DAMPER

摘要

Control apparatus such as a fire damper or duct damper consisting of a housing having a series of blades pivotally mounted therein and extending transversely across the housing. Each blade has a gear pinion drivably connected thereto which engages in mesh with gear teeth of a rack formed on an operating member which is linearly slidable to effect pivotal movement of the blades so as to open or close the fire damper or duct damper.