Shroud and cyclonic cleaning apparatus incorporating same

• US 5,853,440 A
• Filed: 08/14/1997
• Issued: 12/29/1998
• Est. Priority Date: 12/28/1994
• Status: Expired due to Fees

• Current Assignee: Notetry Limited
• Original Assignee: Notetry Limited
• Inventors: Dyson, James
• Primary Examiner(s): SMITH, DUANE
• Application Number:
  US08/860,362
• Time in Patent Office: 502 Days
• Field of Search: 55/345, 55/337, 55/391, 55/410, 55/459.1, 55/449, 55/473, 55/DIG. 3, 15/353
• US Class Current: 55/337
• CPC Class Codes: A47L 9/1633 Concentric cyclones
• CPC Class Codes: B04C 11/00 Accessories, e.g. safety or control devices, not otherwise provided for , e.g. regulators, valves in inlet or overflow ductingwith electrostatic precipitating arrangements B03C3/14
• CPC Class Codes: B04C 5/10 with perforated walls
• CPC Class Codes: B04C 5/26 for series flow
• CPC Class Codes: Y10S 55/03 Vacuum cleaner

Abstract

The invention provides a shroud (10; 40) for use in apparatus incorporating cyclonic dust separation structure for separating dirt and dust from an airflow, the shroud (10; 40) including a perforated portion (14; 44) having a multiplicity of perforations (30; 46) for allowing the airflow to pass therethrough. According to invention, the perforated portion (14) has a lower edge (16) and a lip (18) depending therefrom, the lip (18) including a parallel-sided portion (34) having an inclined distal end and a step (38) formed radially inwardly of the parallel-sided portion (34) and at the proximal end thereof. The invention improves performance of the dust separation apparatus in conjunction with which the shroud (10; 40) is utilized.

Claims

1. A shroud for use in apparatus incorporating cyclonic dust separation means for separating dirt and dust from an airflow, the shroud comprising a perforated portion having a lower edge and a lip depending therefrom, the lip comprising a parallel-sided portion having an inclined distal end, wherein a step is formed radially inwardly of the parallel-sided portion and at the proximal end thereof.

2. A shroud as claimed in claim 1, wherein the breadth of the step is substantially equal to the breadth of the parallel-sided portion.

3. A shroud as claimed in claim 1 or 2, wherein the height of the step is substantially equal to the breadth thereof.

4. A shroud as claimed in any one of claims 1 or 2 wherein the breadth of the parallel-sided portion is substantially 2 mm.

5. A shroud as claimed in any one of claims 1 or 2 wherein the parallel-sided portion extends substantially parallel to the longitudinal axis of the shroud.

6. A shroud as claimed in any one of claims 1 or 2 wherein the lip extends substantially 15 mm below the lower edge of the perforated portion.

7. A shroud as claimed in any one of claims 1 or 2 wherein the distal end of the lip is inclined at an angle of substantially 45°

to the parallel sides of the lip.

8. A shroud as claimed in any one of claims 1 or 2 wherein the perforated portion is cylindrical.

9. Apparatus as claimed in claim 1 wherein the cyclonic dust separation means comprise a low efficiency cyclone and a high efficiency cyclone positioned downstream of the low efficiency cyclone, the shroud being positioned between the two cyclones.

10. Apparatus as claimed in claim 9 wherein the apparatus consists of a vacuum cleaner.

11. A shroud as claimed in claim 3 wherein the parallel-sided portion extends substantially parallel to the longitudinal axis of the shroud.

12. A shroud as claimed in claim 4 wherein the parallel-sided portion extends substantially parallel to the longitudinal axis of the shroud.

13. A shroud as claimed in claim 3 wherein the perforated portion is cylindrical.

14. A shroud as claimed in claim 4 wherein the perforated portion is cylindrical.

15. A shroud as claimed in claim 5 wherein the perforated portion is cylindrical.

16. A shroud as claimed in claim 6 wherein the perforated portion is cylindrical.

17. A shroud as claimed in claim 7 wherein the perforated portion is cylindrical.

18. A shroud as claimed in claim 11 wherein the perforated portion is cylindrical.

19. A shroud as claimed in claim 12 wherein the perforated portion is cylindrical.