Chimney draft control device

Claim 1

A draft control device for a chimney of a fireplace and the like comprising: a. a generally rectangular hollow box-like member having six sides including one open side that can be fixed over the top of a chimney and a closed side opposite from said one side, and four sides, including two sets of opposite sides, each having a vent; b. at least one shutter pivotally mounted on said member adjacent each of said side vents for movement by wind forces; and c. rigid linkage means for pivotally interconnecting said shutters for each of said sets of vented opposite sides to provide two shutter sets wherein one shutter for each of said two sets of opposite vented sides will be moved away from its vent when the other shutter is moved towards its vent by pivotal movement of said other shutter by said wind forces, d. the linked shutters of one of said two shutter sets having their pivotal mountings to said member offset from those of the other of said shutter sets so as to avoid jamming of said linkage means, e. said shutters being pivotally mounted on said member such that their pivotal movement will be about a generally horizontal axis when said open side of said member is fixed over said chimney top, f. said pivotal mountings of said linked shutters of one of said two shutter sets being then offset generally vertically from those of the other of said shutter sets, g. each of said shutters being then mounted for pivotal movement adjacent its upper end by said pivotal mountings, h. said linkage means for each of said shutter sets comprising a rigid rod having a length greater than the space between the set of vented opposite sides shuttered by one of said shutter sets and having its opposite ends respectively indirectly pivotally connected to one of the shutters forming said one shutter set, and i. said indirect pivotal connection being through a rigid arm having two opposite ends with only one of said two opposite ends being fixed to said one of said shutters and the other of said two opposite ends being pivotally connected to said rod.