Surface cleaning head

1. A surface cleaning head for a surface cleaning apparatus comprising:

a) a brush chamber comprising a dirty air inlet and a rotary brush;

b) a dirty air outlet, and a dirty airflow path extending between the dirty air inlet and the dirty air outlet;

c) an air turbine positioned in an air turbine chamber wherein the air turbine chamber is isolated from the dirty airflow path, the air turbine being drivingly connected to the rotary brush; and,

d) a dirt tray in the airflow path downstream of the rotary brush, the dirt tray having a collection surface.

2. The surface cleaning head of claim 1 , wherein the dirt tray is positioned upstream from the air turbine.

3. The surface cleaning head of claim 2 , further comprising a first air flow path extending from a turbine air chamber air inlet to the dirty air outlet wherein the air turbine is positioned in the first air flow path and a second air flow path from the dirty air inlet to the dirty air outlet.

4. The surface cleaning head of claim 1 , wherein the air turbine chamber comprises an air turbine airflow path extending from an air turbine chamber air inlet to the dirty air outlet and the air turbine is positioned air turbine airflow path.

5. The surface cleaning head of claim 4 , wherein the air turbine chamber air inlet is separate from the dirty air inlet.

6. The surface cleaning head of claim 5 , wherein the dirty air outlet is downstream of the dirty air inlet and the air turbine chamber air inlet.

7. The surface cleaning head of claim 4 , wherein the dirty air outlet is downstream of the dirty air inlet and the air turbine chamber air inlet.

8. The surface cleaning head of claim 1 , wherein the air turbine chamber is positioned above the dirty airflow path.

9. The surface cleaning head of claim 1 , wherein the air turbine chamber is positioned above the dirt tray.

10. The surface cleaning head of claim 1 , wherein the air turbine chamber is positioned adjacent a lateral side of the surface cleaning head.

11. The surface cleaning head of claim 1 , further comprising a dirt barrier positioned between the dirty air inlet and the dirt tray and the collection surface is positioned below an upper end of the dirt barrier.

12. The surface cleaning head of claim 11 , wherein the dirt barrier is integrally formed with the collection surface.

13. The surface cleaning head of claim 1 , wherein the dirt tray extends laterally across the surface cleaning head.

14. The surface cleaning head of claim 1 , wherein the collection surface is formed by a lower wall of the surface cleaning head.

15. The surface cleaning head of claim 1 , further comprising a drive linkage that drivingly connects the air turbine to the rotary brush and comprises a power output shaft, a portion of the power output shaft positioned exterior of the air turbine chamber and a fan belt drivingly connecting the power output shaft to the rotary brush.

16. The surface cleaning head of claim 1 , further comprising a first air flow path extending from a turbine air chamber air inlet to the dirty air outlet wherein the air turbine is positioned in the first air flow path and a second air flow path from the dirty air inlet to the dirty air outlet.

17. The surface cleaning head of claim 1 , wherein the surface cleaning head is an auxiliary surface cleaning head and the outlet is adapted to be removably connected to an airflow conduit of the surface cleaning apparatus.

18. A surface cleaning head comprising:

a) a brush chamber comprising a dirty air inlet and a rotary brush;

b) a dirty air outlet, and a dirty airflow path extending between the dirty air inlet and the dirty air outlet;

c) an air turbine drivingly connected to the rotary brush; and,

d) a dirt tray in the airflow path downstream of the rotary brush, the dirt tray having a collection surface and a lateral extent that is generally the same as that of the dirty air inlet.