US2225932A

US2225932A - Refrigeration apparatus

Info

Publication number: US2225932A
Application number: US284635A
Authority: US
Inventors: Harold D Shaw
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1939-07-15
Filing date: 1939-07-15
Publication date: 1940-12-24
Anticipated expiration: 1957-12-24

Description

Dec. 24, 1940. H. D. SHAW REFRIGERATION APPARATUS Filed July 15, 1939 INVENTOR HAROLD D. SHAW.

WITN ESS ES:

BY Z

ATTOR EY Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE 2,225,932 REFRIGERATION APPARATUS Pennsylvania Application my 15, 1939, Serial No. 284,635

Claims.

My invention relates to refrigeration apparatus and particularly to a defrosting signal for refrigeration apparatus.

In refrigeration apparatus, particularly of the 5 domestic type, it is well known that frost builds up on the evaporator or cooling element of the refrigerator and that periodic defrosting is necessary. While many automatic defrosting schemes have been suggested, it is still advantageous for reasons of cleanliness and cost of manufacture to manually defrost the cooling element. However, the operator of the refrigerator in many instances neglects to defrost the cooling element and. if frost builds up to a suificient l5 thickness, it deleteriously affects the operation and efficiency of the refrigerating mechanism.

It is, therefore, an object of my invention to provide a visual signal which indicates when the cooling element of the refrigerator should be de- 20 frosted.

It is another object of my invention to provide a visual defrosting signal which utilizes the same light source that is used for illuminating the food storage compartment of the refrigerator.

25 It is another object of my invention to provide for changes either in quality or quantity of light which is transmitted from a light source to indicate when defrosting is necessary.

It is a further object of my invention to pro- 30 vide a novel light transmitting means for indicating when defrosting is necessary.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with 35 the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a front view of a portion of a domestic refrigerator illustrating one embodiment of my invention;

40 Fig. 2 is a sectional view of the refrigerator shown in Fig. 1 taken on line 11-11 thereof;

Fig. 3 is a fragmentary detailed View of a portion of a refrigerator illustrating a second embodiment of my invention; and,

-13 Fig. 4 is a fragmentary detailed view of a portion of a refrigerator illustrating a third embodiment of my invention.

Referring specifically to Figs. 1 and 2 for a detailed description of my invention, numeral 50 generally indicates a refrigerator cabinet including heat insulated walls I! which define a food I storage compartment l3. A cooling element It, preferably of the evaporative type, abstracts heat from the food storage compartment l3, refriger- 55 ant belhg circulated therethrough by a conventional refrigerating system (not shown). A shelf |5 is positioned in the food storage compartment and supports a receptacle It for storing meats and the like directly below the evaporator It.

A door I! closes the food storage compartment 5 l3 and, when in its closed position, forces a plunger l8 of a door-operated switch I! inwardly, thus breaking an electrical circuit from line L1 In to contacts 2| and to an incandescent lamp 22. When the door I! is opened, the plunger I8 is 10 forced outwardly by a spring 23 -so that the contacts 2| are closed and the incandescent lamp 22 is energized to illuminate the interior of the food storage compartment |3.

In accordance with the first embodiment of the invention shown in Figs. 1 and 2, heat-

insulating blocks

25 and 25 are attached to the bottom of the evaporator I4 by screws 21, the block 25 being positioned near the front of the evaporator and the block 26 near the rear thereof. The front block is provided with an ornamental front surface 28 and with a cut-out portion 29 in communication with the compartment l3 and preferably adjacent a corrugation 3| of, the evaporator II. t

As best shown in Fig. 2, a light-transmitting device 30 comprises two

rods

32 and 33. The

rods

32 and 33 are supported by the

blocks

25 and 26 and are spaced apart at 34 in the cut-out portion, 29 of the block 25. One end 35 of the rod "30 extends outwardly of the block 25 and an end 36 of the rod 33 is bent downwardly at 31 and extends in close proximity to the incandescent lamp 22. The rods are preferably formed of a methyl methacylate resin known by the trade-marked 35 name Lucite, although they may be formed of fused quartz, glass or any fairly efficient lighttransmitting material. The trade-marked material Lucite is especially applicable because it is an efficient light transmitter, may be made of 40 different colors, and transmits light around bends with very little loss in intensity.

In operation, when the cooling element It is not in need of defrosting and the door H is opened, the incandescent lamp 22 is energized and light therefrom not only illuminates the food storage compartment l3, but is also transmitted along rod 33, across the space 34 between the rods and through rod 32 to the visible end 35 thereof. The end 35 therefore glows and shows that the cooling element It is not in need of defrosting. When frost builds up on the cooling element H to a predetermined degree, for example, V}. of an inch, it also builds up on corrugation 3| and closes the space 34 between

rods

32 and 33.

2 2,225,932 I 7 When this occurs. light is no longer transmitted ing normal operation, a source of light and tothefrontrodflandthecxposedendflthereof ceases to glow, thereby giving a visual indication that the cooling clement ll should be defrosted. Eitherorbothrods flandllmaybe made of colored material so that colored light is visible at the expmed end 88 of the rod 32.

In the second embodiment of my invention:

shown in Fig. 3, the rods "and 33 are arranged 10 as shown in Figs. 1 and 2 but a third continuous rod II is also supp rted by the blocks fl and I8.-

Rod 38 has one end It adjacent the incandescent lamp 2! and the other exposed end ll thereof positioned directly below end I! of rod 32. The advantage of such an arrangement is that the end ll of rod 38 will always glow when door I! is open whether defrosting is necessary or not, thus calling the operator's attention to the defrost indicator. If desired, end it of rod 32 may glow with light of one color, for example, green, while end I! of rod a may glow with another color, for example, red.

The third embodiment of my invention disclosed in Fig. 4 of the drawing is constructed exactly the same as that shown in Fig. 3 except that an exposed colorless focusing device 4! collects light from

rods

32 and 38 so that, if rods 32 and ll are of diiierent colors, as frost builds up in the space ,between rods 32 and", the color .3 of the light will change in the focusing device 42, this indicating the need for defrosting. This embodiment also has the advantage that the device 42 always glows when the door I1 is open with some color of light, thus calling the operator's attention to the defrost indicator.

From the foregoing, it will be apparent that I have provided an improved defrosting indicator for refrigerators in which the source of light which illuminates the interior of the food storage 40 compartment is utilized. I furthermore provide a defrosting indicator which is attractive in appearance and inexpensive to install in a refrigerator.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is: v

1. In refrigeration apparatus, the combination of a cooling element which collects frost during normal operation, a source of light and means for transmitting light from the source to a location where it is readily visible and for varying the light transmitted as a signal when defrosting is necessary, said means comprising a light- Q transmitting material having at least a part thereof disposed adjacent to the cooling element and having a break therein so positioned-.that

whenthe' frost builds up on the cooling element to a predetermined degree it enters the break and varies the light transmitted by said lighttransmitting material.

2. In refrigeration apparatus, the combination of a cooling element which collects frost durmeans for transmitting light from the-source to a location where it is readily visible and for varying the light transmitted as a signal when defrosting is necessary, said means comprising a plurality of light-transmitting devices, at least one'of which is disposedadiacent the cooling element with a break therein so arranged that .whcn the frost on the cooling element builds up to a predetermined thickness it enters the break and varies the light transmitted by one of the devices.

8. In refrigeration apparatus, the combination of a cooling element which collects frost during normal operation, a source of light, means for transmitting light from the source to a location where it is readily visible'and for varying the light transmitted as a signal when defrosting is necessary, said means comprising a plurality of light-transmitting devices, at least one of which is dispwed adjacent to the cooling element with a break therein so arranged that when the frost on the cooling element builds up to a predetermined thickness, it enters the break and 'varies the light transmitted by one of the devices, and means for focusing the light from both of said devices at a single point.

4. In refrigeration apparatus, the combination of a cooling element which collects frost during normal operation, a source of light, means for transmitting light from the source to a location where it'is readily visible and for varying the light transmitted as a signal when defrosting is necessary, said means comprising a plurality of. light-transmitting devices, at least one of which is disposed adjacent to the cooling element with a space therein so arranged that when the frost on the cooling element builds up to a predetermined thickness, it enters the space and varies the light transmitted by one of the devices, and means for focusing the light for both of, said devices at a single point, said devices transmitting different colored light so that the color changes at said point when the frost builds up to a predetermined thickness.

5. In refrigeration apparatus, the combination of a refrigerator cabinet embodying a food storage compartment and having an access opening thereto, a door for closing the access opening, a

cooling element disposed in the food storage com- I partment which collects frost during normal operation, a source of light, means for transmitting light from the source to a location where I it is readily visible and for varying the light transmitted as a signal when defrosting is necessary,