Abstract:
A solar panel securing system is provided. In another aspect, a solar or photovoltaic panel assembly is mounted to a building roof in a screw-free manner. Another aspect employs a snap-in connection between a member pre-assembled to a solar panel and a roof-mounted bracket. A further aspect adhesively bonds a bracket directly to a glass surface of a solar panel. A method of securing a solar panel is additionally provided.

Description:
BACKGROUND AND SUMMARY 
       [0001]    The present application relates generally to an attachment system and more particularly to a solar panel securing 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]    Other traditional constructions use heavy metal roof hooks that are mounted by driving screws through the roof into underlying studs. A raised arm of these roof hooks is screwed or bolted to an elongated roof rail or to a frame surrounding a peripheral edge of a solar panel. This leads to roof leaks and is clumsy to install. Additionally, peripheral frames add undesireable cost and weight to the solar panel assembly, and make them more difficult to raise onto a building roof. 
         [0004]    In accordance with the present invention, a solar panel securing system is provided. In another aspect, a solar photovoltaic panel assembly is mounted to a building roof in a screw-free manner. Another aspect employs a snap-in connection between a member pre-assembled to a solar panel and a roof-mounted fastening bracket. A further aspect adhesively bonds a bracket directly to a glass surface of a solar panel so that the expense and weight of a peripheral solar panel frame are avoided. Pivoting of one side of a solar panel relative to a roof rail is also employed to assist in ease of installation. A method of securing a solar panel is additionally provided. 
         [0005]    The present solar panel securing 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 and/or snap-in tab. In an aspect of the present system, a solar panel is quickly and easily secured to a building roof in a fast manner without requiring the installer to juggle multiple parts such as screws. In another aspect, a fastening bracket is very inexpensive to manufacture. Furthermore, a section of the present system is pre-assembled upon a building roof via an easy to install roof clamp and rail, and another mating section is pre-assembled to the solar panel, prior to assembly of the solar panel assembly to the fastening system. An aspect of the fastening bracket of the present securing system ideally allows for tolerance variations and part expansion. Moreover, an aspect allows for use of a frameless glass solar panel thereby reducing part cost and weight. 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 
         [0006]      FIG. 1  is a top perspective view showing a preferred embodiment system securing a solar panel to rails located on a building roof; 
           [0007]      FIG. 2  is a top perspective view showing the preferred embodiment system mounted to the rail; 
           [0008]      FIG. 3  is a bottom perspective view showing the preferred embodiment system securing a pair of the solar panels to the rail; 
           [0009]      FIG. 4  is a side elevational view showing the preferred embodiment system securing the solar panels; 
           [0010]      FIG. 5  is a top perspective view showing a fastening bracket and roof clamp of the preferred embodiment system; 
           [0011]      FIG. 6  is a top perspective view showing the fastening bracket of the preferred embodiment system; and 
           [0012]      FIG. 7  is a top perspective view showing the fastening bracket and roof clamp of an alternate embodiment system. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIGS. 1-3  illustrate a building having a flat roof  21  upon which is located a pair of parallel rails  23 . Each rail  23  has a generally inverted T-shape including an upstanding flange  25  and a flat base  27 . Ballast, such as bricks  29 , rest upon base  27  to hold each rail  23  upon roof  21  without piercing the roof by screws or the like. Rails  23  are preferably pultruded and resinated, long strand fiberglass which advantageously does not require electrical grounding, avoids corrosion and is light weight. Alternately, the rails can be aluminum, steel or other materials although various advantages will not be realized. Auxiliary roof components, preferably multiple photovoltaic or solar panels  31 , are secured to flanges  25  by way of multiple securing systems  33 . Each solar panel  31  includes metal and glass sheets with silicon wafers, preferably without peripherally surrounding mounting frames. 
         [0014]    Referring to  FIGS. 3 ,  4  and  5 , each securing system  33  includes a roof clamp  41 , a catch or fastening bracket  43 , and hinge brackets  45 . Each roof clamp  41  is attached to flange  25  of rail  23 . Each roof clamp  41  includes a saddle  51 , a flange engaging wedge  53 , and an elongated shaft or securing member  55 . A generally C-shaped leaf spring (not shown) has pins at one end attached to holes in saddle  51 , and is trapped between a head of shaft  55  and wedge  53  at the other end. The spring serves to retain wedge  53  to saddle  51  in a pre-assembled state prior to flange installation while also biasing wedge  53  into a clamping position toward a top wall of saddle  51  and flange  25 . Thus, camming action of flange-engaging wedge  53  along diagonal internal surfaces of saddle  51  compresses roof clamp  41  to flange  25  of rail  23 . Tightening of a nut  57  onto shaft  55  secures wedge  53 , and thus roof clamp  41 , to the flange. When an installer manually pushes a proximal exposed end of shaft  55  (opposite its head) toward saddle  51 , against the biasing force of the spring and through an oversized hole in the top wall of the saddle, wedge  53  is pushed to an open position allowing flange access into an opening of saddle  51 . Notably the same shaft  55  that secures roof clamp  41  to rail  23  also secures an auxiliary-retaining device, such as fastening bracket or catch  43 , along a top surface of saddle  51 . 
         [0015]    Saddle  51 , wedge  53 , shaft  55 , the spring and optionally fastening bracket  43  are pre-assembled prior to placing roof clamp  41  in the proximity of rail flange  25 . “Pre-assembled” for the clamp refers to the components being attached as a single unit such that shaft  55 , and optionally a very loose engagement of nut  57  (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 near the work site, at a remote site, or at the factory in which roof clamp  41  is manufactured. When wedge  53  is retracted to trap flange  25  between an inner foot of the wedge and the inner opening edge of saddle  51 , a portion of shaft  55  extends beyond the top surface of saddle  51  such that the proximal threaded end of shaft  55  also provides an attachment point for fastening bracket  43  and nut  57 . The roof clamp preferably attaches to the rail flange due to lateral compression of the wedge but without flange piercing or side-mounted threaded screws. Alternately, the rails and flanges can be replaced by a turned standing seam where metal roof section are joined together. 
         [0016]    Each hinge bracket  45  has a pair of generally triangularly shaped side plates  71  joined by a top plate  73  spanning therebetween. A pivot pin  75  also bridges between lower corners of side plates  71 . A Raybond™ brand polyurethane adhesive is used to directly attach top plate  73  to a bottom surface of the solar panel glass. The assembly is preferably done off-site before the solar panel is raised onto the building roof. Hinge brackets  45  can be made from stamped metal or an injection molded polymer. 
         [0017]    Referring now to  FIGS. 4-6 , fastening bracket  43  is preferably stamped metal and includes 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 . Each hook  105  has an undercut access slot or receptacle  107  and a leading tip. A locking tab  109  is upwardly and inwardly turned from an edge of base  101 . Tab  109  includes a generally vertical segment  111 , an acutely angled diagonal segment  113 , a pair of longitudinally severed and shorter finger segments  115 , and an undulating and offset central tongue segment  117  (optionally with a raised bead  119 ) adjacent a distal end thereof. Slots  107  are all openly accessible generally facing toward tab  109  although the farthest slots are also upwardly facing. Furthermore, a slotted or oversized aperture  121  is centrally provided in bottom wall  101  to receive the threaded end of shaft  55  for nut attachment thereto. Fastening bracket  43  has a generally U-shape when viewed from its end, such as in  FIG. 6 . 
         [0018]    Fastening bracket  43  and hinging brackets  45  advantageously provide a pivoting fastening motion for the solar panel  31  shown to the right of  FIG. 4 , and a linear snap-in motion to attach the solar panel  31  shown to the left of  FIG. 4 . Initially, during installation, a pair of hinging brackets  45  on one side of the left-shown solar panel  31  have their pivot pins  75  inserted into slots  107  located farthest from locking tabs  109  of the associated fastening brackets on a first of the roof rails. Thereafter, on the opposite right side of the left-shown solar panel  31 , pins  75  of the left-shown hinge brackets  45  are pushed down diagonal segments  113  of locking tabs  109  until they deflect tongue segments  47  and are trapped between a crotch of each closest slot  107  and ends of finger segments  45 . This provides a single motion, snap-in and locking function. Each locked pin  75  can be removed if the installer retracts tab  109  while pull up pin  75 . The right-shown solar panel  31  has hinge brackets and pivot pins which engage the non-snap-in slotted side of fastening brackets  43  in a similar manner. 
         [0019]    Finally, an alternate embodiment catch or fastening bracket  143  is shown in  FIG. 7 . This fastening bracket  143  is like that of the prior embodiment, except that an elastomeric and resilient polymeric block  145  is located between side walls  147  and above a base wall  149 . Block  145  has a lateral groove  151  aligned with the adjacent pair of hook slots  153  farthest away from a locking tab  155 . Block  145  compensates for hinge bracket-to-fastening bracket movement, thermal expansion of a roof clamp  157  and fastening bracket  143  relative to the solar panel, and to dampen vibrations. Moreover, this fastening bracket  143  is secured to roof clamp  157  and the roof 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. No. 7,758,011 entitled “Adjustable Mounting Assembly for Standing Seam Panels” which issued to Haddock on Jul. 20, 2010; U.S. Pat. No. 7,386,922 entitled “Snow-Guard Clamping Unit” which issued to Taylor et al. on Jun. 17, 2008; and U.S. Pat. No. 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 additional locking tabs can be attached to a single bracket although some of the present advantages may not be obtained. Furthermore, the brackets can be injection molded from a polymer, cast from aluminum, or otherwise differently manufactured, however, various advantages may not be achieved. The roof rail can also have a different shape and be alternately secured to the roof although certain advantages may not be observed. A peripheral frame on the solar panel can be attached to the snap-in tab and/or hooks instead of the pivot pin, however, various advantages may not be achieved. The fastening bracket can be alternately mounted directly to the rail or building although some advantages may be missed. 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.