Multiple candle wick assemblies and methods and appartus for making the same

Abstract

Apparatus for making wax-coated candle wick assemblies are provided within include a wax applicator sized and configured to receive therein a multiple candle wick construction having first and second spaced apart candle wicks and a ladder filament connected to and extending back and forth between the first and second candle wicks so as to establish respective crossing portions that are spaced apart from one another along a lengthwise direction of the wick construction. A forming device is positioned relative to the inlet of the wax applicator channel to assist in folding the candle wick construction about a longitudinal axis thereof and into a generally U-shaped configuration such that conveyance of the candle wick construction through the wax applicator will sequentially fold the candle wick construction into such U-shaped configuration and maintain such U-shaped configuration by the application of wax thereon.

Claims

1. An apparatus for making a wax-coated candle wick assembly comprising: a wax applicator which includes a wax applicator channel having an inlet and an outlet, the wax applicator channel being sized and configured to receive therein a multiple candle wick construction having first and second spaced apart candle wicks and a ladder filament connected to and extending back and forth between the first and second candle wicks so as to establish respective crossing portions that are spaced apart from one another along a lengthwise direction of the wick construction; a forming device positioned relative to the inlet of the wax applicator channel which is sized and configured to assist in folding the candle wick construction about a longitudinal axis thereof and into a generally U-shaped configuration; and a conveyance system which conveys the candle wick construction sequentially into the inlet of the wax applicator channel in operative association with the forming device to thereby cause the crossing portions of the ladder filament to be folded about the longitudinal axis of the candle wick construction and into the generally U-shaped configuration, and then through the applicator channel to allow a wax sheath to be applied therein onto the candle wicks and crossing portions of the ladder filament to thereby maintain the candle wick construction in the generally U-shaped configuration thereof so as to obtain the candle wick assembly.

2. The apparatus according to claim 1, wherein forming device comprises a longitudinally oriented fixed-position forming mandrel, wherein the candle wick assembly may be folded about the forming mandrel and assume the generally U-shaped configuration.

3. The apparatus according to claim 2, wherein the fixed-position forming mandrel is a fixed-position wire, rod or plate positioned at least partly within the wax applicator channel.

4. The apparatus according to claim 1, wherein the forming device comprises a forming die positioned at the inlet of the wax applicator channel to cause the candle wick construction to be folded about the longitudinal axis thereof into the generally U-shaped configuration.

5. The apparatus according to claim 1, wherein the forming device comprises a wax filament that is capable of being introduced into the inlet of the wax applicator channel simultaneously with the candle wick construction, wherein the candle wick construction is capable of being folded about the wax filament into the generally U-shaped configuration thereof.

6. The apparatus according to claim 1, wherein the forming device comprises a stationary forming wire having a positionally fixed proximal end, the forming wire extending from the proximal end through the inlet of the wax applicator channel so as to terminate a predetermined distance at a free distal end thereof within the applicator channel.

7. The apparatus according to claim 1, further comprising a spool having wound thereon a supply of the candle wick construction in a substantially flat configuration.

8. The apparatus according to claim 1, wherein the wax applicator further includes an outlet forming die having an outlet orifice.

9. The apparatus according to claim 1, further comprising a cooling system downstream of the outlet of the wax applicator channel so as to cool the wax sheath and maintain the candle wick assembly in the generally U-shaped configuration thereof.

10. The apparatus according to claim 9, wherein the conveyance system comprises a product spool downstream of the cooling system for taking up the wax-coated candle wick assembly, and a drive motor for driving the product spool to wind the wax-coated candle wick assembly onto the product spool and cause conveyance of the multiple candle wick construction through the applicator channel of the wax applicator and downstream cooling system.

11. The apparatus according to claim 10 which further comprises a second wax applicator and a second cooling system positioned downstream of the first-mentioned cooling system and upstream of the product spool.

12. The apparatus according to claim 11 wherein the second wax applicator includes second inlet and outlet forming dies each having second inlet and outlet orifices, respectively, to further assist in forming the candle wick assembly into the U-shaped configuration.

Description

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

(1) The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:

(2) FIG. 1 is a perspective schematic view of a burning candle which embodies a multiple (dual) candle wick assembly in accordance with an embodiment of the invention;

(3) FIG. 2 is an enlarged cross-sectional elevational view of the multiple candle wick assembly that is employed in the candle depicted in FIG. 1;

(4) FIGS. 3 and 4 are front and rear enlarged schematic perspective views of a multiple (dual) candle wick construction in accordance with an embodiment of this invention;

(5) FIG. 5 is a schematic view of an apparatus by which the multiple candle wick construction shown in FIGS. 3 and 4 may be manufactured;

(6) FIG. 5A is an enlarged view of the inlet die associated with the first wax applicator depicted in FIG. 5;

(7) FIGS. 6 and 7 are schematic cross-sectional views of the multiple candle wick construction taken along lines 6-6 and 7-7 in FIG. 5, respectively; and

(8) FIGS. 8A-8D depict alternative structural embodiments for a forming device that may be employed in the apparatus of FIG. 5 so as to assist in folding the candle wick construction about its longitudinal axis.

DETAILED DESCRIPTION

A. Definitions

(9) As used herein and in the accompanying claims, the terms below are intended to have the following definitions:

(10) “Filament” means a fibrous strand of extreme or indefinite length.

(11) “Fiber” means a fibrous strand of definite length, such as a staple fiber.

(12) “Yarn” means a collection of numerous filaments or fibers which may or may not be textured, spun, twisted or laid together.

(13) “Knit” or “knitted” refers to the forming of loops of yarn with the aid of thin, pointed needles or shafts. As new loops are formed, they are drawn through those previously shaped. This inter-looping and the continued formation of new loops produces a knit material.

(14) “Braid” or “braided” refers to a relatively narrow textile band or cord formed by plaiting or intertwining three or more strands of yarn diagonally relative to the production axis of the band or cord so as to create a regular diagonal pattern down its length.

(15) “Woven” means a fabric structure formed by weaving or interlacing warp-wise and weft-wise yarns or filaments of indefinite length at substantially right angles to one another.

(16) “Warp-wise” and “weft-wise” denote the general orientations of yarns as being generally in the machine direction and cross-machine direction, respectively.

(17) “Laid-in yarn” refers to the yarn or yarns that are laid-in with the warp yarns and do not form part of the fabric, e.g., do not form interlocking loops such that the warp yarns are knit around such laid-in yarns.

(18) “Wick curl” is the arc from the top of the wax pool to the terminal end of the wick that is formed by the wick after it is burned in the candle, expressed in degrees. Preferably, the wicks as disclosed herein exhibit a wick curl having no more than about 90° (i.e., so that the terminal end of the wick does not extend substantially beyond a horizontal plane relative to a vertical axis of the candle in which the wick is formed).

(19) “Self-trimming” is the regulation of the wick height and length, to an acceptable size so that it burns clean with little carbon build-up or smoking, by the candle burning process. A certain amount of “wick curl” is required for a wick to be “self-trimming”.

(20) “Self-supporting” refers to a property of a wick whereby a finite length of the wick remains generally oriented along the wick's elongate axis when held upright without lateral support.

(21) “Stable wax pool” means a wax pool that has attained a maximum diameter which does not increase over time during candle burning.

(22) “Uniform diameter wax pool” refers to a wax pool that has a substantially uniform circular diameter.

(23) “Burn rate” is the amount of wax fuel, expressed by weight, consumed over a period of time, e.g. grams of wax fuel per hour (gm/hr).

(24) “Flexural stiffness” or “bending stiffness” is the property of an elongate yarn or filament to bend under applied force with sufficient memory to return to its original elongate state. Yarns and fibers having relatively high flexural or bending stiffness will also typically possess a relatively high Young's modulus. Those fiber elements which require a relatively high flexural or bending stiffness will thus typically possess a Young's modulus of between about 0.5 to about 10 MPa, e.g., between about 0.5 to about 5.0 MPa or between about 1.0 to about 3.0 MPa.

(25) “Multiple” means at least two, e.g., two, three, four or more.

B. Description of Preferred Exemplary Embodiments

(26) Accompanying FIG. 1 depicts an exemplary burning candle 10 which includes a body 12 formed of a solid, combustible candle wax material provided in a container C formed of any suitable material, e.g., glass, metal, ceramic or the like. The candle wax material forming the body 12 of the candle 10 is provided with dual (two) wicks 14a, 14b in accordance with an embodiment of the present invention embedded therein. The flame 16 burning at the top end of the candle body 12 creates a generally circularly shaped (as viewed from above) molten wax pool 18 which serves as a reservoir of fuel to be supplied by the wick 14 to allow combustion to continue.

(27) As is shown in FIG. 1, each of the wicks 14a, 14b exhibits a wick curl that is opposite to one another. That is, each of the terminal end portions of the wicks 14a, 14b is arced laterally relative to the wick's elongate axis A.sub.l so that a portion thereof extends generally at a right angle (e.g., about 90°) relative to the elongate axis A.sub.l (see FIG. 2).

(28) As a result, the terminal ends of the wicks 14a, 14b are generally positioned at the edge of the flame 16 thereby allowing the terminal end portion of the wicks 14a, 14b to themselves to be combusted. As can be appreciated, and as was discussed above, such controlled wick curl and wick combustion allows the wicks 14a, 14b to be self-trimming.

(29) The wicks 14a, 14b are provided as part of a self-supporting wick assembly 30 which may be embedded in the wax body 12 of the candle 10. One advantage of the wick assembly 30 containing multiple wicks 14a, 14b is that it may be inserted into a conventional metal anchor tab 22 that is used by numerous manufacturers to anchor a single wick into the wax body of the candle.

(30) As shown more specifically in FIG. 2, a multiple wick construction 20 includes individual wicks 14a, 14b that are cross-connected to one another by a ladder filament 32. In order to enhance the self-supporting characteristic of the individual wicks 14a, 14b, a stiffener filament 24a, 24b may be provided as part of the wick structure. More than two wicks 14a, 14b may be provided, e.g., a third (or more) wick 14c as shown in FIG. 2 could also be provided in accordance with the embodiments disclosed herein.

(31) Each of the wicks 14a, 14b (or 14c) may be in the form of conventional braided, knit or woven fibrous yarns formed of conventional wick fibers, e.g., cotton, rayon, bamboo, linen, hemp and/or other cellulosic fibers. In one embodiment, the wicks 14a, 14b may be knit as described more fully in U.S. Pat. No. 6,699,034, the entire content of which is expressly incorporated hereinto by reference. Braided wicks that may be employed in the practice of this invention are also well known in the art as evidenced by U.S. Pat. Nos. 1,496,837, 1,671,267, and 5,124,200, the entire contents of each being expressly incorporated hereinto by reference.

(32) If the wicks 14a, 14b are braided, then the ladder filament 32 may be stitched to each which 14a, 14b in a zig-zag manner so as to join the wicks 14a, 14b together in a parallel spaced-apart manner with the ladder filament 32 extending therebetween as shown in FIG. 2. Alternatively, if the wicks 14a, 14b are in the form of a knit or woven fibrous structure, then the ladder filament 32 may be laid-in as part of the knitting or weaving process to form the dual wick construction 20 depicted in FIG. 2. In certain preferred embodiments, the ladder filament 32 is laid-in during a warp knit weft insertion process whereby the individual wicks 14a, 14b are knit in a warp-wise direction and the ladder filament 32 is laid in the knit wicks in weft-wise direction. In all cases, the individual crossing portions 32a of the ladder filament 32 will preferably be substantially orthogonal (90°+/−) relative to the longitudinal axes A1, A2 of the wicks 14a, 14b.

(33) As noted previously, the wicks 14a, 14b are formed of a conventional candle wick material, e.g., yarns comprised of cotton, rayon, linen, hemp, bamboo and/or other cellulosic fibers. The stiffener elements 24a, 24b, on the other hand may be a monofilament or spun yarn formed of any suitable synthetic or natural fibrous material provided it imparts the requisite stiffening properties to the wicks 14a, 14b so the wicks will substantially not bend under gravitational force (e.g., a sufficient stiffness whereby a length of each wick 14a, 14b of about 6 inches or less will remain substantially horizontal when held in a horizontal plane at an end thereof). Thus, stiffener elements 24a, 25b having a flexural stiffness (Young's modulus) of between about 0.5 to about 10 MPa can satisfactorily be employed in the practice of the embodiments of this invention.

(34) One suitable class of materials from which the stiffener elements 24a, 24b may be made include thermoplastics, e.g., polyolefins such as polypropylene or polyethylene, nylons, polyesters and the like. In some embodiments, the stiffener elements 24a, 24b are monofilaments of polypropylene as such a material provides the desired stiffness in order to promote self-supporting capabilities to the wicks 14a, 14b so as to be capable of extending upright along the axes A1, A2, respectively, without the aid of external support. In addition, the monofilaments forming the stiffener elements 24a, 24b will exhibit a required melting temperature of greater than the melt temperature of the wax body 12, e.g., greater than about 220° F. (105° C.). One preferred form of wick stiffener elements 24a, 24b can therefore be polypropylene monofilaments having a diameter from about 0.001 inch to about 0.05 inch, for example about 0.003 inch to about 0.01 inch.

(35) The stiffener elements 24a, 24b may also be formed of a multifilamentary yarn of spun natural fibers, such as cotton or rayon, provided with a coating material to impart stiffness to the yarn. Suitable thermoplastic coating materials such as polyolefins, nylons, polyesters, polyurethanes and the like may be employed for the purpose of imparting stiffness to the natural fibers of the multifilamentary yarn so that the elements 24a, 24b will exhibit the desired flexural stiffness as discussed previously. A finished multifilamentary yarn of spun natural fibers coated with a suitable thermoplastic coating material can be between about 750 denier to about 5000 denier, for example between about 1200 denier to about 3600 denier.

(36) A wick assembly 30 which includes the wick construction 20 is shown in FIGS. 3 and 4. Important to the embodiments disclosed herein, the wick construction 20 is folded about its central longitudinal axis A.sub.L such that the crossing portions 32a form a curved (generally U-shaped) configuration thereby establishing a generally concave central region 35 between the adjacent wicks 14a, 14b along the lengthwise extent of the wick assembly 30. It will be observed that the distance between the adjacent wicks 14a, 14b while in such curved configuration is less as compared to the distance between the adjacent wicks 14a, 14b when the crossing portions 32a of the ladder filament 32 are oriented in a substantially axially straight (non-curved or flat) configuration (e.g., as shown in FIG. 2). The distance between the adjacent wicks 14a, 14b can vary depending on a number of factors, e.g., the nominal size of the wick assembly 30 that may be desired for end use applications and/or candle manufacturing apparatus. It is preferred however that the wicks 14a, 14b not be in physical contact with one another when the wick construction 20 is in a folded configuration.

(37) The wick construction 20 is maintained in the folded or curved configuration (i.e., such that the adjacent wicks 14a, 14b are closer to one another as compared to the non-curved configuration) by a wax sheath 50. In the embodiments depicted, the wax sheath 50 will likewise assume a generally U-shaped cross-sectional shape having a concavity 50a corresponding to the generally concave central region 35 of the crossing portions 32a of the ladder filament and an opposite convexity which coats the curved crossing portions 32a.

(38) The ladder filament 32 preferably possesses sufficient flexural stiffness in order be sufficiently resilient and exert a spring bias force to spread the wicks 14a, 14b when the wick construction 20 is folded into a U-shaped configuration as discussed above. The ladder filament 32 may thus be similar to the stiffener elements 24a, 24b and thus may be formed of a thermoplastic polymer, e.g., polyolefins, such as polypropylene, nylons, polyesters and the like or thermoplastic coated multifilamentary yarns of spun natural fibers. In one embodiment, the ladder filament is a polypropylene monofilament having a diameter of between about 0.004 inch to about 0.015 inch, e.g., about 0.008 inch. Alternatively, the ladder filament 32 may be a spun yarn, in which case the ladder filament will not necessarily possess inherent resiliency. A spun yarn may therefore be employed in those instances where wick spreading is not a desired feature of the candle.

(39) All of the thermoplastic components of the wick assembly 30, e.g., the stiffener elements 24a, 24b and the ladder filament 32 will be consumed by the flame 16 thereby allowing the wicks 14a, 14b to curl outwardly as described above. Thus, all thermoplastic elements near the flame 16 will be consumed to thereby leave only the wicks 14a, 14b in contact with the liquid wax pool 18.

(40) A schematic diagram of a continuous manufacturing apparatus and process to form the multiple wick assembly 30 is depicted in accompanying FIG. 5. As shown, the process initially involves supplying a continuous ribbon of the wick construction 20 from a spool 60. When supplied from the spool 60, the wick construction 20 will be in an essentially flat condition, i.e., the wicks 14a, 14b and the crossing portions 32a of the ladder filament 32 will each be positioned within a common horizontal plane extending out of the plane of FIG. 5. Only the wick 14a is therefore depicted in FIG. 5.

(41) As is perhaps better shown in the enlargement of FIG. 5A, the substantially flat ribbon of the wick construction 20 will be fed through an inlet forming die 62-1 associated with a first wax application 62. According to the embodiment depicted, a forming wire 64 is provided which curvilinearly extends from a fixed end 64a to a free terminal end 64b located a predetermined distance L.sub.w within the cylindrical wax application channel 63 of the wax applicator 62. As is perhaps better shown by the enlarged view of FIG. 5A, the forming wire 64 is substantially coaxially disposed within the die orifice 62-1a of the inlet forming die 62-1 and is positioned between the wicks 14a, 14b (it being understood that only wick 14a is visible in FIG. 5a).

(42) The forming orifice 62-1a of the inlet forming die 62-1 is sized and configured such that movement of the wick construction 20 in the direction of arrow A will cause the wick construction 20 to be coaxially folded about the forming wire 64 thereby assuming a generally U-shaped configuration whereby the wicks 14a, 14b are brought physically closer together while the crossing portions 32a of the ladder filament are convexly bowed. Since a length of the forming wire 64 extends for into the cylindrical wax application chamber 63, the wick construction 20 will be maintained in such a U-shaped configuration while wax is being applied therewithin from the wax reservoir 65. Excess wax supplied to the first wax applicator 62 may be returned to the wax reservoir and/or directed to a collection site (not shown) for later reuse or waste disposal.

(43) The now initially waxed wick assembly (designated as an intermediate wax-sheathed wick assembly 30′ in FIG. 6) is pulled through an outlet die orifice 62-2a associated with an outlet die 62-2 and a downstream cooling system 66 (e.g., a liquid (water) cooling bath and/or spray system and/or a forced air cooling system). It will be understood that the first wax applicator 62 serves to provide an initial wax sheath 50′ so as to maintain the intermediate wick assembly 30′ in a generally U-shaped configuration.

(44) The intermediate wick assembly 30′ continues to be conveyed sequentially through a further downstream inlet forming die 68-1, a second wax applicator 68 and an outlet forming die 68-2. The forming die 68-1 will include a forming orifice 68-1a which is sized and configured to further fold the intermediate wick assembly 30′ into a more pronounced U-shaped configuration (i.e., whereby the wicks 14a, 14b are separated by a lesser dimension) so that additional wax can be supplied thereto from a wax reservoir 69. Upon being further conveyed through the forming orifice 68-2a of the outlet forming die 68-2 and cooled within the second cooling system 70 (e.g., a liquid (water) cooling bath and/or spray system and/or a forced air cooling system), the final wax sheath 50 is provided and the wick assembly 30 assumes its final U-shaped configuration as shown in FIG. 7 (see also FIGS. 3 and 4). Here again, any excess wax provided to the wax applicator 68 may be returned to the wax reservoir 69 and/or directed to a collection site for reuse or waste disposal. The final wick assembly 30 discharged from the cooling system 70 may be taken up on a product spool 72 for shipment and further processing as a component part of candles.

(45) As is shown in FIG. 5, the product spool 72 may be mounted on an axle driven by a drive motor 74 to cause the ribbon of the wick construction 20 and then subsequently the intermediate wick assembly 30′ and final wick assembly 30 to be conveyed through the various unit operations in the direction of conveyance arrow Ac. Those in this art may however contrive other means for conveyance through the unit operations needed to form the wick assembly 30.

(46) The process and apparatus shown in FIG. 5 may be modified in various ways. For example, the described process may be discontinuous such that the intermediate wick assembly 30′ is taken upon on an intermediate spool. The wick assembly 30′ on such a take-up spool may then be transported to a final assembly location whereby the wick assembly 30 is formed by providing the final wax coating 50 onto the intermediate wick assembly 30′.

(47) Alternatively or additionally, as noted briefly above, the apparatus previously discussed may be provided with various types of forming devices. While a stationary (fixed position) forming wire 64 as described above can satisfactorily be employed in the formation of the candle wick assembly 30, other configurations of forming devices may be envisioned by those skilled in this art. For example, as shown in FIG. 5, the forming device may be embodied in a wax filament 61a of suitable diameter which may be supplied via a supply roll 61 upstream of the forming die 62-1 and continuously conveyed together with the ribbon of the candle wick construction 20 through the wax applicator 63. The wax filament 61a may therefore be formed of substantially the same wax material as the wax material applied by the wax applicator 63. The wax filament 61a may thus initially provide a structural mandrel to assist in formation of the wax construction 20 in a U-shaped configuration but will thereafter melt within the wax applicator 63 upon application of additional wax material so as to integrally meld with such additional wax material and form the sheath 50.

(48) As shown in FIG. 8A, the forming device may be embodied in a multilobal forming orifice 80 provided as an integral part of the inlet die 62-1 to the wax applicator 62. An upper lobe 80a of the forming orifice 80 can be provided so as to accommodate either the fixed position forming wire 64 or the continuously supplied wax forming filament 61a as described previously while an opposed pair of forming lobes 80b, 80c will assist in folding the wick construction 20 into its U-shaped configuration. Fixed-position forming mandrels may also be provided such as a fixed position forming rod 82 supported within the wax applicator channel 63 by supports 82a as depicted by FIG. 8B or a forming plate 84 having a lengthwise extending convex forming bead 84a along an edge thereof as depicted in FIGS. 8C and 8D.

(49) It will also be appreciated that the forming device(s) and the ribbon of the candle wick construction 20 may be introduced into the wax applicator channel in other orientations as compared to that depicted in the accompanying Figures. For example, the forming device(s) and the ribbon of the candle wick construction 20 may be reversed as compared to that depicted so that the candle wick assembly 30 assumes an upside down U-shaped configuration, e.g., the candle wick construction 20 is positioned above the forming wire 65 or other forming device(s) that may be provided as viewed in the Figures.

(50) Other changes and modifications can be envisioned. In this regard, the assembly shown in FIG. 1 is depicted as being part of a so-called plug candle whereby the wick assembly 30 is inserted into a pre-formed hole in the solid wax body 12. In such a case, therefore, the wick assembly 30 will retain its structural characteristics along the lengthwise extent thereof but will allow the wicks 14a, 14b to separate as described previously at the upper terminal end when lit.

(51) Alternatively, the wick assembly 30 may be provided as a self-supporting structure in a poured candle manufacturing process, i.e., a process whereby molten wax fuel is poured into a mold in which the wick assembly 30 is positioned. Contact between the molten wax and the wax sheath 50 will thus cause the latter to melt and become a physical part of the wax fuel which in turn allows the wicks 14a, 14b to separate in the molten wax, e.g., by virtue of the resilient spring force provided by the cross-connected ladder filament 32. The stiffener elements 24a, 24b will thus retain the self-supporting characteristics of the individual wicks 14a, 14b during such separation and will therefore retain the wicks 24a, 24b in an upright manner until the molten wax solidifies. A terminal end portion of the wick assembly 30 that was not contacted by the molten wax during the pouring operation will thus extend upwardly from the candle body and present itself as a single wick element. Upon being lit, however, the wax sheath 50 will melt along with the other thermoplastic filament components to allow the wicks 14a, 14b to spread apart and thereby function as previously described.

(52) Various modifications within the skill of those in the art may therefore be envisioned and implemented without departing from the spirit and scope of the invention described herein. Therefore, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.