US20120298188A1 - Method and Apparatus for Forming and Mounting a Photovoltaic Array - Google Patents

Abstract

A photovoltaic (PV) module framing and coupling system 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 apparatus provides a parallel coupling for securely interlocking the outside surfaces of parallel frame members together in a side to side arrangement to form an array with improved structural load distribution. The coupling 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 apparatus may further provide a rotating portion and locking portion, mounting brackets for direct connection to a mounting surface, grounding teeth, and a twist-lock engagement means for interlocking and aligning PV modules in the array.

Description

CROSS REFERENCES
• The present application is a continuation of application Ser. No. 13/351,397, filed Jan. 17, 2012, which is a continuation of application Ser. No. 12/594,935 filed Oct. 6, 2009, now U.S. Pat. No. 8,109,048, issued Feb. 7, 2012. The foregoing applications are incorporated by reference in their entirety as if fully set forth herein.
BACKGROUND
• 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 examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.
SUMMARY OF THE 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 following embodiments and aspects thereof are described and illustrated in conjunction with systems, apparatus, tools, and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other advantages or improvements.
• 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.
• In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
• Demonstrative embodiments are illustrated in referenced figures and drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
• 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 ofFIG. 7 at a larger scale;
• FIG. 9 shows a typical prior art PV array;
• FIG. 10 is a perspective view of the PV array ofFIG. 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.
DETAILED DESCRIPTION OF THE INVENTION
• Referring toFIGS. 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 denominated10 herein. While various terms may have their ordinary meaning or particular meaning in the art, for ease of understanding there is provided herein, both below and at other locations in this specification, a non-limiting explanation as to the minimum scope intended for understanding of the present specification. Terms may be in singular or plural or any tense while retaining the same general meaning 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 EmbodimentStructure
• FIGS. 1-24 depict a first embodiment of the present invention.FIG. 1 provides a perspective view of a photovoltaic orPV module11 with a hybrid, strut-like frame12. Each PV module is made of substantially identical construction. As is typical in the art,frame12 comprises fourframe members13 which are assembled aroundPV laminate20 and secured by optional adhesive betweenframe members13 andlaminate20 and frame screws18U,18L at the corners. Thecomplete PV module11 is typically assembled in this way at a PV module manufacturing facility; then a plurality of one-piecePV module assemblies11 are transported to a particular job site and mounted to a building or other structure to form aPV array10. In other embodiments we contemplate the assembly offrames12 aroundPV laminates20 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 frame12 may include substantially similar construction on all four sides ofPV module11.Top surface14 offrame12 is the surface which faces the same direction as the cells (not shown) inPV laminate20. Frame outsidesurface16 comprises a multifunction female channel portion orslot26 for the purpose of interlockingPV modules11 together and connecting to a roof or other mounting surface as will be discussed below.Frames12 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 module11 further comprises positive22pos and negative22neg output cables with positive24pos and negative24neg plugs as are typical in the art. In other embodiments multi-conductor cables are utilized. Output cables22pos,22neg originate in a rear-mountedelectrical box21.
• FIG. 2 depicts a perspective view of an interlocking device orparallel coupling50awhich may be utilized to interlock the outside surfaces16 of two adjacent PV module frames12 via a twist-lock action. This first embodiment contemplates a one-pieceparallel coupling50acomprising arotating portion100 withshaft portions102A,102B protruding from each side. The end ofshaft portion102A comprises a first key or lockingportion104A, and the end ofshaft portion102B comprises a second key or lockingportion104B. Both lockingportions104A,104B rotate with theshaft portions102A,102B upon rotation of rotatingportion100 with a wrench.
• Rotatingportion100 further comprises an optionaltop spring106U andbottom spring106L 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 interlockedPV modules11.Bores110U and110L (not viewable here) in rotatingportion100 are provided to house and structurally support springs106U,106L respectively.Springs106U,106L 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 providecoupling50awithout springs sinceframe12 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. Rotatingportion100 comprises fourflat faces116 so that rotatingportion100 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 androtating portion100 could be simply rounded, slotted, bored, or knurled depending on the type of wrench which is utilized.Shaft portions102A,102B further comprise optional reduceddiameter portions114A,114B to help guide and hold afree PV module11 which is being moved into position for coupling. Rotating portion100 (except forsprings106U,106L),shaft portions102A,102B, and lockingportions104A,104B may be machined from a single piece of solid metal, such as steel or aluminum. In anotherembodiment rotating portion100 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 coupling50aas described herein.
• Expanding the discussion now to further includeFIG. 3, which depicts a cross-section cut through twoadjacent PV modules11A,11B which are coupled together with acoupling50a, it can be seen that first lockingportion104A may be specially shaped to be the first of the two lockingportions104A,104B which is inserted into afirst slot26A ofPV module11A. Lockingportion104A may be provided withcurved surfaces118U,118L on opposite corners which allow lockingportion104A to be rotated in a clockwise manner inside ofslot26A until locking portion stops120AU,120AL contact upper122AU and lower122AL inside surfaces ofslot26A respectively. With reference toFIGS. 16-24, which will be discussed in more detail below, one skilled in the art will recognize that the width of lockingportion104A is slightly less than the height A ofopenings27A,27B inslots26A,26B, while the length is approximately equal to the height B inside ofslot26A. Therefore lockingportion104A may be inserted when it is oriented in afirst position91 and captured behind male features or flanges108AU,108AL when it is rotated clockwise. After approximately 90 degrees of clockwise rotation, when locking portion stops120AU,120AL are reached coupling50ais said to be in a third position93 (see below for discussion of an intermediate second position92).
• Accordingly,second locking portion104B may be specially shaped to be the second of the two lockingportions104B,104A to be inserted into asecond slot26B inPV module11B. This first embodiment contemplates a shape for lockingportion104B which is capable of passing between male features or flanges108BU and108BL for approximately the first 45 degrees of clockwise rotation of coupling50a. Thus the intermediate position of approximately 45 degrees of clockwise rotation is said to be thesecond position92. The shape of lockingportion104B is similar to lockingportion104A except that material has been removed in theclearance zones124U,124L directly oppositecurved surfaces118U,118L on lockingportion104A. Thus, orientation of coupling50ainfirst position91 and insertion of lockingportion104A intoslot26A followed by a rotation tosecond position92 results in lockingportion104A being captured byslot26A and lockingportion104B being correctly oriented for insertion intoslot26B. Furthermore, insertion of lockingportion104B intoslot26B followed by an additional rotation of approximately 45 degrees clockwise tothird position93 results in lockingportion104B being captured byslot26B. Rotation ceases when locking portion stops120AU,120AL contact surfaces122AU,122AL insideslot26A and locking portion stops120BU,120BL contact surfaces122BU,122BL insideslot26B, and at this point theoutside surfaces16A and16B ofPV modules11A and11B 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 thelocking portions104A,104B and theslots26A,26B, all of which are within the scope of the present invention. For example, some embodiments may utilize lockingportions104A,104B which are identical in shape but simply rotated at different angles from each other relative toshaft portions102A,102B. 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 installedPV array10 sincefirst position91 can only be reached when lockingportion104B is not insideslot26B. 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.
• Lockingportions104A,104B further comprise tapered surfaces105AU,105AL,105BU, and105BL to guide them into position as coupling50ais rotated and raised teeth112AU,112AL,112BU, and112BL for cutting intoframe12 and ensuring solid electrical ground contact between twoadjacent PV modules11 when they are coupled together. Teeth112AU,112AL,112BU,112BL also provide structural support by counteracting forces which tend to slide coupling50alengthwise inslots26A,26B. Inother embodiments teeth112 are provided in different locations than those shown here, and in stillother embodiments teeth112 are replaced by a separate grounding washer, such as a star washer, which is positioned between a portion of coupling50aandframe12.
• As shown inFIG. 3,slots26A,26B from two adjacent, interlockedmodules11A,11B compriseopenings27A,27B which allow insertion ofcouplings50ain a direction which may be substantially parallel with the plane oflaminates20A,20B and substantially perpendicular withoutside surfaces16A,16B. Flanges108AU,108AL,108BU,108BL, which are located nearopenings27A,27B create (by virtue of their position) inside surfaces109AU,109AL,109BU,109BL ofslots26A,26B which are available for use bycouplings50aand brackets132 (see below) as a bearing surface. Inside surfaces are shown here as being substantially perpendicular toPV laminate20. However, other embodiments provide sloped and curved surfaces109AU,109AL,109BU,109BL.
• FIG. 3 further reveals frame inside surfaces17A,17B; frame bottom surfaces15A,15B; frame screw holes19AU,19AL,19BU,19BL for frame screws18B,18U; and frame recesses126A,126B for capturingPV laminates20A,20B. This view also shows how substantially constant spacing betweenPV modules11 in anarray10 is automatically determined by the width of rotatingportion100, with minor material and assembly tolerance issues being allowed by variable compression amounts onsprings106U,106L. For example, manufacturing of a perfectlysquare PV module11 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. Thesprings106U,106L 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 twoadjacent PV modules11A,11B which are coupled together with twocouplings50a. Sinceslots26A,26B may run substantially the whole length offrames12A,12B,couplings50amay 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 acorner130 of eachPV module11 the flanges108AU,108AL,108BU,108BL are cut off thus allowingcoupling50ato easily slide from the seam between one set ofPV modules11 over to the seam between an adjacent pair ofPV modules11 when coupling50ais infirst position91 as discussed above.
• Referring now toFIGS. 5-6,FIG. 5 depicts a perspective view of a heightadjustable bracket132 which is suitable for connection to aPV module11 of the first embodiment of the present invention, andFIG. 6 shows a cross-section cut through twoadjacent PV modules11A,11B which are coupled together with acoupling50a(not picture here for clarity, seeFIG. 3). An L-shapedbracket132 comprises a z-axis orvertical adjustment slot140 and a y-axis adjustment slot142 (coordinate system based on plane of mounting surface, seeFIG. 7). Achannel bolt136 withbolt head137, which is threaded into achannel nut134, is utilized to attachbracket132 tooutside surface16B offrame12B.Channel nut134 is shaped to fit insideslot26B and to be captured behind flanges108BU,108BL. This embodiment contemplates a simple rectangular shape forchannel nut134 withnut134 being inserted atcorner130 and slid into position.Threading bolt136 intonut134, slidingbracket132 betweenbolt head137 and frame outsidesurface16B, and then tighteningbolt136 serves to pullnut134 solidly against flanges108BU,108BL thereby rigidly securingbracket132 to frame12B. And sinceslot26B runs substantially the whole length offrame12B,bracket132 can be attached to substantially any point along the length, which will be referred to as the x-axis direction. Therefore, slot26B along withslot140 andslot142 allows for 3 dimensional adjustability ofbracket132, enabling greatly simplified installation via much easier lining up ofbrackets132 with rafters (which typically run in the y-axis direction) and much easier leveling and aligning of PV modules withinarray10.Lag screw138 provides a means of directly securingbracket132, and thereforearray10, to a mountingsurface144, such as a roof without any other support structure as is typical in prior art systems.
• Please note that whileFIG. 6 shows a connection ofbracket132 toright frame12B, it can be connected to anyoutside surface16, and furthermore it can be reversed so thatlag screw138 is positioned beneath thePV module11 to which it is connected. Inother embodiments nut134 comprises a rectangular shape with two opposing rounded corners, similar to lockingportion104B, so that it can be inserted intoslot26B from any point alongframe12B and then twisted 90 degrees to tuck behind flanges108BU,108BL. In stillother embodiments nut134 is a standard hexagonal-shaped nut.
• One alternate embodiment removes lower flanges108AL,108BL fromslots26A,26B and the lower portions of lockingportions104A,104B resulting in a one-sided locking action instead two as with the first embodiment.
First EmbodimentBasic Operation
• Referring toFIGS. 7-8 andFIGS. 10-11, aPV array10 according to the first embodiment of the present invention is shown installed on the roof of abuilding146.FIG. 7 depicts a perspective view of building146 withPV array10 shown attached to aroof144R which serves as a suitable mountingsurface144.Roof rafters148 are just beneath the top surface of the roof and are shown as dashed lines.Brackets132 can be seen in this view along the front ofPV array10.Brackets132 are oriented such that lag screws138 are hidden under PV modules.Brackets132 can be seen attached toslots26 on theoutside surface16 of the lowest row of threePV modules11, onebracket132 perPV module11.Brackets132 have been adjusted in theirrespective slots26 in the x-axis direction such that eachbracket132 lines up with arafter148. Since lining up ofbrackets132 withrafters148 is only required with certain types of roofs and mounting surfaces, other embodiments providebrackets132 which are not lined up with rafters, but rather attach directly to the mounting surface at any desired point. In still other embodiments,brackets132 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 thesame PV array10 fromFIG. 7 at a larger scale. This figure helps to clarify the fact thatPV array10 is connected toroof144R without the use of strut or other supports.Brackets132 connect frames12 directly toroof144R, andcouplings50ainterlock PV modules11 together. In contrast,FIG. 9 shows a typical prior art PV array10PA without the benefit of an interlocking system as disclosed herein. PV modules11PA are first linked together by struts131PA. Struts131PA are then attached to a mounting surface (not shown) via brackets132PA. As can be seen here strut131PA is a device which is at least as wide as two PV modules11PA and is designed to support the opposing sides of at least two PV modules11PA. 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 struts131PA are designed to span between modules11PA means that a lot of extra material is required. The additional expense and installation time required to utilize strut131PA is a significant drawback to prior art systems.
• FIG. 10 shows a perspective view of thesame PV array10 fromFIG. 7 except thatarray10 is being viewed from the back (exactly 180 degrees around from theFIG. 7 view) with building146 removed to reveal the back side ofPV array10. In this view it is now evident that a row of threebrackets132 is located along everyhorizontal seam150 betweenPV modules11 and along the top154 and bottom156 edges ofarray10. This method of relatively evenly distributingbrackets132 acrossarray10 is not possible with prior art strutless systems which utilize series couplings (see discussion below).
• FIG. 11 shows a cross-section cut through PV array10 (fromFIG. 7) just abovecouplings50aand looking perpendicular toarray10 thereby revealing the locations ofcouplings50aand brackets132 (roofing material not shown beneatharray10 for clarity).Couplings50aare shown interlocking allPV modules11 inarray10 at all horizontal150 and vertical152 seams betweenPV modules11. Inother embodiments couplings50aare only utilized on eitherhorizontal seams150 orvertical seams152. The arrangement of couplings as shown here creates a double structure or parallelinterlock support system160 forarray10 along both the x and y-axes as will be discussed below. Eachframe12 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 ofPV laminate20; (b) interconnectingmodules11 together with a structural support system (in order to increase structural integrity and minimize the number of required connection points to mounting surface144); and (c) providing a means for attachingarray10 to mountingsurface144 via foot-type or bracket members.
First EmbodimentSeries and Parallel Coupling Theory
• FIG. 12 provides a simplified top view of two adjacent rectangular frames A and B. Lines C₁, C₂, C₃, and C₄represent places along the seam between the two frames A and B where couplings can theoretically be placed. Couplings which connect at lines C₁and C₂are 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 K₁and K₂are 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 K₁and K₂are the only places around the perimeter where a coupling can be inserted into the outside surface of a first frame member B₄and continue through into a second frame member B₃which is around the corner from the point of insertion. Thus, lines C₃and C₄are shown extending from parallel frame members A₂, B₄into the orthogonal frame members B₁, B₃and A₁, A₃. 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 K₁, K₂. Series couplings are so named because they link two frame members, such as A₃and B₃, end to end.
• In order to understand the operation ofPV array10 of the first embodiment, it is important to first understand how the forces that are presented toPV array10 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 theroof144R or mountingsurface144 viabrackets132 that mount the PV system, and thesebrackets132 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 mountingsurface144. A coupling device for interlockingframe members13 provides an opportunity to furthersupport frame members13 by locking it toadjacent frame members13. For anindividual PV module11 eachframe member13 acts as a separate structural entity which is supported byPV laminate20 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 thatPV module11 comprises substantiallystraight frame members13, then the possible shapes (in a top view) for flat-plate PV module11 are a triangle, rectangle, pentagon, hexagon, etc. All such shapes are suitable for use with the present invention.
• FIGS. 13-14 showgeneric PV arrays10P and10S, comprising fourPV modules11A,11B,11C,11D with adjacent frame members13A1,13B1;13A2,13C2;13B2,13D2;13C1,13D1 respectively. These two figures demonstrate the two basic types of couplings which are possible in a rectangular array:parallel couplings50 andseries couplings62. When straight-sided PV modules11A,11B,11C,11D are assembled to form substantiallyrectangular PV arrays10P and10S, the result is a plurality offrame members13 which are immediately adjacent to each other (withinarrays10P,10S) and a plurality offrame members13 around the perimeter ofarrays10P,10S.FIG. 13 showsparallel couplings50 that each connect two adjacent and substantiallyparallel frame members13 side to side.FIG. 14 showsseries couplings62 that each connect two substantiallycollinear frame members13 end to end.
• As shown inFIG. 13,parallel couplings50 allow a force F₁applied toPV module11B to be distributed between the PV modules immediately adjacent to it,11A and11D, along paths P₁, P₂, P₃, as well as out to the moreremote PV module11C along paths P₄and P₅. This distribution of forces is enabled sinceparallel couplings50 allow both the connection offrame members13 end to end and side to side. For example, frame members13B1 and13A1 are interlocked in addition to the orthogonal pair of frame members13B2 and13D2. This connection of orthogonal pairs offrame members13 enables the connection of each row ofPV modules11A,11C, to theadjacent row11B,11D and allows force F1 to be distributed across all the PV modules inarray10P, thus strengthening the entire frame structure supporting PV laminates20. However,series couplings62, as shown inFIG. 14, will only allow forces to be distributed down therows11A,11C and11B,11D which are attached in this way. The same force F₁presented tomodule11B in this case can only take paths P₁₀and P₁₁, thus preventing the distribution of loads toPV modules11A,11C.
• Whileseries couplings62, 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 frame12 (though such potential is not realized in prior art couplings).
• Parallelinterlock support system160 operates as follows. Thespecialized slot26 allowscouplings50ato securely connect the sides of each immediately adjacent and parallel pair offrame members13. It is common for installation technicians to step on aPV laminate20 during installation. This action provides a localized load such as would generate force F₁. In prior art strutless systems, force F₁is translated to the frames which are nearest to the point of loading, and eachframe member13 is acting mostly independently since there are no securely connected additional supporting members nearby. In the first embodiment of the present invention, however, force F₁presented to the top ofPV laminate20 is shared byframe12 which surroundsPV laminate20 as well as the fourframe members13 which are coupled to the loadedPV laminate20. Thus, it can be seen that a support grid is created by the simple and rapid connection ofcouplings50atoadjacent frames12. This grid is evenly distributed in the x and y directions throughoutarray20, and the doubled support members run beneath the edges of eachPV laminate20. The result is aPV array10 which can be mounted to a roof or other mountingsurface144 without the need for costly and heavy strut (or other structural members). Furthermore, the increased spanning capabilities provided by the parallelinterlock support structure160 significantly reduce the number of connection points (and therefore brackets132) for a givensize array10 on a given mountingsurface144 as compared to prior art strutless systems.
• FIG. 15 shows a prior art strutless PV array210PA with PV modules211PA, brackets232PA, and series couplings250PA. 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 brackets232PA is also increased relative to the inventive device of the first embodiment because spans betweenbrackets232A cannot be as long.
First EmbodimentCoupling 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 coupling50ainto one of the threediscrete positions91,92,93 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 ofPV modules11 inPV array10. Positioning mode secures coupling50ato onePV module11 of a pair ofPV modules11 to be interlocked. Since the positioning of PV modules can be difficult, particularly on sloped roofs, positioning mode insures that coupling50awill stay in position as the two modules are guided together. Thus, inpositioning mode coupling50ais either firmly secured or loosely attached to onePV module11.
• Locked mode is the mode that all couplings are left in oncearray10 is fully installed. Locked mode securely interlocks twoadjacent PV modules11 together thereby forming a parallelinterlock support system160 as discussed above. In lockedmode coupling50ais firmly secured to two adjacent PV modules. This mode also automatically grounds the two interlockedmodules11 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 ofmodules11 and between rows. Thus a complete x-y grounding matrix results so that only one ground wire needs to be run fromPV array10 to the grounding equipment for the site.
• Sliding mode is primarily used during installation and removal ofPV modules11 inarray10. Sliding mode partially decouples two interlocked PV modules so that coupling50amay be repositioned or slid all the way downslot26 and over intoslots26 for an adjacent PV module pair inarray10. This allows removal of anindividual PV module11 that is surrounded byadjacent PV modules11 installed on all sides. Thus in slidingmode coupling50ais 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 EmbodimentCoupling Process
• FIGS. 16,19, and22 depict a perspective view ofcoupling50ain each of its threediscrete positions91,92,93 respectively as it is utilized to interlock twoadjacent frames12A,12B together (only a portion offrames12A,12B are shown so that lockingportions104A,104B are revealed). Please note that since coupling50amay be installed in either frame first,FIGS. 16,19, and22show frames12A, and12B in opposite positions than inFIG. 3.FIGS. 17-18 show front and back side views respectively of coupling50ainfirst position91.FIGS. 20-21 show front and back side views respectively of coupling50ainsecond position92.FIGS. 23-24 show front and back side views respectively of coupling50ainthird position93. The following description also referencesFIGS. 2-3 since some parts are easier to see in closer views.
• The process of interlocking twoadjacent frames12A,12B is as follows. First, coupling50ais oriented infirst position91, which aligns the length of lockingportion104A with the length ofslot26A, then inserted at substantially any point alongframe12A intoslot26A. While inserting, the direction of travel is substantially parallel with the plane oflaminate20A and substantially perpendicular to the length ofslot26A.Coupling50ais inserted until lockingportion104A hits the back ofslot26A orrotating portion100 contacts outsidesurface16A offrame12A.FIG. 16 shows coupling50ainfirst position91 and fully inserted. For convenience, we contemplate alignment of rotating portion flat faces116 at 45 degrees to the plane oflaminate20 when in first position91: this way the corner point of rotatingportion100 is pointing straight up and is therefore easy to align by eye. Of course other orientations forflat faces116 will work just as well. One skilled in the art will recognize that springs106U,106L are oriented such that they are not touchingframes12 in first position91 (since they line up withopening27A,27B ofslot26A,26B). Therefore, a return tofirst position91, even after thecomplete array10 has been installed, will enable sliding mode since it is not locked onto either frame and sincesprings106U,106L are not compressed.
• The second step is to rotatecoupling50aintosecond position92 in order to enable positioning mode as is depicted inFIGS. 19-21. Though lighter duty springs may be used, we contemplate the use of relatively stiff springs forsprings106U,106L since movement of themodules11 inarray10 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 movecoupling50afromfirst position91 tosecond position92, a wrench is applied to rotatingportion100 to rotate it approximately 45 degrees clockwise. In thisposition locking portion104A is locked ontoframe12A and springs106U,106L are partially compressed. Please note that during the first part of the 45 degree rotation fromfirst position91 tosecond position92, tapered surfaces105AU,105AL engage with flanges108AU,108AL to pull the locking portion further into the slot. By guiding lockingportion104A into place, tapered surfaces105AU,105AL also enable an increased range of acceptance angles for initial alignment of lockingportion104A and therefore increase the flexibility and ease of use ofcoupling50asince it doesn't have to be “dead on” in order to rotate. As coupling50ais being rotated from first91 to second92 position, teeth112AU,112AL begin to bite into flanges108AU,108AL when the end of tapered surfaces105AU,105AL is reached. From this point on through the rest of the full 90 degree throw, the surfaces of lockingportion104A which are in contact with flanges108AU,108AL remain relatively parallel with flanges108AU,108AL. Therefore, the force applied bysprings106U,106L effectively squeezes coupling50aabout flanges108AU,108AL and it is held in a stable position if the wrench is removed from rotatingportion100. Thus,second position92, as shown inFIG. 19, is a stable discrete position with coupling50aattached only to frame12A. Thesecond frame12B can now be moved into or out of position without knockingcoupling50aout of position. Unlike some prior art systems which require bothPV modules11A,11B to be in place and aligned before a coupling can be connected, the inventive device of the first embodiment allows free positioning of modules withcoupling50aconnected to one of them in positioning mode. For example, in some cases it may be advantageous to insert couplings into somePV modules11 on the ground before taking them up to a roof to be mounted. Inother cases couplings50amay be locked ontoPV modules11 at the factory prior to shipping. Also, when interlocking a free PV module to an already mounted PV module, coupling50amay be attached to either the free PV module or the already mounted PV module. Positioning mode is enabled since lockingportion104B is shaped such that it only begins to lock itself ontoframe12B when coupling50ais being rotated fromsecond position92 tothird position93.
• FIGS. 22-24 depictcoupling50ainthird position93, securely attached toframes12A,12B in locked mode. The process of rotating fromsecond position92 tothird position93 is basically the same as that from first91 to second92. A wrench is used to rotaterotating portion100. Tapered surfaces105BU,105BLguide locking portion104B intoslot26B and teeth112BU,112BL begin to bite into flanges108BU,108BL when the end of tapered surfaces105BU,105BL is reached. Arrival atthird position93 is signaled by locking portion stops120AU,120AL contacting upper122AU and lower122AL inside surfaces ofslot26A respectively and120BU,120BL contacting upper122BU and lower122BL inside surfaces ofslot26B respectively. Locking portion stops120AU,120AL,120BU,120BL 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 coupling50afromfirst position91 tothird position93causes locking portion104A to bear against inside surfaces109AU,109AL ofslot26A androtating portion100 viasprings106U,106L to bear against an opposing frame surface, outsidesurface16A. Sincesprings106U,106L act to transfer forces from rotatingportion100 toframes12A,12B, they are also referred to as force transfer portions. Likewise lockingportion104B bears against inside surfaces109BU,109BL ofslot26B androtating portion100 viasprings106U,106L bears against an opposing frame surface, outsidesurface16B. Thus it is clear that coupling50asecurely interlocksPV modules11A and11B together by bearing against opposing surfaces on eachframe12A,12B upon rotation of rotatingportion100.
• 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 ofPV arrays10 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 formedPV array10.
First EmbodimentInstallation Methods
• Referring toFIGS. 7-8 andFIGS. 10-11, the basic steps involved in the forming and mounting ofPV array10 according to the second embodiment of the present invention may be as follows:
• Step 1: Secure afirst PV module11 toroof144R with at least onebracket132.
• Step 2: Interlock asecond PV module11 to thefirst PV module11 with at least oneparallel coupling50awhich interlocks the sides of twoadjacent frame members13 together in parallel.
• Step 3: Attachsecond PV module11 toroof144R with at least onebracket132.
• Step 4: Repeat steps 2 and 3 for all remainingPV modules11 inPV array10, successively interlocking eachnew PV module11 to the side of amounted PV module11 and attaching at least onebracket132 to each module.
• The details ofStep 2 above may be as follows: insert coupling50aintoslot26 of the mountedPV module11, rotate rotatingportion100 tosecond position92 with a wrench thereby enabling positioning mode, matesecond PV module11 withcoupling50a, rotate coupling50atothird position93 thereby enabling locked mode. The wrench is operated from above by sliding wrench between the two modules11 (which may be as close as approximately ¼″ apart). Alternately coupling50amay be placed on thefree module11 for positioning mode instead of the mountedmodule11.
• The details ofStep 3 may be as follows: install bracket flashing or mounting plate, loosely installbracket132 on mounting plate, attachbracket132 toPV module11 at any point along the side where it lines up with required bracket placement,secure bracket132 to mounting plate. Since there are many types of mounting surfaces, there, of course numerous ways thatbrackets132 can be installed. Thus, the inventive system of the first embodiment providesslot26 and heightadjustable bracket132 in order to provide maximum flexibility in adapting to almost any mounting situation.
• Parallel couplings50amay be used at substantially any point in any horizontal150 or vertical152 seam between adjacent PV modules. Eachseam150,152 may include one, multiple, or nocouplings50adepending on the installation requirements. Substantially allbrackets132 may be attached by slidingchannel nuts134 intoslots26 from the end, aligning withbracket132, and screwingbolt136 intochannel nut134 to capturebracket132.
• Final tightening of eachcoupling50aandbracket132 connection is flexible and does not necessarily coincide with initial placement inarray10 of thatmodule11. This flexibility allowsPV modules11 to be temporarily positioned in the array while others are positioned or while wiring or other installation issues are handled. Since allcouplings50aare capable of being tightened from the top,PV modules11 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 thatPV modules11 can be installed in any order and in substantially any shape forPV array10 as long as eachnew PV module11 is interlocked to amounted PV module11, and allnew modules11 are added to a mounted module which has a portion of aframe member13 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 outmodules11 in the middle to avoid vents or other obstructions. In another example, each row ofPV modules11 may be displaced by a specific amount for architectural reasons or to match a roof line.
• If amodule11 needs to be removed from the middle of a formed array for servicing, the required steps may be as follows. First, move allcouplings50awhich are connected to it back intofirst position91 with a wrench from above thereby enabling sliding mode for each. Then slide all loosenedcouplings50aover to neighboringmodules11. In some cases abracket132 may prevent sliding in one direction but not both.Brackets132 are typically installed with one per module, so there is normally at least one direction to slide. If twobrackets132 are required, then couplings50aare not used in between the twobrackets132. Next, loosenbolts136 which connectbrackets132 toframes12 on the effectedmodule11 and lift it straight up and out of array10 (disconnecting wires before moving it too far). In this way anindividual PV module11 that is installed in the middle ofarray10 may be removed without requiring the removal of the surroundingmodules11, thereby substantially saving time during troubleshooting and maintenance as compared to prior art systems.
• In anotherembodiment PV modules11 comprise non-rectangular shapes such as triangular or hexagonal and the coupling system works in the same manner as described above. In anotherembodiment PV modules11 are small enough to not require onebracket132 per module. In this embodiment multiple modules are interlocked together and then one of the group is attached toroof144R withbracket132. In yet anotherembodiment PV array10 is mounted to a ground-mounted rack system instead ofroof144R with no change in the basic installation method outlined above except thatbrackets132 are attached to the rack instead ofroof144R. In still another embodiment groups of standard-sized PV modules11 are interlocked together viacouplings50aon the ground and then hoisted to a roof wherebrackets132 are used to secure them in place.
First EmbodimentAdvantages
• 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, coupling50amaximizes structural integrity relative to size by operating onframe12 in a direction substantially perpendicular to outside surface16 (instead of parallel to it). This fact enables the cost-effective creation of flanges108AU,108AL,108BU,108BL inframe12 extrusion which provide a thick and very strong surface that coupling50autilizes as a wall for holding the ends of lockingportions104A,104B. This arrangement results in a very high pull-out strength as compared to the press-fit resistance provided by prior art systems. The flanges108AU,108AL,108BU,108BL are described as cost-effective since they run longitudinally in the same direction that an extrusion process would run in order to extrudeframe members13 in a typical manufacturing process. Creation of equivalent flanges running at 90 degrees to flanges108AU,108AL,108BU,108BL 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, attachingcoupling50atooutside surface16 offrame12 with locking portions that engage positively inside both the top and bottom frame member flanges108AU and108AL, allows coupling50ato resist forces that would separate the opposing frame outside surfaces16, 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, teeth112AU,112AL,112BU,112BL enhance the longitudinal holding strength ofcoupling50asince they are circular to facilitate biting intoframe12 as rotatingportion100 is rotated to lockcoupling50a. 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 ofsprings106U,106L. 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 EmbodimentStructure
• 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 interlockedmodules211A,211B and a perspective view of four interlockedPV modules211A,211B,211C,211D respectively.Slot26A,26B is removed from two opposingframe members13 yielding a hybrid, strut-like frame212 with twoun-slotted frame members913 and two slottedframe members213.Un-slotted frame members913 may be smaller and lighter weight than slottedframe members213. In another embodimentun-slotted frame members913 are made from a lightweight plastic material and are primarily used to protect laminate20 edges (instead of providing structural support). In anotherembodiment frame members913 are not used at all.
• Frames212A,212B,212C,212D each comprise anoutside surface216A,216B,216C,216D; aninside surface217A,217B,217C,217D; atop surface214A,214B,214C,214D; and abottom surface215A,215B,215C,215D (not all surfaces viewable in these drawings). Four interlockedPV modules211A,211B,211C,211D are oriented such thatslots226A,226B withopenings227A,227B parallel each other andslots226C,226D with openings227C,227D parallel each other. The twomodules211A,211B comprise slot inside surfaces209AU,209AL,209BU,209BL (modules211B,211C comprising like surfaces which are not labeled). Thus, all slottedframe members213, except those around the perimeter ofarray10, may be located immediately adjacent to other slottedframe members213, and allun-slotted frame members913, except those around the perimeter ofarray10, may be located immediately adjacent other un-slotted frames sides913. Thedesignation PV module211 refers to any PV module inarray10 and thedesignation212 refers to anyPV module211 frame inarray10. Likewise a slot226 refers to anyslot226A,226B,226C,226D withinarray10.
• 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 coupling50awith aparallel coupling50bin some locations. In other locations aparallel coupling50jis utilized in place of coupling50a. In locations where twoframe members13 have been changed toun-slotted frame members913 there are no couplings since there is noslot26 for coupling connection.Parallel coupling50bis also referred to as a double coupling or series-parallel coupling50bbecause it further comprises aseries coupling portion162 which is utilized to provide a series coupling connection to a second pair of adjacent PV modules. Thusparallel coupling50binterlocks fourPV modules211A,211B,211C,211D instead of two as is typical in prior art systems. A more detailed description of the layout ofcouplings50band50jis provided below. Allcouplings50jand50bare shown here inhorizontal seams150, but other embodiments provide allcouplings50jand50binvertical seams152. In still other embodiments framemembers13 are substantially similar on all four sides and therefore couplings50jand50bare located in both the horizontal150 andvertical seams152.
• FIG. 27 depicts a perspective view of a generally rectangular-shapedparallel coupling50b.Coupling50bcomprises twoparallel coupling portions50bband aseries coupling portion162.Parallel coupling portions50bbare similar tocouplings50j(described below) except that they may be shaped slightly differently in order to work well withseries coupling portion162. For example, in one embodimentparallel coupling portions50bbare similar tocouplings50jexcept that they further comprise retainer portions which enable them to be movably secured toseries coupling portion162, thereby allowingcoupling50bto be deployed as a one-piece unit in the field. In the present embodiment underdiscussion coupling portions50bbare the same ascouplings50jthus allowingcoupling50bto be a three piece unit comprising twoparallel coupling portions50bband oneseries coupling portion162. In another embodiment more than twocoupling portions50bbare utilized for additional strength. In still another embodimentseries coupling portion162 comprises retainer portions which enableparallel coupling portions50bbto be movably secured toseries coupling portion162, thereby resulting in a one-piece coupling50b.
• Referring toFIGS. 25-27,series coupling portion162 comprises afirst side164 adapted to mate withoutside surfaces216A,216C of the four interlockedPV modules211A,211B,211C,211D.First side164 comprises three male protrusions which mate withframes212A,212C to increase the strength offrames212A,212C at the point of coupling.Male protrusion165 is adapted for insertion intoauxiliary slots224A,224C inframes212A,212C and may be tapered slightly to insure a snug fit is maintained despite tolerance issues.Male protrusion166 is adapted for insertion intoslots226A,226C inframes212A,212C and comprisesteeth168U,168L which bite intoframes212A,212C to insure solid electrical ground contact and to enhance the structural connection betweenPV modules211A,211C.Male protrusion166 may be tapered.Male protrusion167 is adapted to slide just beneathframes212A,212C and may be tapered as well. In other embodimentsmale protrusions165,166,167 may not be tapered.Series coupling portion162 further comprises at least two slots orholes170A,170B which allow insertion ofparallel coupling portions50bbas discussed below and asecond side172 which faces away fromPV modules211A,211C whenseries coupling portion162 is installed. In anotherembodiment teeth168U,168L are replaced by teeth on a different surface ofseries coupling portion162 or a different portion ofcoupling50b. In other embodimentsseries coupling portion162 has various numbers of male protrusions. In still another embodiment there are no male protrusions onseries coupling portion162. We contemplate makingseries coupling portion162 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 ofparallel coupling50jwhich comprises all of the same portions as coupling50aexcept the following. First,shaft portion102A, designated here as232A, has been extended by approximately the width ofbracket132. Second, rotatingportion100 has been replaced by rotatingportion200 comprising foursprings236A,236B,236C,236D, (not all viewable here), two for each side ofcoupling50joriented approximately 180 degrees apart. And third, spring bores110U,110L have been replaced by spring bores240A,240B,240C,240D to correspond withnew springs236A,236B,236C,236D.Coupling50jfurther comprises lockingportions204A,204B which function the same as lockingportions104A,104B. All remaining portions ofcoupling50jare the same as coupling50aand are thus not specifically designated here.Parallel coupling portion50bbin this second embodiment is the same as coupling50jand thus also references the same designations.
• FIG. 29 shows a perspective view of heightadjustable bracket132 andparallel coupling50j. Another advantage of the second embodiment of the present invention is thatextended shaft portion232A allowscoupling50jto perform a dual function of interlocking adjacent PV modules together as discussed above while also attachingbracket132 toPV module11. 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 thatvertical adjustment slot140 inbracket132 is approximately perpendicular to slot26A,26B, and that springs236A,236B,236C,236D are oriented so that infirst position91 all four springs are free and uncompressed in the same way as coupling50a. Many other spring variations are possible within the scope of the present invention.
• FIG. 30 provides a cross-section showing twoadjacent PV modules212A,212B which are interconnected withcoupling50j.Coupling50jis shown infirst position91 as discussed above. When rotated approximately 90 degrees, coupling50jinterlocks frames212A and212B together and simultaneously compressesbracket132 againstframe212A. Thus,channel nut134 andchannel bolt136 are no longer needed.
Second EmbodimentOperation
• FIG. 31 is the same asFIG. 11 except thatPV array10 utilizes the framing and coupling system of the second embodiment.Brackets132 are shown in the same locations except now they are connected toframes212A,212B,212C,212D viacouplings50j, thereby reducing total part count and installation time required forPV array10. Series-parallel couplings50bbridge the corner points where the four corners ofPV modules211A,211B,211C,211D meet. For example, acoupling50bis shown bridging acorner point295 where fourPV modules211A,211B,211C,211D meet.Parallel coupling portions50bbinterlock modules211A,211B and211C,211D whileseries coupling portion162interlocks modules211B,211D and211A,211C. Please note that a second series coupling portion between211A,211C is possible but not required sinceparallel coupling portions50bblock frame212A to frame212B and frame212C to frame212D along withseries coupling portion162.
• Thus, the two axis parallelinterlock support system160 from the first embodiment is replaced by a single axis parallelinterlock support system260 which may run along the x-axis or y-axis. As shown inFIG. 31,parallel coupling portions50bbandparallel couplings50jlockadjacent frame members213 side to side in parallel which creates vertical rows of pairedframe members213 along the y-axis.Series coupling portions162interlock frame members213 longitudinally along the x-axis, thereby connecting the vertical rows and increasing the overall strength of the system.Series coupling portion162 is located betweenrotating portion100 and outside surface offrames216. And sinceparallel coupling portion50bbis rotatable relative toseries coupling portion162, a rotation of rotatingportion100 firmly compressesseries coupling portion162 intoframes212A,212C. This action serves to substantially increase the strength offrames212A,212C relative to a z-axis load (such as wind) in the region ofcoupling50bsince z-axis loads are distributed longitudinally down frames212A,212C. While some prior art couplings do also provide increased z-axis strength due this same effect,series coupling portion162 may be substantially stronger for the following reasons: (a) sinceseries coupling portion162 is not fully contained within a slot or internal cavity offrames212A,212C, it is able to be much taller in the z-direction thereby increasing strength; (b)coupling portion162 is secured toframes212A,212C by a compressive force about a portion offrames212A,212C which increases strength instead of a tensile force which tends to deform the frame and decrease strength; (c)coupling portion162 comprises upper165 and lower167 male protrusions which tend to prevent deformation offrames212A,212C under load since they prevent widening of opening227A as seen inFIG. 25; and (d)coupling portion162 has no fixed center point and therefore may be slid inslots226A,226C to match up with high load areas.
• Accordingly, a rotation ofparallel coupling portion50bbfromfirst position91 tothird position93causes locking portion204A to bear against inside surfaces209AU,209AL ofslot226A androtating portion200 viasprings236A,236C to bear againstseries coupling portion162 which in turn bears against an opposing frame surface, outsidesurface216A. In this case the bearing action of rotatingportion200 is transferred throughsprings236A,236C andseries coupling portion162 to frame212A. Therefore springs236A,236C andseries coupling portion162 are also referred to as force transfer portions. Since there is noseries coupling portion162 betweenrotating portion200 andframe212B, this portion of the coupling process proceeds the same as discussed above formodule12B. That is, lockingportion204B bears against inside surfaces209BU,209BL ofslot226B androtating portion100 viasprings236B,236D bears against an opposing frame surface, outsidesurface216B. Thus, PV frames212A and212B are locked tocoupling50bvia rotation of rotatingportion200 fromfirst position91 tothird position93. The other half ofcoupling50boperates in the same way to lockframes212C and212D to coupling50b. Thus it is clear thatcoupling50bsecurely interlocksPV modules211A,211B,211C, and211D together by bearing against opposing surfaces on eachframe212A,212B,212C,212D upon rotation of rotatingportions200. In other embodiments devices which are removable from amounted PV module211 along withcoupling50b, such as washers, pressure distribution plates, and springs, are placed betweencoupling50bandframe212. In these cases such devices are sometimes referred to as force transfer portions and are considered to be part ofcoupling50bin the same way that series coupling portion is so incorporated. On the other hand, brackets and struts which span betweenPV modules211 and/or are attached to a mounting surface are not considered to be a part ofcoupling50bsince they are not removable withcoupling50b.
• As shown inFIG. 30, the second embodiment of the present invention provides a means for reducing parts and labor costs by combining the function of attachingbracket132 with the function of interlocking twoadjacent PV modules211A,211B. 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 offrame212A.
• The basic steps involved in the forming and mounting ofPV array10 according to the second embodiment of the present invention may be as follows:
• Step 1: Secure afirst PV module211 to a mountingsurface144 with at least onebracket132.
• Step 2: Interlock asecond PV module211 to thefirst PV module211 with at least oneparallel coupling50bor50jwhich interlocks the sides of two adjacent frame members together in parallel.
• Step 3: Attachsecond PV module211 to mountingsurface144 with at least onebracket132.
• Step 4: Repeat steps 2 and 3 for all remainingPV modules211 inPV array10, successively interlocking eachnew PV module211 to the side of amounted PV module211 and attaching at least onebracket132 to each module.
• Parallel couplings50bmay be used at substantially all corner points295 where fourPV modules211 meet. Substantially all brackets which are mounted in the seams betweenPV modules211 may be attached viacouplings50j. Final tightening of eachcoupling50b,50jandbracket132 connection is flexible and does not necessarily coincide with initial placement inarray10 of thatmodule211. This flexibility allowsPV modules211 to be temporarily positioned in the array while others are positioned or while wiring or other installation issues are handled. Since allcouplings50band50jare capable of being tightened from the top,PV modules211 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 thatPV modules211 can be installed in any order and in substantially any shape forPV array10 as long as eachnew PV module211 is interlocked to amounted PV module211, and allnew modules211 are added to a mounted module which has a portion of aframe member213 free (not already interlocked to another PV module). Stepped arrays as discussed above are not possible when usingcouplings50b.
• In another embodiment which is similar to the first embodiment discussed above,couplings50jreplacecouplings50athereby enabling the capture ofbrackets132 withcouplings50j, 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 coupling50ahas been altered and a retaining element has been added. Instead of bearing against vertically oriented opposing surfaces onframe12, aparallel coupling50cis provided to bear against horizontally oriented opposing surfaces onframe12.
• FIG. 32 shows a perspective view ofparallel coupling50cwhich has been installed intoslots26A,26B of twoadjacent PV modules11A,11B but not fully tightened down.Frames12A,12B have been cut away so that coupling50cshows in this view.FIG. 33 provides an exploded view of the two sides of aretainer portion354L,354R.FIG. 34 provides a cross-section view cut through twoadjacent PV modules11A,11B which are coupled together withparallel coupling50c. The cross section is cut partially throughcoupling50cas indicated.
• Referring toFIGS. 32-34, coupling50ccomprisesretainer portion354 which holds a lockingportion304 and anut portion306 viaposition tabs362. Lockingportion304 may comprise afirst side304A for locking withframe12A and asecond side304B for locking withframe12B.Nut portion306 may comprise afirst side306A for securing to frame12A and asecond side306B for securing to frame12B.Retainer portion354 may comprise two substantiallyidentical halves356L,356R which mate together via male and female arm pairs358LM,358RF and358LF,358RM. Twohalves356L,356Rcapture locking portion304 andnut portion306 and hold them in position as coupling50cis inserted intoslots26A,26B. During insertion, snap-lock portions360LA,360LB,360RA,360RB flex downward then snap back up into position once inserted past flanges108AU,108BU. We contemplate makingretainer portion354 out of a plastic material, though many other semi-flexible materials are also suitable. A bolt or threadedrotating portion300 comprises ahead352 which accepts a tool from above and is used to tighten and loosencoupling50caboutframes12A,12B. Lockingportion304 comprises a hole for rotatingportion300 which is larger than the outside diameter of rotatingportion300 and is not threaded.Nut portion306 is drilled and tapped for the threads on rotatingportion300 and comprisesteeth364 for biting intoframes12A,12B when coupling50cis tightened, thereby providing electrical ground continuity betweenmodules11A,11B and enhancing the structural connection ofcoupling50c. We contemplate making lockingportion304, andnut portion306 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 ofcoupling50c.Coupling50cmay be pre-assembled in a factory bymating halves356L,356R about lockingportion304 andnut portion306 so that coupling50cmay be deployed as a one-piece unit ready for installation in the field. To install, coupling50cis inserted at substantially any point alongslot26A inPV module11A.Coupling50cis inserted with snap-lock portions360LA,360RA pointing towardsopening27A inslot26A and with a direction of travel which is substantially parallel with the plane oflaminate20A and substantially perpendicular to the length ofslot26A.Coupling50cis inserted until snap-lock portions360LA,360RA clear flange108AU and snap into place.Coupling50cis now in positioning mode and ready to be coupled toPV module11B. With coupling50cbeing held in place byretainer portion354,PV modules11A and11B 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 coupling50cis held in position during this phase byretainer portion354 instead of lockingportions104A,104B. To complete the coupling operation, coupling50cis inserted intoslot26B until it snaps in place as described above. Then a driver is used to engagerotating portion head352 and rotaterotating portion300 which pullsnut portion306 towardslots26A,26B and pushes lockingportion304 away fromslots26A,26B.
• More specifically, rotation of rotatingportion300causes locking portion304 andnut portion306 to move closer together which in turn causes lockingportion304 to bear against inside surfaces309AL,309BL ofslots26A,26B andnut portion306 to bear against opposing surfaces, bottom surfaces15A,15B offrames12A,12B. Thus it is clear thatcoupling50csecurely interlocksPV modules11A and11B together by bearing against opposing surfaces on eachframe12A,12B upon rotation of rotatingportion300. As lockingportion304 andnut portion300 tighten aboutframes12A,12B position tabs362 bend or break since they are overpowered by the force delivered by the driver to rotatingportion300. Once rotatingportion300 is tight, coupling50cis now in locked mode. Sliding mode can be accessed at any time by looseningrotating portion300, which is still accessible from the top even afterarray10 has been formed. As with the first embodiment, sliding mode allows sliding ofcoupling50cover to aneighboring seam150 or152 so that a module can be removed from the middle of a formedPV array10.
• In other embodiments a surface area of contact between lockingportion304 and frames12A,12B is increased by widening or removing altogether flanges108AL,108BL. Another embodiment extends lockingportion304 andnut portion306 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 anotherembodiment locking portion304 comprises a spring element for bearing against an inside surface of slot226. In yet anotherembodiment retainer portion354 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 lockingportions204A,204B androtating portions200 have been altered slightly.
• FIG. 35 depicts a perspective view of aparallel coupling50dinstalled in twoadjacent PV modules211A,211B andFIG. 36 presents a perspective view ofcoupling50dwith a rotating portion400CD which has been slid over to the right (see below for explanation).FIG. 37 provides a cross section cut through a seam between fourPV modules211A,211B,211C,211D which have been interlocked together with coupling50d, andFIG. 38 depicts a perspective view of four interlockedPV modules211A,211B,211C,211D. As is consistent with the present invention,parallel coupling50dcomprises locking portions404AC,404BD and rotating portions400AB,400CD which serve to compressframes212 upon movement ofcoupling50dinto locked mode. Locking portions404AC,404BD differ from lockingportions104A,104B in that they have been elongated withseries coupling portions462 to bridge between the two pairs ofPV modules211A,211C and211B,211D; thus enablingcoupling50dto interlock four adjacent PV modules in a similar manner to the second embodiment except without requiring a separateseries coupling portion162.Coupling50dis deployable in the field as a one-piece unit which is capable of interlocking fourPV modules211A,211B,211C,211D together. Instead of utilizing twoparallel coupling portions50bbplusseries coupling portion162 as discussed for the second embodiment, this embodiment essentially allows two coupling members to share two locking portions404AC,404BD thereby creating a “double coupling” device.
• Since locking portions404AC,404BD can no longer rotate withinslots26A,26B,26C,26D to tightencoupling50d, threadedshaft portions402A,402B,402C,402D (not all visible) replaceshaft portions232A,232B and thread into threadedholes490A,490B,490C,490D (not all visible) in locking portions404AC,404BD. Opposite ends ofshaft portions402A,402B and402C,402D are provided with opposite handed threads so that rotation ofshaft portions402A,402B,402C,402D causes locking portions404AC,404BD to move horizontally in opposite directions from each other according to the arrow shown inFIG. 36. Rotating portions400AB,400CD replacerotating portions100 and function the same except that rotating portions400AB,400CD are decoupled fromshaft portions402A,402B,402C,402D allowing them to move horizontally independently fromshaft portions402A,402B,402C,402D according to the arrow shown onFIG. 36. Rotating portions400AB,400CD, however, cannot rotate independently from theirrespective shaft portions402A,402B and402C,402D as they are provided with hexagonal bores492AB,492CD to match hexagonal portions494AB,494CD which may be rigidly connected or formed fromshaft portions402A,402B and402C,402D respectively. In other embodiments hexagonal parts are provided with other shapes to achieve the same functionality.
• Referring specifically toFIG. 37, it is evident that a rotation of rotating portion400AB with a wrench in a first direction causes locking portions404AC,404BD to pullframes212A,212B towards each other. Since rotating portion400AB is slidable, it slides along hexagonal shaft portion494AB until it is contacting bothoutside surfaces216A,216B ofPV modules211A,211B. Additional rotation in the first direction after bothframes212A,212B have contacted rotating portion400AB causes locking portion404AC to bear against inside surfaces209AU,209AL ofslot226A and rotating portion400AB to bear against an opposing frame surface, outsidesurface216A. Likewise, rotation of rotating portion400AB causes locking portion404BD to bear against inside surfaces209BU,209BL ofslot226B and rotating portion400AB to bear against an opposing frame surface, outsidesurface216B. Thus, PV frames212A and212B are locked tocoupling50dvia rotation of rotating portion400AB. The other half ofcoupling50doperates in the same way to lockframes212C and212D to coupling50d. Thus it is clear thatcoupling50dsecurely interlocksPV modules211A,211B,211C, and211D together by bearing against opposing surfaces on eachframe212A,212B,212C,212D upon rotation of rotating portions400AB,400CD.
• Once both rotating portions400AB and400CD have been rotated into their fully tightened positions, coupling50dis in locked mode as discussed earlier. Rotation of rotating portion400AB in a second direction which is opposite the first direction decouplesPV modules211A and211B. If both rotating portions400AB and400CD are rotated so as to decouplePV modules211A,211B and211C,211D respectively, then coupling50dis shifted into sliding mode and is therefore free to slide completely over into the slots of eitherPV modules211A,211B or211C,211D.
• FIGS. 35 and 37 also reveal raised portions or teeth496AC and496BD on locking portions404AC,404BD which bite intoframes212A,212B,212C,212D when coupling50dis tightened thereby providing a reliable electrical ground connection between all fourPV modules211A,211B,211C,211D and enhancing the structural properties ofcoupling50d. These drawings also show optional retainer portions454AC,454BD on the top and bottom of locking portions404AC,404BD. Retainer portions454AC,454BD may comprise a flexible material which allows insertion ofcoupling50dinto a pair ofslots226A,226B from the end but preventscoupling50dfrom 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 twoPV modules211 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 forsprings236A,236B,236C,236D; incorporation of aseries coupling portion462 into locking portions404AC,404BD eliminates the need forseries coupling portion162; and manufacturing costs may be reduced. However,series coupling portion462 is not as strong asseries coupling portion162 since it must be contained withinslots226A,226B.
Additional Embodiments
• FIGS. 39-40 depict a perspective view and a cross section cut between two interlockedPV modules211A,211B respectively for an alternate embodiment which is similar to the fourth embodiment as shown inFIGS. 35-38. This embodiment, which helps to lower manufacturing costs, provides aparallel coupling50ein which rotating portions400AB,400CD have been eliminated in favor of a plurality ofrotating portions500. This arrangement enables the attachment ofcoupling50etoframes212 via a bearing action against two opposing surfaces which are both inside of slot226 instead of one internal and one external as shown for the fourth embodiment. Locking portions504AC,504BD are almost the same as before, but now retainer portions454AC,454BD and teeth496AC,496BD have been eliminated. Locking portions504AC,504BD are rigidly joined together by y-axis spacer block574 withx-axis spacer screw576.Spacer screw576 is in place as shown during initial installation so that each module can be slid up to screw576. But if a module needs to be removed fromarray10 after compete installation,spacer screw576 is removed andcoupling50eis slid completely over to the nexthorizontal seam150. Locking portions504AC,504BD also compriseseries coupling portions562 as before. Rotatingportions500 compriseshaft portions502 which may be threaded and further provided with a cupped end for biting intoframes212 to insure reliable electrical ground and to enhance the structural properties ofcoupling50e. Thus, rotatingportions500 comprise a portion which resides inside of slots226 and a portion which resides outside offrames212. The external portion ofrotating portions500 may also comprise a hexagonal or other shapedhead portion503 which allows rotation from above similar to rotating portions400AB,400CD.
• Referring toFIG. 40 and the coupling process betweenPV modules211A,211B, a rotation of rotatingportions500 causes them to bear against inside surfaces507A,507B ofslots226A,226B thereby forcing locking portions504AC,504BD to bear against opposing inside surfaces509AU,509AL,509BU,509BL, thereby securely coupling the sides ofadjacent PV modules211A and211B together. Since coupling50e, like coupling50d, is designed to connect four adjacent PV modules together, one skilled in the art will recognize that the coupling ofmodules212C and212D utilizes the same process as just discussed forPV modules212A and212B. Thus it is clear thatcoupling50esecurely interlocksPV modules211A,211B,211C, and211D together by bearing against opposing surfaces on eachframe212A,212B,212C,212D upon rotation of rotatingportions500.
• In another embodiment similar to the previous the half of locking portions504AC,504BD thatinterlock PV modules211C,211D together is eliminated along withseries coupling portion562. This leaves a two-module parallel coupling which is possibly suitable for use inPV array10 along withcouplings50e(like at the ends of rows). In another embodiment a coupling is formed out of a single locking portion504AC along with associated rotatingportions500 from coupling50e. 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 slot226 (for increased strength). Furthermore, there is no press-fit action and the grounding is provided by rotatingportions500. Another embodiment is similar to the embodiment ofFIGS. 39-40 except thatspacer block574 is slidably held between locking portions504AC,504BD via pins between locking portions and is taller than slot opening227A. 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 interlockedPV modules11A,11B and a perspective view respectively for an alternate embodiment which is similar to the first embodiment as shown inFIGS. 1-24, but may lower manufacturing costs. This embodiment provides acoupling50fwith lockingportions604A,604B which are threaded into rotatingportion600 viashaft portions602A,602B instead of being rigidly connected thereto. Rotatingportion600 has also been trimmed down in size so that coupling50fcan not only be slid into theslots26A,26B 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.Springs606U,606L on rotatingportion600 are smaller than before but function the same.Shaft portions602A,602B are provided with opposite threading so that rotation of rotatingportion600causes locking portion604A to bear against inside surface109AU,109AL ofslot26A androtating portion600 to bear against an opposing surface, outsidesurface16A offrame12A. Likewise, lockingportion604B bears against inside surface109BU,109BL ofslot26B androtating portion600 bears against an opposing surface, outsidesurface16B offrame12B. Thus it is clear thatcoupling50fsecurely interlocksPV modules11A,11B together by bearing against opposing surfaces on eachframe12A,12B upon rotation of rotatingportion600.
• In another embodiment similar to the previous one discussed, lockingportion604A andshaft portion602A is replaced by lockingportion104A andshaft102A from the first embodiment.
• FIGS. 43-44 depict a perspective view and a cross section cut between two interlockedPV modules11A,11B respectively for an alternate embodiment which is similar to the third embodiment as shown inFIGS. 32-34. This embodiment lowers the amount of installation time required by replacingrotating portion300 with ashaft750 andcams780A,780B on aparallel coupling50g.Cams780A,780B are rigidly connected to rotatingportion700 which is rotatable aboutaxle788 with a wrench from above.Shaft750 comprises a flat,narrow portion774 with a hole (not visible) thatshaft788 runs through, amedium diameter portion775, alarger diameter portion776, and ahead portion752. Awasher portion706 withsides706A,706B is positioned onshaft portion776 and comprises a bore (not viewable) larger thanshaft portion776 but smaller than a diameter ofhead portion752. A lockingportion704 withsides704A,704B is positioned onshaft portion775 and comprises a bore (not viewable) larger thanshaft portion775 but smaller thanshaft portion776. Lockingportion704 comprisesthicker portions785A,785B and is pushed down ontoledge788 byretainer springs756A,756B (in direction of arrow) when not installed.
• To operate, cams780A,780B are rotated so that they are not touching lockingportion704. Then coupling50gis snapped ontoframe12A. We contemplate makingsprings756A,756B out of a flexible material such as rubber or similar so that they allow lockingportion704 andwasher portion706 to open up when pushed ontoframe12A.Thicker portions785A,785B in conjunction withsprings756A,756B prevent coupling from falling off, thus enabling positioning mode.Frame12B and coupling50gare wedded in the same fashion. Once coupling50gis loosely positioned onto bothframes12A,12B, then a wrench is used to rotaterotating portion700 which in turn rotatescams780A,780B, which force lockingportion704 andwasher portion706 to move toward each other. This movement causes lockingportion704 to bear against inside surfaces309AL,309BL ofslots26A,26B andwasher portion706 to bear against opposing surfaces, bottom surfaces15A,15B offrames12A,12B. Thus it is clear that coupling50gsecurely interlocksPV modules11A,11B together by bearing against opposing surfaces on eachframe12A,12B upon rotation of rotatingportion700. Raisedteeth764 bite intoframes12A,12B upon tightening, thereby ensuring ground contact and enhancing structural properties as described earlier. In another embodiment springs756A,756B comprise a resting position as depicted and therefore do not push locking portion down ontoledge788 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 rotatingportion700.
• FIGS. 45-46 depict a perspective view and a cross section cut between two interlockedPV modules11A,11B respectively for an alternate embodiment which is similar to the third embodiment as shown inFIGS. 32-34. This embodiment may provide a lower manufacturing cost by replacingretainer portion354 withretainer springs856A,856B between a lockingportion804 and a nut portion806. Similar to the previous embodiment, acoupling50hcomprises retainer springs856A,856B which pull a lockingportion804 withsides804A,804B down onto aledge888 when not installed (in direction of arrow).Coupling50his snapped ontoframe12A and temporarily held in place during positioning mode bysprings856A,856B andthicker portions885A,885B of lockingportion804.Thicker portions885A,885B may also be sized to provide a positive engagement for lateral loads. Rotation of rotatingportion300 causes the coupling to shift to locked mode as described for the third embodiment. Another variation of this embodiment providessprings856A,856B which are in their resting state as shown so thatledge888 is not needed. Yet another variation replacesthicker portions885A,885B with teeth that interlock with frame and another provides grounding spikes on lockingportion804.
• FIGS. 47-48 depict a cross section cut between two interlockedPV modules11A,11B and a perspective view respectively for an alternate embodiment which is similar to the first embodiment as shown inFIGS. 1-24. The primary distinction of the present embodiment, which describes acoupling50i, is that lockingportions104A,104B have been replaced by pairs of locking portions904AU,904AL and904BU,904BL respectively. The paired locking portions904AU,904AL and904BU,904BL are provided with ridged camming surfaces982AU,982AL,982BU,982BL which are adapted to bear against inside surfaces909AU,909AL,909BU,909BL when arotating portion900 is rotated. Rotatingportion900 is rigidly connected to locking portions904AU,904AL,904BU,904BL via a pair of shafts (not visible) which run throughretainer portions954A,954B.Retainer portions954A,954B may be made of a flexible material so that insertion ofretainer portions954A,954B intoslots26A,26B deforms or bends retainer portion enabling positioning mode. Ridges on ridged camming surfaces982AU,982AL,982BU,982BL bite intoframes12A,12B upon rotation thereby securing ground contact and increasing the strength ofcoupling50i. Locking portions904AU,904AL,904BU,904BL comprise flattenedportions980A,980B which enable insertion when properly aligned withslots26A,26B since they reduce the overall width to less than opening27A,27B. Thus, insertion of locking portions904AU,904AL,904BU,904BL intoslots26A,26B followed by a rotation ofnut portion900 causes locking portions904AU,904AL,904BU,904BL to bear against opposing surfaces909AU,909AL,909BU,909BL, thereby securely coupling the sides ofadjacent PV modules11A and11B together. In another embodiment locking portions904AU,904AL,904BU,904BL are rotated 90 degrees from the orientation shown so that rotation of rotatingportion900 causes a camming action between the back ofslot26 and inside surfaces109AL,109AU. In anotherembodiment retainer portions954A,954B are eliminated in favor of an offset cam arrangement similar to the first embodiment where one cam is insertable in bothfirst position91 andsecond position92.
• FIGS. 49-50 depict an embodiment which is similar to the second embodiment discussed above except that aspacer block274 has been added.FIG. 49 is the same as26 exceptspacer block274 is shown installed ontoseries coupling portion162 via aslot276 on the bottom side.FIG. 50 provides a perspective view ofspacer block274 which further revealsslot276 and a bottom mountedwire clip285 for securingPV module11 output wires22neg,22pos. Securing wiring in this way is a substantial improvement over prior systems sincewire clip285 provides a means of preventing wires from unsightly and unsafe drooping onto roof surfaces. Furthermore, thehorizontal seam150 betweenPV modules211A,211B and211C,211D is set for this embodiment slightly wider than the width of wiring plugs24neg,24pos; therefore troubleshooting and maintenance ofPV array10 wiring systems is greatly simplified since one can easily snapspacer block274 up and off from the top and pull wires22neg,22pos right up throughseam150 for inspection and repair. No decoupling ofPV modules11A,11B is required in order to maintain the wiring system between them. In another embodiment a wire clip comprises a spring clip which snaps intoslot26A thereby allowing the strapping of wires substantially along the whole length offrame26A. In still another embodiment a hingedwire clip285 snaps intoslot26A and swings underneathmodule11 to hide it, then back up into the gap betweenmodules11 to allow access.
• FIGS. 51-52 depict an embodiment of the present invention which is similar to the second embodiment discussed above except thatPV array10 is installed on anopen canopy structure144C instead ofroof144R. Installation on adifferent mounting surface144 forPV array10 requires minor changes tobrackets132 andseries coupling portions162 as will be discussed below.
• FIGS. 51 and 52 depict a perspective view and a side view respectively ofPV array10 installed oncanopy structure144C.Canopy144C comprisespurlins180 which are supported bygirders182 which in turn are supported byvertical columns184. We contemplatevertical columns184 of approximately the same height for this embodiment in order to demonstrate that substantially any tilt angle (from flat to vertical) forPV array10 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 onPV array10.PV array10, as shown inFIG. 51, comprises a total of sixteen PV modules which are mechanically interlocked in groups of four withcouplings50bin the same manner described inFIGS. 25-28. Use of adifferent mounting surface144 in this embodiment requires slight changes to the brackets and the layout ofseries coupling portions162. The detail inFIG. 51 shows adouble bracket186 which is utilized to directly connect twoframes212 topurlins180 in the centralvertical seam152 where the groups of fourPV modules211A,211B,211C,211D come together.Double bracket186 comprisesvertical portions187L,187R withvertical adjustment slots188 for connecting toframes212 in the same way asbracket132 only this bracket connects to twoadjacent PV modules211. Each horizontal row along the centralvertical seam152 comprises onedouble bracket186, but not all are visible here.Double bracket186 further comprisesU-bolt slots190L,190R (not all visible),U-bolt192, nut andwasher193 for securingdouble bracket186 topurlin180, and aseries coupling portion962.PV modules211 are secured to the other two purlins by means of abracket132U which is similar todouble bracket186 except that there is only onevertical portion187 since this is the last row ofPV modules211.
• 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 array10 as shown inFIG. 51 would normally require an additional layer of PV frame support members131PA betweenpurlins180 and PV frames212 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 parallelinterlock support system160 which only requires connection of PV frames212 to the threepurlins180 as shown. In other embodiments it is desired to minimize the size offrames212, therefore additional purlins may be used, but still not as many prior art systems require. Inother embodiments brackets132 are formed in different shapes to facilitate connection to the shape of mountingsurface144. 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 anarray10. 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 mountingsurface144 and another portion which is shaped to optimize connection to at least onePV frame212, is asuitable bracket132 for use with the present invention.
• FIGS. 53-54 show an alternate embodiment ofPV array10 which further comprises a snap-inconduit box195.FIG. 53 depicts a perspective view of two interlockedPV modules12A,12B which are at the end of a row.FIG. 54 shows a perspective view ofconduit box195.Conduit box195 snaps intoslots26A,26B via spring clips197.Hole196 in the rear ofconduit box195 allows wiring fromarray10 to pass intobox195, then out throughconduit198 connected tobox195. An optional cover plate forconduit box195, as are typical in the art, is not shown here. Use ofconduit box195 along withPV array10 greatly simplifies wiring since all wiring can be routed through gaps betweenPV modules12, then intoconduit box195 and out throughconduit198 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 box195 may also enhance the aesthetics ofarray10 since it may be manufactured to match PV modules frames. In otherembodiments conduit box195 is more firmly attached toframes12A,12B by connecting it via bolts orcouplings50jinstead of spring clips197, 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 ofPV module11 as shown inFIG. 1. APV module411 with aPV laminate420 and aframe412 is shown.Frame412 comprises twoframe members413 withslots426 on opposite sides of a laminate back plane orbase409. Devices such asbase409, as are known in the art, may serve to insulate a roof or provide structural support toPV laminate20 or both.Base409, however, is not rigid enough to fully supportPV laminate420, and thus framemembers413 are glued, fastened, or otherwise adhered to base409 orlaminate420 or both in order to provide structural support toPV module411 and to provide a means for interlocking the sides of an array ofPV modules411 together.Base409 may be adhered to the underside ofPV laminate420. SincePV laminate420 is supported byframe members413 andbase409, it mayoverhang frame members413 as shown. In anotherembodiment frame members413 enclosebase409.
• Other embodiments add different features. For example, one embodiment adds a ball and detent to lockingportion104A,104B to prevent lockingportion104A,104B from disengaging or working its way free and provide a position location stop. Another provides a quick-release handle attached to rotatingportion100. The handle is tucked just lower thanlaminate20 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 slot26 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.
• While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced be interpreted to include all such modifications, permutations, additions, and sub-combinations as are within their true spirit and scope.

Claims (22)

1. A photovoltaic module comprising a frame with an outward facing groove and a coupling, said coupling comprising a locking portion, said outward facing groove comprising a locking portion stop, and said locking portion comprising a radially extending portion adapted to resist rotation of said locking portion beyond a predetermined rotational position.

2. A photovoltaic module according toclaim 1, wherein said coupling is adapted to rotate essentially about an axis, said radially extending portion extending radially from said axis.

3. A photovoltaic module according toclaim 1, wherein said locking portion comprises a key portion.

4. A photovoltaic module according toclaim 1, wherein said locking portion stop is a hard stop.

5. A photovoltaic module according toclaim 4, wherein said hard stop is adapted to inhibit rotation of said coupling beyond said predetermined rotational position.

6. A photovoltaic module according toclaim 4, wherein said hard stop is adapted to inhibit rotation of said coupling after connection to said frame.

7. A photovoltaic module according toclaim 1, wherein said coupling is not wider than a width of said photovoltaic module.

8. A photovoltaic module according toclaim 1, wherein said locking portion has at least one tapered surface, said at least one tapered surface at least partially leading said key portion further into said outward facing groove upon rotation of said coupling.

9. A photovoltaic module according toclaim 1, wherein rotation of said coupling rotates said locking portion such that said locking portion connects with said frame.

10. A photovoltaic module according toclaim 1, wherein rotation of said coupling rotates said locking portion such that said frame captures said locking portion.

11. A photovoltaic module according toclaim 1, wherein said radially extending portion has at least one tapered surface said at least one tapered surface at least partially leading said key portion further into said outward facing groove upon rotation of said coupling.

12. A photovoltaic module according toclaim 1, wherein said radially extending portion comprises two substantially curved surfaces on opposite corners.

13. A photovoltaic module according toclaim 1, wherein said outward facing groove comprises a slot.

14. A photovoltaic module comprising a frame with an outward facing groove and a coupling, wherein:

said coupling comprises a key having a width slightly less than a height of an opening of said outward facing groove and a longest dimension approximately equal to a height inside of said outward facing groove.

15. A photovoltaic module according toclaim 14, wherein said width is approximately 0.7 to 0.9 times said height of said opening of said outward facing groove.

16. A photovoltaic module according toclaim 14, wherein said key is adapted to rotatably engage with said frame.

17. A photovoltaic module according toclaim 14, wherein said longest dimension in an insertion position essentially aligns with said outward facing groove.

18. A photovoltaic module according toclaim 14, wherein said outward facing groove extends substantially the length of a frame member of said frame.

19. A photovoltaic module according toclaim 14, wherein said key comprises a locking portion.

20. A photovoltaic module according toclaim 14, wherein said key has at least one tapered surface, said at least one tapered surface at least partially leading said key further into said outward facing groove upon rotation of said coupling.

21. A photovoltaic module according toclaim 14, wherein said outward facing groove comprises a locking portion stop.

22. A photovoltaic module according toclaim 14, wherein said outward facing groove comprises a slot.

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