Patent Publication Number: US-11658384-B1

Title: Antenna apparatus mounting system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/959,148, filed Jan. 9, 2020, the disclosure of which is hereby expressly incorporated by reference herein in its entirety. 
    
    
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one aspect, a mounting system for an antenna apparatus having a housing enclosing antenna components and a leg extending from the housing includes a base securable to a surface and configured to receive a bottom portion of the leg and a locking assembly defined at the bottom portion of the leg and moveable between a first position, wherein the leg is removable from the base, and a second position, wherein the leg is lockingly secured within the base. 
     In another aspect, an antenna apparatus includes a housing enclosing antenna components, a leg extending from the housing, a base securable to a surface and configured to receive a bottom portion of the leg, and a locking assembly defined at the bottom portion of the leg and moveable between a first position, wherein the leg is removable from the base, and a second position, wherein the leg is lockingly secured within the base. 
     In another aspect, a method of mounting an antenna apparatus to a surface, wherein the antenna apparatus includes a housing enclosing antenna components and a leg extending from the housing, includes securing a base to a surface, disposing a bottom portion of the leg in the base, moving a locking assembly from a first position, wherein the leg is removable from the base, into a second position, wherein the leg is lockingly secured within the base. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG.  1    is a not-to-scale diagram illustrating a simple example of communication in a satellite communication system; 
         FIG.  2    is an isometric view of an antenna apparatus shown mounted to a surface with a mounting system; 
         FIG.  3    is a top isometric exploded view of the mounting system of  FIG.  2   ; 
         FIG.  4    is a bottom isometric exploded view of the mounting system of  FIG.  2   ; 
         FIG.  5    a partial isometric exploded view of the a locking assembly of the mounting system of  FIG.  2   ; 
         FIG.  6    is a cross-sectional view of the mounting system of  FIG.  2    shown in an unlocked configuration; and 
         FIG.  7    is a cross-sectional view of the mounting system of  FIG.  2    shown in a locked configuration. 
     
    
    
     DETAILED DESCRIPTION 
     Systems are currently being deployed to provide high-bandwidth, low-latency network communication via constellations of satellites in low Earth orbit (LEO).  FIG.  1    is a not-to-scale schematic diagram that illustrates a simple example of communication in such a system  100 . An endpoint terminal  102  is installed at a house, a business, a vehicle, or another location where it is desired to obtain communication access via a network of satellites. A communication path is established between the endpoint terminal  102  and a first satellite  104 . In the illustrated embodiment, the first satellite  104 , in turn, establishes a communication path with a gateway terminal  106 . In another embodiment, the first satellite  104  may establish a communication path with another satellite prior to communication with a gateway terminal  106 . The gateway terminal  106  is physically connected via fiber optic, Ethernet, or another physical connection to a ground network  108 . The ground network  108  may be any type of network, including the Internet. 
     Embodiments of the present disclosure are directed to configurations for endpoint terminals  102  (or user terminals) used for network communications to and from a satellite. In particular, the exemplary embodiments of the present disclosure are directed to an antenna apparatus  200  including an antenna system designed for sending and/or receiving radio frequency signals to and/or from a satellite or a constellation of satellites. 
     Referring to  FIG.  2   , the antenna apparatus  200  includes a housing  202 , within which an antenna aperture (not shown) and other electronic components are disposed. In accordance with embodiments of the present disclosure, the antenna apparatus  200  and its housing  202  are designed for durability and reliability in an outdoor environment. 
     In the illustrated embodiment, the antenna apparatus  200  includes a single leg  204  extending from the housing  202 . The leg  204  may be defined by a generally hollow cylindrical or tubular body  206 , although other configurations may be used. With a hollow configuration, any necessary wiring or electrical connections may extend into and within the interior of the body  206  of the leg  204  up into the housing  202  of the antenna apparatus  200 . 
     The leg  204  may extend from the housing  202  at substantially a center point of the housing  202 . The center mount location allows for symmetry and balance when the antenna apparatus  200  is mounted to a surface. However, in other embodiments, the leg  204  may be attached to the housing  202  at an offset location depending on the configuration and weighting of the antenna apparatus  200 . Moreover, in other embodiments, more than one leg may extend from the housing  202 . 
     The lower end of the leg  204  is mountable to a mounting surface S to position the antenna apparatus  200  for an unimpeded view of the sky. As non-limiting examples, the antenna apparatus  200  may be mounted on the roof or wall of a building, a tower, a natural structure, a ground surface, or to any other appropriate mounting surface having unimpeded communication with the sky. After the antenna apparatus  200  is mounted on an external surface of a building, moreover, any cabling can be connected to an outlet external to the building or it can be routed through an opening into an outlet internal to the building. 
     The lower end of the leg  204  is mountable to a mounting surface S via a mounting system  210 . In general, the mounting system  210  includes a base  214  securable to a surface S and configured to receive a bottom portion of the leg  204 , and a locking assembly  218  defined at the bottom portion of the leg  204  and moveable between a first position, wherein the leg  204  is removable from the base  214 , and a second position, wherein the leg  204  is lockingly secured within the base  214 . 
     Referring to  FIGS.  3 - 6   , an exemplary embodiment of the mounting system  210  will now be described in greater detail. As noted above, the mounting system  210  includes a base  214  securable to a surface and configured to receive a bottom portion of the leg  204 . As may best be seen by referring specifically to  FIGS.  3  and  4   , the base  214  is a suitable shape, size, and configuration to be secured to a mounting surface and to provide stability for the antenna apparatus  200  when mounted to the surface through the base  214 . 
     Although the base  214  may be any suitable configuration, in the illustrated embodiment, the base  214  is of a generally truncated pyramidal shape having first, second, third, and fourth sides  220   a ,  220   b ,  220   c , and  220   d  extending upwardly from corresponding bottom edges  222   a ,  222   b ,  222   c , and  222   d . First, second, third, and fourth corners  224   a ,  224   b ,  224   c , and  224   d  are defined between respective bottom edges  222   a / 222   b ,  222   b / 222   c ,  222   c / 222   d , and  222   d / 222   a . At least one, and preferably first, second, third, and fourth mounting holes  226   a ,  226   b ,  226   c , and  226   d  are defined at each respective corner  224   a ,  224   b ,  224   c , and  224   d  of the base  214  and are configured for receiving a fastener, such as a bolt, for mounting the base  214  to a surface. A cavity (not labeled) may be defined at each corner for providing better access to the mounting hole. Additional holes and receptacles may extend through the base to accommodate any wiring coming from a building, etc. 
     The sides  222   a - 222   d  terminate at their upper edges in a truncated vertex  224 . The truncated vertex  224  defines the top opening of a substantially centered leg receptacle  228  extending along a height of an interior of the base  214 , as shown in  FIGS.  6 - 7   . The leg receptacle  228  is configured to receive a portion of the locking assembly  218  extending from the leg  204 . In that regard, in some aspects, the locking assembly  218  can be understood to be an extension of a bottom portion of the body  206  of the leg  204 . 
     Referring specifically to  FIGS.  3 - 7   , the locking assembly  218  defined at the bottom portion of the leg  204  and configured to lockingly secure the leg  204  within or to the base  214  will now be described. In general, the locking assembly  218  includes a cam assembly  230  configured to interface with an interference assembly  234  for moving the interference assembly  234  between a first, unlocked position (see  FIG.  6   ), wherein the leg  204  may be moved into and out of the leg receptacle  228 , and a second locked position, wherein the leg  204  is lockingly secured within the leg receptacle  228  (see  FIG.  7   ). 
     In one embodiment, the interference assembly  234  is generally configured as a cylindrical extension of the body  206  at the bottom of the leg  204  that is configured to expand, at least in part, when received within the leg receptacle  228  to define an interference or press fit between the leg  204  and the interior of the base  214 . In the depicted exemplary embodiment, the interference assembly may be defined by a first hollow cylinder  240  having an upper cylinder portion  240   a  configured to be secured within the bottom interior of the leg body  206  (such as by threading), and a lower cylinder portion  240   b  configured to extend within the leg receptacle  228  of the base  214 . In that regard, the lower cylinder portion  240   b  has a first outer diameter less than the inner diameter of the leg receptacle  228  such that the lower cylinder portion  240   b  may be received within the leg receptacle  228 . Moreover, the lower cylinder portion  240   b  has a length extending along a majority of the height of the base  214  when received within the leg receptacle  228 . 
     An annular shoulder  242  may separate the upper and lower cylinder portions  240   a  and  240   b  and may be receivable within a correspondingly-shaped receptacle or bore  243  defined at the upper end of the base  214  surrounding the leg receptacle  228 . In this manner, the annular shoulder  242  may rest against an interior shoulder defined by the bore  243  to appropriately locate the lower cylinder portion  240   b  within the leg receptacle  228  when initially inserted. The annular shoulder  242  also provides a hard stop against which the lower end of the leg  204  may abut when the upper cylinder portion  240   a  is received therein. 
     The interference assembly  234  further includes a second hollow cylinder  244  coaxially located (i.e., nested) on the lower cylinder portion  240   b  of the first hollow cylinder  240 . In that regard, the second hollow cylinder  244  has an inner diameter at least slightly greater than the outer diameter of the lower cylinder portion  240   b  of the first hollow cylinder  240 , and a length similar to the lower cylinder portion  240   b  of the first hollow cylinder  240 . Moreover, the second hollow cylinder  244  has an outer diameter at least slightly less than the inner diameter of the leg receptacle  228 . In this manner, the second hollow cylinder  244 , while nested on the lower cylinder portion  240   b  of the first hollow cylinder  240 , may be received within the leg receptacle  228  of the base  214 . In that regard, when received within the leg receptacle  228  of the base  214 , the second hollow cylinder  244  is circumferentially disposed between the lower cylinder portion  240   b  and the base  214 . 
     The second hollow cylinder  244  has an axial length substantially similar to the lower cylinder portion  240   b . In that regard, the second hollow cylinder  244  is coaxially disposed on the lower cylinder portion  240   b  such that it extends between the annular shoulder  242  and a bottom end of the lower cylinder portion  240   b . The second hollow cylinder  244  is retained in its axial position on the lower cylinder portion  240   b  by the annular shoulder  242  and a cap  252  moveable secured to the bottom end of the lower cylinder portion  240   b  (described in more detail below). 
     The second hollow cylinder  244  is configured to radially expand when the interference assembly  234  is moved into the locking position. More particularly, the second hollow cylinder  244  moves between a first, unexpanded radial configuration when the interference assembly  234  is in the first, unlocked position (see  FIG.  6   ), and a second, expanded radial configuration when the interference assembly  234  is in the second, locked position (see  FIG.  7   ). In the second, expanded radial configuration, the outer diameter of the second hollow cylinder  244  is increased (compared to the first, unexpanded radial configuration) to define an interference or press fit between the second hollow cylinder  244  and the base  214 . 
     The second hollow cylinder  244  may be made from a suitably deformable material to support its radial expansion. Moreover, in some embodiments, an elongated slot may extend along the length of the second hollow cylinder  244  to facilitate radial expansion of the second hollow cylinder  244 , like a split ring. Further, in some embodiments, the second hollow cylinder  244  may have a high friction outer surface, such as a knurled outer surface (not shown), to increase the locking interface between the second hollow cylinder  244  and the base  214  when expanded. 
     The second hollow cylinder  244  may be moved between the first, unexpanded radial configuration and the second, expanded radial configuration through a suitable wedge assembly  248 . The wedge assembly  248  is generally configured to apply an interior radial expansion force against the cylindrical wall of the second hollow cylinder  244  to radially expand the second hollow cylinder  244 . With the second hollow cylinder  244  radially expanded, the interference assembly  234  securely locks the leg  204  within the base  214 . 
     In the depicted exemplary embodiment, the wedge assembly  248  is defined in part by a cap  252  that is configured to be wedged between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b  of the first hollow cylinder  240 . The cap  252  has an overall cylindrical shape defined by a circular base  254  and an annular rim  256  extending upwardly from a perimeter of the base  254 . The circular base  254  and the annular rim  256  collectively define a cylindrical cap receptacle  258  configured to receive the bottom end of the lower cylinder portion  240   b  when the cap  252  is moved upwardly into engagement with the lower cylinder portion  240   b.    
     When the cap  252  is engaged with the lower cylinder portion  240   b , the annular rim  256  of the cap  252  extends between the exterior surface of the lower cylinder portion  240   b  and the interior of the second hollow cylinder  244 . More specifically, the annular rim  256  is configured to be wedged between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b . When wedged between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b , the annular rim  256  imposes a radial expansion force on the second hollow cylinder  244 . 
     To help facilitate the radial expansion of the second hollow cylinder  244  at the wedged interface, the annular rim  256  includes an exterior ramp surface  260  that tapers inwardly (toward the center of the cap  252 ) as it extends from the base  254 . With the exterior surface of the annular rim  256  tapered inwardly in this manner, the annular rim  256  has an overall annular wedge shape that can slide into wedged engagement between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b . To that end, the annular rim  256  may be hereinafter referred to as the first annular wedge  256  having an exterior ramp surface  260 . 
     The exterior ramp surface  260  of the first annular wedge  256  is moveable into mating, sliding engagement with a correspondingly-shaped interior ramp surface  262  of a second annular wedge  264  defined at the lower end of the second hollow cylinder  244 . As the cap  252  is moved upwardly into engagement with the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b , the exterior ramp surface  260  of the cap  252  slides along the interior ramp surface  262  of the second hollow cylinder  244 . The interface of the exterior and interior ramp surfaces  260  and  262  facilitates sliding, axial movement of the cap  252  relative to the second hollow cylinder  244 . 
     Moreover, as the cap  252  is moved into wedged engagement with the nested second hollow cylinder  244 /lower cylinder portion  240   b , the first annular wedge  256  exerts an outward radial expansion force on the second hollow cylinder  244  to radially expand the second hollow cylinder  244 . The lower cylinder portion  240   b  may be configured to react any inward radial force imposed by the annular rim  256  as it moves into wedged engagement with the nested second hollow cylinder  244 /lower cylinder portion  240   b . In a radially expanded state, the second hollow cylinder  244  is press fit within the base  214  to secure the leg  204  within the leg receptacle  228 . 
     It can be appreciated that when the first annular wedge  256  is moved upwardly into engagement with the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b , the cap  252  imposes a majority of the radial expansion force at the bottom of the second hollow cylinder  244 . In that regard, a suitable interface may be defined at the upper ends of the nested second hollow cylinder  244 /lower cylinder portion  240   b  to support radial expansion of the second hollow cylinder  244 . For instance, the lower cylinder portion  240   b  of the first hollow cylinder  240  may include an exterior, radially expanding third annular wedge  266  extending around it upper perimeter (just below the annular shoulder  242 ). 
     An exterior ramp surface (not labeled) of the third annular wedge  266  is slidably mateable with a correspondingly-shaped interior ramp surface (not labeled) of a fourth annular wedge  268  defined at the upper end of the second hollow cylinder  244 . When mated (i.e., nested), the fourth annular wedge  268  of the second hollow cylinder  244  may slide against the third annular wedge  266  of the lower cylinder portion  240   b . In the least, the ramped interface between the upper ends of the second hollow cylinder  244  and the lower cylinder portion  240   b  may help reduce any mechanical stresses on the upper end of the second hollow cylinder  244  during radial expansion. 
     The cap  252  is pulled axially upwardly into wedged, mating engagement with the nested second hollow cylinder  244 /lower cylinder portion  240   b  through the cam assembly  230 . In the depicted exemplary embodiment, the cam assembly  230  is generally configured as a cam lever moveable between a first, unlocked position, wherein the cap  252  is in a first wedged position relative to the nested second hollow cylinder  244 /lower cylinder portion  240   b  ( FIG.  6   ), and a second, locked position, wherein the cap  252  is in a second, wedged position relative to the nested second hollow cylinder  244 /lower cylinder portion  240   b  ( FIG.  7   ). 
     In the first wedged position, the first annular wedge  256  of the cap  252  is located between the bottom ends of the nested second hollow cylinder  244 /lower cylinder portion  240   b  but exerts minimal to no radial expansion force on the second hollow cylinder  244 . However, the first annular wedge  256  of the cap  252  is positioned to be pulled axially upwardly into further wedged engagement with the nested second hollow cylinder  244 /lower cylinder portion  240   b . In that regard, a suitable initial radial clearance may be defined between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b  to facilitate axial movement of the cap  252  from the first wedged position into the second wedged position. In the depicted exemplary embodiment, the lower cylinder portion  240   b  may include a reduced diameter portion  259  at its bottom end that defines an initial radial separation or space between the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b . When in the first wedged position, the cap  252  may be pulled axially upwardly into the second, wedged position to exert a radial expansion force on the second hollow cylinder  244 . 
     The cam assembly  230  for selectively pulling the cap  252  up into the second, wedged position for radially expanding the second hollow cylinder  244  will now be described in detail. As noted above, the cam assembly  230  is generally configured as a cam lever moveable between a first, unlocked position ( FIG.  6   ) and a second, locked position ( FIG.  7   ). 
     Although any suitable cam assembly may be used, in the depicted exemplary embodiment, the cam assembly  230  includes a handle  270  extending from a cam head  274  that is pivotally secured to a cam pin  278  located inside the leg  204 . The handle  270  extends from the cam head  274  through an opening  280  in the leg  204  such that it may be grasped by a user to rotate the cam head  274  about an axis of the cam pin  278  between the unlocked and locked positions. 
     The axis of the cam pin  278  is substantially transverse to a longitudinal center axis of the leg  204 , and the handle  270  extends from the cam head  274  substantially transversely to the axis of the cam pin  278 . Moreover, in the first, unlocked position, the handle  270  extends through the opening  280  substantially transversely to the longitudinal axis of the leg  204 , and in the second, locked position, the handle  270  is in substantially parallel alignment with the longitudinal axis of the leg  204 . 
     A grasping portion  272  of the handle  270  may substantially abut against the leg  204  in the locked position (with suitable clearance therebetween, such as through a standoff, not labeled) to stow the handle  270  against the leg  204  after the leg  204  is secured within the base  214 . In that regard, the handle  270  may include a suitable bend, curvature, or contour between the grasping portion  272  and the cam head  274  to facilitate movement of the handle  270  between the unlocked and locked positions while connected to the cam head  274 . 
     As the cam head  274  is moved by the handle  270  from the unlocked position into the locked position, it pulls upwardly on the cap  252 , as noted above. In that regard, the cam head  274  is coupled to the cap  252  such that the cap  252  moves axially within the leg  204  as the cam head  274  is rotated between the unlocked and locked positions. In the depicted embodiment, the cap  252  is coupled to the cam head  274  through an anchor pin  276 . 
     At its upper end, the anchor pin  276  is transversely and pivotally connected to the cam pin  278 , and at its opposite, lower end, the anchor pin  276  is transversely coupled to the cap  252  (such as by threading or the like). In that regard, the anchor pin  276  extends through the axially aligned hollow interiors of the first and second hollow cylinders  240  and  244  along the length of the interference assembly  234 . As the cam head  274  is rotated into the locked position, as shown in  FIG.  7   , it imposes an axial pulling force on the anchor pin  276  to move the cap  252  axially upwardly into the second, wedged position. 
     The cam head  274  pivots against a pivot plate or washer assembly  282  as it is moved between the unlocked and locked positions. The washer assembly  282  is positioned substantially transversely to the axis of the anchor pin  276  to provide a surface against which the cam force of the cam head  274  may be opposed. In the depicted embodiment, the washer assembly  282  is received within an upper open end of the upper cylinder portion  240   a , and the anchor pin  276  passes through a central opening of the washer assembly  282 . 
     The washer assembly  282  may rest atop a biasing member, such as compression spring  286  to urge the washer assembly  282  up into engagement with the cam head  274 . The compression spring  286  is disposed within a bore  290  defined at the upper end of the upper cylinder portion  240   a . The bore  290  includes an interior, bottom annular shoulder  294  to oppose the compression force of the compression spring  286 . 
     The cam head  274  is configured to impose a downward cam force on the washer assembly  282  (against the force of the spring  286 ) when it is pivoted about the axis of the cam pin  278  into the locked position (see  FIG.  7   ). In that regard, the cam pin  278  passes through the cam head  274  at an off-center location to define an eccentric portion  275  of the cam head  274 . As the cam head  274  is pivoted about the axis of the cam pin  278  (through movement of the handle  270 ), the eccentric portion  275  moves down into engagement with the washer assembly  282  to apply downward pressure on the washer assembly  282 . 
     The washer assembly  282  opposes the downward cam force of the cam head  274  through the biasing force of the spring  286 . In that regard, as the eccentric portion  275  moves down into engagement with the washer assembly  282 , the spring  286  opposes the downward cam force and causes the cam pin  278  to translate vertically away from the washer assembly  282 . As the cam pin  278  moves vertically away from the washer assembly  282 , it pulls upwardly on the anchor pin  276 , which correspondingly pulls the cap  252  upwardly into the locked, second wedged position. After reaching the locked position, the opposing force of the spring  286  helps retain the eccentric portion  275  of the cam head  274  in engagement with the washer assembly  282  by pushing up on the washer assembly  282 . With the eccentric portion  275  secured in its locked position against the washer assembly  282 , the cap  252  is heled in its second, wedged position between the cylinders  240   b  and  244 . 
     To move the cam assembly  230  back into the unlocked position, the pulling force on the handle  270  must overcome the biasing force of the spring  286 . Specifically, when the pulling force on the handle  270  back down towards the unlocked position (see  FIG.  6   ) overcomes the biasing force of the spring  286 , the cam head  274  to may correspondingly pivot against the washer assembly  282  to move the eccentric portion  275  out of engagement with the washer assembly  282 . When the eccentric portion  275  moves out of engagement with the washer assembly  282 , the cam pin  278  and therefore the anchor pin  276  move axially downward, releasing the cap  252  from its second, wedged position between the cylinders  240   b  and  244 . 
     As can be appreciated from the foregoing, as the handle  270  and cam head  274  pivot into the locked position, the cam head  274  draws the washer assembly  282  and the cap  252  towards each other. The clamping distance of the cam assembly  230 , or the distance that the washer assembly  282  and cap  252  travel toward each other, is sufficient to move the first annular wedge  256  of the cap  252  into the second wedged position relative to the nested bottom ends of the second hollow cylinder  244  and the lower cylinder portion  240   b . In this second wedged position, the cap  252  applies a radial expansion force on the second hollow cylinder  244 , thereby lockingly securing the leg  204  within the leg receptacle  228 . 
     The clamping distance of the cam assembly  230  can be adjusted as needed to accommodate mounting systems having a different height or configuration. Moreover, it can be appreciated that the spring  286  helps accommodate tolerances of the mounting system  210 . For instance, the spring  286  may compress to allow the handle  270  and cam head  274  to be fully rotated into the locked position, which may not otherwise be possible due to tolerances in the base  214 , interference assembly  234 , cam assembly  230 , etc. 
     As noted above, the second hollow cylinder  244  may have a high friction exterior surface to increase the locking interface between the second hollow cylinder  244  and the base  214 . However, it can be appreciated that a high friction interface between the second hollow cylinder  244  and the base  214  is not desired when initially inserted the interference assembly  234  into the leg receptacle  228 . 
     In that regard, a sufficient radial clearance is initially defined between the unexpanded second hollow cylinder  244  and the interior of the leg receptacle  228  such that the high friction exterior surface does not grip against the interior of the base  214 . Accordingly, the second hollow cylinder  244  may be initially inserted into the leg receptacle  228  of the base  214  in its initial unexpanded (unlocked) state without having to overcome the friction force. Thereafter, when moved into the expanded (locked) position, the high friction exterior surface of the second hollow cylinder  244  grips against the interior surface of the leg receptacle  228  to further increase the locking interface between the interference assembly  234  and the leg receptacle. 
     However, it can further be appreciated that the interior surfaces of the interference assembly  234  need to be low friction to facilitate sliding movement relative to one another. For instance, the interior surface of the second hollow cylinder  244  and the exterior surface of the lower cylinder portion  240   b  of the first hollow cylinder  240  should be able to slide axially relative to one another during assembly of the interference assembly  234  and/or during radial expansion of the second hollow cylinder  244 . 
     However, with a low friction interface defined between the second hollow cylinder  244  and the lower cylinder portion  240   b , the second hollow cylinder  244  and the lower cylinder portion  240   b  may undesirably rotate relative to one another (about the center longitudinal axis of the interference assembly  234 ) during assembly and/or during use of the mounting system  210 . Accordingly, the interference assembly  234  may include an anti-rotation mechanism configured to substantially prevent the second hollow cylinder  244  from rotating relative to the lower cylinder portion  240   b  (and vice versa). 
     Referring to  FIG.  5   , in the depicted exemplary embodiment, the anti-rotation mechanism is defined by an axial protrusion  310  extending radially from the lower cylinder portion  240   b  that is axially receivable within a correspondingly shaped axial slot  314  extending along the second hollow cylinder  244 . In particular, the axial protrusion  310  extends radially from the third annular wedge  266  of the lower cylinder portion  240   b , and the axial slot  314  extends downwardly from the top edge of the second hollow cylinder  244 . In this manner, when the lower cylinder portion  240   b  is nested within the second hollow cylinder  244  with the protrusion  310  and slot  314  axially aligned, the protrusion  310  is received within the slot  314 . When the axial protrusion  310  is axially received within the slot  314 , the protrusion  310  and slot  314  interfere to prevent the second hollow cylinder  244  and lower cylinder portion  240   b  from rotating relative to one another. 
     Referring to  FIGS.  6  and  7   , the method and operation of the mounting system  210  for selectively locking the leg  204  within the base  214  will now be described. As can be seen in  FIG.  6   , the locking assembly  218  is initially in an unlocked state with the handle  270  extending substantially transversely from the body  206  of the leg  204 . When unlocked, the eccentric portion  275  of the cam head  274  is rotated out of engagement with the washer assembly  282 . The cap  252  is in the first wedged position but exerts minimal to no radial expansion force on the second hollow cylinder  244 . 
     In this unlocked state, the interference assembly  234  extending from the bottom of the leg  204  is axially inserted into leg receptacle  228  of the base  214 . Once disposed within the leg receptacle  228 , the handle  270  may be rotated upwardly into the locked position, rotating the eccentric portion  275  of the cam head  274  down into engagement with the washer assembly  282 . The washer assembly  282  reacts the downward force of the cam head  274  (through the biasing force of the spring  286 ), and the cam pin  278  translates upwardly. As the cam pin  278  moves upwardly, it pulls axially upwardly on the anchor pin  276  and therefore the cap  252 . The cap  252  is pulled up into the second wedged position where it imposes a radial expansion force on the second hollow cylinder  244  to secure the interference assembly  234  within the leg receptacle  228 . 
     While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives consistent with the present disclosure and the appended claims. 
     References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that 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. 
     Language such as “top”, “bottom”, “upper”, “lower”, “vertical”, “horizontal”, “lateral”, in the present disclosure is meant to provide orientation for the reader with reference to the drawings and is not intended to be the required orientation of the components or to impart orientation limitations into the claims. 
     In the drawings, some structural or method features may be shown in specific arrangements and/or orderings. However, it should be appreciated that such specific arrangements and/or orderings may not be required. Rather, in some embodiments, such features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments and, in some embodiments, it may not be included or may be combined with other features. 
     While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure.