US 2607086 A
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Description (OCR text may contain errors)
Aug. 19, 1952 r R. SAUNDERS 2,607,086
. REFRIGERATOR DOOR CONSTRUCT LON a Filed June 23, 1948 Patented Aug. 19, 1952 Application t'll Illa 23, 1948, Serial Nafaaszci n1 Great Britain July 11, 1947 1 5 Claims. (o1. zit-35) This invention relates to thermally insulated chambers such as refrigerators, cold storage chambers and the like. It is, of course, well known that, in the case of domestic and other refrigerators, cold storage chambers and the like, there is a considerable temperature difference on opposite sides of the door, which temperature difference may be 70 or even more, particularly where thedeep freezing process is in. use. Here'- tofore the joint around the door has been made by means of one or-more rubber or like gaskets which are pressed into contact with the door frame and with a not inconsiderable pressure. With refrigerators, cold storage chambers and the like as previously constructed, trouble has been experienced'from the fact that when the door is opened moisture condenses around the door frame, which moisture, after the door is closed. turns to ice with; theresult that the gasket or gaskets is or are frozen to the door frame. Considerable force will then be necessary to open the door which is often damaged or distorted in the process. The chief object of the present invention is to overcome this disadvantage.
According to the main feature of the present invention, the door when closed is adapted to define a closed chamber or peripherally extending space around its edge between the inside and outside of the refrigerator, cold storage chamber or the like, and means are provided for maintaining said chamber at a temperature above freezing point.
Conveniently the. door, when. closed, is, adapted to form two such chambers between its edge and the door frame.
According to another feature of the present invention, the use of rubber or like gaskets is dispensed with and a metal to metal joint is employed between the door and the door frame. In this case, and particularly where the frame of the door and the door frame are in the form of metal castings, it is desirable to use a metal of low thermal conductivity such as magnesium or a magnesium alloy. Also where the frame of the door and the door frame are metal castings, it is necessary to make the frames in two parts which are heat-insulated from one another in order to prevent the conduction of heat from the insulated Figure 1 is afrontele'valtion of :door and. framing" tte 'the present invention,
Figure 2 is asecti'on unlined- 1131 "lii'gure 1 and V a Figure sis a sectionon Mei- 4 of Figure 1. Referring now to the accompanying drawings, inthe embodiment of the present invention therein illustrated the doorirame: t0 and the framing ll of the door itself aramaeesame form of castings of a metal of low thermalconductivity, such as magnetiumor a magnesium alloy. The door l0 itself 'is lagged "with cork or'other suitable material in any desired manner as at l2, this forming no part of' thepresent invention and the chamber'i's sinularly laggedysee I3. It follows thatas theidoor frame "1- and' the framing H of the door iaerraramaeeer metal or other thermally conductive material, some means must be provided rroe reveaung-tne-eonduction or heat from theoutside-"to the inside of the. refrigerator, cold storage chamber or the like, and with this obj'ect in view thedoor frame HI and the framing l-I': ofthe door are each made in two parts, a front: or exterior part with rear or exterior party-fies shown in Figures 2: and 3) anda strip of heat insulating material it, such for example rubber or the material sold. under the trade-mark Tufnol, or other resilient thermally insulating material is inserted between the two parts, which are, of course, suitably held together to form the complete frames.
The framing H of the'door is. substantially semi-circular in cross-section and the door framing I 0 may also be regarded as being of circular shape in cross-section as will be seen from the drawings. The door frame l0, however, is provided around its front with a bead l5 which may be substantially circular in cross-section and the framing I I of the door is provided at the rear with an annular bead IS. The parts are so proportioned that with the door closed the bead l 5 on the door frame In contacts with the framing I l of the door and, also, the back of the door frame Ill contacts with the bead l 6 on the framing H of the door. In addition to the front and back contacts between the door frame and the framing of the door, the two heat insulating strips M in the frames likewise contact each other (see Figures 2 and 3). The door when closed thus serves to define two closed chambers or spaces l1 and I8 which extend peripherally all around its edge. By making the frames of a metal or allow or other thermally conductive material such as that referred to above it is easy to secure air-tight joints where the parts are in direct contact without the use of high pressures such as are necessary when rubber or like gaskets and wooden frames are used. Furthermore, the strength of the metal frames is such that there will be no tendency of the same to distort so that air-tight joints will always be maintained. H A I I a Now it will be appreciatedtliatwith metal to metal joints such as those described above the tendency of the joint to freeze up due to the condensation of moisture when the door is opened is considerably enhanced. In order to avoid all possibility of the door freezing up, means are provided for heating the air within the closed chambers defined by the door when closed to a temperature above freezing point. means may be employed for heating the air with in the closed chambers without departing from the scope of the present invention. For example, low temperature electrical heaters l9 may be'employed and they may be thermostatically cona claim 1 inwhich the interiorly and exteriorly dis- Any' suitable Yposed portions of the said door frame and said trolled. The air within the two closedchambers l1 and 18 may be heated to the same temperature or to diflerent temperatures as desired.
Means may be provided for draining. away any moisture which condenses in the closed chambers. z v
The circular bead l5 all around-the edge ofthe front of the door serves vnot only to provide one oi. the joints between the door frame; and the framing for the door but, also serves as aconvenient means of hinging" the door (see 20) and carrying the fastening means (not shown).
Ifdesired, the'door; when, closed; ,may be adapted to define onlya single closed-chamber, or more than two closed chambers around its edge without departing from the scope of the present invention. 1 Y I Also, whilstit is preferred to. make the frames of metal andito dispense with-the use of gaskets. the feature .of the present invention l whereby the door when closed :defines oneor more closed chambers around its. edge, which chamber or chambers is or are heated to a, temperature above freezing point, may also .be usefully applied to wooden, plastic or other doors with the joints formed of rubber orlike gaskets'or, in some cases,
I claim: I
l. A thermally insulated chamber ofthe class described, said chamber having an opening therein, comprising: a-door frame of thermally conductive material mounted in said-opening'and 4 comprising interiorly and exteriorly disposed portions thermally insulated from each other; a door comprising a framing of thermally conductive material hingedly mounted in said door frame, said framing comprising interiorly and exteriorly disposed portions thermally insulated from each other, said door frame and said framing of said door being shaped for direct contact therebetween at the interior and exterior portions thereof and defining a peripherally extending space therebetween when the door is closed; and a heater disposed in said peripheral space, for maintaining the temperature in said space above the freezing point.
2. A thermally insulated chamber according to framing of said door are thermally insulated from one another at the peripheral portions thereof each by a strip of resilient thermally insulating material, the arrangement being such that when the door is closed said strips engage each other dividing said peripheral space intotwo portions interiorly andexteriorly disposed with respect to each other. i
3. A thermally insulated chamber'according to claim 2 wherein said heater comprises at least one low. temperature electrical heater disposed in one of said portions of said peripheral space.
4. A thermally insulated chamber according to claim 3 wherein the two portions of said peripheral space are heated to different temperatures.
5. A thermally insulated chamber according to claim 3 wherein said low temperature electrical heater is thermostatically controlled.
REFERENCES CITED The following references are of record in the file of this patent: a
UNITED STATES PATENTS