Ring rolling from metal blanks

Abstract

A method of rolling a ring from a metal blank comprises mounting the blank ( 2 ) on a mandrel ( 4 ) between two forming rolls ( 6 ) located on opposite sides of the mandrel axis. A pair of lower growth control rolls ( 12 ) are located below and with their axes parallel to and on opposite sides of the mandrel axis ( 8 ), and a pair of upper growth control rolls ( 16 ) are arranged above and with their axes parallel and on opposite sides of the mandrel axis ( 8 ). The spacing between the pair of upper growth control rolls is different from that between the pair of lower growth control rolls. As the ring is rolled, both the forming rolls and the growth control rolls are engaged with it. In a modification of the method, the upper growth control rolls are replaced by a single roll ( 20 ) with its axis disposed directly over the mandrel axis.

1 . A method of rolling a ring from a metal blank, comprising mounting the blank on a mandrel between two forming rolls located on opposite sides of the mandrel axis, with a pair of lower growth control rolls located below and with their axes parallel to and on opposite sides of the mandrel axis, and a pair of upper growth control rolls arranged above and with their axes parallel and on opposite sides of the mandrel axis, wherein the spacing between the pair of upper growth control rolls is different from the spacing between the pair of lower growth control rolls; and rolling the ring between the forming rolls with the growth control rings engaging the ring. 
   
   
       2 . A method according to  claim 1  wherein the spacing between the pair of upper growth control rolls is less than the spacing between the pair of lower growth control rolls. 
   
   
       3 . A method according to  claim 1 , wherein the lower growth control rolls are located relative to the mandrel axis with their axes disposed at an angle in the range 50° to 70° below the horizontal plane containing the mandrel axis. 
   
   
       4 . A method according to  claim 3 , when said angle is at least 60°. 
   
   
       5 . A method according to  claim 1 , wherein the upper growth control rolls are located relative to the mandrel axis with their axes disposed at an angle in the range 50° to 80° above the horizontal plane containing the mandrel axis. 
   
   
       6 . A method according to  claim 5 , wherein said angle is in the range 65° to 70°. 
   
   
       7 . (canceled) 
   
   
       8 . A method according to  claim 1 , wherein the mandrel axis and the axes of the forming rolls are in the same horizontal plane. 
   
   
       9 . A method according to  claim 1 , wherein the mandrel axis is disposed below a horizontal plane containing the forming roll axes. 
   
   
       10 . A method according to  claim 9 , wherein the mandrel axis is disposed at an angle no greater than 10° below the horizontal plane containing the forming roll axes. 
   
   
       11 . A method according to  claim 10 , wherein the angle is no greater than 5°. 
   
   
       12 . A method of rolling a ring from a metal blank, comprising mounting the blank on a mandrel between two forming rolls located on opposite sides of the mandrel axis, with a pair of lower growth control rolls located below and with their axes parallel to and on opposite sides of the mandrel axis, and a single upper growth control roll arranged above and with its axis parallel and directly over the mandrel axis, and rolling the ring between the forming rolls with the growth control rings engaging the ring. 
   
   
       13 . A method according to  claim 12 , wherein the lower growth control rolls are located relative to the mandrel axis with their axes disposed at an angle in the range 50° to 70° below the horizontal plane containing the mandrel axis. 
   
   
       14 . A method according to  claim 13 , when said angle is at least 60°. 
   
   
       15 . A method according to  claim 12 , wherein the mandrel axis and the axis of the forming rolls are in the same horizontal plane. 
   
   
       16 . A method according to  claim 12 , wherein the mandrel axis is disposed below a horizontal plane containing the forming roll axes. 
   
   
       17 . A method according to  claim 16 , wherein the mandrel axis is disposed at an angle no greater than 10° below the horizontal plane containing the forming roll axis. 
   
   
       18 . A method according to  claim 17 , wherein the angle is no greater than 5°.