U.S. patent number 3,837,134 [Application Number 05/378,320] was granted by the patent office on 1974-09-24 for sheet metal faced slab door.
This patent grant is currently assigned to Acorn Building Components, Inc.. Invention is credited to Joseph DiFazio.
United States Patent |
3,837,134 |
DiFazio |
September 24, 1974 |
SHEET METAL FACED SLAB 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 edge portions, covering the stile edges, and
terminating in bent edge flanges which loosely extend into their
adjacent groove. The adjacent pair of edge flanges within each
groove are spaced apart from each other and from the bottom of the
groove. A T-shaped spacer is arranged with its head portion
overlapping the adjacent edge portions and its leg inserted between
adjacent flanges and terminating in a free barbed end engaged with
the groove wall inwardly of the flanges for locking the metal edge
portions against springing away from the frame stiles and for
forming a thermal insulating between the flanges.
Inventors: |
DiFazio; Joseph (Warren,
MI) |
Assignee: |
Acorn Building Components, Inc.
(Detroit, MI)
|
Family
ID: |
23492654 |
Appl.
No.: |
05/378,320 |
Filed: |
July 11, 1973 |
Current U.S.
Class: |
52/784.13;
52/800.14 |
Current CPC
Class: |
E06B
3/825 (20130101) |
Current International
Class: |
E06B
3/82 (20060101); E04b 001/68 (); E04b 002/28 () |
Field of
Search: |
;52/468,619,620,615,573 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sutherland; Henry C.
Attorney, Agent or Firm: Cullen, Settle, Sloman &
Cantor
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 internal vertical groove extending the full height thereof,
each groove being generally T-shaped in cross-section and having
wider side walls perpendicular to the stile edge and opening onto
the stile edge to form the head of T-shaped groove, said wider side
walls tapering inwardly and terminating in narrower side walls
parallel to the wider side walls to form the leg of the T-shaped
groove and each of the opposite vertical faces of the frame covered
by a metal sheet, which sheets overlap and are 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 portions overlapping their adjacent
stile exposed edges up to the groove head, the improvement
comprising:
each of the free edges of said edge portions being bent
approximately perpendicularly thereto and inwardly relative to
their respective stiles to form a flange arranged approximately
parallel to the plane of the sheets and loosely inserted within its
adjacent stile groove wider side wall, which is roughly parallel to
said flanges and with the wider side walls being of sufficient
width so that the adjacent flanges are horizontally spaced apart
from each other a considerable distance;
and with the wider side walls of the grooves being of sufficient
depth so that said flanges terminate at a considerable distance
away from the bottoms of their respective grooves;
each groove having a T-shaped, in cross-section, plastic spacer
strip whose leg is inserted between the pair of flanges and having
a barbed free end portion extending beyond the pair of flanges
towards the bottom of the groove with the barbed portion
interlocking with the narrower side walls of the groove near the
bottom thereof, and the head of the strip spanning the space
between the flanges and overlapping and in contact with the edge
portion areas adjacent to the flanges along substantially the full
length of the stiles, with the strip extending substantially the
full length of the groove;
and upper and lower end cap strips secured to and enclosing said
horizontal rails and said vertical stiles;
and the strip head holding the said overlapped edge portion areas,
and thereby the edge portions, against their stile edges, and
holding said flanges between the wider side walls with the barbed
leg thus holding and locking the head against outward movement
relative to the groove and simultaneously forming a thermal barrier
between the flanges, which thermal barrier is sealed by the head
contacted against said edge portion areas.
2. A door as defined in claim 1, and each said strip leg being
tapered along its cross-section length, with the wide part thereof
being at said head, and the opposite faces of said leg engaging its
adjacent flange face for thereby wedging said flanges apart and
frictionally engaging the legs and flanges together.
Description
BACKGROUND OF INVENTION
The invention herein relates to an improvement of the type of slab
doors illustrated, for example, in the U.S. Pat. to Pease, No.
3,153,817 issued Oct. 17, 1964, or in my prior application, Ser.
No. 216,053 filed Jan. 7, 1972 now Pat. No. 3,786,609. 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
around the vertical exposed edges of the frame stiles and then are
further bent into vertical flanges which are inserted within
vertically extending channels formed in the stiles. Thus, the edges
of the sheet metal facings are spaced away from each other to form
a thermal barrier which prevents heat transfer between the outer
and inner metal facings.
In such type construction, the edge portions of the facings, that
is the portions overlapping the edges of the frame stiles, tend to
bow away from the frame stiles. Although the metal facings and
their edge portions are adhesively secured to the frame, including
to the stile edges, the tendency of the metal edge portions to bow
and separate from the stile edges remains due to the inherent
springiness of the metal and the relative movements of the metal
and frame caused by normal expansion and contraction thereof. This
bowing affects the fit of the door within its frame. It also may
cause breaks or gaps in the sealing between the various parts,
through which moisture and dirt may penetrate to cause rotting.
Thus, the invention herein relates to an improvement in the means
for sealing the metal facing edges of 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 around the exposed vertical
stile edges and then further bent into flanges loosely fitted into
vertically extending grooves formed in the stiles of the wood
frame. The grooves are deeper than the flanges.
Thereafter, the leg of a T-shaped plastic sealing strip is inserted
between each adjacent pair of flanges, with the head of the T-shape
overlapping the bent metal portions adjacent the flanges. The strip
legs extend deeper into the groove, than do the flanges, and their
legs terminate in sharp barbs that engage with the groove walls.
Thus, the metal edge portions are positively held against the
stiles and locked against bowing outwardly therefrom. Meanwhile,
the strip legs act as thermal barriers and the strip heads act as
seals between adjacent facing edges, over the groove and also,
against the door frame. The strip legs may also be wedge shaped to
wedge the adjacent flanges apart for tighter locking.
With this construction, wide dimensional tolerances are permissable
in forming the flanges and grooves, eliminating the need for
accurate construction, while still insuring a rigid, well sealed
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, and showing a portion of the door outer
frame.
FIG. 4 is an enlarged, partially cross-sectional view taken in the
direction of arrows 4--4 of FIG. 1, showing the sheet metal edges
bowed, and a sealing strip removed.
FIG. 5 is an enlarged perspective view of the upper left hand
corner of the door as illustrated in FIG. 1, but with the corner of
the cap strip and a portion of the metal facing removed for
illustration purposes.
FIG. 6 is a view similar to FIG. 3, but showing a modified, i.e.,
wider sealing strip for wedging the flanges.
DETAILED DESCRIPTION
The slab door 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.
T-shaped 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 sheet metal
pieces 15, each having its opposite edges perpendicularly bent into
edge portions 16 overlapping its adjacent stile edge, and
terminating in inwardly extending, bent edge flanges 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 any suitable adhesive and their edge flanges 17 each extend into
the wider or head portion of their adjacent grooves 14. As
illustrated in FIG. 3, the edge flanges 17 are loosely inserted
within the grooves, i.e., spaced from the groove walls and bottom,
so as to readily compensate for misalignment or inaccuracies in
dimension.
After assembly of the sheet metal facing pieces adhesively upon the
frame, a T-shaped sealing or spacer strip 20 is applied in the
space between the bent edge flanges 17 at each of the opposite
edges of the slab. The leg 21 of the strip is inserted between the
flanges 17 and extends into the narrower part of the groove 14,
where sharp barbs 22, formed on the end of the leg, bite into or
grip the groove walls. The head 23 of the strip overlaps the areas
of the metal edge portions 16 adjacent the flanges. As seen in FIG.
4, the head 23 is somewhat V-shaped before application to the
groove, so that it may flatten out and apply a springy pressure
against the overlapped sheet metal. Preferably the strip is formed
of a plastic material, such as polyethylen, which is somewhat
springy or resilient, but stiff enough so that the barbs will grip
the wood walls of the groove.
The slab may be filled with a suitable foam plastic filler 24
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 25 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 door, first the frames are formed
out of suitable wood strips with the stiles grooved. Thereafter,
the sheet metal facing pieces are applied. Then the strips 20 are
inserted along the vertical edges. 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.
FIG. 4 illustrates, to an exaggerated scale the outward bowing of
the metal edges away from the stiles, which could happen in the
absence of the strips 20. However, the strips pull and hold the
metal against the stile edges due to the leg barbs locking against
the groove walls, plus the pressure of the head against the metal
edge portions.
Moreover, the strip head portions act as a sealing strip against
the vertical members of the outer or fixed frame 26 of the doorway
as illustrated in FIG. 3. This simultaneously applies an inward
pressure on the strip to keep it well seated in place dispite such
relative movement of the parts as may occur due to expansions and
contractions.
FIG. 6 illustrates a strip 20a whose leg 21a is widened and thus,
more wedge shaped, to thereby apply a wedging or separating force
against the flanges 17. This further seals the parts against
moisture or dirt penetration, particularly since the sheet metal is
inherently springy so as to resist such force.
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.
* * * * *