Abstract:
A vertical support system includes a first articulated leg assembly configured to carry a first load, the first articulated leg assembly being selectively movable between a first retracted configuration and a first loaded configuration and a second articulated leg assembly configured to carry a second load substantially kinematically identical to the first articulated leg assembly, the second articulated leg assembly being selectively movable between a second retracted configuration and a second loaded configuration. The arrangement of axis of rotations and offset angles of the first and/or second lees of each articulated leg assembly may produce a lateral width ratio. A first vertical footprint of the first articulated leg assembly overlaps a second vertical footprint of the second articulated leg assembly when the leg assemblies are retracted.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND 
     Retractable vertical support systems, such as retractable aircraft landing gear, may extend over a lateral maximum width while retracted that exceeds a desired lateral width. In some cases, the excessive lateral maximum width may require landing gear enclosures that protrude laterally beyond a desired fuselage lateral width. Similarly, retractable vertical support systems may extend a longitudinal maximum length while retracted that exceeds a desired longitudinal length. 
     SUMMARY 
     In some embodiments of the disclosure a vertical support system is provided that comprises: a first articulated leg assembly configured to carry a first load, the first articulated leg assembly being selectively movable between a first refracted configuration and a first loaded configuration; and a second articulated leg assembly configured to carry a second load substantially kinematically identical to the first articulated leg assembly, the second articulated leg assembly being selectively movable between a second retracted configuration and a second loaded configuration; wherein a lateral width ratio is equal to a value of less than about 0.6, the lateral width ratio being defined as a ratio of (1) a minimum lateral width between the lateral extents of the first wheel assembly and the second wheel assembly when the first articulated leg assembly is in the first retracted configuration and the second articulated leg assembly is in the second refracted configuration to (2) a maximum lateral width between the lateral extents of the first wheel assembly and the second wheel assembly when the first articulated leg assembly is in the first loaded configuration and the second articulated leg assembly is in the second loaded configuration. 
     In other embodiments of the disclosure, a vertical support system is provided that comprises: a first articulated leg assembly configured to carry a first load, the first articulated leg assembly being selectively movable between a first refracted configuration and a first loaded configuration; and a second articulated leg assembly configured to carry a second load substantially kinematically identical to the first articulated leg assembly, the second articulated leg assembly being selectively movable between a second retracted configuration and a second loaded configuration; wherein the first articulated leg assembly and the second articulated leg assembly are located as mirror images of each other while the first articulated leg assembly is in the first loaded configuration and the second articulated leg assembly is in the second loaded configuration; and wherein the first articulated leg assembly and the second articulated leg assembly are not located as mirror images of each other while the first articulated leg assembly is in the first retracted configuration and the second articulated leg assembly is in the second retracted configuration. 
     In yet other embodiments of the disclosure, a retractable vertical support system is provided that comprises: a first articulated leg assembly comprising a first primary axis of rotation and a first primary plane coincident with the first primary axis, wherein the first articulated leg assembly is selectively movable between a first extended configuration and a first retracted configuration; and a second articulated leg assembly substantially kinematically similar to the first articulated leg assembly, the second articulated leg assembly comprising a second primary axis of rotation substantially fixed relative to the first primary axis of rotation and substantially parallel to the first primary axis of rotation, the second articulated leg assembly comprising a second primary plane coincident with the second primary axis and substantially parallel to the first primary plane, wherein the second articulated leg assembly is selectively movable between a second extended configuration and a second retracted configuration; wherein when the first articulated leg assembly is in the first retracted configuration, substantially all of the first articulated leg assembly is located between the first primary plane and the second primary plane; wherein when the second articulated leg assembly is in the second retracted configuration, substantially all of the second articulated leg assembly is located between the first primary plane and the second primary plane; wherein when the first articulated leg assembly is in the first extended configuration, substantially all of the first articulated leg assembly is located exterior to the space between the first primary plane and the second primary plane; wherein when the second articulated leg assembly is in the second extended configuration, substantially all of the second articulated leg assembly is located exterior to the space between the first primary plane and the second primary plane; wherein the first articulated leg assembly extends a first extended maximum radial distance from the first primary axis of rotation when the first articulated leg assembly is in the first extended configuration, wherein the first articulated leg assembly extends a first retracted maximum radial distance from the first primary axis of rotation when the first articulated leg assembly is in the first retracted configuration, and wherein the first extended maximum radial distance is greater than the first retracted maximum radial distance; wherein the second articulated leg assembly extends a second extended maximum radial distance from the second primary axis of rotation when the second articulated leg assembly is in the second extended configuration, wherein the second articulated leg assembly extends a second retracted maximum radial distance from the second primary axis of rotation when the second articulated leg assembly is in the second retracted configuration, and wherein the second extended maximum radial distance is greater than the second retracted maximum radial distance; and wherein the distance between the first primary plane and the second primary plane is less than each of the first extended maximum radial distance and the second extended maximum radial distance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description: 
         FIG. 1  is an orthogonal bottom view of a portion of an aircraft comprising a vertical support system in a loaded configuration according to an embodiment of the disclosure; 
         FIG. 2  is an orthogonal front view of a portion of the aircraft of  FIG. 1  with the vertical support system in a loaded configuration; 
         FIG. 3  is an oblique view of a portion of the aircraft of  FIG. 1  with the vertical support system in a retracted configuration; 
         FIG. 4  is an orthogonal bottom view of a portion of the aircraft of  FIG. 1  showing a support of the vertical support system; 
         FIGS. 5A-5G  are oblique views showing both a first retractable system of the vertical support system of  FIG. 1  and a second retractable system of the vertical support system of  FIG. 1  in retracted configurations, first extended configurations, second extended configurations, third extended configurations, fourth extended configurations, fifth extended configurations, and loaded configurations, respectively; 
         FIGS. 6A-6C  are oblique views of both the first retractable system and the second retractable system, the first retractable system, and the second retractable system, respectively, in each of the configurations of  FIGS. 5A-5G , with the retracted configurations and loaded configurations in solid lines and intermediate configurations in broken lines; 
         FIGS. 7A-7G  are orthogonal front views showing both the first retractable system and the second retractable system in retracted configurations, first extended configurations, second extended configurations, third extended configurations, fourth extended configurations, fifth extended configurations, and loaded configurations, respectively; 
         FIGS. 8A-8C  are orthogonal front views of both the first retractable system and the second retractable system, the first retractable system, and the second retractable system, respectively, in each of the configurations of  FIGS. 7A-7G , with the retracted configurations and loaded configurations in solid lines and intermediate configurations in broken lines; 
         FIGS. 9A-9G  are orthogonal left views showing both the first retractable system and the second retractable system in retracted configurations, first extended configurations, second extended configurations, third extended configurations, fourth extended configurations, fifth extended configurations, and loaded configurations, respectively; 
         FIGS. 10A-10C  are orthogonal left views of both the first retractable system and the second retractable system, the first retractable system, and the second retractable system, respectively, in each of the configurations of  FIGS. 9A-9G , with the retracted configurations and loaded configurations in solid lines and intermediate configurations in broken lines; 
         FIGS. 11A-11G  are orthogonal top views showing both the first retractable system and the second retractable system in retracted configurations, first extended configurations, second extended configurations, third extended configurations, fourth extended configurations, fifth extended configurations, and loaded configurations, respectively; 
         FIGS. 12A-12C  are orthogonal top views of both the first retractable system and the second retractable system, the first retractable system, and the second retractable system, respectively, in each of the configurations of  FIGS. 11A-11G , with the retracted configurations and loaded configurations in solid lines and intermediate configurations in broken lines; 
         FIGS. 13A-13G  are orthogonal bottom views showing both the first retractable system and the second retractable system in retracted configurations, first extended configurations, second extended configurations, third extended configurations, fourth extended configurations, fifth extended configurations, and loaded configurations, respectively; and 
         FIGS. 14A-14C  are orthogonal bottom views of both the first retractable system and the second retractable system, the first retractable system, and the second retractable system, respectively, in each of the configurations of  FIGS. 13A-13G , with the retracted configurations and loaded configurations in solid lines and intermediate configurations in broken lines. 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and/or methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. 
     In some cases, it may be desirable to provide a vertical support system, such as aircraft landing gear, that is retractable into a compact spatial envelope. In some embodiments of the disclosure, a vertical support system is provided that comprises two kinematically identical articulated leg assemblies that may be retracted and/or folded into a compact spatial envelope. In some embodiments, the compact spatial envelope may be located primarily within a fuselage of an aircraft so that a lateral width of the fuselage may be reduced and/or so that no enclosures exterior to the fuselage are needed to house the retracted vertical support system. 
     Referring to  FIGS. 1-3 , a portion of an aircraft  100  according to an embodiment of the disclosure is shown. Aircraft  100  may be described as generally comprising a front  102 , rear  104 , left  106 , right  108 , top  110 , and bottom  112  and the following description and associated drawings may generally utilize directional indications to assist in identifying the directional orientation of the aircraft  100  and/or components of the aircraft  100  without the requirement that such an indication is an absolute identification of a directional extent of the aircraft  100 . In other words, the above described directional indications are intended to generally clarify orientations of the components of the aircraft  100  relative to each other and to provide context to the associated figures. The same directional indicators are utilized in the discussion and associated figures that comprise the aircraft  100  and/or components of the aircraft  100  to provide a consistent frame of reference throughout the disclosure. 
     The aircraft  100  further comprises a longitudinal axis  114 , a lateral axis  116 , and a vertical axis  118 . The lateral axis  116  generally extends longitudinally in a front-rear direction relative to the aircraft  100 . The longitudinal axis  114  generally extends laterally in a left-right direction relative to the aircraft  100 . The vertical axis  118  generally extends vertically in a top-bottom direction relative to the aircraft  100 . The longitudinal axis  114 , lateral axis  116 , and vertical axis  118  intersect each other at an origin  120  and may generally be described as defining a three dimensional Cartesian coordinate system. The aircraft  100  further comprises a lateral bisection plane  122 , a longitudinal bisection plane  124 , and a vertical bisection plane  126 . The lateral bisection plane  122  is generally coincident with the longitudinal axis  114  and the vertical axis  118 . The longitudinal bisection plane  124  is generally coincident with the lateral axis  116  and the vertical axis  118 . The vertical bisection plane  126  is generally coincident with the lateral axis  116  and longitudinal axis  114 . 
     While the axes  114 ,  116 , and  118  and bisection planes  122 ,  124 , and  126  are generally defined to reflect a traditional aircraft coordinate system, the location of the origin  120  relative to the aircraft  100  and the orientation of the axes  114 ,  116 , and  118  relative to the aircraft  100  and/or to a primary direction of forward movement of the aircraft  100  may be described differently without impact to the functionality of the aircraft  100  and/or the components of the aircraft  100  disclosed herein. In other words, unless otherwise noted herein, the defined orientations of the axes  114 ,  116 , and  118  and bisection planes  122 ,  124 , and  126  are provided as a frame of reference against which the aircraft  100  and the components of the aircraft  100  may be consistently described. 
     Referring now to  FIGS. 1 and 2 ,  FIG. 1  is an orthogonal bottom view of a portion of the aircraft  100  and  FIG. 2  is an orthogonal front view of the same portion of the aircraft  100 . The aircraft  100  generally comprises a fuselage  128  that comprises a bay  130  generally defined by bay walls  132  that generally bound a bay space  134 . The aircraft  100  further comprises a vertical support system  200  configured to selectively vertically support at least a portion of the aircraft  100 , a component of the aircraft  100 , and/or an object at least partially carried by the aircraft  100 . In alternative embodiments, the fuselage  128  may comprise no bay  130 , the bay  130  may be differently shaped, and/or the bay space  134  may be otherwise defined as a portion of an aircraft other than the fuselage  128 . Regardless the shape, size, and/or location of the bay  130 , the bay space  134  is configured to selectively allow ingress of at least a portion of the vertical support system  200  into the bay space  134  and/or egress of at least a portion of the vertical support system  200  out of the bay space  134 . 
     The vertical support system  200  may be referred to as a landing gear system and/or other weight bearing support system. The vertical support system  200  generally comprises a structural support  202  and two retractable systems  204 ′,  204 ″ connected to the support  202 . As explained herein, in some embodiments, the similarities between the retractable systems  204 ′,  204 ″, physically, spatially, and/or kinematically, allow for the use of the reference number modifier, ′, or a “prime symbol,” to denote a first and/or left side system or component while the use of the reference number modifier, ″, or a “double prime symbol,” denotes a second and/or right side system or component. The retractable systems  204 ′,  204 ″ may generally comprise components configured to enable selective retraction movements and extension movements that increase and decrease, respectively, an amount of the retractable systems  204 ′,  204 ″ located within the bay space  134 . In the embodiment shown, the retractable system  204 ″ comprises substantially identical components to the components of the retractable system  204 ′. Accordingly, in the embodiment shown, the retractable system  204 ″ is also substantially kinematically identical to the retractable system  204 ′. For example, in the embodiment shown, any of the components of the retractable system  204 ′ may be supplanted for use of the related component of the retractable system  204 ″ without changing the shape, size, structure, functionality, and/or kinematic behavior of the retractable system  204 ″. 
     The retractable system  204 ′ and the retractable system  204 ″ may not be complete mirror images of each other about the lateral bisection plane  122 . In the embodiment shown, identical components of the retractable system  204 ′ and retractable system  204 ″ are vertically aligned with each other. Further, the retractable system  204 ″ is laterally located relative to the lateral bisection plane  122 , as viewed from the rear, in the same way the retractable system  204 ′ is laterally located relative the lateral bisection plane  122 , as viewed from the front. Similarly, the retractable system  204 ″ is longitudinally located relative to the longitudinal bisection plane  124 , as viewed from the right, in the same way the retractable system  204 ′ is longitudinally located relative the longitudinal bisection plane  124 , as viewed from the left. While the retractable system  204 ′ and the retractable system  204 ″ are identical both physically and kinematically in this embodiment, alternative embodiments may comprise physical differences between components and/or kinematic differences between the retractable system  204 ′ and the retractable system  204 ″. 
     Still referring to  FIGS. 1 and 2 , the retractable system  204  comprises an articulated leg assembly  300  and components for kinematically restraining and selectively causing movement of the articulated leg assembly  300 . The articulated leg assembly  300  generally comprises an upper leg  302  movably connected to the structural support  202  and a lower leg  304  movably connected to the upper leg  302 . The retractable system  204  further comprises an actuator  206 , a lower linkage  208 , a bay door  210 , a door linkage  212 , and a wheel assembly  214 . In some alternative embodiments, the wheel assembly  214  may comprise a tricycle type wheel assembly. The actuator  206  is selectively controllable to vary in length and is connected between the structural support  202  and the upper leg  302 . In some embodiments, the actuator  206  may additionally serve to provide primary shock absorption and/or damping of applied loads, such as, but not limited to, landing loads. The lower linkage  208  controls the movement of the lower leg  304  relative to the upper leg  302  and comprises a compressible feature and is connected between the structural support  202  and the lower leg  304 . The bay door  210  may be hinged to the fuselage  128  to selectively enclose the bay space  134 . The door linkage  212  is connected between the upper leg  302  and the bay door  210 . The wheel assembly  214  is generally carried by the lower leg  304  and comprises a brake  216  and a tire  218 . 
     Most generally, the vertical support system  200  is operable to selectively move the retractable system  204  between a retracted configuration and an extended configuration. In the retracted configuration, the vertical support system  200  may comprise a greatly reduced maximum lateral width as compared to the maximum lateral width of the vertical support system  200  in an extended configuration. The retracted configuration may be a configuration in which the vertical support system  200  is selectively stowed when not configured for vertically supporting at least a portion of the aircraft  100 , a component of the aircraft  100 , and/or an object at least partially carried by the aircraft  100 . In some embodiments, the vertical support system  200  may require no sponsons or other structures that laterally protrude beyond the fuselage  128  to receive the retracted vertical support system  200 . In some embodiments, the above-described retraction capability may provide a more stealth aircraft  100 , a reduced radar signature of the aircraft  100 , and/or a reduction in aerodynamic drag of the aircraft  100 . 
     The extended configuration may be a configuration in which the vertical support system  200  is selectively deployed when configured for vertically supporting at least a portion of the aircraft  100 , a component of the aircraft  100 , and/or an object at least partially carried by the aircraft  100 . It will be appreciated that while the retracted configuration and extended configuration may represent configurations near opposing ends of a continuous spectrum of possible configurations, in some embodiments, the retracted configuration and the extended configuration may not represent the most retracted configuration and the most extended configuration, but rather, may represent a desired retracted configuration and desired extended configuration around which some features and/or functionality of the vertical support system  200  are designed. 
     Still referring to  FIGS. 1 and 2 , vertical support system  200  is shown with the retractable systems  204  in a loaded configuration. The loaded configuration comprises the retractable system  204  being extended to the extended configuration and then loaded with weight of at least a portion of the aircraft  100 , a component of the aircraft  100 , and/or an object at least partially carried by the aircraft  100 . In this embodiment, the vertical support system  200  is generally designed so that when the vertical support system  200  is loaded with an appropriate apportionment of aircraft related weight, the tires  218 ′,  218 ″ substantially mirror each other&#39;s lateral and longitudinal locations. When the aircraft related weight is greater than or less than that described above and/or when the vertical support system  200  is under additional impact loads or reduced loads, the tires  218 ,  218 ″ may not reach and/or maintain the above-described lateral and/or longitudinal mirroring. 
     Referring now to  FIG. 3 , an oblique view of the portion of the aircraft  100  is shown with the vertical support system  200  in a retracted configuration and with the bay doors  210 ′,  210 ″ closed. In this embodiment, the entirety of the retractable systems  204 ′,  204 ″ are housed within the bay space  134 . 
     Referring now to  FIG. 4 , an orthogonal bottom view of the portion of the aircraft  100  is shown with all but the structural support  202  of the vertical support system  200  removed. The structural support  202  generally comprises a laterally extending brace  220 , two vertically downward extending arms  222 , two sets of lower linkage upper standoffs  224 , two sets of upper actuator standoffs, and two sets of upper leg standoffs  228 . The arms  222  generally extend down from the lateral ends of the brace  220 . Each of the arms  222  generally carries a set of the lower linkage upper standoffs  224  and a set of the upper leg standoffs  228 . The lower linkage upper standoffs  224  and the upper leg standoffs  228  generally protrude toward the lateral bisection plane  122  and generally comprise plate-like structures with through holes for accepting associated pins and/or fasteners. The holes of the set of upper leg standoffs  228  are generally coaxial and are configured to receive a complementary primary pin  306 . In this embodiment, the holes of the set of upper leg standoffs  228  and the primary pin  306  are each coaxial with a primary axis of rotation  308  about which the upper leg  302  may rotate as described herein. The primary axes of rotation  308 ′,  308 ″ are substantially parallel to each other and intersect the lateral bisection plane  122  at a primary axis longitudinal incidence angle  310 . In this embodiment, the primary axis longitudinal incidence angle  310  may be equal a value in a range of about 0 degrees to about 24 degrees, about 6 degrees to about 18 degrees, about 10 degrees to about 14 degrees, or equal to about 12 degrees. The lower linkage upper standoffs  224  similarly comprise plate-like structures with through holes for accepting pins and/or fasteners about which the lower linkage  208  may rotate. In this embodiment, the upper actuator standoffs are laterally opposite the upper leg standoffs  228 , are located near the intersection of the brace  220  and the arm  222 , and are vertically higher than the upper leg standoffs  228 . The upper actuator standoffs similarly comprise plate-like structures comprising through holes configured for accepting pins and/or fasteners about which the actuator  206  may rotate. 
     Still referring to  FIGS. 1-4 , the upper leg  302  generally comprises a proximal end configured for attachment to the upper leg standoffs  228  through the use of the primary pin  306  (see  FIG. 4 ). In this embodiment, the upper leg  302  generally extends from the primary axis of rotation  308  at an upper leg offset angle  312  (see  FIG. 13G ) equal to a value in a range of about 50 degrees to about 90 degrees, about 60 degrees to about 80 degrees, about 69.2 degrees to about 73.2 degrees, or equal to about 71.2 degrees relative to the primary axis of rotation  308  as viewed from below. The upper leg  302  generally terminates at a distal end configured for attachment to a proximal end of the lower leg  304 . In this embodiment, the upper leg  302  and the lower leg  304  each comprise coaxial through holes configured to receive a secondary pin  314 . The through holes of the distal end of the upper leg  302 , the through holes of the proximal end of the lower leg  304 , and the secondary pin  314  are coaxially aligned with a secondary axis of rotation  316  about which the lower leg  304  may rotate. In this embodiment, the secondary axis of rotation  316  generally intersects the lateral bisection plane  122  at a secondary axis longitudinal incidence angle  318  (see  FIGS. 11G and 13G ). In this embodiment, the secondary axis longitudinal incidence angle  318  may be equal to a value in the range of about 0 degrees to about 30 degrees, about 10 degrees to about 20 degrees, about 13.7 degrees to about 17.7 degrees, or equal to about 15.7 degrees as viewed from below. In this embodiment, the lower leg  304  generally extends from the secondary axis of rotation  316  at a lower leg offset angle  320  (see  FIGS. 11G and 13G ) relative to the secondary axis of rotation  316 . In this embodiment, the lower leg offset angle  320  may be equal to a value in a range of about 70 degrees to about 90 degrees, about 75 degrees to about 88 degrees, about 81.5 degrees to about 85.5 degrees, or equal to a value of about 83.5 degrees as viewed from below. Further, a wheel assembly axis of rotation  230  may generally be orthogonal to the lateral bisection plane  122  as viewed from below when the retractable system  204  is in the loaded configuration. Still further, while the primary axis of rotation  308  is substantially parallel to the vertical bisection plane  126  as viewed from the left, the secondary axis of rotation  316  generally intersects the vertical bisection plane  126  at a secondary axis vertical incidence angle  322  as viewed from the left. In this embodiment, the secondary axis vertical incidence angle  322  may be equal to a value in a range of about 0 degrees to about 8 degrees, about 1 degree to about 7 degrees, about 2 degrees to about 6 degrees, or equal to a value of about 4 degrees as viewed from the left. 
     Referring again to  FIGS. 1 and 2 , the upper leg  302  comprises lower actuator standoffs  324  configured to receive a pin and/or other fasteners to provide a movable connection between the actuator  206  and the upper leg  302 . Similarly, the lower leg  304  comprises lower linkage lower standoffs  326  configured to receive a pin and/or other fasteners to provide a movable connection between the lower linkage  208  and the lower leg  304 . Because the actuator  206  comprises a selectively variable length between the upper actuator standoffs of the structural support  202  and the lower actuator standoffs  324  of the upper leg  302 , retractable system  204  may be variably controlled over a range of configurations generally between the retracted configuration of  FIG. 3  and the loaded configuration of  FIGS. 1 and 2 . 
     Referring now to  FIGS. 5A-5G , a series of oblique views of the retractable systems  204 ′,  204 ″ are shown in a retracted configuration ( FIG. 5A ), a plurality of intermediate configurations in order of increasing stages of extension ( FIGS. 5B-5E ), an extended configuration ( FIG. 5F ), and a loaded configuration ( FIG. 5G ). 
     Referring now to  FIG. 6A , an oblique bloom display of the retractable systems  204 ′,  204 ″ in each of the configurations of  FIGS. 5A-5F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 6B , an oblique bloom display of the retractable system  204 ′ in each of the configurations of  FIGS. 5A-5F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 6C , an oblique bloom display of the retractable system  204 ″ in each of the configurations of  FIGS. 5A-5F  and with the various configurations spatially overlapping each other is shown. 
     Referring now to  FIGS. 7A-7G , a series of orthogonal front views of the retractable systems  204 ′,  204 ″ are shown in a retracted configuration ( FIG. 7A ), a plurality of intermediate configurations in order of increasing stages of extension ( FIGS. 7B-7E ), an extended configuration ( FIG. 7F ), and a loaded configuration ( FIG. 7G ). It will be appreciated that, in this embodiment, the orthogonal rear views of the retractable systems  204  are not provided because they would be identical to orthogonal front views of the retractable systems  204 . 
     Referring now to  FIG. 8A , an orthogonal front bloom display of the retractable systems  204 ′,  204 ″ in each of the configurations of  FIGS. 7A-7F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 8B , an orthogonal front bloom display of the retractable system  204 ′ in each of the configurations of  FIGS. 7A-7F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 8C , an orthogonal front bloom display of the retractable system  204 ″ in each of the configurations of  FIGS. 7A-7F  and with the various configurations spatially overlapping each other is shown. 
     Referring now to  FIGS. 9A-9G , a series of orthogonal left views of the retractable systems  204 ′,  204 ″ are shown in a retracted configuration ( FIG. 9A ), a plurality of intermediate configurations in order of increasing stages of extension ( FIGS. 9B-9E ), an extended configuration ( FIG. 9F ), and a loaded configuration ( FIG. 9G ). It will be appreciated that, in this embodiment, the orthogonal right views of the retractable systems  204  are not provided because they would be identical to orthogonal left views of the retractable systems  204 . 
     Referring now to  FIG. 10A , an orthogonal left bloom display of the retractable systems  204 ′,  204 ″ in each of the configurations of  FIGS. 9A-9F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 10B , an orthogonal left bloom display of the retractable system  204 ′ in each of the configurations of  FIGS. 9A-9F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 10C , an orthogonal left bloom display of the retractable system  204 ″ in each of the configurations of  FIGS. 9A-9F  and with the various configurations spatially overlapping each other is shown. 
     Referring now to  FIGS. 11A-11G , a series of orthogonal top views of the retractable systems  204 ′,  204 ″ are shown in a retracted configuration ( FIG. 11A ), a plurality of intermediate configurations in order of increasing stages of extension ( FIGS. 11B-11E ), an extended configuration ( FIG. 11F ), and a loaded configuration ( FIG. 11G ). 
     Referring now to  FIG. 12A , an orthogonal top bloom display of the retractable systems  204 ′,  204 ″ in each of the configurations of  FIGS. 11A-11F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 12B , an orthogonal top bloom display of the retractable system  204 ′ in each of the configurations of  FIGS. 11A-11F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 12C , an orthogonal top bloom display of the retractable system  204 ″ in each of the configurations of  FIGS. 11A-11F  and with the various configurations spatially overlapping each other is shown. 
     Referring now to  FIGS. 13A-13G , a series of orthogonal bottom views of the retractable systems  204 ′,  204 ″ are shown in a retracted configuration ( FIG. 13A ), a plurality of intermediate configurations in order of increasing stages of extension ( FIGS. 13B-13E ), an extended configuration ( FIG. 13F ), and a loaded configuration ( FIG. 13G ). 
     Referring now to  FIG. 14A , an orthogonal bottom bloom display of the retractable systems  204 ′,  204 ″ in each of the configurations of  FIGS. 13A-13F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 14B , an orthogonal bottom bloom display of the retractable system  204 ′ in each of the configurations of  FIGS. 13A-13F  and with the various configurations spatially overlapping each other is shown. Referring now to  FIG. 14C , an orthogonal bottom bloom display of the retractable system  204 ″ in each of the configurations of  FIGS. 13A-13F  and with the various configurations spatially overlapping each other is shown. 
     In operation, the retractable systems  204  and wheel assemblies  214  may initially be stowed in the bay space  134  and the bay  130  may be substantially enclosed by bay doors  210  when the retractable systems  204  are in the retracted configuration shown in  FIG. 3 . Next, the actuators  206  may be increased in length to move the retractable systems  204  to the intermediate configuration shown in  FIGS. 5A ,  7 A,  9 A,  11 A, and  13 A. Next, the actuators  206  may be further increased in length to move the retractable systems  204  to the intermediate configuration shown in  FIGS. 5B ,  7 B,  9 B,  11 B, and  13 B. Next, the actuators  206  may be increased in length to move the retractable systems  204  to the intermediate configuration shown in  FIGS. 5C ,  7 C,  9 C,  11 C, and  13 C. Next, the actuators  206  may be further increased in length to move the retractable systems  204  to the intermediate configuration shown in  FIGS. 5D ,  7 D,  9 D,  11 D, and  13 D. Next, the actuators  206  may be further increased in length to move the retractable systems  204  to the intermediate configuration shown in  FIGS. 5E ,  7 E,  9 E,  11 E, and  13 E. Next, the actuators  206  may be further increased in length to move the retractable systems  204  to the extended configuration shown in  FIGS. 5F ,  7 F,  9 F,  11 F, and  13 F. The extended configuration may be associated with the position of the retractable systems  204  while the aircraft  100  remains airborne and is preparing for landing. Next, the aircraft  100  may land and come to rest, thereby causing loading of the retractable systems  204  and resulting in configuration of the retractable systems  204  in the loaded configuration shown in  FIGS. 5G ,  7 G,  9 G,  11 G, and  13 G. In some cases, the above actions may generally be performed in reverse, such as during a take-off sequence of the aircraft  100 , to once again stow the retractable systems  204  and wheel assemblies  214  in the bay space  134 . 
     Referring back to  FIGS. 9A-9G  and  FIGS. 11A-11G , it can be seen that, in this embodiment, the tires  218  are not longitudinally aligned in any of the retracted configuration and intermediate configurations of  FIGS. 9A-9F  and  FIGS. 11A-11F . However, upon achievement of the loaded configuration of  FIG. 9G  and  FIG. 11G , the tires  218  are substantially longitudinally aligned with each other. In other words, while the tires  218  are not mirror images of each other about the lateral bisection plane  122  in the retracted configuration and intermediate configurations, the tires  218  are mirror images of each other about the lateral bisection plane  122  when the retractable systems  204  are in the loaded configuration. While the wheel system  214  may be the load that is carried while the retractable system  204  retracts and extends in this embodiment, in alternative embodiments, a different load may be carried by the retractable system  204 . For example, in some embodiments, a load such as, but not limited to, a weapon, gun, camera, sensor, display, loud speaker, missile, water cannon, and/or any other suitable load may be carried by the retractable system. 
     Now referring back to  FIGS. 11A-12A  and  FIGS. 13A-14A , the retractable systems  204 ′,  204 ″ may comprise a minimum lateral width  232  associated with the retracted configuration and a maximum lateral width  234  associated with the loaded configuration. In some embodiments, a lateral width ratio of the minimum lateral width  232  to the maximum lateral width  234  may be equal to a value in a range of about 0.2 to about 0.6, about 0.3 to about 0.5, or equal to a value of about 0.4. 
     Still referring to  FIGS. 11A ,  11 G,  13 A, and  13 G, the articulated leg assemblies  300  may comprise primary planes  328  that are coincident with the primary axis of rotation  308  and that are substantially parallel relative to each other. In this embodiment, substantially all of the articulated leg assemblies  300 , but for the portions of the upper leg  302  that is not located between the primary axis of rotation  308  and the secondary axis of rotation  316 , are located between the primary planes  328  when the articulated leg assemblies  300  are in the retracted configuration. Further, in this embodiment, substantially all of the articulated leg assemblies  300 , but for the portions of the upper leg  302  that is not located between the primary axis of rotation  308  and the secondary axis of rotation  316 , are located exterior to the space between the primary planes  328  when the articulated leg assemblies  300  are in the extended configuration and/or the loaded configuration. In some embodiments, a distance between the primary planes  328  may be less than a maximum combined length of the upper leg  302  and lower leg  304  as measured orthogonally from the primary axis of rotation  308  with the articulated leg assembly  300  in the extended configuration and/or the loaded configuration. 
     In some cases, the above-described compact storage of the retractable systems  204  may be at least partially attributable to the asymmetrical and/or general lack of laterally mirrored spatial orientation of the retractable systems  204 ′,  204 ″ relative to the lateral bisection plane  122 . Still further, it will be appreciated that the above-described lateral width ratio may be affected by adjusting one or more of a length of the upper leg  302 , a length of the lower leg  304 , the primary axis longitudinal incidence angle  310 , the upper leg offset angle  312 , the secondary axis longitudinal incidence angle  318 , the lower leg offset angle  320 , the secondary axis vertical incidence angle  322 , and/or any other variable that may alter the kinematic behavior of the retractable systems  204 . In some cases, the retractable systems  204  may generally achieve compact retracted configurations in part as a function of the retractable systems  204 ′,  204 ″ not only folding to reduce the individual vertical footprints but also as a function of the retractable systems  204 ′,  204 ″ comprising vertical footprints that vertically overlap each other. 
     At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R l , and an upper limit, R u , is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R l +k*(R u −R l ), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Unless otherwise stated, the term “about” shall mean plus or minus 10 percent. Of the subsequent value. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention.