Abstract:
A fastening system is provided. In another aspect, a hook fastens a photovoltaic panel assembly to a building roof. Another aspect employs catches that removeably attach an auxiliary component, such as a solar panel frame, to a building in hinge and slide motions for engagement of the catches. A method of installing a fastening system is additionally provided.

Description:
BACKGROUND AND SUMMARY 
       [0001]    The present application relates generally to an attachment system and more particularly to a photovoltaic panel fastening system for a building. 
         [0002]    Conventional photovoltaic or solar panels are mounted to roofs of buildings through screw-in clips or the like. Examples of such conventional devices are disclosed in U.S. Patent Publication No. 2011/0088740 entitled “Photovoltaic Panel Clamp” which published to Mittan et al. on Apr. 21, 2011, and U.S. Pat. No. 6,672,018 entitled “Solar Module Mounting Method and Clip” which issued to Shingleton on Jan. 6, 2004, both of which are incorporated by reference herein. Such conventional methods cause the installer to juggle many loose fasteners while simultaneously holding heavy solar panels and/or roof mounting components, often on a tilted metal roof in unpleasant weather conditions. Furthermore, such traditional multi-piece screw or bolt arrangements take considerable time to install while also having inconsistent installation torque values, especially in the common situation where many of these solar panel mounting devices are required for each roof. 
         [0003]    In accordance with the present invention, a fastening system is provided. In another aspect, a hook fastens a photovoltaic panel assembly to a building roof. Another aspect employs catches that removeably attach an auxiliary component, such as a solar panel frame, to a building in hinge and slide motions for engagement of the catches. A method of installing a fastening system is additionally provided. 
         [0004]    The present attachment system is advantageous over traditional devices. For example, in one aspect, a simplified installation motion is employed to engage an auxiliary component, such as a photovoltaic panel assembly, with a mounting hook. In an aspect of the present attachment system, an auxiliary roof component is quickly and easily secured to a building roof in a fast manner without requiring the installer to juggle multiple parts. In another aspect, a catch of the fastening system is very inexpensive to manufacture and assemble. Furthermore, the present fastening system is preassembled to a building roof via an easy to install roof clamp, prior to assembly of the solar panel assembly to the fastening system. The catch of the present attachment system ideally allows for tolerance variations and part expansion. Additional advantageous and features of the present invention will become apparent in the following description and appended claims, taking in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a perspective view showing a preferred embodiment fastening system securing photovoltaic panel assemblies to a building roof; 
           [0006]      FIG. 2  is an exploded perspective view showing the preferred embodiment fastening system; 
           [0007]      FIG. 3  is a perspective view showing the preferred embodiment fastening system retaining photovoltaic panel frames; 
           [0008]      FIG. 4  is an end elevational view showing the preferred embodiment fastening system retaining the frames; 
           [0009]      FIG. 5  is a perspective view showing the preferred embodiment fastening system; 
           [0010]      FIG. 6  is a cross-sectional view, taken along line  6 - 6  of  FIG. 4 , showing the preferred embodiment fastening system retaining the frames; 
           [0011]      FIG. 7  is an end elevational view showing a pair of preferred embodiment fastening systems retaining the photovoltaic panel assemblies; and 
           [0012]      FIG. 8  is a perspective view showing a catch of an alternate embodiment fastening system. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIGS. 1 and 7  illustrate a building  21  having a tilted roof  23 , preferably made from sheet metal sections joined together at folded over, raised standing seams  25 . Auxiliary roof components, preferably multiple photovoltaic or solar panel assemblies  27 , are secured to seams  25  by way of multiple fastening systems  29 . Each photovoltaic panel assembly includes metal and glass sheets  30  with silicon wafers, attached to peripheral mounting frames  111 . Each fastening system  29  includes a roof clamp  31  and a catch or mounting bracket  33 . 
         [0014]    FIGS.  2  and  4 - 6  depict roof clamp  31  attached to seam  25  of roof  23 . Roof clamp  31  includes a saddle  41 , a roof seam-engaging wedge  43 , and an elongated shaft or securing member  45 . A generally C-shaped leaf spring  47  has pins at one end attached to holes in saddle  41 , and is trapped between a head of shaft  45  and wedge  43  at the other end. Spring  47  serves to retain wedge  43  to saddle  41  in a pre-assembled state prior to seam installation while also biasing wedge  43  into a clamping position toward a top wall of saddle  41  and seam  25 . Thus, camming action of roof seam-engaging wedge  43  along diagonal internal surfaces of saddle  41  compresses roof clamp  31  to seam  25 . Tightening of a nut  49  onto shaft  45  secures wedge  43 , and thus roof clamp  31 , to the seam. When an installer manually pushes a proximal exposed end of shaft  45  (opposite its head) toward saddle  41 , against the biasing force of spring  47  and through an oversized hole in the top wall of the saddle, wedge  43  is pushed to an open position allowing seam access into an opening of saddle  41 . Notably the same shaft  45  that secures roof clamp  31  to roof  23  also secures an auxiliary-retaining device, such as catch  33 , to roof  23  along a top surface of saddle  41 . 
         [0015]    Saddle  41 , roof seam-engaging wedge  43 , shaft  45 , spring  47  and optionally catch  33 , are pre-assembled prior to placing roof clamp  31  in the proximity of roof seam  25 . “Pre-assembled” for the clamp refers to the components being attached as a single unit such that shaft  45 , and optionally a very loose engagement of nut  49  (so as to provide lost motion movement of the spring and wedge relative to the saddle), keep them attached together. This can be achieved either on the ground at the work site, at a remote site, or at the factory in which roof clamp  31  is manufactured. When wedge  43  is retracted to trap seam  25  between an inner foot of the wedge and the inner opening edge of saddle  41 , a portion of shaft  45  extends beyond the top surface of saddle  41  such that the proximal threaded end of shaft  45  also provides an attachment point for catch  33  and nut  49 . The roof clamp preferably attaches to the roof seam due to lateral seam compression of the wedge but without seam piercing or side-mounted threaded screws. 
         [0016]    Referring now to  FIGS. 3-5  and  7 , catch  33  is preferably a stamped metal bracket including a generally flat and rectangular base wall  101 , upwardly bent side walls  103  and at least two, and more preferably four, hooks  105  disposed upon side walls  103  adjacent corners of the catch. The side walls are of reduced height between the associated pairs of hooks. Each hook  105  has an inwardly facing access slot  107  defined by a somewhat triangularly shaped inside wall surface. Moreover, an upwardly pointed barb  109  extends from an upper edge of side wall  103  below each hook  105  to gouge into a bottom of frame  111  secured in access slot  107 . Barbs  109  may optionally serve as electrical grounding connections to frame  111 . 
         [0017]    A slotted aperture is centrally provided in bottom wall  101  of catch  33  to receive the threaded end of shaft  45  for nut attachment thereto. Furthermore, at least two tabs  121  are downwardly bent from bottom wall  101  of catch  33 . These tabs  121  assist in orienting catch  33  relative to saddle  41  of roof clamp  31  prior to full securing of nut  49  on shaft  45 . Catch  33  has a generally U-shape when viewed from its end, such as in  FIG. 6 . 
         [0018]    Catch  33  advantageously provides a hinge and slide fastening motion for photovoltaic panel assembly  27 . More specifically, the installer first couples each of the preassembled roof clamps  31 , including catches  33 , onto roof seams  25  in a single top down, manually actuated motion; spring  47  will thereby cause the camming action to laterally move wedge  43  into compression against seam  25 . Nuts  49  are then rotatably tightened on only the hinge side fastening systems  29 , preferably near the lower edge of the tilted roof  23  first (the rightmost system  29  shown in  FIG. 7 ). Secondly, the installer aligns one of the photovoltaic panel assemblies above the associated lower catches  33  designated for same (e.g., two or more for each bottom and top side). Next, the installer inserts and engages a distal end  123  of a first frame  111  of one side of panel assembly  27  into slot  107  between hook  105  and barb  109 . Fourthly, the installer downwardly pivots the opposite top side of panel assembly  27  about the already engaged catch  33  in a hinged manner. Fifthly, each opposite top catch  33  (shown as the leftmost system  29  in  FIG. 7 , which is closer to a peak of roof  23 ), whose nut  49  is engaged but still loose, is then laterally slid to engage its hook  105  with its associated second frame  111 ; this thereby inserts and engages distal end  123  of this second frame  111  within access slot  107  of the second and top catch  33 . Sixthly, after the uphill, top frame  111  of the photovoltaic panel assembly is securely engaged by the associated top catches  33 , the installer uses a tool, such as a socket wrench, to tighten nuts  49  on the associated fastening assemblies  29 . The nut tightening serves multiple purposes: to secure the catches to the roof clamps in frame mounting positions, and to secure the roof clamps to the roof seams. Finally, a second photovoltaic assembly  27  can be secured to the now stationary opposite hooks of the up-hill catch  33  while a further uphill catch is adjustable slid to engage a frame in a similar manner to the preceeding steps (as shown to the left of  FIG. 7 ), and so on. Furthermore, all of these panel assemblies and components can be easily disassembled by loosening the single nut on each fastening system  29 . 
         [0019]    Finally, an alternate embodiment catch or mounting bracket  233  is shown in  FIG. 8 . This catch  233  is made by stamping and bending a sheet metal piece to form inwardly curved end wall hooks  235  laterally outboard of a primarily flat bottom wall  237 . Each hook  235  has a generally C-shape with an internal access slot for receiving a photovoltaic panel frame as in the prior embodiment. Stiffening beads  239  are also stamped into end wall hooks  235  and at least one hole  241  is pierced or drilled into bottom wall  237 . Moreover, catch  233  is secured to a roof clamp in the same manner as the prior embodiment. 
         [0020]    While various aspects of the present fastening system have been disclosed, it should be appreciated that modifications can be made. For example, the present accessory mounting brackets or catches can be secured to conventional roof clamps such as those disclosed in the following U.S. Pat. Nos. 7,758,011 entitled “Adjustable Mounting Assembly for Standing Seam Panels” which issued to Haddock on Jul. 20, 2010; 7,386,922 entitled “Snow-Guard Clamping Unit” which issued to Taylor et al. on Jun. 17, 2008; and 5,715,640 entitled “Mounting Device for Controlling Uplift of a Metal Roof” which issued to Haddock on Feb. 10, 1998; except many of the present advantages will not be realized. These patents are incorporated by reference herein. Moreover, more or less hooks and barbs can be attached to a single bracket although some of the present advantages may not be obtained. It is also envisioned that the fastening system is attachable to an exterior side of a building or a ground-based structure, although various advantages may not be achieved. Furthermore, the catches can be injected molded from a polymer, cast from aluminum, or otherwise differently manufactured, however, various advantages may not be obtained. The frame can also have a different shape although certain advantages may not be observed. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the present invention.