US 3178896 A
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Description (OCR text may contain errors)
United States Patent C) 3,178,896 BEER KEG COOLER Biorn P. Sandsto, 215 Main St., Sausalito, Calif. Filed Apr. 6, 1964, Ser. No. 357,616
Claims (Si. 62-3) This invention relates to a new and improved beer keg cooler for use in cooling small beer kegs and other items, characterized by the simplicity of its cooling system and the portability and freedom from moving parts of the cooler itself.
A primary feature of this invention is that it is a compact and lightweight refrigeration system having no moving parts. The refrigerator element preferably utilizes a plurality of bismuth telluride semiconductor thermoelectric modules which effectively operate to pump heat out of the space and object to be cooled. When utilized to cool a keg of beer, this invention serves as a portable and convenient means of providing cooling for such a keg at any time or location. It also serves to cool cans and bottles of beverages as well as other small items.
Still another feature of this invention is that it is adapted to cool-a small capacity keg of draft beer (eg. nine quarts) such as that keg currently manufactured by the Reynolds Metals Co. Even though such a keg is designed to fit in a standard home refrigerator, it occupies a considerable proportion of the available space in such a refrigerator. The present invention provides cooling for such a keg in the home, thereby avoiding the necessity of utilizing valuable home refrigerator space.
A further advantage of the present invention is that it greatly facilitates the use of draft beer in kegs for private and home consumption. Some advantages of draft beer arezsuperior taste, lower price, no problem of disposal of bottles or cans, and smaller bulk for a given quantity of beer.
A principal objection to draft beer in kegs has been the large size of the keg for use inthe home and the problem of-cooling both vin the home and out-of-doors. The present invention solves these problems by providing a system which can cool a small keg both indoors and out-of-doors.
A still further featureof this invention is the provision of anlelectrical control system and refrigeration element which can be powered "by either conventional A.C. power or -a D.C. battery or generator source as found in an automobile, boat or airplane. When utilized with a battery source, the cooler can easily be operated out-of-doors.
A further advantage of this invention is the incorporation of semiconductor thermoelectric crystals, which contain no moving parts, consume little power, comprise a refrigeration system of light weight and small volume, can be removed as one unit, and are reliable and longy lasting.
A still further advantage of the invention is that the cooler can be used to refrigerate beer cans or bottles or other food, simply by placing such items in the cooler when not using a keg.
Further features of the invention are: the provision of an idler switch which minimizes battery drain when desired; the provision of inner and outer doors to avoid cooling losses when Atapping the keg and serving beer; the provision for cooling by air convection as well as conductionA through metal; Vprovision for stacking the coolers on one another, thereby facilitating shipping and storage; and lowcost of production and ease of operation.
Other objectsof the present invention will become apparent upon reading the following specification and referring to the accompanying drawings.
In the drawings:
FIG. l is a top plan of a beer keg cooler constructed 3,178,896 Patented pr. 20, 1965 in accordance with the present invention, with a segment of the cover broken away to expose `a portion of the refrigeration apparatus.
FIG. 2 is an enlarged vertical sectional view taken substantially along line 2-2 of FIG. l, showing the cooler with beer keg, partially broken away, in place and with inner and outer doors secured.
FIG. 3 is a fragmentary enlarged sectional view of a semiconductor refrigeration module used with the cooler.
FIG. 4 is a wiring diagram of the power and control circuit utilized in connection with the refrigeration module.
Draft beer has consistently enjoyed widespread popularity in commercial eating and drinking establishments. However, its acceptance for home or picnic consumption has been limited because of the large and unwieldy kegs which were required for containers. These kegs could only lbe, kept cold under such conditions by some awkward means of ice cooling. The problems of size and ease of handling have recently been solved by the introduction of the nine-quart keg by the Reynolds Metals Co. VHowever, the problem of practical cooling both in and out-ofdoors has still remained. This problem is solved by the present invention, which provides refrigeration means for a small keg which can easily be utilized both in and out-of-doors.
Essentially, the present invention consists of an insulated and refrigerated container especially dimensioned and designed to carry the small nine-quart size beer keg 7. Referring to FIG. l, the container 1 is of rectangular shape and of a size adequate to hold the desired size of beer keg. The container is provided with an outer door 2, for access to the interior. Referring to FIG. 2, the outer door 2 is held in place by means of a magnetic gasket 3. Container 1, as well as outer door 2, are preferably formed of polyurethane or equivalent insulation 4 to minimize heat loss by conduction, encased by a fiberglass outer case 5 and an aluminum inner case 6.
A beer keg of typical construction is shown in place within the container. The keg 7 is guided into the container and held securely in place by a plurality of nylon runners 8 extending longitudinally along the sides of the interior surface of the container. These runners improve circulation of air around keg 7. Beer keg 7 is retained in the container when outer door 2 is opened to tap the keg by means of an inner door 9 which is formed with a round opening of lesser dimension than the container which provides Vfor tapping the keg and drawing beer from the tapping spout 11. Door 9 is only'removed when keg 7 is removed. This arrangement minimizes heat intrusion into the container when it is necessary to remove the outer door 2. Inner door 9 is held in place by means of friction-type fasteners 10, extending inwardly from the door. Inner door 9 is formed with a flange 12, extending inwardly from the opening in the door. Flange 12 acts as a drip catcher to control dripping from the spout into the interior or inner door opening after the keg has been tapped. Flange 12 guides any'drops from the spout to a piece of household-type sponge 13 which is placed in recess 14 formed in the inner surface of outer door 2.
Container 1 is formed with a recessed carrying handle 15 which preferably does not project above the level of the top of the container, and allows stacking of a plurality of containers on top of each other for convenient shipping and pre-sale or pre-rental storage. A plurality of raised studs or rubber rests 16 are aflixed to the bottom of the container opposite carrying handle 15 to-protect the surface of the container from scratching or marring where resting on that surface.
Cold plate 17 is fixed at the end of the interior of container 1 opposite doors 2, 9 and is dimensioned to bear against the bottom rim 22 of keg 7 in heat conducting relation. Plate 17 also is in heat convection relation with the interior of the container. Thus the apparatus is effective with keg 7 or with other items, such as cans and hotties. Plate 17 is cooled by conduction by means of cold block 18 which is directly connected to the refrigeration means hereinafter described. Both cold plate t7 and cold block 18 are composed of `a suitable thermally conductive material such as aluminum. Beer keg 7 is filled by the manufacturer with draft beer through filler opening 19 at the lower end of the keg and then sealed with ller seal 20. When keg 7 is in place in container 1l, the entire circumference of rim 2l of beer keg 7 bears directly on face 22 of cold plate 17. Thus, keg '7 is directly cooled by conduction through cold plate 17.
Cold plate 17 is formed with a large surface area exposed to the air in the interior of container ll. Thus, keg 7 and the interior of container 1 are cooled by air convection as well as by conduction. Cold plate 17 is secured to cold block 1S by means of recessed screws 23.
The heart of refrigeration system 24 is a combination of semiconductor modules. When current is passed through a bismuth telluride crystal, it transforms thermal energy at one pole into electrical energy at that pole. This electrical energy is then re-transformed into thermal energy at the opposite pole. An effective heat transfer is thus effected in the overall system and one pole becomes cold while the opposite pole becomes hot. The polarity of this heating-cooling effect can be reversed by reversing the direction of the current flow through the crystal. A crystal is made up of a donor or N-type portion joined to an acceptor or P-type material. By connecting a plurality of such crystals in series in an electrical circuit, the total heat pumping effect can be increased directly proportional to the number of crystals used.
Referring to FIG. 3, module 25 is shown comprising a plurality of individual bismuth telluride semiconductor crystals 26, each having an N-pole and a P-pole. Refrigeration element 24 is comprised of an appropriate plurality of modules 25. The crystals are connected in series by means of conducting strips 27. The module is held together by means of two strips of an epoxy, non-electrically-conductive bonding material 2S. Each of the strips 28 is faced on the outward side with an aluminum strip 29 to facilitate thermal conduction. By combining means for the removal of heat transformed with means for thermally insulating the hot side from the cold side of module 25, a simple, practical and commercially effective refrigerator can be constructed. Such a module as shown in FIG. 3 is presently commercially available as a unit.
Since thermal energy appears at the hot side of the module 25, provision must be made to dispose of the heat drawn out of the keg 7 and the interior of container It. This is accomplished by means of heat sink 30 which bears directly on the hot side of refrigeration element 2d.. Heat sink 3ft is formed with `a plurality of cooling fins 31, which dissipate heat drawn to them from keg '7 and interior of container il, via the cold plate 17, cold block 18 and refrigeration element 24. Since cooling ns 31 dispose of heat by means of convection, provision is made for openings in container ll in the form of a plurality of air vents at 32 and 33. Outside air drawn across cooling fins 31 is heated up and flows out again. Heat sink 30 is anchored to container 3l by means of bolts 34 and 35 which screw into threaded portions of fiberglass wall 36, thereby thermally insulating heat sink 3ft from cooled portions of the container. The heat sink end of container 1 is formed with indentation 37, to force a greater quantity of air from vents 32 and 33 across cooling fins 3l of heat sink 30.
The end of container l housing refrigeration element Z4 is formed as a separate shell 38, to fit on the main section of container 1 by means of pressure at points 39. Refrigeration element 24 is made as a plug-in unit for easy replacement. To replace element 24, it is only necessary t remove cover 3S and remove heat sink 30 by means 4l of bolts 54 and 35. This provides simple and rapid servicing of the refrigeration element and accompanying electrical controls.
Refrigeration element 24 is controlled and powered by the circuit shown in FIG. 4. Two semconductor modules it? and il are shown in series, being essentially the type of module previously described as 25 in FfG. 3. Thermal cut-off switch 42; is connected in series between modules 4U and 4l to cut off current flow should the modules overheat. When the modules have cooled down to a point within their operating temperatures, switch 42 will close again to resume operation. Modules 46 and 41 can be powered by either standard v. A.C., 60 cycle house current or by a direct current source, as is found in automobile batteries.
For use with an alternating current house supply, lines 42 and 43 are plugged into a wall socket. Voltage is stepped-down through transformer 44 to about 5.5 v. This voltage is rectified in the full-Wave rectifier circuit comprising diodes 45 and (i6 and is then smoothed out through inductanee choke 47 to provide a DC. current for modules 4G and 4l.
For use with an automobile direct current supply, lines t3 and 49 or 48 and Sil are plugged into the auto cigarette lighter receptacle through a special plug of commercially available type. For an automobile with a 6 v. system, lines 48 and i9 should be used and for a l2 v. system, lines 43 and 50 should be used. The plug for these lines can be polarized to avoid using the wrong set of leads with the appropriate system. The automobile D.C. supply is reduced to 5 v. through resistor Sil.
For full load of operation, when maximum cooling is desired, switch 52 remains closed. However, when the `ambient temperature is low or when minimum battery drain is desired, switch 52 should be opened, current to be reduced and power to be consumed in resistor 53, so that the system can be said to he idling This idling" condition is desirable when the unit is used in a boat, plane or auto when the motor is not running.
Although the foregoing invention has been described in some detail, by way of illustration and example for purposes of clarity of understanding it is understood that certain changes and modifications may be practiced Within the spirit of the invention and scope of the appended claims.
What is claimed is:
l. A refrigeration system comprising,
an insulated container for holding and insulating an object to be cooled, said container having an aperture in one wall for installation of said object to be cooled, an insulated outer door for said aperture,
an inner door immediately inside said outer door, said inner door having an aperture smaller than said aperture in said wall positioned for access to said object while preventing a substantial intrusion of ambient air into the interior of said insulated container, a heat conduction element in said container positioned in heat transfer relationship to said object to be cooled inside said container,
a semiconductor thermoelectric element in heat transfer relationship to said heat conduction element,
a heat dispersal element in heat transfer relationship to said semiconductor thermoelectric element, and electrical means for energing said semiconductor thermoelectric element.
2. A system according to claim l, which further comprises a magnetic gasket to secure said outer door to said insulated container.
3. A system according to claim l, in which said outer door is formed with a recess on its inner surface to hold a sponge, and said inner door is formed with a flange extending inwardly from the edge of said aperture in said inner door, toward the center of said insulated container to cause drops of liquid from the opening of an object to 5 6 be cooled to flow along said flange to a spouse held in said means located at said end of said container for forcing recess in said outer door. said rim of said beer keg in place in heat conducting 4. A system according to claim 1, which further conirelation with said heat conduction element, said prises a snap pressure lock to secure said inner door to said means permitting access to said keg for removal of insulated container. 5 beer Within said keg.
5. A refrigeration system comprising,
r C' E an insulated container for holding and insulating a Re@ ences lted by the Kammer beer keg to be cooled, said container having an end UNITED STATES PATENTS opening, a door for said end opening, said beer 1,939,568 9/12 McLain S18-359 keg having a rim, 10 1,818,437 8/ 31 Stuart 62-3 a heat conduction element in said container remote 2,228,848 1/41 Reilly 62-389 from said door, 2,959,925 11/60 Frantti 62-3 a semiconductor thermoelectiic element in heat trans- 2,991,628 7/61 Tuck 62-3 fer relationship to said heat conduction element, 3,018,631 1/ 62 Bury 62--3 a heat dispersal element in heat transfer relationship i5 3,048,020 8/62 Jones 62-3 to said semiconductor thermoelectric element, l. electrical means for energizing said semiconductor ROBERT A' OLEARY Plmary Examiner thermoelectric element, and WILLIAM I. WYE, Examiner,