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[0001]    The invention relates to accessories for suspended ceiling grid construction and, in particular, to a seismic clip for stabilizing the grid members. 
       PRIOR ART 
       [0002]    U.S. Pat. Nos. 5,046,294; 7,293,393; and 7,552,567 are examples of seismic clips used to limit movement of the ends of grid tee members at the perimeter of a suspended ceiling grid. There remains a need for an improved seismic clip that, while being economical, is both versatile and easy in installation and rugged in its construction. In particular, the clip should be capable of being both snapped over a grid tee and slipped onto the grid tee end to satisfy the installer&#39;s preference or need. The installation of an individual clip should not require a high assembly force or complicated manipulation since a typical job will require the assembly of a clip and tee to be repeated numerous times. 
       SUMMARY OF THE INVENTION 
       [0003]    The invention provides a seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The disclosed clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled. More specifically, a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. As a related added benefit, the alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a perspective view of the seismic clip of the invention installed on the end of a grid tee and a wall angle; 
           [0005]      FIG. 2  is a side elevational view of the seismic clip, grid tee and wall angle assembly; 
           [0006]      FIG. 3  is a front elevational view of the seismic clip; 
           [0007]      FIG. 4  is a right side elevational view of the seismic clip; 
           [0008]      FIG. 5  is a left side elevational view of the seismic clip; 
           [0009]      FIG. 6  is a top view of the seismic clip; 
           [0010]      FIG. 7  is a side view of the prior art. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0011]    Referring now to the drawings, a seismic clip is used to tie or anchor a grid tee  11  to a wall angle  12 . The illustrated wall angle  12  is of a conventional construction being roll-formed sheet metal typically 10′ or 12′ long (or metric equivalent) and having perpendicular legs  13  of, normally, ⅞″ (or metric equivalent) width. The free edges of the legs  13  are folded back to form stiffening hems  14 . As is conventional, a vertical leg  13  of the wall angle  12  is attached to a wall  16  with screws, nails, staples, or the like at ceiling level. 
         [0012]    The illustrated grid tee  11  can be a main tee or a cross tee, these terms being commonly understood in the industry. Relatively long main tees are assembled with shorter cross tees to make up a suspended grid for supporting rectangular ceiling panels. A conventional tee  11  has a lower flange  17 , a vertical stem or web  18 , and an upper reinforcing or stiffening hollow bulb  19  usually rectangular in form and nominally ¼″ (or metric equivalent) in width. 
         [0013]    The seismic clip  10  is preferably a unitary stamping made of suitable metal such as 0.028″ hot dipped galvanized (H.D.G.) sheet steel. The geometry of the seismic clip  10  is described with reference to its installed orientation. 
         [0014]    In plan view, shown in  FIG. 6 , the clip  10  has a generally T-shaped configuration. The clip  10  is essentially symmetrical about a central vertical plane that when installed on a tee  11 , coincides with the plane of the web  18  of the tee. The clip  10  includes a pair of coplanar wings  21  that are perpendicular to and extend in opposite directions away from the central plane of symmetry. In an elevational view, shown in  FIG. 3 , the wings  21  are generally rectangular. Tabs  22  that serve as hooks are lanced or stamped from the central areas of the wings  21 . The tabs  22  remain connected to the wings  21  at their upper regions  23  and lie in generally vertical planes, but preferably diverging from the plane of the wings at about  5  degrees, spaced slightly behind the plane of the wings. At the distal upper corners of the wings  21  are holes  24  for receiving screws or nails to fasten the clip  10  to a wall  16 . At the distal lower corners of the wings are similar holes  26  and, optionally concentric small circular embossments or standoffs that assist in keeping the clip in alignment with the planes of the wall  16  and ceiling by accounting for the thickness of the hems  14 . 
         [0015]    A central section or saddle  31  of the clip  10 , forming the stem section of the T-shape of the clip seen in plan view, is proportioned to fit over the bulb  19  and web  18  of the end of a grid tee  11 . The saddle  31  is a double wall structure; the walls, designated  32 ,  33 , are in parallel vertical planes. The walls  32 ,  33  are spaced apart by an upper web  34 . The web  34  is preferably dimensioned to closely fit the walls  32 ,  33  on the sides of the grid tee bulb  19 . 
         [0016]    Below their bulb engaging areas, the saddle walls  32 ,  33  are arranged to be spaced from the web  18  of the grid tee  11 . An elongated horizontal slot or opening  36  is formed in each saddle wall  32 ,  33  so that the slots oppose one another. Above the slot  36  on each wall  32 ,  33  are a pair of holes  37 . Adjacent a forward end or edge  38  of each wall, a tab  39  of trapezoidal shape is bent inwardly from a line or base  41  of attachment with the main body of the respective wall. In its free state, each tab  39  has an upper free or distal horizontal edge  42  configured, when assembled with a tee to extend beneath the bulb  19  and be spaced slightly from the tee web  18 . 
         [0017]    On the right saddle wall  32  there is stamped or lanced a tab  43 . The tab  43  is angled inward and upward from a line or base  44  of attachment with the wall proper. The tab profile is that of a polygon with a forward edge  46  that angles rearwardly and upwardly from its base  44 , an upper horizontal free edge  47 , and a rearward edge  48  perpendicular to its base. Ideally, the tab  43  is similar to the leading tab  39  such that these tabs lie in a common plane and their respective bases  41 ,  44  and upper edges  42 ,  47  lie along common lines. 
         [0018]    The clip  10  can, at the option of the installer, be assembled on the end of a grid tee  11  by either snapping it over the top of the bulb  19  or by sliding the tee and clip relative to one another in the longitudinal direction of the tee. A line  51  is embossed in the left saddle wall  33  to mark a distance of ¾″ from the plane of the wings  21  to be used as a gauge for the installer where a building code requires the grid tee to be installed not closer than this dimension from the vertical leg  13  of the wall angle  12 . The clip  10  is assembled on a wall angle by lowering it onto the vertical leg  13  with the hooks or tabs  22  behind the leg and the main clip body in front of the leg. This can be done before or after the clip is assembled with the tee. 
         [0019]    The front or leading tabs  39  on the saddle walls  32 ,  33  facilitate assembly of the clip onto the tee where the tee is inserted longitudinally into the clip. The leading edges of the tabs  39  guide the grid tee web  18  towards the center of the clip without impeding relative longitudinal motion. The free edges  42  of the tabs  39  are spaced only a limited distance greater than the thickness of the web  18 , so that the bulb  19  is roughly centered before the bulb engages the saddle  31 . 
         [0020]    The lanced tab  43  serves to align the tee  11  and clip  10  so that the clip is restrained from tilting excessively upwardly. This is accomplished by the lanced tab  43  engaging the underside of the reinforcing bulb  19  with its upper edge  47 . The lanced tab  43  can be proportioned to allow some tilt between the clip  10  and tee  11  for ease of assembly and compatibility with various sized reinforcing bulbs. Such tilting is restricted so that where the clip  10  is positioned on the end of the grid tee  11  prior to positioning of the clip onto the wall angle  12 , the tilt is not severe enough to prevent the tabs or hooks  22  from contacting the wall and slipping behind the wall angle  12 . Reference is made to  FIG. 7  where a prior art clip is seen to be free to tilt on a grid tee, pivoting about a point  56  of a tab. It will be seen in this figure that the lower edges of the clip wings can strike the upper edge of a wall angle  12  and prevent the hooks of such prior art design from slipping behind the vertical leg  13  of the wall angle  12 . The lanced tab  43  of the present invention can prevent this excessive tilting of the clip  10  thereby facilitating rapid assembly of the clip to the wall angle. Moreover, under seismic conditions, when a cross tee slips outwardly off the wall angle and gravity pulls down on the cross tee to prior art clip assembly, some damage may occur with loosening of the friction fit of the clip to the wall angle and tilting of the clip may occur. With the prior art clip under severe conditions excessive tilting may occur (similar to the showing in  FIG. 7 ) and contribute to tile fall out. The lanced tab  43  of the invention wedges the bulb  19  between the lower side of the saddle  31  and the upper edge  47  of the tab  43  thus preventing this excessive tilting. 
         [0021]    The clip  10  can be secured to the wall  16  after it is properly located on the wall angle with screws or nails in some or all of the wing holes  24 ,  26 . Depending on the applicable building code, self-drilling screws can be driven into the reinforcing bulb  19  through the holes  37  that abut the sides of the bulb  19  to lock the clip  10  and tee  11  against relative movement. In other cases where limited movement between the clip  10  and tee  11  is desired, a self-drilling screw can be located at the center of the slot  36  and driven into the tee web  18 . 
         [0022]    It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.

Summary:
A seismic clip for suspended ceiling grid tees that offers high strength, rigidity, versatility and ease of assembly while improving the ability of a clip to self-align with a grid tee. The clip includes a lanced tab that serves to establish and maintain alignment of the clip body and the tee to which it is assembled whereby a tendency of a clip to be tilted upwardly relative to the tee is eliminated or greatly reduced. The alignment tab serves to initially align the clip and tee either when it is assembled by snapping it over the tee or by sliding the tee endwise into the clip. The tab is configured so that it does not unduly add to the assembly force level when the clip is snapped over the tee or when the tee and clip are slipped endwise together.