Claims
- 1. A refrigerator door assembly mountable within the opening in the wall of a refrigerated cabinet comprising
- a door mounting frame having an outer peripheral portion mountable within said cabinet opening,
- a plurality of insulated doors mounted for pivotal movement on said frame,
- said frame including at least one mullion extending between top and bottom sides thereof and against which said doors close,
- said mullion including a first metallic structural frame member,
- a plastic insulating plate positioned rearwardly of said first metallic frame member.
- said mullion including a first metallic structural frame member,
- a plastic insulating plate positioned rearwardly of said first metallic frame member,
- a metallic channel shaped frame member having forwardly directed legs engageable with said insulating plate, and
- means extending through said plastic insulating plate positively interconnecting said first and channel shaped frame members with said plastic insulating plate interposed therebetween.
- 2. The refrigerator door assembly of claim 1 in which said insulating plate defines a rearwardly opening channel within which said channel shaped frame member is mounted.
- 3. The refrigerator door assembly of claim 1 in which said first structural frame member and said channel shaped frame member are made of different materials.
- 4. The refrigerator door assembly of claim 3 in which said first structural frame member is made of aluminum, and said channel shaped frame member is made of steel.
- 5. A refrigerator door assembly mountable within the opening in the wall of a refrigerated cabinet comprising
- a door mounting frame having an outer peripheral portion mountable within said cabinet opening,
- a plurality of insulated doors mounted for pivotal movement on said frame,
- said frame including at least one mullion extending between top and bottom sides thereof and against which said doors close,
- said mullion including a first metallic structural frame member,
- a second metallic frame member disposed rearwardly of said first frame member,
- a magnetically attractable sealing plate positioned forwardly of said first frame member against which said doors close,
- non-metallic insulating and retaining means surrounding said first structural frame member and supporting said sealing plate in thermally isolated relation to a front side of said first structural frame member,
- said insulating and retaining means including an insulating plate between said first and second frame members, and
- means interconnecting said first and second frame members with said insulating plate secured therebetween separating said first frame member from said second frame member.
- 6. The refrigerator door assembly of claim 5 in which said insulating and retaining means define air insulating spaces adjacent forward and opposite lateral sides of said first structural frame member.
- 7. The refrigerator door assembly of claim 5 in which said interconnecting means includes a stud connected between said frame members.
- 8. The refrigerator door assembly of claim 5 in which said insulating and retaining means includes means defining a front wall adjacent a front side of said first structural frame member and means defining side walls adjacent opposed lateral sides of said structural frame member, and said insulating plate is engageable with said side walls.
- 9. The refrigerator door assembly of claim 8 in which said side walls include means for releasably engaging and supporting said sealing plate in outwardly spaced relation to the front wall of said insulating and retaining means.
- 10. The refrigerator door assembly of claim 5 including a rigid plastic spacer plate interposed between said sealing plate and a front side of said first structural frame member, first fastener means connecting said spacer plate to said first structural frame member without contact with said sealing plate, and second fastener means connecting said sealing plate to said spacer plate without contact with said first structural frame member.
- 11. The refrigerator door assembly of claim 10 including a door accessory mounted on said sealing plate, and accessory fastener means for connecting said accessory to said spacer plate without contacting said first structural frame member.
- 12. The refrigerator door assembly of claim 5 in which said second frame member is a C-shaped channel having forwardly directed legs engaging said insulating plate.
- 13. The refrigerator door assembly of claim 12 in which said first structural frame member has a central hollow portion which defines a central air insulating space and outwardly extending flanges on opposed sides thereof.
- 14. The refrigerator door assembly of claim 13 in which said first frame member is made of aluminum, and said second frame member is made of steel.
- 15. A refrigerator door assembly mountable within the opening in the wall of a refrigerated cabinet comprising
- a door mounting frame having an outer peripheral portion mountable within said cabinet opening,
- a plurality of insulated doors mounted for pivotal movement on said frame,
- said frame including at least one mullion extending between top and bottom sides thereof and against which said doors close,
- said mullion including a first metallic structural frame member,
- a plastic insulating plate positioned rearwardly of said first metallic frame member,
- a metallic channel shaped frame member having forwardly directed legs engageable with said insulating plate, and
- means for interconnecting said first and channel shaped frame members with said plastic insulating plate interposed therebetween,
- said mullion including a forwardly positioned magnetically attractable plate against which said doors close, and
- non-metallic insulating and retaining means for supporting said sealing plate in thermally isolated relation to a front side of said first structural frame member.
- 16. The refrigerator door assembly of claim 15 in which said insulating and retaining means includes non-metallic means which encapsulate said first structural frame member.
- 17. The refrigerator door assembly of claim 16 in which insulating and retaining means define air insulating spaces adjacent forward and opposite lateral sides of said first structural frame member.
- 18. The refrigerator door assembly of claim 17 in which said insulating and retaining means includes said insulating plate and defines an air insulating space between said channel shaped frame member and a rear side of said first structural frame member.
- 19. The refrigerator door assembly of claim 17 in which said insulating and retaining means includes said insulating plate, and said insulating plate is rigidly interposed between said forwardly directed legs of said channel shaped frame member and said first structural frame member.
- 20. The refrigerator door assembly of claim 36 in which said insulating and retaining means includes means defining a front wall adjacent a front side of said first structural frame member and means defining side walls adjacent opposed lateral sides of said structural frame member, and said insulating plate is engageable with said side walls.
- 21. The refrigerator door assembly of claim 20 in which said side walls include means for releasably engaging and supporting said sealing plate in outwardly spaced relation to the front wall of said insulating and retaining means.
- 22. The refrigerator door assembly of claim 21 in which said side walls are formed with opposing channel shaped terminal ends for captively receiving opposed lateral sides of said sealing plate.
- 23. The refrigerator door assembly of claim 22 in which said side walls of said insulating and retaining member include first side walls extending rearwardly of the front wall of said insulating and retaining means at locations closely adjacent the opposed lateral sides of said structural frame member and second side walls disposed in outwardly spaced relation to said first side walls for defining air insulating spaces adjacent said lateral sides of said structural frame member.
- 24. The refrigerator door assembly of claim 23 in which said sealing plate retaining channels of said insulating and retaining member are formed at the forward terminal ends of said second side walls.
- 25. The refrigerator door assembly of claim 24 including fastener means for releasably connecting said first and second side walls to prevent disengagement of the opposite lateral sides of said sealing plate from said side wall channels.
- 26. The refrigerator door assembly of claim 15 including a rigid non-metallic spacer plate interposed between said sealing plate and said front wall of said first structural frame member, first fastener means connecting said spacer plate to said first structural frame member without contact with said sealing plate, and second fastener means connecting said sealing plate to said spacer plate without contact with said first structural frame member.
- 27. The refrigerator door assembly of claim 26 including a door accessory mounted on said sealing plate, and accessory fastener means for connecting said accessory to said spacer plate without contacting said first structural frame member.
- 28. The refrigerator door assembly of claim 26 in which said spacer plate is made of rigid plastic material.
- 29. The refrigerator door assembly of claim 36 in which said insulating and retaining means includes a channel shaped member having a front wall disposed in closely adjacent relation to a front side of said structural frame member and rearwardly directed side walls, and a cover plate which includes said insulating plate engageable with said rearwardly extending side walls for closing a rear side of said insulating and retaining means channel member.
- 30. A refrigerator door assembly mountable within the opening in the wall of a refrigerated cabinet comprising
- a door mounting frame having an outer peripheral portion mountable within said cabinet opening,
- a plurality of insulated doors mounted for pivotal movement on said frame,
- said frame including at least one mullion extending between top and bottom sides thereof and against which said doors close,
- said mullion including a first metallic structural frame member,
- a plastic insulating plate positioned rearwardly of said first metallic frame member,
- a metallic channel shaped frame member having forwardly directed legs engageable with said insulting plate, and
- means including a stud connected between said first structural frame member and said channel shaped frame member for interconnecting said first and channel shaped frame members with said plastic insulating plate interposed therebetween.
- 31. The refrigerator door assembly of claim 30 in which said stud includes a head intermediate its ends for forcing and retaining said insulating plate against a rear side of said structural plate against a rear side of said first structural frame member.
- 32. The refrigerator door assembly of claim 31 in which said stud has a forward end in engagement with said first structural frame member and a rear end extending through said channel shaped frame member, and a fastener engageable with said rear end of said stud for retaining said channel shaped member against said insulating plate.
- 33. A refrigerator door assembly mountable within the opening in the wall of a refrigerated cabinet comprising
- a door mounting frame having an outer peripheral portion mountable within said cabinet opening,
- a plurality of insulated doors mounted for pivotal movement on said frame,
- said frame including at least one mullion extending between top and bottom sides thereof and against which said doors close,
- said mullion including a first metallic structural frame member having a central hollow portion which defines a central air insulating space and outwardly extending flanges on opposed sides thereof,
- a plastic insulating plate positioned rearwardly of said first metallic frame member,
- a metallic channel shaped frame member having forwardly directed legs engageable with said insulating plate, and
- means for interconnecting said first and channel shaped frame members with said plastic insulating plate interposed therebetween.
- 34. The refrigerator door assembly of claim 33 in which said structural frame member hollow portion has an elongated cross sectional configuration with one long side thereof defining a front face of said structural frame member and a second long side defining a rear face of said structural frame member.
- 35. The refrigerator door assembly of claim 34 in which said outwardly extending flanges of said structural frame member extend outwardly from said hollow section with front sides thereof in substantially coplanar relation to said front face of said structural frame member.
DESCRIPTION OF THE INVENTION
This is a continuation in part of application Ser. No. 131,182, filed Dec. 10, 1987 Pat. No. 4,852,303.
The present invention relates generally to door assemblies for commercial refrigerators and freezers, and more particularly, to an improved more thermally efficient mullion for the door mounting frame of such door assemblies.
Insulated glass door assemblies, such as used in commercial refrigerators and freezers in supermarkets and the like, generally comprise a plurality of insulated glass doors mounted for swinging movement in a door mounting frame, which in turn is mounted within the opening of a wall of a refrigerator cabinet or the like. The door mounting frame extends about the periphery of the opening in the cabinet wall and includes one or more mullions that extend vertically between the top and bottom perimeters of the frame to provide rigidity for the frame and a sealing surface against which the swinging sides of the doors engage when closed.
Because the insulated doors usually comprise a plurality of glass panes, they are relatively heavy and require a sturdy and rugged frame for supporting their weight and for withstanding abusive repeated opening and closing that occurs in commercial establishments. The mullions, therefore, typically include a metal structural frame member, such as an aluminum extrusion, which is highly heat conductive. Moreover, in order to provide a magnetically attractive sealing surface against which a door mounted magnetic gasket is engageable for establishing reliable sealing contact, it is common to affix a metal sealing plate to the front of the mullion.
For ensuring reliable contact of the magnetic gasket with the sealing strip, notwithstanding adjustable mounting of the door in the frame, the sealing strip typically is sized larger than the magnetic gasket, and indeed, generally extends completely across the width of the mullion so that it serves as a sealing surface for doors mounted on both sides thereof. As a result, even when the doors are in their closed positions, the metal sealing plate on the mullion often extends between the ambient air and refrigerated sides of the sealing gasket. If preventative measures are not taken, portions of the sealing plate exposed to the ambient air for prolonged periods will cool below the dew point temperature of the ambient air, resulting in the formation of frost on the surface of the sealing plate. Further frosting problems result when metal accessories, such as lock plates, lighting fixtures, or the like are affixed to the mullion. In an effort to prevent such frost buildup, it has been the practice to electrically heat the metal frame and sealing plate so as to maintain exposed portions of the sealing plate and accessories above the dew point temperature of the ambient air. Such electrical heating can significantly increase the operating cost of the refrigerator or freezer unit.
While considerable efforts have been directed toward combating condensation build up and minimizing heating requirements, such as by insulating the frame or interrupting the heat conductive path through the frame by means of thermal barriers or breaks, these efforts have not been entirely successful and often complicate the manufacture of the frame. For example, one approach has been to create a thermal break in the door mounting frame by forming the aluminum extrusion with a channel shaped opening, pouring hot melt plastic material into the opening which solidifies in intimate contact with the channel, and thereafter severing the channel to separate the frame into independent sections separated by the solid plastic. Such procedure is highly time consuming, and hence, significantly adds to the manufacturing cost of the product. Proposals to change the material of the frame so that it is less expensive or less heat conductive generally have not been adopted, usually by reason of strength considerations and the desire that the frame have an attractive metal finish consistent with existing commercial freezers and refrigerators.
It is an object of the present invention to provide an improved, more thermally efficient mullion for the door mounting frame of commercial refrigerator and freezer door assemblies. A related object is to provide such a mullion that has relatively high strength and rigidity and is adapted for condensation-free use in commercial refrigerator and freezer units with reduced electrical heating requirements.
Another object is to provide a mullion of the above kind which has a thermal break between separate inner and outer structural frame members of the mullion. A related object is to provide such a mullion which is of relatively simple construction and lends itself to economical manufacture.
A further object is to provide a mullion as characterized above which includes a magnetically attractive sealing plate mounted in thermally isolated relation to the structural frame members.
Still a further object is to provide a mullion of the foregoing type that includes a sealing plate mounting means which encapsulates a forwardmost structural frame member for thermally insulating the sealing plate from the refrigerated zone.
Yet another object is to provide such a mullion which permits secure, thermally-insulated mounting of metallic accessories, such as door lock plates, lighting fixtures, and the like.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:
FIG. 1 is perspective of a refrigerator door assembly having a door mounting frame with a mullion in accordance with the present invention;
FIG. 2 is an enlarged fragmentary section taken in the plane of line 2--2 in FIG. 1, showing the mullion of the present invention with the free swinging sides of a pair of doors on opposed sides thereof in their closed position;
FIG. 3 is an enlarge partial plan view of a front of the illustrated mullion, showing accessories mounted therein;
FIG. 4 is a fragmentary vertical section of the illustrated mullion, taken in the plane of line 4--4 in FIG. 3;
FIG. 5 is a fragmentary transverse section of an alternative embodiment of a mullion in accordance with the present invention, with the free-swinging sides of a pair of doors shown in phantom in their closed position on opposed sides of a front side of the mullion;
FIG. 6 is an enlarged partial plan view of a front side of the mullion shown in FIG. 5, showing an accessory mounted thereon; and
FIG. 7 is a fragmentary section, taken in the plane of line 7--7 in FIG. 6.
US Referenced Citations (3)
| Number |
Name |
Date |
Kind |
|
3673735 |
Winsler et al. |
Jul 1972 |
|
|
4815245 |
Gartner |
Mar 1989 |
|
|
4831780 |
Bockwinkel |
May 1989 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
| Parent |
131182 |
Dec 1987 |
|
Patent Grant
4941289
