Vehicle structural beam and method of manufacture

Abstract

A vehicle structural beam, such as a door intrusion beam, which possesses an elongate tubular beam part which at opposite ends is provided with mounting flanges for securement to a vehicle frame. The elongate tubular beam part and the flanges provided at opposite ends are defined by an integral, one-piece, monolithic steel structure which has been initially roll-formed from an elongate flat metal sheet to define the closed tubular structure of the tubular beam part, and which has been subjected to heating and quenching so that the elongate tubular beam part is of relatively high strength steel throughout its entire length, whereas the integrally and monolithically joined end flanges remain as lower strength steel which has been significantly unaffected by the heat treatment and quenching so as to permit appropriate shaping thereof and ease of welding to the vehicle frame.

1 - 24 . (canceled)  
     
     
         25 . A method of forming a metallic item comprising the steps of: 
 trimming the opposed lateral edges of a continuous metal blank to create a plurality of cut-outs in the opposed lateral edges;    forming the continuous metal blank into a tubular shape;    welding along the length of the tubular shape, whereby the lateral edges are joined only in the areas between the cut-outs;    cutting the welded tubular shape in the areas of the cut-outs thereby creating a plurality of items; and    opening an end of each item to create a non-tubular portion on the item.    
     
     
         26 . A method as defined in  claim 25  wherein said step of opening an end further comprises the step of angling a portion of the end.  
     
     
         27 . A method of forming an item comprising the steps of: 
 trimming a continuous metal strip to form a plurality of indentations in the opposed lateral edges;    rollforming the continuous metal strip into a continuous tubular shape wherein the opposed lateral edges engage each other;    welding the engaging untrimmed lateral edges of the continuous tubular shape;    cutting the welded continuous tubular shape in the area of the indentations thereby creating a plurality of items; and    opening an end of each item to create a non-tubular end.    
     
     
         28 . A method as defined in  claim 27  wherein said opening step includes opening both ends of each item to create non-tubular ends.  
     
     
         29 . A method as defined in  claim 27  further comprising the step of forming an angled bracket from the end.  
     
     
         30 . A method of forming doorbeams comprising the steps of: 
 providing a continuous web of flat stock having a pair of opposed linear edges;    trimming at least one of the linear edges at spaced locations along the length of the flat stock creating trimmed edges and leaving untrimmed edges;    forming the trimmed flat stock into a generally tubular shape with the untrimmed linear edges engaging one another;    welding the engaging untrimmed lateral edges of the generally tubular shape;    severing the welded tubular shape in the area of the trimmed lateral edges thereby creating a plurality of tubular lengths; and    opening at least one end of each tubular length in the area of the trimmed edges to create a bracket.    
     
     
         31 . The method of  claim 30  wherein said step of opening at least one end of the tubular length further comprises a final forming step of forming a relatively flat end on the tubular length in the area of the trimmed edges.  
     
     
         32 . The method of  claim 31  further comprising the step of angling the relatively flat end.  
     
     
         33 . A method of forming doorbeams comprising the steps of: 
 providing a continuous web of sheet stock having a pair of lateral edges;    forming the continuous web into a generally closed configuration with at least portions of the lateral edges engaging one another;    joining the engaging portions of the lateral edges in first longitudinal segments separated by unjoined portions of the lateral edges in second longitudinal segments;    severing the joined closed configuration in the unjoined second longitudinal segments thereby creating a plurality of lengths; and    opening at least one end of each length to create a bracket.    
     
     
         34 . The method of  claim 33  further comprising the step of forming a relatively flat bracket.  
     
     
         35 . The method of  claim 33  further comprising the step of forming an angled portion in the bracket.  
     
     
         36 . The method of  claim 33  wherein said step of joining the lateral edges includes welding.