional view of a tooth assembly of an attachment system in accordance with particular configurations of the present disclosure; 
         FIG. 2B  shows a half sectional perspective view of an insert in accordance with particular configurations of the present disclosure; and  FIG. 2C  shows a half sectional perspective view of a retainer pin in accordance with particular configurations of the present disclosure. 
         FIG. 3A  shows an exploded top sectional view of another tooth assembly of an attachment system in accordance with particular configurations of the present disclosure; 
         FIG. 3B  shows a half sectional perspective view of an insert in accordance with particular configurations of the present disclosure; and  FIG. 3C  shows a half sectional perspective view of a magnetic coupler in accordance with particular configurations of the present disclosure. 
         FIG. 4A  shows a perspective view of a mechanical removal tool that may be utilized to remove a magnetic coupler in accordance with particular configurations of the present disclosure;  FIG. 4B  shows a side view of the mechanical removal tool of  FIG. 4A . 
         FIG. 5  shows a top view of a heating element that may be utilized to remove the magnetic coupler in accordance with particular configurations of the present disclosure. 
         FIG. 6A  shows a top view of a magnetic coupler in accordance with particular configurations of the present disclosure;  FIG. 6B  shows a half sectional side view of the magnetic coupler of  FIG. 6A ; and  FIG. 6C  shows a bottom view of the magnetic coupler of  FIG. 6A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An attachment system in accordance with particular configurations of the present disclosure is described herein with particular reference to the attachment and removal of replaceable teeth to and from excavating equipment, such as dragline buckets, and more particularly to the attachment and removal of replaceable teeth to and from the assemblies disclosed in U.S. Pat. Nos. 5,337,495, 6,502,336, and 7,032,334, the disclosures of which are incorporated herein by reference. Those skilled in the art will understand, however, that configurations of the present disclosure may be applicable to other machines using replaceable parts. Examples of such machines may include downhole drills and related tools, conveyor belt parts, center wear shrouds and wing shrouds on dragline buckets, track shoes for tracked vehicles, machine gun and artillery breech parts, cutting edges, pins, protectors, ripper components, and the like. 
     Referring to the drawings and to  FIG. 1  in particular, the tooth assembly of this invention is generally illustrated by reference numeral  1  and may be mounted on a conventional tooth horn  2  of the bucket or shovel of a conventional excavator. The tooth assembly  1  may include a wedge-shaped adapter  3  fitted with a removable tooth point  15 , which may have a contact edge  18  and may be mounted on the adapter  3  by means of one or more (e.g., a pair of) tooth point retainer pins  33 . Each of tooth point retainer pins  33  may extend through a tooth point retainer pin opening in a tooth point side wall of the removable tooth point  15  and may thread into one or more (e.g., a pair of) inserts  49 , which may be seated on sides of (e.g., opposing sides of) the adapter  3 . In certain configurations, the tooth assembly  1  may include a transversely-mounted top wear cap and bottom wear cap, each of which may be bolted to the adapter  3  by means of side plate bolts. In some configurations, the adapter  3  may include a wedge-shaped adapter base that may taper from a base plate to a nose ridge of the adapter  3  and may terminate at a nose of the adapter  3 . A base plate lock opening for receiving a spool and a companion wedge and for mounting the adapter  3  on the tooth horn  2  may be provided in a base plate of the adapter base. A pair of transverse, vertically-oriented, spaced stabilizing slots may be provided in the sides of the adapter base. Spaced, parallel top rib slots may be provided transversely in the top tapered face of the base plate of the adapter base, and, in certain configurations, the top rib slots may be T-shaped. Similarly, a pair of spaced, T-shaped bottom rib slots may be provided in one or more of a bottom tapered surface and a face of the base plate of the adapter base along the same relative position as the top rib slots. The top rib slots and bottom rib slots may alternatively be shaped in one or more of a “dove-tail” and alternative locking configuration, according to the knowledge of those skilled in the art. 
     Adapter  3  may be coupled to tooth horn  2  using pin assembly  34 . During excavation and/or mining operations, adapter  3  may be subject to significant wear and tear. Extreme shock loading may be experienced as removable adapter  3  impacts adjacent earth, rocks, and other abrasive material. Therefore, it may be desirable to make adapter body  3  readily replaceable with a new or reconditioned component of similar or identical configuration. Otherwise, one or more of tooth horn  2 , buckets, shovels, and other excavation equipment would need to be replaced more frequently, which may increase equipment and labor costs associated therewith. By providing a removable adapter  3  at the location of tooth horn  2 , which may otherwise experience substantial wear, the service life of such equipment may be prolonged by replacing selected parts associated with the excavation equipment. 
     In order to prevent excessive wear of tooth horn  2 , for example, adapter  3  may be coupled with tooth horn  2 . Consequently, adapter  3  may at least partially conceal and/or protect tooth horn  2  from abrasive materials during excavation. Tooth horn  2  may be configured to be received in an opening in adapter  3 . When adapter  3  and tooth horn  2  are coupled, first and second sides of tooth horn  2  may be disposed adjacent to first and second sides of adapter  3 . 
     The configuration of adapter  3  and tooth horn  2  may vary significantly within the teachings of the present invention. For example, although adapter  3  is described above as having first and second tapered surfaces, in other configurations, adapter  3  may include only one tapered side. Alternatively, adapter  3  may not have any tapered sides. Furthermore, although adapter  3  is described above as having first and second sides that are generally parallel to one another, in other configurations, one or both of first and second sides may be tapered, such that the first and second sides may not be parallel to one another. Similar alterations may be made to tooth horn  2  within the teachings of the present disclosure. In general, the configurations of the excavation components may be selected to receive and provide protection from excessive wear caused during excavation operations. 
     Tooth horn  2  may include a pin bore  58  that may originate at a first side of tooth horn  2  and extend at least partially through tooth horn  2 . In  FIG. 1 , pin bore  58  extends through tooth horn  2  from a first side to a second side. Pin bore  58  may be configured to at least partially receive pin assembly  34  therein. Pin bore  58  and pin assembly  34  may cooperate to provide for one or more of simplified installation and removal of adapter  3  from tooth horn  2 . Accordingly, adapter  3  may be installed, removed, or replaced by an operator in the field, quickly and easily. Additionally, the configuration of pin bore  58  and pin assembly  34  may prevent shifting of a tool body with respect to tooth horn  2  during use thereof. 
     In certain configurations, pin assembly  34  may include an elongate insert  60  and a plug  69 . Insert  60  may be configured to be at least partially received within pin bore  58 . Accordingly, the shape and size of pin bore  58  may correspond to the shape and size of insert  60 . The configurations of pin bore  58  and insert  60  may vary significantly within the teachings of the present invention. In particular configurations, insert  60  may be of a geometric shape that may include a number of sides of equal width. Because the shape of pin bore  58  may correspond to the shape of insert  60 , pin bore  58  may be of a geometric shape that may include a number of sides of equal width. In particular configurations, insert  60  and pin bore  58  may each be of a shape having between three and eight sides. Nevertheless, insert  60  and pin bore  58  may be of any suitable geometric shape. Pin assembly  34  may include one or more plugs  69 , which may be configured to cooperate with a plug bore in insert  60 . The plug bore may extend at least partially through insert  60  and may be configured to at least partially receive one or more plugs  69  therein. In  FIG. 1 , the plug bore extends entirely through insert  60  from a first end to a second end. Accordingly, the plug bore may be configured to receive a first plug at first end and a second plug at a second end. It is recognized, however, that the plug bore may not extend entirely through insert  60 . When the plug bore does not extend entirely through insert  60 , a single plug  69  may be used. 
     In operation, plugs  69  and insert  60  may cooperate to couple adapter  3  to tooth horn  2  in an installed configuration. The sides of tooth horn  2  may include respective openings, which may be configured to receive a portion of one or more plugs  69  at least partially therethrough. The respective positions of the openings upon the sides of adapter  3  may be selected to align with the first and second ends of pin bore  58 , respectively. When adapter  3  is properly positioned upon tooth horn  2 , pin bore  58  and the openings may be aligned such that one or more of an imaginary central axis, an approximately-central axis, and one or more other longitudinal axes may extend through the openings of adapter  3  and insert  60 . In the installed position, a plug  69  may be inserted through each opening of adapter  3  and into at least a portion of pin bore  58  to couple adapter  3  to tooth horn  2 . In the correct installed position, plugs  69  may be recessed from the sides of adapter  3  by approximately 0.125 to 1.000 inches. In particular configurations, plugs  69  may be recessed from the sides of adapter  3  by 0.25 to 0.5 inches. 
       FIGS. 2A-2C  show various views of the coupling between adapter  3  and the removable tooth point  15  shown in  FIG. 1 . As described above, insert  49  may be positioned in a recess of adapter  3 . Tooth point  15  subsequently may be positioned onto adapter  3 . Thereafter, a retainer pin  33  may be coupled to each insert  49  by threading or another appropriate coupling mechanism. Insert  49  may be appropriately shaped to prevent rotation within adapter  3  when installed. For example, as shown in  FIG. 2B , insert  49  may be hexagonally shaped and may include a threaded interior portion that may be configured to receive retainer pin  33 . As shown in  FIG. 2C , retainer pin  33  may be threaded and may include a recessed portion configured to receive a tool for threading retainer pin  33  into insert  49 . 
     Adapter  3  may be coupled to tooth horn  2  using pin assembly  34  in a manner similar to the coupling between adapter  3  and the removable tooth point  15  shown in  FIG. 2A . In particular, insert  60  may be positioned in pin bore  58 , and adapter  3  subsequently may be positioned onto tooth horn  2 . Thereafter, a plug  69  may be placed in each pin bore  58  and coupled to each plug bore in insert  60  by threading or another appropriate coupling mechanism. As shown in  FIG. 1 , insert  60  may be cylindrical; however, in certain configurations, insert  60  may be appropriately shaped to prevent rotation within tooth horn  2  when installed (e.g., hexagonally shaped similar to insert  49 ). Further, in certain configurations, such as those depicted in  FIG. 1 , insert  60  may extend across tooth horn  2  from a first side thereof to a second side thereof. Insert  60  may include a threaded interior portion that may be configured to receive a plug  69  that is similar to the threaded portion of insert  49  shown in  FIG. 2B . Plug  69  may be threaded and may include a recessed portion configured to receive a tool for threading plug  69  into insert  60 , each of which may be similar to the corresponding portions of retainer pin  33  shown in  FIG. 2C . 
       FIGS. 3A-3C  show various views of a coupling between adapter  3  and the removable tooth point  15  implementing a magnetic coupler  61  and an insert  41  in accordance with certain configurations. In certain configurations, the pairing of insert  41  and magnetic coupler  61  may be used interchangeably with the pairing insert  49  and retainer pin  33  to couple adapter  3  and the removable tooth point  15  together. Accordingly, magnetic coupler  61  may be used together with insert  41  to secure tooth point  15  to adapter  3  in lieu of a threaded retainer pin  33  and a threaded insert  49 . For example, as depicted in  FIG. 3A , tooth point  15  may be coupled to adapter  3  by placing insert  41  in a recess of adapter  3 , positioning tooth point  15  onto adapter  3 , and positioning magnetic coupler  61  onto insert  41 . Magnetic coupler  61  may provide a high strength magnetic bond that may securely couple adapter  3  to tooth point  15 . Magnetic coupler  61  may be placed into recess  43  that is formed in insert  41 , as shown in  FIG. 3B . Placing magnetic coupler  61  into recess  43  may substantially reduce or eliminate the movement or drift of magnetic coupler  61  relative to insert  41  during the operation of excavation equipment. In some configurations, recess  43  may be formed to provide 0.010 inches of clearance around a diameter of magnetic coupler  61 . Alternatively, in other configurations, magnetic coupler may be of any appropriate size and may be formed to fit with any appropriate clearance of insert. In certain configurations, insert  41  may be formed with both recess  43  and a threaded portion, such that insert  41  may be configured receive either of magnetic coupler  61  or a retainer pin  33 . 
     Adapter  3  may be coupled to tooth horn  2  using the pairing of insert  41  and magnetic coupler  61  or a combination of features thereof with insert  60  in a manner similar to the coupling between adapter  3  and the removable tooth point  15  shown in  FIG. 3A . In certain configurations, insert  60  may be formed with a recess similar to recess  43  of insert  41 , as shown in  FIG. 3B , rather than a threaded interior portion. Accordingly, magnetic coupler  61  may be used together with insert  60  to secure adapter  3  to tooth horn  2  in lieu of a threaded plug  69  and a threaded version of insert  60 . For example, similarly to the coupling between adapter  3  and the removable tooth point  15  shown in  FIG. 3A , adapter  3  may be coupled to tooth horn  2  by positioning insert  60  into pin bore  58 , positioning adapter  3  over tooth horn  2 , and positioning magnetic coupler  61  onto the recess of insert  60 . In some configurations, insert  60  may be formed with both a recess similar to recess  43  of insert  41  and a threaded portion, such that insert  60  may be configured receive either of magnetic coupler  61  or a threaded plug  69  as described above. 
     In particular configurations, magnetic coupler  61  may be manufactured in part from any high strength magnetic material, including, but not limited to, neodymium and samarium-cobalt magnetic materials. As shown in  FIG. 3C  magnetic coupler  61  may be generally cylindrically-shaped or disk-shaped with a cylindrical bore, such as bore  63 , placed through the center. In alternative configurations, however, magnetic coupler  61  may be rectangular, ovular, hexagonal, or any other suitable shape, and recess  43  and the recess formed in insert  60  may be of a similar shape. Magnetic coupler  61  may include a rare earth material core  64  that may be at least partially enclosed by a shield  65 . Shield  65  may be at least partially enclosed by a protective cup  66 . In some configurations, shield  65  may be formed from a brass material, and protective cup  66  may be formed from a steel material. At least partially enclosing rare earth material core  64  with shield  65  and protective cup  66  may enable magnetic coupler  61  to direct the magnetic force of rare earth material core  64  in a single direction, which may be the direction projecting outwardly from a magnetic face  62  in  FIGS. 3A and 3C . Additionally, protective cup  66  may protect rare earth material core  64  from chipping or breaking due to the forces placed upon rare earth material core  64  during the operation of excavating equipment. Protective cup  66  thereby protects the integrity of rare earth material core  64  of magnetic coupler  61 . In some configurations, magnetic coupler  61  is formed without one or more of a shield and a protective cup to utilize the magnetic force provided by rare earth magnetic core  64  in directions other than or in addition to the direction projecting outwardly from magnetic face  62 . 
     As shown in  FIG. 3B , insert  41  may include a recess  42 , which may be formed to receive a coupler guide  70  therein. Insert  60 , as modified to couple with magnetic coupler  61 , also may include an additional recess corresponding to recess  42  that also may be formed to receive coupler guide  70  therein. In particular configurations, coupler guide  70  may be generally T-shaped with a substantially elongated longitudinal portion and a cross-piece or disk-shaped portion attached at the base thereof. Coupler guide  70  may facilitate the rapid and safe installation of magnetic coupler  61  onto insert  41 . For example, to install magnetic coupler  61  onto or within insert  41 , insert  41  may be positioned in adapter  3 , and tooth point  15  may be positioned onto adapter  3 . Magnetic coupler  61  may be placed onto an elongated portion of coupler guide  70  through bore  63  of magnetic coupler  61  with magnetic face  62  positioned away from the cross-piece or the disk-shaped portion attached at the base of coupler guide  70  and towards adapter  3 . Coupler guide  70  may be formed from a non-magnetic material to ensure that magnetic coupler  61  may not be attracted to and may not bond with coupler guide  70 . Coupler guide  70  (with magnetic coupler  61  placed thereon) may be positioned in one or more of recess  42  formed in insert  41  and the corresponding recess formed in insert  60 . A force subsequently may be applied to slide magnetic coupler  61  forward on coupler guide  70  until the magnetic force provided by magnetic coupler  61  secures magnetic coupler  61  to insert  41 . If, for example, magnetic coupler  61  becomes attracted to or obstructed by an edge of adapter  3  during an attempted installation, coupler guide  70  may be used to shift and move magnetic coupler  61  until magnetic coupler  61  clears an obstructing edge of adapter  3  and slides into the opening of adapter  3  thereby coupling to insert  41 . 
     In certain configurations, magnetic coupler  61  may be of sufficient length to secure adapter  3  to tooth horn  2  by contacting the sides of an opening in adapter  3  through which magnetic coupler  61  is placed. Magnetic coupler  61  thereby may prevent adapter  3  from disengaging from tooth horn  2  during the operation of excavation equipment or other replaceable machine parts. In certain configurations, magnetic coupler  61  may be of sufficient length to secure tooth point  15  to adapter  3  by contacting the sides of an opening in adapter  3  through which magnetic coupler  61  is placed. Magnetic coupler  61  thereby may prevent tooth point  15  from disengaging from adapter  3  during the operation of excavation equipment or other replaceable machine parts. Once coupled to one or more of insert  41  and insert  60 , bore  63  may be filled with a bore filler material that may be formed to be the same size and width as bore  63 . A bore filler material may prevent dust, rock fragments, or other abrasive material from entering magnetic coupler  61  during operation. For example, bore  63  may be filled with a neoprene cylinder that may be formed to fit into and fill the area of bore  63 . In alternative configurations, one or more of insert  41  and insert  60  and respective bores therefor may be omitted and magnetic coupler  61  may couple directly with one or more of tooth horn  2  and adapter  3 . 
     Magnetic coupler  61  may allow quick and efficient replacement of machine tool parts. For example, tooth point  15  may be coupled to adapter  3  using magnetic coupler  61 , and, subsequently, tooth point  15  may be removed quickly and efficiently utilizing one or more of mechanical replacement tool  40  and a heating element  80 , which is described below in more detail, as tooth point  15  degrades or wears out during use. By substantially reducing a replacement time of replaceable parts, magnetic coupler  61  may allow longer utilization of excavating equipment and other machine parts with less idle time. 
       FIGS. 4A ,  4 B, and  5  show various systems and methods for removing magnetic coupler  61  from one or more of insert  41  and insert  60 . In some configurations, magnetic coupler  61  may be tapped or threaded from an exterior surface thereof, such that mechanical removal tool  40  may couple with magnetic coupler  61 . As shown in  FIGS. 4A and 4B , mechanical removal tool  40  may be threaded at an end thereof Consequently, mechanical removal tool  40  may be threaded onto a threaded or tapped portion of magnetic coupler  61 . A force may subsequently be applied to slide a portion of mechanical removal tool  40  with rapid and high-force movement against a supporting rear portion of mechanical removal tool  40 , such that mechanical removal tool  40  may break the magnetic coupling of magnetic coupler  61  to one or more of insert  41  and insert  60 . In some configurations, a rapid, strong force may be sufficient to break the magnetic bond created by magnetic coupler  61 . Subsequently, one or more of tooth point  15  and adapter  3  may be removed and replaced, and magnetic coupler  61  may be reused or discarded. 
       FIG. 5  shows a heating element  80  that may be used, in some configurations, to break the magnetic bond of magnetic coupler  61 . Heating element  80  may utilize standard  110  volt alternating current to create heat in excess of 500 degrees Fahrenheit. In general, however, heating element  80  may provide heat in any suitable manner and to any suitable degree. Heating element  80  may be inserted into bore  63 . The heat provided by heating element  80  may serve to remove the magnetic properties of magnetic coupler  61 . For example, neodymium, which may be utilized in particular configurations, may lose its magnetic properties when heated to a temperature of approximately 375 degrees Fahrenheit. Thus, heating element  80  may be used to quickly and safely remove magnetic coupler  61 , such that a replacement magnetized magnetic coupler  61  may be installed. 
       FIGS. 6A-6C  show magnetic coupler  61  as described above with respect to  FIGS. 3A and 3C .  FIG. 6A  shows a top view of a magnetic coupler  61  with magnetic face  62  facing towards the viewer. As shown in  FIG. 6A , magnetic coupler  61  may include rare earth material core  64  with a cylindrical cut-out forming bore  63 . Rare earth material core  64  may be at least partially enclosed by shield  65 . Shield  65  may be at least partially enclosed by protective cup  66  to protect the integrity of core  64 . Rare earth material core  64 , shield  65 , and protective cup  66 , together with one or more of insert  41  and insert  60  may be referred to as a magnetic coupling assembly.  FIG. 6B  shows a half sectional side view of magnetic coupler  61  that shows bore  63 , rare earth material core  64 , shield  65 , and protective cup  66 . In some configurations, magnetic coupler  61  may be threaded at tap  67 , which may allow magnetic coupler  61  to be coupled to mechanical removal tool  40  for removal.  FIG. 6C  shows a bottom view of magnetic coupler  61  with magnetic face  62  facing away from the viewer.  FIG. 6C  shows protective cup  66  and bore  63 . In some configurations, magnetic coupler  61  may have a diameter of 2.0 inches and a length of 1.25 inches. In alternative configurations, magnetic coupler  61  may be configured to have any appropriate dimension based on the particular application and equipment magnetic coupler  61  is coupling. 
     In certain configurations, the position of magnetic coupler  61  and one or more of insert  41  and insert  60  may be interchangeable. 
     In alternative configurations, magnetic coupler  61  may be formed integrally with one or more of tooth horn  2 , adapter  3 , and tooth point  15 . In such alternative configurations, magnetic coupler  61  may be disposed in the one or more of tooth horn  2 , adapter  3 , and tooth point  15  in place of one or more bores and recesses in the one or more of tooth horn  2 , adapter  3 , and tooth point  15 . 
     Further, in some configurations, one or more of insert  41  and insert  60  may be formed integrally with one or more of tooth horn  2 , adapter  3 , and tooth point  15 . In such configurations, magnetic coupler  61  may be disposed in the one or more of tooth horn  2 , adapter  3 , and tooth point  15  in place of one or more bores and recesses in the one or more of tooth horn  2 , adapter  3 , and tooth point  15 . 
     While the invention has been described in connection with various example structures and illustrative embodiments, it will be understood by those skilled in the art that other variations and modifications of the structures, configurations, and embodiments described above may be made without departing from the scope of the invention. For example, this application comprises possible combinations of the various elements and features disclosed herein, and the particular elements and features presented in the claims and disclosed above may be combined with each other in other ways within the scope of the application, such that the application should be recognized as also directed to other embodiments comprising other possible combinations. Other structures, configurations, and embodiments consistent with the scope of the claimed invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and the described examples are illustrative with the true scope of the invention being defined by the following claims.