Patent ID: 6077016
Filing Date: 2000-06-20
Classification: B42C,Y10T

Abstract:
A method of roughening a surface of a book block spine formed of a plurality of individual printed sheets clamped together, comprising the following steps:(a) effecting a relative movement between the book block spine and a circular roughening tool parallel to a length dimension of the book block spine; said roughening tool having a plurality of cutting tool bits, said plurality of cutting tool bits together defining a cutting plane;(b) rotating said roughening tool about a rotary axis; and(c) positioning said roughening tool such that(1) said cutting plane defined by said plurality of cutting tool bits is oriented face-to-face with said surface of said book block spine;(2) said rotary axis forms an angle of more than 90.degree. with a vector starting at a point of intersection between the surface of the book block spine and said rotary axis and in a direction opposite the direction of said relative movement between the roughening tool and the book block spine, as observed from the roughening tool, said cutting plane thus forming an acute angle with said surface of said book block spine;(3) said cutting tool projects bilaterally beyond said book block spine; and(4) said tool bits are thus caused to penetrate into said surface simultaneously along a first circularly arcuate portion of said cutting tool and a second circularly arcuate portion of said cutting tool; said first and second arcuate portions being diametrically opposite one another relative to said rotary axis, whereby arcuate markings cut into said surface of said book block spine along said first circularly arcuate portion of said cutting tool have a depth different from arcuate markings cut into said surface of said book block spine along said second circularly arcuate portion of said cutting tool.