You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
This invention is directed to a suspended ceiling construction and more particularly to a suspended ceiling construction having inclined transitional zones between areas of different elevation. 
     BACKGROUND OF THE INVENTION 
     Suspended ceilings are commonly used in office buildings, schools and other large buildings and comprise a supporting grid of horizontal intersecting supports which receive panels typically called acoustic panels. Ceilings of this type became popular because of a combination of low cost, desirable acoustic damping properties, ease of installation, an ability to accommodate and hide overhead air conditioning ducts, electrical wiring and plumbing conduits, and providing a plenum for return air. Although early suspended ceilings were flat, it did not take long for the industry to provide more complex shapes, typically having recesses providing improved acoustic damping properties, improved eye appeal and elevated lighting fixtures. 
     Disclosures relevant to the disclosure of this invention are found in U.S. Pat. Nos. 3,119,475; 3,275,817; 3,286,427; 4,004,390; 4,055,930; 4,115,970; 4,438,613; 4,827,687; 5,177,923 and 5,647,182. 
     SUMMARY OF THE INVENTION 
     A problem has always existed in providing transitional areas between areas of different elevation in suspended ceilings. The transitional areas are typically made by workmen at the site. The result is that the quality of construction and its eye appeal depend on the ability of the person at the job site. Thus, the results are normally unpredictable—some jobs look fine and others looked awkward. 
     Architects and designers are not currently able to achieve the same standard quality for the look and performance on different projects based on the ability of craftsmen and their methods of handling irregularities and transitions. In addition, architects and designers cannot produce custom designs using commodity materials without incurring significant labor costs and the risk of poorly executed plans. This invention allows irregularities that occur on a project to be handled in a uniform manner and thereby give architects and designers the options to use a standard ceiling construction method in handling irregularities and elevation changes. 
     A transition zone is provided between different levels of planar ceiling sections. The gridwork for the planar ceiling sections comprises conventional intersecting T-bars suspended by wires from an overlying support. In this invention, the connections between the inclined gridwork of the transition zone and the planar ceiling sections is done by connectors or clips that are crimped onto the T-bar supports or which are supported by the T-bar supports. 
     The shape of the connectors or clips at any particular location depends on how many T-bar supports intersect at the junction of the planar ceiling section and the transition zone. For example, where an inclined T-bar support of the transition zone intersects a mid-point of a horizontal T-bar, the clip comprises a pair of aligned channels crimped onto the horizontal T-bar support and a single perpendicular channel crimped onto the inclined T-bar support. The exact shape of the clips accordingly depends on the situation at the junction between the transition and horizontal T-bar supports. A surprisingly few clips can accommodate almost any practical situation. This is largely true because the angles required between the transition gridwork and horizontal gridwork is accommodated simply by bending the clip to the desired angle. 
     This invention also allows economies in the construction of transition zones between ceiling sections of different elevation. In the past, all transition zones were fabricated on the job site. In this invention, the gridwork of repeated custom ceiling configurations, such as pyramidal sections, are fabricated in a shop on a jig, transported to the job site and simply dropped in place, crimping the connectors onto the T-bar supports as needed. 
     It is an object of this invention to provide an improved ceiling construction. 
     Another object of this invention is to provide new methods and techniques for creating different ceiling layouts and designed using industry standard grid systems to provide improved suspended ceiling construction assemblies. 
     A more specific object of this invention is to provide an improved ceiling construction in which transitional areas between planar ceilings of different elevation are handled in an easy manner providing uniform results. 
     Another object of this invention is to provide improved transitional areas for suspended ceilings. 
     A further object of this invention is to provide manufactured assemblies for installation in new or existing acoustical ceiling systems. 
     These and other objects and advantages of this invention will become more apparent as this description proceeds, reference being made to the accompanying drawings and appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of part of a suspended ceiling, viewed from above, illustrating a ceiling recess of common shape; 
     FIG. 2 is an isometric view of a clip used in the construction of the grid of FIG. 1; 
     FIG. 3 is an isometric view of another clip used in the construction of the grid of FIG. 1; 
     FIG. 4 is an isometric view of another clip used in the construction of the grid of FIG. 1; 
     FIG. 5 is an isometric view of a typical inclined support used in the inclined transition area; 
     FIG. 6 is an isometric view of another clip used in the construction of the grid of FIG. 1; 
     FIG. 7 is an isometric view of part of a suspended ceiling, viewed from above, illustrating an unusual ceiling construction; 
     FIGS. 8-10 are isometric view of additional clips needed to construct the ceiling of FIG. 7; 
     FIG. 11 is an isometric view of part of a suspended ceiling, viewed from above, illustrating a typical transition area dictated by the shape of the area in which the ceiling is located; and 
     FIG. 12 is an isometric view of an additional clip used to construct the ceiling of FIG.  11 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, a suspended ceiling  10  comprises a grid  12  suspended by wires, straps or other tensile supports  14  from an overlying support  15  which is typically the underside of a poured concrete floor of the next story of a multistory building, roof joists in a single story building or the like. The ceiling  10  includes a horizontal flat area  16  and one or more recesses  18  providing improved acoustic damping, improved eye appeal, a position for an elevated lighting fixture or the like. 
     The recess  18  provides an elevated horizontal area  20  connected by an annular transition area  22 . Although the recess  18  may be of any suitable size and shape, it is illustrated as being of a typical size and typical proportion. The horizontal area  20  is shown to be 2′×4′ which is also the dimension of the top of the transition area  22 . The base of the transition area  22  is shown to be 4′×6′ and the vertical separation between the horizontal areas  16 ,  20  is shown to be 7″. It is evident that all these dimensions manifestly may vary. 
     The grid  12  comprises a series of horizontal intersecting supports  24 . Although the supports  24  may be of any suitable type, they are illustrated as conventional T-bar supports having a vertical leg  26  and a horizontal cross-bar  28 . The supports  24  are connected together at their horizontal intersections in a conventional manner to provide a lightweight, surprisingly sturdy grid for receiving horizontal panels  30  thereby providing the horizontal ceiling area  16 . 
     The elevated horizontal area  20  and the transition area  22  provide a support structure  31  made of a plurality of horizontal intersecting supports  32  substantially identical to the supports  24  in the sense of being conventional T-bar supports. The structure  31  is illustrated to provide three types of inclined supports  33 ,  34 ,  35 . The supports  33  extend perpendicularly to the horizontal supports  24 ,  32  and terminate at the support  24 . The supports  34  extend along the corners of the recess  18  which is may be thought of as a truncated pyramid having a square or rectangular bottom and which provide a support for an inclined flat panel. The supports  35  extend perpendicularly to the supports  24 ,  32  and comprise an upwardly angled extension of supports  37 . 
     The supports  33  connect to a mid-point of the supports  24 ,  32  by the use of connectors or clips  36 . As shown in FIG. 2, the clips  36  provide a pair of aligned channels  38  for receiving the horizontal cross-bar of the supports  24 ,  32  and a third channel  40  perpendicular to the channels  38 . The channels  38 ,  40  are sufficiently wide to receive the cross-bar  28  of the supports  24 ,  32  and thus are the same width as the cross-bars  28  and are conveniently 1″ long. The cross-bars  28  are referred to in the industry as being of 1″ width, which is a nominal dimension because the exact dimension is {fraction (15/16)}″. Each channel  38 ,  40  is bounded by tabs  42 ,  44  which are crimped over the horizontal cross-bar of the supports  32 ,  33  and thereby secure the clip  36  and the support  33  to the support  32 . The tabs  42 ,  44  are of any convenient size and typically are ⅜″ tall. It will be seen from FIG. 1 that there is one clip  36  at the top and one clip  36  at the bottom of each inclined support  33 . 
     The inclined supports  34  connect to the horizontal supports  24  by clips  46 ,  48 . The inclined supports  34  create a particular problem because of the angle between the supports  34  and the upper and lower horizontal supports  32 ,  24 . The clip  46  secures the upper end of the inclined support  34  to the horizontal support  32  at one of the corners. The clip  46  comprises a pair of channels  50  diverging at a right angle  52  and a third channel  54  diverging midway between the channels  50 , i.e. at an angle  54  of 135°. The channels  50 ,  54  are sufficiently wide to receive the cross-bar of the supports  24  and thus are nominally 1″ across and conveniently 1″ long. Each channel  50 ,  54  is bounded by tabs  58 ,  60  which are crimped over the horizontal cross-bar of the supports  32 ,  34  and thereby secure the clip  46  and the support  34  to the upper supports  32 . The tabs  58 ,  60  are of any convenient size and typically are ⅜″ tall. 
     As shown best in FIGS. 4 and 5, the clip  48  is secured to the lower end of the inclined support  34  and abuts but is not connected to the lower horizontal supports  24  at one of the intersection. More specifically, the clip  48  is designed to transfer part or all of the load of the transition area  22  and the horizontal area  20  to the lower horizontal supports  24  without making a rigid connection between the inclined support  34  and the lower horizontal supports  24 . 
     To this end, the clip  48  comprises a single channel  62  sized to receive the cross-bar at the lower end of the support  34  and provides tabs  64  for crimping the clip  48  to the support  34 . The opposite end of the clip  48  provides a pair of long tabs  66  each of which is folded back on itself to provide a folded edge  68  and a notch  70  for abutting the T-bar support  24  as will be explained more fully hereinafter. The angle  72  provided by the notch  70  is preferably 90°. The channel  62  resides midway between the tabs  66  so the angle  74  between the channel  62  and the tabs  66  is 135°. 
     As shown best in FIG. 5, the support  34  is not rigidly connected to the supports  24 . Instead, the clip  48  is attached to the support  34  and the folded edges  68  of the tabs  66  simply rest in the corner provided by the intersecting horizontal supports  24 . The importance of the notch  70  should now be apparent. If the clip  48  provided an outwardly protruding point instead of the notch  70 , the point would interfere with the components of the T-bars  24  at their junction. Instead, the notch  70  is recessed so there is no interference between the clip  48  and components of the supports  24  that are at the intersection. In addition, the ends of the overlapping tabs  68  are perpendicular to the vertical legs of the support  34  thereby providing a positive stop. 
     Referring to FIGS. 1 and 6, the supports  35  connect to a the supports  24 ,  32  by the use of clips  84  at a location where an additional horizontal support  37  is located in the flat ceiling area  16 . As shown in FIG. 6, the clips  84  provide a pair of aligned channels  86  for receiving the horizontal cross-bar of the support  24  and a pair of aligned channels  88  perpendicular to the channels  86 . The channels  86 ,  88  are sufficiently wide to receive the cross-bars  28  of the supports  24 ,  35 ,  37  and thus are typically 1″ across and conveniently 1″ long. Each channel  86 ,  88  is bounded by tabs  90 ,  92  which are crimped over the horizontal cross-bar  28  of the supports  24 ,  35 ,  37  and thereby secure the clip  48  and the support  35  to the supports  24 ,  37 . The tabs  90 ,  92  are of any convenient size and typically are ⅜″ tall. It will be seen from FIG. 1 that there is one clip  36  at the top and one clip  84  at the bottom of each inclined support  35 . 
     An important feature of the clips  36 ,  46 ,  48 ,  84  is that they are made of a thin metal, e.g. 30 to 26 gauge, so they may be bent to accommodate any practical angle between the upper supports  32  and the lower supports  24 . For example, in FIG. 5, the clip  46  is bent along a line  94  and the clip  48  is bent along a line  96  to accommodate the angle between the upper and lower horizontal ceiling areas  16 ,  20 . This means that any rectangular or square truncated pyramidal recess can be constructed using only conventional T-bar supports and either the three clips  36 ,  46 ,  48  or including the fourth clip  84  because the clips can be bent to accommodate any practical angle between the upper supports  32  and the lower supports  24 . 
     It will accordingly be seen that the horizontal supports  24  support the horizontal area  20  and the transition area  22  because there are no wires or other means supporting the horizontal supports  32  or the clips  36 ,  46 ,  48  from the overlying support. It will also be seen that the horizontal area  20  receives a ceiling panel which may be of an acoustic type, a lighting fixture, a decorative panel or the like. It will be seen that the grid  12  of the ceiling  10  is supported by a lower set of horizontal supports acting through the tensile members  14  from an overlying member and an upper set of horizontal supports, comprising the periphery of the area  20 , is supported only through the lower set of horizontal supports. 
     Installation of the ceiling  10  should now be apparent. At the job site, the horizontal supports  24  are suspended from the overlying support  15 , leveled, and connected together at their intersections in a conventional manner. On a jig in the shop, a module comprising the grid  31  is prepared by attaching the supports  32  together and securing the inclined supports  33 ,  34  to the supports  32 . The module is transported to the job site and each grid  31  is dropped into the opening which comprises the recess  18 . The lower ends of the inclined supports  33  are attached to the horizontal supports  24  and the lower ends of the inclined supports  34  simply rest on the supports  24  at their intersection. As used herein, the phrase “job site” is used to mean the building where the ceiling of the invention is being installed. The word “shop” is used to mean a location of the contractor rather than the building owner, typically at the place of business of the contractor, and distant from the job site. 
     A great many installations may be constructed with a relatively few clips in accordance with this invention. For example, the ceiling  10  is made with four different clips as shown in FIGS. 2-4 and  6 . 
     Referring to FIGS. 7-10, there is illustrated a ceiling  100  featuring a series of downwardly extending truncated pyramidal projections  102 , rather than upwardly extending pyramidal recesses shown in FIG.  1 . In the ceiling  100 , a gridwork  104  comprises a series of intersecting T-bar supports  106  suspended from an overhead support  107  by wires  108 . The pyramidal projections  102  accordingly each provide a flat area  110  bounded by T-bar supports  112  and a transition area  114  or  116 . 
     The transition areas  114 ,  116  are illustrated to be slightly different for purposes of illustration. The transition area  114  comprises a series of inclined T-bar supports  118  intersecting a mid-point of the T-bar supports  112 ,  106  in a simple three way junction which can be constructed by use of the clip  36  shown in FIG.  2 . Both transition areas  114 ,  116  provide inclined T-bar supports  120  intersecting the supports  112  at the corners of the flat areas  110 . These junctions can be constructed using the three way clip  46  of FIG. 3 in the manner shown in the single pyramid of FIG.  1 . 
     At the intersection  122 , which is characterized by a continuous support  106  along one edge of the intersection, a connector or clip  124  (FIG. 8) secures the supports  106 ,  120  together. The clip  124  comprises a pair of aligned channels  126  for receiving the continuous support  106  and three channels  128 ,  130 ,  132  spaced equidistantly between the channels  126 . Tabs  134  are provided adjacent each of the channels  126 ,  128 ,  130 ,  132  for securing the clip  124  to the supports  106 ,  120 . The channels  128 ,  132  may be bent along imaginary lines  136 ,  138  to accommodate the angle that the inclined support  120  makes with the horizontal. 
     At the intersection  140  where eight supports come together, the clip  142  (FIG. 9) is provided, having eight equidistantly spaced channels  144 . Those channels  144  that receive the horizontal supports  106  remain in the plane of the clip  142  and those channels  144  which receive the inclined supports  120  may be bent along imaginary lines  146  to accommodate the angle. One or more tabs  148  adjacent each channel are crimped onto the horizontal rib of the T-bar supports  106 ,  120 . 
     At the intersections  150  where three supports come together, the clip  46  (FIG. 3) is used to connect the horizontal and inclined supports together. At the intersections  152  where three supports come together, the clip  36  (FIG. 2) is used to connect the horizontal and inclined supports together. 
     In the event the supports  106  were to intersect in a corner of the building, a clip  154  (FIG. 10) is provided. The clip  154  provides channels  156  for receiving the horizontal supports  106  and a channel  158  equidistant between the channels  156  for receiving an inclined support  106 . 
     It will accordingly be seen that the supports  106 ,  120  provide recesses for receiving suitable ceiling panels. It will likewise be seen that the ceiling of FIG. 7 is supported from a upper set of horizontal supports  106  while a lower set of horizontal supports, comprising the periphery of the areas  110 , are unsupported from an overlying member or beam except through the upper supports  106 . The ceiling  100  of FIG. 7 shows two different designs, i.e. the inverted pyramid at the far left is different than the other three inverted pyramids. A ceiling made in the design shown at the far left requires five different clips, i.e. the clips of FIGS. 8-10 plus the clip  36  of FIG.  2  and the clip  46  of FIG. 3. A ceiling made in the design shown in the other three inverted pyramids requires only four different clips, i.e. the clips of FIGS. 8-10 plus the clip  46  of FIG.  3 . 
     Referring to FIG. 11, a suspended ceiling  160  of different configuration is illustrated. The ceiling  160  shows a typical example of a ceiling where the elevation of the ceiling is changed for any number of reasons and comprises an upper ceiling area  162 , a lower ceiling area  164  and a transition zone  166  between the areas  162 ,  164 . The ceiling area  162  comprises a grid of suitable intersecting horizontal supports, such as conventional T-bar supports  168  suspended from an overlying member  169  by wires or straps  170 . Similarly, the ceiling area  164  comprises a grid of suitable intersecting horizontal supports  172  suspended from an overlying member by wires or straps  174 . It will be seen that the periphery of the ceiling area  162  is bounded by continuous supports  178  while the periphery of the lower ceiling area  162  is bounded by continuous supports  180 . The supports  178 ,  180  may be made continuous, of course, by securing pieces end to end. 
     At the intersection  182 , a clip or connector  184  (FIG. 12) is provided to secure the supports together and accordingly provides a pair of channels  186 ,  188  for receiving the supports  178 , a pair of channels  190  for receiving inclined supports  192  and a channel  194  for receiving a diagonal support  196 . One or more tabs  198  adjacent each channel  186 ,  188 ,  190 ,  192  are provided for crimping the channels to the supports. Because of the inclination of the supports  192 ,  196 , the channels  190 ,  192  may be bent along imaginary lines  202  to accommodate the angle. 
     At the intersection  204 , the four way clip  84  (FIG. 6) may be used to connect the continuous supports  178 ,  180  to the inclined supports  192 . Because the upper and lower ceiling areas  160 ,  162  are both supported by the wires  170 ,  174 , there is little force transferred through the transition area  166  except for the weight of the ceiling panels in the transition area. In such circumstances, the upper end of the diagonal support  196  may be provided with a clip  48  (FIG. 4) which simply rests on the flattened face of the clip  84 . 
     It will be seen that the intersection  214  is similar to the intersection at the bottom of FIG. 5 except it is a four way junction rather than a five way junction. Accordingly, the bottom of the diagonal support  196  may be provided with the clip  48  (FIG. 4) and simply abut the intersection of the supports  180  which requires the three way junction clip  36  of FIG.  2 . 
     The intersection  216  will be seen to be identical to other three way intersections. The horizontal supports  178  may accordingly be secured to the inclined supports  192  by the three way clips  36  shown in FIG.  2 . The intersection  218  will be seen to be identical to the bottom of FIG.  5  and may be handled similarly. 
     The intersection  220  is a three way corner with the diagonal support making a 135° angle with each of the supports  178 . Accordingly, the three way connector  46  (FIG. 3) may be used. 
     The ceiling  160  of FIG. 11 shows two different designs, i.e. on the lower right, the downwardly inclined supports  192  align with the horizontal supports  206  while on the upper left, the downwardly inclined supports do not align with the horizontal supports. A ceiling made in the design shown at the lower right requires only four different clips: a five way junction clip  184  for each intersection  182 , a three way junction clip  36  and clip  48  for each intersection  214 , and either a four way junction clip  84  or a two way junction clip  208  for each four way junction. A ceiling made in the design shown at the upper left requires only a few clips: a three way junction clip  46  for each intersection  220 , a four way junction clip  84  and a clip  48  for each intersection  218 , and either a four way junction clip  84  or a two way junction clip  208  for each four way junction. 
     It will accordingly be seen that many different suspended ceiling configurations may be assembled from suitable supports and a modest number of clips of this invention. 
     Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

Summary:
A suspended ceiling provides horizontal areas of different elevation and a transitional area between the horizontal areas. The ceiling comprises a grid of horizontal intersecting supports and panels received by the supports. The transitional area is constructed by inclined supports connected to the horizontal supports by clips of special design. In a situation where three supports converge, a clip is provided having three channels diverging at appropriate angles. In a situation where four supports converge, a clip is provided having four channels diverging at appropriate angles. The clips include tabs which are crimped over the horizontal supports and the inclined supports of the transition area. The clips are of metal and of sufficiently thin gauge so they can be bent to provide the angles necessary in the transition area. An important feature of the invention is the ability to make modules comprising the grid for transition areas on a jig in a shop and transport it to a job site for installation.