Abstract: A damper comprising a duct defining an air flow path, opposing damper blades pivotally mounted within the duct, each damper blade having an end that is pivotally mounted in cantilevered fashion in the duct so that an opposing end is free to move within the duct, wherein each damper blade is planar in shape, cooperating flow straightening members disposed centrally in the air flow path, an air flow sensor for generating a signal cooperatively disposed between the flow straightening members, and an actuator for pivoting each damper blade within the duct in response to the signal from the air flow sensor to vary the damper blade position and thereby maintain a desired velocity of air exiting the damper.

Abstract: A fire damper comprising a housing, a louver member rotationally engaged within the housing, the louver member having a substantially gas tight seal with the housing when the louver member is in a closed position, a biasing member disposed outside of the housing and engaged with the louver member for moving the louver member from an open position and holding the louver member in the closed position, a temperature sensitive member releasably connected to the louver member, the temperature sensitive member for releasing the louver member from the open position at a predetermined temperature, and the louver member further comprising insulation material to control heat transfer through the louver member for a predetermined period of time.

Abstract: A moisture elimination louver includes a housing which allows fluid flow between an air inlet opening on an upstream side of the housing and an air outlet opening on a downstream side of the housing with a plurality of moisture elimination separator plates positioned within the housing such that respective moisture eliminating air flow channels are formed between each adjacent pair of the separator plates. The moisture elimination louver is modified to included one or more air flow sensors by positioning each of the air flow sensor(s) within a different respective one of the air flow channels.

Abstract: An air flow measurement station with orthogonally mounted damper includes a station housing which encloses a damper with a plurality of movable damper blades. The damper blades are oriented in a substantially horizontal direction. The housing also encloses a plurality of air flow sensing vanes which are oriented in a second direction orthogonal to the first direction. With this orientation, the air flow sensing vanes can be positioned very close to the damper without creating dead air spaces such that reliable air flow sensing can be accomplished while keeping the station housing relatively compact.

Abstract: A universal damper mounting system and method for mounting a damper within an opening in a wall includes the use of a plurality of metal straps, each of which is initially formed into an roughly S shape with one leg being longer than the thickness of a wall into which the damper is being installed and also being longer than an opposite leg. The damper includes a rectangular housing with top and bottom peripheral sealing flanges on one side of the housing. A first pair of the straps are abutted against the top sealing flange and a second pair are abutted against the bottom sealing flange with the opposite leg of each strap being folded over a respective one of the top or bottom sealing flanges. The damper is then placed in the wall opening and the terminal ends of the long legs of each strap are bent upward or downward, depending upon the position, to overlap the wall surface. The straps thus serve to retain the damper in the wall.

Abstract: 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 damper, motor and drive linkage fit within a single, integrated housing which can be secured within a wall opening from a single side thereof.

Abstract: An adjustable damper for controlling air flow from one area to another includes a rectangular frame forming an opening with a number of movable vanes positioned to selectively close off or open up the opening. Positioned between each pair of vanes in the frame is a stationary pitot-static sensing vane. Each pitot-static sensing vane can also be shaped as an air foil and includes an upstream chamber connected to a ram air input aperture and a downstream chamber connected to a downstream static aperture. Each of the chambers is connected to one portion of a pressure sensing instrument, such as, for example, a diaphragm type differential pressure sensor, in order to sense air flow velocity across the damper.

Abstract: 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.

Abstract: A mounting bracket for securing a damper in an opening formed in a wall includes four generally L-shaped segments surrounding the damper sleeve. Each segment has a generally planar wall-engaging plate and a generally planar sleeve-engaging plate. The wall-engaging plate and the sleeve-engaging plate form the L-shape of the segment. Each segment also includes a land extending generally perpendicular to the wall-engaging plate. Two of the segments are end segments and the other two of the segments are intermediate segments. The land of each end segment is connected to the land of its adjacent intermediate segment and the lands of the intermediate segments are connected together. The segments can be removed from and replaced around the damper sleeve by bending of the land connections between the segments.

Abstract: A protective damper for controlling the flow of fluid through a ceiling diffuser has a frame defining an opening through which the fluid flows. A barrier has a closed position which prevents the flow of fluid through the opening and an open position which allows fluid flow through the opening. The barrier is restricted to linear movement between the open and closed positions. A spring is operably coupled with a shaft and exerts a bias on the shaft tending to rotate the shaft on its longitudinal axis in one direction. An actuator is operably coupled with the shaft and rotates the shaft about its longitudinal axis in the opposite direction when the actuator is energized. An elongated rigid element is pivotally coupled with the shaft and with the barrier, respectively.

Abstract: A fluid flow control damper having one or more blades for sensing pressures to determine velocity pressure in the flow stream. The airfoil damper blade has fluid intake openings in a portion of the blade which extends into the fluid stream upstream of the damper and it has inlet openings in a portion of the blade which extends into the stream downstream of the damper. Pressurized fluid from each side of the damper is conducted through separate chambers in the blade and through outlets on the blade axis to instrumentation which reads the pressures and computes the pressure differential between the pressures at each side of the damper. The pressure inlet openings are disposed in elongated channels along the side edges of the blade to protect the inlets from spurious pressure fluctuations which would adversely affect the accuracy of the pressure sensings.

Abstract: A fire and smoke damper equipped with a thermal responsive electric switch for closing the damper responsive to the elevation of the ambient temperature above a first predetermined level. Control circuitry is provided for permitting selective override of the switch for opening the damper from a remote control panel so that toxic fumes and smoke may be vented through the damper. A second thermal responsive switch operable at a higher predetermined temperature is interposed in the control circuit to insure that the damper may not be opened by the override circuit in the event that such higher ambient temperature has been reached in the location of the damper.

Abstract: An improved actuator for the damper of a ridge vent. The actuator includes coil springs constructed from a shape-memory alloy. The springs are contracted below a selected temperature at which the damper is to open, and the contracted springs maintain the damper closed on its seat. Above the transformation temperature of the springs, they expand and raise the damper off of its seat to an open position for venting of air through the ridge vent.

Abstract: A fire damper operated by an air motor for incorporating into the pneumatic piping system of a building. The damper motor holds the damper open under the influence of pressurized air from the system. A valve actuator in the flow channel of the damper has a fusible link maintaining the actuator in a standby condition. Temperature sufficient to destroy the integrity of the link permits an abutment on the actuator to swing to a position allowing the valve member to shift to interrupt the air pressure applied to the motor. This closes the damper. The damper may also be closed independently of operation of the actuator by interrupting the flow of pressurized air to the motor.

Abstract: A hollow airfoil damper blade formed by sheet metal. The walls of the blade are formed by two sheets crimped together at the edges. The blade tapers from the center toward the edges and has two pairs of V-shaped stiffening ribs formed by corrugations in the sheets. The ribs project nearly one half the blade thickness to enhance the strength of the blade and its resistance to deflection. The ribs cooperate to form a channel which closely receives a stub axle in each of its ends to provide for pivotal mounting of the damper blade. The axles are contacted directly by and welded to each of the ribs.

Abstract: An access door which covers and seals an access opening in a ventilating duct. The edge of the access opening is strengthened by a dual density gasket having a U-shaped hard portion which is applied to the duct edge. A softer sealing element projects from the hard portion of the gasket and is sealed against from the inside by the door so that the duct pressure enhances the seal. The door is a sheet metal panel having a stepped configuration and a peripheral flange for contact with the seal elements. The door is held over the access opening by retainer straps having adjustment screws.

Abstract: A transversely circular fire damper having a butterfly type blade operated by a jack shaft spaced longitudinally of the housing from the blade axle. Linkage including an "over center" stop rotates the blade in one direction by operation of a motor coupled with the shaft. A clutch in the form of a pair of relatively telescoped members secured together with entectic solder is connected with the jack shaft and the motor so that the shaft is released from the motor when the ambient temperature reaches a point high enough to melt the solder. The jack shaft is spring biased in a direction to close the damper blade under such condition.

Abstract: A fire damper with mounting structure which permits the dampers easy installation in a building ventilation duct or passage without the use of conventional, external flanges which must be bolted on at the installation site. The damper includes a peripheral frame having internally threaded, tubular elements secured to the inside of the frame and aligned with apertures extending through the frame. Threaded studs in the elements have self-boring, conical noses so that the studs may be advanced into gripping engagement with the proximal building wall.

Abstract: A fire and smoke damper having an electric motor coupled with the damper to hold the damper blades open when the motor is energized. A spring associated with the motor provides torque for closing the blades when the supply of electrical energy to the motor is interrupted. A thermal responsive electrical switch is mounted on the damper and incorporated in the electric circuit which supplies energy to the motor so that the motor is de-energized and the damper is closed when the ambient temperature reaches a predetermined level.