U.S. patent application number 10/939039 was filed with the patent office on 2006-03-16 for heat exchange method for melting plate candle.
Invention is credited to Joel E. Adair, S.G. Dwyer, Elizabeth J. Jameson, Chris A. Kubicek, Padma Prabodh Varanasi.
Application Number | 20060057525 10/939039 |
Document ID | / |
Family ID | 36034435 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060057525 |
Kind Code |
A1 |
Adair; Joel E. ; et
al. |
March 16, 2006 |
Heat exchange method for melting plate candle
Abstract
The present invention relates to melting plate candles which
employ heat conductive elements to distribute heat from a burning
flame at a wick to a support plate for a solid fuel and to the body
of said solid fuel, so as to more rapidly liquefy the solid fuel,
such as paraffin wax, and to more uniformly and intensely heat such
fuels to increase the efficiency of consumption thereof and to more
rapidly release volatile materials contained within said fuels. The
heat conductive support plate is configured so as to have a
capillary pedestal upon the surface thereof, which cooperatively
engages a wick holder comprising a preferably consumable wick and
heat conductive fins which conduct heat from a flame upon said wick
to said support plate, said wick holder further engaging said
capillary pedestal in such a locking manner as to resist accidental
removal from said pedestal. The fuel may be provided in various
forms, configured to cooperatively engage said wick holder and
support plate, and may comprise various volatile materials. The
capillary pedestal, in conjunction with the wick holder, causes
rapid and complete flow of the liquefied fuel to said wick.
Inventors: |
Adair; Joel E.; (Racine,
WI) ; Dwyer; S.G.; (Racine, WI) ; Jameson;
Elizabeth J.; (Racine, WI) ; Kubicek; Chris A.;
(East Troy, WI) ; Varanasi; Padma Prabodh;
(Racine, WI) |
Correspondence
Address: |
S.C. JOHNSON & SON, INC.
1525 HOWE STREET
RACINE
WI
53403-2236
US
|
Family ID: |
36034435 |
Appl. No.: |
10/939039 |
Filed: |
September 10, 2004 |
Current U.S.
Class: |
431/291 |
Current CPC
Class: |
F23D 3/16 20130101 |
Class at
Publication: |
431/291 |
International
Class: |
F23D 3/16 20060101
F23D003/16 |
Claims
1. A candle comprising a meltable solid fuel element, a melting
plate upon which said fuel element rests, and a wick holder
comprising a wick and heat conductive fins positioned so as to
collect heat from a flame upon said wick and to conduct such heat
to said fuel element and to said melting plate, said wick holder
engaging said meltable solid fuel element, with said heat
conductive fins being insulated so as to prevent loss of said heat
to the atmosphere.
2. The candle of claim 1, wherein said fuel element further
comprises one or more volatile active materials.
3. The candle of claim 2, wherein said wick holder comprises two
heat conductive heat fins which are joined by a heat conductive
element which passes through the hottest portion of said flame.
4. The candle of claim 3, wherein said meltable solid fuel element
comprises a replaceable fuel element cooperatively engaging said
heat conductive melting plate and wick holder.
5. The candle of claim 4, wherein the replaceable fuel element
further comprises a starter bump on the top surface thereof, in
close proximity to said wick, for ease of lighting said wick.
6. A candle as set forth in claim 3, wherein said melting plate
further comprises a raised heat conductive portion by which heat is
conducted from a flame upon said wick to said melting plate and to
said solid fuel element, whereby a pool of heated liquid fuel is
created, said melting plate being configured to cause the flow of
said heated liquid fuel toward said wick holder.
7. The melting plate candle of claim 1, wherein said wick holder is
configured so as to engage a capillary pedestal on said melting
plate.
8. The melting plate candle of claim 1, wherein said wick holder
further comprises heat conductive members configured so as to
transfer heat from said heat conductive fins to said solid fuel
element.
9. A candle comprising a meltable solid fuel, a support plate upon
which said fuel rests, and a pedestal located on said support plate
which cooperatively engages the base portion of a wick holder
comprising a wick, said wick holder conducting heat from a flame
upon said wick to said solid fuel and said support plate by means
of heat fins which contact said flame, said fins being insulated so
as to inhibit heat loss between said flame and said solid fuel.
10. The candle of claim 9, wherein said wick holder comprises a
plurality of heat conductive fins which are joined by a heat
conductive element which passes through the flame.
11. The candle of claim 10, wherein said meltable solid fuel
comprises a replaceable fuel element cooperatively engaging said
support plate, pedestal, wick holder, and heat conductive fins.
12. The candle of claim 10, wherein said support plate further
comprises a heat conductive portion by which heat is conducted from
a flame upon said wick to said solid fuel element, whereby a pool
of heated liquid fuel is created, said support plate being
configured to cause the flow of said heated liquid fuel toward said
wick holder.
13. The candle of claim 9, wherein said support plate is treated so
as to be self cleaning.
14. A candle consisting of a fuel holder comprising a heat
conductive surface shaped to hold and melt a solid fuel material
included in a replaceable solid fuel element further comprising a
wick holder including a wick and heat fins, and to form a pool of
liquid fuel, said surface further comprising a capillary pedestal
which lockingly engages said wick holder, wherein said heat fins
are configured so as to come in close proximity to the hottest
portion of a flame on said wick and to conduct heat from said flame
to said fuel element, the tips of said heat fins being connected by
heat conductive means passing directly through the hottest portion
of said flame, and wherein said surface is shaped so as to cause
said pool of liquid fuel to flow to said wick.
15. The candle of claim 14, wherein said replaceable fuel element
is configured to cooperatively engage said wick holder.
16. The candle of claim 14, wherein said replaceable fuel element
further comprises one or more volatile active materials.
17. The candle of claim 14, wherein the replaceable fuel element
further comprises a starter bump on the top surface thereof, in
close proximity but not in contact with said wick for ease of
lighting said wick.
18. The candle of claim 15, wherein said heat conductive surface
further comprises raised heat conductive areas.
19. The candle of claim 14, wherein said heat conductive surface is
treated so as to be self cleaning.
20. A replaceable fuel element for a melting plate candle, said
fuel element comprising a solid fuel material cooperatively
engaging a wick holder comprising a wick, said wick holder
configured so as to lockingly engage a capillary pedestal on said
melting plate candle, and further comprising heat fins which pass
through a flame upon said wick and conduct heat from said flame to
said fuel element by means of branches which extend outward from
said fins into said fuel element.
21. The fuel element of claim 20, further comprising a volatile
material.
22. The fuel element of claim 20, wherein the surfaces of said fins
are insulated so as to prevent loss of heat to the atmosphere.
23. A replaceable fuel element for a melting plate candle, said
fuel element comprising a solid fuel material cooperatively
engaging a wick holder comprising a wick, said wick holder
configured so as to lockingly engage a capillary pedestal on said
melting plate candle, and further comprising heat fins which pass
through a flame upon said wick and conduct heat from said flame to
said fuel element by means of branches which extend outward from
said fins into said fuel element, said fins being insulated so as
to inhibit heat loss between said flame and said solid fuel.
Description
RELATED APPLICATION(S)
[0001] Not applicable.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a means for providing an
improved heat exchange method utilizing a wick clip or wick holder
assembly in a melting plate candle or other candle assembly, having
a replaceable wick and/or fuel puck. This invention is most
particularly designed to be used in a melting plate candle having
means to provide a capillary feed between the wick holder and the
melting plate, as well as in jar candles or conventional container
candles.
[0005] 2. Description of the Related Art
[0006] Clips which locate and secure wicks for candles and for
devices which dispense vapors into the ambient air are well known
in the art, and useful in many applications. In candles, such clips
provide a means to position the wick for the most efficient
provision of fuel, such as candle wax, to the flame, while in vapor
dispensing devices, such wick clips secure a wick by which a
vaporizable liquid is delivered from a reservoir to an exposed
surface.
[0007] More recently, melting plate candles and simmer plate
dispensers have been used to provide rapid melting of a solid fuel
element and/or rapid dispensing of a vaporizable material to the
atmosphere. An example of such a dispensing device is shown in U.S.
Pat. No. 6,780,382, issued Aug. 24, 2004, in which a dispenser for
active materials is shown. This reference, incorporated herein by
reference, illustrates a melting plate dispenser of volatile
materials comprising a solid fuel containing active material, a
consumable wick, and a heat conductive base having conductive
elements, and the configuration of such elements.
[0008] In application Ser. No. 09/747,525, filed Dec. 20, 2000, a
melting plate candle comprising solid fuel, a consumable wick, a
concave melting plate comprising a lobe by which heat is conducted
from the flame upon the candle to the plate, and the configuration
of such elements, are shown.
[0009] In addition to the above, application Ser. No. 10/780,028,
filed Feb. 17, 2004, teaches a candle comprising solid fuel, a
melting plate, a lobe that engages a wick holder which comprises a
wick and which conducts heat to said lobe and to said melting
plate. In this application, said wick holder engages said lobe in
such a manner as to create a capillary flow of melted fuel to the
wick itself.
[0010] In each of the above references, the melting plate candle
provides a relatively rapid means for heating the solid fuel to its
melting point, thereby improving efficiency of the candle. However,
it has now been found that even more efficient, and more
particularly, more rapid melting of the solid fuel may be achieved
by means of specific modifications of the wick holding device.
SUMMARY OF THE INVENTION
[0011] The present invention, designed for use with a candle holder
or dispenser of actives as described above, but suitable for use
with most forms of container candles and/or dispensing devices,
provides a means for a more rapid melting of the solid fuel
element, resulting in a more rapid release of any volatile
materials therein, and the creation of a more uniform pool of
liquified fuel for consumption. This goal is achieved by a
combination of specific measures to extract heat from the flame on
the candle wick, and to more efficiently deliver said heat to the
solid fuel element.
[0012] Specifically, the preferred wick holder of the present
invention comprises a wick holder designed to provide heat fins, a
wick positioning holder, and a base preferably designed to not only
engage a similarly shaped portion of the bottom of the container in
such a manner as to prevent its easy displacement from the bottom
of the container, but to also create a capillary flow of melted
wax, or liquefied active containing material, between the wick
holder itself and the portion of the bottom by which it is engaged.
The heat fins of said wick holder are so designed as to be
positioned in the main combustion zone of the flame upon the wick
which is held by said wick holder. That is, the tips of the heat
fins are so located as to be in the blue region of the flame,
thereby obtaining the maximum heat from said flame. Various means
to accomplish this goal are available. First, one or both of the
heat fins may be so shaped as to curve inwardly to a position
whereby the tip itself is in the flame. Secondly, a thin highly
conductive metal element, such as a metal strip or wire, may
connect the tips of the heat fins and pass through the blue region
of the flame, so as to extract heat therefrom even as the flame
flickers.
[0013] Preferably, the engaging and positioning means for the wick
clip, preferably located on the bottom of the container near the
center thereof, is a raised protrusion or pedestal, similar to a
capillary lobe, and having a configuration by which the wick holder
may be locked in place. Alternatively, the engagement means may
comprise a depression in, or undercut portion of, the bottom of the
container. The wick holder may comprise a ring of plastic or metal
which engages said pedestal or depression, and has a portion which
snaps over said pedestal in such a manner as to grip an undercut
portion thereof. Alternatively, the wick holder may be designed so
as to be inserted, with pressure, into a depression having a
defined opening, and which then radially expands to resist removal
from said opening, or engages a wider portion of said depression in
such a manner as to inhibit removal there from without further
radial compression of the wick holder. Exemplary of such designs
are spider-type legs, or a skirt, which can engage, or snap around
a central pedestal or bump having a depressed area between the top
of the pedestal and the bottom of the container. Other means for
lockingly engaging the wick holder to the capillary pedestal, or
the bottom surface, of the candle container are available, and
preferably constitute means which will prevent accidental
displacement of the wick holder, but which may be released so as to
permit replacement of the wick holder at the discretion of the
consumer.
[0014] The present invention thus provides a candle or lamp device
capable of rapidly and completely melting a solid fuel to form a
large liquid pool, thereby improving distribution of any volatile
materials present in the fuel, and ensuring efficient and complete
utilization of all of the fuel provided, while providing increased
safety and convenient refilling. Further, the concept of the
present invention offers highly decorative as well as functional
candles and lamps, which may utilize a variety of gel and solid
fuels, with the significant advantages of permitting rapid and
convenient replacement of one fuel element by another at the desire
of the consumer, without the need to clean or scrape the container
in which said candle is utilized to remove a body of unburned fuel
after the bulk of the previous fuel element has been consumed.
[0015] These and other embodiments of the invention shall be
illustrated in the figures and description which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates the basic concept of a melting plate
candle of the prior art, in simplified perspective view, of which
the present invention constitutes an improvement.
[0017] FIG. 2 illustrates a basic melting plate candle, in
simplified cross section, absent the locking wick holder and
improvements of the present invention.
[0018] FIG. 3 is a simplified cross section of a melting plate
candle, showing the capillary pedestal, the locking wick holder
with fins in accordance with the present invention, and the
relationship between the elements.
[0019] FIG. 4 is an exploded view of a melting plate having a
capillary pedestal, with a wick holder as described herein with
fins and incorporated wick, and a fuel element.
[0020] FIG. 5 is a perspective view of the assembled melting plate,
wick holder, and fuel element of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Ordinary candles comprise a vertical, self-supporting body
or column of wax, with a substantially horizontal top and a central
longitudinal wick which extends through and above the wax. The
exposed portion of the wick above the solid wax is lighted by a
flame, and the heat generated by the flame melts a small volume of
the wax at the top of the candle, adjacent the wick, establishing a
puddle or reservoir of molten wax to serve as fuel for the flame on
the wick, and to release any volatile actives present therein. The
capillary attraction of the molten wax and the wick, which is
generally a structure of closely related fibers, causes the molten
wax to travel through the wick to the flame, by which it is
consumed. As the wax is consumed in this manner, the body of wax
diminishes and the top surface thereof progressively lowers. The
upper portion of the wick, extending above the lowering wax, is
generally consumed by the flame. The flame in such a candle remains
in the same position relative to the horizontal center of the
candle, but decreases in height relative to the surface upon which
the candle rests, from the start to the end of the burn, at which
time all or at least most of the wax has been consumed.
[0022] Also well known are such candles as votive candles and tea
lights. For purpose of discussion, tea lights shall be considered
to be relatively small candles in which a body of paraffin is
located in a container, having a wick centrally disposed, while
votive candles shall be considered to be candles of similar size
provided without a container. At the lower end of the wick is
typically found a wick clip having a flat horizontal bottom
surface, which functions to retain the wick in its perpendicular
position, even as the paraffin is melted and liquefied by the heat
of the flame. In most such votive candles and tea lights, the wick
is a cotton material saturated with paraffin, and burns with the
paraffin, thus being consumable. In such candles, or lights or
warmers employing the same, the visible flame moves lower, or
closer to the bottom surface of the container as the fuel and wick
are consumed, down to the level of the bottom of the wick. Further,
after consumption of all of the wax above this point in the unit,
the container (of the tea light), the unburned wax, and the wick
clip remain to be disposed of by the consumer. As a safety
consideration in such candles, the wick is normally crimped or
terminated at a point about 0.25 inches above the bottom of the
wax, so as to cause the flame to extinguish above the bottom of the
container, and to thus prevent the heat of the flame from reaching
the surface upon which the candle is positioned, preventing damage
to such surface, and reducing the likelihood of igniting possible
contaminants such as burnt matchsticks remaining at the bottom of
the candle, or carbonaceous remains of the consumable wick. Such an
arrangement also has the detriment of leaving a small volume of
unburned wax in the bottom of the container when the flame
extinguishes.
[0023] As utilized herein, the term melting plate candle shall
encompass the combination of a solid fuel element and a heat
conductive container or holder for the fuel. The terms fuel
container and fuel holder shall be meant to encompass a support
plate or melting plate comprising means to contain and melt the
fuel element, and a wick holder engaging a wick and said support
plate, said wick holder comprising heat conductive elements, such
as fins, referred to hereinafter as either wick fins or heat fins.
Said wick holder shall also encompass a base having a skirt or legs
configured to engage a complimentarily shaped pedestal portion of
the support plate, and to transfer heat from a flame upon said wick
to said melting plate. Thus, the support plate functions to hold
the fuel element, to retain the wick holder, and to conduct heat to
the solid fuel element to thereby melt said fuel element to provide
a liquid fuel to feed to the flame via the wick. Moreover, the base
portion of the wick holder engages, by the use of legs or skirt
means, a pedestal on the surface of said support or melting plate
in such a manner as to resist detachment from the melting plate,
while also providing a means for transporting liquid fuel from the
support plate to the wick by capillary action. Thus, the pedestal
to which the wick holder is attached may be referred to as a
capillary pedestal, whereas in conventional melting plate candles,
in which no locking or attachment means is present to secure the
wick holder to the base of the melting plate, the wick holder may
be said to engage a capillary lobe. The capillary pedestal of the
present invention may thus be considered to be a capillary lobe
having an undercut or other means by which a wick holder may be
engaged so as to resist accidental displacement. The wick holder
may thus be considered to be locked in place to the capillary
pedestal, although it is removable by the consumer for
replenishment of the wick and/or the fuel element, by exertion of
sufficient force to overcome the engaging pressure. As will be
appreciated, the manufacturer may provide melting plate devices,
wicks and wick holder assemblies, and solid fuel elements, either
together, or independently (separately), and the consumer may join
the separate elements to form a melting plate candle, fuel burner,
or dispenser of active materials, with the option to change wicks
and fuel elements at will. In a preferred embodiment of the
invention, the wick, wick holder, and fuel element may be provided
as a unitary replacement element to be utilized with a separately
provided melting plate.
[0024] An element of the present invention constitutes a capillary
pedestal on the melting plate, which pedestal provides a locating
device for a complementarily shaped wick holder, creates a site for
capillary feed of fuel to the wick, and provides a means for heat
transfer from the flame to both the melting plate and the solid
fuel. The wick holder, in addition to providing a mounting means
for the wick, has a base which closely conforms to the capillary
pedestal in such a manner as to create a capillary feed by which
melted wax flows to the wick as fuel. Moreover, the capillary
pedestal of the present invention is configured so as to engage
said wick holder in such a manner that it may not be easily or
accidentally removed from said pedestal. This may be accomplished,
for example, by means of an undercut in the side of the pedestal,
which undercut engages a complimentarily shaped leg or skirt of the
wick holder, which leg or skirt may be made of a resilient
material, such as a heat conductive metal, which is biased inwardly
on the pedestal in the area of the undercut therein, so as to
resist removal. This capillary pedestal and locking mechanism is
set forth and claimed in U.S. patent application Ser. No.
10/______, filed ______, 2004, in the names of Kubicek et al.
[0025] In addition to the base and/or skirt of the wick holder
being a heat conductive element, the wick holder preferably also
provides an additional heat conductive element such as a fin or
fins, which are in close proximity to, or in contact with the
flame, and thereby conduct the maximum possible heat back to the
wick holder base, and thus to the capillary pedestal, and thereby
to both the melting plate and the fuel. It is to be understood that
this arrangement of elements provides for much greater control of
the degree of heating of the pool of melted wax, and the pool
temperature, by virtue of the ability to control the amount of heat
conducted to the pool by either the skirt of the wick holder or by
the fins thereof. This may be accomplished by selection of the
number of fins, for example, or control of the conductivity
thereof, such as by choice of position relative to the flame, or
material of construction. This in turn is most important in candles
which dispense a volatile material, such as a fragrance, where a
rapid temperature rise to the most effective temperature for
volatilization of the active material is desired. Such a rapid
temperature rise clearly results in a more rapid melt of the fuel
element, and a more rapid dispensing of volatile material. In fact,
with the present invention, it is possible to tailor a melting
plate candle to a specific volatile active to be contained within a
fuel element, by permitting control of the amount of heat conducted
to the pool of melted fuel, and thus controlling the temperature
thereof.
[0026] The material of which the melting plate and the heat fins
are fashioned should be of high thermal diffusivity, i.e. have high
thermal conductivity, low density, and low specific heat. It has
been found that the material of the wick clip should have a thermal
capacity above 0.10 cal/.degree. C. but below 0.30 cal/.degree. C.
Such low thermal capacities decrease the melt time associated with
melting the solid fuel element, and higher values tend to starve a
newly initiated flame of heat, causing it to extinguish. The
preferred materials may be such metals as aluminum and copper. By
use of such metals, one obtains the least resistance to heat
transfer from the flame to the puck. Moreover, the region of said
fins between the flame and the wax or the base of the wick holder
should be insulated, so as to prevent loss of heat to the
surrounding atmosphere, by either radiation or convectional means.
The insulating material may be any conventional non-combustible
material which may be readily applied to the surface of the heat
fins, by any conventional method. In addition, it is beneficial to
extend one or more portions of the wick holder base outward into
the wax puck, so as to preferably transfer heat directly to the
fuel element, rather than to the melting plate base. This also has
the benefit of minimizing the supply of liquified fuel to the wick
near the exhaustion of the fuel supply, thereby reducing the
likelihood of flaring or re-ignition of the candle at the end of
its life. Still another factor of the effectiveness of the transfer
of heat from the heat fin to the solid fuel is the size of the heat
fin, specifically with respect to surface area. The cross sectional
area of the fins should be large enough to efficiently convey the
collected heat. During the melting of the fuel element, it is
desired that the heat transfer between the fin and the fuel be
maximized, so relatively large horizontal surfaces are desirable.
After the fuel has melted and formed a pool of liquid, it is
desirable to minimize the heat transfer from the fins to the pool.
The relationship between the horizontal wick clip area and the fuel
element, or votive, may be represented by the so called "Quasivoto
factor", defined as the fin surface area divided by the vertical
cross section of the votive. For most efficient utilization, the
"Quasivoto factor" should be greater than 0.25 but less than 0.75
before the fuel element is melted, and between 0.125 and 0.25 after
the fuel element has fully melted. Advantage may be taken of the
variable height of the molten pool of fuel by shaping the heat fins
so as to be wide in the pre-melt pool, but narrower in the post
melt pool. Still further, it has been calculated that the total
cross sectional area of the fins at a point corresponding to the
height of the wick should be less than approximately 1/4 the cross
sectional area of the fins at a height corresponding to the surface
of the solid fuel element, for a wick clip having a thermal
diffusivity between 1.times.10.sup.-5 and 15.times.10.sup.-5
m.sup.2 per second.
[0027] Alternative aspects of the present invention provide for the
fuel element to be provided as a separate element which is
complementarily shaped relative to the wick holder, so as to fit
around the wick holder in its position on the capillary pedestal of
the melting plate. While it is possible for a permanent wick and
wick holder assembly to be provided as a part of the melting plate,
in the preferred embodiments of the invention the wick holder,
wick, and fuel element are provided to the consumer as a single
unit. Alternatively, the wick and wick holder may be provided as a
single unit, with individual separate fuel units, perhaps
containing differing fragrances, for example, to be combined with a
melting plate. In this manner, wick holders of differing shape and
configuration may be combined with fuel elements of appropriate
configuration which differ in color or scent, for example.
[0028] In addition, it has been found beneficial to insulate the
area of contact between the wick holder and the capillary lobe of
the melting plate candle holder so as to cause the greatest amount
of heat flow from the flame to the wick fins to the wax puck
itself, so as to most rapidly melt the wax puck. Thus, it is to be
noted that while the present invention is described in terms of a
melting plate candle comprising a capillary lobe and
complimentarily shaped wick clip base, it is possible to apply the
invention to wick clips to be employed in candles comprising a
non-conductive base, whereby the heat is transferred directly to
the wax puck by means of the heat fins, rather than to both the wax
puck and a heat conductive melting plate base. In either case, it
is proposed that the highly heat conductive heat fins are so
positioned as to capture the maximum heat output of the candle
flame, by being located in the blue region of the flame, that the
heat fins be insulated in the area between the flame and the solid
fuel element, with which the heat fins are in direct contact, and
that maximum release of the heat from the wick fins to the solid
fuel element be achieved. This may preferably be achieved by
forming leaves or branches which extend from the fins, or from the
wick holder base to which the heat fins attach, into the solid fuel
element itself. Of course, the heat fins may also be so shaped as
to maximize surface contact thereof with the solid fuel.
[0029] Accordingly, it is evident that the melting plate is
preferably comprised of a heat conductive material, such as a
metal, although less conductive materials, such as glass or ceramic
may be employed. The preferred material for use as the melting
plate is polished aluminum, due to its high efficiency as a
conductor of heat, its light weight, and for aesthetic reasons. It
is also possible that the melting plate may constitute a
non-conductive body having a conductive surface applied thereto,
such as a less conductive surface having a thin layer of metal
applied thereto. In this regard, it is noted that the surface of
the melting plate may also have a coating of a surface tension
modifying material applied thereto for purposes of preparing a self
cleaning or easy cleaning melting plate. For example, a thin layer
of a polytetrafluoroethylene material may be applied over a rough
surface to provide a smooth wetting surface upon which molten wax
will flow easily, and which will enable easy removal of solidified
wax upon extinguishing the flame and allowing the candle to
cool.
[0030] The melting plate, which may act both as a fuel container
and a heat transfer means to heat the fuel, is shaped so as to
collect the melted or liquefied fuel at its lowest point, at which
point a wick is preferably located by means of a wick holder
positioned upon a capillary pedestal, so as to ensure that all fuel
is fed to the wick, whereby the maximum consumption of the fuel is
achieved. Thus, the melting plate is preferably shaped as a bowl,
or in the form of a funnel, with the lowest portion thereof
preferably, but not necessarily, centered. The entire interior
surface of the fuel container is preferably highly heat conductive,
and supports, contains, and heats the fuel, although containers in
which only a small portion of the interior surface acts as a
melting plate are within the scope of the present invention.
Candles employing such melting plates shall be referred to,
collectively, as melting plate candles. The melting plate itself
may, of course, be essentially flat, with raised edges or a
surrounding wall to contain the melted fuel.
[0031] Moreover, the melting plate helps to control the shape and
depth of the pool of fuel which is burned at the wick, and to
maintain the constancy thereof. It is to be understood that the
fuel utilized in the present invention may be initially in solid or
gel form, but must be in liquid form for moving up the wick by
capillary action to the flame, where it is consumed. Thus, the fuel
used with the melting plate candle shall be such that it will not
be transported by wicking action at ambient or room temperature,
but requires heating to a liquefied state, i.e. melting, to be
subject to capillary or wicking action. For convenience, the term
solid fuel shall be used hereinafter to refer to fuel in either a
gel or conventional solid state, such as conventional candle wax,
preferably in the form of a hard, shaped body or "puck" of wax. It
is also to be understood that the fuel consumed in the flame at the
burning wick is drawn by the wick from a liquid pool of fuel, which
pool is formed by melting the solid fuel, and heating said liquid
pool by conductive heat transfer from the melting plate and heat
exchange elements provided by the wick holder, in addition to the
radiant heat from the flame on the wick. By the use of the melting
plate and heat fin technology of the present invention in addition
to the conventional radiant heating of the surface of the fuel, the
size, volume, depth, and temperature of the liquid pool of fuel are
better regulated. And, as a result of greater control of heat
transfer to the fuel, a melted, liquid pool thereof is more rapidly
formed and heated to a desired temperature. Because the speed of
achieving a uniformly heated liquid pool of fuel is increased, a
more efficient consumption of the fuel results, and a more complete
usage of available fuel due to the decrease of fuel left unburned
on the surface of the melting plate, as well as a more rapid and
efficient release of any volatile active materials in said fuel,
such as fragrances. In preferred embodiments of the present
invention, a pool of liquid, i.e. melted, fuel rests upon the
surface of the heat conductive melting plate. This pool of fuel may
initially contain unmelted fuel in the solid state, as well as
melted fuel, and the elevated temperature of the pool achieved by
the present invention aids in assuring a complete melting of the
solid wax puck and complete and optimized dispersal of any volatile
active materials present in the fuel
[0032] Generally, the melting plate device embodies both a melting
plate and secondary heat conductive elements, which secondary
elements are to be provided as part of the wick holder and pass
through or are in close proximity to the flame, to ensure more
uniform and rapid distribution of heat from the flame upon the
wick. The wick is affixed in its preferred position by means of the
wick holder. The wick, which is preferably a consumable wick, may
be any filamentary body which is sufficiently sturdy, which will
burn with a steady flame, and which is capable of drawing up the
molten candle fuel by capillary action. Such a wick may be of any
conventional consumable wick material, such as cotton, cellulose,
nylon, or paper, but may be non-consumable as well. The wick holder
and wick may preferably be located in the center of the candle, or
may be off-center as desired. The presence of two or more wicks,
and associated wick holders and capillary pedestals, is also within
the scope of the present invention. In the present invention, the
wick is preferably positioned in a wick holder which engages the
melting plate by means of an appropriately located capillary
pedestal on the melting plate, which serves to locate the wick
holder (and thus, the wick), to transmit heat from the flame on the
wick to both the fuel and the melting plate, and by means of the
capillary nature of the appropriately sized gap formed by the fit
of the pedestal in relationship to the wick holder, to enhance flow
of fuel to the wick. Moreover, the wick holder is preferably
configured so as to also engage the fuel element in a lock and key
relationship and to position it on the melting plate in the
preferred location.
[0033] A heat conductive element constitutes the melting plate
itself, which may comprise portions formed, raised, or bent to be
in closer proximity to the flame, such as a raised section of the
plate, e.g. the upper edge of the raised side of the melting plate.
For example, the melting plate may constitute a bowl shaped
container having its outer periphery in close proximity to the
flame, such as a container in which the side wall of the bowl is
formed so that the lip of the upper opening curves back toward the
center of the bowl, and thus toward the flame. The melting plate
may also have secondary heat conductive elements, such as one or
more raised portions which act not only to absorb and distribute
heat by conduction, but to channel or direct the flow of liquid
fuel to the wick. Such raised portions may constitute areas of
material having higher heat conductivity than surrounding areas of
the container. In such examples, the support plate may comprise a
less conductive material, such as glass, and the principal heat
exchange may be by radiant heat and conducted heat by means of the
secondary heat conductive elements of the wick holder. It may thus
be seen that the wick holder assembly, comprising a wick, and a
fuel element, in conjunction with a base configured so as to
complimentarily engage a capillary pedestal, may be utilized in any
candle container comprising a capillary pedestal.
[0034] In the present invention, a capillary pedestal both engages
and positions the aforementioned wick, wick holder, and fuel
element in such a manner as to provide the most advantageous
positioning thereof, as well as to create a capillary flow of
melted fuel from the melting plate to the wick positioned in the
wick holder, which is placed in such close relationship to the
capillary pedestal as to create a very narrow gap between the
pedestal and the wick holder. By virtue of this narrow gap, which
may be from approximately 0.01 to about 0.04 inches, preferably
about 0.02 inches, liquefied fuel rises to the wick for
consumption. It should be noted that it is within the scope of the
invention that the capillary action may be improved as a result of
grooves cut in the pedestal, or in the wick holder, and that the
wick holder may be held away from the pedestal by the presence of
appropriately positioned and sized bumps located on either the
pedestal, the wick holder, or the melting plate. Moreover, the
capillary forming combination of elements may constitute a concave
depression in the melting plate, rather than a raised male
pedestal, and the wick holder in such case may be an appropriately
shaped male member which fits closely within the depression so as
to create a capillary gap between the members, by which fuel is fed
to the wick, and having engagement means to prevent its accidental
removal from said depression. Still further, it is contemplated
that the capillary pedestal, in a male configuration, or a female
depressed configuration, need not constitute a circular member, but
may be of any shape, such as for example cylindrical, pyramid
shaped, square, oval, triangular, or any other desired shape, in
combination with a like-shaped and appropriately dimensioned wick
holder and locking means. It is also to be noted that the capillary
pedestal need not transmit liquid fuel to the wick at all parts of
the perimeter of the capillary pedestal. For example, a circular
capillary pedestal in conjunction with a circular wick holder need
only create a capillary gap for a limited portion of its
circumference, such as for 90, 180, or 270 degrees. Thus, the wick
holder need not be in a close enough proximity to the pedestal
throughout the total area of engagement therewith to provide a full
capillary effect, but only in sufficient area to provide an
adequate flow of fuel to the wick to maintain the flame upon said
wick.
[0035] Additionally, primary heat conductive elements are separate
assemblies which are utilized in conjunction with the melting plate
and consumable wick and wick holder. The primary heat conductive
element may take the form of heat fins or heat conductive surfaces
attached to the wick holder, and having either vertical or
horizontal orientation or elements of both. In preferred
embodiments, such heat conductive elements are heated by direct
contact with the flame, and conduct such heat to both the melting
plate and to the fuel so as to more efficiently heat the fuel. The
heat conductive elements of the wick holder, hereinafter
exemplified as heating fins, although not limited to fins per se,
and intended to encompass other heat conductive extensions of the
wick holder which may serve this function, may be of any highly
heat conductive material, and may be either formed as an extension
of the wick holder or joined to said wick holder in such a manner
as to conduct heat from the flame to that portion of the wick
holder which is engaged by the capillary pedestal and/or the
melting plate. The wick holder thus comprises fins, a means to hold
the wick, the wick, and a base configured so as to engage the
melting plate via a capillary pedestal or lobe, and to transfer
heat from said fins to said melting plate. Where plural fins are
employed, which do not contact the flame itself, it is preferred to
join the upper tips of such fins by means of a highly heat
conductive element, such as a metal wire or metal connecting piece.
Suitable and exemplary, although clearly not the only possible heat
fins are illustrated in U.S. Pat. No. 6,780,282, issued Aug. 24,
2004, incorporated herein by reference. Moreover, the fins should
be insulated in that region below the flame in which they are
exposed to the ambient atmosphere, so as to prevent radiation and
loss of heat to the surrounding area.
[0036] It is to be understood that the wick holder and associated
primary heat conductive elements are meant to be so situated and
shaped as to engage or interlock with a replaceable solid fuel
element. In a similar fashion, the melting plate and/or the fuel
container may be formed in such a manner as to permit placement of
fuel elements of specific configuration, such as wax pucks having a
complementary configuration, for example, in a preferred position
in proximity to the heat conductive elements themselves, or to the
wick holder, in such a manner as to maximize heat transfer from the
melting plate to said fuel elements. In the most preferred
embodiment, additional heat conductive elements are present as an
element of the wick holder, in the form of extending legs or leaves
from the base of said wick holder into the body of the solid fuel
element. In said most preferred embodiment of the invention, there
is a capillary pedestal present on the melting plate, positioned in
such a manner as to also transfer heat to the fuel element, and
configured so as to engage a wick holder holding a consumable wick
and having one or more heat conductive fins, and a fuel element
such as a wax puck. Further, the engagement of the wick holder with
the capillary pedestal is such as to provide a capillary effect
between the two for feeding fuel to the wick. In this embodiment,
the consumer may purchase a replacement fuel element comprising a
wax puck and a wick holder and wick, configured so as to engage a
matching capillary pedestal on the melting plate in such a manner
as to position the fuel element and the wick holder, and having a
heat conductive element in the appropriate location to most
efficiently melt the fuel element. Alternatively, the consumer may
purchase an assembly comprising a wick holder and wick, with
separately available appropriately shaped fuel elements.
[0037] The use of the melting plate technology of the present
invention may also provide such advantages as elimination of
tunneling, significant reduction of retention of wax at the
conclusion of the burn, and elimination of walking or off-center
wicks, while also giving a larger pool of liquid wax with a
relatively small flame in a relatively short time period. In
addition, the container may be of almost any shape desired,
providing for great aesthetic possibilities. Since the fuel
element, either alone or in combination with a wick and wick
holder, may be provided as a separate unit, the consumer may be
provided a great number of choices as to the color, content, and
nature of the fuel, and the configuration of the fuel element may
be varied to provide a large choice of shapes, such as seasonably
decorative items. For example, shapes such as pumpkins may be
provided for Halloween, wreaths for Christmas, and flowers for all
seasons. In addition, the fuel element preferably is configured as
to cooperatively engage both the melting plate and the wick holder,
which wick holder in turn engages the capillary pedestal on the
melting plate, in such a manner as to provide the consumer the
greatest degree of ease in placement of the fuel element in optimal
position in the melting plate candle, with the least possibility of
incorrect placement. Further, the melting plate or support plate
may have decorative features, such as designs, embossed, etched,
printed, or stamped thereon.
[0038] Accordingly, the present invention provides a melting plate
candle, wherein said candle comprises a container for a fuel
element comprising a fuel selected from the group consisting of
paraffin, beeswax, montan wax, carnauba wax, microcrystalline wax,
polyvinyl acetate, fatty alcohols, fatty acids, fatty esters, and
gels incorporating such fuels; in a form selected from the group
consisting of pucks, donuts, chips, slivers, balls, pellets,
shavings, particulates, cubes, discs, three dimensional shapes, and
wafers, or in any other suitable shape. Said fuel element may
optionally further comprise such volatile active materials as
fragrances, air fresheners, deodorizers, odor eliminators, odor
counteractants, insecticides, insect repellants, herbals, medicinal
substances, disinfectants, sanitizers, mood enhancers, aroma
therapy compositions, and the like. Such solid fuel may be colored
for decorative effect, if so desired, and may be shaped to fit any
given configuration of melting plate and/or wick holder. For
example, the bottom of a solid fuel element should be curved
complementarily to the shape of the melting plate upon which it is
to rest, and have melting temperatures above ambient, but below the
flame temperature of a wick burning such fuel.
[0039] These and still other advantages of the present invention
will be apparent from the description which follows, which
description is merely of preferred embodiments, and not indicative
of the full scope of the invention.
[0040] FIGS. 1 and 2 illustrate the broad concept of a melting
plate candle in its most basic form, such as set forth in Ser. No.
09/747,525, filed Dec. 20, 2000, incorporated herein in its
entirety by reference. The teachings of said pending patent
application do not illustrate the capillary pedestal and wick
holder assembly of the present invention, nor the primary heat
conductive members comprising heat fins passing through the hottest
region of the flame with regions thereof insulated to prevent heat
loss to the atmosphere. As illustrated, a heat conductive melting
plate container, 2, is provided, which transfers heat obtained from
the heat source, a flame (not shown) located on wick 3, by means of
heat conduction, to the solid fuel element, 4, which rests upon the
surface of the melting plate. For purposes of illustration, and for
clarity, but intending no limitation, the wick is illustrated in
FIGS. 1 and 2 as being of a relatively large diameter, rather than
as a fibrous wick of small diameter. It is to be understood that
the wick is positioned within and attached to the solid fuel
element, 4, such as with a wick clip (not shown in FIGS. 1 and 2).
The melting plate, 2, as shown in FIGS. 1 and 2, is heated directly
by a flame on the wick, 3, by radiation, as a result of the melting
plate being shaped so as to have a portion, shoulder 18, in
proximity to the flame, the diameter of the melting plate bowl
being such as to permit the inner surfaces thereof to absorb
appreciable amounts of heat from the flame.
[0041] The melting plate of FIGS. 1 and 2 is shaped so as to have a
raised outer shoulder, 18, thereby containing the resultant pool of
melted fuel. It is to be understood that the melting plate may be
in the form of a tray, bowl, concave plate, or other configuration
which is capable of holding a pool of hot liquid fuel, and is
preferably shaped so as to funnel or channel the liquefied, i.e.
melted, fuel to the wick. The melting plate may constitute a
container in itself, as shown, or may be surrounded by a separate
container. In the embodiment shown in FIGS. 1 and 2, the melting
plate rests upon a non-conductive base, 11, or legs of
non-conductive or insulating material, so as to permit placement
upon a table, counter, or other surface. The non-conductive base,
as illustrated, comprises contact points, 12, so as to minimize the
amount of contact between the base and the melting plate, and to
create an insulating air gap, 13, between the melting plate and the
surface upon which the assembly rests.
[0042] The melting plate may be of any heat conductive material,
such as brass, aluminum, steel, copper, stainless steel, silver,
tin, bronze, zinc, iron, clad materials, heat conductive polymers,
ceramics, glass, or any other suitable heat conductive material or
combination of such materials. As shown in FIG. 2, the fuel is
preferably located in direct contact with the surface of the
melting plate, 2, which plate may, if desired, be constructed so as
to have a non-conductive lower surface, so that the melting plate
may rest upon a table surface or such. Such a configuration may
result from a clad material, a conductive melting plate material
coated on the external surface with a non-conductive material, a
non-conductive material having an insert of a heat conductive
material, or other suitable arrangements to permit the melting
plate to be cool enough on the bottom surface to permit ease of
handling, and/or placement upon surfaces not suitable for contact
with heated bodies.
[0043] The wick, 3, preferably constitutes a conventional
consumable wicking material, such as such as cotton, cellulose,
nylon, or paper, or the like, which by capillary action will carry
liquid fuel to the flame. Alternatively, nonconsumable wicks may
comprise such materials as porous ceramics; porous metals; fiber
glass; metal fiber; compressed sand, glass, metal, or ceramic
microspheres; foamed or porous glass, either natural or man-made,
such as pumice or perlite; gypsum; and chalk. However, for purposes
of the present invention, the use of conventional consumable wicks
is preferred. The wick, 3, may be located in the center of the
melting plate, 2, or may be off-center as desired, provided that
the melting plate is configured so as to channel or funnel melted
fuel to said wick. As illustrated, the wick may be positioned in
conjunction with a starter bump, 6, of wax in the top surface of
said fuel element, 4, for ease of lighting. The presence of two or
more wicks is also within the scope of the present invention. The
wick is provided in conjunction with the wick holder assembly, the
preferred configuration of the wick holder being such as to
cooperatively engage a complimentarily shaped capillary pedestal,
22, on the melting plate, as shown in FIGS. 3, 4, and 5, discussed
hereinafter.
[0044] FIG. 3 illustrates a melting plate container, 2, comprising
a concave base, and having a raised pedestal or protrusion, 22,
located near the center thereof, said pedestal being shaped so as
to engage the legs or skirt, 23, of a wick holder, 7. The wick
holder itself is comprised of a central wick holding means, 5, a
wick, 3, and heat fins, 9, located so as to absorb heat from a
flame, 1, upon said wick mounted in said wick holder, and to permit
flow of said heat from said flame to said base of said melting
plate container, 2, and to the solid fuel element, 4. The tips of
said wick fins are joined by a highly conductive wire, 8, or other
highly conductive means. Further, the fins are provided with
insulated areas, 10, between a point below the contact of the fin
with the flame, or below the point of joinder by the conductive
wire, to a point near or below the surface of the solid fuel
element. The legs or skirt, 23, of said wick holder fit in close
proximity to the sides, 24 of said pedestal, 22, and engage an
undercut, 25, in the side surface of said pedestal, by means of
shoulder 26, in such a manner as to resist removal there from. The
legs or skirt, 23, and the base, 27, of said wick holder and the
sides, 24, and top, 28, of said pedestal are in close proximity, so
as to permit maximum resistance to separation, and so as to create
a gap resulting in a capillary flow of melted wax from the bottom
of the melting plate container, 2, to the top of said pedestal, 28.
In addition, highly heat conductive leaves or branches, 16, extend
outward from the bottom of said wick holder into the body of the
fuel element, so as to assist in rapid melting thereof. Such leaves
or branches are preferably of the same material as the base of said
wick holder. The bottom, 27, of said wick holder is shown to be in
close proximity to the top, 28, of said pedestal, assuring a rapid
and even flow of liquefied fuel to the wick, held in position so as
to contact said fuel by wick holding means 5. Although the
invention is illustrated in terms of a melting plate candle, it may
be equally as effective in the context of a candle jar, tea light,
or votive holder.
[0045] In FIG. 4, an exploded perspective view of the invention is
shown, with a bowl shaped melting plate container, 2, which
comprises a capillary pedestal, 22, located in approximately the
center thereof. A wick holder, 7, is shown above the capillary
pedestal, the wick holder being shaped in such a manner as to fit
closely over said capillary pedestal, and to tightly engage an
undercut therein so as to be locked in position. The wick holder,
as illustrated, further comprises the wick, 3, heat fins, 9, joined
by wire 8, and a heat conductive leaf or wing 16. A solid fuel
element, 4, is shown, having a cut out portion, 6, through which
the heat fin and wick assembly may pass, so as to place the wick in
close proximity to the top surface of said fuel element. The solid
fuel element is shown as a wax puck, although other shapes may
clearly be used within the scope of the present invention. To
prevent difficulty in lighting the wick, a starter bump of fuel may
be provided in close proximity to the wick, 3. As illustrated in
FIGS. 1, and 2, this bump is most easily molded directly into the
shape of the fuel element, and provides a ready source of liquid
fuel to the wick when a match or other appropriate source of flame
is employed to start the wick burning, which source of flame will
melt the starting bump to thus create an initial pool of liquid
fuel.
[0046] FIG. 5 shows the embodiment of FIG. 4 in operational
configuration, showing the relationship of the elements in position
for lighting of the wick, 3, wherein the melting plate, 2, is shown
with a fuel element, 4, positioned on the capillary pedestal (22,
not visible) and centered around a wick holder assembly with the
heat transfer fin, 9, and wick, 3, extending through the opening,
30.
[0047] Thus, when using a solid fuel, such as wax, in conjunction
with a heat conductive wick holder, solid fuel refill units may be
shaped to fit the shape of the melting plate, with a specific
relationship to the wick holder, which itself is engaged with the
melting plate by a locking means. For example, the melting plate
may be a decoratively shaped container, and wax may be provided in
the form of refills specific for the container shape selected, such
as round, square, oval, rectangular, triangular, or otherwise, so
shaped that the wick holder assembly incorporated with the wax
refill unit will fit and engage a complementarily shaped capillary
pedestal.
[0048] The use of a melting plate with additional heat conductive
elements, such as the partially insulated heat fins and joining
wire illustrated, offers a number of distinct advantages. First, it
permits a larger pool of liquid fuel, due to improved heat
conduction into the fuel, which results in more rapid formation of
the pool. This in turn allows better regulation of the size and
shape, as well as the temperature, volume, and depth of the
liquefied wax pool to allow more efficient use of fuels present. In
fact, melting plates of the present invention permit ease of
refill, with little or no cleaning. In most instances, no cleaning
is required, but if desired, the plate may be conveniently washed
in a manner such as a dish, plate of bowl is washed, in a wash
basin or in a dishwasher. The use of a capillary pedestal in the
heat plate, in conjunction with heat fins on the wick holder, also
reduces or eliminates retention of solidified excess fuel when the
candle is allowed to burn itself out, and permits more complete and
uniform burning of fuel elements which are other than round, i.e.
square, oval, triangular, or in the shape of a flower or decorative
object, etc. Further, the melting plate technology in conjunction
with a capillary pedestal and complimentary wick holder, results in
devices which may be self extinguishing, and improvements in or
elimination of typical burning problems encountered with candles,
such as tunneling, drowning, collapsing, cratering, and wick drift.
Candles utilizing the melting plate technology of the present
invention are also more forgiving of formulation or process
variances. And, more importantly, the presence of a locking
configuration of the wick holder and the capillary pedestal
provides a margin of safety and convenience not previously
available.
[0049] While the present invention has been described with respect
to what are at present considered to be the preferred embodiments,
it is to be understood that the invention is not to be limited to
the disclosed embodiments. To the contrary, the invention is
intended to cover various modifications and equivalent arrangements
within the spirit and scope of the appended claims. The scope of
the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent
formulations and functions.
INDUSTRIAL APPLICABILITY
[0050] The melting plate and heat conductive element candles of the
present invention, utilizing a capillary pedestal and
correspondingly shaped locking wick holder having fins which
contact the hottest portion of the flame upon the wick, but are
elsewhere insulated to prevent heat loss, can be used in connection
with a large variety of solid fuels. The conductive materials of
which the melting plate and heat fins may be constructed are
commonly available, and the various configurations are readily
produced. There is considerable interest for candles having
extended burn times, and for refillable candles or solid fuel
lamps, particularly for melting plate candles which are resistant
to accidental release of the wick holder assembly.
* * * * *