Note: Descriptions are shown in the official language in which they were submitted.
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METHOD OF MAKING THERMAL BARRIER LINEAL METAL SHAPES
Background of the Invention
The present invention is in the field of metal
construction shapes and particularly those shapes used in
the construction of metal windows and doors and frames
therefor.
With the advent of metal construction used in
curtain wall and other metal window and door enclosures,
problems of heat conduction have arisen. The use of
1~ aluminum for the metal frames caused a greater transfer
of heat between wall elements than had heretofore taken
place in previous types of such construction. An insula-
tion problem or the necessity for a thermal break con-
struction element was thus essential. Various types of
thermal breaks have been constructed, some of which have
been satisfactory, but have been too costly. Other types
have met with varying degrees of success.
Most thermal break constructions are currently
formed by pouring in place an insulating material into
the metal members or by mechanically joining the metal
members and insulating member by deformation of the metal
members. U. S. Patents 3,204,324, 3,3g3,487, 3,624,885
and 3,634,565 are illustrative of the former type of
constructions. U. S. Patents 3,093,217, 3,114,179,
3,420,026, and 3,411,995 are illustrative of the latter
type of construction. U. S. Patents 3,411,254, 3,289,377,
3,o55,468 and 2,654,920 disclose additional prior art
thermal break constructions.
The present invention eliminates the necessity of
expensive jigs which are required with pouring operations.
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In the instant invention, unit deformation force
required is substantially reduced. Ileat generated by metal
deformation is eliminated and metal marring and defacing
is reduced.
Thermal break construction ~oints or lineal
shapes of this invention have more uniform strength than
prior art joints. They are simple and easy to fabricate.
The use of jig boxes and table space are minimized.
It is a primary object of the present invention
to provide a thermally insulating break in metal construction
shapes by a mechanical interference fit.
Summary of the Invention
me present invention relates broadly to a method
of forming or incorporating a thermally insulating barrier
or material in metal construction shapes. Metal lineal
shapes are extruded or otherwise formed in such a manner
so as to accept an insulating material or barrier previously
formed in such a shape as to fit or be received by the metal
lineal shapes. m e insulating material is then joined with
the metal shapes by mechanical means to form a composite
single-piece construction material or shape. In effect,
three lineal shapes, two metal and one insulating or
plastic, are joined together by an inter~erence fit to
form the composite building shape.
Adhesives may be applied to the metal members,
plastic members or both. The insulating materials may be
plastic, wood, paper, foamed plastic, nylon, PVC, urethane,
styrene, polyethylene, pressed wood, "Bakelite", glass,
ceramic materials and the like. Plastic is preferred and
~some reSiliency in the insulating material is also preferred.
The metal shapes are preferably aluminum and may be extruded,
cQsT, wrou~ht, or othcrwlse formed. The term alumlnum includes
aluminum and aluminum alloys customarlly used ln the constructlon
lndustry, especially in the making of windows, doors, curtain
walls and frames therefor. Aluminum extrusions are preferred.
Dimensional tolerances are essential.
This invention is defined as a method of forming a
thermal barrier lineal metal construction shape comprising the
steps of: aligning a pair of lineal metal shapes ad~acent each
other in generally parallel spaced apart relation, each of the
metal shapes having a top surface, bottom surface and vertical
wall surface, and each of the metal shapes having a channel therein
of a predetermined size adapted to receive a lineal insulating
shape and one of the channels facing the other of the channels;
aligning ad~acent to the channels of the metal shapes and
therebetween the channels, a lineal insulating shape adapted to
be received by the channels, the insulating shape having a top
surface, bottom surface and vertical side wall surfaces, and the
insulating shape being of a predetermined size so related to the
size of the channels that an interference fit is obtained when
the insulating shape is inserted in the channels and, applying
mechanical forces to move the channels of the metal shapes towards
each other to thereby bring together the metal shapes and the
insulating shape to form an interference fit between the metal
shapes and the insulating shape, the interference fit occurring
between the top surface and bottom surface of the lineal metal
shapes and the top surface and bottom surface of the lineal
insulating shape, thereby forming a unitary lineal thermal
barrier construction shape.
Brief Descriptlon of the Drawings
Fig. 1 is a view in cross-section illustrating the
positions of one type of lineal metal shape and one type of
lineal lnsulating shape ~ust prlor to belng brought together
to form the unitary thermal break construction element.
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FLg. ]A Is a view simL].Ir to that o~ Fl~. 1 illustra-
tin~ the unitary construction elemcnt forme~ by bringing togetllcr
the lineal shapes shown in Fig. 1.
Figs. 2-5 are cross-sectlonal views illustrating
alternate forms of lineal metal shapes suitable for use ln
the inherent invention.
Figs. 6-10 are cross-sectional views showing alternate
forms of lineal insulating members suitable for ~oining any of
the various metal shapes seen in Figs. 1-5.
Fig. 11 is a top plan view illustrating one method of
~oining together the lineal metal and insulating shapes of
Figs. 1-10.
Fig. 12 is also a top plan view illustrating another
method of ~oining together the lineal metal and insulating shapes
of Figs. 1-10.
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Description of the Preferred Embodiment
Referring now to the drawings, Figs. 1J lA and
2-5 illustrate various metal shapes or receptacles which
are suitable for use in the present invention. Figs. 1,
lA and 6-10 illustrate various insulating member shapes
or barrier concepts which may be used in the instant
invention. Any of the insulating members may be Joined
with any of the metal shapes and vice versa. A shape is
defined as a product that is long in relation to its
l~ cross~sectional dimensions and has a cross-section other
than that of sheet, plate, rod, bar, tube or wire. Metal
shapes may be extruded, cast, wrought or otherwise formed.
Aluminum extrusions are preferred. The insulating shape
may also be extruded, cast or otherwise formed. Plastics are
preferred, but all materials having thermal insulating
properties are suitable.
Of the plastics, PVC (polyvinylchloride), and
urethane foam are especially preferred. A cast polyurethane
self-skinning foam or a free foam P~C are particularly
recommended.
As can be seen in the drawings, the receptacles
may be of various configurations. The opening or channel
for receiving the insulating barrier is generally ~ a
somewhat rectangular construction in cross-section. A
receptacle configuration such as that of Fig. 1 is preferred,
wherein a plurality of teeth or small projections extend
from the receptacle in the receiving area for the barrier. - -
When metal shape and barrier are brought together, as
seen in Fig. lA, the teeth protrude into the barrier
to assist in holding it in a desired position. Suitable -
adhesives may be placed in the channel of the metal shape
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on the barrier shape or on both such shapes so as to
more firmly bond them together. With proper dimensional
tolerances, gluing or adhesive joining can be eliminated
entirely if desired.
A barrier or insulating member of a conflguration
as seen in Fig. 7 is highly desirable as it provides a
flush surface when joined with the receptacle of
Figs. 1-~. me barrier of Fig. 9 is especially suitable
for the receptacle of Fig. 5. The barrier of Fig. 1 is
1~) the simplest and most economical barrier shape
The size and weight of the receptacles and their
corresponding barrier is largely determined by strength
and use specifications. In general, sizing the barrier
is a function of obtaining the overall strength, i.e.
the minimum thickness required for a given application
and desired interference fit within the receptacle.
For a receptacle having teeth or similar type ~ojection
serrations, an interference formula of T = t + 0.3~t is
desirable, when T = total barrier thickness (inches)
,~ and t = receptacle opening (inches). See Fig. l; a "T"
up to 0.270" has been tested. For a smooth receptacle,
i.e. the types of Figs. 2-5, the following formula is
prepared: T = t + 0.117t. Tests have been made of a
"T" up to 0.160 inches.
When using aluminum, a receptacle of the type
of Fig. 2 is not as desirable as the other shapes shown
since aluminum has a tendency to push too far into the
barrier. A hard, smooth barrier could overcome this
limitation.
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The two lineal metal shapes and the single lineal
barrier or insulating shape are joined together by an
interference fit to form a composite building shape.
Predetermined designed and sized metal and barrier
lineals are aligned and mechanically pushed to~;ether
to form the interference fit between the barrier and
the metal shapes The lineals may be aligned in a
brake and then pushed together or the lineals may be
moved through a series of rollers which force the
ll~ shapes together as they travel past the wheels.
Adhesives may be used to supply some or all of the force
required to hold the metal and barrier members together
as a composite shape.
Fig. 11 illustrates one of the simplest forms
of the present invention wherein lineal metal shapes 20
and 21 of the configuration of ~ig. 1 are aligned in or
between brake shoes or vice faces 22 and 23 respectively,
wherein the edges 24 and 25 extend into the openings
or channels 26 and 27, respectively. A barrier or
_3 insulating lineal shape 30 is placed between the metal
shapes 20 and 21 and aligned therewith as shown in Figs. 1
and 11. When the shapes are in this aligned position,
forces are simultaneously applied to the brake shoes 22
and 23 so as to move them in the directions of the arrows.
When the barrier 30 and metal shapes 20 and 21 are firmly
joined together as shown in Fig. lA, the brake shoes 22
and 23 are returned to their non-compressed or open
positions and the composite or unitary construction
shape 35 removed from the brake.
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If desired or necessar~, a suitable adhesive may
be placed on the surfaces of the receptacle openings or
channels 28 and 29 or on the surfaces 32 and 33 of the
member 30 which are to be placed in said openings or
on all of said surfaces,
In Fig, 12, which is another method of forming
the interference fit, the member 20, 21 and 30 are
aligned similarly as in Fig. 11 and then are moved and
driven through a series of rollers 40 in the direction
of the arrow 41 until the unitar~ shape or composite is
formed. The rollers 40 are spaced apart at desired
intervals with ever decreasing space therebetween, As
the members 20 and 21 move through the rollers 40 in
the direction o~ the arrow 41, the~ are moved towards
the barrier 30 moving along therewith until the composite
35 is formed. The shapes 20, 21 and 30 may be fed into
the roller by any suitable feed means.
Although the foregoing invention has been described
in some detail by wa~ of illustration and example for
purposes of clarity of understanding, it is understood
that certain changes and modi~ications may be practiced
within the spirit of the invention as limited onl~ b~
the scope of the appended claims.
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