Abstract:
An apparatus and device are provided for a self-propelled roping training system. The apparatus includes an endless track comprising a plurality of corner sections, each of the plurality of corner sections comprising an arc length, a carriage assembly comprising a front slider assembly coupled with the track and a rear slider assembly coupled with the track, and a self-propelled vehicle coupled with the carriage assembly configured to follow a path defined by the endless track.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of and claims priority to U.S. Provisional Patent Application No. 61/909,916 entitled “SNOW VEHICLE SUSPENSION SYSTEM” and filed on Nov. 27, 2013 for Allen Mangum, which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates in general to tracked vehicles and in particular to a tracked vehicle suspension with leaning capability. 
       BACKGROUND 
       [0003]    Tracked vehicles have long been used for travel over snow. Generally, snowmobiles are used for various applications including trail riding, mountain riding, and touring. Additionally, many types of wheeled vehicles have been converted for travel over snow and ice. For example, Ford Model-T automobiles and even older types were long ago converted for use in winter snows by bolting drive tracks and skis where the wheels were originally. More recently, a number of people and companies have offered components, kits, and whole assemblies to convert ordinary motorcycles, ATVs, and other wheeled vehicles for winter use. Some of these are easily reversible, and the skis and drive tracks can be removed and the original wheels reinstalled for summer use. 
         [0004]    Regardless of whether the vehicle is a snowmobile or a wheeled vehicle converted to a tracked vehicle, tracked vehicles typically include a drive shaft mounted to a suspension system that supports the endless track. The drive shaft typically includes drive sprockets that engage the endless track. Irregularities in the snow and ice covered terrain cause the suspension system to move. Shock absorbers are typically used to absorb the movement of the suspension system. Common suspension systems are configured to collapse towards the tracked vehicle when absorbing the movement. However, in some situations, the irregularities in the terrain cause movement in the suspension away from the tracked vehicle that is not accommodated by the suspension system. 
       SUMMARY 
       [0005]    An apparatus and system for a tracked vehicle suspension is disclosed. The apparatus, in one embodiment, includes a tunnel having upper rollers for supporting an upper portion of the endless track, and a front strut coupling track slides to the tunnel. Each of the track slides includes a plurality of lower rollers for supporting a lower portion of the endless track. In one embodiment, the front strut includes a lower tube for engaging a cross shaft disposed between the track slides. The cross shaft may be formed with a protruding fulcrum about which the lower tube pivots such that the front strut pivots laterally with respect to the track slides. 
         [0006]    In one embodiment, the front strut includes an upper tube coupled at each end with the tunnel and side tubes coupling the upper tube with the lower tube. The apparatus may also include a front shock absorber coupled at a first end with the upper tube and coupled at a second end with a cross bar disposed between the track slides. 
         [0007]    In another embodiment, the apparatus includes a rear strut coupling the track slides to the tunnel, where the rear strut engages a rear cross shaft disposed between the track slides such that the rear strut is substantially laterally fixed in relation to the track slide. The apparatus may also include a rear shock absorber coupled at a first end with the rear strut and coupled at a second end with a cross bar disposed between the track slides. In one embodiment, the track slides, the front shock, the rear shock, the front strut, the rear strut, the plurality of upper rollers, and the plurality of lower rollers are disposed within the endless track. 
         [0008]    In one embodiment, the apparatus also includes a bushing disposed between the fulcrum and the lower tube, and a positionable adjuster disposed on the cross shaft, where the positionable adjuster comprises an exterior surface that engages an end of the lower tube to limit the pivoting of the front strut about the fulcrum. The exterior surface may vary in diameter to adjust a range of pivoting motion of the front strut. 
         [0009]    The system, in one embodiment, includes the above described apparatus together with a motorcycle frame. The tunnel, for example, may be coupled with a subframe, and a strut disposed between the subframe and a motorcycle frame. In one embodiment, the strut rigidly couples the subframe with the motorcycle frame, such that the subframe is substantially fixed in relation to the motorcycle frame. 
         [0010]    In another embodiment, the motorcycle frame is coupled with a front suspension system. The front suspension system may include a pair of shock absorbers coupled with the motorcycle frame at upper ends of the pair of shock absorbers, and a steering ski disposed between the pair of shock absorbers at lower ends of the pair of shock absorbers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which: 
           [0012]      FIG. 1  is a side view diagram illustrating one embodiment of a track conversion system for a motorcycle in accordance with embodiments of the invention; 
           [0013]      FIG. 2  is a side view diagram illustrating one embodiment of the rear track assembly for converting a motorcycle to a snow vehicle in accordance with embodiments of the invention; 
           [0014]      FIGS. 3   a  and  3   b  jointly depict embodiments of directions of pivoting with reference to the front and rear struts in accordance with embodiments of the invention; 
           [0015]      FIG. 4  is a perspective view diagram illustrating one embodiment of the front strut in accordance with embodiments of the invention; 
           [0016]      FIG. 5  is an exploded view diagram illustrating one embodiment of the front strut in accordance with embodiments of the invention; and 
           [0017]      FIG. 6  is a cross sectional diagram illustrating one embodiment of the front strut in accordance with embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available snow vehicle conversion kits for motorcycles. Accordingly, the subject matter of the present application has been developed to provide a snow suspension system that overcomes at least some shortcomings of the prior art. 
         [0019]      FIG. 1  is a side view diagram illustrating one embodiment of a track conversion system for a motorcycle in accordance with embodiments of the invention. The track conversion system  100  comprises, in one embodiment, a motorcycle  102  with an engine  103  which has had its front wheel  104  and rear wheel  106  and rear swing-arm suspension removed. In one embodiment, a single front steering ski  108  and a rear track drive assembly  110  replace the front wheel  104  and the rear wheel  106 , respectively. Examples of a front steering ski  108  capable of use with embodiments of the invention include a dual- or tri-keel ski manufactured by Simmons, Inc. of Providence, Utah. 
         [0020]    The rear track drive assembly  110 , in one embodiment, includes a tubular subframe  111  that attaches to the motorcycle  102  with a rear swing arm pin  112  and a solid strut  114  that replaces the original shock. The top part of the rear track drive assembly  110  is thus rigidly attached with the frame of the motorcycle and does not move with reference to the frame. A tunnel assembly  116  attaches to both sides of the tubular subframe  111  with tunnel side skirts  118  and provides protective cover for the top of a drive track  120  and mounting for a track roller  122 , forward and aft adjustable shocks  124  and  126 , and forward and aft track struts  128  and  130 . One example of a track suitable for use with the rear track drive assembly  110  is a Camoplast Challenger Track, 121″ long, 12¾″ wide, 1¾″ deep lug, manufactured by Camoplast of Quebec Canada. 
         [0021]    The forward and aft shocks  124  and  126 , and the forward and aft track struts  128  and  130  together support a hyfax slide suspension  132 . A hyfax is a sacrificial plastic glide which runs the length of two parallel rear suspension rails  134  and  136  on both sides. Polystyrene and graphite glide materials can be used because they provide very smooth contact surfaces to the track  120  and low operational friction especially when lubricated with snow. 
         [0022]    An adjustable limit strap  138  controls the initial upward tilt of the hyfax slide assembly  132  to the ground and snow underneath. The limiter strap  138  may include adjustment holes in the middle of the strap. Shortening the limiter strap  138  will increase pressure on the front ski  108  and will provide more steering control on steep slopes. Conversely, lengthening the limiter strap  138  will lighten the front ski pressure. Adjusting the limiter strap shifts the center of gravity either forwards or towards the rear, thereby adjusting the center of gravity closer to or farther from the front ski  108 . The adjustable limiter strap  138  determines how far away the forward shock  124  can push down the leading edge of the hyfax slide assembly  132 . The front leading edge of the hyfax slide suspension  132  is also turned up to provide an approach angle in the range of between about 5 and 30 degrees. 
         [0023]    During acceleration and increased loading, the leverage and geometry of the adjustable shock and strut combination is such that the center-point of the track  120 , that is supporting the backend weight of snow bike system  100 , will dynamically shift further back. The front of the snow bike system  100  will have to take more of the static weight as a result, and the increased static weight will keep the front ski  108  down on the ground and better maintain steering. Such is represented in  FIG. 1  by the “dynamic loading point” arrow which can shift forward or back. 
         [0024]    A rear track roller  139 , in one embodiment, is mounted to the rear end of hyfax slide suspension  132 . A jackshaft  140  in a sealed case couples the engine power on a chain and sprocket to a more outboard position where it can power a forward track roller and track drive wheel (covered by tunnel  118  and not shown in  FIG. 1 ) inside the front loop of track  120 . 
         [0025]    In one embodiment, the length of the rear strut  130  is adjustable. The degree coupling of the back suspension and the amount of lift that will develop on the front ski  108  when climbing a hill can be changed by adjusting the length of rear strut  130 . Such adjustment also affects how independent the front and back portions of the hyfax suspension  132  will be from one another, as well as the rear ride height of motorcycle  102 . 
         [0026]    The geometric relationship of the front and rear adjustable shocks  124  and  126  with their associated front and rear struts  128  and  130  balances the pressures applied to the snow between the front and back halves of the track  120  under the hyfax slide suspension  132 . In one embodiment, about 13″ of vertical travel is achieved. 
         [0027]    The system  100 , as depicted, includes a drive system jackshaft  140 . The jackshaft  140 , beneficially, positions the drive to the outside of the tunnel rail  118  and allows the above described width of the track  120 . In one embodiment, the snow bike system  100  described is a conversion or add-on kit to modify a previously manufactured motorcycle  102  to allow efficient over the snow and ice travel. The front wheel  104 , the rear wheel  106 , and the swing arm suspension are removed, in one embodiment, to allow for the conversion of the motorcycle into a snow vehicle. A single steering ski assembly  108  is installed in the place of the front wheel to provide for steering. A rear track drive assembly  132  is installed in the place of the rear wheel and swing arm suspension. The rear track drive assembly  132 , in one example, includes track slides  134 ,  136  and a track  120  coupled to the engine  103  via the chain case  140 . The track  120  may be driven between a forward track roller and a rear track roller  139  suspended with and positioned fore and aft of the track slides  134 ,  136 . 
         [0028]      FIG. 2  is a side view diagram illustrating one embodiment of the rear track assembly for converting a motorcycle to a snow vehicle in accordance with embodiments of the invention. As depicted, the rear track assembly  200  includes a track tunnel  202  rigidly attached to the underside of a tubular frame  204 . Track tunnel  202  has opposite side skirts that provide for the rigid, not-suspended mounting of a jackshaft  206 , top track roller  208 , a front track roller and drive sprocket  210 , front shock  212 , rear shock  214 , front strut  216 , and rear strut  218 . As used herein, the terms “front” and “rear” refer to a position on the snow vehicle with reference to the ski. For example, the front shock  212  refers to the shock that is closer to the ski, and the rear shock  214  refers to the shock that is farther away from the ski. 
         [0029]    The jackshaft  206  is in a sealed case and is mounted to the track tunnel  202  such that the transmission of power can be carried from the engine  103  ( FIG. 1 ) to a track  220  through the front track roller and drive sprocket  210 . Conventional designs do not drive the front track roller and instead include a long transmission and driveshaft mechanisms to drive one of the aft rollers. The jackshaft  206  may include a disc brake and caliper operated by a right-hand handlebar-mounted hydraulic master cylinder on the motorcycle  102 . 
         [0030]    The suspension system is configured to collapse flat. The separation distance increases between the front track roller and drive sprocket  210  and a rear belt roller  222  as trail impacts (i.e., changes in terrain) and weight load changes are absorbed. The arcing movement of front strut  216  is especially responsible for this behavior. The suspension system is further configured by the placement of rear strut  218  such that the front of a hyfax slide assembly  224  will be forcefully cantilevered or kicked up relative to the rear belt roller  222  at particular points of the track belt collapse. 
         [0031]    The front shock  212  and front strut  216  are strategically disposed in the front half of the suspension system and track drive assembly  200  to control the response of the front portion of the track slide  224  to loads and acceleration. The rear shock  214  and rear strut  218  are disposed in the aft half of the suspension system and track drive assembly  200  to control the response of the rear belt roller  222  and back portion of the track slide  224  to loads and acceleration. 
         [0032]    In one embodiment, a back arm slide mechanism included in the rear strut  218  permits the length of the rear strut to slip between a minimum extension position and a maximum extension position. When the rear strut  218  is in the minimum extension position, the front portion of track slide  224  is cantilevered up relative to the rear belt roller  222  and back portion of the track slide  224 . This, beneficially, increases the angle of attack or approach of the track. The rear strut is configured, in one embodiment, to transition between the minimum extension position and the maximum extension position by inserting shims  219 . 
         [0033]    The drive system is such that a first drive chain (not shown) is provided from engine  103  ( FIG. 1 ) to the jack shaft  206  inside tunnel  202 . The jack shaft  206  transfers engine driving power to the outside left of tunnel  202 . A secondary chain (not shown) drives from jack shaft  206  to front track roller and drive sprocket  210  such that the system drives off the front of the track  220 . Chain tensioners are included on both drive chains to accommodate different sprocket gearing options. The secondary chain drive system is sealed inside a chain case. A typical drive system uses O-ring chains, 4140 Chrome-Moly steel axles, CNC machined drive sprockets and bearing cages, and over-sized sealed axle bearings. 
         [0034]    In one embodiment, the front suspension assembly (the front shock  212  and front strut  216 ) are configured to operate independently from the rear suspension assembly (the rear shock  214  and rear strut  218 ). Stated differently, in one embodiment, there is no mechanical coupling between the front and rear suspension assemblies such that movement in one affects or causes movement in the other. 
         [0035]    As depicted, both the front strut  216  and the rear strut  218  are disposed between the tunnel (formed by side shrouds  209  and the tubular frame  204 ) and the slide rails  224 . Both the front strut  216  and the rear strut  218  are pivotally connected with the slide rails  224  and the side shrouds  209 . As will be discussed in greater detail below with reference to  FIGS. 3   a - 6 , in one embodiment, the front strut  216  may be configured to pivot both laterally and longitudinally while the rear strut  218  only pivots longitudinally. The pivoting of the front and rear struts  216 ,  218  is described in greater detail with reference to  FIGS. 3   a  and  3   b.    
         [0036]      FIGS. 3   a  and  3   b  jointly depict embodiments of directions of pivoting with reference to the front and rear struts  216 ,  218  in accordance with embodiments of the invention.  FIG. 3   a  is a side view diagram illustrating a simplified embodiment of the front and rear struts. As described above, the front strut  216  and the rear strut  218  are configured to collapse towards the slide rail  224  depending on the terrain. In other words, bumps or other irregularities in the terrain encountered by the rear suspension system cause the slide rail to move towards the tunnel. This movement is dampened by the shocks of the front and rear suspension assemblies. Stated differently, the movement is absorbed by the collapsing of the front and rear struts  216 ,  218  as depicted by arrow  302 . The depicted pivoting is along a longitudinal axis of the snow vehicle. The longitudinal axis is an imaginary axis that extends from the front of the snow vehicle to the rear of the snow vehicle through a center of gravity. 
         [0037]      FIG. 3   b  is a block diagram illustrating one embodiment of the front strut  216  in accordance with embodiments of the invention. As will be discussed in greater detail below, the front strut  216  is configured to pivot longitudinally (see  FIG. 3   a ) and laterally. Lateral pivoting, or side-to-side pivoting, allows for better handling and traction. In one embodiment, the front strut  216  is configured with adjustable lateral pivoting. Stated differently, the front strut  216  is configured to have a range of lateral motion in the range of between about 0 and 10 degrees  304 . 
         [0038]    In one embodiment, the rear strut  218  is fixed laterally and only allowed to pivot longitudinally, as in  FIG. 3   a . This beneficially allows for a snow vehicle that, when positioned on a substantially flat surface, is capable of standing without the need of, for example, a kick stand. In other embodiments, the rear strut  218  may be configured to pivot laterally. 
         [0039]      FIG. 4  is a perspective view diagram illustrating one embodiment of the front strut  216  in accordance with embodiments of the invention. The front strut  216 , in one embodiment, pivotally couples the side shrouds  209  and the slide rails  224 . The side shrouds  209  are fixedly coupled with the motorcycle frame while the slide rails  224  move with reference to the side shrouds  209  in response to changes in the terrain and load applied by the motor and the rider. 
         [0040]    The front strut  216  may be formed of a tubular steel welded to form a generally triangular frame as depicted. Other geometries are contemplated. The front strut  216 , in one embodiment, includes a lower tube  402 , an upper tube  404 , and side tubes  406  coupling the lower and upper tubes  402 ,  404 . The lower tube  402  is configured to engage a cross shaft  408  that is disposed between the slide rails  224 . As will be discussed in greater detail below with reference to  FIGS. 5 and 6 , the lower tube  402  is configured to engage the cross shaft  408  and enable the front strut  216  to pivot laterally. This is achieved via a knuckle formed on the cross shaft  408  upon which the lower tube  402  is seated and allowed to rock from side to side. Positionable adjusters  411  limit the range of side-to-side pivoting of the front strut  216 . 
         [0041]    The rear strut  218  (see  FIGS. 2 and 3   a ), in one embodiment, does not pivot laterally. Stated differently, the rear strut  218  is laterally fixed so that any lateral movement in the slide rails  224  is translated to the side shrouds  209 , and vice versa. That is to say if the rider of the vehicle leans to one side, the lateral leaning movement translates from the frame and the side shrouds  209  through the rear strut  218  and to the rear of the slide rails  224 . The front strut  216 , however, is able to pivot laterally, and therefore not all of the lateral leaning is translated to the front of the slide rails  224 . Only after the lateral leaning has caused the lower tube  402  to contact either the cross shaft  408  or the adjuster  411  does the lateral leaning movement transfer to the front of the slide rails  224 . This results in a torsional twisting of the slide rails  224 . In other words, as the vehicle leans to one side, the front portion of the slide rails  224  twists with relation to each other and remains in contact with the terrain. This beneficially improves traction because the track is not lifting off the ground when the vehicle leans to one side or the other. 
         [0042]    Additionally, this twisting motion gives the rider the sensation that the track behaves more like a traditional rounded motorcycle tire, instead of a track with a hard edge. One benefit of a laterally rigid rear strut is the ability for the vehicle to stand without the use of a kickstand. In other words, if both the front and rear struts pivoted laterally, the vehicle may require a kickstand. Another benefit of the rigid rear strut is the ability to “side hill” on the vehicle. Side hilling is a technique for traversing across an incline which requires the rider to “carve” or otherwise utilize the side of the track to maintain an elevation on the incline (otherwise, the vehicle naturally tends to go downhill). The rigid rear strut allows the rider to “set” the track and cut across the incline or hillside. 
         [0043]    Also depicted is the front shock  212 . The front shock  212  is coupled, at an upper end, with the upper tube  404  via a spherical rod-end joint and at a lower end with a shock cross shaft (not shown). The rod-end joint allows the front shock  212  to pivot laterally with the front strut  216 . A limiter strap  410  may flexibly couple the upper tube  404  with a limiter cross shaft  412 . 
         [0044]      FIG. 5  is an exploded view diagram illustrating one embodiment of the front strut  216  in accordance with embodiments of the invention. The front strut  216 , as described above, may be formed of tubular steel. In other embodiment, the front strut  216  may be formed of other rigid materials including, but not limited to, metal alloys, and composite materials. The front strut  216  may be tubular for weight savings, or substantially solid for increased rigidity. 
         [0045]    The front strut  216  includes the upper tube  404 , the lower tube  402 , and the side tubes  406 . The upper tube  404  may also include a shock mount  502  for pivotally coupling with the upper end of the front shock. The lower tube  402  is formed with a diameter selected to receive the cross shaft  408 , and a knuckle  504  formed on the cross shaft  408 . The knuckle  504 , in one embodiment, is integrally formed with the cross shaft  408 . In other words, the knuckle  504  and the cross shaft  408  may be machined from a common block of material. In an alternative embodiment, the knuckle  504  may be formed separately and attached to the cross shaft  408 . The knuckle  504 , as depicted, may have a generally rounded profile to enable the lateral pivoting of the front strut  216 . In other words, the knuckle  504  functions as a fulcrum about which the lower tube  402  pivots, and subsequently, the entire front suspension assembly (i.e., front strut  216  and front shock). 
         [0046]    The lower tube  402 , therefore, is formed with an opening sufficient to receive the cross shaft  408  and the knuckle  504 . In one embodiment, the lower tube  402  has an opening in the range of between about 1 and 1.5 inches. The diameter of the knuckle  504 , in one embodiment, is in the range of between about 0.5 and 0.875 inches. Accordingly, the difference in diameters of the opening and the knuckle is in the range of between about 0.25 and 0.75 inches. A bushing  506  may be configured to be disposed in the gap between the lower tube  402  and the knuckle  504 . The bushing  506 , in one embodiment, is a polymer-based ring configured to prevent metal on metal wear of the lower tube and the knuckle. The bushing  506 , in one embodiment, may be formed of polytetrafluoroethylene (PTFE), or other suitable polymers. The bushing may be press fit onto the knuckle  504 . In one embodiment, the bushing  506  is formed with an interior profile selected to engage the knuckle  504 . In other words, the interior surface of the tubular bushing  506  may be formed to match the profile of the knuckle  504 . In a further embodiment, the outer surface of the bushing  506  is configured to engage the interior surface of the lower tube  402 . Accordingly, in one embodiment, the bushing may have a rounded interior surface to engage the knuckle  504 , and a planar exterior surface to engage the lower tube  402 . 
         [0047]    Snap rings  508  may be positioned adjacent the bushing  506  to maintain the position of the bushing between the knuckle  504  and the lower tube  402 . The snap rings  508  may be configured to engage a slot in one of the lower tube  504 , or alternatively, the cross shaft  408 . 
         [0048]    In one embodiment, the positionable adjusters  411  are positioned at each end of the lower tube  402  to limit the lateral pivoting of the front strut  216 . The adjusters  411 , as depicted, are configured with stepped profile that is insertable into the lower tube  402 . Each adjuster  411  may be configured with a lock screw  509  for fixing the position of the adjuster  411  with reference to the cross shaft  408 . The diameter of each step  510  decreases as the distance from the lock screw increases. Each step  510  is configured to function as a stop or landing pad for an edge  512  of the lower tube  402 . As the front strut  216  laterally pivots, the edge  512  will encounter one of the steps  510  and prevent any further lateral pivoting. By changing the position of the adjusters  411 , the rider may influence the range of lateral pivoting of the front strut  216 . In other words, if the adjuster  411  is positioned farther away from the lower tube  402 , the lower tube is able to pivot through a greater degree of movement. Conversely, changing the position of the adjuster  411  to fully engage the lower tube (i.e., steps  510  fully inserted into the lower tube  402 ) causes the adjuster  411  to prevent any lateral pivoting of the front strut  216 . Accordingly, the adjusters  411  beneficially allow the rider to fine tune the range of lateral motion of the front strut  216 . 
         [0049]      FIG. 6  is a cross sectional diagram illustrating one embodiment of the front strut  216  in accordance with embodiments of the invention. As described above, the cross shaft  408  and the knuckle  504  are insertable into the lower tube  402  so that the knuckle  504  functions as a pivot point, or fulcrum, for the lower tube  402 . Lateral pivoting of the front strut  216  causes the edge  512  of the lower tube  402  to engage a selected step  510  of the adjuster  411 . The adjuster  411  may have a stepped profile, as depicted, or alternatively, a gradually decreasing in diameter profile so that finite adjustments are possible. 
         [0050]    In one embodiment, the bushing  506  is press fit onto the knuckle before inserting the cross shaft  408  into the lower tube  402 . Generally, the steps for assembling the pivoting assembly are as follows: press fit bushing onto knuckle, insert first snap ring into lower tube, insert cross shaft into lower tube, insert second snap ring on opposite side of knuckle from first snap ring, and position the adjusters. 
         [0051]    Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the subject matter of the present disclosure should be or are in any single embodiment. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
         [0052]    Furthermore, the described features, advantages, and characteristics of the subject matter of the present disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the subject matter may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages will become more fully apparent from the following description and appended claims, or may be learned by the practice of the subject matter as set forth hereinafter. 
         [0053]    Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
         [0054]    Additionally, instances in this specification where one element is “coupled” to another element can include direct and indirect coupling. Direct coupling can be defined as one element coupled to and in some contact with another element. Indirect coupling can be defined as coupling between two elements not in direct contact with each other, but having one or more additional elements between the coupled elements. Further, as used herein, securing one element to another element can include direct securing and indirect securing. Additionally, as used herein, “adjacent” does not necessarily denote contact. For example, one element can be adjacent another element without being in contact with that element. 
         [0055]    Furthermore, the details, including the features, structures, or characteristics, of the subject matter described herein may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, however, that the subject matter may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosed subject matter. 
         [0056]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.