The present invention relates to cappings for use in conservatory roof construction.
A typical glazing bar comprises an extruded aluminium elongate member having an upstanding central web and a cross-bar in the form of say transverse side arms depending from each side thereof to support glazing panels to either side thereof. The glazing bar is provided with upper and lower cappings. The cappings are made of plastics having relatively thin single skin walls.
In one known construction the upper and lower capping have gaskets along edges thereof between which roof panels, usually glazing panels, are to be retained, and means for locating the cappings on the bar. The flexibility of the single skin aids sealing of the cappings with the roof panel, but has disadvantageous thermal properties. In addition the single skin open profiles can be vulnerable to distortion under certain circumstances, for example, during transit and handling and sometimes under the influence of solar radiation, especially in the case of dark colours.
To deal with the problem of distortion aluminium cappings have been used but aluminium has a poor thermal performance relative to plastics material.
Cappings of single wall plastics material are also used for other structural members of a conservatory roof, such as ridge beams and in valley constructions, where similar problems exist due to exposure of the cappings to solar radiation.
The present invention aims to provide a solution.
According to the present invention there is provided a capping of plastics material for location on a structural member of a conservatory roof, wherein the capping is twin-walled and has means for location thereof on the structural member.
The structural member may be, for example, a glazing bar, a ridge beam or of a valley construction.
In one preferred embodiment the invention provides a glazing bar and an upper capping therefor of plastics material and means for locating the capping on the glazing bar, the glazing bar having a stem and lateral flange means for supporting roofing panels directly or indirectly, and wherein the upper capping comprises at least a twin wall construction.
For cappings of the invention, multiple walls with spacing webs may be used. Conveniently a twin wall construction is employed having inner and outer walls having a plurality of spaced webs extending therebetween to divide the twin wall construction into a plurality of chambers. Alternatively additional walls can be added to form further chambers.
Insulation material, such as foamed plastics materials, for example of PVC or other suitable materials may, be added to the walls or to fill the chambers for enhanced thermal effects. More usually a capping of the invention has a top and two depending sides. The depending sides have a gasket along edges thereof for sealing on roofing panels retained on the glazing bar. The edges thereof extend between the ends of the inner and outer walls of the capping. The gasket conveniently forms part of said edge spanning the gap between the ends of the inner and outer walls. The gasket preferably includes a body connecting with the capping and one or more lips, which branch from the body and engage the roofing panel. More particularly the inner wall terminates at a greater distance from the roof panel than the outer wall so that the gasket is at least partially concealed by the outer wall.
More preferably, the glazing panel further comprises a lower capping, which is of twin wall construction, although it could have more than two walls. As with the upper capping web elements between the inner and outer walls define a plurality chambers. The twin skin construction, with or without foam, serves to provide improved thermal insulation compared with the known single wall cappings. The lower capping includes means for locating it with respect to the glazing bar.
More particularly, end edges of the lower capping carry respective gaskets to engage with the underside of the roofing panels.
When the upper capping is in place a duct is formed underneath it, between it and the roofing panels. More correctly two ducts are formed, one each side of the glazing bar upstand. Those ducts form a useful insulating chamber, however it has been found that the thermal insulating properties may be further enhanced if the duct is sub-divided.
Accordingly, another preferred embodiment of the invention provides a glazing bar and an upper capping therefor of plastics material and means for locating the capping on the glazing bar, and wherein the glazing bar has a stem and lateral flange means for supporting roofing panels, and wherein the space within the capping between the stem and the roofing panel is divided into at least two chambers.
More preferably, the space is divided into inner and outer chambers. The division may be by projections formed on the stem and extending towards the inside wall of the capping. More preferably, the division is formed by projections that depend from the inside of the capping. Preferably the projections extend up to said stem. However, it is not essential that the projection make physical contact with the stem. It can stop short of the stem and still give advantageous thermal barrier effects. Where the division branches from the stem it can stop short of the capping. More preferably the dividing wall or projection is arcuate as seen in cross-section.
The various aspects of the invention will now be described further hereinafter, by way of example only, with reference to the accompany drawings; in which:
Referring firstly to
The capping in the embodiment of
It will be noted that the inner and outer end regions are spaced by different amounts from the roofing panel. More particularly, the inner end region 62 is disposed a greater distance from the roofing panel than the outer end region 64. Thus the line between the ends as inclined relative to the roofing panel rather than parallel thereto. As mentioned above, this is advantageous, because it enables the gasket to be at least partially concealed by the outer walls.
The gasket may be a separate component from the capping, but preferably it is formed integrally with it. Conveniently it is bonded in place. It may be formed as a co-extrusion, or as a post-extrusion.
The construction of
Referring now to
It will be understood that the division of the space within the capping according to this aspect of the invention could be applied to cappings having a single wall construction rather than those having the multi-wall construction of the present invention.
The presence of the insulating foam may avoid the need for the dividing webs 48,86. In other words the capping can be formed as a sandwich comprising skins of plastics sandwiching the foamed insulation layer therebetween.
Whilst the invention has been described with reference to cappings for glazing bars, it will be appreciated that the invention may also be applied to other plastics cappings used in conservatory roof construction, such as cappings for ridge beams and for valley constructions and especially those in positions exposed to direct sunlight.
Number | Date | Country | Kind |
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0315328.5 | Jul 2003 | GB | national |
0315476.2 | Jul 2003 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB04/02833 | 7/1/2004 | WO | 7/31/2006 |