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CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/896,013, filed Mar. 21, 2007. 

   BACKGROUND 
   The present disclosure is directed to a wall angle that may be advantageously used as part of a suspension grid for either a drywall ceiling or for a suspended ceiling having lay-in or drop-in panels or tiles. In either case, the wall angles have vertical legs by which the wall angles are secured to the wall, and horizontal ledges that support the ends of tee-runners or beams and cross-tees that span the ceiling between opposed walls. When used as part of a drywall suspension system, the lower surfaces of the wall angles and associated beams do not need to be finished, as they are not seen after the drywall is fixed, by screws, to the suspension grid. Such is not the case when the suspension system is used for supporting lay-end ceiling tiles or panels. However, in both cases, it is important to maintain accurate spacing of the grid members, since the drywall and ceiling panels are in regular, rectangular shapes and sizes, typically 48 or 96 inches on center for drywall and 24 inches on center for ceiling tiles. 
   Wall angles having tabs or other structures for positioning and fixing the ends of the beams supported thereon are shown in, e.g., published U.S. patent applications 2006/0010811, 2006/0010812, and 2007/002690, which are incorporated herein by reference. The tabs or other structures shown in these published applications serve to ensure that the beams are properly spaced for their intended application. 
   SUMMARY OF THE DISCLOSURE 
   In one aspect of the disclosure, a wall angle for a suspended ceiling, which may either be a drywall suspended ceiling or a lay-in tile suspended ceiling, has a cross-section forming a substantially right angle of the vertical leg and a horizontal leg. The horizontal leg is adapted to support an inverted tee-runner that has a vertical web and opposed flanges, the opposed flanges being adapted to rest on the horizontal leg of the wall angle. The horizontal leg is formed with a plurality of pairs of locating tabs, at least one tab in each pair being upwardly extending and vertically-oriented. The tabs in each pair are spaced apart a distance sufficient to accommodate the width of the opposed flanges of the tee-runner. At least one of the tabs in each pair has a downwardly extending detent adapted to permit installation of a tee-runner, but to inhibit removal of the tee-runner. The pairs of tabs are spaced, on center, a pre-determined distance that depends upon the intended application of the wall angle. 
   In keeping with another aspect of the disclosure, the detent may comprise either an upper portion of the tabs that is folded downwardly or, alternatively, a lanced-out portion of the tabs. 
   In keeping with another aspect of the disclosure, the wall angle has opposed first and segment end segments that are complementarily-shaped so that when the wall angle is used with a second wall angle in end-to-end relationship, the first end segment of the wall angle mates with the second end segment of the second wall angle to properly position the wall angles relative to each other. This ensures that the locating tabs on adjacent wall angles are properly spaced. In keeping with another aspect of the disclosure, the first end segment is offset from the remainder of the wall angle so as to provide a stop for abutment by the second end segment of the second wall angle. Additionally, and preferably, the first and second end segments have interlocking members, the interlocking members may be complementarily-shaped. 
   In keeping with another aspect of the disclosure, the wall angle may include bendable tabs that help to secure the tee-runner to the wall angle. More specifically, the horizontal leg of the wall angle may have a tab that is foldable back onto one of the flanges of the tee-runner. Additionally, the vertical leg of the wall angle may have a tab that is bendable therefrom and adapted to be secured to the web of the tee-runner. 
   Other features of the disclosure will become apparent upon reference to the following detailed description and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a fragmentary perspective view of a suspension grid for a drywall ceiling or a suspended ceiling in accordance with a first embodiment of the present disclosure. 
       FIG. 2  is a perspective view of the wall angle shown in  FIG. 1 . 
       FIG. 3  is a front view of the wall angle of  FIG. 2 . 
       FIG. 4  is a top view of the wall angle of  FIG. 2 . 
       FIG. 5  is an end view of the wall angle of  FIG. 2 . 
       FIG. 6  is a perspective view of a second embodiment of a wall angle according to the present disclosure. 
       FIG. 7  is a perspective view of a third embodiment of a wall angle according to the present disclosure. 
       FIG. 8  is a perspective view of a fourth embodiment of a wall angle according to the present disclosure. 
       FIG. 9  is a front view of the wall angle of  FIG. 8  in combination with a tee-runner, which is shown in profile. 
       FIG. 10  is a perspective view of a fifth embodiment of a wall angle according to the present disclosure. 
       FIG. 11  is a front view of the wall angle of  FIG. 10  in combination with a tee-runner, which is shown in profile. 
       FIG. 12  is a perspective view of a sixth embodiment of a wall angle according to the present disclosure. 
       FIG. 13  is a front view of the wall angle of  FIG. 12  in combination with a tee-runner, which is shown in profile. 
       FIG. 14  is a perspective view of a seventh embodiment of a wall angle according to the present disclosure. 
       FIG. 15  is a front view of the wall angle of  FIG. 14  in combination of a tee-runner, which is shown in profile. 
       FIG. 16  is a front view of a wall angle having a tab on its vertical leg as an alternative to that shown in  FIG. 14 . 
       FIG. 17  is an end view of the wall angle of  FIG. 16 . 
       FIG. 18  is a fragmentary perspective view of the inter-connecting ends of wall angles in accordance with the present disclosure showing two alternatives for one of the ends. 
       FIG. 19  is a first alternative to the inter-connecting ends shown in  FIG. 18 . 
       FIG. 20  is a second alternative to the inter-connecting ends shown in  FIG. 18 . 
       FIG. 21  is a third alternative to the inter-connecting ends shown in  FIG. 18 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Turning to  FIG. 1 , there is seen a suspension grid system, generally designated  10 , using a wall angle, generally designated  12 , in accordance with the present disclosure. In a typical installation, a pair of wall angles  12  are secured to opposed walls  14  through their vertical legs  16  by e.g. screws  18 , although nails, staples, and/or adhesives may also be used for this purpose. The horizontal legs or ledges  20  of the wall angles  12  support the ends of the beams or tees  22 . If the grid is used in a drywall ceiling, the drywall sheets (not shown) are secured directly to the bottom sides of the horizontal flanges  24  of the beams  22  by screws. If the grid is used for a suspended ceiling, the top sides of flanges  24  and the horizontal legs  20  of the wall angle support the edges of lay-in tiles or panels (also not shown). The wall angles described herein may be used with either a dry wall suspended ceiling or a lay-in panel suspended ceiling, without departing from the disclosure. 
   In keeping with one aspect of the disclosure, the horizontal legs  20  of the drywall angles  12  are provided with pairs of regularly spaced tabs for locating and securing the beams  22  to the wall angles  12 . To this end, and with reference to  FIGS. 1-5 , a first embodiment of a wall angle  12  according to the present disclosure is shown. The wall angle  12  has a pair of tabs  26  lanced or punched from the horizontal ledge  20  of the wall angle  12 . Both of the tabs  12  extend in a substantially vertical direction from the horizontal ledge. In the case of a wall angle for use with a dry wall grid suspension system, the pairs of tabs are preferably spaced 8 inches on center along the length of the wall angle, while the pairs of tabs are preferably spaced 24 inches on center along the length of the wall angle in the case of a wall angle for use in a drop-in tile-grid suspension system. In the embodiment of  FIGS. 1-5 , the tabs  26  are punched from the horizontal ledge  20  of the wall angle  12  so that the holes in the ledge  20  created thereby are outside of the space between the tabs  26 . However, the tabs  26  could be punched from the ledge  20  so that the holes created thereby are between the tabs  28 , as shown in  FIG. 6 , without departing from the disclosure. 
   The tabs  12  in each pair are spaced apart a distance sufficient to accommodate the width of the flanges  24  of an associated runner, and are preferably spaced apart a distance approximately equal to the width of the flanges  24  so that an associated runner  22  may be located between the tabs by moving it downwardly in a substantially vertical direction. 
   In order to prevent the runners  22  from being displaced from the wall angles  12  by an upwardly vertically-directed force, the tabs  26  include downwardly-directed detents  28  which allow the beams to be located between the tabs in a vertically downward motion, but prevent removal by a vertically upward motion. Preferably, the detents  28  engage the top sides of the flanges  24  of the beam  20  to provide for a more positive restraint against upward movement of the beam relative to the wall angle. As shown in  FIGS. 1-5 , the detents  28  may be lanced or punched from the central portion of the tabs  26  so as to extend downwardly from the upper portion of the tabs  26 . Alternatively, the detents  28  may be formed simply by bending downwardly the top portion of the tabs  26 , as shown in the embodiment of  FIG. 7 , without departing from the disclosure. 
   When used in a suspended ceiling grid for drop-in tiles, the tabs  26  are preferably sized in width so that when they are punched from the horizontal leg of the wall angle, they do not extend out from vertical leg a distance that would cause them to interfere with the drop-in ceiling panels. 
   Turning to  FIG. 8 , an alternate embodiment of a wall angle  30  according to the present disclosure as shown. Like the earlier described embodiments, the wall angle  30  includes spaced pairs of locating tabs  32 ,  34  lanced or punched from the horizontal ledge  36  of the wall angle  30 . The tab  32  extends generally upwardly from the horizontal ledge  36  and, as best seen in  FIG. 9 , serves to locate an edge of the flange  24  of a beam  22  to maintain the desired spacing of the beams. Tab  34  extends generally horizontally toward tab  32 , and may be formed with an embossment  38  for additional structural integrity. 
   With reference to  FIG. 9 , a beam is mounted to a wall angle  30  by first sliding one flange of the beam under the tab  34  and moving the beam laterally toward the tab  34  until the edge of the other flange clears the tab  32  and both flanges are supported directly upon the flat portion of the horizontal ledge  36  of the wall angle  30 . The runner is then moved laterally back toward the tab  32  until the edge of the flange abuts the tab  32 . Optionally, the tab  34  may include a downwardly projecting detent  39  that engages the edge of a hem on the flange to prevent inadvertent dislocation of the beam  22  relative to the wall angle  30  should the beam  22  become subjected to a clockwise rotational force (when viewed in  FIG. 9 ). 
   As noted above, when the wall angle of the present disclosure is used as part of a suspended ceiling grid, the bottom surface of the horizontal ledge remains visible after installation. In order to provide the lower surface of the horizontal ledge with a continuous surface, which may be more esthetically pleasing, the wall angle may have a cap  40  applied thereto as shown in  FIG. 8 . A longitudinal grove  42  is formed at the base of the vertical leg  44  to provide a securing surface for one edge of the cap  40 , the other edge being folded over the edge of the horizontal edge  36  in a standard hem  46 , all of which may be accomplished in a standard roll-forming operation. 
   Turning to  FIG. 10 , there is seen a further alternative embodiment of a wall angle according to the present disclosure that is a modification of the embodiment of  FIGS. 8 and 9 . As such, the same reference numerals will be used with respect to the  FIG. 10  embodiment, as well as the other illustrated embodiments, when referring to structures that correspond to those shown in  FIGS. 8 and 9 . 
   In the  FIG. 10  embodiment, the wall angle  30  includes an additional tab  48  punched from the horizontal ledge  36 . This tab  48  is bendable by a grid installer approximately 180° so as to lie against the flange  24  of a beam  22  whose edge is located by the vertical tab  32 , thus more securely locating the beam relative to the wall angle. See  FIG. 11 . The tab  48  may be formed so that its free end is displaced slightly upwardly from the plane defined by the horizontal ledge  36  to make it easier for the installer to grasp the tab for bending. The end  50  of the tab  48  may also be formed with a generally concave shape for the same reason. 
     FIGS. 12 and 13  show a further embodiment of a wall angle  30  according to the present disclosure that is also similar to the embodiment of  FIGS. 8 and 9  with respect to the tab  34 . However, in place of the tab  32 , the wall angle  30  of  FIGS. 12 and 13  includes a second tab  52  lanced from the horizontal ledge  36  of the wall angle  30 . This second tab  52  has a free end  54  displaced upwardly from the horizontal plane defined by the horizontal ledge for engaging the edge of one of the flanges  24  to locate the beam  22 . The other tab  34  holds the beam  22  in place. Preferably, the free end  54  of the tab  52  is bent downwardly to provide a larger surface for engagement with the edge of the flange. 
   Under certain circumstances, there may be a need to provide for a more secure attachment of the grid system to the wall angle. One such circumstance is where the suspension system is being installed in a region where seismic activity is relatively common. Securing the perimeter of the grid system to the wall angle helps to ensure that the suspended ceiling will not collapse during a seismic event due to the ends of the beams being displaced laterally off of the horizontal ledge of the wall angle. To this end, the vertical leg  44  of the wall angle  30  also preferably includes a “seismic” tab  56  that, after the runner is positioned relative to the wall angle by the tabs on the horizontal ledge  36  is bent outwardly from the vertical leg  44  of the wall angle so as to lie alongside the vertical web of the runner. The tab  56  includes an aperture  57  that serves as a pilot hole for receiving a screw or pop rivet (not shown), thus providing a positive attachment of the runner to the wall angle. 
     FIGS. 14 and 15  show a further embodiment of a wall angle in accordance with the present disclosure that combines opposed pairs of locking tabs  48 , similar to the  FIG. 10  embodiment, with the seismic tab  56  as shown in  FIG. 12 . 
     FIGS. 16 and 17  show a further embodiment of a wall angle according to the present disclosure that is similar to that shown in  FIGS. 14 and 15  in that the horizontal ledge includes the vertical locating tabs  32  and the vertical leg includes a seismic tab  56 . However, the seismic tab  56  is lanced from the vertical leg so that the hinge line formed between the tab and the vertical leg when the tab is folded out is at an angle relative to vertical (best seen in  FIG. 16 ). As seen in  FIG. 17 , the angled hinge line results in the free end  58  of the tab  56  extending at an angle downwardly toward the horizontal ledge when the tab  56  is bent outwardly so that it closely lies over one of the flanges of the beam and inhibits upward movement of the beam relative to the wall angle. The tab  56  also includes a slot  60  for receiving a screw/rivet (not shown) that secures the tab  56  to the vertical web of the beam  22 . The slot  60  permits limited movement of the grid toward and away from the wall angle, while the grid is still positively affixed thereto. 
   As can be appreciated, if the grid system extends more than the length of a single wall angle, care must be taken in locating the second wall angle to ensure that the proper center-to-center spacing of the pairs of locating tabs is maintained. To this end, another aspect of the present disclosure is providing the wall angle with complementarily-shaped and, preferably, interlocking end segments. 
   With respect to  FIG. 18 , a wall angle  70 A in accordance with the present disclosure has locating tabs  26 , as shown and described in connection with  FIGS. 1-5 . As can be appreciated, however, the locating tabs could take any of the other forms discussed above. The wall angle  70 A includes first end  72  that is formed so that the vertical and horizontal components of the wall angle are displaced or swaged inwardly and upwardly, respectively, relative to the vertical and horizontal components of the remainder of the wall angle. Assuming that the wall angle  70 A is first secured in place, the complementarily-shaped end  74  of a second wall angle  70 B is slid past the displaced end until its end  75  abuts the shoulder  76  that defines the transition between the end segment  72  and the remainder of the wall angle  70 A. This abutting contact ensures that the proper center-to-center spacing of the pairs of locating tabs from one wall angle to the next is maintained. 
   In keeping with another aspect of the disclosure, the end segments of the wall angle are provided with complementary interlocking members to secure the adjacent wall angles to each other. With reference again to  FIG. 18 , the end  72  of the wall angle  70 A is formed with a protrusion  78  lanced from the horizontal ledge of the wall angle so as to extend upwardly therefrom. The mating end segment  74  on wall angle  70 B is formed with a tab  80  that slides over the protrusion  78  and includes an aperture  82  sized to receive and capture the protrusion  78 . Disconnecting the end segment  74  from the end segment  72  requires deflection of the tab  80  to release the protrusion  78 . The horizontal ledge of the end  74  also includes two apertures  84  that serve as pilot holes for receiving fasteners, such as screws, in order to provide a more permanent attachment of adjacent wall angles to each other, while the vertical leg of the end  72  includes two apertures  85  that serve as pilot holes for fasteners that both secure the ends  72 ,  74  to each other and the wall angles  70 A,  70 B to the wall. 
   Variations on the interfitting and interlocking structures on the wall angle ends are contemplated and can take any of a number of different forms, all well within the capabilities of a person skilled in the art. For example, with reference to  FIG. 18 , the tab  80  on the second end segment  74  of wall angle  70 C may be formed so that a cover  86  overlies the aperture. With reference to  FIG. 19 , one end segment  74  can be formed with an elongated tongue  88  formed on one or both of the vertical and horizontal legs of the wall angle (both, in the illustrated embodiment), with the complementary end  72  being formed with a slot  90  for receiving each of the tongues  88 . With reference to  FIG. 20 , one end  72  can be formed with one or more tongues  92  that are received in slotted, raised segments  94 , through which each of the tongues extends when the ends are connected. The tongue  92  is preferably formed with a detent  96  that prevents withdrawal of the tongue  94  from the slotted, raised segment  94  after interconnection of the wall angles. The base of the tongue  92  may also be provided with one or more embossments  98  to further stiffen the tongue.  FIG. 21  discloses an embodiment functionally similar to that in  FIG. 18 , except that the protrusion  78  is differently shaped, as is the corresponding aperture  82  and the tab  80 . The tab  80  further includes stiffening embossments  98 . 
   While the wall angle has been described in terms of certain specific embodiments, there is no intention to limit the invention to the same. Instead, the invention is defined by the scope of the following claims.

Summary:
A wall angle for a suspended ceiling, which may either be a drywall suspended ceiling or a lay-in tile suspended ceiling, has a cross-section forming a substantially right angle of the vertical leg and a horizontal leg. The horizontal leg is adapted to support an inverted tee-runner that has a vertical web and opposed flanges, the opposed flanges being adapted to rest on the horizontal leg of the wall angle. The horizontal leg is formed with a plurality of pairs of locating tabs, at least one tab in each pair being upwardly extending and vertically-oriented. The tabs in each pair are spaced apart a distance sufficient to accommodate the width of the opposed flanges of the tee-runner. At least one of the tabs in each pair has a downwardly extending detent adapted to permit installation of a tee-runner, but to inhibit removal of the tee-runner. The pairs of tabs are spaced, on center, a pre-determined distance that depends upon the intended application of the wall angle.