| 摘要 |
The open cross-section of a ventilator is covered by an array of flaps (18), extending parallel to one another in a vertical line between side pieces (14) of the frame or housing, and pivoted about pins (16) installed off-centre at uniform vertical spacing (a). The pins run through channels in the bodies (22) of the flaps close to the roots of the blades (26), whose tips are angled (27) to make contact with sealing lips (36) on the adjacent bodies in the closed position. <IMAGE> |
