US2284905A - Evaporative cooler - Google Patents

Description

V R. C. JACKSON EVAPORATIVE COOLER June 2, 1942.

Filed Nov. 13, 1940 2 Sheets-Sheet l INVENTOR. ROY C. JACKSON ATTORNEK June 2, 1942.

R. c. JACKSON 2,284,905

EVAPORATIVE COOLER Filed Nov. 13, 1940 2 Sheets-Sheet 2 I INVENTOR. ROY c, JACKSON Ar'ToR/vEK Patented June 2, 1942 entries STATES PATENT orrice This invention relates to refrigeration and more particularly to apparatus for maintaining such matter as foods, beverages and the like at a suitable temperature lower than that of the surrounding atmosphere. v

An object of my invention is to provide refrigeration apparatus adapted to keep foods and similar matter at or below What is ordinarily termed a safe temperature, which apparatus takes advantage of the principle of absorption of heat by an evaporating liquid and thereby is enabled to cool efiiciently wthout having to resort the contents of the receptacles.

A further object in this connection is to improve upon prior evaporative coolers by providing means for delivering water to the absorbent material of the several receptacles which operates by gravity alone, i. e., independently of capillary action thereby assuring not only continuity and dependability'of supply but also that the supply to each'of' the receptacles will be of ample quantity to maintain the entire exterior surface of each of the receptacles at or near the saturation point so as to maximize the rate of evaporation therefrom. v

Another object of my invention is the provision of means for inducing a draft of air through the cabinet of the apparatus and for deflecting it around and against the'several moistened receptacles as a further contributing factor toward maintaining maximum rate of evaporation.

Another object is the provision of means for supplying moisture to the-receptacles within the housing which includes an open reservoir to which water is supplied'to a suitable float valve to maintain the water within the reservoir at a lore-determined 'level and thereby make the supply of water to the cooling receptacles independent of the pressure fluctuation to which water supplied by closed conduits usually is subject.

A further object in this connection is to design the reservoir and arrange it Within the cabinet in such amanner that it serves the double service of supplying moisture to the receptacles and supporting them in apendulous manner so as to permit the air circulating through the cabinet to contact all parts of each receptacle.

Still another object isto provide in one of the modifications of my apparatus to be described in detail hereinbelow electrically propelled draft inducing means energization of which depends upon closing a switch controlled by a thermostat which is enclosed within a receptacle closely resembling the refrigerating receptacles so that it is subjected to the same thermic conditions as those which prevail within the food storing receptacles; j

Yet another object of my present invention is to make the benefit 'of household refrigeration available for service in communities where electriciservice is not available, by providing a draft inducing device which depends on solar energy for its operation and thereby dispenses with any necessity for connecting the apparatus to a source of electriccurrent.

The invention possesses other objects and features" of advantage, some of which with the foregoing will be set forth inthe following description'of the preferred forms of my invention which are illustrated in the drawings accompanying and formingpart ofthe specifications. It is to be understood that I do not limit myself to the showing made by the said drawings and description as I may adopt variations of the preferred forms within the scope of my invention as set forth in the claims;

Referring to the drawings: 1

Figure 1 is a perspective viewof one form of my invention embodied as a household refrigerator.

Figure 2 is a transverse vertical sectional view,

' the plane .of section being indicated by line 2--2 of Figure 1 and the direction of view by the arrows.

Figure 3 is a view similar to- Figure 2 taken upon the lines 33 of- Figure 1 with the direction of view as indicated.

Figure 4 is a longitudinal :vertical medial sectional View, the plane of section being indicated by the lines 4-4 of- Figure 2 and the direction of view by the arrows: Portions of the figure are broken away to reduce its length.

Figure 5 is a view of side'elevation of one of the receptacles for matter to be refrigerated and which forms a portion of the cooling apparatus of the present invention.

Figure 6 is an enlarged detailed View in transverse vertical sections taken through the trough or reservoir which is employed for supporting and supplying water to the several food storage receptacles.

Figure 7 is a view similar to Figure 6 but showing a slightly modified form of reservoir or trough.

Figure 8 is a detailed View in transverse vertical section through the thermostatic control valve for the draft inducing mechanism of Figure 4.

Figure 9 is a view in side elevation of a slightly modified form of my refrigerating apparatus wherein the draft inducing device depends upon solar energy for its actuation.

One form of the refrigerating apparatus embodying the principles of the present invention is illustrated in Figures 1 to 4 inclusive. It comprises a housing or cabinet, I I, preferably divided by a transverse partition, I2, so as to provide two compartments, I3 and I4, respectively. The compartment I3 is intended to accommodate the draft inducing apparatus which is indicated in its entirety at I6; whereas the compartment I4 is the food storage compartment and is adapted to receive the plurality of receptacles II. Consequently convenience is afforded by the easy access to the compartment I4 for which purpose a hinged lid I8 is provided.

Extending vertically all the way around the upper edge of the compartment I4 is a reservoir or trough 2| which is open at the top and to which water is supplied as by a suitable conduit 22 controlled by a valve 23. Preferably this valve 23 is actuated by a float 24 disposed within the trough 2| the parts being so arranged that when the level of the water within the trough drops below a predetermined minimum the valve 23 will be opened so as to permit an additional supply of water to enter the trough. For the purpose. of facilitating cleansing the interior of the cabinet II I prefer that the trough 2| be removable. For this purpose it is adapted to rest loosely upon a strip of moulding 26 affixed to the interior surface of the cabinet I I within the compartment I4 so spaced below the upper edge of the cabinet that the trough 2| can rest thereupon without interfering with hinges of lid I8. The trough 2| is intended to serve the double function of supplying moisture in the necessary quantity to the several receptacles I! at the same time supporting them in a pendulous position so as to permit access of the air circulating through the cabinet II to the entire exterior surface of all of the receptacles.

Each of the receptacles I'I comprises a pouch 3| of absorbent material and a hook 32 preferably of rust-proof metal affixed the upper edge of pouch 3| and extending therefrom far enough to enable it to be engaged upon the upper edge 33 of the outer wall 34 of the trough 2|. Each receptacle I1 is also preferably provided with a wick 36 of absorbent material extending from the upper edge of the pouch 3| and preferably overlying the hook 32, the wick 36 being of such length that its distal end 31 is adapted to drape through the water 38 within the trough when the associated hook 32 is engaged in the described manner upon the front wall 34 thereof. This wick 36 is adapted to carry water by capillary action from the trough 2| over the edge 33 of the front wall 34 and thence downward by a combined gravity and capillary action to the body of the pouch 3| so as to aid in keeping the pouch 3| moistened. However, I have found it expedient to provide additional means for supplying moisture to the several receptacles which operate by gravity only and thereby dispense with the necessity of relying upon capillary attraction for the conduction of the desired moisture. A plurality of perforations 4| are provided in the outer wall 34 of the trough 2| preferably throughout its entire length and arranged in a line closely adjacent the bottom edge of the wall 34. For the purpose of regulating the rate at which water can flow through the perforations 4| I prefer to provide a sheet of pervious material such as fabric 42 against the inner face of this outer wall 34 of the trough and covering all of the perforations 4|. A supply of sand 43 in the bottom of the trough 2| serves as an aid to retain the sheet 42 in place against the wall 34 and it also aids in distributing the water evenly to all of the perforations 4| and in retarding the rate of flow therethrough.

Figure 7 illustrates a slightly modified form of flow regulating apparatus as in the previously described modification a sheet 42 prime of pervious fabric lies against the inner face of the outer Wall 34 prime of the trough 2| prime but instead of employing sand to retain the sheet 42 prime in position a metal plate 46 is employed. This plate is pressed against the sheet 42 prime as by a plurality of springs 41. One leg 48 of each of these springs 41 is afiixed to the inner face of the plate 46 whereas the other leg 49 bears slightly against a substantially vertical portion 5| of a suitable bracket 52 rigidly disposed within the trough 2| prime. The plate 46 is adapted to be raised and lowered so as to vary the position of its lower edge 53 with relation to the perforations 4| prime with the result that the plate 46 operates as a valve which can be adjusted to regulate the rate of flow of the water through the perforations 4| prime. To effect facile adjustment of the plate 46 I have provided a plurality of rods 56 affixed at their lower end to the plate 46 and extending upwards therefrom so as to enable their upper end 51 to extend through brackets 58 rigid with the wall 34 prime of the trough 2| prime wherein the upper ends 5'I of the rods 56 are threaded so as to receive nuts 59, there being two such nuts upon each rod 58. The nuts 59 of each pair are disposed upon opposite sides of the associated bracket 58 with the result that manipulation of the nuts 59 will not only permit variation in the position of the plate 46 with respect to the perforations 4| prime but also by tightening the nuts 59 against the bracket 58 the plate can be locked securely in selected position. I have found that the rate of flow of water through the perforations 4| prime can be regulated with such a degree of nicety of means of the plate 46 and its rods 56 that an effect best described as sweating can be produced, that is to say so slowly can water be permitted to flow through the perforations that drops will form very slowly along the bottom edge of the trough and before these drops acquire sufficient size and weight to drop from the trough that moisture which is collecting on the outside of the trough at portions thereof contacted by any of the receptacles II will be absorbed into the fibers of the pouch 3| thereof. 1

Towards this same end the cross-sectional configuration of the trough 2| or 2| prime as the case might be is of importance. Reference to Figures 2, 6 and '7 will reveal that the outer wall 34 and the inner wall 6| prime unparallel instead of the outer wall 34 or 34 prime as the case might be slope downwards and slightly outwards the purpose being to insure adequate contact and pressure of the fabric of the pouch 3| of each of the several receptacles against that portion of the outer wall 34 where moisture liberated from the trough is liberated from the perforations 4|. In other words, the fabric'of which the pouches 3| are formed is caused to break slightly where it bends around the extreme lower edge of the wall 34 of the trough upon which the receptacles are supported. I also prefer that thebottom wall 52 of the trough 2| instead of being horizontal slopes outward and downward toward the lower edge of the outer wall 34. This produced an oblique angle between the bottom wall 5| and the outer wall 34, the effect of which is to minimize the tendency for drops of water to adhere unduly long to the bottom of the trough and it also prevents water from adhering to the under surface of bottom wall 52 by capillary attraction and creeping along the bottom wall between it and the supporting strip 26 as would be the case'were the bottom 62 horizontal.

Thus it may beseen that I have provided means for supplying moisture in any desired quantity, within limit, to the upper reaches of this fabric of which the several pouches 3| areformed which means operates entirely by gravity and without placing any dependence upon capillary attraction. Being supplied in this mangreatest efiiciency as far as refrigerating any matter such as foods, beverages and the like which may be disposed within the pouches 3| of the receptacles H. In other words, the apparatus of the present invention instead of depending upon mechanical refrigerating machinery operates solely upon the well known olla principle which relies solely upon the evaporation of ever the lid 8 is raised. Also included in the circuit is a thermally responsive switch indicated inits entirety at 83 (see Fig. 8) preferably of well known construction and adapted to close the circuit by bringing into contact 84 together when the temperature rises beyond a pre-determined maximum. However, in view of the fact that in the refrigerating apparatus of the present invention the entire interior of the cabinet is not kept at a low temperature but instead only result that the thermic conditions within the receptacle 36 coincide quite closely to those which prevail within each of the food receiving receptacles II. I have also found it expedient to provide means for insuring a certain degree of thermal inertia for retarding the rate at which the thermostatic switch 83 responds to temperature fluctuation and for this purpose the contacts 34 are preferably immersed in a bath of oil 87 contained within a sealed container 88, the entire container being hung within the absorbent sheathing of the receptacle 86 with the conductors extending therethrough to permit their facile connection to the conductors 8| in a suitable manner.

In order to promote distribution of the refrigerating air throughout the entire interior of the blast of air from the fan 12in the entire moisture from the exterior surface of a container to keep the contents of that container at a temperature materially below that of the surrounding atmosphere.

To enhance the rate of evaporation of the moisture of the pouches 3| to a still further degree means are provided for inducing a draft or a flow of air through the cabinet I in the modiflcation illustrated in Figures 1 to 4 inclusive the electrically operated draft inducing mechanism H5 is relied upon. This comprises a'motor 1| operably coupled to a fan 12 and supported as by a suitable. spider construction 13 within a relatively large duct 14 which extends from an opening 76 in the associated end wall 11 to and through the partition l2. Preferably both ends of the duct 14 are'provided with screens 18 and 19 respectively. I prefer that the motor H be energized through the expedient of conductors 8| which lead through a switch 82 (see Fig. 4)

which automatically operates to close the circuit when the cover or lid I8 is closed and to open the circuit and thereby stopthe fan 12 wheninterior of the compartment l4.

Figure 9 illustrates a modified form of my refrigeration apparatus which has been provided for the purpose of making this device available for use in those rural districts where electric service is not provided. Instead of employing a motor driven fan to induce the draft of air through the cabinet this modification employs a stack ml the flue of which communicates through a suitable adapter I02 with the interior of the cabinet prime. This stack is preferably dark in color on its outer surface and is exposed to the direct rays of the sun so that it will absorb a relatively large amount of solar energy causing the air within the flue to become heated and thus caused to rise by thermo action in this manner creating a draft which will draw air through the cabinet I Thus it becomes apparent that the apparatus of the present invention not only serves to refrigerate such matter as foods and beverages eiiiciently and inexpensively but it also overcomes at least two of the inherent disadvantages of more conventional, mechanical household refrigerators, to-wit: the drying out of foodstuffs as the result of the absorption of a large proportion of the moisture of the air within a mechanical refrigerator and the overlapping of flavors and odors of diiferent foods stored within the same compartment. Not only does the continuous circulation of air through the housing consider toward this end but it is also obvious that the storage of the several different items of food Within separate individual containers is of importance in this connection.

I claim:

1. Refrigerating apparatus comprising a housing, a trough extending horizontally therein and adapted to receive a supply of Water, a number of receptacles adapted to receive matter to be refrigerated, each of said receptacles comprising a pouch of absorbent material, a supporting hook afiixed thereto in position to be engaged upon an edge of said. trough, and a wick extending from said pouch into said trough, and means supplementary to said wicks for delivering'water by gravity from said trough to said receptacles.

2 Refrigerating apparatus comprising a housing, a trough extending horizontally therein and adapted to receive a supply of water, a number of receptacles adapted to receive matter to be refrigerated, each of said receptacles comprising a pouch of absorbent material, a supporting hook affixed thereto in position to be engaged upon an edge of said trough, and a wick extending from said, pouch into said trough, said trough having perforations therein through which water flows by gravity onto said receptacles, and means for regulating the rate of flow through said per forations.

3. Refrigerating apparatus comprising a housing, a trough extending horizontally therein and adapted to receive a supply of water, a number of receptacles adapted to receive matter to be refrigerated, each of said receptacles comprising a pouch of absorbent material, a supporting hook affixed thereto in position to be engaged upon an edge of said trough, and a wick extending from said pouch into said trough, said trough having perforations therein through which water flows by gravity'onto said receptacles, and means for regulating the rate of flow through said perforations comprising means through which water seeps relatively slowly disposed within said trough in position to cover the inner ends of said perforations.

4. In refrigerating apparatus, a reservoir adapted to contain a supply of water and having perforations in a wall thereof, a receptacle adapted to receive matter to be refrigerated and comprising a pouch of absorbent material and means for supporting said receptacle with said pouch in contact with said reservoir adjacent said perforations, a sheet of pervious material within said reservoir covering said perforations to retard the flow of water therethrough, and means retaining said sheet in operative position with respect to said perforations.

5. In refrigerating apparatus, a reservoir adapted to contain a supply of water and having perforations in a wall thereof, a receptacle adapted to receive matter to be refrigerated and comprising a pouch of absorbent material and means for supporting said receptacle with said pouch in contact with said reservoir adjacent said perforations, a sheet of pervious material within said reservoir covering said perforations to retard the flow of water therethrough, and means retaining said sheet in operative position with respect to said perforations comprising a plate behind said sheet and resilient means behind said plate pressing said plate and sheet toward said wall.

6. In refrigerating apparatus, a reservoir adapted to contain a supply of water and having perforations in a wall thereof, a receptacle adapted to receive matter to be refrigerated and comprising said receptacle with said pouch in contact with said reservoir adjacent said perforations, a sheet of pervious material within said reservoir covering said perforations to retard the flow of water therethrough, and means retaining said sheet in operative position behind said sheet and resilient means behind said plate pressing said plate and sheet toward said wall, and adjustable means for shifting said plate to regulate flow of water through said perforations.

7. In refrigerating apparatus, a reservoir having perforations in a wall thereof adjacent the bottom of said reservoir and a receptacle adapted to receive matter to be refrigerated and comprising a pouch of absorbent material and means for supporting said receptacle upon said wall, said wall sloping downwards and outwards to insure contact of said receptacle therewith adjacent said perforation.

8. In refrigerating apparatus, a reservoir having perforations in a wall thereof adjacent the bottom of said reservoir, a receptacle adapted to receive matter to be refrigerated and comprising a pouch of absorbent material and means for supporting said receptacle upon said wall, said wall sloping downwards and outwards to insure contact of said receptacle therewith adjacent said perforations, and means for directing a flow of air against said receptacle.

ROY CLAY JACKSON.

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