US 2858408 A
Description (OCR text may contain errors)
Oct. 28, 1958 L F. BARROERO 2,858,408
REFRIGERATED FREEZER CABINETS HAVING HEATED DOOR FRAMES AND DOORS THEREFOR Filed 091:. 25, 1957 II I VII/Illa I Ii 3 33 -7 Z2 INVENTOR. 7 "I/IIIII/ tau/s AfiIPPOEPO 4 I a 50 M W M ing past the door edges into the cabinet.
United States Patent Louis F. Barroero, San Leandro, Application October 25, 1957, Serial No. 692,486
1 Claim. (Cl. 219-19) This invention relates 'to refrigerated freezer cabinets and more particularly to a refrigerated freezer cabinet having heated doors and door frames.
Refrigerated freezer display cabinets have come into extensive use in grocery stores and the like for storage, display and sale of frozen foods. However, most such cabinets have been of the top opening variety rather than of an upright type with front opening doors, primarily because of the difliculty of maintaining the doors of such upright cabinets free from ice.
Although upright refrigerator cabinets with front opening doors have been used for years in the handling of non-frozen foods, it has been found that such an arrangement could notbe eifectively used when frozen foods are to be handled, because of the tendency for the doors to ice up and resist easy opening. I have found that such icing is a result of maintaining the inside of the cabinet at a temperature below freezing, and also that it is practically impossible to prevent air from leak- As a'result, the relatively warm room air contacts portions of the door and door frame which are held below freezing by the low temperature inside the cabinet, and the incoming air cools to condense the water therein on the door and door frame, which water then freezes into ice, causing the door to stick to the door frame. This elfect is noted to some extent in front opening cabinets having swinging doors, but is much more prevalent in sliding doors, as the doors are much harder to seal against air flow therepast. Furthermore, in sliding doors, ice will tend to form on the trackways and guides on which the doors slide, again preventing easy door opening.
I have found that the objectionable icing of vertically A disposed freezer doors can be eliminated by embedding heating elements around the peripheries of the door frame and the doors to maintain the temperature of the contacting surfaces thereof above the freezing temperature of water. With these surfaces maintained above the freezing point, air leaking between the doors and door frames will not condense and freeze on the doors and door frames. With this problem eliminated, the primary drawback to the successful use of front opening freezer cabinets is removed.
It is the primary object of this invention to provide a vertically disposed freezer cabinet having a front opening door fram and door with means to heat the said frame and door to prevent icing therebetween.
It is a further object of the invention to provide a freezer cabinet having a door frame and a front opening door therefor with means to heat said frame and door around the peripheries thereof to prevent icing thereof by air leaking therepast.
Other objects and advantages will become apparent in the course of the following detailed description.
In the drawings, forming a portion of this application, and in which like parts are designated by like reference numerals throughout the same,
Fig. 1 is a front elevational view of a refrigerator Patented Oct. 28, 1958 2 cabinet and a door assembly embodying the principles of the invention. i
Fig. 2 is a sectional view taken on line 2--2 of Fig. 1.
Fig. 3 is a sectional view taken on line 3-3 of Fig. 1.
Fig. 4 is a sectional view taken on line 4-4 of Fig. 1.
Referring now to the drawings, the reference numeral 10 designates generally a vertically disposed refrigerated freezer cabinet in which door frame 11 is mounted in the front wall thereof. The vertically disposed door frame 11 is metallic, preferably aluminum, and comprises upper and lower frame members 12 and 13, and two side members 14 and 16. Two sliding doors 17 and 18 are mounted in door frame 11 for sliding movement relative thereto in a manner to be hereinafter described.
The sliding doors 17 and 18 are constructed generally in accordance with my prior Patent No. 2,701,395, ,entitled Refrigerator Door, issued February 8, 1955, whereby each door has upper and lower channel members 21 and 22 and side channels 23 and 24, and a double paned glass window 26. The channel members 21, 22, 23 and 24 are metallic and preferably aluminum. A handle 27 is attached to each door to enable the. doors to be opened.
A roller assembly 28 fits within a dovetailed groove 29 formed longitudinally in the upper door channel 21 and has its roller riding in a depending trackway 31 formed integrally with the upper frame member 12 of door frame 11, so that the door may slide open relative to the frame. Two such roller assemblies 28 are'provided for each door, each roller assemblybeing disposed'adjacent a side edge of the door. The lower door channel member 22 has a similar longitudinal groove 32 slidably embracing the longitudinally extending rib or track member 33 formed on the lower; door frame member'13, to properly guide the door in its opening and closing movement. Door 18 is similarly suspended from trackway 34 and guided by rib 36.
Each of the door channel members 21, 22, 23 and 24 has therein a thermally non-conductive core, preferably a wood fillet, 37, 38, 39 and 40, respectively. Insulated sealing strips 41, 42, 43 and 44 are applied to the rear surfaces of these wooden fillets, as illustrated, with sealing strip 44 being provided with rearwardly extending ribs 46 to engage door 18 and seal oflf air flow therebetween when the doors are closed.
The door frame 11 is mounted to the cabinet 10 with a Z-shaped insulation strip 47 interposed therebetween. As shown in Fig. 3, an insulating strip 48 extends along the door frame member 14, to be engaged by door 17 when the latter is in closed position, to prevent air flow therebetween, and also to cushion the door upon closing thereof.
A plurality of electrical resistance heating elements 51 are wound around the periphery of the door frame 11 in generally parallel spaced relationship, these elements being held in heating contact or engagement with the door frame by the insulating strip 47. Although four such elements are shown in the drawing, it is contemplated that more or less than this number may be employed, if desired. The heating elements 51 can be connected in series or parallel arrangement, again as desired, and are then connected to a suitable electric power source by suitable means (not shown). It will be noted that all of the heat generated in these resistance elements will be absorbed by the door frame, as the insulating strip 47 will prevent heat flow from the heating elements 51 to the body of the cabinet 10.
The doors 17 and 18 are also provided with heating means embedded around the peripheries thereof. As will be seen in the drawings, the wooden fillets 37, 38, 39 and 40 have longitudinally extending grooves 52, 53, 54 and 55, respectively, therein adjacent the top, bottom and sides of the doorchannels 21, 22, 23 and 24, respectively,
.,-.Similarly,'"the frameheating elements 51 associated to .receive the electrical v resistance hea'tingelements 56, which thus surround the door. Again, although two such resistance elements are shown, more or less than this number may be employed, if desired. The heating eledesired, and are then connected by a flexible electrical cord (not shown) to a sourceiof electrical power.
I As will be seen in Fig. 2, the top frame member 12 will be heated by the heating elements 51, with the heat being conducted through the metal frame to heat the trackways 31 and 34. The heating elements'56 in the top channel 21 of the door will heat the channel 21, such heat I being conducted upwardly to the roller assembly 28. This combined heating willthen prevent; any icing of the trackways or the rollers so that the door may be easily with the loweriframemember 13will heat the guide. ribs 33am 36, while the door heating elements 56 will heat }the' lowen-door channel 22jto prevent any icing of the ribs or the-door channel.
In like-manner, the sideframe'member 14..and the M side door channel-23r are-both heated to prevent any ice from formingbetween the door and theframe which wouldv prevent'opening of the-doors. Also, the side channel member 24 of door 17 and the side channel 23 of door 17 are both heated so that no ice may form therebetween when the doors are closed, again preventing the doors .fromfreezing together when closed.
It is to beunderstood that the'doorframe and doors the dors,:alone, although thebest results will be obtained by the heating of both.
'4 The form of the invention shown" herein is a preferred embodiment of the same, and various changesmay be made in the shape, size and arrangement of parts without departing from the.spirit of the invention or the scope of the attached claim.
Having thus described my invention, what I claim and desire to secure by Letters Patent is:
A refrigerated freezer cabinet, a vertically disposed metallic door frame mounted in the front wall of 'said cabinet, a heat insulating strip disposed around said door frame and between said door frame and said front wall, upper and lower track members formed on said door frame, a pair of doorseach'having a'metallic periphery and a longitudinal groove along the bottom side thereof, roller members carried by the upper sides of said doors, said doors being mounted-in said door frame with said roller members engaging said upper track members and said groove embracing said lower track members for guided sliding movement of saiddoors in said door frame, an -electrical.resistance'element 'disposed.around the periphery of said'door'frameIand between said door frame and said insulating strip .to. heat said door frame and said track members formed thereon, and an electrical resistance element embedded in each of said doorsaround the peripheries thereof in heating relation to said metallic peripheries, 'rollermembers and grooves.
" ReferencesCited in the file of this patent UNITED STATES PATENTS 1,561,290 Wicke Nov. 10, 1925 1,894,205 Stollsteimer Jan. 10, 1933 2,400,168 Roach May 14, 1946 2,460,469 Rifkin et al Feb. 1, 1949 2,515,294 w Cowgill July 18, 1950 2,690,585 Nordahl Oct. 5, 1954 2,701,395 Ba'rroero Feb. 8, 1955 2,731,804 Grubbs "1. Jan. 24,- 1956 2,811,406 Moore et a1 Oct. 29, 1957