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US 4,474,167 AGranted
Latch for a butterfly damper
OwnerFrancis J. McCabeinventor
Life of this patent
Estimating the term…
Abstract
An air/smoke/fire damper including a frame and a pair of damper blades pivoted for rotation within the frame between an open and a closed position, and comprising a heat responsive latch including mounting straps associated with each of the damper blades; a fusible link engaging one of the mounting straps; and a hook pivotally associated with the other mounting strap and extending over the edges of the damper blades and into engagement with the fusible link. Also, a locking mechanism for restraining the blades in the closed position upon release of the heat responsive latch, and a retaining lug for preventing blade buckling in the closed position.
Claims28
A damper comprising:
- (a) a frame;
- (b) a pair of blades supported within the frame and adapted for movement between an open and a closed position;
- and
- (c) heat responsive latching means for restraining the blades in the open position, and for releasing the blades when the ambient temperature around the latching means reaches a preselected value, wherein the latching means comprises:
- (i) mounting means operatively associated with an outer surface of each of the blades;
- (ii) fusible link means, a first end of which is attached to the mounting means associated with one of the blades and adapted to separate when the preselected ambient temperature is reached;
- and
- (iii) linkage means comprising mounting strap means and hook means, one end of said mounting strap means being attached to the mounting means associated with the other of the blades, and the other end of which includes a slot for engaging said hook means, the hook means being disposed to extend over edges of the blades for attachment to a second end of the fusible link means so that the blades are restrained in the open position until the preselected ambient temperature is reached.
5 more elements
A damper comprising:
- (a) a frame;
- (b) at least one blade supported within the frame and adapted for movement between an open and a closed position;
- (c) latching means for restraining the blade in the open position, and for releasing the blade when the ambient temperature around the latching means reaches a preselected value;
- and
- (d) locking means for maintaining the blade in the closed position after the blade is released by the latching means, wherein the locking means comprises a resilient spring element, one end of which is attached to the damper frame, and the other end of which extends outwardly from the damper frame and into the path of movement of a closing blade, and wherein the resilient spring element includes a leading edge, the terminating end of which is notched or chamfered to facilitate movement of the blade.
2 more elements
A damper comprising:
- (a) a frame;
- (b) a pair of blades supported within the frame and adapted for movement between an open and a closed position;
- and
- (c) heat responsive latching means for restraining the blades in the open position, and for releasing the blades when the ambient temperature around the latching means reaches a preselected value, wherein the latching means comprises:
- (i) mounting means operatively associated with a surface of each of the blades;
- (ii) fusible link means, a first end of which is attached to the mounting means associated with one of the blades, adapted to separate when the preselected ambient temperature is reached;
- and
- (iii) linkage means pivotally associated with respect to the mounting means associated with the other of the blades and including hook means having a shank portion disposed to extend over edges of the blades and an end portion adapted for attachment to a second end of the fusible link means so that the blades are restrained in the open position until the preselected ambient temperature is reached;
- (iv) wherein the end portion of the hook means contacts one of the blades of the damper, and wherein the end portion forms an angle with the shank portion which develops a resultant vector force between the blade of the damper and the end portion of the hook means which is not less than the colinear force needed to cause separation of the fusible link means.
6 more elements
A damper comprising:
- (a) a frame;
- (b) at least one blade supported within the frame and adapted for movement between an open and a closed position;
- (c) latching means for restraining the blade in the open position, and for releasing the blade when the ambient temperature around the latching means reaches a preselected value;
- (d) locking means for maintaining the blade in the closed position after the blade is released by the latching means;
- and
- (e) restraining means adapted to prevent the edge of the damper blade from being forced away from the frame in a radial direction, thereby preventing buckling of said blade.
3 more elements
Dependencies are inferred from the claim text.