Surface cleaning apparatus
View Patent ↗A surface cleaning apparatus comprises an air flow path extending from a dirty air inlet to a clean air outlet and includes a suction motor. The surface cleaning apparatus may be battery powered and/or may have a power requirement of 200 Watts or less. A cyclone chamber is provided in the air flow path and has an air outlet which is covered by a screen. In one embodiment, there is an absence of a vortex finder. In another embodiment, a vortex finder that extends into the cyclone chamber less than the height of the cyclone inlet and optionally less than the height of the cyclone inlet may be provided.
1. A surface cleaning apparatus comprising:
(a) a cyclone chamber having a longitudinal axis defining a longitudinal direction, an end wall, a cyclone air inlet located at a longitudinal position along the longitudinal axis, wherein air exits the cyclone air inlet into the cyclone chamber in an air inflow direction, the cyclone air inlet being quadrilateral in shape in a direction perpendicular to the air flow direction;
(b) a screen positioned in the cyclone chamber upstream of an air outlet of the cyclone, the screen comprising at the longitudinal position both a solid wall portion and a fluid permeable portion, the solid wall portion facing the cyclone air inlet, the fluid permeable portion containing air flow passages, and the fluid permeable portion being spaced around the longitudinal axis from the cyclone air inlet, wherein the solid wall portion extends continuously around at least one quarter of a circumference of the screen; and,
(c) a suction motor in fluid communication with the cyclone chamber,
wherein a projection of the cyclone air inlet in the air inflow direction does not intersect the solid wall portion and,
wherein the solid wall portion has a height extending in the longitudinal direction that is greater than a height of the cyclone air inlet in the longitudinal direction and,
wherein the solid wall portion has a height extending in the longitudinal direction that is less than about half a length of the screen in the longitudinal direction.
2. The surface cleaning apparatus of claim 1 wherein the screen has an interior volume that is fully open in that the interior volume is free of other structures.
3. The surface cleaning apparatus of claim 1 wherein the solid wall portion has a distal end spaced from the end wall of the cyclone chamber by a first distance and the cyclone air inlet has a distal end spaced from the end wall of the cyclone chamber by a second distance and the first distance is greater than the second distance.
4. The surface cleaning apparatus of claim 1 wherein air rotates in the cyclone chamber in a direction and a height of the solid wall portion in the longitudinal direction decreases in the direction.
5. The surface cleaning apparatus of claim 1 wherein the cyclone air inlet is configured to direct air entering the cyclone chamber to rotate around the screen in a direction so that the air rotating in the direction adjacent the screen has a height in the longitudinal direction and a height of the solid wall portion in the longitudinal direction is greater than the height of the air rotating in the direction adjacent the screen.
6. The surface cleaning apparatus of claim 1 wherein at least a portion of the screen is tapered.
7. The surface cleaning apparatus of claim 1 wherein the screen is tapered.
8. The surface cleaning apparatus of claim 1 wherein the screen has a first end located at an air outlet end of the cyclone chamber and a second opposed end axially inwardly therefrom and at least a portion of the screen towards the second opposed end is tapered.
9. The surface cleaning apparatus of claim 1 wherein the cyclone air inlet has a first end located at an air outlet end of the cyclone chamber and a second opposed end located axially inwardly therefrom and the screen has a first end located at an air outlet end of the cyclone chamber and a second opposed end axially inwardly therefrom wherein a portion of the screen positioned axially inwardly from the second opposed end of the cyclone air inlet is tapered.
10. The surface cleaning apparatus of claim 1 wherein the cyclone air inlet has a first end and a second opposed end located axially inwardly therefrom and the screen has a first end and a second opposed end axially inwardly therefrom wherein a portion of the screen positioned axially inwardly from the second opposed end of the cyclone air inlet is tapered.
11. The surface cleaning apparatus of claim 1 wherein the cyclone air inlet is rectangular in shape.
12. The surface cleaning apparatus of claim 1 wherein the solid wall portion is integral with the screen.