Patent ID: 7398938
Filing Date: 2008-07-15
Classification: B02C,D21D

Abstract:
1. A refining cone having a working surface, a radially inner end and a radially outer end, the working surface including a plurality of bars having inner and outer ends, laterally spaced by intervening grooves and extending generally outwardly toward said outer end across said conical surface, said plurality of bars being curved with the shape of a logarithmic type spiral from the inner to the outer ends of the bars, wherein the shape of said bars conforms within manufacturing tolerances to the mathematical expression in polar coordinates in an original x-y plane orthogonal to the cone axis: where and this curve projected onto the working surface has a shape change according to the following formulae: where “r” is the radial position along the centerline of the bar, “a” is a scale parameter for r and αis the intersecting angle between any tangent to the curve and the generatrix of the coordinate system, Gw