Patent Publication Number: US-2017350128-A1

Title: Concealed panel clip for standing seam roof system

Description:
BACKGROUND OF THE INVENTION 
     Standing seam roof systems (SSRS) are applied over new metal building structures, or as retrofit systems over existing building roofs. Usually, these roof systems include roll-formed steel or aluminum roof panels. The panels may be roll formed in a fabrication shop and then delivered to the job site, or may be rolled at the job site with portable roll forming equipment. SSR systems are designed to be able to resist environmental loading such as rain, snow, hail, and wind and to remain weather tight. Specialized hold down clips have been designed to accomplish this task, and are future utilized to hold the roof panels to the substructure. These hold down clips are often rigid and restrictive in order to provide the necessary resistance to the forces (e.g., uplift forces) that the roof routinely experiences. However, the roof panels expand and contract due to, among other things, temperature fluctuations. A hold down clip that restricts movement of the panels due to uplift forces yet provides flexibility for the panels to shift may be desirable. 
     SUMMARY OF THE INVENTION 
     The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify critical elements of the invention or to limit the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description presented below. 
     In one embodiment, a standing seam roof clip system has a clip base with a horizontal portion and a vertical portion extending upwardly therefrom, and a clip tab comprising a return bend having a “U” configuration extending from a lower end of a vertical back surface, and a top portion comprising a hook for engaging with a roof panel. An interlocking element is formed in the vertical portion of the clip base, and has at least one seat with a substantially a “J” configuration which extends upwardly and outwardly from the vertical portion of the clip base and a respective shoulder extending from a top edge of the vertical portion of the clip base in a reverse “U” configuration. A roof panel is joined to the roof clip via the clip tab to form a seam; and the clip tab return bend engages with the clip base shoulder and seat. 
     In another embodiment, a standing seam roof clip system includes a clip base and a clip tab. The clip base includes a substantially horizontal portion and a vertical portion extending upwardly from the horizontal portion in an “L” configuration. An interlocking element is formed in the vertical portion and includes at least one seat having substantially a “J” configuration formed into and extending upwardly and outwardly from the vertical portion of the clip base; and a respective shoulder extending from a top edge of the vertical portion of the clip base in a reverse “U” configuration. The clip tab has a return bend having a “U” configuration extending from a lower end of a substantially vertical back surface, and a top portion comprising a hook for engaging with a roof panel. A plurality of apertures are formed into the clip base horizontal portion in a predetermined pattern. Additionally, the clip base vertical portion further includes at least one tab support extending perpendicularly therefrom. A roof panel is joined to the roof clip via the clip tab to form a seam; and the clip tab return bend engages with the clip base shoulder and seat to prevent vertical movement of the roof panel due to uplift forces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a panel clip according to one embodiment of the invention. 
         FIG. 2  is a blown up front perspective view of the panel clip of  FIG. 1 . 
         FIG. 3  is a rear perspective view of the panel clip of  FIG. 1 . 
         FIG. 4  is a blown up rear perspective view of the panel clip of  FIG. 1 . 
         FIG. 5  is a side view of the panel clip of  FIG. 1 . 
         FIG. 6  is a section view of the panel clip of  FIG. 1  engaged with a roof panel. 
         FIG. 7 a    is a close up view of a 360 degree seam formed between the panel clip and the roof panel, according to one embodiment of the invention. 
         FIG. 7 b    is a close up view of a 360 degree seam with a reverse hook formed between the panel clip and the roof panel, according to another embodiment of the invention. 
     
    
    
     WRITTEN DESCRIPTION 
     The present invention is directed to improved embodiments of standing seam roof systems which are typically applied over metal building structures, or as a retrofit roof system for existing buildings. Standing seam roof systems usually include roll formed steel or aluminum roof panels, which may be roll formed in a fabrication shop and delivered to the job site, or alternately, rolled at the job site with portable roll-forming equipment. The roof panels may be secured to the substructure with specialized hold down clips, which may allow the panels to move somewhat freely without damaging the substructure. The clips may be concealed below, and inside a high rib of the SSRS roof panels. Hold down clips thus provide for the structural connection between the SSRS panels and the subframing (e.g., steel framing, steel decking, wood framing, wood decking, concrete, etc.) without the need for fasteners that are exposed to the weather. 
     There are many considerations that go into the design of the clips, including the temperature range that the SSRS will be exposed to from the outside, the average temperature inside the substructure, how large the SSRS panels are (and especially, the distance between the expansion joints which allow the panels to move), and the coefficient of thermal expansion of the connected elements. 
     SSRS panels and clips may be connected together with interlocking folds that may be partially formed during the panel rolling process. The SSRS clips may include clip tabs which may be formed to match the configuration of a high rib of the SSRS panel such that a tight fit is achieved between the SSRS panel and the corresponding clip. In a typical configuration, two SSRS panels may be interlocked, with the SSRS clip sandwiched between female and male ribs of the respective SSRS panels. To form the tight connection between the SSRS panels and clips, an electric seaming machine with uniquely shaped forming wheels, which may match the SSRS panel configuration, completes the interlocking processes by inelastically intertwining the clip and the panel into an interlocked seam. 
     SSRS are designed to be remain weather tight in undesirable environmental conditions, such as rain, snow, hail, and wind. Due to the exposure to these adverse elements, SSRS may include coatings designed to resist the effects of corrosion and weathering. SSRS panels are designed to expand and contract with changes in temperatures independent of the supporting substructure. However, traditional hold down clips may be rigid and restrictive, thus preventing the free movement of the SSRS panels. 
     The standing seam roof systems disclosed herein provide overall improved performance and flexibility as compared to prior art systems. The present invention utilizes a two piece configuration comprising roof panels that interlock in a unique way via a specially designed roof clip such that the overall performance of the roof system is significantly improved and is more economical. As described in detail below, the uniquely designed clip may have increased resistance to wind or uplift forces and increased ability to translate horizontally to accommodate greater roof run distances and/or movement of the roof panels due to temperature fluctuations. 
     Referring now to the figures, the roof clip assembly  10  includes a clip base  100  and a clip tab  200 . The clip tab  200  is in slideable engagement with the clip base  100 . As will become apparent from the description below, the clip base  100  is secured to a substructure  20  ( FIG. 6 ), and the clip tab  200  connects to the roof panels to provide means for movably securing roof panels to the substructure  20 . 
     With reference now to  FIGS. 2 and 4 , the clip base  100  comprises an “L” shaped member having a bottom horizontal portion  105  extending to a substantially 90 degree bend  107  leading to a back vertical portion  110 . Reinforcement ribs  112  may be stamped into the back vertical portion  110 . The reinforcement ribs  112  may provide strength to the clip base  110  and prevent buckling due to compression forces received by the SSRS. The bend  107  may additionally include areas of reinforcement  108 . 
     A plurality of apertures  115  may be formed into the bottom portion  105  for engaging with the substructure  20  ( FIG. 6 ). The apertures  115  may be provided in a variety of predetermined sizes and/or pattern configurations which may allow the clip base  100  to attach to any substructure  20 . The pattern of the apertures  115  formed in the bottom portion  105  may be determined based on the length and width of the bottom portion  105 , as well as the particular requirements of the supporting structure. For example, the apertures  115  may be configured to accommodate, for example, steel cold formed purlins, bar joists, steel decking, wood decking, wood joists, and other secondary support systems. 
     Z purlins are commonly used in the metal building industry as substructure  20 . Z purlins have a tendency to rotate torsionally when loaded. Typically, to prevent the torsional rotation, the z-purlins require independent bracing. Here, the pattern of the apertures  115  formed into the bottom portion  105  of the clip base  110  may be configured such that, when the clip base  100  is secured to the substructure  20 , the clip  10  recognizes increased resistance to torsional rotation. In operation, the torsional forces are transferred from the z purlin to the clip base  100  and into the clip tab  200 . The forces may be transferred even when the clip tab  200  is shifted from its preferred position due to thermal expansion or contraction of the SSRS. Thus, the need for additional torsional bracing is advantageously eliminated. 
     The clip base  100  may be secured directly to the supporting substructure  20  via the apertures  115  using any appropriate mechanical fastener, such as self-drilling screws, screw bolts, nuts and bolts, wood screws, deck screws, shot pins, rivet, et cetera. Further, the clip base  100  may be secured to the substructure  20  via welding, such as spot welding, for example. 
     Moving on, the back vertical portion  110  may include at least one tab interlocking element  120 , comprising a seat  125  and a shoulder  130 . The seat  125  may be punched out of the back vertical portion  110  and have a substantially “J” configuration. Thus, the seat  125  may include a bottom portion  125  extending outwardly from the back vertical portion  110  and a spine  127 , forming an upwardly directed opening  128  therein. 
     The shoulder  130  may extend 180 degrees downwardly from the back vertical portion  110  to form an inverted “U” having an upper curved portion  132  and a vertical portion  134 , forming a space  136  therebetween ( FIG. 2 ). The shoulder vertical portion  134  may extend into the upwardly directed opening  128  of the seat  125 . The shoulder  130  may extend the majority of the length of the clip base  100  to engage as much of the clip tab  200  as possible. In one embodiment, illustrated by the figures, the clip base  100  includes two shoulders  130 , one on either end of the clip base  100 . It may be advantageous for the shoulder(s)  130  to extend the majority of the length of the clip base  100  so that the upper curved portion  132  may support the high rib  302  of the roof panel  300  ( FIG. 6 ). The horizontal portion  305  of the roof panel high rib  302  may rest firmly on the shoulders  130  to provide support for gravity loading (e.g., foot traffic, snow, et cetera). 
     The clip base  100  may further include additional tab supports  140  which may extend outwardly in a direction perpendicular to the back vertical portion  110 . The tab supports  140  may provide still additional support for the high rib  302  of the roof panel  300 , as illustrated in  FIG. 6 . In combination, the shoulder(s)  130  and the tab supports  140  may be sufficient to support a substantial majority of the SSRS panel during periods of downward loading. 
     Continuing on, the clip tab  200  may be configured to slideably engage with the clip base seat  125  and the shoulders  130 . Accordingly, the clip tab  200  may be formed at the bottom by a “U” shaped return bend  210  extending from a substantially vertical back surface  214 . The return bend  210  may initially slideably engage with a shoulder  130  located at a first end of the clip base  100 . The return bend  210  may be respectively received by the shoulder  130  such that a free end  212  of the return bend  210  rests in the space  136  formed by the shoulders  130  ( FIGS. 1, 3, 5 ). The clip tab  200  may then be slid into position, wherein the clip tab  200  is fully engaged with the respective shoulder(s) on the clip base  100 . The return bend  210  may further rest in the seats  125  formed into the clip base  100 . 
     The combination of the seats  125  and the shoulders  130 , when engaged with the clip tab  200 , prevents vertical movement of the clip tab  200  as a result of uplift loads on the roof. However, the clip tab  200  is allowed to freely slide longitudinally as a result of shifting roof panels  300 . The clip tab  200  may only be limited in its longitudinal slide length by the length of the clip base  100 , as the clip tab  200  may be unable to maintain connection of the roof panels  300  with the substructure  20  if the clip tab  200  becomes unconnected from the clip base  100 . However, the seat  125  and shoulders  130  may be designed to allow the clip base  100  to maintain excellent resistance to uplift forces, even when the slide limits are approached (e.g., near disengagement of at least one end of the clip tab  200  from the respective interlocking member  120 ). 
     As noted above, the clip tab  200  may be allowed to freely slide longitudinally along the length of the clip base  100 . The clip base  100  may be configured to engage with any length clip tab  200 . For sliding clip tabs  200 , such as those described herein, the range of longitudinal movement may be virtually unrestricted in order to accommodate various amounts of panel movement. Thus, as is understood by those in the art, the roof clip  10  simultaneously provides for anchorage of the SSRS panels to the supporting substructure while resisting uplift forces and for the clip to freely float due to movement of the roof panels caused by thermal expansion and contraction. 
     Floating roof systems may still require a point of anchorage somewhere along the length of the panel  300  to ensure that the panels  300  stay connected to the substructure. At the point of anchorage, no movement of the panels  300  is allowed, and the longitudinal forces from downslope drag loads are delivered from the point of anchorage to the substructure. The exact position of the anchorage may vary. Accordingly, another embodiment of the clip assembly may include a base portion  100  and a clip portion  200  that are fixed together such that sliding is prevented. 
     The clip tab  200  may be connected to the roof panels  300  via a top portion hook  215 . The top portion  215  of the clip tab  200  may be uniquely formed to match the unseamed shape of the SSRS panel  300 , as required by the particular panel. In one embodiment, illustrated best in  FIG. 3 , the top portion  215  extends from the back surface  214  and includes an approximately 90 degree bend  216  from the back surface  214 , leading to a substantially horizontal portion  218 . The horizontal portion  218  concludes in a 180 degree bend  220  to complete the top portion  215 . 
     The clip tab top portion  215  may be formed to match the unseamed shape of the respective SSRS panel  300 , as required. The clip tab top portion  215  may be roll formed with the SSRS panels according to known technology (e.g., with an electric seaming machine). The respective SSRS panels and the clip tab  200  may be inelastically folded to form a complimentary 360 degree seam  400  ( FIG. 7 a   ). Alternately, the respective SSRS panels and the clip tab  200  may be inelastically folded to form a 360 degree seam having a reverse bend  400 ′ ( FIG. 7 b   ). 
     Typically, under uplift loading, the seams  400 ,  400 ′ formed between the SSRS panels  300   a,    300   b  receive a significant amount of force, causing the flat sections  310  of the panels to bow upwards between the high ribs  302 . This may cause the seams  400 ,  400 ′ to pull apart. Therefore, one of ordinary skill in the art may recognize that the 360 degree seam with the reverse bend  400 ′ may be preferable to prevent the seams  400 ′ from pulling apart when the SSRS experiences uplift loading. When extreme uplift loads are applied to the SSRS panels  300 , and the SSRS panels  330  would otherwise begin to pull apart at the seams  400 ′, the reverse bend  405  locks the panels  300  in place on the clip  10 . Accordingly, greater loads can be recognized without damaging the SSRS panels  300  and/or clips  10 . 
     The electric seaming machine must have rollers designed to join the SSRS panels and clip tab  200  tightly together according to the various configurations described herein or otherwise known in the art. In order to accomplish this, the clip tabs  200  may be joined to the roof panels in sections. However, a single clip  10  may not extend the entire length of the roof panel. Accordingly, in order to accommodate smooth run-on of the rollers of the electric seaming machine onto the clip tab  200 , the clip tab  200  may be equipped with mitered ends  230  to prevent the rollers from pushing the clip tab  200  as the rollers move over the clip tab ends  230 . The mitered ends  230  may prevent sudden impacts to the edge of the clip tab  200  by the seaming machine. If the seaming machine hits a squared-off end, the clip tab  200  may be pushed forward and out of the desired position. Therefore, the mitered ends  230  may keep the seaming machine rollers from pushing the clip tab  200  off center as it runs therealong. The clip tab  200  may be mitered at both ends to accommodate seaming operations in either direction. 
     The clip tab  200  and/or roof panels  300  may additionally be provided with a bead of sealant to afford further resistance to moisture penetration. A sealant bead may be optionally applied inside the bend  216  in the top portion  215  of the clip tab  200 . A sealant bead may additionally be place at an underside of the unseamed female SSRS panel  300   b.  In this way, as the seaming machine rolls along the length of the panels  300   a,    300   b  to form the seals  400 ,  400 ′, the sealant beads may flow together at the ends of the clip tab  200 . It may be understood by those of skill in the art that the sealant beads are preferably aligned as described above to ensure that the clip tab  200  is completely encapsulated with sealant on both side of the clip tab  200 , including around the ends  230  of the clip tab  200 . 
     The roof clip  10  may be made of any appropriate material, such as strengthened plastic, steel, aluminum, et cetera. In a preferred embodiment, the clip assembly  10  is manufactured from stainless steel, and is factory assembled such that the clip tab  200  is engaged with the clip base  100  to form the clip assembly  10 , which is shipped at one piece. 
     Many different arrangements of the described invention are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention are described herein with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the disclosed improvements without departing from the scope of the present invention. Further, it will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures and description need to be carried out in the specific order described. The description should not be restricted to the embodiments described herein.