| 摘要 |
An adjustable damper for controlling air flow between portions of a building includes a plurality of vanes positioned in a frame opening, which vanes are selectively, simultaneously rotatable between open and closed positions. A reversible motor and an actuating linkage on one side of the damper drives a first vane axle about an axis, and a vane linkage on the opposite side, rotates the other vanes along with the first vane. The actuating linkage includes a shaft which is offset from the first vane axis, which shaft is turned by the motor between open and closed positions. A linkage arm pivotally connects the shaft and the vane axle and the linkage arm is bent at an angle such that, when the shaft is rotated to the closed position, the linkage arm is rotated to an over center position in which it securely latches the vanes in a closed position. The latch is thus automatically secured when the motor rotates the shaft to the closed position and automatically released when the motor rotates the shaft away from the closed position.
|
