Solar panel rack

Information

  • Patent Grant
  • 9166521
  • Patent Number
    9,166,521
  • Date Filed
    Monday, December 8, 2014
    10 years ago
  • Date Issued
    Tuesday, October 20, 2015
    9 years ago
Abstract
A solar panel rack may comprise a vertical support, a transverse support, brackets attaching hollow beams to the transverse support, and brackets configured to attach solar panels or solar panel assemblies to the hollow beams. Internal splices may couple collinearly arranged hollow beams in the solar panel rack. Some or all of these components may be formed from folded sheet metal blanks comprising bend lines predefined by bend-inducing features formed in the blanks. Preformed slots, holes, or other openings in the sheet metal blanks may predefine the relative positions of various components in the solar panel rack and predefine the positions of solar panels or solar panel assemblies to be supported by the solar panel rack. Individual components of the solar panel rack may be useful in other structures and applications apart from solar panel racks.
Description
FIELD OF THE INVENTION

The invention relates generally to the collection of solar energy, and more particularly to solar panel mounting racks and their components.


BACKGROUND

Ground-mounted photovoltaic solar panels are conventionally supported on solar panel mounting racks. Commercially available solar panel racks are typically produced using aluminum extruded sections or steel roll formed sections in order to provide the structural strength required to withstand loads associated with outside conditions such as wind and snow.


SUMMARY

Solar panel racks, their components, and related methods by which the solar panel racks may be manufactured, assembled, and used are disclosed.


A solar panel rack comprises two or more hollow sheet metal beams arranged side by side and in parallel with each other to define a plane, a transverse support comprising two or more notches located in its upper edge, and two or more first sheet metal brackets. The plane defined by the hollow sheet metal beams may be, for example, located parallel to and above upper surfaces of the hollow sheet metal beams. Each first sheet metal bracket has an outer cross-sectional shape substantially conforming to an inner cross-sectional shape of a corresponding notch in the transverse support, has an inner cross-sectional shape substantially conforming to the outer-cross sectional shape of a corresponding hollow sheet metal beam, is positioned in the corresponding notch in the transverse support, and is attached to and supports the corresponding hollow sheet metal beam at least partially within the corresponding notch in the transverse support. The solar panel rack also comprises one or more second sheet metal brackets, each of which has an inner cross-sectional shape substantially conforming to the outer cross-sectional shape of a corresponding hollow sheet metal beam, is positioned on and attached to the corresponding hollow sheet metal beam, and is configured to couple to a solar panel or solar panel assembly to position and attach the solar panel or solar panel assembly to the solar panel rack in a desired location in the plane defined by the hollow sheet metal beams.


The hollow sheet metal beams may be formed by bending sheet metal blanks along bend lines predefined in the sheet metal blanks by bend-inducing features. In some variations, the bend-inducing features each have a length A and each have a radius of curvature R at each end, where R is approximately a minimum radius of curvature required to prevent cracking at ends of the bend-inducing features upon bending of the blank along the bend lines, and A is less than or equal to about 6R, or A is greater than or equal to about 2R and less than or equal to about 6R.


Sheet metal blanks from which the hollow sheet metal beams are formed may comprise preformed tabs and slots configured to secure the sheet metal blank in its beam configuration upon bending of the blank into the beam configuration. In addition, or alternatively, the sheet metal blanks may comprise preformed slots or other openings configured to predefine the locations at which other components of the solar panel rack are attached to the hollow sheet metal beams. These preformed slots or other openings may thereby also predefine the locations at which solar panels or solar panel assemblies are to be attached to the solar panel rack.


The transverse support may be formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features. A sheet metal blank from which a transverse support is formed may comprise one or more preformed tabs or slots configured to engage one or more corresponding slots or tabs in a first sheet metal bracket to at least partially secure the first sheet metal bracket in position on the transverse support. The transverse support may comprise flanges that form side walls for the notches in the upper edge of the transverse support, and such flanges on opposite sides of a notch may be attached to opposite sides of a first sheet metal bracket positioned in the notch.


The first sheet metal brackets may be formed by bending sheet metal blanks along bend lines predefined in the sheet metal blanks by bend-inducing features. A sheet metal blank from which a first sheet metal bracket is formed may comprise one or more preformed tabs or slots configured to engage one or more corresponding slots or tabs in the transverse support to at least partially secure the first sheet metal bracket in position on the transverse support. Each first sheet metal bracket may extend beyond the transverse support in both directions along its corresponding hollow sheet metal beam, and be configured to be progressively less stiff with increasing distance from the transverse support. Each first sheet metal bracket may comprise upper flanges configured to be closed around a hollow sheet metal beam to capture the hollow sheet metal beam within the first sheet metal bracket. The first sheet metal brackets may be initially formed with their upper flanges in an unbent, open configuration to allow positioning of hollow sheet metal beams within the first sheet metal brackets, after which the upper flanges may be closed to capture the hollow sheet metal beams within the first sheet metal bracket. Alternatively, the first sheet metal brackets may be initially formed with their upper flanges in a bent, closed position. In the latter case, the upper flanges may be opened to allow positioning of a hollow sheet metal beam within the first sheet metal bracket and then closed to capture the hollow sheet metal beam.


The second sheet metal brackets may be formed by bending sheet metal blanks along bend lines predefined in the sheet metal blanks by bend-inducing features. Each second sheet metal bracket may comprise one or more upwardly pointing tabs configured to contact features on a solar panel or solar panel assembly to position the solar panel or solar panel assembly in a desired location. Each second sheet metal bracket may additionally, or alternatively, comprise one or more upwardly pointing tabs configured to be clinched to features on a solar panel or solar panel assembly to attach the solar panel or solar panel assembly to the solar panel rack. A pair of two such clinching tabs may be configured to be simultaneously clinched to attach two solar panels or solar panel assemblies to the solar panel rack at the same time.


The solar panel rack may also comprise a hollow sheet metal beam arranged collinearly with one of the two or more side-by-side hollow sheet metal beams, and an expandable and collapsible sheet metal splice. The expandable and collapsible sheet metal splice may be formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features. The expandable and collapsible sheet metal splice is configured to be bent along predefined bend lines to assume a collapsed configuration. While in the collapsed configuration, the splice may be inserted into adjoining ends of the collinear hollow sheet metal beams. The splice may then be expanded to a configuration having an outer cross-sectional shape conforming to and tightly fitting an internal cross-sectional shape of the collinear hollow sheet metal beams, and attached to both of the collinear hollow sheet metal beams to couple the collinear hollow sheet metal beams to each other.


Solar panel racks, their components, and related manufacturing and assembly methods disclosed herein may advantageously reduce material, manufacturing and installation costs for solar panel systems. This may result from a reduced amount of material used in the solar panel rack design, the use of cost-effective manufacturing methods, reduced shipping costs of solar panel rack components, which may be shipped to an installation site as substantially flat sheet metal blanks prior to bending to form the components, reduced storage space required for the components, and reduced labor requirements for installing the solar racks and/or an increased rate of installation.


These and other embodiments, features and advantages of the present invention will become more apparent to those skilled in the art when taken with reference to the following more detailed description of the invention in conjunction with the accompanying drawings that are first briefly described.





BRIEF DESCRIPTION OF THE DRAWINGS


FIGS. 1A-1C show several views of a portion of an example solar panel rack with solar panels mounted on the rack (FIGS. 1A, 1B) and without solar panels mounted on the rack (FIG. 1C).



FIGS. 2A-2B show a transverse support in an example solar panel rack (FIG. 2A) and an expanded view (FIG. 2B) of a notch in the transverse support configured to receive and attach to a beam bracket that is configured to attach a longitudinal beam to the transverse support.



FIGS. 3A-3C show beam brackets attached to and positioned in notches in a transverse support (FIG. 3A), an expanded view of a beam bracket positioned in a notch with its upper flanges open to receive a longitudinal beam (FIG. 3C), and an expanded view of a bracket positioned in a notch with the bracket's upper flanges closed (FIG. 3B).



FIGS. 4A-4C show longitudinal beams positioned in beam brackets attached to a transverse support, with the upper flanges of the beam brackets open (FIG. 4A) and closed (FIG. 4B, 4C) to secure the longitudinal beams to the transverse support.



FIGS. 5A-5D show several views of a beam bracket configured to attach longitudinal beams to transverse support structures in the example solar panel rack.



FIG. 6A shows a sheet metal blank that may be folded to form a hollow longitudinal beam for the example solar panel rack, FIG. 6B shows an expanded view of a portion of the blank of 6A, FIGS. 6C-6H show several views of the longitudinal beam at different stages of folding, FIG. 6I shows an expanded view of a sheet metal blank as in 6A comprising bend-inducing features formed with a lance, and FIG. 6J shows an expanded view of a sheet metal blank as in 6A comprising bend-inducing features formed by laser-cutting.



FIGS. 7A-7G show several views of a collapsible and expandable internal splice and its use in coupling two hollow beam sections together to form a longer hollow beam.



FIGS. 8A and 8B show a longitudinal beam end cap (FIG. 8B) and three such end caps at the ends of longitudinal beams in a portion of a solar panel rack (FIG. 8A).



FIGS. 9A and 9B show perspective and side views, respectively, of a panel bracket configured to attach the corners of four neighboring solar panels to a longitudinal beam in the example solar panel rack, FIG. 9C shows a panel bracket attached to a longitudinal beam, and FIGS. 9D-9G show successive stages of attaching four neighboring solar panels to the example solar panel rack using the panel brackets.



FIGS. 10A-10C illustrate a clinching process by which two neighboring solar panels may be simultaneously secured to the example solar panel rack by the panel bracket of FIGS. 9A-9G.





DETAILED DESCRIPTION

The following detailed description should be read with reference to the drawings, in which identical reference numbers refer to like elements throughout the different figures. The drawings, which are not necessarily to scale, depict selective embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.


As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. Also, the term “parallel” is intended to mean “parallel or substantially parallel” and to encompass minor deviations from parallel geometries rather than to require that any parallel arrangements described herein be exactly parallel. Similarly, the term “perpendicular” is intended to mean “perpendicular or substantially perpendicular” and to encompass minor deviations from perpendicular geometries rather than to require that any perpendicular arrangements described herein be exactly perpendicular.


This specification discloses solar panel mounting racks, their components, and related methods by which the solar panel racks may be manufactured, assembled, and used. As illustrated in the various figures, the disclosed solar panel racks may be used, for example, in a ground-mounted configuration to support photovoltaic panels in fixed positions to collect and convert solar radiation to electricity. Other configurations and applications for the disclosed solar racks will also be described below.


Various components of the disclosed solar panel racks including, for example, the hollow beams, beam brackets, internal expandable beam splices, and solar panel brackets further described below, may be advantageously used in other structures unrelated to solar panels or to the collection of solar energy. The discussion of these components in relation to their roles in the disclosed solar panel rack is not intended to limit the scope of their potential use.


Referring now to FIGS. 1A-1C, an example solar panel rack 100 comprises a vertical support 105, a transverse support 110 attached to an upper portion of the vertical support, and three hollow beams 115 supported by transverse support 110. Hollow beams 115 are arranged in parallel orientations, with their upper surfaces defining a plane in which solar panels are to be supported. In the illustrated example, hollow beams 115 are secured in notches 117 (FIG. 2A) in transverse support 110 by beam brackets 120. Panel brackets 125, attached to hollow beams 115, are configured to attach solar panels 130 to the upper surfaces of beams 115.


Although the illustrated solar panel rack comprises three parallel hollow beams, more generally the solar panel rack comprises two or more parallel hollow beams arranged to define a plane in which solar panels are to be supported. Transverse support 110 and hollow beams 115 may be configured so that the plane in which the solar panels are supported is tilted with respect to vertical, rather than oriented horizontally. The tilt angle may be selected to allow the solar panels to better collect solar energy. (In this specification, “vertical” indicates the direction opposite to the force of the Earth's gravity). For example, and as illustrated, vertically oriented substantially identical notches 117 in the upper edge of transverse support 110 may be located to secure the beams 115 at progressively varying heights so that the beams can define a plane having a desired tilt angle. Further, beams 115 may have non-rectangular cross-sections (FIG. 6D) such that flat upper surfaces of the hollow beams are angled with respect to the vertical to define the desired tilted plane. The upper edge of transverse support 110 may be angled substantially parallel to the intended plane of the solar panels, as illustrated, to provide clearance for the solar panels.


The portion of the example solar panel rack illustrated in FIGS. 1A-1C may be repeated as a unit to form a linearly extending, modular, solar panel rack of desired length. In such linearly extending solar panel racks, corresponding hollow beams in adjacent repeating units may be arranged collinearly and spliced together with internal expandable splices 135 as further described below. Two or more such linearly extending solar panel racks may be arranged in parallel and side-by-side to support two or more corresponding spaced-apart rows of solar panels in an array of solar panels.


Individual solar panels to be supported by solar panel rack 100 may have, for example, a width of about 0.9 meters to about 1.3 meters and a length of about 1.5 meters to about 2.5 meters. More generally, such solar panels may have any suitable dimensions. The width of the solar panel rack may be selected, for example, to be approximately equal to an integer multiple of the solar panel width or length, or to a sum of integer multiples of the solar panel width and the solar panel length. As illustrated, for example, the solar panel rack may have a width approximately equal to twice the length of a solar panel. More generally, solar panel rack 100 may have any suitable width. Solar panels may be grouped into assemblies of solar panels prior to being installed on solar panel rack 100. Such a solar panel assembly may be handled and installed similarly to as described herein for an individual solar panel.


Beams 115 may have lengths of, for example, about 3 meters to about 8 meters. The beam lengths may be selected, for example, to be approximately equal to an integer multiple of the solar panel width or length, or to a sum of integer multiples of the solar panel width and the solar panel length. Two or more beams 115 may be spliced together as noted above to form part of a solar panel rack having an overall length of, for example, about 24 meters to about 96 meters supported by multiple transverse supports 110 and corresponding vertical supports 105. Though FIGS. 1A-1C show a single transverse support used to support one beam-length of solar panel, in other variations two or more transverse supports 110, with corresponding vertical supports 105, may be spaced along a beam-length of the solar panel. For example, in linearly extending solar panel racks comprising beams collinearly spliced together to lengthen the rack, there may be one, two, or more than two transverse supports spaced along the solar panel rack between beam splices or between the end of the solar panel rack and a beam splice.


Although the example solar panel rack of FIGS. 1A-1C is shown comprising a vertical support, a transverse support, hollow beams, brackets for attaching the hollow beams to the transverse support, and brackets for attaching the solar panels to the hollow beams, variations of the solar panel rack may lack any one of these components, or lack any combination of these components, and may comprise additional components not shown.


Transverse supports, hollow beams, and brackets used in the solar panel racks disclosed in this specification may advantageously be formed by bending sheet metal blanks into the desired shape. Flat sheet metal blanks from which these components are formed may be patterned, for example, with slits, grooves, score lines, obround holes, or similar bend-inducing features that define predetermined bend lines along which the sheet metal blanks may be bent to form the desired structures.


Such bend-inducing features may include, for example, slits, grooves, displacements, and related bend-inducing features as disclosed in U.S. Pat. Nos. 6,877,349, 7,152,449, 7,152,450, 7,350,390, and US Patent Application Publication No. 2010/0122,563, all of which references are incorporated herein by reference in their entirety. A “displacement” as disclosed in these references is a bend-inducing feature comprising a tongue of material defined in a sheet metal blank by a cut or sheared edge located on or adjacent the bend line, with the tongue displaced at least partially out of the plane of the sheet metal blank before the sheet metal blank is bent along that bend line. The use of bend-inducing features, particularly those disclosed in these references, may increase the precision with which the sheet metal blanks may be bent into the desired components and reduce the force necessary to bend the blanks. The bend-inducing features disclosed in the cited references may exhibit edge-to-face engagement, as described in the references, upon bending. Such edge-to-face engagement may contribute to the precision with which bending may be accomplished and to the stiffness and strength of the resulting component.


Example flat sheet metal blanks from which hollow beams 115 may be formed in some variations are illustrated in FIGS. 6A-6J and described below. For other components of solar panel rack 100 for which no corresponding flat sheet metal blank with bend-inducing features is illustrated, the predetermined bend lines defined by bend inducing features in such sheet metal blanks should be understood to be located at positions corresponding to the bends evident in the finished structures shown in the drawings.


In some variations, transverse supports, hollow beams, and/or brackets used in the solar panel may be formed from sheet metal blanks without the use of bend-inducing features to predefine the bend lines. In such variations, the sheet metal blanks may be bent into the desired shape using, for example, conventional press-brake, stamping press, or roll-forming technology.


Sheet metal blanks for the components of solar panel rack 100, including bend-inducing features if used, may be formed using laser cutting, computer numerical controlled (CNC) metal punching, and/or metal stamping, for example. Such techniques allow for low cost manufacturing of the components.


The use of sheet metal components in solar panel rack 100 allows such components to be attached to each other using sheet metal screws or other sheet metal fasteners, rather than with double sided bolt/washer/nut fastener assemblies which can be difficult and slow to install. The single sided installation process of driving a sheet metal screw using, for example, a magnetic electric drive attachment may be advantageous for both the reduced cost of the fasteners and the increased ease and speed of installation. The use of sheet metal components as described herein may also reduce the overall amount and weight of material used in the solar panel racks while maintaining desired stiffness and strength. Nevertheless, as suitable, one or more components not formed from bent sheet metal, such as cast, extruded, or machined components, for example, may be substituted for the sheet metal components otherwise described in this specification.


The individual components of the example solar panel rack 100 of FIGS. 1A-1C are next described in further detail with respect to additional drawings.


Referring again to FIGS. 1A-1C, vertical support 105 may be, for example, any conventional pile or post suitable for supporting solar panel rack 100 and may be formed from any suitable material. Vertical support 105 may have a Σ (sigma) cross section, for example. Although FIGS. 1A-1C show only one vertical support 105 attached to transverse support 110, other variations of the solar panel rack may use two or more such vertical supports spaced apart and attached to transverse support 110. For ground-mounted configurations, vertical support 105 may be, for example, driven into the ground, ballasted with respect to the ground, screwed into the ground, or affixed to or upon the ground by any other suitable means.


As illustrated in the various figures, transverse support 110 has a saddle shape selected to reduce the amount of material necessary to provide sufficient strength and stiffness to support beams 115 and solar panels 130. As noted above, notches 117 in the upper edge of transverse support 110 are configured to receive brackets 120 and beams 115. Any other suitable shape or configuration for transverse support 110 may also be used.


Transverse support 110 may be attached to vertical support 105 using bolt/washer/nut assemblies or any other suitable fasteners or method. Attachment may be accomplished, for example, with suitable fasteners passing through vertical slots in vertical support 105 and through horizontal slots in transverse support 110. Alternatively, attachment may be accomplished, for example, with suitable fasteners passing through horizontal slots in vertical support 105 and through vertical slots in transverse support 110. Such arrangements of vertical and horizontal slots provide an adjustment that may be used to compensate for imprecision in the placement of vertical support 105 with respect to other vertical supports in the solar panel rack.


Referring now to FIGS. 2A and 2B, in the illustrated example transverse support 110 is formed from a flat sheet metal blank that is bent along predefined bend lines to form panel section 110a, upper flange 110b, and lower flanges 110c. Upper flange 110b and lower flanges 110c are bent perpendicular to panel 110a to impart stiffness to panel 110a. The sheet metal blank for transverse support 110 is also bent along predefined bend lines to form flanges 110d, which are oriented perpendicular to panel 110a to form side walls to notches 117. Panel 110a includes one or more tabs 140 projecting into each notch 117. Variations including two or more tabs per notch, for example, may have one or more tabs projecting into the notch from either side of the notch. In variations having only one projecting tab per notch, the tabs on the outer notches may preferably be located on the sides of the notches interior to the solar panel rack, away from the edges of the solar panel rack. Tabs 140 may be defined in the sheet metal blank by sheared or cut edges, and remain in the plane of panel 110a, or at least substantially parallel to the plane of panel 110a, when flanges 110d are bent perpendicular to panel 110a. As described below, tabs 140 may be inserted into slots or other openings in brackets 120 to temporarily secure brackets 120 in notches 117 without the use of fasteners. Although two tabs 140 are used for each notch 117 in the illustrated example, any other suitable number of tabs 140 may be used per notch. Alternatively, flanges 110d may comprise one or more preformed slots or other openings into which one or more tabs on brackets 120 may be inserted to temporarily secure brackets 120 in notches 117. In the illustrated example, the dimensions and cross-sectional shape of notches 117 in transverse support 110 are selected to conform to the shape of brackets 120 and to provide a friction fit for brackets 120.


The predefined bend lines in the sheet metal blank for transverse support 110 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. The sheet metal blank for transverse support 110 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 1.9 millimeters. Any other suitable material and thickness may also be used.


Referring now to FIGS. 3A-3C, 4A-4C, 5A, and 5B, in the illustrated example bracket 120 is formed from a flat sheet metal blank that is bent along predefined bend lines to form bottom panel 120a, side panels 120b, and upper flanges 120c. Side panels 120b are bent with respect to bottom panel 120a to form a bracket shape conforming to the shape of notch 117 (Figure B) and to the cross-sectional shape of beams 115 (FIG. 6D). Upper flanges 120c may be bent to close (FIG. 3B) and to open (FIG. 3C) the upper end of bracket 120. Side panels 120b comprise slots 120d configured and positioned to engage with corresponding tabs 140 on flanges 110d of transverse support 110 when brackets 120 are properly positioned in notches 117 in transverse support 110.


The predefined bend lines in the sheet metal blank for bracket 120 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. The sheet metal blank for bracket 120 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 1.9 millimeters. Any other suitable material and thickness may also be used.


Once bent into shape, brackets 120 are inserted into notches 117 and temporarily secured in place by engaging tabs 140 on transverse support 110 with slots 120d on brackets 120. Beams 115 are positioned in place in brackets 120 (FIG. 4A), and then upper flanges 120c of brackets 120 are bent into their closed positions (FIGS. 4B, 4C) to capture beams 115 within brackets 120. Sheet metal fasteners may then be driven through preformed holes 110e in flanges 110d of transverse support 110 and through correspondingly aligned preformed holes 120e in bracket 120 into beams 115 to secure the brackets 120 and the beams 115 to transverse support 110. Additional sheet metal fasteners may be driven through preformed holes 120f in upper flanges 120c of brackets 120 into beams 115 to further secure beams 115 to brackets 120. The sheet metal fasteners attaching transverse support 110 and brackets 120 to beams 115 may preferably be self-drilling fasteners that drill into and engage beams 115. The use of such self-drilling fasteners allows the position of transverse supports 110 and vertical supports 105 along beams 115 to be selected at the installation site to adapt to local circumstances, such as to rocks or other objects that might interfere with or constrain the positioning of vertical supports 105. Alternatively, the sheet metal fasteners attaching transverse support 110 and brackets 120 to beams 115 may engage preformed holes in beams 115. (Preformed holes referred to here and elsewhere in the specification are formed in corresponding sheet metal blanks prior to bending of the sheet metal blanks to form the desired components).


The ability to temporarily position brackets 120 in transverse support 110 without the use of fasteners, by means of the tab and slot arrangement just described, allows beams 115 to be positioned in the solar panel rack prior to final attachment of the brackets using sheet metal screws. A benefit of this arrangement is that installers need not handle multiple components at one time, nor are fasteners handled at that same time as well. De-coupling complex installation steps may facilitate faster installation as well as lower the labor costs and skill required.


The inventors have recognized that hollow sheet metal beams such as beams 115 may buckle under load if they are supported by hard narrow edges that concentrate the reaction force from the supporting structure onto a narrow region of the hollow beam. Brackets 120 increase the load capacity of beams 115 by distributing the force from the load on beams 115 along the length of the brackets. This helps to prevent buckling that might otherwise occur if the force from the load on beams 115 were concentrated at the hard upper edge of transverse support 110. Further, each bracket 120 is shaped so that its stiffness progressively and gradually decreases with distance in both directions away from transverse support 110 along its beam 115. (The stiffest portion of a bracket 120 is the central region of the bracket that is in contact with and supported by transverse support 110). Because of this progressive decrease in stiffness, the ends of brackets 120 away from transverse support 110 displace significantly downward under load and consequently do not themselves present hard edges that promote buckling of beams 115.


Referring now to FIGS. 5A-5D, in the illustrated example brackets 120 have stiffness that progressively decreases with distance from transverse support 110 because bottom panels 120a, side panels 120b, and upper flanges 120c all have widths that progressively decrease from a wide central portion to narrower portions at the panel's outer edges, farthest from transverse support 110. That is, material has been removed from central regions of the panels away from the transverse support 110, with the regions from which material has been removed having widths that increase with distance from transverse support 110. This configuration enhances load capacity in all four primary load directions—vertically upward, downward, and in both lateral directions. Any other suitable shape or configuration of brackets 120 may also be used to provide the progressive decrease in stiffness just described. For example, the progressive decrease in stiffness of the bracket may alternatively be provided by progressive changes in width of only some of its panels, although such a configuration may not enhance load capacity in directions perpendicular to the panels that do not exhibit progressively reduced stiffness. Further, although the illustrated brackets 120 are symmetric about transverse support 110 and about hollow beams 115, neither of these symmetries is required.


The use of brackets 120 exhibiting progressive decreases in stiffness as described in this specification may advantageously increase the capacity of a solar panel rack to handle high loads caused by wind or snow, for example.


Referring now to FIGS. 6A-6J, in the illustrated example each beam 115 is formed from a flat sheet metal blank 145 (FIGS. 6A-6C, 6I, 6J) that is bent along predefined bend lines to form a beam 115 having a quadrilateral cross-section comprising bottom panel 150a, side panel 150b, top panel 150c, side panel 150d, and closure flanges 150e and 150f (FIGS. 6D-6H). Upon bending of sheet metal blank 145 into the desired cross-sectional shape, flange 150e and bottom panel 150a overlap, and flange 150f and side panel 150d overlap. Flanges 150e and 150f may then be fastened to the panels with which they overlap using sheet metal fasteners passing through preformed holes, for example, or by any other suitable method, to secure beam 115 in its closed configuration.


In the illustrated example, beam 115 is secured in its closed configuration using tabs and slots preformed in sheet metal blank 145. As illustrated, flange 150f comprises a repeating pattern of tabs 155 and flange 150e comprises a corresponding repeating pattern of slots 160 formed along the bend line between flange 150e and side panel 150d. When sheet metal blank 145 is bent to form the desired cross-sectional shape, tabs 155 remain in the plane of bottom panel 150a, or at least substantially parallel to the plane of bottom panel 150a, and thus protrude from flange 150f. These protruding tabs 155 may be inserted through corresponding slots 160 (FIGS. 6E, 6G) and then bent to lie flat along side panel 150d (FIGS. 6F, 6H) to secure bottom panel 150a to side panel 150d.


Preformed tabs 155 may be formed as tongues of material defined by a cut or sheared edge, with the tongues displaced at least partially out of, but still substantially parallel to, the plane of sheet metal blank 145 prior to bending (FIGS. 6B, 6C, 6I). This may be accomplished using sheet metal lancing methods, for example. Alternatively, preformed tabs 155 may be formed as tongues of material defined by a laser-cut edge, with the tongues remaining within the plane of sheet metal blank 145 prior to bending of the blank (FIG. 6J).


The use of integrated tabs 155 and slots 160 as just described allows sheet metal blank 145 to be bent into shape and joined to itself to form a beam 115 without the use of welding, fasteners, or other means of joinery. Such other means of joinery may be used in addition to such tabs and slots if desired, however.


As noted above, beams 115 as illustrated have quadrilateral cross-sectional shapes. Such quadrilateral cross-sectional shapes may allow beams 115 to provide optimal load capacity in all four primary load directions—vertically upward, downward, and in both lateral directions. (Lateral loads may be caused by wind, for example). Other cross-sectional beam shapes may also be used, however, if suitable.


Sheet metal blank 145 may comprise preformed holes or slots into which tabs on panel brackets 125 are to be inserted, as further described below. Alternatively, sheet metal blank 145 may comprise predefined features that, upon folding of the blank, form tabs on beam 115 that may be inserted into preformed holes or slots on panel brackets 125. Such tab and slot arrangements predefine the locations of panel brackets 125, and thus of solar panels 130, with respect to the beams in solar panel rack 100. This promotes installation speed and prevents errors that might otherwise occur in positioning panel brackets 125 and solar panels 130 on solar panel rack 100.


The predefined bend lines in sheet metal blank 145 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. Sheet metal blank 145 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 0.9 millimeters or about 1.2 millimeters. Any other suitable material and thickness may also be used.


The inventors have determined that the resistance of beams 115 to buckling under stress may be promoted by particular configurations of bend-inducing features used to define the bend lines in sheet metal blank 145. The inventors have recognized that a beam's resistance to buckling increases as the length of the individual bend-inducing features defining the bend lines is shortened. As further explained below, the inventors have also recognized that there is typically a practical lower limit to the length of a bend-inducing feature, with that lower limit related to the composition and the thickness of the sheet of material. These opposing trends result in optimal ranges for the lengths of bend-inducing features used to define bend lines in sheet metal blanks to be formed into hollow beams such as beams 115.


Referring now to FIG. 6I, bend lines in sheet metal blank 145 may be defined by rows of spaced-apart displacements 165, each of which has a length along the bend line identified as “A” in the drawing. Each displacement 165 comprises a cut or sheared edge 165a of a tongue of material 165b. Severed edge 165a is at least partially curved, and typically has ends that diverge away from the bend line. Tongue 165b is displaced at least partially out of the plane of sheet metal blank 145 at the time displacement 165 is formed, prior to bending of the blank, but remains attached to and substantially parallel to the blank. Lateral ends of the severed edge 165a, and thus of tongue 165b, have a radius of curvature R (not shown).


If the radius of curvature R of the ends of the displacements is too small, the sheet metal blank may crack at the ends of the displacements upon folding of the blank. The inventors have determined that the radius of curvature R of the ends of the displacement 165 in sheet metal blank 145 should be selected to be Rmin, or larger than but approximately Rmin, where Rmin is the minimum radius of curvature that may be used without initiating cracking at the ends of the displacements upon folding the sheet metal blank to form the beam. The practical lower limit to the length of a displacement 165 is approximately 2Rmin. Typically, larger sheet thicknesses require a larger radius of curvature R to prevent cracking. More brittle materials also require a larger radius of curvature. The inventors have also found that resistance to beam buckling decreases with increasing displacement length “A”, and that resistance to beam buckling has typically decreased significantly for displacements having a length “A” greater than approximately 6Rmin. Thus inventors have determined that bend inducing displacements to be used in forming a hollow sheet metal beam 115 preferably have a length “A” that satisfies the relationship A≦˜6Rmin, or more preferably satisfies the relationship ˜2Rmin≦A≦˜6Rmin.


Referring now to FIG. 6J, bend lines in sheet metal blank 145 may alternatively be defined by rows of spaced-apart “smile shaped” slits 170, with adjacent slits on alternating sides of the bend line. Slits 170, which penetrate through sheet metal blank 145, define tongues 170a that remain in the plane of sheet metal blank 145 prior to bending. As illustrated, lateral ends of the slits 170 diverge away from the bend line. Each of slits 170 has a length along the bend line identified as “A” in the drawing. The inventors have determined that such bend-inducing smile-shaped slits to be used in forming a hollow sheet metal beam 115 preferably have a length “A” that falls within the same range as that for the use of displacements as discussed above. That is, the length A of the smile shaped slits should satisfies the relationship A≦˜6Rmin, or more preferably satisfies the relationship ˜2Rmin≦A≦˜6Rmin, where Rmin is the minimum radius of curvature that may be used for displacements (as discussed above) without initiating cracking at the ends of the displacements upon folding the sheet metal blank to form the beam.


Beams 115 may be formed, for example, from galvanized steel sheets having a thickness of about 0.9 millimeters or about 1.2 millimeters and bend lines defined by displacements or smile-shaped slits, as described above, having lengths of about 9 millimeters or less.


As noted above, two beams 115 may be arranged collinearly in a solar panel rack 100 and spliced together using internal splices 135. Referring now to FIGS. 7A-7G, in the illustrated example a splice 135 may be formed from a sheet metal blank that is bent along predefined bend lines to form a short hollow beam section having a quadrilateral cross-section comprising bottom panel 175a, side panel 175b, top panel 175c, side panel 175d, and closure flange 175e. Panels 175a, 175b, 175c, and 175d correspond in position, shape, and orientation to panels in beam 115. Closure flange 175e may be bent into contact with and optionally fastened to side wall 175b. Outer cross-sectional dimensions of splice 135 approximately match the internal cross-sectional dimensions of beams 115, to allow a tight fit between the splice and a beam as further described below. Splices 135 may have a length, for example, of about 0.25 meters to about 1.0 meters.


Splice 135, and the sheet metal blank from which it is formed, also comprise two or more additional predefined bend lines which may be bent with low force to partially collapse splice 135. In the illustrated example, splice 135 comprises predefined low-force bend lines 180 and 185 running parallel to the long axis of the splice in side panels 175b and 175d, respectively, which are positioned on opposite sides of splice 135. These low force bend lines allow splice 135 to be partially collapsed (FIG. 7C), and then inserted into an end of a hollow beam 115 (FIGS. 7D and 7E). Typically, splice 135 is inserted into beam 115 to a depth of about one half the length of splice 135, as shown in FIG. 7A, for example. A second hollow beam 115 may then be slid over the remaining exposed half length of splice 135.


Splice 135, in its collapsed configuration, may thus be positioned entirely within two adjacent and collinear hollow beams 115. Sheet metal fasteners may then be inserted through preformed clearance holes 190 (FIG. 7E) in each of the two hollow beams 115 to engage preformed holes in side panels 175b and 175d of splice 135 to pull splice 135 into its expanded configuration (FIGS. 7F, 7G). The two hollow beams 115 are thereby coupled to each other through their attachment to splice 135. (Note that in order to show a perspective view of an expanded splice 135 in position inside a hollow beam 115, FIG. 7G shows only one of the two hollow beams 115 typically coupled to such a splice).


Further, because the outer cross-sectional dimensions of splice 135 approximately match the internal cross-sectional dimensions of beams 115, when splice 135 is expanded within beams 115 the splice's top, bottom, and side panels fit tightly against the corresponding panels of the beams 115. This provides strength and stiffness that allows splice 135 and its attached beams 115 to handle multidirectional loads. In addition, splice 135 does not interfere with the positions of other components of solar rack 100 that are attached to beams 115, such as panel brackets 125 for example, because splice 135 in its final configuration is located within beams 115.


Hollow beams 115 may optionally comprise preformed holes 195 (FIG. 7E) through which a screwdriver or other object may be temporarily inserted as a stop to control the depth to which a splice 135 is inserted into a hollow beam 115.


The predefined bend lines in the sheet metal blank for splice 135 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. The sheet metal blank for splice 135 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 0.9 millimeters to about 1.2 millimeters. Any other suitable material and thickness may also be used.


Referring now to FIGS. 8A and 8B, solar panel rack 100 may also comprise end caps 200 inserted into and closing the ends of hollow beams 115 at the ends of solar panel rack 100. An end cap 200 may be formed from a sheet metal blank bent along predefined bend lines to form end panel 205a and side flanges 205b. End panel 205a may be inserted into the end of a hollow beam 115, with tabs 205c on end panel 205a engaging corresponding preformed slots in the hollow beam 115 to retain the end cap in the hollow beam. Alternatively, hollow beam 115 may comprise tabs that are inserted into preformed slots in side flanges 205b to retain the end cap in the hollow beam. In either case, side flanges 205b may extend outward from and collinearly with hollow beam 115 to support an overhanging portion of a panel bracket 125 positioned at the end of hollow beam 115 (FIG. 8A).


The predefined bend lines in the sheet metal blank for end cap 200 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. The sheet metal blank for end cap 200 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 0.5 millimeters to about 1.2 millimeters. Any other suitable material and thickness may also be used.


Referring now to FIGS. 9A-9G, in the illustrated example a panel bracket 125 is formed from a sheet metal blank that is bent along predefined bend lines to form a top panel 210a, side panels 210b bent downward from top panel 210a to conform to the cross-sectional shape of a hollow beam 115, four positioning tabs 210c located in a square or rectangular arrangement in a central portion of top panel 210a and extending upward from panel 210a, four solar panel clinching tabs 210d extending upward from panel 210a and each positioned adjacent to a positioning tab 210c, and flanges 210e bent perpendicularly outward from side panels 210b to stiffen side panels 210b.


Side panels 210b of panel brackets 125 comprise tabs 210f that may be inserted into preformed slots in a hollow beam 115 to position the panel brackets at desired locations on the hollow beam (FIGS. 9B, 9C). As further described below, panel brackets 125 are configured to properly position and attach the corners of up to four solar panels 130 to a hollow beam 115. This arrangement allows the preformed slots in hollow beams 115 to predefine the positions of solar panels 130 on solar panel rack 100.


To position and attach solar panels 130 to solar panel rack 100, panel brackets 125 are first positioned on hollow beams 115 using the tab and slot arrangement described above. Panel brackets 125 may then be further secured to the beams with sheet metal fasteners driven through preformed holes 215 in side panels 210b into preformed holes in hollow beams 115. Solar panels 130 are then guided into position by contact between outer edges of solar panels 130 and positioning tabs 210c, as well as by contact between solar panels 130 and clinching tabs 210d (FIGS. 9D-9G).


Clinching tabs 210d are configured to be clinched around industry-standard features 220 on solar panels 130 to attach the solar panels to panel brackets 125 and thus to hollow beams 115 (FIGS. 10A, 10C). In the illustrated example, a pair of clinching tabs 210d located on the same side of a hollow beam 115 may be simultaneously clinched around features 220 on adjacent solar panels 130 using a conventional clinching tool shown in FIG. 10B in its open 225A and clinched 225B configurations. This simultaneous clinching method increases the speed of installation. Optionally, solar panels 130 may be further secured to panel brackets 125 with fasteners passing through preformed holes in panel bracket 125. Features 220 may be flanges on an outer frame of solar panel 130, for example.


In addition to positioning solar panels 130 and attaching them to beams 115, panel brackets 125 also better distribute the load from solar panels 130 along beams 115 than would be the case if the solar panels were attached directly to beams 115. The ability of a single panel bracket 125 to position and attach corners of up to four solar panels to solar panel rack 100 may reduce part counts and labor, and thus cost.


Although panel brackets 125 are shown has having particular numbers of positioning and clinching tabs, any suitable number of such tabs may be used.


The predefined bend lines in the sheet metal blank for panel bracket 125 may comprise any suitable bend-inducing features as described herein, known in the art, or later developed. The sheet metal blank for panel bracket 125 may be formed, for example, from galvanized steel sheet having a thickness, for example, of about 1.5 millimeters. Any other suitable material and thickness may also be used. Bend lines between top panel 210a and side panels 210b may preferably be predefined, for example, by bend-inducing features disclosed in US Patent Application Publication No. 2010/0122,563.


Although the illustrated examples of solar panel rack 100 are described above as configured for ground mounting, solar panel rack 100 may alternatively be mounted on roof-tops. Variations of solar panel rack 100 to be roof-top mounted may use vertical supports 105 as described above, or substitute any suitable vertical support. Any suitable method of attaching solar panel rack 100 to a roof-top may be used.


As illustrated, transverse support 110 in solar panel rack 100 is statically mounted to vertical supports 105 so that solar panel rack 100 maintains a fixed orientation. In other variations, transverse support 110 may be pivotably mounted to vertical supports 105, by any suitable pivot mechanism, to rotate around an axis extending parallel to the long axes of hollow beams 115. This arrangement allows transverse support 110 and beams 115 to be rotated so that solar panels 130 track motion of the sun across the sky during, for example, the course of a day or the course of a year. Any suitable rotation drive may be used to rotate the upper portion of such a solar panel rack 100 in this manner.


Although solar panel rack 100 is described above as supporting photovoltaic solar panels, in other variations the solar panel racks described herein may be used to support solar water heating panels rather than, or in addition to, photovoltaic solar panels. Any suitable modification may be made to the solar panel racks described herein to accommodate mounting such solar water heating panels.


Further, although the rack structures disclosed herein have been described as supporting solar panels, they may instead be used to support reflectors such as mirrors, for example, used to direct solar radiation to a solar energy receiver, for example. Such rack structures supporting reflectors may be statically mounted, or pivotably mounted as described above so that the reflectors may be rotated about an axis to track motion of the sun.


The hollow beams, beam brackets, and hollow beam splices described above are not restricted to use in solar panel racks but may instead be used individually or in any combination with each other in any structure for which they are suitable. Further, the cross-sectional shapes of hollow beams, beam brackets, and splices as disclosed herein are not restricted to the particular quadrilateral cross-sectional shapes shown in the drawings, but instead may take any shape suitable for the purpose for which the beams, beam brackets, or splices are employed. The hollow beam splices described herein are not restricted to use in coupling hollow beams formed from folded sheet metal, but may instead be used to couple hollow beams, tubes, or pipes formed by any method including cast, extruded, or machined hollow beams. Generally, the cross-sectional shape of the splice in its expanded form should conform to and tightly fit an inner cross-sectional shape of the hollow beams, pipes, or tubes to be coupled. Similarly, the cross-sectional shape of a beam bracket should conform to and tightly fit an outer cross-sectional shape of the hollow beam that it is supporting.


This disclosure is illustrative and not limiting. Further modifications will be apparent to one skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims.

Claims
  • 1. A solar panel rack comprising: at least first and second hollow sheet metal beams arranged side by side and in parallel with each other to define a plane, each hollow sheet metal beam having a closed configuration of side walls along its longitudinal axis defining a hollow cross-section perpendicular to its longitudinal axis;a transverse support comprising two or more notches located in its upper edge;two or more first sheet metal brackets, each first sheet metal bracket having an outer cross-sectional shape substantially conforming to an inner cross-sectional shape of a corresponding notch in the transverse support, having an inner cross-sectional shape substantially conforming to the outer-cross sectional shape of a corresponding one of the first and second hollow sheet metal beams, positioned in the corresponding notch in the transverse support, and attached to and supporting the corresponding hollow sheet metal beam at least partially within the corresponding notch in the transverse support;one or more second sheet metal brackets, each second sheet metal bracket having an inner cross-sectional shape substantially conforming to the outer cross-sectional shape of a corresponding one of the first and second hollow sheet metal beams, positioned on and attached to the corresponding hollow sheet metal beam, and configured to couple to a solar panel or solar panel assembly to position and attach the solar panel or solar panel assembly to the solar panel rack in a desired location in the plane defined by the first and second hollow sheet metal beams;a third hollow sheet metal beam arranged collinearly with the first or the second hollow sheet metal beam and having a closed configuration of side walls along its longitudinal axis defining a hollow cross-section perpendicular to its longitudinal axis; andan expandable and collapsible hollow sheet metal beam having a closed configuration of side walls along its longitudinal axis defining a hollow cross-section perpendicular to its longitudinal axis, the expandable and collapsible hollow sheet metal beam configured to be bent along predefined bend lines to assume a partially collapsed configuration, inserted while in the partially collapsed configuration into adjoining ends of the collinear hollow sheet metal beams, expanded to a configuration having an outer cross-sectional shape conforming to and tightly fitting an internal cross-sectional shape of the collinear hollow sheet metal beams, then attached to both of the collinear hollow sheet metal beams to splice the collinear hollow sheet metal beams to each other.
  • 2. The solar panel rack of claim 1, wherein each of the first, second, and third hollow sheet metal beams is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 3. The solar panel rack of claim 2, wherein the bend-inducing features each have a length A and each have a radius of curvature R at each end, where R is approximately a minimum radius of curvature required to prevent cracking at ends of the bend-inducing features upon bending of the blank along the bend lines, and A is less than or equal to about 6R.
  • 4. The solar panel rack of claim 3, wherein A is greater than or equal to about 2R.
  • 5. The solar panel rack of claim 1, wherein each of the first, second, and third hollow sheet metal beams is formed by bending a sheet metal blank comprising preformed tabs and slots configured to secure the sheet metal blank in a hollow beam configuration upon bending of the blank into the hollow beam configuration.
  • 6. The solar panel rack of claim 1, wherein each of the first, second, and third hollow sheet metal beams is formed by bending a sheet metal blank comprising preformed slots or other openings configured to predefine the locations at which solar panels or solar panel assemblies are to be attached to the solar panel rack.
  • 7. The solar panel rack of claim 1, wherein the transverse support is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 8. The solar panel rack of claim 1, wherein the transverse support comprises flanges forming side walls for the notches, and the side walls of each notch are attached to opposite sides of one of the first sheet metal brackets positioned in the notch.
  • 9. The solar panel rack of claim 1, wherein the transverse support is formed by bending a sheet metal blank comprising one or more preformed tabs or slots configured to engage one or more corresponding slots or tabs in one of the first sheet metal brackets to at least partially secure the first sheet metal bracket in position on the transverse support.
  • 10. The solar panel rack of claim 1, wherein each first sheet metal bracket is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 11. The solar panel rack of claim 1, wherein each first sheet metal bracket is formed by bending a sheet metal blank comprising one or more preformed tabs or slots configured to engage one or more corresponding slots or tabs in the transverse support to at least partially secure the first sheet metal bracket in position on the transverse support.
  • 12. The solar panel rack of claim 1, wherein each first sheet metal bracket extends beyond the transverse support in both directions along its corresponding hollow sheet metal beam and is progressively less stiff with increasing distance from the transverse support.
  • 13. The solar panel rack of claim 1, wherein each first sheet metal bracket comprises upper flanges configured to be closed around the corresponding hollow sheet metal beam to capture the corresponding hollow sheet metal beam within the first sheet metal bracket.
  • 14. The solar panel rack of claim 1, wherein each second sheet metal bracket is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 15. The solar panel rack of claim 1, wherein each second sheet metal bracket comprises one or more upwardly pointing tabs configured to contact features on a solar panel or solar panel assembly to position the solar panel or solar panel assembly in a desired location.
  • 16. The solar panel rack of claim 15, wherein the one or more upwardly pointing tabs on each second sheet metal bracket configured to contact features on a solar panel or solar panel assembly to position the solar panel or solar panel assembly in a desired location are located in a square or rectangular arrangement in a central portion of a top panel of the second sheet metal bracket and extend upward from the top panel.
  • 17. The solar panel rack of claim 1, wherein each second sheet metal bracket is configured to position and attach adjacent corners of four solar panels or solar panel assemblies to the solar panel rack.
  • 18. The solar panel rack of claim 1, wherein each second sheet metal bracket comprises one or more upwardly pointing tabs configured to be clinched to features on a solar panel or solar panel assembly to attach the solar panel or solar panel assembly to the solar panel rack.
  • 19. The solar panel rack of claim 18, wherein a pair of two clinching tabs are configured to be simultaneously clinched to attach two solar panels or solar panel assemblies to the solar panel rack.
  • 20. The solar panel rack of claim 1, wherein the expandable and collapsible hollow sheet metal beam is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 21. The solar panel rack of claim 1, wherein: each of the first, second, and third hollow sheet metal beams is formed by bending a sheet metal blank comprising preformed tabs and slots configured to secure the sheet metal blank in a hollow beam configuration upon bending of the blank into the hollow beam configuration and comprising preformed slots or other openings configured to predefine the locations at which solar panels or solar panel assemblies are to be attached to the solar panel rack;the transverse support is formed by bending a sheet metal blank comprising one or more preformed tabs or slots configured to engage one or more corresponding slots or tabs in one of the first sheet metal brackets and each first sheet metal bracket is formed by bending a sheet metal blank comprising one or more preformed tabs or slots configured to engage the one or more corresponding slots or tabs in the transverse support; andeach second sheet metal bracket comprises one or more upwardly pointing tabs configured to contact features on a solar panel or solar panel assembly to position the solar panel or solar panel assembly in a desired location and one or more upwardly pointing tabs configured to be clinched to features on a solar panel or solar panel assembly to attach the solar panel or solar panel assembly to the solar panel rack.
  • 22. The solar panel rack of claim 21, wherein the expandable and collapsible hollow sheet metal beam is formed by bending a sheet metal blank along bend lines predefined in the sheet metal blank by bend-inducing features.
  • 23. The solar panel rack of claim 21, wherein the one or more upwardly pointing tabs on each second sheet metal bracket configured to contact features on a solar panel or solar panel assembly to position the solar panel or solar panel assembly in a desired location are located in a square or rectangular arrangement in a central portion of a top panel of the second sheet metal bracket and extend upward from the top panel.
  • 24. The solar panel rack of claim 21, wherein each second sheet metal bracket is configured to position and attach adjacent corners of four solar panels or solar panel assemblies to the solar panel rack.
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No. 13/543,569 titled “Solar Panel Rack” and filed Jul. 6, 2012, issued as U.S. Pat. No. 8,936,164 B2, which is incorporated herein by reference in its entirety.

US Referenced Citations (418)
Number Name Date Kind
387651 Maxim Aug 1888 A
624144 Wilmot May 1899 A
649387 Wright et al. May 1900 A
649762 Saltzkorn et al. May 1900 A
800365 Ebert Sep 1905 A
975121 Carter Nov 1910 A
1295769 Kux Feb 1919 A
1405042 Kraft Jan 1922 A
1468271 Bechtel Sep 1923 A
1557066 Krantz Oct 1925 A
1698891 Overbury Jan 1929 A
1699693 Eisenhauer Jan 1929 A
1746429 Kelleweay Feb 1930 A
1810842 Moecker, Jr. Jun 1931 A
2127618 Riemenschneider Aug 1938 A
2158972 Weindel, Jr. May 1939 A
2339355 Rutten Jan 1944 A
2339863 Knoop Jan 1944 A
2423863 Wales Jul 1947 A
2480034 Lapp Aug 1949 A
2484398 Bell et al. Oct 1949 A
2512118 Snow Jun 1950 A
2515067 Wright et al. Jul 1950 A
2560786 Wright et al. Jul 1951 A
2577588 Paige Dec 1951 A
2625290 Kice et al. Jan 1953 A
2638643 Olson May 1953 A
2771851 McGregor Nov 1956 A
2825407 Widell Mar 1958 A
2869694 Breckheimer Jan 1959 A
2880032 Barenyi Mar 1959 A
2882990 Mustoe Apr 1959 A
2901155 Vines Aug 1959 A
2916181 Pfister et al. Dec 1959 A
2926831 Strange Mar 1960 A
2947436 Kappen Aug 1960 A
2948624 Watson et al. Aug 1960 A
2976747 Schatzschock et al. Mar 1961 A
3039414 Rosanes Jun 1962 A
3090087 Miller May 1963 A
3094158 Reid Jun 1963 A
3094229 Johnson et al. Jun 1963 A
3095134 Jacke Jun 1963 A
3107041 Wagner, Jr. Oct 1963 A
3107807 Bergh et al. Oct 1963 A
3120257 Webers et al. Feb 1964 A
3129524 Hayslett Apr 1964 A
3135527 Knapp Jun 1964 A
3156232 Pollock et al. Nov 1964 A
3159156 Incledon Dec 1964 A
3191564 Fraze Jun 1965 A
3204849 Vinney Sep 1965 A
3205600 Snyder Sep 1965 A
3216644 Harrison et al. Nov 1965 A
3217437 Cobb Nov 1965 A
3228710 Chodorowski Jan 1966 A
3234704 Burgess et al. Feb 1966 A
3246796 Euglander et al. Apr 1966 A
3258380 Fischer et al. Jun 1966 A
3313080 Gewiss Apr 1967 A
3318301 Schibley May 1967 A
3341395 Weber Sep 1967 A
3344641 Pomory Oct 1967 A
3353639 Andrinssi Nov 1967 A
3357078 Moltchan Dec 1967 A
3361320 Bobrowski Jan 1968 A
3455018 Collins Jul 1969 A
3457756 Rohde Jul 1969 A
3474225 Leedy Oct 1969 A
3521536 Waldbauer et al. Jul 1970 A
3538982 Fiori Nov 1970 A
3590759 Hendrie et al. Jul 1971 A
3626604 Pierce Dec 1971 A
3638465 Lickliter et al. Feb 1972 A
3638597 Brown Feb 1972 A
3666607 Weissman May 1972 A
3688385 Brown Sep 1972 A
3717022 DuBois Feb 1973 A
3731514 Deibele, Jr. May 1973 A
3756499 Giebel et al. Sep 1973 A
3774434 Bock Nov 1973 A
3776015 Chartet Dec 1973 A
3779282 Klees Dec 1973 A
3788934 Coppa Jan 1974 A
3851912 Grosseau Dec 1974 A
3854859 Sola Dec 1974 A
3862562 Kruger Jan 1975 A
3867829 Bock Feb 1975 A
3878438 Weisman Apr 1975 A
3879240 Wall Apr 1975 A
3882653 Ollman May 1975 A
3890869 Van Cleave Jun 1975 A
3907193 Heller Sep 1975 A
3914974 DeVore Oct 1975 A
3938657 David Feb 1976 A
3943744 Marsh et al. Mar 1976 A
3952574 Speidel Apr 1976 A
3963170 Wood Jun 1976 A
3994275 Williams Nov 1976 A
4004334 Greenley Jan 1977 A
4011704 O'Konski Mar 1977 A
4027340 Hadtke Jun 1977 A
4058813 Risko Nov 1977 A
4102525 Albano Jul 1978 A
4120084 Wallman Oct 1978 A
4132026 Dodds Jan 1979 A
4133198 Huda et al. Jan 1979 A
4133336 Smith Jan 1979 A
4141525 Miller Feb 1979 A
4145801 Schrecker et al. Mar 1979 A
4166565 Webinger Sep 1979 A
4170691 Rogers Oct 1979 A
4190190 Halonen Feb 1980 A
4215194 Shepherd Jul 1980 A
4230058 Iwaki et al. Oct 1980 A
4245615 Moss Jan 1981 A
4289290 Miller Sep 1981 A
4305340 Iwaki et al. Dec 1981 A
4327835 Leger May 1982 A
4352843 Eckert Oct 1982 A
4362519 Gault Dec 1982 A
4383430 Klaus May 1983 A
4401341 Hirabayashi et al. Aug 1983 A
4406505 Avramovich Sep 1983 A
4421232 Konaka Dec 1983 A
4428599 Jahnle Jan 1984 A
4457555 Draper Jul 1984 A
4468946 Driear Sep 1984 A
4469273 Smith Sep 1984 A
4469727 Loew Sep 1984 A
4479737 Bergh et al. Oct 1984 A
4489976 Flaherty Dec 1984 A
4491362 Kennedy Jan 1985 A
4510785 Triouleyre et al. Apr 1985 A
4515004 Jaenson May 1985 A
4542933 Bischoff Sep 1985 A
4557132 Break Dec 1985 A
4558582 Meinig Dec 1985 A
4559259 Cetrelli Dec 1985 A
4596356 Chaussadas Jun 1986 A
4597374 Igarashi Jul 1986 A
4621511 Knudson Nov 1986 A
4628661 St. Louis Dec 1986 A
4645701 Zarrow Feb 1987 A
4650217 Ehrlund Mar 1987 A
4672718 Schlueter et al. Jun 1987 A
4676545 Bonfilio et al. Jun 1987 A
4735077 Doring et al. Apr 1988 A
4760634 Rapp Aug 1988 A
4792082 Williamson Dec 1988 A
4792085 Waring et al. Dec 1988 A
4803879 Crawford Feb 1989 A
4819792 Christian Apr 1989 A
4831711 Rapp May 1989 A
4837066 Quinn et al. Jun 1989 A
4869539 Cassese Sep 1989 A
4887862 Bassi Dec 1989 A
4898326 Edwards et al. Feb 1990 A
4950026 Emmons Aug 1990 A
4951967 Michalik Aug 1990 A
5022804 Peterson Jun 1991 A
5077601 Hatada et al. Dec 1991 A
5105640 Moore Apr 1992 A
5148600 Chen et al. Sep 1992 A
5148900 Mohan Sep 1992 A
5157852 Patrou et al. Oct 1992 A
5195644 Schmid Mar 1993 A
5205476 Sorenson Apr 1993 A
5211047 Kaneyuki May 1993 A
5211330 Frey May 1993 A
5225799 West et al. Jul 1993 A
5227176 McIntyre-Major Jul 1993 A
5234246 Henigue et al. Aug 1993 A
5234727 Hoberman Aug 1993 A
5239741 Shamos Aug 1993 A
5255969 Cox et al. Oct 1993 A
5259100 Takahashi Nov 1993 A
5262220 Spriggs et al. Nov 1993 A
5284043 Hayashi Feb 1994 A
5292027 Lueke Mar 1994 A
5297836 Parry-Williams Mar 1994 A
5302435 Hashimoto Apr 1994 A
5316165 Moran, Jr. May 1994 A
5333519 Holliday et al. Aug 1994 A
5362120 Cornille, Jr. Nov 1994 A
5372026 Roper Dec 1994 A
5377519 Hayashi Jan 1995 A
5378172 Roberts Jan 1995 A
5390782 Sinn Feb 1995 A
5392629 Goss et al. Feb 1995 A
5415021 Folmer May 1995 A
5427732 Shuert Jun 1995 A
5432989 Turek Jul 1995 A
5440450 Lau et al. Aug 1995 A
5452799 Sutherland Sep 1995 A
5460773 Fritz et al. Oct 1995 A
5466146 Fritz et al. Nov 1995 A
5475911 Wells et al. Dec 1995 A
5496067 Stoll et al. Mar 1996 A
5497825 Yu Mar 1996 A
5524396 Lalvani Jun 1996 A
5533444 Parks Jul 1996 A
5545026 Fritz et al. Aug 1996 A
5568680 Parker Oct 1996 A
5571280 Lehrer Nov 1996 A
5587914 Conradson et al. Dec 1996 A
5592363 Atarashi et al. Jan 1997 A
5615795 Tipps Apr 1997 A
5619784 Nishimoto et al. Apr 1997 A
5620623 Baker Apr 1997 A
5630469 Butterbaugh et al. May 1997 A
5640046 Suzuki et al. Jun 1997 A
5660365 Glick Aug 1997 A
5679388 Fritz et al. Oct 1997 A
5692672 Hunt Dec 1997 A
5701780 Ver Meer Dec 1997 A
5704212 Erler et al. Jan 1998 A
5709913 Andersen et al. Jan 1998 A
5725147 Ljungstrom et al. Mar 1998 A
5737226 Olson et al. Apr 1998 A
5740589 Palau Dominguez Apr 1998 A
5789050 Kang Aug 1998 A
5828575 Sakai Oct 1998 A
5855275 Hunter et al. Jan 1999 A
5882064 Emmons Mar 1999 A
5885676 Lobo et al. Mar 1999 A
5932167 Fritz et al. Aug 1999 A
6021042 Anderson et al. Feb 2000 A
6055788 Martin et al. May 2000 A
6065323 Arduino et al. May 2000 A
6071574 Weder Jun 2000 A
6120257 Saiki et al. Sep 2000 A
6132349 Yokoyama Oct 2000 A
6144896 Kask et al. Nov 2000 A
6148600 Farmer et al. Nov 2000 A
6158652 Ruiz et al. Dec 2000 A
6194653 McMiller et al. Feb 2001 B1
6210037 Brandon, Jr. Apr 2001 B1
6210623 Fritz et al. Apr 2001 B1
6216644 Eroglu et al. Apr 2001 B1
6220654 Sommer Apr 2001 B1
6233538 Gupta et al. May 2001 B1
6279288 Keil Aug 2001 B1
6296300 Sato Oct 2001 B1
6296301 Schroeder et al. Oct 2001 B1
6299240 Schroeder et al. Oct 2001 B1
6330153 Ketonen et al. Dec 2001 B1
6373696 Bolognia et al. Apr 2002 B1
6386009 Ni et al. May 2002 B1
6391424 Suzuki May 2002 B1
6400012 Miller et al. Jun 2002 B1
6412325 Croswell Jul 2002 B1
6467475 Leutner et al. Oct 2002 B2
6467624 Lofgren et al. Oct 2002 B1
6481259 Durney Nov 2002 B1
6490498 Takagi Dec 2002 B1
6558775 Suzuki May 2003 B1
6588244 Chevalier Jul 2003 B2
6592174 Rollin et al. Jul 2003 B1
6599601 Fogle et al. Jul 2003 B2
6626560 Caferro et al. Sep 2003 B1
6631630 Pourboghrat et al. Oct 2003 B1
6640599 Persson Nov 2003 B1
6640605 Gitlin et al. Nov 2003 B2
6643561 Torvinen Nov 2003 B1
6647693 Bromberg Nov 2003 B2
6648159 Prutkin et al. Nov 2003 B2
6658316 Mehta et al. Dec 2003 B1
6677562 Oshima et al. Jan 2004 B2
6688043 Feder et al. Feb 2004 B1
6722013 Rapp Apr 2004 B1
6728114 Serjack et al. Apr 2004 B2
6745608 Miura Jun 2004 B2
6761502 Bishop et al. Jul 2004 B2
6805566 Chia-Chen Oct 2004 B2
6821606 Suzuki Nov 2004 B2
6831255 Levi et al. Dec 2004 B1
6837334 Le Prevost Jan 2005 B1
6844050 Noilhan Jan 2005 B2
6868708 Carlsson et al. Mar 2005 B2
6877349 Durney et al. Apr 2005 B2
6917017 Moon et al. Jul 2005 B2
6936795 Moon et al. Aug 2005 B1
6940716 Korinsky et al. Sep 2005 B1
6941786 Cooper et al. Sep 2005 B1
6943744 Vezmar Sep 2005 B1
6986273 Rager Jan 2006 B2
7000978 Messano Feb 2006 B1
7014174 Roberts et al. Mar 2006 B2
7032426 Durney et al. Apr 2006 B2
7051768 Takahashi May 2006 B2
7069758 Kariakin et al. Jul 2006 B2
7099154 Ishiyama Aug 2006 B2
7099160 Ice Aug 2006 B1
7126819 Liang Oct 2006 B2
7140672 Chernoff et al. Nov 2006 B2
7152449 Durney et al. Dec 2006 B2
7152450 Durney et al. Dec 2006 B2
7156200 Dershem et al. Jan 2007 B2
7167380 Ice Jan 2007 B2
7185934 Saeki Mar 2007 B2
7222511 Durney et al. May 2007 B2
7225542 Chernoff et al. Jun 2007 B2
7243519 Chuang Jul 2007 B1
7263869 Durney et al. Sep 2007 B2
7264304 Carcioffi Sep 2007 B2
7275403 Meyer Oct 2007 B2
7281754 Behr Oct 2007 B2
7296455 Durney Nov 2007 B2
7331505 Holley, Jr. Feb 2008 B2
7350390 Durney et al. Apr 2008 B2
7354639 Durney et al. Apr 2008 B2
7374810 Durney et al. May 2008 B2
7412865 Durney Aug 2008 B2
7440874 Durney et al. Oct 2008 B2
7464574 Durney et al. Dec 2008 B2
7503623 Favaretto Mar 2009 B2
7534501 Durney May 2009 B2
7560155 Durney et al. Jul 2009 B2
7640755 Kateman Jan 2010 B1
7866099 Komamine et al. Jan 2011 B2
8052100 Zante et al. Nov 2011 B2
8092529 Malaviya et al. Jan 2012 B2
8114524 Durney Feb 2012 B2
8377566 Durney et al. Feb 2013 B2
8438893 Durney et al. May 2013 B2
8495997 Laubach Jul 2013 B1
8505258 Durney Aug 2013 B2
20010010167 Leek Aug 2001 A1
20020153371 Oshima et al. Oct 2002 A1
20020163173 Ruehl et al. Nov 2002 A1
20020184936 Gitlin et al. Dec 2002 A1
20020185892 Rima et al. Dec 2002 A1
20030037586 Durney et al. Feb 2003 A1
20030062739 Bock Apr 2003 A1
20030104916 Suzuki Jun 2003 A1
20040035175 Karhumaki Feb 2004 A1
20040076800 Noilhan Apr 2004 A1
20040079353 Dimitrios Apr 2004 A1
20040103707 Winters Jun 2004 A1
20040130182 Bangle et al. Jul 2004 A1
20040134250 Durney et al. Jul 2004 A1
20040206152 Durney et al. Oct 2004 A1
20040207228 Gebreselassie et al. Oct 2004 A1
20040216399 Yamada et al. Nov 2004 A1
20050005670 Durney et al. Jan 2005 A1
20050042432 Jones et al. Feb 2005 A1
20050061049 Durney et al. Mar 2005 A1
20050064138 Durney et al. Mar 2005 A1
20050088014 Woodson et al. Apr 2005 A1
20050097937 Durney et al. May 2005 A1
20050117300 Prasher et al. Jun 2005 A1
20050120766 Friedman et al. Jun 2005 A1
20050126110 Durney et al. Jun 2005 A1
20050161979 Chernoff et al. Jul 2005 A1
20050167459 Storer Aug 2005 A1
20050168014 Chernoff et al. Aug 2005 A1
20050174732 Lin Aug 2005 A1
20050189790 Chernoff et al. Sep 2005 A1
20050189791 Chernoff et al. Sep 2005 A1
20050257589 Durney et al. Nov 2005 A1
20050284088 Heath Dec 2005 A1
20060021413 Durney et al. Feb 2006 A1
20060044755 Ishiyama Mar 2006 A1
20060053706 Russell Mar 2006 A1
20060053857 Durney Mar 2006 A1
20060059807 Zimmerman et al. Mar 2006 A1
20060061966 Korinsky et al. Mar 2006 A1
20060075798 Durney et al. Apr 2006 A1
20060096100 Stol et al. May 2006 A1
20060130551 Durney et al. Jun 2006 A1
20060175871 Eipper et al. Aug 2006 A1
20060181846 Farnsworth et al. Aug 2006 A1
20060207212 Durney Sep 2006 A1
20060213245 Durney Sep 2006 A1
20060232052 Breed Oct 2006 A1
20060232934 Kusamoto et al. Oct 2006 A1
20060237996 Eipper et al. Oct 2006 A1
20060261139 Durney Nov 2006 A1
20060277965 Durney Dec 2006 A1
20070113614 Durney et al. May 2007 A1
20070117502 Kim May 2007 A1
20070123113 Durney May 2007 A1
20070146988 Yamagishi et al. Jun 2007 A1
20070206353 Boone et al. Sep 2007 A1
20070231062 Durney Oct 2007 A1
20070241587 Fleming Oct 2007 A1
20070262128 Durney Nov 2007 A1
20070271793 Mellis et al. Nov 2007 A1
20070286722 Lan Dec 2007 A1
20080016937 Durney et al. Jan 2008 A1
20080048366 Durney Feb 2008 A1
20080054683 Takeda Mar 2008 A1
20080063834 Durney et al. Mar 2008 A1
20080079201 Durney Apr 2008 A1
20080098787 Durney et al. May 2008 A1
20080121009 Durney et al. May 2008 A1
20080187427 Durney Aug 2008 A1
20080193714 Durney et al. Aug 2008 A1
20080250837 Durney Oct 2008 A1
20080271511 Durney et al. Nov 2008 A1
20080276682 Durney Nov 2008 A1
20090100893 Durney et al. Apr 2009 A1
20090100894 Durney et al. Apr 2009 A1
20090100895 Durney et al. Apr 2009 A1
20090194089 Durney et al. Aug 2009 A1
20090205387 Durney et al. Aug 2009 A1
20090297740 Durney Dec 2009 A1
20100132769 Potter et al. Jun 2010 A1
20100201158 Miyashita Aug 2010 A1
20110008573 Durney Jan 2011 A1
20110094559 Potter et al. Apr 2011 A1
20110265860 Ciasulli et al. Nov 2011 A1
20110287228 Durney et al. Nov 2011 A1
20120097816 Tamm et al. Apr 2012 A1
20120285515 Sagayama Nov 2012 A1
20130048056 Kilgore et al. Feb 2013 A1
20130091786 DuPont et al. Apr 2013 A1
Foreign Referenced Citations (13)
Number Date Country
1915550 Feb 2007 CN
10054349 May 2002 DE
202008001010 May 2008 DE
102009019829 Nov 2010 DE
202011001320 Jun 2011 DE
2146160 Jan 2010 EP
2362161 Aug 2011 EP
3089172 Sep 2000 JP
4688951 May 2011 JP
2007038760 Apr 2007 WO
2007134114 Nov 2007 WO
2008124642 Oct 2008 WO
2010006735 Jan 2010 WO
Non-Patent Literature Citations (14)
Entry
International Search Report, PCT/US14/4226, Oct. 22, 2014, 3 pages.
Derwent Abstract Accession No. 1995-280162/37, M21, JP 3474242 B2 (Amada Co Ltd) Dec. 8, 2003.
Derwent Abstract Accession No. 1999-340844/29, P52, JP 11 123458 A (Meiji Nat Kogyo KK) May 11, 1999.
Derwent Abstract Accession No. 80-C6243C/12, FR 2428372 A (Merlin & Gerin Sa) Feb. 8, 1980.
Derwent Abstract Accession No. 83-G2401K/19, FR 2514103 A (Grun) Apr. 8, 1983.
Derwent Abstract Accession No. 97-345802132, P52, JP 9 141333 A (Kokusai Denki Kk) Jun. 3, 1997.
Derwent Abstract Accession No. 98-265616124, P52, JP 10 085837 A (Mitsubishi Electric Corp) Apr. 7, 1998.
EasyBend™—Complex Bending Made Easy, © 2004 Mate Precision Tooling Inc., Anoka, Minnesota.
Patent Abstracts of Japan, vol. 015, No. 006 (M-1066), Jan. 8, 1992 (JP 02-258116A).
Publication “Office dA” by Contemporary World Architects, Rockport Publishers, Inc., Gloucester, Massaschusetts, 2000, pp. 15, 20-35.
“Hold the Press”, Eureka Magazine, Aug. 2007, vol. 27, No. 8, Findlay Publications Ltd., Darford Kent UK, pp. 12-13.
Snap to it, International Sheet Metal Review, Sep./Oct. 2005, p. 40-42.
SnapLock™—Fabricated Joints Without Welding, © 2002 Mate Precision Tooling, Inc., Anoka, Minnesota.
Singh, H., “Sheet Metal Hydroforming”, Fundamentals of Hydroforming, Society of Manufacturing Engineers, Dearborn, Michigan (2003), pp. 29-35.
Related Publications (1)
Number Date Country
20150090680 A1 Apr 2015 US
Continuations (1)
Number Date Country
Parent 13543569 Jul 2012 US
Child 14563600 US