US2030923A - Display refrigerator accessory - Google Patents

Description

Feb. 18, 1936. 4

G. J. HOPKINS DI SPLAY REFRIGERATOR ACCESSORY Filed Jan. 29, 1934 2 SheetsSheet l George [lop/(ins duel/wai Feb. 18, 1936. H Ns 2,030,923

DISPLAY REFRIGERATOR ACCES SORY Filed Jan. 29, 1934 2 Sheets-Sheet 2 ZZZ Li li 2 (II I I, IiIi I I;

glwuentoz Patented Feb. 18, 1936 DISPLAY REFRIGERATOR ACCESSORY George J. Hopkins, Kendallville, Ind., assignor to McCray Refrigerator Company, Kendallville, Ind., a corporation of Indiana Application January 29, 1934, Serial No. 708,816

1 Claim.

The present invention relates to display refrigerator accessori s and more particularly to drip pans designed for disposition below the refrigerating coils of refrigerators to catch the drip of n 5 moisture condensation therefrom.

The principal objects of the invention are to provide a drip pan of the character above indicated whose under surf-ace is composed of a material tending to prevent moisture condensation l0 thereon; to provide such a drip pan whose under surface tends to prevent moisture condensation from piling up in increasing quantities; to provide such a drip pan whose under surfaceis of a rough character tending to prevent moisture condensation thereon from running together into larger drops to thereafter fall onto the food displayed within the interior of the refrigerator; and, to provide such a drip pan whose under surface is disposed at such an angle that the surface tension of condensed moisture thereon. tends to prevent a flow of the moisture of condensation into larger drops.

It is a well known fact that the air within a.

refrigerator is maintained; at a temperature of substantiallythat cf the refrigerating coils. In certain types of refrigerators, and particularly those known as the display type, the refrigerating coils are disposed within the case longitudinally thereof and near the under side of its top. Warm air rushing into the refrigerator when the doors thereof are opened is laden with a certain amount of moisture. The warm air impinging on the cold refrigerating coils causes moisture to condense and as these drops of water pile up in increasing quantities, they form larger drops which subsequently fall from the refrigerating coils into the interior of the case.

To catch these drops of water thus falling from the refrigerating coils, refrigerator manufacturers have located drip pans below the coils which carry off the falling drops of water. These drip pans have been made of metal such as of galvanized iron and the like but the objection of falling drops of water has not been completely solved since the under side of such a drip pan itself, which is of course at the temperature of the interior of the refrigerating case, likewise causes moisture condensation to gather and thereafter drop onto the displayed food. It is likewise known that metal has relatively high heat conductivity, the table of thermal conductivity showing that a metallic surface has a heat conductivity of 750 B. t. u.s per square foot per degree per hour per inch of thickness. Any heat therefore that impinges upon the metallic surface of such a metal drip pan is rapidly dissi- I pated to the surrounding metallic area and when it is remembered that for every pound of water 1000 B. t. u.s must be removed to condense it from its vapor state to its liquid state,.a great 5 amount of heat is taken up by this metal drip pan. Thus it will be seen that inasmuch as the entire surface of the drip pan is within a narrow'range of the temperature of the interior ofthe case, vapor in the inrushing warm air impinging on 10 the surface of the drip pan will be condensed thereon because its surface is below: the dew point of the inrushing outside air. The problem is thus I not to prevent moisture condensation for this is impossible as long as the interior case temperature is below the dew point of the inrushing outside air; the problem is to minimize thismoisture condensation on the under surface of the drip pan to such an extent that the drops which do form will not pile up in increasing quantities to 20 thereafter fall into the case interior.

Many materials have a heatconductivity flow of less than 25 B. t. u.s per square foot per de-, I gree per hour per inch of thickness, two materials particularly notedfrom the table of thermal con- 25 ductivity-rubber and woodhaving approximately 1 B. t. u. flow per square foot per degree per hour per inch of thickness. Thus itwill be seen that heat applied to such a surface'tends to flow relatively very slowly as compared or 30 contrasted With heat applied to a metallic surface. Since a certain amount of heat is liberated with every particle of moisture that is condensed from the inrushing outside moisture laden air, this liberation of heat raisesthe temperature of 35 the surface on which the moisture or vapor condenses or is deposited. But since the heat flow through rubber, wood and other materialshaving a small heat conductivity flow is relatively negligible as compared with metal, the heat tends 40 to remain in the spot where it is liberated, maintaining the temperature of that area at a higher level than that of the surrounding area. Subsequent condensation or piling up at the heated point is thus curtailed. Thus it will be seen that although moisture will condense upon the sur- 7 face of the rubber, wood or other material having a relatively low heat conductivity flow, the amount of moisture deposited on the under sur- 5 face of the drip pan will be very much less than it would be in instances of a metallic under surface. Certain other materials, such as fibre compositions and the like, are of course adaptable for use as drip pans, it being understood that 55 the rubber coated drip pan herein shown and; described is merely exemplary.

It is likewise the problem to prevent such drops of moisture as do condense on the underside of the drip pan, formed from material with a relatively low heat conductivity flow, from running together to form larger drops to thereupon fall into the inside of the display case. The weight of a drop of water resolves itself into two compo-- nents-one parallel with the plane of the drip pan and the other perpendicular thereto. These two forces are of course opposed by the well known force "surface tension. This force of surface tension is even'g'reater in instances where a rough surface is used. Thus a forty-five degree angle slope of the bottom side of the drip pan is theo-- retically preferable though not always practicable for space saving reasons. But any slope tends to prevent directly dripping of the condensed moisture, and particularly in instances where the surface is rough such as a rubber surface.

Illustrative embodiments of the invention are shown in the accompanying drawings, wherein:

Figure 1 is a. front elevational view of a display refrigerator, a portion thereof being broken away on line l--l of Figure 2 to better show parts of the interior thereof;

Figure 2 is an enlarged sectional view on line 2-2 of Figure 1;

Figure 3 is an enlarged sectional view thereof on line 3-3 of Figure 1;

Figure 4 is a sectional view on line 4-4 of ure 3;

Figure 5 is a fragmentary sectional view of the drip pan per se;

Figure 6 is a fragmentary view, that portion in section being on line 6-6 of Figure 5;

Figure 7 is an enlarged view of a modified form of drip pan; and

Figure 8 is a sectional view thereof on line 8-8 of Figure 7.

Referring then to the drawings in which like parts of the structure are designated by the same numerals in the several views, a refrigerator, here shown as of the'display type, comprises the base I, front panels 2, 3, ends 4, 5, top 6, rear sliding doors I, 8 giving access to its interior, and triple spaced panes of'glass 9, l0, and II permitting food within thecase to be viewed by prospective purchasers.

A plurality of refrigerating coils I 2 running longitudinally of the case are suspended below the under side of the top of the case in any suitable manner as by a plurality of spaced hangers l3 secured to the under side of the top of the case as by'the bolts H.

A pair of trough-shaped drip pans of the-character illustrated in Figures 1 to 6 inclusive are suspended below the refrigerating coils for the entire length of the coils as bythe spaced hangers l5 to catch the drip of moisture condensation falling from the coils and comprise a metallic upper surface iii of galvanized iron or the like, sloping toward the end of the case, secured to the wood strips i! as by the hanger screws l8. A drain apron I9 is supported at the adjacent ends of the drip pan as best seen in Figures 4, 5 and drain conduits are provided at the end of each drip pan to carry away the water falling therein,

covered by a roughened rubber coating 22, all as best illustrated in Figure 5. This rubber coated pan is secured to the wood strip as by the screws 23.

As heretofore suggested, the under surface of the drip pan of the instant invention is composed of a material. having a relatively-negligible heat conductivity flowas compared with that of a metallic under surface, and although the under surface 22 of the drip pan is here illustrated as of roughened rubber, it will be understood that other materials having a heat conductivity flow of less than 25 B. t. u.s per square foot per degree per hour per inch of thickness give satisfactory results. As further suggested herein, the opposite lengths of the trough-shaped drip panare prefposed members 25, 26 disposed beneath the re-' frigerating coils and secured to hangers 21 in spaced relation to each other adjacent their inner' longitudinalsides. A fiat metallic pan 28 is suspended below the spaced opening between the members 25, 26 and parallel thereto by means oi brackets 29 which are preferably spot welded to the upper surface thereof and are detachably hooked over the hangers 21, as best seen in Figure 8.

A second metallic fiat pan 30 having a roughened rubber coating 3| embraces the pan 28 and its wooden base 32 to which both are secured as by the screws 33. The drip of moisture condensation from the coils falls onto the members 25 or 26 from which it runs to the pan 28 which carries the water away in a manner similarto that described in connection with the form of drip pan shown in Figure 5.

It will thus be seen that a novel type of drip pan for use in catching-the drip of moisture conprovided with an under surface formed of a ma-' terial which tends to prevent moisture condensation thereon but also tends to prevent the piling up of the moisture in increasing quantities on its under surface to thereafter run together and fall onto the food displayedwithin the refrigerator.

While but several embodiments of this invention have been herein shown and described, it will be understood that details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claim.

I claim:

A drip pan adapted for disposition below a refrigerating coil having an under roughened surface of a material with a heat conductivity flow of less than two B. t. u.s per square foot per degree per hour per inch of thickness;

GEORGE J. HOPKINS.

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