Abstract:
A steaming pitcher for preparing hot beverages with a liquid crystal thermometer attached to an exterior surface of the pitcher for detecting the temperature of any liquid contained therein. The liquid crystal thermometer eliminates the need for conventional food service thermometers that are placed in the liquid being heated.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to steaming pitchers for making hot beverages, and more particularly to temperature monitoring devices for detecting the temperature of fluids heated within steaming pitchers. 
     2. Description of the Relevant Art 
     The current practice in the specialty coffee industry is to use food service thermometers with metal probes that clip onto the edge of a steaming pitcher which is used to heat liquids such as milk. The individual heating liquid in the pitcher uses the thermometer to gauge the temperature of the milk as the milk is being steamed or frothed with a steam wand on a machine such as an espresso machine. The milk is then added to fresh brewed espresso to make the desired specialty coffee drink—a cappuccino or caffe latte, for example. 
     The problems typically encountered when using this type of thermometer are numerous. If the volume level of the milk in the steaming pitcher does not rise above the middle of the thermometer&#39;s probe, the temperature indicated on the dial will be inaccurate. When “frothing” milk for a cappuccino, the foam created has a low density, the temperature of which is not accurately measured using a conventional thermometer. 
     Operators need to periodically adjust the thermometer to assure accurate measure of temperature. Conventional thermometers, because they are directly exposed to the milk, must be kept clean to assure safety in terms of public health. Conventional thermometers are relatively fragile—they need to be replaced fairly often as they break or are found to be inaccurate. 
     One of the most common mistakes made by individuals who prepare specialty coffee drinks, such as cappuccino, is “scalding” the milk. Scalding is the process by which milk or other liquid is heated above a critical temperature, approximately 175° F. at which point the proteins in the milk are degraded. This not only affects the flavor of the drink produced, but more importantly, poses a threat of burning the consumer of the drink. This occurs very frequently, even when a conventional thermometer is used. 
     It has now been found that a liquid crystal thermometer (hereinafter “LCT”), properly affixed to a steaming pitcher solves each of the aforementioned problems. Although placing a thermometer on the exterior of a container is not new, the application to a steaming pitcher to solve problems unique to steaming pitchers is. For example, U.S. Pat. No. 5,304,003 to Winninger teaches the use of a LCT that is applied to the exterior surface of a back wall of an aquarium with the graduations facing the interior of the aquarium. Use of clear adhesive to form an airtight attachment of the LCT to the aquarium back wall enables one to view the LCT graduations through the aquarium walls from the front of the aquarium. Winninger&#39;s use of a inwardly facing LCT and use of transparent adhesives are not useful with respect to steaming pitchers which are typically made from stainless steel which is a well known opaque material. 
     U.S. Pat. No. 5,588,747 to Blevins discloses a LCT affixed to the exterior of a measuring cup which is preferably insulated. The thermometer, by design, is not used to detect the temperature of the contents of the cup particularly with respect cups that are insulated. Instead, the substances that will eventually be added to the cup are allowed to flow over the exterior of the cup and the thermometer until the substances reach the desired temperature. The substances are then placed in the cup. 
     Bleven&#39;s use of a LCT on the exterior of the container for measuring temperature of substances allowed to flow over the thermometer will not solve the problems associated with steaming pitchers. It is imperative that the thermometer affixed to the exterior of a steaming pitcher be able to accurately detect the temperature of the steaming pitcher contents while being heated in the pitcher and not before being introduced into the pitcher. 
     It is thus an object of the invention to provide a thermometer for steaming pitchers that is durable and will withstand substantial cycling between heating, cooling and cleaning cycles. Another object of the invention is to provide a thermometer that will accurately gauge the temperature of the liquid in the steaming pitcher. A further object of the invention is to provide a thermometer that cuts down on the effort needed to clean the temperature sensing device. 
     SUMMARY OF THE INVENTION 
     The steaming pitcher of the present invention is based on the recognition that conventional thermometers used to monitor the temperature of fluids in a pitcher have numerous flaws which affect the user&#39;s ability to make a desirable hot beverage. The invention described herein is a LCT for measuring temperatures from about 135° F. to 175° F. It consists of a plastic strip, with liquid crystal boxes indicating temperature, and one box at 155° F. offset to more easily read the desired temperature when steaming milk for specialty coffee drinks like cappuccinos. The thermometer is slightly thicker than a sheet of paper and can be secured to a pitcher by means of a self-adhesive backing which will withstand the temperature extremes of cycling a pitcher through heating, cooling and reheating but also from the potentially harsh effects of washing the pitcher to which the thermometer is attached. 
     In one embodiment, the LCT is integrated into the body of the steaming pitcher so that it is permanent. The LCT is fixed to the pitcher with adhesive such as in the form of a self-adhesive strip. 
     Because of the high degree of thermal conductivity and the low positioning of the LCT on the lower portion of the steaming pitcher, the LCT will give a more accurate indication of the temperature of the milk within the pitcher, particularly in low volume situations or when “frothing” milk from a cappuccino. LCTs never need adjustment. Temperature is thus always measured accurately. 
     As the LCT is affixed to the exterior of the steaming pitcher, it eliminates the necessity of inserting a conventional thermometer into the milk, completely removing any public health risk associated with introducing a potential bacteria-ridden object into the holding portion of a pitcher. 
     An LCT is a relatively durable device which provides an easy means of replacement, i.e., the LCT need only be removed from the outside of the pitcher by defeating the strength or holding power of the adhesive used to hold the LCT to the pitcher. This is accomplished by the implementation of physical force or with suitable adhesive solvents as is well known in the art. 
     A liquid crystal thermometer properly affixed to a steaming pitcher should be both more accurate and more easy to use than a conventional thermometer thereby minimizing the propensity of heating the milk above the desired temperature. With the ideal temperature indicator offset in the design of the unit, ease of reference to determine when the milk has accurately reached the ideal temperature of 155° F. is achieved. These and other objects and features of the present invention will be apparent from a review of the drawings and a reading of the following detailed description of the invention. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a steaming pitcher/thermometer assembly according to one embodiment of the invention. 
     FIG. 2 is a front elevational view of a LCT according to one embodiment of the invention. 
     FIG. 3 is a partial sectional view of a steaming pitcher/thermometer according to one embodiment of the invention. 
     FIG. 4 is a partial sectional view of a steaming pitcher/thermometer according to one embodiment of the invention. 
     FIG. 5 is a partial sectional view of a steaming pitcher/thermometer according to one embodiment of the invention. 
     FIG. 6 is a partial front elevational view of a steaming pitcher/thermometer according to one embodiment of the invention. 
     FIG. 7 is a perspective view of a food service thermometer in the prior art. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a pitcher  10  is shown. Pitcher  10  has a main body  12  to which a handle  14  is affixed. Main body  12  has a bottom  15  and portions which define a receptacle  16  for receiving and containing fluids. A liquid crystal thermometer  18  is affixed to main body  12 . Preferably, LCT  18  is secured to Pitcher  10  with an adhesive strip  20  as shown in FIG.  3 . To maximize the accuracy and effectiveness of LCT  18 , LCT  18  is preferably situated on pitcher  10  in close proximity to bottom  15  to ensure that the fluid temperature is accurately detected no matter what volume of receptacle  16  is occupied by fluid. 
     LCT  18  has a plurality of compartments  20  which house the liquid crystal compositions. It is to be understood that the particular liquid crystal compositions are not part of the invention. Compartments  20  are preferably labeled with numeric designations  22  which signify the particular temperature in either Celsius or Fahrenheit (° F. shown), that is being detected by the particular compartment. 
     To render LCT  18  more convenient for the purpose of preparing particular beverages such as cappuccino, center compartment  24  is sized to be larger than the remaining compartments  20 . Compartment  24  is enlarged to designate and emphasize the preferred temperature of the liquid being heated. It is to be understood that the liquid crystal compositions situated in compartments  20  can be formulated for a wide range of temperatures. Preferably, the temperature range that can be detected by LCT  18  is about 120° F. to 190° F. 
     The temperatures detected by the liquid crystals in the plurality of compartments  20  are preferably detected in 5° F. increments but can be detected in a variety of incrementally sized steps such as 1° F. steps, 2° F. steps, 10° F. steps, etc. It should be further understood that the size and shape of compartments  20  are subject to many variations depending upon the needs of the user. For example, compartments  20  can be made large, square and/or oval in shape, with large numeric designations to accommodate an individual with failing eyesight. In an alternate embodiment, only one compartment  20  is provided that contains a liquid crystal formula that is formulated to detect the optimum desired temperature of the fluid being heated. 
     To further accentuate compartment  24 , an additional reference designation such as arrow  26  can be provided as a visual reference as shown in FIGS. 1 and 2. An optional visual reminder to clean the steaming wand used to froth the liquids being heated after use can be provided by including the term “CLEAN”  27  situated above a first compartment set  28  and “WAND”  29  situated above a second compartment set  30 . The terms can be placed on any location on LCT  18  to improve the functionality of LCT  18 . 
     Unlike the prior art references discussed above and as shown in FIG. 7, LCT  18  is particularly suited for attachment on the exterior of steaming pitchers which are invariably made from stainless steel. As is well known in the art, stainless steel is a good heat conductor so that any heat detected by LCT  18  on an exterior surface of pitcher  10  will accurately depict the temperature of the fluid being heated. 
     LCT  18  can be secured to pitcher  10  in a variety of ways in a variety of positions. As shown in FIGS. 3 and 4, LCT  18  is secured to pitcher  10  via an adhesive layer  32 . In one embodiment, a self-adhesive strip is provided on a back side  34  of LCT  18  for ease of attachment to pitcher  10 . In another embodiment as shown in FIGS. 4 and 6, LCT  18  is set into a depression  36  formed on pitcher  10  to protect the edges of LCT  18  from being pried off through the course of normal use and cycling. Depression  36  is preferably as deep as LCT  18  and adhesive layer  32 . Alternatively, a clear transparent coating can be placed over LCT  18  to provide further protection against wear as shown in FIG.  5 . 
     In other embodiments, LCT  18  can be placed at locations other than close to bottom  15  and can be placed in a vertical or diagonal position relative to the longitudinal axis of pitcher  10 . 
     While the invention has been particularly shown and described with reference to the aforementioned embodiments, it will be understood by those skilled in the art that various changes in form, composition and detail may be made therein without departing from the spirit and scope of the invention. Thus, any modification to the shape, configuration and/or composition of the elements comprising the invention is within the scope of the present invention.