US3871815A

US3871815A - Candle for producing a colored flame

Info

Publication number: US3871815A
Application number: US441349A
Authority: US
Inventors: Jean Cangardel
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-03-08
Filing date: 1974-02-11
Publication date: 1975-03-18
Anticipated expiration: 1992-03-18
Also published as: DE2364506A1; GB1405230A; FR2220579B1; FR2220579A1

Abstract

A candle for producing a colored flame. The candle is formed of a central rod made of metaldehyde embedded in a body made of a mixture of stearic acid and a metal stearate which imparts the desired color to the candle flame. The central rod preferably has a polygonal (e.g., square) cross-section and guides a cup-like member at the top of the candle that improves the uniformity of burning.

Description

United States Patent [191 Cangardel [451 Mar. 18, 1975 CANDLE FOR PRODUCING A COLORED FLAME [76] Inventor: Jean Cangardel, Saint Front sur Lemance, 47500 Fumel, France [22] Filed: Feb. 11, 1974 [21] Appl. No.: 441,349

[30] Foreign Application Priority Data Mar. 8, 1973 France 73.08409 [52] U.S. Cl 431/126, 44/75, 431/293 {51] Int. Cl. Cllc 5/00 [58] Field of Search 431/126, 288, 293; 44/75 [56] References Cited UNITED STATES PATENTS 2.092.,471 9/1973 Pomije 431/293 3586473 6/1971 Galloway 431/126 3,630,697 12/1971 Duling 44/7.5

FOREIGN PATENTS OR APPLICATIONS 1,059,605 6/1959 Germany 1. 44/7.5

Primary Examiner-Edward G. Favors Attorney, Agent, or FirmBrumbaugh, Graves, Donohue & Raymond [57] ABSTRACT A candle for producing a colored flame. The candle is formed of a central rod made of metaldehyde embedded in a body made of a mixture of stearic acid and a metal stearate which imparts the desired color to the candle flame. The central rod preferably has a polygonal (e.g., square) cross-section and guides a cup-like member at the top of the candle that improves the uniformity of burning.

13 Claims, 2 Drawing Figures CANDLE FOR PRODUCING A COLORED FLAME BACKGROUND OF THE INVENTION The present invention relates to candles for use in decorative lighting. More particularly, this invention concerns candles which produce a colored flame.

Candles of the aforementioned kind giving a colored flame are disclosed in my French Pat. No. 72 42287, filed Nov. 28, 1972. These candles comprise a rod made of a mixture of metaldehyde and a suitable metal compound for imparting the desired color to the candle flame. The sides of the rod are surrounded by a wax or stearin casing.

The candles disclosed in said French Patent Application have a disadvantage in that it is difficult to obtain uniform combustion from one candle end to the other. If the stearin casing uncovers the metaldehyde rod on one side more than the other, this unbalance tends to be accentuated by the flow of melted stearin downwards at this point. There is therefore a risk of forming channels along which the rod burns at the sides. Furthermore, it is difficult to obtain a uniform composition for charging the meltaldehyde rod with a metal salt.

SUMMARY OF THE INVENTION An object of the present invention is to provide a candle giving a colored flame which is easy to manufacture, which provides a uniform color and which burns uniformly from one end to the other.

This object, as well as other objects which will become apparent from the discussion that follows, is achieved, according to the present invention, by providing a central rod of substantially pure metaldehyde and surrounding this rod with a fusible body made of a composition that includes stearic acid. The metaldehyde rod therefore acts as a wick for the candle and yields a blue flame. Flames of various other colors may be obtained in accordance with the invention by mixing a metal stearate in the composition of the body. The metal stearate is preferably mixed in such proportion as to comprise 5 to percent by volume of the body composition.

Instead of a pure metaldehyde rod, it is also possible to provide a rod made ofa mixture of metaldehyde and paraformaldehyde provided that the proportion of metaldehyde is at least 70 percent by volume.

The fusion temperature ofthe body composition may be controlled by including paraffin (i.e., paraffin wax") in the composition. The greater the proportion of paraffin. the lower will be the fusion temperature of the composition and, consequently, the higher will be the rate of burning. Preferably, the proportions of steuric acid. paraffin and metal stearate (if used) in the body composition are so determined that the fusion temperature of the composition lies in the range of 50 to 65 C. This range of fusion temperatures results in a convenient rate of burning.

In order to prevent non-uniform combustion due to excessive melting of the body composition on one side of the candle. means are provided at the top ofthe candle. in accordance with the present invention, to control the position and flow of the melted portion of the body composition. Preferably, this means is constructed as a cup-like member including a conical collar which slopes gently downward towards the exterior of the candle body and extends beyond the outer periphery of the body, and a central sleeve which surrounds and is guided by the rod. If the rod is formed with a polygonal (e.g., square) cross section. the central sleeve may be made cylindrical and be guided along the longitudinal (vertical) edges of the rod. The cup-like member is preferably made of thinfheatconducting metal. As the candle burns, the composition of the body in intimate contact with the heated cup-like member melts and makes contact-with the rod in the interstices between the sides of the rod and the cylindrical sleeve, thus enabling the metal stearate to come in contact with the rod and impart the desired color to the flame.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the present invention will now be described in connection with FIGS. 1 and 2 of the drawing. Identical elements in FIGS. 1 and 2 are designated with the same reference numerals.

As the figures show, the candle essentially comprises a central rod 1 having a square cross-section. The rod 1 is encased along substantially its entire length ina 'body 2. The cross-sectional shape of the body 2 may be circular, as shown in FIG. 2, or may be any other shape as is conventional in the candle-making art.

According to the present invention, the central rod 1 is preferably made of essentially pure metaldehyde.

, Metaldehyde is a solid substance which is a trimeric of acetaldehyde, or ethylic aldehyde. The complete formula of metaldehyde is wherein each CH is substituted in a meta position.

Instead of a pure metaldehyde rod, it is also possible to provide a rod made ofa mixture of metaldehyde and paraformaldehyde provided that the proportion of metaldehyde is at least percent by volume. That is, the rod mixture may consist of 70 to percent metaldehyde combined with 30 to 0 percent paraformaldehyde.

The body 2 of the candle is made of a composition which includes stearic acid, also known as stearin or stearine. In order to lower the fusion temperature of the composition, and thus increase the rate of burning,

it may be desirable to add paraffin sometimes called paraffin wax to the composition. In particular, it

has been found that a mixture of stearic acid and paraffin giving a fusion temperature in the range of 50 to 65 C yields a convenient rate of burning.

Thus, the composition of the body 2 can include stearic acid alone (the burning rate of which is relatively low) or a mixture of stearic acid and paraffin. Paraffin cannot be used alone because the burning rate of the candle would be excessive.

In addition to stearic acid and paraffin. the composition of the body 2 may include a suitable metal stearate for imparting the desired color to the flame. If a metal stearate is used, it is suggested that it be added to the composition of the body 2 so that it comprises to I57! by volume of the composition.

By way of example, a decorative green color is obtained with copper stearate, whereas lithium stearate imparts a red color and sodium stearate imparts a yellow color to the flame. In the absence of a metal stearate. the metaldehyde rod will burn with a natural blue flame. Depending upon the stearate used and the desired color intensity. the content of the composition of the body 2 can be adjusted in the proportions indicated. Alternatively, of course. a number of stearates can be mixed in order to add colors, but many other stearates are likewise capable of giving the other colors of the spectrum.

In order to ensure that the candle burns uniformly a cup-like member 3 is disposed at the top of the candle. in accordance with the invention. the cup comprising a conical outer portion 4 forming a collar sloping gently downwards towards the exterior and extending beyond the outer periphery of the body 2. The slope of the collar 4 may be about for example. although this value is not critical. and the outer edge 5 of the collar may advantageously extend l to 2 mm beyond the outer surface of the body 2.

The cup assembly 3 also comprises a central cylindrical sleeve 6 of such diameter that the assembly can slide and be guided along the vertical edges 7 of the rod 1, thus preventing the collar from tilting.

By way of example. the cross-section of the rod 1 may advantageously be a square having 12 mm sides. The rod is embedded in a cylindrical body 2 which may be 28 mm in diameter. The collar 4 may have an external diameter of 32 mm and its sleeve 6 may have an internal diameter of 17.5 mm. The cup assembly 3 may be made of a single piece of thin sheet metal. such as copper. brass or aluminum. which is a good conductor of heat. For example, the sheet metal may be 0.02 mm thick.

When the candle is burning. the cup assembly 3 is heated by the flame 8, melting and penetrating into the body 2. In each of the spaces or interstices 9 between a flat surface of the rod 1 and the inner surface of the cylindrical sleeve 6, melted composition containing the metal stearate accumulates in contact with the rod 1 and is vaporized by the base of the flame, liberating products which help to supply the flame and to produce its color.

At the same time. the sleeve 6 is guided on the vertical edges 7 of the rod 1, the melting point of which is at or approximately 380 and which is consequently always solid in the region affected by sleeve 6. Accordingly, the cup assembly 3 is guided by the rod 1 so that its edge 5 is always exactly horizontal, and any excess of melted material flows off the edge 5 of the cup 3 without forming a pad that would prevent the descent of the cup.

' As a result, the candle combustion is uniform and occurs under the same conditions whenever the candle is burning. The color of the flame is always uniform since the stearates used are uniform fusible substances which mix intimately and perfectly in all proportions with the stearic acid to which they are added.

If it is desired to manufacture candles. according to the invention, which produce a flame that varies in color during combustion as described in my French Patent application referred to above, the metaldehyde rod 1 can be molded in a body 2 comprised of successive layers of a mixture of stearic acid and the stearates giving the desired colors. The manufacture of such candles is much easier than in the case where the composition of the rod itself has to vary along its length.

Although the present invention has been described with reference to a preferred embodiment thereof. it will be understood that the invention is susceptible to various modifications, changes and adaptations as will occur to those skilled in the art. It is therefore intended that the scope of the present invention be limited only by the following claims and their equivalents.

I claim:

1. A candle for producing a colored flame compris' mg:

a. a central rod made of at least percent metaldehyde;

b. a body surrounding said rod and made ofa compo sition including stearic acid.

2. The candle defined in claim 1, wherein said rod is made of a mixture containing. by volume. 70 to percent metaldehyde and 30 to 0 percent paraformaldehyde.

3. The candle defined in claim 1, wherein said rod is made of substantially pure metaldehyde.

4. The candle defined in claim 1, wherein said composition includes a metal stearate for giving the candle flame the desired color.

5. The candle defined in claim 4, wherein the proportion of said metal stearate in said composition is 5 to 15 percent by volume.

6. The candle defined in claim 1, wherein said composition includes paraffin for lowering the fusion temperature of said body.

7. The candle defined in claim 6, wherein the proportion of said paraffin in said composition is chosen such that said fusion temperature lies in the range of 50 to 8. The candle defined in claim 1, further comprising means disposed at the top of the candle for causing said composition to melt uniformly at the exterior of said body.

9. The candle defined in claim 8, wherein said means includes a collar surrounding said rod for directing said composition, in the liquid state, away from said body.

10. The candle defined in claim 8, wherein said means is a cup-like member including a conical collar sloping gently downward towards the exterior of said body and extending beyond the outer periphery of said body. and a central sleeve surrounding and guided by said rod.

11. The candle defined in claim 10, wherein said rod has a polygonal cross-section and said sleeve is cylindrical and has a diameter such that it is centered and guided by the longitudinal edges of said polygonal rod.

12. The candle defined in claim 11, wherein said rod has a square cross-section.

13. The candle defined in claim 8, wherein said means is made of thin. heat-conducting metal.

Claims

1. A CANDLE FOR PRODUCING A COLORED FLAME COMPRISING: A. A CENTRAL ROD MADE OF AT LEAST 70 PERCENT METALDEHYDE; B. A BODY SURROUNDING SAID ROD AND MADE OF A COMPOSITION INCLUDING STEARIC ACID.

2. The candle defined in claim 1, wherein said rod is made of a mixture containing, by volume, 70 to 100 percent metaldehyde and 30 to 0 percent paraformaldehyde.

7. The candle defined in claim 6, wherein the proportion of said paraffin in said composition is chosen such that said fusion temperature lies in the range of 50* to 65* C.

8. The candle defined in claim 1, further comprising means disposed at the top of the candle for causing said composition to melt uniformly at the exterior of said body.

10. The candle defined in claim 8, wherein said means is a cup-like member including a conical collar sloping gently downward towards the exterior of said body and extending beyond the outer periphery of said body, and a central sleeve surrounding and guided by said rod.

13. The candle defined in claim 8, wherein said means is made of thin, heat-conducting metal.