Abstract:
A solar panel assembly attachment apparatus is provided. In another aspect, a single piece and entirely metallic grounding clip is employed. A further aspect includes a clip or fastener which provides both frame grounding and a frame-to-strut attachment. In still another aspect, a grounding clip having barbs is linearly slid onto a solar panel frame and the clip additionally includes one or more flexible wings which are removably snap-fit into a slot of an elongated and rigid strut.

Description:
BACKGROUND AND SUMMARY 
     The present invention relates generally to a solar panel assembly attachment apparatus and more particularly to a grounding clip which attaches a solar panel frame to a strut. 
     Traditionally, peripheral mounting frames holding solar or photovoltaic panels are mounted to a supporting structure on a building roof or on the land through use of threaded fasteners and multi-piece brackets. Exemplary traditional devices are disclosed in U.S. Pat. No. 7,758,011 entitled “Adjustable Mounting Assembly for Standing Seam Panels” which issued to Haddock on Jul. 20, 2010, and U.S. Pat. No. 6,105,317 entitled “Mounting System for Installing an Array of Solar Battery Modules of a Panel-Like Configuration on a Roof” which issued to Tomiuchi et al. on Aug. 22, 2000. These patents are incorporated by reference herein. These devices, however, solely provide frame retention, and are time consuming and complex to install on a job site, such as on top of a windy roof, which thereby incurs significant labor expense and effort. 
     Another solar panel module fastener is disclosed in German Patent Publication No. 10 2010 022 556 invented by Klaus Hullmann et al. While this fastener is a noteworthy advance in the industry, further improvements are desirable. 
     Finally, various conventional devices have been used to provide electrical grounding to solar panel assemblies. For example, a grounding lug is attached to a solar panel frame by screws and a wire that extends through a cradle of the lug is retained therein by one or more set screws. An example of this is disclosed in  FIG. 1  and the background section of U.S. Pat. No. 7,195,513 entitled “Self-Locking Wire Termination Clip” which issued to Gherardini et al. on Mar. 27, 2007, and is incorporated by reference herein. This patent highlights many of the disadvantages of this lug and threaded fastener approach. Furthermore, this conventional lug and threaded fastener device is time consuming and difficult to install on site and is not easily suited for pre-assembly. 
     In accordance with the present invention, a solar panel assembly attachment apparatus is provided. In another aspect, a single piece and entirely metallic grounding clip is employed. A further aspect includes a clip or fastener which provides both frame grounding and a frame-to-strut attachment. In still another aspect, a grounding clip having barbs is linearly slid onto a solar panel frame and the clip additionally includes one or more flexible wings which are removably snap-fit into a slot of an elongated and rigid strut. In yet another aspect, two spaced apart and generally C-shaped clamps are coupled to a central mounting section including flexible wings. A method of grounding and attaching a solar panel frame is also disclosed. 
     The present invention is advantageous over traditional devices. For example, the clip of the present apparatus is inexpensive to manufacture and install. Furthermore, the present grounding clip is suitable for pre-assembly to the frame offsite or at a manufacturing plant, thereby improving quality and reducing assembly cost. Moreover, the present grounding clip allows for simple linear frame attachment and simple linear strut attachment free of extraneous loose parts such as threaded fasteners, nuts and brackets. The multiple clamp and barb configurations of the present apparatus also advantageously increase the electrical grounding continuity and reliability to the solar panel frame as compared to conventional devices. Additional advantages and features of the present invention will become apparent from the following description and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the present solar panel assembly attachment apparatus in a fully installed condition; 
         FIG. 2  is an exploded perspective view showing the apparatus; 
         FIG. 3  is a front perspective view showing the apparatus; 
         FIG. 4  is a back perspective view, taken somewhat opposite that of  FIG. 3 , showing the apparatus; 
         FIG. 5  is a front perspective view showing a clip of the apparatus; 
         FIG. 6  is a top elevational view showing the clip of the apparatus; and 
         FIG. 7  is an end elevational view showing the apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-4 , a solar panel assembly attachment apparatus  11  includes elongated and rigid struts  13 , solar panel modules or assemblies  15 , and grounding clips  17 . Struts  13  are either mounted to vertical legs  19  attached to land, or are bolted onto a roof clamp or other structure on the top or side of a building. Each solar panel assembly  15  includes a glass photovoltaic panel  21  and a metallic frame  23 . 
     Strut  13  has a uniform generally U-cross-sectional shape defined by upstanding side walls  31  joined by a bottom wall  33 . A reverse-turned wall  35  extends from a top end of each side wall  31  and terminates in a downwardly directed edge  37 . An elongated slot or channel  39  is defined between walls  35 . Optional mounting holes  41  are provided in bottom wall  33  to allow for bolt or other building attachment. Strut  13  is preferably stamped or rolled from aluminum or steel. 
     Referring now to  FIGS. 3-7 , grounding clip  17  includes a pair of spaced apart clamps  51  and  53 , an upper bridge  55  and a mounting section  57 . Each clamp  51  and  53  has a generally C-shape defined between an upper wall  61 , a lower wall  63  and a back wall  65 , thereby creating an openly accessible receptacle  67  therebetween. Furthermore, a lead-in wall  69  upwardly and outwardly angles away from upper wall  61  to ease insertion of a flat lateral flange  81  of frame  15  therein during assembly. A pair of pointed barbs  83  internally project from each upper section of clamps  51  and  53 . Each barb  83  cuts into and gouges the adjacent surface of flange  81  to scrape off the anodized coating on the aluminum frame  15  thereat. This provides multiple satisfactory electrical grounding paths between the base material of the frame and the clip. This can be achieved by the simple linear insertion of the clamps of the clip onto the flange of the frame without the need for rotation or a threaded attachment. Furthermore, a stiffening bead  85  is centrally provided on each upper wall  61  and back wall  65  to control the desired flexure of clamps  51  and  53 . 
     Mounting section  57  includes a frame  101  and flexible wings  103 . Frame  101  includes at least two, and more preferably four, members  105 , the majority of which is longitudinally elongated generally perpendicular to a plane connecting bottom walls  63  of the clamps. Each wing  103  is laterally located generally between a pair of members  105  and is flexibly attached at an inwardly tapered distal end  107  of frame  101 . A free-end  109  of each wing  103  is located closest to bridge  55 . Furthermore, an offset step  121  is located along a longitudinal length of each wing  103  located closer to free end  109  than distal end  107 . Catches  123  diagonally project from lateral edges of step  121  of each wing to aid in securing each edge  37  of reverse-turned walls  35  to steps  121  of the clip when fully installed. 
     A longitudinally elongated stiffening bead  125  is also provided along a lower diagonally angled segment of each wing  103 . Moreover, tapered ends  107  of mounting section  101  abut against each other in a offset crossing manner so as to deter buckling or collapsing of the mounting section during installation or removal of the clip from the strut. Each end of clip  17  includes a downwardly stepped locating tab  131 . This tab fits within channel  39  of strut  13  to deter undesired rotation of clip  17  relative to the strut when installed. 
     It is also noteworthy that the spaced apart and multiple clamps  51  and  53  of grounding clip  17  provide a longer and more secure attachment geometry to frame  15  while also providing four redundant electrical grounding paths. In other words, the clamp spacing relative to the wings deters inadvertent knocking off of the clip from the frame during strut attachment. In one construction, clip  17  electrically grounds frame  15  to strut  13  or, in another construction, may alternately have a hole for receiving a screwed-on eyelet or other separate wire along bridge  55  to thereby ground frame  15  to a separately wired circuit. 
     When fully installed, the solar panel hides a majority of the clip. This feature advantageously deters theft of the solar panel by making it less clear to a casual observer that compression together of the wings will allow detachment of the clip from the strut. Clip  17  is preferably stamped from a Magni coated spring steel, but alternately may be made from stainless steel. 
     While various features of the present solar panel assembly attachment apparatus have been disclosed herein, other variations may be employed. For example, a greater quantity of barbs or pointy projections may be provided on either the upper and/or lower walls of each clamp of the clip. Furthermore, a greater quantity of frame-engaging clamps can also be located on the clip although some benefits may not be achieved. Similarly, one or more wings (for example, four) can be employed for the clip although various advantages may not be realized. Alternately, the solar panel frame and/or strut can have differing shapes, flanges and slots for contacting with the present clip, for example, a flat sheet or tubular member with a rectangular hole therein, although certain advantages may not be obtained. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. 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. Moreover, when the terms “top,” “bottom,” “side,” “upper,” “lower”, “end,” “above,” “below,” or the like are used, it is not intended to limit the orientation of the part since it is envisioned that the present apparatus can be inverted or positioned in many different ways. Similarly, the terms “first,” “second” and the like should not limit the quantity of parts since these designations are merely intended as identifiers. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.