characterised by a special design with respect to properties of the material of non-metallic articles to be ground, e.g. strings (cutting profiles into the treads of tyres B29D30/68)

Full Title

Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor (B24B11/00 - B24B21/00 take precedence; honing machines or devices using abrading blocks performing axial and rotary movements superimposed on one another B24B33/00) > characterised by a special design with respect to properties of the material of non-metallic articles to be ground, e.g. strings (cutting profiles into the treads of tyres B29D30/68)