Roll formed conduit fitting

Abstract

A tool roll forms an end of a thick walled conduit so that a conventional compression fitting may be used. The tool can include a forming roller with two ridges to make two ferrule-receiving seats in the conduit and a pair of edges forming witness lines that indicate when the seats have been fully formed by the tool. In addition the witness lines are located to show when a conduit had been fully inserted into a fitting and when the fitting has been fully made up.

1 . A tool for roll forming an end portion of a conduit to form a seat for a ferrule on the outer surface of the conduit, the tool comprising:
 a frame;   a forming roller mounted on the frame for rotation about an axis;   a support on the frame facing the forming roller supporting the conduit for rotation about an axis parallel to the axis of the forming roller;   a mechanism for moving the forming roller and support toward each other so that they may engage the surface of the conduit;   the forming roller being cylindrical and having a cylindrical surface to engage the surface of the conduit to smooth the outer surface of the conduit when the tool is rotated relative to the conduit and the mechanism moves the forming roller and the support so they engaged surface of the conduit;   the forming roller further including a first circumferential ridge rising a first distance above the cylindrical surface of the forming roller and shaped and contoured to form a first seat for a first ferrule in the surface of the conduit.   
     
     
         2 . The tool of  claim 1  including a first circumferential edge rising a second distance above the cylindrical surface of the forming roller, the second distance being less than the first distance, the first edge making a witness line on the surface of the conduit when the tool is rotated relative to the conduit. 
     
     
         3 . The tool  claim 2  including a second circumferential edge rising above the cylindrical surface of the forming roller, the first circumferential edge being spaced a predetermined distance from the second circumferential edge the second edge making a witness line on the surface of the conduit when the tool is rotated relative to the conduit. 
     
     
         4 . The tool of  claim 3  in which the first edge and the second edge extend the same distance above the cylindrical surface of the forming roller. 
     
     
         5 . The tool of  claim 1  wherein the forming roller includes a tapered surface axially spaced from the ridge, the tapered surface starting from the cylindrical surface and increasing in diameter as the axial distance from the ridge increases, the tapered surface forming an inward taper on the outside surface of an end portion of the conduit as the forming roller engages the surface of the conduit. 
     
     
         6 . The tool of  claim 5  including a first circumferential edge rising a second distance above the cylindrical surface of the forming roller, the second distance being less than the first distance, the first edge making a witness line on the surface of the conduit when the tool is rotated relative to the conduit. 
     
     
         7 . The tool  claim 6  including a second circumferential edge rising above the cylindrical surface of the forming roller, the first circumferential edge being spaced a predetermined distance from the second circumferential edge the second edge making a witness line on the surface of the conduit when the tool is rotated relative to the conduit. 
     
     
         8 . The tool of  claim 7  in which the first edge and the second edge extend the same distance above the cylindrical surface of the forming roller. 
     
     
         9 . The tool of  claim 8  wherein the distance between the first and second edges corresponds to a desired travel of a nut driving a ferrule into sealing engagement with the conduit. 
     
     
         10 . The tool of  claim 8  where in the distance above the cylindrical surface of the first and second edges is selected so that the first and second edges do not engage the surface of the conduit until the seat has been formed to the desired depth. 
     
     
         11 . The tool of  claim 1  including a first stop surface fixed with respect to the frame and positioned to limit movement of the conduit in one axial direction when the tool is rotated relative to the conduit. 
     
     
         12 . The tool of  claim 11  including a second stop surface spaced from the first stop surface and fixed with respect to the frame, the second stop surface being position to limit axial movement of the conduit in a second axial direction opposite the first axial direction. 
     
     
         13 . The tool of  claim 12  wherein the first and second stop services are positioned to cooperate with the groove in the mandrel. 
     
     
         14 . The tool of  claim 11  further including a mandrel, the mandrel locking to an inside surface of the conduit and having a group positioned a predetermined distance from an end face of the conduit when the mandrel is locked to the conduit. 
     
     
         15 . The tool of  claim 14  wherein the mandrel includes at least one radially expandable member for locking the mandrel to the conduit. 
     
     
         16 . The tool of  claim 14  wherein the mandrel includes a positioning face to locate the mandrel with respect to an end face of the conduit. 
     
     
         17 . The tool of  claim 1  including a second circumferential ridge rising above the cylindrical surface of the forming roller, the second circumferential ridge being shaped and contoured to form a second seat for a second ferrule. 
     
     
         18 . The tool of  claim 17  including first and second circumferential edges rising a second distance above the cylindrical surface of the forming roller, the first and second circumferential edges forming a pair of parallel circumferential witness lines on the surface of the conduit when the tool is rotated relative to the conduit. 
     
     
         19 . The tool of  claim 18  including a tapered surface rising from the cylindrical surface and shaped to form an inward taper on an end portion of the conduit when the tool is rotated relative to the conduit. 
     
     
         20 . The tool of  claim 19  further including a mandrel proportioned to engage the interior of the conduit and having a pair of parallel positioning faces, the tool having first and second stop surfaces, each positioned to engage one of the positioning faces to limit axial movement of the conduit when the tool is rotated relative to the conduit.