US2932545A - Magnetic door latching arrangement for refrigerator - Google Patents

Description

April 12, 1960 T. P.v FOLEY 2,932,545

MAGNETIC DOOR LATCHING ARRANGEMENT FOR REFRIGERATOR Filed Oct. a1, 1958 INVENTOR.

THOMAS P. FOLEY United States Patent ice MAGNETIC noon LATCHING ARRANGEMENT FOR REFRIGERATOR Thomas P. Foley, Louisville, Ky., assignor to General Electric Company, a New York corporation Application October 31, 1958, Serial No. 771,000

3 Claims. (Cl. 312-296) The present invention relates to and has for its principal object an improved magnetic door latching arrangement for a refrigerator in which the magnetic member is formed as an integral portion of at least one of the opposed heat insulating surfaces around the periphery of the cabinet member or door member.

In accordance with the present invention, there is provided a refrigeration unit including a cabinet member and a door member having opposed abutting surfaces when the door is in the closed position. In order to provide a force for maintaining the door in the closed position there is provided as an integral part of at least one of these surfaces, a portion formed from a pulverant mag- ;netic oxide material in a resinous binder which portion is :magnetized to produce a magnetic flux. ;tion of the abutting surface of the opposite member com- ;prises' a magnetically attractable means which is attract- .ed to the magnetized portion of the one surface and which provides a closed magnetic path between the two abutting surfaces when the door member is in the closed posi- ;tion relative to the cabinet member.

At least a por- For a better understanding of the invention reference :may be had to the accompanying drawings in which:

invention;

Fig. 2 is a sectional view illustrating details of the imagnetic latching arrangement between the abutting sur- ;faces of the cabinet and door members;

Fig. 3 is a sectional view showing the magnetic portions of the abutting surfaces slightly separated to illusatrate the pole arrangement; and

Fig. 4 is a partial view of the magnetized portion of the door illustrating another pole arrangement.

Referring now to the drawing, there is shown in Fig. l a refrigerator including a cabinet 2 of sheet metal shaped to provideouter walls 3 and aface portion 4 framing an access opening to astorage compartment 6 of the refrigerator. A door 7 is provided for closing the access opening of the cabinet, the door being pivotable to the open and closed position on hinges (not shown) connecting one side of the door with the cabinet. A softflexible gasket 8 extending around the outer extremity of the door provides a means for sealing the space between the door and the cabinet around the access opening to the cabinet.

As may be seen in Fig. 2, the refrigerator cabinet includes an inner liner 9 shaped to fit within theouter walls 3 and to form the food storage compartment within the cabinet. On thefront face 4 of the cabinet between t he shaped metallic portions of .theouter walls 3 and the 2,932,545 Patented Apr. 12, 1 960 2 or resinous material.Suitable insulation 14 fills the space between the inner and outer walls of both the cabinet member 2 and the door member 7.

In the illustrated embodiment of the invention, the inner wall of the door comprises a door-shelf structure 13 and an abutting surface portion orsection 16 which has at least a portion thereof arranged in abutting relation with thefront face 4 of the cabinet when the door 7 is in the closed position across the access opening of the cabinet. The abutting portion orsection 16 includes only a narrow strip of the inner door on the side of the door opposite from the hinges. It is possible to form the inner liner with the door-shelf structure 13 and thesection 16 formed as a single piece of plastic or resinous material. However, in the preferred embodiment illustrated in the drawings, the abuttingsection 16 and the innerdoor shelf structure 13 are two separate members and the reasons for this arrangement will be explained hereinafter.

In the illustrated embodiment of the invention, thesection 16 is provided with a raised portion or an outwardly protrudingportion 17 which contacts thefront surface 18 of the breaker strip 11 Whenever the door is in the closed position. When the door 7 is moved into the closed position, the protrudingportion 17 engages the surface of the breaker strip 11 and causes the remaining portions of the door to be maintained a predetermined distance away from thefront face 4 of the cabinet. Other than the surface of the protrudingportion 17, only thegasket 8, which extends outwardly beyond the protrudingportion 17, touches thefront face 4 of the cabinet. The gasket seals the entire peripheral portion of the door against thefront face 4 around the access opening to the cabinet.

In order to maintain a compressive force on thegasket 8 and in order to maintain the door in the closed position with respect to the cabinet, a magnetic latch arrangement is provided which creates a force attracting the door toward thefront face 4 of the cabinet. The mag netic force is created by making at least one of theheat insulating members 11 or 16 out of a resinous or plastic compound containing a pulverant magnetic oxide material thoroughly mixed or blended therein. This compound is extruded or formed in a manner well known in the art into the desired shape and is then magnetized to properly orient the domains of the magnet particles to create a magnetic flux. Referring now to Fig. 2, both the breaker strip 11 and theabutting section 16 are formed of this material. Portions of these members have been magnetized to provide pole faces, which are attracted to each other. As may be seen in Fig. 3, a portion of the abuttingsection 16 has been magentized such that thesurface 19 of theprotruding portion 17 is a north pole and thesurface 21 is a south pole. The breaker strip is so magnetized as to provide a south pole on thesurface 18 and a north pole on theinner surface 22. Thus, thesurface 19 of the abuttingsection 16 of the door is attracted to thesurface 18 of the breaker strip 11 of the cabinet and provides a force for maintaining the door in the closed position with respect to the cabinet. It should be understood that the powdered magnetic material is blended throughout themembers 11 and 16 and only that portion of the powdered -material which is actually magnetized is shown in Figs.

2 and 3.

The powdered magnetic material may be any of the magnetic oxide materials now on the market such as the ferrite materials comprising a compound of the reaction product of a metal oxide and an iron oxide having the empirical formula MFe O wherein M represents a bivalent metal such as cobalt, copper, barium, or a mixture of these metals. The ferrite has a crystalline structure and is generally formed by sintering the metal oxide with iron oxide at a relatively high temperature. The powdered ferrite material is mixed with a resinous or plastic binder such as polystyrene and is then extruded or molded into any desired shape or dimensions, as for example, the shape of theheat insulation members 11 and 16. The body thus manufactured may be magnetized in any well known manner to provide the desired pole surfaces, and a permanent magnet is obtained with an extremely high coercive force.

It should be pointed out that due to the large surface area of the abutting surfaces the magnetic forceformaintaining the door in the closed position can be made extremely great. However, only a portion of the surface on each ofthe membersneed be magnetized and, by proper selection of the amount of magnetized surface area, a force can be obtained WhlCh'iS just sufiicient to compress thegasket 8 and to produce a sufficient holding force to maintain the door in the closed position. Since it is easier to form the members 1'1 and 16 entirely of this ferrite or iron oxide material in a resinous or plastic base, it is desirable that these members be as small as possible. Thus, as shown in the preferred embodiment of the invention, themember 16 forms a separate portion from the inner door-shelf structure 13. However, it is possible to form the entire inner door of powdered magnetic oxide material and magnetize only that portion of the door which abuts thebreaker strip 11 of the cabinet. Also, only a part of the breaker strip 11 need be formed of this ferrite or'magnetic oxide containing material with the remainder comprising a somewhat less expensive heat insulating plastic material.

It should also be noted that certain portions of themembers 11 and 16 can be magnetized in ways other than that illustrated in Fig. 3. Thus, as may be seen in Fig. 4, thesection 16 can be magnetized to provide a plurality of adjacent pole surfaces of opposite polarity, such as the alternating north, south poles shown. In such an instance the breaker strip 11, or opposite member, is magnetized to provide complementary pole surfaces'arranged to be attracted to these alternating north, south .poles of the abuttingsection 16.

Further, only one of the opposed abutting surfaces need be a magnetized member if the other or-opposite member is formed of a magnetically attractable material such as the steel portion of the cabinet member 2. The magnetically attractable material can be the steel portion of thefront face 4 of the cabinet or it can be a magnetically attractable insert placed opposite the magnetizedportion of the one member.

While there has been shown and described a particular embodiment of the present invention it will be obvious to those skilled'in the art that various changes and modifications may be made therein without departing from the invention, and it is intended by the appended claims to cover all such changes and modifications as come within the true spirit and scope of the invention.

What I claim is:

1. A refrigeration unit comprising a cabinet including a plurality of heat insulating walls enclosing a food storage chamber having an opening on one side,-a heat insulating plastic section surroundingthe periphery of said opening, a door having a heat insulating plastic section arranged around-the periphery thereof and arranged to j move into 'abuttingjrelationship with said heat insulating plastic section of "said' cabinet member when "said door is in the closed position-across saidopening," at least a portion of one of said heat insulating plastic sections being tion being magnetized to produce a magnetic flux emanating from pole faces on the surface thereof and an armature on the opposite abutting section disposed to provide a closed path for said magnetic flux when said door is in the closed position so that a force is created between said abutting sections for maintaining said door in a closed position.

2. A refrigerating unit comprising a cabinet including a plurality of heat insulating Walls enclosing a storage chamber having an opening on one side, aplastic breaker strip section surrounding the periphery of said opening, a door hinged to one side of said cabinet, a heat insulating plastic section arranged around the periphery of said door and arranged to move into abutting relationship with said breaker strip section when said door is in the closed position across said openings, each of saidplastic sections having at least a portion thereof containing a pulverant ferrite material blended into the plastic material, said ferrite containing portions of said' plastic sections being magnetized to produce a magnetic flux emanating from pole faces on the surfaces of said portions, said ferrite containing portion of said heat insulat ing plastic section of said door having magnetic pole faces on the surface thereof opposite from the magnetic pole faces on the abutting'surface of said ferrite containing section of said cabinet so that said sections provide a closed magnetic path for maintaining said door in the closed position.

3. A refrigeration unit comprising a cabinet including a plurality of heat insulating walls enclosing a food storage chamber having an opening on one side, a heat insulating plastic section surrounding the periphery of said'opening, a door hinged to one side of said cabinet and pivotable across said opening, said door also having a heat insulating plastic section arranged around the periphery thereof, said heat insulating plastic section on said door including a protruding portion having the surface thereof adapted tov move into abutting relationship with a portion of said heat insulating plastic section of said cabinet when said door is in the closed position across'said opening, said protrudingportion adapted-to maintain a predetermined space between said door and the front of said cabinet, a soft flexible gasket extending outwardly from said door beyond'saidprotruding portion and disposed around the outer extremity'of said door for sealing the space between said door and said cabinet around the opening to said storage chamber, each of said heat insulatingfplastic sections havingat least their abutting: portions formed of a pulverahtferrite material blended into theplastic of said section, said abutting portions being magnetized to provide a magnetic flux for attracting one of said portions relative to the other so that a 'magn'eticforceis created for maintaining said door in the closed position relative to said cabinet with said 'soft flexible gasket sealing the space between said-door and said cabinet.

References 'Cited in the file ofthis' patent UNITED STATES PATENTS

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