DISPENSER WITH AN IMPROVED HEATER ARRANGEMENT.

Abstract

A heating device for a volatile material dispenser includes a cylinder defining an opening and a heating element embedded within the cylinder. The dispenser further includes a housing configured to receive a refill containing a volatile material and a wick. The housing includes a first cavity configured to support the heating element. Additionally, the dispenser is configured such that, when the refill is inserted into the housing, the opening receives the wick, creating a radial space between the heating element and the wick.

Description

DISPENSER WITH AN IMPROVED HEATER ARRANGEMENT CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority over U.S. patent application No. 16 / 743,939, filed on January 15, 2020, the full content of which is incorporated by reference for all purposes. REFERENCE TO RESEARCH OR DEVELOPMENT SPONSORED BY THE FEDERAL GOVERNMENT Not applicable BACKGROUND OF THE INVENTION This disclosure relates generally to a system for dispensing a composition, and more particularly to a dispenser that utilizes an improved heater arrangement. Several volatile material dispensers are known in the prior art and generally include a housing with a refill inserted therein. The refill typically includes a container for holding the volatile material. In some dispensers, the volatile material is passively emitted from the dispenser itself. In other dispensers, a diffusion element is used to facilitate the dispensing of the volatile material. Examples of diffusion elements include heaters such as positive temperature coefficient (PTC) heaters, piezoelectric elements, fans, aerosol actuators, and the like. Regardless of how the volatile material is emitted, once the volatile material has been consumed from the refill, the refill is removed by the user and replaced with a new one. One type of volatile material dispenser, sometimes called a plug-in scented oil dispenser, includes a housing and a heater located within the housing. A refill for use with a plug-in scented oil dispenser typically includes a container with a volatile material inside and a wick in contact with the volatile material that extends out of the refill. When the refill is inserted into the dispenser, at least a portion of the wick is positioned next to the heater, so that the volatile material moving through the wick is vaporized by the heater. The volatile material dispenser typically includes a plug assembly with electrical prongs that extend out of the housing. The electrical prongs are inserted into a standard electrical outlet and then supply power to the volatile material dispenser.One such dispenser is disclosed in U.S. Patent Commonly Assigned No. 9,669,126, which is incorporated herein by reference in its entirety. Plug-in scented oil dispensers may also utilize a fan to assist in vaporizing and dispersing the volatile material. However, existing dispensers have performance issues. For example, a common problem with existing dispensers is condensation buildup. Because a dispenser actively or passively emits volatile material, the gas inside the housing can have a high relative humidity. Therefore, condensation is likely to form on an interior surface. Different ventilation systems have been used in existing dispensers in an attempt to minimize condensation formation; however, these methods do not provide a complete solution. Furthermore, existing ventilation systems can disrupt or inhibit plume dispersion. That is, using certain prior art ventilation configurations, a plume released by a dispensing system can be negatively affected, which can result in suboptimal distribution of the material by the dispensing system.Furthermore, another problem is the heater's poor efficiency. More specifically, existing dispensers do not effectively convert energy into thermal energy to help volatilize the volatile material. Therefore, there is a need for a dispenser that includes a heater arrangement that provides improved performance and other features to minimize the potential for condensation. BRIEF DESCRIPTION OF THE INVENTION According to one embodiment, a heater arrangement for a volatile material dispenser includes a cylinder defining an opening and a heating element embedded within the cylinder. The dispenser includes a housing configured to receive a refill containing a volatile material and a wick, and the housing includes a first cavity configured to support the heater arrangement. Furthermore, the dispenser is configured such that, when the refill is received into the housing, the opening receives the wick, forming a radial space between the heater arrangement and the wick. According to another embodiment, a volatile material dispenser includes a housing configured to receive a refill containing a volatile material and a wick, wherein the housing includes a first cavity that supports a heater arrangement. The heater arrangement includes a cylinder, a heater chassis, and a heating element embedded in the cylinder. The cylinder defines an opening, and the heater chassis defines a passage configured to be axially aligned with the cylinder opening. The dispenser is configured such that, when the refill is received into the housing, the cylinder opening is axially aligned with the wick, and a radial space is formed between the heater arrangement and the wick. According to another embodiment, a volatile material dispenser includes a housing configured to receive a refill containing a volatile material and a wick. The housing has a heater arrangement configured to volatilize the volatile material into a vapor plume. The volatile material dispenser further includes a top cover comprising an annular wall with a first surface, a second surface, an outer rim, and an inner rim defining a central opening for the emission of volatile material through it. The inner rim is raised relative to the outer rim. The heater arrangement comprises a heating element retained within a cylinder and a heater housing defining a passage through it.Furthermore, the cylinder comprises a main surface and a chimney defining an opening, wherein the chimney may be raised with respect to the main surface of the cylinder and is gradually narrowed from a first end close to the main surface to a second end distal to the main surface. The cylinder is coupled to the heater chassis and constitutes less than 40% of the heater arrangement's volume. Additionally, the dispenser is configured such that, when the refill is received inside the housing, the wick is axially aligned with the central opening of the top cover, the cylinder opening, and the passage in the heater chassis, and the wick extends through the passage in the heater chassis and into the cylinder opening such that a distal end of the wick is positioned below the second end of the cylinder. According to another embodiment, a volatile material dispenser includes a housing and a top cover. The housing is configured to receive a refill containing a volatile material and a wick and includes a first cavity that supports a heater arrangement. The top cover is configured to fit the housing and defines a central opening through which a plume of vapor exits the housing. Furthermore, the top cover includes an annular wall having a first surface, a second surface opposite it, an outer edge, and an inner edge that defines a central opening, wherein the central opening defines an axial direction. The outer and inner edges are concentric and lie in different planes.The second surface extends radially inward from the outer edge, curving in a first axial direction to a depression, and then gradually curving in a second direction opposite to the first axial direction until it meets the inner edge. Furthermore, the dispenser is configured so that, when the top lid is attached to the housing, the second surface faces the first cavity. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a symmetrical front view of a dispensing system including a dispenser and a refill according to an embodiment of the present disclosure; FIG. 2 is a symmetrical front view of the dispenser in FIG. 1; FIG. 3 is a symmetrical front view of the replacement part in FIG. 1; FIG. 4 is a rear isometric view of the dispenser in FIG. 1, including an upper housing and a lower housing; FIG. 5 is a front isometric view of the upper housing of FIG. 4; FIG. 6 is another front isometric view of the upper housing of FIG. 4; FIG. 7 is a front isometric view of the lower housing of FIG. 4; FIG. 8 is a rear isometric view of the lower housing of FIG. 4; FIG. 9 is a rear isometric view of the dispenser in FIG. 1; FIG. 10 is an elevation view of the left side of the dispensing system of FIG. 1; FIG. 11 is a top plan view of the dispensing system of FIG. 1 FIG. 12 is a cross-sectional view of the dispensing system of FIG. taken through line 12-12 of FIG. 11; FIG. 13 is a front isometric view of a heater arrangement according to an embodiment of the present disclosure; FIG. 14 is an exploded view of the heater arrangement of FIG. 13; FIG. 15 is an electrical schematic of the heater arrangement of FIG. 13; FIG. 16 is a plan view of the heater arrangement of FIG. 13; FIG. 17 is a cross-sectional view of the heater arrangement of FIG. 16 taken through line 17-17 of FIG. 16; FIG. 18 is a schematic of a heater arrangement according to an embodiment of the present disclosure; FIG. 19 is a schematic of a heater arrangement according to another embodiment of the present disclosure; FIG. 20 is a schematic of a heater arrangement according to another embodiment of the present disclosure; FIG. 21 is a schematic of a heater arrangement according to another embodiment of the present disclosure; FIG. 22 is a schematic of a heater arrangement according to another embodiment of the present disclosure; FIG. 23 is a partial isometric view of the dispensing system of FIG. 1 which includes the heater arrangement of FIG. 13; FIG. 24 is a front isometric view of a top cover according to an embodiment of the present disclosure; FIG. 25 is a plan view of the top cover of FIG. 24; FIG. 26 is a cross-sectional view of the top deck of FIG. 25 taken through line 26-26 of FIG. 25; FIG. 27 is a schematic of a top cover according to another embodiment of the present disclosure; FIG. 28 is a schematic of a top cover according to another embodiment of the present disclosure; FIG. 29 is a schematic of a top cover according to another embodiment of the present disclosure; and FIG. 30 is a schematic of a heater arrangement according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION This disclosure pertains to heater arrangements for dispensers of volatile materials that are highly efficient while providing an improved plume and preventing condensation formation within the dispenser. Heating arrangements according to the embodiments of this disclosure generally require less energy to dispense a volatile material. For example, dispensers according to the embodiments of this disclosure preferably require 2.0 watts (W) or less to operate, whereas existing dispensers sometimes require more than 2.0 W. Furthermore, dispensers according to the embodiments of this disclosure have generally been found to outperform existing dispensers.More specifically, when operated with comparable power inputs, dispensers according to the embodiments described herein are capable of emitting more volatile material than existing dispensers. Furthermore, dispensers according to the embodiments described herein exhibit an improved plume output (i.e., the plume is visibly stronger and more consistent) and reduced condensation formation within the plume. While this disclosure can be implemented in many different forms, it should be considered only as an example of the disclosure principles and is not intended to limit the disclosure to the embodiments illustrated. The dispensers described herein can be used as plug-in devices, configured to be inserted into a power outlet for operation. Alternatively, the aspects described herein can be used in alternative dispensers, such as standalone devices or handheld devices powered by a battery. Figures 1-29 illustrate a particular embodiment of a dispensing system 100 according to this disclosure. Referring to Figure 1, the dispensing system 100 comprises a dispenser 102 that generally includes a housing 104 having an internal cavity 106 for accepting a refill of volatile material 108 and a heater arrangement 110 (see, for example, Figure 13).The volatile material refill 108 may be similar in structure and function to the refill disclosed in U.S. Patent 2019 / 0091365 filed July 25, 2018, which disclosure is incorporated herein by reference in its entirety. The dispenser 102 further includes a top cover 112, a visual indicator 114, and a control dial 116. Each of the top cover 112, the control dial 116, the visual indicator 114, and the housing 104 are configured to be assembled together as shown in an exploded view of FIG. 2. When assembled, the dispenser 102 defines a longitudinal axis 120.Housing 104, top cover 112, visual indicator 114, and control dial 116 may be similar in structure and function to the housing, top cover, visual indicator, and control dial disclosed in a United States patent application entitled "Dispenser with a Visual Indication System," which was filed on the same day by the same assignee as this disclosure and is incorporated herein by reference in its entirety. Referring to FIG. 3, the refill 108 includes a container 126 with a volatile material inside (not shown), wherein the container 126 is adapted to be retained by the housing 104 of the dispenser 102 (see, for example, FIG. 1). The container 126 includes a retention mechanism 128 for holding a wick 130 inside the container 126 and a body 132 with the volatile material disposed therein. The body 132 includes a base portion 134 and a side wall 136 extending upwards to a top portion 138. In one instance, the side wall 136 can be either cylindrical or rectangular, although other side wall configurations are possible. The top portion 138 can also be integral with a neck 140.The neck 140 includes a threaded portion 142 disposed on an outer surface thereof and a filling opening 146 disposed through an upper portion 148 thereof, wherein the filling opening 146 allows access to the volatile material. The retention mechanism 128 is disposed within the neck 140 and further includes a sheath 150 that extends around at least a portion of the wick 130 to protect it. In the present embodiment, a free upper end 152 of the wick 130 extends above a distal edge 154 of the sheath 150. Returning to FIG. 1, although a specific dispenser and container are described in detail, it is intended that the heater arrangements disclosed herein may be used in conjunction with any type of replacement and / or container. For example, useful replacements include, but are not limited to, the containers described in U.S. Patent No. 7,032,831 and the containers described in U.S. Patent No. 2011 / 0139885, both of which are owned by the same assignee as this disclosure and are incorporated herein by reference in their entirety. Furthermore, it is intended that the heater arrangement disclosed herein may be used in conjunction with other dispenser arrangements, such as the fan arrangement described in U.S. Patent No.2018 / 0103507 filed on October 7, 2016, which is also owned by the same assignee as this disclosure and is incorporated herein by reference in its entirety. The volatile material disposed of in container 126 can be any type of volatile material adapted for dispensing into an environment. For example, container 126 may include a cleaner, insecticide, insect repellent, insect attractant, disinfectant, mold or mildew inhibitor, fragrance, disinfectant, air purifier, aromatherapy fragrance, antiseptic, odor eliminator, positive-scented volatile material, air freshener, deodorizer, or similar products, and combinations thereof. Additives, such as fragrances, preservatives, disinfectants, mold or mildew inhibitors, or similar products, and combinations thereof, may be included in the volatile material. For example, the fluid may include OUST®, an air and carpet disinfectant for residential, commercial, and institutional use, or GLADE®, a household deodorizer, both sold by SC Johnson and Son, Inc. of Racine, Wisconsin.The volatile material additionally or alternatively comprises any fluid known to those skilled in the art that can be dispensed from a container. Therefore, container 126 is adapted to dispense any number of different fluid formulations. In FIG. 4, the housing 104 generally includes an upper housing 158 and a lower housing 160 configured to be joined together to define the internal cavity 106. The upper housing 158 and the lower housing 160 comprise a thin-walled material and can be formed using methods known in the art, such as thermoforming or injection molding. Referring particularly to FIG. 5, the upper housing 158 comprises an upper tubular wall 162 defining a circular receiving opening 164 disposed at a first upper end 166 thereof. The upper tubular wall 162 further defines an upper cavity 168 extending from the circular receiving opening 164 to a lower edge 170 disposed at a second upper end 172 thereof.A first latch 174 and a second latch 176 extend substantially perpendicularly from the lower edge 170 and are substantially coplanar with parts of the upper tubular wall 162. In FIGS. 7 and 8, the lower housing 160 comprises a central cylindrical portion 180 defining a channel 182 through it. Two elongated guide posts 184 extend upwards from a first lower end 186 of the lower housing 160 and are generally parallel to the longitudinal axis 120. The elongated guide posts 184 extend from the first lower end 186 on opposite sides of a first channel end 188 of the channel 182 and are provided to secure the heater arrangement 110 (see, for example, FIG. 12) therein, which will be described in more detail below. Returning to FIG. 4, the upper housing 158 and the lower housing 160 are configured to join together. More specifically, the upper housing 158 is configured to receive the elongated guide posts 184 of the lower housing 160, and the first latch 174 and second latch 176 of the upper housing 158 are configured to engage with a first latch receiving structure 192 and a second latch receiving structure 194 of the lower housing 160, respectively. Furthermore, as more clearly seen in FIG. 9, a first hemicylindrical extension 198 of the upper housing 158 and a second hemicylindrical extension 200 of the lower housing 160 connect to create a cylindrical extension 202, which defines a cylindrical receiving chamber 204 configured to receive and retain a plug assembly 206 therein.The plug assembly 206 may extend from the cylindrical receiving chamber 204 defined by the upper housing 158 and the lower housing 160 of the casing 104. The plug assembly 206 may include two electrical prongs 208 adapted for insertion into a conventional electrical outlet. Although the plug assembly 206 is shown as a conventional plug assembly for the United States, a plug assembly adapted for use in any other country may be used. In addition, the plug assembly 206 may include any feature known in the art; for example, the plug assembly 206 may be partially or fully rotatable, similar to the plug assemblies disclosed in Patent No. 8,821,171 filed September 22, 2011, and Patent No. 8,858,236 filed October 28, 2011, which disclosures are incorporated by reference in their entirety. Figures 10 and 11 show a side elevation view and a top plan view of the dispensing system 100, respectively. Figure 12 illustrates a cross-sectional view of the dispensing system 100 taken through line 12-12 of Figure 11. Referring particularly to Figure 12, the channel 182 of the lower housing 160 is configured to receive the wick 130 of the refill 108. That is, the refill 108 can be inserted into the housing 104 by introducing the wick 130 upwards through the channel 182 of the lower housing 160 into the internal cavity 106 of the housing 104 along a direction defined by the longitudinal axis 120, the axis being preferably substantially vertical when the dispenser 102 is in use. Furthermore, the heater arrangement 110 is arranged within the internal cavity 106 in such a way that it is supported by the lower housing 160. As shown in Figures 13-17, the heater arrangement 110 generally uses a heating element to provide heat to the wick 130, which ultimately converts a volatile material (e.g., a fragrance oil) into a vapor or gas. Specifically, as best seen in Figure 14, the heater arrangement 110 uses a heating element 212 comprising a resistor 214 that is encapsulated, embedded, or otherwise arranged within a cylinder 216. The cylinder 216 is configured to be supported by a heater chassis 218 having an upper end 220 and a lower end 222. More specifically, when the heater arrangement 110 is assembled, the cylinder 216 is configured to rest on the upper end 220 of the heater chassis 218.The heater chassis 218 is preferably made of a material with good radiation resistance properties, such as high-temperature nylon. Preferably, the cylinder 216 is made of a highly heat-conducting material, such as a ceramic metal composite with a high metal content (e.g., aluminum). The incorporation of a ceramic metal composite with high metal content results in improved heat transfer through the cylinder 216. Alternatively, the cylinder 216 and / or any encapsulation arranged within it may comprise other types of thermally conductive material. Furthermore, in some embodiments, the cylinder 216 may comprise a resistive metal oxide coating deposited by spray coating or sputtering, or it may not comprise any coating at all.Furthermore, in some embodiments, cylinder 216 may be coated with a metal oxide coating having a precise resistance value to create a desired resistance value for heater arrangement 110. One or more connectors 224 are integrated into or connected to the ends of the resistor 214. As best seen in FIG. 15, the one or more connectors 224 extend out of the resistor 214 and terminate at terminals 228. The connectors 224 or terminals 228 can be connected to a power supply, a circuit board, and / or other electrical components of the dispensing system 100. In the illustrated embodiment, the connectors 224 extend from the heating element 212 (the resistor 214 in the present embodiment) to a power supply 230 (e.g., the plug assembly 206 shown in FIG. 9). Returning to FIG. 14, the cylinder 216 generally comprises an annular body 232 having a peripheral rim 234, a first inner rim 236 defining an opening 238, and a main surface 240 extending between them. As best seen in FIG. 17, which is a cross-sectional view of the heater arrangement 110 taken through line 17-17 of FIG. 16, the peripheral rim 234 and the first inner rim 236 are arranged in different planes. That is, the first inner rim 236 is raised relative to the peripheral rim 234 and the main surface 240 by a height H. Preferably, the height H is between approximately 1 millimeter (mm) and 10 mm. In some embodiments, the height H may be less than 3 mm. Referring again to FIG. 17, the main surface 240 extends radially inward from the peripheral edge 234 to the first inner edge 236, and a heating chimney 242 curves outward from the main surface 240 to the first inner edge 236. Consequently, the heating chimney 242 and the first inner edge 236 are raised relative to the main surface 240 and the peripheral edge 234 of the cylinder 216. Furthermore, the heating chimney 242 tapers gradually from a first end 244 close to the main surface 240 to a second end 246 distal to the main surface 240. The main surface 240 extends substantially flat from the peripheral edge 234 until it reaches the first end 244 of the heating chimney 242. The heating chimney 242 curves gradually until it reaches the first inner edge 236 and the second end 246.Thus, the main surface 240 extends from the peripheral edge 234 in such a way that it is flat for at least 50% of a radial distance between the peripheral edge 234 and the first inner edge 236. In some embodiments, the main surface 240 may extend flat for more than 60% of the radial distance between the peripheral edge 234 and the first inner edge 236. However, in some embodiments, the main surface 240 may extend flat for less than 50% of the radial distance between the peripheral edge 234 and the first inner edge 236. Returning to FIG. 14, the heater frame 218 defines a passage 248 through it, which is configured to receive the wick 130 (see, for example, FIG. 12), as will be described in more detail below. Furthermore, the heater frame 218 is configured to engage with the cylinder 216 by means of latches 250 that extend substantially parallel to the axis 120, which is axially aligned with the passage 248. The latches 250 are configured to engage with the latch-receiving portions 252 of the cylinder 216. Consequently, when assembled, the opening 238 of the cylinder 216 and the passage 248 of the heater frame 218 are configured to be substantially axially aligned. In the illustrated embodiment, cylinder 216 generally constitutes less than 40% of the heater arrangement 110, which comprises both cylinder 216 and heater frame 218.In some embodiments, cylinder 216 may constitute less than 50%, 38%, or 30% of the heater arrangement 110. The geometry and material composition of the heater arrangement 110 can be determined by finite element analysis (FEA) to improve or optimize heat transfer through the heater arrangement 110. That is, the particular geometries of cylinder 216 and heater housing 218 can be determined using FEA to improve heater performance. Referring again to FIG. 17, the opening 238 and the passage 248 preferably do not have a constant diameter throughout. More specifically, the opening 238 comprises a first diameter d1 defined by the first inner edge 236, and a second diameter d2 defined by a second inner edge 254 of the cylinder 216, wherein the first diameter d1 is preferably smaller than the second diameter d2. Similarly, the passage 248 of the heater frame 218 comprises a diameter d3 adjacent to the lower end 222 thereof. The passage 248 adjacent to the upper end 220 of the heater frame 218 has a diameter that is substantially equivalent to the diameter d2 defined by the second inner edge 254 of the cylinder 216. Alternatively, in some embodiments, the upper end 220 of the heater frame 218 may have a diameter that is either larger or smaller than the diameter d2.However, preferably, the diameter d3 is larger than both the diameter d2 and the diameter d1. As best seen in FIGS. 18-22, which illustrate example schematics of the passage 248 and opening 238 of heater arrangement 110, the components of heater arrangement 110 (i.e., heater chassis 218 and cylinder 216) are configured to define a restriction channel 256. That is, the passage 248 and opening 238, when axially aligned, gradually converge from the lower end 222 of the passage 248 to the first inner edge 236 of the opening 238. In other words, the restriction channel 256 of heater arrangement 110 restricts, narrows, or otherwise converges from diameter d3 to diameter d1. Diameter d3 is therefore larger than diameter d1. The restriction channel 256 can restrict in several different ways. For example, referring to FIG. 18, the restriction channel 256 can be iteratively restricted using a plurality of conical steps.More specifically, the restriction channel 256 can extend from the lower end 222, which has a consistent diameter d3, for a distance of a mm. The restriction channel 256 can then converge at an angle θ for b mm, measured along axis 120. From there, the channel 256 can extend with a uniform diameter d4 for c mm until it is restricted again at an angle β for d mm. The channel 256 can then continue again with a substantially constant diameter d5 for e mm until it reaches the heater chimney 242, at which point it is restricted at an angle θ for H mm (i.e., until it reaches the first inner edge 236, which has diameter d1). Alternatively, referring to FIG. 19, the channel 256 can be substantially narrowed at an angle δ from the lower end 222 to the first inner edge 236, terminating at the chimney 242.Figures 20 and 21 show two alternative configurations of the restriction channel 256 of the heater arrangement 110. Figures 20 and 21 are substantially similar to Figures 18 and 19, respectively, except that they do not terminate in a chimney (see, for example, the chimney 242 in Figures 18 and 19). That is, the main surface 240 is substantially flat from the peripheral edge 234 to the first inner edge 236. Furthermore, in either of the aforementioned embodiments, the straight-walled conical portions may be replaced by curved conical portions, an example of which is shown in Figure 22. Returning to FIG. 12, when the refill 108 is attached to the dispenser 102, the wick 130 is configured to extend through the passage 248 of the heater chassis 218 and into the opening 238 of the cylinder 216. Generally, a gap, G1, is defined by a distance measured substantially perpendicularly from an outer periphery of the free upper end 152 of the wick 130 to an inner periphery or inner wall 258 of the cylinder 216 adjacent to it. Alternatively, the gap, G1, can be defined by an area extending radially outward from the outer periphery at the free upper end 152 of the wick 130 to the inner periphery or inner wall 258 of the cylinder 216 adjacent to it.Furthermore, alternatively, the gap, G1, can define a volume between the outer periphery of wick 130 and the inner periphery or inner wall 258 of cylinder 216 that defines the opening 238 measured along a distal portion 260 of wick 130. In some cases, the distal portion 260 of wick 130 is defined as portions of wick 130 received by the opening 238, and adjacent to or otherwise surrounded by cylinder 216. That is, the distal portion 260 of wick 130 is any portion of wick 130 that is radially surrounded by cylinder 216. Alternatively, in some cases, the distal portion 260 of wick 130 can be defined as portions of wick 130 beyond the distal edge 154 of sheath 150. That is, the distal portion 260 would be any portion of the wick 130 that is not enclosed or radially surrounded by the sheath 150. Referring to FIG. 12, the gap, G1, must be large enough to allow sufficient airflow through the heater arrangement 110, but small enough to provide sufficient heat transfer to the wick 130. The gap, G1, can be between approximately 0.1 mm and 2.5 mm. Preferably, the gap G1 is less than 1 mm. In some embodiments, the gap G1 is less than 0.5 mm. In the illustrative embodiments, the gap is substantially constant, both radially about axis 120 and longitudinally along axis 120 in the region where the wick 130 and the heating arrangement 110 or the cylinder 216 overlap. In other embodiments, the gap may be non-uniform, and the above values ​​may represent maximum, minimum, or average radial gap amounts.For example, in a case where the separation G1 is defined in terms of a mean cross-sectional area, G1 may be the mean cross-sectional area measured between the outer periphery of a distal portion 260 of the drill bit 130 and the inner wall 258 that defines the opening 238, taken along a length of the distal portion 260 of the drill bit 130 and substantially perpendicular to the axis 120. In this case, for example, G1 may be between about 10 mm² and about 40 mm². Preferably, in this case, G1 is less than 30 mm². As another example, in a case where the gap G1 is defined in terms of an average volume measured between the outer periphery of the distal portion 260 of the drill bit 130 and the inner wall 258 of the cylinder 216 along the distal portion 260 of the drill bit 130, G may be between approximately 50 mm13 and 250 mm3 in some cases. Furthermore, G may be between approximately 100 mm and 200 mm133 in some cases.In this case, G1 is preferably less than approximately 100 mm3. Returning to FIG. 17, the passage 248 in the heater chassis 218 is sized so that the wick 130 can easily pass through it. More specifically, the diameter d3 is larger than the diameter D of the distal portion 260 or the free upper end 152 of the wick 130. Furthermore, the opening 238 is smaller than the outer periphery of the wick 130 (i.e., the diameter d1 is smaller than the diameter D of the wick). Consequently, the wick 130 can extend through passage 248 of the heater chassis 218 and into opening 238 of cylinder 216 to just below the first inner edge 236 of cylinder 216. The portions of the opening 238 beyond the free upper end 152 of the wick 130 thus converge to create a venturi effect. That is, because a cross-sectional area of ​​the opening 238 converges from the lower end 222 of the heater chassis 218 toward the first inner edge 236, the airflow through it can naturally increase its velocity. Heat from the heater arrangement 110 travels inward through the air gap G1 to the wick 130 by conduction and radiation and becomes trapped around the wick 130, thereby increasing the overall temperature in the gap G1 and consequently in the wick 130, creating a heat distribution around a circumference of the wick 130, and further increasing the volatilization of the volatile material in the wick 130. In one respect, the heat can be distributed substantially evenly around a circumference of the wick.Furthermore, or alternatively, the heat can be distributed substantially uniformly along the wick 130 and / or the heater arrangement 110. In another respect, the heater arrangement 110 can apply a greater or lesser amount of heat to different longitudinal or radial portions of the wick 130, for example, by positioning the heater closer to or further from the wick, forming the housing 104 from a more or less thermally conductive material in different longitudinal or radial positions, adding one or more additional heaters in different locations, or modifying the geometry of the housing 104 so that it is closer to or further from the wick 130 in different locations. Figures 24-26 show various views of the upper deck 112. Referring particularly to Figure 24, the upper deck 112 includes an annular wall 264 having a first surface 266, a second surface 268 (see, for example, Figure 26), and an annular rim 270 extending from an outer edge 272 thereof. The annular rim 270 comprises a plurality of latches 274 that are configured to be received and secured by the receiving portions 276 of the control dial 116 (see, for example, FIG. 23). In the illustrated embodiment, the top cover 112 includes three latches 274; however, alternative embodiments may include more or fewer latches. Referring to Figures 24-26, the annular wall 264 of the top cover 112 includes an inner rim 278 extending inward from the outer rim 272. As is more clearly seen in Figure 26, the outer rim 272 and the inner rim 278 are oriented in different planes such that the inner rim 278 defines a higher portion of the top cover 112. In the illustrated embodiment, the inner rim 278 and the outer rim 272 are separated by a height h. In some cases, the height h may be between 1 mm and 10 mm. In some embodiments, the height h may be less than 5 mm. In some embodiments, the height h may be less than 3 mm. Furthermore, the second surface 268 extends convexly from the outer rim 272 to the inner rim 278. More specifically, the annular wall 264 extends downwards in a first direction towards a depression 280, so that the second surface 268 is convex.From depression 280, the second surface 268 curves convexly in a second direction until it meets the inner edge 278. Thus, the inner edge 278 defines a central opening 282, and the second surface 268 defines a convergent structure around the central opening 282 for the emission of volatile material through it. It should be understood, however, that the top cover 112, according to alternative embodiments, can be tapered from the outer edge 272 towards the central opening 282 and the inner edge 278 in different ways. For example, referring to FIG. 27, the channel 280 (see, for example, FIG. 26) can be omitted so that the top cover 112 curves gradually from the outer edge 272 to the inner edge 278 in one direction. Although the second surface 268 is convex in the illustrated embodiment, it can be concave in other embodiments. Furthermore, referring to FIG. 28, the annular wall 264 can form an angle from the outer edge 272 or the channel 280 to the inner edge 278. That is, the annular wall 264 is generally straight from the outer edge 272 to the channel 280, and from the channel 280 to the inner edge 278 to define a funnel-like structure for the emission of volatile material through the central opening 282.Furthermore, referring to FIG. 29, the annular wall 264 can curve in multiple directions as it extends from the outer edge 272 to the inner edge 278. More specifically, the second surface 268 can include a convex portion 268a and a concave portion 268b that define a smooth curved surface for directing volatile material through the central opening 282. Preferably, the convex portion 268a is adjacent to the inner edge 278 and the concave portion 268b is adjacent to the outer edge 272. Returning to FIG. 26, in the present embodiment, the first surface 266 of the upper cover 112 projects in front of the second surface 268 and can generally follow the same shape as the second surface 268. That is, the first surface 266 can extend from the outer edge 272 to the inner edge 278 while curving in the first direction along the axis 120 opposite the inner edge 278 to the depression 280. From the depression 280, the first surface 266 can gradually curve in the second direction along the axis 120 opposite the first direction until it meets the inner edge 278. Thus, the first surface 266 is generally concave. Similar to the heater arrangement 110 discussed earlier (see, for example, FIG. 17), and referring back to FIG. 26, the use of a converging configuration helps to concentrate and guide steam out of a dispenser. That is, because the second surface 268 curves gradually from a diameter w1 to a diameter w2 defined by the central opening 282, the top cover 112 generally defines a converging outlet to provide a venturi effect on the steam flow out of the dispenser. In the illustrated embodiment, diameter w1 is the diameter defined by the channel 280. Preferably, this diameter is between 50% and 80% of diameter w1. In some cases, diameter w2 is between 60% and 70% of diameter w1. Furthermore, the second surface 268 is preferably smooth. Thus, the second surface 268 is generally a continuous curve from the outer edge 272 to the inner edge 278.As a result, a venturi effect is established, which ultimately increases the speed of the steam flow through it to enhance the release of steam to a surrounding area. Referring now to FIG. 25, the annular wall 264 further defines a plurality of openings 284 arranged around the central opening 282. In the illustrated embodiment, the plurality of openings 284 decrease in size as they are positioned further from the central opening 282. That is, the plurality of openings 284 near the outer edge 272 are smaller than the plurality of openings 284 near the inner edge 278. The plurality of openings 284 may be incorporated to provide ventilation capabilities and alternative routes for the release of volatile material through them, thereby preventing the recirculation of vapor within the housing, which is a major cause of condensation. Although the illustrated embodiment comprises a plurality of openings, other embodiments of this disclosure may include a top cover having more, fewer, or no openings in a variety of designs and configurations.Furthermore, the plurality of openings 284 may include beveled, threaded, or straight edges. More particularly, in the illustrated embodiment, the plurality of openings 284 includes beveled edges 286 to minimize the flow of disruptive vapor out of the casing (i.e., the plume). Preferably, the plurality of openings 284 includes chamfered edges 286 adjacent to the second surface 268. Furthermore, the dispensers according to the embodiments described herein exhibit enhanced airflow control. For example, referring to Figure 12, the relationship between the arrangement of the heater 110, the wick 130, and the housing 104, in addition to the presence of the plurality of openings 284 with beveled edges 286, results in reduced air recirculation within the internal cavity 106, which ultimately reduces the potential for condensation formation within the housing 104. Moreover, the minimal recirculation allows for greater release of volatile material into the surroundings, which can result in a visibly strong and consistent plume. Referring again to FIG. 12, the arrangement of heater 110 is configured to receive the wick 130 and thus convert the localized heating of the resistor 214 into a radiant heat source surrounding the wick 130 on multiple sides. More specifically, the wick 130 can extend through the passage 248 of the heater 218 chassis into the opening 238 of the cylinder 216. The arrangement of heater 110, in general, and resistor 214, in particular, are positioned close to the upper, free end 152 of the wick 130, leading to increased evaporation of the fluid drawn from the container 126 by the wick 130. In one embodiment, also as seen in FIG. 12, the arrangement of the heater 110 extends longitudinally above the free upper end 152 of the wick 130 to continue heating the volatilized material, even after the material has dispersed from the wick 130.Therefore, as the volatilized material exits the heater arrangement 110, it will continue to be heated within the internal cavity 106, which can actually increase the energy in the volatilized material and thus the velocity of the volatilized material out of the dispenser 102. This configuration can also allow the heater to be arranged closer to the central opening 282 of the top cover 112, again retaining the volatilized material at an elevated temperature as it travels through the internal cavity 106, thereby decreasing condensation of the material and promoting the dispersion of the volatilized material into the environment. The arrangement of heater 110 according to the present disclosure results in improved heating of the wick 130. In particular, the arrangement of heater 110 results in uniform and consistent heating of the wick 130 compared to existing dispensers. This improvement is a result of the design choices described above, particularly the use of a ceramic metal composite with a high metal content (e.g., aluminum). By embedding the heating element 214 in a highly conductive material, the heat from the element 214 is readily distributed throughout the cylinder 216 to create a substantially uniform temperature profile, which positively impacts the overall performance of the dispenser 102. For example, according to the present embodiment, the main surface 240 of the cylinder 216 experiences a temperature gradient (or temperature difference) of less than 20°C.In some embodiments, the main surface 240 of the cylinder 216 experiences a temperature gradient (or temperature difference) of less than 15°C. This temperature gradient is significantly reduced compared to existing dispensers, which can experience temperature gradients of 20°C to 40°C. Temperature gradients of this magnitude can disrupt the flow of vapor exiting a dispenser. More specifically, a plume being dispensed by the dispenser can be drawn or attracted to a hot side of the heater arrangement, which can cause air recirculation within the internal cavity and subsequent condensation. Referring again to FIG. 17, it should be understood that the performance of the heater arrangement 110 can be achieved using a variety of heat sources. That is, the heating element 212 having the single resistor 214 is not the only heat source that, combined with aspects of this disclosure, can result in improved heater performance. For example, referring now to FIG. 30, a heater arrangement 300 according to an embodiment of this disclosure generally includes at least one heat source 302, which may be a resistor (such as, for example, the resistor 214 shown in FIGS. 14 and 17), an embedded wire, or any other heat source known in the art. However, embodiments of this disclosure may use more than one heat source. For example, the heater arrangement 300 may include the heat source 302 in combination with one or more additional heat sources 304.More specifically, heat source 302 of heater arrangement 300 can be a resistor, and heat sources 304 can be additional resistors. These resistors can be distributed along heater arrangement 300 in various ways, such as circumferentially, longitudinally, laterally, etc. As another example, heat source 302 of heater arrangement 300 can be an embedded wire, and heat sources 304 can be a combination of resistors and / or embedded wires. Again, these heat sources 302 and 304 can be arranged along heater arrangement 300 circumferentially, longitudinally, laterally, etc. Furthermore, in some embodiments, heat sources 302 and 304 of heater arrangement 300 can be discrete resistors mounted on a printed circuit board.Therefore, heater arrangements according to the realizations of this disclosure may incorporate any heat source or combination of heat sources known in the art. An experiment was conducted to compare the performance of the heater arrangement 110 with a diffusion element of an existing dispenser. Three devices were tested. A first device (Device 1) is similar to the device described herein with respect to Figures 1-26 and included the heater arrangement 110 as shown and described with respect to Figures 12-17 and further included the top cover 112 as shown and described with respect to Figures 23-26. A second device (Device 2) is a device currently sold by SC Johnson & Son, Inc. under the name Glade® Plug-lns® and detailed in Belongia et al. US Pat. Pub. 2012 / 0275772. A third device (Device 3) is another plug-in dispenser known and sold on the market. All three devices were tested with a refill filled to an equal level of a consistent formula. The test facility was an environmentally controlled room maintained at 70° Fahrenheit (±2° F). Each device was operated at its respective intended operating power. The results of the experiment are shown in Table 1 below. Table 1 Duration (days) Total volatile material released (g) Input power (watts) Efficiency factor (mg / hour / watt) Device 1 11.3 17.8 1.8 36.5 Device 2 19.3 17.8 2.2 17.5 Device 3 22 17.8 1.7 19.8 With reference to Table 1, Device 1 required less power to release the volatile material than Device 2 and Device 3. Furthermore, Device 1 demonstrated a substantial increase in the emission of volatile material, resulting in a reduction of the time required to release 17.8 grams (g) of volatile material. Again, Device 1 closely resembles the dispensing system 100 described herein with respect to Figures 1-26. Therefore, the heater arrangement 110 described above results in increased heater performance. In the analysis phase of the experiment, once the tests were completed and the corresponding data collected, an efficiency factor for the device was calculated for each of them using the equation: Device efficiency factor = Overall weight loss per hour / power Since both devices are designed to operate at different power levels, the device efficiency factor (DEF) is used to compare the overall performance of the two devices. The calculated DEF is shown in Table 1 above. In summary, Device 1 has a significantly higher output rate per unit watt than Device 2 and Device 3. In fact, the DEF of Device 1 is more than twice that of Device 2 and almost twice that of Device 3. In other words, the amount of energy required to operate Device 1 is a fraction of the energy required for Device 2 and Device 3 to achieve the same or higher output rate. Consequently, Device 1 experiences energy savings and greater efficiency.This improved performance is the result of the design choices discussed above, particularly, for example, the choice of material for the heater arrangement 110, the geometry of the heater arrangement 110, the geometry of the top cover 112, and the arrangement or proximity of the wick 130 to the heater arrangement 110. In the illustrated embodiments, the efficiency factor of the heaters disclosed herein is greater than or equal to approximately 25. In other illustrative embodiments, the efficiency factor of one or more of the heaters disclosed herein is greater than or equal to approximately 40, greater than or equal to approximately 45, or greater than or equal to approximately 50. INDUSTRIAL APPLICABILITY Numerous modifications of the present invention will be evident to those skilled in the art from the foregoing description. Therefore, this description is to be illustrative only and is presented to enable those skilled in the art to carry out and use the invention. Exclusive rights to all modifications falling within the scope of the appended claims are reserved.

Claims

CLAIMS 1. A heater arrangement for a dispenser of volatile materials, the heater arrangement comprising: a cylinder defining an opening; and a heating element embedded in the cylinder, wherein the dispenser includes a housing configured to receive a refill containing a volatile material and a wick, the housing including a first cavity configured to support the heater arrangement, and wherein the dispenser is configured such that, when the refill is received inside the housing, the opening receives the wick inside so that a radial space is formed between the heater arrangement and the wick.

2. The heater arrangement according to claim 1, wherein the cylinder is made of an aluminum and ceramic composite.

3. The heater arrangement according to claim 2, wherein the heater arrangement further includes a heater frame configured to support the cylinder.

4. The heater arrangement according to claim 3, wherein the cylinder constitutes less than 50% of the heater arrangement.

5. The heater arrangement according to claim 3, wherein the cylinder constitutes less than 38% of the heater arrangement.

6. The heater arrangement according to claim 3, wherein the heater chassis is made of nylon.

7. The heater arrangement according to claim 3, wherein the heater chassis defines a passage, wherein the heater chassis passage is configured to be coaxial with the cylinder opening.

8. The heater arrangement according to claim 7, wherein the dispenser is configured such that, when the refill is received inside the housing, the wick extends through the passage in the heater chassis and into the opening of the cylinder so that a distal end of the wick sits below an inner edge of the cylinder.

9. The heater arrangement according to claim 8, wherein the radial gap is formed between an inner surface of the cylinder and an outer surface of the wick, wherein the radial gap is between 0.1 millimeters and 1 millimeter.

10. The heater arrangement according to claim 1, wherein the heater arrangement is configured to be substantially axially aligned with a distal end of the wick.

11. The heater arrangement according to claim 1, wherein the cylinder comprises an annular body having a peripheral edge, an inner edge, and a main surface extending between them, wherein the inner edge defines the opening, and wherein the inner edge and the peripheral edge are arranged in different planes.

12. The heater arrangement according to claim 11, wherein the main surface extends from the peripheral edge to the inner edge, wherein the main surface is flat adjacent to the peripheral edge and curved adjacent to the inner edge.

13. The arrangement of heaters according to claim 11, wherein the main surface is flat for more than 50% of a radial distance from the peripheral edge to the inner edge.

14. The arrangement of heaters according to claim 11, wherein an inner diameter of the opening defined by the inner edge of the cylinder is smaller than an outer diameter of the wick.

15. The heater arrangement according to claim 1 further comprising an upper cover, wherein the upper cover includes an annular wall having a first surface, a second surface opposite the same, an outer edge and an inner edge defining a central opening, wherein the outer edge and the inner edge are axially aligned and arranged in different planes, and wherein the annular wall extends radially inwards from the outer edge, curving in a first axial direction opposite the inner edge to a depression and gradually curving in a second axial direction opposite the first axial direction until it meets the inner edge.

16. The heater arrangement according to claim 15, wherein the upper cover further comprises a plurality of openings arranged around the central opening.

17. The arrangement of heaters according to claim 16, wherein the plurality of openings near the outer edge are smaller than the plurality of openings near the inner edge.

18. The arrangement of heaters according to claim 16, wherein each of the plurality of openings comprises a beveled edge.

19. The arrangement of heaters according to claim 18, wherein the beveled edge is arranged close to the second surface of the annular wall.

20. The heater arrangement according to claim 15, wherein the second surface defines a defined converging outlet between the basin and the inner edge, and wherein the second surface curves gradually from the basin to the inner edge.

21. A volatile material dispenser, comprising: a housing configured to receive a refill containing a volatile material and a wick, the housing including a first cavity supporting a heater arrangement, wherein the heater arrangement comprises a cylinder, a heater chassis, and a heating element embedded in the cylinder, wherein the cylinder defines an opening and the heater chassis defines a passage configured to be axially aligned with the cylinder opening, and wherein the dispenser is configured such that, when the refill is received within the housing, the cylinder opening is axially aligned with the wick, and a radial space is formed between the heater arrangement and the wick.

22. The volatile material dispenser according to claim 21 further comprising an upper cover, wherein the upper cover includes an annular wall having a first surface, a second surface opposite it, an outer edge and an inner edge defining a central opening, wherein the central opening defines an axial direction, wherein the outer edge and the inner edge are concentric and arranged in different planes, and wherein the annular wall extends radially inwards from the outer edge, curving in a first axial direction opposite the inner edge to a depression and gradually curving in a second direction opposite the first axial direction until it meets the inner edge.

23. The volatile material dispenser according to claim 22, wherein the dispenser is configured such that, when the refill is received inside the housing, the wick extends through the passage of the heater chassis and into the opening of the cylinder, such that a distal end of the wick sits below the inner edge of the cylinder.

24. The volatile material dispenser of claim 21 further comprises an upper cover, wherein the upper cover includes an annular wall having a first surface, a second surface opposite it, an outer edge, and an inner edge defining a central opening, wherein the central opening defines an axial direction, wherein the outer edge and the inner edge are concentric and arranged in different planes, and wherein a portion of the annular wall extends radially inward in an axial direction toward the inner edge.

25. The volatile material dispenser according to claim 24, wherein the annular wall extends radially inwards from the outer edge, curving in an axial direction towards the inner edge.

26. The volatile material dispenser according to claim 21, wherein a diameter of the opening defined by the cylinder is less than an outer diameter of the wick.

27. A volatile material dispenser, comprising: a housing configured to receive a refill containing a volatile material and a wick, the housing having a heater arrangement configured to volatilize the volatile material into a vapor plume, wherein the volatile material dispenser further includes a top cover comprising an annular wall with a first surface, a second surface, an outer edge, and an inner edge defining a central opening for the emission of volatile material through it, wherein the inner edge is raised relative to the outer edge, wherein the heating arrangement comprises a heating element retained within a cylinder and a heating chassis defining a passage through it, the cylinder comprising a main surface and a chimney defining an opening,wherein the chimney is raised above the main surface of the cylinder and tapers gradually from a first end close to the main surface to a second end distal to the main surface, wherein the cylinder is coupled to the heating chassis and constitutes less than 40% of the volume of the heating arrangement, and wherein the dispenser is configured such that, when the refill is received inside the housing, the wick is axially aligned with the central opening of the top cover, the cylinder opening, and the passage in the heater chassis, and the wick extends through the passage in the heater chassis and into the cylinder opening so that a distal end of the wick sits below the second end of the cylinder.

28. A volatile material dispenser, comprising: a housing configured to receive a refill containing a volatile material and a wick, the housing including a first cavity supporting an arrangement of heaters, and a top cover configured to engage with the housing and defining a central opening through which a plume of vapor exits the housing, wherein the top cover includes an annular wall having a first surface, a second surface opposite it, an outer edge and an inner edge defining a central opening, wherein the central opening defines an axial direction, and the outer edge and the inner edge are concentric and lie in different planes,where the second surface extends radially inwards from the outer edge, curving in a first axial direction to a depression and gradually curving in a second direction opposite to the first axial direction until it meets the inner edge, wherein the dispenser is configured so that, when the top lid is attached to the housing, the second surface is oriented towards the first cavity.

29. The volatile material dispenser according to claim 28, wherein the inner edge and the outer edge are arranged in planes that are axially separated by between 1 millimeter and 5 millimeters.

30. The volatile material dispenser according to claim 28, wherein the first surface of the annular wall is concave.

31. The volatile material dispenser according to claim 28, wherein the second surface of the annular wall is convex.

32. The volatile material dispenser according to claim 28, wherein the top cover further comprises a plurality of openings arranged around the central opening.

33. The volatile material dispenser according to claim 32, wherein the plurality of openings near the outer edge are smaller than the plurality of openings near the inner edge.

34. The volatile material dispenser according to claim 32, wherein at least one of the plurality of openings comprises a beveled edge.

35. The volatile material dispenser according to claim 34, wherein the beveled edge is arranged close to the second surface of the annular wall.

36. The volatile material dispenser according to claim 34, wherein each of the plurality of openings comprises a beveled edge.

37. The volatile material dispenser according to claim 28, wherein the second surface defines a defined converging outlet between the bucket and the inner edge, and wherein the second surface curves gradually from the bucket to the inner edge.

38. The volatile material dispenser according to claim 28, wherein a diameter of the central opening is between 50% and 80% of a diameter defined by the bucket.

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