WO2006087564A1

WO2006087564A1 - A dispensing apparatus

Info

Publication number: WO2006087564A1
Application number: PCT/GB2006/000558
Authority: WO
Inventors: John Burgess
Original assignee: Aroma Cair Ltd
Priority date: 2005-02-16
Filing date: 2006-02-16
Publication date: 2006-08-24
Also published as: GB2423253A; GB0503222D0

Abstract

A dispensing apparatus for dispensing essential oils comprising an absorbent element (40) and an air impeller (41 ) to generate the flow of air across the absorbent element. The apparatus includes an oil supply unit (1 ) having a mounting arrangement to receive the neck of an inverted bottle (30). The mounting arrangement defines a liquid flow-path (10) extending from the recess to a dispensing point, from which the oil passes to the absorbent pad, and an air-flow path (16) extending to the recess. A solenoid (20) control valve may be actuated to open the air-flow path for a predetermined time to permit air to flow through the path and into the bottle thus allowing a predetermined quantity, for example one drop, of liquid to be dispensed from the bottle on to the absorbent element.

Description

A DISPENSING APPARATUS

THE PRESENT INVENTION relates to a dispensing apparatus and more particularly relates to a dispensing apparatus for dispensing essential oils, in which essential oils are applied to an absorbent pad, and in which a stream of air is blown across the absorbent pad with a fan.

Essential oils are being used increasingly as a therapeutic measure, and for other purposes, and when an essential oil is utilised it is preferable that the oil is vaporised so that a person who is to be exposed to the essential oil may breath the vapour.

Various types of apparatus for dispensing essential oils and therapeutic aromas have been proposed previously. Examples of such prior proposed apparatus include aromatherapy burners and nebulisers.

A typical burner uses a candle to heat and vaporise an essential oil or aromatic liquid which has a therapeutic effect. Such burners can be dangerous insofar as candle flames can cause fires, hot liquids can scald children and children can swallow the liquids when the apparatus is not in use.

A further problem with burners is that typically the candle becomes used up too soon, for example mid-way through the night. Also a problem with burners is they cannot be controlled automatically so that they come on and go off at predetermined time intervals. Prior proposed nebulisers do not have a good facility to distribute therapeutic aromas around a room, and typically they do not have appropriate controls for controlling the operation of the nebulisers.

A problem that exists in connection with apparatus which utilises essential oils is that the essential oils tend to be very corrosive and attack many materials that are in common use.

The present invention seeks to provide a dispensing apparatus suitable for use in dispensing essential oils which does not use heat in the dispensing process, and which also does not use CFCs, thus being environmentally friendly. The invention also seeks to provide, in a preferred embodiment, an apparatus that is pre-programmed, or pre-programmable, and which does not need to be manually activated. Thus, the preferred embodiment of the invention will operate on an automatic basis to supply air and essential oils.

According to one aspect of this invention there is provided a dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement, a mounting arrangement having a recess configured to receive the neck of an inverted bottle, a liquid flow-path extending from the recess to a dispensing point, and an air-flow-path extending from the recess to a valve, there being a valve member which closes the valve, and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path.

According to another aspect of this invention there is provided a dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement having a recess receiving the neck of an inverted bottle, the bottle containing a liquid to be dispensed, the oil supply unit defining a liquid flow-path in communication with the interior of the bottle and extending from the recess to a dispensing point, and an air-flow-path, in communication with the interior of the bottle and extending from the recess to a valve, there being a valve member which closes the valve and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path and into the bottle, to enable liquid to flow from the bottle through the liquid flow-path to the dispensing point.

Preferably the liquid flow-path is aligned with the axis of the recess, and the air-flow-path is off-set from the axis of the recess, the bottle being provided with an insert in the neck of the bottle, the insert carrying an outwardly directed tube, communicating with the interior of the bottle and aligned with the axis of the bottle, positioned to be aligned with the said liquid flow-path, the insert carrying a further tube extending into the interior of the bottle, off-set from the axis of the bottle, the second tube being positioned to be in communication with the air-flow-path.

Conveniently the bottle contains an essential oil, or a mixture of essential oils.

Advantageously the controlled mechanism is controlled by a controller, the controller being a programmable controller.

Preferably the programmable controller is programmed to open the valve at predetermined time intervals, with the valve being open for said predetermined time on each occasion it is opened. Alternatively the controller incorporates a sensor responsive to the concentration of the dispersed liquid in the atmosphere, such as a gas chromatograph sensor.

Conveniently an integral mounting block defines the liquid flow-path, the airflow-path and the recess configured to receive the neck of the inverted bottle, the mounting block also defining a valve seat of the valve.

In one embodiment the integral mounting block is formed of anodised aluminium, which is a material resistive to the corrosive attack of essential oils.

Conveniently the recess is provided with a removable insert, the insert defining a screw-thread to co-operate with a screw-thread on the bottle. The insert is preferably made of a plastic resistant to essential oils, and is thus easily replaceable.

Preferably the valve seat is a conical valve seat at an open end of the air-flow- path and the valve member is a resilient O-ring mounted on a conical or frusto-conical support element.

Advantageously the controlled mechanism to move the valve member is actuated by a solenoid.

Conveniently the valve member is mounted on an extension of the armature of the solenoid.

Conveniently the length and diameter of the liquid flow-path, and the duration of opening of the valve as controlled by the controller are such that a single drop of oil is supplied to the absorbent element. Preferably the duration of opening of the valve is four-hundredths of a second.

In an alternative embodiment the valve is a plug valve and the controlled mechanism is a motor.

Preferably the air impeller is a fan.

Conveniently the air impeller is controlled, by a controller, to be actuated during predetermined periods of time.

According to a further aspect of this invention there is provided a dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement, a mounting arrangement having a recess configured to receive the neck of an inverted bottle, a liquid flow-path extending from the recess to a dispensing point, and an air-flow-path extending from the recess to a valve, there being a valve member which closes the valve, and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path, the controlled mechanism being controlled by a sensor responsive to the concentration of a predetermined component in the atmosphere.

According to yet another aspect of this invention there is provided a dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement having a recess receiving the neck of an inverted bottle, the bottle containing a liquid to be dispensed, the oil supply unit defining a liquid flow-path in communication with the interior of the bottle and extending from the recess to a dispensing point, and an air-flow- path, in communication with the interior of the bottle and extending from the recess to a valve, there being a valve member which closes the valve and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path and into the bottle, to enable liquid to flow from the bottle through the liquid flow-path to the dispensing point, the controlled mechanism being controlled by a sensor responsive to the concentration of the dispensed liquid in the atmosphere.

Advantageously the sensor responsive to concentration is a gas chromatograph sensor.

Preferably a sensor is provided, responsive to a predetermined level of liquid in the inverted bottle, to actuate an alarm when the level of liquid falls below a predetermined level.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIGURE 1 is a side view, partly in phantom, of an oil supply unit,

FIGURE 2 is a view, from underneath, showing parts in phantom, of a mounting block forming part of the unit of Figurei ,

FIGURE 3 is a side view, with parts shown in phantom, of the mounting block of Figure 2, and

FIGURE 4 is a diagrammatic view of a dispensing unit incorporating an absorbent pad and a fan, FIGURE 5 is a diagrammatic view of another form of dispensing unit,

FIGURE 6 is a view of an alternative valve arrangement, and

FIGURE 7 is a view of part of a further embodiment.

It has now been found that, for essential oils to be most effective, the essential oils should be delivered in the form of a vapour, with the vapour having a predetermined concentration in the atmosphere. If there is insufficient vapour, then the essential oil does not provide the desired effect. If there is too much vapour, then the essential oil can prove to be an irritant.

The inventors of the present invention have appreciated that essential oils may be utilised in a domestic or office environment in order to relieve some or all of the symptoms of stress, and also the present inventors have appreciated that essential oils may be used in other environments, with the essential oils providing a therapeutic, antiseptic or antiviral effect. The present inventors have therefore attempted to devise a dispensing apparatus suited for the dispensing of essential oils, with the dispensing apparatus being capable of being operated to provide an atmosphere in which the essential oils have a desirable concentration.

Essential oils have to be delivered in very small quantities, in such a dispensing apparatus, since otherwise there is a grave risk that the concentration of essential oil in the atmosphere will be excessive, which is undesirable. Essential oils are oily and relatively viscous, and consequently it is difficult to devise a valve which acts directly on the essential oil to control the flow of essential oil.

The invention will be described with reference to various preferred embodiments. Referring initially to Figure 1 of the accompanying drawings, an oil supply unit 1 is illustrated, which may be operated to provide a series of drops of a liquid, such as an essential oil, with the drops being provided in a controlled manner. The oil supply unit forms part of a dispensing apparatus which includes an absorbent pad and a fan, as will be described in more detail below.

The oil supply unit of Figure 1 comprises a support plate 2. The support plate 2 is provided with a plurality of apertures, 3, 4, 5, 6, the purpose of which will become clear from the following description.

A mounting block 7 is provided, the mounting block 7 being of generally cylindrical form and having, extending from its lower face 8, a centrally mounted hollow spigot 9. The mounting block is an integral element and may be formed of metal or of a suitable plastics material. Preferably the mounting block is formed of anodised aluminium, which is a material that is not attacked by the essential oils.

The hollow spigot 9 forms the lower end of a liquid flow passage or inner tube 10 which extends vertically through the block from the spigot 9 to the centre of a recess 11 formed in the upper face 12 of the block 7. The recess 11 is of circular form, and is provided with a substantially flat base 13. An upstanding collar 14 extends upwardly from the base of the recess surrounding the open end of the liquid flow-path 10. The side-wall 15 of the recess 11 may be provided with screw-threading, for a purpose that will become clear from the following description.

A second flow-path 16, which is an air-flow-path, is provided in the block communicating with part of the base 13 of the recess 11 at a point outside the collar 14. The air-flow-path 16 extends downwardly beneath the recess 11 and is then cranked to extend substantially horizontally to a conical valve seat 17 formed in the peripheral side-wall of the mounting block 7. At least part of the air-flow-path has a small cross-section, for a reason which will become clear below.

The base 8 of the mounting block 7 is provided with a screw-threaded blind bore 18.

The mounting block 7 is secured to the plate 2 by inserting the spigot 9 through the aperture 3 and aligning the blind bore 18 with the aperture 4. A screw 19 is inserted through the aperture 4 into the blind bore 18 to secure the mounting block firmly in position on the plate 2.

A solenoid unit 20 is provided. The solenoid 20 is provided with two threaded blind bores 21 , 22 formed in its base to be co-aligned with the apertures 5, 6 formed in the mounting plate 1 and to receive screws 23, 24 which pass through the apertures 5, 6 to secure the solenoid unit 20 to the mounting plate 1.

The solenoid unit 20 contains a solenoid coil which surrounds part of an armature. The armature moves when a current is supplied to the coil. Projecting from one side of the solenoid unit is an armature extension 25 made of anodised aluminium. The armature extension 25 is biased, by means of a spring 26, to an extended position. The end part 27 of the armature extension 25 is of conical form, thus having a form generally corresponding to that of the conical seat 17. A resilient O-ring 28 is provided mounted in a peripheral groove formed on the conical end part 27 of the armature extension 25, the O-ring 28 ordinarily being in engagement with the wall of the conical seat 17 to form a substantially gas-tight seal. The O-ring 28 thus constitutes a valve member which initially closes the valve. The O-ring 28 is preferably formed of a silicone rubber which resists the corrosive effects of essential oil and essential oil vapour. The end part 27 of the armature extension 25 is conical but could be frusto-conical. Thus the air-flow-path is usually sealed by the valve to prevent the flow of air. the air-flow-path may be opened by actuating the solenoid to withdraw the O-ring 28 from the conical seat.

In use of the oil supply unit a bottle 30, containing essential oil, is mounted on the mounting block 7, in an inverted orientation. The bottle 30 is provided with a relatively narrow neck 31 , which is received in the recess 11 formed in the upper face 12 of the mounting block 7. The exterior of the neck 31 may be threaded to be threadingly engaged with the threaded side-wall 15 of the recess 11.

Mounted within the neck of the bottle is an insert 32, which may be formed of a plastics material, the insert 32 having a peripheral flange 33 which extends outwardly over the free end of the neck 31 of the bottle. The insert then extends into the neck of the bottle forming a cup-like portion which has a planar base 34. The base 34 carries a first relatively long tube 35 which extends into the interior of the bottle, at a position off-set from the axis of the bottle, and a second relative short tube 36 which extends towards the open end of the neck of the bottle, and which is axially located. Each tube is open at both ends.

It is to be understood that when the bottle 30 has been inverted and engaged with the mounting block, the axially positioned tube 6 formed on the insert 32 in the neck 31 of the bottle 30 is received within the collar 14 provided on the base 13 of the recess 11 , so that the tube 36 is in communication with the liquid flow passage 10. The tube 36 may be a friction sealing fit within the collar 14. The tube 35 which extends towards the interior of the bottle is in communication with the space surrounding the collar 36 and is thus in effective communication with the air- flow-path 16 in the mounting block which is associated with the conical seat 17.

The flange 33 of the insert 32 forms an air-tight seal with the base of the recess 11. If the material of the insert 32 is hard, so that an air-tight seal is not created, then an additional annular seal may be provided in the base of the recess 11 to engage the neck 31 of the bottle 30, the annular seal being formed of a resilient material.

A sensor arrangement is provided to sense when the level of liquid within the inverted bottle is relatively low. The sensor arrangement comprises a light source 37 which directs a beam of light across the narrow part of the neck 31 of the bottle, at a point above the level of the insert 32. The light source may be a monochromatic light source or may be a light source which produces a pulse-coded beam of light. A sensor 38 is provided on the opposite side of the bottle to sense the light from the light source. The light from the light source is such that the light is at least partially absorbed by the essential oil. The sensor 38 will therefore only sense the light beam at a substantial intensity when the level of oil in the bottle is very low, and the uppermost surface of the essential oil within the bottle is contained within the narrow part of the neck 31 of the bottle. The sensor 38 is connected to actuate an alarm device 39 which may be an audible device such as a bell or "whistle" or may be a visible device such as a flashing light. It is to be appreciated, therefore, that when the level of essential oil within the bottle 30 reaches a predetermined minimum value the alarm will be actuated, and a person using the dispensing device will know it is time to replace the bottle with a fresh bottle of essential oil.

The oil supply of unit 1 is located above a pad 40 of absorbent material, and an air impeller, for example a fan 41 , driven by a motor 42, is provided to draw air over the absorbent pad, as shown in Figure 4. The solenoid unit 20, in the arrangement shown in Figure 4, is controlled by a controller 43 to open the valve for predetermined periods of time, and the controller 43 also controls the fan motor 42.

The controller 43 is associated with a keypad unit 44 to enable the controller to be programmed so that the oil dispensing unit and the fan are operated during selected periods of time.

It is to be understood that the solenoid within the solenoid unit 20 may be actuated to withdraw the armature extension 25 from the seat 17, disengaging the O-ring 28 from the seat 17, against the bias of the spring 26, and thus opening the valve. Typically the valve is opened for a period of between two and eight-hundredths of a second, and preferably the valve is opened for four- hundredths of a second. This will allow a small quantity of air to enter the airflow-path 16, and consequently to enter the space within the recess 11 and also within the cup-like insert 32 provided in the bottle 30. The amount of air that can flow depends upon how long the valve is open, and the cross-section of the smallest cross-section part of the air-flow-path The air may flow through the pipe 35 which extends into the interior of the bottle 30, reducing a partial vacuum that exists within the bottle. The quantity of air that is introduced is such that, as the vacuum is reduced, a predetermined quantity (such as one drop) of essential oil may flow, from the bottle 30, through the pipe 36 provided on the insert 32 and through the inner tube liquid flow passage 10 to emerge through the spigot 9, from which it is dispensed on to the absorbent pad. The length and diameter of the inner tube are such that a single drop of oil forms on the open end of the spigot 9 following each opening of the valve formed by the O-ring 28.

The open end of the spigot 9 is a dispensing point for the oil from the bottle on to the absorbent pad 40. The oil is thus passed to the absorbent pad. The fan 41 , which is also controlled by the controller 43, will draw air past the absorbent pad, and the essential oil will vaporise and be carried by the air stream generated by the fan. Consequently the essential oil will be dispensed in the form of an airborne aroma.

As the predetermined quantity of oil, i.e. the single drop of oil, flows from the bottle, so the pressure of air remaining within the bottle will reduce to reestablish the partial vacuum. Once the partial vacuum has been reestablished within the bottle, no further oil will flow from the bottle until the solenoid is reactivated to re-open the valve.

It is to be appreciated, therefore, that by controlling the solenoid appropriately essential oil can be dispensed over any desired period of time at any selected effective flow-rate.

The controller 43 may be programmed in many different ways to actuate the solenoid in many different desired manners, using the key pad unit 44 which has key buttons 45 and a display 46.

For example, the solenoid may be controlled by the programmed controller 43 so that the solenoid is actuated for a very brief period of time, such as four- hundredths of a second, at regular intervals, for example once an hour. The duration of actuation of the solenoid may be pre-set and non-adjustable to be sufficient to enable sufficient air to flow past the O-ring 28 provided on the armature extension 25 of the solenoid unit 20, so that a predetermined quantity, such as a single drop, of essential oil may flow from the bottle 30 and be dispensed through the spigot 9 to fall on to the absorbent pad. The fan may be controlled to be actuated for a predetermined period of time wherever oil has been dispensed, so that a sufficient stream of air is drawn past the absorbent pad to vaporise the oil, or substantially all of the oil, so that the oil can be dispensed in the form of an airborne aroma. Thus the key pad unit 44 can be used to select the duration of fan operation. The controller will be programmed by the key pad unit to dispense a further drop or drops of oil at selected time intervals, such as one hour intervals.

The controller may be programmed, with the key pad unit 44, so that the described dispensing unit will only operate for selected periods of time during a particular 24-hour cycle. Thus, for example, the controller 43 may be programmed to activate the dispensing apparatus for a period between 5 am and 8 am each morning, and for a period between 9 pm and midnight each night, so that the dispensing apparatus may be located, for example, in a bedroom, and consequently the essential oil will be dispensed when the occupant of the bedroom is going to bed and as the occupant of the bedroom is waking and getting up in the morning. Of course, the controller may be programmable to actuate the dispensing unit at any desired time or times during a day.

Figure 5 illustrates a modified embodiment of the invention. Many of the components of Figure 5 are similar to those described above and like reference numerals have been used for like parts which will not be redescribed in detail. In the embodiment of Figure 5 a gas chromatograph sensor 47 is provided, which is responsive to the concentration of essential oil within the atmosphere. The sensor 47 is connected to the controller 43.

It is thus to be appreciated that in use of the embodiment of Figure 5, whenever the gas chromatograph sensor 47 senses that the concentration of essential oil within the atmosphere is below a predetermined threshold, the controller 43 will be actuated to operate the solenoid 20 and thus open the valve to permit a predetermined quantity, for example one drop, of essential oil to be dispensed, and also to actuate the fan 41. The period of time for which the fan 41 is actuated may be pre-selected using a key pad equivalent to the key pad 44 of the embodiment of Figure 4, and the duration of operation of the fan may be selected in accordance with the size of the room in which the dispensing apparatus is being utilised.

It is to be appreciated that by setting up the gas chromatograph sensor appropriately, the dispensing apparatus as described in Figure 5 may be operated to maintain a substantially constant concentration of essential oil in the atmosphere within a specific room in which the apparatus is installed. This may of particular value if the essential oil is being used for therapeutic, antiseptic or antiviral purposes.

Whilst, in the embodiments described above, one particular type of valve has been described, it is to be appreciated that alternative forms of valve can be used to control the flow of air through the air-flow-path. Figure 6 illustrates a modified embodiment of the invention in which the mounting block 7 is provided with an internal plug valve to perform the function of the solenoid actuated valve of the above-described embodiment. Thus, referring to Figure 6, the block 7 defines a cylindrical blind bore 47 formerly a valve seat which intersects the air-flow-path 16. Received within the blind bore 47 is a plug 48 provided with a diametrically extending bore 49 which constitutes a moveable valve member. The plug 48 is formed as one end of a shaft 50, the shaft 50 being driven by motor 51 , which may be a stepping motor. The motor is actuated by the controller 43.

With the shaft 50 in an initial position the bore 49 extends across the blind bore 47 at a position in alignment with the gas flow-path 16 which is intersected by the blind bore 47, but the bore 49 and the plug 48 extends transversely or substantially at right angles to the axis of the air-flow-path 16.

Thus, in the position illustrated in Figure 6, the valve is closed as no air can flow through the air-flow-path 16. If the shaft 50 is rotated by 90°, the bore 49 is brought into alignment with the parts of the air-flow-path 16 on the opposed sides of the blind bore 47, permitting the flow of gas. It is envisaged, therefore, that the motor 51 will be controlled to bring the plug 48 to a position in which the bore 49 is aligned with the adjacent parts of the air-flow-path 16 for a predetermined period of time, such as four-one-hundredths of a second, to enable a sufficient quantity of air to flow through the air-flow-path 16 to enable one drop of oil (or some other predetermined quantity of oil) to be dispensed from the bottle 30. The motor will then move the plug 48 to a position equivalent to that illustrated, in which the valve is closed.

The valve of Figure 6 can be used with the controller 43 as described in Figure 4, and also with the controller 43 and the associated gas chromatograph sensor 47 as described in Figure 5.

Figure 7 illustrates the upper part of a mounting block 7 of a further embodiment of the invention, showing the recess 11 and the upstanding collar 14. It is the recess 11 which is to receive the neck of the bottle 30. Whilst, in the previously described embodiment, the side-wall of the recess is threaded, in this embodiment an insert 60 of a plastics material is provided dimensioned to be inserted into the recess 11. The insert 60 is of "cup"-shape having an upstanding side-wall 61 and a substantially flat base 62. The base 62 has a central aperture to receive the collar 14. The insert 60 is a friction fit within the recess 11. The innermost part of the side-wall 61 of the insert 60 is provided with a screw-threading 63 to co-operate with screw- threading provided on the neck of the bottle 30. The insert is preferably formed of a plastics material which is resistant to the corrosive effect of essential oils. The insert is dimensioned to be received as a friction fit within the recess 11 , so that the insert can be removed from the recess 11 , to be replaced by a fresh insert, should the screw-threading 63 deteriorate or become worn. When used in this Specification and Claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

Claims

CLAIMS:

1. A dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement, a mounting arrangement having a recess configured to receive the neck of an inverted bottle, a liquid flow-path extending from the recess to a dispensing point, and an air-flow-path extending from the recess to a valve, there being a valve member which closes the valve, and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path.

2. A dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement having a recess receiving the neck of an inverted bottle, the bottle containing a liquid to be dispensed, the oil supply unit defining a liquid flow-path in communication with the interior of the bottle and extending from the recess to a dispensing point, and an air-flow-path, in communication with the interior of the bottle and extending from the recess to a valve, there being a valve member which closes the valve and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path and into the bottle, to enable liquid to flow from the bottle through the liquid flow-path to the dispensing point.

3. A dispensing apparatus according to Claim 2 wherein the liquid flow- path is aligned with the axis of the recess, and the air-flow-path is off-set from the axis of the recess, the bottle being provided with an insert in the neck of the bottle, the insert carrying an outwardly directed tube, communicating with the interior of the bottle and aligned with the axis of the bottle, positioned to be aligned with the said liquid flow-path, the insert carrying a further tube extending into the interior of the bottle, off-set from the axis of the bottle, the second tube being positioned to be in communication with the air-flow-path.

4. A dispensing apparatus according to Claim 3 wherein the bottle contains an essential oil, or a mixture of essential oils.

5. A dispensing apparatus according to any one of the preceding Claims wherein the controlled mechanism is controlled by a controller, the controller being a programmable controller.

6. A dispensing apparatus according to Claim 5 wherein the programmable controller is programmed to open the valve at predetermined time intervals, with the valve being open for a said predetermined time on each occasion it is opened.

7. A dispensing apparatus according to any one of Claims 1 to 4 wherein the controller incorporates a sensor responsive to the concentration of the dispersed liquid in the atmosphere.

8. A dispensing apparatus according to any one of the preceding Claims wherein an integral mounting block defines the liquid flow-path, the air-flow- path and the recess configured to receive the neck of the inverted bottle, the mounting block also defining a valve seat of the valve.

9. A dispensing apparatus according to Claim 8 wherein the integral mounting block is formed of anodised aluminium.

10. A dispensing apparatus according to Claim 8 or claim 9 wherein the recess is provided with a removable insert, the insert defining a screw-thread to co-operate with a screw-thread on the bottle.

11. A dispensing apparatus according to any one of Claims 8 to 10 wherein the valve seat is a conical valve seat at an open end of the air-flow-path and the valve member is a resilient O-ring mounted on a conical or frusto-conical support element.

12. A dispensing apparatus according to Claim 11 wherein the controlled mechanism to move the valve member is actuated by a solenoid.

13. A dispensing apparatus according to Claim 12 wherein the valve member is mounted on an extension of the armature of the solenoid.

14. A dispensing apparatus according to anyone of Claims 1 to 10 wherein the valve is a plug valve and the controlled mechanism is a motor.

15. A dispensing apparatus according to Claim 5 or any Claim dependent thereon wherein the length and diameter of the liquid flow-path, and the duration of opening of the valve as controlled by the controller are such that a single drop of oil is supplied to the absorbent element.

16. A dispensing apparatus according to Claim 15 wherein the duration of opening of the valve is four hundredths of a second.

17. A dispensing apparatus according to any one of the preceding Claims wherein the air impeller is controlled, by a controller, to be actuated during predetermined periods of time.

18. A dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement, a mounting arrangement having a recess configured to receive the neck of an inverted bottle, a liquid flow-path extending from the recess to a dispensing point, and an air-flow-path extending from the recess to a valve, there being a valve member which closes the valve, and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path, the controlled mechanism being controlled by a sensor responsive to the concentration of a predetermined component in the atmosphere.

19. A dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement having a recess receiving the neck of an inverted bottle, the bottle containing a liquid to be dispensed, the oil supply unit defining a liquid flow-path in communication with the interior of the bottle and extending from the recess to a dispensing point, and an air-flow-path, in communication with the interior of the bottle and extending from the recess to a valve, there being a valve member which closes the valve and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path and into the bottle, to enable liquid to flow from the bottle through the liquid flow-path to the dispensing point, the controlled mechanism being controlled by a sensor responsive to the concentration of the dispensed liquid in the atmosphere.

20. A dispensing apparatus according to Claim 7 or any Claim dependent thereon, or Claim 18 or Claim 19 wherein the sensor responsive to concentration is a gas chromatograph sensor.

21. A dispensing apparatus according to any one of the preceding Claims wherein a sensor is provided, responsive to a predetermined level of liquid in the inverted bottle, to actuate an alarm when the level of liquid falls below a predetermined level.

22. A dispensing apparatus, the dispensing apparatus comprising an absorbent element, and an air impeller to generate a flow of air across the absorbent element and an oil supply unit to supply oil to the absorbent element, the oil supply unit having a mounting arrangement, the mounting arrangement having a recess configured to receive the neck of an inverted bottle, a liquid flow-path extending from the recess to a dispensing point, and an air-flow-path extending from the recess to a valve, there being a valve member which closes the valve, and a controlled mechanism to move the valve member to open the valve for predetermined times to permit the flow of air through the air-flow-path, an integral mounting block, formed of anodised aluminium, defining the liquid flow-path, the air-flow-path and the recess configured to receive the neck of the inverted bottle, the mounting block also defining a valve seat forming the valve seat of the valve, the valve seat being a conical valve seat at an open end of the air-flow-path, the valve member being a resilient O-ring mounted on a conical or frusto-conical support element mounted on an extension of the armature of a solenoid, wherein the liquid flow-path is aligned with the axis of the recess, and the air-flow-path is off-set from the axis of the recess, the bottle being provided with an insert in the neck of the bottle, the insert carrying an outwardly directed tube, communicating with the interior of the bottle and aligned with the axis of the bottle, positioned to be aligned with the said liquid flow-path, the insert carrying a further tube extending into the interior of the bottle, off-set from the axis of the bottle, the second tube being positioned to be in communication with the air-flow-path.