Patent Description:
Many devices and apparatuses have been developed for delivering a fragrance (such as an air freshener) or insecticide (for example, citronella) to an environment of use. Some devices disseminate the fragrance or insecticide (collectively referred to as a compound) using passive means. Examples of devices with passive means include devices having a compound evaporate from a substrate or membrane which disseminate the compound into the environment. Other passive devices have a reservoir which contains a compound which is released into the environment as the compound evaporates.

In addition to the aforementioned passive devices, active devices have been developed to aid in the dissemination of the compound. Some active devices have fans which enhance the dissemination of a compound from either a substrate, membrane or reservoir. Still other devices have a heat source, separately or in combination with a fan, to disseminate the compound into the environment.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> describe alternative volatile dispensers.

There is a need in the art for an improved apparatus for enhanced compound delivery.

According to an aspect of the present invention, there is provided a dispensing device according to claim <NUM>.

The above and other aspects of the present invention will be apparent from the following description of the preferred embodiments of the invention and from the accompanying drawings.

Referring generally to <FIG>, <FIG>, and, in particular to <FIG>, a centrifugal fan device <NUM> not forming part of the claimed invention is described and includes a base <NUM>, a compound permeable substrate <NUM>, a fan assembly <NUM> and a cover <NUM>.

The base <NUM> has an annularly shaped reservoir <NUM> into which a compound <NUM> is disposed. The compound <NUM> may include a fragrance, insecticide, odor eliminator, or any other substance known to those skilled in the art capable of being emitted from the reservoir <NUM> as described in further detail below. The annularly shaped reservoir <NUM> defines a cylindrically shaped center cavity <NUM> into which the fan assembly <NUM> is disposed. A cap, such as plug <NUM>, has a complementary annular shape to that of the reservoir <NUM>, which completely covers the reservoir <NUM>. Although the base <NUM> of device <NUM> is annularly shaped, the base can be triangular, rectangular, pentagonal, etc..

The compound permeable substrate <NUM> is advantageously annularly shaped, and is adapted to be disposed over the plug <NUM>. A plurality of wicks <NUM> extend from a horizontal surface <NUM> into the reservoir <NUM> and are, thus, in contact with the compound <NUM>. A series of bores <NUM> in the plug <NUM> are of a sufficient size to allow the wicks <NUM> to extend down from the horizontal surface <NUM>, through the plug <NUM>, to the reservoir <NUM> below. As a result, the compound <NUM> is able to be wicked from the reservoir <NUM> up the plurality of wicks <NUM> to the horizontal surface <NUM>.

The fan assembly <NUM> includes a housing <NUM> which contains an electric motor <NUM> and batteries <NUM>, although other means for powering the electric motor may be used. Further, the fan assembly <NUM> includes a centrifugal fan <NUM>. The centrifugal fan <NUM> further comprises a plurality of fan blades <NUM>. Advantageously, a base <NUM> of the centrifugal fan <NUM> is approximately at the same level as a horizontal surface <NUM> of the compound permeable substrate <NUM>.

Advantageously, the electric motor <NUM> propels the centrifugal fan <NUM> with RPMs between <NUM> and <NUM>,<NUM> and, preferably, between <NUM> and <NUM> RPMs. Further, advantageously, the centrifugal fan <NUM> has between <NUM> and <NUM> blades <NUM> and, preferably, between <NUM> and <NUM> blades. The centrifugal fan <NUM> has a fan blade outlet angle (β) between <NUM>° and <NUM>° and, preferably, between <NUM>° and <NUM>°. The centrifugal fan <NUM> has a fan blade inner height (Hi) between <NUM> and <NUM> and, preferably, between <NUM> and <NUM>, and has a fan blade outlet height (Ho) between <NUM>% and <NUM>% of the fan blade inlet height and, preferably, <NUM>% of the inlet height. The centrifugal fan <NUM> has a fan blade inner radius (Ri) between <NUM> and <NUM> and a fan blade outer radius (Ro) of greater than or equal to (≥) <NUM>. Although the plurality of blades <NUM> are shown as straight, it is contemplated that curved blades may also be used.

The cover <NUM> is disposed over the centrifugal fan <NUM>. The cover comprises a plurality of apertures <NUM>. The cover <NUM> provides for a side air passage from the centrifugal fan <NUM> to the outside environment, as identified by arrows <NUM>. In one advantageous form, the passage is provided by a gap between the cover <NUM> and the base <NUM>. The cover <NUM> is attached to the base <NUM> using a plurality of legs <NUM>.

During use of the centrifugal fan device <NUM>, the electric motor <NUM>, powered by batteries <NUM>, drives the centrifugal fan <NUM> to rotate, thereby drawing air in from the environment through the apertures <NUM> in the cover <NUM>, as indicated by arrow <NUM>. The air continues axially downward to the centrifugal fan <NUM>. Then, the centrifugal fan <NUM> forces the air over the horizontal surface <NUM> of the compound permeable substrate <NUM> and, finally, the air exits the device <NUM> through the gap between the cover <NUM> and base <NUM>, as identified by arrows <NUM>.

Since the centrifugal fan <NUM> is substantially at the same height as a horizontal surface <NUM>, and it directly forces air across the surface, the size of the horizontal surface <NUM> is minimized, as compared to the size it would have to be to achieve the same compound dispersement were the fan not at the same height as the substrate.

In addition, the centrifugal fan device <NUM> allows for a <NUM> degree dispersion of a compound <NUM> using the centrifugal fan <NUM>, which draws air axially downward, in towards a center of the device, and blows air radially <NUM> degrees over a compound permeable substrate <NUM>, which, as a result, becomes an evaporating surface.

Although the reservoir <NUM> is located below the centrifugal fan <NUM> in device <NUM>, a reservoir and compound permeable substrate can be located above the centrifugal fan, e.g., in the cover section of the device.

Referring now to <FIG>, where like elements to those in <FIG> have been increased by <NUM>, centrifugal fan device <NUM> represents an alternative examplewhich is essentially the same as that of centrifugal fan device <NUM>, except for having a different cover. Accordingly, various elements, which are the same as those in centrifugal fan device <NUM>, are not specifically repeated here, as they are essentially the same as those in centrifugal fan device <NUM>.

Cover <NUM> comprises a disc <NUM> which is disposed over aperture <NUM>. A plurality of legs <NUM> attach the disc <NUM> to a main portion <NUM> of the cover. During use of the centrifugal fan device <NUM>, when the centrifugal fan motor <NUM> is energized, thereby causing the centrifugal fan <NUM> to spin, air is drawn in from the environment between the disc <NUM> and a main portion of the cover <NUM>, as indicated by arrow <NUM>. Air continues through the aperture <NUM>, as indicated by arrow <NUM>, and is then blown radially <NUM> degrees over the horizontal surface <NUM> of the compound permeable substrate <NUM>, which thereby acts as an evaporating surface for the compound <NUM>.

<FIG> illustrate an embodiment of a centrifugal fan device <NUM> that is activated by a manual drive mechanism as opposed to an electric motor. The centrifugal fan device <NUM> includes a housing <NUM> comprising a base <NUM> and a cover <NUM>. A fan assembly <NUM> and a manual drive mechanism <NUM> are disposed within the housing <NUM>. The base <NUM> is generally bowl shaped and includes a circular aperture <NUM> disposed in a bottom <NUM> of the base <NUM>. An annularly shaped refill <NUM> is disposed within the base <NUM>. The refill <NUM> includes an annularly shaped reservoir <NUM> into which a liquid compound <NUM> is disposed. It is contemplated that the reservoir <NUM> and base <NUM> may be a single component. Indeed, various alternative embodiments of the refill are discussed in greater detail hereinbelow.

Referring more particularly to <FIG>, the refill <NUM> further includes an annularly shaped permeable substrate <NUM>, which is adapted to be in fluid communication with the reservoir <NUM>. In the present embodiment, the permeable substrate <NUM> includes a horizontal surface <NUM> having a plurality of wicks <NUM> extending therefrom. The horizontal surface <NUM> is substantially parallel to a top surface 330A of the liquid compound <NUM> disposed in the reservoir <NUM>. The plurality of wicks <NUM> extend from the horizontal surface <NUM> into the reservoir <NUM>, thereby putting the horizontal surface <NUM> of the permeable member <NUM> in communication with the liquid compound <NUM>. The horizontal surface <NUM> and the plurality of wicks <NUM> are made of a liquid permeable material, which allows the liquid compound <NUM> to be absorbed therein. For example, in a preferred embodiment, the horizontal surface <NUM> and the wicks <NUM> are preferably made of a porous plastic such as polyethylene, polypropylene, polyvinylidene fluoride, and polycarbonate. The horizontal surface <NUM> and the wicks <NUM> of the liquid permeable
substrate may also be made of bonded capillary structures that are made of polymeric fibers bonded together. Materials used to make these bonded capillary structures include polyester, polyolefins, nylon, cellosics, acetate, and other fibers. It is contemplated that the wick may be made out of other materials capable of absorbing the liquid compound. Further, the horizontal surface <NUM> and the wicks <NUM> may be separate pieces or they may be made integral.

With reference again to <FIG> and <FIG>, the cover <NUM> is adapted for interfitting relationship with the base <NUM>. The cover <NUM> includes a plurality of feet <NUM> depending from a lower edge <NUM> thereof (see <FIG>). The feet <NUM> are capable of frictionally engaging with an inner sidewall <NUM> of the base <NUM> to prevent the cover <NUM> from releasing from the base <NUM> or rotating during use. Other connections known to those of skill in the art may also be used to releasably attach the cover <NUM> to the base <NUM>. <FIG> and <FIG> show that the cover <NUM> also includes an aperture <NUM> disposed in an upper end <NUM> thereof. Further, a plurality of vents <NUM> are disposed in a sidewall <NUM> of the cover <NUM>, which allow air laden with the compound <NUM> to exit the device <NUM>.

With reference still to <FIG> and <FIG>, the cover <NUM> further includes a cylindrical support <NUM> suspended within the cover <NUM>. The cylindrical support <NUM> has open upper and lower ends 360A, 360B, respectively, and is suspended within the cover <NUM> by three arms <NUM>, which extend from an inner sidewall <NUM> of the cover <NUM> to the cylindrical support <NUM>. The cylindrical support <NUM> is adapted to help support and retain the fan assembly <NUM> and drive mechanism <NUM> within the housing <NUM>.

Turning to <FIG>, <FIG> and <FIG>, the fan assembly <NUM> generally includes a centrifugal fan <NUM> and a pivot <NUM>. The centrifugal fan <NUM> includes a plurality of fan blades <NUM> extending from a central barrel <NUM> thereof. <FIG>, <FIG>, and <FIG> illustrate that an annular plate <NUM> connects and covers an outer portion of the plurality of fan blades <NUM>. A gap <NUM> formed between the annular plate <NUM> and the barrel <NUM> allows air to be drawn into the fan <NUM> as described in further detail below. The barrel <NUM> is shaped to receive the cylindrical support <NUM> of the cover <NUM> when the device <NUM> is assembled. As shown in <FIG>, the fan <NUM> further includes a cylindrically shaped axle <NUM> that is located within the barrel <NUM> and extends upwardly from a bottom end <NUM> thereof. An upper end <NUM> of the axle <NUM> includes a plurality of teeth <NUM>. The teeth <NUM> include sloped first sides <NUM> and vertical second sides <NUM>.

Referring again to <FIG>, <FIG> and <FIG>, the pivot <NUM> includes a bottom portion <NUM> and a plurality of arms <NUM> extending from the bottom portion <NUM>. Turning to <FIG>, the barrel <NUM> of the fan <NUM> is received within the arms <NUM> of the pivot <NUM>. A groove <NUM> located on the bottom end <NUM> of the barrel <NUM> rests on a cone-shaped projection <NUM> extending from the bottom <NUM> of the pivot <NUM>. The cone-shaped projection <NUM> acts as a pivot point about which the fan <NUM> rotates within the device <NUM>.

Referring to <FIG> and <FIG>, the pivot <NUM> is designed to fit within a central cavity <NUM> of the annularly shaped refill <NUM> and base <NUM> when the device <NUM> is assembled. As shown in <FIG>, the arms <NUM> include main portions <NUM> that extend upwardly from the bottom portion <NUM> of the pivot <NUM> and overhang portions <NUM> that extend outwardly approximately <NUM>° from the main portions <NUM>. The overhang portions <NUM> extend above the horizontal surface <NUM> of the permeable substrate <NUM> of the annular refill <NUM>. Distal end portions <NUM> of the overhang portions <NUM> are received within the feet <NUM> of the cover <NUM> to prevent the pivot <NUM> from rotating when the fan <NUM> rotates. Receipt of the arms <NUM> of the pivot <NUM> within the feet <NUM> may be accomplished by friction fit or other securing means known to those in the art in order to retain the pivot <NUM> and fan <NUM> within the cover <NUM>. The retention of the pivot <NUM> and fan <NUM> allows the cover <NUM> and fan assembly <NUM> to be removed from the base <NUM> as a single unit (see <FIG>).

Referring now to <FIG>, <FIG> and <FIG>, the various components of the drive mechanism <NUM> will be described. The drive mechanism <NUM> includes a plunger <NUM>, a screw <NUM>, a spring <NUM>, a ratchet <NUM>, and a ratchet cover <NUM>. The plunger <NUM> comprises a circular button <NUM> and a cylindrical wall <NUM> depending from an underside <NUM> of the button <NUM> (see <FIG> and <FIG>). The cylindrical wall <NUM> of the plunger <NUM> is shaped to fit within the cylindrical support <NUM> of the cover <NUM>. Hooks <NUM> that are disposed on a distal end of the cylindrical wall <NUM> interact with the cylindrical support <NUM> to prevent the plunger <NUM> from being removed from the housing <NUM>. The screw <NUM> extends from the underside <NUM> of the button <NUM> within the cylindrical wall <NUM>. When the plunger <NUM> is attached to the housing <NUM> the button <NUM> substantially covers the aperture <NUM> in the cover <NUM>, which provides for a gap <NUM> between the button <NUM> and the cover <NUM> to allow air to enter the housing.

As shown in <FIG>, the ratchet <NUM> includes a disc-shaped cap <NUM> and a cylindrical tube <NUM> depending from an underside <NUM> of the cap <NUM>. A plurality of teeth <NUM> also depend from the underside <NUM> of the cap <NUM>. The teeth <NUM> include sloped first sides <NUM> and vertical second sides <NUM>. The teeth <NUM> on the ratchet <NUM> are designed to interact with the plurality of teeth <NUM> on the axle <NUM> of the centrifugal fan <NUM>. As shown in <FIG>, the ratchet <NUM> further includes a slot <NUM> within the cap <NUM>, which is shaped to receive the screw <NUM> therethrough in a screw-type engagement to convert vertical movement of the plunger <NUM> into rotational movement of the fan <NUM>.

Referring now to <FIG>, the ratchet cover <NUM> includes a cylindrical body <NUM> having a closed top end <NUM>. The ratchet cover <NUM> is designed to fit over the ratchet <NUM> and the axle <NUM> to retain the ratchet <NUM> in the housing <NUM> when the device <NUM> is assembled. An aperture <NUM> is disposed in the top end <NUM> of the ratchet cover <NUM> (see <FIG>), which is designed to allow the screw <NUM> to pass through the ratchet cover <NUM> into the ratchet <NUM>.

After assembly, the cover <NUM>, the fan assembly <NUM>, and the drive mechanism <NUM> may be inserted onto the base <NUM> as a single cover unit <NUM> (see <FIG>). Removal of the cover unit <NUM> allows for access to the refill <NUM> for inspection or replacement. It is further contemplated that the base <NUM> may include an aperture <NUM> disposed in a sidewall <NUM> of the base <NUM> (see <FIG>). The aperture allows a user to see whether a refill <NUM> has been inserted into the device <NUM>, the level of liquid compound <NUM> left in the refill <NUM>, or allows a user to view a color of the reservoir to indicate the type of compound <NUM> disposed within the refill <NUM> without removing the cover unit <NUM>. Alternatively, the base <NUM> may be made of a transparent material in order to allow a user to view the refill <NUM> or the base <NUM> may be eliminated altogether and the refill <NUM> adapted to interact and be retained to the cover unit <NUM>.

When the cover unit <NUM> and base <NUM> are combined, the plurality of fan blades <NUM> are disposed at approximately the same height as the horizontal surface <NUM> of the permeable substrate <NUM>. By connecting the plurality of blades <NUM> from above with the annular plate <NUM>, and positioning the horizontal surface <NUM> of the permeable substrate <NUM> adjacent the bottom of the fan, a large amount of surface area of the horizontal surface <NUM> is exposed. The liquid compound <NUM> disposed within the refill <NUM> is wicked up through the plurality of wicks <NUM> into the horizontal surface <NUM> of the permeable substrate <NUM>. In this passive state, the compound <NUM> evaporates from the horizontal surface <NUM> of the permeable substrate <NUM> and exits the device <NUM> through the plurality of vents <NUM> in the cover <NUM>. The plurality of wicks <NUM> continually draw the liquid compound <NUM> into the horizontal surface <NUM> of the permeable surface <NUM> allowing the liquid compound <NUM> to be dispersed throughout the horizontal surface <NUM>. The plurality of wicks <NUM> allow the liquid compound <NUM> to be dispersed around the horizontal surface <NUM> such that one area of the horizontal surface <NUM> does not include considerably more liquid compound <NUM> than other areas. The uniform dispersal of the liquid compound <NUM> around the horizontal surface <NUM> creates a uniform diffusion profile, such that similar amounts of the fragrance are evaporated from all areas of the horizontal surface <NUM> even in the passive state, thereby allowing the liquid compound <NUM> to be dispersed <NUM>° around the device <NUM>.

At any time, a user may activate the device <NUM> to release a greater amount of compound <NUM> by providing a downward force F on the plunger <NUM>. Application of the force F on the plunger <NUM> causes the screw <NUM> to move vertically downward through the slot <NUM> in the ratchet <NUM>, which causes the ratchet <NUM> to rotate in a first direction. Rotation of the ratchet <NUM> in the first direction causes the vertical sides <NUM> of the ratchet teeth <NUM> to engage with the vertical sides <NUM> of the axle teeth <NUM>, thereby causing the fan <NUM> to rotate. The rotating fan <NUM> draws air into the housing <NUM> of the device <NUM> through the gap <NUM> between the button <NUM> and the cover <NUM> as identified by arrow A. The air thereafter enters the fan <NUM> through the gap <NUM> between the barrel <NUM> and the annular plate <NUM>. The plurality of blades <NUM> forces the air over the horizontal surface <NUM> of the permeable substrate <NUM>. Subsequent to passing over the horizontal surface <NUM> of the permeable substrate <NUM>, the air is laden with the compound <NUM> and exits the housing <NUM> of the device <NUM> through the plurality of vents <NUM> in the cover <NUM>. In the present embodiment, the air is exhausted from the vents <NUM> radially about a full <NUM>° of the device <NUM>. During this active state, an increased rate of the compound <NUM> is released from the device <NUM> as compared to the passive state. Additionally, similar to the passive state, in the active state there is a uniform diffusion profile such that similar amounts of the compound are evaporated from all areas of the horizontal surface <NUM> of the permeable substrate <NUM>. In other embodiments the air may be exhausted from the vents <NUM> about only a portion of the device <NUM>.

When the downward force F is removed from the plunger <NUM>, the spring <NUM> biases the plunger <NUM> upwardly to the unactuated position. The upward movement of the plunger <NUM> causes the upward movement of the screw <NUM> through the slot <NUM> in the ratchet <NUM>. This upward movement causes the ratchet <NUM> to rotate in a second opposite direction. When the ratchet <NUM> rotates in the second direction, the sloped sides <NUM> of the ratchet teeth <NUM> are able to ride up and over the sloped sides <NUM> of the axle teeth <NUM>, thereby allowing the ratchet <NUM> to rotate without causing the fan <NUM> to rotate.

Referring now to <FIG>, the refill <NUM> will be described with greater particularity. The reservoir <NUM> of the refill <NUM> has a generally U-shaped cross-section and includes inner and outer sidewalls <NUM>, <NUM>, respectively, and a bottom wall <NUM>. In the present embodiment the reservoir <NUM> includes a top wall <NUM> that is integral with the inner and outer sidewalls <NUM>, <NUM> to enclose the reservoir <NUM>. However, in other embodiments the top wall <NUM> may be separable or entirely omitted. The top wall <NUM> is set below a top edge <NUM> of the reservoir <NUM> and defines a recess <NUM>. In other embodiments, the top wall <NUM> is not recessed and may be flush with the top edge <NUM> or raised thereabove. The top wall <NUM> also includes a plurality of bores <NUM> disposed therein, which correspond with the plurality of wicks <NUM> as described below.

As shown in <FIG>, the horizontal surface <NUM> of the compound permeable substrate <NUM> sits within the recess <NUM> such that the horizontal surface <NUM> is flush or substantially flush with the top edge <NUM> of the reservoir <NUM>. The wicks <NUM> extending from the horizontal surface <NUM> extend through the bores <NUM> in the top wall <NUM> of the reservoir <NUM>. In the present embodiment there are <NUM> wicks <NUM> and <NUM> bores <NUM>, however, four or more wicks <NUM> and bores <NUM> may be used. For example, in one preferred embodiment, the refill <NUM> includes <NUM> to <NUM> wicks <NUM> and bores <NUM>. The wicks <NUM> have a length L and the horizontal surface <NUM> has a width W. A ratio of the length L of the wicks <NUM> and the width W of the horizontal surface <NUM> is preferably between <NUM>:<NUM> and <NUM>:<NUM>. More preferably the ration between L and W is between <NUM>:<NUM> and <NUM>:<NUM>. In a preferred embodiment the wicks <NUM> extend to just above or are in contact with the bottom wall <NUM> of the reservoir <NUM>, which allows the wicks <NUM> to stay in communication with the liquid compound <NUM> in the reservoir <NUM> as the compound <NUM> is used. The horizontal surface <NUM> of the annularly shaped permeable substrate <NUM> has an outer diameter Do and an inner diameter Di. A ratio of the outer diameter Do and inner diameter Di of the permeable substrate is preferably between <NUM>:<NUM> and <NUM>:<NUM>, and more preferably about <NUM>:<NUM>. The central cavity <NUM> of the annular refill <NUM> has an inner diameter DC.

Referring now to <FIG>, in an alternative embodiment, the permeable substrate <NUM> includes only the plurality of wicks <NUM> extending through bores <NUM> in the top wall <NUM> of the reservoir <NUM>. The wicks <NUM> allow the compound <NUM> to be wicked out of the reservoir <NUM> and into the air, which is then emitted passively or exhausted out of the device <NUM> when the fan <NUM> is activated. In particular embodiments, the wicks <NUM> may be positioned to a varying extent above the top wall <NUM> of the reservoir <NUM> to release more or less of the compound <NUM>. Further, although the wicks <NUM> are shown centered and equidistant within the reservoir <NUM>, the wicks <NUM> may be located anywhere within the reservoir <NUM> and top wall <NUM>.

With reference to <FIG>, it is shown that the horizontal surface <NUM> of the permeable substrate <NUM> need not extend continuously around the reservoir <NUM> and may be designed to comprise other shapes than depicted in prior embodiments. For example, the horizontal surface <NUM> of the permeable substrate <NUM> may comprise a circle, a wedge, a triangle, a rectangle, or any other geometric shape that can rest on, or otherwise be disposed above, the top wall <NUM> of the reservoir <NUM> and provide adequate surface area for compound dispersal (see <FIG>). Further, as shown in <FIG>, the horizontal surface <NUM> of the permeable substrate <NUM> may be configured to cover only a portion of the annular top wall <NUM> of the reservoir <NUM>.

The present centrifugal fan devices <NUM>, <NUM>, <NUM> provide features and advantages not found in prior art devices for delivering a fragrance or insecticide. For example, the combination of the centrifugal fan and its location adjacent the compound permeable substrate allow for better compound delivery, as compared to other known passive and/or heated devices.

A further advantage of the present centrifugal fan devices is that they allows for a small, more compact device, due to better air flow across the compound permeable substrate. As a result, the present centrifugal fan devices allow the compound permeable substrate to have a smaller surface area and require fewer wicks and/or allow for a reduction in the size of wicks, as compared with prior art devices, in order to achieve the same compound delivery to the environment of use.

An additional advantage of the present centrifugal fan devices is that they have less resistance to air flow, as a result of the present configuration forcing the air along the surface of the permeable member instead of against the surface, thus requiring a minimal amount of energy to operate and, therefore, prolonging battery life in the electronic devices, as compared with prior devices.

The exemplary embodiments disclosed herein are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description.

Other embodiments of the disclosure including all the possible different and various combinations of the individual features of each of the foregoing described embodiments and examples are specifically included herein.

Claim 1:
A dispensing device <NUM>, comprising:
a housing <NUM>;
a fan <NUM>; and
a refill <NUM>, wherein the refill <NUM> comprises
an annular reservoir <NUM> having a compound <NUM> disposed therein; and
an annular permeable substrate <NUM> in fluid communication with the compound <NUM> disposed in said annular reservoir <NUM> and configured to release the compound <NUM> in a first passive state, wherein the compound <NUM> is released from the permeable substrate <NUM> according to a uniform diffusion profile, and
wherein the fan <NUM> is configured such that rotation of the fan <NUM> causes air to pass over the permeable substrate <NUM> to release the compound <NUM> in a second, active state;
characterised in that said fan is a centrifugal fan <NUM>; and in that the permeable substrate <NUM> includes a horizontal surface <NUM> having at least one wick <NUM> extending from the horizontal surface <NUM> into the compound <NUM> disposed in the reservoir <NUM>, wherein the horizontal surface <NUM> and the at least one wick <NUM> have a T-shaped cross-section in radial direction.