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BACKGROUND OF THE INVENTION 
     The invention relates to suspended ceiling construction and, in particular, to features of specialty suspended ceilings utilizing irregularly shaped metal panels. 
     PRIOR ART 
     U.S. Pat. Nos. 4,744,188 and 5,195,289 disclose suspended ceiling structures that are constructed as “islands” such that they are horizontally spaced from any surrounding walls and, often, are at a level or elevation different from other ceiling structure. These specialty ceilings are made available to allow architects and designers to create unique structures with dramatic visual effects not available with conventional plain rectangular grid suspension ceilings. These patents are directed to hardware for creating the perimeter of the island with pre-manufactured trim. Island ceilings constructed in accordance with these patents are typically limited to use of conventional rectangular or square grids with lay-in panels. The use of such grid within a non-rectangular island boundary can be difficult and time consuming to construct. Moreover, the limitation of using a rectangular grid can often result in a compromise over what an architect would prefer. It follows that there exists a need in the art, particularly in the area of suspended island ceilings, to enable the use of non-rectangular or non-standard rectangular panels or planks within the perimeter of the island to afford greater design freedom to the architect or designer. 
     SUMMARY OF THE INVENTION 
     The invention provides a ceiling construction, particularly suited for suspended island ceilings, in which individual panels collectively forming the expanse of the ceiling are of a configuration distinctive from conventional rectangular or square grid panels. The panels can thereby create a unique custom look to the ceiling. Moreover, where the perimeter or edges of the island ceiling are curvilinear, the individual ceiling panels in the perimeter areas can be configured to produce and/or compliment the desired curved form. 
     With the use of Autocad® or other computer-aided design programs and computer-aided manufacture, it is possible for an architect or designer to draw an island ceiling to his or her exact specifications on a computer and then use the computer drawing to instruct a sheet metal forming machining to create the panels of the present invention for the construction of the specified ceiling. The expanse of the ceiling, according to the invention, is divided into sections. The sections are formed by correspondingly shaped sheet metal panels or planks. In general, the planks are characterized by having two generally opposed straight sides and two generally opposed free-form sides, the latter being straight, concave, convex or any combination of these shapes. The straight sides of the panels have flanges that abut flanges of adjacent panels. Preferably, at least one of the abutting flanges has a hollow form adapted to mate with a special clip, such as disclosed in the aforementioned U.S. Pat. No. 5,195,289. The clips or mounting brackets are positioned on the ends or free form edges of the panel and connect with trim strips or channels. The clips are adapted to effectuate a connection with a trim strip in any of a broad range of intersection angles between the trim and the panel flange supporting the clip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an island ceiling structure constructed in accordance with a first embodiment of the invention, a conventional suspended grid ceiling being shown fragmentarily in the background; 
     FIG. 2 is a reflected plan view (a view from the underside) of the island ceiling of FIG. 1; 
     FIG. 3 is a fragmentary sectional view of a portion of the island ceiling taken along the lines  3 — 3  indicated in FIG. 2; 
     FIG. 4 is a fragmentary elevational view, partially in section, of the island ceiling taken along the lines  4 — 4  in FIG. 2; 
     FIG. 5 is a fragmentary elevational view, partially in section, of the island ceiling taken in the plane  5 — 5  indicated in FIG. 2; 
     FIG. 5 a  is an enlarged fragmentary cross-sectional view of a pair of abutting trim strips corresponding to the lower central area of FIG. 5; 
     FIG. 6 is a fragmentary cross-sectional view of a modified form of a ceiling panel constructed in accordance with the invention; 
     FIG. 7 is a fragmentary cross-sectional view of another modified form of the ceiling panel of the invention; 
     FIG. 8 is a fragmentary perspective view of a ceiling panel, trim mounting clip and perimeter trim, partially exploded; 
     FIG. 9 is a plan view of an elongated free-form suspended ceiling island constructed in accordance with the invention; 
     FIG. 10 is a perspective view of still another form of a ceiling panel constructed in accordance with the invention; 
     FIG. 11 is a fragmentary perspective view of the panel of FIG. 10, with a trim mounting clip attached thereto; and 
     FIG. 12 is a fragmentary sectional view taken in a vertical plane through portions of several ceiling panels like those illustrated in FIG.  10 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIGS. 1-5, there is shown a first embodiment of the invention in the form of a suspended island ceiling  10 . The illustrated island  10  is circular and comprises a central circular area  11  and an annular area  12  surrounding the central area. The central area  11  includes a grid made up of conventional suspended ceiling tees. Certain ones of the grid tees are cut short from their standard lengths of 2, 4 or 12 feet, for example, to fit within the circular area  11 . A plurality of the cut ends of the grid tees  13  are fitted with clips or brackets  14  such as disclosed in aforementioned U.S. Pat. No. 5,195,289. The clips  14  are fabricated from sheet metal stock and include a U-shaped body  16  sized to snuggly fit over the bulb of a standard grid tee which is, typically ¼″ wide. As shown, the body  16  in its normal installed orientation has its U-shape inverted and mounts in the manner of a paddle. The clip  14  also includes a trim mounting member or plate  17 . A tab  18 , stamped out of the plane of the mounting member  17  and bent to a perpendicular orientation, is pivotally mounted to the U-shaped body  16  by a rivet  19 . Pivotal movement about the rivet  19  allows the mounting member  17  to align in tangency with a trim strip or channel  21  of a type, for example, disclosed in aforementioned U.S. Pat. No. 5,195,289. Such trim strips  21  are arranged front-to-front as shown in FIG.  5  and discussed below. In FIG. 4, the clip  14  has a vertically extended mounting member  17  to accommodate a relatively wide (in the vertical direction) trim strip  21 . Sheet metal screws  26  are used to retain the brackets  14  in place on the ceiling structure to be described. 
     With reference to FIG. 5, a conventional grid tee  13  is shown at the right. A bracket or clip  14  assembled and retained on the tee by the screw  26  carries a convex channel-shaped trim strip  21 . The trim channel  21  includes a vertical wall  27  (which is curved in a horizontal plane in the various embodiments disclosed herein) and a pair of horizontally extending flanges  28 . The same numerals are used to designate like parts in the taller trim strip  21  of FIG.  4 . For purposes of this disclosure, the trim strip  21  is convex where its radius of curvature is on the side of the wall  27  where the flanges  28  exist and is concave where its radius of curvature is on the side of the wall remote from where the flanges exist. The trim mounting member  17  includes a pair of reverse or inwardly bent tabs or flanges  29  at its upper and lower ends which are adapted to push into the space between the trim strip flanges  28  such that edges  31  of these tabs  29  snap behind edges  32  of in-turned hems  33  on the trim strip flanges  28  thereby effectuating a concealed connection between the trim strip  21  and bracket  14  as well as the ceiling structures to which the bracket body  16  is attached. 
     More specifically, the central area  11  of the island ceiling  10  is bounded by a circular arrangement of arcuate convex segments of the trim strip  21 . These segments of trim strip  21  are carried on the grid tees  13  by a plurality of the clips  14  distributed about the periphery of the circular area  11  and connected to such segments of trim strip by the snap-in process described above. It will be appreciated that the angular adjustability of the bracket mounting member  17  allows this assembly to be accomplished regardless of the angle at which the trim strip and grid tee intersect. 
     The foregoing description is an example of the application of the prior art disclosed in aforementioned U.S. Pat. No. 5,195,289. The present invention involves the construction of a suspended ceiling island or part thereof which is comprised of a plurality of sheet metal panels and, for the present purposes, can be described as “gridless”In the embodiment of FIGS. 1-5, the sheet metal panels are designated by the numeral  36 . These panels  36  form the annular area  12  and are arranged in but one example of the versatility of the invention. As will be understood, the panels of the invention can provide an infinite number of island designs with or without integration with other kinds of ceiling systems. 
     The panels  36  are preferably fabricated from sheet metal such as steel or aluminum and are characterized by generally opposed straight sides  37 ,  38  and generally opposed free form sides  39 ,  40 . In the illustrated case of FIGS. 1-5, the free form sides  39 ,  40  are circular arcs that are concentric with one another; however, it will be apparent from the discussion below with respect to FIG.  9  and from an understanding of the invention, that the free form sides  39 ,  40  can take any desired shape including straight, convex, concave and combinations of any of these shapes. The straight sides  37 ,  38  of the panels  36  are shown in cross-section in FIG.  3 . One side  38  includes a straight upstanding flange  42  while the other side  37  has a J-shaped flange  43 . More specifically, the J-shaped flange  43  comprises an upstanding main flange wall  44 , a horizontal web  46  and a depending minor flange wall  47 . The walls  44 ,  47  and web  46  create a hollow analogous to the hollow of a reinforcing bulb of a conventional grid tee. Importantly, the dimensions of the J-shaped flange  43 , namely the height of an upper surface  48  of the web above a lower face  49  of the panel  36  is nominally 2.5″, the same as the height of a bulb of a grid tee and the width across the outer faces of the flange walls  44 ,  46  is 0.25″, the same as the typical width of a bulb of a grid tee. This enables the use of a standard clip or bracket  14  that can be used both with conventional grid tees and with the ceiling panels of the present invention. The brackets  14  can be attached and fixed with screws  26  to one or both ends of the J-flange  43  at the free form sides  39 ,  40  as needed. 
     As depicted in FIG. 3, the panels are joined by assembling the flange  38  into the hollow of the flange  37 ; this can be done by either hooking the flange  37  over the upper edge of the flange  38  or by slipping the flange  38  into the hollow. The flanges  37 ,  38  have aligned holes  51  to receive suspension wires  52  to support the panels  36  from a superstructure as is known in the art. The flanges  37 ,  38  are abutted with the lower panel faces  49  coplanar and can be held in this position by sheet metal screws  53 . Ordinarily in this and other embodiments a panel is assembled with adjacent panels by laterally aligning the adjacent straight side flanges lengthwise with each other. 
     With reference to FIG. 5, arcuate lengths of concave trim strip or channel  21  is abutted in face-to-face relation to the convex trim strip  21  joined to the grid tees  13  of the central circular area  11 . The panels  36  are joined to the concave trim channels  21  by snapping the attached brackets  14  into this trim. Similarly, the convex trim  21  on the outer periphery of the annular area  12  is mounted to the panels  36  by snapping the clips  14  attached on the radially outward ends of the J-channels  43  into the trim as suggested in FIG.  4 . 
     FIG. 6 illustrates, in cross-section, a modification of a ceiling panel in accordance with the invention. In this modification, a panel  56  has two generally opposed straight sides  57 ,  58  and two generally opposed free-form sides as described before in connection with the panel  36 . The straight side  57  has a flange  59  with an inverted G-shaped hollow cross-section. The G-shape or form is comprised of a generally vertical main flange wall  61 , a horizontal web  62 , a depending minor flange wall  63  and a horizontal in-turned lip  64 . The flange walls  61 ,  63  have aligned holes  66  for receiving suspension wires  67 . The opposed straight side  58  of the panel  56  has an upstanding flange  68  which may be over bent to an included angle of slightly less than 90° from the main part of the panel  50 . The flange  68  is sufficiently tall to extend into the space or hollow of the channel-like area between the flanges  61 ,  63  of an abutting panel  56 . The upper free edge of the flange  68  is bent along the lines parallel to the main part or panel proper  50  to form a detent groove  71  and a leading cam surface  72 . The cam surface  72  facilitates insertion of its associated flange  68  into the channel of the adjacent panel flange. The over square bend of the flange  68  and the other related geometry of the panel  56  allows the detent groove to interconnect with the adjacent panel  56  and support its associated panel from this adjacent panel, the latter being carried by the suspension wires  67 . The channel formed by the flange walls  61  and  63  and web  62  has a width and height above the lower panel face  49  corresponding to a standard grid tee bulb height and width as explained above so that a standard clip  14  can be used as described. 
     FIG. 7 illustrates a cross-sectional view of a set of panels  76  similar to those of FIG.  6 . The same reference numerals are used as in FIG. 6 to identify like elements. In this modification, a straight panel side  77 , corresponding to the straight side  58  of the panel  56  in FIG. 6, has a stepped flange  78  rather than the generally straight flange  68  of the panel  56  of FIG.  6 . The stepped flange  78  gives the appearance in the finished ceiling greater visual detail than the panel of FIG. 6 but is otherwise the same in function. 
     FIGS. 9-12 illustrate another embodiment of the ceiling panels or planks  81 . As in the previous embodiments, the panels  81  are formed of sheet metal and each has a main part or a panel proper  50  that is generally planar or flat. Each panel  81  has two generally opposed straight edges or sides  83 ,  84  and two generally opposed free form edges or sides  86 ,  87 . The straight edges have upstanding flanges  88 ,  89  while free form edges  86 ,  87  typically, but not necessarily, are simply cut or trimmed in the plane of the panel and are devoid of any flange or hem. One flange  88 , has an inverted J-shape formed by a generally vertical main flange wall  93 , a horizontal web  94 , and a depending minor flange wall  95 . As in previously described embodiments, the channel of the flange formed by the walls  93 ,  95  and web  94  conform to standard tee grid geometry, with a height above a lower face  49  of the panel proper  50  and a width of ¼″. Holes  90  are spaced along the main flange wall  93  below a lower edge of the minor wall  95 , to receive suspension wires  96 . 
     For most of its length, the flange  89  on the panel side  84  opposed to the flange  88  is a simple upturned wall. Spaced inwardly from its ends, the flange  89  has integral J-hooks  97  dimensioned to fit snuggly over the channel-shape of the J-flange  88 . As shown in FIG. 11, the spacing of the hooks  97  from the respective ends of their flanges  89 , or the proximate free form side,  86  or  87  of the panel  81  exceeds the length of the clips  14 . This ensures that there is no interference between a clip  14  and the flange hooks  97 . The height of the main length of the flange  89  is such that its upper edge does not interfere with suspension wires  96  threaded through the holes  90  in an abutting flange wall  93 . 
     The construction of the panel  81  enables a ceiling to be progressively erected in a relatively simple manner since the second and subsequent panels can be readily hung on the preceding panel by positioning its hooks  97  over the J-flange  88  of the preceding panel  81  while the latter is suspended by wires  96 . Clips  14  are positioned on the ends of the flanges  88  of some or all of the panels  81  to enable installation of desired face trim  21  of the type previously described. 
     The panels of the various embodiments are described as having generally planar or flat main portions or faces. It will be understood that this characterization includes main panel portions that are textured, apertured, corrugated or similarly treated for visual and/or functional reasons. In the illustrated examples, the panels are fabricated of one piece of sheet metal, such as steel or aluminum, and are stamped and/or bent into their respective configurations from flat or roll sheet stock. It will also be understood that the flanges of the generally opposed straight sides serve to stiffen the panels in addition to providing for interconnection of panels and trim and for suspension of the panels. In general, the straight sides of the panels are non-parallel where an overall free form island ceiling is specified. In the illustrated embodiments, the free form sides overlie the flange elements of the trim strips or channels to enable the trim strips to support these sides against excessive sagging. 
     While the invention has been shown and described with respect to particular embodiments thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiments herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly, the patent is not to be limited in scope and effect to the specific embodiments herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.

Summary:
A suspended ceiling island is constructed of sheet metal panels that since they are assembled without a supporting gridwork can be configured to create substantially any desired free form island shape. Typically, the panels have a pair of generally opposed straight sides and a pair of generally opposed free form sides. The straight sides, ideally, include upstanding flanges that are used to stiffen, interconnect and suspend the panels. Additionally, the flanges can be shaped into hollow sections similar to standard grid tee shapes to enable the use of standard hardware to attach trim strips to the perimeter of the island.