U.S. patent number 3,786,609 [Application Number 05/216,053] was granted by the patent office on 1974-01-22 for cored insulated door.
This patent grant is currently assigned to Acorn Products Company. Invention is credited to Joseph Difazio.
United States Patent |
3,786,609 |
Difazio |
January 22, 1974 |
CORED INSULATED DOOR
Abstract
A slab door formed of a wood frame having a wide, deep,
vertically extending groove formed in the exposed edges of each of
the opposite vertical frame stiles, and each face of the frame
being covered by a thin sheet of metal whose opposite vertical
edges are bent into flanges covering the stile edges and loosely
extending into their adjacent groove. The adjacent pair of flange
portions within each groove are spaced apart and bonded together by
a plastic filler material. Thus, a rigid slab unit is formed by the
sheets of metal bonded together at their vertical edge flanges and
adhesively secured to the frame, with the sheets being thermally
insulated from each other by the plastic material which also seals
the vertical edges of the slab against moisture penetration.
Inventors: |
Difazio; Joseph (Warren,
MI) |
Assignee: |
Acorn Products Company
(Detroit, MI)
|
Family
ID: |
22805476 |
Appl.
No.: |
05/216,053 |
Filed: |
January 7, 1972 |
Current U.S.
Class: |
52/784.13;
52/794.1; 52/309.5; 52/309.9 |
Current CPC
Class: |
E06B
3/825 (20130101); E06B 2003/7023 (20130101) |
Current International
Class: |
E06B
3/82 (20060101); E06B 3/70 (20060101); E04b
001/68 (); E04b 002/28 () |
Field of
Search: |
;52/615,619,620,573,398,399,403 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,066,229 |
|
Apr 1967 |
|
GB |
|
1,227,345 |
|
Mar 1960 |
|
FR |
|
402,353 |
|
Nov 1965 |
|
CH |
|
Primary Examiner: Sutherland; Henry C.
Attorney, Agent or Firm: Cantor; Bernard J.
Claims
Having fully described an operative embodiment of this invention, I
now claim:
1. In an insulated sheet metal slab door formed of a rectangular
shaped wood frame comprising a pair of vertical stiles joined
together at their upper and lower edges by horizontal rails, with
the opposite vertical exposed edges of the stiles each having a
central vertical groove extending the full height thereof, and each
of the opposite vertical faces of the frame covered by a thick
sheet of metal, which sheets overlap and are adhesively secured to
the faces of the stiles and rails, and with the opposite edge
portions of each of the sheets bent approximately perpendicular to
the planes of the sheets to form edge flanges overlapping their
adjacent stile exposed edges up to the groove, the improvement
comprising:
each of the free edges of said flanges being bent approximately
perpendicularly thereto and inwardly relative to their respective
stiles to form a flange edge portion arranged approximately
parallel to the plane of the sheets and loosely inserted within its
adjacent stile groove, with the grooves having side walls which are
roughly parallel to said flange edge portion and with the grooves
being of sufficient width so that the adjacent flanges edge
protions are horizontally spaced apart from each other a
considerable distance, and each flange edge portion is also spaced
a considerable distance away from its adjacent groove side
wall;
and with the grooves being of sufficient depth so that said edge
portions terminate at a considerable distance away from the bottoms
of their respective grooves;
and with the space between each pair of flange edge portions being
substantially filled with a heat insulating plastic material which
is positively bonded to the opposing faces of said pairs of flange
edge portions for the full height of the stile and substantially
the full depth of said flange edge portions, with the flange edge
portions being otherwise free of and spaced away, by open spaces,
from the side walls and bottoms of the grooves;
and upper and lower end cap strips secured to and enclosing said
horizontal rails and said vertical stiles;
and plastic material bonded to the opposing sheet metal faces,
filling the space between the sheets and within the frame;
whereby a rigid structural slab unit is formed of the two sheets of
metal secured together, along their vertical flange edge portions,
and adhesively secured to the frame, and wherein the plastic
material forms a heat insulating joint between the adjacent
vertical edges of the sheet and also seals the vertical edges of
the slab including the stiles and the grooves therein against
moisture penetration.
Description
BACKGROUND OF INVENTION
The invention herein relates to an improvement of the type of slab
doors illustrated, for example in the Patent to Pease, No.
3,153,817 issued Oct. 27, 1964. In this type of construction, a
slab door is formed of a wood frame with a sheet metal facing on
the opposite sides of the door and with the interior of the frame,
between the sheets of metal, filled with a foamed plastic material.
The opposite edges of the sheets are bent into flanges around the
vertical exposed edges of the frame stiles and are bent into
vertically extending channels formed in the stiles. The purpose of
such groove is to space the edges of the sheet metal facings away
from each other to prevent heat transfer and thereby form a thermal
seal.
In such type slab door construction, it is necessary to accurately
dimension the sheet metal edge flanges as well as the grooves in
the stiles in order to assemble and hold the parts together.
Moreover, the parts are movable relative to each other under heavy
strain or load so that the slab unit is not as rigid as would be
desirable. In addition, the groove forming gap between the sheet
metal facings, tends to accumulate dirt and moisture which
ultimately works its way between the sheet metal facings and the
wood frames thus causing decaying of the slab unit.
Thus, the invention herein relates to an improvement in the
foregoing type of slab door construction which obviates many of the
above problems.
SUMMARY OF INVENTION
The invention herein contemplates forming a rigid slab door unit
out of a wood frame covered with sheet metal facings, with the
opposite edges of the sheet metal bent into flanges fitted into
vertically extending grooves formed in the stiles of the wood
frame. The grooves are made relatively wide and deep, with wide
dimensional tolerances and the flanges loosely fit into them.
Thereafter, the adjacent facing portions of each pair of flanges
are bonded togehter with a strong, positively acting bonding
material to thus not only seal the groove, but also rigidly
interconnect the sheet metal facing pieces together. In addition,
the sheet metal facings are adhesively secured to the wood frame so
that the entire unit is rigid, sealed together to prevent moisture
penetration and the opposite sheet metal facing pieces are
thermally insulated from each other.
With this construction, wide dimensional tolerances are permissible
in forming the flanges and grooves, eliminating the need for
accurate construction, while still insuring a rigid slab unit.
These and other objects and advantages of this invention will
become apparent, upon reading the following description, of which
the attached drawings form a part.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a slab door unit.
FIG. 2 is a slightly enlarged disassembled perspective view of the
parts forming the slab door.
FIG. 3 is an enlarged cross-sectional view taken in the direction
of arrows 3--3 of FIG. 1.
FIG. 4 is an enlarged, partially cross-sectioned view taken in the
direction of arrows 4--4 of FIG. 1.
FIG. 5 is an enlarged perspective view of the upper left hand
corner of the slab unit as illustrated in FIG. 1, but with the
bonding material not yet installed, and
FIG. 6 is a view similar to FIG. 5, but showing the complete
bonding installation.
DETAILED DESCRIPTION
The slab door unit 10 is formed of a wood frame 11 which comprises
vertical wood stiles 12 joined to upper and lower horizontal wood
stiles 13 to form the rectangular inner frame. Additional rails may
be provided for reinforcement, as necessary, and for mounting of
locks, handles and the like.
Grooves 14 are formed in the vertical, opposite or exposed outer
edges of the stiles and extend the full height of each of the
stiles.
The opposite faces of the frame 11 are covered with thin sheet
metal pieces 15, each having its opposite edges bent into edge
flanges 16 terminating in inwardly extending, bent edge flange
portions 17 which are approximately parallel to the plane of the
sheet metal.
The metal sheets are adhesively bonded to the wood frame by means
of a suitable adhesive 18 and their edge flange portions 17 each
extend into their adjacent groove 14. As illustrated in FIGS. 3 and
5, the edge flange portions 17 are loosely inserted within the
grooves with the grooves being deeper and wider than the flanges so
as to readily compensate for misalignment or inaccuracies in
dimension.
After assembly of the sheet metal facing pieces adhesively upon the
frame, the space between the bent edge flange portion 17 at each of
the opposide edges of the slab is filled with a thermoplastic
bonding filler material 20 to fill the space from top to bottom of
the door and from side to side of the space between the flange
portions. The thermoplastic bonding material 20 is characterized by
being relatively viscous or gummy and self-bonding or adhering to
the metal flange portions. A number of commercially available
plastic materials may be used, as for example from those selected
among the polyurethanes which may be manually applied while
viscous, like a strip of rope, and which will cure and bond firmly
to the sheet metal to form a strong joint therewith. Another
suitable plastic is an epoxy based material, which is
thermosetting. An example of such material is commercially
available from Products Research & Chemical Corporation, and
identified by the trade designation of RE-150-61, which is
characterized by air curing in roughly 24 hours at room temperature
to form a hard, solid filler.
Where desired, the slab may be filled with a suitable foam plastic
filler 21 within the frame and between the metal sheets and bonded
thereto to thereby further rigidify and solidify the slab. In
addition, upper and lower cap strips 22 are adhesively or
mechanically fastened to the upper and lower edges of the slab,
namely the exposed upper and lower edges of the respective rails
13.
To manufacture the foregoing slab unit, first the frames are formed
out of suitable wood strips with the stiles grooved and thereafter
the sheet metal facing pieces are applied. The bonding material is
then inserted within the space between the adjacent flange edges
for solidifying and bonding thereto. Where the foam filling is
applied within the slab interior, it may be applied by inserting
unfoamed beads of foamable polyurethane or the like plastic which
may then be foamed in place by the application of heat to the
completed slab for expansion and filling the spaces within the slab
and bonding to the metal.
The complete slab unit is rigid, with the metal facings bonded
together at their edges to provide a rigid exterior skin but with
the bonding material providing a wide thermal joint between the
opposite surfaces of the slab to reduce heat transfer therebetween,
as well as to seal the edges against moisture penetration.
* * * * *