Vacuum Cleaner

Abstract

A floor-care vacuum cleaner comprising a floor-contracting body having an air inlet (16) for vacuuming-up dust, a fan (26) driven by a motor (22) permanently installed in the body, and means for accommodating at least one on-board battery (34) as a source of power for the motor.

Description

[0001] This invention relates to vacuum cleaners.

[0002] The development of the modern vacuum cleaner in recent years has been characterised by the use of more and more powerful motors. Installed powers of 1500 w or even more are now common, most of which is expended in sucking air through ever more complicated filtration systems. Yet these formidable machines (at least when sold for domestic use) have a very low utilisation; the average person spends only a few minutes a week vacuuming his/her home.

[0003] We have recognised that the conventional approach to vacuum cleaner design is in fact misconceived. Because utilisation is so low, we have determined that it is possible with appropriate design to provide a vacuum cleaner which can dispose of a practical weekly duty cycle using no more energy than can be stored in a reasonably sized battery or set of batteries, for example of the Ni--Cd type.

[0004] Therefore, the present invention provides in one aspect a floor-care vacuum cleaner comprising a floor-contacting body having an air inlet for vacuuming-up dust, a fan driven by a motor permanently installed in the body, and means for accommodating at least one on-board battery as a source of power for the motor.

[0005] Preferably the motor is of at least 200 w, and more preferably at least 250 w, rated power.

[0006] Preferably the battery or batteries have a total capacity of at least 2.5 Ah, and more preferably at least 3 Ah.

[0007] A significant advantage brought by the invention is that the vacuum cleaner can be "cordless" and the user is spared the inconvenience of trailing an electric cable connected to a mains socket.

[0008] One important preferred feature of a vacuum cleaner according to the first aspect of the invention is that the fan is located upstream of dust collecting means.

[0009] In a second aspect the invention provides a floor-care vacuum cleaner having an air inlet for vacuuming-up dust from a floor, a fan driven by a motor of at least 200 w rated power and located upstream of dust collecting means, and means for accommodating at least one on-board battery as a source of power for the motor.

[0010] In an embodiment of the invention the fan may be located upstream of the air inlet, the arrangement being such that a flow of air from the fan draws in dust-bearing air through the air inlet.

[0011] There may be an agitator for disturbing dust from a carpeted floor so that it is entrained by air entering the air inlet.

[0012] There may be means for passing an airflow from the fan through the dust collecting means, and means for diverting at least part of the airflow if the exit thereof from the dust collecting means is impeded, the arrangement being such that at least a substantial proportion of dust entrained in the to-be-diverted air is captured.

[0013] Preferably the diverting means is a porous conduit between the fan and the dust collecting means.

[0014] There may be means for passing a portion of the airflow from the fan through the motor as cooling air and thence returning it to the airflow. Alternatively the motor can have its own internal fan to take in clean air for cooling and then to discharge it into the main dust-laden airflow.

[0015] A preferred form of the invention is an upright vacuum cleaner, although its application to the cylinder type of cleaner is not excluded. In an upright cleaner, the handle may include the means for accommodating at least one battery.

[0016] The dust collecting means may comprise a disposable container formed of porous filtering material. Alternatively a re-usable and preferably washable bag or rigid container may be employed.

[0017] In an upright cleaner according to the invention, the dust collecting means may be contained within or may be carried by a handle of the vacuum cleaner, the porous conduit extending upwardly to deliver dust-laden air to an upper part of the dust collecting means.

[0018] The cleaner may comprise a fence bounding at least a substantial proportion of the rear periphery of the air inlet, the fence being displaceable between a retracted position when the floor surface is carpeted and a deployed position when the floor surface is uncarpeted, so as to reduce the ingress of air to the air inlet around the periphery thereof.

[0019] Preferably the battery is rechargeable, the vacuum cleaner being in combination with a docking station having battery charging means, the cleaner and the docking station having complementary electrical connectors where by the at least one battery of the cleaner can be charged without removal from the cleaner.

[0020] An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, wherein:

[0021] FIG. 1 is a side elevation of a first embodiment of a vacuum cleaner of the invention.

[0022] FIG. 2 is a diagrammatic vertical cross-section through the vacuum cleaner of FIG. 1;

[0023] FIG. 3 is a diagrammatic horizontal cross-section on line 3-3 of FIG. 2;

[0024] FIGS. 4 and 5 are respectively whole and partial side elevations of other vacuum cleaners according to the invention; and

[0025] FIGS. 6 and 7 are respectively horizontal (plan) and vertical sections through a further vacuum cleaner according to the invention.

[0026] Referring to FIGS. 1, 2 and 3, an upright floor-care vacuum cleaner comprises a body 10 which contacts a floor 12 to be cleaned via wheels 14. As known per se, the underside of the body, at least when standing on a hard floor surface, is close to but not touching the floor and has an air inlet 16 for sucking in air and entrained dust from the floor.

[0027] A handle 18 is provided for manipulation of the cleaner, and a dust-collecting bag is suspended from the handle in a well-ventilated casing 20 and connected to an air outlet 21 from the body.

[0028] Within the body 10 is provided a permanently-installed 24V DC motor 22 of 250 w rated power. On an output shaft 24 of the motor is provided a centrifugal fan 26 for sucking air in through the inlet 16. The output shaft 24 also carries a pulley which via a belt 29 drives a beater rotor or agitator 28 which extends across the air inlet. As known per se the rotors carry respective oppositely-handed helical beater bars or brushes 30 which beat a carpet being cleaned to dislodge dust so that it can be entrained by the air entering the air inlet. The bars or brushes also serve (due to their helical shape) to sweep dust towards the centre of the air inlet, whereat the entry to the fan 26 is located. A fence or air dam 32 is slidably mounted in a slot extending across the rear and sides of the periphery of the air inlet. When the cleaner is used on carpet, the fence is pushed up into the slot by the carpet or can be retracted manually or automatically. When the cleaner is used on a hard floor, the fence drops downwardly to contact the floor and reduce the ingress of air other than from the front of the cleaner, when it is drawn across the area swept by the beater bar.

[0029] The motor is shown here as having a fore-and-aft orientation with an inclined axis, but other dispositions are possible eg. with a vertical axis (see FIG. 6) or cross-wise across the cleaner body. The latter avoids the need to wist the belt drive through 90.degree..

[0030] The motor 22 is powered by a Ni--Cd battery 34 (or other battery type having adequate capacity within the space available for it) removeably received in a housing 36 on the top of the cleaner. The battery has a capacity of 3 Ah, which would give around 15 minutes usage of the cleaner per charge at full motor power of 250 w. Using the cleaner at reduced power (less power is required for a hard floor) will give a longer duty cycle. A power control advantageously can be provided on the handle 18 for this purpose, together with an on-off switch.

[0031] A recessed plug 38 is provided on the body 10 so that the cleaner can be parked in a docking station when not in use, and the battery connected to a charger within the docking station. Thus the cleaner can be kept fully charged and ready for use; a modern electronically-controlled charger can maintain the battery in optimum condition and ensure maximum life. Alternatively the battery can be removed for charging separately, and preferably replaced by a further previously-charged battery so that the cleaner remains immediately available.

[0032] Air is taken in by the fan through the air inlet and discharged radially outwardly into a plenum chamber 40 and then into an delivery passage 42. Some of the air passes through the motor to cool it, and rejoins the main air flow further downstream.

[0033] The delivery passage delivers the air and entrained dust to the air outlet 21, and thence into the bag 50. The bag is of a small-pored permeable filter material which due to its large surface provides only a small resistance to the escaping air whilst effectively retaining dust and other debris. The bag can be re-usable but preferably is disposable and discarded when full.

[0034] FIG. 4 shows a second embodiment in which the battery 34 is replaced by several (eg. three or four) smaller batteries 52 stacked in series in a hollow portion of the handle 18. This enables the body 10 to be made flatter, and thus more able to be directed under furniture etc. This embodiment is otherwise as described with reference to FIGS. 1 to 3.

[0035] Referring to FIG. 5, in this embodiment a sintered porous tube 54 extends from the air outlet 21 upwardly to the top of a disposable dust bag 56 which is carried by the handle 18. Entrained dust is carried at high velocity up the tube 54 by the airflow and is delivered to the bag.

[0036] The porous tube acts as a bypass for the air if the bag surface becomes clogged. Air can escape through its permeable surface, but much of the entrained dust will still pass into the bag, (unless the bag is badly clogged) due to its momentum and to the velocity of the remaining airflow into the bag. The small-pored material of the sintered tube prevents substantial escape of dust through the wall of the tube, and the tube itself can be washed periodically to remove dust adhering to its wall. The porous tube has the advantage that the cleaner can be operated for a short period without significant loss of suction if the bag 56 is clogged. Thus a cleaning cycle may be completed and the bag emptied more conveniently at the end of the cycle, rather than mid-way through it.

[0037] It will be noted that in all described embodiments and contrary to conventional practice, the fan 26 is upstream of the dust-collecting bag. This enables the fan to drive the air through the filter constituted by the bag, rather than suck it through a filter downstream of a dust-collecting bag as in conventional cleaners. This more efficient arrangement is preferred because it permits a significantly smaller motor to be used, and assists in making a self-contained battery-powered cordless design practicable.

[0038] In the embodiment of FIGS. 6 and 7 the fan 26 also is upstream of the vacuuming air inlet 16. Air is drawn into the fan at fan inlet 60 and directed along a shaped duct 62 which delivers it through an elongated nozzle 64 extending across the full width of vacuuming air inlet 16, where it passes at high velocity through an agitator chamber 66 across the top of beater rotors (agitators) 28. This high velocity flow causes suction at the air inlet 16, causing air to be drawn in together with loose dust, which has been disturbed by the rotors 28 which rotate clockwise as seen in FIG. 7. The dust-laden air then passes as previously described via delivery passage 42 to the dust-collecting bag 50. This embodiment avoids the contamination of the fan 26 by dust-laden air.

[0039] Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other disclosed and/or illustrated features.

Claims

1-18. (canceled)

19. A floor-care vacuum cleaner comprising a floor-contacting body having an air inlet for vacuuming-up dust, a fan driven by a motor permanently installed in the body, and means for accommodating at least one on-board battery as a source of power for the motor.

20. A vacuum cleaner as claimed in claim 19 wherein the motor is of at least 200 w rated power.

21. A vacuum cleaner as claimed in claim 19 comprising a battery or batteries having a total capacity of at least 2.5 Ah.

22. A vacuum cleaner as claimed in claim 19 wherein the fan is located upstream of dust collecting means.

23. A vacuum cleaner as claimed in claim 22 comprising means for passing an airflow from the fan through the dust collecting means, and means for diverting at least part of the airflow if the exit thereof from the dust collecting means is impeded, the arrangement being such that at least a substantial proportion of dust entrained in the to-be-diverted air is captured.

24. A vacuum cleaner as claimed in claim 23 wherein the diverting means is a porous conduit between the fan and the dust collecting means.

25. A vacuum cleaner as claimed in claim 24 wherein the dust collecting means comprises a disposable container formed of porous filtering material.

26. A vacuum cleaner as claimed in claim 24, being an upright vacuum cleaner and wherein the dust collecting means is contained within or is carried by a handle of the vacuum cleaner, the porous conduit extending upwardly to deliver dust-laden air to an upper part of the dust collecting means.

27. A vacuum cleaner as claimed in claim 19 wherein the fan is located upstream of the air inlet, the arrangement being such that a flow of air from the fan draws in dust-bearing air through the air inlet.

28. A vacuum cleaner according to claim 27 comprising an agitator for disturbing dust from a carpeted floor so that it is entrained by air entering the air inlet.

29. A vacuum cleaner as claimed in claim 19 comprising means for passing a portion of the airflow from the fan through the motor as cooling air and thence returning it to the airflow.

30. A vacuum cleaner as claimed in claim 19 wherein the motor has a cooling fan for passing cooling air through the motor and thence delivering it to the airflow from the first-mentioned fan.

31. A vacuum cleaner as claimed in claim 19, being an upright vacuum cleaner.

32. A vacuum cleaner as claimed in claim 31 comprising a fence bounding at least a substantial proportion of a rear periphery of the air inlet, the fence being displaceable between a retracted position when the floor surface is carpeted and a deployed position when the floor surface is uncarpeted, so as to reduce the ingress of air to the air inlet around the periphery thereof.

33. A vacuum cleaner as claimed in claim 31 comprising a handle wherein the means for accommodating the at least one battery are provided.

34. A vacuum cleaner as claimed in claim 19 wherein the at least one battery is rechargeable, the vacuum cleaner being in combination with a docking station having battery charging means, the cleaner and the docking station having complementary electrical connectors whereby the at least one battery of the cleaner can be charged without removal from the cleaner.

35. A floor-care vacuum cleaner having an air inlet for vacuuming-up dust from a floor, a fan driven by a motor of at least 200 w rated power and located upstream of dust collecting means, and means for accommodating at least one on-board battery as a source of power for the motor.

36. A vacuum cleaner as claimed in claim 35 comprising means for passing an airflow from the fan through the dust collecting means, and means for diverting at least part of the airflow if the exit thereof from the dust collecting means is impeded, the arrangement being such that at least a substantial proportion of dust entrained in the to-be-diverted air is captured.

37. A vacuum cleaner as claimed in claim 36 wherein the diverting means is a porous conduit between the fan and the dust collecting means.