US2126285A

US2126285A - Refrigerator

Info

Publication number: US2126285A
Application number: US501188A
Authority: US
Inventors: James E Schaaf
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1930-12-10
Filing date: 1930-12-10
Publication date: 1938-08-09
Anticipated expiration: 1955-08-09

Description

E. SCHAAF i dms gzamr Aug. 9, 1938.

2 7 z V I E E Q Ti :TE.

INVENTOR JAMES E. SCHAAF A ORNEY Patented Aug. 9, 1938 REFRIGERATOR James E. Schaaf, Nufley, N. 1., assigns:- to General Electric Company, a corporation of New York Application December 10, I930, Serial No. 501,188

The invention relates to a freezing or cold storage construction, to a storage ice box of commercial or household typ or to a display casing, hereinafter referred to generically as a refrigerator, of the type of such constructions in which the storage space is cooled by circulation of air exposed to a refrigerating coil and the invention specifically relates to means for defrosting such coil,

It is a present practice in vending package foodstuffs, such as meats and other edibles, to freeze the products at a very low temperature, usually below 50 F. Such goods must be maintained at a low sub-freezing temperature until ready to be used and tend to deteriorate if subjected for even a short period of time to any relatively high temperatures, even to a subatmospheric temperature as low as or F. Refrigerators of this type now in gen- 20 eral use accumulate layers of snow and ice on the refrigerant carrying coil, condensed thereon from the moisture containing air which is introduced into the storage compartment whenever the door thereto is opened. Such coils are com- .25 monly defrostedsimply by shutting off the supply of refrigerating liquid to the coils and exposing the coils to the heating influence of the external atmospheric air. It has also been suggested to defrost by chemical action and by ap- 30 plying heat to the coils from heating wires. This means, of course, that not only are the coils heated but the storage space open thereto is also heated above its operating temperature with consequent ruiningof the contained food stuffs. To avoid this it is a present practice to remove the food stuffs from the refrigerator while the coils are being defrosted. This practice, however, necessitates the use of two refrigerators and especially in the case of large refrigerators commonly used in stores there is involved the labor and inconvenience of handling large amounts of frozen materials every time it is necessary to defrost the coils.

The primary object of the present invention is to provide a simplified means for defrosting the coils of refrigerators without the usual incidental raising of temperature of the storage space.

Broadly, this object of the invention is attained by dividing the refrigerator into a storage compartment and a coil containing compartment with doors or valves therebetween which can be opened during the normal operation of the refrigerator, and which can be closed to insulate the storage space from the heating effect of whatever agency may be utilized to raise the temperature in the coil compartment in defrosting the coils.

While a closed storage compartment in a well insulated refrigerator casing will maintain its low operating temperature for a period of time sufficient to permit the defrosting of the coils, the frequent opening of the door as would be the case in a busy store, has the effect of raising the temperature higher than is desirable before the coils can be defrosted by the usual air exposure method. It is therefore desirable to minimize the length of time during which the storage space is deprived of the cooling effect of the coils as herein featured.

Accordingly, the present disclosure features the utilizing of heating means in place of or supplementing the usual air heating for accelerating the defrosting action on the coils and at the same time to prevent the transference of this heat to the storage space with its low temperatured contents.

Broadly, this phase of the invention is attained in the illustrated embodiment of the invention by providing air heating devices and a fan insorted into the coil compartment or preferably built into the refrigerator, for blowing a. current of heated air across the coils thereby to melt the frost thereon more quickly than could be done by simple exposure to the external atmospheric air and to contain this current within the outlines of the closed cell containing compartment.

Still another object of the invention is to provide for an automatic control of the storage space insulating features, and of the coil heating features above outlined, organized and arranged so that the coil will be defrosted automatically and quickly whenever the insulating effect of the frost on the coils has resulted in a rise of temperature in the storage compartment, and to provide for a system of controls by means of which the refrigerator as a whole will be restored to its normal, operative working condition automatically when the defrosting of the coils has been completed.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of mechanism embodying the invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the drawings:

Fig. 1 is a view in vertical section taken from front to rear of a refrigerator illustrating a preferred embodiment of the invention and taken on the line I-l of Fig. 2 looking in the direction indicated by the arrows and partly broken away to economize in space;

Fig. 2 is a horizontal, sectional view taken through the refrigerator shown in Fig. 1 and taken on the line 22 of Fig. 1 looking downwardly as indicated by the arrows; and

Fig. 3 is a diagrammatic showing of the electric wiring connecting the several electrical parts shown in the preceding figu es.

In the drawings there is shown an electric refrigerator including a heat insulating casing lfl with its interior divided by a horizontally extending heat insulating partition ll into an upper relatively small coil and mechanism containing compartment I2 and a lower relatively large storage compartment I3. The upper compartment i2 is provided with an opening II for permitting access to this compartment and with a door ii for closing opening N. The storage compartment I3 is provided with an opening l5 closed by a door H. The compartment I2 is provided with a refrigerating coil l8 through which refrigerating liquid is pumped from a refrigerating machine I! driven by motor 28. The drip from the coil I8 is received in drip pan 2! discharging into drain pipe 22. The two compartments with their incidental connecting passageways form an air conduit containing the air cooling coil l8. In general it is to be understood that the refrigerator as thus far described follows conventional structures and is illustrated simply to show a structure adapted to receive the defrosting devices herein featured.

The partition H is provided adjacent its front and rear edges respectively with a hot or rather relatively warm air duct 23 and a cold air duct 24 normally placing the compartments l2 and IS in pneumatic intercommunication. The primary feature of novelty in this disclosure is that the ducts 23 and 24 are provided respectively with doors or valves 25 and 26 which may be moved to and from, opened and closed position when desired, so as to insulate the compartments l2 and I3 from each other and thus prevent any heat transference from one to the other. It is within the scope of this disclosure to close and open these doors by hand and to secure them in place either by the frictional fit of the doors in their associated openings or by suitably positioned temporary fastening means.

It is also a feature of novelty of the disclosure to provide means for insuring a quicker defrosting of the coils than would be obtained simply by following the usual practice of exposing them to the external atmospheric temperature by opening door l5. For this purpose, there is positioned in the coil compartment I2 a plurality of horizontally spaced apart and vertically extending electric heaters 21 preferably positioned on a supporting frame 28 demountably hung from hooks 29 depending from the top of the casing "I. Positioned at one end of the compartment l2 and preferably supported on the frame 28 is an electric fan 39 disposed to discharge air against and across the heaters 21 to create a horizontally extending whirl of warm air about the coil to raise its temperature to the defrosting point. It is obviously possible to include the fan and heaters in an electric circuit which could be plugged into the ordinary house circuit by leads extendingthrough doop opening ll in those cases where the heater and fan constituted elements arranged to be removed from the refrigerator when not in use.

The more pretentious showing herein illustrated includes means for automatically defrosting the coils and thus avoiding any necessity of personal attention to the refrigerator to maintain its eillciency. It is obviously within the scope of the disclosure to control the opening and closing movement of the doors 25 and 26 and to control the heating devices 21 and 30 independently of each other. In the illustrated disclosure, both the doors and the heaters are controlled automatically in proper time sequence and thermostatically by the temperatures in either of the compartments or at the coils themselves, but it is obviously within the scope of the disclosure to otherwise control the closing of the doors or valves 23 and 24 which insulate the storage compartment.

In the illustrated form of the invention the doors 25 and 26 are moved into closed position by the energizing of pairs of solenoids 3i and 32 for each door. The plungers 33 of each set of solenoids are connected by chains at with the doors therebelow and the parts are arranged with the four solenoids controlling the doors connected in series and so disposed that when current is passed through the same, the plungers 33 are lifted simultaneously by electromagnetic action and act on the doors to move the same from the open position shown in Fig. 1 into an elevated and closed position. The interception of current flow through the solenoids releases the lifting efi'ect on the plungers and the doors are permitted to fall by gravity into their normally open position as indicated in Fig. 1.

In this disclosure it is intended that the casing Ill be internally wired as far as possible and with the circuits organized so that the door controlling solenoids and the heating devices are included in the motor circuit which supplies the refrigerant motor 20. This motor circuit is designed to be connected to a source of energy indicated by electric supply leads 35 and 36 and which may be the house lighting circuit.

Referring to the wiring diagram shown in Fig. 3, there is disclosed a motor circuit including a conductor 31 which extends from energy source lead 35 to the motor 20, and therethrough back to the lead 36 forming the other side of the energy source, through a. two-point relay switch 38. Conductor 42 leads from armature 39 back to the lead 36 forming the opposite side of the energy source. A main hand control switch 43 is contained in the conductor 42 and is disposed in some convenient position exteriorly of the casing II]. It is also understood that the motor circult may be controlled by the usual thermostats (not shown) for maintaining the refrigerator at its preset low temperature during normal operation.

shunted off the motor circuit is a heating device circuit including conductor 44 extending from lead 35 through the two pairs of door operating solenoids 3| and 32, through the series of heaters 21 and through the motor of fan 3|), all disposed in series, to the other point 45 of the circuit closer or switch 38. The armature 39 is so disposed that when shifted from the full line into the dotted line position shown in Fig. 3, the armature is moved into such position by a relatively weak electromagnet 46, contained in a thermostat circuit shunted between conductors l2 and 3T. One end of the magnet 46 is connected by conductor 41 to conductor 42 and the other end is connected to conductor 31 through a conductor 48 containing a minimum temperature thermostat II, the movable element Iii of which is normally in open position and is set to close at a relatively low temperature, in the instant case at 10' 1''.

me armature I! is restored to its normal position closing the motor circuit by means of an electromagnet I designed to overcome the force of the electrom'agnet 40 at the time when electromagnets 4t and II are energized. Thiselectromagnet Ii is contained in a maximum temperature thermostat circuit, one end being defined by conductor 52 leading to conductor 42 and the other end connected through conductor 53 with conductor 32 through a maximum temperature controlled thermostat 84 which is positioned directly on the uppermost coil 55 or otherwise disposed so as to be-connected thermally to the coil II and thus controlled by the temperature of the coil. The movable element It of thermostat I4 is normally in open circuit position and is designed to close when the temperature at the upper coil 55 reaches that point which experiments with refrigerators indicate is the point at which the requisite ,defrosting of the coils takes place and in the illustrated case it is' assumed that thermostat 54 will close at a temperature three or four degrees above 32' F.

In operation. and assuming first that the device is in its simplest form, that is with

doors

25 and 28 actuated by hand, and without the electrical devices herein illustrated, it will be necessary in order to defrost the coils, simply to shut off the motor 20, to close the drop doors 2! and 28 and open door IE to expose the coil to the heating effect of the external air. In due course, the warm external air will gradually melt the snow and ice formed on the coil, the resultant water dripping into the pan 2i and discharging from the refrigerator through drain pipe 22. During this time the usual air flowing communication between the compartments i2 and i3 will be intercepted so that during the time when the upper part of the refrigerator containing the compartment i2 is being gradually heated to atmospheric temperature, the frozen food stufls in the lower compartment it will usually be in suflicient bulk to maintain their frozen condition without materially lowering the temperature at least for a time duration suflicient to permit the coil to become defrosted. This will be true especially if care is exercised not to open door ii any more than is necessary. After the coil has been sufficiently defrosted to restore it to its requisite cooling capacity. the motor 20 is started, thus forcing the refrigerating'liquld through the coil and shortly thereafter the drop doors may be opened manually, thus restoring the refrigerator to its normal, active condition. This condition can be continued until another defrosting of the refrigerator is necessary.

In those cases where the drop doors 25 and 26 are designed to be opened and closed by mechanical action in distinction from manual action, this can be effected by door lifting solenoids Si, 32, such as herein disclosed, acting on their respective doors and the circuit through which may be controlled by the manual actuation of a suitable circuit closer, which, of course, may be same circuit closer or switch which controls the motor 20 in conventional refrigerators now in general use.

In those cases where it is desired to provide heating means to heat the coils in addition to, or to take the place of. the external air, electric the structure of the refrigerator or, as herein suggested, may constitute a removable strucmre which can be introduced through the opening l4 and hung in position at one side of the coils during the time the coils are being defrosted. The addition of the electric fan disposed as herein suggested to blow air across the heaters and on to the coils has the efl'eet of accelerating the defrosting action and in this connection it is suggested that the fan be disposed so as to draw external air into the coil compartment, permit the heating of the same as it is passed across the heater, and to permit the moisture containing air to be discharged from the refrigerator.

In the illustrated embodiment of the invention, the several door lifting solenoids and coil heating means are operatively connected to function under the control of thermostats, in turn controlled by the temperature conditions in both of the compartments. It is obviously possible to control the door closing solenoids and/or the heaters and fan by a single minimum and maximum temperature thermostat positioned in the coil compartment. Referring to the details of the speciflc disclosure herein illustrated and particularly to the diagram of wiring thereof shown in Fig. 3, it will be noted that with the main switch 4! closed, the parts will be in the position indicated in the several figures with current passing through the motor circuit from lead It, conductor 21, motor 20, contact point 4i, armature 38, conductor 42, hand switch 42, to lead 36. Frost will eventually accumulate on the coil ill to such an extent that it will tend to form a heat insulator on the coil thus mimmizing its activity with the result that there is a slow raising of temperature in the storage compartment it. The thermostat 49 is set to close the circuit through electromagnet 46 at some preset temperature, in general practice selected at about 10 F. Closing the circuit through element iii of thermostat 49 completes a minimum temperature electromagnet circuit from conductors 31 and it through electromagnet 4B and conductors 41 and 42. Energizing electromagnet 46 swings armature 39 from the full line into the dotted line position shown in Fig. 3, thus automatically and simultaneously intercepting the current flow through the motor circuit and establishing a current flow through the circuit which contains the heating parts. Tracing this last circuit, it will be seen that it extends from lead 25, through conductor 44, through the several door actuating solenoids II and 32, through the several heaters 21, through the motor of fan 30, through contact point 45, armature 39 and conductor 42 to lead 36. The passing of current through the solenoids BI, 32, energizes them and thus causes them to elevate their plungers 33 to swing the doors 25 and 26 upwardly and into position closing their respective air ducts 22 and 24 and this condition will continue so long as the circuit is closed through the solenoids. As the doors are closed the fan starts to blow air across the heaters, thus heating the air and blowing the heated air in a circular horizontal path through and about the coil i8 with the result that the frost and ice thereon is melted and the moisture laden warm air discharged either through the door opening H or through air discharging vents particularly arranged for this purpose. frost is discharged from the coil, the coil compartment will gradually raise in temperature and the thermostat 84 therein is set to close the cirheaters such as herein disclosed may be built into cult at some preselected temperature, selected to Asthe,

correspond to that temperature at which the coil will become completely defrosted. It is herein suggested that the thermostat 54 be set to close at a temperature slightly above the melting point of ice. say about 34 F. The closing of the circuit through the thermostat 54 will establish a maximum temperature electromagnet circuit from lead 35,

conductors

31 and 53, electromagnet Ii, conductors 62 and 42 to lead 36. The encrgizing of electromagnet 5| acts on the armature l! to swing the same from the dotted line back into the full line position shown in Fig. 3, thus restoring the parts to their initial, normal, operative condition. This has the effect of intercepting the current flow through the heating devices and in the absence of current in the solenoids 3| and II, the doors 25 and 26 are permitted to fall by gravity into their normal, open position drawing with them the plungers 33. The circuit through the motor 2|! is re-establlshed and the refrigerator is restored to its operative condition.

By means of the device described, it is possible to defrost the coil without perceptibly raising the temperature in the storage compartment, thus maintaining its contents at the requisite low temperature necessary to maintain the contents in the original frozen condition.

As the storage compartment is insulated from the heat effects of the defrosting agencies in the coil compartment, there is avoided the present necessity of removing the contents to another refrigerator. The refrigerator can be maintained in active use, independently of any defrosting action in the coil compartment. It is possible to open the door I! during the defrosting process in the normal operation of vending the contents without appreciably or materially raising the temperature in the storage compartment due to the large mass of frozen material usually contained in such compartments which will absorb the small amount of heat introduced with the air. This is particularly true where means are provided to accelerate the defrosting and thus reduce the time delay when the refrigerant is inactive as where heaters of high heating capacity are used for a brief period of time. Such high capacity heaters might be introduced into the coil compartment or rendered active when store conditions demand a quick defrosting and restoring of the refrigerating activity as during a busy period. The actuation of the defrosting mechanism such as the glowing of the usual heater, 28, or the activity of the fan 30 on the closing of the doors 25-25, indicates to the attendant that defrosting is necessary and he could refrain from opening the doors any more than is necessary or he might turn on the installed heaters or introduce the additional heaters if necessary. In this way the activity of the several elements of the defrosting mechanism indicate by their action the time when defrosting is necessary as well as the beginning and duration of the defrosting period.

It is obviously within the scope of the disclosure to so adjust the controllng thermostat or thermostats that the defrosting will be attained within narrow ranges of temperature raise. The controls can be set to attain an automatic defrosting following even a slight accumulation of frost on the coil thus maintaining the coil at its maximum cooling efficiency. In actual practice, the parts can be set to defrost say once every two or three hours which will be with sufilcient rapidity to maintain efliciency under normal working conditions in a store or shop where business is sufllciently active to necessitate the opening and greases closing of door I! frequently or the defrosting action may be clock controlled to take place at night or whenever the refrigerator is not in active use.

While the invention has been described in connection with a refrigerator of the type commonly employed in butcher and other shops and stores, the features herein disclosed may be adapted for use in other locations where it is necessary to defrost refrigerating coils and it is suggested that the disclosure with obvious changes in details may adapted for display cases, household refrigerators, ice boxes, water coolers and for use in refrigerating plants and in scientific and laboratory devices.

I claim:

1. A refrigerator including a heat insulating casing and a horizontally extending heat insulating partition dividing the casing interior into an upper coil compartment and a lower storage compartment, said compartments being both insulated from the external atmosphere during the normal operation of the refrigerator, and adapted to be insulated from each other, a refrigerating coil in the upper compartment, each of said compartments provided with door-closed openings permitting access to their associated compartments and the opening to the coil compartment when opened permitting the exposing of the coil to the heating effect of the external air to defrost the coil, said partition provided with a pair of air circulation ducts normally placing the compart ments in intercommunication, and each of said ducts provided with a heat insulating door for closing the same and when closed for preventing heat transference from the relatively high temperatured upper compartment into the relatively cool lower compartment whereby the storage space may be shut off from the heating effects of the external air acting on the coil during defrosting.

2. A refrigerator provided with a coil containing compartment and with a. storage compartment and with a heat insulating partition separating the compartments, said partition having an air duct normally placing the compartments in intercommunication, a door for closing said duct and thus intercepting both air communication and heat transference between the compartments and thermostatically controlled and electrically actuated means for controlling the opening and closing movements of said door.

3. A refrigerator provided with a storage compartment and with a coil compartment and having openings therebetween normally placing the compartments in intercommunication, a refrigerating coil in said coil compartment adapted to be exposed to agencies to defrost the.same, and solenoids for closing said openings whereby the storage compartment may be closed oil from the coil compartment and from the effects of any coil heating agency therein during defrosting and a thermostat within the refrigerator operatively connected to said solenoids to control the same automatically by temperature conditions in the refrigerator.

4. A refrigerator provided with a coil containing compartment and with a storage compartment and having an air duct normally placing the compartments in intercommunication, means in the coil compartment for raising the temperature therein, a thermostat in the storage compartment for controlling said temperature raising means and a door for closing said duct to thus intercept communication between the compartments while said temperature raising means is functioning.

5. In a refrigerator, the combination of a refrigerating coil which becomes covered with frost when in use, means for defrosting said coils, said means including an electric heater in spaced relation to the coil and a fan directed to blow air therefrom across the heater across the intervening space and on to the coil.

6. A refrigerator containing a coil compartment and a storage compartment normally in intercommunication, a coil in the coil compartment spaced from one of the walls thereof, a heater disposed in said coil compartment to defrost the coil and means for intercepting communication between the compartments whereby the storage compartment may be shut oil from and thus unaffected by heat from said heater.

7. In a device of the class described, the combination of a coil compartment having a refrigerating coil therein, a storage compartment adapted to be open to the coil compartment and otherwise insulated therefrom, means forming an electric circuit including electrically actuated mechanism for intercepting communication between said compartments and thermostatically actuated control means in one of said compartments for causing said mechanism to function.

8. In a device of the class described, the combination of a coil compartment having a refrigerating coil therein, a storage compartment normally open to the coil compartment, means forming an electric circuit including electrically actuated mechanism for intercepting communication between said compartments and for heating said coil and thermostatically actuated control means in one of said compartments for causing said mechanism to function.

9. A refrigerator including a heat insulating casing, a horizontally extending heat insulating partition dividing the interior of the casing into an upper coil containing compartment and a lower storage compartment and said partition adapted to heat insulate the compartments from each other, a refrigerating coil in the upper compartment, means for selectively placing the compartments in fluid communication whereby air cooled in the upper compartment is permitted to circulate between the compartments and for intercepting such fluid communication to intercept the air circulation between the compartments and thus prevent heat transference from the upper to the lower compartment and means for exposing the coil to a heating agency to defrost the same without heating the storage compartment.

10. In a refrigerator, the combination of means providing a storage space, refrigerating means for causing cold air to circulate through said space, controlled means for exposing said refrigerating means to a heating agency to defrost the same, and means for insulating said space from the effects of said heating agency and for intercepting any flow of air between the refrigerating means and the storage space.

11. In a refrigerator, the combination of structural parts providing a cold storage space, and a mechanism containing space, means in said mechanism containing space normally disposed for supplying cold air to the storage space, and means for sealing the cold storage space from the heating effect of the external atmosphere and from the mechanism containing space whereby a sub-atmosphere temperature may be maintained in the storage space for a period of time even in the absence of the means which normally supplies the cold air.

12. A refrigerator provided with a, storage space, a conduit communicating with the storage space, a refrigerating coil in said conduit for cooling the air therein and in the storage space, said conduit provided with means for defrosting the coil comprising a normally closed entrance opening adapted to be opened to expose the coil to the heating effect of the external air to defrost the coil, valvular means for separating the storage space from the coil and thus selectively control the flow of air either through said conduit alone or through both the conduit and storage space and thermostatically controlled means operatively connected to said valvular means for controlling said flow of air.

13. In a refrigerator. having a freezing compartment open at one end and providing a. space at said end substantially free of obstructions to the free circulation of air, a door closing the open end of the compartment, an electric heating element supported within the compartment adjacent the door exposed to the interior of the compartment, including a cylindrical coil having its outer surface entirely exposed to heat the air as it passes about the same in said space and adapted to be removable bodily through the open end of the compartment when the door is removed from its compartment closing position, and an electric circuit including said heating element.

14. The combination with a refrigerating coil, of an electric heating coil arranged in proximity thereto, and thermostatically controlled and automatically operated means for energizing said heating coil and for causing the refrigerating coil to become inactive when ice and snow accumulates on the refrigerating coil whereby the refrigerating coil is freed from the ice and snow.

15. In a refrigerator, structural parts forming a freezing chamber, cooling mechanism including a heat-transferring element exposed in said chamber, heating means independent of the cooling mechanism for defrosting said element and a thermostat connected thermally to said heat transferring element, controlled by the temperature thereof and independent of the operativeness of the cooling mechanism for causing the heating means to function.

16. In a refrigerator, the combination of a, mechanism containing chamber, cooling mechanism including a heat transferring element in the chamber, electrically energized heating means in the chamber creating a flow of warm air impinged on said element, means forming an electrict circuit including said heating means and a control switch, an electromagnetic control for the switch and control means including a pair of spaced apart thermostats, one connected thermally to the heat transferring element and both independent of the operativeness of the cooling mechanism and acting selectively on said electromagnetic control for opening and closing the switch and thus controlling the functioning of the heating means.

17. In a. refrigerator, structural parts on which ice and snow are liable to form, means for exposing said parts to a heating agency to melt the accumulated ice and snow and means including an electric circuit containing electrically actuated devices controlled by the temperature of the surfaces on which the ice or snow forms for causing said heat exposing means to function.

18. In a refrigerator, the combination with a refrigerating machine including a motor and refrigerating coils supplied thereby, of an electric heating device adjacent the coils to heat the same, means formingan electric circuit including said motor and heating device, and a two-way switch for selectively closing and opening the circuit through the motor while respectively opening and closing the circuit through the heating device and thermostats controlled by the temperature in the refrigerator for controlling said switch.

19. In a refrigerator, structural parts forming a mechanism containing compartment, cooling mechanism in said compartment, heating means in said compartment for heating the cooling mechanism, a storage compartment adapted to be cooled by said cooling mechanism and thermostatically controlled means governed by the temperature in said storage compartment for causing the heating means to function.

20. In a refrigerator, the combination of cooling means, a heater and thermostatically controlled means for blowing a current of hot air at a temperature greater than 32 F. from the heater across the cooling means.

21. In a refrigerator, the combination of a freezing compartment provided with cooling means for creating a temperature in said compartment lower than 34 F., heating means in said compartment to create a temperature in said compartment greater than 34 F., a thermostat exposed to the temperature condition at said cooling means for controlling the cooling means and another thermostat for controlling the heating means.

22. In a refrigerator, the combination with a refrigerating machine including a motor and refrigerating coils supplied thereby, of an electric heating device adjacent the coils to heat the same to free them of frost accumulations, means including the motor forming a motor circuit, means including the heating device forming a heating circuit, a two-way switch for selectively opening one circuit while closing the other, thermostatically controlled means for moving the switch into one of its circuit closing positions, and another thermostatically controlled means for moving the switch into its other circuit closing position.

23. In a refrigerator, structural parts forming a mechanism containing compartment, cooling mechanism in said compartment, heating means in said compartment for heating the cooling mechanism, thermostatically controlled means governed by the temperature in said refrigerator for causing the heating means to function, other thermostatically controlled means for causing the cooling mechanism to function, and each of said thermostatically controlled means including a thermostat circuit and a thermostat for opening and closing its associated circuit, the thermostat which controls the closing of the motor circuit set to close at a temperature above a relatively high temperature and to open below said temperature and the thermostat which controls the closing of the heater circuit set to close at a relatively low temperature.

24. A mechanical refrigerator provided with a storage space, defrosting means for the refrigerator means for insulating said means from said storage space, whereby the defrosting means when active will not effect the contents of thestorage space, and a thermostatic control for the defrosting means, said control being operatively responsive to the temperature conditions in the refrigerator.

25. A refrigerator provided with a storage space, an air conduit communicating with the storage space, a refrigerating coil in said conduit for cooling the air therein and in the storage space, said coil adapted to be exposed to a heating agency to defrost the same, means for causing a current of heated air to flow through the conduit and thermostatically controlled means for controlling said last named means.

26. In a device of the class described, the combination of a storage compartment and a coil compartment, a coil in the coil compartment, said coil having capacity to reduce the temperature of the contents of the storage compartment to less than 10 F., means for raising the temperature in the coil compartment to a temperature greater than 32 F. thereby to defrost said coil, and means for insulating the storage compartment from the eflects of said defrosting means.

27. In an electric refrigerator, including cooling mechanism, and an electrically operated device for raising the temperature of the coils thereof above the surrounding atmospheric temperature, a switch in the current supply line leading to said device, and a thermostat in circuit with said temperature raising device controlled by the temperature at the coils for controlling an operation of said switch.

28. In an electric refrigerator including cooling mechanism and a coil, and defrosting means for the coil, an electro magnetic switch in the current supply line for said defrosting means, and means controlled by the ice formation on the coil for controlling the operation of said switch.

29. In combination with a refrigerating coil, of an electric heating coil arranged in proximity thereto, and automatically operated means for energizing said heating coil at irregular intervals controlled by the temperature conditions at a point in spaced relation to the coils whereby the refrigerating coil is freed from snow and ice.

30. A mechanical refrigerator provided with a mechanism containing chamber and a storage chamber, normally active mechanism contained in the mechanism containing chamber for supplying a current of cold air to the storage chamher to maintain the same between a preset maximum and minimum cooling temperature, means for intercepting the fluid communications between the chambers, and for closing the storage chamber when it is desired to defrost the mechanism in the mechanism containing chamber.

31. The combination with a refrigerating coil of heating means including a thermostat controlled by the temperature of space cooled by the coil for raising the temperature of the coil to free the same of adhering snow and ice whenever the temperature of the space cooled by the coil reaches that prefixed maximum which is controlled by the setting of the thermostat.

32. The combination with a refrigerating coil for cooling a space remote therefrom, of an electric heating means in spaced relation to the coil for heating the same and means controlled by the temperature in said space for energizing said heating means.

33. In a mechanical refrigerator, cooling means for creating a temperature therein less than 32 F., defrosting means independent of the cooling means for creating a temperature therein above 32 F., to melt ice accumulation on the cooling means and a thermostatic control for said defrosting means operable automatically whenever the temperature within the refrigerator reaches a. prefixed low temperature below 32 F.

34. A defrosting mechanism for use in connection with a mechanical refrigerator having a chilling element, the same consisting of a thermally sensitive element, a device connected thereto to be controlled thereby, said device being capable of emanating vibrations on to the chilling element,

the thermally sensitive element being located to be responsive to the chilling element on which frost is permitted to accumulate, the presence of said frost serving to effect the thermally sensitive element and then cause said device to operate when the refrigerator is to be defrosted.

35. A mechanical refrigerator including a refrigerating unit on which ice is liable to form, means forming an electric circuit including a motor driven refrigerating apparatus for supplying said unit, means forming an electric circuit including a device for defrosting the ice on the unit and a thermal responsive unit exposed to the thermal influence of a space cooled by said refrigerating unit and operatively connected to both of said circuits simultaneously to open the circuit to the motor of the refrigerating apparatus and to close the circuit to the defrosting device.

36. Refrigerating apparatus comprising in combination a cabinet having a food compartment and a second compartment, a cooling element in said second compartment for cooling said food compartment, means for exposing said cooling element to the air outside of said cabinet and circulating such air over the cooling element for defrosting said element, and means for isolating the food compartment from the second compartment for preventing the access of external air to the food compartment during the defrosting period.

37. Refrigerating apparatus comprising in combination a cabinet having a food storage portion and a second portion, a cooling element in said second portion, and means for exposing said second portion including said cooling element to the environment temperature outside of said cabinet while sealing said food storage portion from said environment temperature.

38. Refrigerating apparatus comprising in combination a cabinet having a food storage portion and a second portion, a cooling element in said second portion, means for exposing said cooling element to the air outside of said cabinet and preventing said outside air from entering said food storage compartment, and means for circulating said outside air over said cooling element.

39. Refrigerating apparatus comprising in combination, a cabinet having a food storage compartment therein, a cooling element for cooling the food compartment, means for isolating the food compartment from the cooling element and for exposing said cooling element to air externally of said cabinet, and means for forcing air externally of said cabinet over said cooling element.

40. Refrigerating apparatus comprising in combination a cabinet, an insulated shelf in said cabinet, said shelf being provided with an opening dividing said cabinet into a plurality of compartments, a cooling element in one of said compartments, means for circulating air over said cooling element in one compartment and through said opening into the other compartment for cooling said other compartment, means for exposing said cooling element to the air outside of said cabinet and means for closing said opening in said shelf.

41. Refrigerating apparatus comprising in combination, a cabinet having a food storage compartment therein, a cooling element for cooling the food compartment, a door for closing an opening leading into said storage compartment and electrical means operable simultaneously with the closing movement of the door for increasing the temperature of the cooling element to cause defrosting thereof.

42. Refrigerating apparatus comprising means for dividing the interior thereof into a cooling chamber and a storage chamber, valvular means for controlling fluid communication between the chambers, refrigerating mechanism including a cooling element in the cooling chamber and electrically actuated power means for operating the refrigerating mechanism, electrically actuated defrosting means in the cooling chamber, and means including electric circuits comprising the power means and the defrosting means for moving the valvular means into position to intercept the fluid communication between the chambers for causing the refrigerating mechanism to become functionally inactive and for causing the defrosting means to become active.

43. In a mechanical refrigerator the combination of a casing provided with a partition for dividing the interior of the casing into a cooling compartment and into a storage space, said partition provided with openings providing communication between the compartments, doors for said openings coacting with the shelf for insulating the compartments from each other when the doors are closed, refrigerating mechanism including a cooling element in the cooling compartment, heating means in the cooling compartment for defrosting the cooling element, current supply lines for supplying electric current to both the refrigerating mechanism and the heating means, and control means including a switch contact for connecting and disconnecting said refrigerating mechanism from the supply lines and a switch contact for connecting and disconnecting the heating means from the supply lines and said control means also including a thermostat located in the storage space and operatively connected to control one of said switch contacts thermostatically.

44. In a refrigerator, the combination of means providing a storage space adapted to receive merchandise, refrigerating means for causing cold air to circulate through said space and about said merchandise to cool the same by direct air contact, controlled means for exposing said refrigerating means to a heating agency to defrost the same, controlled means for exposing the refrigerating means to the external air during defrosting and means for insulating said space from the effects of said heating agency.

45. In a refrigerator, structural means forming a freezing compartment separate from the rest of the refrigerator interior, means including an air port for exposing the interior of the compartment at will to infiltration of external air and the expulsion therefrom of defrosting air, means providing an opening between the freezing compartment and the rest of the refrigerator interior, a closure for the same, means for creating a freezing temperature in said compartment, means including an electric heater having a plurality of exposed coils and mounted in said compartment and means for drawing air into the compartment through the air port and for passing the same across the exposed coils of the electric heater to heat the air so passed across the heater and freezing means and for discharging the same from the compartment during the time when said closure is in position closing the opening.

46. A refrigerator including an outlining casing of unitary construction and provided with at least one opening permitting access directly into the interior of the casing, heat insulating means including a shelf connecting the upstanding walls 01 the casing, dividing the interior thereoi' into two superposed compartments and acting to heat insulate the compartments from each other, said shelf provided with a pair of horizontally spaced apart openings, one forming a vertically directed updraft conduit and the other forming a vertically directed downdraft conduit, a cooling element in one of said compart- 10 ments located between the pair of openings,

means for circulating air horizontally over said cooling element, through the conduits and thus from one compartment into the other, means for exposing said cooling element to the air outside or the casing and said insulating means including doors for closing the openings in the shell and thus constituting a control for the air communication as well as heat transference between the compartments.

JAMES E. SCHAAI".

DISCLAIM ER 2,126,285.James E. Schaaf, Nutley, N. J. REFRIGERATOR. Patent dated August 9, 1938. Disclaimer filed July 19, 1939, by the assignees, General Electric Company and General Motors Corporation.

Hereboy enter this disclaimer of claims 6, 10, 11, and 26 of said patent.

[ flieial Gazette August 8, 1939.]

means including a shelf connecting the upstanding walls 01 the casing, dividing the interior thereoi' into two superposed compartments and acting to heat insulate the compartments from each other, said shelf provided with a pair of horizontally spaced apart openings, one forming a vertically directed updraft conduit and the other forming a vertically directed downdraft conduit, a cooling element in one of said compart- 10 ments located between the pair of openings,

JAMES E. SCHAAI".

Hereboy enter this disclaimer of claims 6, 10, 11, and 26 of said patent.

[ flieial Gazette August 8, 1939.]