Electrically heated vapor dispensing apparatus

An electrically heated apparatus for dispensing fragrancing materials and other volatile substances to an enclosed volume such as the interior of a room which includes a base having a base portion which is generally planar in structure having a top surface, and a bottom surface from which extends perpendicularly two (or more) suitably dimensioned electrical plugs. The base portion further includes incorporated within its construction a heating means which, when the electrical plugs are connected to a suitable electrical source, said heating means is energized, resulting in the heating of the base portion. Further, the base portion of the invention includes a radiator means. The apparatus further includes a volatile substance container which contains a quantity of a volatile substance such as a fragrance or perfume, a disinfecting composition, or an insecticide. The radiator means provides a surprisingly uniform temperature across the top surface of the base portion.

The present invention relates to electrically heated vapor dispensing 
apparatus of the type commonly used for dispensing fragrancing materials 
and other volatile substances to an enclosed volume such as the interior 
of a room. 
Electrically heated vapor dispensing apparatus of different types are known 
to the art. For example, from UK patent application No. 2117639 to 
Brookes, therein is described an air freshening device which includes an 
electrical plug having a base, a lid, and a heat barrier plate interposed 
therebetween. The device further includes an impregnated paper tablet and 
vertical air flow passages. The lid further includes a heating element as 
well as a light emitting diode indicating operation of the heating 
element. In use, the impregnated paper tablet is heated by the heating 
element, thus volatilizing the material contained therein, generally a 
perfume, which then passes through the vertical air flow passages to the 
surrounding ambient environment. A further device is one which is 
disclosed in EP Appn. 92101394.2 to Lempidakis wherein is also provided an 
electrically heated air freshening device having means for controlling 
natural airflow through the device and thereby release of a volatile 
substance. 
Therein is also described in U.S. Pat. No. 5,402,517 to Gillett an 
apparatus for emitting a volatile chemical agent, with means for adjusting 
the heating of a volatilizable material. 
There is also known a tamper resistant container for use in conjunction 
with an electrically heated vapor dispensing apparatus from U.S. Pat. No. 
4,849,606 to Martens III. The Martens' device includes a tamper resistant 
package which includes a container having a free-standing rib extending 
from the bottom in an upward direction. The open side of the container is 
covered with a vapor permeable membrane, and the container itself contains 
a quantity of a fragrance material in a carrier gel. The technical 
advantage of such container is recited as a reduced propensity for the 
damage of the membrane during the handling and insertion of said container 
into an electrically heated vapor dispensing apparatus which is 
dimensioned for receiving the container. 
While these recited apparatus are useful, they are not without their 
disadvantages, a major disadvantage being in that they are either 
complicated in their construction and consequently are labor intensive in 
their manufacture and/or are expensive in their design and consequently 
are not particularly suited to be used as single-use, i.e., disposable 
devices. These and other shortcomings present in prior art devices also 
evidence the real and continuing need for improvements to electrically 
heated vapor dispensing apparatus. These and other shortcomings present in 
prior art devices have prompted the inventors to produce the present 
invention. 
Accordingly, it is an object of the invention to provide an electrically 
heated vapor dispensing apparatus which is relatively simple in its 
construction, is effective in dispensing an amount of a volatile substance 
to an ambient environment such as the interior of a room, and due to its 
economic materials and method of construction, may be disposed of after 
one use. 
It is a further object of the invention to provide an improved electrically 
heated vapor dispensing apparatus which may be used a plurality of times 
in conjunction with a replaceable volatile substance in a suitable 
container. 
It is a yet further object of the invention to provide an improved method 
for the manufacture of an electrically heated vapor dispensing apparatus. 
It is a still further object of the invention to provide a method for 
dispensing a volatile substance to an ambient environment such as a closed 
room or any other closed space which comprises the step of: providing an 
electrically heated vapor dispensing apparatus as described herein which 
is in electrical connection with a suitable power source.

The electrically heated vapor dispensing apparatus according to the 
invention includes a base portion which is generally planar in structure 
having a top surface, and a bottom surface from which extends 
perpendicularly two (or more) suitably dimensioned electrical plugs. The 
base portion further includes incorporated within its construction a 
heating means which, when the electrical plugs are connected to a suitable 
electrical source, said heating means is energized, resulting in the 
heating of the base portion. Further, the base portion of the invention 
includes a radiator means which is in physical contact with the top 
surface of the base portion and preferably is coincident with 
substantially the entire top surface of the base portion such that the 
radiator means is a thin sheet or film layered and registered in 
contacting the top surface. 
Turning now to FIG. 1, there is depicted a base portion (10) according to a 
preferred embodiment of the present invention. The base portion includes a 
base (12) which has a top surface (not shown) which is substantially 
completely covered by the radiator means (14) which is layered in register 
and in physical contact therewith. The base portion further includes 
electrical plugs (16) which in the present and following figures 
illustrating the invention, are two spade type plugs which are in 
conventional use in North America. It is to be understood however that 
other configurations for suitable electrical plugs may be used for example 
those of circular cross section such as are in present use in Europe, 
three spade type plugs having the configuration in conventional use in the 
United Kingdom, as well as spade type plugs at a tilted or slanted angle 
as is in conventional use in Australia. The precise dimensions and 
configuration of these electrical plugs are not critical, but need only 
correspond to the dimensions required for the electrical wall receptacles 
into which the electrical vapor dispensing apparatus is intended to be 
connected to a suitable power source. Thus, by variation of these 
electrical plugs (16), the apparatus according to the present invention, 
may be readily adapted to be used virtually anywhere in the world. 
With regard to the radiator means (14), said means is a heat conducting 
material and is preferably a thin plate, sheet, film, or tape which may be 
readily affixed to the top surface of the base portion and to 
substantially cover (which is to be understood as most, i.e., in excess of 
75% of the of the area) of the top surface. Most desirably, the radiator 
means is a thin metal or metallic film or foil having a thickness of 
between about 0.01 to about 2 millimeters, and more preferably from about 
0.1-1 millimeter. Such a plate, sheet, film, or tape may simply layered or 
stacked on top of the top surface of the base (12). Desirably, such a 
plate, sheet, film, or tape is directly applied to the top surface of the 
base (12) with the aid of a suitable adhesive material interposed between 
the radiator means (14) and the top surface of the base (12). Such an 
adhesive material is desirably present in an amount which is sufficient to 
provide proper adhesion between the top surface of the base and the 
radiator means. Further, desirably such an adhesive layer is not so thick 
as to substantially reduce the transfer of heat from the base to the 
radiator means. Desirably, the radiator means is a metallic plate, sheet, 
film or tape such one formed from on including iron, gold, silver, lead, 
chromium, aluminum, nickel, copper of virtually any other heat conducting 
metal including alloys which includes of one or more of the above such as 
brass, bronze, tin and zinc, as well as ferrous alloys, stainless steel, 
aluminum alloys and the like. Most desirably the radiator means (14) is 
tape or film having an adhesive deposited on one side which is then 
readily adherable to the top surface of the base (12). 
Alternatively, the radiator means (14) may be a metallic material or a 
material which contains metallic particles other than those recited above 
which are applied to the top surface of the base (12). For example, 
radiator means (14) may be directly deposited by vapor deposition 
techniques, or may be a metallic material or metallic particle containing 
material which is applied by sputter-coating techniques, as well as 
mteallic particles contained within a coating composition which may be 
directly laid on the top surface, such as be screen printing techniques. 
In such a method, the coating composition may require subsequent drying or 
curing of said composition prior to the use of the apparatus according to 
the invention. 
Turning now to FIG. 3, therein is depicted a side view of the base portion 
(10) according to FIG. 1. As is therein illustrated, the radiator means 
(14) is layered in register with the top surface (not shown) of the base 
(12). The base portion (10) further includes two electrical plugs (16) 
which extend perpendicularly from post portion (18) of the base (12) and a 
portion of each of the plugs (16) is are embedded within said post portion 
(18). It is to be understood that the post portion (18) depicted is an 
integral part of the base (12) and if the base (12) is of a sufficiently 
thick dimension to contain the heating means and provide a support for the 
plugs (160, the post portion (18) may be omitted from the construction of 
the base (12). 
With reference now to FIG. 4, therein is shown a cross-sectional view taken 
along line "a--a" of FIG. 1., as well as being similar to that depicted in 
FIG. 3. Illustrated in this cross-sectional view is a heating means (20) 
in electrical communication with each of the electrical plugs (16). The 
heating means (20) may be any electrical resistance device which, when 
connected to the power source such as available in a wall outlet, causes 
the generation of heat which is then dissipated into the base (12). A wide 
variety of known electrical devices may be used and generally any which 
includes a resistance element such as a bulb filament, a wire segment such 
as as of nichrome wire, but is most desirably an electrical resistor 
device as is commonly known in the electronic arts. It is required only 
that the heating means provide sufficient heat such that when dissipated 
into the base portion causes the volatilization of the volatile substance 
as will be described in more detail hereafter. 
Turning now to FIG. 5, there is illustrated a side view of two plugs (16) 
and the preferred embodiment of the heating means (20), viz., an 
electrical resistor. With regard to the selection of the resistor, any 
which generates an appropriate amount of heat to induce the volatilization 
of the volatile material in the apparatus according to the present 
invention may be used, while at the same time does not undesirably soften 
or melt the material of which the base portion is formed. It is to be 
understood that the actual selection of such a suitable electrical 
resistor is in part dependent upon the power source to which it is to be 
attached, as well as on the characteristics of the vaporizable material 
with which it is to be used. By way of non-limiting example, for use with 
a 120 v, 50/60 cycle alternating circuit power source (such as in common 
use in North America) an electrical resistor especially an electronic 
resistor device rated from between 0.1 and 2 watts, and having a 
resistance in the range of from 1 to 100,000 ohms is generally appropriate 
for use. A specific preferred embodiment is described in the Example, 
below. The electrical resistor namely, an electronic resistor device 
includes two resistor leads, i.e., wires which extend from the resistor, 
and one of each wires (22) is in electrically conductive contact with a 
plug (16). While not illustrated in particular detail, it will be 
understood that any means for effecting such an electrically conductive 
contact may including but not limited to: a crimped or soldered connection 
between the wires (22) and the plugs (16) as well as wrapping or otherwise 
contacting a portion of the wires (22) with the plugs (16). 
With regard to the base (12) as well as its integral post portion (18) (if 
present), such is desirably formed from a thermoplastic or thermosetting 
polymeric material which has sufficient heat tolerance such that it is not 
undesirably softened or melted when the heating means incorported within 
is energized during normal use of the appratus. Such may be any of a 
variety of known materials which by way of example include polymers and/or 
copolymer resin compositions based on: nylons, polyethylene terephthalate, 
polybutylene terephthalate, polyolefins, styrenes, polyacetal resins, 
polysulfones, as well as others which exhibit such desired heat tolerance 
properties as denoted above. Such mateirials may be blends of one or more 
such polymers and/or copolymers, as well as commerically available 
polymeric compositions which may include additives or modifiers such as 
fillers including talc, comminuted carbons such as carbon black, glass 
fibers, glass beads, any of a variety of fire retardant materials, as well 
as colorants, pacifiers, pigments, and the like. The inclusion of one or 
more conventional additives to the polymer may be desired to adjust the 
properties thereof, such as to impart desirable physical properties such 
as stiffness, and/or heat transfer characteristics of the polymer 
material. Of such polymer and/or copolymer resin compositions, 
thermoplastic resins which may be used in an injection molding process are 
desirably used. An advantage of the use of such an injectable polymeric 
material is that in the manufacture of the base portion, the heating means 
and the plugs may be first preassembled, subsequently inserted into a 
suitable die cavity, and afterwards a quantity of the injectable polymer 
resin may be introduced into the die cavity to form the base in a single 
manufacturing step. In such a step, the plugs (16) may be positioned 
within the base (12), and at the same time the polymer resin composition 
envelops the heating means at all sides. Thereafter, the radiator means 
(14) may be applied in register with the top surface of the base (12) in 
order to form the base portion (10) according to the electrically heated 
dispensing apparatus within the scope of the present invention. 
A specific and surprising technical advantage of the construction of the 
base portion (10) according to the present invention includes the 
excellent and uniform heat distribution characteristics which are 
provided. With reference now to FIG. 2, therein is illustrated a top view 
of the base portion (10) according to FIG. 1. The top surface includes a 
radiator means and further depicted on FIG. 2 are further reference 
characters which indicate particular regions of the radiator means. More 
particularly, in FIG. 2, "A1" represents the region of a first corner, "A2 
the region of a second corner, "A3" the region of a third corner, and "A4" 
the region of a fourth corner of the radiator means (14). Further, the 
letter "C" indicates the central region of the same radiator means (14). 
The present inventors have surprisingly found that when a base portion 
according to FIG. 1 was constructed, but without the use of a radiator 
means, that a wide and disparate variation in the temperatures observed at 
each of these indicated regions occurred. These results are illustrated on 
Table I below. The inventors have also surprisingly observed that a 
significant improvement in the temperature characteristics are provided by 
the base portion (10) according to the present invention than might be 
expected. Surprisingly, the present inventors have found that not only was 
the differential in temperature between the central region C and any of 
the corner regions A1, A2, A3 or A4 of the radiator means no more than a 
few degrees in temperature (celsius), which provided that the temperature 
gradient across the surface of the radiator means (14) was low, and was 
almost level as compared to the base portion without the radiator means 
(14). Further surprisingly, as compared to a similar base portion without 
the heat radiator means, the temperature of the central region C was 
significantly higher than when the radiator means (14) was included in the 
construction of the base portion (10). Such observations are more fully 
described in conjunction with the Example below. Generally, any of the 
corner regions were within 5.degree. C. of the central region, and are 
more desirably within 3.degree. C. of the central region of the radiator 
means (14) of the base portion (10) according to the invention. 
Turning now to FIG. 6 there is illustrated in an exploded view the elements 
which comprise a first preferred embodiment of an electrically heated 
vapor dispensing apparatus (60) according to the present invention. 
Therein is provided a base portion generally indicated as (10), which 
includes a base (12) having extending perpendicularly from a bottom 
surface thereof two plugs (16). On the opposite surface, the top surface, 
is a radiator means (14) layered in register with the top surface (not 
shown) of the base (12). Next (intended to be layered in register) is a 
volatile substance container (62) which contains a quantity of a volatile 
substance such as a fragrance or perfume, a disinfecting composition, or 
an insecticide. The next element which is included in this preferred 
embodiment is a shell generally referenced as (70), said shell (70) 
including a top wall (72) have a plurality of openings (74) passing 
therethrough. The shell (70) also includes two opposite side walls (76) 
and (78) (not shown) which have extending downwardly beyond their 
corresponding bottom edges (77), (79) a snap lock tab (80) which is 
suitably dimensioned to be engaged with at least a portion of the base 
(12) of the base portion (10) when the apparatus is assembled. The shell 
(70) is hollow in its interior and is suitably dimensioned to accommodate 
and completely confine the volatile substance container (62) within its 
interior when the shell (70) is affixed to the base (10). In this figure, 
the volatile substance container (62) is in the form of a porous container 
(63) which includes within a quantity of a vaporizable material as will be 
described in more detail below. 
While optional, it may be further desired to include a cover film (90) 
which cover film may be any vapor impermeable or poorly vapor permeable 
material. The cover film itself may include an adhesive on one side 
thereof which is intended to cover and seal all of the openings (74) which 
may be when present in the shell (70). The cover film (90) itself may 
include a graspable portion thereof such as extended tab (92) illustrated 
on FIG. 6. The presence of such a tab, although not necessary, greatly 
facilitates the ability of an individual to grasp the cover film and 
remove it from the top wall (72) of the shell prior to the insertion of 
the apparatus into a wall outlet. While such a cover film is optional the 
inclusion of such a cover film is especially advantageous. The use of such 
a cover film (90) slows or halts the volatilization of the volatile 
substance from the interior of the apparatus and maintains the same in a 
ready-to-use condition for the ultimate consumer. The consumer of the 
product then needs only remove the cover film (90) and subsequently insert 
the plugs (16) into a suitable wall outlet which acts to connect them to a 
suitable power source. 
With regard to the volatile substance (62) as illustrated in FIG. 6, 
therein is depicted one embodiment of such container which is in the form 
of a block (63) of a porous material. Preferably, such a porous material 
is a porous polymeric material such as a sintered polymer material which 
may be immersed, doused, or otherwise supplied with a quantity of a 
volatile substance such as a fragrance or perfume, disinfecting 
composition or insecticide which is entrained therein and when the porous 
material is heated to the temperatures provided by the base portion (10) 
of the apparatus according to the invention, induces the volatilization of 
the said volatile substance. Further preferably the porous material may be 
a porous ceramic material which may be any of a large class of 
nonmetallic, inorganic materials containing high proportions (i.e., at 
least 75% wt.) of silicon, silicon oxide, silicates as well as other 
materials not particularly elucidated here, and which have a porous 
structure which acts to absorb or entrain the volatile substance used. 
These include clays, porcelains, terra cotta, talc, cements as well as 
other ceramic materials which are known to the art which feature a porous 
structure. Such may be formed into a suitably dimensioned configuration, 
such as is described herein using conventional casting or molding 
techniques. It is further contemplated that none, all or part of the 
surface of such a block (63) constructed of a ceramic material may be 
glazed, coated or at least partially encased in an impermeable container. 
It is yet a further embodiment a fibrous material which is porous and which 
may be used to entrain quantity of the volatile substance as described 
above may also be used as the volatile substance container (62) as 
depicted in FIG. 6. Non-limiting examples of such fibrous material may be 
of any construction, such as a block, pad or sponge of compressed, woven 
or non-woven fibrous material which may be inserted into the electrically 
heated vapor dispensing apparatus as described in FIG. 6. Exemplary 
fibrous materials include naturally occurring or synthetic fibrous 
materials as well as blends of two or more such fibrous materials. 
Advantageously, those based on naturally occurring or regenerated 
cellulose fibers in the form of compressed blocks may be utilized, with 
compressed sheet-like constructions especially to be preferred. Absorbent 
celluslose comprising paper pads or sheets are particularly advantageously 
used. Such cellulosic construction is desirably utilized as it is 
excellent in entraining a quantity of the volatile substance, may be 
easily and cheaply produced, and has little likelihood of ignition or 
charring when heated to an appropriate volatilization temperature. 
Turning now to FIG. 7 there is illustrated a second preferred embodiment of 
the electrically heated vapor dispensing apparatus (60) according to the 
present invention. The present apparatus is similar in most respects to 
the apparatus illustrated on FIG. 6 and corresponding elements are 
corespondingly numbered. In this second embodiment, the construction of 
the volatile substance container (62) differs from that previously 
described in FIG. 6. According to FIG. 7, the volatile substance container 
(62) comprises a container element (94) which has contained therein a 
quantity of a volatile substance composition (96), which may be in a 
liquid form, or in a solid, or semi-solid form such as a gell or 
paste-like form. The container element in (94) may be any housing of a 
configuration which is suited for the retention of the volatile substance 
composition (96) contained therein, is constructed of a material which is 
impermeable or only poorly permeable to said volatile substance 
composition (96) contained within, and which is suitably dimensioned to 
fit between the top surface of the base portion (10) and within the 
interior of the shell (70). Any variety of materials may be used in the 
construction of this container element (94) including, but not limited to, 
polymeric materials, metallic materials, as well as those formed from 
paper constructions such as paper coated on one or more surfaces with a 
material which resists the permeation of the volatile substance into the 
paper. 
Turning now to the volatile substance composition (96) such may be solid, 
or semi-solid form such as a gel or paste-like form. By way of 
non-limiting example such compostions include a gelling agent which may be 
any of those known to the art such as fumed silica, DBS, carageenan as 
well as others not denoted here. The advantage of the utilization of such 
a volatile substance composition (96) is that generally, compared to other 
forms, such a composition provides ability to include therein a high 
proportion of the volatile substance intended to be delivered by the 
apparatus with respect to its base or carrier component. The volatile 
substance composition (96) may also be a porous substrate such as the 
porous ceramic or porous polymer material described in cojunction with the 
block (63) which contains a quantity of a volatile substance. 
Desirably although not illustrated in FIG. 7, it is to be clearly 
understood that a single or bi-layered or multi-layered film (97) may be 
provided to cover the volatile substance composition (96) within the 
volatile substance container (62). Such a film may be a single layer film, 
such as a vapor permeable membrane. Alternatively a single layer film 
which is vapor impermeable may be used, such as a film of a polymer 
exhibiting good vapor barrier properties or a metal film or foil. In such 
an embodiment, the vapor impermeable film is removed such as by peeling 
off from the volatile substance container (62) prior to the use of the 
apparatus. In a further alternative, the film may be a bi-layered or 
multilayered film which includes a vapor permeable membrane layer, and a 
vapor impermeable membrane layer. In such a construction, the vapor 
permeable membrane layer is layered between the volatile substance 
composition (96) and the vapor impermeable layer, and in use, desirably 
the vapor impermeable layer is removed such as by peeling off said layer 
and may be discarded. The vapor permeable membrane layer is retained as 
part of the volatile substance container (62) and covers the volatile 
substance composition (96) which may then be used in the apparatus 
according to the invention. Such single layer, bi-layer and multilayer 
films are known to the art and include those formed from polyolefins 
including for example polyethylene and polypropylene especially low 
density grades of such polyolefins; copolymers such as ethylvinylacetate 
copolymers, as well as other commercially available membrane materials 
including Teslin, silicone coated paper as well as Tyvek (DuPont, 
Wilmington Del.) may be useful as vapor permeable membrane, single layer, 
bi-layer and multilayer films are known to the art which are useful as 
vapor impermeable films include virtually any known to the art such as 
metal foils, polymeric films having a sufficiently high barrier property 
to the volatile material such as fluoropolymer contiaining films and PVDC. 
Methods for affixing such films to the volatile substance being suitably 
affixed such as by heat sealing, gluing, or other affixing via appropriate 
means to the container element (94). This may be facilitated by including 
a flange (95) which extends along the periphery of the container element 
(94). In this manner, when a vapor permeable membrane is provided such 
permits the volatile substance to pass from the container element (94) yet 
denying the passage of the volatile substance composition (96) contained 
therein to phycially flow out or fall out. Where there is provided a 
single or multi-layer, especially a bi-layered film having a vapor 
impermeable layer such as a metal foil or vapor impermeable polymer film, 
such a construction is particulary advantageous for use where the 
apparatus of the invention may be used a plurality of times. In such case, 
the volatile substance container (62) may be provided as a refill 
cartridge to a consumer, who need only remove the vapor impermable layer 
prior to inserting the volatile substance container (62) in contact with 
the base portion (10) of the apparatus according to the invention. 
Turning now to FIG. 8 there is illustrated in perspective view the elements 
which may be used to construct a third preferred embodiment of the 
electrically heated vapor dispensing apparatus according to the invention, 
again generally indicated as (60). Therein as depicted, is included a base 
portion generally referred to as (10) which includes a base (12) having 
perpendicularly extending downwardly from bottom face thereof two plugs 
(16). The base portion further includes a top face (98) which has 
extending perpendicularly therefrom four walls (100), (102), (104), (106) 
which are generally rectangular in configuration and which are joined at 
corners, the said four walls defining a generally square enclosure (108) 
which extends from the top surface (98) of the base (12). Within the 
enclosure (108) and at top surface the base (12) thereof, is located the 
radiator means (14) here here illustrated as a metal foil which is adhered 
to the top surface within the confines of the enclosure. It is also to be 
noted that the dimensions of the walls are such that a marginal recess 
(112), (114) as well as (116), (118) (not visible), is present between the 
corresponding outermost edge of the base portion with the corresponding 
wall (100), (106) and although not visible shown in FIG. 8, such a recess 
exists at the base of each of the further walls (102), (104). 
Further illustrated in FIG. 8 is an shell (70) having side walls (76), 
(78), (124) and (128) as well as a top wall (72). The top wall includes a 
plurality of openings (74) passing therethrough which are configured in 
the form of a decorative "flower petal" pattern which defines open 
passages between the interior of the shell (120) and the exterior, i.e., 
the ambient environment within which the electrically heated vapor 
dispensing apparatus is to be used. The shell (70) itself is dimensioned 
such that it may be slidably fitted upon the base portion (10) whereby the 
side walls (76), (124), (78) and (128) encase the walls (100), (106), 
(104) and (102) extending from the top surface (98) of the base (12). 
Desirably, these side walls (76), (124), (78) and (128) preferably rest in 
the recesses (112), (114), (116) and (118) (the latter of the two which 
are not shown). In this manner, either of the volatile substance 
containers (62) depicted and which have been described previously may be 
disposed within the enclosure (108) of the base portion (10) may be 
encased by the shell (70). Such volatile substance containers (62) may be 
either of the types as have been discussed with reference to FIG. 6 and 
FIG. 7. 
The shell (70) and the base portion (10) may be interconnected by any 
suitable means, i.e., chemical means such as by disposing an adhesive 
material between portion of the shell (70) and the base portion (10) 
especially such as at the position of one or more of the recesses (112), 
(114), (116) and (118) of the base (10); by mechanical means such as by 
friction fitting, or as by providing snap-fitting elements such as 
described previously; or, by welding or melting, a portion of the shell 
(70) to bond it to the base portion (10). 
Further, as has been noted previously, as it is contemplated that such an 
assembled electrically heated vapor dispensing apparatus (60) as is 
depicted in FIG. 8 may be expected to have a shelf life between its 
fabrication and the time of its use, such apparatus may also be provided 
with a cover film (90) which optionally includes a graspable tab (92) as 
has been discussed with reference to FIG. 6 and/or FIG. 7. 
Turning now to FIG. 9 there is yet a further preferred embodiment of an 
electrically heated vapor dispensing apparatus (60) according to the 
present invention, in a partially assembled form. The apparatus according 
to the depicted embodiment is designed to be used a multiplicity of times 
as opposed to those more appropriate for a single use as disclosed and 
described in FIG. 1 through FIG. 8. 
With regard to FIG. 9 therein depicted is a base portion (10) having a base 
(12) further including plugs (16) extending perpendicularly downwardly 
therefrom from a bottom surface, as well as a radiator means (14) disposed 
on the top surface (not shown) of the base (12). In this embodiment, the 
radiator means (14) is an aluminum foil tape or film which is adhered 
directly to the said top surface. 
Further as shown, the shell (70) is mechanically engaged and "locked" to 
the base portion (10) by means of snap locking tabs (80), (81) (not shown) 
which grasps opposite edges of the base (10) and thereby engages and 
retains the shell (70) to the base portion (10). 
The shell (70) includes at least one end wall (124) which includes an 
opening (154) therethrough to the interior of the shell (70) and such 
opening (154) is desirably a generally rectangular shaped opening (154) 
which is of sufficient size and suitably dimensioned to permit the 
insertion of either form of volatile substance container (62) as depicted 
and has been described in more detail with reference to earlier figures. 
Optionally such a volatile substance container (62) further includes a 
single or bi-layered or multi-layered film (97) which has also been 
previously described. Additionally, while not shown, the end wall (156) 
opposite to that of the end wall (124) having the opening therein (154) 
may be either solid, or may include a further opening therethrough to the 
interior of the shell (70). The embodiment according to FIG. 9 may also 
further include a cover film (90) which further includes a grasping tab 
portion (92) to facilitate its removal from the top wall (150) of the 
shell. 
FIG. 9 illustrates a fourth particularly preferred embodiment of the 
electrically heated vapor dispensing apparatus according to the invention 
which is designed to be used a plurality of times. Namely, such an 
embodiment anticipates that once the volatile substance is dispensed from 
the volatile substance container (62) and that once emitted to a 
surrounding environment, the volatile substance container (62) may be 
readily removed and disposed of. Thereafter, the a further volatile 
substance container (62), of either type shown in FIG. 9 may be introduced 
into the apparatus (60) and the apparatus (60) thus reused. In such a 
manner, a yet further economy attendant upon the use of the apparatus 
according to the invention is possible, while retaining the beneficial 
volatile substance delivery characteristics as has been described 
previously in conjunction with the embodiments of FIG. 6-FIG. 8. 
Turning now to FIG. 10 therein is disclosed a fifth preferred embodiment 
(60) according to the present invention which is one which may be used 
once or which may be used a plurality of times. The apparatus generally 
indicated as (60) includes a base portion (10) having a base (12) having 
two downwardly perpendicularly extending plugs (16) from a bottom surface, 
and a radiator means (14) disposed theron and covering substantially all 
of the top surface (not shown) of the base portion. Further extending 
upwardly substantially perpendicularly from the top surface of the base 
portion are two parallel walls (162), (164). The walls are positioned 
slightly inwardly from the corresponding edges (166), (168) of the base 
(12) so to define recesses (170), (172) between the base of each wall and 
their corresponding edge. Although not depicted in the figure, it is to be 
understood, however, that the walls (162), (164) may rise perpendicularly 
upwardly from the and be coincident with the edges (166), (168) of the 
base (12) in which case no such recesses (170), (172) would be present. 
Optionally, but in certain cases desirably, on the interior face of each 
of the walls (162), (164) is a longitudinally extending rib (174), (176) 
(not shown) which partially, or substantially along the complete width of 
the corresponding wall and parallel to the top surface of the base (12) 
and extends inwardly towards the opposite facing parallel wall. The 
function of these optional longitudinal ribs is to engage portions of a 
volatile container (62)which is intended to be inserted between the 
parallel walls (160), (162) when the apparatus (60) is used. 
The apparatus (60) further includes a shell (70) having at least two side 
walls (76), (78) which are parallel to one another, and each of which are 
contiguous to opposite edges of the top wall (72). The top wall (78) 
further includes a plurality of passages (74) may be included passing 
through the top wall (72) of the shell (70). Such passages provide means 
for the volatilized volatile substance to escape into the ambient 
environment, although it is to be appreciated that the volatilized 
volatile substance may also escape at either of the open ends (190), (192) 
of the shell (70). 
The electrically heated vapor dispensing apparatus according to the 
embodiment illustrated in FIG. 10 is formed by the combination of the 
shell (70) which is affixed to the base portion (10) in such a manner that 
the corresponding walls (76), (78) of the shell (70) are affixed to 
encompass corresponding parallel walls (164), (162) respectively of the 
base portion (10). Such affixing to one another by mechanical or chemical 
means as has been described above with reference to the embodiments 
discussed in the prior figures. Thereafter, either volatile substance 
container (62) depicted and also described previously is inserted into the 
interior of the apparatus (60) between the parallel walls (164), (162) 
where the longitudinal ribs (174), (176) when present, may facilitate 
their retention within the apparatus (60). 
According to FIG. 10, a specific embodiment of an electrically heated vapor 
dispensing apparatus having a "slideway" is provided, wherein such an 
apparatus construction features a repeated use of the said apparatus prior 
to its disposal. 
Turning now to FIG. 11 therein is illustrated in an exploded view the 
elements of a sixth preferred embodiment of the electrically heated vapor 
dispensing apparatus (60) according to the invention which does not 
include a shell. 
As is shown on FIG. 11, the apparatus (60) includes a base portion (10) 
having a base (12) which includes plugs (16) extending perpendicularly 
from a bottom surface therefrom and radiator means (14) disposed on the 
face of the top surface. Further extending perpendicularly from the second 
face therefrom are two spaced apart walls (196), (198), each of which has 
a flange portion (200), (202) which desirably extends in the direction of 
the opposite wall, and most desirably is perpendicular to the wall from 
from which the flange extends. Further desirably, the each flange portion 
(200), (202) extends perpendicularly from the edge of the wall (196), 
(198) which is distal from the base (12), which is at a height above the 
base (12). 
The electrically heated vapor dispensing apparatus according to this sixth 
preferred embodiment, may be assembled by inserting either of the volatile 
substance containers (62) as depicted on the figure, both of which have 
been described in detail previously. Either of these two elements may be 
slidably inserted and disposed between the radiator means (14), the walls 
(196), (198) and at least a portion of the respective flanges (200), 
(202). Such a slidably fittable assemblage may be readily produced with 
good tolerances of the respective corresponding elements. 
FIG. 12 illustrates a seventh preferred embodiment of the electrically 
heated vapor dispensing apparatus (240) according to the present 
invention. 
Turning now with attention to the apparatus (60) depicted on FIG. 12, such 
an apparatus comprises the base portion (10) which includes the base (12) 
having perpendicularly extending plugs (16) extending from a bottom 
surface and a top surface upon which is disposed a radiator means (14). 
With specific attention to the embodiment illustrated on FIG. 12 it is to 
be noted that the radiator means (14) is in the form of a rigid metallic 
plate which is not necessarily adhered to the top surface (not shown) of 
the base (12), but rather includes recessed portions (204), (206) which 
are dimensioned to be fitted between the base portions (208), (210) of two 
upwardly extending side clip walls (212), (214) which extend from the base 
(12) in a generally perpendicular upwardly from the base (12). The distal 
ends of each of the side clip walls (212), (214) include integrally molded 
snap fit locking means (216), (218) which are suitably dimensioned to 
ultimately retain a correspondingy dimensioned volatile substance 
container (62) which may be inserted between the side clip walls (212), 
(214). 
The apparatus (60) further includes a volatile substance container (62) 
which herein is depicted as a porous ceramic element or a porous polymeric 
element (63) containing a quantity of a volatile substance entrained 
within. The volatile substance container (62) is dimensioned to desirably 
include corresponding recesses (218), (220) which are dimensioned to 
permit the passage of the side clip walls (212), (214). 
Alternatively, the apparatus (60) further includes a volatile substance 
container (62) which is herein depicted as a container element (94) which 
has contained therein a quantity of a volatile substance composition (96), 
which may be in a liquid form, or in a solid, or semi-solid form such as a 
gell or paste-like form. Such has been described previously, particularly 
in conduction with FIG. 7. This volatile substance container (62) is 
dimensioned to desirably include corresponding recesses (240), (242) 
within the flange (95) which are dimensioned to permit the passage of the 
side clip walls (212), (214). 
The electrically heated vapor dispensing apparatus (60) according to the 
seventh preferred embodiment is readily produced by merely physically 
inserting the volatile substance container (62) between the side clip 
walls (212), (214) until the container (62) is fully seated therein, and 
thereby permitting the snap lock elements (250), (252) to engage and to 
retain the volatile substance container (62) in a "locked" position. Such 
an arrangement also insures that the radiator means (14) is retained in 
the position intermediate and in physical contact with the base (12) and 
the volatile substance container (62). Advantageously, the volatile 
substance container (62) includes recesses (218), (220) which facilitate 
assembling the apparatus (60). 
Although the embodiment of the apparatus (60) according to FIG. 12 is most 
useful as a single-use device, i.e., as disposal after the volatile 
substance is volatilized from within the volatile substance container 
(62), it is anticipated that the said container may be removed by 
disengaging the snap lock elements (250), (252), removing the volatile 
substance container (62) and replacing it with a further container having 
a quantity of volatile substance therein. 
It is also to be understood that a raised or embossed, as well as a printed 
decorative design (230) may be included as part of the volatile substance 
container (62) so to improve the attractiveness thereof. 
It is to be understood that the volatile substances which may be dispensed 
utilizing the apparatus described herein specifically includes insect 
repellent compositions, deodorizing compositions, medicinal compounds, 
herbal compositions as well as disinfectant compositions Especially 
preferred as volatilizable materials are those which emanate a fragrance 
or scent when volatilized, and are generally scented oils or perfumes 
which may be a pure essence oil or which may be a mixture of constituents 
such as a minor amount of a perfume or pure essence oil diluted in a 
greater volume of a volatile liquid base such as an alcohol. Many such 
materials are known to the art, and although not specifically described 
here, may be used and are to be particularly considered within the scope 
of the present invention. 
As will be realized by a reading of the foregoing specification, the 
electrically heated vapor dispensing apparatus according to the present 
invention provides substantial contribution to the art in providing an 
apparatus which is inexpensive to make, may be economically disposed of, 
even after one use, but may also be reused a plurality of times and which 
due to its elegant and simple design, is reliable in its operation. 
Further, the apparatus according to the present invention has overcome 
many of the inherent shortcomings in the art, namely the effective 
distribution of heat and in the reliable, long-term, uniform 
volatilization of a volatile substance which is contained within such an 
apparatus whereby at a low power consumption required for its operation, a 
uniform and stable delivery rate of the volatile substance may be provided 
over nearly the complete life cycle of such a product. Further, the 
apparatus ensures that the volatile substance, whether encapsulated in a 
gel, gel-like, semi-solid, pasty carrier and/or in one of the porous 
materials, i.e., porous polymer and/or ceramic, is safely and uniformly 
delivered to an ambient environment such as the interior of the room or 
other closed volume of space. 
EXAMPLE 
A base portion (10) similar as depicted on FIGS. 1-4 was manufactured. The 
base portion (10) comprised a 1000 ohm resistor having a power rating of 
1/4 watt, with the first end thereof connected via a first resistor lead 
wire to a first plug and the other end thereof similarly connected via the 
other lead wire. The ends of these wires were crimped to the ends of the 
plugs. Subseqently the thus assembled resistor and plugs were inserted 
into a suitably dimensioned die cavity and an amount of polypropylene was 
injected therein. The thus formed base was ejected from the die cavity. 
The top surface of the base was 13/8 inch by 13/8 inch. The thickness of 
the top surface was 1/8th inch, and the bottom surface included a 
centrally located post portion having a thickness of 1/8th inch, a width 
of 1 inch and a length of 3/4 inch. The resistor and the base portions of 
the two spade-type plugs were fully embedded in the base portion and/or 
the post portion. 
The base thus produced was then inserted into a wall outlet of the type 
conventionally found in North America, which provided 120v alternating 
current, 50/60 cycles operation for at least 5 minutes, or until steady 
state heating of the base occurred. Temperature reading were taken using a 
surface temperature probe at the central region, and in each of the the 
regions of the four corners as is illustrated on FIG. 2. These results are 
reported on Table I, below. 
Subsequently, the base was removed from the outlet, cooled and a piece of 
an aluminum foil tape was adhered to and covered substantially all of the 
top surface of the base. Again, this base according to the invention was 
then inserted into a wall outlet of the type conventionally found in North 
America, which provided 120v alternating current, 50/60 cycles operation 
for at least 5 minutes, or until steady state heating of the base 
occurred. Temperature reading were taken using a temperature probe at the 
central region, and in each of the the regions of the four corners as is 
illustrated on FIG. 2. These results are reported on Table I, below. 
TABLE I 
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temperature of 
temperature of 
base according to 
region of base: 
base invention 
______________________________________ 
C 91.67.degree. C. 
58.33.degree. C. 
A1 61.67.degree. C. 
57.22.degree. C. 
A2 45.56.degree. C. 
56.67.degree. C. 
A3 52.22.degree. C. 
57.78.degree. C. 
A4 57.22.degree. C. 
56.11.degree. C. 
______________________________________ 
While the invention is susceptible of various modifications and alternative 
forms, it is to be understood that specific embodiments thereof have been 
shown by way of example in the drawings which are not intended to limit 
the invention to the particular forms disclosed; on the contrary the 
intention is to cover all modifications, equivalents and alternatives 
falling within the scope and spirit of the invention as expressed in the 
appended claims.