Abstract:
A fastening system especially well suited for use with solar panel systems that enables an electrical connection to be made between two metallic frame components that are secured together. The fastening assembly includes a spring clip and a threaded bolt that engages within a hole in the spring clip. The spring clip has a leaf spring like shape. The threaded bolt has a head portion shaped to permit it to be inserted in a channel of a frame member, then rotated ninety degrees, which flattens the spring clip and enables it to retain the threaded bolt in an upright orientation ready for use. After being rotated ninety degrees, the head is retained in the channel as well. The fastening assembly can be inserted into a suitable sized channel of a frame member at any point along the channel, thus significantly simplifying and expediting the assembly of solar panel modules onto a supporting frame element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/250,895 filed on Oct. 13, 2009. The disclosure of the above application is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to electrical grounding devices and methods, and more particularly to an electrical grounding device and method that enables positive electrical contact to be made between electrically conductive panels or components. 
       BACKGROUND 
       [0003]    In various applications, especially when connecting solar panel modules to a supporting frame structure, there is a need to make a ground connection between the metal frame of the module and the metal material of the supporting frame when the module is secured to the frame. Various types of metal washers have been proposed, with each having various limitations. 
         [0004]    In many applications, especially those involving the assembly of solar panel modules onto ground surface or a roof top, the need to be able to assemble the modules to a frame structure quickly, efficiently, and without the need for special tools, is also a major consideration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a side view of one embodiment of the fastening assembly of the present disclosure; 
           [0006]      FIG. 2  is a side view of the spring panel of the assembly of  FIG. 1  but with a spring clip and a fastening member of the fastening assembly both rotated 90 degrees from the orientation shown in  FIG. 1 ; 
           [0007]      FIG. 3  is a perspective view of the fastening assembly; 
           [0008]      FIG. 4  is a plan view of the spring clip with the threaded bolt removed; 
           [0009]      FIG. 5  is an end view of just the spring clip of the fastening assembly; 
           [0010]      FIG. 6  shows a first operation in using the fastening assembly to secure a frame portion of a solar panel module to a frame member, wherein a head portion of a fastening member of the assembly is orientated in a channel of the frame member; 
           [0011]      FIG. 7  shows the head portion pushed down and rotated 90 degrees to hold the spring clip, as well as the fastening member being used with a separate nut to secure the frame portion of the solar panel module to the frame member so that the spring clip ensures electrical contact between the frame portion and the frame member; 
           [0012]      FIG. 8  shows an another embodiment of the spring clip used to form the fastening assembly of  FIG. 1 ; 
           [0013]      FIG. 9  shows still another embodiment of the spring clip that may be used to form the fastening assembly of  FIG. 1 ; 
           [0014]      FIG. 10  shows still another embodiment of the spring clip that may be used to form the fastening assembly of  FIG. 1 ; 
           [0015]      FIG. 11  shows a top perspective view of another embodiment of the spring clip; and 
           [0016]      FIG. 12  shows a bottom perspective view of the spring clip of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIGS. 1 and 2 , there is shown a fastening assembly  10  in accordance with one embodiment of the present disclosure. The fastening assembly  10  generally includes a threaded bolt  12  and a spring clip  14 . The threaded bolt  12  has a threaded shaft  16  and a head portion  18 . The head portion  18  has a first dimension, noted by arrow  20  in  FIG. 1 , that is longer than a second dimension  22 , as indicated in  FIG. 2 . In one application, the length of the threaded shaft  16  is sufficient to extend through the thickness of a frame portion of a solar panel module so that the fastening assembly  10  can be used to secure a solar panel module to a frame member. However, it will be appreciated that the length and overall dimensions of both the threaded bolt  12  and the spring clip  14  will need to be adjusted to meet the requirements of the specific application at hand. The threaded bolt  12  may be made from any suitable metal or other material. 
         [0018]    Referring to FIGS.  1  and  3 - 5 , the spring clip  14  can be seen in greater detail. The spring clip  14  is preferably made from a resilient material, for example spring steel, although other materials having a degree of flexibility or resiliency may be employed. The spring clip  14  has a leaf-spring like shape that defines a central portion  24  with a hole  26 , and opposing end portions  28 . The opposing end portions  28  each are formed by a folded over section of material, as best visible in  FIGS. 1 and 3 , and each includes a generally perpendicularly extending tab  30  as seen in  FIG. 3 . On each opposing end portion  28  is a projecting tooth  32  that may be formed by simply partially punching out a small portion of material from the opposing end portions  28  before the portions  28  are folded over onto one another. This way when the opposing end portions  28  are folded over to take the shape as shown in  FIG. 3 , the projecting teeth  32  will be projecting in opposing directions. This feature is shown particularly well in  FIG. 5 . The tabs  30  may have a width, as defined by arrow  34  in  FIG. 5 , that allows the tab to rest in a channel of a frame member, as will be explained further in the following paragraphs. 
         [0019]    The hole  26  ( FIG. 4 ) preferably also has a plurality of radial cuts or slots  26 ′ that enables the threaded shaft  16  of the bolt  12  to be more easily threaded into and through the spring clip  14  and retained therein. For the solar panel application mentioned herein, the diameter of the threaded shaft  16  will also preferably be selected so that the threaded shaft  16  can extend through a channel formed in the frame member of the solar panel module. 
         [0020]    Referring now to  FIGS. 6 and 7 , the use of the fastening assembly  10  in securing a solar panel module to a frame member will be described. In  FIG. 6  the fastening assembly is first placed with the head portion  18  of the threaded bolt  12  in a channel  36  of a frame member  38 . The head portion  18  is oriented so that its narrower dimension (defined by arrow  22  in  FIG. 2 ) can be extended part way into the channel  36 . The user then grasps the threaded shaft  16  and pushes in a downward direction in accordance with arrow  40  with sufficient force to flatten the spring clip  14 . While the spring clip  14  is held in its flattened orientation, the user rotates the threaded shaft  16  in accordance with directional arrow  42  so that the head portion  18  is turned about 90 degrees into the orientation shown in  FIG. 7 . When the user releases the threaded shaft  16 , the spring clip  14  maintains the head portion  18  against the inside surfaces  44   a  of shoulder portions  44  of the frame member  38 , as shown in  FIG. 7 . The length of the head portion  18 , as defined by arrow  20  in  FIG. 1 , is such that once the head portion  18  is turned to the position shown in  FIG. 7  it is captured in the channel  36  and cannot be removed therefrom. 
         [0021]    The user may thereafter adjust the longitudinal positioning of the fastening assembly  10  along the length of the frame member  38 , if needed, by pressing down on the threaded shaft  16 , rotating the head portion  18  back into the position shown in  FIG. 6 , sliding the fastening assembly  10  to the desired position, and then rotating the head portion  18  back into the position shown in  FIG. 7  and then releasing the threaded shaft  16 . 
         [0022]      FIG. 7  illustrates the threaded shaft  16  of the threaded bolt  12  having been inserted through a suitable opening in a frame portion  46  of a solar panel module  48 . Once nut  50  is tightened down, the teeth  32  are able to dig or “bite” into the metallic surfaces of the frame member  38  and the frame portion  46 , and form an electrically conductive grounding path through the spring clip  14 . Typically the frame member  38  will be coupled to ground via a suitable cable. Thus, the fastening assembly  10  not only functions to provide a quick and easy to use mechanism for securing the solar panel  48  to the frame member  38 , but also a mechanism for automatically creating an electrically conductive path between the two frame components  46  and  38 . 
         [0023]      FIG. 8  shows a spring clip  14   a  that forms another embodiment of the spring clip  14 . The spring clip  14   a  is somewhat similar in construction to the spring clip  14  and includes a central portion  24   a  having an opening  26   a , and opposing end portions  28   a . The opening  26   a  engages the threaded shaft  16  of the bolt  12 . The opposing end portions  28   a  each include oppositely projecting pairs of teeth  32   a  and tabs  30   a  for maintaining the spring clip  14   a  centered along the longitudinal centerline of the frame member  38 . Spring clip  14   a  otherwise operates in the same fashion as described for the spring clip  14 . However, the spring clip  14   a  includes tabs  50  formed from punched out sections of the opposing end portions  28   a . The tabs  50  serve to provide stop members that define a predetermined spacing between two adjacently positioned ones of the solar panel modules  48  when the two adjacent solar panel modules  48  are abutted against the tabs  50  while being secured to the frame member  38 . Thus, the spring clip  14   a  not only functions to provide an excellent grounding path between the solar panel modules(s)  48  and the frame member  38 , but also functions to maintain the spacing between adjacent modules  48  in accordance with a predetermined, desired spacing. 
         [0024]    Referring to  FIG. 9  a spring clip  14   b  is illustrated in accordance with another embodiment of the spring clip  14 . The spring clip  14   b  similarly includes a central portion  24   b  having an opening  26   b , opposing end portions  28   b , and opposing pairs of teeth  32   b . However, a length of material  52  extends from each of the opposing end portions  28   b  and is partially folded over on itself to form two tabs  30   b  and  50 ′. The tabs  30   b  (only one being visible in  FIG. 9 ) serve to maintain the spring clip  14   b  centered along the channel  36  of the frame component  38 , while the tabs  50 ′ act as stop members to maintain a predetermined spacing between adjacently positioned solar panel modules  48 . 
         [0025]    Referring to  FIG. 10 , a spring clip  14   c  in accordance with still another embodiment of the spring clip  14  is shown. The spring clip  14   c  similarly includes a central portion  24   c  having an opening  26   c , and opposing end portions  28   c . The opposing end portions  28   c  each have two pairs of oppositely projecting teeth  32   c  projecting therefrom. However, the opposing end portions  28   c  are formed from folded over sections of material that each include tabs  30   c  (only one being visible in  FIG. 10 ) for centering the spring clip  14   c  along the channel  36  of the frame member  38 , as well as a folded distal edge that forms an upwardly projecting tab  50 ″. The upwardly projecting tabs  50 ″ in this instance extend the full width of the central portion  24   c  and serve to act as stop members to maintain a predetermined spacing between two adjacently positioned solar panel modules  48 . 
         [0026]    Referring to  FIGS. 11 and 12 , there is shown a spring clip  14   d  in accordance with yet another embodiment of the present application. The spring clip  14   d  is also made from a metallic material that has good electrical conductivity properties and is resistant to corrosion from the elements, for example stainless steel. The spring clip  14   d  may include a central portion  24   d  having an opening  26   d  with a plurality of radially arranged slots  27   d . Side portions  29   d  extend generally perpendicularly from the central portion  24   d  and have a predetermined spacing, defined by arrow  31   d . The spacing defined by arrow  31   d  controls the spacing between two adjacent solar panel modules  48  that are positioned to abut the side portions  29   d  when positioned on the frame member  38 . 
         [0027]    Opposing end portions  28   d  of the spring clip  14   d  are formed from folded over sections of material and project in opposite directions from the central portion  24   d . Opposing end portions  28   d  may each include an integrally formed tab  30   d  and a plurality of pairs of oppositely projecting teeth  32   d . Tabs  30   d  rest in the channel  36  ( FIG. 6 ) when the spring clip  14   d  is positioned on the frame member  38  and maintain the spring clip  14   d  aligned with the longitudinal axis of the frame member  38  during the assembly process. Teeth  32   d  may be punched out before folding over the material that helps form the opposing edge portions  28   d , thus forming a plurality of pairs of aligned teeth that project in opposite directions from the opposing end portions  28   d . The spring clip  14   d  otherwise operates in the same fashion as the spring clips  14 ,  14   a ,  14   b  and  14   c  to form a means for providing an electrically conductive path between the solar panel module  48  and the frame member  38  once the module  48  is secured to the frame member  38 , and also to maintain the desired spacing between adjacently positioned modules  48 . 
         [0028]    The ability of the fastening assembly  10  to hold the threaded bolt  12  in an upright manner within the channel  36  of the frame member is a significant benefit. Often the frame member  38  is several feet long, and often may be four foot, eight foot, or even longer in overall length. The ability of the user to position the fastening assembly  10  at a desired, approximate point along the length of the frame member  38  is a significant advantage in reducing the assembly time required for the user to install a solar panel system. Often such systems may involve several, or possibly dozens or even hundreds of independent solar panel modules that must be installed on a plurality of frame members with suitable grounding washers or like implements being used with the fasteners that are used to fasten the modules to their respective frame members. With previously developed grounding implements adapted to fit in a channel of a frame member, the grounding implement often needs to be inserted at one end of the channel and then slid to the approximate longitudinal point along the channel where it will be fastened. This can take considerable time, especially in installations where dozens or hundreds of solar panel modules are being installed. The construction of the fastening assembly  10  of the present disclosure enables it to be inserted directly into the channel at the approximate point where the user anticipates it will be fastened to the frame member  38 , thus eliminating the need to install it from one open end of the channel. Advantageously, the spring clip  14 ,  14   a ,  14   b  or  14   c  operates to maintain the entire assembly at the desired location while the frame member is being handled and the solar panel module  48  secured thereto. 
         [0029]    While the fastening assembly  10  has been described as being well suited for use in the assembly of solar panel systems, it will be appreciated that the fastening assembly is also expected to find utility in a wide variety of other applications as well. The fastening system  10  may be used in virtually any application where two components need to be secured together, and an electrically conductive path formed between them as the securing operation is completed. 
         [0030]    While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.