Control gate or valve for mixer for liquid concrete, has semicircular disc on central pivot, movable in front of D-shaped aperture

摘要

The disc (1) has a circular outer edge and may be a segment of a circle slightly less than a full semicircle. Its curved edge seals against the curved edge of a D-shaped opening (10) with a flat floor (12). Two actuator cylinders (20,30) pull on chains (5) which may turn the valve from a closed to an open position.