Roller Set Having a Burnishing Roller

Abstract

A roller set for roll forming pipe elements has an outer roller that engages the pipe element at three points to prevent teetering of the pipe element. The outer roller has a summit positioned on a raised feature, the summit comprising a curved surface adapted to burnish the pipe elements.

What is claimed is: 
     
         1 . A pipe element, comprising:
 an outer surface surrounding a longitudinal axis;   at least one end; and   a groove positioned in said outer surface proximate to said at least one end, said groove extending circumferentially around said pipe element, said groove comprising:   a first side surface proximate to said at least one end,   a floor surface contiguous with said first side surface, and   a second side surface contiguous with said floor surface, said second side surface being in spaced relation to said first side surface, and wherein   said first side surface projects radially outwardly beyond a remainder of said outer surface of said pipe element; and   wherein a portion of said outer surface extending between said first side surface and said at least one end comprises a conical taper.   
     
     
         2 . The pipe element according to  claim 1 , further comprising a tooling mark positioned in said outer surface and extending circumferentially around said pipe element. 
     
     
         3 . The pipe element according to  claim 2 , wherein said tooling mark comprises a depression in said outer surface. 
     
     
         4 . The pipe element according to  claim 1 , wherein said first side surface is oriented substantially perpendicularly to said longitudinal axis. 
     
     
         5 . The pipe element according to  claim 4 , wherein said floor surface is oriented substantially parallel to said longitudinal axis. 
     
     
         6 . The pipe element according to  claim 5 , wherein said second side surface is oriented substantially angularly with respect to said longitudinal axis. 
     
     
         7 . The pipe element according to  claim 5 , wherein said second side surface is oriented substantially perpendicularly to said longitudinal axis. 
     
     
         8 . A pipe element, comprising:
 an outer surface surrounding a longitudinal axis;   at least one end; and   a groove positioned in said outer surface proximate to said at least one end, said groove extending circumferentially around said pipe element, said groove comprising:   a first side surface proximate to said at least one end, said first side surface being substantially perpendicular to said longitudinal axis,   a floor surface contiguous with said first side surface and oriented substantially parallel to said longitudinal axis, and   a second side surface contiguous with said floor surface and oriented substantially angularly with respect to said longitudinal axis, and wherein   said first side surface projects radially outwardly beyond a remainder of said outer surface of said pipe element; and   wherein a portion of said outer surface extending between said first side surface and said at least one end comprises a conical taper.   
     
     
         9 . The pipe element according to  claim 8 , further comprising a tooling mark positioned in said outer surface and extending circumferentially around said pipe element. 
     
     
         10 . The pipe element according to  claim 9 , wherein said tooling mark comprises a depression in said outer surface. 
     
     
         11 . In combination, at least one pipe element according to  claim 8  and a coupling, said coupling comprising:
 a plurality of segments attached end to end surrounding a central space, said at least one pipe element being received within said central space; 
 each of said segments having at least one key projecting toward said central space, said at least one key engaging said groove, said at least one key comprising: 
 a first key surface oriented substantially perpendicularly to said longitudinal axis and engaged with said first side surface of said groove; 
 a second key surface contiguous with said first key surface and facing said floor surface of said groove; and 
 a third key surface contiguous with said second key surface, said third key surface being angularly oriented with respect to said longitudinal axis and engaged with said second side surface of said groove. 
 
     
     
         12 . The combination according to  claim 11 , wherein said third key surface has an orientation angle relative to said longitudinal axis equal to an orientation angle of said second side surface. 
     
     
         13 . The combination according to  claim 11 , wherein said coupling further comprises connection members positioned at opposite ends of each of said segments, said connection members being adjustably tightenable for drawing said segments toward one another and said at least one key on each of said segments into engagement with said groove. 
     
     
         14 . The combination according to  claim 13 , wherein said connection members on each of said segments comprise a pair of projections, one said projection being positioned on each of said opposite ends of said segments, said projections having holes to receive a fastener, said fastener being adjustably tightenable. 
     
     
         15 . The combination according to  claim 11 , wherein said coupling comprises two of said segments.