Patent Description:
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 airflow. The movement and circulation of the airflow 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 generally located within a cage which allows an airflow to pass through the housing while preventing users from coming into contact with the rotating blades during use of the fan.

<CIT> describes a fan which does not use caged blades to project air from the fan assembly. Instead, the fan assembly comprises a base which houses a motor-driven impeller for drawing an airflow into the base, and a series of concentric, annular nozzles connected to the base and each comprising an annular outlet located at the front of the nozzle for emitting the airflow from the fan. Each nozzle extends about a bore axis to define a bore about which the nozzle extends.

Each nozzle is in the shape of an airfoil may therefore be considered to have a leading edge located at the rear of the nozzle, a trailing edge located at the front of the nozzle, and a chord line extending between the leading and trailing edges. In <CIT> the chord line of each nozzle is parallel to the bore axis of the nozzles. The air outlet is located on the chord line, and is arranged to emit the airflow in a direction extending away from the nozzle and along the chord line.

Another fan assembly which does not use caged blades to project air from the fan assembly is described in <CIT>. This fan assembly comprises a cylindrical base which also houses a motor-driven impeller for drawing a primary airflow into the base, and a single annular nozzle connected to the base and comprising an annular mouth/outlet through which the primary airflow is emitted from the fan. The nozzle defines an opening through which air in the local environment of the fan assembly is drawn by the primary airflow emitted from the mouth, amplifying the primary airflow. The nozzle includes a Coanda surface over which the mouth is arranged to direct the primary airflow. The Coanda surface extends symmetrically about the central axis of the opening so that the airflow generated by the fan assembly is in the form of an annular jet having a cylindrical or frusto-conical profile.

The user is able to change the direction in which the air flow is emitted from the nozzle in one of two ways. The base includes an oscillation mechanism which can be actuated to cause the nozzle and part of the base to oscillate about a vertical axis passing through the centre of the base so that that air flow generated by the fan assembly is swept about an arc of around <NUM>°. The base also includes a tilting mechanism to allow the nozzle and an upper part of the base to be tilted relative to a lower part of the base by an angle of up to <NUM>° to the horizontal.

<CIT> describes a bladeless fan including a nozzle and a means for generating airflow passing through the nozzle. The nozzle comprises a shell roughly in the shape of a sphere, a cavity located in the shell, and an exhaust port formed in the shell. The shell is provided with a recess located downstream of the exhaust port.

<CIT> describes a bladeless fan comprising a main body having a circular air outlet around a cavity. An inner cavity wall comprises apertures that extend between an external face of the main body and the cavity. The cavity also comprises a central convex form, from which airflow entering the cavity through the apertures impinges.

<CIT> describes a bladeless fan having an airflow ring attached to a base. A motor housing comprises a convex form located between the base and the airflow ring. Airflow, generated by the motor, exits the base around the edge of the convex form and flows into the airflow ring.

According a first aspect there is provided a nozzle for a fan assembly The nozzle comprises an air inlet for receiving an air flow, a first air outlet for emitting an air flow and a second air outlet for emitting an air flow. The first and second air outlets comprise a pair of curved slots that are provided on a face of the nozzle, and the first and second air outlets are diametrically opposed and oriented towards a convergent point. The nozzle further comprises an intermediate surface that spans an area between the first and second air outlets. In other words, the intermediate surface extends across the distance that separates the first and second air outlets. The first and second air outlets are discrete. In other words, the first air outlet and the second air outlet are physically separated from one another. Preferably, the intermediate surface is outward facing, i.e. faces away from the centre of the nozzle.

The face of the nozzle comprises the intermediate surface. The intermediate surface may extend at least partially across the face the nozzle. The intermediate surface may be flat or at least partially convex. The first air outlet and the second air outlet are oriented towards a convergent point that is located on a central axis of the face of the nozzle.

The nozzle may further comprise a nozzle body or outer casing that defines one or more outermost surface of the nozzle. The nozzle body or outer casing therefore substantially defines the external shape or form of the nozzle. The face of the nozzle may therefore comprise the intermediate surface and a portion of the nozzle body that extends around or surrounds the periphery of the intermediate surface. The nozzle body may define an opening and the intermediate surface may then be exposed within the opening. The opening may be provided at the face of the nozzle.

The intermediate surface may define a portion of the first and second air outlets. The first air outlet may defined by a first portion of the nozzle body and a first portion of the intermediate surface and the second air outlet may be defined by a second portion of the nozzle body and a second portion of the intermediate surface. The nozzle may define a generally elliptical opening or gap between the intermediate surface and the nozzle body, and the pair of curved slots may then be provided by separate portions of the opening. Portions of the opening between the pair of curved slots may each be occluded by one or more covers. The one or more covers may be moveable between a closed position in which the portions of the opening between the pair of curved slots are occluded and an open position in which the portions of the opening between the pair of curved slots are open. Alternatively, the one or more covers are fixed, and then preferably are integral with one or more of the nozzle body and the intermediate surface of the nozzle.

Preferably, the curved slots are arcuate. More preferably, the curved slots are shaped as arcs of a single circle and are diametrically opposed to one another. The curved slots may therefore comprise two congruent arcuate slots that are diametrically opposed on the face of the nozzle body, and are preferably shaped as circular arcs.

The first and second air outlets may be oriented to direct an air flow over at least a portion of the intermediate surface. The first and second air outlets may be arranged to direct the air flow emitted therefrom such that the air flow passes across at least a portion of the intermediate surface. The first and second air outlets may be arranged to direct an air flow over a portion of the intermediate surface that is adjacent to the respective air outlet.

A forwardmost point of an outer wall of the nozzle may be in front of a forwardmost point of the intermediate surface. Alternatively, a forwardmost point of an outer wall of the nozzle may be flush with a forwardmost point of the intermediate surface.

The nozzle may have an elliptical face. Preferably, the nozzle has a circular face. The opening may then be generally annular. Preferably, the nozzle is generally cylindrical, ellipsoidal or spheroidal in shape. In particular, the nozzle may have the general shape of a right circular cylinder or truncated sphere. Preferably, the nozzle has the general shape of a truncated sphere, with a first truncation forming the face of the nozzle and a second truncation forming at least part of a base of the nozzle.

The nozzle may further comprise a base that is arranged to be connected to a fan assembly, and the base may then define the air inlet of the nozzle. The angle of the face of the nozzle relative to the base may be fixed. Preferably, the angle of the face of the nozzle relative to the base is from <NUM> to <NUM> degrees, is more preferably from <NUM> to <NUM> degrees, and is yet more preferably from <NUM> to <NUM> degrees.

The nozzle further comprises a single internal air passageway extending between the air inlet and both the first and second air outlets. The nozzle further comprises a valve for controlling an air flow from the air inlet to the air outlets. Preferably, the first and second air outlets together define a combined/aggregate air outlet of the nozzle, and the valve then comprises one or more valve members which are moveable to adjust the size of the first air outlet relative to the size of the second air outlet while keeping the size of the combined/aggregate air outlet of the nozzle constant. The valve may comprise one or more valve members that are moveable to simultaneously adjust the size of the first air outlet and inversely adjust the size of the second air outlet. The valve may be arranged such that movement of the one or more valve members simultaneously adjusts the size of the first air outlet and inversely adjusts the size of the second air outlet whilst keeping the aggregate size of the first and second air outlets constant. Preferably, the one or more valve members are moveable through a range of positions between a first end position in which the first air outlet is maximally occluded and the second air outlet is maximally open and a second end position in which the first air outlet is maximally open and the second air outlet is maximally occluded.

The one or more valve members may be arranged to move translationally (i.e. without rotation), and preferably rectilinearly (i.e. in a straight line). The one or more valve members may be arranged to move laterally relative to a body of the nozzle, and optionally may also be arranged to move laterally relative to the external guide surface.

For each of the valve members, the valve member may have a shape that corresponds with a shape of an opposing portion of the nozzle body. In particular, the valve member may have a radius of curvature that is substantially equal to a radius of curvature of the opposing portion of the nozzle body.

Also described herein is a nozzle for a fan assembly. The nozzle comprises an air inlet for receiving an air flow, a first air outlet for emitting an air flow and a second air outlet for emitting an air flow. The first and second air outlets comprise a pair of curved slots that are provided on a face of the nozzle, and the first and second air outlets are oriented towards a convergent point. The first air outlet and the second air outlet may be oriented towards a convergent point that is located on a central axis of the face of the nozzle.

Also described herein is a fan assembly comprising an impeller, a motor for rotating the impeller to generate an air flow, and a nozzle according to any of the first and second aspect for receiving the air flow. The fan assembly may comprise a base upon which the fan assembly is supported, and an angle of the face of the nozzle relative to the base of the fan assembly may be fixed. Preferably, the angle of the face of the nozzle relative to the base of the fan assembly is from <NUM> to <NUM> degrees, is preferably from <NUM> to <NUM> degrees, and is more preferably from <NUM> to <NUM> degrees. The base of the fan assembly is preferably provided at a first end of a body of the fan assembly, and the nozzle is then preferably mounted to an opposite second end of the body of the fan assembly. Preferably, the motor and the impeller are housed within the body of the fan assembly.

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

There will now be described a nozzle for a fan assembly which is capable of generating a well-focussed jet of air with high flow rate and low pressure drop thereby providing improved energy efficiency. The term "fan assembly" as used herein refers to a fan assembly configured to generate and deliver an airflow for the purposes of thermal comfort and/or environmental or climate control. Such a fan assembly may be capable of generating one or more of a dehumidified airflow, a humidified airflow, a purified airflow, a filtered airflow, a cooled airflow, and a heated airflow.

The nozzle comprises an air inlet for receiving an air flow, a first air outlet for emitting an air flow and a second air outlet for emitting an air flow. The first and second air outlets comprise a pair of curved slots that are provided on a face of the nozzle that are diametrically opposed and oriented towards a convergent point. The first and second air outlets are therefore discrete (i.e. are physically separated from one another). The nozzle further comprises an intermediate surface that spans an area between the first and second air outlets. In other words, the intermediate surface extends across the area or space that separates the first and second air outlets. This intermediate surface comprises an external surface of the nozzle and is preferably outward facing (i.e. faces away from the centre of the nozzle). The first and second air outlets are discrete (i.e. are physically separated from one another).

The face of the nozzle may comprise the intermediate surface. The intermediate surface may then extend at least partially across the face the nozzle. The intermediate surface may be flat or at least partially convex. The first air outlet and the second air outlet may be oriented towards a convergent point that is located on a central axis of the face of the nozzle.

The nozzle may further comprise a nozzle body or outer casing that defines one or more outermost surface of the nozzle. The nozzle body or outer casing therefore substantially defines the external shape or form of the nozzle. The face of the nozzle may therefore comprise the intermediate surface and a portion of the nozzle body that extends around or surrounds the periphery of the intermediate surface. The nozzle body may define an opening and the intermediate surface may then be exposed within the opening such that the intermediate surface provides an external surface of the nozzle. The opening may be provided at the face of the nozzle.

The intermediate surface may define a portion of the first and second air outlets. In particular, the first air outlet may defined by a first portion of the nozzle body and a first portion of the intermediate surface and the second air outlet may be defined by a second portion of the nozzle body and a second portion of the intermediate surface. The first portion of the intermediate surface (i.e. that partially defines the first air outlet) may have a shape that corresponds with a shape of the opposing, first portion of the nozzle body. In particular, the first portion of the intermediate surface may have a radius of curvature that is substantially equal to a radius of curvature of the opposing, first portion of the nozzle body. The second portion of the intermediate surface (i.e. that partially defines the second air outlet) may have a shape that corresponds with a shape of the opposing, second portion of the nozzle body. In particular, the second portion of the intermediate surface may have a radius of curvature that is substantially equal to a radius of curvature of the opposing, second portion of the nozzle body.

The nozzle may define a generally elliptical opening or gap between the intermediate surface and the nozzle body, and the pair of curved slots may then be provided by separate portions of the opening. Portions of the opening between the pair of curved slots may each be occluded by one or more covers. The one or more covers may be moveable between a closed position in which the portions of the opening between the pair of curved slots are occluded and an open position in which the portions of the opening between the pair of curved slots are open. Alternatively, the one or more covers are fixed, and then preferably are integral with one or more of the nozzle body and the intermediate surface of the nozzle.

It is preferable that the curved slots are arcuate. The term "arcuate" as used herein refers to the shape of an arc, wherein an arc is a segment or part of a curve. An arc that comprises a segment of an ellipse is called an elliptical arc. More preferably the curved slots comprise two congruent arcuate slots that are diametrically opposed on the face of the nozzle body, and are preferably shaped as circular arcs. The term "congruent arcs" as used herein refers to arcs of the same ellipse that have the same arc measure/arc angle.

The term "air outlet" as used herein refers to a portion of the nozzle through which an air flow escapes from the nozzle. In particular, in the embodiments described herein, each air outlet comprises a conduit or duct that is defined by the nozzle and through which an air flow exits the nozzle. Each air outlet could therefore alternatively be referred to as an exhaust. This contrasts with other portions of the nozzle that are upstream from the air outlets and that serve to channel an air flow between an air inlet of the nozzle and an air outlet.

It is preferable that the first and second air outlets are each oriented to direct an emitted air flow over at least a portion of the intermediate surface. In other words, the first and second air outlets may be arranged to direct the air flow emitted therefrom such that the air flow passes across at least a portion of the intermediate surface. In particular, the first and second air outlets may be arranged to direct an air flow over a portion of the intermediate surface that is adjacent to the respective air outlet. Preferably, the first and second air outlets are oriented to emit an air flow in a direction that is substantially parallel to a portion of this intermediate surface that is adjacent to the air outlet. It is then preferable that the intermediate surface is shaped so that the intermediate surface diverges or veers away from the direction in which the air flows are emitted from the first and second air outlets so that these air flows can collide at and/or around the convergent point without interference from the intermediate surface. Emitting the air flows across the intermediate surface minimizes disruption of the air flows as they initially leave the nozzle, with the subsequent departure of the air flows from the intermediate surface then allowing for the formation a separation bubble between the intermediate surface, the emitted air flows and the convergent point. The formation of a separation bubble can assist in stabilizing the resultant jet or combined air flow formed when the two opposing air flows collide. This intermediate surface of the nozzle can therefore be considered to be an external guide surface that assists in guiding the air flows emitted from the first and second air outlets to the convergent point.

<FIG> are external views of a fan assembly <NUM> that has an elongate annular nozzle <NUM>. The nozzle <NUM> therefore comprises two parallel, straight sections <NUM>, <NUM> each adjacent a respective elongate side of an opening <NUM>, an upper curved section <NUM> joining the upper ends of the straight sections <NUM>, <NUM>, and a lower curved section <NUM> joining the lower ends of the straight sections <NUM>, <NUM>. The upper and lower curved section <NUM>, <NUM> of the elongate annular nozzle <NUM> are blocked so that no air flow can exit the elongate annular nozzle <NUM> through the curved sections <NUM>, <NUM>. Rather, the air flow is permitted to exit the elongate annular nozzle <NUM> through separate elongate, linear air outlets <NUM>, <NUM> which extend along the parallel side sections <NUM>, <NUM> of the elongate annular nozzle <NUM>.

<FIG> shows a perspective view of the fan assembly <NUM> and <FIG> is a front view of the fan assembly <NUM>. <FIG> then shows a sectional view through a body or stand <NUM> of the fan assembly taken along lines A-A of <FIG>, whilst <FIG> shows a perspective view of a nozzle <NUM> of the fan assembly <NUM>. The fan assembly <NUM> comprises the body or stand <NUM> with the elongate annular nozzle <NUM> being mounted on the body <NUM>. The body <NUM> is substantially cylindrical and comprises an air inlet <NUM> through which an airflow enters the body <NUM> of the fan assembly <NUM>, and the air inlet <NUM> comprises an array of apertures formed in the body <NUM>. Alternatively, the air inlet <NUM> may comprise one or more grilles or meshes mounted within windows formed in the body <NUM>.

<FIG> illustrates a sectional view through the fan assembly <NUM>. The body <NUM> houses the impeller <NUM> for drawing an airflow through the air inlet <NUM> and into the body <NUM>. The impeller <NUM> is connected to a rotary shaft <NUM> extending outwardly from a motor <NUM>. In the fan assembly illustrated in <FIG>, the motor <NUM> is a DC brushless motor having a speed which is variable by a control circuit <NUM> in response to control inputs provided by a user. The motor <NUM> is housed within a motor housing that comprises an upper portion <NUM> connected to a lower portion <NUM>. The upper portion <NUM> of the motor housing further comprises an annular diffuser <NUM> in the form of curved blades that project from the outer surface of the upper portion <NUM> of the motor housing.

The motor housing <NUM>, <NUM> is mounted within a duct that is mounted within the body <NUM>. The duct comprises a generally frusto-conical upper wall <NUM>, a generally frusto-conical lower wall <NUM> and an impeller shroud <NUM> located within and abutting against the lower wall <NUM>. A substantially annular inlet member <NUM> is then connected to the bottom of the duct for guiding the primary airflow into the impeller housing. An air inlet of the duct is therefore defined by the annular inlet member <NUM> provided at the bottom end of the duct. An air vent/opening <NUM>, through which the primary airflow is exhausted from the body <NUM>, is then defined by the upper portion <NUM> of the motor housing and the upper wall <NUM> of the duct.

A flexible sealing member (not shown) is attached between the upper wall <NUM> of the duct and the body <NUM> to prevent air from passing around the outer surface of the duct to the inlet member <NUM>. The sealing member preferably comprises an annular lip seal, preferably formed from rubber.

The nozzle <NUM> is mounted on the upper end of the body <NUM> over the air vent <NUM> through which the primary airflow exits the body <NUM>. The nozzle <NUM> comprises a neck/base <NUM> that connects to upper end of the body <NUM> and has an open lower end which provides an air inlet <NUM> for receiving the primary airflow from the body <NUM>. The external surface of the base <NUM> of the nozzle <NUM> is then substantially flush with the outer edge of the body <NUM>. The base <NUM> therefore comprises a housing that covers/encloses any components of the fan assembly <NUM> that are provided on an upper surface of the body <NUM>, which in <FIG> includes the control circuit <NUM>.

As described above, the nozzle <NUM> has an elongate annular shape, often referred to as a stadium or discorectangle shape, and defines a correspondingly shaped opening or bore <NUM> having a height (as measured in a direction extending from the upper end of the nozzle to the lower end of the nozzle <NUM>) greater than its width (as measured in a direction extending between the side walls of the nozzle <NUM>), and a central axis (X).

The air inlet <NUM> of the elongate annular nozzle <NUM> is arranged to receive an air flow from the air vent/opening <NUM> through which the primary airflow is exhausted from the body <NUM>. A single internal air passageway <NUM> extends around the elongate annular nozzle <NUM> and receives the air from the air inlet <NUM>. When air flows from the air vent/opening <NUM> into the air inlet <NUM> of the elongate annular nozzle <NUM> it is split in two and flows in opposite angular directions about the bore <NUM> of the elongate annular nozzle <NUM> through the internal air passageway <NUM>. Air guide vanes (not shown) are provided on an inner surface of the parallel side sections <NUM>, <NUM> to turn the vertically oriented air flow through <NUM>° towards the linear air outlets <NUM>, <NUM> which are provided on a forward facing surface of the elongate annular nozzle <NUM>.

<FIG> then show a first embodiment of a fan assembly <NUM> according to the present invention. Although the fan assemblies <NUM>, <NUM> look quite different the bodies <NUM>, <NUM> of the fan assemblies are essentially the same. For this reason the description of the body <NUM> will not be repeated. However, as can clearly be seen, a key difference between the fan assemblies <NUM>, <NUM> is that the fan assembly <NUM> of <FIG> does not have an elongate annular nozzle with linear air outlets. Rather, the nozzle <NUM> of the fan assembly <NUM> has the general shape of a truncated sphere with the air outlets <NUM>, <NUM> of the nozzle <NUM> comprising a pair curved slots provided on a face <NUM> of the nozzle <NUM>.

In the illustrated embodiment, the nozzle <NUM> is mounted on the upper end of the body <NUM> over the air vent through which an airflow exits the body <NUM>. The nozzle <NUM> has an open lower end which provides an air inlet <NUM> for receiving the airflow from the body <NUM>. The external surface of an outer wall of the nozzle <NUM> then converges with the outer edge of the body <NUM>.

The nozzle <NUM> comprises a nozzle body, outer casing or housing <NUM> that defines the outermost surfaces of the nozzle and therefore defines the external shape or form of the nozzle <NUM>. In the illustrated embodiment, the nozzle body/outer casing <NUM> of the nozzle <NUM> has the general shape of a truncated sphere, with a first truncation forming a circular face <NUM> of the nozzle and a second truncation forming a circular base <NUM> of the nozzle body/outer casing <NUM>, and the angle (α) of the face <NUM> of the nozzle body <NUM> relative to the base <NUM> of the nozzle body <NUM> is fixed. In the illustrated embodiment, this angle (α) is approximately <NUM> degrees; however, the angle of the face <NUM> relative to the base <NUM> of the nozzle body <NUM> could be anything from <NUM> to <NUM> degrees, is more preferably from <NUM> to <NUM> degrees, and is yet more preferably from <NUM> to <NUM> degrees.

In the illustrated embodiment, the first truncation provides that the diameter (DN) of the nozzle body <NUM> is approximately <NUM> times greater than the diameter (DF) of the circular face <NUM> of the nozzle body <NUM>; however, the diameter (DN) of the nozzle body <NUM> could be anything from <NUM> to <NUM> times greater than a diameter (DF) of the circular face <NUM> of the nozzle body, and is preferably from <NUM> to <NUM> times greater. The second truncation then provides that diameter (DN) of the nozzle body <NUM> is also approximately <NUM> times greater than the diameter (DB) of the circular base <NUM> of the nozzle body <NUM>; however, the diameter (DN) of the nozzle body <NUM> could be anything from <NUM> to <NUM> times greater than the diameter (DB) of the circular base <NUM> of the nozzle body <NUM>, and is preferably from <NUM> to <NUM> times greater.

The nozzle body <NUM> defines an opening at the circular face <NUM> of the nozzle body <NUM>. The nozzle <NUM> then further comprises a fixed, external guide surface <NUM> that is located concentrically within the opening at the circular face <NUM> of the nozzle body <NUM> such that this external guide surface <NUM> is at least partially exposed within the opening, with a portion of the nozzle body <NUM> extending around the periphery of the guide surface <NUM>. The external guide surface <NUM> is therefore outward facing (i.e. faces away from the centre of the nozzle).

In the illustrated embodiment, this guide surface <NUM> is convex and substantially disk-shaped; however, in alternative embodiments the guide surface <NUM> could be flat or only partially convex. An inwardly curved upper portion 2230a of the nozzle body <NUM> then overlaps/overhangs a circumferential portion 2250a of the guide surface <NUM>. The outermost, central portion 2250b of the convex guide surface is then offset relative to the outermost point of the open circular face <NUM> of the nozzle body <NUM>. In particular, the outermost point of the open circular face <NUM> of the nozzle body <NUM> is in front of the outermost portion 2250b of the guide surface.

The circumferential portion 2250a of the guide surface <NUM> and an opposing portion of the nozzle body <NUM> together define a generally annular gap <NUM> between them, with two diametrically opposed portions of this gap <NUM> then forming a pair of congruent, circular arc shaped slots that provide the first and second air outlets <NUM>, <NUM> of the nozzle <NUM>. The guide surface <NUM> therefore provides an intermediate surface that spans the area between the first and second air outlets <NUM>, <NUM>. In other words, the guide surface <NUM> forms an intermediate surface that extends across the space that separates the first and second air outlets <NUM>, <NUM>. As will be described in more detail below, in at least one configuration of the nozzle <NUM>, the portions of the gap <NUM> that separate the pair of arcuate slots are then covered/occluded.

In the illustrated embodiment, the pair of arcuate slots that provide the first and second air outlets <NUM>, <NUM> each have an arc angle (β) (i.e. the angle subtended by the arc at the centre of the circular face <NUM>) of approximately <NUM> degrees; however, they could each have an arc angle of anything from <NUM> to <NUM> degrees, preferably from <NUM> to <NUM> degrees, and more preferably from <NUM> to <NUM> degrees. Consequently, the area of the gap <NUM> can be anything from <NUM> to <NUM> times greater than the area of each of the first and second air outlets <NUM>, <NUM>, is preferably from <NUM> to <NUM> times greater, and is more preferably from <NUM> to <NUM> times greater.

The first and second air outlets <NUM>, <NUM> are approximately the same size and together form an aggregate or combined air outlet of the spherical nozzle <NUM>. The first air outlet <NUM> and the second air outlet <NUM> are located on opposing sides of the guide surface <NUM>, and are orientated to direct an emitted air flow over a portion of the guide surface <NUM> that is adjacent to the respective air outlet and towards a convergent point that is aligned with a central axis (Y) of the guide surface <NUM>. The first air outlet <NUM>, the second air outlet <NUM> and the guide surface <NUM> are then arranged such that emitted air flows are directed over a portion of the guide surface <NUM> that is adjacent to the respective air outlet. In particular, the air outlets <NUM>, <NUM> are arranged to emit an air flow in a direction that is substantially parallel to the portion of the guide surface <NUM> adjacent the air outlet <NUM>, <NUM>. The convex shape of the guide surface <NUM> then provides that the air flows emitted from the first and second air outlets <NUM>, <NUM> will depart from the guide surface <NUM> as they approach the convergent point so that these air flows can collide at and/or around the convergent point without interference from the guide surface <NUM>. When the emitted air flows collide, a separation bubble is formed that can assist in stabilising the resultant jet or combined air flow formed when two opposing air flows collide.

The construction and operation of the nozzle <NUM> will be described in more detail below in relation to <FIG>. <FIG> shows a perspective view of the nozzle <NUM> of the fan assembly <NUM> of <FIG>. <FIG> then show top, front and side views of the nozzle <NUM>. <FIG> then shows a sectional view through line A-A of <FIG>, whilst <FIG> shows a sectional view through line B-B of <FIG>. <FIG> and <FIG> then show top and perspective views of the nozzle <NUM> with the guide surface and an upper portion of the nozzle body removed.

As described above, the nozzle <NUM> has the general shape of a truncated sphere, with a first truncation forming a circular face <NUM> of the nozzle and a second truncation forming a circular base <NUM> of the nozzle body <NUM>. The nozzle body <NUM> therefore comprises an outer wall <NUM> that defines the truncated spherical shape. The outer wall <NUM> then defines a circular opening on the circular face <NUM> of the nozzle <NUM> and a circular opening on the circular base <NUM> of the nozzle body <NUM>. The nozzle body <NUM> also comprises a lip <NUM> that extends inwardly from the edge of the outer wall <NUM> that forms the first truncation. This lip <NUM> is generally frustoconical in shape and tapers inwardly towards the guide surface <NUM>.

The nozzle body <NUM> further comprises an inner wall <NUM> that is disposed within the nozzle body <NUM> and that defines the single internal air passageway <NUM> of the nozzle <NUM>. The inner wall <NUM> is entirely curved and has a generally circular cross-section, with the cross-sectional area of the inner wall <NUM> in a plane that is parallel to either the face <NUM> or base <NUM> of the nozzle body <NUM> varying between the air inlet <NUM> and the one or more air outlets <NUM>, <NUM>. In particular, the inner wall <NUM> widens or flares outwardly adjacent the air inlet <NUM> and then narrows adjacent the air outlets <NUM>, <NUM>. The inner wall <NUM> therefore generally conforms to the shape of the nozzle body <NUM>.

The inner wall <NUM> has a circular opening at its lower end that is located concentrically within the circular opening of the circular base <NUM> of the nozzle <NUM>, with this lower circular opening of the inner wall <NUM> providing the air inlet <NUM> for receiving the airflow from the body <NUM>. The inner wall <NUM> also has a circular opening at its upper end that is located concentrically within the circular opening of the circular face <NUM> of the nozzle body <NUM>. An inwardly curved upper end of the inner wall <NUM> then meets/abuts with the lip <NUM> that tapers inwardly from the outer wall <NUM> to define the circular opening of the circular face <NUM> of the nozzle body <NUM>.

The guide surface <NUM> is then located concentrically with the upper circular opening of the inner wall <NUM>, and offset relative to the upper circular opening of the inner wall <NUM> along the central axis of the upper circular opening of the inner wall <NUM>, such that the gap <NUM> is therefore defined by the space between the inner wall <NUM> and an adjacent portion of guide surface <NUM>. The inwardly curved upper end of the inner wall <NUM> then overlaps/overhangs the circumferential portion 2250a of the guide surface <NUM> to ensure that the angle at which an air flow exits the nozzle <NUM> is sufficiently shallow to optimise the resultant air flow generated by the nozzle <NUM>. In particular, the angle at which an air flow exits the nozzle <NUM> will determine the distance of the convergent point along the central axis (Y) of the guide surface <NUM> and the angle at which air flows will collide at the convergent point. The tapering outer surface of the lip <NUM> then minimises the impact of this overhang on the angular range through which the air flow can be varied.

In this embodiment, two separate valve mechanisms are then located beneath the guide surface <NUM>. The first of these is a flow vectoring valve that is arranged to control the air flow from the air inlet <NUM> to the first and second air outlets <NUM>, <NUM> by adjusting the size of the first air outlet <NUM> relative to the size of the second air outlet <NUM> while keeping the size of the aggregate air outlet of the nozzle <NUM> constant. The second of these valve mechanisms is a mode switching valve that is arranged to change the air delivery mode of the nozzle <NUM> from a directed mode to a diffuse mode. Both valve mechanisms will be described in more detail below.

The nozzle <NUM> further comprises an internal air directing or diverting surface <NUM> beneath both valve mechanisms, with the air directing surface <NUM> being arranged to direct the airflow within the single air inlet passageway <NUM> towards the gap <NUM>, and therefore towards the first and second air outlets <NUM>, <NUM>. In this embodiment, this air directing surface <NUM> is convex and substantially disk-shaped, and is therefore similar in form to the guide surface <NUM>, and is aligned/concentric with the guide surface <NUM>. Both valve mechanisms are therefore housed within a space defined between the guide surface <NUM> and the air directing surface <NUM>.

In this embodiment, the internal air passageway <NUM> that extends between the air inlet <NUM> and the gap <NUM> forms a plenum chamber that functions to equalise the pressure of the air flow received from the body <NUM> of the fan assembly <NUM> for more even distribution to the gap <NUM>, and therefore to the air outlets <NUM>, <NUM>. The air directing surface <NUM> therefore forms an upper surface of the plenum chamber defined by the internal air passageway <NUM>.

The flow vectoring valve comprises a single valve member <NUM> mounted beneath the guide surface <NUM> and above the air directing surface <NUM>. The flow vectoring valve member <NUM> is arranged to move laterally (i.e. translationally) relative to the guide surface <NUM> between a first end position and a second end position. In the first end position the first air outlet <NUM> is maximally occluded (i.e. occluded to the maximum extent possible, such that the size of the first air outlet is at a minimum) by the valve member <NUM> and the second air outlet <NUM> is maximally open (i.e. open to the maximum extent possible, such that the size of the second air outlet is at a maximum), whilst in the second end position the second air outlet <NUM> is maximally occluded by the valve member <NUM> and the first air outlet <NUM> is maximally open. When the valve member <NUM> moves between its two extreme positions the size/open area of the aggregate/combined air outlet remains constant.

When at a minimum the first and/or second air outlets <NUM>, <NUM> may be fully occluded/closed. However, when at a minimum the first and/or second air outlets <NUM>, <NUM> may be at least open to a very small extent as doing so can provide that any tolerances/inaccuracies arising during manufacture will not lead to small gaps that could induce additional noise (e.g. whistling) when air passes through.

In the illustrated embodiment, the valve member <NUM> has a first end section 2280a that maximally occludes the first air outlet <NUM> when the valve member <NUM> is in the first end position, and an opposing second end section 2280b that maximally occludes the second air outlet <NUM> when the valve member <NUM> is in the second end position. The distal edges of the first and second end sections 2280a, 2280b of the valve member <NUM> are both arcuate in shape so as to correspond with the shape of an opposing surface of the nozzle body <NUM> that partially defines the corresponding air outlet. In particular, the distal edge of each valve member has a radius of curvature that is substantially equal to a radius of curvature of the opposing surface of the nozzle body <NUM>. The first end section 2280a of the valve member <NUM> can therefore abut (i.e. touch or be adjacent/proximate to) an opposing surface when in the first end position in order to occlude the first air outlet <NUM>, with this opposing surface thereby providing a first valve seat, whilst the second end section 2280b of the valve member <NUM> can abut (i.e. touch or be adjacent/proximate to) an opposing surface when in the second end position in order to occlude the second air outlet <NUM>, with this other opposing surface thereby providing a second valve seat. In addition, the arcuate shape of the distal edges of the first and second end sections 2280a, 2280b of the valve member <NUM> also provide that the distal edge of the first end section 2280a will be substantially flush with an adjacent edge of the guide surface <NUM> when in the second end position and that the distal edge of the second end section 2280b will be substantially flush with an adjacent edge of the guide surface <NUM> when in in the first end position.

The flow vectoring valve further comprises a valve motor <NUM> that is arranged to cause lateral (i.e. translational) movement of the valve member <NUM> relative to the guide surface <NUM> in response to signals received from the main control circuit. To do so, the valve motor <NUM> is arranged to rotate a pinion <NUM> that engages with a linear rack 2280c provided on the valve member <NUM>. In this embodiment, the linear rack 2280c is provided on an intermediate section of the valve member that extends between the first and second end sections 2280a, 2880b. Rotation of the pinion <NUM> by the valve motor <NUM> will therefore result in the linear movement of the valve member <NUM>.

The mode switching valve is arranged to change the air delivery mode of the nozzle <NUM> from a directed mode to a diffuse mode. In the directed mode, the mode switching valve closes off all but the first and second air outlets <NUM>, <NUM> that are used to provide a directed air flow from the nozzle (i.e. covers/occludes those portions of the gap <NUM> that separate the pair of arcuate slots). In this directed mode, the flow vectoring valve is then used to control the direction of the air flow emitted from the nozzle <NUM> by just the first and second air outlets <NUM>, <NUM>. When switching from directed mode to diffuse mode, the mode switching valve opens the remainder of the gap <NUM> (i.e. opens those portions of the gap <NUM> that separate the pair of arcuate slots). In this diffuse mode, the entire gap <NUM> can then become a single air outlet of the nozzle <NUM> thereby providing a more diffuse, low pressure flow of air. In addition, the opening up of the entire gap <NUM> by the mode switching valve provides that the air leaving the nozzle <NUM> can be distributed around the entire periphery/circumference of the guide surface <NUM> and all directed to the convergent point such that the resultant air flow generated by the nozzle <NUM> will be directed substantially perpendicular relative to the face <NUM> of the nozzle <NUM>. In this embodiment, the angle of the face <NUM> of the nozzle <NUM> relative to the base <NUM> of the nozzle <NUM>, and therefore relative to the base of the fan assembly <NUM>, is such that when positioned on an approximately horizontal surface the resultant air flow generated by the fan assembly <NUM> when the nozzle <NUM> is in the diffuse mode will be directed in a generally upwards direction.

In the illustrated embodiment, the mode switching valve comprises a pair of mode switching valve members 2290a, 2290b mounted beneath the guide surface <NUM> and above the air directing surface <NUM>. These mode switching valve members 2290a, 2290b are arranged to move laterally (i.e. translationally) relative to the guide surface <NUM> between a closed position and an open position. In the closed position, the portions of the gap <NUM> between the arcuate slots (i.e. between the slots that provide the first and second air outlets <NUM>, <NUM>) are occluded by the mode switching valve members 2290a, 2290b, whilst in the open position the portions of the gap <NUM> between the arcuate slots are open. These mode switching valve members 2290a, 2290b can therefore be considered to be moveable covers for those portions of the gap <NUM> that are between the arcuate slots.

In the illustrated embodiment, the mode switching valve members 2290a, 2290b are arranged such that in the closed position they each occlude the separate, diametrically opposed portions of the gap <NUM> that are between one end of the first air outlet <NUM> and an adjacent end of the second air outlet <NUM>. To do so, the mode switching valve members 2290a, 2290b are arranged such that in the closed position they each extend between opposing ends of the first air outlet <NUM> and the adjacent end of the second air outlet <NUM>.

Each of the mode switching valve members 2290a, 2290b is substantially planar, with a distal edge of the valve member then being arcuate in shape so as to correspond with the shape of an opposing surface of the nozzle body <NUM> that partially defines the gap <NUM>. In particular, the distal edge of each valve member has a radius of curvature that is substantially equal to a radius of curvature of the opposing surface of the nozzle body <NUM>. The distal edge of each of the valve members 2290a, 2290b can therefore abut against the opposing surface (i.e. the corresponding valve seat) when in the closed position in order to occlude a portion of the gap <NUM> between the arcuate slots. In addition, the arcuate shape of the distal edge of each of the valve members 2290a, 2290b also provides that the distal edge will be substantially flush with an adjacent edge of the guide surface <NUM> when in the open position. Each of the mode switching valve members 2290a, 2290b is then provided with a valve stem 2290c, 2290d that extends from the proximal edge of the valve member.

The mode switching valve further comprises a mode switching valve motor <NUM> that is arranged to cause lateral (i.e. translational) movement of the mode switching valve members 2290a, 2290b relative to the guide surface <NUM> in response to signals received from the main control circuit. To do so, the valve motor <NUM> is arranged to cause rotation of a pinion <NUM> that engages with linear racks provided on each of the valve stems 2290c, 2290d. Rotation of the pinion <NUM> by the valve motor <NUM> will therefore result in the linear movement of both valve members 2290a, 2290b. In this embodiment, rotation of the pinion <NUM> by the valve motor <NUM> is achieved using a set of gears, with a drive gear mounted on the shaft of the valve motor <NUM> engaging a driven gear that is fixed to the pinion <NUM>, with the driven gear and the pinion <NUM> thereby forming a compound gear.

In the embodiment illustrated in <FIG>, the mode switching valve further comprises two pairs of movable baffles <NUM>, <NUM> that are arranged to assist with channelling the air emitted from the first and second air outlets <NUM>, <NUM> respectively when the nozzle <NUM> is in directed mode. In particular, the first pair of movable baffles 2293a, 2293b are arranged to assist with channelling the air emitted from the first air outlet <NUM> when the nozzle <NUM> is in directed mode, whilst the second pair of movable baffles 2294a, 2294b are arranged to assist with channelling the air emitted from the second air outlet <NUM> when the nozzle <NUM> is in directed mode. These two pairs of movable baffles <NUM>, <NUM> are therefore arranged to be extended when the nozzle <NUM> is in directed mode, and retracted when the nozzle <NUM> is in diffuse mode so as to avoid the baffles from obstructing the gap <NUM>.

Each pair of movable baffles <NUM>, <NUM> comprises a first moveable baffle 2293a, 2294a and a second moveable baffle 2293b, 2294b, with the first moveable baffle 2293a, 2294a and second moveable baffle 2293b, 2294b being provided at opposite ends of an elongate strut 2293c, 2294c. Each moveable baffle 2293a, 2293b, 2294a, 2294b has an approximately L-shaped cross section, with a first planar section extending downwardly from the end of the strut 2293c, 2294c to which the baffle is attached, and a second planar section then extending from the bottom end of the first planar section in a direction that is parallel with the length of the strut 2293c, 2294c. The first and second planar sections of each baffle then also extend in a direction that is perpendicular to the length of the strut 2293c, 2294c. The first planar section of each baffle then defines an end of one of the first and second air outlets <NUM>, <NUM>. A distal edge of the second planar section of each baffle is then arcuate in shape so as to correspond with the shape of an opposing surface of the nozzle body <NUM> that partially defines the gap <NUM>. The distal edge of the second planar section of each baffle can therefore abut against an opposing surface when in the closed position. The second planar section of each baffle is then further arranged to overlap with a portion of the proximal edge of an adjacent mode switching valve member 2290a, 2290b so as to ensure that there is no route by which air can exit the nozzle <NUM> between the baffle and the adjacent mode switching valve member 2290a, 2290b.

In this embodiment, these pairs of movable baffles <NUM>, <NUM> are arranged to move laterally (i.e. translationally) relative to the guide surface <NUM> between an extended position when the nozzle <NUM> is in directed mode and a retracted position when the nozzle <NUM> is in diffuse mode. To do so, each pair of movable baffles <NUM>, <NUM> is provided with an actuator arm 2293d, 2294d that extends perpendicularly from the corresponding strut 2293c, 2294c at a position part-way between the ends of the strut 2293c, 2294c. These actuator arms 2293d, 2294d are each provided with a linear rack that engages with the pinion <NUM> of the mode switching valve. Rotation of the pinion <NUM> by the mode switching valve motor <NUM> will therefore result in the linear movement of both pairs of movable baffles <NUM>, <NUM>. Consequently, when the mode switching valve is used to change the air delivery mode of nozzle <NUM> between directed mode and diffuse mode, activation of the mode switching valve motor <NUM> will cause rotation of the pinion <NUM> that will in turn cause mode switching valve members 2290a, 2290b to move between a closed position and an open position, and will also simultaneously cause the pairs of movable baffles <NUM>, <NUM> to move between an extended position and a retracted position.

In <FIG> the nozzle <NUM> is shown in directed mode, with the mode switching valve members 2290a, 2290b in the closed position and both pairs of movable baffles <NUM>, <NUM> in the extended position. The portions of the gap <NUM> that are between the first air outlet <NUM> and the second air outlet <NUM> are therefore occluded by the mode switching valve members 2290a, 2290b, with the first planar section of each pair of movable baffles <NUM>, <NUM> then defining opposite ends of the first and second air outlets <NUM>, <NUM> in order to assist in channelling the air over the guide surface <NUM> and towards the convergent point.

In order to switch the nozzle <NUM> to diffuse mode, the mode switching valve motor <NUM> is activated so as to cause a rotation of the pinion <NUM> that will in turn cause mode switching valve members 2290a, 2290b to move from the closed position to the open position. In the open position, the mode switching valve members 2290a, 2290b are retracted into the space defined between the guide surface <NUM> and the air directing surface <NUM> such that they no longer obstruct the portions of the gap <NUM> that are between the first air outlet <NUM> and the second air outlet <NUM>. Simultaneously, this rotation of the pinion <NUM> will also cause the pairs of movable baffles <NUM>, <NUM> to move from the extended position to the retracted position. In the retracted position, the pairs of movable baffles <NUM>, <NUM> are retracted into the space defined between the guide surface <NUM> and the air directing surface <NUM> such that they no longer obstruct the portions of the gap <NUM> that are between the first air outlet <NUM> and the second air outlet <NUM>. Preferably, when switching the nozzle <NUM> from directed mode to diffuse mode, the flow vectoring valve motor <NUM> is also activated so as to cause a rotation of the pinion <NUM> that will in turn cause the flow vectoring valve member <NUM> to move to a central position in which the first air outlet <NUM> and the second air outlet <NUM> are equal in size. In this configuration, the entire gap <NUM> then becomes a single air outlet of the nozzle <NUM> thereby providing a more diffuse, low pressure flow of air.

In the embodiment illustrated in <FIG>, the nozzle <NUM> is also arranged so that the position of the pair of arcuate slots on the circular face of the nozzle <NUM> can be varied. Specifically, the angular position of the pair of arcuate slots with respect to the central axis (YY) of the guide surface <NUM> is variable. The nozzle <NUM> therefore further comprises an outlet rotation motor <NUM> that is arranged to cause rotational movement of the pair of arcuate slots around the central axis (YY) of the guide surface <NUM>. To do so, the outlet rotation motor <NUM> is arranged to cause rotation of a pinion <NUM> that engages with an arc-shaped rack <NUM> that is connected to the air directing surface <NUM>. The air directing surface <NUM> is then rotationally mounted within the nozzle body <NUM>, with the flow vectoring valve and mode switching valve mechanisms then being supported by the air directing surface <NUM>. Rotation of the pinion <NUM> by the outlet rotation motor <NUM> will therefore result in the rotational movement of the air directing surface <NUM> within the nozzle body <NUM> that will in turn cause rotation of both the flow vectoring valve and mode switching valve around the central axis (YY) of the guide surface <NUM>. Given that the pair of arcuate slots that form the first and second air outlets <NUM>, <NUM> are defined by those portions of the gap <NUM> that are not occluded by the mode switching valve members 2290a, 2290b, rotation of the mode switching valve results in a change in the angular position of the pair of arcuate slots with respect to the central axis (YY) of the guide surface <NUM>.

Turning now to <FIG>, these show three potential resultant air flows that can be achieved, when the nozzle <NUM> is in directed mode, by varying the size of the first air outlet <NUM> relative to the size of the second air outlet <NUM> while keeping the size of the aggregate directed mode air outlet of the nozzle <NUM> constant.

In <FIG>, the flow vectoring valve is arranged with the flow vectoring valve member <NUM> in the central position in which the first air outlet <NUM> and the second air outlet <NUM> are equal in size such that an equal amount of air flow is emitted from the first air outlet <NUM> and the second air outlet <NUM>. The first and second air outlets <NUM>, <NUM> are oriented towards the convergent point that is aligned with the central axis (YY) of the guide surface <NUM>. When the two air flows have the same strength, as will be the case in the <FIG>, the resultant air flow will be directed forwards from (i.e. substantially perpendicular relative to) the face <NUM> of nozzle <NUM>, as indicated by arrows AA.

In <FIG>, the flow vectoring valve is arranged with the flow vectoring valve member <NUM> in the first end position in which the first air outlet <NUM> is maximally occluded and the second air outlet <NUM> is maximally open. This means that most, if not all, of the air flow entering the nozzle <NUM> will be emitted through the second air outlet <NUM>. The air flow will be directed to flow over the guide surface <NUM> as normal, but since it will not collide with any significant air flow that is emitted from the first air outlet <NUM> it will continue on its flow path, as indicated by arrows BB.

In <FIG>, the flow vectoring valve is arranged with the flow vectoring valve member <NUM> in the second end position in which the second air outlet <NUM> is maximally occluded and the first air outlet <NUM> is maximally open. This means that most, if not all, of the air flow entering the nozzle <NUM> will be emitted through the first air outlet <NUM>. The air flow will be directed to flow over the guide surface <NUM> as normal, but since it will not collide with any significant air flow that is emitted from the second air outlet <NUM> it will continue on its flow path, as indicated by arrows CC.

It will be readily understood that the examples of <FIG> are merely representative, and actually represent some of the extreme cases. By utilising a control circuit to control the flow vectoring valve motor <NUM> connected to the flow vectoring valve member <NUM> it is possible to achieve a wide variety of resultant air flows. The direction of the resultant air flows can be further varied by controlling the outlet rotation motor <NUM> to adjust the angular position of the first and second air outlets <NUM>, <NUM>.

<FIG>, <FIG> then show sectional views of a second embodiment of a nozzle <NUM> for a fan assembly. In this second embodiment, the nozzle <NUM> is suitable for use with a fan body that is substantially the same as that described above and the fan body has therefore not been further illustrated nor described. However, rather than having a truncated spherical shape, the nozzle <NUM> of this further embodiment is generally cylindrical in shape such that there are differences in the construction of the nozzle <NUM> and also differences in the flow vectoring valve provided within the nozzle <NUM>.

In this embodiment, the nozzle <NUM> has an open lower end which provides an air inlet <NUM> for receiving an airflow from the body of the fan assembly. The nozzle <NUM> is arranged such that the external surface of an outer wall of the nozzle <NUM> will then converge with the outer edge when mounted on the fan body.

The nozzle <NUM> comprises a nozzle body, outer casing or housing <NUM> that defines the outermost surfaces of the nozzle and therefore defines the external shape or form of the nozzle <NUM>. In the illustrated embodiment, the nozzle body/outer casing <NUM> of the nozzle <NUM> has the general shape of a right circular cylinder, and therefore has a circular face <NUM> and a circular base <NUM>. The angle of the face <NUM> of the nozzle body <NUM> relative to the base <NUM> of the nozzle body <NUM> is fixed. In the illustrated embodiment, this angle is <NUM> degrees such that the circular face <NUM> and circular base <NUM> are substantially parallel.

The nozzle <NUM> then further comprises a fixed, external guide surface <NUM> that is located concentrically within the opening at the circular face <NUM> of the nozzle body <NUM> such that this external guide surface <NUM> is at least partially exposed within the opening, with a portion of the nozzle body <NUM> extending around the periphery of the guide surface <NUM>. The external guide surface <NUM> is therefore outward facing (i.e. faces away from the centre of the nozzle).

In the illustrated embodiment, this guide surface <NUM> is convex and substantially disk-shaped; however, in alternative embodiments the guide surface <NUM> could be flat or only partially convex. An inwardly curved upper portion 3230a of the nozzle body <NUM> then overlaps/overhangs a circumferential portion 3250a of the guide surface <NUM>. The outermost central portion 3250b of the convex guide surface is then offset relative to the outermost point of the open circular face <NUM> of the nozzle body <NUM>. In particular, the outermost point of the open circular face <NUM> of the nozzle body <NUM> is in front of the outermost portion 3250b of the guide surface.

The circumferential portion 3250a of the guide surface <NUM> and an opposing portion of the nozzle body <NUM> together define a generally annular gap between them, with two diametrically opposed portions of this gap <NUM> then forming a pair of congruent, circular arc shaped slots that provide the first and second air outlets <NUM>, <NUM> of the nozzle <NUM>. The guide surface <NUM> therefore provides an intermediate surface that spans the area between the first and second air outlets <NUM>, <NUM>. In other words, the guide surface <NUM> forms an intermediate surface that extends across the space that separates the first and second air outlets <NUM>, <NUM>. In this embodiment, the portions of the gap that separate the pair of arcuate slots are each occluded by fixed covers (not shown). In contrast with the nozzle <NUM> of the first embodiment, the nozzle <NUM> of this second embodiment therefore only has a single, directed mode and does not have a separate diffuse mode.

In the illustrated embodiment, the pair of arcuate slots that provide the first and second air outlets <NUM>, <NUM> each have an arc angle (i.e. the angle subtended by the arc at the centre of the circular face <NUM>) of approximately <NUM> degrees; however, they could each have an arc angle of anything from <NUM> to <NUM> degrees, preferably from <NUM> to <NUM> degrees, and more preferably from <NUM> to <NUM> degrees.

The first and second air outlets <NUM>, <NUM> are approximately the same size and together form an aggregate or combined air outlet of the spherical nozzle <NUM>. The first air outlet <NUM> and the second air outlet <NUM> are located on opposing sides of the guide surface <NUM>, and are orientated to direct an emitted air flow over a portion of the guide surface <NUM> that is adjacent to the respective air outlet and towards a convergent point that is aligned with a central axis (YY) of the guide surface <NUM>. The first air outlet <NUM>, the second air outlet <NUM> and the guide surface <NUM> are then arranged such that emitted air flows are directed over a portion of the guide surface <NUM> that is adjacent to the respective air outlet. In particular, the air outlets <NUM>, <NUM> are arranged to emit an air flow in a direction that is substantially parallel to the portion of the guide surface <NUM> adjacent the air outlet <NUM>, <NUM>. The convex shape of the guide surface <NUM> then provides that the air flows emitted from the first and second air outlets <NUM>, <NUM> will depart from the guide surface <NUM> as they approach the convergent point so that these air flows can collide at and/or around the convergent point without interference from the guide surface <NUM>. When the emitted air flows collide, a separation bubble is formed that can assist in stabilizing the resultant jet or combined air flow formed when two opposing air flows collide.

In this embodiment, the nozzle body <NUM> comprises an outer wall <NUM> that defines the cylindrical shape of the nozzle <NUM> and the single internal air passageway <NUM> of the nozzle <NUM>. The outer wall <NUM> also defines the circular opening on the circular face <NUM> of the nozzle <NUM> and the circular opening on the circular base <NUM> of the nozzle body <NUM>. The lower circular opening of the outer wall <NUM> provides the air inlet <NUM> for receiving the airflow from the fan body. The nozzle body <NUM> also comprises the upper portion 3230a that curves inwardly towards the central axis of the guide surface <NUM>.

The guide surface <NUM> is then located concentrically with the upper circular opening of the outer wall <NUM>, and offset relative to the upper circular opening of the outer wall <NUM> along the central axis of the upper circular opening of the outer wall <NUM>, such that the gap is therefore defined by the space between the upper circular opening of the outer wall <NUM> and an adjacent portion of guide surface <NUM>.

A flow vectoring valve is then located beneath the guide surface <NUM>. The flow vectoring valve is arranged to control the air flow from the air inlet to the first and second air outlets <NUM>, <NUM> by adjusting the size of the first air outlet <NUM> relative to the size of the second air outlet <NUM> while keeping the size of the aggregate air outlet of the nozzle <NUM> constant.

The flow vectoring valve comprises a first valve member <NUM> and a second valve member <NUM> that cooperate to adjust the size of the first air outlet <NUM> relative to the size of the second air outlet <NUM> while keeping the total air outlet of the nozzle <NUM> constant. To do, the first valve member <NUM> and the second valve member <NUM> are linked so that they move simultaneously. The first valve member <NUM> and the second valve member <NUM> are therefore each arranged to be pivotable relative to the both the nozzle body <NUM> and the guide surface <NUM> between a first end position and a second end position. In the first end position the first air outlet <NUM> is maximally occluded (i.e. occluded to the maximum extent possible, such that the size of the first air outlet is at a minimum) by the first valve member <NUM> whilst the second air outlet <NUM> is maximally open (i.e. open to the maximum extent possible, such that the size of the second air outlet is at a maximum). In the second end position the second air outlet <NUM> is maximally occluded by the second valve member <NUM> whilst the first air outlet <NUM> is maximally open.

In this embodiment, the first valve member <NUM> is pivotally mounted beneath the guide surface <NUM> at a location adjacent to the first air outlet <NUM> and the second valve member <NUM> is pivotally mounted beneath the guide surface <NUM> at a location adjacent to the second air outlet <NUM>. The first valve member <NUM> is then linked to the second valve member <NUM> by a coupler <NUM> such that first valve member <NUM> and the second valve member <NUM> pivot simultaneously. The guide surface <NUM>, first valve member <NUM>, second valve member <NUM> and the coupler <NUM> therefore form a planar quadrilateral linkage, specifically a parallelogram four-bar linkage. The first valve member <NUM> and the second valve member <NUM> therefore each comprise a link portion 3281a, 3282a, with a first end of the link portion being connected to the coupler <NUM> by a hinge and a second end of the link portion being connected to the underside of the guide surface <NUM> by another hinge. These link portions of the first and second valve members <NUM>, <NUM> therefore function as cranks of the four-bar linkage.

The first valve member <NUM> then further comprises a first valve arm 3281b that is arranged to maximally occlude the first air outlet <NUM> when the first valve member <NUM> is in the first end position and the second valve member <NUM> further comprises a second valve arm 3282b that is arranged to maximally occlude the second air outlet <NUM> when the valve member <NUM> is in the second end position. The first valve arm 3281b extends from the first valve member <NUM> into the first air outlet <NUM> and the second valve arm 3282b extends from the second valve member <NUM> into the second air outlet <NUM>. In particular, the first valve arm 3281b extends from the first end of the link portion 3281a of the first valve member <NUM>, and the second valve arm 3282b extends from the first end of the link portion 3282a of the second valve member <NUM>.

The flow vectoring valve further comprises a rod <NUM> that is connected to the coupler <NUM> such that movement of the rod <NUM> causes simultaneous movement of the first valve member <NUM> and second valve member <NUM>. In this embodiment, the rod <NUM> extends out of the nozzle <NUM> through the centre of the guide surface <NUM>, with an external portion 3284a of the rod <NUM> being arranged to provide a user operable handle and an internal portion 3284b of the rod <NUM> being pivotally connected to the coupler <NUM>. Between the external portion 3284a of the rod <NUM> and the pivotal connection of the rod <NUM> to the coupler <NUM>, the rod <NUM> is then also pivotally connected just beneath the guide surface <NUM>.

The nozzle <NUM> then further comprises an internal air directing/diverting surface <NUM> disposed between the first valve member <NUM> and the second valve member <NUM> that is arranged to direct an airflow received from/within the single air inlet passageway <NUM> towards the first and second air outlets <NUM>, <NUM>. In this embodiment, this air directing surface <NUM> is convex, is substantially disk-shaped, and is mounted on to the lower surface of the coupler <NUM>. The air directing surface <NUM> therefore moves with the coupler <NUM> and is at all times disposed between the rearmost ends of the first valve member <NUM> and the second valve member <NUM> irrespective of the positions of the first valve member <NUM> and the second valve member <NUM>. In addition, the surfaces of each of the first valve arm 3281b and the second valve arm 3282b that face the single internal air passageway <NUM> are then also arranged to direct an airflow received from/within the single air inlet passageway <NUM> towards the first and second air outlets <NUM>, <NUM> respectively. In particular, these air directing surfaces of each of the first valve arm 3281b and the second valve arm 3282b are arranged to be generally continuous with the air directing surface <NUM>.

In this embodiment, the internal air passageway <NUM> that extends between the air inlet <NUM> and the first and second air outlets <NUM>, <NUM> forms a plenum chamber that functions to equalise the pressure of the air flow received from the fan body for more even distribution to the first and second air outlets <NUM>, <NUM>. The air directing surface <NUM> therefore forms an upper surface of the plenum chamber defined by the internal air passageway <NUM>.

<FIG> show two potential resultant air flows that can be achieved by varying the size of the first air outlet <NUM> relative to the size of the second air outlet <NUM> while keeping the size of the aggregate air outlet of the nozzle <NUM> constant.

In <FIG>, the flow vectoring valve is arranged with the first and second valve members <NUM>, <NUM> in the central position in which the first air outlet <NUM> and the second air outlet <NUM> are equal in size such that an equal amount of air flow is emitted from the first air outlet <NUM> and the second air outlet <NUM>. The first and second air outlets <NUM>, <NUM> are oriented towards the convergent point that is aligned with a central axis (YY) of the guide surface <NUM>. When, as will be the case in the <FIG> the two air flows have the same strength, the resultant air flow will be directed forwards from (i.e. substantially perpendicular relative to) the face <NUM> of nozzle <NUM>, as indicated by arrows AAA.

In <FIG>, the flow vectoring valve is arranged with the first valve member <NUM> and second valve member <NUM> in the first end position in which the first air outlet <NUM> is maximally occluded and the second air outlet <NUM> is maximally open. This means that most, if not all, of the air flow entering the nozzle <NUM> will be emitted through the second air outlet <NUM>. The air flow will be directed to flow over the guide surface <NUM> as normal, but since it will not collide with any significant air flow that is emitted from the first air outlet <NUM> it will continue on its flow path, as indicated by arrows BB.

It will be readily understood that the examples of <FIG> are merely representative, and actually represent some of the extreme cases. By utilising the user operable handle portion of the rod <NUM> that is connected to the flow vectoring valve members <NUM>, <NUM> it is possible to achieve a wide variety of resultant air flows.

<FIG> shows an alternative embodiment of the flow vectoring valve to that of the second embodiment. Whilst the flow vectoring valve of the second embodiment comprises a pair of linked pivoting valve members, the flow vectoring valve of this alternative embodiment makes use of a single pivoting valve member <NUM>. In the embodiment of <FIG>, the flow vectoring valve therefore comprises a single valve member <NUM> that is pivotally mounted directly behind the central axis (YY) of the guide surface <NUM>. The valve member <NUM> comprises a valve member body having a rear air directing surface 3280a, a central hinge arm 3280b that extends from the front surface of the valve member body and that pivotally connects the valve member <NUM> behind the guide surface <NUM>, and a pair of opposing valve arms 3280c, 3280d that extend toward the first and second air outlets <NUM>, <NUM> respectively. In use the valve member <NUM> can then pivot in a first direction such that the first valve arm 3280c moves into and closes off/occludes the first air outlet <NUM>, and can pivot in a second direction, opposite to the first direction, such that the second valve arm 3280d moves into and closes off/occludes the second air outlet <NUM>. In this embodiment, rather than having a smooth convex rear air directing surface, the rear air directing surface 3280a of the valve member <NUM> has a more pointed shape that directs or deflects an airflow within the single internal air passageway <NUM> towards the first and second air outlets <NUM>, <NUM>. The first and second valve arms 3280c, 3280d then preferably extend from opposing sides of the directing surface 3280a and are continuous with the directing surface 3280a.

It will be appreciated that individual items described above may be used on their own or in combination with other items shown in the drawings or described in the description and that items mentioned in the same passage as each other or the same drawing as each other need not be used in combination with each other. In addition, the expression "means" may be replaced by actuator or system or device as may be desirable. In addition, any reference to "comprising" or "consisting" is not intended to be limiting in any way whatsoever and the reader should interpret the description and claims accordingly.

Furthermore, although the invention has been described in terms of preferred embodiments as set forth above, it should be understood that these embodiments are illustrative only. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims. For example, those skilled in the art will appreciate that the above-described invention might be equally applicable to other types of environmental control fan assemblies, and not just free standing fan assemblies. By way of example, such a fan assembly could be any of a freestanding fan assembly, a ceiling or wall mounted fan assembly and an in-vehicle fan assembly.

By way of further example, each of the flow vectoring valve mechanisms described above are interchangeable between the nozzle embodiments. In particular, a single linearly moveable valve member such as that described in relation to the first embodiment could be used in the second embodiment. A single pivoting valve member or a pair of linked pivoting valve members such as that described in relation to the second embodiment could also be used in the first nozzle embodiment.

In addition, whilst in the first embodiment the portions of the gap between the first and second directed mode air outlets are occluded by moveable covers, they could equally be occluded by fixed covers, as is the case in the second embodiment, such that the nozzle of the first embodiment would then only have a single directed mode of air delivery. Inversely, the fixed covers of the second embodiment could be replaced by moveable covers such as those described in relation to the first embodiment, thereby providing the nozzle of the second embodiment with both directed and diffuse air delivery modes.

This dual mode configuration is particularly useful when the nozzle is intended for use with a fan assembly that is configured to provide purified air as the user of such a fan assembly may wish to continue to receive purified air from the fan assembly without the cooling effect produced by the higher pressure, focussed airflow provided in directed mode. For example, this may be the case in winter when the user may consider the temperature to be too low to make use of the cooling effect provided by the directed mode airflow. In such a situation, the user can control the air delivery mode by manipulating the user interface. In response to these user inputs, a main control circuit would then cause the mode switching valve members to move from the closed position to the open position so that the entire gap then becomes a single air outlet of the nozzle thereby providing a more diffuse, low pressure flow of air. Furthermore, in preferred embodiments, the angle of the face of the nozzle relative to the base of the nozzle, and therefore relative to the base of the fan assembly, is such that when positioned on an approximately horizontal surface the resultant air flow generated by the fan assembly when the nozzle is in the diffuse mode will be directed in a generally upwards direction. These embodiments therefore also provide that the diffuse mode airflow is delivered to the user indirectly, thereby further decreasing the cooling effect produced by the airflow.

Furthermore, the nozzles and outlets of the above described embodiments could have different shapes. For example, rather than having the general shape of a circular arc, the slots that provide the first and second air outlets could each be non-circular, elliptical arcs. Similarly, rather than having the general shape of a sphere, the nozzle of the first embodiment could have the general shape of a non-spherical ellipsoid or spheroid. The nozzle of the first embodiment could also have the general shape of an elliptic cylinder, rather than having the general shape of a right circular cylinder. Also, the face of the nozzle could also differ in shape. In particular, rather than being circular, the face of the nozzle could have the shape of a non-circular ellipse.

Additionally, whilst in the above described embodiments air is prevented from exiting the portions of the gap that separate the first and second air outlets by fixed or moveable covers that occlude these portions, in an alternative embodiment the single internal air passageway could be shaped so that the air flow does not reach these portions of the gap. In particular, the single internal air passageway could be provided with sidewalls that are generally parallel with and extend between the end of the curved slot that provides the first air outlet and an adjacent end of the curved slot that provides the second air outlet. The single internal air passageway would then not extend beyond the ends of the air outlets and would only extend from the distal curved side/edge of one air outlet to the distal curved side/edge of the other outlet, and under the corresponding portion of the intermediate/guide surface. The single internal air passageway would still provide a plenum region for the air flow received through the air inlet of the nozzle but would restrict this to a region below and between the air outlets.

Claim 1:
A nozzle for a fan assembly (<NUM>), the nozzle comprising:
an air inlet (<NUM>) for receiving an air flow, a first air outlet (<NUM>) for emitting an air flow and a second air outlet (<NUM>) for emitting an air flow;
wherein the first and second air outlets comprise a pair of curved slots that are provided on a face (<NUM>) of the nozzle (<NUM>);
wherein the first and second air outlets (<NUM>, <NUM>) are diametrically opposed and oriented towards a convergent point; and
wherein the nozzle (<NUM>) further comprises an intermediate surface that spans an area between the first and second air outlets, and
wherein the first and second air outlets are oriented to direct an airflow over at least a portion of the intermediate surface, and wherein the face of the nozzle comprises the intermediate surface, and wherein the first air outlet and the second air outlet are oriented towards a convergent point located on a central axis of the face of the nozzle (<NUM>), and
further comprising a single internal air passageway (<NUM>) extending between the air inlet and both the first and second air outlets, and characterised in that the nozzle for a fan assembly further comprises a valve (<NUM>) for controlling an air flow from the air inlet to the air outlets.