| 摘要 |
<p>The disc has a frictional film (2) comprising a groove (4a). The groove exhibits an undercut (6) in the area of groove edges. The groove can be inserted in the film by die-cutting, blasting or milling. Depth (tH) of the undercut amount to fifteen to twenty five percentage of the groove depth (tN). Circumference (dH) of the undercut amounts to seventy to eighty percentage of the groove depth. An independent claim is also included for a method of inserting a groove in a frictional film of a friction disc.</p> |
