WO2017186641A1

WO2017186641A1 - Candle with a self-extinguishing wick

Info

Publication number: WO2017186641A1
Application number: PCT/EP2017/059657
Authority: WO
Inventors: Vincent KRISTEN
Original assignee: Bolsius International B.V.
Priority date: 2016-04-26
Filing date: 2017-04-24
Publication date: 2017-11-02
Also published as: EP3448972A1; PL416987A1

Abstract

The present invention relates to a candle with a self-extinguishing wick which by itself ceases to burn in the final phase of candle burning. More in particular, the present invention relates to a candle with a self-extinguishing wick, the lower section of which is clamped in a cylindrical holder made of deformable material, wherein the wick holder is at least partially surrounded by a protective sustainer made of high temperature-resistant polymeric material and embedded from the bottom in the matching candle seat, characterized in that the whole wick holder is placed inside the protective sustainer.

Description

CANDLE WITH A SELF-EXTINGUISHING WICK

The present invention relates to a candle with a self-extinguishing wick which by itself ceases to burn in the final phase of candle burning.

EP 1 792 971 discloses a candle with a self-extinguishing wick the lower section of which is clamped in a cylindrical holder made of deformable material. The wick holder comprises two - one placed above the other - partially overlapping and permanently connected portions. The upper, fixing portion of the holder is made of metal, preferably copper. The lower portion of the holder is made of a polymeric material, preferably polypropylene, has a front cavity open towards the bottom of the candle and acts as a protective sustainer, wherein the cavity is filled with plastically deformable material, preferably paraffin or wax. From the bottom, the both sections of the holder are embedded in the properly matching candle seat.

In the known embodiment of the candle, the fixation area for the wick in the metal holder is extended upwards outside the limits of the sustainer, and therefore in the final stage of wick burning this exposed portion of the holder becomes very hot. Consequently, the sustainer and paraffin surrounding the wick are exposed to substantial heat which can result in deformation or melting of the sustainer, and in a second aspect, in melting and liquefaction of paraffin surrounding the wick fixation area. As a result, the sustainer with the wick holder lose their stability and are subject to undesired tilting.

In such a situation, the wick - instead of extinguishing - absorbs the liquid paraffin which fuels the flame and may cause flashover.

WO 03/016443 A shows a wick holder of a non-combustible polymeric material, having a bore into which the wick is inserted, and which allows extinction of the candle flame on the wick when the flame and fuel level reach the wick holder. The disadvantage is that the higher position of the wick alone does not induce sufficient safety for the candle, so that for example a burning without a surrounding container carries an unacceptable risk.

EP 1 054 054 A shows a candle on a plate (display) with a wick holder having a substantially open edge to allow penetration of the bottom end of the wick through the base of the holder such that the distance between the bottom end of the wick and the plate is minimal. This grants for an optimization of the candle performance and achieves as completely as possible wax composition. However, a disadvantage is that the safety is not guaranteed if the candle should operate without a plate, nor does this setup guarantee extinction of the candle flame in due time.

It is an object of the present invention to provide a simple, reliable and efficient way for secure holding one or more self-extinguishing wicks in a candle.

It is a further object of the invention to provide a candle with a self-extinguishing wick without having to compromise or restrict the aesthetic design of the candle.

A candle with a self-extinguishing wick, the lower section of which is clamped in a cylindrical holder made of deformable material, wherein the wick holder is at least partially surrounded by a protective sustainer made of a high temperature resistant polymeric material and embedded from the bottom in the matching candle seat, according to the invention is characterized in that the whole wick holder is placed inside the protective sustainer.

In an embodiment of the invention, the protective sustainer has a cylindrical profile and at the bottom it is terminated in a radial flat flange tightly fitting the candle bottom. Such flat flange ensures sufficient stability to the protective sustainer.

In another embodiment, the upper portion of the protective sustainer has a cylindrical profile, whereas its lower portion has a profile similar to a cone with a front cavity. In order to improve the fixation of the wick holder and its sustainer, at the bottom the holder has an outwardly projecting rim with a conical profile. The wick holder is made of metal, which provides a stable fixation of the lower section of the wick. On the other hand, the holder sustainer is made of a polymeric material resistant to high temperature, such as polycarbonate or modified polyamide.

With the solution according to the invention, wax or paraffin surrounding the fixation area of the wick is not subject to melting since the metal wick holder is effectively insulated from it by means of a protective sustainer made of a high temperature-resistant polymeric material.

Preferably, the upper portion of the protective sustainer extends beyond the top portion of the wick holder. As such, the portion of the wick which extends above the cylindrical wick holder will be shielded only by the upper portion of the protective sustainer so that the flame is kept at a sufficient distance from the wick holder in final stages of wick burning. In this way, the extending portion of the sustainer enhances insulation of the wick holder, and effectively prevents, in a first aspect, heating of the holder, thereby avoiding deformation and melting of the polymeric sustainer, and in a second aspect, melting and liquefaction of neighbouring wax or paraffin. By extension, the extending portion of the sustainer averts undesired tilting of the sustainer and wick holder, and also prevents the wick from absorbing liquid wax or paraffin which fuels the flame. As a result, in the final phase of candle burning, the tightly shielded wick goes out by itself since paraffin is no longer supplied to it. Hence, the extending portion of the sustainer substantially increases the safety during the final stages of wick burning.

More preferably, the wick is held substantially above the candle bottom within the sustainer by the wick holder. In particular, the wick is held above the candle bottom by the wick holder such that the wick does not contact the candle bottom. In this way, the risk of fuelling the wick by capillary effect in the situation that liquid paraffin or wax would be leaked and transported to the sustainer, is reduced.

The inventors have found that an optimal efficacy of a self-extinguishing wick in a candle according to the present invention is strongly dependent on certain dimensions. More in particular, the inventors have tested and determined several dimensional values of components such that an optimal efficacy of a candle with self-extinguishing wick according to the invention is guaranteed.

In an embodiment, 10-50% of the total length of the sustainer, more preferably 15-40% of the total length of the sustainer, and most preferably 20-30% of the total length of the sustainer extends beyond the top portion of the wick holder.

In another or further embodiment, the extending portion of the sustainer extends for 10-60%, more preferably 20-50% and most preferably for 30-40% of the length of the wick holder beyond the top portion of the wick holder.

In another embodiment, the sustainer extends for at least 2 mm beyond the top portion of the wick holder.

In some embodiments, the total length of the sustainer is at least 20% larger than the length of the wick holder. More preferably, the total length of the sustainer is between 20% and 250%, more preferably between 30% and 240%, more preferably between 40% and 230%, and most preferably between 50% and 220% larger than the total length of the wick holder.

In an embodiment, a metal cylindrical wick holder with a length of 6-10 mm is tightly enclosed by a polymeric sustainer with a total length of 9-35 mm. The sustainer comprises a cone-like lower portion with a front cavity, and an upper portion which extends for 1-8 mm, more preferably for 1.5-6 mm, and most preferably for 2-5 mm, such as 3 mm beyond the top portion of the wick holder.

In an embodiment, both the protective sustainer and wick holder have an essentially cylindrical profile, more preferably, the lower portion of the sustainer radially expands towards the bottom of the protective sustainer, for instance either conically or as a flat flange. The upper portion of the protective sustainer has preferably an outer diameter of 3-10 mm, more preferably 4-8 mm and most preferably 5-7 mm. In another or further embodiment, the bottom of the lower portion of the protective sustainer can have an outer diameter of 7-15 mm, preferably 8-12 mm, and most preferably 9-11 mm.

The protective sustainer may comprise walls having a thickness of 0.5-2 mm, and more preferably 1-1.5 mm.

As mentioned above, the inventors have found that at least some of the disclosed dimensions are essential for the optimal efficacy of the self-extinguishing wick of a candle of the present invention.

Description of the figures

The present invention is shown in embodiments illustrated in Figs. 1-10. Embodiments according to the present invention comprise the feature that the protective sustainer extends beyond the top portion of the wick holder.

Fig. 1 shows a vertical cross section of the candle with a self-extinguishing wick according to the present invention and Fig. 2 shows an enlarged sectional view of the lower part of the candle according to Fig. 1.

Figs. 3 and 4 show a variation of the candle depicted in figs. 1 and 2. Fig. 3 shows a vertical cross section of an embodiment of a candle wherein the lower portion of the wick is held in an elevated position by the wick holder, as compared to the wick of the candle illustrated in figs. 1 and 2. Fig. 4 shows an enlarged sectional view of the lower part of the candle according to Fig. 3.

Fig. 5 shows a vertical cross section of an embodiment of a self-extinguishing candle according to the present invention, and fig . 6 shows an enlarged sectional view of the lower part of the candle according to fig 5.

Figs. 7 and 8 illustrate a variation of the candle depicted in figs. 5 and 6. More in particular, fig. 7 shows a vertical cross section of an embodiment of a self-extinguishing candle wherein the lower section of the wick is held at an elevated position by the wick holder, as compared to the wick of the candle illustrated in figs. 5 and 6. Fig. 8 shows an enlarged sectional view of the lower part of the candle according to fig. 7.

Fig. 9 illustrates (a) an embodiment of a sustainer enclosing a wick holder, (b) a vertical cross section of the embodiment, and (c) a top view of the embodiment. Fig. 10 shows (a) another embodiment of a sustainer enclosing a wick holder, (b) a vertical cross section of the embodiment, and (c) a top view of the embodiment.

A candle 12 according to the invention has a self-extinguishing wick 1 the lower section 2 of which is clamped in a cylindrical holder 3 in the form of an easily deformable metal tube, made preferably of copper, zinc coated if necessary. At the bottom, the wick 1 holder 3 has an outwardly projecting rim 4 with a conical profile and it is positioned entirely inside a protective sustainer 5 made of a high temperature-resistant polymeric material, preferably modified polyamide or polycarbonate. From the bottom, the sustainer 5 with the tightly fitting holder 3 are embedded in the properly matching candle seat 6 that is formed in the candle bottom 7. In the embodiment according to figs. 1 and 2, the upper portion 5a of the sustainer 5 has a cylindrical profile, whereas its lower portion 5b has a profile similar to a cone with a front cavity 9. In this embodiment, the wick 1 holder 3 is basically placed in the upper portion 5a of the sustainer 5, whereas the lower section 2 of the wick 1 reaches the candle bottom 7. Opposed thereto, figs. 3 and 4 illustrate an embodiment wherein the lower portion 2 of the wick is clamped above the candle bottom 7 by the wick holder 3, thereby defining a cavity 9 in the sustainer 5. Such feature allows reducing the risk of fuelling the wick 1 by capillary effect in the situation that liquid paraffin or wax would be leaked and transported to the sustainer 5.

As shown in Figs. 5 and 6, the sustainer 5 has a cylindrical profile and at the bottom it is terminated in a radially spread-out, flat flange 8 tightly fitting the candle bottom 7. In the illustrated embodiment, the wick 1 reaches to the bottom 7 of the candle 12.

Figs. 7 and 8 show an embodiment of a self-extinguishing candle wherein the sustainer 5 has a cylindrical profile and at the bottom it is terminated in a radially spread-out, flat flange 8 tightly fitting the candle bottom 7. In the embodiment illustrated in figs. 7 and 8, the wick 1 is clamped in an elevated position by the wick holder 3, and does not reach to the bottom 7 of the candle 12, thereby providing a cavity 9 in the sustainer 5. This prevents that the wick 1 would be fuelled by capillary effect in the situation when liquid paraffin or wax would be leaked and transported to the sustainer 5.

Figs. 9 and 10 are detailed illustrations of preferred embodiments of the sustainer 5 and wick holder 3 as shown in figs. 1 to 4, and figs. 5 to 8, respectively. Fig. 9 illustrates an embodiment according to the present invention, wherein the upper portion 5a of the sustainer 5 has a cylindrical profile, and the lower portion 5b of the sustainer 5 has a conical profile comprising a front cavity. Fig. 10 shows an embodiment of the present invention wherein the upper portion 5a of the sustainer 5 has a cylindrical profile of which the lower portion terminates at the bottom in a radially flat flange 8. In both embodiments of figs. 9 and 10, the upper portion 5a of the sustainer 5 extends beyond the top portion 11 of the wick holder 3, this extending portion 10 of the sustainer 5 enhances insulation of the wick holder 3, thereby preventing heating of the holder 3 which could result in deformation and melting of the sustainer 5, and melting and liquefaction of neighbouring candle material which may serve as fuel. The uppermost or extending portion 10 of the sustainer 5 guarantees in this way a more reliable, safe and efficient extinction of the candle flame in final stages of wick 1 burning.

Figs. 9 and 10 furthermore illustrate the total length a of the protective sustainer 5, the length b of the extending portion 10 of the protective sustainer 5, and the length c of the wick holder 3 placed inside the protective sustainer 5. In addition, the outer di and inner c diameter of the upper portion 5a of the protective sustainer 5, and the outer cb and inner d₄ diameter of the lower portion 5b of the protective sustainer 5 are indicated in fig. 9 and fig. 10.

Reference numeral list

I - wick

2 - lower section of the wick

3 - wick holder

4 - rim of the wick holder

5 - sustainer

5a - upper portion of the sustainer

5b - lower portion of the sustainer

6 - candle seat

7 - candle bottom

8 - flange of the sustainer

9 - cavity in the sustainer

10 - extending portion the sustainer

I I - top portion of the wick holder

12 - candle with self-extinguishing wick a - total length of the sustainer

b - length of extending portion of the sustainer

c - length of wick holder

di - outer diameter of upper portion of the sustainer da - inner diameter of upper portion of the sustainer

d3 - outer diameter of lower portion of the sustainer

d₄ - inner diameter of lower portion of the sustainer

Examples

Example 1

The efficacy of a self-extinguishing candle according to the present invention was evaluated by a comparative experiment. For this purpose, 20 self-extinguishing candles according to the present invention wherein the sustainer extends for 20% of its total length beyond the top portion of the wick holder, 20 candles wherein the top portion of the wick holder extends for 25% of its total length beyond the sustainer (control group 1), and 20 candles wherein the top portion of the wick holder and the top portion of the sustainer are equally levelled (control group 2). The candles of all groups comprised paraffin as burning fuel, and showed equal dimensions. The sustainer and wick holder of the candles of different groups showed equal dimensions, such that the position of the top portion of the wick holder relative to the sustainer was the sole difference between the candles of different groups. The wicks of all tested candles contacted the bottom of the candles.

The wicks of all 60 candles were lit at the same time in room with a minimal amount of air displacement and atmospheric air comprising sufficient levels of oxygen for the candles to completely burn up. Extinction of a candle was therefore independent from its surroundings, and completely relied upon the self-extinguishing feature of the candles. The following parameters were monitored :

(i) occurrence of flashover from the wick to the paraffin ;

(ii) occurrence of leaking of liq uid paraffin during burning of the candle : all candles were placed on separate plates and candles which leaked liquid paraffin onto the plate were counted ;

(iii) occurrence of safe self-extinction : a candle is considered to effectively self-extinct when no leakage or no flashover has occurred prior to self-extinction of the candle;

(iv) occurrence of deformation or melting of the sustainer after self-extinction of the candle : candles which show a deformation or, at least partially, melted sustainer after extinction were counted ; and,

(v) tilting of the sustainer after self-extinction of the candle: after extinction of candles, the angle in which the sustainer was tilted compared to the position of the sustainer prior to burning is measured . Results are summarized in Table 1.

Table 1 - Results from comparative experiment. Candles according to the present invention comprised a sustainer which extends beyond the top portion of the wick holder, whereas candles from control group 1 comprised a wick holder of which the top portion extended above the sustainer, and control group 2 showed candles wherein the top portion of the wick holder is equally leveled with the top portion of the sustainer. Groups of 20 candles were compared with regard to (i) occurrence of flashover; (ii) occurrence of leakage of liquid paraffin; (iii) occurrence of effective self-extinction; (iv) occurrence of deformation or melting of sustainer; and, (v) tilting of the sustainer after self-extinction of the candle

It's clear from the results summarized in table 1 that candles according to the present invention show a substantial increase in the occurrence of safe self-extinction due to the decrease in the occurrence of flashover and leakage during burning of the candle. In addition, candles according to the present invention show a reduced occurrence of deformation of melting of the sustainer and a decrease in the average tilting of the sustainer, thereby reducing the risk of flashover or leakage.

Example 2

Analogously to the experiment in example 1, 20 candles according to the present invention were lit and allowed to self-extinct. In this experiment, all 20 candles belonged to the embodiment of the invention wherein the lower portion of the wick was spaced from the bottom of the candle such that there was no direct contact between the lower portion of the wick and the bottom of the candle. The candles were lit and evaluated for the same parameters as discussed in example 1.

It was observed that all candles showed a safe self-extinction due to the absence of any flashover or leakage. Furthermore, it was found that none of the candles comprised a deformed or melted sustainer. The average tilting remained approximately 3°.

Claims

1. A candle 12 with a self-extinguishing wick 1, the lower section of which is clamped in a cylindrical holder 3 made of deformable material, wherein the wick 1 holder 3 is at least partially surrounded by a protective sustainer 5 made of high temperature-resistant polymeric material and embedded from the bottom in the matching candle seat 6, characterized in that the whole wick 1 holder 3 is placed inside the protective sustainer 5.

2. Candle 12 according to claim 1, characterized in that the protective sustainer 5 extends beyond the top portion 11 of the wick 1 holder 3.

3. Candle 12 according to claim 2, characterized in that the extending portion 10 of the protective sustainer 5 extends for 10-50% of the total length a of the sustainer 5 beyond the top portion 11 of the wick 1 holder 3.

4. Candle 12 according to claim 2 or 3, characterized in that the extending portion 10 of the protective sustainer 5 extends for 10-60% of the length c of the wick holder beyond the top portion 11 of the wick 1 holder 3.

5. Candle 12 according to any one of claims 2-4, characterized in that the extending portion 10 of the protective sustainer 5 extends for at least 2 mm beyond the top portion 11 of the wick 1 holder 3.

6. Candle 12 according to any one of claims 2-5, characterized in that, the total length a of the protective sustainer 5 is between 20% and 250% larger than the total length c of the wick 1 holder 3.

7. Candle 12 according to any one of the previous claims, characterized in that the lower section of the wick is spaced above the candle bottom 7.

8. Candle 12 according to any one of claims 1-7, characterized in that the upper portion 5a of the protective sustainer 5 has a cylindrical profile which at the bottom terminates in a radial flat flange 8 tightly fitting the candle bottom 7.

9. Candle 12 according to any one of claims 1-7, characterized in that the upper portion 5a of the protective sustainer 5 has a cylindrical profile, whereas its lower portion 5b has a profile similar to a cone with a front cavity.

10. Candle 12 according to any one of the previous claims, characterized in that the wick 1 holder 3 has an outwardly projecting rim 4 with a conical profile.

11. Candle 12 according to any one of the previous claims, characterized in that the wick 1 holder 3 is made of metal.

12. Candle 12 according to any one of the previous claims, characterized in that the protective sustainer 5 is made of a high temperature-resistant polymeric material.

13. Candle 12 according to claim 12, characterized in that, the high temperature-resistant polymeric material is selected from the group comprising polycarbonate and modified polyamide.