Vacuum cleaner

1. A vacuum cleaner comprising:

a housing having a suction nozzle;

a source of suction in fluid communication with the suction nozzle for generating a working airstream through the suction nozzle;

a separating and collection assembly for separating and collecting debris from the working airstream;

an agitator provided within the suction nozzle; and

a sole plate defining a suction inlet for the suction nozzle and provided on a lower side of the suction nozzle, wherein the sole plate comprises a front wall, a rear wall, and a plurality of upwardly-curved cross ribs extending between the front and rear walls;

wherein the cross ribs are curved at a center of the cross ribs between the front and rear walls.

2. The vacuum cleaner of claim 1 , wherein the cross ribs define a tunnel forming a debris path, such that debris may pass beneath the cross ribs through the tunnel in a substantially lateral direction along the debris path before being ingested through the suction inlet.

3. The vacuum cleaner of claim 1 , wherein the sole plate secures the agitator within the housing.

4. The vacuum cleaner of claim 3 , wherein the sole plate comprises agitator mounting locations configured to mount the agitator adjacent the suction inlet.

5. The vacuum cleaner of claim 3 , wherein the agitator comprises a rotatable brushroll positioned within the suction nozzle adjacent the suction inlet for rotational movement about an axis.

6. The vacuum cleaner of claim 5 , wherein the cross ribs define a tunnel with a debris path axis that is spaced from the axis.

7. The vacuum cleaner of claim 5 , wherein the brushroll comprises a dowel with a plurality of bristles projecting from the dowel, and a plurality of grooves formed on the dowel for clearance of the cross-ribs.

8. The vacuum cleaner of claim 1 , wherein the cross ribs define a substantially semicircular gap between a surface to be cleaned and a bottom of the cross ribs.

9. The vacuum cleaner of claim 1 , wherein multiple suction nozzle openings are defined by spaces between the cross ribs and the front and rear walls to collectively form the suction inlet.

10. The vacuum cleaner of claim 1 , wherein the sole plate further comprises a belt guard.

11. The vacuum cleaner of claim 1 , wherein the housing comprises an upright unit coupled with a base unit adapted to be moved over a surface to be cleaned, and wherein the suction nozzle, agitator, and sole plate are provided with the base unit.

12. The vacuum cleaner of claim 11 , wherein the base unit comprises an upper base housing and the sole plate is fastened to the underside of the upper base housing.

13. The vacuum cleaner of claim 11 , wherein the source of suction comprises a motor/fan assembly carried by the upright unit.

14. The vacuum cleaner of claim 1 , wherein the collection assembly comprises a cyclone separator separating contaminants from a working airstream and a removable debris cup receiving the separated contaminants from the cyclone separator.

15. The vacuum cleaner of claim 1 , wherein no portion of the plurality of cross ribs extends below the front and rear walls.

16. The vacuum cleaner of claim 1 , wherein the sole plate comprises a perimeter frame defined by the front and rear walls, and further defined by side walls extending between the front and rear walls, wherein no portion of the plurality of cross ribs extends below the perimeter frame.

17. A vacuum cleaner comprising:

a housing having a suction nozzle;

a source of suction in fluid communication with the suction nozzle for generating a working airstream through the suction nozzle;

a separating and collection assembly for separating and collecting debris from the working airstream;

an agitator provided within the suction nozzle; and

a sole plate defining a suction inlet for the suction nozzle and provided on a lower side of the suction nozzle, wherein the sole plate comprises a front wall, a rear wall, and a plurality of cross ribs extending between the front and rear walls;

wherein the cross ribs define a gap between a surface to be cleaned and a bottom of the cross ribs, wherein the gap comprises a substantially semicircular gap between the surface to be cleaned and the bottom of the cross ribs.

18. The vacuum cleaner of claim 17 , wherein the cross ribs have an arched shape that spans between the front and rear walls.