Note: Descriptions are shown in the official language in which they were submitted.
~g300
This invcntion relates to thermally insulated
frames for use in buildings~ and more particularly
to frames comprising inner and outer metal frame
members interconnected by a thermal barrier for
retarding heat conduction between the interior ~nd
exterior of a building.
In present-day building constructions9 it is well
known to employ structural frames of metal for such
elements as door and window frames and sashes. Metal
18 frames afford various advank~ges9 including durability
and ease of installatio~ and maintenance~ Owing,
however, to the rela~ively high thermal conductivity
of metals, a metal frame which is exposed to both the
interior and exterior of a building provides a p~th
for rapid heat~transfer through the building wall,
derogating from de~ired therm~l insulation of the
.~tructure. The minimizing of such heat losses is
especially important from the standpoint of ~nergy
consump~ion.
Accordingly) lt ha~ been proposed to provide metal
frames (e.g. window and door frames) as assemblies o~
inner and outer metal frame members separated ~rom
each other but interconnected structurally by a so~
called then~al break or barrier, viz. a body or bodie~
of material of thermal conductivi~y lower tha~ the
metal. For example, the interconnectting thermal
barrier may be con~t~t~ted of polyurethane poured into
and solidified between the inner and outer frame
members while be;ng laterally confiened a~ by a metal
wall initially farmed integrally wit~ and extending
betwee~ he in~er ~nd ou~er frame members but machined
away after the polyurethane has solidified; such
arrangement~, however, are inconvenien~ly complex and
, , ` ~
' .'.' ..' ,' ~ , . ' .
- ': , :.
ll~g3~0
- 2 -
difficult to produce, owing inter alia to the fact
that substantial time is required for solidific~tion
of the thermal barrier material. Alternatively, a
thermal break may be constituted of extruded plastic
members (commonly fabricated of polyvinyl ~hloride)
of roll-lock or snap-on type but again, k~own forms
of such members tend to be structurally complex,
inconvenient to install, and/or vulnerable to dis-
engagement especially when a frame assembly incorpor-
~0 ating them is sub~ected tQ rotational stress. In
addition, use of the latter members generally
requires observance of very close dimensional
tolerances.
The present invention broadly con~emplates the
provision of a thermally insula~ed frame comprising
spared }nner and outer metal frame members e~tending
in parallel planes to each other and interconnected
by a pair of substantially rigid par~llel elon~ate
thermally insulating channel members which bridge the
gap between the frame members and which are disposed
with the legs of each channel member pro~ecting
towards the legs of the other ch~nnel member, each
channel member having one leg engaged in a groove in
one of the frame member~ and its other leg engaged in
a groove in the other fr~me member, the two ch~nnel
members forming with the frame members a laterally
- en losed lengthwise~extending air space in the g2p~
bo~h side walls of each groove being formed with
leng~hwise extending serrations and the legs of the
ch~nnel members h~ving both sides thereof formed with
a plurality of lengthwise extending barb~ which inter-
lock with the grooves to retain he legs in the grooves9
~he cross-secti~nal dimensions vf each of which grooves
is sufficiently large in relation to those of the leg
to enable the leg to be press-fitted into the groove.
~ 16~30~
The term "~che~nally insulating~', as used herein
with reference^to the channel member~, means hat the
materia~ of w~ich the channel members are made has
substantially lower the~mal conductivity than the
5 frame member~ Typically or preferably, the channel
members are extrusions constituted of an organic
polymeric material, e.g. a synthetic resin such as
polyvinyl chloride, and are not only self-sustaining
in shape but are characterized by relstively high
tensile and compression strength.
In the frame according to the present invention,
the facing channel members cooperatively constitute
a thermal barrier of boxlike configuration affording
desirable structural strength~ and assuring th~t when ^
the assembly is subjected to rotational stress about
its long axis the individuaI channel members are
under tension and compression rsther than flexural
stress, thereby to ~ake advantage of the mechanical
properties of a thenaally insulating material such as
polyvlnyl chloride which, though having low flexural
strength, has substantial tensile and compres~ive
strength. Espe~ially important for attainment of the
desired results are the prov~sion of longitudin~l
barbs on each side of each channel member leg and the
complementary provis~on of longitudinal serrations on
both facing wall~ of each frame member grooveO The
interlocking thereby achieved (effected b~ force it
of the legS into the grooves; i.e. by defonma ion of
the ~u~stantially rigid vin~l under force with cold
30 ~ ow of the barbs in~co place such that the barbs are
wedged and retained under the serrations ) preve~ts
dislodgment of the shannel members under torsional
forces9 but, adYantageously, is a~tainable with
relatively wide dimensional tolerances, owing to the
presence of barbs and mating wall serrations on both
sides of each leg.
1~6~330~
Production of ~he completed assembly is rapid
and simple, requiring no time delay for solidification
of the thermal barrier, nor any step of removing an
initial llquîd-containing metal w~ll or bridge between
the inner and outer metal frame members. The thermal
barrier has highly satisfactory insulating properties,
owing to the superior insulating effect of the air
space defined between thP channel members within the
gap as well as to the l~w thermal conductivity of the
channel members themselves. Consequently, frames
embodying the inYention can be used for a wide variety
of building elements, including ~but not limited to)
window frames 9 door frames and the like.
The invention will now be described in more detail
with reference by way of example to the accompanying
drawimgs in which:
Figure 1 is a simplified ragmentary perspective
view of an illustrative frame assembly embodying the
present invention in a particular form;
Figure 2 i5 an enlarged sectional view s~f the
thermal barrier channel members and ~s~ociated portions
of the metal frsme members of the assembly of Figure 1,
and
Figure 3 is a fragmentary ~ectional plan view of
a window frame incorporating the invention.
Referring first to Figures 1 ~nd 2, there i.~
shown a building s~ructure frame assem.~ly 10 embodyi~g
the inventio~ and comprising an inner metal frame member
11, an outer me~al frame member 12, and a then~al
b~rrier or bre~k 14 comprising a pair of facing9
thermally insulating channel members 16 that ~nter-
connect the two metal ~rame members. As will be
understoodS ~he assembly 10 is inten~ed to represent,
in a somewhat simplified schematic way, a frame
~such as a window or door frame) arranged to be
1 ~g3~0
- 5 -
mounted in a building wall such that the inner frame member 11
is exposed to the interior of the building and the outer frame
member 12 is exposed to the exterior of the building.
Each of the frame members 11 and 12 is an elongate unitary
integral member formed of a metal such as aluminium (i.e. pure
aluminium metal or an alloy thereof) and is conveniently
produced by extrusion in conventional manner. For simplicity
of illustration, the members 11 and 12 are shown as having
cross sections or profiles which are mirror images of each
other, but in practice (as will be understood particularly by
reference to Figure 3, described below), these members need
not be identical or even similar in configuration except in the
respective connecting portions 13, 15 thereof immediately
adjacent the thermal barrier. Each of these portions 13, 15 is
of substantially H-section and portion 13 is integrally
connected to the main body of the frame member 11 by the
extremity of one limbs 13a of the portion, portion 15 being
similarly integrally connected to the main body of the member 12
by the extremity of one limb 15a of the portion.
The portions 13 and 15 of members 11 and 12 are disposed in
closely spaced parallel relation to each other so as mutually to
define a parallel-sided, elongate gap 18 between khem. Specific-
ally, in the illustrated embodiment, this gap is defined between
a planar longitudinal surface 21 of portion 13 facing portion 15,
~5 and a planar longitudinal surface 22 of portion 15 facing
portion 13.
Each of the channel members 16 is a substantially rigid
element composed of a material which is substantially lower in
therma} conductivity than is the metal of frame members 11 and 12.
In the present embodiment of the invention, the members 16 are
made of polyvinyl chloride and are produced by extrusion in
conventional manner, being dimensioned to be self-sustaining in
shape. As shown, each of the channel members 16 has a central
web 24 and a pair of parallel legs 25 and 26 respectively
extending along opposite edges of the web. In the assembly of
Figures 1 and 2, the legs of each of the two channel members 16
'
3 ~ ~
- 6 -
project toward the legs of the other channel member. The two
channel members extend along the gap 18 in facing, spaced
parallel relation to each other so as to bridge the gap and to
interconnect the frame members 11 and 12 to form therewith a
structurally stable assembly having a laterally enclosed longit-
udinal air space in the gap.
The cross-bar 17 and the two limbs of each of the H-section
portions 13, 15 together form a first groove 28 extending along
the gap for receiving one of the legs of one of the channel
members 16, and a second, oppositely opening groove 30 extending
along the gap for receiving one of the legs of the other of the
channel members 16, such that the legs of each channel member
are resp~ctively received in grooves of the two frame members on
opposite sides of the gap. It will be seen that the groove 28
on each side of the gap is aligned with the groove 30 on the
same side of the gap, such that the two channel members 16 (which
- are equal to each other in width) are disposed in register with
each other to constitute a thermal barrier of box-like
configuration.
Each of the grooves 28 has two facing side walls 32a and
32b each of which bears plural parallel longitudinal serrations
34. It will be understood that these serrations are rib-like
projections protruding toward the centre of the groove from the
walls and extending along the length of the groove. Similarly,
each of the grooves 30 has two facing side walls 36a and 36b
each bearing plural parallel longitudinal serrations 38 identical
to the serrations 34 of the grooves 28~ The serrations are
integral with the groove walls, and may be produced conveniently
by use of an appropriately configured extruding die in the
extrusion of the members 10 and 11.
Each of the channel member legs 25 and 26 has two opposed
side surfaces 40a and 40b bcth bearing plural, resiliently
deformable parallel longitudinal barbs 42 for simultaneously
interlocking with the facing wall serrations 34 or 38 of a
groove 28 or 30 when the leg is received in the groove, thereby
to retain the leg in the groove. As will be seen, the trailing
,-c ~
~?' ~
~ ~6~d30
- 7 -
edges of the barbs extend at an acute engle to the central
plane of symmetry of the leg so that the rearward portions of
the barbs are undercut. These barbs are projections
extending along the full length of the channel member legs and
are integral therewith, being formed during extrusion of the
channel members.
The cross-sectional dimensions of each groove 28 and 30 are
sufficiently large, in relation to the channel member leg
received therein, to enable press-fitting insertion of the leg
in the groove. That is to say, the relative dimensions of the
groove and leg are such that, with the metal frame members 11
and 12 positioned as hown in Figures 1 and 2, the channel
members 16 can be mounted (to interconnect the frame members) by
force fitting insertion of their legs in the grooves; and when
so mounted, they are retained in place by interference of the
barbs of the channel member legs with the serrations of the
groove walls along both sides of each leg. To accommodate the
deformation of the channel member legs necessary to achieve the
described force fitting, it is advantageous to so shape and
dimension the grooves that when the legs are finally inserted,
there is a space 44 between the extremity o~ each leg and the
bottom of the groove in which the leg is received.
lt will be appreciated that in the ~rame assembly o~
Figures 1 and 2, the inner and outer metal ~rame members 11
and 12 are completely thermally isolated from each other by
th~ thermal barrier 14 constituted by the pair of channel
members 16 and the confined air space within gap 18. The
components of this assembly are readily and conveniently
manu~actured as by conventional extruding techniques, and are put
3~0
8 -
together with advantageous facility by simple
positioning of the metal frame members and force
fittin~ of the thermally insulated channel members
into place. The produced a~sembly is structurally
stable and fully capa.ble of withstanding the loads
to which suc~ rames are ordinarily subJected in use.
By way of illustration of one spe~ific
environment of use f~r the frame assembly o the
present invention, there is shown in Figure 3 an
exemplary type of window fr~me system incorporating
the invention. This system9 adapted to be mounted
in a building wall (not shown), includes a window
frame assembly 50 arranged to be fixedly secured at
a windo~ opening of a wall as by fasteners 52 and to
support, for independent vertical sliding movement,
a window screen 54, an upper window sash 56, and a
lower window ~ash 58, ~he screen 54 being located
on the outer side of the building.
The window frame assembly 50 comprises an in~er
extruded aluminum frame member 60 and an outer
aluminum frame member 62 which a~e intercon~ected but
thermally isolated by a thermal barrier 14a in
accordance with the invention. The thermal barrier 14
can be essentially identical ~o the thermal b~rrier 14
of Figure~ 1 and ?; thus ~s shown, it is con~t~tuted
of a facing pair of thermally insulated channel
members 16 having barbed legs force-fit~ingly recgi~ed
~ ~errated grooves fonmed in the frame members 60 and
62 slong he gap 18 defined between ~he frame members.
Similarly, the window sash 56 comprises an inner
extruded aluminum frame member 64 and an outer extrude~
aluminum frame member 66 which cobperatively hold an
a~sembly 68 of glas~ window panes. The in~er and
outer fr~me members of the sash 56 are interconneoted
3 0 ~
but thermally isolated by means of a therDal barrier 14b
which can again be essentially identical to the barrier 14
of Figures 1 and 2. The sash 58 may be of like
construction with inner and outer extruded ~luminum frame
members 70 and 72 interconnected by a thermal barrier 14c
of the same typeO As will be appreciated, in Figure 3,
features of structure of the rame system not pertinent
to the present invention have been omitted for simplicity
of illustration,
