Abstract:
The present invention discloses a method and apparatus for quickly heating a predetermined volume of viscous fluid and dispensing it efficiently at one or more selected temperatures. The viscous fluid includes non-volatile constituent parts. In one embodiment, the predetermined volume of viscous fluid is partially housed in a predelivery chamber separate from the main fluid reservoir. A heater assembly heats the viscous fluid in the predelivery chamber in a short time period and in small volumes to prevent overheating and adversely effecting the composition of the viscous fluid. To avoid continually heating the viscous liquid, a timer circuit is used in one embodiment.

Description:
FIELD OF THE INVENTION 
     This invention relates in general to heating and dispensing apparatus used for fluid which includes substantial non-volatile constituent parts and more specifically to a hot fluid dispenser which only heats a portion of the fluid before it is dispensed. 
     BACKGROUND INFORMATION 
     Fluids such as body lotions and oils are commonly applied to the human skin to address dry skin problems, eczema and other skin disorders. These lotions are typically stored in containers at ambient air temperature and are applied to the body by means such as squirt bottles and hand pump dispensing apparatus. These lotion dispensers unfortunately produce the lotions at temperatures well below the normal skin temperature of the human body (i.e., somewhat less than 98.6°). Not only is the application of body lotions at cool temperatures uncomfortable for infants, the elderly and the general user, the cooler temperatures prevent the lotion from adequately penetrating the pores of the skin since the cool temperature makes the skin ports constrict rather than open up to receive the body lotions. 
     Although attempts have been made to heat fluids prior to this application, these devices generally heat the fluids in mass in a bulk storage container. Over time, this process resulted in separation and breakdown of the natural composition of the body lotions or fluids, thus reducing their effectiveness. For example, the paraffins in some lotions tend to break down when heated to temperatures above 110° F. for extended periods to time. Further, the continual heating and cooling of the lotion causes a coagulation of the non-volatile components when the solvents evaporate which over time can clog the pumping or dispensing mechanism, as well as destroy a larger portion of the lotion, which is expensive. Additionally, the amount of time required to heat larger containers of body lotions is not practical for a user which prefers the lotion to be heated in a matter of minutes or seconds. Leaving lotion heated for extended periods of time can also cause bacteria, algae and other undesired microorganisms to grow in the lotion. 
     In addition to heating the bulk storage container, some have also applied heat to a dispensing tube of commercial pumps. Fluid in the dispensing tube can cool between uses, so heat is applied to this tube to avoid cooling. However, heating a small portion of the fluid can evaporate the solvent components in the fluid which makes the remaining fluid more viscous. Maintaining a desired viscosity is important to avoid potential clogging of the dispensing tube and/or otherwise ruining the fluid. The heat is applied to the storage container and dispensing tube continually. However, applying heat continually consumes costly energy and is impractical for a consumer unit which may only be required infrequently. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a method and apparatus for quickly heating a predetermined volume of body lotion and dispensing the body lotion efficiently at a selected temperature. The predetermined volume of body lotion is housed in a predelivery chamber separate from the main fluid reservoir. The present invention is generally a portable device which may be operated manually, or more typically, electrically. 
     It is thus one object of the present invention to provide lotion heater assembly which heats the lotion in a short time period and in small volumes to prevent overheating and adversely effecting the lotion composition. Thus, in one aspect of the present invention, a heating element is coupled to the predelivery chamber as opposed to in a heating plate “jacket” or other device which heats the main fluid reservoir. The present invention heats only a predetermined volume of lotion in the predelivery chamber which is soon used by the consumer or masseuse applying the lotion. This avoids subjecting a volume of the lotion to heating over long periods of time. 
     It is another object of the present invention to provide a pumping assembly which either manually or automatically pumps a predetermined increment of lotion which has been spontaneously heated. In one aspect of the present invention, the heating element may be in operable contact with the predelivery chamber or dispensing spout to provide immediate heating of the lotion prior to dispensing. 
     It is another object of the present invention to provide a heated fluid pump which can be used with conventional lotions commonly purchased by the household consumers so as to not require unique and expensive compositions specialized for heating. Thus, the heating apparatus may be universally used with substantially all lotions currently sold over the counter. Conversely, specially formulated lotions specifically designed for heating may be sold either independently or in conjunction with the heated fluid pump. 
     Additionally, in another embodiment of the present invention a small container or tube with a predetermined volume of lotion may be sold which is designed to custom fit the interior of the heated fluid pump. This configuration allows the container or cup to be readily disposed of after use to avoid the need to clean or otherwise maintain the main fluid reservoir of the fluid pump. The cup, in one embodiment, may resemble a plastic cup with a foil cover, such as a yogurt cup, and the lotion may be exposed for use by either removing a pull tab cover or by piercing the foil cover with a sharpened suction tube at the bottom of the main fluid reservoir. A hole in the cup could be pierced by a sharp point on the inside of the lid so that pressure would not build in the cup. 
     Additionally, it is another object of the present invention to provide a thermostatically controlled heating element which assures the proper lotion temperature during all period of use. Thermostatic control reduces the risk of malfunction which could overheat the lotion. Thus, the device is safe for infants, the elderly and for others especially sensitive to heated products. Additionally, the pumping and dispensing apparatus of the present invention creates a predetermined even flow of heated lotion which prevents waste or overuse. 
     The advantages of using heated lotions are numerous over applying cold lotions to the human body. The advantages include: 
     1) Heated lotions tend to penetrate the skin better. The human skin temperature is approximately 95°. If 75° or cooler ambient air temperature lotion is applied to 95° skin, the ports of the human body tend to close. However, if 120° lotion is applied the ports tend to open, allowing for better and deeper penetration of the lotion. 
     2) Heated lotions have lower viscosity than cooler lotion which allows for better penetration. Lotions with lower viscosity are thinner and thus easier to apply and penetrate the skin better than cooler lotions. 
     3) Heated lotions have less drag or friction when applied by a masseuse or the user because of the lower viscosity. This allows less pulling on the skin or stretching and is applied easier and in a more desirable fashion than cooler lotions. 
     4) Heated lotions are cost effective since less lotion is more efficiently absorbed and the user thus saves money. Additionally, heated lotions cover more area and leave less waste atop the skin to evaporate based on the higher penetration rates. 
     5) Heated lotions have a therapeutic affect on joint aches for people suffering from arthritis, sore muscles, over exertion, and other afflictions. Some of these therapeutic effects may be attributed to the sensual appeal of heated lotions. 
     6) Heated lotions feel better when applied to cold skin whereas cold lotions have a shocking effect to the skin, especially to infants and the elderly. Thus, the present invention eliminates the need of parents to try to warm lotions by hand rubbing before applying lotions to a baby or other person. Additionally, the portable heating apparatus alleviates the problem of parents attempting to heat lotions by submerging bottles in hot water or using heating elements like ovens or microwaves which may potentially overheat lotions and may burn the child. 
     Other objects, features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view illustrating an embodiment of a lotion pump which allows selecting at least two set temperatures for heating the lotion; 
     FIG. 2 is a right side elevational view showing the lotion pump of FIG. 1; 
     FIG. 3 is a left side elevational view showing the lotion pump of FIG. 1; 
     FIG. 4 is a front elevational view showing the lotion pump of FIG. 1; 
     FIG. 5 is a back elevational view showing the lotion pump of FIG. 1; 
     FIG. 6 is a top plan view showing the lotion pump of FIG. 1; 
     FIG. 7 is a bottom plan view showing the lotion pump of FIG. 1; 
     FIG. 8 is a side-sectional view depicting an embodiment of the lotion pump which has a check valve and a resistance type heat element; 
     FIG. 9 is a block diagram of the electronics within an embodiment of the lotion pump; 
     FIG. 10 is a side-sectional view showing an embodiment of the fluid conduit; 
     FIG. 11 is a side view illustrating an embodiment of the check valve spring; 
     FIG. 12 is a side-sectional view illustrating a mushroom shaped embodiment of the check valve nozzle; 
     FIG. 13 is a top view showing the heater clip which used to hold the heating elements against the predelivery chamber; 
     FIG. 14 is a side view illustrating a predelivery chamber; 
     FIG. 15 is a top cross-sectional view schematically showing a first embodiment of the interior configuration of the predelivery chamber; 
     FIG. 16 is a top cross-sectional view schematically showing a second embodiment of the interior configuration of the predelivery chamber with additional heat-transfer surface area; 
     FIG. 17 is a top cross-sectional view schematically showing a third embodiment of the interior configuration of the predelivery chamber with additional surface area; 
     FIG. 18 is a top cross-sectional view schematically showing a fourth embodiment of the interior configuration of the predelivery chamber which has a heat retaining central portion; 
     FIG. 19 is a front elevational view showing another embodiment of a lotion pump which does not have a temperature select feature; 
     FIG. 20 is a top-sectional view of the lotion pump of FIG. 19 which shows the pumping assembly; and 
     FIG. 21 is a side elevational view of a fluid conduit which does not have a check valve and has a positive temperature coefficient (PTC) heater. 
    
    
     DETAILED DESCRIPTION 
     The heated lotion pump is generally comprised of a main fluid reservoir, a pumping assembly, and a heater assembly which may be used is conjunction with a predelivery chamber to heat a predetermined volume of lotion. The apparatus is portable, and may be operated either manually (for dispensing), or more commonly operated electrically. The heated lotion pump is reusable, can be filled over and over again with various types of products and can be disassembled for easy cleaning. 
     The present invention allows delivery of heated lotion on demand in just a few seconds or up to 30 minutes with temperatures varying from 80° to 180°, depending upon factory installed components and end use. Additionally, the lotion pump has safeguards to prevent overheating and/or electrical shock. In a preferred embodiment of the present invention, a manually controlled thermostat may be used to adjust the lotion temperature to the specification and comfort of the user. A number of temperatures could be utilized which would be selected by way of a hi/low switch, a slider switch, a rotary potentiometer, or the like. Further, a thermal cut-out (TCO), bi-metallic switch or the like can be used as a thermal fuse which trips when the temperature exceeds a predetermined threshold. In other embodiments, a positive temperature coefficient (PTC) which is capped to provide less than 300° F. heat could also provide further safeguards. 
     With reference to FIGS. 1-8, the heated lotion pump  100  is respectively illustrated in a perspective, right side, left side, front, back, top, bottom, and side-sectional views. The plastic enclosure includes a main portion  104 , a front portion  108  and a exterior top or lid  112 . Preferably, the main body portion  104 , front portion  108  and lid  112  are injection molded with a composite plastic. In this embodiment, the front portion  108  includes a base portion  120 . The main portion  108  may also have a molded-in tank to serve as the main fluid reservoir  800  and which may have various configurations depending on the specific application of the present invention. For example, a masseuse may order an enclosure with a main fluid reservoir  800  that has a much larger storage volume as compared to a consumer model which may need the lotion pump  100  for home use only. The main fluid reservoir  800  generally has a high polish finish and funnels towards an outlay  804  near the bottom where the lotion is directed toward the gear pump spur  808 . Thus, gravity is used to provide the lotion to the feed pump  808 , although alternatively a siphon type feed mechanism could be used. The gear pump spur  808  has two interlocking gears (see FIG. 16) which serve to pump the lotion through the fluid conduit. The temperature of the main fluid reservoir  800  is largely unaffected by the heating element and is generally an ambient temperature. In one embodiment, a battery box  700  with, for example, two AA batteries, an electrical outlet  116  and enclosure for the gear pump assembly  812  also are molded into the main body for simplicity and economy. The materials for the enclosure preferably will be ABS plastic in a number 2 finish or polycarbonates for parts exposed to heat, although any numerous types of materials may be used. For parts exposed to the heated lotion, nylon and/or polypropylene is preferred. 
     A single injection molded part in the same finish and material as the main body makes up the front portion  108  of the finished unit  100  as well as a bottom portion or base plate  120 . In other embodiments however, the bottom portion  120  could be separate to ease manufacturing. Additionally, a single injection plastic molded cap or lid  112  may be utilized which has the same material and finish of the main body portion  104 . The lid  112  is generally a user removable cover to close the lotion tank  800  and which also permits access for cleaning purposes. The bottom portion  120  of the enclosure may also include one or more leg portions and/or non-skid rubber feet for resting the dispensing unit on furniture. In one aspect of the present invention, an insulating wall  2100  (see FIG. 21) could be used to isolate the heater assembly  816  of the product from the main fluid reservoir  800 , to further reduce unintentional heat coupling to the main fluid reservoir  800 . The insulating wall  2100  may also support and attach to the heater assembly  816 . 
     The tank body  820  is generally plastic, metal or any combination of metals and plastics. Preferably the plastics proximate to the heating area contain a polycarbonate or the like to meet code requirements related to fire or overheating. In some embodiments, the tank  820  may be interchangeable to allow changing of the contents and may include a storage portion to receive a disposable bag and/or yogurt cup type container with a seal that can be pierced by a portion of the pumping/dispensing assembly  100 . Additionally, the tank  820  may have a level indicator and a filling port to quickly allow the addition of new lotion. Furthermore, the tank  820  may have a pressure device to provide better flow in the unit, a preheater and/or a special coupling valve for removal or flow control. Preferably, the tank/body  820  is constructed of a shatter resistant plastic, and holds a volume of between about 2 and 20 ozs. of lotion in a consumer design or more in a commercial design. 
     The pump assembly  812  is used to dispense the lotion from the tank body  820  and may be manually operated or electrically powered. The electric power could be supplied by 120 or 240 V AC  power supply, batteries (3 V DC ), a 12 V DC  power supply, and/or other known power sources. The pump spur  808  is preferably a gear type, but may be an impeller, a diaphragm, a piston, or a roller and tube (no touch) type which could be driven by a rotary motor, piston motor, linear magnetic device or vibrator. One or more check valves  828  could be used to control backflow and prevent air lock and nozzle drip. Furthermore, the pump assembly  812  could have special amounts of insulation to reduce noise. The pump assembly  812  may additionally include numerous disassembly features to allow for cleaning and maintenance. 
     The heating element  832  is a PTC type, a variety of resistance types which may be printed/laminated to a flexible film or fabric, or the like. The heating element  832  preferably is adjacent to a predelivery chamber  836 , i.e., a chamber of a pipe to allow heating only a portion of the lotion which will immediately be dispensed as opposed to heating the total volume of lotion  800  maintained in the tank body  820 . The embodiment in FIG. 8 shows a resistance type heating element  836  clamped to the predelivery chamber  836 . The shape of the chamber  836  or pipe can be straight or varied to improve efficiency of heat transfer and may contain a baffle system for internal heating. The baffle system would serve to increase the ratio of surface area to chamber volume so that heat transfer is maximized. Additionally, various conducting materials may be used to store heat and make the heat transfer more evenly to the lotion. Accordingly, a heat conducting material which is known in the art such as stainless steel, aluminum with a protective coating and/or other conductive materials could be used. Further, the wall of the predelivery chamber  836  is thin to more easily conduct heat. The heating element  832  is preferably thermostatically controlled and is preferably interactive with the controls for the pump to allow the heating of the lotion to be controlled between a temperature of between about 80° and 180° F. Preferably, when the tank body  820  and/or predelivery chamber  836  is empty, the heating element  832  will automatically shut off to prevent overheating of the unit. Additionally, a circuit breaker, such as a TCO, is provided to prevent electrical overloading of the heater and which may include a fuse to prevent overheating. The heater assembly  816  is additionally insulated for optimum performance and to again prevent overheating of the tank body  820 , pump  812  and/or other components of the lotion pump  100 . After the last activation of the pump, the temperature of the predelivery chamber  836  is maintained for period of time, for example, 20 or more minutes. 
     A thermal sensor  840  may be utilized to allow the pump to be operational only when the lotion in the predelivery chamber  836  is at its proper delivery temperature. The thermal sensor  840  may be any number of thermostats commonly known in the art, such as a solid state device, thermistor or bi-metallic switch. The thermal sensor  840  works in concert with the heating element  832  under the direction of a control circuit to thermostatically regulate the temperature of the dispensing chamber  836 . Preferably, the range of set temperature is adjustable. Additionally, the thermal sensor  840  could be monitored to prevent activation of the pump assembly until the lotion is properly heated. 
     The lotion would preferably be heated “in-line” on its way to the delivery point where the lotion will be delivered at a temperature preferably at about 115°. Thus the temperature inside the dispensing chamber tube  836  is to be somewhat higher and in the range of between 120 and 140° F. The gear pump spur  808  pushes the lotion into the dispensing chamber  836  which has an accommodation on the side for a heating element  840  to be press fitted. Generally, the PTC heating element consumes about 5-40 watts while active. To direct the flow of the heated lotion from the top of the dispensing chamber  836  to the delivery point, the dispensing chamber  836  is fitted with a dispensing spout  844 . 
     The drive train used for the pump assembly  812  includes molded plastic gears. The gears are preferably made of Delrin™ because of its lubricity and wear resistance properties. Although, other known compositions could also be used. The gears are designed to fit the size and output requirements of the pump assembly  812 . A motor  824  with a pinion gear  848  drives a first gear  852  which drives a second gear  856 . Two pump spur gears  808  are driven by the second gear  856 . An o-ring  860  seals the drive train from the lotion conduit to avoid possible leakage. In a preferred embodiment a check valve  828  may be interconnected to the dispensing spout to prevent lotions from inadvertently dripping during periods of non-use. Additionally, the check valve  828  keeps air from interacting with the lotion in the lotion conduit which keeps the lotion from drying out and possibly plugging the lotion conduit. 
     Additionally, there is an accommodation to fit a printed circuit board (PCB)  864  in lower part of the front of the lotion pump  100 . The PCB  864  generally accommodates the electronic functions of the lotion pump  100 . With reference to FIG. 9, a block diagram of the electronic functions is shown. The power switch  136  activates a power supply  900  to condition and convert the input power from any of the various sources to the proper output power. A control circuit  904  manages the operation of the lotion pump  100  which includes such operations as the thermostat function and automatic power-down function. 
     The thermostat function controls the temperatures of the predelivery chamber  836  and avoids overheating. A set temperature switch  128  allows selecting the desired set point for the lotion. The set temperature switch  128  could be a slider switch allowing a variable range or is preferably a two position switch allowing two set points. In embodiments with a single set temperature, the set temperature switch  128  is not required. The control circuit  904  reads the set temperature select switch  128  to activate the heat element  832  accordingly. To known when the predelivery chamber  836  is adequately heated, the temperature sensor  840  is monitored. The status LED  132  be used to indicate when the desired temperature of the lotion is achieved and/or that the power switch  136  has activated the pump  100 . The lotion pump  100  takes approximately 60 seconds to reach temperature after activation of the power switch  136 . If an overheat sensor  908 , such as a TCO, indicates a thermal run-away condition, the control circuit  904  can deactivate the heat element  832  in order to reduce the risk of fire or burns. 
     The control circuit  904  also manages the automatic pumping function. When the pump button  124  is activated, the pump assembly  812  is powered which causes flow in the lotion conduit. To prevent not adequately cooled lotion from being dispensed, the control circuit  904  could prevent activation of the pump  812  if the lotion has not reached its set point. In other embodiments however, the pump button  124  could avoid the control circuit  904  and directly activate the pumping assembly. The pump button  124  is preferably a momentary switch that indicates to the control circuit  904  a predetermined volume should be dispensed. 
     The timer circuit  912  saves energy and prevents continual heating of the lotion in the predelivery chamber  836 . Continual heating can reduce the lotion to its non-volatile constituent parts. The timer is preferably set for 20 or more minutes. After the power switch  136  is activated, the starts counting its 20 minutes, for example. Each depression of the pump button  124  resets the 20 minute timer. If the 20 minutes expires, the lotion pump  100  is automatically powered down. This power down function saves energy and avoids ruining the lotion with excessive heating. Additionally, activating the power switch  136  a second time could immediately power down the lotion pump  100 . The power switch  126  is preferably a momentary switch that activates the lotion pump  100  for a short period of use (e.g., 20 or more minutes). 
     The momentary power switch  136  effectively is the mechanism which first applies power to the heat element  832 . It is a momentary contact, i.e. touch on/touch off (power relay). Preferably it  136  has a very light touch so that its  136  use does not tend to skid the lotion pump  100  on the support surface and so that lotion saturated hands can activate it  136  without slipping. Although a custom molded square shape is proposed for the power switch  136 , as appreciated by one in the art, the actual geometric configuration of the switch  136  is not important to the functional attributes of the product  100 . The momentary pump button  124  is preferably a soft touch switch that allows power to be delivered to the pump motor  824  as long as its is depressed. No specific switch  124  is proposed or is required although a custom molded “button” which is sealed against lotion intrusion is preferred. 
     Additionally, the status LED  132  preferably has the ability to glow either a red or green color to respectively indicate that the lotion is being heated and the lotion is ready for use. The color change is accomplished by the reverse polarity of the LED  132 . Although other embodiments could have a single color LED which only indicates power is active. Further, any display which allows display of this information could be used. 
     With reference to FIG. 10, a side-sectional view of the fluid conduit  1000  is shown. The fluid conduit  1000  is defined by an elbow joint  1004 , the predelivery chamber  836 , the dispensing spout  844 , and the check valve  828 . The elbow joint  1004  begins with a diameter which is less than the predelivery chamber  836  and the dispensing spout  844  ends with a diameter which is less than the predelivery chamber  836 . The diameter of the predelivery chamber  836  is larger to accommodate a predetermined volume of lotion which is heated. Having a larger diameter predelivery chamber  836  allows for more efficient heating of the lotion with the heating element  832 . The dispensing spout  844  is molded to include a means for attaching the heat sensor  840 . Lotion resistant plastic nylon or polypropylene is preferably used to make the dispensing spout  844  and elbow joint  1004 . 
     FIGS. 10-12 show two embodiments of the check valve  828  which is used to seal the end of the dispensing spout  844 . In FIG. 10, the check valve is comprised of a ball bearing nozzle and spring and in FIGS. 11 and 12 the check valve is comprised of a mushroom shaped rubber nozzle  1200  and spring  1100 . The nozzle seal prevents air from entering the liquid conduit  1000 . A stem  1204  of the mushroom shaped rubber nozzle  1200  rests inside the spring  1100  to form the valve. While being disassembled, the mushroom shape keeps the spring  1000  and nozzle  1200  together. During dispensing, the pressure created by the pump assembly  812  compresses the spring  1100  by pushing the nozzle  1200  away from the dispensing spout  844 . Once the pressure subsides, the nozzle  1200  presses against the delivery end of the dispensing spout  844  to seal the fluid conduit  1000 . 
     With reference to FIG. 13, a heater clip  1300  is depicted from a top view. The heater clip  1300  clamps two resistive heating elements to the predelivery chamber  836 . Spring steel is the preferred material for the heater clip  1300 , but other materials and clamps could be used. 
     FIG. 14 shows a side view of the predelivery chamber  836 . A single tube of stainless steel or coated aluminum is preferred for the predelivery chamber  836 . Preferably, the chamber  836  can hold a predetermined volume of lotion of 10-20 cc. With references to FIGS. 15-18, sectional views of the predelivery chamber  836  are shown. The various configuration in FIGS. 16-18 maximize the surface area and heat transfer from the metal to the fluid conduit  1000 . The embodiments in FIGS. 16 and 17 have additional surface area  1604 ,  1700  which thermally conducts with the outside of the chamber  1600 . When the outside of the chamber  1600  is heated, the additional surface area  1604 ,  1700  conducts this heat to the interior of the chamber more efficiently than the embodiment in FIG. 15, for example. The embodiment in FIG. 18 has a heat retaining core  1800  which retains heat to more quickly bring lotion entering the chamber  836  to the set point temperature. 
     With reference to FIGS. 19-21, another embodiment of the invention is shown. This embodiment has neither a set temperature select button  128  nor a check valve  828 . Accordingly, only one predetermined set point is available and air can enter the fluid conduit  1000 . Referring specifically to FIG. 20, a cross-section which reveals the gear pump spurs  808  is illustrated. Next, FIG. 21 shows the fluid conduit  1000  attached to an insulating wall  2100 . The insulating wall  2100  helps shield the main fluid reservoir  800  from the heating elements  832 . The absence of a check valve  828  allows the lotion to at least partially drain from the predelivery chamber  836  back into the main fluid reservoir  800 . The embodiment in FIG. 21 uses a PTC heater as the heating element  832 . 
     The above discussion generally discussed dispensing of body lotions, however other fluids (e.g., moisturizers, shaving cream or hair conditioners), oils (e.g., massage oil), food products (e.g., cheese, syrup or chocolate), and other items which are commonly used in households and require heating in small portions could also be dispensed. Any liquid which has substantial non-volatile constituent parts which will not evaporate is a candidate for this invention. In other words, liquids which would tend to concentrate if the solvents contained therein evaporate would benefit most from this invention. For example, liquids such a tap water, salt water, or relatively pure alcohol would not have substantial non-volatile constituent components. 
     Even though the temperature sensor is shown outside the predelivery chamber, other embodiments could embed the sensor inside the predelivery chamber. Integrating the temperature sensor in this way would provide for more accurate measurements. 
     While various embodiments of the present invention have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention.