US 3254503 A
Description (OCR text may contain errors)
June 7, 1966 w. G. RUNDELL 3,254,503
FROST PREVENTER FOR FREEZER APPARATUS Filed Dec. 29, 1964 2 Sheets-Sheet 2 INVENTOR WILLIAM G. RUNDELL ATTORNEY United States Patent O 3,254,503 FROST PREVENTER FOR FREEZER APPARATUS William G. Rundell, Smyrna, Del., assigner to Clark Equipment Company, a corporation of Michigan Filed Dec. 29, 1964. Ser. No. 421,890 6 Claims. (Cl. 62--275) This invention relates to improvements in freezer and refrigerator cabinet construction, and more particularly to electrical means mounted on the cabinet of a refrigerator or freezerfor preventing the formation of condensation and the freezing of condensation adjacent the doors thereof.
In the dispensing type of commercial freezer cabinets, a plurality of doors are usually provided which comprise closures for compartments in which refrigerated merchandise such as frozen foods are stored. The interior of a freezer cabinet is maintained at a low temperature, and despite' insulation the temperature adjacent the doors thereof is usually below the temperature of the surrounding air inasmuch as the refrigerated air chills the marginal portions `of the door, the door openings and the frame work of the cabinet adjacent the doors. As a result, condensation tends to form upon these parts which, in turn, leads to frosting which tends to cause the doors to adhere to the frame thus making it difficult to open and close the doors.
The -art has been cognizant of the above problem for many years, and various kinds'of heating means associated with the doors or cabinet of such freezer units have been previously provided for minimizing condensation.
One of the problems unsolved heretofore has been to provide in such refrigerating cabinets eliicient heating means, as aforesaid, which is relatively simple and inexpensive, while at the same time being combined with the refrigerating cabinet in a relatively unobtrusive location and being also readily serviceable without disassembly of parts of the cabinet extraneous to the heatl ingl means.
The invention disclosed herein is directed to a frost preventing device for refrigerator or freezer cabinets which is efficient, simple in construction, relatively in-` expensive, and which surrounds independently each of the compartment openings, being located intermediate,
to provide improved frost prevention apparatus for refrigerator and freezer doors and cabinets of the dispensing type.
Other objects, advantages and features of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing, wherein: v
FIGURE 1 is a front elevational view, broken away in part, of a standup type freezer unit which embodies my invention.
FIGURE 2 is a sectional view taken along line 2--2 of FIG. 1; and
FIGURE 3 is an enlarged perspective view of a section of the conduit and heating wire associated with the cabinet shown in FIGS. 1 and 2.
Referring now in detail to the drawings, numeral indicates a standup, two-door, commercialtype reachin freezer cabinet which is provided with, among other things, interior shelving, not shown, and a pair of vertically extending dispenser openings 12 closed by a pair of doors 14 suitably hinged at the outer edges thereof, as indicated at numerals 15. The usual refrigeration or freezer and wiring and control assemblies are contained within an upper cabinet portion 16, and a control panel 18 is located at the one forward corner thereof for controlling the operation of the freezer unit, including an on-off switch 20 which controls the operation of the heating device of the present invention. A vertical center strip 22 forms the inner margins of openings 12, being filled with suitable insulation 24, such as a foamed plastic material, and forms a vertically extending opening 26 which is covered by a breaker strip 28.
Each of the doors 14 includes a projecting peripheral por-tion 30 which extends completely around each door in overlapping relationship to the adjacent front wall portions of the Cabinet providing thereby a peripheral space 32 formed between the forward cabinet walls and the projecting portion 30 of each door. Each door has an interior wall 36 suitably connected to a bracket member 38 which extends completely around the door and is secured to a wall portion of the outer section of the door, as shown in FIG. 2. The interior of each door is filled with an insulating material of any suitable kind. A flexible gasket and bumper member 40 is secured to bracket 38 and encloses a magnetic element 42 located on each door for securing it in a closed position in known manner.
A moulding track 46 is secured to the forward Wallv of the cabinet by any suitable means, such as metal screws, and surrounds completely each of openings 12, said moulding track being located in space 32 outwardly of the periphery of each opening 12 and inwardly of the outer edge of overlapping projecting portion 30 of each door 14. A snap-on curved moulding member 48 of a flexible metal material is adapted to engage in snap-on fashion forwardly extending curved side portions. 50 of the moulding track so as to form a conduit 51 for receiving a heating or resistor wire 52 having an insulator 54. sections which are spliced together at the ends thereof by splicer brackets or clips 56. The heating wire 52 extends through openings, not shown, located in the rear of the clips 56 which are located above openings 12 of the respective doors, and extend into the upper portion 16 of the cabinet for connection to a source of electricity, the heating wire circuit of which is controlled by switch 20. The hinge 15 of each door is located outwardly of the vertical outer portion of the respective conduit 51 which is adjacent and parallel to the hinge so that said outer conduit portion is exposed when the door is substantially fully open, thereby permitting servicing of the heating wire in each said outer conduit portion without removing the door.
In operation, the electrical conductor which connects heating wires 52 to the electrical supply is controlled by switch 20 to provide sufficient heat to the conductive conduit 51 and the portion of the cabinet within space 32 adjacent each opening 12 to increase the temperature thereof suiiiciently to prevent the formation of any ice or frost thereon and dry any condensation that may have accumulated on the surface thereof, thus preventing the freezing of condensation between the sealing gasket of the door, as shown at 40 and 42, and the adjacent surface of the cabinet.
From the foregoing it will be noted that my invention provides a relatively simple, low-cost heating apparatus for the purpose specied, the conduit portion of which is conveniently located outside of the cabinet in a space provided between the forward cabinet walls and the peripheral portion of the door so that the complete heating wire assembly is hidden from the View of an observer located in the front `of the cabinet whenever the doors Conduit 51 preferably comprises a plurality of are closed. Furthermore, the snap-on conduit construction 51 may be readily disassembled for servicing the heating wires merely by opening the doors of the freezer, removing two or more of the splice clips 56, and then removing thek snap-on mo-ulding sections 48 to expose whatever portion Vor portions of the heating wires it is desired to examine, service or replace. Heretofore it has not been possible togain -access to the heating wires of externally heated refrigerator or freezer cabinet units without first disassembling portions of the unit, such as -by first removing the doors from the cabinet portion of the unit.
The present invention provides 1a number of advantages and improvements over the prior art, and it will now be apparent to those skilled in the art that various changes in the structure and relative arrangement of parts may be made without departing from the scope of my invention.
1. In arefrigerated cabinet having an opening in a wall thereof and a hinged door comprising a closure for said opening which includes a peripheral por-tion extending in forward overlapping relation to the marginal portion `of the cabinet wall adjacent the opening and means extending about the opening Iand sealing between the cabinetwall and the door in a closed position, a conduit secured to the wall of the cabinet which surrounds the open-- ing in the wall at a location with the space formed by the peripheral -portion of the. door overlapping the cabinet Wall, the outer vertical run of said conduit being located transversely inwardly of the door hinge and the inner vertical run yof said conduit being located transversely outwardly of the sealing means, and an electric heating element extending through said conduit for preventing the formation -of condensation on the cabinet Wall.
2. In a refrigerated cabinet having an opening in a wall thereof and a hinged door comprising a closure for said opening which includes la peripheral portion extending in forward overlapping relation to the marginal portion of the cabinet wall adjacent the opening, a track- Way secured to the wall of the cabinet which surrounds completely said opening and which is located inwardly -of the outer edges of the door in closed position, snapon means registrable with said trackway for forming a conduit, and an electric heating element extending through said conduit and connected to a power source for heating the outer cabinet wall in the area adjacent the opening thereof.
3. A refrigerated cabinet as claimed in claim 2 wherein the outer vertical portion of said conduit is located transversely inwardly of the door hinge so that when the door is in an open position the snap-on conduit portion is removable from the trackway.
4. A refrigerated cabinet as claimed in claim 2 wherein said conduit is formed of .a plurality of sections, and means for securing together the opposed ends of said sections to form a continuous conduit.
5. In a refrigerated cabinet, an opening in a wall thereof, a hinged door comprising a closure for said opening including a peripheral portion extending in forward yoverlapping lrelation to the marginal portion of the cabinet wall adjacent the opening, an electrical conduit Secured to the exterior of the cabinet wall, surrounding said opening Iand ilocaited inwardly of fall outer edges of theV door iso as to be hidden from the View of an observer when the door is closed, and `an electric heating element in said conduit for heating the cabinet wall, said conduit being delined by -a pair of elongated elements at least one of which is of general channel section, a first of said elements being fastened to the wall and the second being frictionally engaged therewith.
6. A refrigerated cabinet having a pair of transversely spaced and vertically extending openings in a wall thereof, a pair of hinged doors comprising closures for said openings, each of said doors including a peripheral portion extending in overlapping relation to the portion of the cabinet wall adjacent the respective openings, conduit means secured to the cabinet wall surrounding each opening. each said conduit means being located in the space provided between the cabinet wall and 4the overlapping peripheral portion of each door so that with the doors closed neither of said conduits is readily visible, and an electric heating element in each of said conduits for preventing'the formation of frost or condensation on said cabinet wall.
References Cited by the Examiner UNITED STATES PATENTS 1,141,188 6/1915 Johnson 189 85 2,420,240 5/1947 Haggerty 62-275 2,449,384 9/1948 Hursey 62-275 2,731,804 1/1956 Gfuhhs 62-275 2,807,942 10/1957 Dahigreh 26-275 2,809,402 10/1957 Southworth 20-35 WILLIAM J. WYE, Primary Examiner.