Shut-off device

A shut-off device for progressive regulation of the flow rate of a fluid flowing in a pipe, said shut-off device comprising:

• (a) a main shut-off member independently pivotable about a spindle passing though the pipe in order to close the pipe, the spindle being located substantially in the center of said main shut-off member;
• and
• (b) at least one drive flap able to pivot about the spindle and to act mechanically on said main shut-off member in such a way as to turn said member about the spindle, wherein said main shut-off member includes a transverse hollow cylindrical housing for the spindle, said housing having at least on one end an opening in the form of a slot which is parallel to the spindle and through which the at least one drive flap passes, the opening intercepting, in a plane perpendicular to the spindle, an angle allowing the at least one drive flap to pivot through a maximum angle .o slashed. relative to said main shut-off member;
• wherein said main shut-off member also is traversed by at least one orifice that can be closed by at least one shut-off flap which is pivotable about the spindle, and can regulate the rate of flow of the fluid through the orifice;
• and wherein a single flap can serve as both the shut-off flap and the drive flap, said main shut-off member beginning to pivot about the spindle, from an initial closed position, when the drive flap is at a predetermined non-zero angular distance from said member, thus allowing the fluid to flow only through the orifice until said main shut-off member begins to open.