Gasket and mandrel assembly for pipe joints

Abstract

A gasket and mandrel assembly, including a gasket having an annular main body portion with an anchor flange and a pipe sealing portion. The gasket is foldable between a folded position in which the pipe sealing portion is disposed substantially within the main body portion and an unfolded position in which the pipe sealing portion extends outwardly of the main body portion along its longitudinal axis. A pair of mandrels are respectively fitted on opposite sides of the folded gasket to enclose most of the gasket for casting the gasket within a wall in a concrete structure. At least one of the mandrels includes an annular outer surface aligned parallel or substantially parallel with the longitudinal axis of the gasket. Removal of the mandrels results in the cast opening in the concrete structure having a circular inner surface which is disposed parallel or substantially parallel to the longitudinal axis of the gasket and the resulting opening such that, if the gasket should fail, the gasket may be removed from the opening and an expansion-type gasket may be sealingly compressed against the opening surface with an expansion band assembly.

1 . A gasket and mandrel assembly, comprising:
 a gasket, comprising:
 an annular main body portion; 
 an anchor flange extending radially outwardly from said main body portion; 
 a pipe sealing portion extending from said main body portion, said pipe sealing portion positionable in a folded condition in which said pipe sealing portion is disposed at least partially within said main body portion; and 
   a mandrel assembly having a longitudinal axis, comprising:
 a first mandrel including at least one annular outer surface disposed at an angle of between 0.5° and 7° with respect to said longitudinal axis; and 
 a second mandrel made at least in part of a resilient material, said first and second mandrels cooperable with one another to substantially enclose at least a portion of said gasket with said anchor flange of said gasket exposed externally of said mandrels. 
   
     
     
         2 . The gasket and mandrel assembly of  claim 1 , wherein said at least one annular outer surface of said first mandrel is disposed at an angle of between 0.5° and 4° with respect to said longitudinal axis. 
     
     
         3 . The gasket and mandrel assembly of  claim 1 , wherein said at least one annular outer surface of said first mandrel is disposed at an angle of between 1.5° and 2.5° with respect to said longitudinal axis. 
     
     
         4 . The gasket and mandrel assembly of  claim 1 , wherein said first mandrel is formed at least in part of a rigid material and includes an annular cavity within which at least a portion of said gasket is receivable. 
     
     
         5 . The gasket and mandrel assembly of  claim 1 , wherein said first and second mandrels include cooperating engagement structures. 
     
     
         6 . The gasket and mandrel assembly of  claim 1 , wherein said pipe sealing portion of said gasket is foldable between a first position in which said pipe sealing portion is disposed substantially within said main body portion of said gasket and a second position in which said pipe sealing portion extends away from said main body portion along said longitudinal axis. 
     
     
         7 . The gasket and mandrel assembly of  claim 1 , wherein said anchor flange comprises at least one undercut, at least a portion of one of said first and second mandrels received within said undercut. 
     
     
         8 . The gasket and mandrel assembly of  claim 1 , wherein one of said first and second mandrels includes an annular front face disposed generally transverse to said longitudinal axis, said front face having a convex profile, and the other of said first and second mandrels includes an annular rear face disposed generally transverse to said longitudinal axis, said rear face having a concave profile. 
     
     
         9 . The gasket and mandrel assembly of  claim 1 , wherein said outer annular surface is formed as a portion of a separate component attached to said first mandrel. 
     
     
         10 . A mandrel assembly for use in casting a gasket within a wall of a structure, comprising:
 a first mandrel having a longitudinal axis, a first face disposed substantially transverse to said longitudinal axis, and at least one annular outer surface disposed at an angle of between 0.5° and 7° with respect to said longitudinal axis; and   a second mandrel formed at least in part of a resilient material and having a second face disposed substantially transverse to said longitudinal axis.   
     
     
         11 . The mandrel assembly of  claim 10 , wherein said at least one annular outer surface of said first mandrel is disposed at an angle of between 0.5° and 4° with respect to said longitudinal axis. 
     
     
         12 . The mandrel assembly of  claim 10 , wherein said at least one annular outer surface of said second mandrel is disposed at an angle of between 1.5° and 2.5° with respect to said longitudinal axis. 
     
     
         13 . The mandrel assembly of  claim 10 , wherein said first mandrel is formed at least in part of a rigid material and includes an annular cavity. 
     
     
         14 . The mandrel assembly of  claim 10 , wherein said first face of said first mandrel has a convex profile, and said second face of said second mandrel has a concave profile. 
     
     
         15 . The mandrel assembly of  claim 10 , wherein said first and second mandrels include cooperating engagement structures. 
     
     
         16 . The mandrel assembly of  claim 10 , wherein said outer annular surface is formed as a portion of a separate component attached to said first mandrel. 
     
     
         17 - 23 . (canceled)