[0001] The invention relates to a new method of embodying composite metal window and/or
door frame members that incorporate two sections, one exposed to the external environment,
the other facing indoors, interconnected in a rigid fit by way of one or more plugs
fashioned from a heat-insulating material. In the composite assembly thus created,
one prevents any transfer of heat from taking place between the two component sections
separated by the plug. Prior art methods adopted hitherto in the attempt to achieve
this end-result have consisted in utilizing chemical substances or other means to
preassemble the two component sections prior to their leaving the factory.
[0002] Composite metal frame members have also been made which consist in two or more components
united by the insertion of longitudinal jointing sections or lengths of heat-insulating
material; assembly of such a composite member often involves additional extruding
and bending operations, and at all events, a firm and durable joint cannot be guaranteed.
The consequent drawbacks of such an assembly system are serious, and obvious.
[0003] Accordingly, the main object of the invention is to provide a special method of assembling
two component sections, one exposed to the external environment, the other to the
internal, which can be performed by hand simply locating one or more special bridging
plugs, fashioned from PVC or another heat-insulating material, between the two.
[0004] The method disclosed permits of embodying metal door and window frame members having
the same features as those currently manufactured and distributed in a preassembled
package with heat-insulation barrier already built in, but at lower cost. Thus, one
can obtain the same end-result utilizing commonplace extruded sections in aluminium
or other metal, but delaying embodiment of the heat-insulation barrier until the moment
that these are joined together by way of the plugs.
[0005] An additional object of the invention is that of providing a method whereby metal
component sections and plugs can be fitted together simply by locating and snapping
into place, affording a rigid, durable assembly and avoiding further mechanical operations.
[0006] The stated objects are achieved by adoption of a composite metal frame member as
characterized in the appended claims, incorporating two metal component sections and
a non-metallic bridging plug.
[0007] The invention will now be described in detail, by way of example, with the aid of
the acompanying drawings, in which:
fig 1 is the section through a first metal component according to the invention;
fig.2 is the similar section through a second metal component according to the invention,
designed to pair with the first component of fig 1;
fig 3 shows the same section through an alternative embodiment of the second component
of fig 2;
fig 4 shows the front elevation and the plan of a bridging plug according to the invention;
fig 5 is a side elevation of the plug in fig 4;
fig 6 is a cross section through the plug of fig 4;
fig 7 is a section through the composite assembly of component sections and bridging
plug, according to the invention.
[0008] With reference to fig 1 of the drawings, 1 denotes a metal component exhibiting box
section and affording a recess in which a plug of given appropriate shape and dimensions,
preferably quadrangular, may be inserted.
[0009] The component 1 exhibits a substantially rectangular cross section, in which the
sides of the box profile are denoted 2, 3, 4 and 5; two of the sides 4 and 5 are run
out into extensions 41 and 51 terminating at a given point in respective lips 6 and
ich are bent inwards and disposed parallel to the transverse side 3 of the box.
[0010] 101 denotes the recess thus encompassed by 6, 7, 41, 51 and 3, which serves to accommodate
a bridging plug according to the invention (see figs 4, 5 & 6).
[0011] 8 denotes a second component section (see fig 2) designed to pair with the first
section 1, which in the example illustrated appears trapezoidal, having a base 9,
and similarly angled sides 10 and 11.
[0012] The one angled side 11 terminates in a lip 12 that is bent back parallel with the
base side 9, whereas the corresponding lip 13 at the end of the remaining angled side
10 is extended and bent back further in the direction of the base through a stretch
14 that lies parallel with the self-same side 10.
[0013] 15 denotes a rib issuing from the base side 9, which is disposed parallel with the
angled side 10 and in alignment with the stretch 14 bent upward from the relative
lip 13.
[0014] A further rib 16 departs from the base side 9 at a point approximately half way along
its length, in this instance extending parallel with and through an identical distance
to the angled side 10.
[0015] The rib 16 terminates in two lips, one of which, denoted 17, is bent back toward
the first mentioned angled side 11 and exhibits identical geometry to the relative
lip 12, whereas the other, denoted 18, is bent inward at an angle of 45° in the opposite
direction, i.e. toward the remaining angled side 10.
[0016] 19 denotes a further rib which departs from the main central rib 16 and extends toward
the angled side 10 and the open side of the trapezium, terminating in a respective
lip 20 that is bent back toward the lip denoted 18. It will be observed in fig 2 that
these two lips 18 and 20 also exhibit matching geometry. Thus embodied, the second
component section 8 offers a substantially three-sided trapezoidal recess 108, encompassed
by 9, 11, 12, 16 and 17, that combines with the quandrangular recess 101 of the component
1 described above in accommodating a bridging plug, embodied according to the invention,
by means of which the assembly is rendered a stable, composite member.
[0017] In fig 3 of the drawings, 81 denotes an alternative embodiment of the second component
section 8 which affords a trapezoidal recess 118 exhibiting the same effective dimensions
as that denoted 108, though encompassed laterally only in part; in this instance two
short ribs 21 and 22 replace the full-length sides.
[0018] Figs 4, 5 and 6 show elevations and a sectional view of the bridging plug disclosed,
which is fashioned from a heat-insulating material such as PVC. It will be observed
from the front elevation (fig 4) that the plug exhibits a main centre piece 23 and
is of essentially, though not perfectly rectangular shape. The departure from perfect
rectangularity consists in the fact that the top side 24 is broken by two slots 25,
one at either end, right and left; thus one has two end pieces 26 separated in part
from the centre piece 23, but joined thereto by the base 27 which is common to all
three.
[0019] It is an essential feature of the end pieces 26 that they appear shorter than the
corresponding parallel ends 124 of the centre piece 23.
[0020] Fig 5 shows a side elevation of the bridging plug, which illustrates the proportions
of the end piece 26, and the profile of the base and top part. It will be observed
from the elevation of fig 5 and the cross section of fig 6 that the plug exhibits
a base 28 the shape of which is, if not absolutely rectangular, at all events quadrangular,
in order to permit of its being forced lengthwise and fitting snugly into the recess
101 of the first component section 1. Needless to say, the ultimate sectional profile
of the recess 101 and the base 28 of the plug is a matter of choice, dependent simply
on the fact of the one matching the other.
[0021] Each end piece 26 comprises a pair of identical and symmetrically disposed tongues
29 that are separat y a gap 30, exhibiting the outline of a trapezium
with the smaller base 31 at bottom, which opens out internally into the relative slot
25.
[0022] The tongues are possessed of outer surfaces which converge upwards from a given point,
presenting a tapered profile; more exactly, the tapering stretch 32 of each surface
is separated from the base 28 by an undercut 33 the position of which corresponds
to that of a similar undercut 133 running the entire length of the centre piece 23,
at either side.
[0023] The cross section of fig 6, taken through the A-B cutting plane marked in fig 4,
shows the composition of the top part of the plug profile, in which the tapered part
of the centre piece 23 is matched to the trapezoidal recess 108 or 118 of the second
component section, whilst that of the end pieces 26 shows slightly proud at either
side, by reason of the tapering stretches 32 being set at a wider angle, and remains
marginally short at the top.
[0024] Fig 7 shows the first component section 1 and the second component section 8 fitted
together by way of the bridging plug, with the base 28 accommodated and held fast
by the quadrangular recess 101, and the tapered part of the centre piece 23 seated
in the trapezoidal recess 108. Rigidity is imparted to the composite assembly by the
snap fit between the two tongues 29, which are rendered flexible thanks to the gap
30 provided between them, and the lips 12 and 17 offered by the second component section
8.
[0025] The undercuts 33 and 133 provided in the plug serve to accommodate the two sets of
lips 6-7 and 12-17, which hold the plug fast and rigid and are separated by a given
distance, denoted 34, which establishes the break in continuity of the composite metallic
frame member required in order to create a barrier to the transfer of heat between
indoor and outdoor surface areas.
1) A composite assembly of two metal sections and a non-metallic bridging plug united
rigidly to the end of embodying heat-insulated door and window frame members, of the
type comprising a first component section facing indoors, a second component exposed
to the external environment, and an interconnecting component in heat-insulating material,
characterized
in that the first component section (1) exhibits a cross sectionial outline appearing
substantially as a rectangle two parallel sides (4, 5) of which are integral with
extensions (41, 51) projecting beyond one of the transverse sides (3) and terminating
in respective lips (6, 7) that are bent symmetrically inwards in such a way as to
create a substantially three-sided recess (101) the open side of which is bounded
by the two lips (6, 7);
in that the second component section (8) exhibits a substantially trapezoidal cross
sectional outline in which two similarly angled sides (10, 11) converge toward a base
side (9) from which an intermediate rib (16) of length equal to the angled sides departs
and extends symmetrically with one such side (11), terminating in a lip (17) that
is disposed parallel to the base (9) and symmetrical with an identical lip (12) issuing
from the end of the symmetrically disposed converging side (11), in such a way as
to create a substantially three-sided trapezoidal recess (108) the open side of which
is bounded by the two lips (12, 17);
in that the interconnecting component consists in a bridging plug fashioned in heat-insulating
material and comprising a centre piece (23) the top tapered part of which issues from
a discernable base (28), and two end pieces (26) issuing likewise from the base, separated
from the centre piece by respective slots (25) and consisting each one in a pair of
identical and symmetrically disposed tongues (29), separated by a gap (30), the outermost
surfaces of which exhibit symmetrical tapering stretches (32) that converge upward
and stand marginally proud of the corresponding tapered cross sectional outline of
the centre piece (23);
in that the base (28) of the bridging plug exhibits cross sectional shape such as
matches that of the recess (101) offered by the first component section (1), and when
inserted thereinto, is held in place by the respective pair of lips (6, 7);
in that the top tapered part of the centre piece (23) of the plug exhibits cross sectional
shape such as matches that of the recess (108) offered by the second component section
(8), and when forced into position therein, is held in place by the snap joint created
between the respective pair of lips (12, 17) and the tongues (29) of the end pieces,
the tapering stretches (32) of which are rendered flexible by virtue of the gap (30)
existing between them; and in that, following location of the bridging plug, the first
and second component sections (1, 8) are separated by a given distance (34) that provides
the barrier across which transfer of heat between the two metallic components is inhibited.
2) Composite frame member as in claim 1, wherein the base (28) of the bridging plug
and the recess (101) created in the first component section (1) exhibit matching quadrangular
cross sectional profiles.
3) Composite frame member as in claim 1, the second component section (8) of which
exhibits a variation in embodiment (81) whereby the same substantially three-sided
trapezoidal recess (118) is bounded on either side by a pair of identical and symmetrically
disposed ribs (21, 22).
4) Composite frame member as in claim 1, wherein the paired tongues (29) of each end
piece (26) of the bridging plug are separated by a gap (30) that exhibits the shape
of a trapezium having its lesser base (31) located at bottom, coinciding with the
base (28), and opens out internally into a relative slot (25).
5) Composite frame member as in claim 1, wherein the tapering stretches (32) of the
paired tongues (29) of each end piece are separated from the base (28) by relative
undercuts (33), the position of which corresponds to similar undercuts (133) running
the entire length of the centre piece (23) at either side, and wherein the purpose
of such undercuts (33, 133) is to locate against and remain axially fast in relation
to the lips (6, 7) offered by the first component section (1) and the lips (12, 17)
offered by the second component section (8).
6) Composite frame member as in claim 1, wherein single lengths of the component sections
(1, 8) are joined rigidly to form the composite member by insertion into the respective
recesses (101, 108) and snapping in place of a plurality of bridging plugs, arranged
either close together or spaced apart.
7) Composite frame member as in claim 1, wherein the bridging plug fashioned in heat-insulating
material is embodied in PVC.