A FAN
FIELD OF THE INVENTION
The present invention relates to a fan. Particularly, but not exclusively, the present
invention relates to a floor or table-top fan, such as a desk, tower or pedestal fan.
BACKGROUND OF THE INVENTION
A conventional domestic fan typically includes a set of blades or vanes mounted for
rotation about an axis, and drive apparatus for rotating the set of blades to generate an
air flow. The movement and circulation of the air flow creates a 'wind chill' or breeze
and, as a result, the user experiences a cooling effect as heat is dissipated through
convection and evaporation. The blades are generated located within a cage which
allows an air flow to pass through the housing while preventing users from coming into
contact with the rotating blades during use of the fan.
WO 2009/030879 describes a fan assembly which does not use caged blades to project
air from the fan assembly. Instead, the fan assembly comprises a cylindrical base which
houses a motor-driven impeller for drawing a primary air flow into the base, and an
annular nozzle connected to the base and comprising an annular air outlet through
which the primary air flow is emitted from the fan. The nozzle defines a central
opening through which air in the local environment of the fan assembly is drawn by the
primary air flow emitted from the mouth, amplifying the primary air flow.
WO 2010/100452 also describes a similar fan assembly. Within the base, the impeller
is located within an impeller housing, and the motor for driving the impeller is located
within a motor bucket which is mounted on the impeller housing. The impeller housing
is supported within the base by a plurality of angularly spaced supports. Each support
is, in turn, mounted on a respective support surface extending radially inwardly from the
inner surface of the base. In order to provide an air tight seal between the impeller
housing and the base, a lip seal is located on an external side surface of the impeller
housing for engaging the internal side surface of the base.
WO 2010/046691 also describes a fan assembly. The fan assembly comprises a
cylindrical base which houses a motor-driven impeller for drawing a primary air flow
into the base, and an annular nozzle connected to the base and comprising an annular air
outlet through which the primary air flow is emitted from the fan. The fan assembly
comprises a filter for removing particulates from the air flow. The filter may be
provided upstream from motor-driven impeller, in which case particulates are removed
from the air flow prior to passing through the impeller. This protects the impeller from
debris and dust that may be drawn into the fan assembly and which may damage the fan
assembly. Alternatively, the filter may be provided downstream from the motor-driven
impeller. In this configuration it is possible to filter and clean the air drawn through the
motor-driven impeller, including any exhaust emissions, prior to progression through
the elements of the fan assembly and supply to the user.
It is an object of the present invention to provide an improved fan assembly which
overcomes some of the disadvantages of the prior art, or at least provides an alternative
fan assembly.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a fan assembly comprising:
a body comprising means for generating an air flow;
a nozzle mountable on the body for receiving the air flow from the body and for
emitting the air flow;
nozzle retaining means for releasably retaining the nozzle on the body, the
nozzle retaining means having a first configuration in which the nozzle is retained on
the body and a second configuration in which the nozzle is released for removal from
the body; and
a manually actuable member located on the nozzle for effecting movement of
the nozzle retaining means from the first configuration to the second configuration.
The provision of a manually actuable member for effecting movement of the nozzle
retaining means from the first configuration to the second configuration allows the
nozzle to be rapidly and easily released for removal from the body. By providing the
manually actuable member on the nozzle it is possible to release the nozzle from the
body and remove it in a single action, as the manually actuable member is lifted off with
the nozzle. Once the nozzle has been released it may be pulled away from the body by a
user, for example for cleaning or replacement of the nozzle, or for the cleaning or
replacement of another component, such as a filter.
The nozzle retaining means is biased towards the first configuration, such that the
nozzle is retained on the body in its normal state. Biasing means is preferably provided
for biasing the manually actuable member towards the first position. The biasing means
may conveniently be in the form of a compression spring, but other forms of biasing
means are also envisaged within the scope of the invention.
The manually actuable member is preferably moveable from a first position to a second
position to effect movement of the nozzle retaining means from the first configuration
to the second configuration. The manually actuable member is preferably depressible.
The manually actuable member may conveniently take the form of one or more buttons
which are located on an exterior surface of the nozzle and may conveniently be pressed
by a user. In an embodiment of the invention the nozzle may be provided with two
diametrically opposed buttons on a base of the nozzle such that a user may grasp the
base of the nozzle in both hands and press the buttons with their thumbs while lifting
the nozzle from the base. This configuration provides a particularly easy method of
removal.
The manually actuable member preferably comprises a seal member to prevent air flow
generated by the fan assembly from leaking out during use of the fan. The seal member
preferably seals against a surface of the nozzle when the manually actuable member is
in its first position.
The nozzle retaining means preferably comprises a detent which is moveable relative to
the nozzle and the body to retain the nozzle on the body in the first configuration, and to
release the nozzle for removal from the body in the second configuration. The detent of
the nozzle retaining means is preferably provided on the nozzle. The detent is preferably
moveable from a first position to a second position to release the nozzle for removal
from the body.
Preferably the nozzle retaining means comprises biasing means for biasing the detent
towards the first position. The biasing means may conveniently be the same biasing
means that biases the nozzle retaining means towards its first configuration.
Alternatively, an additional biasing means may be provided. Preferably the detent is
pivotably moveable relative to the nozzle and the body.
In an embodiment of the invention the manually actuable member and the detent may be
formed as a single component, with the manually actuable member being provided at
one end and the detent being provided at the other. When this member is pivotably
mounted on the nozzle manual pressure on the manually actuable member overcomes
the biasing force of the biasing member and causes the manually actuable member and
the detent to pivot, such that the detent moves to its second position for removal of the
nozzle from the body.
The detent is preferably arranged to engage an outer surface of the body to retain the
nozzle on the body. The detent is preferably arranged to engage a recessed portion of
the outer surface of the body to retain the nozzle on the body.
The nozzle preferably defines an opening through which air from outside the fan
assembly is drawn by the air emitted from the nozzle. The fan assembly preferably
comprises a filter upstream from the air inlets.
The user experience is improved with a nozzle which is securely held in place, yet may
be quickly and easily removed in a single action. It is desirable to provide a nozzle
which may be located on the body just as easily, and so in a second aspect the present
invention provides a fan assembly comprising:
a body comprising an inlet, an outlet and means for generating an air flow
through the body; and
a nozzle mountable on the body for receiving the air flow from the body and for
emitting the air flow,
wherein the body and the nozzle have cooperative inclined surfaces configured
to assist alignment of the nozzle on the body.
The cooperative inclined surfaces are complementary and configured such that they are
able to slide relative to one another when they come into contact and guide the nozzle
into the correct position for engagement with the body. The arrangement of the inclined
surfaces is such when the body is situated on a surface, such as a floor or table, and the
inclined surfaces are caused to slide relative to one another they cause nozzle to rotate
relative to the body. This results in a "self twist" docking mechanism for the nozzle on
the base which doesn't rely on a user perfectly aligning the nozzle and the body.
The inclined surfaces are preferably undulating. The term "undulating" as used herein
describes a sinuous, wave-like surface which has a plurality of peaks and troughs.
Preferably the cooperative inclined surface on the body comprises a top edge of the
body. Preferably the cooperative inclined surface on the nozzle comprises a surface
located in a channel in a base of the nozzle.
The body is preferably cylindrical, although elliptical shaped bodies will also be able to
function in a similar manner.
Preferably the nozzle comprises a nozzle retaining means for retaining the nozzle on the
body. An outer surface of the body preferably comprises recesses for receiving a portion
of the nozzle retaining means.
The inclined surfaces preferably define opposing pairs of peaks and troughs. The
recesses are preferably located on the peaks. The inclined surfaces preferably comprise
a pair of diametrically opposed peaks and a pair of diametrically opposed troughs.
The fan assembly preferably comprises a filter upstream from the air inlet, and so in a
third aspect the present invention provides a fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body;
a nozzle removably mounted on the body for receiving the air flow from the
body and for emitting the air flow; and
a filter surrounding at least a portion of the body upstream from the air inlet, the
filter being held captive on the fan assembly between the nozzle and a portion of the
body while remaining free to move relative to the body and the nozzle,
and wherein the filter is removable from the fan assembly only after removal of
the nozzle from the body.
The filter is securely held in place when the nozzle is mounted on the body, but it is not
connected to either the body or the nozzle. The term "connected" as used herein implies
some degree of interlocking, or inter-engagement, and does include the fact that the
filter is in contact with the body and the nozzle. The filter may be considered to be loose
fitting as it is free to move relative to the body and nozzle. The filter may simply be
lowered onto the body and then secured in place by the engagement of the nozzle with
the base. There is no need to make any connection between the filter and the body, other
than lowering the filter into place. This provides a convenient and easy way to fit and
remove the filter.
The body preferably comprises a seat for the supporting the filter. Preferably the seat
comprises an upwardly facing surface for supporting the filter. Preferably the seat is
substantially orthogonal to a longitudinal axis of the body.
The body preferably comprises a lower body section and an upper body section and the
seat projects outwardly from the upper body section. The means for generating the air
flow through the body may conveniently be located within the upper body section, and a
control circuit for controlling the means for generating the air flow may conveniently be
located within the lower body section. The lower body section preferably also
comprises means for rotating the upper body section relative to the lower body section.
The means for rotating the upper body preferably comprises an oscillation mechanism
for oscillating the upper body back and forth relative to the lower body.
Preferably the diameter of the lower body section is larger than the diameter of the
upper body section. An outer edge of the seat is preferably substantially flush with an
outer surface of the lower body section. When the filter is located on the body it
preferably rests on the on the seat and an outer surface of the filter is preferably
substantially flush with an outer surface of the lower body section.
The fan assembly preferably further comprises sealing means for forming a seal
between the filter and at least the body to define a flow path between a downstream
surface of the filter and the air inlet of the body.
Sealing means is preferably provided for forming a seal between a filter other
components of the fan assembly, and so in a fourth aspect the present invention
provides a fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body;
a nozzle for receiving the air flow from the body and for emitting the air flow;
a filter upstream from the air inlet and having an upstream surface and a
downstream surface;
a seat on the body having an upwardly facing surface for supporting the filter;
and
sealing means for forming a seal between the filter and the body to define a flow
path between the downstream surface of the filter and the air inlet.
It is important to ensure that all of the air entering the body has passed through the filter.
This facilitates the removal of particulate matter from the air flow entering the body,
which is beneficial for both the internal workings of the fan assembly and ensures that
the air flow emitted from the nozzle is free from particulate matter. This enables
impurities to be removed from the air in the space in which the fan is located. In order
to effectively do this it is important to ensure that all of the air entering the body has
passed through the filter. This is achieved by providing the sealing means which define
a flow path between a downstream surface of the filter and the air inlet of the body.
When the fan assembly draws air into the body it is drawn through the filter.
Preferably the sealing means comprises at least one sealing member provided on the
nozzle. Preferably the sealing means comprises at least one sealing member provided on
the body. Preferably the sealing means comprises a first sealing member provided on
the body and a second sealing member provided on the nozzle. Preferably the sealing
means comprises at least one sealing member provided on the filter. More preferably the
filter is provided with at least two sealing members.
The filter is preferably supported on a seat which extends substantially orthogonal to a
longitudinal axis of the body. Preferably the upwardly facing surface is inclined
downwardly away from a longitudinal axis of the body. A lower seal member is
preferably provided adjacent the seat for forming a seal against a bottom surface of the
filter. An upper seal member is preferably provided on the nozzle for forming a seal
against an upper surface of the filter. The sealing means are preferably annular.
It is desirable that a filter is provided upstream of the air inlets, and so in a fifth aspect
the present invention provides a fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body, the body having a lower body section and an upper body section
capable of rotation relative to the lower body section;
a nozzle for receiving the air flow from the body and for emitting the air flow;
a filter upstream from the air inlet; and
a seat on the upper body section for supporting the filter such that the filter
rotates relative to the lower body section when the upper body section is caused to
rotate,
wherein the seat has an upwardly facing surface for supporting the filter.
Since the upper body is rotatable relative to the lower body it is advantageous for the
filter to be supported by a seat on the upper body section. In order for the filter to
function properly it needs to be sealed to the fan assembly in order to define a flow path
between a downstream surface of the filter and the air inlet of the body. Preferably the
seat is provided with a seal for forming a sealing engagement with the filter. With the
filter supported on the upper body section it is able to rotate with the upper body section
and the seals are not disturbed. However, if the filter was supported on the lower body
section then at least one of its seals would drag against the body when the upper body
section was rotated. This is undesirable as it increases the likelihood of air leaking
around and bypassing the filter.
The seat is preferably substantially orthogonal to a longitudinal axis of the upper body
section. Preferably the lower body section and upper body section are cylindrical and
the seat projects radially from the upper body section. Preferably the diameter of the
lower body section is larger than the diameter of the upper body section. Other shapes
for the upper and lower body sections are also envisaged, for example, they may be
square, rectangular, triangular, or any other regular or irregular shape. It is preferred that
the outer edges of the lower body section extend beyond those of the upper body
section.
Preferably the seat projects radially from the upper body section. Preferably an outer
edge of the seat is substantially flush with an outer surface of the lower body section.
The lower body section preferably comprises means for rotating the upper body section
relative to the lower body section. Preferably the means for rotating the upper body
section comprises an oscillation mechanism.
The filter is preferably tubular and surrounds at least a portion of the body. Preferably
the filter extends 360° around the body. Alternatively, the filter may preferably extend
radially around at least a portion of the body.
When the filter is on the seat an outer surface of the filter is preferably substantially
flush with an outer surface of the lower body section. This provides a more aesthetically
pleasing product as the filter and lower body section have a sleek profile. It is further
preferred that when the nozzle is mounted on the body an outer surface of the filter is
substantially flush with an outer surface of a base portion of the nozzle. Again, this
helps to integrate the filter into the fan assembly and provides a more visually appealing
appearance as the filter and the lower body section form a contiguous outer surface.
Preferably the seat comprises a first section which extends substantially perpendicular
to a longitudinal axis of the upper body section and a second section which is inclined
downwardly relative to the longitudinal axis. The filter preferably comprises a plurality
of wedge-shaped projections on a lower surface. The wedge-shaped projections are
preferably angularly spaced around the periphery of the filter. The wedge-shaped
projections preferably taper upwardly and inwardly from an outer edge of the filter
towards the longitudinal axis. When the filter is placed onto the body the wedge-shaped
projections cooperate with the inclined surface of the seat to centre the filter on the
body. The cooperating surfaces of the wedge-shaped projections and the inclined
surfaces slide relative to one another such that the filter is effectively able to self-centre
on the body in a position substantially parallel to a surface on which a base of the body
is situated.
The filter preferably comprises a filter media comprising a HEPA filter. The filter
preferably comprises a filter media comprising an activated carbon cloth filter. The
filter media may preferably be pleated in order to increase the available surface area of
the filter media. The filter preferably comprises a perforated shroud surrounding a filter
media of the filter. The shroud serves to protect the filter media from damage, e.g.
during transit, and it also comprises apertures which are sized to prevent larger particles
from coming into contact with the filter media. In addition, the shroud provides an
attractive outer surface for the filter, which complements the body and nozzle of the fan
assembly.
The fan assembly is preferably provided with a seat for supporting the filter, and so in a
sixth aspect the present invention provides a fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body;
a nozzle for receiving the air flow from the body and for emitting the air flow;
and
a filter upstream from the air inlet; and
a seat on the body, the seat comprising an upwardly facing surface for
supporting the filter.
Preferably the seat is substantially orthogonal to a longitudinal axis of the body.
Preferably the body is cylindrical. Preferably the seat projects radially from the body.
Preferably the upwardly facing surface is inclined downwardly away from a
longitudinal axis of the body.
Preferably the seat comprises a first section which projects radially from the body
substantially perpendicular to the longitudinal axis and a second section which is
inclined downwardly away from the longitudinal axis. Preferably the body comprises a
lower body section and an upper body section and the seat projects radially outwardly
from the upper body section.
Preferably the diameter of the lower body section is larger than the diameter of the
upper body section. Preferably an outer edge of the seat is substantially flush with an
outer surface of the lower body section. When the filter is on the seat an outer surface of
the filter is preferably substantially flush with an outer surface of the lower body
section.
The lower body section preferably comprises means for rotating the upper body section
relative to the lower body section. Preferably the means for rotating the upper body
section comprises an oscillation mechanism.
The filter preferably comprises a plurality of wedge-shaped projections on a lower
surface. The wedge-shaped projections preferably taper upwardly and inwardly from an
outer edge of the filter towards the longitudinal axis. The wedge-shaped projections are
preferably angularly spaced around the periphery of the filter. When the filter is placed
onto the body the wedge-shaped projections cooperate with the inclined surface of the
seat to centre the filter on the body. The cooperating surfaces of the wedge-shaped
projections and the inclined surfaces slide relative to one another such that the filter is
effectively able to self-centre on the body in a position substantially parallel to a surface
on which a base of the body is situated.
In a seventh aspect the invention provides a fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body, the body comprising a lower body section and an upper body
section, the upper body section housing the means for generating the air flow and the
lower body section housing a control circuit for controlling the means for generating the
air flow; and
a nozzle for receiving the air flow from the body and for emitting the air flow,
wherein the lower body section comprises an outer wall and an inner wall, the
outer wall and inner wall defining an outer cavity surrounding an inner cavity, and
wherein the control circuit is located within the inner cavity surrounded by the inner
wall.
Providing the control circuit within an inner cavity of the lower body section provides
protection for the various elements of the control circuit against damage caused by the
ingress of fluid, e.g. water, into the fan assembly. If fluid comes into contact with the
fan assembly, e.g. as a result of a spillage, it is likely to run off the outer surfaces of the
fan assembly. However, if the fluid does manage to penetrate into the lower body of the
fan assembly it will be collected within the outer cavity where it cannot come into
contact with any of the elements of the control circuit.
Preferably the outer cavity comprises a floor surface located between the outer wall and
the inner wall. Preferably the floor surface comprises a plurality of drain holes. The
drain holes provide a pathway for fluid to exit the outer cavity, thus preventing the outer
cavity from becoming full and overflowing. Preferably the drain holes are angularly
spaced about the outer cavity.
Preferably the floor surface is inclined downwardly from the inner wall towards the
outer wall. Preferably the drain holes are located adjacent the outer wall. This
arrangement aids drainage by directing any fluid in the outer cavity towards the drain
holes.
Preferably the outer wall and the inner wall are annular. The inner wall is preferably
taller the outer wall. Preferably a top edge of the inner wall terminates adjacent a lower
surface of the upper body section.
Preferably a passageway is provided from an inner surface of the inner wall to an outer
surface of the outer wall for conveying a power supply cable from the control circuit. A
sealing member for sealing the power supply cable to the passageway to prevent the
ingress of fluid into the inner cavity is preferably provided.
Preferably a bottom surface of the body is provided with a plurality of feet for
supporting the fan assembly. The feet serve to raise the bottom surface above the
surface upon which the fan assembly is being supported, e.g. a floor surface or the
surface of a table. This ensures that the outlet from the drain holes does not become
blocked by the support surface and fluid is able to flow freely from the outer cavity
through the drain holes.
Preferably a filter is provided surrounding at least a portion of the body upstream from
the air inlet.
The fan assembly preferably comprises means for rotating the upper body relative to the
lower body. The means for rotating the upper body preferably comprises an oscillation
mechanism. Preferably the means for rotating the upper body section is located within
the outer cavity of the lower body section. As with the control circuit, this provides
protection for the rotation means from damage caused by the ingress of fluids into the
lower body section.
Features described above in connection with the first aspect of the invention are equally
applicable to each of the second to seventh aspects of the invention, and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
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 of a fan;
Figure 2 is a front view of the fan;
Figure 3 is a side view of the fan;
Figure 4 is a side sectional view through the fan taken along line A-A in Fig. 2;
Figure 5a is a front sectional view through the fan taken along line B-B in Fig. 3 with
the nozzle engaged on the body, Figure 5b is a front sectional view through the fan
taken along line B-B in Fig. 3 with the nozzle released from the body;
Figure 6 is a front perspective view of the base of the fan;
Figure 7 is a side sectional view of the base of the fan;
Figure 8 is a front sectional view of the base of the fan;
Figure 9 is a perspective view from below of the nozzle removed from the base;
Figure 10 is bottom view of the nozzle removed from the base;
Figure 11 is a top view of the lower body section of the fan;
Figure 12 is a perspective view of the filter removed from the fan;
Figure 13 is a perspective view of the filter on the body of the fan; and
Figure 14 is a perspective view of the filter from below.
DETAILED DESCRIPTION OF THE INVENTION
Figures 1 to 3 are external views of a fan 10, and Figures 4 and 5 show sectional views
through lines A-A and B-B of Figures 2 and 3 respectively. In Figures 4 and 5 the top
portion of the nozzle has been omitted in order to improve the clarity of the remainder
of the fan 10. In overview, the fan comprises a body 12, a removable filter 14 mounted
on the body 12, and an annular nozzle 16 mounted on the body 12. The filter 14 rests on
an annular flange 54 extending radially outwardly from the body 12, and its removal
from the body is prevented by the presence of the nozzle 16. In order to remove the
filter 14 from the fan 10 the nozzle 16 must first be removed.
The annular nozzle 16 has an air outlet 18 for emitting a primary air flow from the fan
10 and defines a bore 19, or opening, through which air from outside of the fan
assembly 10 is drawn by the air emitted from the outlet 18. The body 12 further
comprises a user interface for allowing a user to control the operation of the fan 10. The
user interface comprises a user-operable button 20 to enable a user to operate the fan 10.
The fan 10 may also be provided with a remote control unit for controlling the operation
of the fan 10. The remote control unit may be provided with a plurality of user-operable
buttons and may advantageously be mounted on the nozzle 16 when not in use. A
variety of mounting mechanisms are envisaged, but in one embodiment the remote
control unit may be provide with a magnet for attaching to a corresponding magnet
housed within the nozzle 16.
The nozzle 16 has an elongate annular shape. The nozzle 16 comprises an outer wall 28
extending about an annular inner wall 30. In this example, each of the walls 28, 30 is
formed from a separate component. Each of the walls 28, 30 has a front end and a rear
end. The rear end of the outer wall 28 curves inwardly towards the rear end of the inner
wall 30 to define a rear end of the nozzle 16. The front end of the inner wall 30 is
folded outwardly towards the front end of the outer wall 28 to define a front end of the
nozzle 16. The front end of the outer wall 28 is inserted into a slot located at the front
end of the inner wall 30, and is connected to the inner wall 30 using an adhesive
introduced to the slot. The inner wall 30 extends about an axis X to define the bore 19
of the nozzle 16.
The inner wall 30 is shaped so that the external surface of the inner wall 30, that is, the
surface that defines the bore 19, has a number of sections. The external surface of the
inner wall 30 has a convex Coanda surface 32 located adjacent the mouth 18 and over
which the mouth 18 directs the air emitted from the fan 10, a diffuser surface 34 located
downstream of the Coanda surface 32 and a guide surface 36 located downstream of the
diffuser surface 34. The diffuser surface 34 is arranged to taper away from the central
axis X of the opening 19 in such a way so as to assist the flow of air emitted from the
fan 10. A visually appealing tapered surface 38 is located downstream from the guide
surface 36.
The rear end of the outer wall 28 is shaped to overlap the rear end of the inner wall 30 to
define the air outlet 18, or mouth, of the nozzle 16 between the inner surface of the
outer wall 28 and the outer surface of the inner wall 30. The air outlet 18 is in the form
of a slot with a width which is preferably substantially constant about the axis X, and is
in the range from 0.5 to 5 mm. The overlapping portions of the outer wall 28 and the
inner wall 30 are substantially parallel, and are arranged to direct air over the Coanda
surface 32 of the inner wall 30.
The outer wall 28 and the inner wall 30 define an interior passage 44 for conveying air
to the air outlet 18. The interior passage 44 extends about the bore 19 of the nozzle 16.
The nozzle 16 further comprises two curved seal members 112 each for forming a seal
between the outer wall 28 and the inner wall 30 at the top and bottom curved sections of
the nozzle 16, so that there is substantially no leakage of air from the curved sections of
the interior passage 44 of the nozzle 16. The mouth 18 may thus be considered to
comprise two elongate outlets each located on a respective long side of the central
opening 19.
In order to direct the primary air flow into the mouth 18, the nozzle 16 comprises a
plurality of stationary guide vanes 120 located within the interior passage 44 and each
for directing a portion of the air flow towards the mouth 18. The guide vanes 120 are
integral with the internal surface of the outer wall 28 of the nozzle 16. The guide vanes
120 are curved so that there is no significant loss in the velocity of the air flow as it is
directed into the mouth 18. The guide vanes 120 are substantially vertically aligned and
evenly spaced apart to define a plurality of passageways between the guide vanes 120
and through which air is directed into the mouth 18. The even spacing of the guide
vanes 120 provides a substantially even distribution of the air stream along the length of
the section of the mouth 18.
The guide vanes 120 are preferably shaped so that a portion of each guide vane 120
engages the external surface of the inner wall 30 of the nozzle 16 so as to urge apart the
overlapping portions of the internal surface of the outer wall 28 and the external surface
of the inner wall 30. This can assist in maintaining the width of each outlet at a
substantially constant level along the length of each section of the mouth 18. Additional
spacers may be provided along the length of each section of the mouth 18, also for
urging apart the overlapping portions of the internal surface of the outer wall 28 and the
external surface of the inner wall 30, to maintain the width of the outlet 18 at the desired
level.
The outer wall 28 comprises a base 40 which is connected to an open upper end of the
body 12, and which has an open lower end which provides an air inlet 42 for receiving
the primary air flow from the body 12.
The base 40 of the nozzle 16 is provided with a sealing member 130 which extends
around the inner periphery of the base 40. The sealing member 130 is an annular rubber
seal and is attached to a support member 132 which is located within the base 40 of the
nozzle 16. The support member 132 is itself annular and surrounds the air inlet 42 and is
attached to the base 40 of the nozzle 16, for example by a plurality of screws.
As can best be seen in Figs. 6 to 8, the body 12 comprises a substantially cylindrical
main body section 50 mounted on a substantially cylindrical lower body section 52.
The main body section 50 and the lower body section 52 are preferably formed from
plastics material. The main body section 50 has a smaller external diameter than the
lower body section 52 and an annular flange 54 extends radially from a lower portion of
the main body section 50 such that the outer edge of the annular flange 54 is
substantially flush with the external surface of the lower body section 52. The annular
flange 54 comprises a first portion 54a which extends perpendicularly away from the
main body section 50, and a second portion 54b which tapers downwardly away from
the first portion 54a. An annular seal 56 is provided around the main body section 50 at
the junction of the main body section 50 and the annular flange 54. The annular seal 56
may conveniently be formed from a rubber material and it is received in an annular
groove 58 defined by the first portion 54a of the annular flange 54 and an annular rib 60
which extends radially from the main body section 50.
The fan 10 comprises a mechanism for releasably retaining the nozzle 16 on the body
12. Fig. 5a illustrates a first configuration of the mechanism when the nozzle 16 is
retained on the body 12, whereas Fig. 5b illustrates a second configuration of the
mechanism when the nozzle 16 is released from the body 12. The mechanism for
releasably retaining the nozzle 16 on the body 12 comprises a pair of detents 200 which
are located on diametrically opposed sides of the nozzle 16. Each detent 200 is
pivotably moveable between a deployed position for retaining the nozzle 16 on the body
12, and a stowed position, in which the nozzle 16 can be removed from the body 12.
Resilient elements 204, such as compression springs, are located within the nozzle 16
for biasing the detents 200 towards their deployed positions.
The nozzle 16 comprises two diametrically opposed manually actuable buttons 202
which are operable to move the detents 200 between the deployed position, in which the
nozzle 16 is retained on the body, and the stowed position, in which the nozzle 16 can
be removed from the body 12. The buttons 202 are mounted on the nozzle 16 for
pivoting movement from a first position, in which the detents 200 are in their deployed
position, to a second position, in which the detents 200 are in their stowed position. The
first and second positions of the buttons 202 are shown in Figs. 5a and 5b respectively.
The buttons 202 are biased into their first position by the resilient elements 204 which
are provided behind the buttons 202 and urge them into their first position. The strength
of the resilient elements 204 is selected such that the biasing force can be overcome by a
user grasping the nozzle 16 and pressing with their fingers. An advantage of providing
the buttons 202 on the nozzle 16 is that the nozzle 16 may be quickly and easily
released and removed from the body 12 in a single step. A user simply needs to grasp
the nozzle 16, depress the buttons 202 and lift the nozzle 16 away from the base 12.
The base 40 of the nozzle 16 comprises two diametrically opposed apertures 206 which
have a diameter slightly larger than that of the buttons 202, such that the buttons 202
can project through the apertures 206. Rubber seals 208 are provided surrounding the
periphery of the buttons 202, and the seals 208 are urged into sealing engagement with
an inner wall of the base 40 surrounding the periphery of the apertures 206 when the
buttons 202 are in their first position. This prevents air from flowing out of the apertures
206 during use of the fan 10.
As can best be seen in Figs. 5a, 5b and 6, the outer surface of the main body section 50
of the base 12 comprises a pair of diametrically opposed recesses 210. When the
detents 200 are in their deployed position they engage the recesses 210 on the outer
surface of the main body section 50 of the base 12 to prevent the nozzle 16 from
becoming withdrawn from the body 12, for example if the fan apparatus 10 is lifted by a
user gripping the nozzle 16. When a user depresses the buttons 202 this moves the
detents 200 from their deployed position to their stowed position. In the stowed position
the detents 200 are not engaged with the recesses 210, and the nozzle 16 may be
removed from the body 12.
Referring now to Figs. 6 to 10, the base 40 of the nozzle 16 and the main body section
50 of the base 12 comprise complementary features which cooperate to facilitate
location of the nozzle 16 on the base 12. The base 40 of the nozzle 16 comprises an
annular channel 134 which surrounds the air inlet 42. The annular channel 134 is
defined by an outer annular wall 148 and an inner annular wall 150. The outer annular
wall 148 and inner annular wall 150 depend downwardly from the nozzle 16 and the
inner annular wall 150 extends beyond the outer annular 148, such that it extends into
the main body section 50 of the base 12 when the nozzle 16 is located on the base 12.
The annular channel 134 has an undulating profile, such that when viewed from below
it has two diametrically opposed low points 136a,b and two diametrically opposed high
points 138a,b. The low points 136a,b of the annular channel 134 are offset from the high
points 138a,b such that a line bisecting the low points 136a,b is orthogonal to a line
bisecting the high points 138a,b. The low points 136a,b of the annular channel 134 are
aligned with the buttons 202 on the nozzle 16. Two ribs 140 extend across the width of
the annular channel 134 in a rear half of the nozzle 16 and further serve to aid in the
correct fitting of the nozzle 16 on the base 12, as will be described in more detail below.
The main body section 50 of the base 12 comprises an outer casing 24 which defines the
side walls of the main body section 12. The main body section 50 is cylindrical and the
top edge 26 of the outer casing 24 has an undulating profile, such that it has two
diametrically opposed high points 142a,b and two diametrically opposed low points
144a,b. The high points 142a,b of the top edge 26 of the outer casing 24 are offset from
the low points 144a,b of the top edge 26 of the outer casing 24 such that a line bisecting
the high points 142a,b is orthogonal to a line bisecting the low points 144a,b. As can
best be seen in Fig. 10, a locating notch 146 is provided in a rear portion of the outer
casing 24 depending downwardly from the top edge 26. The recesses 210 on the outer
surface of the outer casing 24 are adjacent the high points 142a,b of the top edge 26.
When attaching the nozzle 16 to the base 12 it is important to ensure that nozzle 16
faces in the correct direction. To prevent incorrect attachment of the nozzle 16 to the
base 12 the nozzle 16 is provided with ribs 140 which extend across the annular channel
134 in a rear portion of the nozzle 16. The ribs 140 are arranged to be received in the
notch 146 which is provided in a rear portion of the top edge 26 of the outer casing 24
to ensure that the nozzle can only be fitted in the correct orientation. If an attempt is
made to attach the nozzle 16 in an incorrect position it will be unsuccessful as the ribs
140 will abut the top edge 26 of the outer casing 24 and prevent further insertion of the
nozzle 16 into the base 12.
Once care has been taken to ensure that the rear portion of the nozzle 16 is aligned with
the rear portion of the base 12 the nozzle 16 be lowered onto the base 12 with the
buttons 202 being generally aligned with the detents 200 on the outer surface of the
outer casing 24. The undulating top edge 26 of the outer casing 24 is arranged to be
received into the annular channel 134 of the base 40 of the nozzle 16. The undulating
surfaces of the top edge 26 and the annular channel 134 are complementary such that
the high points 142a,b of the outer casing 24 are received within the low points 136a,b
of the outer casing. Similarly, the low points 144a,b of the outer casing 24 align with the
high points 138a,b of the annular channel 134. The complementary nature of the
surfaces is such that the undulating top edge 26 of the outer casing 24 is able to slide
over the undulating surface of the annular channel 134 until it is received in the correct
position. The sliding movement of the top edge 26 relative to the annular channel 134
causes the nozzle 16 to rotate about the longitudinal axis of the nozzle 16 and base 12.
This provides a convenient location mechanism which does not rely on the user
precisely aligning the nozzle 16 on the base 12.
Referring now to Figs. 6 to 8, the main body section 50 comprises an air inlet 22 in the
form of a plurality of apertures formed in the outer casing 24 of the body 12, and
through which a primary air flow is drawn into the body 12 from the external
environment. In this embodiment the air inlet 22 comprises an array of apertures
formed in the section of the outer casing 24 of the body 12 which is defined by the main
body section 50. Alternatively, the air inlet 22 may comprise one or more grilles or
meshes mounted within windows formed in the outer casing 24. The main body section
50 is open at the upper end (as illustrated) for connection to the base 40 of the nozzle
16, and to allow the primary air flow to be conveyed from the body 12 to the nozzle 16.
A lower surface of the main body section 50, located below the air inlet 22, is lined with
noise absorbing material 23, preferably an acoustic foam material, to suppress noise
generated during operation of the fan 10.
The lower body section 52 comprises the aforementioned user interface and a control
circuit, indicated generally at 62, for controlling various functions of the fan 10 in
response to operation of the user interface. The lower body section 52 also houses a
mechanism for oscillating the main body section 50 relative to the lower body section
52. The operation of the oscillation mechanism is controlled by the control circuit 62 in
response to the user's depression of the appropriate button on the remote control unit.
The range of each oscillation cycle of the main body section 50 relative to the lower
body section 52 is preferably between 60° and 120°, and the oscillation mechanism is
arranged to perform around 3 to 5 oscillation cycles per minute. A mains power cable
64 for supplying electrical power to the fan 10 extends through an aperture formed in
the lower body section 52.
Referring now to Fig. 11, it can be seen that the lower body section 52 comprises an
outer wall 53, which defines the outer cylindrical surface of the lower body section 52
and an inner wall 55. A first cavity 57 is defined between the outer wall 53 and the inner
wall 55. The inner wall is annular and defines an inner cavity 59 which encloses all of
the electrical components of the lower body section 52, such as the control circuit 62
and oscillation mechanism. The cavity 57 provides protection for the electrical
components of the lower body section 52 in the event of water, or other liquid, ingress
into the base 12. If the fan 10 comes into contact with a liquid, e.g. spillage of a
beverage, then any water which penetrates the base 12 will be received within the
channel 57, and prevented from entering the inner cavity 59 and coming into contact
with the electrical components of the lower base section 52, such as the control circuit
62. Drainage holes 4 1 are provided in a floor surface 43 of the first cavity 57. The
drainage holes 41provide an outlet to permit any water collected in the first cavity to
flow out of the lower base section 52 and onto a surface on which the fan assembly 10 is
supported. As can best be seen in Fig. 8, the floor surface 43 is inclined outwardly and
downwardly away from the longitudinal axis of the lower body section 52 to direct the
flow of liquid towards the drainage holes 41. As can best be seen in Figs. 7 and 8, the
lower body section 52 is provided with feet 89 which support the fan assembly on a
surface, such as a floor or table. The feet 89 raise the floor surface 43 above the surface
on which the fan assembly 10 is supported, to provide a flow path for liquid exiting the
drainage holes 41. A passageway 87 is provided through the first cavity 57 to convey
the power supply cable 64 away from the control circuit 62. The passageway 87 ensures
that the power supply cable 64 does not come into contact with liquid in the first cavity
57 and a seal is provided between the passageway 87 and the power supply cable 64 to
prevent liquid ingress.
Turning now to Figs. 12 -14, these show the filter 14 according to the present invention.
The filter 14 is a tubular, barrel-type filter and comprises a two-layer structure of filter
media. Any number of alternative combinations of filter media are envisaged within the
scope of the present invention, but filter 14 comprises an outer layer 160 of a pleated
HEPA filter surrounding an inner layer 162 of activated carbon cloth. The two layers
160, 162 are encapsulated by top and bottom end caps 164, 166, which are annular
members with a generally U-shaped cross section. The filter 14 further comprises a
perforated shroud 168 in the form of a tubular plastic member which surrounds the filter
media and comprises an array of apertures which act as an air inlet 170 of the filter 14 in
use of the fan 10. Alternatively, the air inlet 170 of the shroud 168 may comprise one or
more grilles or meshes mounted within windows in the shroud 168. It will also be clear
that alternative patterns of air inlet arrays are envisaged within the scope of the present
invention.
As can best be seen in Fig. 14, the shroud 168 is connected to the bottom end cap 166
by means of connecting ring 172, which is glued to the shroud 168 and bottom end cap
166 to retain them in a spaced relationship. The shroud 168 protects the filter media
from damage, for example during transit, and also provides a visually appealing outer
surface for the filter 14, which is in keeping with the overall appearance of the fan 10.
The shroud 168 defines the air inlet 170 for the filter 14 and the array of apertures are
sized to prevent larger particles from entering the filter 14 and blocking, or otherwise
damaging, the filter media.
A lower surface 174 of the connecting ring 172 is provided with a plurality of angularly
spaced wedge-shaped projections 176. The wedge-shaped projections 176 are inclined
inwardly and upwardly from an outer periphery of the connecting ring 172 towards its
longitudinal axis. The filter 14 does not interlock with any other component of the fan
10, and for this reason it may be considered to be loose fitting. When the filter is located
on the base 12 of the fan 10 it rests on the annular flange 54 and the wedge-shaped
projections 176 cooperate with the tapered second portion 54b of the annular flange 54
to help centre the filter 14 on the base 12. The wedges 176 slide over the tapered portion
54b until the filter 14 is substantially parallel to the surface on which the fan 10 is
sitting. When the oscillation mechanism is activated to cause the main body section 50
to oscillate relative to the lower body section 52 the filter 14 moves with the main body
section 50.
As noted above, when the filter 14 is located on the base 12 of the fan 10 is sits on the
annular flange 54. The annular seal 56 forms a seal against the bottom end cap 166 of
the filter 14 to prevent leakage of air between the bottom of the filter 14 and the base
12. The filter 14 is located upstream from the air inlets 22 of the main body section 50,
such that the air drawn into the main body section 50 by the impeller 80 is filtered prior
to entering the main body section 50. This serves to remove any particles which could
potentially cause damage to the fan 10, and also ensures that the air emitted from the
mouth 18 is free from particulates.
When the nozzle 16 is located on the body 12, as described above, the sealing member
130 on the base 40 of the nozzle 16 forms a seal against the top end cap 164 of the filter
14 to prevent leakage of air between the top of the filter 14 and the nozzle 16. The top
and bottom seals to the filter 14 define a flow path, such that all air drawn into the main
body section 50 by the impeller 80 must pass through the filter 14.
Referring back to Figs. 7 and 8, the main body section 50 comprises a duct 70 having a
first end defining an air inlet 72 of the duct 70 and a second end located opposite to the
first end and defining an air outlet 74 of the duct 70. The duct 70 is aligned within the
main body section 50 so that the longitudinal axis of the duct 70 is collinear with the
longitudinal axis of the body 12, and so that the air inlet 72 is located beneath the air
outlet 74.
The air inlet 72 is defined by an outwardly flared inlet section 76 of an outer wall 77 of
the duct 70. The inlet section 76 of the outer wall 77 is connected to an impeller
housing 78 of the outer wall 77. The impeller housing 78 extends about an impeller 80
for drawing the primary air flow into the body 12 of the fan 10. The impeller 80 is a
mixed flow impeller. The impeller 80 comprises a generally conical hub 82, a plurality
of impeller blades 84 connected to the hub 82, and a generally frusto-conical shroud 86
connected to the blades 84 so as to surround the hub 82 and the blades 84. The blades
84 are preferably integral with the hub 82, which is preferably formed from plastics
material.
The impeller 80 is connected to a rotary shaft 90 extending outwardly from a motor 92
for driving the impeller 80 to rotate about a rotational axis. The rotational axis is
collinear with the longitudinal axis of the duct 70. In this embodiment, the motor 92 is a
DC brushless motor having a speed which is variable by the control circuit 62 in
response to user selection. The maximum speed of the motor 92 is preferably in the
range from 5,000 to 10,000 rpm. The motor 92 is housed within a motor housing. The
outer wall 77 of the duct 70 surrounds the motor housing, which provides an inner wall
95 of the duct 70. The walls 77, 95 of the duct 70 thus define an annular air flow path
which extends through the duct 70. The motor housing comprises a lower section 96
which supports the motor 92, and an upper section 98 connected to the lower section 96.
The shaft 90 protrudes through an aperture formed in the lower section 96 of the motor
housing to allow the impeller 80 to be connected to the shaft 90. The motor 92 is
inserted into the lower section 96 of the motor housing before the upper section 98 is
connected to the lower section 96.
The lower section 96 of the motor housing is generally frusto-conical in shape, and
tapers inwardly in a direction extending towards the air inlet 72 of the duct 70. The hub
82 of the impeller 80 has a conical inner surface which has a similar shape to that of a
contiguous part of the outer surface of the lower section 96 of the motor housing.
The upper section 98 of the motor housing is generally conical in shape, and tapers
inwardly towards the air outlet 74 of the duct 70. The upper section 98 of the motor
housing comprises an annular diffuser 100. The diffuser 100 comprises a plurality of
blades 102 for guiding the air flow towards the air outlet 74 of the duct 70. The shape
of the blades 102 is such that the air flow is also straightened as it passes through the
diffuser 100. The diffuser 100 comprises 1 1 blades 102. One of the blades 102 defines
a passageway through which a cable passes to the motor 92.
The outer wall 77 of the duct 70 comprises a diffuser housing 104 connected to the
upper end of the impeller housing 78, and which extends about the diffuser 100. The
diffuser housing 104 defines the air outlet 74 of the duct 70. The internal surface of the
diffuser housing 104 is provided with grooves which receive the outer edges of the
blades 102. The diffuser housing 104 and the upper section 98 of the motor housing
define a diffuser section of the air flow path through the duct 70.
The upper section 98 of the motor housing is perforated. The inner surface of the upper
section 98 of the motor housing is lined with noise absorbing material, preferably an
acoustic foam material, to suppress broadband noise generated during operation of the
fan 10. The noise absorbing material is not shown in the Figures so as to not obscure
the perforations in the upper section 98 of the motor housing.
A retaining ring 124 is provided in an upper portion of the main body section 50 for
preventing the motor housing from falling out of the main body section 50, for example
during transit. The retaining ring 124 is provided with four angularly spaced recesses
126, the top side of which can be seen in Fig. 6. Located within each of the recesses 126
is a foam pad. The angularly spaced foam pads are arranged such that when the
retaining ring 124 is secured to the main body section 50 the foam pads rest on
corresponding angularly spaced members 128 which project outwardly from an outer
surface of the diffuser housing 104. The foam pads reduce the transmission of vibrations
from the motor housing 94 to the retaining ring 124.
The retaining ring 124 further comprises an annular sealing member 154. The annular
sealing member 154 extends around the periphery of the retaining ring 124 and is
trapped between the outer surface of the retaining ring 124 and the inner surface of the
main body section 50. The sealing member 154 has a lip 156 which extends radially
inwardly towards the longitudinal axis of the motor housing. The lip 156 is arranged
such that when the nozzle 16 is located on the main body section 52 of the base 12 the
lip 156 seals against an outer surface of the downwardly depending inner annular wall
150 defining the inner wall of the annular channel 134. This seal prevents the leakage of
air as it passes from the air outlet 74 of main body section 50 and into the air inlet 42 of
the nozzle 16. This ensures that the fan 10 can function even in the absence of the filter
14.
Referring to Figs. 7 band 8, the impeller housing 78 is mounted on an annular seat 106
located within the main body section 50 of the body 12. The seat 106 extends radially
inwardly from the inner surface of the outer casing 24 so that an upper surface of the
seat 106 is substantially orthogonal to the rotational axis Z of the impeller 80.
An annular seal 108 is located between the impeller housing 78 and the seat 106. The
annular seal 108 is preferably a foam annular seal, and is preferably formed from a
closed cell foam material. The outer diameter of the annular seal 108 is preferably
smaller than the inner diameter of the outer casing 24 so that the annular seal 108 is
spaced from the inner surface of the outer casing 24.
To operate the fan 10 the user presses button 20 of the user interface or a button on the
remote control, in response to which the control circuit 62 activates the motor 92 to
rotate the impeller 80. The rotation of the impeller 80 causes a primary air flow to be
drawn through the air inlets 170 of the filter 14, through the two layers 162, 164 of filter
media, and into the body 12 through the air inlet 22. Particles are thus removed from the
air flow upstream from the air inlets 22 and do not enter the body 12. The user may
control the speed of the motor 92, and therefore the rate at which air is drawn into the
body 12, by pressing the appropriate buttons on the remote control.
The rotation of the impeller 80 by the motor 92 generates vibrations which are
transferred through the motor housing and the impeller housing 78 towards the seat 106.
The annular seal 108 located between the impeller housing 78 and the seat 106 is
compressed under the weight of the duct 70, the impeller 80, the motor housing and the
motor 92 so that it is in sealing engagement with the upper surface of the seat 106 and
the impeller housing 78. The annular seal 108 thus not only prevents the primary air
flow from returning to the air inlet 72 of the duct 70 along a path extending between the
inner surface of the outer casing 24 of the main body section 50 and the outer wall 77 of
the duct 70, but also reduces the transmission of these vibrations to the seat 106, and
thus to the body 12 of the fan 10.
The air flow entering the body 12 through the air inlet 22 passes to the air inlet 72 of the
duct 70. Within the duct 70, the primary air flow passes through the impeller housing
78 and the diffuser housing 104 to be emitted from the air outlet 74 of the duct 70 and
into the air inlet 42 of the nozzle 16.
Within the interior passage 44 of the nozzle 16, the primary air flow is divided into two
air streams which pass in opposite angular directions around the bore 19 of the nozzle
16. As the air streams pass through the interior passage 44, air is emitted through the air
outlet 18. The emission of the primary air flow from the air outlet 18 causes a
secondary air flow to be generated by the entrainment of air from the external
environment, specifically from the region around the nozzle 16. This secondary air
flow combines with the primary air flow to produce a combined, or total, air flow, or air
current, projected forward from the nozzle 16.
Each of the air streams enters a respective one of the two vertically extending sections
of the interior passage 44 of the nozzle 16, and is conveyed in a substantially vertical
direction up through each of these sections of the interior passage 44. The set of guide
vanes 120 located within each of these sections of the interior passage 44 directs the air
stream towards the section of the mouth 18 located adjacent that vertically extending
section of the interior passage 44. Each of the guide vanes 120 directs a respective
portion of the air stream towards the section of the mouth 18 so that there is a
substantially uniform distribution of the air stream along the length of the section of the
mouth 18. The guide vanes 120 are shaped so that each portion of the air stream enters
the mouth 18 in a substantially horizontal direction.
The primary air flow emitted from the mouth 18 is directed over the Coanda surface 34
of the nozzle 14, causing a secondary air flow to be generated by the entrainment of air
from the external environment, specifically from the region around the mouth 18 and
from around the rear of the nozzle 16. This secondary air flow passes predominantly
through the central opening 19 of the nozzle 16, where it combines with the primary air
flow to produce a total air flow, or air current, projected forward from the nozzle 16.
The even distribution of the primary air flow along the mouth 18 of the nozzle 16
ensures that the air flow passes evenly over the diffuser surface 34. The diffuser surface
34 causes the mean speed of the air flow to be reduced by moving the air flow through a
region of controlled expansion. The relatively shallow angle of the diffuser surface 34
to the central axis X of the opening 19 allows the expansion of the air flow to occur
gradually. A harsh or rapid divergence would otherwise cause the air flow to become
disrupted, generating vortices in the expansion region. Such vortices can lead to an
increase in turbulence and associated noise in the air flow, which can be undesirable,
particularly in a domestic product such as a fan. In the absence of the guide vanes 120
most of the primary air flow would tend to leave the fan 10 through the upper part of the
mouth 18, and to leave the mouth 18 upwardly at an acute angle to the central axis of
the opening 19. As a result there would be an uneven distribution of air within the air
current generated by the fan 10. Furthermore, most of the air flow from the fan 10
would not be properly diffused by the diffuser surface 34, leading to the generation of
an air current with much greater turbulence.
The air flow projected forwards beyond the diffuser surface 34 can tend to continue to
diverge. The presence of the guide surface 36 extending substantially parallel to the
central axis X of the opening 19 tends to focus the air flow towards the user or into a
room.
The invention is not limited to the detailed description given above. Variations will be
apparent to the person skilled in the art.
For example, the base and the nozzle of the fan may be of a different shape and/or
shape. The outlet of the mouth may be modified. For example, the outlet of the mouth
may be widened or narrowed to a variety of spacings to maximise air flow. The air flow
emitted from the mouth may pass over a surface, such as a Coanda surface, but
alternatively the air flow may be emitted through the mouth and projected forward from
the fan without passing over an adjacent surface. The Coanda effect may be effected
over a number of different surfaces, or a number of internal or external designs may be
used in combination to achieve the flow and entrainment required. The diffuser surface
may be comprised of a variety of diffuser lengths and structures. The guide surface may
be a variety of lengths, and may be arranged at a number of different positions and
orientations as required for different fan requirements and different types of fan
performance.

CLAIMS
1. A fan assembly comprising:
a body comprising an air inlet, an air outlet, and means for generating an air
flow through the body, the body comprising a lower body section and an upper body
section, the upper body section housing the means for generating the air flow and the
lower body section housing a control circuit for controlling the means for generating the
air flow; and
a nozzle for receiving the air flow from the body and for emitting the air flow,
wherein the lower body section comprises an outer wall and an inner wall, the
outer wall and inner wall defining an outer cavity surrounding an inner cavity, and
wherein the control circuit is located within the inner cavity surrounded by the inner
wall.
2. A fan assembly as claimed in claim 1, wherein the outer cavity comprises a floor
surface located between the outer wall and the inner wall.
3. A fan assembly as claimed in claim 2, wherein the floor surface comprises a
plurality of drain holes.
4. A fan assembly as claimed in claim 3, wherein the drain holes are angularly
spaced about the outer cavity.
5. A fan assembly as claimed in claim 3 or claim 4, wherein the drain holes are
located adjacent the outer wall.
6. A fan assembly as claimed in any one of claims 2 to 4, wherein the floor surface
is inclined downwardly from the inner wall towards the outer wall.
7. A fan assembly as claimed in any preceding claim, wherein the outer wall and
the inner wall are annular.
8. A fan assembly as claimed in any preceding claim, wherein the inner wall is
taller than the outer wall.
9. A fan assembly as claimed in any preceding claim, wherein a bottom surface of
the body is provided with a plurality of feet for supporting the fan assembly.
10. A fan assembly as claimed in any preceding claim, further comprising a filter
surrounding at least a portion of the body upstream from the air inlet.
11. A fan assembly as claimed in claim 10, wherein the filter is tubular and
surrounds at least a portion of the body.
12. A fan assembly as claimed in claim 11, wherein the filter extends 360° around
the body.
13. A fan assembly as claimed in claim 10, wherein the filter extends radially
around at least a portion of the body.
14. A fan assembly as claimed in any one of claims 10 to 13, wherein the filter
comprises a filter media comprising a HEPA filter.
15. A fan assembly as claimed in any one of claims 10 to 14, wherein the filter
comprises a filter media comprising an activated carbon cloth.
16. A fan assembly as claimed in any one of claims 10 to 15, wherein the filter
comprises a perforated shroud surrounding a filter media of the filter.
17. A fan assembly as claimed in any one of claims 10 to 16, wherein the body
comprises a seat for the supporting the filter.
18 A fan assembly as claimed in claim 17, wherein the seat comprises an upwardly
facing surface.
19. A fan assembly as claimed in claim 17, wherein the seat is substantially
orthogonal to a longitudinal axis of the body.
20. A fan assembly as claimed in any preceding claim, wherein the lower body
section and the upper body section are cylindrical and the diameter of the lower body
section is larger than the diameter of the upper body section.
21. A fan assembly as claimed in claim 20, as dependent on any one of claims 17 to
19, wherein an outer edge of the seat is substantially flush with an outer surface of the
lower body section.
22. A fan assembly as claimed in any preceding claim, wherein the lower body
section comprises means for rotating the upper body section relative to the lower body
section.
23. A fan assembly as claimed in claim 21, wherein the means for rotating
comprises an oscillation mechanism.
24. A fan assembly as claimed in claim 22 or claim 23, wherein the means for
rotating the upper body section is located within the inner cavity of the lower body
section.
25. A fan assembly as claimed in any preceding claim, wherein the nozzle defines
an opening through which air from outside the fan assembly is drawn by the air emitted
from the nozzle.