| 摘要 |
The head has a body formed of two halves (16a, 16b) and designed to accommodate an attack pulley (14) with support units (13a, 13b). The half (16a) is symmetrical with respect to a plane perpendicular to a rotation axis of the pulley. The half (16b) is symmetrical with respect to another plane that is perpendicular to a rotation axis of the former plane and passing through the rotation axis of the pulley. |
