Note: Descriptions are shown in the official language in which they were submitted.
CA 02338894 2001-02-28
TITLE: Improvements in and relating to roof beams.
DESCRIPTION
This invention concerns improvements in and relating to roof beams for
use in forming glazed roofs, especially conservatory roofs, and particularly
conservatory roofs having hipped ends where roof beams are supported
additionally by jack rafters.
So-called Georgian style conservatory roofs usually have a hipped end
that is square at its corners. Roof beams for supporting glazing panels
extending from a ridge-end to the corners often have one or more jack rafters
connected between those beams and the eaves of tlhe conservatory roof
Typical roof beams comprise an aluminium glazing bar having a cross bar
and an upstand glazing panels being supported on either side of the crass bar
and bottom uPVC cappings conceal the aluminium glazing bar and have gasket
material on edges thereof to seal against top and bottom surfaces of the
glazing
panels. There is a demand for the top cappings of the roof beams to be
decoratively profiled but that requires complicating cutting of jack rafter
cappings
to abut neatly against the main roof beam cappings.
Another problem with the fitting of jack rafters is that if they are slightly
out
of true in either the vertical or horizontal planes, that can be very
noticeable from
inside the conservatory because the jack rafter bottom capping will not b a
flush
with the main roof beam capping.
CA 02338894 2001-02-28
2
An object of this invention is to provide a roof' beam for use in forming a
glazed roof, which can avoid one or more of the aforementioned problems.
According to a first aspect of this invention thE;re is provided a roof beam
construction for use in constructing conservatory roofs comprising a glazing
bar
and an upper capping therefor having gaskets along edges thereof between for
sealing on roofing panels retained on the glazing bar and means for locating
the
capping on the glazing bar, wherein the upper capping has a top and depending
sides, the top being in the form of a duct having .a base and a decoratively
profiled top.
The depending sides of the upper capping are preferably flat.
By having the sides of the capping flat, a capping for a jack rafter need
only be cut straight to abut neatly against the flat side of the upper capping
of a
main roof beam.
The roof beam of the first aspect of the invention preferably also
comprises a lower capping mounted on the glazing bar and having gaskets
along edges thereof, roofing panels being retainable between the respective
gaskets of the upper and lower cappings.
According to a second aspect of this invention there is provided a roof
. beam construction for use in constructing conser'~atory roofs comprisiing a
glazing bar and upper and lower cappings therefor having gaskets along edges
thereof between which roofing panels are to be retained and means for locating
the cappings on the glazing bar, wherein the lower capping is formed in two
parts, the first having the gaskets on its edges and having its base extending
CA 02338894 2001-02-28
3
beyond its sides to provide locations for attachment of the second part which
is
shaped to provide ledges on opposite sides thereof.
The ledges are provided so that jack rafter' bottom cappings can be
extended over those ledges, whereby the meeting of the rafter bottom capping
with the bottom capping of the main roof beam is concealed from below.
Preferred roof beams of the invention will have both upper cappings
according to the first aspect of the invention and lower cappings according to
the
second aspect of the invention.
The invention further provides a roof construction comprising roof beams
according to any aspect of the invention, with or without jack rafters, and
supporting glazing panels therebetween.
A preferred upper capping according to the invention has formations
depending from the base of its profiled top for engagement with the glazing
bar
head to retain the capping thereon.
Gaskets for the upper capping are preferably on inwards returns of the
capping sides the returns preferably being resiliently flexible, whereby when
in
place on a glazing bar, the gaskets are concealed from view.
Lower cappings for roof beams of the invention preferably rely on gasket
strips on the free edges to overlie the glazing bar cross bar ends to be
trapped
between the glazing bar and the roofing panels thereon.
This invention will now be further described, by way of example on ly, with
reference to the accompanying drawings, in which:
Figure 7 is a schematic plan view of a Georgian style conservatory roof;
CA 02338894 2001-02-28
4
Figure 2 is an end view of a Georgian style roof beam assembly; and
Figure 3 is an isometric view of a Georgian roof beam assembly with jack
rafter but omitting glazing panels.
Referring to Figure 1 of the accompanying clrawings, a Georgian style
conservatory has a hipped roof 10 with a first part 12 having a ridge 14 and
transom roof beams 16 extending at right angles thE:refrom down to eaves 18.
The kipped part 20 of the roof from a pair of roof beams 22 extending
downwardly from the ridge end to corners of the roof. Because of the steepness
of the angle of these roof beams and consequently t:he angle of glazing panels
24, the beams 22 and their cappings have to be of different shape from those
of
the transom roof beams. Georgian style conservatory roofs also have jack
rafters 26 which connect the diagonal beams 22 to thE: eaves.
Figures 2 and 3 of the accompanying drawings show a roof beam system
for the kipped part of the Georgian style conservatory roof of Figure 1 and in
particular for the roof beams 22 and jack rafters 26.
Roof beams 22 comprise a glazing bar 30, an upper capping 32 and a
lower capping 34. In use, roofing panels 24, such as of translucent plastics
material, for example, polycarbonate, will have their edges sandwiched between
the upper capping 32 and the lower capping 34 on opposite sides of the roof
beam arrangement.
The glazing bar 30 is extruded from aluminium and generally of T-section
but inverted in use having a cross bar 36 and an upstanding limb 38. Th us,
the
glazing bar 30 has a pair of flanges 40 forming the cross bar, which are
returned
CA 02338894 2001-02-28
back on themselves at their remote ends 41. The upstanding limb 38 has a first
part 42 extending from the cross bar 36 that has a single web and includes a
screw port 44 and a second double web ducted part 48. The top of the limb 38
forms an upwardly open channel 50 having sides 52. On the inside of each side
52 is a series of notches 54 forming downwardly open recesses.
Each flange 40 has a first_ part generally sloping slightly downwards from
the limb 38 and a second part which forms a trough 58 remote from the limb 38.
The upper capping 32 is extruded from uPVC and is generally of inverted V-
section but comprises a decoratively shaped top 60 and flat sides 62. The tap
60 is formed as a duct having a flat base 63 joining tops of sides 62 and
strengthening webs 65 from the centre of base 63 diagonally to spaced points
of
the top 60.
The sides 62 are stepped inwards at their bottom edges to form gasket
receiving edges 64 inwards of the sides 62. The edges 64 are thinner than the
sides of the capping and are resiliently flexible by means of a line of
weakness,
thinning of the material where the edges and sides nneet. That allows a spring
action to urge gaskets 66 on the edges 64 onto the glazing panels to improve
the seal.
- The rubber or synthetic elastomeric material gaskets 66 are co-extruded
or bonded onto the edges 64. The gaskets 66 are formed as strips having
divergent deformable sides 67, 68. As can be seen, when the upper capping is
pressed onto the glazing bar, the gaskets are hidden effectively by the
overhang
of the returned sides of the capping. Furthermore, the returned sides may
CA 02338894 2001-02-28
6
provide the capping with greater resilience, so that the capping can form a
good
seal against glazing panels and also to reduce the risk of the capping
splitting
where sides 62 join the top 60 by application of excessive force in fitting
the
capping. Internally of the capping and depending from base 63 of the top
profile
are a pair of resilient divergent filaps 69 having outwardly projecting lips
70 at the
ends. These flaps slot into the channel 50 of the limb 38 and the lips 70 are
retained by the notches 54 when the capping is pressed onto the glazing bar.
The lower capping 34 is in two parts 74, 76 both being formed as a uPVC
extrusion. The first part 74 is formed as a channel having a base with two
angled facets 78 and upstanding side walls 80. FrE:e edges of the walls carry
co-extruded or bonded gaskets 82 of rubber or synthetic elastomeric material,
extending inwardly.
The gaskets 82 having resiliently deformable projections 84, 86 on their
upper surfaces along their free edges and generally centrally thereof
respectively.
The base of the capping part 74 extends beyond the sides 80 to form lips
88 on which the second part 76 of the lower capping locates. The second part
76 has a flat base 90 and sides 92 than have firstly a decoratively profile
(94),
irLwards steps to provide outer ledges 96 and finally straight parts 98 that
overlie
the sides of the first lower capping part 74. Internally of the capping part
76 are
lips 100 that sit on the lips 88 of the first capping part 74 to retain the
capping
part 76 in place. The second capping part 76 will be slightly resilient to a
Ilow its
sides to bend slightly for it to snap onto the first capping part.
CA 02338894 2001-02-28
7
The form of the upper and lower cappings are useful in accommodating
finking of jack rafters 26 to the glazing bars 22 (see f=figure 2). The
connections
between the jack rafters 76 and the glazing bars can be, for example, as shown
in co-pending patent application number GB 232310i'A. There is a demand for
glazing bar cappings to be decorative. However, if the upper capping is
decoratively profiled over the full depth of its sides, upper capping 102 for
the
jack rafter has to be cut to match, which is difficult and time consuming to
do
accurately on site. However, by having the decorative profiling for the upper
capping at its top leaving the sides flat, there is relatively little
difficulty in straight
cutting of a jack rafter upper capping end to match.
Also, internally of the roof, where the jack raflrer meets the main glazing
bar, if the bottom capping 104 is not cut sufficiently accurately or the jack
rafter
is slightly skewed, the meeting between the jack rafter bottom capping and a
coriventional glazing bar bottom capping can have <~ spoiled appearance. By
providing a bottom capping for the glazing bars ~'.2 that has ledges 96 on
opposite sides thereof, the jack rafter bottom cappings can extend onto the
ledges and so the meeting of the jack rafter and glazing bar bottom cappings
is
effectively hidden from below, so any misalignment will not be apparent.
Where the glazing bars 22 reach the eaves of i:he roof at a corner the first
bottom capping part 74 can be extended over the eaves to provide a drainage
path to the guttering. The second part 76 has to be cut to length to abut
internal
cladding at the eaves. Using corner connectors of thE; type described on our
co-
,i,,
CA 02338894 2001-02-28
pending application number (our reference P4500) bottom capping part can be
cut straight across, otherwise it will need to be mitred into the corner.
The decorative top 60 of the upper capping being in the form of a duct
acts as a drainage passage. If the upper capping is cut back at all under a
ridge
end apron, any water penetration under the apron can drain away through the
duct and out into guttering at the eaves.
