US2071148A - Defrosting signal for refrigerators - Google Patents

Description

. 1937- H. J. WEISBERG ET AL 2,071,148

DEFROSTING SIGNAL FOR REFRIGERATORS Filed March 27, 1935 INVENTOR 1 I? azz efif fi ATTOR EY t Patented m. 16, 1931 ,PATENToFI-ICE ,DEFROSTING SIGNAL iron j nnmrcnnarons Harold J. Weisbcrg, ism-neon, and Charles E. Ide,

Greece, N. Y.

Application March 27, 1935, Serial No. 13,306

Y ZClaims. (o 171-311),

. The so-called electric refrigerators are pro vided with a freezing unit' comprising,one or more coils of pipe, which are part of the refrigerating apparatus-byfwhich the low tempera-* 'ture is secured in the refrigerator. The moisture of the air condenses on these pipes and. freezes thereon, forming a coating of frost or ice thereon. This frost. is not .as-good a conductor of heat as is the pipe or pipes which it covers, and it therefore interferes with the absorption of heat from the atmosphereof the refrigerator and interferes with the efficiency of the refrigeration. From timeto time this frost must be removed from the coils of pipe, which is,easily done by simply turning off the-current, which permits the coils and the frost to gradually warm up, so that the frost melts off or is easily broken off of the pipes.. This is called defrosting the refrigerator and must be done from time to time.

,For the purpose of indicating that'a layer of ice has formed on the pipes sufflciently thick so that it should be removed therefrom, an indicatorhas been provided which indicates that the frost or ice is of objectionable thickness and should be removed from the pipes. A

The ordinary electric refrigerator that is used in private homes is provided with a door which closes the open space inside the refrigerator in which food is.kept. Many ofsuch refrigerators are provided with a lamp inside the refrigerator which lights only when thedoor is open, that is,

a the opening of'the door closes a switch which causes the .lamp to light up when the door is opened, and opens the switch, or causes the light'to go out, when the door is closed.'

One of the objects of our invention is to provide a special lightinside or outside of the refrigerator that will light on the opening of the door only when thepipes should be defrosted.

Another'object of the invention is to make the accumulation-of ice complete thecircuit so that the auxiliary light will light up, and indicatev that the refrigerator should be defrosted, when the .door is open.

These and other objects of the invention will be illustrated in the drawing, described in the specification and pointed out in the claims at the end thereof.

In the drawing:

Figure 1 is a front elevation of the freezin Y unit, with the lamp circuits therefor.

Figure 2 is a side elevation of the freezing unit.

In the drawing like reference numerals indicate like parts.

g In the drawing reference'numeral I indicates the housing of the freezing unit. 'This housingis closed at the front by a door 2; Pans of water can be placed in this housing for the purpose of turning it into ice. Below this housing is placed This housing is supported from the structure one side of the freezing unit depend brackets I,

which brackets extend down along the side of the freezing unit. On these brackets is supported a cross bar 8, which is preferably made of insulating materiahsu'ch as bakelite, porcelain, etc. On this crossbar is mounted a strip of brass 9, or other conducting material, which brass is suitably spaced from the refrigerating unit or the coils thereof, so that an air gap of predetermined width ordinarily exists between them. This brass strip is connected by the conductor l0 1:0 the conductor H. The conductor i 2 is connected to the conductor l3 by the switch I, which isoperated by the door.

When the door is opened the conductor I3 is energized, and energizes the lamp l5 and the conductor l6, which is grounded on the housing. The circuit of the lamp l5, however, remains open until the layer of ice I1 forms sui'hciently thick to bridge the gap between the brass plate and the housing I or one or more of the coils 4 thereof. This layer of ice closes the circuit and causes the lamp ii to light when the door is opened, or when the switch I4 is otherwise closed.

' of the refrigerator by the posts 5 and 6. Two or .four of these'posts are used, depending on the type of the refrigerator. From the posts 5, 5 on thickness as to interfere with the efficiency of I the refrigeration, and the freezing unit should be defrosted. This is done by shutting ofhthe current from the refrigerator. When the defrosting is complete, and the current is turned on again, the lamp l5 will remain dead until the frost has accumulated to a sufficient thickness to again make it desirable to defrost the refrigerator. Thereafter it will again light up until the frost or ice has been removed.

The lamp i5 can be either on the outside or inside of the refrigerator, and can be operated independently of the lamp l8. So far as this lamp I5 is concerned, the switch M can be kept permanently closed or may be omitted altogether, that is, the circuit may be fully established without the switch, but the switch is shown because it is sufficient for the signal to light merely on the opening of the door. This means saving of current.

If the switch I4 is closed, or is omitted from the circuit, the current will flow as soon as the least amount of frost accumulates and makes contact with the contact plate. In such case the current would melt the frost and break the contact. With the switch normally open, no current can flow and the frost can accumulate until the contact is fully established, with no possibility of melting the frost by resason of the flow of any current. When the switch is closed by the door, or otherwise, after the frost has fully accumulated the current can flow and the lamp will light, and during the short time that the door is open the flow of current cannot melt the frost sufiiciently to break the circuit or put out the special lamp that indicates that the freezing unit should be defrosted.

To avoid melting the frost and avoid interfering with the circuit that is closed by it when the current flows, a small lamp is used, that is, one that has a small consumption of watts.

This device applies to any mechanical refrigeration as well as to electrical refrigeration.

We claim:

1. In an electric or mechanical refrigerator the combination of a freezing unit on which frost is adapted to accumulate, a large contact plate suitably spaced from said freezing unit and insulated therefrom, a lamp circuit connected to said freezing unit and said contact plate, said circuit being closed between the freezing unit and the contact plate by the accumulation of frost on the freezing unit, said lamp circuit having a lamp therein capable of lighting with a low consumption of watts.

2. In an electric or mechanical refrigerator the combination of a freezing unit on which frost is adapted to accumulate, a large contact plate suitably spaced from said freezing unit and insulated therefrom, a lamp circuit connected to said freezing unit and said contact plate, said circuit being closed between the freezing unit and the contact plate by the accumulation of frost on the freezing unit, a switch in said circuit by which the circuit may be otherwise opened and closed; said lamp circuit having a lamp therein capable of lighting with a low consumption of watts, said switch being normally open.

HAROLD J. WEISBERG.

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