Patent Publication Number: US-11648642-B2

Title: Smoothing round internal passages of additively manufactured parts using metallic spheres

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of, and claims priority to, and the benefit of, U.S. application Ser. No. 15/957,873 filed Apr. 19, 2018 and entitled “SMOOTHING ROUND INTERNAL PASSAGES OF ADDITIVELY MANUFACTURED PARTS USING METALLIC SPHERES,” which is incorporated by reference herein in its entirety for all purposes. 
    
    
     FIELD 
     The present disclosure relates generally to methods of finishing internal portions of additively manufactured components and, more particularly, to methods in which a series of spheres is used to smooth walls of circular passageways extending within additively manufactured components. 
     BACKGROUND 
     Fabrication processes such as additive manufacturing enable fabrication of article geometries that are difficult or otherwise impossible to make by other fabrication techniques. For example, components in gas turbine engines may include internal passages for conveying coolants or lubricants. Additive manufacturing and other advances permit such passages to be formed with complex geometries in thin wall structures and with high-aspect ratios (e.g., the ratio of passage length to passage diametric size). However, due to the additive manufacturing process, and even in other fabrication processes, the internal surfaces of these passages can be rough following the fabrication process. If left in the final component, this surface roughness has the potential to interfere with fluid flow through the passageways. 
     A technique for smoothing surface roughness or polishing internal surfaces of conduits or passages in metal components is referred to as ballizing, where a machine having a push rod is used to push a sphere of known diameter through a machined and generally linear bore hole. A force that the sphere exerts on the workpiece as it traverses the length of the bore hole shapes and polishes the inner surface of the conduit. Conventional ballizing techniques typically utilize straight bore holes and thus have difficulty smoothing surfaces of conduits or passages having curved portions. 
     SUMMARY 
     A method for smoothing surface roughness within an internal passageway is disclosed. In various embodiments, the method comprises the steps of determining a diameter of the internal passageway; urging a first sphere into the internal passageway and to a first distance along a length of the internal passageway, the first sphere having a first sphere diameter greater than or equal to the diameter of the internal passageway; and urging a second sphere into the internal passageway, the second sphere having a second sphere diameter greater than or equal to the diameter of the internal passageway, the second sphere urging the first sphere to a second distance along the length of the internal passageway, whereby an inner surface of the internal passageway is smoothed by the first sphere along the second distance of the length and the inner surface of the internal passageway is further smoothed by the second sphere along the first distance of the length. 
     In various embodiments, the method further comprises comprising urging a third sphere into the internal passageway, the third sphere urging the second sphere to the second distance along the length of the internal passageway and the first sphere to a third distance along the internal passageway. In various embodiments, the method further comprises urging subsequent spheres into the internal passageway until the first sphere exits the internal passageway. In various embodiments, the second distance is measured from an inlet of the internal passageway. In various embodiments, the second distance is measured from a starting point within the internal passageway. 
     In various embodiments, the diameter of the internal passageway is an average diameter. In various embodiments, the first sphere diameter is equal to the diameter of the internal passageway. In various embodiments, the second sphere diameter is equal to the first sphere diameter. In various embodiments, the second sphere diameter is greater than the first sphere diameter. In various embodiments, the internal passageway is substantially straight along the length. In various embodiments, the internal passageway has a curved portion along the length. 
     In various embodiments, a set of spheres remaining in the internal passageway is urged to exit the internal passageway using at least one of a flexible rod and a source of pressurized air. In various embodiments, a set of spheres remaining in the passageway is urged to exit the internal passageway using one or more subsequent spheres having a subsequent sphere diameter less than or equal to the first sphere diameter. 
     A method for smoothing surface roughness within an internal passageway is disclosed. In various embodiments, the method comprises the steps of determining a diameter of the internal passageway; urging a first sphere into the internal passageway and to a first distance along a length of the internal passageway, the first sphere having a first sphere diameter greater than or equal to the diameter of the internal passageway; and urging a second sphere into the internal passageway, wherein the second sphere has a second sphere diameter greater than the first sphere diameter, the second sphere urging the first sphere to a second distance along the length of the internal passageway, whereby an inner surface of the internal passageway is smoothed by the first sphere along the second distance of the length and the inner surface of the internal passageway is further smoothed along a first portion of the length. 
     In various embodiments, the method further comprises urging a third sphere into the internal passageway, the third sphere urging the second sphere to the second distance along the length of the internal passageway and the first sphere to a third distance along the internal passageway, the third sphere having a third sphere diameter greater than the second sphere diameter. In various embodiments, the method further comprises urging subsequent spheres into the internal passageway until the first sphere exits the internal passageway. In various embodiments, a set of spheres remaining in the internal passageway is urged to exit the internal passageway using at least one of a rod and a source of pressurized air. 
     A method for smoothing surface roughness within an internal passageway is disclosed. In various embodiments, the method comprises the steps of determining a diameter of the internal passageway; developing a first sphere progression through a length of the internal passageway, each member within the first sphere progression having a first diameter greater than or equal to the diameter of the internal passageway, an inner surface of the internal passageway being smoothed by the first sphere progression along the length; and developing a second sphere progression through the length of the internal passageway, each member within the second sphere progression having a second diameter greater than the first diameter, the inner surface of the internal passageway being further smoothed by the second sphere progression along the length. 
     In various embodiments, the method further comprises developing a final sphere progression, wherein each member within the final sphere progression has a final diameter less than a largest sphere diameter associated with any previous sphere progression developed within the internal passageway. In various embodiments, the internal passageway includes a curved portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the following detailed description and claims in connection with the following drawings. While the drawings illustrate various embodiments employing the principles described herein, the drawings do not limit the scope of the claims. 
         FIG.  1    is a cross sectional schematic view of a gas turbine engine, in accordance with various embodiments; 
         FIG.  2    is a cross sectional schematic view of a passageway extending through the interior of an additively manufactured part, in accordance with various embodiments; 
         FIGS.  3 A,  3 B and  3 C  are cross sectional schematic views of an internal passageway undergoing a ballizing process, in accordance with various embodiments; 
         FIGS.  4 A,  4 B and  4 C  are cross sectional schematic views of an internal passageway undergoing a ballizing process, in accordance with various embodiments; 
         FIG.  5    is a cross sectional schematic view of an internal passageway undergoing a ballizing process, in accordance with various embodiments; and 
         FIG.  6    is a cross sectional schematic view of an internal passageway undergoing a ballizing process, in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that changes may be made without departing from the scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. It should also be understood that unless specifically stated otherwise, references to “a,” “an” or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, all ranges may include upper and lower values and all ranges and ratio limits disclosed herein may be combined. 
     Referring now to the drawings,  FIG.  1    schematically illustrates a gas turbine engine  20 . The gas turbine engine  20  is disclosed herein as a two-spool turbofan that generally incorporates a fan section  22 , a compressor section  24 , a combustor section  26  and a turbine section  28 . Alternative engines might include an augmenter section (not shown) among other systems or features. The fan section  22  drives air along a bypass flow path B in a bypass duct defined within a nacelle  15 , while the compressor section  24  drives air along a primary or core flow path C for compression and communication into the combustor section  26  and then expansion through the turbine section  28 . Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it will be understood that the concepts described herein are not limited to use with two-spool turbofans as the teachings may be applied to other types of turbine engines, including three-spool architectures. 
     The gas turbine engine  20  generally includes a low speed spool  30  and a high speed spool  32  mounted for rotation about an engine central longitudinal axis A relative to an engine static structure  36  via several bearing systems  38 . It should be understood that various bearing systems at various locations may alternatively or additionally be provided and the location of the several bearing systems  38  may be varied as appropriate to the application. The low speed spool  30  generally includes an inner shaft  40  that interconnects a fan  42 , a low pressure compressor  44  and a low pressure turbine  46 . The inner shaft  40  is connected to the fan  42  through a speed change mechanism, which in this gas turbine engine  20  is illustrated as a fan drive gear system  48  configured to drive the fan  42  at a lower speed than the low speed spool  30 . The high speed spool  32  includes an outer shaft  50  that interconnects a high pressure compressor  52  and a high pressure turbine  54 . A combustor  56  is arranged in the gas turbine engine  20  between the high pressure compressor  52  and the high pressure turbine  54 . A mid-turbine frame  57  of the engine static structure  36  is arranged generally between the high pressure turbine  54  and the low pressure turbine  46  and may include airfoils  59  in the core flow path C for guiding the flow into the low pressure turbine  46 . The mid-turbine frame  57  further supports the several bearing systems  38  in the turbine section  28 . The inner shaft  40  and the outer shaft  50  are concentric and rotate via the several bearing systems  38  about the engine central longitudinal axis A, which is collinear with their longitudinal axes. 
     The air in the core flow path is compressed by the low pressure compressor  44  and then the high pressure compressor  52 , mixed and burned with fuel in the combustor  56 , and then expanded over the high pressure turbine  54  and low pressure turbine  46 . The low pressure turbine  46  and the high pressure turbine  54  rotationally drive the respective low speed spool  30  and the high speed spool  32  in response to the expansion. It will be appreciated that each of the positions of the fan section  22 , the compressor section  24 , the combustor section  26 , the turbine section  28 , and the fan drive gear system  48  may be varied. For example, the fan drive gear system  48  may be located aft of the combustor section  26  or even aft of the turbine section  28 , and the fan section  22  may be positioned forward or aft of the location of the fan drive gear system  48 . 
     Various components of the gas turbine engine  20  include conduits or passageways extending through the component or a portion thereof. For example, components in the gas turbine engine  20  may include internal passageways for conveying a coolant. Such components include, for example, the blades and the stators that comprise the compressor and turbine sections described above. Such components may also comprise passageways for conveying bleed air from the compressor to other areas of the gas turbine engine  20  benefitting from a source of high-pressure cooling fluid. Other components comprising conduits or passageways include the lubrication system, where lubricants are delivered from a pump to bearings and the like. Many of these various components are constructed using additive manufacturing techniques and include conduits or passageways having curved portions with rough internal surfaces following their manufacture. 
     Referring now to  FIG.  2   , a component  200 , fabricated through additive manufacture, is illustrated. The component  200  includes a passageway  202  extending from a first end  204  to a second end  206 . The passageway  202  is defined by an inner surface  208  that, in various embodiments, is generally circular in cross section from the first end  204  to the second end  206 . As illustrated, the inner surface  208  of the passageway  202  may be characterized by an undesirable degree of surface roughness following initial fabrication through additive manufacture. In various embodiments, the passageway  202  is curved at one or more portions along a length defined by an arc-length distance from the first end  204  to the second end  206 . As illustrated, for example, the passageway  202 , in various embodiments, includes a first curved portion  210  downstream of the first end  204 , followed by a substantially straight portion  212 , and then followed by a second curved portion  214  upstream of the second end  206 . In various embodiments, the first curved portion  210  may be characterized such that a line of sight does not exist between the location of the passageway  202  where the first curved portion  210  commences and the location of the passageway  202  where the first curved portion  210  terminates, or where the substantially straight portion  212  commences. A similar characterization applies to the second curved portion  214  or any additional curved portions that may be present in a passageway. The disclosure that follows provides, among other things, a technique and method to reduce the surface roughness of the passageway  202  within the component  200 , or other components having a various numbers of curved or straight passageways. 
     Referring now to  FIGS.  3 A,  3 B and  3 C , a series of steps is illustrated whereby a component  300  undergoes a finishing process following initial fabrication through, for example, additive manufacture. Similar to the component  200  described above with reference to  FIG.  2   , the component  300  includes a passageway  302  having an undesirable degree of surface roughness. The passageway  302  extends from a first end  304  to a second end  306  and is defined by an inner surface  308  that, in various embodiments, is generally circular in cross section from the first end  304  to the second end  306 . In various embodiments, the inner surface  308  may be defined by a diameter, D, that is the intended diameter of the inner surface  308  or of the passageway  302 . In various embodiments, the inner surface  308  may be defined by an average diameter  310 , D avg , that takes into account the surface roughness along a length of the passageway  302  or at least a portion thereof. For example, in various embodiments, the average diameter is the mean between a nominal or intended diameter of the inner surface  308  or the passageway  302  and a minimum diameter—e.g., a diameter that takes into account the peaks of the surface roughness extending inward from the inner surface  308 . In various embodiments, the average diameter is the mean between a maximum diameter—e.g., a diameter that takes into account the troughs of the surface roughness extending outward from the inner surface  308 —and a minimum diameter—e.g., a diameter that takes into account the peaks of the surface roughness extending inward from the inner surface  308 . 
     Referring to  FIG.  3 A , a first sphere  320  is inserted through the first end  304  of the passageway  302 , followed by a second sphere  322 . The second sphere  322  serves to force the first sphere  320  through the passageway  302  and to further smooth the passageway  302  behind the first sphere  320 . In various embodiments, the first sphere  320  defines an outer surface  324  that is generally spherical in shape and has a first sphere diameter  326 . In various embodiments, the first sphere diameter  326  is equal to the average diameter  310  of the passageway  302 . As the first sphere  320  traverses the passageway  302 , the outer surface  324  of the first sphere  320  flattens and generally smooths the surface roughness present on the inner surface  308  of the passageway  302 . As the first sphere  320  traverses the passageway  302 , the inner surface  308  includes a smooth surface  328  that becomes progressively longer along the length of the passageway  302  as the first sphere  320  traverses the passageway  302 . Contrarily, as the first sphere  320  traverses the passageway  302 , the inner surface  308  includes a rough surface  330 —i.e., the unsmoothed surface ahead of the first sphere  320 —that becomes progressively shorter as the first sphere  320  traverses the passageway  302 . 
     Referring now to  FIGS.  3 B and  3 C , the first sphere  320  is illustrated having traversed nearly the entire length of the passageway  302 , followed by the second sphere  322 . The first sphere  320  and the second sphere  322  are urged along the length of the passageway  302 , from the first end  304  to the second end  306 , by the introduction of subsequent spheres  340  at the first end  304  of the passageway  302 . Each of the subsequent spheres  340  urges the sphere ahead of it and is itself urged by the sphere behind it, such that a progression of spheres  350  extends through the passageway  302 . As the progression of spheres  350  extends through the passageway  302 , the outer surface of each sphere—e.g., starting with the outer surface  324  of the first sphere  320 —progressively smooths the rough surface  330  of the inner surface  308 . As illustrated in  FIG.  3 C , the first sphere  320  will eventually exit the passageway  302  at the second end  306 , followed by each of the subsequent spheres  340 . Subsequent spheres  340  are continually added and urged through the passageway  302  until a desired smoothness to the inner surface  308  of the passageway  302  is achieved. Once the desired smoothness is achieved, any spheres remaining in the passageway  302  may be urged toward and through the second end  306  using a flexible rod or high pressure air introduced at the first end  304 . In various embodiments, the first sphere begins smoothing starting not from the first end  304  or inlet to the passageway  302 , but from a starting point within the passageway, such occurring, for example, with passageways having a first portion with a larger diameter than the diameter of a second portion with a smaller diameter commencing from the starting point. In various embodiments, each of the spheres comprises a metallic composition having a hardness—e.g., a hardness measured by a Rockwell or Brinell scale—that is harder than the material surrounding the passageway. 
     Referring now to  FIGS.  4 A,  4 B and  4 C , a series of steps is illustrated whereby a component  400  undergoes a finishing process following initial fabrication through, for example, additive manufacture. Similar to the component  200  described above with reference to  FIG.  2   , the component  400  includes a passageway  402  having an undesirable degree of surface roughness. The passageway  402  extends from a first end  404  to a second end  406  and is defined by an inner surface  408  that, in various embodiments, is generally circular in cross section from the first end  404  to the second end  406 . In various embodiments, the inner surface  408  may be defined by an average diameter, D avg , that takes into account the surface roughness along a length of the passageway  402  or at least a portion thereof. 
     Referring to  FIG.  4 A , a first progression of spheres  450  is illustrated extending through the passageway  402 . In various embodiments, the first progression of spheres  450  starts with the progression of spheres  350  discussed above with reference to  FIG.  3 C . More specifically, the undesired roughness in the passageway  402  may undergo a first smoothing step by urging a first plurality of spheres through the passageway  402  until a desired smoothing is achieved and the first smoothing step is complete. As indicated in  FIG.  4 A , each one of the first plurality of spheres is identified with the numeral “1.” Each one of the first plurality of spheres is also defined by a first sphere diameter, D 1 . Similar to the discussion above, in various embodiments, the first sphere diameter D 1  is equal to the average diameter D avg  of the passageway  402  prior to smoothing. 
     Following completion of the first smoothing step, a second plurality of spheres is urged through the passageway  402  until a second progression of spheres  452  is developed, extending from the first end  404  to the second end  406  of the passageway  402  or for a portion of the length thereof. As indicated in  FIGS.  4 A and  4 B , each one of the second plurality of spheres is identified with the numeral “2.” Each one of the second plurality of spheres is also defined by a second sphere diameter, D 2 . In various embodiments, the second sphere diameter D 2  is larger than the first sphere diameter D 1  by a first diameter difference, ΔD 1 =D 2 −D 1 . The larger second sphere diameter D 2  and, more particularly, the first diameter difference ΔD 1  is selected to further smooth the inner surface  408  of the passageway  402  until a second smoothing step is complete. 
     Referring now to  FIG.  4 C , following completion of the second smoothing step, a third plurality of spheres is urged through the passageway  402  until a third progression of spheres  454  is developed, extending from the first end  404  to the second end  406  of the passageway  402  or for a portion of the length thereof. As indicated in  FIG.  4 C , each one of the third plurality of spheres is identified with the numeral “3.” Each one of the third plurality of spheres is also defined by a third sphere diameter, D 3 . In various embodiments, the third sphere diameter D 3  is larger than the second sphere diameter D 2  by a second diameter difference, ΔD 2 =D 3 −D 2 . The larger third sphere diameter D 3  and, more particularly, the second diameter difference ΔD 2  is selected to yet further smooth the inner surface  408  of the passageway  402  until a third smoothing step is complete. In various embodiments, progressively larger spheres may follow the third plurality or progression of spheres to affect a desired smoothness. In various embodiments, ΔD i  (i=1, N) has a value equal to one (1) to ten (10) microns. In various embodiments, each of the spheres comprises a metallic composition having a hardness—e.g., a hardness measured by a Rockwell or Brinell scale—that is harder than the material surrounding the passageway. 
     Referring now to  FIG.  5   , a process  500  is illustrated whereby a component having an internal passageway is fabricated and followed by a series of steps for smoothing an inner surface of the internal passageway. According to the process, a component having an internal passageway is fabricated at a first step  502 . In various embodiments, the component is fabricated using an additive manufacturing process. Once the component is fabricated, a first smoothing step  504  contemplates developing a first progression of spheres having a first diameter, D 1 , within the passageway. In various embodiments, the first smoothing step  504  is completed and a determination is made whether a desired smoothness within the passageway is achieved  506 . If the desired smoothness is achieved, the first progression of spheres is removed from the passageway and the process  500  is terminated  520 . 
     If the desired smoothing is not achieved, a second smoothing step  508  contemplates developing a second progression of spheres having a second diameter, D 2 , within the passageway. As described above with reference to  FIGS.  4 A,  4 B and  4 C , the second diameter D 2  is larger than the first diameter D 1  by a first diameter difference, ΔD 1 =D 2 −D 1 . In various embodiments, the second smoothing step  508  is completed and a determination is made whether a desired smoothness within the passageway is achieved  510 . If the desired smoothness is achieved, the second progression of spheres is removed from the passageway and the process  500  is terminated  520 . 
     If the desired smoothing is not achieved, a third smoothing step  512  contemplates developing a third progression of spheres having a third diameter, D 3 , within the passageway. As described above with reference to  FIGS.  4 A,  4 B and  4 C , the third diameter D 3  is larger than the second diameter D 2  by a second diameter difference, ΔD 2 =D 3 −D 2 . In various embodiments, the third smoothing step  512  is completed and a determination is made whether a desired smoothness within the passageway is achieved  514 . If the desired smoothness is achieved, the third progression of spheres is removed from the passageway and the process  500  is terminated  520 . If the desired smoothing is not achieved, subsequent smoothing steps  516  are performed as may be required, using spheres having progressively larger diameters, D i , (i=4, N), until the desired smoothness is achieved, at which point the spheres having an Nth diameter, D N , are removed. 
     Referring now to  FIG.  6   , a series of steps is illustrated whereby a component  600  undergoes a finishing process following initial fabrication through, for example, additive manufacture. In various embodiments, the component  600  includes a passageway  602  that may be similar to the component  200  described above with reference to  FIG.  2   , including having an undesirable degree of surface roughness. In various embodiments, the passageway  602  is straight or substantially straight, such that the passageway includes no curves along its length. The passageway  602  extends from a first end  604  to a second end  606  and is defined by an inner surface  608  that, in various embodiments, is generally circular in cross section from the first end  604  to the second end  606 . In various embodiments, the inner surface  608  may be defined by an average diameter  610 , prior to smoothing, that takes into account the surface roughness along a length of the passageway  602  or at least a portion thereof. 
     In various embodiments, a first ball, identified with the numeral “1,” is inserted into the passageway  602  at the first end  604 , followed sequentially by a second ball, identified with the numeral “2,” a third ball, identified with the numeral “3,” and a fourth ball, identified with the numeral “4.” Each sphere has a progressively larger diameter, such that D 4 &gt;D 3 &gt;D 2 &gt;D 1 . Subsequent spheres, having progressively larger diameters, D i , (i=5, N) may follow, as may be required. In various embodiments, the progression of spheres having progressively larger diameters D i  (i=1,N) is used to smooth the inner surface  608  until a desired smoothness is achieved. In various embodiments, where the material comprising the component  600  is sufficiently soft, the progression of spheres having progressively larger diameters D i  (i=1,N) may also be used to enlarge the diameter of the passageway  602  from the average diameter  610  following initial fabrication of the component  600  to a final diameter  614 . In various embodiments, following the final sphere being inserted—e.g., Sphere  4  having diameter D 4 —a rod  612  may be employed to urge the final sphere and any preceding spheres remaining within the passageway  602  out the second end  606  of the passageway  602 . In various embodiments, progressively larger spheres may follow to affect a desired smoothness or enlargement. In various embodiments, the difference between sphere diameters has a value equal to one (1) to ten (10) microns. In various embodiments, each of the spheres comprises a metallic composition having a hardness—e.g., a hardness measured by a Rockwell or Brinell scale—that is harder than the material surrounding the passageway. 
     In various embodiments, a source  616  of high pressure air may also be used to urge the spheres remaining in the passageway  602  out the second end  606 . In various embodiments, the rod  612 , which may be a flexible rod capable of negotiating curved passageways, or the source  616  of high pressure air, may be used with any of the other embodiments described above to remove one or more spheres remaining in a passageway—e.g., the passageway  302  referred to above with reference to  FIGS.  3 A,  3 B and  3 C  or the passageway  402  referred to above with reference to  FIGS.  4 A,  4 B and  4 C —following smoothing or diameter increasing processes. In various embodiments, spheres having smaller diameters than the spheres remaining in a straight or curved passageway may be used to urge any spheres remaining in the passageway out an exit portion of the passageway. 
     Finally, it should be understood that any of the above described concepts can be used alone or in combination with any or all of the other above described concepts. Although various embodiments have been disclosed and described, one of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. Accordingly, the description is not intended to be exhaustive or to limit the principles described or illustrated herein to any precise form. Many modifications and variations are possible in light of the above teaching. 
     Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials. 
     Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment”, “an embodiment”, “various embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.