Laundry appliance

1. A laundry appliance comprising an outer housing defining a washing space, a drum mounted rotatably in the outer housing and a door in the outer housing closing the washing space, the drum comprising an inner side wall and an outer side wall separate from the inner side wall, the inner and outer side walls being perforated to allow washing liquid to flow into and out of the drum via the perforations, wherein the area of the perforations per unit area of the outer side wall is greater than the area of the perforations per unit area of the inner side wall.

2. A laundry appliance as claimed in claim 1 , wherein all of the perforations are circular.

3. A laundry appliance as claimed in claim 1 or 2 , wherein the perforations in the inner side wall are all the same size.

4. A laundry appliance as claimed in claim 3 , wherein all of the perforations in the outer side wall are larger than any of the perforations in the inner side wall.

5. A laundry appliance as claimed in claim 4 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 10% greater than the total area of the perforations in the inner side wall per unit area thereof.

6. A laundry appliance as claimed in claim 5 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 20% greater than the total area of the perforations in the inner side wall per unit area thereof.

7. A laundry appliance as claimed in claim 1 or 2 , wherein the perforations in the outer side wall are all the same size.

8. A laundry appliance as claimed in claim 7 , wherein all of the perforations in the outer side wall are larger than any of the perforations in the inner side wall.

9. A laundry appliance as claimed in claim 8 , wherein each of the perforations in the outer side wall is larger than each of the perforations in the inner side wall.

10. A laundry appliance as claimed in claim 9 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 10% greater than the total area of the perforations in the inner side wall per unit area thereof.

11. A laundry appliance as claimed in claim 9 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 20% greater than the total area of the perforations in the inner side wall per unit area thereof.

12. A laundry appliance as claimed in claim 8 , wherein each perforation in the outer side wall is radially aligned with one of the perforations in the inner side wall.

13. A laundry appliance as claimed in claim 8 , wherein each of the perforations in the outer side wall is larger than each of the perforations in the inner side wall.

14. A laundry appliance as claimed in claim 1 or 2 , wherein each perforation in the outer side wall is radially aligned with one of the perforations in the inner side wall.

15. A laundry appliance as claimed in claim 1 or 2 , wherein all of the perforations in the outer side wall are larger than any of the perforations in the inner side wall.

16. A laundry appliance as claimed in claim 1 or 2 , wherein the inner side wall is rigidly attached to the outer side wall and is rotatable therewith.

17. A laundry appliance, comprising an outer housing and a drum mounted rotatably therein, the drum comprising an inner side wall and an outer side wall separate from the inner side wall, the inner and outer side walls being perforated to allow washing liquid to flow into and out of the drum via the perforations,

wherein the area of the perforations per unit area of the outer side wall is greater than the area of the perforations per unit area of the inner side wall and

wherein the inner side wall is rotatably mounted so as to be rotatable separately from the outer side wall.

18. A laundry appliance as claimed in claim 1 or 2 , further comprising a watertight tub in which the drum is rotatably mounted, and wherein the drum is rotatable about an axis which is substantially horizontal.

19. A laundry appliance comprising an outer housing and a drum mounted rotatably therein, the drum comprising an inner side wall and an outer side wall, the inner and outer side walls being perforated to allow washing liquid to flow into and out of the drum via the perforations and the inner side wall being rotatable at least in part relative to the outer side wall wherein the area of the perforations per unit area of the outer side wall is greater than the area of the perforations per unit area of the inner side wall.

20. A laundry appliance as claimed in claim 19 , wherein all of the perforations are circular.

21. A laundry appliance as claimed in claim 19 or 20 , wherein the perforations in the inner side wall are all the same size.

22. A laundry appliance as claimed in claim 19 or 20 , wherein the perforations in the outer side wall are all the same size.

23. A laundry appliance as claimed in claim 19 or 20 , wherein all of the perforations in the outer side wall are larger than any of the perforations in the inner side wall.

24. A laundry appliance as claimed in claim 23 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 10% greater than the total area of the perforations in the inner side wall per unit area thereof.

25. A laundry appliance as claimed in claim 23 , wherein the total area of the perforations in the outer side wall per unit area thereof is at least 20% greater than the total area of the perforations in the inner side wall per unit area thereof.

26. A laundry appliance as claimed in claim 19 or 20 , wherein each perforation in the outer side wall is radially aligned with one of the perforations in the inner side wall.