Abstract:
Provided is an internal structural mullion for a standing seam panel system. A two-piece assembly includes a man extrusion having one hooked portion and a secondary extrusion having an opposing hooked portion. A cavity is defined on the main extrusion, and the secondary extrusion includes a foot wherein upon insertion of the foot into the cavity, the foot forms a fulcrum about which the secondary extrusion can bend away from the main extrusion and be tightened or loosened by the tightening or loosing of a screw, as a result forming a clamp for engaging panels of the panel system with variable pressure. Further, when clamped a continuous gasket seal occurs at a level just inside the panels so as to form a barrier against the intrusion of water.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The instant application claims benefit of provisional application Ser. No. 61/118,703 filed Dec. 1, 2008 and provisional application Ser. No. 61/226,875 filed Jul. 20, 2009, the disclosures of which are herein incorporated by reference. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The instant invention relates to the joining of panels that contain upright legs at their edges. In particular, described is an aluminum joining member, or mullion, which can span great distances and which allows for the free movement of the panels both pivotally about the mullion and vertically with respect to the substrate, while at the same time forming a water-tight seal. 
     2. Description of the Related Art 
       FIG. 1  shows a typical, prior art joint member. In the field of building materials composed of exterior panels which incorporate extensions in the form of legs or flanges along their sides, systems such as shown in  FIG. 1  are available to join together two such panels. Drawbacks exist in these and other types of joining members. 
     U.S. Pat. No. 4,222,210 to Hanstein et al. teaches a conversion muntin including a muntin cover element and a clamping strip. U.S. Pat. No. 4,332,119 to Toews shows a claw engaging means for rectangular panels. U.S. Pat. No. 6,164,024 to Konstantin describes a glazing panel system held together with a batten joining connector. U.S. Pat. No. 6,536,175 to Contero teaches an assembly of panels and jointing elements wherein the jointing element is U-shaped. 
     Prior art hooking portions can cause great pressure against the panels without leaving room for rotation of the panel elements relative to the clamping system. Furthermore, prior art systems are relatively weak when it comes to spanning between girts, and they cannot be notched when an architect does not want the glazing system to protrude too far from the plane of the wall girts. Finally, there are no provisions for accepting reinforcing steel bars and therefore the distances they span can be quite limited. These and other drawbacks are solved by the instant invention, as follows. 
     SUMMARY 
     This invention comprehends a mullion wherein, at a typical joint, two panels are firmly held but simultaneously allowed to expand or contract longitudinally relative to the aluminum members which hold them, while at the same time the mullion can span great distances with adequate support while further maintaining a water-tight seal. 
     It is therefore the objective of the instant invention to provide an aluminum joining member (mullion) which can be installed on a wall and wherein the mullion is initially partially open so as to easily receive the legs or flanges of the panels but also wherein the batten is designed to be flexible to the point where it can be drawn tightly to clamp upon the two legs of the panels. 
     It is further the objective to provide a two-piece mullion wherein when the mullion is closed (clamped), via the pressure of an internal screw system, a continuous gasket seal occurs at a level just inside the panels so as to form a harrier against the intrusion of water. 
     Another feature involves a series of detents at the innermost portion of the mullion to allow separate clips to engage those detents in such a way as to secure the mullion to a substrate (such as a horizontal girt) and still allow a sliding action to accommodate the thermal differential movement between the mullion and the substrate. 
     Yet another feature of the mullion includes a secondary extrusion which for the considerable widening of the hooking portions which engage the panels. 
     Accordingly, what is provided is an internal structural mullion for a standing seam panel system, comprising a main extrusion having an open side, an opposing closed side, an innermost portion, and a main hooked portion opposite the innermost portion. The main extrusion further comprises a cavity defined along the open side proximate to the innermost portion, and a screw track defined within the open side adapted to receive a screw. A secondary extrusion has a first leg portion, a medial leg portion, an end leg portion, and a leg hooked portion. A screw hole is defined through the medial leg portion positioned to be in alignment with the screw track of the main extrusion; and, the secondary extrusion further comprises a foot formed integral to the first leg portion and configured to seat within the cavity of the main extrusion. Thus, wherein upon insertion of the foot into the cavity, the leg hooked portion opposes the main hooked portion and the foot forms a fulcrum about which the secondary extrusion can bend away from the main extrusion and be tightened or loosened by the tightening or loosing of the screw, as a result forming a two-piece clamp for engaging panels of the panel system with variable pressure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a prior art mullion. 
         FIG. 2  shows a top cross-section of the instant invention&#39;s main extrusion. 
         FIG. 3  shows a top cross-section of the instant invention&#39;s secondary extrusion. 
         FIG. 4  shows a top cross-section of the main mullion assembled with joined main extrusion and secondary extrusion. 
         FIG. 5  shows a top cross-section of the assembled mullion exploded to show the relation to a fastener, clamping screw, and panels. 
         FIG. 5   a  shows a top cross-section of an embodiment of the mullion wherein the main extrusion is configured to receive one or snore reinforcing steel bars. 
         FIG. 6  shows a side elevation view of the assembled mullion fastened to a girt after notching of the it unionassembly. 
         FIG. 7  shows a side elevation view of the assembled mullion fastened to a girt without notching. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a prior art panel joining member comprising two hooked portions. The panel joining member is one, integral piece having a bolt and nut which, when tightened, limits hooked portions. Of note is that the pressure provided by the joining member in this configuration is not easily made variable, not readily accessible, and as located, the range of panel-applied pressure is limited. 
     With reference then to  FIGS. 2-7  representing the instant invention, the instant mullion includes an extruded, main mullion piece or main extrusion  20  and a secondary extrusion  30 , thus being a two-piece assembly. The extrusions  20 ,  30  typically travel the entire height of the panels and are made of metal such as aluminum, but they can be constructed of any rigid polymer or composite. Since typically running the height of the panels, one or more of the views of the drawings are depicted in cross-section and the side elevational views of  FIGS. 6 and 7  show only one fastening point. Accordingly, “a” as used in the specification and claims as it relates to components including but not limited screws, tracks, washers, and holes may mean one or more because there typically will be a plurality of components along the entire height of the mullion and panel. 
     Main extrusion  20  has an innermost portion  26  which is innermost relative to a wall of a building or the like, and main hooked portions  4 ,  4 ′ at the opposite end, furthest away from building. Main extrusion  20  also has an open side  20   a  and a closed side  20   b . Closed side  20   b  refers to the side of the main extrusion  20  which does not receive any additional components. Open side  20   a , opposing closed side  20   b , is configured to receive the secondary extrusion  30 . To receive secondary extrusion  30 , main extrusion  20  includes a cavity  21  defined along the open side  20   a , as further described. 
     Secondary extrusion  30  has a first leg portion  31   a  medial leg portion  32 , an end leg portion  33 , and a foot  34  defined integral with the first leg portion  31 . Medial leg portion  32  is offset from the first leg portion  31  to generally be non-coplanar. End leg portion  33  is substantially co-planar with first leg portion  31  and thus offset from the medial leg portion  32 . Foot  34  of secondary extrusion  30  is placed within cavity  21  of main extrusion  20 , resulting in a hinge-like fulcrum by which secondary extrusion  30  is adapted to bend away from main extrusion  20  and thus widen the gap formed between the hooking portions  4 ,  4 ′ while still being maintained on main extrusion  20 . Accordingly, the secondary extrusion  30  forming part of the assembled mullion is removably inserted into the main extrusion  20 . Of note also is that using the instant two-piece configuration with a hinge-like fulcrum, the secondary extrusion  30  is caused to spring open slightly relative to the main extrusion  20 . This wide “open” position allows easy insertion of the panels  1 ,  1 ′ ( FIG. 5 ). 
     With reference to  FIG. 5 , as above, the main extrusion  20  and the secondary extrusion  30  terminate, respectively, in the mirroring hooking portions  4 ,  4 ′. As part of the instant system typically at least a pair of the two panels  1  and  1 ′ meet at a joint  1   a , and the panels  1 ,  1 ′ have standing flanges  2 ,  2 ′ and detents  5 ,  5 ′ near the bases of the flanges  2 ,  2 ′. Hooking portions  4 ,  4 ′ therefore engage the detents  5 ,  5 ′ of the panels  1 ,  1 ′. The main hooked portion  4  of the main extrusion  20  engages one detent  5 . The hooked portion  4 ′ of the secondary extrusion  30  engages the opposing detent  5 ′, but only when a screw fastener  7  (which may be spaced approximately 12″ o.c.) has been inserted and tightened. As designed, tips  4   a  and  4   b  of hooking portions  4  are generally U-shaped with a low profile relative to hooked portions  4 ,  4 ′ to leave room for rotation of panels  1 , I′ relative to the main extrusion  20  and secondary extrusion, as a result keeping the panels  1 ,  1 ′ lodged but without excessive positive pressure. 
     A screw hole  32   a  is defined through the medial leg portion  32 . A screw track  14  is defined within the open side  20   a  of main extrusion  20 . Both components are adapted to receive a screw  7 . Therefore, when screw  7  is driven tight through screw hole  32   a  in medial leg portion  32 , secondary extrusion  30  engages the top of screw track  14 , thus limiting the extent the hooking portions  4 ,  4 ′ can exert pressure against the panels  1 , P. 
     The main extrusion further comprises an internal leg  22  formed parallel to the screw track  14 . Internal leg  22  spans a distance between the open side  20   a  and the closed side  20   b  of main extrusion  20 . Internal leg  22  has two internal leg ends  22   a ,  22   b . One end  22   b  is formed integral to the closed side  20   b  of main extrusion  20 . The other internal leg end  22   a  terminates at the open side  20   a  to form a gasket-abutting end. 
     Secondary extrusion  30  includes opposing nubs  35 ,  36  formed below the end leg portion  33 . In this manner a gasket seat  23  is defined. A rubber strip or similar gasket  21   a  is fixed within gasket seat  23 . When screw fastener  7  is tightened as described above, gasket  21   a  is driven against internal leg end  22   a  of main extrusion  30 , thus causing a water seal. Further, the connection between internal leg  22  with gasket  21   a  restricts future movement of internal leg  22  either inward or outward relative to the building to enhance structural integrity. 
     With further reference to  FIG. 5   a , shown is an embodiment wherein the main extrusion  20  is configured to receive one or more reinforcing steel bars  53   a ,  53   b . Main extrusion  20  is hollow to define extrusion interior  20   d . L-shaped finger  20   c  abuts open side  20   a  adjacent to screw track  14 . L-shaped finger  20   c  is configured to capture one end of a small reinforcing bar  53   a , while the other end of small reinforcing bar  53   a  is situated abutting innermost portion  26  of main extrusion  20  between alternate screw track  14   b  and open side  20   a . A larger reinforcing bar  53   b  can also be situated generally parallel to small reinforcing bar  53   a  within extrusion interior  20   d  having one end situated between the other side of alternate screw track  14   b  and closed side  20   b , with its other end situated between screw track  14  and closed side, proximate to internal leg  22 . As herein defined, “alternate screw track  14   b ” is configured similar to screw track  14  but it is positioned trans-axially to screw track  14 . Alternate screw track  14   b  can be used for some building configurations which require or can accommodate certain interior fastening systems, but as shown it also serves as a means for spacing reinforcing bars  53   a ,  53   b . Because the instant main extrusion  20  is adapted to contain reinforcing steel bars  53   a ,  53   b , the system can span large distances with great strength. 
     Referencing again  FIG. 5 , and further  FIGS. 6 and 7 , at least one pair of slots  24 ,  25  are defined at the innermost portion  26  of main extrusion  20 . Under certain conditions then, a clip  50  may be employed to engage slots  24 ,  25  for the purpose of fastening mullion to a building substrate. “Substrate” as defined herein means the building itself a building column, or any structural member in a framed wall supported by a column such as a horizontal girt  70 . Such fastening will take place via screw fasteners  60 ,  61  which pass through the clip  50  and into the substrate. The clip ends  51 ,  52  at the ends of clip  50  are smaller than slots  24 ,  25 , thus allowing the mullion to move vertically, unrestricted, to accommodate expansion or contraction differences with the substrate. Of note is that in some instances clip  50  does not have to be used. But when there is no horizontal surface to screw to on the substrate, such as when the girt  70  is composed of an angle and a leg of the angle protrudes towards the outside of the building, clip  50  provides the transition. 
     As shown with reference to  FIGS. 6 and 7 , mullion  10  (main extrusion and secondary extrusion and all associated components assembled) rests directly against a typical girt  70  and is fastened to it via screws  60 ,  61 . Said screws pass through slotted holes  71 ,  72 , which are defined throughout internal leg  22  and innermost portion  26  along the height of the mullion  10 . Slotted holes  71 ,  72  are offset from screw tracks  14  so that screws  61 ,  62  can penetrate unabated into extrusion interior  22   d  and through innermost portion  26  then into girt  70  while crossing above (or below) each screw track  14 ,  14   b  (notably screws  60 ,  61  would also travel between reinforcing steel bars  53   a ,  53   b ). Thus, because of slotted holes  71 ,  72 , mullion  10  while fastened is allowed to move vertically in the event of expansion and contraction differences with the typical girt  70 . A rectangular stainless steel washer  74  has two holes through which screws  60  and  61  can pass. The function of the stainless steel washer  74  is to bridge the gap caused by the slotted holes  71 ,  72  (See  FIG. 7 ). 
     In  FIG. 6 , the mullion assembly has been notched to accommodate a condition wherein the mullion is required to extend outward only a short distance from the face of girt. In this case, fasteners will pass through slotted holes  71 ,  72  in the wall of mullion  10 , the slots again being designed to allow vertical movement of the mullion relative to the substrate girt. Again, a stainless steel rectangular washer  74  is employed to cover the slotted openings. Of note is that because gasket  21   a  ( FIGS. 2-5 ) is at a point just inboard of the panels, the water seal is viable in either the notched or full depth configurations.