| 摘要 |
PURPOSE:To improve a cooling efficiency by a constitution wherein the projected part of a spider is exposed from the opening of a cap when a movable sheave and the cap are moved forward to the maximum limit. CONSTITUTION:When the movable sheave 23 and the cap 24 are moved forwzrd with respect to the fixed sheave 23, a part of each arm 21b of the spider 21 is exposed from each opening 24c of the cap 24 gradually, and the parts of each arms 21b are exposed perfectly when they are moved forward to the maximum limits thereof as shown by an imaginary line. Whereby, the parts of each arms 21b are rotated in atmosphere and the cooling effect to the spider 21 is increased, further, the parts of each arms 21b function as fan plates to mix the atmosphere near the surface of the cap 24 and increase the cooling effect with respect to the cap 24. Furthermore, the ventilation of outer and inner air through each openings 24c is increased and thereby discharging a heat in the movable sheave 22 and the cap 24 efficiently. |
