Method of making rim having opposite hollow flanges

Abstract

Disclosed is a method of making a rim having hollow flanges formed on its opposite annular edges. It comprises the steps of: cutting an elongated metal band of a fixed width to provide metal strips of a predetermined length; rolling a selected metal strip into a ring; welding the opposite ends of the ring; curling each annular edge of the ring outward; and roll-forming the main annular part to define a well along the center line of the main annular part. The method further comprises the steps of: bending the opposite bead areas toward the center well; closing the gap between each curl edge and the counter bead area; and unbending the opposite bead areas into the final rim shape.

What is claimed is:  
     
         1 . A method of making a rim having hollow flanges formed on its opposite annular edges comprising the steps of: 
 cutting an elongated metal band of a fixed width to provide metal strips of a predetermined length,    rolling a selected metal strip of the predetermined length into a ring;    welding the opposite ends of the ring;    curling each annular edge of the ring outward; and    rolling the main annular part of the ring into a required shape.    
     
     
         2 . A method of making a rim having hollow flanges formed on its opposite annular edges according to  claim 1 , wherein the opposite ends of the ring are flash butt-welded; and the burr or flash is removed from the welded part of the ring.  
     
     
         3 . A method of making a rim having hollow flanges formed on its opposite annular edges according to  claim 2 , wherein the main annular part of the ring is sandwiched between inner and outer rolls, and is roll-formed to define a well along the center line of the main annular part.  
     
     
         4 . A method of making a rim having hollow flanges formed on its opposite annular edges according to  claim 3 , wherein it further comprises the steps of: 
 bending the opposite bead areas toward the center well;    closing the gap between each curl edge and the bead area; and    unbending the opposite bead areas into the final rim shape.    
     
     
         5 . A method of making a rim having hollow flanges formed on its opposite annular edges according to  claim 3 , wherein it further comprises the steps of: 
 closing the gap between each curl edge and the counter bead area; and    raising each closed curl edge into the final rim shape.