Cornerbead structure

Abstract

A cornerbead for installation at a drywall outside corner includes a substrate forming a nose and first and second elongated flanges. Each flange has an inner edge and an opposing outer edge and joins an opposing side of the nose at the flange's respective inner edge. The outer edge of each flange is uneven.

1 . A cornerbead for installation at a drywall outside corner, the cornerbead comprising a substrate forming a nose and first and second elongated flanges, each flange having an exterior surface and an interior surface and having an inner edge and an opposing outer edge, each flange joining an opposing side of the nose at the flange's respective inner edge, and wherein the outer edge of each flange is uneven. 
     
     
         2 . A cornerbead according to  claim 1 , further comprising an adhesive at the interior surface of the first flange, whereby upon placing the cornerbead at a drywall outside corner the adhesive attaches the cornerbead to the drywall. 
     
     
         3 . A cornerbead according to  claim 1 , further comprising a pressure-sensitive adhesive at the interior surfaces of the first and second flanges, whereby upon placing the cornerbead at a drywall outside corner the adhesive attaches the cornerbead to the drywall. 
     
     
         4 . A cornerbead according to  claim 1 , wherein the outer edge of each flange is formed with a plurality of notches spaced apart evenly therealong. 
     
     
         5 . A cornerbead according to  claim 1 , wherein the outer edge of each flange is formed with a plurality of notches spaced apart therealong, the notches each being up to about ⅛ inch deep and up to about ⅛ inch across. 
     
     
         6 . A cornerbead according to  claim 1 , wherein the outer edge of each flange is formed with a plurality of notches, wherein the notches are at a spacing of at least about ⅛ inch along the outer edge of the flange. 
     
     
         7 . A cornerbead according to  claim 1 , wherein the outer edge of each flange is formed with a plurality of notches spaced apart therealong, the notches each being at least about 1/16 inch deep and at least about 1/16 inch across. 
     
     
         8 . A cornerbead according to  claim 1 , wherein the first flange is formed with holes penetrating from the exterior surface to the interior surface. 
     
     
         9 . A cornerbead according to  claim 8 , wherein the first flange is formed with a plurality of rows of holes, the rows of holes extending lengthwise of the first flange. 
     
     
         10 . A cornerbead according to  claim 8 , wherein the aggregate area of holes per unit area of flange is greater toward the outer edge of the first flange than toward the inner edge of the first flange. 
     
     
         11 . A cornerbead according to  claim 1 , wherein the first flange is formed at its interior surface with projections that space the interior surface from the drywall structure when the cornerbead is installed. 
     
     
         12 . A cornerbead according to  claim 1 , wherein the first flange is formed at its interior surface with a plurality of ribs extending lengthwise of the flange. 
     
     
         13 . A cornerbead according to  claim 11 , wherein the first flange is formed with a plurality of rows of holes, the rows of holes extending lengthwise of the flange and being aligned with respective ribs whereby the holes interrupt the ribs. 
     
     
         14 . A cornerbead for installation at a drywall outside corner, the cornerbead comprising:
 a substrate forming a nose and first and second elongated flanges, each flange having an exterior surface and an interior surface and having an inner edge and an opposing outer edge, each flange joining an opposing side of the nose at the flange's respective inner edge, and the first flange being formed with holes penetrating from the exterior surface to the interior surface,   and wherein the outer edge of each flange is sufficiently uneven that in the event that after installation of the cornerbead the nose of the cornerbead should be struck sufficiently hard to form a crack in hardened drywall compound at the outer edge of the flange, propagation of the crack along the outer edge of the flange is substantially avoided.   
     
     
         15 . A cornerbead according to  claim 14 , wherein the first flange is formed with holes penetrating from the exterior surface to the interior surface, and the aggregate area of holes per unit area of flange is greater toward the outer edge of the first flange than toward the inner edge of the first flange. 
     
     
         16 . A cornerbead according to  claim 14 , wherein the first flange is formed at its interior surface with a plurality of ribs extending lengthwise of the flange and the first flange is formed with a plurality of rows of holes, the rows of holes extending lengthwise of the flange and being aligned with the ribs whereby the holes interrupt the ribs.