U.S. patent application number 11/676598 was filed with the patent office on 2007-06-14 for dispenser assemblies and systems including a heat storage unit.
Invention is credited to Amil J. Ablah, Brian L. Clothier, Stephen B. Leonard, David P. Mather.
Application Number | 20070131676 11/676598 |
Document ID | / |
Family ID | 33552015 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070131676 |
Kind Code |
A1 |
Clothier; Brian L. ; et
al. |
June 14, 2007 |
DISPENSER ASSEMBLIES AND SYSTEMS INCLUDING A HEAT STORAGE UNIT
Abstract
A heat storage unit (2) includes a body having a passage (12)
formed therein through which a flowable product passes. A heatable
element (10) is incorporated within the body of the heat storage
unit (2) in thermal communication with the passage (12). Meanwhile,
a heat-retentive material (8) is in thermal communication with the
heatable element (10). The heatable element (10) includes either a
magnetically-compatible material or a microwave-compatible material
that is heated by locating the heatable element in a field (F)
generated by a charging device (6), for example.
Inventors: |
Clothier; Brian L.;
(Wichita, KS) ; Leonard; Stephen B.; (Franksville,
WI) ; Mather; David P.; (Milwaukee, WI) ;
Ablah; Amil J.; (Wichita, KS) |
Correspondence
Address: |
S.C. JOHNSON & SON, INC.
1525 HOWE STREET
RACINE
WI
53403-2236
US
|
Family ID: |
33552015 |
Appl. No.: |
11/676598 |
Filed: |
February 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10875169 |
Jun 25, 2004 |
|
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11676598 |
Feb 20, 2007 |
|
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60482867 |
Jun 27, 2003 |
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Current U.S.
Class: |
219/618 |
Current CPC
Class: |
F28D 20/0056 20130101;
Y02E 60/14 20130101; H05B 6/802 20130101; H05B 6/62 20130101 |
Class at
Publication: |
219/618 |
International
Class: |
H05B 6/00 20060101
H05B006/00 |
Claims
1-53. (canceled)
54. A pad for heating and dispensing a flowable product, the pad
comprising a porous body comprised of a heat-retentive material and
either a magnetically-compatible material or a microwave-compatible
material that is heatable by locating the magnetically-compatible
material or microwave-compatible material in an
externally-generated field.
55. The pad of claim 54, wherein the porous body comprises at least
one layer of a magnetically-compatible graphite-based material that
is sandwiched between layers of the heat-retentive material.
56. The pad of claim 54, wherein the porous body comprises flakes
of a magnetically-compatible graphite-based material incorporated
within the heat-retentive material.
57. The pad of claim 54, wherein the heat-retentive material
comprises a solid-to-solid phase change material.
58. The pad of claim 54, wherein the heat-retentive material has a
specific heat of at least about 0.4 calories per gram-degree
Celsius.
59. The pad of claim 54, wherein the heat-retentive material has a
specific heat of at least about 0.5 calories per gram-degree
Celsius.
60. The pad of claim 54, wherein the heat-retentive material
comprises a polymer selected from the group consisting of
polyethylene, polypropylene, and nylon.
61-91. (canceled)
92. The pad of claim 54, further comprising a burstable pouch
containing the flowable product, the burstable pouch being
incorporated within the porous body in thermal communication with
the magnetically-compatible material or the microwave-compatible
material, wherein the flowable product is dispensed from the porous
body by compressing the burstable pouch.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/482,867, filed Jun. 27, 2003.
FIELD OF THE INVENTION
[0002] Our invention relates to a heat storage unit for a flowable
product and to dispenser assemblies and systems utilizing such a
heat storage unit. The heat storage unit is heatable by either
induction heating or microwave heating. Our invention also relates
to a method of manufacturing a heat storage unit.
BACKGROUND OF THE INVENTION
[0003] Dispenser assemblies for dispensing a heated product are
known in the art. Conventional dispenser assemblies typically
include a container for holding a flowable product, a mechanism to
expel the product from the container, and, in some instances, an
electrical heating element for heating the product prior to being
dispensed. For example, each of U.S. Pat. No. 3,144,174 to
Abplanalp and U.S. Pat. No. 3,644,707 to Costello discloses an
aerosol dispenser assembly having a heating element for heating a
flowable product, such as shaving cream, prior to dispensing. In
each of these patents, the heating element is disclosed as being an
electrical resistance heating element. However, the Abplanalp
patent also suggests that the dispenser assembly may use heating
elements having "other conventional forms," including an "induction
type" heating element.
[0004] The Costello patent further discloses that a heat storage
medium, such as water, alcohol, powdered metal, or the like, may be
used to absorb and retain heat generated by an electric resistance
heating coil. According to the Costello patent, the heat-retaining
medium stores heat for only a few minutes so that after the
dispenser assembly is unplugged from a wall socket, warm shaving
cream is still available for a single shave.
SUMMARY OF THE INVENTION
[0005] Our invention provides an improved heat storage unit and a
method of manufacturing the same, a dispenser assembly, and a
system for heating a flowable product, which is easy to use, fast,
safe, and is capable of heating a flowable product during extended
periods of use.
[0006] In one aspect, our invention relates to a heat storage unit
for heating a flowable product. The heat storage unit comprises a
body having a passage formed therein through which a flowable
product passes, a heatable element, and a heat-retentive material.
The heatable element is incorporated within the body in thermal
communication with the passage, and comprises either a
magnetically-compatible material or a microwave-compatible
material. The heat-retentive material is in thermal communication
with the heatable element, and comprises a solid-to-solid phase
change material.
[0007] Preferably, the heatable element comprises a
magnetically-compatible material that is heatable by locating the
heatable element in a magnetic field. The heatable element may
comprise a ferromagnetic material, such as stainless steel or a
temperature sensitive alloy, or a graphite-based material, such as
a flexible graphite-based sheeting material or a rigid
graphite-filled polymer. The heat storage unit may also include a
radio frequency identification tag that stores information about
the heat storage unit or about a flowable product used therewith.
The heat storage unit can be configured as a cartridge that is
detachably securable to a variety of different flowable product
dispensers, as an overcap for an aerosol container, or as a porous
pad.
[0008] Alternatively, instead of a magnetically-compatible
material, the heatable element may comprise a microwave-compatible
material that is heatable by exposing the heat storage unit to
microwave radiation.
[0009] In another aspect, our invention relates to a heat storage
unit for heating a flowable product that includes a body having a
passage formed therein through which a flowable product passes, a
heatable element, and a heat-retentive material. The heatable
element is incorporated within the body in thermal communication
with the passage, and comprises either a magnetically-compatible
material or a microwave-compatible material. The heat-retentive
material lines at least a portion of the passage and is in thermal
communication with the heatable element. The heatable element is
heated by locating the heatable element in a field generated
external to the heat storage unit. The heat storage unit does not
include any components for generating a field to heat the heatable
element, and, preferably, is cordless.
[0010] In still another aspect, our invention relates to a pad for
heating and dispensing a flowable product. The pad includes a
porous body and a burstable pouch. The porous body comprises a
heat-retentive material and either a magnetically-compatible
material or a microwave-compatible material. The burstable pouch
contains the flowable product, and is incorporated within the
porous body in thermal communication with the
magnetically-compatible material or the microwave-compatible
material. The flowable product is dispensed from the porous body by
compressing the burstable pouch.
[0011] In yet another aspect, our invention relates to a system
that includes a heat storage unit and a charging device. The heat
storage unit comprises a body having a passage formed therein, a
heatable element incorporated within the body in thermal
communication with the passage, and a heat-retentive material in
thermal communication with the heatable element. The heatable
element comprises either a magnetically-compatible material or a
microwave-compatible material. The heat storage unit is detachably
docked with the charging device, such that when the charging device
is activated, a field is generated that encompasses the heatable
element of the heat storage unit, thereby raising the temperature
of the heatable element.
[0012] In another aspect, our invention relates to a method of
manufacturing a heat storage unit. The method comprises the steps
of molding a heat-retentive body, molding a heatable element of
either a magnetically-compatible material or a microwave-compatible
material in thermal contact with the heat-retentive body, and
forming a passage through the heat storage unit, the passage
defining a flow path for a flowable product. An insulating layer
can be over-molded at least partially about the outside of the heat
storage unit. A radio frequency identification device can be
attached to the heat storage unit to store information about the
heat storage unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is a simplified cross-sectional view of a system
according to a first embodiment of our invention taken along line
1A-1A shown in FIG. 1D, including a heat storage unit and a
wall-mounted charging device. Hatching of the heat storage unit has
been omitted for clarity throughout the drawing figures.
[0014] FIGS. 1B and 1C are simplified cross-sectional views showing
alternative configurations of the heat storage unit of the first
embodiment of our invention, taken along line 1B-1B shown in FIG.
1D.
[0015] FIG. 1D is a perspective view showing the relationship of
the heat storage unit to the charging device in the system of FIG.
1A.
[0016] FIGS. 1E and 1F are perspective views showing various
dispenser assemblies employing a heat storage unit according to the
first embodiment.
[0017] FIG. 2A is a cross-sectional view of a hot-shave dispenser
assembly employing a heat storage unit according to a second
embodiment, attached to a wall-mounted charging device.
[0018] FIG. 2B is a perspective view of the hot-shave dispenser
assembly of FIG. 2A, attached to a wall-mounted charging
device.
[0019] FIG. 2C is a perspective view showing how, in one example,
the dispenser assembly of FIG. 2A attaches to the charging
device.
[0020] FIG. 3A is a cross-sectional view of a hot-shave dispenser
assembly employing a heat storage unit according to a third
embodiment, attached to a wall-mounted charging device.
[0021] FIG. 3B is a perspective view of the hot-shave dispenser
assembly of FIG. 3A, attached to a wall-mounted charging
device.
[0022] FIG. 4A is a perspective view of a hot-shave dispenser
assembly employing a heat storage unit according to a fourth
embodiment.
[0023] FIG. 4B is a perspective view of a system including the
hot-shave dispenser assembly and heat storage unit of FIG. 4A and a
wall-mounted charging device.
[0024] FIG. 4C is a cross-sectional view of the system of FIG. 4B,
taken along line 4C-4C shown in FIG. 4B.
[0025] FIG. 4D is a cross-sectional view of an alternative
configuration to that shown in FIG. 4C.
[0026] FIG. 4E is a cross-sectional view of another alternative
configuration to that shown in FIG. 4C.
[0027] FIG. 5A is a cross-sectional view of a hot storage unit
configured as a porous pad, in accordance with a fifth embodiment
of our invention.
[0028] FIG. 5B is a perspective view of a system including the
porous pad of FIG. 5A and a charging device.
[0029] FIG. 5C is a cross-sectional view of the system of FIG. 5B,
taken along line 5C-5C shown in FIG. 5B.
[0030] FIG. 6 is a schematic representation of the electronic
components of the charging device of the various embodiments.
[0031] FIG. 7 is a flow chart illustrating a method of
manufacturing the heat storage unit of FIG. 1A.
[0032] FIG. 8 is a flow chart illustrating a method of
manufacturing the heat storage unit of FIG. 1B.
[0033] FIG. 9 is a flow chart illustrating an alternative method of
manufacturing the heat storage unit of FIG. 1B.
[0034] Throughout the drawing figures, like or corresponding
reference numerals denote like or corresponding elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Our invention relates generally to a heat storage unit, a
dispenser assembly, and a system for heating a flowable product,
such as a cleaning solution, an air freshener, a shaving gel or
cream, a lotion, an insecticide, or the like. More specifically,
the system of our invention includes a heat storage unit 2 that is
capable of being used either as part of a dispenser assembly or
alone, and a charging device 6 for charging, or energizing, the
heat storage unit. The terms "charging" and "energizing" are used
interchangeably herein to mean to impart energy to the heat storage
unit by, among other ways, exposing the heat storage unit to a
magnetic field or to microwave radiation. The heat storage unit 2
serves to impart heat to a flowable product prior to the flowable
product being dispensed.
[0036] The heat storage unit 2 comprises a heat-retentive material
8 and a heatable element 10 arranged in thermal communication with
each other. A passage 12 is formed in the body of the heat storage
unit 2 and defines a flow path through which the flowable product
passes during dispensing. The heat storage unit 2 also may
optionally include an insulating shell layer 24 that covers at
least a portion of the surface of the heat storage unit 2. When the
heat storage unit 2 is docked with the charging device 6 and the
charging device is activated, the heat storage unit 2 develops and
stores heat, thereby becoming charged. The heat storage unit 2,
thus charged, gradually meters out heat to the flowable product in
the passage 12, so as to provide heat over an extended period of
time.
[0037] The heatable element 10 preferably comprises a
magnetically-compatible material ("MCM"). As used herein, the term
"magnetically-compatible material" means a material that is capable
of being heated by exposure to an alternating magnetic field,
specific examples of which are discussed in more detail below.
Preferably, the heatable element 10 comprises a ferromagnetic metal
or alloy, such as, for example, stainless steel or a temperature
sensitive alloy ("TSA"). TSAs lose their magnetic properties when
heated above a specific temperature, thereby providing a built-in
safety mechanism to prevent overheating. U.S. Pat. No. 6,232,585,
which is incorporated by reference herein, discloses examples of
ferromagnetic materials suitable for use as the heatable element
10.
[0038] Alternatively, the heatable element 10 could comprise a
graphite-based material, such as GRAFOIL.RTM. or EGRAF.TM.
sheeting, which are flexible graphite sheeting materials available
from Graftech Inc. of Lakewood, Ohio (a division of UCAR Carbon
Technology Corporation). Another preferred graphite-based material
is a rigid graphite-filled polymer material available under the
designation BMC 940 from Bulk Molding Compounds, Inc. of West
Chicago, Ill. Still other rigid, graphite-based materials having
smaller amounts of polymer filler than the BMC 940 may also be
used. These graphite-based materials are discussed in U.S. Pat.
Nos. 6,657,170 and 6,664,520, the disclosure of each of which is
incorporated by reference herein.
[0039] GRAFOIL.RTM. and EGRAF.TM. sheeting are graphite sheet
products made by taking high quality particulate graphite flake and
processing it through an intercalculation process using strong
mineral acids. The flake is then heated to volatilize the acids and
expands to many times its original size. No binders are introduced
into the manufacturing process. The result is a sheet material that
typically exceeds 98% carbon by weight. The materials are flexible,
lightweight, compressible, resilient, chemically inert, fire safe,
and stable under load and temperature.
[0040] GRAFOIL.RTM. or EGRAF.TM. sheeting are significantly more
electrically and thermally conductive in the plane of the sheet
than in a direction through the plane. It has been found
experimentally that this anisotropy has two benefits. First, the
higher electrical resistance in the through-plane direction allows
the material to have an impedance at 20-50 kHz that allows a
magnetic induction heater operating at such frequencies to
efficiently heat the material while the superior thermal
conductivity in the plane of the sheet enables the sheet to be
quickly and uniformly heated across its entire width. Second,
successive layers of GRAFOIL.RTM. or EGRAF.TM. sheeting can be
inductively heated simultaneously, even if each layer is
electrically insulated from the next. For example, each layer of
GRAFOIL.RTM. sheeting in a laminated structure comprising several
layers of GRAFOIL.RTM. sheeting sandwiched between layers of an
insulative or heat-retentive material can be inductively heated at
approximately equal heating rates.
[0041] The BMC 940 rigid graphite-filled polymer material also has
advantages for use as the heatable element 10 of our invention. Its
ability to be injection or compression molded into complex shapes
allows it to be easily formed into any desired shape or size.
[0042] Alternatively, instead of MCMs, the heatable element 10
could comprise a microwave-compatible material ("MiCM"). The term
"microwave-compatible material" is used herein to refer to any
dielectric insulator that absorbs energy when exposed to microwave
radiation (i.e., electromagnetic radiation having a frequency in
the range of about 300 Megahertz to about 300 Gigahertz), thereby
causing a heating effect within the MiCM.
[0043] Preferably, the heat-retentive material 8 comprises a
solid-to-solid phase change material. Solid-to-solid phase change
materials reversibly store large amounts of latent heat per unit
mass through solid-to-solid, crystalline phase transformations at
unique constant transformation temperatures that are well below
their respective melting points. The transformation temperature can
be adjusted over a wide range of temperatures, from about
25.degree. C. to about 188.degree. C., by combining different
solid-to-solid phase change materials. U.S. Pat. Nos. 6,316,753 and
5,954,984, which are incorporated by reference herein, each
contains a discussion of solid-to-solid phase change materials
suitable for use in our invention.
[0044] The solid-to-solid phase change material preferably contains
at least a polyethylene resin, and may also include structural
additives, thermal conductivity additives, antioxidants, and the
like. Preferably, at least about 70% by weight of the
heat-retentive material is a polyethylene resin, such as a low
density polyethylene resin or a linear low density polyethylene
resin. Examples of preferred resins for use in our invention
include: a linear low density polyethylene resin designated as GA
564 from Equistar Chemicals, LP of Houston, Tex.; a metallocine
linear low density resin designated as mPact D139 from Phillips
Petroleum Company of Houston, Tex.; and a low density polyethylene
resin designated as LDPE 6401 from Dow Plastics of Midland, Mich.
Other polyethylene resins of varying densities can also be used in
our invention.
[0045] One or more antioxidants may be added to the polyethylene
resin, by compounding or the like, in order to deter deterioration
of the heat-retentive material during its life of periodic exposure
to temperatures above its crystalline melting temperature. Examples
of preferred antioxidants include: IRGANOX.RTM. 1010 or
IRGANOX.RTM. 1330 produced by Ciba Specialty Chemicals of
Switzerland; UVASIL.RTM. 2000 LM produced by Great Lakes Chemical
Corporation of West Lafayette, Ind.; ULTRANOX.RTM. 641 and
WESTON.TM. 618 produced by GE Specialty Chemicals of Parkersburg,
W. Va.; and DOVERPHOS.RTM. S-9228 produced by Dover Chemical Corp.
of Dover, Ohio. Preferably, the antioxidant(s) comprise no more
than about 1.0% by weight of the heat-retentive material.
[0046] Structural and/or thermal conductivity materials, such as,
for example, chopped glass fiber, glass particles, carbon powders,
carbon fibers, and the like, may also be added to the polyethylene
resin in amounts up to about 30% by weight of the heat-retentive
material by compounding, or the like. Chopped glass fiber, for
example, imparts structural strength to the heat-retentive material
when heated above the melting point of the polyethylene resin. A
suitable chopped glass fiber is 415A CRATEC.RTM. chopped glass
strands, available from Owens Corning, which are particularly
formulated to optimize glass/polymer adhesion.
[0047] Low density polyethylene and linear low density polyethylene
resins incorporating carbon powder such as MPC Channel Black
produced by Keystone Aniline Corporation of Chicago, Ill., and
XPB-090 produced by Degussa Chemicals of Akron, Ohio, exhibit not
only improved structural integrity at high temperatures and
improved thermal conductivity, but also a reduction in the
oxidation rate of the polyethylene.
[0048] In summary, a particularly preferred heat-retentive material
8 is a solid-to-solid phase change composite having at least about
70% by weight polyethylene content and from 0% to about 30% by
weight of additives such as antioxidants, thermal conductivity
additives, structural additives, or the like.
[0049] While the use of a solid-to-solid phase change material as
the heat-retentive material is preferred for prolonged heating
applications, other heat-retentive materials that store and release
sensible heat can be used if a shorter heating period is
acceptable. Suitable alternative heat-retentive materials include
polymers such as thermoplastics, thermoset resins, and elastomers,
preferably, polyethylene, polypropylene, or nylon, to name a few
examples. Preferably, the heat-retentive material has a specific
heat of at least about 0.2 calories per gram-degree Celsius; more
preferably, at least about 0.4 calories per gram-degree Celsius;
and most preferably, at least about 0.5 calories per gram-degree
Celsius. As used, herein, the term "heat-retentive material" means
a polymeric material that has a specific heat of at least about 0.2
calories per gram-degree Celsius, preferred examples of which are
mentioned above.
[0050] The insulating layer 24 provides a surface that will remain
cool to the touch, while also limiting the dissipation of heat from
the heat storage unit 2 to the ambient surroundings. Preferably,
the insulating layer 24 includes an inner layer of insulating
material adjacent to an outer shell layer. The inner layer of
insulating material is designed to withstand the maximum
temperatures of the heat-retentive material 8 and the heatable
element 10, while at the same time providing a high insulative
value so as to prevent the surface of the adjacent outer shell
layer from becoming too hot. Many known fiber, foam, or non-woven
insulating materials may be used for this inner layer. Examples of
preferred insulating materials include MANNIGLASS.RTM. B1200 and
V1900, available from Lydall of Troy, N.Y. Many known types of
plastic materials, such as, but not restricted to, polypropylene,
polyethylene, various engineered resins, and acrylonitrile
butadiene styrene ("ABS"), can be used to construct the outer layer
of the insulating shell layer 24.
[0051] Next, several preferred embodiments of our invention are
described below. It should be understood, however, that various
features of each of these embodiments could be added, omitted,
and/or combined in different ways depending on the particular
features desired.
First Embodiment
[0052] A first preferred embodiment of our invention is described
below with reference to FIGS. 1A-1F. In this embodiment, the heat
storage unit 2 is configured as a removable, cordless cartridge
that can be used with each of a plurality of different types of
dispenser assemblies. In this embodiment, the heatable element 10
is an MCM.
[0053] In operation, the heat storage unit 2 is plugged into a
charging device 6. The charging device 6 is then activated to
generate a high-frequency alternating magnetic field F, which
causes eddy current heating, hysteresis heating, resistive heating,
or a combination of these types of heating along the path of the
constrained induced current. The heat-retentive material 8 absorbs
and retains the heat generated by the heatable element, thereby
energizing the heat storage unit 2. Once charged, the heat storage
unit 2 can be removed from the charger and installed in any one of
a number of different dispensers, such as those shown in FIGS. 1E
and 1F. The heat storage unit 2 then dissipates heat stored in the
heatable element 10 and the heat-retentive material 8 to the
flowable product. Depending on the particular application, the heat
storage unit 2 can be configured to retain its charge anywhere from
several minutes to several hours. One skilled in the art will
readily understand that the heat-retentive ability of the heat
storage unit 2 will largely depend on the size and arrangement of
the heatable element 10, the heat-retentive material 8, and the
insulating shell 24.
[0054] The heat storage unit 2 of the first embodiment may be
configured in a variety of different ways, a few of which are
illustrated by FIGS. 1A-1C. One of ordinary skill in the art will,
of course, recognize that the arrangement and size of the heatable
element 10 and the heat-retentive material 8 can be varied
depending on the desired heating parameters such as maximum
temperature, heat retention time, and energizing time, and the
desired flowable product dispensing capabilities such as dispensing
rate and quantity.
[0055] In a first variation of the first embodiment, shown in FIG.
1A, the heatable element 10 and the heat-retentive material 8 are
formed together as a uniform mixture of heatable and heat-retentive
material. The exterior of the unitary heatable element 10 and the
heat-retentive material 8 mixture is coated with an insulating
layer 24. A circuitous passage 12 is formed through the heat
storage unit 2 and defines a long flow path for the flowable
product during dispensing. An inlet 16 and an outlet 18 are formed
at opposite ends of the passage 12. The length of the circuitous
passage 12 provides a large interface between the heat storage unit
2 and the flowable product, thereby allowing heat to be rapidly
transferred to the flowable product. Preferably, the passage 12 is
at least twice as long as any dimension of the heat storage unit 2.
Since heat can rapidly be transferred to the flowable product as it
flows through the passage 12, the heat storage unit 2 is able to
provide "point of use" heating. That is, the heat storage unit 2 of
this configuration is able to heat the flowable product at
essentially the same rate it is dispensed.
[0056] In this arrangement, the heatable material and
heat-retentive material are preferably both moldable materials such
as, for example, BMC 940 graphite-filled polymer material and
solid-to-solid phase change composite material, respectively. A
method of manufacturing the heat storage unit 2 of this first
variation is described with reference to FIG. 7. First, in step
701, the heatable material and the heat-retentive material are
mixed. The mixture of the heatable material and the heat-retentive
material may be accomplished by a separate mixing process, or
alternatively, the two materials could simply be allowed to mix as
they are being injected into the molds. Next, in steps 703a and
703b, the heat storage unit 2 is molded in two separate halves.
Each half of the heat storage unit 2 is molded with half of the
contour of the circuitous passage 12. The first and second halves
of the heat storage unit 2 are then ejected from their respective
molds in steps 705a and 705b. The two halves of the heat storage
unit 2 are then arranged adjacent one another and melt-bonded
together in step 707 with the passage 12 extending therethrough. In
step 709, the insulating layer 24 is over-molded about the outside
of the heat storage unit 2. While the heat storage unit 2 is
described, with reference to FIG. 7, as being formed in two halves
and then melt-bonded together, the heat storage unit 2 could
alternatively be molded as a single unit. Moreover, the heat
storage unit 2 of this variation could be manufactured by injection
molding, compression molding, or any other suitable molding
technique.
[0057] FIG. 1B illustrates a second variation of the first
embodiment. In this second variation, the heat storage unit 2 is
constructed similarly to the first variation shown in FIG. 1A,
except that instead of the heatable element 10 and the
heat-retentive material 8 being formed together as a mixture of
heatable and heat-retentive materials, these two elements are
discretely formed, as described below with reference to FIG. 8. In
this variation, heatable material is provided in step 801. In steps
803a and 803b, the heatable element 10 is molded in two separate
pieces, each piece defining half of the passage 12. The two halves
are then ejected from their respective molds in step 805a and 805b.
In step 807 the two halves of the heatable element 10 are assembled
adjacent one another and melt-bonded together to form the heatable
element 10 with the passage 12 formed therethrough. The
heat-retentive material is then over-molded about the exterior of
the heatable element 10 in step 809 to form the heat storage unit
2. The insulating layer 24 is over-molded about the outside of the
heat storage unit 2 in step 811. In this variation, the passage 12
is configured as a circuitous passage, substantially the same as
that depicted in FIG. 1A and discussed above. The materials used
for the heat-retentive material 8 and the heatable element 10 are
preferably the same as those discussed above with respect to FIG.
1A.
[0058] In an alternative construction, the second variation of the
first embodiment could be constructed with the heat-retentive
material 8 at its interior. The method of manufacturing this
particular alternative is described with reference to FIG. 9. In
this alternative of the second variation, heat-retentive material
is provided in step 901. In steps 903a and 903b, the heat-retentive
material 8 is molded in two separate pieces, each piece defining
half of the passage 12. The two halves of the heat-retentive
material 8 are then ejected from their respective molds in step
905a and 905b. In step 907, the two halves of the heatable element
10 are joined together by, for example, melt-bonding, to form the
heat-retentive material 8 with the passage 12 formed therethrough.
The heatable material is then over-molded about the exterior of the
heat-retentive material 8 in step 909 to form the heat storage unit
2. The insulating layer 24 is over-molded about the outside of the
heat storage unit 2 in step 911.
[0059] FIG. 1C illustrates a third variation of the first
embodiment. In this variation, the heat-retentive material 8 and
the heatable element 10 are formed separately. Instead of a long
circuitous passage as in the first two variations, the passage 12
in this variation comprises an enlarged reservoir 20 formed in the
interior of the heat storage unit 2. The reservoir 20 has an inlet
16 and an outlet 18 positioned at substantially opposite ends of
the reservoir 20, and defines a flow path for the flowable product.
The reservoir 20 is sized to hold at least one dose, and as many as
five doses, of the flowable product. A "dose" of the flowable
product, as used herein, is defined as the amount of the product
typically dispensed with each actuation of a particular dispenser
assembly. (For example, an average dose of shaving cream or gel is
between about 5 grams and about 15 grams, while an average dose of
liquid cleanser dispensed from a spray bottle dispenser is between
about 0.5 grams and about 1.5 grams.) This arrangement, in which
only a small amount of the flowable product is heated, is known as
"one shot" heating. In other words, a finite number of shots or
doses (at least one) of material is heated at a given time. This
type of arrangement may be preferable when the flowable product is
to be heated to a high temperature, or when the size and cost of
the heat storage unit 2 are considerations. Also, applications such
as lotion dispensers, spray bottles, and shaving creams or gels, in
which only a few doses of product are successively dispensed at one
time, are particularly amenable to this type of "one shot"
heating.
[0060] The heatable element 10 in the third variation comprises a
number of strips of GRAFOIL.RTM. or EGRAF.TM. sheeting positioned
in the interior of the reservoir 20, such that they will be in
direct contact with the flowable product contained therein. As can
be seen in FIG. 1C, the heat-retentive material 8 is in thermal
communication, but not necessarily direct contact, with the
heatable element 10. That is, heat is transferred to the
heat-retentive material 8 via conduction through the flowable
product. FIG. 1C depicts the heatable element 10 as a pair of
parallel strips, however, any number of strips may effectively be
used. It should be apparent that the greater the total surface area
of the strips (as determined by the size, shape, and number of the
strips), the faster the heatable element 10 will be able to heat
the flowable product. Thus, the size, shape, and number of strips
making up the heatable element 10 in this third variation of the
first embodiment can be chosen based on the type of flowable
product used and the desired rate of heating. Furthermore, various
other arrangements of the heat-retentive material 8 and heatable
element 10 are also available, as would be understood by one of
ordinary skill in the art. For example, the location of the
heatable element 10 and the heat-retentive material 8 could be
reversed, the heatable element 10 and the heat-retentive material 8
could be located directly adjacent to one another either inside or
outside the reservoir, etc.
[0061] Furthermore, one of ordinary skill in the art will recognize
that the "point of use" heat storage units 2 shown in FIGS. 1A, 1B,
and 3A, could also be effectively used for "one shot" heating by
simply reducing the length of the passage 12 formed therein. Since
the heat storage unit 2 need not heat the flowable product as fast
as it is dispensed in a "one shot" system, the passage need only be
long enough to accommodate one dose or shot of the flowable product
at a time. In this modified arrangement, the passage 12 would
function essentially as a long, narrow version of the reservoir of
FIGS. 1C and 2A. By using the shortened passage 12 in this
variation, the size of the heat storage unit 2, and consequently
the cost, would be advantageously reduced. Conversely, if the
surface area of the heatable elements 10 in the "one shot" heat
storage units 2 of FIGS. 1C and 2A was increased, it would be
possible to achieve a heat transfer rate sufficient for "point of
use" heating with this type of arrangement as well. This increase
in surface area of the heatable element might be accomplished by,
for example, increasing the number of strips, making the strips
longer and thinner, and/or making the strips corrugated or
accordion-shaped.
[0062] As described above, the cartridge heat storage units 2 of
the first embodiment can be used with various types of dispenser
assemblies. FIG. 1E illustrates a cartridge heat storage unit 2
according to the first embodiment inserted in a hand-held scrub
brush dispenser 200. The passage 12 in the heat storage unit 2
forms part of a dispensing path of the flowable product through the
scrub brush dispenser. The scrub brush dispenser 200 has a
container 30 for housing a flowable product, such as a cleaning
solution, and an actuator 36 connected to a pumping device (not
shown) for dispensing the flowable product. When a user depresses
the actuator 36, the flowable product is pumped from the container
30, through the heat storage unit 2, and out of a dispenser exit
opening (not shown) formed in the bottom of the scrub brush
dispenser 200. Each single depression of the actuator 36 expels one
dose of the heated flowable product.
[0063] FIG. 1F depicts a cartridge heat storage unit 2 according to
the first embodiment inserted in a spray bottle dispenser 100. The
spray bottle dispenser 100 functions similarly to the scrub brush
dispenser 200 and also includes a container 30 for holding a
flowable product, such as a cleaning solution, and an actuator 36
connected to a pumping device (not shown) for dispensing the
flowable product. When the actuator 36 of the spray bottle
dispenser 100 is pressed, the flowable product is pumped from the
container 30, through the heat storage unit 2, and out of a
dispenser exit opening 38 as a heated spray. Each single depression
of the actuator 36 expels one dose of the heated flowable
product.
[0064] The charging device 6 of the first embodiment, as best seen
in FIG. 1A, generally comprises an electrical plug deck 64, a
circuit board 50, a magnetic field generator 52, and a detection
device 58.
[0065] The plug deck 64 is conventional and serves to both supply
power from a standard alternating current (A/C) wall socket S to
the other electronics of the charging device 6, and to support the
charging device 6 in the wall socket S. Alternatively, the charging
device can be equipped with an electrical adapter cord (not shown)
for connection to a remote outlet or to a vehicle lighter socket,
or the charging device might be configured as a battery-powered
portable or table-top unit.
[0066] When activated, the field generator 52 generates a
high-frequency, alternating magnetic field F that induces an
electromotive force ("EMF") in the heatable element 10. In a
preferred embodiment, the EMF induced in the heatable element 10
spawns "eddy currents," which cause the element 10 to heat up in
direct relation to the power (I.sup.2R) of the current through the
element 10. It should be understood, however, that the heatable
element in other embodiments of our invention can also be designed
to experience Joule heating via magnetically induced currents
constrained to flow in a wire segment of the heatable element
and/or to experience hysteresis heating as a result of its presence
in the magnetic field.
[0067] As shown in more detail in FIG. 6, the circuit board 50
preferably includes (i) a rectifier 54 for converting alternating
current from the wall outlet to direct current, (ii) a solid-state
inverter 68, coupled to the rectifier 54, for converting the direct
current into ultrasonic frequency current for powering the field
generator 52 (preferably from about 20 kHz to about 100 kHz), and
(iii) a microprocessor-based control circuit 56, including a
microprocessor operably coupled with the inverter 68 for control
thereof. The control circuit 56 may also include a circuit
parameter sensor 70 coupled with the control circuit 56 for
measuring a parameter related to or dependent on the load
experienced by the circuit. This parameter sensor 70 can be, for
example, a current sensor within the inverter 68 that measures
current through one of the inverter's switching transistors. An
indicator light 62 can also be provided to signal, for example,
when the field generator 52 is activated and/or when the heat
storage unit 2 is fully charged.
[0068] Preferably, the field generator 52 comprises a copper-based
induction coil that is either printed on or otherwise applied to
the circuit board 50. The field generator 52 could alternatively be
comprised of other metal or alloy wires or coils that generate a
magnetic field when alternating current is passed through them, and
may be embodied as a separate element from the circuit board 50, as
shown in the drawing figures. Induction coils can have either flat
or curved configurations, but a cylindrical coil is preferred
because it provides the most efficient heating. Preferably, the
induction coil is positioned such that when the heat storage unit 2
is docked with the charging device 6, the distance between the
induction coil and the heatable element 10 is less than about 0.7
cm. Larger distances can be used, but will require more power to be
supplied to the induction coil to generate a magnetic field large
enough to heat the heatable element 10, since the required power is
proportional to the square of the distance between the coil and the
heatable element.
[0069] As described above, the magnetic field is generated external
to the heat storage unit 2, i.e., by the charging device 6, and the
heat storage unit 2 does not itself include any components for
generating the magnetic field. Alternatively, the induction coil 52
can be incorporated within the body of the heat storage unit 2, in
fixed proximity to the heatable element 10, as shown in FIG. 4E.
Opposite ends of the induction coil 52 can be electrically
connected to a pair of electrical contacts 28 that is accessible
from the exterior of the heat storage unit 2. Meanwhile, the
charging device 6 has a pair of corresponding electrical contacts
72 that, when the heat storage unit 2 is docked with the charging
device 6, provides an electrical connection between the induction
coil 52 and the plug deck 64 of the charging device 6.
[0070] Optionally, a radio-frequency identification ("RFID") reader
or reader/writer 58 can also be coupled to the control circuit 56.
RFID is a type of automatic identification technology, similar to
bar code technology, except that RFID uses radio frequency instead
of optical signals. The reader (or reader/writer) 58 produces a
low-level radio frequency magnetic field, typically either at 125
kHz or at 13.56 MHz. This magnetic field emanates from the reader
(or reader/writer) 58 by means of a transmitting antenna 132,
typically in the form of a coil. Meanwhile, the heat storage unit 2
can include an RFID tag 22 (as best seen in FIGS. 1D and 2A), which
typically includes an antenna and an integrated circuit (not
shown). The RFID tag 22 is preferably affixed to the outside of the
heat storage unit 2, such as by adhesive, bonding, fasteners, or
the like. Alternatively, the RFID tag 22 may be formed integrally
with the heat storage unit 2, such as, for example, by being molded
within a portion of the heat storage unit 2, or applied to the
container 30.
[0071] The RFID system can be either a read-only or a read/write
system. Read-only systems, as their name suggests, permit the
reader to receive information from the tag, but not vice versa.
Read/write systems, on the other hand, permit two-way communication
between the tag and the reader/writer, and each of these components
typically includes an electronic memory for storing information
received from the other component. The preferred embodiment
described herein utilizes a read/write RFID system.
[0072] In order to assure high integrity, interference-free
transmissions between the RFID tag 22 and the reader/writer 58, the
control circuit 56 preferably limits transmissions between the tag
22 and the reader/writer 58 to times when the field generator 52 is
not generating a magnetic field F. Some RFID systems, however, such
as the TagSys C330 RFID tag and P031 RFID reader are able to
communicate even when the field generator 52 is generating a
magnetic field F.
[0073] The RFID tag 22 can be used to signal the reader/writer 58
whenever an appropriate heat storage unit 2 is placed in the
charging device 6, so that the control circuit 56 can activate the
field generator 52. Thus, the field generator 52 will not be
activated if an improper object, or no object at all, is placed in
the charging device 6. Applying an RFID tag 22 to the container 30,
instead of or in addition to the heat storage unit 2, can prevent
charging of the heat storage unit if an inappropriate container is
connected to the heat storage unit, or if no container is connected
to the heat storage unit, thereby enhancing the safety of the
system.
[0074] In a more advanced embodiment, the RFID tag 22 can also
transmit to the reader/writer 58 information regarding preferred
heating conditions (e.g., heat at 180.degree. F. (82.2.degree. C.)
for five minutes, "off" for one minute, and so on) for the
particular heat storage unit 2 used. The RFID tag 22 can also be
used to transmit information to the reader/writer 58 regarding the
identity of the flowable product to be used with the heat storage
unit 2, such as, for example, a liquid cleaning solution, shaving
cream or gel, lotion, or the like, in addition to or instead of
transmitting detailed heating instructions. The control circuit 56,
meanwhile, may also include an electronic memory 134 having stored
therein multiple heating algorithms, each one designed for heating
a different type of flowable product formulation. Thus, whenever a
heat storage unit 2 containing a particular type of flowable
product is placed in the charging device 6, the RFID tag 22
transmits to the reader/writer 58 the identity of the flowable
product, and the control circuit 56 initiates the appropriate
heating algorithm for that formulation.
[0075] Optionally, there may be provided a writable electronic
memory (not shown) associated with the RFID tag 22. The writable
electronic memory may contain stored information, which is
periodically updated by transmissions from the reader/writer 58,
such as information relating to the heating history of the heat
storage unit 2. This way, a real-time clock 136 connected to the
control circuit 56 can keep track of how long a particular heat
storage unit 2 has been heated and how recently. In this manner,
the control circuit 56 can effectively prevent overheating of the
heat storage unit 2, as in the case when the heat storage unit 2
has not fully dissipated the heat stored therein when it is again
plugged into the charging device 6. Instead of, or in addition to,
the electronic memory, the RFID tag may be provided with a
temperature sensor (not shown). An example of a read/write system
with temperature sensing capability is the TagSys C330 RFID tag
with an external temperature sensor and the accompanying P031 RFID
reader, mentioned above. The temperature sensor can be placed in
thermal communication with the portion of the heat storage unit 2
whose temperature is advantageously monitored during the charging
process, and thus is useful in preventing the heat storage unit 2
from being over-charged. It is also possible for the temperature
sensor to indicate to a user, either graphically, pictorially, or
audibly, the temperature of the heat storage unit 2.
[0076] Alternatively, if an MiCM is used as the heatable element
10, the charging device may be configured to generate an electric
field having a frequency in the microwave range. The microwave
charging device could be configured either as a specialized
charging device similar to that of FIG. 1A except having a
microwave generator rather than a magnetic field generator, or as a
conventional microwave oven.
Second Embodiment
[0077] A second preferred embodiment of our invention is described
with reference to FIGS. 2A-2C. In this embodiment, as best seen in
FIG. 2A, the heat storage unit 2 is configured as an overcap 40
that is detachably securable to a pressurized container 30 that
contains a flowable aerosol product. The overcap 40 and container
30 together comprise an aerosol dispenser assembly 300. The overcap
40 is detachably secured to the container 30 by a retaining lip
formed in the interior of the overcap 40. In this embodiment, the
overcap 40 substantially covers the exterior of the container 30.
The overcap 40 is adapted to engage an attachment portion 66 formed
on the charging device 6 for storage and during charging.
[0078] The heat storage unit 2 of this embodiment is configured
similarly to the third variation of the first embodiment, discussed
above and depicted in FIG. 1C. The heat storage unit 2 of this
embodiment is configured with the heat-retentive material 8 and the
heatable element 10 formed separately. The passage in this
embodiment is an enlarged reservoir 20 formed in the interior of
the heat storage unit 2. The reservoir 20 has an inlet 16 and an
outlet 18 positioned at substantially opposite ends of the
reservoir 20, and defines a flow path for the flowable product. The
reservoir 20 is sized to hold at least one dose, and as many as
five doses, of the flowable product, i.e., it is a "one shot"
system as described above. A valve stem 34 is disposed in an
opening 32 formed in the top of the container 30, and is in
communication with the inlet 16 of the heat storage unit 2. An
actuator 36 is formed in the overcap 40 directly above the valve
stem 34. When the actuator 36 is depressed, it in turn depresses
the valve stem 34, thereby causing flowable product to be propelled
from the pressurized container 30, through the inlet 16, into the
reservoir 20 where the flowable product is heated, and ultimately
out the outlet 18 to be dispensed.
[0079] The charging device 6 of this embodiment includes
substantially the same components disclosed above with respect to
the first embodiment, including an electrical plug deck 64, a
circuit board 50, a magnetic field generator 52, and a detection
device 58. The circuit board 50 includes, among other elements, a
control device 56 and a solid-state inverter 68. In this
embodiment, shown in FIG. 2A, the rectifier 54 is depicted as a
separate unit, although this arrangement is not crucial to the
function of this embodiment. The detection device is preferably an
RFID reader/writer 58 and communicates with an RFID tag 22 in the
dispenser housing 40 in the same manner in as the first embodiment
described above. Furthermore, the charging device of this
embodiment includes an activator switch 60 for manually activating
the charging device 6 to begin charging the heat storage unit 2,
and an indicator light 62 for indicating when the charging device 6
is charging. If the RFID tag is a passive, read-only device, then
it is preferably arranged parallel to the reader and no more than
about 3-4 cm from the antenna. Active tags, on the other hand, need
not be parallel, and can be read/written to by the detection device
58 from significantly greater distances.
[0080] If the charging device 6 includes both an RFID reader/writer
58 and a manual activator switch 60, as shown in FIG. 2A, the
charging device 6 will not be activated to generate a magnetic
field F until the RFID reader/writer 58 detects that the dispenser
assembly 300 is placed in the attachment portion 66 and the
activator switch 60 is subsequently depressed. Thus, a user may
attach the dispenser assembly 300 to the attachment portion 66
simply for storage. When the user is next ready to use the
dispenser assembly 300, he or she simply has to depress the
activator switch 60, thereby activating the charging device 6 to
generate a magnetic field F to charge the heat storage unit 2. The
charging device will notify the user by one of the previously
discussed indications (i.e., either indicator light 62 or an
audible signal) when the heat storage unit 2 is fully charged.
Third Embodiment
[0081] A third preferred embodiment of our invention is described
with reference to FIGS. 3A and 3B. As best seen in FIG. 3A, the
heat storage unit 2 is again configured as an overcap 40 of an
aerosol dispenser assembly 300. This embodiment is similar to the
second embodiment in many aspects. In this embodiment, however, the
overcap 40 of the dispenser assembly 300 is smaller and fits only
over the top portion of a container 30.
[0082] The heat storage unit 2 of this embodiment is permanently
installed with the housing 40 of the aerosol dispenser assembly 300
during the manufacturing process. However, in this embodiment, the
heat storage unit 2 is configured as a "point of use" heat storage
unit, similar to that of the first variation of the first
embodiment shown in FIG. 1A. The heat storage unit 2 is constructed
with the heatable element 10 and the heat-retentive material 8
formed together as a uniform mixture of heatable and heat-retentive
material. The exterior of the heatable element 10 and the
heat-retentive material 8 mixture is coated with an insulating
layer 24. A circuitous passage 12 is formed through the heat
storage unit 2 and defines a long flow path for the flowable
product during dispensing. An inlet 16 and outlet 18 are formed at
opposite ends of the passage. An actuator 36 is formed in the
overcap 40 directly above the heat storage unit 2. When the
actuator 36 is depressed, it in turn depresses the heat storage
unit 2, thereby depressing the valve stem 34 and causing flowable
product to be propelled from the pressurized container 30, through
the inlet 16, through the circuitous passage 12 where the flowable
product is heated, and ultimately out the outlet 18 to be
dispensed.
[0083] The charging device 6 of the third embodiment is
substantially similar to that of the second embodiment, except for
the absence of a manual activation switch and the particular
configuration of the attachment device 66. In the third embodiment,
the attachment device 66 takes the form of an arcuate support arm,
which fits around the circumference of the container 30 to secure
the dispenser assembly 300 to the charging device 6. The charging
device 6 includes an electrical plug deck 64, a circuit board 50, a
magnetic field generator 52, and a detection device 58. A detailed
description of the various electrical components will be omitted
since these elements have been previously discussed in detail in
the description of the first and second embodiments.
Fourth Embodiment
[0084] A fourth preferred embodiment of our invention is described
with reference to FIGS. 4A-4E. In this embodiment, the heat storage
unit 2 is configured as an overcap 40 that is detachably securable
to an aerosol container 30 that contains a flowable product such
as, for example, shaving gel. The overcap 40 and container 30
together comprise an aerosol dispenser assembly 300. The overcap 40
is detachably secured to the container 30 by a retaining lip formed
in the interior of the overcap 40. The overcap 40 can be detached
from the container 30 by pressing a release button 42. The
dispenser assembly 300 of this embodiment is used in conjunction
with a charging device 6 that has an opening through which the
overcap 40 extends when the dispenser assembly 300 is docked with
the charging device 6. The overcap 40 can be secured within the
charging device 6 by any suitable means, such as, for example, the
coupling assembly disclosed in commonly-assigned U.S. Pat. No.
6,415,957, the disclosure of which is incorporated by reference
herein.
[0085] In a first variation of this embodiment, shown in FIG. 4C,
the heat storage unit 2 includes a reservoir 20 that is defined by
a chamber comprising the heatable element 10. The heatable element
10 preferably comprises magnetically-compatible stainless steel
having a thickness between about 0.14 cm to about 0.24 cm (about
0.055 inch to about 0.095 inch), most preferably 430 grade
stainless steel with a thickness of about 0.19 cm (0.075 inch). A
sleeve comprising a heat-retentive material 8, preferably
polyethylene having a thickness of about 0.25 cm (0.1 inch), lines
the interior of the reservoir 20. The overcap 40 preferably also
includes an insulating shell 24 made of polypropylene, ABS, or the
like. An air gap 26 may optionally be provided between the heatable
element 10 and the insulating shell 24 to provide additional
insulation.
[0086] The reservoir 20 has an inlet 16 and an outlet 18 positioned
at substantially opposite ends of the reservoir 20. The reservoir
20 is sized to hold at least one dose, and as many as five doses,
of the flowable product, i.e., it is a "one shot" system. A valve
stem 34 is disposed in flow communication with the inlet 16. The
overcap 40 includes an actuator 36 which, when depressed, causes
the flowable product to be propelled from the pressurized container
30, through the inlet 16, into the reservoir 20 where the flowable
product is heated, and ultimately out the outlet 18.
[0087] The charging device 6 of this embodiment includes
substantially the same components disclosed above with respect to
the third embodiment, including, among other things, a plug deck
64, a circuit board 50, an induction coil 52 for generating a
magnetic field F, an activator switch 60, an indicator light 62,
and an RFID reader (not shown) that detects an RFID tag (also not
shown) applied to or incorporated within the overcap 40 or the
container 30.
[0088] In operation, the charging device 6 can be activated
automatically, such as when it is detected that the heat storage
unit 2 is docked with the charging device 6, or manually, by
pressing the activator switch 60. The indicator light 62 can, for
example, be programmed to blink red while the heat storage unit 2
is charging, and turn green when the heat storage unit 2 is fully
charged.
[0089] The temperature to which the heatable element 10 is heated
depends on several factors, including the desired temperature to
which the flowable product is to be heated, as well as the
structure of the heat storage unit 2. Shaving gel, for example,
preferably is heated to a temperature of between about 49.degree.
C. to about 60.degree. C. (about 120.degree. F. to about
140.degree. F.). If the heat unit storage unit is configured as
shown in FIG. 4C and described above, this requires heating the
heatable element 10 to a temperature of between about 54.degree. C.
to about 79.degree. C. (about 130.degree. F. to about 175.degree.
F.).
[0090] A second variation of the fourth embodiment is illustrated
in FIG. 4D. In this variation, the reservoir 20 is defined by a
chamber comprising the heat-retentive material 8, such as
polyethylene or polypropylene. The exterior of the chamber is lined
by a sleeve comprising the heatable element 10. The chamber can be
is formed by injection molding, for example. Alternatively, the
chamber could be manufactured as an extruded sleeve in which the
heatable element, preferably GRAFOIL.RTM. sheeting, is sandwiched
between layers of the heat-retentive material. In yet another
alternative embodiment, the heatable element comprises a porous,
mesh-like, MCM, preferably stainless steel, that is disposed within
the chamber, which is preferably made of polyethylene. Because the
mesh is porous, the flowable product is able to pass directly
through the heatable element, thereby enabling rapid heating of the
flowable product.
[0091] Preferably, in all of the aforementioned embodiments, the
heat storage unit 2 and charging device 6 are configured such that
the maximum distance between the heatable element 10 and the
induction coil 52 is no more than about 0.64 cm (0.25 inch). Larger
distances can be used, but will require a greater input of energy
to the coil to generate a field large enough to heat the heatable
element.
[0092] A third variation of the fourth embodiment is illustrated in
FIG. 4E. This variation is similar to the embodiment shown in FIG.
4C, except that the induction coil 52 is incorporated within the
overcap 40, and corresponding electrical contacts 28 and 72 are
provided on the overcap 40 and the charging device 6,
respectively.
Fifth Embodiment
[0093] A fifth preferred embodiment of our invention is described
with reference to FIGS. 5A-5C. In this embodiment, the heat storage
unit 2 is configured as a flexible, porous pad 44 that functions as
a "hot sponge" for cleaning or personal care treatment applications
such as shaving, for example. A burstable pouch 14, also known as a
blister pack, is incorporated within the pad 44 and contains a
flowable product, such as a cleaning solution or shaving gel.
Suitable burstable pouches for use in our invention are available
from Klocke of America, Inc., among others.
[0094] The pad 44 comprises a combination of heat-retentive and
heatable materials 8, 10. Preferably, the pad comprises two or
three layers of GRAFOIL.RTM. sheeting, with each layer being
sandwiched between a layer of a solid-to-solid phase change
material. Alternatively, the pad could comprise flakes of the
heatable material dispersed throughout the heat-retentive material.
In still further variations, the pad could be comprised of graphite
fibers interspersed within a woven polymer matting material, or the
pad could be comprised of a woven graphite fiber matting material
interwoven with heat-retentive polymer fibers.
[0095] As with the previous embodiments, the heat storage unit 2 of
FIGS. 5A-5C is energized using a charging device 6. The charging
device 6 contains substantially the same functional components
previously described, including, among other things, a circuit
board 50, an induction coil 52 for generating a magnetic field F,
an activator switch 60, and an indicator light 62. In the
embodiment illustrated in FIGS. 5B and 5C, the charging device is
activated manually by pressing the activator switch 60 when the pad
44 is docked with the charging device 6.
[0096] In operation, the flowable product is dispensed from the pad
44 by exerting pressure on the pad 44, which in turn compresses the
burstable pouch 14 and forces the flowable product out of the pouch
and into the pad 44. The pad 44 is porous and contains numerous
passages therein through which the flowable product passes. As the
flowable product makes its way through these passages, the flowable
product is warmed by the heatable and heat-retentive materials that
make up the pad.
[0097] The entire pad 44, including the burstable pouch 14, could
be made to be disposable once the flowable product is depleted, or
the pad 44 could be reused and just the pouch could be replaced as
needed. Alternatively, the pad need not even include a burstable
pouch, and could be used simply by applying the flowable product
directly onto the pad prior to or shortly after heating.
[0098] While our invention has been described with respect to
several preferred embodiments, these embodiments are provided for
illustrative purposes only and are not intended to limit the scope
of the invention. In particular, we envision that the various
features of the several embodiments of our invention may be
combined and modified to suit the needs of a particular
application. For example, the heat storage units of our invention
could advantageously be used with any sort of dispenser and with
any sort of flowable product where it is desirable to dispense the
flowable product at an elevated temperature. Thus, other
applications that might benefit from the advantages of our
invention include, personal products, such as hair spray, hair gel,
mousse, shampoo, conditioner and the like, food products, such as
condiments, ice cream toppings (hot fudge, caramel, etc.), soups,
and the like, industrial products, such as paint sprayers, pressure
washers, and the like, as well as numerous other applications.
Moreover, the preferred methods described for manufacturing the
heat storage unit of our invention are merely representative. The
various method steps described herein can be performed in different
combinations and sequences with each other and with other method
steps not specifically described herein.
[0099] Although specific components, materials, configurations,
arrangements, etc., have been shown and described with reference to
several preferred embodiments, our invention is not limited to
these specific examples. One of ordinary skill in the art will
realize that various modifications and variations are possible
within the spirit and scope of our invention, which is intended to
be limited in scope only by the accompanying claims.
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