Patent ID: 9061345
Filing Date: 2015-06-23
Classification: B21B,B21D,B21H

Abstract:
1. A method of producing continuous rolled flighting, the flighting being suitable for use in screw conveyors and augers, including: forming a continuous helical blade having radially spaced inner and outer helical edges from an elongated metal strip having a first length, a first height and a first thickness, wherein the first length of the strip is greater than its first height and the first height of the strip is greater than its first thickness and the cross-section of said metal strip is substantially constant along its length; wherein said continuous helical blade is formed integrally by (i) an inner helical portion which extends radially from the inner helical edge to a predetermined intermediate radius portion and which extends radially to (ii) an outer helical portion which extends from the predetermined intermediate radius portion to the outer helical edge, the transverse thickness of the continuous helical blade in the inner helical portion decreasing gradually from a maximum value to a minimum value at the intermediate radius portion, and the thickness of the continuous helical blade in the outer helical portion being increased by cold forming from the first thickness of the metal strip forming the helical blade to a second thickness greater than the first thickness, wherein the outer helical portion is thickened from said first metal strip thickness to the second thickness without adding or attaching additional material to the metal strip during forming.