Abstract:
A butter storing and conditioning device which maintains butter at a desired temperature to keep the butter cool enough not to melt and warm enough to easily spread. The device includes a housing which covers the butter while placed upon a butter dish resting on a counter or table top. Heating and cooling means are provided for heating or cooling the air to maintain the butter at the desired temperature. In one embodiment, an air duct is formed by the housing and a fan for circulating air through the housing and past the butter.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a device for storing and conditioning butter and in particular to a device which maintains butter at a predetermined temperature to safely store the butter while not refrigerating the butter and making it too hard to easily use. 
     Butter is not able to maintain a satisfactory consistency over a very large range of temperatures. If refrigerated, it is too hard. If &#34;left out&#34; of the refrigerator at room temperature, it will become too soft or melt at ambient temperatures greater than approximately 80° F. Attempts have been made to introduce air into butter to make it appear softer after refrigeration. Such products, while better, do not solve the underlying problem. 
     Margarine and other similar spreads which remain soft and are easily spread over a large range of temperatures have been developed due to the difficulty in maintaining a satisfactory consistency of butter. Some of these products are soft enough to be spread on bread immediately after refrigeration and remain at a desirable consistency at high ambient temperatures. However, as people understand the health problems associated with margarine and other butter substitutes, they are returning to real butter. 
     It is an object of the present invention to provide a device for storing and conditioning butter by maintaining the butter at a desired temperature at which the butter is not too hard and is not too soft, regardless of the ambient temperature. 
     It is an advantage of the device of the present invention that the butter can be located where it is readily accessible for table use such as a counter top or similar location. The butter is stored at the desired temperature awaiting use. For ease of use, the device includes a housing which is simply dropped over a butter dish that is resting on a counter or table top surface. 
     The housing forms a butter chamber that is open from the bottom. The housing and bottom opening are preferably sized to receive two sticks of butter by placing the housing over the butter sticks. The counter or table top surface closes the open bottom of the butter chamber so that the butter is enclosed within the chamber. A heating and/or cooling device, such as a thermoelectric cooler, is provided in the housing to heat or cool the air as necessary to maintain the butter at an optimum temperature. A thermostat is provided for both determining the current temperature of the air within the butter chamber and for activating the heating and cooling device to either heat or cool, as needed, to produce the desired temperature in the butter chamber. 
     In an alternative embodiment of the device, the housing also includes an air duct which forms a circulation passage for circulating air through the butter chamber and over the butter. A fan is provided to move air through the air duct and the butter chamber. 
     The device also includes a butter dish which is designed for use with the housing and can hold two quarter-pound sticks of butter. The dish is preferably constructed of two identical halves that can be separated from one another so that one half of the dish can be used on the table while the other half is being cleaned. 
     Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the butter storing and conditioning device of the present invention; 
     FIG. 2 is a sectional view of the butter storing and conditioning device of the present invention as seen from substantially the line 2--2 of FIG. 1; 
     FIG. 3 is a perspective view of the housing portion of the butter storing and conditioning device of the present invention; 
     FIG. 4 is a side sectional view of the housing as seen from substantially the line 4--4 of FIG. 3; 
     FIG. 5 is a perspective view of the butter dish portion of the storing and conditioning device; and 
     FIG. 6 is a top plan view of the butter dish shown in FIG. 5. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The butter storing and conditioning device of the present invention is shown in FIGS. 1 and 2. The device includes a housing designated generally as 110 and a butter dish designated as 16. The housing 110 is in the form of a cover 112 and is shown in FIG. 2 resting upon a counter or table top surface 14. The butter dish 16 is also resting on the counter top surface and supports a stick of butter 18. The housing 110 has a butter chamber 120 which has an open bottom 122. The open bottom 122 allows the housing 110 to be dropped over the butter dish whereby the butter dish is enclosed within the chamber 120. An elastomeric seal 19 is provided about the periphery of the open bottom 122 so that when the housing 110 is placed over the butter dish, a seal is formed between the top surface 14 and the housing 110 so that air does not flow in and out of the butter chamber 120. 
     The air within the butter chamber 120 is heated or cooled by a heating and cooling device 21 placed within the butter chamber. In a preferred embodiment, the heating and cooling device is a thermoelectric cooler which can heat or cool. The thermoelectric cooler has a unique characteristic of being able to heat or cool with a simple polarity change. Thermoelectric coolers are available from Marlow Industries, Inc. in Dallas, Tex. A typical single stage thermoelectric cooler consists of two ceramic plates with p- and n-type semiconductor material (bismuth telluride) between the plates. The elements of semiconductor material are connected electrically in series and thermally in parallel. When a positive DC voltage is applied to the n-type thermoelement, electrons pass from the p- to the n-type thermoelement and the cold side temperature will decrease as heat is absorbed. The heat absorption (cooling)is proportional to the current and the number of thermoelectric couples. The heat is transferred to the hot side of the cooler, where it is dissipated into the heat sink and surrounding environment. The range of heat pumping rates for thermoelectric coolers is in milliwatts to hundreds of watts. As a result, they are well suited for use in a butter conditioner where the heating and cooling requirements are small. 
     The thermoelectric cooler is sandwiched between a pair of heat sinks or exchangers, 23, 25. The heat sink 23 extends through the housing 110 so as to be in contact with the surrounding environment. The heat sink 25 is within the housing 110. The thermoelectric cooler moves heat between the two heat sinks. A thermostat 48 is located in the butter chamber to measure the air temperature within the chamber and to control the heating or cooling of the device 21. The thermostat 48 can be preset to a fixed temperature, or the thermostat can be provided with a knob 49 for use in adjusting the desired temperature within the butter chamber based on the user&#39;s preference. While the thermoelectric cooler provides the easiest way to both heat and cool and requires a minimal amount of space, other heating or cooling devices can be used. For example, a small resistance heater can be used to heat the air. A small absorber can be used to cool the air, and depending on how it is figured, an absorber could also be used to heat, as well. The thermoelectric cooler provides the most economical way to both heat and cool, requiring a minimum amount of space within the butter chamber. 
     Through an electric circuit (not shown), feedback is provided from the thermostat 48 that is used to select the polarity of the current provided to the thermoelectric cooler, thus controlling the heating and cooling functions. The thermostat and thermoelectric cooler are powered by a 12 V transformer 50 which plugs into a standard 110 V wall outlet. The transformer is coupled to the housing by wire 52. 
     The desired temperature for maintaining the butter is higher than a refrigerator temperature. It will likely not be higher than 75° F. As a result, it is possible to rely on room temperature air to provide the necessary heat to warm the butter. The thermoelectric cooler may only be used to cool the butter when the room temperature exceeds a given temperature, for example, 75° F. Using the thermoelectric cooler only for cooling purposes can simplify the electronics since there is no longer a need to change the polarity of the current supplied to the cooler. A simple circuit can be used with the thermostat functioning solely as an on-off switch for cooling. 
     An alternative embodiment of the butter storing and conditioning device of the present invention is shown in FIGS. 3 and 4. The device includes a housing designated generally as 10 and the butter dish 16. The housing 10 is in the form of a cover 12 and is shown in FIG. 4 resting upon the counter or table table top surface 14. The butter dish 16, is also resting on the counter top surface supporting the stick of butter 18. The housing 10 has a butter chamber 20 which has an open bottom 22. The open bottom 22 allows the housing 10 to be dropped over the butter dish 16, whereby the butter dish is enclosed within the chamber 20. 
     Two walls 24, 26 which form the butter chamber 20 are formed with circulation holes 28 to allow air to pass through these walls. Preferably, the walls 24, 26 are on opposite ends of the butter chamber to allow air flow throughout the butter chamber as described below. 
     The housing 10 also forms an air duct 30 which allows the air to circulate from one end of the butter chamber, through the air duct 30 and then back into the butter chamber at the opposite end, forming an endless air circulation path. To facilitate air circulation, the air duct 30 is divided into two separate chambers, a fan chamber 32 and an upper plenum 34. A plenum wall 36 separates the fan chamber from the upper plenum. A circulation fan 38 is located within the fan chamber and has an air inlet 40 for receiving air from within the fan chamber. The fan air outlet 42 is located in the plenum wall 36 such that the air from the fan is blown into the upper plenum 34. This creates a higher air pressure within the upper plenum 34, relative to the fan chamber 32 and the butter chamber 20, and a lower air pressure in the fan chamber than in the butter chamber. As a result, air flows from the butter chamber into the fan chamber and from the upper plenum into the butter chamber. This completes the air circulation through the housing 10. The upper plenum 34 is spaced above the butter chamber 20 to form an opening 80 therebetween. The upper plenum is shaped to form a handle for easily grasping the housing. 
     The air within the housing is heated or cooled by heating and cooling devices contained within the air duct 30. As described above, the heating and cooling is preferably accomplished with a thermoelectric cooler 44. The cooler 44 either heats or cools a finned heat sink 46 through which the air from the fan outlet 42 passes. A second heat sink 45 is on the other side of the cooler 44 and extends through the housing 10A thermostat 48, preferably located in the fan chamber 32, is used to regulate the temperature of the air being drawn into the fan chamber from the butter chamber 20. The thermostat 48 can be preset to a fixed temperature or the temperature can be varied by the user as described above. The fan, thermostat and thermoelectric cooler are all powered by the 12V transformer 50. 
     The thermostat 48 is preferably located in the fan chamber where it can measure the temperature of the air as it flows into the fan chamber from the butter chamber. The thermostat can be positioned in other locations within the air duct 30 if desired. The thermoelectric cooler 44 and heat sink 46 are preferably located in the upper plenum 34 near the fan outlet 42 so air from the fan can be directed toward and through the heat sink 46. The thermoelectric cooler and heat exchanger could be located elsewhere in the air duct if desired. 
     With reference to FIGS. 5 and 6, the butter dish 16 is shown which is specifically designed for use with the housings 10, 110 to store and condition butter. The butter dish 16 is constructed of identical halves 56, 58. Each dish half is designed to carry a quarter-pound stick of butter 18. Each dish half includes a lower horizontal support wall 62 having downwardly extending legs 64. The legs 64 raise the horizontal support wall 62 above the counter top surface, allowing air to circulate beneath the horizontal support wall 62. Along one longitudinal edge of the horizontal wall 62, a vertical wall 66 extends upwardly above the height of the butter stick. 
     Each vertical wall 66 includes an upwardly extending tab 68. The tabs 68 provide a grip for grasping the butter dish to carry it from one location to another. Each tab 68 includes a laterally extending boss 70 and a complementary aperture 72. By making the dish halves identical to one another, two dish halves can be positioned side-by-side with the boss 70 of one dish half inserted into the aperture 72 of the other dish half, thereby interlocking the two dish halves together. 
     Each of the tabs 68 has an upwardly extending tab protrusion 74. The protrusion 74 is located off center so that the protrusions of the two halves do not align with one another when the two identical dish halves are placed together. The protrusions are provided to facilitate separation of the two dish halves as they sit on the counter top. By having two separable dish halves, one half can be washed and reloaded with a fresh stick of butter while the other dish half is employed for table use. This would generally make conditioned butter available at all times. Additionally, two sticks of conditioned butter can be available, if needed, for serving a large number of people. 
     The butter storing and conditioning device of the present invention provides a means for regulating the temperature of butter at a desired temperature at which the butter is neither too hard nor too soft and is readily available and easily accessible for use. The device includes a housing which can be placed over the butter while placed on a counter top or table surface. The butter is available for use by simply removing the housing. 
     It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.