Damper

A damper for use in controlling the flow rate or direction of a flow of air or fumes flowing out from a room or space or flowing through a ventilation system, including a housing having at least one inlet opening. The housing has a tubular side wall in which are provided a plurality of outlet apertures opened and closed by associated closure members which are adapted to swing to and away from the side wall, preferable inwardly of the housing. The total flow area of the outlet apertures may be extended to a desired degree by increasing the axial length and diameter of the side wall of the housing, whereby the flow resistance and pressure drop across the damper are reduced.

What is claimed is:

1. A self-contained, motorized damper adapted to be removably mounted on a roof of a building comprising:

an enclosed hollow housing having a circularly tubular side wall, an annular bottom wall arranged perpendicularly to said side wall for mounting said hollow housing onto the roof of the building, a single aperture defined in the center of said bottom wall for admitting air from a space of the building, a plurality of outlet apertures formed in said tubular side wall for allowing said air to flow out of said housing, the total flow area of said outlet apertures being greater than that of said single inlet aperture, and a top wall arranged on said side wall in axially opposed relationship to said bottom wall;

a plurality of movable closure members mounted on said housing adjacent respective ones of said outlet apertures for openably closing said outlet apertures in order to control the flow of air flowing from said housing; and

actuating means for conjointly moving said closure members from a first position wherein all of said closure members close said respective outlet apertures, to a second position wherein all of said members open said respective outlet apertures, said actuating means including a drive motor mounted on the center of said top wall of said hollow housing, a rotatably driven shaft extending from said motor coaxially into said hollow housing, lever means connected to said shaft, and a linkage mechanism connected between said lever and said plurality of movable closure members to conjointly move said closure members in response to rotation of said shaft.

2. A unitary damper adapted for being removably mounted on a roof of a building according to claim 1, wherein said outlet apertures are circumferentially spaced apart from each other at equal angular distances, each of said closure members having an arcuate shape to conform to an arcuate shape of said outlet apertures.

3. A self-contained damper adapted for being removably mounted on a roof of a building according to claim 1, wherein said drive motor comprises an electric servo motor capable of controlling an amount of rotation of said shaft around a longitudinal axis thereof, thereby controlling a flow rate of said air flowing out of said housing.

4. A self-contained damper adapted for being removably mounted on a roof of a building according to claim 1, wherein said total flow area of said outlet apertures is greater than the transverse cross-sectional area of said hollow housing.

5. A self-contained damper adapted for being removably mounted on a roof of a building according to claim 1, wherein said plurality of outlet apertures comprises four outlet apertures circumferentially spaced apart by 90 degrees.

6. A self-contained, motorized dampler for use in a ventilation system for a building having a room to be ventilated, said damper comprising:

an enclosed hollow housing having a bottom annular wall to be used for mounting said damper on a roof of said building, and a circular cylindrical side wall extending substantially at a right angle thereto;

said annular bottom defining in a center thereof an aperture for admitting air from the room into said hollow housing;

said side wall having a plurality of outlet apertures spaced apart circumferentially at equal angular distances from each other;

the total flow area of said outlet apertures being greater than the transverse cross-sectional area defined by said side wall;

a plurality of closure members mounted on said housing adjacent respective ones of said outlet apertures so as to close and open said outlet apertures in response to a requirement for ventilation of the room of the building;

said closure members each being hinged at a first end thereof to said hollow housing for swinging between a first position wherein said closure members are brought into registration with said side wall to close said outlet apertures, and a second position wherein said closure members are swung inwardly away from said side wall to open said outlet apertures; and

actuating means mounted on said housing and including a drive motor for conjointly and adjustably swinging said closure members in response to said requirement of ventilation between said first and second positions;

said drive motor fixedly mounted on said housing and having a rotatable shaft extending within said housing along a central axis of said side wall, said rotatable shaft having a radial lever member fixed thereto; and a linkage assembly arranged between said lever member and said closure members for conjointly swinging said closure members by an amount corresponding to the amount of rotation of said shaft.

7. A self-contained damper according to claim 6, wherein said linkage assembly comprises, for each of said closure members, a link bar pivoted at an end thereof to an outer end of said radial lever member and at the other end thereof to a second end of said closure member.

8. A self-contained damper according to claim 7, wherein said housing comprises a horizontal top wall supporting said motor, and further comprising a roof member provided above said top wall for covering said motor and said housing.