Easy cut suspension grid

Abstract

A grid runner for a suspended ceiling having a lower flange extending generally horizontally, a web extending upwardly from the flange, and walls forming a hollow reinforcing bulb at the upper end of the web, the web lying generally in an imaginary vertical plane, a portion of the walls forming the bulb being disposed on and laterally spaced from the imaginary vertical plane, a wall area of the bulb on an upper side of the bulb bridging the space between the bulb walls on opposite sides of the imaginary plane, the bulb having lower wall portions forming its base and configured such that the bulb will readily collapse at the base when a lateral shear force is applied to the bulb walls by a hand-operated snips whereby the force to manually field cut the tee is reduced.

1 . A grid runner for a suspended ceiling having a lower flange extending generally horizontally, a web extending upwardly from the flange, and walls forming a hollow reinforcing bulb at the upper end of the web, the web lying generally in an imaginary vertical plane, a portion of the walls forming the bulb being disposed on and laterally spaced from the imaginary vertical plane, a wall area of the bulb on an upper side of the bulb bridging the space between the bulb walls on opposite sides of the imaginary plane, the bulb having lower wall portions forming its base and configured such that the bulb will readily collapse at the base when a lateral shear force is applied to the bulb walls by a hand-operated snips whereby the force to manually field cut the tee is reduced. 
   
   
       2 . A grid tee as set forth in  claim 1 , wherein said tee is formed of sheet metal stock that is roll-formed. 
   
   
       3 . A grid tee as set forth in  claim 1 , wherein said bulb includes vertical walls that are generally flat. 
   
   
       4 . A grid tee as set forth in  claim 3 , wherein said vertical walls are greater in vertical length than the horizontal width of the bulb. 
   
   
       5 . A grid tee as set forth in  claim 1 , wherein the upper portion of the bulb comprises a generally horizontal wall. 
   
   
       6 . A grid tee as set forth in  claim 1 , wherein said grid tee includes an upper wall that is slanted from the horizontal. 
   
   
       7 . A grid tee as set forth in  claim 1 , wherein said tee includes an upper wall that is peaked at said imaginary mid-plane of said web. 
   
   
       8 . A grid tee as set forth in  claim 7 , wherein said peaked upper wall is concavely creased on opposite sides of said imaginary mid-plane. 
   
   
       9 . A grid tee as set forth in  claim 1 , wherein said reinforcing bulb has lower wall portions on opposite sides of said imaginary plane, said lower walls being creased concavely to provide a structure which is readily collapsible under lateral loads. 
   
   
       10 . A grid tee as set forth in  claim 9 , wherein said lower wall portions merge with sidewall portions of said bulb at one elevation, and merge with the web of the grid tee at an elevation below said first-mentioned elevation. 
   
   
       11 . A grid tee as set forth in  claim 1 , wherein said lower wall portions lie on each side of said imaginary vertical plane, the lower wall portion area on one side of the imaginary plane being generally higher in elevation than the lower wall portion area on the other side of the imaginary plane whereby said lower wall portion areas are vertically offset from one another and the consequent eccentricity of these lower wall portion areas prevents them from strongly supporting each other against lateral compressive forces developed by the blades of the snips.