A forming die for forming an end of a tube and a method for forming an end of a tube

Abstract

A forming die system and method is used in end forming a pipe or tube for connecting the pipe or tube with a fitting without a sleeve therebetween. The forming die system includes engageable outer dies that together define a bore having a longitudinal axis, die forming surfaces formed on each outer die, grip dies supported in each of the outer dies and configured to hold the pipe or tube, a biasing member that is engageable between a corresponding one of the outer dies and a corresponding one of the grip dies, and a forming pin that is configured to roll around the longitudinal axis in a circular motion at a predetermined angle relative to the longitudinal axis.

1 . A forming die used in end forming a pipe or tube for connecting the pipe or tube with a fitting, the forming die comprising:
 engageable outer dies that each have a die forming surface;   grip dies supported in each of the outer dies and configured to hold the pipe or tube; and   a biasing member that is engageable between a corresponding one of the outer dies and a corresponding one of the grip dies.   
     
     
         2 . The forming die according to  claim 1  further comprising grip die surfaces that are formed on each of the grip dies and have protrusions for holding the pipe or tube. 
     
     
         3 . The forming die according to  claim 2 , wherein the protrusions are teeth or ridges. 
     
     
         4 . The forming die according to  claim 3 , wherein the grip die surfaces are toothed and have between 15 and 30 teeth. 
     
     
         5 . The forming die according to  claim 2 , wherein the grip die surfaces are formed of a carbide deposit material. 
     
     
         6 . The forming die according to  claim 1 , wherein the outer dies are identical in shape and rectangular, the outer dies defining a bore having a longitudinal axis when the outer dies are engaged. 
     
     
         7 . The forming die according to  claim 6 , wherein the die forming surface of each outer die is axially adjacent the grip dies and each die forming surface has axially adjacent conically angled surfaces. 
     
     
         8 . The forming die according to  claim 1 , wherein the biasing member includes disc springs or Bellville washers. 
     
     
         9 . The forming die according to  claim 1 , wherein the outer dies form a gapless parting line therebetween when engaged, the outer dies being symmetrical to each other along the parting line. 
     
     
         10 . The forming die according to  claim 1 , further comprising spring pins that are configured to retain the grip dies within the outer dies. 
     
     
         11 . A forming die system used in end forming a pipe or tube for connecting the pipe or tube with a fitting, the forming die system comprising:
 engageable outer dies that together define a bore having a longitudinal axis and each have a die forming surface;   grip dies supported in each of the outer dies and configured to hold the pipe or tube;   a biasing member that is engageable between a corresponding one of the outer dies and a corresponding one of the grip dies; and   a forming pin that is configured to roll around the longitudinal axis in a circular motion at a predetermined angle relative to the longitudinal axis.   
     
     
         12 . The forming die system according to  claim 11 , wherein the forming pin has a captive surface formed as an annular groove. 
     
     
         13 . The forming die system according to  claim 12 , wherein the forming pin has a protruding stop surface that is radially adjacent the captive surface and configured to contact the outer dies. 
     
     
         14 . The forming die system according to  claim 13 , wherein the protruding stop surface is axially angled relative to a longitudinal axis of the forming pin. 
     
     
         15 . The forming die system according to  claim 11 , wherein the predetermined angle of the forming pin is between 4 and 20 degrees relative to the longitudinal axis. 
     
     
         16 . The forming die system according to  claim 11  further comprising grip die surfaces that are formed on each of the grip dies and have protrusions for holding the pipe or tube. 
     
     
         17 - 18 . (canceled) 
     
     
         19 . The forming die system according to  claim 11 , wherein the die forming surface of each outer die is axially adjacent the grip dies and each die forming surface has conically angled surfaces. 
     
     
         20 . (canceled) 
     
     
         21 . The forming die system according to  claim 11 , wherein the outer dies are engageable to form a gapless parting line between the outer dies, the outer dies being symmetrical to each other along the parting line. 
     
     
         22 . (canceled) 
     
     
         23 . A method of end forming a pipe or tube for connecting the pipe or tube with a fitting, the method comprising:
 providing complementary outer dies that each have a die forming surface;   engaging the outer dies together to define a longitudinal axis;   holding the pipe or tube using grip dies supported in each of the outer dies; and   radially biasing the grip dies toward each other.   
     
     
         24 . The method of end forming according to  claim 23  further comprising rolling a forming pin in a circular motion around the longitudinal axis at a predetermined angle relative to the longitudinal axis. 
     
     
         25 - 30 . (canceled)