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CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of a prior filed, co-pending provisional application Ser. No. 60/958,508, filed Jul. 6, 2007, entitled CURB-MOUNTED SCREEN FOR ROOFTOP EQUIPMENT. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a screen for an air conditioner or other equipment mounted on the roof of a building and supported by an upstanding curb. 
       BACKGROUND OF THE INVENTION 
       [0003]    Air conditioning units and other mechanical equipment are often located on the roof of commercial buildings and other non-residential structures above an opening in the roof through which the necessary mechanical and electrical connections are made. The unit is typically supported on a rectangular curb in register with the opening that projects upwardly from the rooftop and provides the base upon which the unit is supported. However, it is often desired that air conditioners or other curb-mounted mechanical structures, otherwise in plain view, be screened for aesthetic purposes to provide the building with a more pleasing appearance. 
         [0004]    A typical rooftop screen for this purpose is in the form of a rectangular fence, open at the top, preferably having an architecturally pleasing appearance and surrounding the equipment to conceal it from view. The screen is typically attached to the roof or the air conditioning unit. This adds to the cost and labor of installation. Furthermore, if the screen is attached to the unit there is a risk that the installers will insert screws or other fasteners into (Docket 4171) the casing of the unit that could cause damage and possible malfunction of the equipment. An alternative in the prior art is to mount the screen on the roof but with accompanying installation expense. 
       SUMMARY OF THE INVENTION 
       [0005]    In an embodiment of the present invention the aforementioned problem is addressed by providing a screen for rooftop equipment which is mounted on the curb provided on the roof to support the equipment. Horizontal support members of the screen assembly are provided with fasteners that hook over the roof curb to thereby support the screen without attachment to either the equipment on the curb or the underlying roof. 
         [0006]    In another aspect of the invention, the horizontal support members of the screen assembly are provided with spaced fasteners comprising hook-shaped clips engaging the upper edges of the curb and hooked thereover to mount the support members exclusively on the curb without attachment to the underlying roof or the equipment thereon. 
         [0007]    Other advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a building provided with an equipment screen according to the present invention. 
           [0009]      FIG. 2  is an isometric view showing the screen of the present invention mounted on a roof curb and circumscribing an air conditioning unit, panels of the screen in the foreground being removed to reveal the interior construction. 
           [0010]      FIG. 3  is an isometric view similar to  FIG. 2  but with the air conditioning unit removed to reveal the roof curb and screen construction. 
           [0011]      FIG. 4  is an exploded, detail view showing a support rail of the screen assembly and accompanying clips before installation on the roof curb (shown fragmentarily). 
           [0012]      FIG. 5  is a view similar to  FIG. 4  but from the opposite side, showing the support rail installed with the clips hooked over the upper edge of the roof curb. 
           [0013]      FIG. 6  is a fragmentary, elevational detail view showing the support rail installed on one side of the roof curb. 
           [0014]      FIG. 7  is an enlarged, vertical cross-sectional view of a wall of the roof curb showing a support rail and an associated clip hooked over the upper edge of the curb. 
           [0015]      FIG. 8  is a simplified, plan view of the screen shown in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring initially to  FIGS. 1 and 2 , a flat or substantially flat roof  10  of a commercial building presents an essentially horizontal supporting surface from which an upstanding, rectangular curb  12  projects. As will be discussed more fully hereinbelow, the curb  12  extends upwardly from the edges of a rectangular opening  14  in roof  10  revealed in  FIGS. 3 and 8 . Roof-mounted mechanical equipment, illustrated herein by an air conditioning unit  16 , is shown installed on the curb  12  in  FIG. 2  in the usual manner in order to communicate with the ductwork within the building. The curb  12  has four vertical walls  18   a ,  18   b ,  18   c  &amp;  18   d  (see  FIG. 8 ) defining a rectangular configuration in register with the opening  14  thereby presenting an open central area beneath the air conditioning unit  16  for receiving the ductwork and electrical conduits (not shown) connected to the AC unit  16  in the usual manner to permit operation of the unit  16  at the rooftop location. As seen in  FIG. 3  where the unit  16  is removed, horizontal upper edges  20  of the respective curb walls  18   a - d  lie in a common horizontal plane and thereby define a rim of the curb  12  upon which the unit  16  is mounted. 
         [0017]    A rooftop screen  22  is shown in  FIGS. 1-3  and  8  surrounding the curb  12  and, as shown in  FIG. 1 , completely conceals the unit  16  from view at elevations beneath the roof  10 . As is typical, the screen  22  has a rectangular configuration and thus presents four walls, each of which is defined by spaced, upper and lower horizontal frame members  24  and  26  and four corner posts  28  thereby defining the four walls of the screen  22 . In the particular screen  22  illustrated in  FIGS. 1 and 2 , the four vertical wall frames defined by frame members  24 ,  26  and corner posts  28  support a series of elongated, vertical panels  30  arranged side-by-side in each of the wall frames to screen the unit  16  from view. These wall panels  30  may be finished in an architecturally pleasing style as is conventional, and may be removable to provide access to the unit when necessary for maintenance or repairs. In  FIGS. 2 and 3  a number of the panels are removed from the frames in the foreground to reveal details of construction discussed above and to be set forth below. 
         [0018]    The screen  22  is secured to the curb  12  without the use of fasteners that engage either the roof  10  or any part of the unit  16 . As seen in  FIGS. 2 ,  3  and  8 , a pair of horizontal support rails  32  and  34  extend horizontally along two opposed sides of the rectangular curb  12 . Each of the support rails  32 ,  34  extends across the screen  22  from a lower frame member  36  in the foreground of  FIGS. 2 and 3  to a parallel, lower frame member  38  at the rear, both of which are rigidly secured to the parallel members  26  of the lower frame. Three spaced fasteners  40  secure the support rail  32  to one side of the curb  12  and three additional fasteners  40  secure support rail  34  to the opposite side of curb  12 . Although two rails  32  and  34  are shown, it should be understood that support rails on three or all four sides of the curb  12  may be employed in a particular application if desired. Furthermore, the configuration of the screen  22  may be other than rectangular, and other wall configurations (such as a three-wall screen) may be employed as required to provide the desired screening. 
         [0019]    The manner of securing the support rails  32  and  34  to the curb  12  is shown in detail in  FIGS. 4-7 . Although other materials may be used, the rectangular curb  12  illustrated herein is formed from galvanized steel sheet (such as 14 gauge) which presents the four walls  18   a ,  18   b ,  18   c  and  18   d . Wall  18   b  is shown in detail in the vertical cross-section of  FIG. 7 . Wall  18   b  is exemplary and is provided with an integral base flange  42   b  overlying the corresponding edge of the opening  14  ( FIGS. 2 and 3 ). The other walls  18   a ,  18   c  and  18   d  are likewise provided with base flanges that rest on roof  10  at the margin of opening  14 . Flange  42   a , for example, is shown in  FIGS. 2 ,  3  and  8 . 
         [0020]    Referring to  FIG. 4 , three spaced clips  40  are shown secured to support rail  32  and, in  FIG. 5 , are shown in place on curb wall  18   b . Details are revealed in  FIG. 7 , each clip  40  being generally hook-shaped and extending upwardly from support rail  32  and over the upper edge of wall  18   b  (or  18   d ) of roof curb  12  and terminating in a downturned lip  46 . Steel clips may be utilized and welded to the support rail or, as illustrated, secured by screws  41 . As may be appreciated in  FIGS. 4 ,  5  and  7 , the upper edge  44  of the wall  18   b  presents an inverted U-shaped configuration thereby presenting a flat surface over which clips  40  are installed. If desired, each support clip  40  may be secured in its installed position by a screw  47  through the downturned lip  46  of clip  40  and wall  18   b.    
         [0021]    As shown in  FIGS. 3 and 8 , three support clips  40  are used on two opposed sides of the roof curb  12  to secure the screen  22 . Three clips  40  are secured to support rail  34  in the same manner to mount rail  34  on curb wall  18   d . This is an example only and additional clips may be employed as necessary depending upon the particular installation. A wood strip  50  seen in  FIGS. 4 ,  5  and  7  provides a nailer for roofing material (not shown) surrounding the opening  14 . 
         [0022]    The support clips  40  are employed exclusively as the means of securing the support rails  32  and  34  on the curb  12  and thereby mounting the screen  22  at the rooftop location. As the support clips hook over the upper edge of the roof curb, there is no attachment to the underlying roof  10  or the AC unit  16 . Though shown and described in a screen application for unit  16 , it will be appreciated that the curb-mounted screen of the present invention may also be advantageously utilized with other curb-mounted rooftop equipment. 
         [0023]    It should be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims.

Summary:
A curb-mounted screen for roof-top equipment has wall structure spaced outwardly from the curb for concealing the equipment from view. Fasteners secured to generally horizontally extending support members are hooked over the curb to secure the screen thereto without attaching the screen to the underlying roof or the equipment thereon.