Cyclonic vacuum cleaner

Abstract

A vacuum cleaner includes a pair of low efficiency cyclones connected upstream of respective groups of high efficiency cyclones by respective elongate ducts. The high efficiency cyclones of each group can be arranged in a line or a cluster extending away from their respective low efficiency cyclone, such that at least a portion of one side of the low efficiency cyclone is exposed. The high efficiency cyclones can be connected to their respective elongate ducts at respective positions along the length thereof, with each cyclone comprising an inlet connecting to the duct. The inlets of each high efficiency cyclone can be stepped along the axis of the duct with respect to the inlet of each other cyclone of the group, in a direction which extends across the width of the duct.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this invention will now be described by way of examples only and with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of an embodiment of vacuum cleaner in accordance with this invention;

FIG. 2 is a perspective view of the separation stages of the cleaner of FIG. 1;

FIG. 3 is a sectional view along the line III-III of FIG. 2;

FIG. 4 is a sectional view along the line IV-IV of FIG. 2; and

FIGS. 5A to 5E are schematic views of the arrangement of the cyclonic stages of alternative embodiments of vacuum cleaners in accordance with this invention.

Claims

1. A vacuum cleaner comprising a low efficiency cyclone and a plurality of higher efficiency cyclones mounted externally of the low efficiency cyclone, wherein at least two of said high efficiency cyclones are arranged at positions which are spaced apart from the rotational axis of the low efficiency cyclone by respective different distances.

2. A vacuum cleaner as claimed in claim 1, in which said high efficiency cyclones are arranged in a line extending away from said low efficiency cyclone.

3. A vacuum cleaner as claimed in claim 1, in which said high efficiency cyclones are arranged in a cluster extending away from said low efficiency cyclone.

4. A vacuum cleaner as claimed in claim 1, comprising a plurality of low efficiency cyclones connected in series with each other.

5. A vacuum cleaner as claimed in claim 1, comprising a plurality of low efficiency cyclones connected in parallel with each other.

6. A vacuum cleaner as claimed in claim 4, in which the outlet of each low efficiency cyclone is connected to a respective group of high efficiency cyclones.

7. A vacuum cleaner as claimed in claim 4, in which the outlets one low efficiency cyclone is connected to the same plurality of high efficiency cyclones as another low efficiency cyclone.

8. A vacuum cleaner as claimed in claim 1, in which said high efficiency cyclones are arranged in parallel, in series or in a series/parallel configuration with each other.

9. A vacuum cleaner as claimed in claim 1, in which said high efficiency cyclones are arranged in a cluster, one or more of said low efficiency cyclones being arranged peripherally of the cluster.

10. A vacuum cleaner as claimed in claim 1, in which said high efficiency cyclones are arranged in a cluster around one or more low efficiency cyclones.

11. A vacuum cleaner as claimed in claim 1, in which a flow duct extends radially of the or each low efficiency cyclone, at least some of the high efficiency cyclones being connected to the flow duct.

12. A vacuum cleaner as claimed in claim 11, in which the flow duct is elongate, the high efficiency cyclones being positioned at respective positions along the length of the elongate duct.

13. A vacuum cleaner as claimed in claim 12, in which the cross-sectional area of the flow duct varies along its length.

14. A vacuum cleaner as claimed in claim 13, in which the cross-sectional area of the flow duct varies along its length in proportion to the number of cyclones connected downstream thereof.

15. A vacuum cleaner as claimed in claim 11, in which each high efficiency cyclone comprises an inlet connecting to the duct, the inlets being stepped with respect to each other along the axis of the duct in a direction which extends across the width of the duct.

16. A vacuum cleaner comprising a plurality of cyclones connected to an elongate flow duct at respective positions along the length thereof, each cyclone comprising an inlet connecting to the duct, the inlets being stepped with respect to each other along the axis of the duct in a direction which extends across the width of the duct.

17. A vacuum cleaner as claimed in claim 16, in which the cyclones are stepped with respect to each other along the axis of the duct in a direction which extends transverse the longitudinal axis of the duct.

18. A vacuum cleaner as claimed in claim 17, in which the cyclones comprise a rotational axis, the rotational axis of each cyclone being parallel.

19. A vacuum cleaner as claimed in claim 17, in which the rotational axis of each cyclone extends perpendicular to the longitudinal axis of the duct.

20. A vacuum cleaner as claimed in claim 16, in which the duct comprises a first planar wall portion and a second opposed wall portion which converges towards the first planar wall portion, the cyclones comprising inlets positioned along said convergent second wall portion.

21. A vacuum cleaner as claimed in claim 20, in which the first and second wall portions respectively form the roof and floor of the duct, the cyclones depending from the floor.