| 摘要 |
<p>A tubular upstanding wall (7) of a predetermined height and defining a central aperture (11) has an integrally formed, inwardly facing flange (8) on its upper end, and an integrally formed, outwardly facing flange (9) on its lower end. The inwardly facing flange has a sharpened cutting edge (10) thereby forming a razor blade. One or more razor blades are positioned through apertures in a top member and the outwardly facing flange (9) cooperates with the lower face of the top member to control the vertical position of each razor blade.</p> |
