Screw Conveyors, Augers, and Flighting for Use Therein

摘要

In a continuous screw conveyor or auger, the rotatable screw member comprises a helical radial blade (“flighting”) carried on a central driving shaft. The flighting is formed by providing a raw metal strip, generally of uniform thickness, performing optional compression and flaring of the metal strip, and rolling the metal strip between a pair of opposed, preferably offset, conical rolls. In contrast to prior art rolls, the present invention provides on at least one of those rolls a stepped conical rolling surface formed so as to exert a lesser and reducing rolling pressure on an outer portion of the helical blade being formed, thereby to produce a blade in which the outer portion tapers to a thickness which is preferably 125% of the thickness of the ingoing material to provide a greater wear resistant surface, a longer working life to the flighting and improved output performance.

主权项

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; 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 (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 greater than the first thickness of the metal strip forming the helical blade, wherein the outer helical portion is thickened from said first metal strip thickness without adding or attaching additional material to the metal strip during forming.