GB2484318A

GB2484318A - A portable, bladeless fan having a direct current power supply

Info

Publication number: GB2484318A
Application number: GB201016824A
Authority: GB
Inventors: Kevin John Simmonds
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2010-10-06
Filing date: 2010-10-06
Publication date: 2012-04-11
Also published as: WO2012046023A1; GB201016824D0; CN102444628A; TWM434128U; CN202360474U

Abstract

A portable fan assembly includes a body 10 and an air outlet section 14. The body includes an air inlet 18, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet. The air outlet section 14 includes an air passage for receiving the air flow from the body, an air outlet 20 for emitting the air flow from the fan assembly, and an opening through which the air from outside the fan assembly is drawn by the air flow emitted from the air outlet. The fan includes a direct current (DC) power source for supplying a driving voltage to the motor of the body. The power source may be provided by an energy storage device, for example one or more batteries, or by one or more solar cells. A portable fan having a pair of different base stations proving DC power and recharging functions is also disclosed.

Description

A FAN ASSEMBLY

The present invention relates to a fan assembly. In its preferred embodiment, the present invention relates to a battery-powered portable fan assembly.

In a first aspect the present invention provides a portable fan assembly comprising a body comprising an air inlet, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet; an air outlet section comprising an air passage for receiving the air flow from the body, an air outlet for emitting the air flow from the fan assembly, and an opening through which the air from outside the fan assembly is drawn by the air flow emitted from the air outlet; and a direct current (DC) power source for supplying a driving DC voltage to the motor.

The power source preferably comprises an energy storage device for supplying a driving voltage to the motor. The driving vohage is preferably in the range from 4 to 12 \T, and so the fan assembly may comprise at least one battery for supplying the driving voltage to the motor. However, the fan assembly may comprise an alternative low vohage DC power supply, such as one or more solar cells connected to the motor.

The body may comprise a battery compartment for retaining one or more batteries forming a battery pack. The compartment may be accessed by opening a cover formed in the body, for example in a base or a side wall of the body, to allow a discharged battery pack to be replaced by the user. The compartment may be sized to receive any suitable number or type of battery pack required to supply the driving DC vohage to the motor. For example, the compartment may be sized to retain a plurality of batteries for supplying a driving vohage to the motor.

Alternatively, the battery pack may be located within a battery housing. The battery housing may be located within the body, or it may be external to the body. The battery housing may be releasably connected to the body. The releasable connection between the battery housing and the body may be a bayonet or a screw fitting so that the battery

I

housing is rotated relative to the body to release the battery housing. In a preferred embodiment, the body and the battery housing are connected together by means of a push-fit connection. For example, the battery housing may comprise a male connector which is received within a female connector of the body, and which may be retained within the female connector by a catch located within the body. The body may comprise a user-operable release mechanism for releasing the battery housing from the body. For example, the release mechanism may comprise an actuator which is depressible by the user to move the catch to enable the user to pull apart the battery housing and the body.

Where the battery housing is external to the body, the battery housing is preferably releasably connected to a lower end of the body so that the battery housing supports the body of the fan assembly when it is connected to the body. The lower end of the battery housing is preferably substantially parallel to the lower end of the body so that the battery housing may provide a stable platform for supporting the body when the battery housing is connected to the body. When the battery housing is connected to the body, the battery housing and the body are preferably substantially concentric, and may have outer surfaces which are substantially flush. For example, the body and the battery housing may each have a substantially cylindrical outer surface, with the outer diameters of the outer surfaces of the body and the battery housing being substantially equal.

The fan assembly preferably comprises a support for supporting the motor and the impeller. The body preferably comprises a tubular or cylindrical side wall having a bore into which the support is inserted. For example, the support may comprise a frame which is insertable into the bore of the side wall of the body through the lower open end of the side wall. The frame is preferably a tubular frame which is substantially co-axial with the side wall of the body. The frame preferably comprises a plurality of apertures through which the air flow passes between the air inlet and the impeller. A power supply circuit for providing a driving voltage to the motor may be mounted on the support.

During assembly, the motor and impeller may be inserted into the body, through the lower open end of the side wall, before the support is inserted into the body. An actuator may then be connected to the power supply circuit, for example through an aperture formed in the side wall of the body, to enable a user to selectively activate and deactivate the motor. An annular diffuser may be located between the impeller and the air outlet section to control the flow characteristics of the air flow emitted from the impeller before it enters the air outlet section. The diffuser may be integral with the housing of the motor, or it may be a separate component. A base plate may be provided for closing the lower open end of the side wall. The base plate may support the lower end of the support located within the body, and may be connected to the body by a snap-fit connection, screws or other fasteners.

The body preferably comprises an electrical contact for engaging a contact on the battery housing to form an electrical circuit between the battery and the power supply circuit. Each contact is preferably located on or adjacent a respective connector for connecting the battery housing to the body.

The battery pack may be a rechargeable battery pack. Where the battery pack is located within a battery housing, the battery housing may comprise a connector for connecting the battery to an extemal power supply for charging the battery. The connector may comprise an input terminal configured for connection to one of a number of different extemal power sources. For example, the input terminal may be connectable to an AC mains power supply by an adapter for converting the mains power supply to a DC voltage, or to a low voltage DC power source of a vehicle by a suitable lead.

Alternatively, or additionally, the fan assembly may comprise a base station for supplying a charging vohage to the battery. The base station is preferably detachably connectable to the battery housing, preferably to the lower end of the battery housing so that the base station may provide a detachable base for the fan assembly. The base station preferably has a base with a generally circular outer periphery having a diameter which is at least 1.5 times, preferably at least twice, the diameter of the side wall of the body. Ahernatively, the base may have any other desired shape, such as an elliptical or polygonal shape. The base station may be locatable on a rotatable base plate for allowing a user to rotate the fan assembly to re-direct the air flow generated by the fan S assembly. The base plate may be oscillated by an oscillation mechanism to sweep the air flow over an angle, for example around 900.

Again, the releasable connection between the battery housing and the base station may be a bayonet or a screw fitting so that the battery housing is rotated relative to the base station to release the battery housing. In a preferred embodiment, the base station and the battery pack are connected together by means of a push-fit connection. For example, the base station may comprise a male connector which is received within a female connector of the battery housing, and which may be retained within the female connector by a catch located within the battery housing. The battery housing may comprise a user-operable release mechanism for releasing the battery housing from the body. For example, the release mechanism may comprise an actuator which is depressible by the user to move the catch to enable the user to pull apart the battery housing and the base station.

The battery housing preferably comprises a control circuit for providing a voltage simultaneously to the motor and to the battery pack. This can allow a user to operate the fan assembly while recharging the battery pack. The body of the fan assembly may also include an input terminal connected to the power supply circuit for receiving a direct current (DC) voltage, preferably in the range from 4 to 12 \T, from an extemal power source. This allows the fan assembly to operated in the absence of the base station if the battery pack is fully discharged.

As the battery housing has an internal power source, the battery housing may be provided with one or more additional features. For example, the battery housing may comprise a light source, such as a light emitting diode (LED), to allow the battery housing to be used as a torch when the battery housing is connected to or disconnected from the body of the fan assembly. A switch may be located on the base or side wall of the battery housing to allow the user to selectively activate the light source. The light source may be located on a side wall of the battery housing, on an upper surface of the battery housing, or on the connector for connecting the battery housing to the body of the fan assembly.

The connector for connecting the base station to the battery housing is preferably substantially identical to the connector for connecting the battery housing to the base of the fan assembly. This can enable the battery housing and the base station to be connected interchangeably to the body of the fan assembly. For example, a user may selectively connect the base station directly to the body of the fan assembly when operating the fan assembly directly from a mains power supply.

Therefore, in a second aspect the present invention provides a portable fan assembly comprising a body comprising an air inlet, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet; an air outlet section comprising an air passage for receiving the air flow from the body, at least one air outlet for emitting the air flow from the fan assembly, and an opening through which the air from outside the fan assembly is drawn by the air flow emitted from said at least one air outlet; and first and second bases interchangeably connectable to the body for supplying power to the motor, each base comprising, the first base comprising a direct current (DC) power source for supplying a driving vohage to the motor of the body, and the second base comprising an input terminal for receiving a direct current (DC) vohage in the range from 4 to 12 V from an external power source.

Preferably, in order to minimise manufacturing costs the fan assembly has a relatively low number of component parts. For example, part of the air outlet section may be integral with part of the body. In a preferred embodiment the air outlet section comprises an outer section and an inner section which define the air passage, air outlet and the opening, and the body comprises a side wall containing the motor and the impeller. In this case, the outer section of the air outlet section may be integral with the side wall of the body.

The fan assembly is thus preferably a low power fan assembly in which, in use, the motor draws less than 10 W of power, preferably less than 5 W of power.

Each of the inner and outer sections is preferably annular in shape so that the opening is defined by a closed loop. The fan assembly preferably has relatively small dimensions; the diameter of the opening is preferably less than 150 mm, and the height of the fan assembly is preferably less than 250 mm. The fan assembly can therefore be a portable fan assembly, suitable for location on a desk, bench or other item of furniture, or in a car, caravan or other vehicle with a suitable external power supply for driving the motor of the fan assembly.

The air inlet may comprise one or more apertures formed in the side wall of the body and through which the air flow enters the body. The air outlet section may comprise a single air outlet extending about the opening, preferably surrounding the opening.

Alternatively, the air outlet section may comprise a plurality of air outlets spaced about the opening. For example, the air outlet section may comprise a pair of air outlets located on opposite sides of the opening, with each air outlet emitting a respective portion of the air flow.

The, or each, air outlet is preferably in the form of a slot, and which preferably has a width in the range from 0.5 to 5 mm. In a preferred embodiment, the, or each, slot has a width of around 3 mm. Spacers of any suitable shape or design may be formed on the outer section of the air outlet section for engaging the inner section of the air outlet section to maintain a controlled spacing between the inner and outer sections of the air outlet section. Alternatively, the spacers may be formed on the inner section of the air outlet section.

The air outlets(s) are preferably located towards the rear of the air outlet section, and are preferably arranged to direct the air flow through a bore defined by the external surface of the inner section of the air outlet section. The, or each, air outlet is preferably defined by overlapping portions of the external surface of the inner section and the internal surface of the outer section of the air outlet section. Alternatively, the, or each, air outlet may be defined between facing portions of the internal surfaces of the inner and outer sections of the air outlet section.

The air outlet section preferably comprises a surface located adjacent the air outlet(s) and over which the air outlet(s) is arranged to direct the air flow emitted therefrom.

Preferably, this surface is a curved surface, and more preferably is a Coanda surface.

Preferably, the external surface of the inner section of the air outlet section is shaped to define the Coanda surface. A Coanda surface is a known type of surface over which fluid flow exiting an output orifice close to the surface exhibits the Coanda effect. The fluid tends to flow over the surface closely, almost clinging to' or hugging' the surface.

The Coanda effect is already a proven, well documented method of entrainment in which a primary air flow is directed over a Coanda surface. A description of the features of a Coanda surface, and the effect of fluid flow over a Coanda surface, can be found in articles such as Reba, Scientific American, Volume 214, June 1966 pages 84 to 92. Through use of a Coanda surface, an increased amount of air from outside the fan assembly is drawn through the opening by the air emitted from the air outlet(s).

In a preferred embodiment an air flow is created which is emitted from the air outlet section of the fan assembly. In the following description this air flow will be referred to as the primary air flow. The primary air flow passes over a Coanda surface. The primary air flow entrains air surrounding the air outlet section, which acts as an air amplifier to supply both the primary air flow and the entrained air to the user. The entrained air will be referred to here as a secondary air flow. The secondary air flow is drawn from the room space, region or external environment surrounding the mouth of the nozzle and, by displacement, from other regions around the fan assembly, and passes predominantly through the opening defined by the air outlet section. The primary air flow directed over the Coanda surface combined with the entrained secondary air flow equates to a total air flow emitted or projected forward from the air outlet section of the fan assembly.

In a third aspect the present invention provides a portable fan assembly comprising a body comprising an air inlet, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet; an air outlet section comprising an air passage for receiving the air flow from the body, at least one air outlet for emitting the air flow from the fan assembly, and a Coanda surface over which said at least one air outlet is arranged to direct the air flow emitted therefrom; and a direct current (DC) power source for supplying a driving vohage to the motor of the body.

Preferably, the air outlet section comprises a diffuser surface located downstream of the Coanda surface. The diffuser surface directs the air flow emitted towards a user's location while maintaining a smooth, even output.

The Coanda surface preferably extends about an axis which is orthogonal to the plane of the opening. The angle subtended between the Coanda surface and the axis is preferably in the range from 1 to 30°, more preferably in the range from 15 to 25°.

The body and the air outlet section are preferably formed from plastics material. For example, the body and the inner and outer sections of the air outlet section may be formed from a polycarbonate (PC) material, such as a PC/acrylonitrile butadiene styrene (ABS) blend. The impeller and, where provided, the diffuser located immediately downstream from the impeller, are also preferably formed from plastics material, and a PC/ABS blend may also be used to form these components. The support may also be formed from plastics material, but as this component is located mainly within the body it may be foniied from a weaker plastics material, such as a polypropylene/talc blend.

Features described above in connection with the first aspect of the invention are equally applicable to the second and third aspects of the invention, and vice versa.

Preferred features of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front perspective view, from above, of the body of a fan assembly; Figure 2 is an exploded view of the impeller and motor of a motor and impeller unit of the fan assembly; Figure 3 is a front perspective view, from above, of a battery housing of the fan assembly; Figure 4 is a front perspective view, from below, of the body of the fan assembly; Figure 5 is a front perspective view, from above, of the body of the fan assembly with the battery housing connected thereto; Figure 6 is a rear perspective view, from below, of the battery housing; Figure 7 is a front perspective view, from above, of a base station of the fan assembly; Figure 8 is a front perspective view, from above, of the body of the fan assembly with the battery housing and base station connected thereto; Figure 9 is a front view of the body of the fan assembly with the battery housing and base station connected thereto; Figure 10 is a side sectional view taken along line A-A in Figure 9; and Figure 11 is a rear view of the body of the fan assembly with the battery housing and base station connected thereto.

Figures 1 illustrates the main body of a fan assembly 10. The main body has an air inlet section 12 and an air outlet section 14. The air inlet section 12 comprises a generally cylindrical side wall 16 having an air inlet 18 in the form of a plurality of apertures formed in the side wall 16, and through which a primary air flow is drawn into the air inlet section 12 from the external environment. The air outlet section 14 comprises an air outlet 20 for emitting the primary air flow from the fan assembly 10.

The air outlet section 14 comprises an annular outer section 22 connected to and extending about an annular inner section 24. The annular sections 22, 24 of the air outlet section 14 extend about and define an opening 26. Each of these sections may be formed from a plurality of connected parts, but in this embodiment each of the outer section 22 and the inner section 24 is formed from a respective, single moulded part. In this embodiment the outer section 22 is integral with the side wall 16 of the air inlet section 12, but the outer section 22 may be connected to the side wall 16, for example by a snap-fit connection, a bayonet fitting, a screw fitting, gluing, ultrasonic welding or by any other suitable connection. During assembly, the inner section 24 is inserted into the outer section 22 through the open front end 28 of the outer section 22. As shown in Figure 3, the front end 28 is received in a rearwardly-facing annular slot 30 located at the front of the inner section 24. The outer and inner sections 22, 24 may be connected together using an adhesive introduced to the slot 30.

The outer section 22 and the inner section 24 together define an annular interior passage 32 (shown in Figure 10) for conveying the primary air flow to the air outlet 20. The interior passage 32 is bounded by the internal surface of the outer section 22 and the internal surface of the inner section 24. The side wall 16 of the air inlet section 12 has an open upper end 34 defining an aperture through which the primary air flow enters the interior passage 32 from the air inlet section 12.

The air outlet 20 is located towards the rear of the air outlet section 14, and is arranged to emit the primary air flow towards the front of the fan assembly 10, through the opening 26. The air outlet 20 extends at least partially about the opening 26, and preferably surrounds the opening 26. The air outlet 20 is defined by overlapping, or facing, portions of the internal surface of the outer section 22 and the external surface of the inner section 24, respectively, and is in the form of an annular slot, preferably having a relatively constant width in the range from 0.5 to 5 mm. In this embodiment the air outlet has a width of around 3 mm. Spacers 35 may be spaced about the air outlet 20 for urging apart the overlapping portions of the outer section 22 and the inner section 24 to maintain the width of the air outlet 20 at the desired level. These spacers may be integral with either the outer section 22 or the inner section 24, and in this embodiment are integral with the outer section 22.

The air outlet 20 is shaped to direct the primary air flow over the external surface of the inner section 24. The external surface of the inner section 24 comprises a Coanda surface 36 located adjacent the air outlet 20 and over which the air outlet 20 directs the air emitted from the fan assembly 10, and a diffuser surface 38 located downstream of the Coanda surface 36. The diffuser surface 38 is arranged to taper away from the central axis X of the opening 26 in such a way so as to assist the flow of air emitted from the fan assembly 10. The angle subtended between the diffuser surface 38 and the central axis X of the opening 26 is in the range from 5 to 30°, and in this embodiment is around 24°.

As mentioned above, the air inlet section 12 comprises a side wall 16 which is integral with the outer section 22 of the air outlet section 14. The side wall 16 is generally cylindrical in shape, and has an open upper end 34, an open lower end 40 and a bore 42.

The side wall 16 comprises the air inlet 18 through which the primary air flow enters the fan assembly 10. In this embodiment the air inlet 18 comprises an array of apertures formed in the side wall 16. Alternatively, the air inlet 18 may comprise one or more grilles or meshes mounted within windows formed in the side wall 16.

The air inlet section 12 comprises a base plate 44 for closing the open lower end 40 of the side wall 16. The base plate 44 is connected to the side wall 16 of the air inlet section 12 by a snap-fit connection, screws or other form of fastener.

The height of the body of the fan assembly 10 is in the range from 150 to 250 mm, and in this embodiment is around 210 mm. The diameter of the opening 26 defined by the air outlet section 14 increases from the rear of the fan assembly 10 towards the front of the fan assembly 10, and in this embodiment the diameter varies from around 90 mm at the rear of the fan assembly 10 to around 130 mm at the front of the fan assembly 10.

With reference again to Figure 11, the air inlet section 12 houses a motor and impeller unit, indicated generally at 46 in Figure 11, for drawing the primary air flow through the air inlet 18 and into the bore 42. As illustrated in Figure 2, the motor and impeller unit 46 comprises an impeller 48 connected to a rotary shaft 50 extending outwardly from a motor 52. In this embodiment, in use the motor 52 draws less than 10 W of power, preferably less than 5 W of power. The motor and impeller unit 46 is inserted into the air inlet section 12 through the open lower end 40 of the side wall 16. The air inlet section 12 includes an annular diffuser 54 having a plurality of blades for receiving the primary air flow exhausted from the impeller 48 and for guiding the air flow into the air outlet section 14. The diffuser 54 may be integral with the motor and impeller unit 46, or, as in this embodiment, it may be a separate component inserted into the air inlet section 12 before the motor and impeller unit 46 so that it is located adjacent the upper open end 34 of the side wall 16, and is supported by the upper end of the motor and impeller unit 46. The body of the fan assembly 10 may include a ledge 55 extending inwardly from an inner surface of the body to prevent the diffuser 54 from passing beyond the open upper end 34 of the side wall 16.

The motor and impeller unit 46 is supported within the air inlet section 12 by a support 56. The support 56 comprises a generally tubular frame 58 which is co-axial with the side wall 16, and which comprises a plurality of apertures 60 through which the primary air flow passes between the air inlet 18 and the impeller 48. The motor and impeller unit 46 is supported by the upper end of the support 56. The support 56 also retains a power supply circuit 62 which is connected to the motor 52 by a lead (not shown in Figure 10) for providing a driving voltage to the motor 52. Similar to the motor and impeller unit 46, the support 56 is inserted into the air inlet section 12 through the open lower end 40 of the side wall 16. The lower end of the support is supported by the base plate 44, which is attached to the body of the fan assembly 10 once all of the intemal components of the air inlet section 12 have been inserted into the bore 42.

The support base 44 preferably comprises a plurality of resilient retainers 66 for retaining the circuit 62. The circuit 62 comprises an input terminal 68 for receiving a direct current (DC) voltage, preferably in the range from 4 to 13 V, from an extemal power source. The input terminal 68 is configured for connection to an adapter (not shown) for converting an alternating current (AC) voltage, such as a 110 or 220 AC voltage provided by a mains power supply, to a DC voltage, for example a 4.8 V DC voltage. The input terminal 68 is positioned on the circuit 62 so as to be located within a slot 70 formed in the open lower end 40 of the side wall 16 when the support 56 is inserted into the air inlet section 12. The slot 70 is preferably located at or towards the rear of the fan assembly 10.

The circuit 62 also includes a switch 72 for allowing a user to selectively activate and de-activate the motor 52. The switch 72 may protrude through an aperture 74 located on the front of the side wall 16, generally opposite to the input terminal 68, and may be connected to the circuit 62 following the insertion of the circuit 62 into the air inlet section 12. The switch 72 may be in the form of a depressible or rotatable onloff switch, or it may be in the form of a dial for allowing the user to vary the speed of rotation of the impeller 48. The circuit 62 may include a light emitting diode (LED) or other illuminating device for illuminating a portion of the side wall 16 which surrounds the switch 72 when the fan assembly 10 is switched on.

To provide an altemative to connecting the input terminal 68 to an external power supply to drive the motor 52, the fan assembly 10 includes a DC power source for supplying a driving voltage to the motor 52. This allows the user to operate the fan assembly 10 in any desired location.

In this embodiment, the fan assembly comprises a battery pack for supplying a driving voltage to the motor 52. The battery pack is housed within a battery housing 80 which is removably connectable to the body of the fan assembly 10. The battery housing 80 is illustrated in Figures 3 and 6. The battery housing 80 comprises a generally cylindrical side wall 82, an upper plate 84 connected to the upper end of the side wall 82 and a base plate 86 connected to the lower end of the side wall 82. The upper plate 84 is preferably integral with the side wall 82, but it may be connected to the side wall 82 using any suitable connection technique. The base plate 86 is connected to the side wall 82 by a snap-fit connection, screws or other form of fastener.

The upper plate 84 comprises a connector 88 for connecting the battery housing 80 to the base plate 44 of the body of the fan assembly 10. In this embodiment the connector 88 is in the form of a male connector which is integral with the upper plate 84 of the battery housing 80, and which is received within a recessed, female connector 90 formed in the base plate 44 of the body of the fan assembly 10. The male connector 88 is retained within the female connector 90 by a pair of arms 92 located on opposite sides of the female connector 90. Figure 5 illustrates the battery pack 80 when connected to the body of the fan assembly 10. The battery housing 80 is shaped so that it is substantially co-axial with the air inlet section 12 of the body of the fan assembly 10.

The side wall 82 of the battery housing 80 has substantially the same outer diameter as the side wall 16 of the air inlet section 12 SO that the outer surface of the battery housing 80 is substantially flush with the outer surface of the air inlet section 12 of the fan assembly 10.

With reference again to Figures 3 and 4, the battery housing 80 comprises a first pair of contacts 94 for contacting a second pair of contacts 96 on the body of the fan assembly 10 for connecting the battery pack to the motor 52. The first pair of contacts 94 is located on the male connector 88, and the second pair of contacts 96 is located on the female connector 90 so that the contacts 94, 96 engage when the battery housing 80 is connected to the body of the fan assembly 10. Each pair of contacts 94, 96 protrudes through a respective pair of apertures formed in its respective connector 88, 90. The first pair of contacts 94 is connected to the circuit 62, whereas the second pair of connectors 96 is connected to a control circuit 98 located within the battery housing 80 for providing the drive vohage to the circuit 62, and thus to the motor 52. The control circuit 98 is illustrated in Figure 11. The control circuit 98 is connected to a battery pack 100, which in this example comprises three batteries for providing a source of DC voltage for driving the motor 52. The control circuit 98 is connected to the second pair of contacts 96 by a lead 102.

The battery housing 80 is releasable from the base plate 44. This can provide the user with the option of operating the fan assembly 10 either with the battery housing 80 connected to the base of the fan assembly 10, with the driving voltage being supplied to the motor 52 by the battery pack 100, or with the battery housing 80 removed from the base of the fan assembly 10 and with the driving voltage being supplied to the motor 52 through the input terminal 68. Returning to Figure 4, the body of the fan assembly 10 comprises a user operable release mechanism for releasing the battery housing 80 from the body. The release mechanism comprises a depressible actuator 104 which located beneath the input terminal 68, and which is depressible by the user to move the arms 92 relative to the female connector 90 from a retaining position to a release position so that the male connector 88 is released. The release mechanism comprises one or more springs or other biasing members for returning the arms 92 to the retaining position when the actuator 104 is released by the user.

The battery pack 100 may be removable from the battery housing 80 to allow the user to replace the battery pack 100 when it has become discharged. However, in this embodiment the battery pack 100 is rechargeable, and is retained within the battery housing 80 during charging. For example, the battery pack 100 may comprises a plurality of lithium ion batteries, or a plurality of nickel hydride batteries. With reference now to Figures 7 to 11, the fan assembly 10 comprises a base station 110 for providing a charging voltage for charging the battery pack 100. The base station 110 comprises an upper section 112 and a lower section 114 connected to the upper section 112. The upper section 112 is preferably a single piece, and comprises a generally cylindrical side wall 116 having an upper end closed by a circular upper plate 118, and an annular flange 120 extending outwardly from the lower end of the side wall 116.

The flange 120 has a circular outer edge having a diameter which is around twice the diameter of the side wall 116. The lower section 114 is in the form of a circular plate connected to the annular flange 120 of the upper section 112 by screws or other fasteners, and provides a stable platform for supporting the fan assembly 10.

The upper section 112 comprises a connector 122 for connecting the base station 110 to the battery housing 80. Similar to the connector 88, the connector 122 is in the form of a male connector which is integral with the upper section 112, and which is received within a recessed, female connector 124 formed in the base plate 86 of the battery housing 80. The male connector 122 is retained within the female connector 124 by a pair of resilient arms 126 located on opposite sides of the female connector 124.

Figures 8 to 11 illustrate the fan assembly 10 with both battery housing 80 and base station 110 connected to the body of the fan assembly. Again, the base station 110 is shaped so that it is substantially co-axial with the air inlet section 12 of the body of the fan assembly 10. The side wall 116 of the base station 110 has substantially the same outer diameter as the side wall 82 of the battery housing 80 so that the outer surfaces of the side walls 82, 116 are substantially flush.

The base station 110 comprises an input terminal 128, similar to the input terminal 68 of the body of the fan assembly 10, for receiving a direct current (DC) voltage, preferably in the range from 4 to 13 V, from an external power source. The input terminal 128 is configured for connection to an adapter (not shown) for converting an alternating current (AC) voltage, such as a 110 or 220 AC vohage provided by a mains power supply, to a DC voltage, for example a 4.8 V DC vohage. The input terminal 128 is located at the rear of the base station 110, within a moulded housing 130 formed in the upper section 112 of the base station 110. The input terminal 128 is connected to a lead 132 which extends from the input terminal 128 to a third pair of contacts 134. The third pair of contacts 134 is arranged to engage a fourth pair of contacts 136 on the battery housing 80 to enable a recharging vohage to be supplied to the battery pack 100 through the control circuit 98. The third pair of contacts 134 is located on the male connector 122, and the fourth pair of contacts 136 is located on the female connector 124 so that the contacts 134, 136 engage when the battery housing 80 is connected to the base station 110. Each pair of contacts 134, 136 protrudes through a respective pair of apertures formed in its respective connector 122, 124.

The control circuit 98 is preferably arranged to recharge the battery pack 100 while simultaneously supplying a driving vohage to the motor 52. This can enable a user to recharge the battery pack 100 while operating the fan assembly 10.

The battery housing 80 is releasable from the base station 110. Returning again to Figure 6, the battery housing comprises a user operable release mechanism for releasing the battery housing 80 from the base station 110. The release mechanism comprises an actuator 138 which is depressible by the user to move the arms 126 relative to the female connector 124 from a retaining position to a release position so that the male connector 122 is released. The release mechanism comprises one or more springs or other biasing members for returning the arms 126 to the retaining position when the actuator 138 is released by the user.

The male connectors 88, 122 preferably have the same size and shape. This can enable the base station 110 to be connected directly to the body of the fan assembly 10 interchangeably with the battery housing 80. This can provide the user with the option of operating the fan assembly 10 either with the battery housing 80 connected to the base of the fan assembly 10, with the driving voltage being supplied to the motor 52 by the battery pack 100, or with the battery housing 80 removed from the base of the fan assembly 10 and with the driving voltage being supplied to the motor 52 through the input terminal 68.

Thus, to operate the fan assembly 10 the user may (i) connect the input terminal 68 to the mains supply using the adapter, (ii) connect the battery housing 80 to the body of the fan assembly 10, or (iii) connect the base station 110 to either the battery housing 80 (when connected to the body of the fan assembly) or the body of the fan assembly 10 wfth the input terminal 128 connected to the mains supply using the adapter. The user then presses the switch 72, in response to which the circuit 62 activates the motor 52 to rotate the impeller 48. The rotation of the impeller 48 causes a primary air flow to be drawn into the air inlet section 12 through the air inlet 18. The primary air flow passes sequentially through the apertures 60 of the support 56 and through the motor and impeller unit 46 before passing through the open upper end 34 of the side wall 16 and into the air outlet section 14.

Within the air outlet section 14, the primary air flow is divided into two air streams which pass in opposite directions around the opening 26 of the air outlet section 14. As the air streams pass through the interior passage 32, air is emitted through the air outlet 20. The primary air flow emitted from the air outlet 20 is directed over the Coanda surface 36 of the air outlet section 14, causing a secondary air flow to be generated by the entrainment of air from the extemal environment, specifically from the region around the air outlet 20 and from around the rear of the air outlet section 14. This secondary air flow passes through the opening 26 of the air outlet section 14, where it combines with the primary air flow to produce a total air flow, or air current, projected forward from the air outlet section 14.

Claims

CLAIMS1. A portable fan assembly comprising: a body comprising an air inlet, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet; an air outlet section comprising an air passage for receiving the air flow from the body, an air outlet for emitting the air flow from the fan assembly, and an opening through which the air from outside the fan assembly is drawn by the air flow emitted from the air outlet; and a direct current (DC) power source for supplying a driving vohage to the motor of the body.
2. A fan assembly as claimed in claim 1, wherein the power source comprises a battery for supplying power to the motor of the body.
3. A fan assembly as claimed in claim 2, wherein the battery is located within a battery housing.
4. A fan assembly as claimed in claim 3, wherein the battery housing is releasably connected to the body.
5. A fan assembly as claimed in claim 4, wherein the body comprises a user-operable release mechanism for releasing the battery housing from the body.
6. A fan assembly as claimed in claim 4 or claim 5, wherein the battery housing is releasably connected to a lower end of the body.
7. A fan assembly as claimed in any of claims 3 to 6, wherein the battery housing and the body are substantially concentric.
8. A fan assembly as claimed in any of claims 3 to 7, wherein the body and the battery housing have outer surfaces which are substantially flush.
9. A fan assembly as claimed in claim 8, wherein the body and the battery housing each have a substantially cylindrical outer surface, and wherein the outer diameters of the outer surfaces of the body and the battery housing are substantially equal.
10. A fan assembly as claimed in any of claims 3 to 9, comprising a support for supporting the motor and the impeller, and wherein the body comprises an aperture through which the support is inserted into the body.
11. A fan assembly as claimed in claim 10, wherein the lower end of the body comprises an aperture through which the support is inserted into the body.
12. A fan assembly as claimed in claim 10 or claim 11, comprising a power supply circuit mounted on the support for providing a driving vohage to the motor.
13. A fan assembly as claimed in any of claims 2 to 12, wherein the battery is a rechargeable battery.
14. A fan assembly as claimed in claim 13, wherein the battery housing comprises a connector for connecting the battery to a power supply for charging the battery.
15. A fan assembly as claimed in claim 13 or claim 14, wherein the battery housing comprises a control circuit for providing a voltage simultaneously to the motor and to the battery.
16. A fan assembly as claimed in any of claims 13 to 15, comprising a base station for providing a charging vohage for charging the battery.
17. A fan assembly as claimed in claim 16, wherein the base station is detachable to the lower end of the battery housing.
18. A fan assembly as claimed in claim 16 or claim 17, wherein the battery housing comprises a user-operable release mechanism for releasing the battery housing from the base station.
19. A fan assembly as claimed in any of claims 15 to 18, wherein the base station comprises an input terminal for receiving a DC voltage from an external power source.
20. A fan assembly as claimed in any of claims 15 to 19, wherein the base station provides a detachable base for the fan assembly.
21. A portable fan assembly comprising: a body comprising an air inlet, an impeller, and a motor for driving the impeller to draw an air flow through the air inlet; an air outlet section comprising an air passage for receiving the air flow from the body, at least one air outlet for emitting the air flow from the fan assembly, and an opening through which the air from outside the fan assembly is drawn by the air flow emitted from said at least one air outlet; and first and second bases interchangeably connectable to the body for supplying power to the motor, each base comprising, the first base comprising a direct current (DC) power source for supplying a driving voltage to the motor of the body, and the second base comprising an input terminal for receiving a DC voltage from an external power source.
22. A fan assembly as claimed in any of the preceding claims, wherein at least part of the air outlet section is integral with the body.
23. A fan assembly as claimed in any of the preceding claims, wherein the opening is defined by a closed loop of the air outlet section.
24. A fan assembly as claimed in claim 23, wherein the diameter of the opening is less than 15 cm.
25. A fan assembly as claimed in any of the preceding claims, wherein, in use, the motor draws a power which is lower than 10 W, preferably lower than S W.
26. A portable fan assembly substantially as herein described with reference to the accompanying drawings.