| 摘要 |
The roller has several rotating rings (2) with cutter-like outer tyre (3) having a trapezoidal cross-section whose inclined flanks (10,11) on leaving a short side (12) include an angle of 50 to 70 deg. pref. 60 deg which forms a blunt cutting edge (14). The attachments (7,8) protruding axially either side from the outer tyre have approximately the same cross-section. The outer tyre has a cross-section open in the area of the long side (13). The short side is pref. about 10 mm long. The width of the outer tyre and attachments is about 50 mm. The ring has pref. only three spokes (4,5) which are narrow and wider in the axial direction than across same in the hub area. |
