Patent ID: 9550636
Date: 2017-01-24
CPC Classifications: B65G,F16K,G05D,Y10T

Claim:
1. An air flow limiter, comprising: a. a vertically oriented tube; b. a pair of open-ended telescoping tubular segments within the tube, an outer tubular segment being fixed and the other open-ended telescoping tubular segment being slideably movable along the fixed segment in the axial direction; c. a plate extending partially across the interior of the vertically oriented tube, positioned for contacting the movable one of the telescoping tubular segments to limit travel of the moveable telescoping tubular segment, the plate covering an open upper end of the movable telescoping tubular segment upon contact therewith; d. an actuator connected to the plate for selectably limiting travel of said moveable tubular segment; e. a sail positioned in the vertically oriented tube below the telescoping segments; f. a strut connecting the sail and the moveable telescoping tubular segment; the movable telescoping tubular segment moving vertically within the tube unitarily with the sail responsive to upward air flow through the tube against the sail.