Abstract:
A lockable clamping system for use in securing photovoltaic (PV) panels to a frame rail component, wherein the frame rail component includes structure for engaging with a portion of the lockable clamping system. The lockable clamping system may have a clamp member having a body portion, with the body portion having a bore. A fastener may be operatively coupled to the clamp member and may extend through the bore in the clamp member generally perpendicular to the clamp member. The fastener may have a head portion having a key shaped recess, the key shaped recess configured to allow rotation of the fastener only via predetermined security key shaped to engage with the key shaped recess. The clamp member and the fastener may cooperatively operate to clamp adjacently positioned edges of a pair of PV panels to the frame rail component by engagement of a portion of the fastener with a portion of the frame rail component, while rotation of the clamp member is inhibited except through the use of the predetermined security key.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/286,988, filed on Dec. 16, 2009. The entire disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to systems and methods for use in mounting and supporting photovoltaic panels on roofs and other support structures, and more particularly to support frame rail systems and methods for supporting photovoltaic panels on commercial and residential structures, as well as on other forms of support surfaces. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. The use of photovoltaic (“PV”) panels is becoming increasingly popular as a means for providing a supplemental source of electric power in both commercial and residential applications. Such systems may often involve dozens, hundreds or even thousands of independent PV panels. The overall cost of implementing a PV panel system is heavily influenced by the costs associated with installing the PV panels on a roof, wall or other support structure. Presently, frame rails are typically used to support the PV panels above a roof, a wall, or some other support structure. The frame rails have typically been formed with one or more grooves to receive independent fastening brackets. Typically the grooves have been arranged on the frame rails in a specific configuration that requires the frame rails to be laid out such that the external brackets can be attached to the frame rails. This requires the assembler to carefully arrange the frame rails so that no one or more of the rails is orientated incorrectly. 
         [0004]    Still another consideration with present day PV panels is the need to establish a ground path between the frame of each PV panel and the frame rail on which it is being installed. Various means have been developed for this but all have some drawbacks, either in terms or performance or in terms of the time and complexity required to install the grounding implement when assembling the PV panels to their support frame rails. 
         [0005]    Presently there is also a concern with theft of PV panels. As the PV panels can be expensive, the theft concern has taken on greater interest in recent years. Nevertheless, there has not been a satisfactory means for inhibiting the theft of PV panels after they are installed on a structure, short of installing surveillance equipment where the PV panels are in use, or taking other measures that can be costly, time consuming to install or implement, and of limited effectiveness. 
       SUMMARY 
       [0006]    In one aspect the present disclosure relates to a lockable clamping system for use in securing photovoltaic (PV) panels to a frame rail component, wherein the frame rail component includes structure for engaging with a portion of the lockable clamping system. The lockable clamping system may comprise a clamp member having a body portion, with the body portion having a bore. A fastener may be operatively coupled to the clamp member and may extend through the bore in the clamp member generally perpendicular to the clamp member. The fastener may include a head portion having a key shaped recess, the key shaped recess configured to allow rotation of the fastener only via predetermined security key shaped to engage with the key shaped recess. The clamp member and the fastener may cooperatively operate to clamp adjacently positioned edges of a pair of PV panels to the frame rail component by engagement of a portion of the fastener with a portion of the frame rail component, while rotation of the clamp member is inhibited except through the use of the predetermined security key. 
         [0007]    In still another aspect the present disclosure relates to a lockable clamping system for use in securing photovoltaic (PV) panels to a frame rail component. The system may comprise a clamp member having a body portion with the body portion having a bore. A barrel nut may be secured to the clamp member and may have a key shaped recess at one end thereof. The key shaped recess may be adapted to allow rotation of the barrel nut only through the use of a predetermined security key. A T-lug fastener element having a T-member and a threaded shaft is provided. The T-member is adapted to engage the frame rail component within a channel of the frame rail component, and the threaded shaft is adapted to be threadably engaged within internal threads of the barrel nut. The barrel nut, the clamp member and the T-lug fastener cooperatively operate to clamp adjacently positioned edges of a pair of PV panels to the frame rail component and to prevent unclamping of the PV panels from the frame rail component except when the barrel nut is loosened through the use of the predetermined security key. 
         [0008]    In still another aspect a lockable clamping system is provided for use in securing photovoltaic (PV) panels to a frame rail component, where the frame rail component has spaced apart, opposing serrated wall portions. The system may comprise a clamp member having a body portion, with the body portion having a bore. A threaded fastener extends through the bore in the body portion of the clamp member and is secured to the body portion to enable rotational movement relative to the body portion. The threaded fastener includes an enlarged head portion having a key shaped recess at one end thereof. The key shaped recess allows rotation of the threaded fastener only through the use of a predetermined security key that is shaped to engage the key shaped recess. Threads of the threaded fastener are adapted to engage the serrations of the opposing serrated walls of the frame rail component as the threaded fastener is inserted between the serrated wall portions. The threaded fastener cannot thereafter be withdrawn from the frame rail component except when rotating the threaded fastener through use of the predetermined security key. 
     
    
     
       DRAWINGS 
         [0009]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0010]      FIG. 1  is a perspective view of a corner portion of a PV panel with a PV frame member in accordance with one embodiment of the present disclosure, together with a slide on grounding clip that creates a ground path between the PV frame member and a support frame rail on which the PV panel is being supported; 
           [0011]      FIG. 2  is a perspective view of just the grounding clip shown in  FIG. 1 ; 
           [0012]      FIG. 3  is an end view of just the grounding clip; 
           [0013]      FIG. 4  is a cross sectional end view of the frame member with the grounding clip secured thereto, and being supported on a support rail; 
           [0014]      FIG. 5  is a perspective view of a frame rail in accordance with another aspect of the present disclosure, and also illustrating a bracket that may be used with the frame rail to secure the frame rail to a roof or other support surface; 
           [0015]      FIG. 6  is an end view of a locking frame rail system in accordance with another aspect of the present disclosure; 
           [0016]      FIG. 7  is a plan view of a C-clip used with the system of  FIG. 6 ; 
           [0017]      FIG. 8  is a perspective view of the clamp member and the barrel nut secured thereto; 
           [0018]      FIG. 9  is a perspective view of a grounding clip being implemented with a T-lug for use in the system of  FIG. 6 ; and 
           [0019]      FIG. 10  is a perspective view of another form of assembly for locking a clamping member to a frame rail, where the frame rail has a channel having serrated opposing surfaces that threadably engage the threaded shaft. 
       
    
    
       [0020]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0021]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0022]    Referring to  FIG. 1 , there is shown a photovoltaic (“PV”) panel  10  and a grounding clip  12  in accordance with one aspect of the present disclosure. The PV panel  10  includes a PV frame member  14  and a PV element  16  secured to the frame member  14  in any conventional manner. The PV frame member  14  includes a wall portion  18  and a flange portion  20 . The flange portion  20  may have oppositely facing semicircular grooves  20   a  (only one being visible in  FIG. 1 ) running along its full length or formed only at one or more designated areas of the frame member  14 . The flange portion  20  may be integrally formed with the wall portion  18  or it may be mechanically and electrically coupled via suitable conductive fasteners. However, it is believed that a preferred manner of construction for the frame member  14  will be extruding it from a suitable material, for example, but not limited to, aluminum, as a single piece component. Typically four sections of the frame member  14  will be secured to form a square or rectangular shape, although other shapes are certainly possible that employ more or less than four sections of frame member  14 . Typically the adjoining corners of the frame members  14  will be miter cut before being fastened together with suitable, conventional corner fastening elements. 
         [0023]    The grounding clip  12  is constructed of dimensions enabling it to be quickly and easily slid onto the flange portion  20  of the frame member  14  without the need for any external tools. The grounding clip  12  may be made from any electrically conductive material that is resistant to the elements, for example stainless steel. 
         [0024]    With reference to  FIGS. 2 and 3 , the grounding clip  12  is shown in even greater detail. The grounding clip  12  includes a base portion  22  and two arm portions  24  formed to converge slightly towards each other. Each arm portion  24  may also include a semicircular shaped distal edge portion  26   a , and one of the arm portions may include one or more barbs or tooth portions  26   b  projecting outwardly therefrom. The height of the base portion  22 , designated by arrow  28  in  FIG. 3 , is preferably just slightly larger than the thickness of the flange portion  20  of the frame member  14 , as indicated by arrow  30  in  FIG. 1 . The arm portions  24  are further approximately the same length as the flange portion  20 , as indicated by arrow  29  in  FIG. 1 . In this manner when the grounding clip  12  is pushed onto the flange portion  20 , the arm portions  24  expand slightly, aided by the semi-circular shaped distal edge portions  26   a  as they contact the corner edges of the flange portion  20 . Once fully installed, as shown in  FIG. 4 , the semicircular shaped distal edge portions  26   a  engage with the semicircular grooves  20   a  on the flange portion  20  to even further help retain the grounding clip  12  to the flange portion. The squeezing action of the arm portions  24  helps to retain the grounding clip  12  secured to the flange portion  20 , while the teeth  26   b  dig or “bite” into the surface of the support frame rail  32  to make excellent electrical contact with the flange portion  20  and the support frame rail  32 . It will be appreciated that while the semicircular distal edge portions  26   a  and the semicircular grooves  20   a  help to retain the grounding clip  12  to the flange portion  20 , that they are not absolutely essential to the operation of the grounding clip  12 . For example, the arm portions  24  could be formed with a curvature at their distal ends which is sufficient to help spread apart the arm portions during sliding assembly of the grounding clip  12  on to the flange portion  20 . 
         [0025]    By forming the flange portion  20  integrally with the wall portion  18 , a conductive portion of the frame member  14  is provided that is readily accessible to the installer. This enables the grounding clips  12  to be quickly and easily installed on the flange portion  20  before the entire PV panel  10  is installed on one or more external frame rails. Thus, there is no need to position one or more conventional grounding washers between the frame member  14  and the frame rail, and assembly of the PV panels  10  to the frame rails can be done on an even more expedited basis. 
         [0026]    Referring now to  FIG. 5 , there is shown an embodiment of a frame rail  100  in accordance with another aspect of the present disclosure. A principal feature of the frame rail  100  is that it is symmetrical in construction. The advantage that this provides is that the frame rail  100  can be oriented in either of two orientations 180 degrees from one another and still be used to secure mounting brackets and other components to the frame rail  100  that are needed to secure a PV panel, such as PV panel  10 , thereto. Thus, there is less of a need for the installer to be mindful of the exact orientation of the frame rail  100  when securing multiple sections of the frame rail  100  to a roof or other support structure. 
         [0027]    The frame rail  100  includes two inwardly facing ledges  101  forming a top wall  102  and a channel  103 . A bottom wall  104 , sidewalls  106  and an intermediate wall  108  are also included. The top wall  102  has a pair of flanges  110  that define a first pair of co-linear channels  112 . Portions  103   a ,  106  and  108  cooperate to define a hollow area  114  that may extend the entire length of the frame rail  100 . This provides a weight and cost savings. Extending from the intermediate wall  108  is a central wall  111  that connects with the bottom wall  104 . The bottom wall  104  has a pair of flanges  116  that define channels  118 . The sidewalls  106  each have a plurality of linear grooves or serrations  120  integrally formed thereon. Similarly, flanges  116  each include linear grooves or serrations  122 . 
         [0028]    Referring to further to  FIG. 5 , a mounting bracket  124  is shown that may include a wall portion  126  having linear grooves or serrations  128  with a spacing preferably the same as the serrations  120 . The serrations  120 ,  122  and the serrations  128  allow the installer to align and hold the mounting bracket  124  more easily and accurately before drilling a hole in one of the sidewalls  106  to fasten the bracket  124  to the frame rail  100  with an external fastener. 
         [0029]    Referring now to  FIG. 6 , there is shown a locking frame rail system  200  in accordance with another aspect of the present disclosure for lockably securing a pair of PV panels  202  to a frame rail  204 . The system  200  generally includes the frame rail  204 , a T-lug fastening element  206 , and a lockable clamping element  208 . The T-lug fastening element  206  includes a threaded end portion  210  extending from a T-member  211 , and the lockable clamping element  208  includes a barrel nut  212  that extends through a bore  214   a  in a clamp body  214   b  of the member  214 . The barrel nut  212  is internally threaded, as indicated by dashed lines  212   b , and is secured to the clamp member  214  by a C-clip  216 . The C-clip  216  is also shown in  FIG. 7  and the clamp member  214  is also shown in greater detail in  FIG. 8 . The C-clip  216  rests in a groove  212   a  on the barrel nut  212  outer surface adjacent a lower surface of the clamp member  214 . The C-clip  216  thus prevents the barrel nut  212  from being pulled upwardly in the drawing of  FIG. 6  out of the clamp member  214 . Depending legs  214   b  extend from a body portion  214   a  of the clamp member  214  and serve to set a spacing between the edges of frame rails  202  that are being secured by the system  200 . 
         [0030]    Referring to  FIGS. 6 and 8 , the clamp member  214  includes a recess  218  formed concentrically with the bore  214   a . The barrel nut  212  also includes a flanged upper end  222  that is dimensioned similar, but just slightly smaller than, the diameter of the recess  218  so that an upper surface  212   b  of the barrel nut  212  sits approximately flush with an upper surface  214   c  of the clamp body  214   a . The upper surface  212   b  of the barrel nut  212  also includes a key shaped recess  224  that is shaped to fit a security key (not shown) that is used to tighten the barrel nut  212  to the threaded shaft  210  of the T-lug fastening element  206 . The key shaped recess  224  may take any suitable form, so long as it is not able to be engaged securely with a conventional screwdriver or other like implement. One particularly well suited locking fastener that may be readily adapted for use with the barrel nut  212  is the MORTICO® spiral drive system available from Phillips Screw Company of Wakefield, Mass. However, it will be appreciated that virtually any type of security key shape that prevents the use of conventional, tools such as screwdrivers, TORX® bit drivers, etc., may potentially be employed. Once the T-lug fastening element  206  is tightened onto the barrel nut  212 , the clamp member  214  will hold the PV panels  202  securely to the frame rail  204 , and the clamp member  214  cannot be loosened without the appropriately shaped key to engage the key shaped recess  224  in the barrel nut  212 . 
         [0031]    Referring to  FIG. 9 , it can be seen that a grounding clip  300  may also be employed with the T-lug fastening element  206 . The grounding clip  300  may have a generally U-shape with teeth or tangs  302  on both an upper surface  304  and a lower surface  306  of each flange  308 . A babe portion  310  may have a serrated opening  312  that retains the T-lug fastening element  206 . The grounding clip  300  may be made of stainless steel or any other suitable material, and may be interposed between the frame members  202   a  of the PV panels  202  and the ledges  204   a  of the frame rail  204 . The grounding clip  300  provides an electrically conductive path between the frame members of the PV panels  202  and the frame rail  204  supporting the PV panels. 
         [0032]    Referring to  FIG. 10 , a different form of clamp assembly  40   b  is shown that may be used in place of the clamp member  214  and T-lug fastening element  206 . The clamp assembly  400  may be used if a frame rail  204   a  includes an interior channel having serrations  402  along inwardly projecting ledges  404 . The clamp assembly  400  may include a threaded fastener  406  having an enlarged head portion  408  and a threaded shaft  410 . The enlarged head portion  408  may rest within a recess  412  in a clamp member  414 . A C-clip  416  may be secured in a groove (not visible in  FIG. 10 ) in the threaded fastener  406  as described above for the barrel nut  212 , so that the threaded fastener  406  cannot be removed from the clamp member  414 . A security key recess  416  prevents conventional tools from turning the head portion  408 . The threaded shaft  410  engages the serrations  404  in the frame rail  204  to clamp the PV panels  202  to the frame rail  204  without the need for a T-lug element to be positioned within a channel of the frame rail  204   a.    
         [0033]    The various systems and embodiments described above all help to significantly expedite the installation of PV panels. The disclosed embodiments also add a significant degree of security to a PV installation that prevents the removal of the PV panels once they are installed, unless the proper security tool (i.e., key) is used. 
         [0034]    The foregoing description of the various embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. 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. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.