Method and apparatus for manipulating metal workpieces

Abstract

A method of forming a duct section from a web of material includes the steps of forming a series of perforations in a web of material, the series of perforations defining an outline of one of a hole or notch in a finished duct section, forming a male lock bend and a female lock seam in first opposed edges of the web of material, forming flanges in second opposed edges of the web of material, removing the portion of material interior to the series of perforations to form the hole or notch, and bending the web of material to form the finished duct section.

What is claimed is: 
     
         1 . An apparatus for manipulating a sheet of material to form a duct body, said apparatus comprising:
 a platen for supporting said sheet of material;   a plasma cutting apparatus positioned adjacent said platen and arranged for movement with respect to said platen;   a control system in communication with said plasma cutting apparatus, said control system selectively communicating cutting parameter data defining an architecture of a feature to be formed in said sheet of material, to said plasma cutting apparatus; and   wherein said plasma cutting apparatus is selectively moved by said control system in accordance with said cutting parameter data, said plasma cutting apparatus selectively adjusting a distance between said platen and said plasma cutting apparats during an active cutting operation of said plasma cutting apparatus.   
     
     
         2 . The apparatus for manipulating a sheet of material to form a duct body according to  claim 1 , wherein:
 said control system selectively controls said plasma cutting apparatus to issue a non-continuous plasma beam from said plasma cutting apparatus so as to form discrete perforations defining said architecture.   
     
     
         3 . The apparatus for manipulating a sheet of material to form a duct body according to  claim 1 , wherein:
 said control system selectively controls said plasma cutting apparatus to issue a continuous plasma beam from said plasma cutting apparatus when forming said architecture.   
     
     
         4 . An apparatus for manipulating a metal workpiece to form a duct body, said apparatus comprising:
 a surface for supporting said metal workpiece;   a plasma torch positioned adjacent said surface and arranged for movement with respect to said metal workpiece;   a control system in communication with said plasma torch, said control system selectively communicating cutting parameter data defining an architecture of a feature to be formed in said sheet of material, to said plasma cutting apparatus; and   wherein said plasma cutting apparatus is selectively moved by said control system in accordance with said cutting parameter data to ablate away material of said metal workpiece along a path defined by said architecture.   
     
     
         5 . The apparatus for manipulating a sheet of material to form a duct body according to  claim 4 , wherein:
 said control system cycles said plasma torch on and off during said ablation of said material along a path defined by said architecture, thereby forming a series of perforations in said metal workpiece.   
     
     
         6 . The apparatus for manipulating a sheet of material to form a duct body according to  claim 4 , wherein:
 said control system adjusts the distance between the metal workpiece and said plasma torch during said ablation of said material along a path defined by said architecture.   
     
     
         7 . The apparatus for manipulating a sheet of material to form a duct body according to  claim 4 , wherein:
 said control system adjusts an intensity of said plasma torch during said ablation of said material along a path defined by said architecture.