| 摘要 |
PROBLEM TO BE SOLVED: To prevent dew formation on the upper and lower blades while increasing the air volume by increasing the thickness gradually within some range in the direction of an upper coupling cleat supporting part from the circumferential end of left and right blades on the side opposite to the upper and lower blades, employing horseshoe shape above the circular seat at the upper coupling bolt supporting part and bending the left and right blades entirely. SOLUTION: The thickness is increased gradually within some range in the direction of an upper coupling cleat supporting part from the circumferential end of left and right blades 3 on the side opposite to the upper and lower blades 6. Horseshoe shape is employed above the circular seat 5 at the upper coupling cheat supporting part and the left and right blades 3 are bent entirely. Consequently, ventilation resistance is decreased and the air volume is increased while suppressing noise. Furthermore, dew formation on the upper and lower blades is prevented and the wind direction can be deflected inward easily. |
