SUCTION CLEANER

Abstract: A suction cleaner using a dust separator with a separation chamber in which dust is separated from an airstream by centrifugal forces and preferably aided by a spinning rotor in the separation chamber.

Description: Suction Cleaner The present invention relates to a suction cleaner, in particular to a suction cleaner of the type in which dust and other debris are separated from air and collected in a container . It is known to provide a suction cleaner which includes a filter bag, which bag combines an air filtration surface with a debris collection bag. Such cleaners have the disadvantage that, as the debris collection bag fills, the air filtration surface becomes increasingly blocked, resulting in reduced suction for cleaning purposes. The bag then has to be removed for cleaning or, if it is a disposable bag, it has to be replaced by a new bag. It is also known to provide suction cleaners of the so-called "cyclone type", which employ cyclone arrangements to separate debris from an airflow by creating a cyclone effect in the airflow and allowing any debris in the air to fall to the bottom of a cyclone chamber. It is a disadvantage of such cleaners that their operating efficiency is low. It is a further disadvantage of such cleaners that it is necessary to arrange for the axis of the cyclone to be as close to vertical as possible, in order to encourage debris to drop from the air stream under gravity and to prevent the debris rejoining the airstream. It is an object of the present invention to provide a suction cleaner in which the above disadvantage of known suction cleaners are reduced or substantially obviated. The present invention provides a suction cleaner comprising a housing, a motor, a fan blade driveably coupled to the motor, an air inlet located upstream of the motor, a separation chamber in communication with the air inlet and an air outlet from the separation chamber, wherein the cleaner further comprises a rotor mounted for rotation in the separation chamber, the air inlet is arranged so as to provide a rotating air stream in the separation chamber and the air inlet and the air outlet from the separation chamber are arranged so as to provide a reversal, in the axial direction about the axis of rotation, of the rotating air stream in the separation chamber. The rotor may be driven by a motor and preferably comprises one or more separation blades. Alternatively and more preferably it may comprise one or more separation blades and one or more turbine blades. The separation blades of the rotor are preferably located upstream of the mouth of the air outlet from the separation chamber, and the mouth of the air outlet from the separation chamber most preferably comprises a collar which forms part of the rotor and is mounted for rotation with the rotor. The one or more separation blades may be located downstream or upstream of at least one of the debris outlet ports. The rotor preferably comprises one or more turbine blades located downstream of the reversal of the air stream in the separation chamber, which separation chamber is preferably annular in form. In another aspect, the present invention provides a suction cleaner comprising at least one spinning rotor placed in an air stream of the cleaner and a debris collection chamber into which debris is propelled by the spinning rotor. Debris is batted into a collection chamber by a spinning rotor rather than falling under the action of gravity, thus allowing a cleaner according to the present invention to be configured with the spin axis of the rotor (s) at any angle. This capability facilitates a wider variety of embodiments than was possible with prior art cyclone-based cleaners. For instance, a 'cylinder' vacuum cleaner where the 'cylinder' axis is arranged horizontally (see figure 1) is easily realised given the teaching of the present invention. The present invention has the additional advantage of allowing compact design of a cleaner whilst providing efficient debris separation. In another aspect, the present invention provides a suction cleaner comprising a housing, a motor, a fan blade driveably coupled to the motor, an air inlet located upstream of the motor, a separation chamber in communication with the air inlet, an air outlet from the separation chamber and a debris collection chamber wherein the air inlet is arranged so as to provide a rotating air stream in the separation chamber and the separation chamber is provided with at least one debris outlet port located in a peripheral wall of the separation chamber and communicating with the debris collection chamber. Further aspects, advantages and objectives of the invention will become apparent from a consideration of the drawings and the ensuing description, which, by way of example, describe a number of embodiments of the invention. Embodiments of a suction cleaner will now be described with reference to the accompanying drawings, in which Figure 1: A sectional view through the rotor spin axis of a first embodiment of the present invention. Figure 2 A view of a stator. Figure 3 : A sectional view through the rotor spin axis of the first embodiment of the invention incorporating a coarse pre-filter. Figure 4: A sectional view through the rotor spin axis of a third embodiment of the invention allowing for a secondary airflow under low flow conditions. Figure 5: A sectional view through the rotor spin axis of a fourth embodiment of the invention incorporating a turbine to power the rotor under low flow conditions . Figure 6: A sectional view through the rotor spin axis of a fifth embodiment incorporating a motor to assist powering of the rotor. Figure 7 : A perspective view partially cut away of a second embodiment of a suction cleaner. Figure 8 : An exploded view of a part of the cleaner of Figure 7. Figure 9 : A sectional view of the suction cleaner of Figure 7. Figure 10: A sectional view of a sixth embodiment of a suction cleaner . Figure 11: A sectional view of a seventh embodiment of a suction cleaner. Figure 1 shows a first embodiment of the present invention. A motor (2) spins a fan blade contained in a housing (11). The fan draws debris-laden air through a flexible tube (4) , into an inlet chamber (10) ; through a set of stator blades (5) , which change the direction of flow of the debris-laden air; and across a rotor (6) , causing the rotor (6) to spin on its axis (7) . The spinning rotor (β) bats debris out of the air stream; through a debris outlet port (9), arranged tangentially to the circular flow of debris; and into a collection chamber (8), which is advantageously substantially sealed to the atmosphere. Air, now largely free of debris, passes through the rotor (6) and through secondary filter stages (3) where very fine particles are removed from the flow. The cleaned air then passes across the fan, into a clean air exhaust chamber (12) and finally through a clean air outlet (1) . Inlet chamber (10) is annular in section normal to the rotor axis . Substantially sealing the collection chamber to the atmosphere has the effect of greatly increasing separation efficiency by preventing the fan from sucking air in through the debris outlet port (9) and drawing debris particles back into the main airflow. The collection chamber (8) may be either a rigid container to be emptied and reused, or a disposable bag that is discarded and replaced once full. Debris laden air which is shown in Figure 1 entering the inlet chamber (10) radially may advantageously be arranged to enter tangentially to encourage rotation around the rotor spin axis before passing through the stator blades (5). Separation efficiency may be increased by adding multiple, independent rotor stages, arranged in series, coaxially on the rotor support (7) . In addition, a means for removing large debris particles from the flow before the stator stage may be added. This may be a coarse filter (13), as shown in figure 3, which prevents large debris particles from proceeding past the inlet chamber (10), or some alternative large particle separation technique. Figure 3 shows a coarse filter (13) integrated with the first embodiment . One alternative technique for removing large particles from the flow is to arrange for air to enter the inlet chamber (10) tangentially as described above. The resulting cyclone in the inlet chamber (10) may then be used to separate large particles from the flow and divert them to the collection chamber or to a separate collection chamber. The debris outlet port (9) may incorporate a radial baffle to encourage debris that impinges on it to fall into the collection chamber (8) . The rotor (6) of the first and second embodiments are powered by using the energy in the moving air stream passing the rotor (6) . As this energy is reduced under low flow (e.g. suction tube blockage) conditions, provision may be made for a secondary airflow to assist powering the rotor (6) . One such embodiment, shown in Figure 4, incorporates a bypass valve (14) , which opens under low flow conditions, allowing air to pass to the inlet chamber (10) through secondary air inlet (15) . Another embodiment, shown in Figure 5, incorporates a secondary turbine (17), which draws air through a secondary inlet (16) when an air bypass valve (19) opens under low flow conditions. The secondary turbine (17), coupled to the rotor shaft (18) then assists in spinning the rotor (6) . An alternative to assisting the rotor (6) with a secondary airflow is shown in Figure 6. This embodiment incorporates a motor (20), which drives the rotor shaft (18) . The motor (20) may be permanently coupled to the rotor (6), constantly assisting it, or it may be linked through a clutch (21) , which disengages under adequate flow conditions. For example, clutch (21), may be centrifugal, acting to engage when the rotor (6) speed drops below a particular level. As can be seen from Figure 7 , which shows a second embodiment of the invention, a suction cleaner housing shown generally at SUBSTITUTESHEET(RULE26J 710 comprises a casing 702. An air inlet 704 is provided in the wall of the casing 702 for attachment of a flexible tube (not shown) . The air inlet 704 opens into a removable inlet chamber 6 located within the casing 710. A filter 708 is located in the inlet chamber 706 downstream of the inlet 704. A conduit 712 leads from the filter 708 to a separation chamber 14 which is annular in shape. A stator 716, comprises a plurality of fixed blades 732, adjacent pairs of which define an array of nozzles 734 and is located within the separation chamber 714, so that debris laden air entering the chamber 714 via the conduit 712 is directed through the stator 716. A debris outlet port 718 is located in a wall 720 of the separation chamber 714, downstream of the stator 716. The debris outlet port 718 is in communication with a debris collection chamber 722. The separation chamber 714 further comprises an outlet port 724 in which a conduit 726 is received. The conduit 726 opens into a fan housing 728 in which a fan (not shown) is located: The fan is driveably coupled to a motor 30, arranged within a clean air exhaust chamber 736 which is enclosed within the casing 702. A clean air outlet 738 is provided in the wall of the casing 702, downstream of the motor 730. The motor 730 is suitably an electric motor and can be either mains or battery driven. A rotor 740 is mounted for rotation in the separation chamber 714 about a rotor axis substantially coincident with the longitudinal axis of the conduit 724 and the axis of rotation of the fan driveable by the motor 730. The suction cleaner also includes a filter stage 748, located within the conduit 724, directly upstream of the fan housing 728. A suitable design of rotor is shown in detail in Figures 8 and 9. The rotor 740 is mounted for rotation about a rotor axis and comprises separation blades 742 and turbine blades 744. The rotor 740 is further provided with a collar 746 which forms part of the rotor and thus rotates with the rotor. The collar 746 is a close fit within the mouth of the conduit 726 and thus ensures that substantially all of the air stream is drawn through the turbine blades 744. In operation, the motor 730 drives the fan to create an air stream entering the housing at air inlet 704 and leaving the housing at clean air outlet 738. Debris laden air enters the inlet chamber 706 tangentially and is drawn through the filter 8 into the stator 716. Coarse debris which does not pass through the filter 708 is collected in the inlet chamber 706 which can be removed for cleaning. The stator 716 spins the debris laden air. As the debris laden air exits from the nozzles 734 defined by the stator blades 732, the debris entrained in the air is subjected to intense centrifugal forces directing it towards the wall 720 of the chamber 716. The high velocity spinning debris laden air stream passes through the even higher velocity separation blades 742 of the rotor 740. The blades 742 contact the debris in the air and further direct it towards the wall 720 of the chamber 716, and hence through the debris outlet port 718 to the debris collection chamber 722. The air stream from which the debris has been stripped is then diverted sharply through an angle of 180° around its axis of rotation and drawn into the mouth of the conduit 726. The rotating debris is thus removed from the air stream and hence is no longer subject to the centrifugal forces . The clean air then passes along the conduit 726 through the outlet port 722 of the separation chamber 716 and, via the fan housing 728 into the clean air exhaust chamber 730. The clean air is then exhausted to the atmosphere via the clean air outlet 738. The suction cleaner also includes a filter 748 upstream of the fan housing 728 which operates to remove, in particular, fine dust and debris which has not been separated during the passage of the air through the separation chamber 716. In the sixth embodiment shown in Figure 10, a suction cleaner housing shown generally at 410 comprises a casing 402. An air inlet 404 is provided in the wall of the casing 402 for attachment of a flexible tube (not shown) . The air inlet 404 opens into an inlet chamber 406 located within the casing 410. Debris laden air entering the chamber 406 is directed through a stator 434 located within the inlet chamber 406. A debris outlet port 418 is located in the base of the chamber 406, downstream of the array of nozzles 434. The debris outlet port 418 is in communication with a debris collection chamber 422. The chamber 406 further comprises an outlet port 424 in which a conduit 426 is received. The conduit 426 opens into a fan housing (not shown) in which a fan is located. The fan is driveably coupled to a motor (not shown) , arranged within a clean air exhaust chamber (not shown) . A clean air outlet is provided downstream of the motor. The motor is suitably an electric motor and can be either mains or battery driven. A rotor 440 is mounted for rotation in the chamber 406 about a rotor axis substantially coincident with the longitudinal axis of the conduit 424 and the axis of rotation of the fan driveable by the motor, and comprises separation blades 442 and rotor blades 444. The rotor 440 is further provided with a collar 446 which forms part of the rotor and thus rotates with the rotor. The collar 446 is a close fit within the mouth of the conduit 426 and thus ensures that substantially all of the air stream is drawn through the turbine blades 444. In operation, the motor drives the fan to create an air stream entering the housing at air inlet 404 and leaving the housing at the clean air outlet. Debris laden air enters the inlet chamber 406 tangentially and is drawn through the array of nozzles 434 which spin the debris laden air. As the debris laden air exits from the nozzles 434, the debris entrained in the air is subjected to gravitational forces directing it towards the base of the chamber 406 . The high velocity spinning debris laden air stream passes through the even higher velocity separation blades 442 of the rotor 440. The blades 442 contact the debris in the air and further direct it towards the base of the chamber 406, and hence through the debris outlet port 418 to the debris collection chamber 422. The air stream from which the debris has been stripped is then diverted sharply through an angle of 180° around its axis of rotation and drawn into the mouth of the conduit 426. The rotating debris is thus removed from the air stream and hence is no longer subject to the centrifugal forces. The clean air then passes along the conduit 426 through the outlet port 422 of the chamber 406 and, via the fan housing into the clean air exhaust chamber. The clean air is then exhausted to the atmosphere via the clean air outlet. As can be seen from Figure 11, which shows a seventh embodiment of the invention, a suction cleaner shown generally at 110 comprises a housing 102, and a flexible tube 104 attached to the housing 102. An air inlet 106 is provided in the wall of the housing 102 at the point of attachment of the tube 104. The air inletlOδ opens into a chamber 108 located within the housing 110. The chamber 108 is annular in shape. A stator 112, which is shown in more detail in Figure 2, is located within the chamber 108, so that debris laden air entering the chamber 108 at the air inlet 106 is directed through the stator 112. A debris outlet port 114 is located in a wall 116 of the chamber 108, downstream of the stator 112. The debris outlet port 114 is in communication with a debris collection chamber 118, located within the housing 102. The chamber 108 further comprises an outlet port 120 in which a conduit 122 is received. The conduit 122 opens into a fan housing 124 in which a fan (not shown) is located. The fan is driveably coupled to a motor 126, arranged within a clean air exhaust chamber 128 which is enclosed within the housing 102. A clean air outlet 130 is provided in the wall of the housing 102, downstream of the motor 126. The motor 126 is suitably an electric motor and can be either mains or battery driven. As can be seen from Figure 2, the stator 112 comprises a plurality of fixed blades 132, adjacent pairs of which define an array of nozzles 134. In operation, the motor 126 drives the fan to create an air stream entering the housing at air inlet 106 and leaving the housing at clean air outlet 130. Debris laden air enters the chamber 108 tangentially and is drawn through the stator 112. The stator 112 spins the debris laden air thus adding to the air flow an axial component, in addition to the tangential components already present. As the debris laden air exits from the nozzles 134 defined by the stator blades 132, a further, radial component to its velocity is added. The high velocity spinning debris laden air stream is then diverted sharply through an angle of 180° into the mouth of the conduit 122 and the debris entrained in the air is subjected to intense centrifugal forces. The rotating debris is thus forced towards the wall 116 of the annular chamber 108, and escapes through the debris outlet port 114 into the debris collection chamber 118, where it is removed from the air stream and hence is no longer subject to the centrifugal forces. The clean air then passes along the conduit 122 through the outlet port 120 of the chamber 108 and, via the fan housing 124 into the clean air exhaust chamber 128. The clean air is then exhausted to the atmosphere via the clean air outlet 130.

Claims: Claims : 1. A suction cleaner comprising a housing, a motor, a fan blade driveably coupled to the motor, an air inlet located upstream of the motor, a separation chamber in communication with the air inlet and an air outlet from the separation chamber, characterised in that the cleaner further comprises a rotor mounted for rotation in the separation chamber, the air inlet is arranged so as to provide a rotating air stream in the separation chamber and the air inlet and the air outlet from the separation chamber are arranged so as to provide a reversal, in the axial direction, about the axis of rotation, of the rotating air stream in the separation chamber. 2. A suction cleaner as claimed in claim 1 characterised in that the reversal of the rotating air stream is through 180°. 3. A suction cleaner as claimed in claim 1 or claim 2 characterised in that the rotor comprises one or more separation blades and is driven by a motor. 4. A suction cleaner as claimed in claim 1 or claim 2 characterised in that the rotor comprises one or more separation blades and one or more turbine blades. 5. A suction cleaner as claimed in claim 3 or claim 4 characterised in that the separation blades of the rotor are located upstream of the mouth of the air outlet from the separation chamber. 6. A suction cleaner according to any of claims 1 to 5 characterised in that the mouth of the air outlet from the separation chamber comprises a collar which forms part of the rotor and is mounted for rotation with the rotor. 7. A suction cleaner as claimed in any of claims 1 to 6 characterised in that it further comprises a debris collection chamber. 8. A suction cleaner as claimed in claim 7 characterised in that there is at least one debris outlet port from the separation chamber in communication with the debris collection chamber. 9. A suction cleaner as claimed in claim 8 characterised in that the at least one debris outlet port is located in a peripheral wall of the separation chamber. 10. A suction cleaner as claimed in any of claims 1 to 9 characterised in that the rotor comprises one or more separation blades located downstream of at least one of the debris outlet ports. 11. A suction cleaner as claimed in any of claims 1 to 9 characterised in that the rotor comprises one or more separation blades located upstream of the at least one debris outlet port. 12. A suction cleaner as claimed in any of claims 4 to 11 characterised in that the rotor comprises one or more turbine blades located downstream of the reversal of the air stream in the separation chamber. 13. A suction cleaner as claimed in any of claims 1 to 12 characterised in that the separation chamber is annular in form. 14. An air filtration device comprising a housing, an air inlet, a separation chamber in communication with the air inlet and an air outlet from the separation chamber, characterised in that the air filtration device further comprises a rotor mounted for rotation in the separation chamber, the air inlet is arranged so as to provide a rotating air stream in the separation chamber and the air inlet and the air outlet from the separation chamber are arranged so as to provide a reversal, in the axial direction, about the axis of rotation, of the rotating air stream in the separation chamber. 15. An air filtration device according to claim 14 characterised in that the mouth of the air outlet from the separation chamber comprises a collar which forms part of the rotor and is mounted for rotation with the rotor. 16. A suction cleaner comprising: -at least one rotor placed in a debris-laden-air stream of the cleaner, which rotor spins when the suction cleaner is in operation; and -a debris collection chamber into which debris is propelled by the spinning rotor. 17. A suction cleaner according to claim 16 in which said debris collection chamber is substantially sealed to the atmosphere. 18. A suction cleaner according to any of claims 16 or 17 in which said at least one rotor is housed within a substantially cylindrical or annular chamber which is entered tangentially by the debris-laden-air stream. 19. A suction cleaner according to any of claims 16 to 18 which further comprises a flow directing means which imparts a change of direction to the debris-laden-air stream prior to the debris-laden-air stream passing the rotor. 20. A suction cleaner according to claim 19 in which said flow directing means consists of at least one stationary stator blade . 21. A suction cleaner according to claim 19 in which said flow directing means consists of at least one orifice or nozzle . 22. A suction cleaner according to any of claims 16 to 21 is which, in normal operation, the rotor is spun solely by the debris-laden-air stream passing the rotor. 23. A suction cleaner according to any of claims 16 to 22 which comprises a plurality of said rotors arranged co- axially . 24. A suction cleaner according to any of claims 16 to 23 which further comprises coarse separation means for separating out relatively large debris from the debris- laden-air stream prior to the debris-laden-air stream passing the spinning rotor. 25. A suction cleaner according to claim 24 which further comprises a second debris collection chamber for collecting relatively large debris seperated out by said coarse separation means . 26. A suction cleaner according to claim 24 in which said coarse separation means comprises a coarse filter. 27. A suction cleaner according to claim 24 in which said coarse separation means comprises a cyclonic separator. 28. A suction cleaner according to claim 24 in which said coarse separation means comprises a separator which utilises the inertia of relatively large debris to separate such relatively large debris from the debris- laden-air stream. 29. A suction cleaner according to any of claims 16 to 28 in which said debris collection chamber is separate from the chamber in which the at least one rotor spins and in which debris is propelled by the spinning rotor into the debris collection chamber via a rotor outlet port. 30. A suction cleaner according to claim 29 which further comprises a baffle arrangement positioned at the rotor outlet port. 31. A suction cleaner according to claim 30 in which the baffle arrangement consists of a set of radial blades. 32. A suction cleaner according to claim 30 in which the baffle arrangement consists of a set of curved blades. 33. A suction cleaner according to any of claims 30, 31 or 32 in which the baffle arrangement consists of set of convoluted blades. 34. A suction cleaner according to any of 16 to 33 claims in which the rotor is configured such that the passing air stream imparts a spinning motion to the rotor. 35. A suction cleaner according to any of claims 16 to 34 in which a spin maintenance means is provided which keeps the rotor spinning in the event that an air stream partial or total blockage occurs . 36. A suction cleaner according to claim 35 in which said spin maintenance means comprises an air-bypass valve which causes additional air to be drawn past the rotor when an air stream partial or total blockage occurs. 37. A suction cleaner according to claim 35 in which said spin maintenance means comprises a motor. 38. A suction cleaner according to claim 37 in which said motor is driven by turbine means driven by a turbine air flow. 39. A suction cleaner according to claim 38 in which said turbine air flow is controlled by an air-bypass valve which causes additional air to be drawn past the turbine when an air stream partial or total blockage occurs. 40. A suction cleaner according to claim 37 in which said motor is an electrical or electronic motor. 41. A suction cleaner according to claim 40 in which said electrical or electronic motor drives said at least one rotor via a clutch means. 42. A suction cleaner according to claim 41 in which said clutch means consists of a centrifugally operated clutch means . 43. A suction cleaner comprising a housing, a motor, a fan blade driveably coupled to the motor, an air inlet located upstream of the motor, a separation chamber in communication with the air inlet, an air outlet from the separation chamber and a debris collection chamber characterised in that the air inlet is arranged so as to provide a rotating air stream in the separation chamber and the separation chamber is provided with at least one debris outlet port located in a peripheral wall of the separation chamber and communicating with the debris collection chamber.

Inventors: SARKER MATTHEW N, WEBSTER CRAIG, SARKER, MATTHEW, N., WEBSTER, CRAIG
Applicants: CAMBRIDGE CONSULTANTS, SARKER MATTHEW N, WEBSTER CRAIG, CAMBRIDGE CONSULTANTS LIMITED, SARKER, MATTHEW, N., WEBSTER, CRAIG
Application year: 1999
Main classification: A47L9
IPC codes: A47L9, B01D45, F04D29