AU721801B2 - Essential oil evaporator - Google Patents

Description

This invention relates to essential oil evaporators, and in particular relates to essential oil evaporators in which the essential oil is heated by a naked flame.

Essential oil evaporators are used to perfume and/or humidify the air. The purpose of such devices is to provide a pleasant or interesting scent to the air, which may also have positive effects on a person's physical and/or mental state.

Conventionally, such evaporators take the form of a one piece body, usually of a ceramic material, foe example vitreous china, stoneware, porcelain, pottery or terracotta material, having a concave bowl at the top, and an aperture permitting access to the interior of the evaporator, to allow the positioning of a heat source on the base of the evaporator, beneath the bowl.

An alternative evaporator has a two piece structure with a base, in which a heat source may be located, and which has appropriate access and vent holes. The base is designed such that a small bowl to hold an essential or fragrant oil may be placed on top of it.

15 The heat source heats the bowl, into which essential or fragrant oils are poured, either alone or with water. Such a heat source may be referred to as a candle, although the currently most preferred form of candle is referred to as a "tea light". Tea lights comprise an aluminium tub in which is located a solid (at room temperature) fuel in which is located a wick. When the wick is lit, at least part of 20 the solid fuel liquefies, supplying fuel to the wick. Other sources of heat may include a candle, such as a paraffin wax candle or an oil burner.

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S" While prior art evaporators function adequately, there are serious concerns about their safety. In recent times in Australia, numerous dwelling fires have been caused by burning candles, those fires resulting in some fatalities. There is anecdotal evidence that at least some of those fires have been caused by candles used in essential oil evaporators.

If a conventional oil evaporator in use is knocked over, the heat source will also AA be knocked over, and as a result it may ignite other material in the immediate area of the evaporator. In addition, some tea lights can reach a flashpoint, at which point the liquefied fuel may ignite in a flare. In such a situation the burning fuel may run from the aluminium tub and ignite nearby material, particularly if the access opening does not have a lip.

Conventional evaporators have other disadvantages. Many models have only small access openings through which insertion, lighting and removal of a candle may take place. Such operations may as a result be quite clumsy. Furthermore, many conventional evaporators have bowls which only hold a small quantity of oil or a mixture of oil and water, for example 50ml. As many candles or tea light last up to 8 or 9 hours, the fluid in the bowl must be topped up several times during the burning time of such a candle. This would not be necessary if the bowl were made larger, but the heating capacity of prior art evaporators is not adequate to bring the fluid in a larger bowl to the temperature required to release scent particles from the oil.

It is an object of this invention to provide an essential oil evaporator which attempts to overcome at least some of the disadvantages of the prior art.

o* The invention provides heating apparatus for heating a substance with a heat asource, said apparatus including a base and a main body portion, said main body a 20 portion being hollow and being adapted to be located on said base, said main abody portion including or being adapted to support a receptacle for said substance, said apparatus functioning such that in use said heat source is :•:located on said base, and said main body portion is located on said base such l athat heat source is surrounded by said main body portion, the heat from said heat source, when said heat source is ignited, being capable of heating said receptacle, and, in turn, said substance, characterised by a safety feature in which said main body portion is adapted to separate from said base when said main body portion is subject to a force of a strength generally sufficient to overturn said heating apparatus, said base and said heat source remaining in place in the event that said body portion separates from said base, and in which S ~zI\said base is adapted to retain a predetermined amount of a fire-retardant fluid, such that in use said fluid surrounds said heat source.

The invention also provides an essential oil evaporator, said evaporator including a base and a main body portion, said base and said main body portion being S. S

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*55555 S S WO 97/17996 PCT/AU96/00710 3 separable, said base being adapted to retain a predetermined amount of water therein, and further being adapted to locate a heat source thereon, said main body portion being adapted to be located on said base, and having a bowl located thereon, said bowl being adapted to receive a predetermined amount of essential oil or a mixture of water and essential oil, said main body portion being open at one end, said open one end being adapted to locate, in use, on said base, said evaporator functioning, in use, such that said heat source is surrounded by water.

In the description and claims of this specification, the terms "candle" and "heat source" are intended to describe a heat source which burn with a naked flame, and includes such items as candles, oil burners and tea lights.

In the description and claims of this specification, the term "essential oil" is intended to describe any substance which when heated releases fragrance, scent or the like, or any humidifying substance or any insecticide or substance which repels insects.

An embodiment of the invention will be described in detail hereinafter, with regard to the accompanying drawings, in which: Fig. 1 is an exploded perspective view of an essential oil evaporator in accordance with an embodiment of the invention; Fig. 2 is a sectional view through the evaporator of Fig. 1; Fig. 3 is a front elevation of part of the evaporator of Fig. 1; and Fig. 4 is a rear elevation of the evaporator of Fig. 1.

Referring firstly to Fig. 1, the essential oil evaporator 10 of one embodiment of the present invention includes a base 12 and a main body portion 14.

WO 97/17996 PCT/AU96/00710 4 Base 12 has the general shape of a saucer, with a circumferential lip 16 surrounding a generally flat surface 18. On surface 18 there are located three radial ribs 20, 22 and 24, which preferably do not extend from lip 18 to the centre of base 12, but leave a clear area 26 around the centre. Preferably, the ribs 22, 24 are located equidistantly 1200 apart -around surface 18, and the inner ends thereof may have pronounced ends against which a candle 48 may rest when located on the aforementioned clear area of surface 18. The ribs 20, 22, 24 are preferably integral with base 12.

Main body portion 14 includes a waisted tubular section 28 surmounted by a bowl 30 at one end and an opening 32 to section 28 at the other end. As an example, the diameter of opening 32 may be about 75mm. Notches 34, 36 and 38, only one of which is shown in Fig. 1, are located in the material of section 28, in the lower wall of section 28. The notches 34, 36, 38 are preferably located equidistantly (at 1200 to each other) around the opening 32, such that they are able to register with ribs 20, 22, 24 when main body portion 14 is located on base 12. The notches 34, 36, 38 are preferably substantially semicircular, and when main body portion 14 is on base 12, they allow the passage of water the use of which will be discussed hereinafter therethrough.

Waisted tubular section 28 is provided with main openings 40, 42, 44, 46, only three of which (40, 42, 46) are shown in Fig.l. These main openings allow, in use, a candle 48 in the evaporator 10 to be observed, for example to ascertain whether the candle 48 is burning or not, and/or may be used to light the candle 48. In a preferment, the main openings may be of differing shapes. Opening (Figs. 1 and 2) is square, openings 42 (Fig. 46 (Fig. 3) are oval, and opening 44 (Fig. 4) is triangular. The main openings may be of any size or shape, and the number of openings and any mix of shapes may be varied. In the illustrated embodiment, the openings 40, 42, 44 and 46 are located about 30mm from the opening 32 of waisted section 28.

Section 28 may also have upper vent holes 50, 52 (Figs. 1 and 54 (Fig. 4) and 56 (Fig. which are located close to bowl 30 and provide exits for the WO 97/17996 PCT/AU96/00710 rising heated air and combustion gases from a lit candle 48. The upper vent holes (50, 52. 54, 56) and the main openings (40, 42, 44, 46) may, apart from having a practical purpose, be provided with a particular decorative shape.

Exemplary shapes shown on the drawings are a triangle, a rectangle and an oval, but any other shape may be contemplated.

The candle 48 is a tea light having an aluminium tub 58, in which is located solid fuel 60, with a wick 62 positioned in the solid fuel In use, the tea light 48 or equivalent heat source is located on surface 18 of base 12. Preferably, the ribs 20, 22, 24 are located, as has been previously described, such that a heat source 48 may be securely located between their inner ends. Water or any other suitable fluid which may act as a fire retardant is poured into base 12, to a level such that when main body portion 14 is located on base 12 a seal is created between the water and the main body portion.

The tea light 48 may then be lit. The bowl 30 of main body portion 14 is filled to about 75% capacity with warm water. The main body portion is then located on base 12, such that recesses 34, 36, 38 interlock with ribs 20, 22, 24 to register the body 14 on base 12. It may be noted that in the "in use" position of the main body portion 14, the recesses or notches 34, 36, 38 allow water in base 12 to migrate through the notches between the interior of main body portion 14 and the exterior. Such interlocking provides stability to the evaporator 10. Five to ten drops of an essential oil are then added to the water in bowl The heat from the burning candle 48 heats bowl 30, and its contents. After a time, the oil/water mix reaches a temperature such that evaporation of the essential oil takes place, releasing the evaporated oil into the atmosphere of the room where the evaporator 10 is situated.

The water seal between the water in base 12 and the lower portion of main body portion 14 is believed to facilitate greater heating efficiency of the evaporator In this way, the bowl 30 may be larger than in the prior art, and yet the WO 97/17996 PCT/AU96/00710 6 evaporator will still function effectively. As has been stated, prior art evaporator bowls have a capacity of about 50ml. The evaporator 10 of the described embodiment of the present invention may have a bowl of some 150mm in diameter, with a fluid capacity of 250m1.

With the arrangement of the described embodiment of the present invention, if the main body portion 14 is knocked over, the base 12 will remain in position, and the candle 48 remains in position on the base 12. If the candle 48 is tipped over, any liquid fuel will be contained in the base 12. Furthermore, the provision of water in base 12 keeps the heat source cool and thus minimises the chances of the heat source flaring. Accordingly, it can be seen that the described embodiment of the present invention is a much safer essential oil evaporator than those of the prior art, and would greatly diminish, if not eliminate, the possibility of such evaporators leading to domestic or other fires.

The embodiment is also an improvement on the prior art in that as the base 12 remains cool, the evaporator 10 may be comfortably carried by the base 12. At the same time, the evaporator 10, when in use, may be placed on a surface without the possibility of the surface being damaged by heat from the evaporator.

The components 12, 14 of the evaporator 10 may be constructed by any known method, such as casting, moulding, hand fabrication or the like, and from materials such as those mentioned in relation to prior art evaporators, as well as polymers, composites, metals or ceramics. Fabrication from ceramic material may involve slip casting or hand potting, followed by glazing and firing.

In an alternative embodiment, the evaporator 10 may be made in three parts.

With such an arrangement, the bowl 30 is separate from the main body portion 14, and in use is adapted to be located on the main body portion. Another embodiment may involve the bowl 30 being somewhat smaller than discussed earlier in this specification.

In other possible embodiments, the ribs 20, 22, 24 on base 12 are omitted, and WO 97/17996 PCT/AU96/00710 7 the base 12 could have no protrusions at all. The base 12 may have a single protruding ring part with cut-outs to allow the passage of water. Any protruding arrangement or recess may be employed without diverging from the object of the invention. Location of the candle 48 or main body portion 14 may also be by mechanical means.

It should also be noted that the shape, number and position of the apertures 42, 44, 46, 50, 52, 54 and 56 may be varied from those shown in the drawings.

It can be seen that this invention provides an improved, safer essential oil evaporator.

The claims form part of the disclosure of this specification.

Claims (14)

1. Heating apparatus for heating a substance with a heat source, said apparatus including a base and a main body portion, said main body portion being hollow and being adapted to be located on said base, said main body portion including or being adapted to support a receptacle for said substance, said apparatus functioning such that in use said heat source is located on said base, and said main body portion is located on said base such that heat source is surrounded by said main body portion, the heat from said heat source, when said heat source is ignited, being capable of heating said receptacle, and, in turn, said substance, characterised by a safety feature in which said main body portion is adapted to separate from said base when said main body portion is subject to a force of a strength generally sufficient to overturn said heating apparatus, said base and said heat source remaining in place in the event 15 that said body portion separates from said base, and in which said base is too. adapted to retain a predetermined amount of a fire-retardant fluid, such ti :to* that in use said fluid surrounds said heat source. o I *9°

2. Heating apparatus according to claim 1, wherein said receptacle is located t°oo or locatable at one end of said main body portion, and the other end of 20 said main body portion is open. too.

3. Heating apparatus according to claim 1 or claim 2, characterised in that .9 said base has a generally planar surface, surrounded by an upraised lip.

4. Heating apparatus according to any preceding claim, characterised in that said base and said main body portion are each provided with means facilitating the location of said main body portion on said base. Heating apparatus according to claim 4, characterised in that said means 9consists of at least one rib located on one of said base and said main /s b ndbody portion, and at least one recess in the other of said base and said main body portion.

6. Heating apparatus according to claim 5, characterised in that said at least one rib is located on said base, and said at least one recess is in said main body portion, at or near said one end.

7. Heating apparatus according to claim 6, characterised in that there are three ribs, and three corresponding recesses.

8. Heating apparatus according to claim 6 or 7, characterised in that said base is generally circular, in that said ribs extend generally radially from said lip towards the centre of said base, and in that said ribs extend only partially towards said centre, the space between the inner ends of said ribs being adapted to receive and retain against lateral movement a heat source.

9. Heating apparatus according to any preceding claim, characterised in that isaid main body portion is provided with at least one aperture, through which it may be observed whether said heat source is or is not alight.

10. Heating apparatus according to any preceding claim, characterised in that at least one vent aperture is provided in said main body portion, proximate said receptacle, in order to provide an outlet for combustion gases and *heated air. :20 11. Heating apparatus according to any preceding claim, characterised in that :d l said main body portion is provided with at least one aperture, through 15which it may be observed whether said heat source is or is not alight. 10. Heating apparatus according to any preceding claim, characterised in that at least one vent aperture is provided in said main body portion, proximate said fre-rceptardacle, in order to provide an outlet for combustion gases and Shen water is located in said base, said water surrounds said heat source, o 20 11, Heating apparatus according to any preceding claim, characterised in that said receptacle and said main body portion are separable.

12. Heating apparatus according to any preceding claim, characterised in that said fire-retardant fluid is water. 3. Heating apparatus according to claim 12, characterised in that in use, t/A when water is located in said base, said water surrounds said heat source, and makes a seal with said other end of said main body portion.

14. Heating apparatus according to any preceding claim, characterised in that said receptacle is a bowl. Heating apparatus according to any preceding claim, characterised in that said substance is an essential oil, or a mixture of an essential oil in water.

16. An essential oil evaporator, said evaporator including a base and a main body portion, said base and said main body portion being separable, said base being adapted to retain a predetermined amount of water therein, and further being adapted to locate a heat source thereon, said main body portion being adapted to be located on said base, and having a bowl located thereon, said bowl being adapted to receive a predetermined amount of essential oil or a mixture of water and essential oil, said main body portion being open at one end, said open one end being adapted to locate, in use, on said base, said evaporator functioning, in use, such that 15 said heat source is surrounded by water. S

17. Heating apparatus substantially as herein described, with reference to the accompanying drawings. o**o* t

18. An essential oil evaporator substantially as herein described, with reference to the accompanying drawings. DATED this 12 May 2000 JOHN CHRISTIANSEN Member, Federation Internationale des Conseils en Propriete Industrielle (International Federation of Intellectual Property Attorneys) Patent Attorney for the Applicants: If PETER WILLIAM DAVEY and AMANDA MARTHA DAVEY