摘要 |
A dispensing apparatus for dispensing a controlled amount of powder, the apparatus comprising a hopper defining an exit aperture; an Archimedes screw rotatably supported in the hopper and configured to expel powder from the exit aperture; an actuator configured to rotate the Archimedes screw; a cover configured to selectively close the exit aperture; and a clutch arrangement between the cover and the Archimedes screw. Movement of the cover is controlled by the Archimedes screw through the clutch arrangement. |