Patent ID: 8152877

Claim:
A surface cleaning apparatus comprising: (a) an air flow passage extending from a dirty air inlet to a clean air outlet; (b) a dirt collection chamber extending between first and second opposed ends; (c) a unidirectional flow cyclone chamber positioned in the dirt collection chamber and comprising an air inlet at the first end, an air outlet at the second end and a cyclone chamber wall extending from the first end towards the second end, the cyclone chamber wall having an end face that is spaced from and faces the second end to define a gap between the end face and the second end, the gap comprising a dirt outlet of the cyclone chamber; (d) a perforated shroud comprising a downstream portion that is positioned between the second end and the end face of the cyclone chamber wall and an upstream portion that is positioned in the cyclone chamber, the upstream portion having a closed end that is distal to the second end, wherein the upstream portion of the shroud tapers inwardly from the downstream portion to the closed end; and (e) a suction motor positioned in the air flow passage.