WO2013124651A1

WO2013124651A1 - Systems and devices for dispensing volatile materials

Info

Publication number: WO2013124651A1
Application number: PCT/GB2013/050411
Authority: WO
Inventors: Martin Butler; Sudhir Dhawan; Paul MARTINGELL
Original assignee: Reckitt & Colman (Overseas) Limited
Priority date: 2012-02-21
Filing date: 2013-02-20
Publication date: 2013-08-29
Also published as: PH12014501886A1; GB2518295B; AU2013223881A1; PH12014501886B1; GB2499589A; GB201414844D0; GB2518295A; ZA201406054B; AU2013223881B2; GB201202914D0

Abstract

A volatile liquid emanation system (1) is described which includes an emanation device (2) and a replaceable refill (2) of liquid: wherein the refill comprises a reservoir housing having walls containing a liquid reservoir of volatile liquid and a wick (7) extending from the interior of the reservoir to the exterior thereof and wherein the refill (2) is sized to fit substantially completely within the device housing.

Description

Systems and devices for dispensing volatile materials

Field of the Invention

The present invention relates to systems and devices for dispensing volatile materials present in formulations such as insecticides, insect repellents and the like into the atmosphere.

Background

A variety of vapour emanating devices are known which function by heating a surface containing a volatile material to release the volatile material from the surface into the atmosphere, such that the material can then function as an insecticide or insect repellent.

Mat-type vapour emanating devices are widely used for such purposes. Mat-type devices are generally two part devices consisting of a heater unit which is a relatively non-disposable part, and a formulation supply unit that contains the volatile material to be dispensed, which is typically a disposable and/or replaceable part.

The heater unit typically comprises a plug pins which are connectable to a power source, such as a mains electric power socket or the like. The power source provides the electrical energy necessary to generate a desired heat in a heating element located within the body of the heater unit. An opening is provided in the body of the heater unit to receive the formulation supply unit such that the formulation can be exposed to the heat generated from the heating element within the heater unit. The opening can assume a variety of shapes and sizes to receive a variety of formulation supply units of various shapes and sizes, generally dictated by the specific manufacturer of the device. The formulation supply unit typically comprises a planar surface, a portion of which contains the volatile material provided within the formulation. The portion of the surface may comprise an exposed porous region, or mat, which is impregnated with the formulation. Upon insertion of the formulation supply unit through the opening in the body of the heater unit, the porous region, or mat, impregnated with the formulation is positioned generally within the region of the heating elements and is therefore exposed to the high temperatures generated by the heating elements. Exposure of the formulation to sufficient temperatures then causes the volatile material present in the formulation to vaporise into the atmosphere, such that the device can function as an insecticide, insect repellent and/or an air freshener. Upon vaporisation of substantially all of the volatile material present in the formulation supply unit, the formulation supply unit is then removed from the heater unit and discarded. The heater unit is then able to receive replacement formulation supply units and as such the user needs to purchase replacement formulation supply units to use with their existing heater unit.

A common problem with such mat-type devices is that the vaporisation of the volatile material occurs quite rapidly such that the formulation supply units typically last for one night, or period of use, before requiring replacement. Further, there are variations between the thicknesses, size, shape, active ingredient properties and manner in which the mats operate between different manufacturers of the formulation supply units. As such, the heater units provided to receive the various types of formulation supply units typically operate over a wide range of operating temperatures (130-180°C). This variation in operating temperatures of the heater units causes a wide variation in the rate of emanation of the volatile material from the various formulation supply units which can be used between differing heater units. This can then result in a formulation supply unit of one manufacture inadequately performing when used with a different type of heater unit. As the formulation supply units in existing mat-type vapour emanating devices require constant replacement, the user's fingers are often in contact with the porous region, or mat, of the unit during the replacement and disposal process. Such exposure to the formulation and the volatile material is undesirable and can contaminate the user's skin. In order to avoid the need to regularly replace the formulation supply unit such that the devices operate for more extended periods of time whilst still utilising the existing heater units, variations to the formulation supply units have been proposed. Such variations include providing the formulation in a longer lasting gel mat on the surface of the formulation supply unit, such that the volatile material emanates at a slower rate when inserted into the heater unit. Such devices may operate for a period of up to 30 days before requiring replacement. To accommodate the longer lasting gel mat and to enable the variation to be used in a variety of existing heater units, the formulation supply unit is in the form of a malleable aluminium tray which is adapted to be received by a variety of heater units. However, as the tray is adapted to loosely fit a variety of heater units, the gel mat is not consistently located adjacent the heating elements of the heater unit. Accordingly it has been found that there is a large variation in the heat received by the gel. This causes large variations in the emanation rates of the volatile material between different devices. Therefore, in order to ascertain the remaining life of the formulation supply unit and therefore the amount of gel present thereon, the user must physically remove the formulation supply unit from the heater unit to inspect the gel, which is a cumbersome and inexact exercise. An improvement over the gel-based systems is available in the form of bottle-type vapour emanating devices which comprise a clear bottle formulation supply unit containing a large amount of formulation in fluid communication with a wicking device. Bottle-type devices provide for extended periods of use, due to their large formulation storage capacity, together with a visual indication of the amount of formulation present in the device so that a user can readily ascertain the operational state of the device. However such devices pose several drawbacks which the present invention overcomes.

Summary of Invention

According to a first aspect of the present invention there is provided therefore a volatile liquid emanation system for comprising an emanation device and a replaceable refill of liquid:

wherein the refill comprises a reservoir housing having walls containing a liquid reservoir of volatile liquid and a wick extending from the interior of the reservoir to the exterior thereof and wherein the refill is sized to fit substantially completely within the device housing;

wherein the device comprises a device housing having walls containing a heater and refill receiving means, the device further comprising plug pins, and wherein the device housing comprises at least one vent hole and at least one refill aperture to permit the refill access to the refill receiving means; and wherein the refill receiving means releasably hold the refill within the device housing such that the reservoir housing wall(s) adjacent the refill aperture(s) is substantially contiguous with the adjacent device housing wall(s).

In the context of the present invention the term "substantially contiguous" is understood to mean that when the refill is releasably held by the refill receiving means the reservoir wall(s) adjacent the refill aperture(s) extend into the aperture(s) but not substantially beyond them such that no part of the refill obviously extends beyond the device housing wall(s) adjacent the aperture(s). In the context of the present invention the term "substantially completely" is understood to mean that when the refill is releasably held by the refill receiving means all of the refill is held within the device housing save for the reservoir wall(s) adjacent the refill aperture(s) extend into the aperture(s) but not substantially beyond same.

Volatile liquid emanation systems according to the present invention are advantageous because they are more child tamper proof than hitherto known emanation systems. In particular as the refill is substantially completely held within the device housing there is no visual stimulus provided which would encourage interaction with the device, such as a bottle of liquid suspended beneath a plug-in device as is typical with the prior art. Furthermore, as the reservoir wall(s) provide a substantially contiguous surface with the device housing wall adjacent the refill aperture, there is no tactile stimulus which would encourage further interaction with the device. The substantially contiguous surface provides no easy tactile purchase surface which would encourage a child to attempt to remove the refill from the device.

Preferably the device is provided with a single refill aperture and therefore only the reservoir housing wall adjacent the refill aperture when the refill is releasably held by the refill receiving means needs be substantially contiguous with the adjacent device housing wall.

Preferably the system of the present invention is an insecticides and/or insect repellent emanation system .

The reservoir housing wall(s) adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means may substantially fill said aperture(s), and preferably said wall(s) fills said aperture(s). This arrangement may be advantageous as it further discourages child tampering due to yet further decreased visual and tactile stimuli that may encourage a child to attempt to remove the refill from the device. This arrangement is further advantageous as the filled aperture(s) resists a child potentially trying to insert a finger or other object into the interior of the device. This latter advantage is particularly important in countries where the electrical sockets do not have an accompanying on/off switch resulting in the device being in an operational mode whenever it is connected to the socket which poses risks of burning should contact be made with the heater and electrical shock if contact is made with electricity carrying wiring within the device. Indeed, when the system is an insecticides and/or insect repellent emanation system the heater must operate at a temperature >150°C (i.e. at a temperature much higher than required for emanating an air freshening composition which typically operate at a temperature of ~70-80°C) and, thus, the risk of burning is much greater.

The device housing preferably comprises a rear wall to which the plug pins are connected, a front wall and side walls therebetween to connect the front wall to the rear wall. The refill aperture is preferably located in the side wall. Most preferably the size of the refill aperture is an area which is less than 50% of the surface area of the front wall, and more preferably the size of the refill aperture is an area which is less than 35% of the surface area of the front wall, and even more preferably the size of the refill aperture is an area which is less than 25% of the surface area of the front wall. It may be advantageous to locate the refill aperture in a side wall of the device housing and to keep the size of the refill aperture small relative to the size of the front wall of the device housing as these properties both serve to minimise the likelihood that a child would realise that the device contains a releasable refill therewithin. The refill is preferably of a shallow elongate cuboid shape, wherein the elongate section is at least 3 times greater than its depth. This shape of refill is particularly advantageous when the refill aperture is located in the side wall of the device housing as aperture will necessarily be narrow due to the shallow nature of the refill and, thus, further reduce the likelihood of a child attempting to insert their finger or another object inside the aperture.

Preferably the refill is provided with a refill carrier member that connects to the reservoir housing to support the wick which may assist in preventing the wick from being damaged on insertion into the device. Preferably the carrier member surrounds a portion or portions of the reservoir housing wall adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means such that the portion or portions of reservoir housing wall and the carrier member are substantially contiguous with each other and substantially contiguous with the adjacent device housing wall(s). The at least one substantially contiguous portion of reservoir housing and carrier member adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means may substantially fill said aperture(s), and preferably said substantially contiguous portion of reservoir housing and carrier member fills said aperture(s).

Alternatively the carrier member may surround the reservoir housing wall(s) adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means such that the carrier member(s) is substantially contiguous with the adjacent device housing wall(s). The at least one substantially contiguous carrier member adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means may substantially fill said aperture(s), and preferably said substantially contiguous carrier member fills said aperture(s). The carrier member preferably covers the side of the wick adjacent to the heater when the refill is located within the device to act as a heat shield against any direct contact between the heater and the wick, thus improving the safety of operation.

The refill preferably comprises engagement means to engage with the refill receiving means, said engagement means may form a part of, or be connected to, one or more of the reservoir walls or may, if present, be formed in or connected to the carrier member. Preferably the engagement means are formed in the carrier member.

The refill receiving means are preferably provided by a refill chassis that supports one or more parts of the refill and/or carrier member when engaged therewith. Preferably the chassis at least partially surrounds and even more preferably substantially completely surrounds the refill and/or carrier member when engaged therewith whilst having one or more vent holes to permit vaporised volatile liquid to escape therefrom. Most preferably the chassis is provided with at least two windows, wherein one window acts as a vent to permit the escape of volatilised liquid therefrom and wherein the other window is located adjacent the heater to permit the heat to more efficiently transfer from the heater to the wick.

The device housing preferably is provide with at least 2 vent holes to promote a flow of air through the device to better emanate the volatile liquid and reduce the formation of condensed volatile liquid within the device housing. According to a second aspect of the present invention there is provided therefore a volatile liquid emanation device for a replaceable refill of liquid insecticides and/or insect repellent, wherein the device comprises:

a device housing having walls containing a heater and refill receiving means, the device further comprising plug pins, and wherein the device housing comprises at least one vent hole and at least one refill aperture to permit, in use, a refill access to the refill receiving means;

and wherein the refill receiving means releasably hold the refill within the device housing such that the reservoir housing wall(s) adjacent the refill aperture(s) is substantially contiguous with the adjacent device housing wall(s). According to a third aspect of the present invention there is provided therefore a refill of volatile liquid for a volatile liquid emanation device:

wherein the refill comprises a reservoir housing having walls containing a liquid reservoir of volatile liquid and a wick extending from the interior of the reservoir to the exterior thereof and wherein the refill is sized to fit substantially completely within a device housing such that the reservoir housing wall(s) adjacent a refill aperture(s) is substantially contiguous with the adjacent device housing wall(s).

The refill may be further provided with a refill carrier member that connects to the reservoir housing to support the wick.

In a most preferred arrangement the refill engagement means are formed via a resilient lug which engages with a corresponding protrusion in the refill receiving means The refill is preferably of a shallow elongate cuboid shape, wherein the elongate section is at least 3 times greater than its depth. This shape of refill is particularly advantageous when the refill aperture is located in the side wall of the device housing as aperture will necessarily be narrow due to the shallow nature of the refill and, thus, further reduce the likelihood of a child attempting to insert their finger or another object inside the aperture.

The carrier member preferably covers the side of the wick adjacent to the heater when the refill is located within the device to act as a heat shield against any direct contact between the heater and the wick, thus improving the safety of operation.

Any of the features described herein may be combined with any of the above aspects in any combination.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the following drawings in which:

Fig. 1 shows a perspective view of an exploded emanation device absent a refill;

Fig. 2 shows a perspective view of an emanation device with a refill;

Fig. 3 shows a perspective view of an emanation device with a refill engaged with a mains electrical socket;

Fig. 4 shows a front view of a refill of volatile liquid;

Fig. 5 shows a side view of a refill of volatile liquid; and

Fig. 6 shows a side view of a refill of volatile liquid. Description of an Embodiment

Figs.1 -3 show several views of an emanation device 2 according to the present invention and reference will be made to each of these figures in describing same. The device 2 is made up of a housing 8 which has plug pins 12 mounted on a rear wall 15 of the housing, the plug pins 12 being arranged to engage with a mains electrical socket 31. The device housing 8 contains vent holes 13 which permit a flow of air through the device 2. Electrically connected to the plug pins is a control unit 29 mounted on a PCB, also mounted on the PCB is a light source such as an LED 32. Adjacent the PCB is a heater 10 which is mounted in the device via formations protruding from the device housing 8. The rear wall 15 of the housing is connected to a side wall 17 in which a part of a refill aperture 14 can be seen. Adjacent the refill aperture 14 is the opening to the device's refill receiving means 1 1 which is provided in the form of chassis 20. The chassis 20 is there to support a refill 3 of volatile liquid therein when the device 2 is being used as part of an emanation system 1 . The chassis 20 is provided with two windows 21 , 21 ' in which one window 21 is in alignment with the heater 10 to better permit heat emitted by the heater 10 in use to enter the chassis 20 and the refill 3 held therein. The other window 21 ' is located in the opposing side of the chassis 20 to window 21 and is present to allow vaporised volatile liquid to escape from the chassis 20 and move toward a vent hole 13. In one wall of the chassis 20 is located a set of switch holding formations 34 that hold a switch 30 mounted on a PCB which in electrical communication with the control unit 29. The switch 30 is mounted in the middle of a partially circular track 33 in which a rotatable dial 24 is mounted such that the track 33 operates as a movement guide for the dial 24. A button 28 is mounted adjacent the switch 30 such that when a user depresses the button 28 they will necessarily activate the switch 30. The device housing 8 has a front wall 16 which also has a side wall 17' wherein side wall 17' has the other part of the refill aperture 14. Side walls 17, 17' are fixed together to retain the aforementioned components therewithin.

The refill 3 is made up of a reservoir 4 of volatile liquid 5, preferably an insecticide and/or insect repellent. The reservoir 4 comprises a reservoir housing 6 having walls containing the reservoir 4, a wick 7 is provided which extends from the interior of the reservoir to the exterior thereof. The refill 3 is shown with a carrier member 18 mounted on to the reservoir housing 6. The refill 3 has a shallow elongate cuboid shape, wherein the elongate section is at least 3 times greater than its depth. The carrier member 18 is mounted on the reservoir housing 6 at either elongate end thereof to extend therefrom over the side of the refill through which the wick 7 protrudes to support same. Preferably a top portion 34 of the carrier member 18 covers one side of the wick 7 such that it is located between the wick 7 and the heater 10 to act as a heat shield in use. The top portion 34 extends from one elongate side of the refill where it assists in filling the aperture 14, which is discussed in more detail below, to the remote end of the top portion 34 in a resilient lug 22 is formed. In the side of the top portion 34 of the carrier member 18 facing the wick 7 is a recess 26 and an abutment member 27 for engagement with the dial 24, discussed in more detail below.

As can be seen from Fig.3, when the refill 3 is held within the device 2, the refill 3 is sized to fit substantially completely within the device housing 8 and that the reservoir housing wall 6 and carrier member 18 adjacent the refill aperture 14 is substantially contiguous with the adjacent device side wall 17,17'. As can be seen "substantially contiguous" is understood to mean that when the refill 3 is releasably held by the refill receiving means 1 1 the reservoir wall 6 and carrier member 18 adjacent the refill aperture 14 extend into the aperture but not substantially beyond them such that no part of the refill 3 obviously extends beyond the adjacent side wall 17,17' of the device housing. As can be seen, "substantially completely" is understood to mean that when the refill 3 is releasably held by the refill receiving means 1 1 all of the refill 3 is held within the device housing 6 save for the reservoir wall 6 and carrier member 18 adjacent the refill aperture 14 which extend into the aperture 14 but not substantially beyond it.

The system 1 shown is advantageous because it is more child tamper proof than hitherto known emanation systems. As the refill 3 is substantially completely held within the device housing 8 there is no visual stimulus provided which would encourage interaction with the device 2, such as a bottle of liquid suspended beneath the device 2 as is commonly the case with prior art devices.

Furthermore, as the reservoir wall 6 and carrier member 18 provide a substantially contiguous surface with the device housing sidewall 17,17' adjacent the refill aperture 14, there is no tactile stimulus which would encourage further interaction with the device 2. The resulting substantially contiguous surface, 17,17',6,18 provides no easy tactile purchase surface which would encourage a child to attempt to remove the refill 3 from the device 2. This arrangement is further advantageous as the filled aperture 14 resists a child potentially trying to insert a finger or other object into the interior of the device 2. This advantage is particularly important in countries where the electrical sockets 31 do not have an accompanying on/off switch resulting in the device 2 being in an operational mode whenever it is connected to the socket 31 which poses risks of burning should contact be made with the heater 10 and electrical shock if contact is made with electricity carrying wiring within the device 2. As Figs. 1 -3 show, the device 2 is provided with a single refill aperture 14 however, more than one aperture could be provided without undue burden on the skilled person.

The rotatable dial 24 provides a tamper-proof ejection mechanism which is shown in Fig.1 as being directly connectable to the refill 3 when engaged with the device 2 such that rotation of the dial 24 will effect linear movement of the refill 3 toward the refill aperture 14. Specifically the dial 24 is provided with an elongate member (not shown) which extends into the window 21 ' of the chassis 20 and further into the recess 26 in the carrier member 18. Clockwise rotation of the dial 24 causes the elongate member to contact and subsequently bear against the abutment member 27 wherein continuing clockwise rotation of the dial 24 forces the refill 3 to move in a linear direction away from the chassis 20 and through the refill aperture 14.

Alternatively the dial 24 may be provided with a gearing mechanism (not shown) which directly engages with a corresponding gearing mechanism (not shown) on the refill 3 such that rotation of the dial 24 causes the gears to move the refill 3 linearly toward the refill aperture 14.

To better ensure that the refill 3 remains connected to the device 2 once inserted therein, the refill has engagement means to engage with the refill receiving means 1 1. As shown clearly in Fig. 4 the refill engagement means are formed in the carrier member 18 via a resilient lug 22 which is arranged to engage with a corresponding protrusion (not shown) in the chassis 20. The resilient lug 22 has to be pushed past the protrusion and, in doing so, a user will be provided with an audible click and can feel positive feedback when a recess in the lug 22 engages with the protrusion to know that the refill is correctly engaged with the chassis 20. This arrangement provides the further advantage that a predetermined amount of rotational force must be applied via the dial 24 in order to deform the lug 22 sufficiently to overcome the protrusion and thus make it further child tamper proof.

In use, the control unit 29 is configured to turn the heater only once the button 28 is depressed and the switch 20 turned on, and the control unit is further configured to turn the heater off after a predefined period of time that is equivalent to a period of time that a user would typically sleep for > 7hrs and < 14hrs, and more preferably between > 10hrs and < 13hrs, and most preferably after 12hrs.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1 . A volatile liquid emanation system for comprising an emanation device and a replaceable refill of liquid:

2. A system according to claim 1 , wherein the device is provided with a single refill aperture.

3. A system according to claim 1 or claim 2, the system is an insecticides and/or insect repellent emanation system.

4. A system according to any preceding claim, wherein the reservoir housing wall(s) adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means substantially fill said aperture(s), and said wall(s) fills said aperture(s).

5. A system according to any preceding claim, wherein the device housing comprises a rear wall to which the plug pins are connected, a front wall and side walls therebetween to connect the front wall to the rear wall.

6. A system according to any preceding claim, wherein the refill aperture is located in the side wall.

7. A system according to any preceding claim, wherein the size of the refill aperture is an area which is less than 50% of the surface area of the front wall, and more preferably the size of the refill aperture is an area which is less than 35% of the surface area of the front wall, and even more preferably the size of the refill aperture is an area which is less than 25% of the surface area of the front wall.

8. A system according to any preceding claim, wherein the refill is of a shallow elongate cuboid shape, wherein the elongate section is at least 3 times greater than its depth.

9. A system according to any preceding claim, wherein the refill is provided with a refill carrier member that connects to the reservoir housing to support the wick.

10. A system according to claim 9, wherein the carrier member surrounds a portion or portions of the reservoir housing wall adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means such that the portion or portions of reservoir housing wall and the carrier member are substantially contiguous with each other and substantially contiguous with the adjacent device housing wall(s).

1 1 . A system according to claim 10, wherein the at least one substantially contiguous portion of reservoir housing and carrier member adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means substantially fill said aperture(s), and preferably said substantially contiguous portion of reservoir housing and carrier member fills said aperture(s).

12. A system according to claim 10, wherein the carrier member surrounds the reservoir housing wall(s) adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means such that the carrier member(s) is substantially contiguous with the adjacent device housing wall(s).

13. A system according to claim 12, wherein the at least one substantially contiguous carrier member adjacent the refill aperture(s) when the refill is releasably held by the refill receiving means substantially fills said aperture(s), and preferably said substantially contiguous carrier member fills said aperture(s).

14. A system according to any of claims 9-13, wherein the carrier member preferably covers the side of the wick adjacent to the heater when the refill is located within the device to act as a heat shield against any direct contact between the heater and the wick.

15. A system according to any of claims 9-14, wherein the refill comprises engagement means to engage with the refill receiving means, said engagement means form a part of, or are connected to, one or more of the reservoir walls or, if present, are formed in or connected to the carrier member.

16. A system according to any preceding claim, wherein the refill receiving means are preferably provided by a refill chassis that supports one or more parts of the refill and/or carrier member when engaged therewith.

17. A system according to claim 16, wherein the chassis at least partially surrounds and even more preferably substantially completely surrounds the refill and/or carrier member when engaged therewith whilst having one or more vent holes to permit vaporised volatile liquid to escape therefrom.

18. A volatile liquid emanation device for a replaceable refill of liquid insecticides and/or insect repellent, wherein the device comprises:

and wherein the refill receiving means releasably hold the refill within the device housing such that the reservoir housing wall(s) adjacent the refill aperture(s) is substantially contiguous with the adjacent device housing wall(s).

19. A refill of volatile liquid for a volatile liquid emanation device:

20. A refill according to claim 19, wherein the refill is provided with a refill carrier member that connects to the reservoir housing to support the wick.

21 . A refill according to claim 19 or claim 20, wherein the refill comprises engagement means to engage with the refill receiving means, said engagement means form a part of, or is connected to, one or more of the reservoir walls or, if present, are formed in or connected to the carrier member.

22. A refill according to any of claims 19-21 , wherein the refill engagement means are formed via a resilient lug which engages with a corresponding protrusion in the refill receiving means

23. A refill according to any of claims 19-22, wherein the refill is of a shallow elongate cuboid shape, wherein the elongate section is at least 3 times greater than its depth.

24. A refill according to any of claims 19-23, wherein the carrier member covers the side of the wick adjacent to the heater when the refill is located within the device to act as a heat shield against any direct contact between the heater and the wick.