Patent Publication Number: US-8109048-B2

Title: Apparatus for forming and mounting a photovoltaic array

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a §371 National Stage Application of International Application No. PCT/US08/04569, filed on Apr. 8, 2008, claiming the benefit of U.S. Provisional Application No. 61/066,001 filed on Feb. 15, 2008, U.S. Provisional Application No. 61/065,417 filed on Feb. 11, 2008, and U.S. Provisional Application No. 60/922,180 filed Apr. 6, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to photovoltaic modules and associated frames and mounting hardware, and more particularly to an improved method and apparatus for forming and mounting a photovoltaic array. 
     2. Background Art 
     Photovoltaic (PV) modules and related mounting hardware are well known and in widespread use. The most common mass-produced PV modules in use today include a laminated portion, or PV laminate, and a frame portion, and are designed specifically to convert light into electricity. The PV laminate portion is for encapsulating solar cells in a substantially flat, weather-tight envelope comprising a laminated construction of various layers including but not limited to glass, clear plastic, encapsulant material (like EVA), active photovoltaic material, interconnecting conductors between solar cells, and a protective backsheet (like PVF film or glass). Photovoltaic laminates are commonly manufactured today in rectilinear shapes like squares, rectangles, triangles, and trapezoids and, due to their fragile nature, are usually completely enclosed by a permanent, substantially rigid, glued-on frame portion which holds and protects the delicate edges of the PV laminate portion and provides a means of supporting the PV laminate and attaching it to other objects without damaging the PV laminate. The combination of the PV laminate portion and the glued-on frame portion is referred to herein as a PV module or framed PV module. The present invention relates to integral frames for standard PV laminates and to the associated mounting hardware which attaches to the integral frames for the purpose of securing the PV module to a roof or support structure. 
     U.S. Pat. No. 5,571,338 to Kadonome, et al. discloses a photovoltaic module comprising a photovoltaic panel having a top edge and a bottom edge. An exterior frame structure attached to edges of the photovoltaic panel defines an upwardly open groove extending along at least the top and bottom edges of the panel to direct rain water away from the underside of the panel. 
     U.S. Pat. No. 7,406,800 to Cinnamon describes an integrated module frame and racking system for a solar panel. The solar panel comprises a plurality of solar modules and a plurality of series couplings or splices (in the form of series couplings) for coupling the plurality of solar modules together. The plurality of splices provide a way to make the connected modules mechanically rigid both during transport to the roof and after mounting for the lifetime of the system, provide wiring connections between modules, provide an electrical grounding path for the modules, provide a way to add modules to the panel, and provide a way to remove or change a defective module. Connector sockets are provided on the sides of the modules to simplify the electrical assembly of modules when the modules are connected together with splices. 
     U.S. Patent Application 20070074755 by Eberspacher, et al. teaches a photovoltaic module with a rigidizing backplane. A solar cell module includes one or more photovoltaic (PV) cells arranged in a substantially planar fashion. Each PV cell has a front side and a back side. The PV cells are adapted to produce an electric voltage when light is incident upon the front side. A rigid back plane is attached to the PV cells such that the back plane provides structural support from the back side. The rigid back plane includes a structural component having a plurality of voids. 
     The foregoing patents reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicant&#39;s acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein. 
     DISCLOSURE OF INVENTION 
     The method and apparatus for forming and mounting a photovoltaic (PV) array of this invention provides a PV module framing and coupling system which enables the attachment of PV modules to a roof or other mounting surface without requiring the use of separate structural support members which attach directly to and span between multiple PV modules in a formed PV array. The inventive apparatus may provide a slidable parallel coupling for securely interlocking the outside surfaces of parallel frame members together in a side to side arrangement, thereby enabling the formation of a PV array with improved structural load distribution. The inventive coupling member may attach to a slot in the frame at substantially any position along the length of the frame thereby enabling the interconnection of adjacent PV modules along both an x and y axis. The inventive apparatus may further provide a rotating portion and locking portion for coupling to frame attachment, mounting brackets for direct connection to a mounting surface, grounding teeth for the automatic creation of a reliable two axis grounding matrix, and a rapid twist-lock engagement means for reliably interlocking and aligning PV modules in the array. 
     It is therefore an object of the present invention to provide a new and improved multipurpose PV module frame which supports a PV laminate and provides an outer slot for engaging slidable couplings which interlock adjacent PV modules and attaching brackets which connect directly to a roof or mounting surface, thereby enabling the attachment of PV modules to a roof or other mounting surface without requiring the use of separate structural support members which attach directly to and span between multiple PV modules in a formed PV array. 
     It is another object of the present invention to provide a new and improved parallel coupling for securely interlocking the outside surfaces of parallel frame members together in a side to side arrangement, thereby enabling the formation of a PV array with improved structural load distribution. 
     Other novel features which are characteristic of the invention, as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawings, in which preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration and description only and are not intended as a definition of the limits of the invention. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. The invention resides not in any one of these features taken alone, but rather in the particular combination of all of its structures for the functions specified. 
     There has thus been broadly outlined the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form additional subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based readily may be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     Further, the purpose of the Abstract is to enable the international, regional, and national patent office(s) and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of this application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. 
     Certain terminology and derivations thereof may be used in the following description for convenience in reference only, and will not be limiting. For example, words such as “upward,” “downward,” “left,” and “right” would refer to directions in the drawings to which reference is made unless otherwise stated. Similarly, words such as “inward” and “outward” would refer to directions toward and away from, respectively, the geometric center of a device or area and designated parts thereof. References in the singular tense include the plural, and vice versa, unless otherwise noted. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
         FIG. 1  is a perspective view of a PV module with a hybrid, strut-like frame; 
         FIG. 2  is a perspective view of a parallel coupling; 
         FIG. 3  is a cross-section cut through two adjacent PV modules; 
         FIG. 4  is a perspective view of two adjacent PV modules coupled together; 
         FIG. 5  is a perspective view of a height adjustable bracket; 
         FIG. 6  is a cross-section cut through two adjacent PV modules; 
         FIG. 7  is a perspective view of building with a PV array attached to a roof; 
         FIG. 8  is a side view of the PV array of  FIG. 7  at a larger scale; 
         FIG. 9  shows a typical prior art PV array; 
         FIG. 10  is a perspective view of the PV array of  FIG. 7  viewed from the back; 
         FIG. 11  is a cross-section cut through a PV array just above the couplings; 
         FIG. 12  is a simplified top view of two adjacent rectangular frames; 
         FIGS. 13-14  show generic PV arrays comprising four PV modules with adjacent frame members; 
         FIG. 15  shows a prior art strutless PV array; 
         FIG. 16  is a perspective view of a coupling; 
         FIGS. 17-18  are front and back side views respectively of a coupling in a first position; 
         FIG. 19  is a perspective view of a coupling; 
         FIGS. 20-21  are front and back side views respectively of a coupling in a second position; 
         FIG. 22  is a perspective view of a coupling; 
         FIGS. 23-24  are front and back side views respectively of a coupling in third position; 
         FIGS. 25-31  depict a second embodiment of the present invention; 
         FIGS. 32-34  depict a third embodiment of the present invention; 
         FIGS. 35-38  depict a fourth embodiment of the present invention; 
         FIGS. 39-40  are a perspective view and a cross section cut between two interlocked PV modules; 
         FIGS. 41-42  are a cross section cut between two interlocked PV modules and a perspective view of a coupling; 
         FIGS. 43-44  are a perspective view and a cross section cut between two interlocked PV modules; 
         FIGS. 45-46  are a perspective view and a cross section cut between two interlocked PV modules; 
         FIGS. 47-48  are a cross section cut between two interlocked PV modules and a perspective view respectively for an alternate embodiment; 
         FIGS. 49-50  depict a further alternate embodiment; 
         FIGS. 51-52  depict a further alternate embodiment as installed on an open canopy structure; 
         FIGS. 53-54  show an alternate embodiment of a PV array with a snap-in conduit box; and 
         FIG. 55  depicts a perspective view of a further alternate embodiment of a PV module. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Referring to  FIGS. 1 through 55 , wherein like reference numerals refer to like components in the various views, there is illustrated therein a new and improved framing and mounting system for photovoltaic arrays, generally denominated  10  herein. For the purposes of this document industry standard definitions for terms will apply when appropriate. Photovoltaic is abbreviated as “PV”. PV laminate refers to an encapsulated group of solar cells. Frame refers to a group of frame members (typically four for a rectangular-shaped PV module) which support and provide rigidity to a PV laminate. PV module refers to a single, one-piece, individually deployable electricity generating device comprising a PV laminate, a frame, and at least two output wires. A PV array refers to a group of PV modules which are deployed together and are a part of the same electricity generating system. A mounting rail or strut is a structural member which connects to the bottom of a PV module via the use of a separate fastener (such as a coupling, bolt, etc.) and which serves to mechanically link two or more PV modules together, thereby providing structural support for the modules and also providing a means for connection to a mounting surface. 
     First Embodiment 
     Structure 
       FIGS. 1-24  depict a first embodiment of the present invention.  FIG. 1  provides a perspective view of a photovoltaic or PV module  11  with a hybrid, strut-like frame  12 . Each PV module is made of substantially identical construction. As is typical in the art, frame  12  comprises four frame members  13  which are assembled around PV laminate  20  and secured by optional adhesive between frame members  13  and laminate  20  and frame screws  18 U,  18 L at the corners. The complete PV module  11  is typically assembled in this way at a PV module manufacturing facility; then a plurality of one-piece PV module assemblies  11  are transported to a particular job site and mounted to a building or other structure to form a PV array  10 . In other embodiments we contemplate the assembly of frames  12  around PV laminates  20  at the final installed location. Thus, the exact location of the manufacturing and assembly steps is non-critical with regards to proper implementation of the present invention. 
     Hybrid, strut-like frame  12  may include substantially similar construction on all four sides of PV module  11 . Top surface  14  of frame  12  is the surface which faces the same direction as the cells (not shown) in PV laminate  20 . Frame outside surface  16  comprises a multifunction female channel portion or slot  26  for the purpose of interlocking PV modules  11  together and connecting to a roof or other mounting surface as will be discussed below. Frames  12  as shown here have the corners cut to allow for a typical butt joint. In other embodiments the frames are joined at the corners via a mitre joint. Furthermore, any of the typical methods for joining framing members at the corners is applicable and covered in the scope of the present invention. Corners may also be fashioned to allow insertion of couplings from the corner and to allow smaller couplings to slide around the corner in a formed array. PV module  11  further comprises positive  22 pos and negative  22 neg output cables with positive  24 pos and negative  24 neg plugs as are typical in the art. In other embodiments multi-conductor cables are utilized. Output cables  22 pos,  22 neg originate in a rear-mounted electrical box  21 . 
       FIG. 2  depicts a perspective view of an interlocking device or parallel coupling  50   a  which may be utilized to interlock the outside surfaces  16  of two adjacent PV module frames  12  via a twist-lock action. This first embodiment contemplates a one-piece parallel coupling  50   a  comprising a rotating portion  100  with shaft portions  102 A,  102 B protruding from each side. The end of shaft portion  102 A comprises a first key or locking portion  104 A, and the end of shaft portion  102 B comprises a second key or locking portion  104 B. Both locking portions  104 A,  104 B rotate with the shaft portions  102 A,  102 B upon rotation of rotating portion  100  with a wrench. 
     Rotating portion  100  further comprises an optional top spring  106 U and bottom spring  106 L to help account for variations in material and assembly tolerances, to mitigate thermal expansion and contraction variance, and to provide a force which resists the unlocking of two interlocked PV modules  11 . Bores  110 U and  110 L (not viewable here) in rotating portion  100  are provided to house and structurally support springs  106 U,  106 L respectively. Springs  106 U,  106 L are shown here as cylindrical springs and may be made from spring steel or other suitable spring material. Other embodiments contemplate springs of other types and shapes, and still other embodiments provide coupling  50   a  without springs since frame  12  under compression provides some spring force. For example, disc washers, wave washers, star washers, finger springs, spiral springs, polyurethane springs, and others are all suitable for use with the present embodiment under discussion. Rotating portion  100  comprises four flat faces  116  so that rotating portion  100  can be easily turned with a typical wrench from above. One skilled in the art will recognize that the number of flat faces could vary and rotating portion  100  could be simply rounded, slotted, bored, or knurled depending on the type of wrench which is utilized. Shaft portions  102 A,  102 B further comprise optional reduced diameter portions  114 A,  114 B to help guide and hold a free PV module  11  which is being moved into position for coupling. Rotating portion  100  (except for springs  106 U,  106 L), shaft portions  102 A,  102 B, and locking portions  104 A,  104 B may be machined from a single piece of solid metal, such as steel or aluminum. In another embodiment rotating portion  100  may be made of a light-weight material such as plastic. However, one skilled in the art will recognize that multiple components could be assembled together and various materials could be used to form the various portions of coupling  50   a  as described herein. 
     Expanding the discussion now to further include  FIG. 3 , which depicts a cross-section cut through two adjacent PV modules  11 A,  11 B which are coupled together with a coupling  50   a , it can be seen that first locking portion  104 A may be specially shaped to be the first of the two locking portions  104 A,  104 B which is inserted into a first slot  26 A of PV module  11 A. Locking portion  104 A may be provided with curved surfaces  118 U,  118 L on opposite corners which allow locking portion  104 A to be rotated in a clockwise manner inside of slot  26 A until locking portion stops  120 AU,  120 AL contact upper  122 AU and lower  122 AL inside surfaces of slot  26 A respectively. With reference to  FIGS. 16-24 , which will be discussed in more detail below, one skilled in the art will recognize that the width of locking portion  104 A is slightly less than the height A of openings  27 A,  27 B in slots  26 A,  26 B, while the length is approximately equal to the height B inside of slot  26 A. Therefore locking portion  104 A may be inserted when it is oriented in a first position  91  and captured behind male features or flanges  108 AU,  108 AL when it is rotated clockwise. After approximately 90 degrees of clockwise rotation, when locking portion stops  120 AU,  120 AL are reached coupling  50   a  is said to be in a third position  93  (see below for discussion of an intermediate second position  92 ). 
     Accordingly, second locking portion  104 B may be specially shaped to be the second of the two locking portions  104 B,  104 A to be inserted into a second slot  26 B in PV module  11 B. This first embodiment contemplates a shape for locking portion  104 B which is capable of passing between male features or flanges  108 BU and  108 BL for approximately the first 45 degrees of clockwise rotation of coupling  50   a . Thus the intermediate position of approximately 45 degrees of clockwise rotation is said to be the second position  92 . The shape of locking portion  104 B is similar to locking portion  104 A except that material has been removed in the clearance zones  124 U,  124 L directly opposite curved surfaces  118 U,  118 L on locking portion  104 A. Thus, orientation of coupling  50   a  in first position  91  and insertion of locking portion  104 A into slot  26 A followed by a rotation to second position  92  results in locking portion  104 A being captured by slot  26 A and locking portion  104 B being correctly oriented for insertion into slot  26 B. Furthermore, insertion of locking portion  104 B into slot  26 B followed by an additional rotation of approximately 45 degrees clockwise to third position  93  results in locking portion  104 B being captured by slot  26 B. Rotation ceases when locking portion stops  120 AU,  120 AL contact surfaces  122 AU,  122 AL inside slot  26 A and locking portion stops  120 BU,  120 BL contact surfaces  122 BU,  122 BL inside slot  26 B, and at this point the outside surfaces  16 A and  16 B of PV modules  11 A and  11 B are said to be coupled or interlocked together (these two terms are used interchangeably throughout this document). Other embodiments contemplate a number of variations on the locking portions  104 A,  104 B and the slots  26 A,  26 B, all of which are within the scope of the present invention. For example, some embodiments may utilize locking portions  104 A,  104 B which are identical in shape but simply rotated at different angles from each other relative to shaft portions  102 A,  102 B. Such embodiments are still capable of providing a solid interlock but do not allow removal of a single module from the middle of a completely installed PV array  10  since first position  91  can only be reached when locking portion  104 B is not inside slot  26 B. Other embodiments include locking portions which are shaped for different angles of rotation other than 45 and 90 as discussed above, while others have locking portions which are shaped for counter-clockwise rotation. 
     Locking portions  104 A, 104 B further comprise tapered surfaces  105 AU,  105 AL,  105 BU, and  105 BL to guide them into position as coupling  50   a  is rotated and raised teeth  112 AU,  112 AL,  112 BU, and  112 BL for cutting into frame  12  and ensuring solid electrical ground contact between two adjacent PV modules  11  when they are coupled together. Teeth  112 AU,  112 AL,  112 BU,  112 BL also provide structural support by counteracting forces which tend to slide coupling  50   a  lengthwise in slots  26 A,  26 B. In other embodiments teeth  112  are provided in different locations than those shown here, and in still other embodiments teeth  112  are replaced by a separate grounding washer, such as a star washer, which is positioned between a portion of coupling  50   a  and frame  12 . 
     As shown in  FIG. 3 , slots  26 A,  26 B from two adjacent, interlocked modules  11 A,  11 B comprise openings  27 A,  27 B which allow insertion of couplings  50   a  in a direction which may be substantially parallel with the plane of laminates  20 A,  20 B and substantially perpendicular with outside surfaces  16 A,  16 B. Flanges  108 AU,  108 AL,  108 BU,  108 BL, which are located near openings  27 A,  27 B create (by virtue of their position) inside surfaces  109 AU,  109 AL,  109 BU,  109 BL of slots  26 A,  26 B which are available for use by couplings  50   a  and brackets  132  (see below) as a bearing surface. Inside surfaces are shown here as being substantially perpendicular to PV laminate  20 . However, other embodiments provide sloped and curved surfaces  109 AU,  109 AL,  109 BU,  109 BL. 
       FIG. 3  further reveals frame inside surfaces  17 A,  17 B; frame bottom surfaces  15 A,  15 B; frame screw holes  19 AU,  19 AL,  19 BU,  19 BL for frame screws  18 B,  18 U; and frame recesses  126 A,  126 B for capturing PV laminates  20 A,  20 B. This view also shows how substantially constant spacing between PV modules  11  in an array  10  is automatically determined by the width of rotating portion  100 , with minor material and assembly tolerance issues being allowed by variable compression amounts on springs  106 U,  106 L. For example, manufacturing of a perfectly square PV module  11  is very difficult. Therefore it is common for PV modules to have widths and lengths that vary by up to ⅛″. In prior art systems this variance is not accounted for. The springs  106 U,  106 L as shown here provide a degree of compliance that helps to mitigate the compounding of tolerance errors and therefore major problems with proper alignment during installation. 
       FIG. 4  depicts a perspective view of two adjacent PV modules  11 A,  11 B which are coupled together with two couplings  50   a . Since slots  26 A,  26 B may run substantially the whole length of frames  12 A,  12 B, couplings  50   a  may be located at substantially any point along the length. Given the high strength connection provided, in practice one to three couplings per seam between two PV modules is typically adequate. At a corner  130  of each PV module  11  the flanges  108 AU,  108 AL,  108 BU,  108 BL are cut off thus allowing coupling  50   a  to easily slide from the seam between one set of PV modules  11  over to the seam between an adjacent pair of PV modules  11  when coupling  50   a  is in first position  91  as discussed above. 
     Referring now to  FIGS. 5-6 ,  FIG. 5  depicts a perspective view of a height adjustable bracket  132  which is suitable for connection to a PV module  11  of the first embodiment of the present invention, and  FIG. 6  shows a cross-section cut through two adjacent PV modules  11 A,  11 B which are coupled together with a coupling  50   a  (not picture here for clarity, see  FIG. 3 ). An L-shaped bracket  132  comprises a z-axis or vertical adjustment slot  140  and a y-axis adjustment slot  142  (coordinate system based on plane of mounting surface, see  FIG. 7 ). A channel bolt  136  with bolt head  137 , which is threaded into a channel nut  134 , is utilized to attach bracket  132  to outside surface  16 B of frame  12 B. Channel nut  134  is shaped to fit inside slot  26 B and to be captured behind flanges  108 BU,  108 BL. This embodiment contemplates a simple rectangular shape for channel nut  134  with nut  134  being inserted at corner  130  and slid into position. Threading bolt  136  into nut  134 , sliding bracket  132  between bolt head  137  and frame outside surface  16 B, and then tightening bolt  136  serves to pull nut  134  solidly against flanges  108 BU,  108 BL thereby rigidly securing bracket  132  to frame  12 B. And since slot  26 B runs substantially the whole length of frame  12 B, bracket  132  can be attached to substantially any point along the length, which will be referred to as the x-axis direction. Therefore, slot  26 B along with slot  140  and slot  142  allows for 3 dimensional adjustability of bracket  132 , enabling greatly simplified installation via much easier lining up of brackets  132  with rafters (which typically run in the y-axis direction) and much easier leveling and aligning of PV modules within array  10 . Lag screw  138  provides a means of directly securing bracket  132 , and therefore array  10 , to a mounting surface  144 , such as a roof without any other support structure as is typical in prior art systems. 
     Please note that while  FIG. 6  shows a connection of bracket  132  to right frame  12 B, it can be connected to any outside surface  16 , and furthermore it can be reversed so that lag screw  138  is positioned beneath the PV module  11  to which it is connected. In other embodiments nut  134  comprises a rectangular shape with two opposing rounded corners, similar to locking portion  104 B, so that it can be inserted into slot  26 B from any point along frame  12 B and then twisted 90 degrees to tuck behind flanges  108 BU,  108 BL. In still other embodiments nut  134  is a standard hexagonal-shaped nut. 
     One alternate embodiment removes lower flanges  108 AL,  108 BL from slots  26 A,  26 B and the lower portions of locking portions  104 A,  104 B resulting in a one-sided locking action instead two as with the first embodiment. 
     First Embodiment 
     Basic Operation 
     Referring to  FIGS. 7-8  and  FIGS. 10-11 , a PV array  10  according to the first embodiment of the present invention is shown installed on the roof of a building  146 .  FIG. 7  depicts a perspective view of building  146  with PV array  10  shown attached to a roof  144 R which serves as a suitable mounting surface  144 . Roof rafters  148  are just beneath the top surface of the roof and are shown as dashed lines. Brackets  132  can be seen in this view along the front of PV array  10 . Brackets  132  are oriented such that lag screws  138  are hidden under PV modules. Brackets  132  can be seen attached to slots  26  on the outside surface  16  of the lowest row of three PV modules  11 , one bracket  132  per PV module  11 . Brackets  132  have been adjusted in their respective slots  26  in the x-axis direction such that each bracket  132  lines up with a rafter  148 . Since lining up of brackets  132  with rafters  148  is only required with certain types of roofs and mounting surfaces, other embodiments provide brackets  132  which are not lined up with rafters, but rather attach directly to the mounting surface at any desired point. In still other embodiments, brackets  132  are adjusted in the x and y directions to line up with ground mounted structures, pier blocks, concrete posts, and specialized mounting hardware such as roof jacks, mounting posts, mounting jacks, tile brackets, specialized brackets, and stand-offs. Since the inventive system provides three dimensional adjustability, it can be connected to almost any suitable mounting surface. 
       FIG. 8  shows a side view of the same PV array  10  from  FIG. 7  at a larger scale. This figure helps to clarify the fact that PV array  10  is connected to roof  144 R without the use of strut or other supports. Brackets  132  connect frames  12  directly to roof  144 R, and couplings  50   a  interlock PV modules  11  together. In contrast,  FIG. 9  shows a typical prior art PV array  10 PA without the benefit of an interlocking system as disclosed herein. PV modules  11 PA are first linked together by struts  131 PA. Struts  131 PA are then attached to a mounting surface (not shown) via brackets  132 PA. As can be seen here strut  131 PA is a device which is at least as wide as two PV modules  11 PA and is designed to support the opposing sides of at least two PV modules  11 PA. A coupling, on the other hand, only joins PV modules together at the seam between the two modules and therefore is not wider than a single module. The fact that struts  131 PA are designed to span between modules  11 PA means that a lot of extra material is required. The additional expense and installation time required to utilize strut  131 PA is a significant drawback to prior art systems. 
       FIG. 10  shows a perspective view of the same PV array  10  from  FIG. 7  except that array  10  is being viewed from the back (exactly 180 degrees around from the  FIG. 7  view) with building  146  removed to reveal the back side of PV array  10 . In this view it is now evident that a row of three brackets  132  is located along every horizontal seam  150  between PV modules  11  and along the top  154  and bottom  156  edges of array  10 . This method of relatively evenly distributing brackets  132  across array  10  is not possible with prior art strutless systems which utilize series couplings (see discussion below). 
       FIG. 11  shows a cross-section cut through PV array  10  (from  FIG. 7 ) just above couplings  50   a  and looking perpendicular to array  10  thereby revealing the locations of couplings  50   a  and brackets  132  (roofing material not shown beneath array  10  for clarity). Couplings  50   a  are shown interlocking all PV modules  11  in array  10  at all horizontal  150  and vertical  152  seams between PV modules  11 . In other embodiments couplings  50   a  are only utilized on either horizontal seams  150  or vertical seams  152 . The arrangement of couplings as shown here creates a double structure or parallel interlock support system  160  for array  10  along both the x and y-axes as will be discussed below. Each frame  12  is referred to as a hybrid, strut-like frame because, unlike most prior art systems, it performs the following basic functions which are normally shared between a PV frame and a strut or similar structural support system: (a) holding and protecting the edges of PV laminate  20 ; (b) interconnecting modules  11  together with a structural support system (in order to increase structural integrity and minimize the number of required connection points to mounting surface  144 ); and (c) providing a means for attaching array  10  to mounting surface  144  via foot-type or bracket members. 
     First Embodiment 
     Series and Parallel Coupling Theory 
       FIG. 12  provides a simplified top view of two adjacent rectangular frames A and B. Lines C 1 , C 2 , C 3 , and C 4  represent places along the seam between the two frames A and B where couplings can theoretically be placed. Couplings which connect at lines C 1  and C 2  are referred to as parallel couplings since a union of frames A and B at these points results in frames A and B being interlocked in parallel. It follows then that any point along the seam between A and B is theoretically capable of receiving a parallel coupling. However, the corner points K 1  and K 2  are special cases since prior art slots in the outside surfaces of frames do not extend all the way to the corner on both sides of a pair of orthogonal frame members. This problem arises from the nature of the aluminum extrusion process (which is how most PV frames are manufactured) and prevents the sliding of parallel couplings all the way to the end on at least two sides of a rectangular PV module. The corners are also a special case for a second reason. The corners K 1  and K 2  are the only places around the perimeter where a coupling can be inserted into the outside surface of a first frame member B 4  and continue through into a second frame member B 3  which is around the corner from the point of insertion. Thus, lines C 3  and C 4  are shown extending from parallel frame members A 2 , B 4  into the orthogonal frame members B 1 , B 3  and A 1 , A 3 . Since the ability to run a coupling into an orthogonal frame member clearly enhances the structural properties (z-axis loads can be distributed over a larger area), prior art couplings fall into two basic categories: parallel couplings which are optimized to connect to the side of a frame member substantially anywhere along the whole length of the member and series couplings which are optimized for the special case of connecting to the ends of frame members at the corner points K 1 , K 2 . Series couplings are so named because they link two frame members, such as A 3  and B 3 , end to end. 
     In order to understand the operation of PV array  10  of the first embodiment, it is important to first understand how the forces that are presented to PV array  10  are distributed across it. Forces can act over the entire surface, such a wind pressure, or forces can be highly localized, such as someone stepping on it. In either case, these forces must find their way to the roof  144 R or mounting surface  144  via brackets  132  that mount the PV system, and these brackets  132  may be some distance away from the point or area of application of the force. In many cases the force must pass across PV modules and the transitions between them in order to make it to mounting surface  144 . A coupling device for interlocking frame members  13  provides an opportunity to further support frame members  13  by locking it to adjacent frame members  13 . For an individual PV module  11  each frame member  13  acts as a separate structural entity which is supported by PV laminate  20  and connected to orthogonal frame members at the corner joints. Even in a hypothetical case of a framed PV laminate which comprises a frame constructed out of a single piece of material (no such example exists to our knowledge), each side of the frame is still a separate structural entity since the sides are mostly separated by the laminate and only connected by a small portion in the corners. Thus, it is important to discuss which frame member and where on the frame member a particular coupling is connected if one wants to understand the structural properties of the coupling. Assuming that PV module  11  comprises substantially straight frame members  13 , then the possible shapes (in a top view) for flat-plate PV module  11  are a triangle, rectangle, pentagon, hexagon, etc. All such shapes are suitable for use with the present invention. 
       FIGS. 13-14  show generic PV arrays  10 P and  10 S, comprising four PV modules  11 A,  11 B,  11 C,  11 D with adjacent frame members  13 A 1 ,  13 B 1 ;  13 A 2 ,  13 C 2 ;  13 B 2 ,  13 D 2 ;  13 C 1 ,  13 D 1  respectively. These two figures demonstrate the two basic types of couplings which are possible in a rectangular array: parallel couplings  50  and series couplings  62 . When straight-sided PV modules  11 A,  11 B,  11 C,  11 D are assembled to form substantially rectangular PV arrays  10 P and  10 S, the result is a plurality of frame members  13  which are immediately adjacent to each other (within arrays  10 P,  10 S) and a plurality of frame members  13  around the perimeter of arrays  10 P,  10 S.  FIG. 13  shows parallel couplings  50  that each connect two adjacent and substantially parallel frame members  13  side to side.  FIG. 14  shows series couplings  62  that each connect two substantially collinear frame members  13  end to end. 
     As shown in  FIG. 13 , parallel couplings  50  allow a force F 1  applied to PV module  11 B to be distributed between the PV modules immediately adjacent to it,  11 A and  11 D, along paths P 1 , P 2 , P 3 , as well as out to the more remote PV module  11 C along paths P 4  and P 5 . This distribution of forces is enabled since parallel couplings  50  allow both the connection of frame members  13  end to end and side to side. For example, frame members  13 B 1  and  13 A 1  are interlocked in addition to the orthogonal pair of frame members  13 B 2  and  13 D 2 . This connection of orthogonal pairs of frame members  13  enables the connection of each row of PV modules  11 A,  11 C, to the adjacent row  11 B,  11 D and allows force F 1  to be distributed across all the PV modules in array  10 P, thus strengthening the entire frame structure supporting PV laminates  20 . However, series couplings  62 , as shown in  FIG. 14 , will only allow forces to be distributed down the rows  11 A,  11 C and  11 B,  11 D which are attached in this way. The same force F 1  presented to module  11 B in this case can only take paths P 10  and P 11 , thus preventing the distribution of loads to PV modules  11 A,  11 C. 
     While series couplings  62 , as are known in the prior art, are clearly less advantageous than parallel couplings, some embodiments of the present invention, as will be discussed below, provide a means for adding a series coupling portion to a parallel coupling thereby creating a series-parallel coupling. There are distinct advantages to such a hybrid coupling since in theory a series coupling may provide more opportunity for enhancing the z-axis strength of frame  12  (though such potential is not realized in prior art couplings). 
     Parallel interlock support system  160  operates as follows. The specialized slot  26  allows couplings  50   a  to securely connect the sides of each immediately adjacent and parallel pair of frame members  13 . It is common for installation technicians to step on a PV laminate  20  during installation. This action provides a localized load such as would generate force F 1 . In prior art strutless systems, force F 1  is translated to the frames which are nearest to the point of loading, and each frame member  13  is acting mostly independently since there are no securely connected additional supporting members nearby. In the first embodiment of the present invention, however, force F 1  presented to the top of PV laminate  20  is shared by frame  12  which surrounds PV laminate  20  as well as the four frame members  13  which are coupled to the loaded PV laminate  20 . Thus, it can be seen that a support grid is created by the simple and rapid connection of couplings  50   a  to adjacent frames  12 . This grid is evenly distributed in the x and y directions throughout array  20 , and the doubled support members run beneath the edges of each PV laminate  20 . The result is a PV array  10  which can be mounted to a roof or other mounting surface  144  without the need for costly and heavy strut (or other structural members). Furthermore, the increased spanning capabilities provided by the parallel interlock support structure  160  significantly reduce the number of connection points (and therefore brackets  132 ) for a given size array  10  on a given mounting surface  144  as compared to prior art strutless systems. 
       FIG. 15  shows a prior art strutless PV array  210 PA with PV modules  211 PA, brackets  232 PA, and series couplings  250 PA. As discussed above, series couplings must be connected at the corners and therefore they cannot be used to connect two adjacent rows together. Thus, brackets between rows must be doubled up (as shown) or specialized (and difficult to install) double brackets must be utilized. And, as mentioned above, the total number of brackets  232 PA is also increased relative to the inventive device of the first embodiment because spans between brackets  232 A cannot be as long. 
     First Embodiment 
     Coupling Modes 
     The unique structure of the framing and coupling systems of the first embodiment enables three distinct modes of operation: positioning mode, locked mode, and sliding mode. In the first embodiment these different modes may be easily accessed via rotation of coupling  50   a  into one of the three discrete positions  91 ,  92 ,  93  as discussed above. Other embodiments access these modes via different means as will be discussed below. 
     Positioning mode is primarily utilized during installation and removal of PV modules  11  in PV array  10 . Positioning mode secures coupling  50   a  to one PV module  11  of a pair of PV modules  11  to be interlocked. Since the positioning of PV modules can be difficult, particularly on sloped roofs, positioning mode insures that coupling  50   a  will stay in position as the two modules are guided together. Thus, in positioning mode coupling  50   a  is either firmly secured or loosely attached to one PV module  11 . 
     Locked mode is the mode that all couplings are left in once array  10  is fully installed. Locked mode securely interlocks two adjacent PV modules  11  together thereby forming a parallel interlock support system  160  as discussed above. In locked mode coupling  50   a  is firmly secured to two adjacent PV modules. This mode also automatically grounds the two interlocked modules  11  to each other and forces them into proper alignment and spacing. The automatic grounding feature of the first embodiment of the present invention provides a substantial improvement over prior art systems because PV modules are electrically grounded to each other both within rows of modules  11  and between rows. Thus a complete x-y grounding matrix results so that only one ground wire needs to be run from PV array  10  to the grounding equipment for the site. 
     Sliding mode is primarily used during installation and removal of PV modules  11  in array  10 . Sliding mode partially decouples two interlocked PV modules so that coupling  50   a  may be repositioned or slid all the way down slot  26  and over into slots  26  for an adjacent PV module pair in array  10 . This allows removal of an individual PV module  11  that is surrounded by adjacent PV modules  11  installed on all sides. Thus in sliding mode coupling  50   a  is loosely attached to two adjacent PV modules. Prior art systems do not teach or imply a PV array coupling and framing system capable of achieving all three of these coupling modes (positioning, sliding, and locked). 
     First Embodiment 
     Coupling Process 
       FIGS. 16 ,  19 , and  22  depict a perspective view of coupling  50   a  in each of its three discrete positions  91 ,  92 ,  93  respectively as it is utilized to interlock two adjacent frames  12 A,  12 B together (only a portion of frames  12 A,  12 B are shown so that locking portions  104 A,  104 B are revealed). Please note that since coupling  50   a  may be installed in either frame first,  FIGS. 16 ,  19 , and  22  show frames  12 A, and  12 B in opposite positions than in  FIG. 3 .  FIGS. 17-18  show front and back side views respectively of coupling  50   a  in first position  91 .  FIGS. 20-21  show front and back side views respectively of coupling  50   a  in second position  92 .  FIGS. 23-24  show front and back side views respectively of coupling  50   a  in third position  93 . The following description also references  FIGS. 2-3  since some parts are easier to see in closer views. 
     The process of interlocking two adjacent frames  12 A,  12 B is as follows. First, coupling  50   a  is oriented in first position  91 , which aligns the length of locking portion  104 A with the length of slot  26 A, then inserted at substantially any point along frame  12 A into slot  26 A. While inserting, the direction of travel is substantially parallel with the plane of laminate  20 A and substantially perpendicular to the length of slot  26 A. Coupling  50   a  is inserted until locking portion  104 A hits the back of slot  26 A or rotating portion  100  contacts outside surface  16 A of frame  12 A.  FIG. 16  shows coupling  50   a  in first position  91  and fully inserted. For convenience, we contemplate alignment of rotating portion flat faces  116  at 45 degrees to the plane of laminate  20  when in first position  91 : this way the corner point of rotating portion  100  is pointing straight up and is therefore easy to align by eye. Of course other orientations for flat faces  116  will work just as well. One skilled in the art will recognize that springs  106 U,  106 L are oriented such that they are not touching frames  12  in first position  91  (since they line up with opening  27 A,  27 B of slot  26 A,  26 B). Therefore, a return to first position  91 , even after the complete array  10  has been installed, will enable sliding mode since it is not locked onto either frame and since springs  106 U,  106 L are not compressed. 
     The second step is to rotate coupling  50   a  into second position  92  in order to enable positioning mode as is depicted in  FIGS. 19-21 . Though lighter duty springs may be used, we contemplate the use of relatively stiff springs for springs  106 U,  106 L since movement of the modules  11  in array  10  may be undesirable once the installation is complete. Springs with a full deflection rating of 100 to 500 pounds may work well, but other spring rates are also suitable. Thus, in order to move coupling  50   a  from first position  91  to second position  92 , a wrench is applied to rotating portion  100  to rotate it approximately 45 degrees clockwise. In this position locking portion  104 A is locked onto frame  12 A and springs  106 U,  106 L are partially compressed. Please note that during the first part of the 45 degree rotation from first position  91  to second position  92 , tapered surfaces  105 AU,  105 AL engage with flanges  108 BU,  108 AU,  108 AL to pull the locking portion further into the slot. By guiding locking portion  104 A into place, tapered surfaces  105 AU,  105 AL also enable an increased range of acceptance angles for initial alignment of locking portion  104 A and therefore increase the flexibility and ease of use of coupling  50   a  since it doesn&#39;t have to be “dead on” in order to rotate. As coupling  50   a  is being rotated from first  91  to second  92  position, teeth  112  AU,  112 AL begin to bite into flanges  108 AU,  108 AL when the end of tapered surfaces  105 AU,  105 AL is reached. From this point on through the rest of the full 90 degree throw, the surfaces of locking portion  104 A which are in contact with flanges  108 AU,  108 AL remain relatively parallel with flanges  108 AU,  108 AL. Therefore, the force applied by springs  106 U,  106 L effectively squeezes coupling  50   a  about flanges  108 AU  108 AL and it is held in a stable position if the wrench is removed from rotating portion  100 . Thus, second position  92 , as shown in  FIG. 19 , is a stable discrete position with coupling  50   a  attached only to frame  12 A. The second frame  12 B can now be moved into or out of position without knocking coupling  50   a  out of position. Unlike some prior art systems which require both PV modules  11 A,  11 B to be in place and aligned before a coupling can be connected, the inventive device of the first embodiment allows free positioning of modules with coupling  50   a  connected to one of them in positioning mode. For example, in some cases it may be advantageous to insert couplings into some PV modules  11  on the ground before taking them up to a roof to be mounted. In other cases couplings  50   a  may be locked onto PV modules  11  at the factory prior to shipping. Also, when interlocking a free PV module to an already mounted PV module, coupling  50   a  may be attached to either the free PV module or the already mounted PV module. Positioning mode is enabled since locking portion  104 B is shaped such that it only begins to lock itself onto frame  12 B when coupling  50   a  is being rotated from second position  92  to third position  93 . 
       FIGS. 22-24  depict coupling  50   a  in third position  93 , securely attached to frames  12 A,  12 B in locked mode. The process of rotating from second position  92  to third position  93  is basically the same as that from first  91  to second  92 . A wrench is used to rotate rotating portion  100 . Tapered surfaces  105 BU,  105 BL guide locking portion  104 B into slot  26 B and teeth  112 BU,  112 BL begin to bite into flanges  108 BU,  108 BL when the end of tapered surfaces  105 BU,  105 BL is reached. Arrival at third position  93  is signaled by locking portion stops  120 AU,  120 AL contacting upper  122 AU and lower  122 AL inside surfaces of slot  26 A respectively and  120 BU,  120 BL contacting upper  122 BU and lower  122 BL inside surfaces of slot  26 B respectively. Locking portion stops  120 AU,  120 AL,  120 BU,  120 BL provide a solid, hard stop which prevents rotation of the wrench any further, therefore significantly simplifying the installation procedure and increasing the quality thereof by eliminating the possibility of over or under-torqued bolts. 
     The above discussion of the coupling process clearly shows how a rotation of coupling  50   a  from first position  91  to third position  93  causes locking portion  104 A to bear against inside surfaces  109 AU,  109 AL of slot  26 A and rotating portion  100  via springs  106 U,  106 L to bear against an opposing frame surface, outside surface  16 A. Since springs  106 U,  106 L act to transfer forces from rotating portion  100  to frames  12 A,  12 B, they are also referred to as force transfer portions. Likewise locking portion  104 B bears against inside surfaces  109 BU,  109 BL of slot  26 B and rotating portion  100  via springs  106 U,  106 L bears against an opposing frame surface, outside surface  16 B. Thus it is clear that coupling  50   a  securely interlocks PV modules  11 A and  11 B together by bearing against opposing surfaces on each frame  12 A,  12 B upon rotation of rotating portion  100 . 
     Please note that this method of interlocking is quite different from most prior art systems which interlock adjacent PV modules by means of a coupling that bears against the frame and a strut, a mounting rail, a bracket, or other structural member which is sandwiched between opposite ends of the coupling. This basic structural difference enables the forming and mounting of PV arrays  10  without requiring the use of separate structural support members (such as strut, mounting rails, and the like) which attach directly to and span between multiple PV modules in a formed PV array  10 . 
     First Embodiment 
     Installation Methods 
     Referring to  FIGS. 7-8  and  FIGS. 10-11 , the basic steps involved in the forming and mounting of PV array  10  according to the second embodiment of the present invention may be as follows: 
     Step 1: Secure a first PV module  11  to roof  144 R with at least one bracket  132 . 
     Step 2: Interlock a second PV module  11  to the first PV module  11  with at least one parallel coupling  50   a  which interlocks the sides of two adjacent frame members  13  together in parallel. 
     Step 3: Attach second PV module  11  to roof  144 R with at least one bracket  132 . 
     Step 4: Repeat steps  2  and  3  for all remaining PV modules  11  in PV array  10 , successively interlocking each new PV module  11  to the side of a mounted PV module  11  and attaching at least one bracket  132  to each module. 
     The details of Step 2 above may be as follows: insert coupling  50   a  into slot  26  of the mounted PV module  11 , rotate rotating portion  100  to second position  92  with a wrench thereby enabling positioning mode, mate second PV module  11  with coupling  50   a , rotate coupling  50   a  to third position  93  thereby enabling locked mode. The wrench is operated from above by sliding wrench between the two modules  11  (which may be as close as approximately ¼″ apart). Alternately coupling  50   a  may be placed on the free module  11  for positioning mode instead of the mounted module  11 . 
     The details of Step 3 may be as follows: install bracket flashing or mounting plate, loosely install bracket  132  on mounting plate, attach bracket  132  to PV module  11  at any point along the side where it lines up with required bracket placement, secure bracket  132  to mounting plate. Since there are many types of mounting surfaces, there, of course numerous ways that brackets  132  can be installed. Thus, the inventive system of the first embodiment provides slot  26  and height adjustable bracket  132  in order to provide maximum flexibility in adapting to almost any mounting situation. 
     Parallel couplings  50   a  may be used at substantially any point in any horizontal  150  or vertical  152  seam between adjacent PV modules. Each seam  150 ,  152  may include one, multiple, or no couplings  50   a  depending on the installation requirements. Substantially all brackets  132  may be attached by sliding channel nuts  134  into slots  26  from the end, aligning with bracket  132 , and screwing bolt  136  into channel nut  134  to capture bracket  132 . 
     Final tightening of each coupling  50   a  and bracket  132  connection is flexible and does not necessarily coincide with initial placement in array  10  of that module  11 . This flexibility allows PV modules  11  to be temporarily positioned in the array while others are positioned or while wiring or other installation issues are handled. Since all couplings  50   a  are capable of being tightened from the top, PV modules  11  can be moved into locked mode at any time. One skilled in the art will recognize that the 2-axis nature of the couplings in the embodiment under discussion means that PV modules  11  can be installed in any order and in substantially any shape for PV array  10  as long as each new PV module  11  is interlocked to a mounted PV module  11 , and all new modules  11  are added to a mounted module which has a portion of a frame member  13  free (not already interlocked to another PV module). It is possible, for example, to mount PV modules in a generally rectangular shape, but then leave out modules  11  in the middle to avoid vents or other obstructions. In another example, each row of PV modules  11  may be displaced by a specific amount for architectural reasons or to match a roof line. 
     If a module  11  needs to be removed from the middle of a formed array for servicing, the required steps may be as follows. First, move all couplings  50   a  which are connected to it back into first position  91  with a wrench from above thereby enabling sliding mode for each. Then slide all loosened couplings  50   a  over to neighboring modules  11 . In some cases a bracket  132  may prevent sliding in one direction but not both. Brackets  132  are typically installed with one per module, so there is normally at least one direction to slide. If two brackets  132  are required, then couplings  50   a  are not used in between the two brackets  132 . Next, loosen bolts  136  which connect brackets  132  to frames  12  on the effected module  11  and lift it straight up and out of array  10  (disconnecting wires before moving it too far). In this way an individual PV module  11  that is installed in the middle of array  10  may be removed without requiring the removal of the surrounding modules  11 , thereby substantially saving time during troubleshooting and maintenance as compared to prior art systems. 
     In another embodiment PV modules  11  comprise non-rectangular shapes such as triangular or hexagonal and the coupling system works in the same manner as described above. In another embodiment PV modules  11  are small enough to not require one bracket  132  per module. In this embodiment multiple modules are interlocked together and then one of the group is attached to roof  144 R with bracket  132 . In yet another embodiment PV array  10  is mounted to a ground-mounted rack system instead of roof  144 R with no change in the basic installation method outlined above except that brackets  132  are attached to the rack instead of roof  144 R. In still another embodiment groups of standard-sized PV modules  11  are interlocked together via couplings  50   a  on the ground and then hoisted to a roof where brackets  132  are used to secure them in place. 
     First Embodiment 
     Advantages 
     The first embodiment of the present invention provides numerous advantages over prior art systems. Inventive features of the present apparatus include, but are not limited to the following: 
     Parallel coupling action—parallel coupling is attachable to substantially the whole length of all four sides of a PV module and securely locks the outside surfaces of parallel frame members together in a side to side arrangement, thereby increasing the structural performance of the PV array. 
     Three mode design—Parallel coupling is shiftable with a wrench into three modes of operation: positioning mode, sliding mode, and locked mode. A positive stop is provided when locked mode is reached. 
     Locking portion—Parallel coupling provides two specially shaped locking portions which are insertable into slots on the outside surfaces of adjacent frame members. Locking portions enable discrete positions of device and provide a positive stop for locked position. 
     Dual bearing action—Parallel coupling interlocks adjacent frame members together by bearing against opposing surfaces on each frame upon rotation of a rotating portion. Locking portion bears against an inside surface of the slot and the coupling bears against an opposing surface. 
     Twist-lock action—Parallel coupling provides a rotating portion which shifts from an unlocked position to a locked position in approximately 90 degrees of rotation. 
     Top accessible—Parallel coupling is accessible from the top even after PV array has been formed. Coupling can be rotated with a wrench from above to shift from locked mode to sliding mode so that coupling can be slid into the slots of neighboring PV modules. In this way a single PV module can be removed from the middle of a formed PV array. 
     One-piece—Parallel coupling is deployable in the field as a one-piece unit. 
     Automatic alignment—Parallel coupling forces interlocked PV modules into alignment along both the x and y axes of PV array. Spacing between modules and height of modules is automatically set upon rotation into locked mode. 
     Automatic grounding—Rotation of parallel coupling into locked mode causes integral teeth to bite into frame members thereby enabling reliable x-y matrix grounding for the whole PV array. Only one wire is required to ground the whole PV array and the ground connection is uncompromised by the removal of a PV module from the PV array. 
     Tolerance compensation—Parallel coupling minimizes alignment problems due to variable tolerances within PV array via an integral spring. Spring also resists unlocking of mechanism over time and helps to minimize grounding problems by maintaining a known amount of force on ground connection. 
     Multifunction frame—A frame is provided which supports PV laminates and eliminates the need for a strut system which links modules together in a PV array. Each frame member comprises a specially shaped slot which enables the connection of parallel couplings and mounting brackets to substantially the whole length of all four sides of a PV module. Furthermore each slot comprises flanges which enable high-strength interlocking and the connection of snap-on options such as cosmetic flashings and debris screens. 
     The above features provide many useful benefits including, but not limited to: strutless design, minimal attachment points, accessible yet hidden wiring, flexible mounting options, three dimensional adjustability, rapid formation of PV array, better load distribution, better airflow, more flexible wiring options, low part count, improved aesthetics due to lower profile and better alignment, and increased flexibility for orientation (landscape or portrait o.k.). 
     When removing the strut from a PV mounting system, significant structural challenges are revealed. We will now discuss in more detail the structural advantages of the first embodiment relative to prior art strutless systems. 
     First, coupling  50   a  maximizes structural integrity relative to size by operating on frame  12  in a direction substantially perpendicular to outside surface  16  (instead of parallel to it). This fact enables the cost-effective creation of flanges  108 AU,  108 AL,  108 BU,  108 BL in frame  12  extrusion which provide a thick and very strong surface that coupling  50   a  utilizes as a wall for holding the ends of locking portions  104 A,  104 B. This arrangement results in a very high pull-out strength as compared to the press-fit resistance provided by prior art systems. The flanges  108 AU,  108 AL,  108 BU,  108 BL are described as cost-effective since they run longitudinally in the same direction that an extrusion process would run in order to extrude frame members  13  in a typical manufacturing process. Creation of equivalent flanges running at 90 degrees to flanges  108 AU,  108 AL,  108 BU,  108 BL as required by prior art systems requires additional machining operations. 
     Second, the major part of the coupling can be located in the gap between modules instead of inside the frame member, thereby reducing the required size for the frame. 
     Third, attaching coupling  50   a  to outside surface  16  of frame  12  with locking portions that engage positively inside both the top and bottom frame member flanges  108 AU and  108 AL, allows coupling  50   a  to resist forces that would separate the opposing frame outside surfaces  16 , especially in comparison to prior art systems. Furthermore, because it is these separating forces that are the primary forces that we need to overcome with such a coupling, and it intrinsically does this in an effective manner, it can be designed smaller than prior art solutions, and will therefore involve lower material costs. 
     Fourth, teeth  112 AU,  112 AL,  112 BU,  112 BL enhance the longitudinal holding strength of coupling  50   a  since they are circular to facilitate biting into frame  12  as rotating portion  100  is rotated to lock coupling  50   a . These teeth therefore resist being dragged along the longitudinal axis. 
     In addition to the structural advantages discussed above, the grounding system provided by the first embodiment of the present invention also has unique benefits. The system is more reliable than the prior art since the amount of force supplied to the grounding means is dependant on the stiffness of springs  106 U,  106 L. Once the correct spring size is determined, all couplings will supply a consistent amount of force to the ground connection and this force will not be dependant on how hard a technician tightens the coupling. 
     It follows from the above discussion that the first embodiment of the present invention provides significant advantages over prior art systems. Other objects and advantages of the present invention will also be discussed. 
     Second Embodiment 
     Structure 
       FIGS. 25-31  depict a second embodiment of the present invention. This embodiment is similar to the first embodiment described above except that it includes minor changes to the framing and coupling systems in order to lower manufacturing costs and simplify installation. 
       FIGS. 25-26  present a cross sectional view of two interlocked modules  211 A,  211 B and a perspective view of four interlocked PV modules  211 A,  211 B,  211 C,  211 D respectively. Slot  26 A,  26 B is removed from two opposing frame members  13  yielding a hybrid, strut-like frame  212  with two un-slotted frame members  913  and two slotted frame members  213 . Un-slotted frame members  913  may be smaller and lighter weight than slotted frame members  213 . In another embodiment un-slotted frame members  913  are made from a lightweight plastic material and are primarily used to protect laminate  20  edges (instead of providing structural support). In another embodiment frame members  913  are not used at all. 
     Frames  212 A,  212 B,  212 C,  212 D each comprise an outside surface  216 A,  216 B,  216 C,  216 D; an inside surface  217 A,  217 B,  217 C,  217 D; a top surface  214 A,  214 B,  214 C,  214 D; and a bottom surface  215 A,  215 B,  215 C,  215 D (not all surfaces viewable in these drawings). Four interlocked PV modules  211 A,  211 B,  211 C,  211 D are oriented such that slots  226 A,  226 B with openings  227 A,  227 B parallel each other and slots  226 C,  226 D with openings  227 C,  227 D parallel each other. The two modules  211 A,  211 B comprise slot inside surfaces  209 AU,  209 AL,  209 BU,  209 BL (modules  211 B,  211 C comprising like surfaces which are not labeled). Thus, all slotted frame members  213 , except those around the perimeter of array  10 , may be located immediately adjacent to other slotted frame members  213 , and all un-slotted frame members  913 , except those around the perimeter of array  10 , may be located immediately adjacent other un-slotted frames sides  913 . The designation PV module  211  refers to any PV module in array  10  and the designation  212  refers to any PV module  211  frame in array  10 . Likewise a slot  226  refers to any slot  226 A,  226 B,  226 C,  226 D within array  10 . 
     In order to maintain structural linking in both the x and y directions, as is shown in the first embodiment described above, the second embodiment of the present invention replaces coupling  50   a  with a parallel coupling  50   b  in some locations. In other locations a parallel coupling  50   j  is utilized in place of coupling  50   a . In locations where two frame members  13  have been changed to un-slotted frame members  913  there are no couplings since there is no slot  26  for coupling connection. Parallel coupling  50   b  is also referred to as a double coupling or series-parallel coupling  50   b  because it further comprises a series coupling portion  162  which is utilized to provide a series coupling connection to a second pair of adjacent PV modules. Thus parallel coupling  50   b  interlocks four PV modules  211 A,  211 B,  211 C,  211 D instead of two as is typical in prior art systems. A more detailed description of the layout of couplings  50   b  and  50   j  is provided below. All couplings  50   j  and  50   b  are shown here in horizontal seams  150 , but other embodiments provide all couplings  50   j  and  50   b  in vertical seams  152 . In still other embodiments frame members  13  are substantially similar on all four sides and therefore couplings  50   j  and  50   b  are located in both the horizontal  150  and vertical seams  152 . 
       FIG. 27  depicts a perspective view of a generally rectangular-shaped parallel coupling  50   b . Coupling  50   b  comprises two parallel coupling portions  50   bb  and a series coupling portion  162 . Parallel coupling portions  50   bb  are similar to couplings  50   j  (described below) except that they may be shaped slightly differently in order to work well with series coupling portion  162 . For example, in one embodiment parallel coupling portions  50   bb  are similar to couplings  50   j  except that they further comprise retainer portions which enable them to be movably secured to series coupling portion  162 , thereby allowing coupling  50   b  to be deployed as a one-piece unit in the field. In the present embodiment under discussion coupling portions  50   bb  are the same as couplings  50   j  thus allowing coupling  50   b  to be a three piece unit comprising two parallel coupling portions  50   bb  and one series coupling portion  162 . In another embodiment more than two coupling portions  50   bb  are utilized for additional strength. In still another embodiment series coupling portion  162  comprises retainer portions which enable parallel coupling portions  50   bb  to be movably secured to series coupling portion  162 , thereby resulting in a one-piece coupling  50   b.    
     Referring to  FIGS. 25-27 , series coupling portion  162  comprises a first side  164  adapted to mate with outside surfaces  216 A,  216 C of the four interlocked PV modules  211 A,  211 B,  211 C,  211 D. First side  164  comprises three male protrusions which mate with frames  212 A,  212 C to increase the strength of frames  212 A,  212 C at the point of coupling. Male protrusion  165  is adapted for insertion into auxiliary slots  224 A,  224 C in frames  212 A,  212 C and may be tapered slightly to insure a snug fit is maintained despite tolerance issues. Male protrusion  166  is adapted for insertion into slots  226 A,  226 C in frames  212 A,  212 C and comprises teeth  168 U,  168 L which bite into frames  212 A,  212 C to insure solid electrical ground contact and to enhance the structural connection between PV modules  211 A,  211 C. Male protrusion  166  may be tapered. Male protrusion  167  is adapted to slide just beneath frames  212 A,  212 C and may be tapered as well. In other embodiments male protrusions  165 ,  166 ,  167  may not be tapered. Series coupling portion  162  further comprises at least two slots or holes  170 A,  170 B which allow insertion of parallel coupling portions  50   bb  as discussed below and a second side  172  which faces away from PV modules  211 A,  211 C when series coupling portion  162  is installed. In another embodiment teeth  168 U,  168 L are replaced by teeth on a different surface of series coupling portion  162  or a different portion of coupling  50   b . In other embodiments series coupling portion  162  has various numbers of male protrusions. In still another embodiment there are no male protrusions on series coupling portion  162 . We contemplate making series coupling portion  162  in a length of approximately 3-12″ and out of a rigid material such as aluminum or steel, though other materials and lengths are possible. 
       FIG. 28  shows a perspective view of parallel coupling  50   j  which comprises all of the same portions as coupling  50   a  except the following. First, shaft portion  102 A, designated here as  232 A, has been extended by approximately the width of bracket  132 . Second, rotating portion  100  has been replaced by rotating portion  200  comprising four springs  236 A,  236 B,  236 C,  236 D, (not all viewable here), two for each side of coupling  50   j  oriented approximately 180 degrees apart. And third, spring bores  110 U,  110 L have been replaced by spring bores  240 A,  240 B,  240 C,  240 D to correspond with new springs  236 A,  236 B,  236 C,  236 D. Coupling  50   j  further comprises locking portions  204 A,  204 B which function the same as locking portions  104 A,  104 B. All remaining portions of coupling  50   j  are the same as coupling  50   a  and are thus not specifically designated here. Parallel coupling portion  50   bb  in this second embodiment is the same as coupling  50   j  and thus also references the same designations. 
       FIG. 29  shows a perspective view of height adjustable bracket  132  and parallel coupling  50   j . Another advantage of the second embodiment of the present invention is that extended shaft portion  232 A allows coupling  50   j  to perform a dual function of interlocking adjacent PV modules together as discussed above while also attaching bracket  132  to PV module  11 . This feature substantially reduces installation time when compared to prior art systems that require the tightening of separate fasteners for couplings and brackets. One skilled in the art will also recognize that vertical adjustment slot  140  in bracket  132  is approximately perpendicular to slot  26 A,  26 B, and that springs  236 A,  236 B,  236 C,  236 D are oriented so that in first position  91  all four springs are free and uncompressed in the same way as coupling  50   a . Many other spring variations are possible within the scope of the present invention. 
       FIG. 30  provides a cross-section showing two adjacent PV modules  212 A,  212 B which are interconnected with coupling  50   j . Coupling  50   j  is shown in first position  91  as discussed above. When rotated approximately 90 degrees, coupling  50   j  interlocks frames  212 A and  212 B together and simultaneously compresses bracket  132  against frame  212 A. Thus, channel nut  134  and channel bolt  136  are no longer needed. 
     Second Embodiment 
     Operation 
       FIG. 31  is the same as  FIG. 11  except that PV array  10  utilizes the framing and coupling system of the second embodiment. Brackets  132  are shown in the same locations except now they are connected to frames  212 A,  212 B,  212 C,  212 D via couplings  50   j , thereby reducing total part count and installation time required for PV array  10 . Series-parallel couplings  50   b  bridge the corner points where the four corners of PV modules  211 A,  211 B,  211 C,  211 D meet. For example, a coupling  50   b  is shown bridging a corner point  295  where four PV modules  211 A,  211 B,  211 C,  211 D meet. Parallel coupling portions  50   bb  interlock modules  211 A,  211 B and  211 C,  211 D while series coupling portion  162  interlocks modules  211 B,  211 D and  211 A,  211 C. Please note that a second series coupling portion between  211 A,  211 C is possible but not required since parallel coupling portions  50   bb  lock frame  212 A to frame  212 B and frame  212 C to frame  212 D along with series coupling portion  162 . 
     Thus, the two axis parallel interlock support system  160  from the first embodiment is replaced by a single axis parallel interlock support system  260  which may run along the x-axis or y-axis. As shown in  FIG. 31 , parallel coupling portions  50   bb  and parallel couplings  50   j  lock adjacent frame members  213  side to side in parallel which creates vertical rows of paired frame members  213  along the y-axis. Series coupling portions  162  interlock frame members  213  longitudinally along the x-axis, thereby connecting the vertical rows and increasing the overall strength of the system. Series coupling portion  162  is located between rotating portion  100  and outside surface of frames  216 . And since parallel coupling portion  50   bb  is rotatable relative to series coupling portion  162 , a rotation of rotating portion  100  firmly compresses series coupling portion  162  into frames  212 A,  212 C. This action serves to substantially increase the strength of frames  212 A,  212 C relative to a z-axis load (such as wind) in the region of coupling  50   b  since z-axis loads are distributed longitudinally down frames  212 A,  212 C. While some prior art couplings do also provide increased z-axis strength due this same effect, series coupling portion  162  may be substantially stronger for the following reasons: (a) since series coupling portion  162  is not fully contained within a slot or internal cavity of frames  212 A,  212 C, it is able to be much taller in the z-direction thereby increasing strength; (b) coupling portion  162  is secured to frames  212 A,  212 C by a compressive force about a portion of frames  212 A,  212 C which increases strength instead of a tensile force which tends to deform the frame and decrease strength; (c) coupling portion  162  comprises upper  165  and lower  167  male protrusions which tend to prevent deformation of frames  212 A,  212 C under load since they prevent widening of opening  227 A as seen in  FIG. 25 ; and (d) coupling portion  162  has no fixed center point and therefore may be slid in slots  226 A,  226 C to match up with high load areas. 
     Accordingly, a rotation of parallel coupling portion  50   bb  from first position  91  to third position  93  causes locking portion  204 A to bear against inside surfaces  209 AU,  209 AL of slot  226 A and rotating portion  200  via springs  236 A,  236 C to bear against series coupling portion  162  which in turn bears against an opposing frame surface, outside surface  216 A. In this case the bearing action of rotating portion  200  is transferred through springs  236 A,  236 C and series coupling portion  162  to frame  212 A. Therefore springs  236 A,  236 C and series coupling portion  162  are also referred to as force transfer portions. Since there is no series coupling portion  162  between rotating portion  200  and frame  212 B, this portion of the coupling process proceeds the same as discussed above for module  12 B. That is, locking portion  204 B bears against inside surfaces  209 BU,  209 BL of slot  226 B and rotating portion  100  via springs  236 B,  236 D bears against an opposing frame surface, outside surface  216 B. Thus, PV frames  212 A and  212 B are locked to coupling  50   b  via rotation of rotating portion  200  from first position  91  to third position  93 . The other half of coupling  50   b  operates in the same way to lock frames  212 C and  212 D to coupling  50   b . Thus it is clear that coupling  50   b  securely interlocks PV modules  211 A,  211 B,  211 C, and  211 D together by bearing against opposing surfaces on each frame  212 A,  212 B,  212 C,  212 D upon rotation of rotating portions  200 . In other embodiments devices which are removable from a mounted PV module  211  along with coupling  50   b , such as washers, pressure distribution plates, and springs, are placed between coupling  50   b  and frame  212 . In these cases such devices are sometimes referred to as force transfer portions and are considered to be part of coupling  50   b  in the same way that series coupling portion is so incorporated. On the other hand, brackets and struts which span between PV modules  211  and/or are attached to a mounting surface are not considered to be a part of coupling  50   b  since they are not removable with coupling  50   b.    
     As shown in  FIG. 30 , the second embodiment of the present invention provides a means for reducing parts and labor costs by combining the function of attaching bracket  132  with the function of interlocking two adjacent PV modules  211 A,  211 B. Thus, the installation of PV array now has one less step. To our knowledge there are no prior art systems which teach a combined functionality coupling which can both couple the sides of two adjacent PV modules together in parallel and simultaneously secure a height adjustable bracket to the side of frame  212 A. 
     The basic steps involved in the forming and mounting of PV array  10  according to the second embodiment of the present invention may be as follows: 
     Step 1: Secure a first PV module  211  to a mounting surface  144  with at least one bracket  132 . 
     Step 2: Interlock a second PV module  211  to the first PV module  211  with at least one parallel coupling  50   b  or  50   j  which interlocks the sides of two adjacent frame members together in parallel. 
     Step 3: Attach second PV module  211  to mounting surface  144  with at least one bracket  132 . 
     Step 4: Repeat steps  2  and  3  for all remaining PV modules  211  in PV array  10 , successively interlocking each new PV module  211  to the side of a mounted PV module  211  and attaching at least one bracket  132  to each module. 
     Parallel couplings  50   b  may be used at substantially all corner points  295  where four PV modules  211  meet. Substantially all brackets which are mounted in the seams between PV modules  211  may be attached via couplings  50   j . Final tightening of each coupling  50   b ,  50   j  and bracket  132  connection is flexible and does not necessarily coincide with initial placement in array  10  of that module  211 . This flexibility allows PV modules  211  to be temporarily positioned in the array while others are positioned or while wiring or other installation issues are handled. Since all couplings  50   b  and  50   j  are capable of being tightened from the top, PV modules  211  can be moved into locked mode at any time. One skilled in the art will recognize that the 2-axis nature of the couplings in the embodiment under discussion means that PV modules  211  can be installed in any order and in substantially any shape for PV array  10  as long as each new PV module  211  is interlocked to a mounted PV module  211 , and all new modules  211  are added to a mounted module which has a portion of a frame member  213  free (not already interlocked to another PV module). Stepped arrays as discussed above are not possible when using couplings  50   b.    
     In another embodiment which is similar to the first embodiment discussed above, couplings  50   j  replace couplings  50   a  thereby enabling the capture of brackets  132  with couplings  50   j , while also retaining the benefits of an all-parallel coupling installation as discussed. 
     Third Embodiment 
       FIGS. 32-34  depict a third embodiment of the present invention. This embodiment is similar to the first embodiment described above except that the orientation of the coupling action of coupling  50   a  has been altered and a retaining element has been added. Instead of bearing against vertically oriented opposing surfaces on frame  12 , a parallel coupling  50   c  is provided to bear against horizontally oriented opposing surfaces on frame  12 . 
       FIG. 32  shows a perspective view of parallel coupling  50   c  which has been installed into slots  26 A,  26 B of two adjacent PV modules  11 A,  11 B but not fully tightened down. Frames  12 A,  12 B have been cut away so that coupling  50   c  shows in this view.  FIG. 33  provides an exploded view of the two sides of a retainer portion  354 L,  354 R.  FIG. 34  provides a cross-section view cut through two adjacent PV modules  11 A,  11 B which are coupled together with parallel coupling  50   c . The cross section is cut partially through coupling  50   c  as indicated. 
     Referring to  FIGS. 32-34 , coupling  50   c  comprises retainer portion  354  which holds a locking portion  304  and a nut portion  306  via position tabs  362 . Locking portion  304  may comprise a first side  304 A for locking with frame  12 A and a second side  304 B for locking with frame  12 B. Nut portion  306  may comprise a first side  306 A for securing to frame  12 A and a second side  306 B for securing to frame  12 B. Retainer portion  354  may comprise two substantially identical halves  356 L,  356 R which mate together via male and female arm pairs  358 LM,  358 RF and  358 LF,  358 RM. Two halves  356 L,  356 R capture locking portion  304  and nut portion  306  and hold them in position as coupling  50   c  is inserted into slots  26 A,  26 B. During insertion, snap-lock portions  360 LA,  360 LB,  360 RA,  360 RB flex downward then snap back up into position once inserted past flanges  108 AU,  108 BU. We contemplate making retainer portion  354  out of a plastic material, though many other semi-flexible materials are also suitable. A bolt or threaded rotating portion  300  comprises a head  352  which accepts a tool from above and is used to tighten and loosen coupling  50   c  about frames  12 A,  12 B. Locking portion  304  comprises a hole for rotating portion  300  which is larger than the outside diameter of rotating portion  300  and is not threaded. Nut portion  306  is drilled and tapped for the threads on rotating portion  300  and comprises teeth  364  for biting into frames  12 A,  12 B when coupling  50   c  is tightened, thereby providing electrical ground continuity between modules  11 A,  11 B and enhancing the structural connection of coupling  50   c . We contemplate making locking portion  304 , and nut portion  306  out of a rigid material such as aluminum or steel, though other materials are also suitable. 
     Operation of the apparatus of the third embodiment is similar to the first embodiment except for the operation of coupling  50   c . Coupling  50   c  may be pre-assembled in a factory by mating halves  356 L,  356 R about locking portion  304  and nut portion  306  so that coupling  50   c  may be deployed as a one-piece unit ready for installation in the field. To install, coupling  50   c  is inserted at substantially any point along slot  26 A in PV module  11 A. Coupling  50   c  is inserted with snap-lock portions  360 LA,  360 RA pointing towards opening  27 A in slot  26 A and with a direction of travel which is substantially parallel with the plane of laminate  20 A and substantially perpendicular to the length of slot  26 A. Coupling  50   c  is inserted until snap-lock portions  360 LA,  360 RA clear flange  108 AU and snap into place. Coupling  50   c  is now in positioning mode and ready to be coupled to PV module  11 B. With coupling  50   c  being held in place by retainer portion  354 , PV modules  11 A and  11 B are free to be moved independently from each other. Thus, this embodiment provides the same independent movement capability in positioning mode as discussed above for the first embodiment, but coupling  50   c  is held in position during this phase by retainer portion  354  instead of locking portions  104 A,  104 B. To complete the coupling operation, coupling  50   c  is inserted into slot  26 B until it snaps in place as described above. Then a driver is used to engage rotating portion head  352  and rotate rotating portion  300  which pulls nut portion  306  toward slots  26 A,  26 B and pushes locking portion  304  away from slots  26 A,  26 B. 
     More specifically, rotation of rotating portion  300  causes locking portion  304  and nut portion  306  to move closer together which in turn causes locking portion  304  to bear against inside surfaces  309 AL,  309 BL of slots  26 A,  26 B and nut portion  306  to bear against opposing surfaces, bottom surfaces  15 A,  15 B of frames  12 A,  12 B. Thus it is clear that coupling  50   c  securely interlocks PV modules  11 A and  11 B together by bearing against opposing surfaces on each frame  12 A,  12 B upon rotation of rotating portion  300 . As locking portion  304  and nut portion  300  tighten about frames  12 A,  12 B position tabs  362  bend or break since they are overpowered by the force delivered by the driver to rotating portion  300 . Once rotating portion  300  is tight, coupling  50   c  is now in locked mode. Sliding mode can be accessed at any time by loosening rotating portion  300 , which is still accessible from the top even after array  10  has been formed. As with the first embodiment, sliding mode allows sliding of coupling  50   c  over to a neighboring seam  150  or  152  so that a module can be removed from the middle of a formed PV array  10 . 
     In other embodiments a surface area of contact between locking portion  304  and frames  12 A,  12 B is increased by widening or removing altogether flanges  108 AL,  108 BL. Another embodiment extends locking portion  304  and nut portion  306  with series coupling portions so that they reach over to the next pair of modules, thereby creating a four module coupling similar the second embodiment above. In another embodiment locking portion  304  comprises a spring element for bearing against an inside surface of slot  226 . In yet another embodiment retainer portion  354  is shaped differently so that it comprises spring elements for the top and bottom flanges. 
     Fourth Embodiment 
       FIGS. 35-38  depict a fourth embodiment of the present invention. This embodiment is similar to the second embodiment as described above except that locking portions  204 A,  204 B and rotating portions  200  have been altered slightly. 
       FIG. 35  depicts a perspective view of a parallel coupling  50   d  installed in two adjacent PV modules  211 A,  211 B and  FIG. 36  presents a perspective view of coupling  50   d  with a rotating portion  400 CD which has been slid over to the right (see below for explanation).  FIG. 37  provides a cross section cut through a seam between four PV modules  211 A,  211 B,  211 C,  211 D which have been interlocked together with coupling  50   d , and  FIG. 38  depicts a perspective view of four interlocked PV modules  211 A,  211 B,  211 C,  211 D. As is consistent with the present invention, parallel coupling  50   d  comprises locking portions  404 AC,  404 BD and rotating portions  400 AB,  400 CD which serve to compress frames  212  upon movement of coupling  50   d  into locked mode. Locking portions  404 AC,  404 BD differ from locking portions  104 A,  104 B in that they have been elongated with series coupling portions  462  to bridge between the two pairs of PV modules  211 A,  211 C and  211 B,  211 D; thus enabling coupling  50   d  to interlock four adjacent PV modules in a similar manner to the second embodiment except without requiring a separate series coupling portion  162 . Coupling  50   d  is deployable in the field as a one-piece unit which is capable of interlocking four PV modules  211 A,  211 B,  211 C,  211 D together. Instead of utilizing two parallel coupling portions  50   bb  plus series coupling portion  162  as discussed for the second embodiment, this embodiment essentially allows two coupling members to share two locking portions  404 AC,  404 BD thereby creating a “double coupling” device. 
     Since locking portions  404 AC,  404 BD can no longer rotate within slots  26 A,  26 B,  26 C,  26 D to tighten coupling  50   d , threaded shaft portions  402 A,  402 B,  402 C,  402 D (not all visible) replace shaft portions  232 A,  232 B and thread into threaded holes  490 A,  490 B,  490 C,  490 D (not all visible) in locking portions  404 AC,  404 BD. Opposite ends of shaft portions  402 A,  402 B and  402 C,  402 D are provided with opposite handed threads so that rotation of shaft portions  402 A,  402 B,  402 C,  402 D causes locking portions  404 AC,  404 BD to move horizontally in opposite directions from each other according to the arrow shown in  FIG. 36 . Rotating portions  400 AB,  400 CD replace rotating portions  100  and function the same except that rotating portions  400 AB,  400 CD are decoupled from shaft portions  402 A,  402 B,  402 C,  402 D allowing them to move horizontally independently from shaft portions  402 A,  402 B,  402 C,  402 D according to the arrow shown on  FIG. 36 . Rotating portions  400 AB,  400 CD, however, cannot rotate independently from their respective shaft portions  402 A,  402 B and  402 C,  402 D as they are provided with hexagonal bores  492 AB,  492 CD to match hexagonal portions  494 AB,  494 CD which may be rigidly connected to or formed from shaft portions  402 A,  402 B and  402 C,  402 D respectively. In other embodiments hexagonal parts are provided with other shapes to achieve the same functionality. 
     Referring specifically to  FIG. 37 , it is evident that a rotation of rotating portion  400 AB with a wrench in a first direction causes locking portions  404 AC,  404 BD to pull frames  212 A,  212 B towards each other. Since rotating portion  400 AB is slidable, it slides along hexagonal shaft portion  494 AB until it is contacting both outside surfaces  216 A,  216 B of PV modules  211 A,  211 B. Additional rotation in the first direction after both frames  212 A,  212 B have contacted rotating portion  400 AB causes locking portion  404 AC to bear against inside surfaces  209 AU,  209 AL of slot  226 A and rotating portion  400 AB to bear against an opposing frame surface, outside surface  216 A. Likewise, rotation of rotating portion  400 AB causes locking portion  404 BD to bear against inside surfaces  209 BU,  209 BL of slot  226 B and rotating portion  400 AB to bear against an opposing frame surface, outside surface  216 B. Thus, PV frames  212 A and  212 B are locked to coupling  50   d  via rotation of rotating portion  400 AB. The other half of coupling  50   d  operates in the same way to lock frames  212 C and  212 D to coupling  50   d . Thus it is clear that coupling  50   d  securely interlocks PV modules  211 A,  211 B,  211 C, and  211 D together by bearing against opposing surfaces on each frame  212 A,  212 B,  212 C,  212 D upon rotation of rotating portions  400 AB,  400 CD. 
     Once both rotating portions  400 AB and  400 CD have been rotated into their fully tightened positions, coupling  50   d  is in locked mode as discussed earlier. Rotation of rotating portion  400 AB in a second direction which is opposite the first direction decouples PV modules  211 A and  211 B. If both rotating portions  400 AB and  400 CD are rotated so as to decouple PV modules  211 A,  211 B and  211 C,  211 D respectively, then coupling  50   d  is shifted into sliding mode and is therefore free to slide completely over into the slots of either PV modules  211 A,  211 B or  211 C,  211 D. 
       FIGS. 35 and 37  also reveal raised portions or teeth  496 AC and  496 BD on locking portions  404 AC,  404 BD which bite into frames  212 A,  212 B,  212 C,  212 D when coupling  50   d  is tightened thereby providing a reliable electrical ground connection between all four PV modules  211 A,  211 B,  211 C,  211 D and enhancing the structural properties of coupling  50   d . These drawings also show optional retainer portions  454 AC,  454 BD on the top and bottom of locking portions  404 AC,  404 BD. Retainer portions  454 AC,  454 BD may comprise a flexible material which allows insertion of coupling  50   d  into a pair of slots  226 A,  226 B from the end but prevents coupling  50   d  from falling back out on its own or from sliding around prior to being shifted into locked mode. Another embodiment is the same as the fourth embodiment except only comprises one rotating portion and is approximately half as long. This embodiment functions the same but is optimized to interlock two PV modules  211  together instead of four. 
     The fourth embodiment provides several advantages relative to some of the other embodiments discussed herein. The sliding capability of rotating portion eliminates the need for springs  236 A,  236 B,  236 C,  236 D; incorporation of a series coupling portion  462  into locking portions  404 AC,  404 BD eliminates the need for series coupling portion  162 ; and manufacturing costs may be reduced. However, series coupling portion  462  is not as strong as series coupling portion  162  since it must be contained within slots  226 A,  226 B. 
     Additional Embodiments 
       FIGS. 39-40  depict a perspective view and a cross section cut between two interlocked PV modules  211 A,  211 B respectively for an alternate embodiment which is similar to the fourth embodiment as shown in  FIGS. 35-38 . This embodiment, which helps to lower manufacturing costs, provides a parallel coupling  50   e  in which rotating portions  400 AB,  400 CD have been eliminated in favor of a plurality of rotating portions  500 . This arrangement enables the attachment of coupling  50   e  to frames  212  via a bearing action against two opposing surfaces which are both inside of slot  226  instead of one internal and one external as shown for the fourth embodiment. Locking portions  504 AC,  504 BD are almost the same as before, but now retainer portions  454 AC,  454 BD and teeth  496 AC,  496 BD have been eliminated. Locking portions  504 AC,  504 BD are rigidly joined together by y-axis spacer block  574  with x-axis spacer screw  576 . Spacer screw  576  is in place as shown during initial installation so that each module can be slid up to screw  576 . But if a module needs to be removed from array  10  after compete installation, spacer screw  576  is removed and coupling  50   e  is slid completely over to the next horizontal seam  150 . Locking portions  504 AC,  504 BD also comprise series coupling portions  562  as before. Rotating portions  500  comprise shaft portions  502  which may be threaded and further provided with a cupped end for biting into frames  212  to insure reliable electrical ground and to enhance the structural properties of coupling  50   e . Thus, rotating portions  500  comprise a portion which resides inside of slots  226  and a portion which resides outside of frames  212 . The external portion of rotating portions  500  may also comprise a hexagonal or other shaped head portion  503  which allows rotation from above similar to rotating portions  400 AB,  400 CD. 
     Referring to  FIG. 40  and the coupling process between PV modules  211 A,  211 B, a rotation of rotating portions  500  causes them to bear against inside surfaces  507 A,  507 B of slots  226 A,  226 B thereby forcing locking portions  504 AC,  504 BD to bear against opposing inside surfaces  509 AU,  509 AL,  509 BU,  509 BL, thereby securely coupling the sides of adjacent PV modules  211 A and  211 B together. Since coupling  50   e , like coupling  50   d , is designed to connect four adjacent PV modules together, one skilled in the art will recognize that the coupling of modules  212 C and  212 D utilizes the same process as just discussed for PV modules  212 A and  212 B. Thus it is clear that coupling  50   e  securely interlocks PV modules  211 A,  211 B,  211 C, and  211 D together by bearing against opposing surfaces on each frame  212 A,  212 B,  212 C,  212 D upon rotation of rotating portions  500 . 
     In another embodiment similar to the previous one the half of locking portions  504 AC,  504 BD that interlock PV modules  211 C,  211 D together is eliminated along with series coupling portion  562 . This leaves a two-module parallel coupling which is possibly suitable for use in PV array  10  along with couplings  50   e  (like at the ends of rows). In another embodiment a coupling is formed out of a single locking portion  504 AC along with associated rotating portions  500  from coupling  50   e . While this embodiment is similar to prior art series couplings, it differs significantly in that the coupling action results from a bearing on two opposing surfaces of slot  226  (for increased strength). Furthermore, there is no press-fit action and the grounding is provided by rotating portions  500 . Another embodiment is similar to the embodiment of  FIGS. 39-40  except that spacer block  574  is slidably held between locking portions  504 AC,  504 BD via pins between locking portions and is taller than slot opening  227 A. This variation works similarly to the fourth embodiment except that instead of rotating portions sliding to set the spacing between modules, it is the spacer block which slides. In still another embodiment multiple spacer blocks are utilized. 
       FIGS. 41-42  depict a cross section cut between two interlocked PV modules  11 A,  11 B and a perspective view respectively for an alternate embodiment which is similar to the first embodiment as shown in  FIGS. 1-24 , but may lower manufacturing costs. This embodiment provides a coupling  50   f  with locking portions  604 A,  604 B which are threaded into rotating portion  600  via shaft portions  602 A,  602 B instead of being rigidly connected thereto. Rotating portion  600  has also been trimmed down in size so that coupling  50   f  can not only be slid into the slots  26 A,  26 B of a neighboring pair of PV modules (in sliding mode), but so that it can also “turn the corner” and move from an x-axis direction slot into a y-axis direction slot and vice versa. This feature enables removal of a PV module even when the slots within the PV array are not aligned in one direction. This may occur in some cases by accident, or in other cases due to tolerance issues, or for architectural reasons. Springs  606 U,  606 L on rotating portion  600  are smaller than before but function the same. Shaft portions  602 A,  602 B are provided with opposite threading so that rotation of rotating portion  600  causes locking portion  604 A to bear against inside surface  109 AU,  109 AL of slot  26 A and rotating portion  600  to bear against an opposing surface, outside surface  16 A of frame  12 A. Likewise, locking portion  604 B bears against inside surface  109 BU,  109 BL of slot  26 B and rotating portion  600  bears against an opposing surface, outside surface  16 B of frame  12 B. Thus it is clear that coupling  50   f  securely interlocks PV modules  11 A,  11 B together by bearing against opposing surfaces on each frame  12 A,  12 B upon rotation of rotating portion  600 . 
     In another embodiment similar to the previous one discussed, locking portion  604 A and shaft portion  602 A is replaced by locking portion  104 A and shaft  102 A from the first embodiment. 
       FIGS. 43-44  depict a perspective view and a cross section cut between two interlocked PV modules  11 A,  11 B respectively for an alternate embodiment which is similar to the third embodiment as shown in  FIGS. 32-34 . This embodiment lowers the amount of installation time required by replacing rotating portion  300  with a shaft  750  and cams  780 A,  780 B on a parallel coupling  50   g . Cams  780 A,  780 B are rigidly connected to rotating portion  700  which is rotatable about axle  788  with a wrench from above Shaft  750  comprises a flat, narrow portion  774  with a hole (not visible) that shaft  788  runs through, a medium diameter portion  775 , a larger diameter portion  776 , and a head portion  752 . A washer portion  706  with sides  706 A,  706 B is positioned on shaft portion  776  and comprises a bore (not viewable) larger than shaft portion  776  but smaller than a diameter of head portion  752 . A locking portion  704  with sides  704 A,  704 B is positioned on shaft portion  775  and comprises a bore (not viewable) larger than shaft portion  775  but smaller than shaft portion  776 . Locking portion  704  comprises thicker portions  785 A,  785 B and is pushed down onto ledge  788  by retainer springs  756 A,  756 B (in direction of arrow) when not installed. 
     To operate, cams  780 A,  780 B are rotated so that they are not touching locking portion  704 . Then coupling  50   g  is snapped onto frame  12 A. We contemplate making springs  756 A,  756 B out of a flexible material such as rubber or similar so that they allow locking portion  704  and washer portion  706  to open up when pushed onto frame  12 A. Thicker portions  785 A,  785 B in conjunction with springs  756 A,  756 B prevent coupling from falling off, thus enabling positioning mode. Frame  12 B and coupling  50   g  are wedded in the same fashion. Once coupling  50   g  is loosely positioned onto both frames  12 A,  12 B, then a wrench is used to rotate rotating portion  700  which in turn rotates cams  780 A,  780 B, which force locking portion  704  and washer portion  706  to move toward each other. This movement causes locking portion  704  to bear against inside surfaces  309 AL,  309 BL of slots  26 A,  26 B and washer portion  706  to bear against opposing surfaces, bottom surfaces  15 A,  15 B of frames  12 A,  12 B. Thus it is clear that coupling  50   g  securely interlocks PV modules  11 A,  11 B together by bearing against opposing surfaces on each frame  12 A,  12 B upon rotation of rotating portion  700 . Raised teeth  764  bite into frames  12 A,  12 B upon tightening, thereby ensuring ground contact and enhancing structural properties as described earlier. In another embodiment springs  756 A,  756 B comprise a resting position as depicted and therefore do not push locking portion down onto ledge  788  when not installed. Another embodiment provides a cam shape which sets the straight-up position as free, then rotating one direction moves to positioning mode and rotating the other way enables locked mode. And another embodiment provides a handle connected to rotating portion  700 . 
       FIGS. 45-46  depict a perspective view and a cross section cut between two interlocked PV modules  11 A,  11 B respectively for an alternate embodiment which is similar to the third embodiment as shown in  FIGS. 32-34 . This embodiment may provide a lower manufacturing cost by replacing retainer portion  354  with retainer springs  856 A,  856 B between a locking portion  804  and a nut portion  806 . Similar to the previous embodiment, a coupling  50   h  comprises retainer springs  856 A,  856 B which pull a locking portion  804  with sides  804 A,  804 B down onto a ledge  888  when not installed (in direction of arrow). Coupling  50   h  is snapped onto frame  12 A and temporarily held in place during positioning mode by springs  856 A,  856 B and thicker portions  885 A,  885 B of locking portion  804 . Thicker portions  885 A,  885 B may also be sized to provide a positive engagement for lateral loads. Rotation of rotating portion  300  causes the coupling to shift to locked mode as described for the third embodiment. Another variation of this embodiment provides springs  856 A,  856 B which are in their resting state as shown so that ledge  888  is not needed. Yet another variation replaces thicker portions  885 A,  885 B with teeth that interlock with frame and another provides grounding spikes on locking portion  804 . 
       FIGS. 47-48  depict a cross section cut between two interlocked PV modules  11 A,  11 B and a perspective view respectively for an alternate embodiment which is similar to the first embodiment as shown in  FIGS. 1-24 . The primary distinction of the present embodiment, which describes a coupling  50   i , is that locking portions  104 A,  104 B have been replaced by pairs of locking portions  904 AU,  904 AL and  904 BU,  904 BL respectively. The paired locking portions  904 AU,  904 AL and  904 BU,  904 BL are provided with ridged camming surfaces  982 AU,  982 AL,  982 BU,  982 BL which are adapted to bear against inside surfaces  909 AU,  909 AL,  909 BU,  909 BL when a rotating portion  900  is rotated. Rotating portion  900  is rigidly connected to locking portions  904 AU,  904 AL,  904 BU,  904 BL via a pair of shafts (not visible) which run through retainer portions  954 A,  954 B. Retainer portions  954 A,  954 B may be made of a flexible material so that insertion of retainer portions  954 A,  954 B into slots  26 A,  26 B deforms or bends retainer portion enabling positioning mode. Ridges on ridged camming surfaces  982 AU,  982 AL,  982 BU,  982 BL bite into frames  12 A,  12 B upon rotation thereby securing ground contact and increasing the strength of coupling  50   i . Locking portions  904 AU,  904 AL,  904 BU,  904 BL comprise flattened portions  980 A,  980 B which enable insertion when properly aligned with slots  26 A,  26 B since they reduce the overall width to less than opening  27 A,  27 B. Thus, insertion of locking portions  904 AU,  904 AL,  904 BU,  904 BL into slots  26 A,  26 B followed by a rotation of nut portion  900  causes locking portions  904 AU,  904 AL,  904 BU,  904 BL to bear against opposing surfaces  909 AU,  909 AL,  909 BU,  909 BL, thereby securely coupling the sides of adjacent PV modules  11 A and  11 B together. In another embodiment locking portions  904 AU,  904 AL,  904 BU,  904 BL are rotated 90 degrees from the orientation shown so that rotation of rotating portion  900  causes a camming action between the back of slot  26  and inside surfaces  109 AL,  109 AU. In another embodiment retainer portions  954 A,  954 B are eliminated in favor of an offset cam arrangement similar to the first embodiment where one cam is insertable in both first position  91  and second position  92 . 
       FIGS. 49-50  depict an embodiment which is similar to the second embodiment discussed above except that a spacer block  274  has been added.  FIG. 49  is the same as  26  except spacer block  274  is shown installed onto series coupling portion  162  via a slot  276  on the bottom side.  FIG. 50  provides a perspective view of spacer block  274  which further reveals slot  276  and a bottom mounted wire clip  285  for securing PV module  11  output wires  22 neg,  22 pos. Securing wiring in this way is a substantial improvement over prior systems since wire clip  285  provides a means of preventing wires from unsightly and unsafe drooping onto roof surfaces. Furthermore, the horizontal seam  150  between PV modules  211 A,  211 B and  211 C,  211 D is set for this embodiment slightly wider than the width of wiring plugs  24 neg,  24 pos; therefore troubleshooting and maintenance of PV array  10  wiring systems is greatly simplified since one can easily snap spacer block  274  up and off from the top and pull wires  22 neg,  22 pos right up through seam  150  for inspection and repair. No decoupling of PV modules  11 A,  11 B is required in order to maintain the wiring system between them. In another embodiment a wire clip comprises a spring clip which snaps into slot  26 A thereby allowing the strapping of wires substantially along the whole length of frame  26 A. In still another embodiment a hinged wire clip  285  snaps into slot  26 A and swings underneath module  11  to hide it, then back up into the gap between modules  11  to allow access. 
       FIGS. 51-52  depict an embodiment of the present invention which is similar to the second embodiment discussed above except that PV array  10  is installed on an open canopy structure  144 C instead of roof  144 R. Installation on a different mounting surface  144  for PV array  10  requires minor changes to brackets  132  and series coupling portions  162  as will be discussed below. 
       FIGS. 51 and 52  depict a perspective view and a side view respectively of PV array  10  installed on canopy structure  144 C. Canopy  144 C comprises purlins  180  which are supported by girders  182  which in turn are supported by vertical columns  184 . We contemplate vertical columns  184  of approximately the same height for this embodiment in order to demonstrate that substantially any tilt angle (from flat to vertical) for PV array  10  is suitable. For example, many prior art systems require a specific slope to a PV array in order for the interlocking or mounting systems to function properly, but the coupling and framing systems described herein do not place any such limitations on PV array  10 . PV array  10 , as shown in  FIG. 51 , comprises a total of sixteen PV modules which are mechanically interlocked in groups of four with couplings  50   b  in the same manner described in  FIGS. 25-28 . Use of a different mounting surface  144  in this embodiment requires slight changes to the brackets and the layout of series coupling portions  162 . The detail in  FIG. 51  shows a double bracket  186  which is utilized to directly connect two frames  212  to purlins  180  in the central vertical seam  152  where the groups of four PV modules  211 A,  211 B,  211 C,  211 D come together. Double bracket  186  comprises vertical portions  187 L,  187 R with vertical adjustment slots  188  for connecting to frames  212  in the same way as bracket  132  only this bracket connects to two adjacent PV modules  211 . Each horizontal row along the central vertical seam  152  comprises one double bracket  186 , but not all are visible here. Double bracket  186  further comprises U-bolt slots  190 L,  190 R (not all visible), U-bolt  192 , nut and washer  193  for securing double bracket  186  to purlin  180 , and a series coupling portion  962 . PV modules  211  are secured to the other two purlins by means of a bracket  132 U which is similar to double bracket  186  except that there is only one vertical portion  187  since this is the last row of PV modules  211 . 
     Regarding the present embodiment under discussion, it is also important to note that there are no strut or PV frame support members required as would be the case for most prior art systems. For example, PV array  10  as shown in  FIG. 51  would normally require an additional layer of PV frame support members  131 PA between purlins  180  and PV frames  212  or as an alternative some prior art systems allow increasing the number of purlins shown to 8 (two per row) instead of adding another layer of structural support (thus the purlins become the PV frame support members). The inventive system of this embodiment however creates a parallel interlock support system  160  which only requires connection of PV frames  212  to the three purlins  180  as shown. In other embodiments it is desired to minimize the size of frames  212 , therefore additional purlins may be used, but still not as many prior art systems require. In other embodiments brackets  132  are formed in different shapes to facilitate connection to the shape of mounting surface  144 . For example, some are shaped to compress a portion of an I-shaped beam whereas others are adapted for connection to circular pipe. Still others are formed as “legs” to allow tilting up one side of an array  10 . One skilled in the art will recognize that there are many different types of brackets which make up the entire scope of the inventive device. Thus, any bracket which has one portion shaped to optimize connection to a mounting surface  144  and another portion which is shaped to optimize connection to at least one PV frame  212 , is a suitable bracket  132  for use with the present invention. 
       FIGS. 53-54  show an alternate embodiment of PV array  10  which further comprises a snap-in conduit box  195 .  FIG. 53  depicts a perspective view of two interlocked PV modules  12 A,  12 B which are at the end of a row.  FIG. 54  shows a perspective view of conduit box  195 . Conduit box  195  snaps into slots  26 A,  26 B via spring clips  197 . Hole  196  in the rear of conduit box  195  allows wiring from array  10  to pass into box  195 , then out through conduit  198  connected to box  195 . An optional cover plate for conduit box  195 , as are typical in the art, is not shown here. Use of conduit box  195  along with PV array  10  greatly simplifies wiring since all wiring can be routed through gaps between PV modules  12 , then into conduit box  195  and out through conduit  198  to inverters or other system equipment. PV installers commonly fashion means for connecting junction boxes to PV array support structures via strut and other materials. However, a ready-made box saves time in cutting strut and custom rigging for each job. Conduit box  195  may also enhance the aesthetics of array  10  since it may be manufactured to match PV modules frames. In other embodiments conduit box  195  is more firmly attached to frames  12 A,  12 B by connecting it via bolts or couplings  50   j  instead of spring clips  197 , in a similar way to the connection of series coupling portions as shown in the second embodiment above. In still other embodiments conduit box is replaced by a simple plate for receiving a strain relief or conduit coupling. 
       FIG. 55  depicts a perspective view of an alternate embodiment of PV module  11  as shown in  FIG. 1 . A PV module  411  with a PV laminate  420  and a frame  412  is shown. Frame  412  comprises two frame members  413  with slots  426  on opposite sides of a laminate back plane or base  409 . Devices such as base  409 , as are known in the art, may serve to insulate a roof or provide structural support to PV laminate  20  or both. Base  409 , however, is not rigid enough to fully support PV laminate  420 , and thus frame members  413  are glued, fastened, or otherwise adhered to base  409  or laminate  420  or both in order to provide structural support to PV module  411  and to provide a means for interlocking the sides of an array of PV modules  411  together. Base  409  may be adhered to the underside of PV laminate  420 . Since PV laminate  420  is supported by frame members  413  and base  409 , it may overhang frame members  413  as shown. In another embodiment frame members  413  enclose base  409 . 
     Other embodiments add different features. For example, one embodiment adds a ball and detent to locking portion  104 A,  104 B to prevent locking portion  104 A,  104 B from disengaging or working its way free and provide a position location stop. Another provides a quick-release handle attached to rotating portion  100 . The handle is tucked just lower than laminate  20  height when in locked mode and can be rapidly rotated by use of a finger-hold. Such a feature may be of use to firemen in an emergency. Another embodiment provides a locking portion which comprises an expansion bolt. Other embodiments provide various devices which snap into or connect to slot  26  such as: tool holders, tools, string line holders, lights, fasteners, cosmetic flashings, architectural features, snow guards, debris screens, rodent screens, signs, cable clips, bird deterrents, and electrical connector housings. 
     The foregoing disclosure is sufficient to enable one having skill in the art to practice the invention without undue experimentation, and provides the best mode of practicing the invention presently contemplated by the inventor. While there is provided herein a full and complete disclosure of the preferred embodiments of this invention, it is not intended to limit the invention to the exact construction, dimensional relationships, and operation shown and described. Various modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention. Such changes might involve alternative materials, components, structural arrangements, sizes, shapes, forms, functions, operational features or the like. 
     Accordingly, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.