Vacuum cleaner

Abstract

 A vacuum cleaner comprises a detachable separation unit having first and second devices 13,26 for separating dirt and dust from an airflow through the cleaner. The dirt and dust separated by the devices 13 is deposited in a first collection region disposed at the bottom of a cyclone chamber 14. The dirt and dust separated by the second device 26 is collected in a second collection region 30 which is normally closed by a valve 35 to prevent air from leaving the cyclone chamber 14. An actuator 34 is provided for automatically opening the valve 35 to release the collected dirt and dust in the second collection region 30 when the unit is detached from the body of the cleaner, so that it can fall from the unit along with dirt and dust from the first region when a flap 17 at the bottom of the chamber 14 is opened.

Description

[0001] This invention relates to a vacuum cleaner.

[0002] Vacuum cleaners all incorporate some form of dust separation apparatus to separate dirt and dust from an induced airflow. Historically, vacuum cleaners were provided with porous filter bags which filter and collect the dust. Once full the dust bag can be discarded and replaced.

[0003] Nowadays it has become fashionable to provide vacuum cleaners with cyclonic separators which can simply be emptied without the need to purchase dust bags. Cyclonic separators also avoid the problem that dust bags can become clogged with dust if they are not changed regularly. A disadvantage of such cyclonic vacuum cleaners is that the dirt and dust collected at the bottom of the cyclone chamber can become re-entrained into the airflow if too much separated dirt and dust accumulates at the bottom of the chamber. Accordingly such cleaners have a limited capacity for separated dirt and dust and need to be emptied regularly. Furthermore, these collected dirt and dust at the bottom of the cyclone chamber tends to expand when there is any airflow through the separator, thereby limiting the capacity of the dirt and dust which can be retained.

[0004] Another disadvantage of known cyclonic vacuum cleaners is that the separated dirt and dust is simply emptied by removing the collection chamber from the cleaner and opening a flap or turning the chamber upside-down. The dirt and dust then falls under gravity into a refuse receptacle. This process is both messy and unhygienic.

[0005] Various solutions to the above mentioned problems have been proposed.

[0006] JP2010119623 discloses a vacuum cleaner having a cyclone separation apparatus which comprises a cylindrical cyclone chamber having a tubular side wall. A region is provided at the lower end of the chamber for collecting matter separated from the airflow by the cyclone separator. An auger is mounted in the collection region of the chamber, the auger having a vane which drives the separated dust downwardly into the collection region and serves to compact the collected dust.

[0007] Our co-pending UK Patent Application No. 1215396.1 discloses a vacuum cleaner having a cyclonic separator having a separation chamber provided with a tubular side wall, an inlet disposed at a first end of the chamber for the fluid to be treated, a primary region disposed at the second end of the chamber for collecting matter separated from the fluid, an auger mounted within the chamber for rotation about the longitudinal axis thereof, the auger having a vane which extends both radially of the chamber and longitudinally of the chamber towards the second end thereof in a first helical direction; and a motor for rotating the auger about the longitudinal axis of the chamber in a direction opposite to said helical direction.

[0008] In use, the auger is rotated and the dust-laden air entering the cylindrical cyclone chamber flows helically within the chamber between adjacent turns of the helically-extending vane. The direction of rotation of the auger is opposite to the helical direction and thus the separated matter is driven by the auger towards the primary collection region and compacted. In this manner, the capacity of the separator for separated matter is substantially increased and the separator has to be emptied less frequently and the risk of re-entrainment of the separated matter is reduced.

[0009] A further separation device is mounted downstream of the cyclone separation device for removing any finer dirt and dust particles. Any dirt and dust particles separated by the downstream cyclone separation device fall down a tubular shaft of the auger towards the primary collection region. In use, the tubular shaft of the auger is normally closed at its lower upper end by a valve, to prevent the flow of air along the shaft and thereby alleviate the risk of separated dirt and dust being carried in the reverse direction along the shaft from the primary collection chamber towards an outlet of the apparatus. The valve serves to retain the dirt and dust particles separated by the downstream cyclone separation device inside the shaft, which acts as a secondary collection region.

[0010] As the amount of retained dirt and dust builds up in the secondary collection chamber during use, the valve is periodically opened to allow the dirt and dust particles separated by the downstream cyclone separation device to fall out of the secondary collection chamber into to the primary collection region. A second valve member arranged at the upper end of the shaft simultaneously closes to continue to prevent the flow of air along the shaft from the primary collection region to the outlet of the apparatus whilst the first valve member is open.

[0011] We have now devised an improved cyclone separation apparatus of the kind disclosed in UK Patent Application No. 1215396.1.

[0012] In accordance with the present invention, there is provided a vacuum cleaner incorporating separation apparatus for separating matter from a flow of fluid, the apparatus comprising:

a first device for separating dirt and dust from the fluid flow,

a second device mounted downstream of the first device for separating dirt and dust from the fluid flow from the first device,

a primary collection chamber for collecting dirt and dust separated by the first device,

a passageway extending from an outlet of the second device to said primary collection chamber for conveying dirt and dust separated by the second device to said collection chamber,

a valve member for closing the passageway during use of the apparatus and arranged to retain dirt and dust separated by the second device in a secondary collection chamber formed by the passageway,

an actuator for opening the valve member, and

means for opening the first valve member to allow dirt and dust to fall out of the unit from the primary and secondary collection chambers, said means being operable when the cleaner is disassembled.

[0013] In use, the valve member is normally closed to prevent the flow of fluid along the passageway and thereby alleviate the risk of separated dirt and dust being carried in the reverse direction along the passageway from the primary collection chamber towards an outlet of the cleaner. Any dirt and dust separated by the downstream separation device is retained by the first valve member. The volume of the secondary collection chamber is sufficient such that it only has to be emptied as frequently as the primary collection chamber. In order to empty the primary collection chamber, the cleaner has to be disassembled and this causes the valve to open allowing the dirt and dust to fall from the secondary collection chamber into the primary collection chamber.

[0014] In this manner, the need to periodically operate the valve to release the dirt and dust separated by the second separation device into the collection chamber is avoided. Also, the need for a further valve is avoided because the valve is opened when the cleaner is disassembled and inoperative.

[0015] Preferably the valve is disposed adjacent the lower end of the passageway.

[0016] Preferably the passageway comprises an elongate tubular duct.

[0017] Preferably the valve opening means comprises an elongate arm which extends along the duct towards the second separation device.

[0018] Preferably the arm extends through the second separation device.

[0019] Preferably the valve is normally biased into its open position.

[0020] Preferably the separation apparatus is provided in a unit which is detachable from a body of the cleaner.

[0021] The valve opening means is preferably operable to open the valve when the unit is detached from the body e.g. for emptying.

[0022] Preferably the valve opening means comprises an actuator moveable between a first position and a second position in which the valve is respectively open and closed, the actuator being normally biased into said first position, the actuator being retained in said second position by a portion of the cleaner when the cleaner is assembled.

[0023] Preferably the actuator is moveable between said first and second positions along a line which extends substantially perpendicular to said elongate arm.

[0024] Preferably the arm comprises a plurality of teeth which are arranged to rotate a rotary toothed member, said member being arranged to cause axial displacement of the elongate arm so as to open and close the valve as the actuator moves between said first and second positions.

[0025] Preferably the primary collection chamber comprises a lower end wall against which the dirt and dust separated by the first device collects, in use said end wall being disposed away from a lower end of the passageway.

[0026] Preferavly the said end wall is arranged to move away from said lower end of the passageway in use to expand the volume of said primary collection chamber.

[0027] An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a separation unit of a vacuum cleaner in accordance with the present invention;

Figure 2 is a sectional view of the separation unit along the line II of Figure 1; and

Figure 3 is a sectional view of the upper portion of the separation unit along the line III-III of Figure 1.

[0028] Referring to Figures 1 and 2 of the drawings, there is shown a dust separation unit of a vacuum cleaner, the unit having a dirty air inlet port 10 and an outlet port 11 for cleaned air. The inlet port 10 extends through the upper end of a tubular side wall 12 of a first separation device in the form of a cyclone separator 13, which is arranged at the lower end of the unit. The cyclone separator 13 comprises a cylindrical cyclone chamber 14.

[0029] The cyclone separator 13 further comprises a tubular outer wall 15 which is a tight but sliding fit around the tubular side wall 12. The upper end of the tubular outer wall 15 is provided with an inwardly directed seal 16, which lightly seals against the exterior surface of the tubular side wall 12. The lower end of the tubular outer wall 15 is provided with a flap or closure 17, which serves to form a bottom end wall of the cyclone chamber 14 and which can be opened to allow separated dirt and dust to be emptied from a first collection region at the bottom of the chamber 14. The flap 17 is connected to the tubular outer wall 15 by a hinge (not shown). A catch 18 is provided for retaining the flap 17 in its closed position.

[0030] The upper end of the chamber 14 is closed by a top wall 19 having a central aperture. A perforated tubular shroud 20 extends around the aperture and depends from the top wall 19 into the cyclone chamber 14.

[0031] An auger 21 is mounted below the shroud 20 at the lower end of the chamber 14 for rotation about the central longitudinal axis thereof. The auger 21 comprises a central axially-extending tubular shaft 22 and a vane 23 which extends helically around the exterior of the shaft 22 in a clockwise direction. In the example shown, the vane 23 has approximately one and a half turns but it will be appreciated that more or fewer turns could be provided. The radial extent of the vane 23 increases towards its lower end, such that the last half turn contacts the interior surface of the tubular side wall 12 of the cyclone chamber 14. The tubular shaft 22 of the auger 21 extends upwardly through the shroud 20, and a flange 24 thereon acts to close the lower end of the shroud 20.

[0032] A motor 33 is arranged to rotate the shaft 22 of the auger 21 about the central longitudinal axis of the cyclone chamber 14.

[0033] The interior of the shroud 20 is fluidly connected via ducts 25 to the upper end of a second separation device 26 comprising an array of high efficiency cyclones 27 which are fluidly connected in parallel. The high efficiency cyclones 27 each comprise a frusto-conical wall having an open lower end through which separated dirt and dust is discharged into a housing 28 having a frusto-conical bottom wall 29 which tapers inwardly and downwardly towards an axially-depending tube 30.

[0034] The tube 30 extends as a close but sliding fit internally of the tubular shaft 22 of the auger 21. The tube 30 defines an elongate second collection chamber 31 having an upper end connected to the housing 28 and a lower end which terminates at the bottom of the chamber 14.

[0035] A valve member in the form of a plunger 35 is arranged at the lower end of the tube 30 to prevent the passage of air out of the chamber 14 and upwardly along the tube 30 towards the high efficiency cyclones 27. An elongate arm 34 extends upwardly along the tube 30 from the plunger 35, a spring 36 acts to bias the arm 34 downwardly to retain the plunger 35 in its normally-open position away from the bottom of the tube 30.

[0036] Referring to Figure 3 of the drawings, the upper end of the arm 34 extends through the second separation device 26 into a gearbox 37 mounted on the top wall of the unit. The upper end of the arm 34 is provided with a series of teeth 38 which mesh with a toothed wheel 39. The wheel 39 is also meshed with a series of teeth 40 provided on the proximal end of a slider arm 41. The distal end of the slider arm 41 comprises a portion 42 which projects out of the gearbox 37 under the outlet port 11 of the unit.

[0037] In use, when the unit is fitted to the body of a vacuum cleaner, the outlet port 11 of the unit is brought into registration with a complementary port on the body. During fitting of the unit, a portion of the body acts on the projecting portion 42 of the slider arm 41 and pushes it inwardly into the position shown in Figure 3. This causes the toothed wheel 39 to rotate and lift the arm 34 against the spring bias, thereby causing the plunger 35 to seal against the bottom of the tube 30.

[0038] In operation of the vacuum cleaner, air is drawn into the inlet 10 of the unit by a motor/fan unit (not shown) mounted downstream of the outlet 11 of the unit. The inlet 10 is connected to a floor-engaging head of the vacuum cleaner, so that dust-laden air enters the cyclone chamber 14 via the inlet port 10. The motor 33 is actuated in order to rotate the auger 21 in the counter-clockwise direction (i.e. opposite to the direction in which the vane 23 is wound).

[0039] The inlet 10 has a tangential orientation with respect to the wall 12 of the cyclone chamber 14 so that a cyclonic air flow is created inside the chamber 14. The air spirals downwardly around the chamber 14 towards its lower end. As the air flows downwards, the volume of air in the spiral flow is constantly being diminished by virtue of it having been drawn radially through the perforated shroud 20 towards the second separation stage 26.

[0040] As the air swirls inside the chamber 14, larger (denser) particles in the rotating airflow have too much inertia to follow the tight curve of the airflow and strike the outside wall 12 of the chamber 14, moving then to the bottom of the chamber 14 where they are deposited.

[0041] The partly cleaned air flowing through the perforated shroud 20 is drawn upwardly and subsequently passes through the ducts 25 and enters the array of high efficiency cyclones 27 which are connected in parallel. The denser particles in the rotating airflow within the high efficiency cyclones 27 strike the frusto-conical wall of the cyclones and fall through the open lower ends of the cyclones 27 into the chamber 28. The cleaned air flows axially out of the top end of the cyclones 27 to the outlet 11 via a filter chamber 44.

[0042] Any dirt or dust separated by the high efficiency cyclones 27 falls onto the frustoconical wall 29 of the filter chamber 28 and into the duct 30, where it is retained by the plunger 35 inside the second collection chamber 31. The plunger 35 acts to prevent dust-laden air from being undesirably drawn out of the cyclone chamber 14 and up the tube 30 directly to the outlet 11 of the apparatus via a reverse flow through the cyclones 27.

[0043] During use, the auger 21 is constantly driven to drive any dirt and dust collected within the bottom of cyclone chamber 14 downwardly. As the volume of the separated matter increases, the auger 21 acts to force it against the flap 17 at the bottom end of the cyclone chamber 14. The tubular outer wall 15 then moves downwardly as the force applied to the flap 117 increases. In this manner the volume available for holding the separated matter at the bottom of the cyclone chamber 14 increases. The reduced pressure inside the cyclone chamber 14 has a tendency to pull the flap 17 upwardly towards the auger 21, thereby maintaining the compactness of the unit and assisting compaction. The increasing diameter of the vane 23 of the auger 120 also enhances the compaction.

[0044] In order to empty the collected dirt and dust, the unit is removed from the body once the vacuum cleaner has been de-energised. This allows the projecting portion 42 of the slider arm 41 to move outwardly under the spring bias, thereby causing the plunger 35 to move away from the bottom of the tube 30. The dirt and dust collected in the second collection chamber 31 then falls out of the unit along with the compacted dirt and dust when the flap 17 is opened.

[0045] A vacuum cleaner in accordance with the present invention is simple in construction yet extremely effective in operation and exhibits a greatly increased capacity for holding collected dirt and dust compared with conventional cyclonic vacuum cleaners. Also, the cleaner can be operated continuously without having to stop to discharge the dirt or dust separated by the high efficiency cyclones.

Claims

1. A vacuum cleaner incorporating separation apparatus for separating matter from a flow of fluid, the apparatus comprising:

a first device for separating dirt and dust from the fluid flow,

a second device mounted downstream of the first device for separating dirt and dust from the fluid flow from the first device,

a primary collection chamber for collecting dirt and dust separated by the first device,

a passageway extending from an outlet of the second device to said primary collection chamber for conveying dirt and dust separated by the second device to said collection chamber,

a valve member for closing the passageway during use of the apparatus and arranged to retain dirt and dust separated by the second device in a secondary collection chamber formed by the passageway,

an actuator for opening the valve member, and

means for opening the first valve member to allow dirt and dust to fall out of the unit from the primary and secondary collection chambers, said means being operable when the cleaner is disassembled.

2. A vacuum cleaner as claimed in claim 1, in which the valve is disposed adjacent a lower end of the passageway.

3. A vacuum cleaner as claimed in claims 1 or 2, in which the passageway comprises an elongate tubular duct.

4. A vacuum cleaner as claimed in any preceding claim, in which the valve opening means comprises an elongate arm which extends along the duct towards the second separation device.

5. A vacuum cleaner as claimed in claim 4, in which the arm extends through the second separation device.

6. A vacuum cleaner as claimed in any preceding claim, in which the valve is normally biased into its open position.

7. A vacuum cleaner as claimed in any preceding claim, in which the separation apparatus is provided in a unit which is detachable from a body of the cleaner.

8. A vacuum cleaner as claimed in claim 7, in which the valve opening means is operable to open the valve when the unit is detached from the body.

9. A vacuum cleaner as claimed in claim 8, in which the valve opening means comprises an actuator moveable between a first position and a second position in which the valve is respectively open and closed, the actuator being normally biased into said first position, the actuator being retained in said second position by a portion of the cleaner when the cleaner is assembled.

10. A vacuum cleaner as claimed in claim 9, in which the actuator is moveable between said first and second positions along a line which extends substantially perpendicular to said elongate arm.

11. A vacuum cleaner as claimed in claim 8 or claim 9, in which the arm comprises a plurality of teeth which are arranged to rotate a rotary toothed member, said member being arranged to cause axial displacement of the elongate arm so as to open and close the valve as the actuator moves between said first and second positions.

12. A vacuum cleaner as claimed in any preceding claim, in which the valve is arranged to close the passageway to prevent the flow of air from said first separation device to said second separation device along the passageway.

13. A vacuum cleaner as claimed in claim 12, in which the primary collection chamber comprises a lower end wall against which the dirt and dust separated by the first device collects, in use said end wall being disposed away from a lower end of the passageway.

14. A vacuum cleaner as claimed in claim 13, in which the said end wall is arranged to move away from said lower end of the passageway in use to expand the volume of said primary collection chamber.

Drawing