Abstract:
A system for retaining and controlling the temperature of a beverage, suitable for installation in an automobile, includes a generally cylindrical, open-topped heat-conductive expandable cupholder, a heat-conductive liner, one or more thermoelectric devices located on a vertical exterior side of the cupholder, a heat sink contacting the thermoelectric device and thermally insulated from the cupholder; and a switch. The placement of the thermoelectric device and an improved arrangement for contact between the cupholder and the cup enable more efficient heat transfer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provision Patent Application Ser. No. 60/496,530, filed Aug. 20, 2003, the entirety of which is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention relates to a thermoelectrically heated and cooled cupholder system and more specifically to such a system wherein a finned Peltier device provides for heat transfer through efficient contact between the cup and the heat transfer surface. 
   BACKGROUND OF THE INVENTION 
   One of the principal drawbacks related to keeping beverages at their proper serving temperature is the tendency for such beverages to assume the ambient temperature in the environment into which they have been placed. A hot beverage, such as coffee or tea, particularly when served in an uninsulated cup, quickly cools. A cold beverage, such as an iced soda, quickly warms to room temperature, causing the ice to melt and dilute the beverage. 
   Various solutions to this problem have been proposed, which act passively to maintain the temperature of the beverage through some kind of insulation. For example, an insulated foam or fiberboard cozy can surround the beverage container, helping the container to retain its heat or to slow the infiltration of heat into a cold beverage. These passive systems slow the process of heat transfer, but they do not eliminate it or compensate for it entirely. 
   On the other hand, several active heat management systems have been developed, which for space and safety purposes make use of a Peltier or thermoelectric device. Such devices are well known in the art to which the present invention relates and consist essentially of a pair of ceramic plates separated by an array of cubes of bismuth telluride or a similar material. When a direct current is applied across the device, heat is moved from one side of the device to the other, producing a cooling effect on one side of the device. If the polarity of the current is reversed, the device becomes an efficient heater. Such devices are generally more efficient at cooling in combination with a heat sink, and because of the polarity-reversing feature of these devices, they are suitable for use where selective heating and cooling operations are desired. 
   For example, in U.S. Pat. No. 5,042,258, an insulated mug is provided with a heat-conductive bottom inner surface and a thermoelectric device in the base of the mug. The base of the mug is provided with heat-conductive fins, and the thermoelectric device, when energized, acts to heat or to cool the container, depending on the polarity of the current. In another example, in U.S. Pat. No. 6,141,969, a cupholder is provided with a thermoelectric device in a similar orientation, with a finned base and insulated sides. 
   One of the drawbacks of these designs is the orientation of the thermoelectric device—namely, at the bottom of the cup or cupholder. This orientation is presumably chosen for two reasons. First, in such an arrangement, the cup or the liquid can be reasonably guaranteed to be in physical contact with the thermoelectric device, which contact aids in the heat transfer as any air between the thermoelectric device and the cup or liquid acts as an insulator, reducing the efficiency. Second, because at least for cooling operations it is necessary to place fins against the heat sink, the ability to place the fins appropriately affects the arrangement of the device members. 
   However, the placement of the thermoelectric device at the bottom of the cup or holder poses the problem of uneven heating or cooling of the contents. Because the portion of the beverage next to be consumed is farthest away from the thermoelectric device, that portion receives very little benefit from the use of the device. Additionally, uneven heating of a hot beverage could cause the liquid at the bottom to become overheated, resulting in a burn injury to the drinker if the heat does not adequately diffuse through the liquid, or, at a minimum, an unpleasant taste if the beverage burns. 
   Moreover, the placement of the thermoelectric device at the bottom reduces the surface area of the contact between the cup or liquid and the heating or cooling surface. This surface area is further reduced because bottoms of beverage containers are rarely uniformly flat; most have bottoms that are shaped for efficient movement through a conveyor system or for stability. A greater heat-conductive surface area results in a more even and efficient cooling or heating process. When the thermoelectric device is oriented at the bottom of the container, the surface area of the contact is typically far smaller than the area of the non-heating, non-cooling surface. 
   Conventional cupholder systems also lack the ability to expand or contract to fit cups and containers of various sizes and profiles, such as cylindrical cans and frusto-conical coffee cups having pitched sides. Because these systems do not expand or contract to meet the cup size, they do not maintain solid, heat-conductive contact with the cup. 
   What is needed, then, is an active heat management system that makes use of thermoelectric technology more effectively than conventional systems, and that maintains better heat-conductive contact with the cup of liquid than conventional cupholder systems, particularly in the context of containers of varying sizes. 
   SUMMARY OF THE PRESENT INVENTION 
   Briefly summarized, the present invention includes a thermoelectrically heated and cooled cupholder system, ideally suited to placement in an automobile, in which the thermoelectric device or devices are placed on the sides of the cupholder so as to maximize the even dispersion of heat into or out of the cupholder. In an alternative embodiment, the cupholder is portable and self-contained. 
   The present invention generally includes an outer frame fabricated of plastic or other suitable material and provided with at least two sets of vents, one set for permitting air intake and the other for permitting air outflow. The interior of the outer frame contains a heat-conductive cupholder member and at least one two-sided thermoelectric device disposed on one of its sides on the side of the cupholder member. The thermoelectric device disposed on one of its sides on the side of the cupholder member. The thermoelectric device is provided with at least one fin, preferably fabricated from aluminum and disposed in heat-conductive contact with the other side of the thermoelectric device. A fan disposed beneath the cupholder is operative to move air through the interior of the outer frame as needed. 
   The cupholder member is formed as a number of sections that are cooperatively oriented to form a generally cylindrical shape. In order to allow for different cup sizes and profiles, the cupholder sections are mounted to the outer frame using a spring-loaded pin-in-groove system, such that the cupholder sections are free to slide to form a wider or narrower cylinder, or even to conform to conform to a non-cylindrical container (such as a cup having pitched sides), as needed. Each pin-in-groove is provided with a spring in order to maintain the cupholder member in the smallest circular profile allowed by the cup placed therein. This maintains pressure against the sides of the container for efficient heat transfer. 
   In a further feature of the present invention, an accordion-style liner is disposed on the inside of the cupholder member. This liner is preferably formed of heat-conductive rubber and is provided with a series of expansion and contraction folds that permit the liner to conform to the cupholder member regardless of the expansion or contraction thereof. The liner serves to prevent liquid, if spilled, from infiltrating the interior of the frame and causing damage to the parts contained therein. 
   The present is further provided with a direct-current electrical supply (for instance, through drawing current from a vehicle&#39;s electrical system in a vehicle-integrated embodiment) and with at least a three-position switch for activating and deactivating the device and specifying a heating or cooling operation. The invention is optionally provided with a variable resistor for specifying the amount of heating or cooling by varying the voltage directed through the thermoelectric devices, or with a thermostat for detecting the temperature of the container and activating or deactivating the device. 
   In an alternative embodiment, the present invention is embodied as a self-contained unit having features generally as described above. In such an embodiment, the invention may include its own battery power (in lieu of a vehicle-based power source) and may have a cup integrated into the system to allow drinking directly from a device according to the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features, embodiments, and advantages of the present invention will become apparent from the following detailed description with reference to the drawings, wherein: 
       FIG. 1  is a plan view in partial cross-section of a device according to the present invention; and 
       FIG. 2  is a lateral cross-sectional view of a device taken along line  2 — 2  in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, a thermoelectrically heated and cooled cupholder system  10  according to the present invention is shown in a plan view in partial cross-section in  FIG. 1 . Outer frame  12  is generally cup-shaped, i.e., generally cylindrical and open at the top thereof, and is ideally integrable with the console of an automobile (not shown), for instance. Outer frame  12  is ideally made of plastic or another similarly suitable material. 
   Outer frame  12  is provided on the interior thereof with a pair of mounting fixtures  14 , which will be described in greater detail below in connection with an expansion feature of the invention. A pair of semi-cylindrical cupholder units  16  cooperate to form a generally cylindrical cupholder member  18 . Cupholder member  18  is ideally made of a heat-conductive material such as aluminum or another metal suitable for conducting heat from or to substantially all of the surface area of cupholder member  18 . 
   Each of the cupholder units  16  is mounted to the outer frame  12  via at least two pins  20  disposed within grooves  22  provided in the mounting fixtures  14 . The grooves  22  are oriented so as to allow the pins  20  to slide therealong to expand or contract the interior space  24  of the cupholder member  18 . This feature of the present invention permits the cupholder member  18  to assume a size that is substantially the same as a beverage container  26  placed inside the cupholder member  18 . 
   In order to maintain the cupholder member  18  at the minimum size adequate to hold a selected container  26 , each of the grooves  22  is provided with a spring  28  between a groove end  30  and the pin  20 . Each spring  28  exerts a positive resistance force against expansion of the cupholder member  18 , which allows the cupholder units  16  to maintain good face contact with the beverage container  26 . 
   The interior of the cupholder member  18  is further provided with a heat-conductive liner  32  made of rubber or another appropriate material. The liner  32  is itself cup-shaped and is provided with a series of folds or reliefs  34  which allow the liner  32  to expand or contract together with the cupholder member  18 . The reliefs  34  are shown in exaggerated detail in  FIG. 1  in order to show their presence. The liner  32  acts to provide a substantially continuous surface within the interior space  24  of the cupholder member  18 . Because of the split nature of cupholder  18 , in the absence of a liner the split would allow any liquid spilled in the interior space  24  to drip into the outer frame  12 , which could damage sensitive electronics or electrical or metal members of the device, or could at least create untidy or unhealthful conditions. Also, a rubber or plastic liner  32  has better gripping properties than does the cupholder member  18 , because of a higher coefficient of friction between rubber or plastic and the metal, paper, or plastic surface of a beverage container  26 . This makes the present invention surer in its ability to hold the beverage container  26  in place, particularly in an automobile application. In a preferred embodiment, the liner  32  is removable for easy cleaning. 
   An additional, optional feature of the present invention is a further cup-holding mechanism  36  disposed on the interior side of each of the cupholder units  16 . The cup-holding mechanism  36  is ideally made of the same heat-conductive material as the liner  32  to allow it to conform to the shape of the container  26 , but may be somewhat more rigid than the liner  32 . 
   Until this point, the heating and cooling feature of the present invention has not been described in detail. The heating and cooling feature is provided using a thermoelectric device  40 , also known as a Peltier device, which makes use of the Peltier effect to transfer heat from one side of the device  40  to the other. Specifically, the thermoelectric device includes a pair of ceramic plates separated by and array of cubes of bismuth telluride or a similar material. When a direct current is applied in a given polarity across the thermoelectric device  40 , heat is transferred from one of the ceramic plates (the source) to the other (the sink), cooling the source side and heating the sink side. If the polarity of the current is reversed, the flow of heat is reversed. This reversibility of the direction of heat flow, as well as the compact nature of the device, makes thermoelectric devices ideal for the application to which the present invention is directed. Peltier devices are generally commercially available and well known in the art to which the present invention relates. 
   A thermoelectric device  40  is disposed on the exterior side of each of the cupholder units  16 . While it is possible to use only a single thermoelectric device  40  (on one of the cupholder units), using multiple thermoelectric devices  40  improves the heating and cooling efficiency of the present invention. Each thermoelectric device  40  is provided with a cooling fin or heat sink  42  having a number of fin projections  44  extending therefrom. Cooling fin  42  is preferably formed of aluminum or an aluminum alloy to allow for maximum heat dissipation. The exact configuration of the fin projections  44  is not important to the invention; one possible design choice is illustrated in  FIG. 1 . Those skilled in the art will recognize that the configuration of the cooling fin  42  and its projections  44  will depend more significantly on the amount of heat dissipation needed and the space constraints within the outer frame  12 . 
   Those skilled in the art will also recognize that a degree of thermal isolation between the cooling fins  42  and the cupholder units  16  will be desirable for greater efficiency of the system. Consequently, insulating foam sections  41  are disposed for this purpose between the cooling fins  42  and the cupholder units  16 . 
   Each thermoelectric device  40  is provided with a direct current power supply (not shown) which is controllable using a switch (also not shown). Ideally the switch will be a three-position switch allowing for activation and deactivation of the devices and selection (during activation) between heating and cooling modes. An optional thermostatic interrupt may be provided to stop the operation of the thermoelectric devices  40  when the container  26  has reached a desired temperature. 
   Referring now to  FIG. 2 , a device according to the present invention is shown in a lateral view in a cross-section taken along line  2 — 2  in  FIG. 1 , with like numbers representing like members. As can be seen in  FIG. 2 , the outer frame  12  is provided with a slot  50  in the top thereof into which a lip  52  of the liner  32  may be inserted for security purposes. The outer frame  12  is further provided with a set of upper vents  54  for allowing air intake and a set of lower vents  56  for allowing air outflow, for a purpose to be described in greater detail momentarily. As can be seen in  FIGS. 1 and 2 , in conjunction, the interior of the outer frame  12  is generally open interbetween the upper and lower vents  54 , 56 , such that air may flow generally therebetween. A fan  58  is mounted at the base  60  of the outer frame  12  and is mounted on a shaft  62  which is connected to a motor (not shown). The fan  58  is driveable, using the motor, to incude a ready flow of air between the upper and lower vents  54 , 56 . This flow of air passes over the fins  42 , and more specifically the fin projections  44 , in order to aid in the dissipation of heat therefrom. 
   If the direct current is connected across the thermoelectric devices  40  at a given polarity, a device according to the present invention operates to cool the interior space  24  of the cupholder member  18 . This is accomplished by the efficient transfer (removal) of heat from the cupholder units  16 , which are ideally in a full-face contact with the beverage container  26 , via the thermoelectric device  40 . This heat is dissipated by the fins  42 , aided by air flow generated by the fan  58 , which is activated during both the heating and cooling modes. If the polarity of the direct current is reversed, ideally using a switch between electrical circuits having opposite directions, heat is instead directed from the thermoelectric devices  40  into the interior space  24  of the cupholder member  18 . As this heating mode of operation serves to heat the interior space  24  at the expense of the finned side of the thermoelectric devices  40 , the fan  58  may be activated to draw ambient air into the region of the finned side of the thermoelectric device  40 , although a portion of the electrical energy used to operate the thermoelectric devices  40  is converted into heat energy and directed to the interior space  24 . The use of thermoelectric devices in the manner indicated allows for an efficiently managed active heat management system for the cupholder  10 . 
   Moreover, the passive features of the cupholder  10 , including the split configuration of the cupholder member  18  into cupholder units  16 , the expandable folded liner  32 , and the pin-in-groove mounting feature  20 , 22  for the cupholder units  16 , create a cupholder wherein various cup  26  sizes and shapes may be contained within the cupholder  10 , while good contact between the cupholder member  18  and the cup  26  is maintained. 
   In view of the aforesaid written description of the present invention, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended nor is to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.