US 3786613 A
The shell of a sheet metal door is formed of two opposed wide, shallow trough-like members each having opposed edge layers folded back upon one another to provide greater thicknesses of metal at the edges than at the panels.
Description (Le texte OCR peut contenir des erreurs.)
Umted States Patent 1 1111 Shepheard Jan. 22, 1974  SHEET METAL DOOR WITH FOAM 1,163,913 12/1915 Hargrave et a1. 52/615 PLASTIC CORE 1,163,914 12/1915 Hargrave et al. 52/619 2,103,407 12/1937 Dean 52/461 Inventor: lham L. Shepheard, 3040 Broad 3,153,817 10/1964 Pease 52/6l9 Creek St., Norfolk, Va.
[22 i June 9, 1972 Primary Examiner-Henry C. Sutherland pp No: 261,425 Asststant HExaminerJames L. Ridgill, Jr.
 ABSTRACT  US. Cl. 52/619, 52/627 The shell of a Sheet metal door i formed f two  lltt. C1. E061) 3/70, E046 2/40 posed wide, Shallow trough like members each h i  Fleld of Search 52/615-623, 459, opposed edge layers f ld d back upon one another to 52/460 627 provide greater thicknesses of metal at the edges than at the panels.  References Cited UNITED STATES PATENTS Shean 52/749 3 Claims, 3 Drawing Figures SHEET METAL DOOR WITH FOAM PLASTIC CORE FIELD OF INVENTION Static Structures, e.g., Buildings, Composite Panel Having Disparate Edging Or lmperforate Face, Inturned Opposed Flanges Form Panel Edge.
PRIOR ART Ohnstrand 786,593; Pease, .lr. 3,153,817; Privas 3,336,713.
OBJECTS In the construction of sheet metal shell, foam plastic core doors, itis generally necessary to form the edges of relatively heavy gauge metal, at least 18 gauge, which is 0.0478 inches thick, so as to withstand the forces-which tend to bend or dent the door, and to provide a sufficiently rigid base for the door hardware. If, as in the present case, the door shell is to be formed of two opposed wide, shallow trough-like-members whose edges are only abutted with minimal contact and not actually joined, 'so as to provide a thermal break, and if the troughs are each formed of a single sheet, the metal that is of sufficient thickness for the edge portion is overly thick for the panels, i.e., the planar portions bonded by the edge portions. This not only makes the door unnecessarily heavyybut results in a waste of metal and excess cost. The object now is to provide a door shell formed of two opposed trough-like members wherein the panel portions are formed of a single layer of a sheet of metal, and wherein the vertical edge portions are formed of two or more layers of the same sheet, which layers are formed by folding the sheet back upon itself to providethe desired numberof layers. Assuming the sheet is 24 gauge, or'0.0239 inch, the edge portions can, by one doubling, be made 0.0478 inch, which is equivalent to 18 gauge or, by folding to provide a thirdlayer, a thickness of an effective 14 gauge can be achieved.
Another object of the invention relates to the use of a foam plastic core for a sheet metal shell door. The vertical edge portions of the .door are so folded as to terminate in wing-like members which project inwardly into the interior of the door and diverge away from one another so that the plasticcore, which is foamed into the door interior between the opposed pan-like shells, will form an interlock with the divergent wings and hold the opposed shells with extra strength against spreading at their edges. It is intended also to provide channel members which fit between the opposed pans to form the top and bottom edges of the door, and
which have slotted angles at their ends so as to fit over the divergent wings of the vertical edges and thereby lock the two shallow trough-like members together.
These and other object will be apparent from the following specifications and drawing, in which:
FIG. 1 is a perspective view of the door;
FIG. 2 is an exploded view of one end of the door before foaming in of the core and with an end plate before installation; and,
FIG. 3 is a fragmentary cross-section along the line 3-3 of FIG. 1.
Referring now-to the drawings, in which like reference numerals denote similar elements, the hollow sheet metal door 2 is comprised of opposed spaced panels 4a and 4b which constitute the door sides and which terminate in vertical edge portions 6a and 6b and horizontal edge portions 8a and 8b.. The hollow interior of the door is filled with foam plastic 10, such as polyurethane which is foamed in place.
The door shell is formed of two wide, shallow troughlike members 12 each formed of a flat sheet of metal which is bent over along opposed edges to form a right angle flange 14, the free portion of which is bent back to form an acute angle flange 16. As will be seen from FIGS. 2 and 3, the layers which form these flanges are bent back upon one another so that the acute angle flange has an outer layer 16a and an inner layer 16b. Likewise, the right angle flange 14 has an outer layer 140 and an inner layer 14b which is formed by the metal which has been bent back upon it, this metal being further bent back to form an inner layer 12b which lies againstthe inner side of the outer layer from which the panel 12 is formed. Thus the thickness of the metal is doubled at the edge portions and along the panel adjacent the edge portions. If, for example, the panel areas are formed of 24 gauge metal, the portions of the door adjacent the vertical edges are provided of a metal thickness equivalent to 18 gauge.
From FIG. 3 it will be apparent that the continuity of the metal from side to side of the door is broken so that the heat transfer from one side of the door to the other is minimal. The plastic which is foamed into the door interior when the opposed sides are supported in a suitable fixture or jig interlocks with the opposed wing-like acute angle flanges 16 so as to hold the two sides of the door firmly together.
The top and bottom edge portions of the door are each formed by a channel 18 which fits between the two trough-like members 12. Each channel 18 has opposed side flanges 20 which are offset inwardly as at 22 to accommodate the added thickness of the inner layers 12b adjacent the edges of the panels 12. The ends of the channels have down-turned flanges 24 which have slots 26 which engage over the bases of the winglike acute angle flanges 16 so as to hold the trough-like members 12 firmer together against any tendency to spread or rack.
If desired, the sheet metal at and adjacent the vertical edge portions of the door can be doubled back upon itself a third or even a fourth time if such additional thickness is desired. Obviously, channels 18 can be formed of metal or whatever gauge is desired at the top and bottom edge portions of the door.
1. In a door, a shell formed of sheet metal, said shell comprising an opposed pair of wide, shallow trough-like members, each having a panel portion and an opposed pair of vertical edge portions integral therewith, each edge portion being comprised of a first flange forming a right angle with the panel portion, and a second flange extending inwardly of the trough-like member from the first flange and forming an acute interior angle therewith,
the metal forming said flanges and the portions of said panel portions adjacent the vertical edge portions being of at least double thickness and the remainder of said panel portions being of single thickness,
4 said opposed end flanges engaging against inner sides of the first flanges, the end flanges of said channels having slots therein accommodating the divergent second flanges at junctures thereof with said first flanges.
2. In a door as claimed in claim 1, foam plastic filling the interior of said door and fonning a unitary mass around divergent second flanges.
3. In a door as claimed in claim 2, the opposed longitudinal side flanges of said channels being offset inwardly adjacent opposite end portions thereof and accommodating the double thickness of the panel portions adjacent vertical edges thereof.
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