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PRIORITY CLAIM 
     The present application is related to and/or claims the benefits of the earliest effective priority date and/or the earliest effective filing date of the below-referenced applications, each of which is hereby incorporated by reference in its entirety, to the extent such subject matter is not inconsistent herewith, as if fully set forth herein: 
     (1) this application constitutes a non-provisional of U.S. Provisional Patent Application No. 62/158,149, entitled ELEMENTS OF A MOVABLE CLOSURE SYSTEM, naming Adam Conley, Robert Carrasca and Christopher Hamlin as inventors, filed May 7, 2015, which is currently or is an application of which a currently application is entitled to the benefit of the filing date. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to movable closures and, more specifically, to a movable closure system. 
     BACKGROUND 
     Windows and doors may be implemented through movable closure systems, which may include one or more slidable elements. Advances in movable closure systems increase the installability and reliability of such systems. Movable closure systems are often customized to fit a particularly-sized aperture through a structure. Providing components which can expand or contract as needed to fit a particular aperture while still providing a tight seal when the system is closed is beneficial. In addition, most movable closure systems enable a view of the outside from within the structure by virtue of use of transparent or semi-transparent panels within the slidable elements. To maximize viewing ability, aspects of the slidable elements other than the panels may be optimized in size. Floor to ceiling panels may be large, necessitating use of heavy glass, so aspects of the system which support glass panels must be sturdy and durable while providing the ability to slide the panels back and forth easily despite the weight of the panels. As with a doorway into a home, business, or other building in which a movable closure system might be installed, locking features are necessary to ensure security. Disclosed herein is a movable closure system produced in view of some of the foregoing objectives. 
     Technical materials which can be regarded as useful for the understanding, searching, and examination of the invention includes:
     U.S. Pat. No. 5,448,855 (Sjoholm), “Sliding Element System,” 1995.   U.S. Pat. No. 8,819,994 (Ingram), “Space Enclosure System,” 2014.   

     The foregoing disclosures are hereby incorporated by reference. 
     SUMMARY 
     This invention relates generally to movable closures and, more specifically, to a movable closure system. In some embodiments, a movable closure system includes, but is not limited to, a plurality of slidable elements supported from above by an adjustable upper track and from below by an adjustable lower track. The width of a slidable element may be aligned with the tracks (a “closed” position of the slidable element) and the slidable elements may slide back and forth on wheels engaging the tracks. The adjustable upper and lower track may have one or more channels running laterally (i.e. from one end of the track to the other) through them. The lateral channels may be configured to permit horizontal wheels of the slidable elements to traverse the tracks. The horizontal wheels may have rounded edges mating with rounded edges of the lateral channels. 
     A slidable element may have an axis of rotation adjacent to one side of the slidable element, the axis of rotation being disposed from the top to the bottom of the slidable element and about which the slidable element may pivot. The axis of rotation may extend through an upper wheel assembly and a lower wheel assembly of the slidable element. Pivoting a slidable element would rotate it such that the width is no longer aligned with the tracks (an “open” position of the slidable element). The pivot may include a rotation of the slidable element to an angle of up to 90 degrees from the tracks. 
     Each slidable element may be configured with a particular lateral location at which that slidable element may be pivoted. The locations where each slidable element may be pivoted may be adjacent to one end of the system, called the stacking end. Upon each slidable element being slidably moved to its particular lateral location adjacent to the stacking end of the system and pivoted about its axis of rotation, a “stack” of adjacent slidable elements rotated to a perpendicular orientation to the track is created and the system is opened. The opposing end of the system to the stacking end is called the closure end. 
     In some embodiments, the adjustable upper track and the adjustable lower track include structures for engaging each particular slidable element at a different lateral location where the particular slidable element may rotate. The system is configured to permit each slidable element to rotate only at the particular lateral location intended for that slidable element. The foregoing structures may include, but are not limited to, an insert guide within the adjustable upper track configured to permit a free wheel assembly of each slidable element to exit the adjustable upper track when the slidable element is slidably moved to the location at which it is intended to pivot. The foregoing structures may also include a hinge block within the adjustable upper track configured to engage a portion of an upper hinge wheel assembly of each slidable element to facilitate the rotation of the slidable element at the location at which it is intended to pivot. 
     The foregoing structures may also include a hinge block within the adjustable lower track configured to engage a portion of a lower hinge wheel assembly of each slidable element to facilitate the rotation of the slidable element at the location at which it is intended to pivot. The foregoing structures may also include distances between the free wheel assembly and upper hinge wheel assembly that are staggered for each adjacent slidable element. The foregoing structures may also include mechanisms for raising a locator pin of an upper hinge wheel assembly into a corresponding locator hole of the hinge block disposed within the adjustable upper track to provide additional support for the suspension of the slidable element through its axis of rotation, the raising occurring in response to the slidable element being pivoted and the free wheel assembly exiting the insert guide. 
     In some embodiments, the system may include structures for ensuring a tight seal exists between each slidable element and between the slidable elements and the jambs to each side of the system, the jambs at least partially providing the edges of the system from the adjustable top track to the adjustable bottom track. The foregoing structures may include, but are not limited to, a static jamb adjacent to the closure end of the system and configured for enabling an installer of the system to vary the lateral position of one edge of the system against which the adjacent slidable element will rest when the system is closed. The foregoing structures may include, but are not limited to, a compression jamb configured for enabling a user of the system to extend the jamb laterally, away from the stacking end of the system, and pressing against the slidable element adjacent to the stacking end when the system is closed. The pressure exerted by the compression jamb pushing against the “first” slidable element (the slidable element which opens first and is located adjacent to the stacking end of the system and adjacent to the compression jamb) is transferred to each slidable element in turn, compressing the slidable elements together and against the static jamb. The foregoing structures may include, but are not limited to, compressible weatherstrips between the slidable elements. A weatherstrip may also be disposed on the static jamb and/or on the compression jamb. The foregoing structures may include, but are not limited to, male and female endcaps between one or more of the slidable elements, the static jamb, and/or the compression jamb, the male and female endcaps interlocking in both a horizontal and vertical axis to assist with the sealing and security of the system when closed. 
     In some embodiments, the system may include structures for providing additional security of the system when closed. The foregoing structures may include the compression jamb which is configured for ensuring that no free wheel assembly is aligned with the insert guide when the system is closed, a first panel interlock engaging a portion of the insert guide when the compression jamb is operated, and a latch of the compression jamb which, when operated from “inside” the structure in which the movable closure system is installed, prevents a handle of the compression jamb from being operated to open the system. 
     In addition to the foregoing, various other methods, systems and/or program product embodiments are set forth and described in the teachings such as the text (e.g., claims, drawings and/or the detailed description) and/or drawings of the present disclosure. 
     The preceding is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is NOT intended to be in any way limiting. Other aspects, embodiments, features and advantages of the device and/or processes and/or other subject matter described herein will become apparent in the teachings set forth herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the present invention are described in detail below with reference to the following drawings, presented in accordance with varied embodiments of the invention: 
         FIG. 1 a    is a front view of a movable closure system  100 . 
         FIGS. 1 b , 1 c , 1 d , 1 e , 1 f , 1 g , 1 h , 1 i , and 1 j    are perspective views of a movable closure system. 
         FIG. 2  is a front view of two adjacent slidable elements. 
         FIGS. 3 a  and 3 b    are a perspective view of a back edge and an exploded view of an adjustable upper track of the movable closure system. 
         FIG. 3 c    is a side cross-sectional view of the upper rail. 
         FIG. 3 d    is a side cross-sectional view of the upper rail with a free wheel assembly in view. 
         FIG. 3 e    is a side cross-sectional view of the upper rail with an upper hinge wheel assembly in view. 
         FIG. 3 f    is a front view of the free wheel and upper hinge wheel assemblies coupled with a pushrod. 
         FIGS. 3 g  and 3 h    are a perspective view and an exploded perspective view of the free wheel assembly. 
         FIGS. 3 i  and 3 j    are a perspective view and an exploded perspective view of the upper hinge wheel assembly. 
         FIG. 3 k    is an exploded view of a clicker subassembly of the free wheel assembly. 
         FIGS. 4 a  and 4 b    are a perspective view and a front view of a movable closure system. 
         FIG. 4 c    is a close-up perspective view of an insert guide of the upper track of the movable closure system. 
         FIG. 4 d    is an additional perspective view of the insert guide of the upper rail, with a dashed line and arrows showing a bi-section location along the upper rail. 
         FIG. 4 e    is a cross-sectional view of the upper rail and insert guide at the bi-section location indicated by the dashed line and arrows, with the free wheel assembly visible. 
         FIG. 4 f    is a cross-sectional view of the upper rail and insert guide at the same bi-section location, but without the free wheel assembly present. 
         FIG. 4 g    is a side view of the free wheel assembly as it would appear when the slidable element of which the free wheel assembly is a part has been opened. 
         FIG. 5 a    is a perspective view of a top portion of a slidable element underneath a hinge block, as viewed from the back of the system. 
         FIG. 5 b    is a top view of the top portion of the slidable element. 
         FIG. 5 c    is a view of the system from the inside, looking particularly at the upper hinge wheel assembly and the hinge block. 
         FIG. 5 d    is a cross-sectional view of the upper rail, hinge block, and upper hinge wheel assembly. 
         FIG. 6 a    is a perspective view of a lower track of the movable closure system. 
         FIG. 6 b    is a side view of a lower rail. 
         FIG. 6 c    is a perspective view of a lower hinge wheel assembly. 
         FIG. 6 d    is an exploded view of a lower hinge wheel assembly. 
         FIG. 6 e    is a perspective view of a lower hinge wheel assembly wheel hub. 
         FIG. 6 f    is a side view of the lower track of the movable closure system with the lower hinge wheel assembly in view. 
         FIGS. 7 a  and 7 b    are a perspective view and an exploded perspective view of a static jamb. 
         FIG. 7 c    is a top view of a portion of the static jamb. 
         FIG. 7 d    is an exploded perspective view of a static endcap assembly. 
         FIG. 7 e    is a top view of a portion of the static jamb. 
         FIG. 7 f    is an exploded perspective view of an adjustment post subassembly. 
         FIGS. 8 a  and 8 b    are a perspective view and an exploded perspective view of a compression jamb. 
         FIG. 8 c    is a top view of the compression jamb. 
         FIG. 8 d    is an exploded perspective view of a compression jamb top endcap assembly. 
         FIG. 8 e    is a bottom view of the compression jamb. 
         FIGS. 9 a  and 9 b    are two front partial cutaway views of portions of the movable closure system. 
         FIGS. 10 a  and 10 b    are two front views of a portion of the movable closure system. 
         FIGS. 11 a  and 11 b    are two cutaway views of portions of a compression jamb. 
         FIGS. 12 a , 12 b , and 12 c    are two front views and a right side view of a portion of the movable closures system. 
         FIGS. 13 a  and 13 b    are a perspective view and an exploded view of the compression mechanism of the compression jamb. 
         FIG. 13 c    is a perspective view of an actuator of the compression mechanism of the compression jamb. 
         FIGS. 13 d  and 13 e    are exploded views of the handle and of the latch of the compression jamb. 
         FIG. 13 f    is an exploded view of a pogo of the compression mechanism of the compression jamb. 
         FIGS. 14 a  and 14 b    are perspective views of a male endcap and a female endcap. 
     
    
    
     DETAILED DESCRIPTION 
     This invention relates generally to movable closures and, more specifically, to elements of a movable closure system. Specific details of certain embodiments of the invention are set forth in the following description and in  FIGS. 1-14   b  to provide a thorough understanding of such embodiments. The present invention may have additional embodiments, may be practiced without one or more of the details described for any particular described embodiment, or may have any detail described for one particular embodiment practiced with any other detail described for another embodiment. 
     Importantly, a grouping of inventive aspects in any particular “embodiment” within this detailed description, and/or a grouping of limitations in the claims presented herein, is not intended to be a limiting disclosure of those particular aspects and/or limitations to that particular embodiment and/or claim. The inventive entity presenting this disclosure fully intends that any disclosed aspect of any embodiment in the detailed description and/or any claim limitation ever presented relative to the instant disclosure and/or any continuing application claiming priority from the instant application (e.g. continuation, continuation-in-part, and/or divisional applications) may be practiced with any other disclosed aspect of any embodiment in the detailed description and/or any claim limitation. Claimed combinations which draw from different embodiments and/or originally-presented claims are fully within the possession of the inventive entity at the time the instant disclosure is being filed. Any future claim comprising any combination of limitations, each such limitation being herein disclosed and therefore having support in the original claims or in the specification as originally filed (or that of any continuing application claiming priority from the instant application), is possessed by the inventive entity at present irrespective of whether such combination is described in the instant specification because all such combinations are viewed by the inventive entity as currently operable without undue experimentation given the disclosure herein and therefore that any such future claim would not represent new matter. 
       FIG. 1 a    is a front view of a movable closure system  100 , in accordance with an embodiment of the invention.  FIGS. 1 b , 1 c , 1 d , 1 e , 1 f , 1 g , 1 h , 1 i   , and  1   j  are perspective views of a movable closure system  100 , in accordance with an embodiment of the invention.  FIGS. 1 a -1 j    show the movable closure system  100  as seen from “inside” a structure in which the movable closure system  100  is installed.  FIG. 1 j    is included to show a view from which various cross sections depicted elsewhere herein are taken. 
     In some embodiments, the movable closure system  100  is a system of slidable elements  102 . Depicted in  FIGS. 1 a -1 i    are three slidable elements,  102   a ,  102   b , and  102   c . Of course, more slidable elements or even fewer (as few as one) slidable elements may be employed to fit a differently-sized aperture or for other reasons. The number of slidable elements depicted in the drawings and accompanying discussion is merely for convenience of understanding and is intended to be non-limiting in nature. The slidable elements may be rectangular. 
     The slidable elements are below an adjustable upper track, which is formed from upper rail  114  and C-channel  116 . The slidable elements are above an adjustable lower track, which includes lower rail  188 . The slidable elements are laterally between a static jamb  200  and a compression jamb  400 . In some embodiments, the movable closure system  100  may be deployed as a door, a window, or as another type of closure of an aperture through a structure. 
     An arrow is present in  FIGS. 1 a -1 i    below the depiction of the system to indicate the direction of travel of slidable elements  102  when closing the movable closure system  100 . Furthermore, the arrows will be present in additional drawings to assist a viewer in understanding which side (inside or outside) of the movable closure system  100  is in view.  FIGS. 1 a -1 i   , having an arrow pointing to the left, depict the system from the “inside.” Drawings which show the arrow pointing to the right depict the system from the “outside.” Of course, “inside” and “outside” are used here in a non-limiting way; it is envisioned that the system could be flipped around for installation (e.g. with the insert guide  104  disposed through upper rail  114  facing the other direction). 
       FIG. 1 a    shows the movable closure system in a closed configuration. When the system is closed, the slidable elements are compressed together from the side through operation of compression jamb  400 . By operating handle  425  during closing of the system, a portion of the compression jamb expands to the left, pressing against the right side of the rightmost slidable element  102   a . Slidable element  102   a  in turn presses against slidable element  102   b , which presses against slidable element  102   c , which presses against the static jamb  200 . Each of the left and right edges of the slidable element includes a compressible weatherstrip, as does the static jamb. As a result, when the compression jamb is operated, the weatherstrips between the slidable elements are compressed and a tight, weatherproof seal is formed between the slidable elements and the jambs on either side of the system. Latch  431  may then be operated to lock the system so that it may not be opened from the outside. In some embodiments, a first panel interlock  608  is present. As may be seen in  FIG. 1 b   , the interlock is disposed near the top edge of the slidable element closest to the compression jamb. The interlock is a vertical tab which fits underneath a hanging vertical portion of insert guide  104 . When the compression jamb is operated, the adjacent slidable element slides away from the compression jamb and the first panel interlock comes to rest underneath the insert guide, providing an additional locking aspect. 
       FIGS. 1 b -1 i    depict the operation of opening the movable closure system  100 . (The aforementioned weatherstrip  198  along each side of the slidable elements may be seen in  FIGS. 1 c  and 1 d   .) Successive slidable elements  102  may be slidably moved into an opening position and pivoted about a hinge axis unique to each slidable element  102 .  FIGS. 1 b -1 d    show slidable element  102   a  in a closed position, partially opened position, and fully opened position respectively. After handle  425  is operated to reverse the expansion of the compression jamb, the slidable elements may slide towards the compression jamb to a position where they may be pivoted open. For example, when pulling handle  118  inwards, slidable element  102   a  pivots about its hinge axis. Pulling the handle and pivoting the slidable element  102   a  causes a free wheel assembly  106   a  exits the insert guide  104 . As will be discussed elsewhere herein, the free wheel assembly  106  is used to movably support the slidable element  102  (in conjunction with upper hinge wheel assembly  108  and lower hinge wheel assembly  110 ) while the element is moved from side to side within the movable closure system  100 . Normally a free wheel assembly is disposed within (i.e. hidden by) the upper rail  114 . However, opening each element causes the free wheel assembly  106  to exit the upper rail  114  through the insert guide  104 . 
     The next slidable element  102   b  may be opened by first sliding the element to the right into position from which it may be pivoted, as seen in  FIGS. 1 e  and 1 f   . Upon reaching the opening position, the slidable element may be opened upon which a mechanism hingeably locks slidable element  102   b  into place about its hinge axis (i.e. so that the slidable element rotates about the hinge axis but cannot be moved laterally). The mechanism which locks the movable slidable elements into place is disclosed elsewhere herein.  FIGS. 1 g  and 1 h    depict a partially opened and fully opened position respectively of slidable element  102   b . As may be seen in  FIG. 1 h   , opening successive slidable elements  102  creates a “stack” of pivoted, opened slidable elements at one end of the movable closure system  100 , called the stacking end  120 . 
     As seen in  FIGS. 1 g  and 1 h   , free wheel assemblies  106   a  and  106   b  are at different distances from the front edge of their respective slidable elements  102   a  and  102   b  (“front edge” referring to the edge of the slidable element  102  facing the closure end  122  of the movable closure system  100 , i.e. the edge of the slidable element  102  in the direction of the arrows). As will be made more clear elsewhere herein, each successive slidable element  102 , when moved to its opening position within the movable closure system  100  (i.e. when its free wheel assembly  106  is positioned to exit the upper rail  114  at the insert guide  104 ), has a distance between the hinge axis for that slidable element  102  and the insert guide  104  smaller than for the previous slidable element  102 . Accordingly, each successive element&#39;s free wheel assembly  106  is further from the front edge of the slidable element  102  on which it is disposed. 
     Continuing the narrative description of the operation of opening the movable closure system, slidable element  102   c  may also be opened by slidably moving it into its opening position. It may too be opened by pivoting it about its hinge axis, hingeably locking the element into place so that it only swivels and does not move from side to side, and adding slidable element  102   c  to the stack as may be seen in  FIG. 1 i   . (Intermediate views between  FIGS. 1 h  and 1 i    showing slidable element  102   c  sliding to the opening position and being partially opened, corresponding to  FIGS. 1 e -1 g    for slidable element  102   b , are omitted.) While the movable closure system  100  depicted in the figures includes only three slidable elements  102 , it is possible to have a larger-scale system with many more slidable elements as needed to fit a particular aperture through a structure. 
     Closing of the movable closure system  100  occurs in reverse of the opening operation. Each slidable element  102  is pivoted with its free wheel assembly  106  going through the insert guide  104  of the upper rail  114 , the slidable element then being slid to the closure end  122  of the tracks, the closure end  122  being the end opposite the stacking end  120  of the tracks. Upon all slidable elements  102  being pivoted and slid away from the stacking end  120  of the movable closure system  100 , the system may be closed through use of a compression jamb or other means. 
       FIG. 2  is a front view of two adjacent slidable elements  102   a  and  102   b , in accordance with an embodiment of the invention. With the upper rail not being present in  FIG. 2 , it may be seen that a slidable element may have two upper wheel assemblies  106  (free wheel assembly) and  108  (upper hinge wheel assembly), the upper wheel assemblies including horizontally-oriented wheels. The lower rail is also not present, so it may be seen that a slidable element may have one lower hinge wheel assembly  110  including horizontally-oriented wheels. 
     Horizontally-oriented wheels offer significant benefits. For example, horizontally-oriented wheels require less space vertically than vertically-oriented wheels. Accordingly, the adjustable upper and lower tracks may be shorter vertically while still accommodating the horizontally-oriented wheels. This enables the movable elements to have more vertical space for glass or other transparent material, providing a greater area of visibility through the slidable elements. Additionally, the lower track in which the lower hinge wheel assembly runs may have a top edge lower to the ground and/or the lower track may be lower profile and need a shallower trench in the ground by virtue of the horizontally-oriented wheels requiring less vertical space than vertical wheels. Horizontally-oriented wheels also facilitate movement of slidable elements about a curved track, or even around a 90-degree angle. 
     Further, the horizontally-oriented wheels have rounded edges, rather than being cylindrical in shape. The rounded edges mate with arcuate channels through the upper and lower tracks. In this manner, more significant portions of the wheels engage the channels through the tracks when compared to flat-edged wheels for improved support of the slidable elements. Additionally, the rounded-edged wheels facilitate entry of the wheels into an insert guide of the upper rail. 
     It may be seen from  FIG. 2  that the lower hinge wheel assembly  110  is set directly below the upper hinge wheel assembly  108  such that a hinge axis  112  runs through and between the upper and lower hinge wheel assemblies. Hinge axis  112  runs through vertically-disposed wheel hub portions of the upper and lower hinge wheel assemblies, the vertically-disposed wheel hub portions forming axles about which the horizontally-oriented wheels rotate. 
     It may also be seen that the two upper wheel assemblies, portions of which extend into upper rail  114 , may have different shapes. Particularly, the upper wheel assemblies may include free wheel assembly  106 , shown as the free wheel assemblies  106   a  and  106   b  seen in  FIG. 2  at the top left of slidable elements  102   a  and  102   b  respectively. The free wheel assembly  106  is disposed nearest the front edge of the slidable element. (The designation of the “front edge” refers to the direction of travel of the slidable elements  102  when closing the movable closure system  100 .) The upper wheel assemblies may also include upper hinge wheel assembly  108 , shown as the upper hinge wheel assemblies  108   a  and  108   b  seen in  FIG. 2  at the top right of the slidable elements  102   a  and  102   b  respectively. 
     In some embodiments, an upper glazing profile  154  can be an object which is coupled to the top edge of a piece of glass or other panel. A lower glazing profile  190  can be an object which is coupled to the bottom edge of the piece of glass or other panel. The upper and lower glazing profiles run substantially from the left edge to the right edge (front edge to back edge) of the panel. Opposite the top edge of the panel is where an upper glazing profile would be inserted into and/or surround an adjustable upper track mounted in the top edge of the aperture. Opposite a bottom edge of the panel, a lower glazing profile is disposed into which the lower hinge wheel assembly engaging the adjustable lower track is be mounted. No vertical panels are required along the edges of the slidable element, other than the pane of glass or other material which makes up the majority of the slidable element, although in some embodiments vertical panels between the upper and lower glazing profiles are present on either edge of the main panel of each slidable element. Each glazing profile may have removable sides. One or more sex bolts (barrel bolts, e.g.) may be used to affix portions of a glazing profile to a glass panel of the slidable element. For manufacturing, distribution, and/or installation ease, different thickness panels are accommodated with using only a single set of glazing profiles, each set making up the two removable sides, and appropriately-sized bolts for the thickness of the panel. Weather-tight seals may be disposed between the tracks and glazing profiles. In some embodiments the seals may be H-shaped weatherstrips. 
     Support portions of the free wheel assembly  106  and upper hinge wheel assembly  108  are set within the upper glazing profile  154 , which, as previously discussed, forms the top portion of the movable element and receives glass or other transparent material (or even materials that are less than transparent). The wheel portions of the free wheel and upper hinge wheel assemblies rise above the upper glazing profile in order to extend into the upper rail. As will be discussed below, the free wheel and upper hinge wheel assemblies are coupled with a pushrod running horizontally through the upper glazing profile. 
     Similarly, support portions of the lower hinge wheel assembly  110  are set within a lower glazing profile  190 , which forms the bottom portion of the movable element for receiving glass or other transparent material. The wheel portions of the lower hinge wheel assembly descend below the lower glazing profile in order to extend into the lower rail. 
     When opening the movable closure system  100 , each slidable element  102  rotates on hinge axis  112  between and through the upper hinge wheel assembly  108  and the lower hinge wheel assembly  110 . Curved arrows in  FIG. 2  show the direction in which the slidable elements  102  would rotate about the hinge axis  112  when each successive slidable element  102  is moved into alignment with the insert guide along the upper rail. 
     As described previously, opening the movable closure system  100  involves moving each slidable element  102  into a position where it may be pivoted about hinge axis  112  extending from the upper hinge wheel assembly  108  to the lower hinge wheel assembly  110 , and where the hinge axis  112  is correctly aligned with a corresponding locator hole for the slidable element through a hinge block disposed within the upper rail. Opening further includes pivoting the slidable element  102  about the hinge axis  112  until it is approximately perpendicular to top and lower tracks of the movable closure system  100  (the tracks not visible in  FIG. 2 , but visible in  FIGS. 1 a -1 i   ). As seen in  FIG. 1 i   , pivoting subsequent slidable elements  102  forms a “stack” of opened slidable elements  102 , stacked at a substantially 90 degree angle to the upper and lower tracks of the system movable closure system  100 . In this way, multiple slidable elements  102  may be rotated and “stacked” near the stacking end  120  of the aperture through the structure in which the movable closure system  100  is deployed. 
     Upon the slidable element  102  being pivoted, it is held in place within the movable closure system  100  only with portions of the upper hinge wheel assembly  108  and the lower hinge wheel assembly  110 , which are the wheel assemblies disposed adjacent to the “back edge” of the slidable element  102  (the “back edge” referring to the edge of the slidable element  102  opposite to the direction of the arrows and opposite the “front edge” of the slidable element  102 , i.e. the back edge is closest to the stacking end). The weight of the slidable element  102  then exerts substantial pressure on the upper hinge wheel assembly  108  and its engagement with the upper rail and hinge block. Without the support of the upper hinge wheel assembly  108  in the upper rail and hinge the slidable element would have a tendency to fall away from the upper track under its own weight. Consequently, sturdy, durable hinge wheel assemblies and locking mechanisms described elsewhere herein are used to withstand the tendency of the slidable element  102  to fall away from the upper track under its own weight. 
       FIGS. 3 a  and 3 b    are a perspective view of a back edge and an exploded view of an adjustable upper track of the movable closure system  100 , in accordance with an embodiment of the invention. In some embodiments, an adjustable upper track may be divided into a C-channel  116  and an upper rail  114 . One or more adjustment blocks  134  may be disposed between the C-channel and the upper rail. The adjustment blocks can vary in height so that the vertical distance between the C-channel and upper rail may vary. The C-channel and upper rail are coupled via fasteners threaded through the C-channel, adjustment blocks, and the upper rail, with the adjustment blocks sized to ensure the top rail from which the slidable elements hang is level, even if the C-channel attached to the structure is not. 
     The upper rail provides a pathway through which the free wheel assembly  106  and the upper hinge wheel assembly  108  (in conjunction with the bottom wheel assembly  110 ) movably support the slidable element  102  while the element is moved from side to side within the movable closure system  100 . As will be discussed below, portions of the upper rail support and/or engage horizontal wheels of the free wheel assembly and upper hinge wheel assembly. 
       FIG. 3 c    is a side cross-sectional view of the upper rail  114 , in accordance with an embodiment of the invention.  FIG. 3 d    is a side cross-sectional view of the upper rail  114  with free wheel assembly  106  in view, in accordance with an embodiment of the invention.  FIG. 3 e    is a side cross-sectional view of the upper rail  114  with upper hinge wheel assembly  108  in view, in accordance with an embodiment of the invention.  FIG. 3 f    is a front view of the free wheel and upper hinge wheel assemblies coupled with a pushrod, in accordance with an embodiment of the invention.  FIGS. 3 g  and 3 h    are a perspective view and an exploded perspective view of the free wheel assembly, in accordance with an embodiment of the invention.  FIGS. 3 i  and 3 j    are a perspective view and an exploded perspective view of the upper hinge wheel assembly, in accordance with an embodiment of the invention.  FIG. 3 k    is an exploded view of a clicker subassembly of the free wheel assembly, in accordance with an embodiment of the invention. 
     As previously disclosed, the free wheel assembly and upper hinge wheel assembly run within (“movably support”) the upper rail when the slidable elements are moved from side to side. In some embodiments, horizontal channels for receiving wheel portions of the free and upper hinge wheel assemblies are disposed from end to end of the upper rail  114 . As best seen in  FIGS. 3 c , 3 d , and 3 e   , the horizontal channels have arcuate portions configured for receiving the horizontal wheels of the top wheel assembly  106  and the upper hinge wheel assembly  108 . 
     Particularly, an upper rail may include the following arcuate portions: an upper load wheel channel  126 , a lower load wheel channel  128 , and an idler wheel channel  130 . The upper load wheel channel is configured for receiving an upper load wheel  136  of the upper hinge wheel assembly  108 . The lower load wheel channel is configured for receiving a lower load wheel  138  of the upper hinge wheel assembly and for receiving a lower load wheel  142  of the free wheel assembly  106 . The idler wheel channel is configured for receiving an idler wheel  140  of the upper hinge wheel assembly and for receiving an idler wheel  144  of the free wheel assembly. It will be noted that the upper load wheel channel is traversed only by an upper load wheel of upper hinge wheel assemblies. The free wheel assemblies do not have an upper load wheel, only a lower load wheel and idler wheel. 
     Also visible in  FIGS. 3 c  through 3 e    is a hinge block recess  124 . The hinge block recess is configured for receiving a hinge block. 
       FIGS. 3 d , 3 e , and 3 f    depict the wheel assemblies as they would appear when the movable elements are not in the opened position (i.e. as they would appear when the movable elements are not swung open about the hinge axis). It will be observed that, when the movable elements are not in the opened position, the free wheel assembly  106  has a button  146  disposed through its rotational axis, the button shown in  FIGS. 3 d  and 3 f    in a raised position. Additionally, the upper hinge wheel assembly  108  has a locator pin  132  disposed through its rotational axis, the locator pin shown in  FIGS. 3 e  and 3 f    in a lowered position. (The full length of the button  146  and locator pin  132  may be seen in  FIGS. 3 h  and 3 j    with exploded views of the free wheel assembly  106  and upper hinge wheel assembly  108 , respectively.) 
     The raised and lowered positions of the button  146  and locator pin  132  are partially driven by compression springs internal to the free wheel assembly  106  and upper hinge wheel assembly  108  respectively. The free wheel assembly and upper hinge wheel assembly are configured via the compression spring for biasing the button and locator pin into a lower position. For example, in  FIG. 3 h    it may be seen that the free wheel assembly compression spring  162  rests on top of a collar portion of button  146  and abuts a bottom portion of the free wheel assembly wheel hub  148 , the free wheel assembly compression spring having a tendency to push the button down and away from the free wheel assembly wheel hub. Likewise, in  FIG. 3 j    it may be seen that the upper hinge wheel assembly compression spring  164  rests on top of a collar portion of locator pin  132  and abuts a bottom portion of the upper hinge wheel assembly wheel hub  150 , the upper hinge wheel assembly compression spring having a tendency to push the locator pin down and away from the upper hinge wheel assembly wheel hub. 
     As seen in  FIG. 3 f   , to drive the up and down action of the button and locator pin, the free wheel assembly  106  and upper hinge wheel assembly  108  are in physical communication via a pushrod  152 , which is disposed within a horizontal cavity across the top of an upper glazing profile  154  of the movable elements. (See  FIGS. 5 a  and 5 b   .) The pushrod may be supported within the upper glazing profile by one or more pushrod standoffs  156 , the pushrod standoffs mounted inside the horizontal top cavity of the upper glazing profile and through which the pushrod may be disposed. As a consequence of the distance between the upper hinge wheel assembly and free wheel assembly becoming shorter with each successive movable element from back to front (discussed above with respect to  FIGS. 1 g  and 1 h   ), the pushrod for each movable element is commensurately shorter from back to front. 
     The pushrod  152  moves from side to side between the free wheel assembly  106  and upper hinge wheel assembly  108 . At each end of the pushrod, it is inserted into the wheel assemblies. For example,  FIGS. 3 g  and 3 h    show that the free wheel assembly wheel hub  148  has an aperture at one end for receiving an end of the pushrod  152 . Within the free wheel assembly is a clicker  168  and a free wheel assembly actuator  160 , the free wheel assembly actuator having a sloped surface that resembles a ramp. When the pushrod is driven into the free wheel assembly, it pushes against the clicker which in turn pushes against the free wheel assembly actuator. The sloped surface of the free wheel assembly actuator pushes against the bottom of the button  146 , driving the button upwards into the raised position and compressing the free wheel assembly compression spring  162 . When pushrod tension is released, the free wheel assembly compression spring pushes against the free wheel assembly wheel hub and the button to drive the button down and away from the free wheel assembly wheel hub. 
     Likewise,  FIGS. 3 i  and 3 j    show that the upper hinge wheel assembly wheel hub  150  has an aperture at one end for receiving the upper hinge wheel assembly actuator  166 , which in turn receives a portion of the pushrod  152  opposite to the pushrod end in contact with the free wheel assembly. The upper hinge wheel assembly actuator also has a sloped surface that resembles a ramp. When the pushrod is driven into the upper hinge wheel assembly, it pushes against the upper hinge wheel assembly actuator. The sloped surface of the upper hinge wheel assembly actuator pushes against the bottom of the locator pin  132 , driving the locator pin upwards into the raised position and compressing the upper hinge wheel assembly compression spring  164 . When pushrod tension is released, the upper hinge wheel assembly compression spring pushes against the upper hinge wheel assembly wheel hub and the locator pin to drive the locator pin down and away from the upper hinge wheel assembly wheel hub. 
     Accordingly it may be seen that when the pushrod is operated, the button and locator pins move in tandem. The button is raised when the locator pin is lowered, and the button is lowered when the locator pin is raised. Particularly, when the button of the free wheel assembly is in the raised position and the button is pushed down at its top, the bottom of the button pushes against the free wheel assembly actuator, which pushes against the clicker, which pushes against the pushrod, which pushes against the upper hinge wheel assembly actuator, which pushes the bottom of the locator pin causing the locator pin to move to the raised position. It will be seen that as a movable element is swung open about its hinge axis, the button is pushed down, engaging the pushrod and raising the locator pin of the upper hinge wheel assembly, which finds a hole in the hinge block for hingeably locking the movable element into place. 
       FIGS. 4 a  and 4 b    are a perspective view and a front view of a movable closure system  100 , with a portion shown in a dashed circle. That portion is enlarged in  FIG. 4 c   , which is a close-up perspective view of an insert guide  104  of the upper rail  114  of the movable closure system  100 , in accordance with an embodiment of the invention. A portion of a free wheel assembly  106  is visible through the insert guide.  FIG. 4 d    is an additional perspective view of the insert guide  104  of the upper rail  114 , with a dashed line and arrows showing a bi-section location along the upper rail.  FIG. 4 e    is a cross-sectional view of the upper rail  114  and insert guide  104  at the bi-section location indicated by the dashed line and arrows, with the free wheel assembly  106  visible.  FIG. 4 f    is a cross-sectional view of the upper rail  114  and insert guide  104  at the same bi-section location, but without the free wheel assembly present.  FIG. 4 g    is a side view of the free wheel assembly as it would appear when the slidable element of which the free wheel assembly is a part has been opened. 
     A slidable element  102  slides along the track until the free wheel assembly  106  is aligned with the insert guide  104 . When the free wheel assembly is aligned with the insert guide, the slidable element is in position for being opened. Upon pulling the handle (where slidable elements have mounted handles) or pulling the edge of the slidable element adjacent to the free wheel assembly, the slidable element pivots about the axis through the upper hinge wheel assembly and the lower hinge wheel assembly (as shown in  FIG. 2 ). The free wheel assembly comes out of the track through the insert guide upon the slidable element being pivoted. In comparing  FIG. 4 f    (showing the cross-sectional view of the upper rail at the bi-section location of the insert guide) with  FIG. 3 c   , it may be seen that the lower load wheel channel  128  and the idler wheel channel  130  have apertures through the upper rail at the insert guide  104 . The foregoing apertures enable the lower load wheel  142  and idler wheel  144  of the free wheel assembly  106  to exit the upper rail upon the slidable element being swung open. 
     In contrast, it will be noted that the upper load wheel channel  126  has no aperture through the insert guide, or at any point along the upper rail. It will also be noted that the free wheel assembly does not have an upper load wheel. As may be seen in  FIG. 3 e   , only the upper hinge wheel assembly  108  has an upper load wheel  136  traversing the upper load wheel channel. The upper hinge wheel assembly&#39;s upper load wheel, which runs through the enclosed upper load wheel channel, ensures that a slidable element does not exit the system when the upper hinge wheel assembly is aligned with the insert guide. If an attempt to open the slidable element occurs when the upper hinge wheel assembly was aligned with the insert guide, the upper load wheel channel of the upper rail would retain the upper load wheel of the upper hinge wheel assembly, preventing the slidable element from rotating. 
     It may therefore be seen that a slidable element is only rotatable about its hinge axis when the slidable element has been slid to a position where the free wheel assembly is aligned with the insert guide, because the insert guide has only an aperture for a lower load wheel and not the upper load wheel of the upper hinge wheel assembly. In addition, as noted above, when the slidable element is opened the weight of the slidable element exerts substantial pressure on the upper hinge wheel assembly and its engagement with the upper rail, so the upper load wheel also provides extra support in tandem with the upper hinge wheel assembly&#39;s lower load wheel when the slidable element is in the open position. 
     It will be noted that insert guide  104  has a ramped surface  158  (referenced by number in  FIG. 4 f    and visible in  FIGS. 4 d  and 4 e   ). It will additionally be noted that button  146  is in a raised position in  FIG. 4 e   . When the slidable element  102  is pulled open, the rounded top portion of the button  146  is engaged by the ramped surface  158  of the insert guide  104 . The action of opening the slidable element pushes the button down via the engagement of the button with the ramped surface.  FIG. 4 g    depicts the free wheel assembly upon exiting the insert guide (i.e. with the button in the lower position). As previously discussed with reference to  FIGS. 3 c -3 j   , the button is in communication with the pushrod  152  such that opening a slidable element engages the pushrod, which in turn causes the locator pin to be driven upward to engage a mating locator hole in the hinge block. In addition, the clicker mechanism  168  visible in  FIG. 3 h    is inline with the actuator blocks of the upper wheel assemblies and pushrod. The clicker includes a cam and spring arrangement which rotates to a locking position upon the engagement of the pushrod by the button. The locking position of the clicker ensures that the pushrod does not move in the opposite direction permitting the locator pin to drop while the slidable element is open. 
     When closing a slidable element (i.e. pivoting it back into place such that the element is disposed underneath the top rail), the insert guide receives the free wheel assembly. It may be seen that the insert guide has an arcuate edge on the left side for receiving the rounded edge of the load wheel of the free wheel assembly. The insert guide has an additional arcuate edge for receiving the rounded edge of the idler wheel of the free wheel assembly. Further, as the slidable element is closed and the free wheel assembly is received by the insert guide, the top of the button  146  passes underneath and presses against the lowest point of ramped surface  158  of the insert guide. The button is thereby pressed downward just enough to trip the clicker mechanism and unlock the pushrod mechanism. The compression spring of the upper hinge wheel assembly expands. The expansion of the upper hinge wheel assembly&#39;s compression spring causes the locator pin to drop down out of the hinge block. The bottom of the locator pin is pressed by the compression spring against the upper hinge wheel assembly actuator. Motion is thereby transferred via the upper wheel assemblies&#39; actuators, the clicker and the pushrod to drive the button back to the raised position. The slidable element may then be slid towards the front edge of the movable closure system as desired. 
       FIG. 5 a    is a perspective view of a top portion of a slidable element underneath a hinge block, as viewed from the back of the system, in accordance with an embodiment of the invention.  FIG. 5 b    is a top view of the top portion of the slidable element, in accordance with an embodiment of the invention.  FIG. 5 c    is a view of the system from the inside, looking particularly at the upper hinge wheel assembly and the hinge block, in accordance with an embodiment of the invention.  FIG. 5 d    is a cross-sectional view of the upper rail, hinge block, and upper hinge wheel assembly, in accordance with an embodiment of the invention. The hinge block  170  is affixed to the underside of the upper rail  114  in the hinge block cavity  124  (hinge block cavity visible in  FIGS. 3 c  and 4 f   , although the upper rail is not depicted in  FIGS. 5 a -5 c    to aid in viewing and understanding, and both the hinge block and upper rail are not depicted in  FIG. 5 b    for the same reason). 
     The hinge block has a plurality of locator holes  172 , each locator hole corresponding to a particular slidable element. The locator hole  172   a  closest to the stacking end of the movable closure system receives the locator pin  132   a  of the upper hinge wheel assembly  108   a  slidable element  102   a  closest to the stacking end of the movable closure system, for example. As previously discussed, when a slidable element is pulled open, the button  146  of the free wheel assembly  106  is engaged by the ramped surface of the insert guide  104  while the free wheel assembly exits the insert guide. The ramped surface of the insert guide presses the button down and in turn causes the locator pin to be raised via the actuators  160  and  166 , clicker  168  and pushrod  152 . The raised locator pin is received by the corresponding locator hole in the hinge block. With the locator pin in place within the hinge block, the slidable element may rotate about an axis extending through the locator pin downward to the bottom wheel assembly. 
     When subsequent slidable elements are slid underneath the hinge block, the upper hinge wheel assembly&#39;s locator pin of each slidable element is engaged with a subsequent hole in the hinge block. It may be seen that a portion of the hinge block is beveled for engaging the locator pin of the upper hinge wheel assembly, pressing it down as the locator pin passes underneath the hinge block while the slidable elements are in motion. 
       FIG. 6 a    is a perspective view of a lower track of the movable closure system, in accordance with an embodiment of the invention.  FIG. 6 b    is a side view of a lower rail, in accordance with an embodiment of the invention.  FIG. 6 c    is a perspective view of a lower hinge wheel assembly, in accordance with an embodiment of the invention.  FIG. 6 d    is an exploded view of a lower hinge wheel assembly, in accordance with an embodiment of the invention.  FIG. 6 e    is a perspective view of a lower hinge wheel assembly wheel hub, in accordance with an embodiment of the invention.  FIG. 6 f    is a side view of the lower track of the movable closure system with the lower hinge wheel assembly in view, in accordance with an embodiment of the invention. In some embodiments, an adjustable lower track  187  includes a lower rail  188  and a lower hinge block  174 . The lower hinge block is laterally disposed within a lower rail hinge block recess  176 . A lower rail includes two channels configured for traversal by idler wheels of the lower hinge wheel assembly  110 . Particularly, a lower rail small idler wheel channel  194  receives a lower hinge wheel assembly small idler wheel  180 . Additionally, a lower rail large idler wheel channel  196  receives a lower hinge wheel assembly large idler wheel  182 . Further, a lower rail hinge block recess  176  is configured for receiving the lower hinge block. The lower hinge block is placed closest to the back side of the movable closure system. 
     Lower hinge wheel assembly  110  includes baseplate  177 , which is affixed to a slidable element in an interior recess of the lower glazing profile  190  (the location of lower glazing profile visible in  FIG. 2 ). A lower hinge wheel assembly wheel hub  178  is suspended from the baseplate with fasteners, and the lower hinge wheel assembly idler wheels rotate about the lower hinge wheel assembly wheel hub. A lower compression spring  184  is retained by lower spring retainer  186 . The lower compression spring and lower spring retainer ensure that the wheels travel smoothly through the adjustable lower track, even if the adjustable lower track is not completely level. 
     It will be noted that the lower hinge wheel assembly wheel hub  178  has a crescent section, the crescent section disposed within the lower rail hinge block recess when the movable closure system is assembled. When a slidable element is pivoted, the lower hinge wheel assembly wheel hub pivots with the slidable element, rotating the crescent section. Additionally, the lower hinge block has a series of notches along its length, each notch corresponding to a particular slidable element. The notch closest to the back side of the movable closure system corresponds to the slidable element closest to the back side of the movable closure system (the element which is pivoted first when the system is being opened). The notches receive the crescent section of the lower hinge wheel assembly wheel hub to prevent the bottom portion of a slidable element from moving except to rotate about the hinge axis. 
       FIGS. 7 a  and 7 b    are a perspective view and an exploded perspective view of a static jamb, in accordance with an embodiment of the invention.  FIG. 7 c    is a top view of a portion of the static jamb, in accordance with an embodiment of the invention.  FIG. 7 d    is an exploded perspective view of a static endcap assembly, in accordance with an embodiment of the invention.  FIG. 7 e    is a top view of a portion of the static jamb, in accordance with an embodiment of the invention.  FIG. 7 f    is an exploded perspective view of an adjustment post subassembly, in accordance with an embodiment of the invention. In some embodiments, static jamb  200  is installed within the aperture through the structure at the closure end  122  of the movable closure system  100  (see  FIG. 1 a   ). Upon installation of the system, the slidable element closest to the closure end (i.e. the slidable element which opens last and closes first, shown as element  102   c  in  FIG. 1 a   ) is adjacent to the static jamb. The static jamb is opposite to the compression jamb  400 , which is installed within the aperture through the structure adjacent to the stacking end  120  of the system (the end where the movable elements will be stacked upon opening the system). 
     During installation of the movable closure system, minor adjustments (+/− an inch, for example) to the size of the static jamb may be performed as one means of ensuring an optimal and sealed fit of the slidable elements between the static jamb and compression jamb when the movable closure system is closed. The adjustments to the static jamb are intended to be made during installation through operation of two adjustment post subassemblies  209  as described below. The adjustments provide means for an installer to account for tolerance issues of the system and the aperture in which it is being installed. Once the adjustments to the size are made, the adjustment post subassemblies are covered by other components of the static jamb (rubber seal  239  and endcaps  205 , e.g.) and inaccessible to the user. 
     The static jamb includes a static C-channel  203  which is attached to the side of the aperture through the structure for the system opposite to where the slidable elements are to stack. A static side rail  201  is couplably received by the static C-channel. At installation, the installer uses fasteners augmented with other materials as needed (shims, e.g.) to couple the static side rail with the static C-channel and ensure the static side rail is plumb, even if the static C-channel attached to the structure within the side of the aperture is not. 
     A static compression bar  202  is received by a recess in the static side rail. The static compression bar is held in place against the static side rail in part with static endcap assemblies  206  located at each end of the static compression bar. A first tension spring  207  couples a first static endcap assembly at the top of the static compression bar to a spring bracket  222  attached (with rivets or threaded fasteners, e.g.) near the top of the static side rail, and a second tension spring couples the second static endcap assembly to another spring bracket attached near the bottom of the static side rail. The static endcap assemblies (specifically, the bar endcaps  217  of the static endcap assemblies) are attached to the top and bottom of the static compression bar. A hook pivot pin  220  to which the tension spring attaches is disposed through the bar endcap and secured by retaining clip  208 . The two tension springs, coupling the two spring brackets attached to the static side rail with the hook pivot pins of the two static endcap assemblies attached to the static compression bar, tensionally bias the static compression bar in the direction of the static side rail. The spring tension thus pulls the static compression bar and static side rail towards each other. Additional structural support for the static compression bar is provided by its position between the upper track and lower track of the system (see  FIG. 1 a   ). 
     At installation, the spring tension and hence the distance between the static compression bar and static side rail may be adjusted through two adjustment post subassemblies  209  mounted to the static side rail and in contact with the static compression bar. Particularly, edges of the static compression bar facing the static side rail come into contact with flange portions of the adjustment post subassemblies, limiting the tensional bias provided by the tension springs of the static compression bar towards the static side rail. 
     As may be best seen in  FIGS. 7 b , 7 e , and 7 f   , the adjustment post subassemblies are disposed between the static side rail and the static compression bar. Each adjustment post subassembly is held in place along the static side rail by a mounting screw  230 , which is disposed through an aperture through the static side rail and threaded into a threaded interior channel of guide post  228 . The opposing side of the guide post has another threaded interior channel for receiving a machine screw  216  with an attached screw bucket  204 . The machine screw is passed through an aperture at the bottom of the bucket portion of the screw bucket, the screw bucket being held in place underneath the head of the machine screw with locknut  214 . The machine screw, with the screw bucket attached below the head of the machine screw by the locknut and the opening of the bucket portion of the screw bucket opposite to the threaded portion of the machine screw, is partially threaded into the guide post. 
     The bucket portion of the screw bucket has an outer diameter sized slightly smaller than the diameter of an aperture through the center of standoff  229 . The screw bucket also has a shelf portion (the shelf portion being co-located with the plane through the bottom of the bucket portion that has the aperture for the machine screw) with a diameter larger than the diameter of the aperture through the center of the standoff. The standoff is seated over the bucket portion of the screw bucket (i.e. the bucket portion passed through the aperture through the center of the standoff) so that the shelf portion of the screw bucket rests against a bottom face of the standoff. The standoff has flanges interfacing with the vertical edges of the static compression bar facing the static side rail. The biasing action of the tension spring which brings the static compression bar towards the static side rail is limited by the flanges of the standoff, the position of which is set by the depth of the machine screw and the screw bucket relative to the guide post. 
     The adjustment in distance between the static compression bar and static side rail is controlled by the installer through operation of the machine screws using a screwdriver. Previous to adhering the rubber seal  239  to the static compression bar, the heads of the machine screws may be accessed with the screwdriver shaft passing through apertures in the static compression bar that are aligned with the adjustment post assemblies and the bucket portions of the screw buckets. The standoffs are moved laterally through motion transferred to them by screwdriver rotation of the machine screws, attached screw buckets, and standoffs, in conjunction with the tension springs. If the screwdriver interfaced with an adjustment post assembly is turned counter-clockwise, the end of the static compression bar nearest to the adjustment post assembly is pulled away from the static side rail as the machine screw rotates out from the guide post and away from the static side rail to which the guide post is mounted. Particularly, the screw bucket attached to the machine screw moves away from the guide post in tandem with the machine screw, and the shelf portion of the screw bucket pulls the standoff in turn. The pulling motion of the standoff away from the static side rail is transferred to the static compression bar by the flanges of the standoff interfacing with the edges of the static compression bar nearest the static side rail. The lateral expansion of the adjustment post assembly therefore works against (i.e. increases) the spring tension pulling the static compression bar towards the static side rail. 
     If the screwdriver interfaced with the adjustment post assembly is turned clockwise, the end of the static compression bar nearest to the adjustment post assembly moves closer to the static side rail as the machine screw rotates into the guide post and towards the static side rail to which the guide post is mounted. Particularly, the screw bucket attached to the machine screw moves towards the guide post in tandem with the machine screw. The tension imparted by the tension spring pulls the static compression bar towards the static side rail as the machine screw is turned, the travel of the static compression bar being limited by the interface of its edges against the flanges of the standoff, the standoff having been positioned by the machine screw, screw bucket, and standoff. As the adjustment post assembly compresses in conjunction the machine screw being rotated into the guide post, the spring tension pulling the static compression bar towards the static side rail is released. 
       FIGS. 8 a  and 8 b    are a perspective view and an exploded perspective view of a compression jamb, in accordance with an embodiment of the invention.  FIG. 8 c    is a top view of the compression jamb, in accordance with an embodiment of the invention.  FIG. 8 d    is an exploded perspective view of a compression jamb top endcap assembly, in accordance with an embodiment of the invention.  FIG. 8 e    is a bottom view of the compression jamb, in accordance with an embodiment of the invention. In some embodiments, compression jamb  400  is installed within the aperture through the structure at the stacking end  120  of the movable closure system (see  FIG. 1 a   ). Upon installation of the system, the slidable element closest to the stacking end (i.e. the slidable element which opens first and closes last, shown as first slidable element  102   a  in  FIG. 1 a   ) is adjacent to the compression jamb. The compression jamb includes a compression jamb C-channel  403 . (Hereafter, parts of the compression jamb with similar names to that of the static jamb or tracks, e.g. the C-channel, will be given a prefix of CJ for “compression jamb.” For example, the compression jam compression bar will be referred to as the CJ compression bar to distinguish it from the static compression bar, etc.). The CJ C-channel  403  is attached to the side of the aperture through the structure for the system adjacent to where the slidable elements are to stack. A CJ side rail  401  is couplably received by the CJ C-channel. At installation, the installer uses fasteners augmented with other materials as needed (shims, e.g.) to couple the CJ side rail with the CJ C-channel and ensure the CJ side rail is plumb, even if the CJ C-channel attached to the structure within the side of the aperture is not. 
     A CJ compression bar  402  is received by a recess in the CJ side rail. The CJ compression bar is held in place against the CJ side rail in part with two CJ compression bar endcap assemblies. Particularly, a CJ top bar endcap assembly  406  is attached to the CJ compression bar at its top, and a CJ bottom bar endcap assembly  407  is attached to the CJ compression bar at its bottom. A first tension spring  410  couples the CJ top bar endcap assembly to a CJ spring bracket  420  attached near the top of the CJ side rail, and a second tension spring couples the CJ bottom bar endcap assembly to another CJ spring bracket attached near the bottom of the CJ side rail. Each of the CJ top bar endcap assembly and the CJ bottom bar endcap assembly have a hook pivot pin  419  disposed through the CJ bar endcap  437  and secured by retaining clip  418 . In the case of the CJ top bar endcap assembly, the hook pivot pin is first inserted through drawbar  436 , which is nestled in between protrusions extending from the top surface of the CJ bar endcap, before the hook pivot pin passes through the CJ bar endcap. A connector loop  438  is attached to the drawbar to complete the CJ top bar endcap assembly. As will be described below, the connector loop is disposed about the wheel hub of the upper hinge wheel assembly of the first slidable element adjacent to the compression bar. As may be seen by comparing  FIGS. 8 c  and 8 e   , while the CJ top bar endcap assembly is coupled with a drawbar and connector loop, the CJ bottom bar endcap assembly is not. 
     As previously disclosed, after installation the compression jamb may be operated via handle  425 . During closure of the system, subsequent to pivoting each of the slidable elements into alignment with the track and sliding them towards the closure end  122 , handle  425  may be rotated to the six o&#39;clock position to control the expansion of a portion of the compression jamb towards the slidable element immediately adjacent to it. Specifically, the handle is linked with compression mechanism  408 , which includes pivoting elements that push against the CJ compression bar  402  moving it away from the CJ side rail  401 . The pushing action of the compression mechanism extends the tension springs  410  that couple the CJ compression bar and the CJ side rail. 
     The action of rotating the handle to extend the CJ compression bar from the compression jamb has several effects. First, the extended CJ compression bar compresses all the slidable elements against one another and against the static jamb at the closure end of the system, sealing the entire movable closure system, compressing the weatherstrips, and interlocking adjoining male and female endcaps of the slidable elements. Second, it moves the free wheel assembly of the first slidable element away from the insert guide such that the first slidable element is prevented from being rotated out of alignment with the tracks. The free wheel assembly, being out of alignment with the insert guide, would be retained by the adjustable upper track if pressure were applied to the handle of the first slidable element. Third, the first panel interlock would slide underneath a hanging vertical tab of the insert guide such that the first panel interlock would be barred by the vertical tab if pressure were applied to the handle of the first slidable element. Fourth, an extension of the compression mechanism rotates into position where the latch may engage with it, preventing the handle on the outside of the system from being operated. 
       FIGS. 9 a  and 9 b    are two front partial cutaway views of portions of the movable closure system, in accordance with an embodiment of the invention.  FIGS. 9 a  and 9 b    depict a portion of the first slidable element  102   a  in relation to a top portion of the CJ compression bar  402 , the hinge block  170  of the adjustable upper track, and the top CJ spring bracket  420  attached to the interior of the CJ side rail near its top, all of which are disposed at the stacking end of the system  120 . For ease of viewing and understanding, certain components are not depicted in  FIGS. 9 a  and 9 b    including the adjustable upper track&#39;s upper rail and C-channel and including the compression jamb&#39;s CJ side rail and CJ C-channel, but it will be understood that in an actual installation the foregoing components would likely be present. 
       FIG. 9 a    shows the first slidable element in alignment with the tracks previous to operation of the compression jamb during a closing operation of the system. It will be noted that a gap exists between the CJ compression bar and the weatherstrip  198   a  of the first slidable element. It should also be noted that the locator pin of the upper hinge wheel assembly  108  is extended into the corresponding locator hole  172   a  of the hinge block  170 . It will also be seen that the CJ tension spring  410  is compressed, such that the CJ compression bar would be retracted into the CJ side rail of the compression jamb. It may also be seen that connector loop  438 , which is mounted by drawbar  436  to the CJ compression bar by way of CJ compression bar endcap  437 , is disposed about the hinge wheel assembly wheel hub  150 . 
       FIG. 9 b    shows the first slidable element in alignment with the tracks subsequent to operation of the compression jamb during a closing operation of the system. As will be discussed more fully below, operation of the handle of the compression jamb extends the CJ compression bar  402  by way of a compression mechanism linked with the handle that comes into contact with the CJ compression bar, pushes it away from the stacking end  120 , and making contact with the edge of the first slidable element  102   a  closest to the stacking end. The pressure applied by the compression mechanism to the CJ compression bar compresses the weatherstrip  198   a , creating a seal between the CJ compression bar and the first slidable element. The first slidable element is pushed towards the closure end of the system. Any slidable elements between the first slidable element and the static jamb are pushed towards the static jamb in turn, and the weatherstrips of each adjoining slidable element compress as does a rubber seal of the static jamb. It will be noted that the gap between the CJ compression bar  402  and the weatherstrip  198   a  has closed. It should also be noted that the upper hinge wheel assembly  108  has moved away from the stacking end  120  and no longer rests directly below the locator hole  172   a  of the hinge block  170  intended for the first slidable element. It will also be seen that the CJ tension spring is extended by the push of the CJ compression bar by the compression mechanism while the CJ side rail to which the CJ spring bracket is attached remains in place. It may also be seen that the hinge wheel assembly wheel hub  150  is disposed to the opposite side of the connector loop  438  from its position in  FIG. 9   a.    
     It will be understood through viewing  FIG. 8 b    that at the bottom portion of the CJ compression bar  402 , another CJ compression spring links the CJ bar bottom endcap assembly  407  with a CJ spring bracket attached to the interior of the CJ side rail near its bottom. During the foregoing operation of the handle of the compression jamb during a closing operation of the system, the compression mechanism in contact with the CJ compression bar also extends the CJ tension spring linking the CJ bar bottom endcap assembly with the CJ spring bracket attached to the interior of the CJ side rail near its bottom. 
     Returning to  FIG. 9 a   , it may be seen that during an opening operation of the system in which the handle of the compression jamb is operated again, the compression mechanism disengages from the CJ compression bar and it is retracted towards the stacking end of the system. Particularly, the spring tension imparted to the CJ tension springs is released, and the CJ tension springs draw the CJ compression bar back into the recess of the CJ side rail. The first slidable element  102   a  is moved towards the stacking end in turn by virtue of the coupling of the CJ compression bar via connector loop  438  disposed about the hinge wheel assembly wheel hub  150  and the drawbar  436  attached to the CJ compression bar by the upper CJ compression bar endcap  437 . The foregoing movement of the first slidable element towards the stacking end of the system helps to move the locator pin of the first slidable element&#39;s upper hinge wheel assembly  108  underneath the locator hole  172   a  defining the top portion of the axis of rotation about which the first slidable element may pivot. 
     As previously disclosed, upon the first slidable element reaching the position where the locator pin of the upper hinge wheel assembly is directly below the corresponding locator hole, the upper free wheel assembly is aligned with the insert guide. The first slidable element may then be pivoted, causing the locator pin to extend into the hinge block as the upper free wheel assembly exits the insert guide. 
     It will be noted that the first slidable element  102   a  is not required to move substantially in order to pivot open. The lateral movement of the first slidable element ranges from the position where it may be pivoted open (i.e. when the locator pin of its upper hinge wheel assembly is immediately below the corresponding locator hole  172   a  of hinge block  172 ) to the position where the first panel interlock interfaces with the vertical tab of the insert guide (i.e. the position to which the CJ compression bar pushes the first slidable element when the system is closed via operation of the compression jamb). 
       FIGS. 10 a  and 10 b    are two front views of a portion of the movable closure system, and  FIGS. 11 a  and 11 b    are two cutaway views of portions of a compression jamb, in accordance with an embodiment of the invention.  FIGS. 10 a  and 10 b    depict a portion of the first slidable element  102   a  in relation to aspects of a compression jamb, including the CJ compression rail  401 , CJ compression bar  402 , compression mechanism  408 , and aspects of the adjustable upper track including upper C-channel  116  and upper rail  114 .  FIGS. 11 a  and 11 b    depict certain aspects of the compression jamb with other aspects being removed for ease of viewing and understanding. It will be understood that in an actual installation all components of the compression jamb would likely be present. For this presentation of the workings of the system,  FIGS. 11 a  and 11 b    correspond to their counterparts  FIGS. 10 a  and 10 b    and show the interior components related to the operation of the compression jamb. 
       FIG. 10 a    shows the first slidable element in alignment with the tracks previous to operation of the compression jamb during a closing operation of the system. It will be noted that a gap exists between the CJ side rail  401  of the compression jamb and slidable element  102   a , and that the CJ compression bar is not visible due to its retraction into the CJ side rail. It should also be noted in both  FIGS. 10 a  and 11 a    that handle  425  of the compression jamb is in the 12 o&#39;clock position (i.e. pointing towards the latch  431 ). It will also be seen that the latch  431  is in an open position (i.e. with the latch cam rotated outwards, towards the stacking end of the system). In  FIG. 11 a    it may also be seen (but not in  FIG. 10 a    albeit still true) that pogos  505  of the compression mechanism  408  are in a lowered position aimed towards the bottom of the system. It will also be seen that the CJ bar endcap assemblies  406  and  407  are not extended because of the spring tension and their coupling with the CJ spring brackets. The spring tension retracts the CJ compression bar which is disposed (but not visible in  FIG. 11 a   ) vertically between the two CJ bar endcap assemblies. It can also be seen that actuator  501  of the compression mechanism  408  is in a low position (relative to  FIG. 11 b   ) and away from latch  431 . Also visible in  FIG. 11 a    are bumpstop assemblies  409 , which are attached to the interior of the recess of the CJ side  401  and serve as bumpers to soften any impact occurring when the CJ compression bar is retracted by the tension springs. 
       FIG. 10 b    shows the first slidable element in alignment with the tracks subsequent to operation of the compression jamb during a closing operation of the system. Operation of the handle  425  extends the CJ compression bar from the CJ side rail by way of the handle&#39;s linkage with the compression mechanism  408  and its pogos  505 , which contact the inside of the CJ compression bar, pushing it away from the stacking end of the system and against the first slidable element  102   a . It will be noted in  FIG. 10 b    that the CJ compression bar  402  is visible due to its extension from the CJ side rail of the compression jamb, and that the gap between the compression jamb and the first slidable element  102   a  has closed. It should also be noted in both  FIGS. 10 b    and  11   b  that handle  425  of the compression jamb is in the 6 o&#39;clock position (i.e. pointing towards the bottom of the system). It will also be seen that the actuator  501  of the compression mechanism is in high position (relative to  FIG. 11 a   ), and that the latch  431  is in a closed position (i.e. with the latch cam rotated clockwise to engage a portion of the actuator). In  FIG. 11 b    it may also be seen (but not in  FIG. 10 b    albeit still true) that pogos  505  of the compression mechanism  408  are in a raised position aimed towards the top of the system. It will also be seen that the CJ bar endcap assemblies  406  and  407  are extended away from the stacking end of the system, lengthening the tension springs attaching the CJ bar endcap assemblies to the CJ side rail via the CJ spring brackets. The CJ bar endcap assemblies, attached at either end of the CJ compression bar, are extended in tandem with the CJ compression bar as the pogos  505  come into contact with the CJ compression bar, pushing the CJ compression bar away from the stacking end of the system and into contact with the first slidable element  102   a . The pogo extension takes place when handle  425  engages actuator  501  to raise the actuator, which is linked through the compression mechanism to the pogos. 
     Returning to  FIG. 10 a   , it may be seen that during an opening operation of the system in which the handle of the compression jamb is operated again, the rotation of the handle from the 6 o&#39;clock position back to the 12 o&#39;clock position lowers the actuator  501  and lowering the remainder of compression mechanism  408  including pogos  505 . (Latch  431 , if engaged, is first rotated counter-clockwise, releasing the latch cam&#39;s engagement with the actuator.) The pogos stop pushing against the CJ compression bar, and the CJ tension springs draw the CJ compression bar back into the recess of the CJ side rail because of the spring tension and their coupling with the CJ spring brackets attached to the interior of the CJ side rail. 
       FIGS. 12 a , 12 b , and 12 c    are two front views and a right side view of a portion of the movable closures system, in accordance with an embodiment of the invention.  FIGS. 12 a , 12 b , and 12 c    depict a portion of the first slidable element  102   a  in relation to portions of the adjustable upper track, including upper C-channel  115 , upper rail  114 , and insert guide  104 , and in relation to an adjacent slidable element  102   b . (It will be understood that in a system with a single slidable element, adjacent to slidable element  102   a  near the closure end would be the static jamb.) Particularly, in view are the upper free wheel assembly of the first slidable element including free wheel assembly wheel hub  148  and free wheel assembly load wheel  142 , as well as first panel interlock  608 . The first panel interlock includes an angled vertical tab, extending above and away from the top edge of the first slidable element. As can best be seen in  FIG. 12 c   , a side cross-sectional view of the adjustable top track and first slidable element  102   a  looking towards the insert guide from the stacking end of the system, the insert guide  104  includes a mating vertical tab underneath which the first panel interlock can pass when the first slidable element is slidably moved towards the closure end of the system. Two locking features are provided by the movement of the first slidable element  102   a  away from the stacking end, the movement depicted beginning in  FIG. 12 a    and completed in  FIG. 12 b   . First, the push by the CJ compression bar against the first slidable element moves the upper free wheel of the first slidable element (free wheel assembly load wheel  142  and free wheel assembly wheel hub  148 , for example) out of alignment with the insert guide. Additionally, the first panel interlock  608  at the top of the first slidable element  102   a  slides underneath the mating vertical hanging tab of the insert guide  104 . The foregoing two movements provide physical locking aspects which prevent the first slidable element  102   a  from being pivoted open subsequent to operation of the compression jamb. (As an additional security measure subsequent to operation of the compression jamb, latch  431  may be turned to prevent the compression jamb handle  425  from being moved until the latch is un-latched.) It should also be noted in  FIG. 12 b    that, subsequent to operation of the compression jamb during closing of the system, the gap between slidable elements  102   a  and  102   b  visible in  FIG. 12 a    is closed, the weatherstrips between the slidable elements are compressed, and the male endcap  205  is mated with female endcap  210 . 
       FIGS. 13 a  and 13 b    are a perspective view and an exploded view of the compression mechanism of the compression jamb, and  FIG. 13 c    is a perspective view of an actuator of the compression mechanism of the compression jamb, in accordance with an embodiment of the invention.  FIGS. 13 d  and 13 e    are exploded views of the handle and of the latch of the compression jamb, in accordance with an embodiment of the invention.  FIG. 13 f    is an exploded view of a pogo of the compression mechanism of the compression jamb, in accordance with an embodiment of the invention. In some embodiment, the compression mechanism  408  includes the actuator  501 , the actuator being swivably linked at its bottom to a straight link bar  502 , which is in turn swivably linked to pogo  505  at the bottom of the compression mechanism. The actuator is also swivably link to a clevis link bar  503 , which is in turn linked to pogo  505  at the top of the compression mechanism. The pogos are linked via pogo brackets  506  to the interior recess of the CJ side rail, as is the actuator. It will be noted that, to reduce the number of parts needed in the system among other reasons, both the upper pogo and lower pogo use the same parts, including the aperture through a portion of the pogos for a link pin with the link bars at the top of the pogos. The clevis link bar is therefore used in conjunction with a clevis pin in order to permit the travel of the pogo through the separated portions of the clevis link bar when the upper pogo swivels. Since nothing interferes with the movement of the link between the actuator and the lower pogo, a straight link bar may be employed instead of a clevis link bar. Turning to  FIG. 13 c   , it may be seen that actuator guides  504  are disposed through actuator travel limiters  509 . The mounting hardware for the actuator passes through the CJ side rail (see, e.g.  FIG. 8 b   ), then through the actuator guides, then through the actuator travel limiters before being fastened with a washer and nut arrangement. The effect is that the actuator is able to slide up and down relative to the CJ side rail. The up and down movement is driven by the compression bar handle  425 , which turns handle gear  426  which gearably interfaces with actuator teeth  507 . (The compression bar handle is mounted using, among other things, handle washer  427  and handle base  428 , with the CJ side rail in between the two.) Particularly, rotation of the compression jamb handle  425  counter-clockwise from the 12 o&#39;clock position to the 6 o&#39;clock position (see, e.g.  FIGS. 11 a  and 11 b   ) moves the actuator upward along the actuator guides attached to the side of the CJ side rail, moving the swivably linked pogos upward in turn. Conversely, rotation of the compression jamb handle  425  clockwise from the 6 o&#39;clock position to the 12 o&#39;clock position moves the actuator downward along the actuator guides, moving the swivably link pogos downward in turn. It should be noted that the foregoing operations are described from the inside of the structure. In some embodiments, a second compression jamb handle may be disposed on the opposite side of the compression jamb and may be operated from the outside of the structure. It may be seen that the actuator has two vertical sets of actuator teeth. One of these interfaces with the handle gear of the compression jamb handle of the system, while another set of actuator teeth interfaces with the handle gear of the compression jamb handle on the outside of the system (if present). It may also be seen that actuator has a latch interface  508  which is configured for mating with latch cam  432 . When the actuator is in the upper position (i.e. compression jamb handle in the 6 o&#39;clock position), the latch  431  may be rotated clockwise such that the latch cam  432  mates with the latch interface. (The latch is mounted using, among other things, latch washer  434  and latch body  433 , disposed with the CJ side rail in between the two.) This interlocking of the latch cam with the latch interface of the actuator prevents the actuator from traveling downward, disabling opening operations of the system. 
     Turning to  FIG. 13 f   , it may be seen that a pogo includes, but is not limited to, a pogo bracket  506  which attaches to the interior recess of the CJ side rail, a pogo pivot pin about which the pogo swivably rotates, the pogo pivot pin passing through the pogo bracket, the pogo base  513 , and secured with pogo pin retaining clip  517 . The pogo base has the aperture at its top through which pivot pins coupling the link bars of the compression mechanism pass. The pogo base has a channel for receiving a compression spring, as does the pogo top  512 . A pogo spring guide passes into the compression spring. A set screw  518  retains the pogo top on the pogo base. Accordingly, it may be seen that the pogo is springably compressible. Pogo top  518  has a rounded end which engages with an interior surface of the CJ compression bar. As the pogo is raised through a plane 90 degrees to the CJ compression bar, it compresses slightly. Past the 90 degree plane it begins to expand by way of the internal compression spring. The pogo then stops at the top of its travel range. The compression through the 90 degree plane means that the compression jamb handle pressure required to close the system increases as the handle is turned until the pogo is nearly at the end of its travel (i.e. at the 90 degree point). Subsequent pressure applied to the compression jamb handle in conjunction with the compression spring and the curved surface of the pogo end against the CJ compression bar cause the pogo to snap into a closed position. The pogos essentially cam past the 90 degree point and provide haptic user feedback similar to a control lever passing a detent. In this way, the CJ compression bar is prevented from retracting without intentional input from a user via operating the compression jamb handle. 
       FIGS. 14 a  and 14 b    are perspective views of a male endcap and a female endcap, in accordance with an embodiment of the invention. In some embodiments, the male endcap  205  and female endcap  210  are disposed in mated pairs at the top and the bottom of the edges of adjacent slidable elements and/or at the top and bottom of the static jamb or the compression jamb. (See, e.g.  FIGS. 1 i , 7 b , 12 a -12 b    for examples of location of the endcaps.) It may be seen that the adjoining endcaps interlock, providing a tighter seal of adjacent panels or jambs. The endcap protrusions (male endcap) and recesses (female endcap) may have both a horizontal and a vertical orientation, as well as a ramped/sloped arrangement, in order to assist the adjacent panels or jambs to align more precisely as they are compressed together during operation of the compression jamb. 
     In some embodiments, when stacking the slidable elements, a “stack holder,” which may be a low-profile right-angled piece affixed to the floor away from the movable closure system  100 , acts as a guide whereby the front edge of each slidable element  102  rotates into position such that each front edge is lined up along the stack holder. Springs may be deployed within the stack holder for springably receiving the front edges of each slidable element  102 . Upon stacking all the slidable elements  102 , the aperture through the structure is fully open. 
     In some embodiments, the upper track and lower track are adjustable to better conform to the surfaces at the top and bottom of the aperture through the structure. For example, if a floor is not perfectly level, the lower track may be adjusted so that a top portion of the lower track is substantially level. This enables rectangular panels to hang from the upper glazing profile and upper track with plumb sides, such that the rectangular panels may move smoothly across the tracks with the lower hinge wheel assembly affixed to the underside of each slidable element also able to move smoothly across the lower track. As previously disclosed, the lower hinge wheel assembly may also be springably deployed such that the slidable elements float along the lower track even if a minor uneven condition exists. In some embodiments, two movable closure systems are installed adjacent to one another, each with its own stack but sharing at least one of the compression jamb, the static jamb, the adjustable upper track, or the adjustable lower track. 
     While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this subject matter described herein. Furthermore, it is to be understood that the invention is defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). 
     While preferred and alternative embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of these preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.

Summary:
Improvements to movable closure systems which aid installability and reliability of said systems can include wheels running along the top and bottom of individual slidable elements, the wheels oriented horizontally and disposed within a track configured for receiving the horizontal wheels. The horizontal wheels reduce the vertical profile of the track-engaging portions of the slidable elements, enabling more of the slidable element to be used for glass or other aesthetically-preferable transparent materials. A track leveling system enables installers to more easily deploy and properly tune the system between floors and casings which are not perfectly flush. A compression jamb permits closure of the system via slidable elements pressing into the jamb to deflect it in order to better seal the closure comprised of the individual slidable elements. A durable hinge mechanism permits the sliding elements to rotate in order to stack the sliding elements at one end of the system.