Patent Publication Number: US-2020298965-A1

Title: Retainer for segmented annular heat shield

Description:
FIELD 
     The present disclosure relates to wheel assemblies, and more specifically to retaining a segmented annular heat shield of a wheel assembly. 
     BACKGROUND 
     Aircraft typically include landing gear for supporting the aircraft above a ground surface and for allowing the aircraft to move relative to the ground surface while remaining supported by the ground surface. The landing gear may include one or more wheel assemblies. Most wheel assemblies include a brake assembly to decelerate or park the aircraft. Aircraft braking, especially during landing, tends to generate significant heat that can damage components of the wheel assembly if such components are not properly shielded. While annular heat shields provide thermal protection, the logistics of assembling, repairing, and/or replacing conventional annular heat shields are burdensome. 
     SUMMARY 
     In various embodiments, the present disclosure provides a retainer for a segmented annular heat shield of a wheel. The retainer may include a first end, a second end opposite the first end, and a body extending between the first end and the second end. Both the first end and the second end may be configured to be coupled to at least one of the wheel and a torque bar. Further, the body may include opposing longitudinal sides configured to respectively engage and secure a respective heat shield segment of the segmented annular heat shield. 
     In various embodiments, each of the opposing longitudinal sides comprises a groove for receiving an edge of the respective heat shield segment. In various embodiments, the first end defines an aperture for receiving a torque bar bolt. In such embodiments, the aperture may be a first aperture, the second end may comprise a flange, the flange may define a second aperture through which a torque bar pin of a torque bar is configured to extend, and the flange may extend substantially perpendicular to the body such that the first aperture and the second aperture lie in perpendicular planes. In various embodiments, at least one of the body, the first end, and the second end of the retainer includes a shoulder configured to engage a torque bar to maintain at least one of a position and orientation of the retainer relative to the torque bar. 
     Also disclosed herein, according to various embodiments, is a wheel assembly. The wheel assembly may include an inboard wheel portion having a rim and a disk. A radially inward surface of the rim and an inboard surface of the disk may define a wheel well cavity configured to house a brake assembly. The wheel assembly may also include a torque bar (e.g., a torque bar of the brake assembly) mounted to the inboard wheel portion. Further, the wheel assembly may include a retainer coupled to the torque bar and disposed radially between the torque bar and the radially inward surface of the rim of the inboard wheel portion. The retainer may include a first end, a second end opposite the first end, and a body extending between the first end and the second end. The body may include opposing longitudinal sides configured to respectively engage and retain a respective heat shield segment of a segmented annular heat shield. 
     In various embodiments, each of the opposing longitudinal sides of the retainer comprises a groove for receiving an edge of the respective heat shield segment. In various embodiments, the wheel assembly further includes a torque bar bolt coupling an inboard end of the torque bar to the rim of the inboard wheel portion, wherein the first end of the retainer defines an aperture through which the torque bar bolt extends. In various embodiments, the aperture is a first aperture, the second end comprises a flange, an outboard end of the torque bar comprises a torque bar pin, the flange defines a second aperture through which the torque bar pin of the torque bar extends, and the flange extends substantially perpendicular to the opposing longitudinal sides such that the first aperture and the second aperture lie in perpendicular planes. The flange may extend radially inward. 
     In various embodiments, the second end of the retainer is radially inward of the first end. In various embodiments, the wheel assembly further includes a torque bar spacer coupled to an inboard end of the torque bar, wherein the torque bar spacer comprises fasteners for securing the respective heat shield segment to the inboard end of the torque bar. The retainer divides a volume between the torque bar and the radially inward surface of the rim of the wheel portion into two air gaps, according to various embodiments. The wheel assembly may further include the segmented annular heat shield, In such embodiments, the torque bar may be a first torque bar of a plurality of torque bars circumferentially distributed around the inboard wheel portion, the retainer may be a first retainer of a plurality of retainers respectively disposed radially between the plurality of torque bars and the radially inward surface of the rim of the inboard wheel portion, and the respective heat shield segment may be one heat shield segment of a plurality of heat shield segments of the segmented annular heat shield. The plurality of heat shield segments may be circumferentially distributed around the inboard wheel portion and disposed and secured between circumferentially adjacent retainers of the plurality of retainers. In various embodiments, respective inboard ends of the plurality of heat shield segments collectively form a chin ring. 
     Also disclosed herein, according to various embodiments, is a method of assembling a wheel assembly. The method may include mounting a first torque bar to an inboard wheel portion of the wheel assembly such that a first retainer is disposed between the first torque bar and a radially inward surface of a rim of the inboard wheel portion. The method may further include mounting a second torque bar to the inboard wheel portion of the wheel assembly such that a second retainer is disposed between the second torque bar and the radially inward surface of a rim of the inboard wheel portion, wherein the second torque bar is circumferentially spaced apart from the first torque bar. Still further, the method may include engaging lateral edges of a heat shield segment with the first retainer and the second retainer. 
     In various embodiments, engaging the lateral edges of the heat shield with the first retainer and the second retainer comprises axially sliding, in an outboard direction, the heat shield segment between the first retainer and the second retainer such that the lateral edges of the segment slide through grooves respectively defined by the first retainer and the second retainer. In various embodiments, the method further includes, before mounting the first torque bar to the inboard wheel portion, inserting a torque bar pin of the first torque bar through an aperture defined in a flange at an end of the first retainer. In such embodiments, mounting the first torque bar to the inboard wheel portion may comprise inserting the first torque bar pin into a torque bar retention slot defined in a web of the inboard wheel portion of the wheel assembly. 
     The forgoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates an aircraft having multiple landing gear, in accordance with various embodiments; 
         FIG. 1B  illustrates a brake assembly, in accordance with various embodiments; 
         FIG. 2  is a perspective view of a wheel assembly, in accordance with various embodiments; 
         FIG. 3  is a perspective view of a retainer for a segmented annular heat shield, in accordance with various embodiments; 
         FIG. 4  is a perspective view of a torque bar and a retainer for a segmented annular heat shield coupled to an inboard wheel portion of a wheel assembly, in accordance with various embodiments; 
         FIG. 5  is an axial view of a retainer, with a torque bar not shown, securing adjacent heat shield segments of a segmented annular heat shield, in accordance with various embodiments; 
         FIGS. 6A and 6B  show a heat shield segment being installed between adjacent retainers, in accordance with various embodiments; 
         FIG. 7  shows a cross-section of a torque bar and a retainer disposed radially between the torque bar and a rim of an inboard wheel portion, in accordance with various embodiments; and 
         FIG. 8  is a schematic flow chart diagram of a method of assembling a wheel assembly, in accordance with various embodiments. 
     
    
    
     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 detailed description and claims when considered in connection with the drawing figures. 
     DETAILED DESCRIPTION 
     The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary 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 logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. 
     As used herein, a first component that is “radially outward” of a second component means that the first component is positioned at a greater distance away from a common axis than the second component. A first component that is “radially inward” of a second component means that the first component is positioned closer to the common axis than the second component. In the case of components that rotate circumferentially about a common axis, a first component that is radially inward of a second component rotates through a circumferentially shorter path than the second component. As used herein, “distal” refers to the direction outward, or generally, away from a reference component. As used herein, “proximal” and/or “proximate” refer to a direction inward, or generally, towards the reference component. 
     Referring now to  FIG. 1A , in accordance with various embodiments, an aircraft  10  includes landing gear, such as a left main landing gear  12 , a right main landing gear  14 , and nose landing gear  16 . The left main landing gear  12 , right main landing gear  14 , and nose landing gear  16  typically support the aircraft  10  when the aircraft  10  is not flying, thereby allowing the aircraft  10  to taxi, take off, and land without damage. In various embodiments, the left main landing gear  12  includes a first wheel  13 A and a second wheel  13 B coupled by an axle  20 . In various embodiments, the right main landing gear  14  includes a first wheel  15 A and a second wheel  15 B coupled by an axle  22 . In various embodiments, the nose landing gear  16  includes a first nose wheel  17 A and a second nose wheel  17 B coupled by an axle  24 . In various embodiments, the aircraft  10  comprises any number of landing gear(s), and each landing gear comprises any number of wheels. In various embodiments, the left main landing gear  12 , right main landing gear  14 , and nose landing gear  16  are retracted when the aircraft  10  is in flight. In various embodiments, one or more of the left main landing gear  12 , right main landing gear  14 , and nose landing gear  16  extends from an underside of a fuselage  28  of the aircraft  10 , or from an underside of the wings  30  thereof. 
     In various embodiments, the aircraft  10  also includes a brake system that is applied to one or more of the wheels  13 A,  13 B,  15 A,  15 B,  17 A,  17 B of one or more of the respective left main landing gear  12 , right main landing gear  14 , and/or nose landing gear  16 . Such brake systems of the aircraft  10  typically comprise a collection of assemblies, subsystems, and/or units that produce output signals for controlling the braking force and/or torque applied at one or more of the wheels  13 A,  13 B,  15 A,  15 B,  17 A,  17 B. Such brake systems typically communicate with the brakes of the left main landing gear  12 , right main landing gear  14 , and/or nose landing gear  16 , and each brake is typically mounted to each wheel  13 A,  13 B,  15 A,  15 B,  17 A,  17 B in order to apply and release braking forces thereon. In various embodiments, the brakes of the aircraft  10  further include a non-rotatable wheel support, the wheels  13 A,  13 B,  15 A,  15 B,  17 A,  17 B mounted to the wheel support for rotation, and a brake disk stack. 
     Referring now to  FIG. 1B , a brake assembly  110  for an aircraft, such as aircraft  10  of  FIG. 1A , is provided, in accordance with various embodiments. The brake assembly  110  interfaces with a bogie axle  112  and a wheel  114  (e.g., the wheels  13 A,  13 B,  15 A,  15 B,  17 A,  17 B of  FIG. 1A ) of the aircraft  10 . The wheel  114  may include a hub  116 , a disk  120  (also referred to as a web portion of a wheel), and a rim  118  (also referred to as a flange portion of a wheel). The wheel assembly and/or brake assembly  110  generally includes a torque take-out assembly (also referred to as a torque plate or a torque plate assembly)  122 , one or more torque bars  124 , a wheel rotational axis  126 , a wheel well cavity  128 , an actuator  130 , multiple brake rotors  32 , multiple brake stators  34 , a pressure plate  36 , an end plate  38 , a heat shield  140 , multiple torque bar bolts  148 , a torque bar pin  151 , a torque bar retention slot  152 , multiple rotor lugs  154 , and multiple stator slots  156 , according to various embodiments. 
     Brake disks (e.g., the interleaved brake rotors  32  and brake stators  34 ) are disposed in the wheel well cavity  128  that is generally and collectively defined by the rim  118 , the disk  120 , and the hub  116 . The brake rotors  32  are typically secured to the torque bars  124 , which are coupled to the rim  118  of the wheel  114 , for rotating with the wheel  114 . The brake stators  34  are typically engaged with the torque take-out assembly (e.g., torque plate assembly)  122 . At least one actuator  130  is typically operable to compress the interleaved brake rotors  32  and brake stators  34  for stopping the aircraft  10  of  FIG. 1A . In the embodiment of  FIG. 1B , the actuator  130  is shown as a hydraulically actuated piston. The pressure plate  36  and end plate  38  are disposed at opposite ends of the interleaved brake rotors  32  and brake stators  34 . 
     Through compression of the brake rotors  32  and brake stators  34  between the pressure plate  36  and end plate  38 , the resulting frictional contact slows, stops, and/or prevents rotation of the wheel  114 . The torque take-out assembly  122  is typically secured to a stationary portion of a landing gear truck, such as a bogie beam or other landing gear strut, such that the torque take-out assembly  122  and brake stators  34  are prevented from rotating during braking of the aircraft  10  of  FIG. 1A . The brake rotors  32  and brake stators  34  are typically fabricated from various materials, such as, for example carbon materials. The brake disks typically withstand and dissipate the heat generated from contact between the brake disks while braking the aircraft  10  of  FIG. 1A . 
     According to various embodiments and with reference to  FIG. 2 , a wheel assembly  200 , which may be similar to wheels  13 A,  13 B,  15 A,  15 B,  17 A,  17 B of  FIG. 1A , is provided. The wheel assembly  200  may be a split wheel assembly and thus may comprise an inboard wheel portion  201  and an outboard wheel portion  202 . Wheel portions  201 ,  202 , for example, may be referred to as wheel halves. The wheel assembly  200  may be implemented with any landing gear of the aircraft  10  (e.g., any of the landing gears mentioned above with reference to  FIG. 1A ), and the wheel assembly  200  may be an inner/inboard wheel assembly or an outer/outboard assembly. Although numerous details are included herein pertaining to the implementation of the wheel assembly  200  in an aircraft, one skilled in the art will realize that a similar wheel assembly may be used in other vehicles, such as cars or motorcycles, and thus the scope of the present disclosure is not necessarily limited to aircraft wheel assemblies. 
     In various embodiments, inboard wheel portion  201  of wheel assembly  200  comprises a hub  206 , a disk  205 , and a rim  204 . Radially outward surface of the rim  204  may define a tube-well  203 . That is, tube-well  203  may be defined by respective flange sections of the inboard wheel portion  201  and the outboard wheel portion  202 . The rim  204 /tube-well  203  may be configured to receive a tire and may form a seal with tire to allow pressurized air to inflate the tire. In various embodiments, the inboard wheel portion  201  also includes a radially outward extending lip  208  located at an inboard end of the inboard wheel portion  201 , and the outboard wheel portion  202  may also include a similar radially outward extending lip or rim  209  located at an outboard end of the outboard wheel portion  202 . 
     In various embodiments, wheel assembly  200  includes tie bolts  207  that extend through the disk  205  to hold together the wheel portions  201 ,  202 . Radially inward of, and generally defined by, the radially inward surface of the rim  204  is the wheel well cavity (e.g.,  128  in  FIG. 1B ) where the brake assembly  110  is disposed. That is, the wheel well cavity  128  ( FIG. 1B ) generally refers to the volume bound by the rim  204  and the disk  205 , according to various embodiments. The wheel assembly  200  includes, according to various embodiments, one or more retainers  210  and one or more torque bars  220 . In  FIG. 2 , some of the torque bars  220  are in order to clearly show the retainers  210 . Generally, each retainer  210  is disposed radially between a respective torque bar  220  and the radially inward surface of the rim  204 , according to various embodiments. 
     For example, an inboard end of each torque bar  220  may be mounted to the rim  204  using a torque bar bolt  221  and an outboard end of each torque bar  220  may be mounted to the disk  205  via insertion of a torque bar pin  222  into a torque bar retention slot  152  of the disk  205 . Each retainer  210  may be coupled to a respective torque bar  220 , as described in greater detail below. Generally, the retainers  210  may be configured to engage and secure heat shield segments, such as heat shield segments  230 A,  230 B,  230 C. That is, a plurality of heat shield segments  230 A,  230 B,  230 C collectively form a segmented annular heat shield, and each of these segments  230 A,  230 B,  230 C is held in place between circumferentially adjacent retainers  210 , according to various embodiments. Additionally, the retainers  210  may provide a heat shielding benefit, as described in greater detail below. In various embodiments, the each heat shield segment  230 A,  230 B,  230 C is a laminated dimpled foil metallic heat shield. 
     In various embodiments, and with reference to  FIG. 3 , a perspective view of the retainer  210  is provided. The retainer  210  may include a first end  211 , a second end  212  opposite the first end  211 , and a body  215  extending between the first end  211  and the second end  212 . The body  215  may include opposing longitudinal sides  217  that are configured to respectively engage and secure a respective heat shield of the segmented annular heat shield. For example, each of the opposing longitudinal sides  217  of the body  215  of the retainer  210  may include/define a groove for receiving an edge of the respective heat shield segment. 
     In various embodiments, and with reference to  FIGS. 2 and 3 , the first end  211  and the second end  212  of the retainer  210  are both configured to be coupled to the wheel (rim  204  or disk  205 ) and/or the torque bar  220 . For example, the first end  211  of the retainer  210  may define a first aperture  213  for receiving the torque bar bolt  221 , and thus the torque bar bolt  221  may extend through both the inboard end of the torque bar and the first end  211  of the retainer  210 . The second end  212  of the retainer  210  may comprise a flange  216 , and the flange  216  may define a second aperture  214  through which the torque bar pin  222  of the torque bar  220  is inserted. That is, the second aperture  214  defined in the flange  216  may fit around the torque bar pin  222  in order to secure the second end  212  relative to the torque bar  220 . In various embodiments, the flange extends radially inward. Accordingly, because the body  215  of the retainer  210  may extend substantially axially (e.g., parallel to the rotational axis of the wheel assembly  200 ), the flange  216  may be substantially perpendicular to the body  215 , and thus the first aperture  213  and the second aperture  214  may lie in substantially perpendicular planes. In various embodiments, the retainer  210  also includes a shoulder  218 , which may be positioned at the first end  211 , at the second end  212 , or along the body  215 , and the shoulder  218  may be configured to engage the torque bar  220  in order to maintain the retainer  210  in a desired position and/or orientation relative to the torque bar  220 . 
     In various embodiments, and with reference to  FIG. 4 , a view of the retainer  210  disposed between the torque bar  220  and the radially inward surface of the rim  204  of the inboard wheel portion  201  ( FIG. 2 ) is provided. In  FIG. 2  the heat shield segments have yet to be installed, and further details pertaining to the installation/assembly method are provided below with reference to  FIG. 8 . In various embodiments, the wheel assembly  200  may further include a torque bar spacer  240  coupled to an inboard end of the torque bar  220 . The first end  211  of the retainer  210  may be compressed between the inboard end of the torque bar  220  and the torque bar spacer  240  (compression may be produced via the preloaded/tensioned torque bar bolt  221 ). The torque bar spacer  240  may include one or more fasteners  241  for securing the respective heat shield segments to the inboard end of the torque bar  220 . That is, in response to the individual heat shield segments being installed between adjacent retainer  210 , the inboard edge of the heat shield segments may be secured from sliding by coupling said segments to the torque bar spacer  240  using fasteners  241 . 
     In various embodiments, and with reference to  FIG. 5 , an axial-looking view of the retainer  210  is provided, with adjacent heat shield segments  230 A,  230 B being secured to the retainer  210 . That is, corresponding edges of the heat shield segments  230 A,  230 B are received into the longitudinal sides  217  (e.g., grooves) of the retainer  210 , according to various embodiments. Engagement between the edges of the heat shield segments  230 A,  230 B and the longitudinal sides  217  of the retainer  210  may be an interference fit. In  FIG. 5 , the torque bar is omitted in order to clearly show the elements/features of the retainer  210 . Thus,  FIG. 5  shows how the second aperture  214  defined in the flange  216  at the second end  212  of the retainer is aligned with the torque bar retention slot  152  defined in the disk  205  (e.g., web) of the inboard wheel portion  201  ( FIG. 2 ), according to various embodiments. 
     In various embodiments, and with reference to  FIGS. 6A and 6B , multiple heat shield segments  230 A,  230 B,  230 C are provided, with one of the heat shield segments ( 230 B) shown in a partially installed state. More specifically,  FIGS. 6A and 6B , according to various embodiments, show how the individual heat shield segments may be installed. With the retainers  210  and the torque bars  220  installed/mounted to the inboard wheel portion  201  ( FIG. 2 ), the individual heat shield segments, such as heat shield segment  230 B, may be aligned and engaged with the longitudinal sides  217  of the circumferentially adjacent retainers  210  and may be subsequently slid along the longitudinal sides  217  of the retainers  210  in an axially outboard direction until an outboard edge of the heat shield segment  230 B is adjacent the disk  205  of the inboard wheel portion  201 . Accordingly, the wheel assembly  200  may include a plurality of pairs of torque bars  220  and retainers  210 , with each pair being circumferentially distributed around the radially inward surface of the rim  204  ( FIG. 2 ) and with each heat shield segment of the plurality of heat shield segments  230 A,  230 B,  230 C being disposed and secured between circumferentially adjacent retainers  210 . 
     In various embodiments, and with reference to  FIGS. 2, 6A, and 6B , the inboard edges  231 A,  231 B,  231 C of the plurality of heat shield segments  230 A,  230 B,  230 C collectively form a chin ring of the wheel assembly. The chin ring may be hoop/ring that extends farther inboard (see  FIG. 6B ) than the inboard lip  208  of the inboard wheel portion  201  of the wheel assembly  200 . The chin ring may provide a thermal barrier to prevent heat radiation from reaching a tire disposed around the wheel in the tube-well  203 . 
     In various embodiments, and with reference to  FIG. 7 , a cross-section of the torque bar  220  and the retainer  210  is provided. In various embodiments, a longitudinal axis of the retainer  210  may not be exactly parallel with a longitudinal axis of the torque bar  220 . Said differently, the second end  212  of the retainer  210  may be radially inward of the first end  211 . Such a configuration may be to ensure clearance between the second end  212  of the retainer  210  and the rim  204  of the wheel. Further, such a configuration may promote convective heat flow out of the inboard side of the wheel. That is, hot airflow may engage the angled/inclined surface of the retainer  210  and may be directed inboard along the retainer  210  to escape the wheel cavity. In various embodiments, the retainer  210  may be oriented in a slightly radially inward direction from the first end  211  to the second end  212  in order to more securely engage the outboard ends of the heat shield segments. Further, the retainer  210  may, in addition to providing a means for retaining the heat shield segments, function as a heat shield by dividing the volume radially outward of the torque bar  220  into two volumes. That is, the retainer  210  may define two air gaps  219 A,  219 B between the torque bar  220  and the radially inward surface of the rim  204 . 
     In various embodiments, and with reference to  FIG. 8 , a schematic flow chart diagram of a method  890  of assembling a wheel assembly is provided. The method  890  may include mounting a first torque bar to a wheel with a first retainer disposed between the torque bar and the wheel at step  892 . The method  890  may further include mounting a second torque bar to wheel with a second retainer disposed between the second torque bar and the wheel at step  894 . Still further, the method  890  may include engaging lateral edges of a heat shield segment with the first retainer and the second retainer at step  896 . 
     In various embodiments, steps  892  and  894  include radially positioning the first and second retainers, respectively, between the respective torque bars and a radially inward surface of an inboard wheel portion of the wheel. In various embodiments, step  896  includes axially sliding, in an outboard direction, the heat shield segment between the first retainer and the second retainer such that the lateral edges of the segment slide through grooves respectively defined by the first retainer and the second retainer. In various embodiments, the method  890  further includes, before step  892 , inserting a torque bar pin of the first torque bar through an aperture defined in a flange at an end of the first retainer. In such embodiments, mounting the first torque bar to the inboard wheel portion may comprise inserting the first torque bar pin into a torque bar retention slot defined in a web of the inboard wheel portion of the wheel assembly. 
     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.” It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/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. All ranges and ratio limits disclosed herein may be combined. 
     Moreover, where a phrase similar to “at least one of A, B, and 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. 
     Also, any reference to attached, fixed, connected, coupled or the like may include permanent (e.g., integral), removable, temporary, partial, full, and/or any other possible attachment option. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials. 
     The steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. 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. Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present disclosure. 
     Any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. Surface shading lines may be used throughout the figures to denote different parts or areas but not necessarily to denote the same or different materials. In some cases, reference coordinates may be specific to each figure. 
     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 is intended to invoke 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.