Note: Descriptions are shown in the official language in which they were submitted.
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Roof Construction
BACKGROUND OF THE INVENTION
This invention concerns roof construction, especially glazed roof
construction.
Glazed roofs, particularly for conservatories are often constructed from
glazing
panels, which may be of glass or of plastics material, such as polycarbonate
or polyvinyl
chloride, supported between glazing bars of aluminium. The glazing panels are
held in
place by cappings that engage with the glazing bars and whose edges sit on the
glazing
panels with gasket material trapped therebetween.
It is known for cappings to be of plastics material typically PVCu, but for
some
applications aluminium cappings are desirable. There are, however, two
problems with
the use of aluminium cappings. The first is that their engagement or direct
contact with
aluminium glazing bars provides a route for cold transference from outside the
roof to
inside where condensation can occur. The second problem is that of fitting the
aluminium capping to the glazing bar. Typically aluminium cappings are fixed
onto
glazing bars with screws through the cappings at spaced intervals. Firstly ,
the screws
can be unsightly but secondly, and more significantly, compression onto
glazing panels
is unevenly distributed along the length of the cappings.
An object of this invention is to provide means whereby use of aluminium
cappings in glazed roof construction may be facilitated.
SUMMARY OF THE INVENTION
According to this invention there is provided a roof beam system for use in
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constructing glazed roofs, the system comprising a glazing bar for supporting
glazed
panels on one or both sides thereof and an aluminium capping for holding down
the or
each glazing panel, the capping being secured to the glazing bar by a plastics
connector.
The glazing bar is preferably of inverted T-section, in use, having a cross
bar and
an upstand. The upstand preferably has a part for engagingly receiving the
connector.
The capping preferably has on its underside means for engagement with the
connector.
The top of the upstand preferably has a channel with notched sides, with which
depending formations of the connector can engage to a desired depth. The
connector
preferably has an inverted T-shaped groove in its top surface for slidingly
receiving a
complementary rib on the underside of the capping.
The capping preferably has co-extruded or bonded gasket material along its
free
edges for sealing against the glazing panels. Separate gasket strips may
alternatively be
provided on the capping free edges.
The connectors being of plastics material form a thermal barner between the
aluminium capping and glazing bar.
The connectors of the invention may be used as a continuous strip extending
substantially the length of the capping. Alternatively spaced connectors may
be used.
The plastics connectors) may be attached to the aluminium capping, by sliding
the connectors along the capping and then the capping with connectors) pressed
down
onto the glazing bar to engage the glazing bar.
BRIEF DESCRIPTION OF THE DRAWING
This invention will now be further described, by way of example only, with
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reference to the accompanying drawing, which is a section through part of a
conservatory roof.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the accompanying drawing, a conservatory roof comprises glazing
panel 10, typically of polycarbonate, polyvinyl chloride or glass, supported
between
glazing bars 12. The panels 10 are held in place by top capping 14 of
aluminium.
The glazing bar 12 is extruded from aluminium and is generally of T-section
but
inverted in use. The glazing bar has a cross bar formed by a pair of flanges
16, which
are turned back on themselves at their remote ends, and an upstanding limb 18.
Each flange 16 has a first part 25 angled downwards slightly relative to the
upstanding limb 18 and a second part which forms a trough 26 remote from the
upstanding limb 18.
The upstanding limb 18 has a first part extending from the cross bar that has
a
single web 28 including a screw port 30 and a second double web ducted part
32. The
webs continue above the ducted part 32 to form an upwardly open channel 20
having
generally parallel sides 22. On the inside of each side is a series of notches
24.
The channel 20 provides a location for engagingly receiving a connector strip
34,
which connects the top capping 14 to the glazing bar 12. The top capping 14 is
generally of inverted V-section but has a flat top 36 and depending outwardly
angled
sides 38. Remote edges of the sides have gaskets 40 thereon formed by co-
extrusion or
bonding of gasket material thereon, such as of rubber or synthetic elastomeric
material.
The remote edges of the sides 38 are formed with T-section channels to receive
part of
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the gasket material to prevent stretching and shrinkage. The gaskets 40 have
three
spaced ribs on their glazing contacting surface that can spread to improve
contact
therewith and hence the seal between the capping and the glazing panels.
The connector strip 34 is made of plastics material and has a top 60 and a
pair of
outwardly extending resilient limbs 62 depending from the top. The top 60 has
a flat top
surface with an inverted T-section groove 64 formed therein. The underside of
the top
has channels 66 formed therein either side of the limbs 62, which enable the
connector
strip to sit on the tops of the webs forming the sides of the channel 20 of
the glazing bar.
Ends of the limbs 62 have ribs 70 that can engage under notches 24 to retain
the
connector strip in place.
On the underside of the flat top 36 of the capping is a T-section rib S0. The
rib
50 slidingly engages in the correspondingly shaped groove 64 in the top of the
connector
strip 34.
The connector strip 34 is slid into position on the capping 14 and then the
assembly pushed down into place on the glazing bar. Because the connector
strip is of
plastics, the limbs 62 are resiliently flexible so that as the strip is pushed
down onto the
glazing bar, the limbs can deform inwards as their ends pass over the notches
24 until the
strip has been pushed down to a desired extent in order to press the gaskets
onto the
glazing panels to form a good seal therebetween.
A bottom capping 80 is shown on the glazing bar cross bar. The capping 80 is
of
channel section and has co-extruded or co-bonded gasket material 82, such as
of rubber
or synthetic elastomeric material, along each top edge. The capping is held in
place by
the gasket material being trapped between the glazing panels and the glazing
bar.
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The connector strip 34 has a number of advantages. The first is to provide a
thermal break between the top capping and the glazing bar. As these are both
of
aluminium, direct contact between them would provide a route for cold
transference
from the outside to cause condensation on the inside of the roof.
Secondly, the engagement between the top capping and the connector strip is
continuous, so that compression on the glazing panel is distributed
substantially evenly
along the length of the capping.
Thirdly, the connector strip controls the distance between the glazing bar and
the
aluminium top capping. Being of plastics, the connector strip can accommodate
variations more easily than the relatively rigid aluminium capping and glazing
bar.
Instead of using a continuous connector strip 34, it is possible to use
shorter
portions thereof at spaced intervals along a glazing bar to connect the
capping to the
glazing bar.
