Roof beams

Abstract: A roof beam for use in forming a conservatory roof, comprising a glazing bar and upper and lower cappings fitted thereto the glazing bar being of generally inverted T-section providing a cross bar and an upstanding limb, the cross bar having a central section and edges in the form of side walls extending above and below the central section to form a recess in the underside of the glazing bar and the side walls having formations thereon for positive engagement with the lower capping, the lower capping comprising a channel section with co-extruded gaskets along edges thereof fitted over upper parts of the side walls.

Description: This invention concerns roof beams, especially for use in constructing conservatories and like structures having roofs comprising panels usually of translucent material supported between roof beams. Translucent panels for conservatory roofs are generally sandwiched at their edges between upper and lower roof beam forming extrusions or cappings coupled to a glazing bar, usually of aluminium. To provide a good seal above and below the translucent panels, provisions are made for the roof beam to retain gaskets in suitable positions. Upper roof beam forming extrusions or cappings may have gaskets formed integrally with panel contacting edges thereof and gaskets for the underside of the panels are usually retained in special formations of the aluminium glazing bars. These gaskets have to be fitted to the extrusions on site which takes up time. Also, the extrusions are more expensive to produce because of the additional gasket retaining formations required. Furthermore, in order to retain the lower beam forming cappings, the aluminium glazing bars require further formations on which the lower beam cappings can locate. In our co-pending British Patent Application No. GB-A-2275958 it was proposed to provide a roof beam construction for use in constructing conservatory roofs comprising a glazing bar and upper and lower cappings therefor having gaskets formed integrally on edges thereof between which a roofing panel is to be retained and means for locating the cappings on said glazing bar, wherein the means for locating the lower capping on the glazing bar comprises the integrally formed gaskets, which in use are trapped between the glazing bar and roofing panel. The lower cappings are formed with either a flat base or with a base having a pair of angled longitudinal facets. For each type of capping the glazing bar, generally an inverted T in section, has its cross bar correspondingly shaped, i.e. either flat or with two angled facets. In forming Victorian style conservatories, both types of glazing bar will usually be used. The glazing bars with the flat base and corresponding cappings are usually used as transom bars extending from opposite sides of a ridge of the conservatory to the eaves and the angled base glazing bars with corresponding cappings are used for forming the Victorian roof end, which is formed with triangular section roofing panels. Thus, in forming a Victorian style conservatory, two different types of glazing bar and lower cappings are required, which adds to the cost. Furthermore, care has to be taken when erecting such a conservatory to ensure that glazing bars are installed in the correct positions. An object of this invention is to provide a glazing bar for construction of roof beams for conservatories, which may have universal application for transom and Victorian situations as defined above. According to the invention there is provided a glazing bar for use in forming a conservatory roof, the glazing bar being of generally inverted T-section comprising providing a cross bar and an upstanding limb, the latter being in the form of a hollow section duct, wherein the cross bar has a central section and side walls that extend below the central section to form a recess in the underside of the glazing bar between the side walls. The side walls of the cross bar preferably also extend above the cross bar. Tops of the side walls preferably have inward returns and the side walls are preferably parallel to the plane of the upstanding limb. The overall height of the cross bar side walls may be chosen to receive transom and Victorian style lower cappings of the same or a similar depth, whilst the recess on the underside of the cross bar can accommodate the angled facets of the Victorian lower capping base. The glazing bars of the invention may also accommodate glazing panels at a variety of angles. Furthermore, as the same glazing bars may be used for transom situations and for roof end situations where glazing panels are angled relative to each other, it may be possible to use the same size top cappings on both rather than having to use a larger size top capping on the roof end glazing bars. The side walls forming the recess below the cross bar may be shaped so as to provide means of engagement with co-operating formations of a lower capping for the glazing bar. Such engagements may comprise, for example, corresponding hook like formations or may comprise ribs that snap fit into channels. Such channels are preferably formed internally of the lower cappings. Thus, with this type of formation for the cross bar, a capping having either a flat base or an angled facet base can be accommodated thereon, so that the need for two different formations of glazing bar can be eliminated. By having the top surfaces of the inward returns of the side walls arcuate or curved, integral gaskets on top edges of the capping can be accommodated irrespective of the angle of the co-extruded gasket. The inward returns of the side walls preferably also have top surfaces that are profiled or roughened in order to provide improved grip for the capping on the underside of the cross bar for co-extruded gaskets on edges of cappings, which in use are sandwiched between the glazing bar and glazing panels. For some situations, especially in large conservatory constructions, where glazing bars will be unsupported over a considerable length, there is a risk of them twisting. In these situations the provision of a ducted upstanding limb may be advantageous. The upstanding limb of the glazing bar of this aspect of the invention may be of any suitable cross section. One suitable cross section is a rectangular cross section but a tapered section either upwardly or downwardly, such as of a triangular cross section, may also be very suitable for the invention, especially in the form of an isosceles triangle either way up. A triangular section duct is believed to be advantageous in providing a self resolving shape for lateral forces. Another type of glazing bar according to this invention has two or more ducts, preferably spaced apart by single web stems. Preferably such ducts are of rectangular, especially square, section. Generally the double web duct should be as small as possible without losing the advantage of strength. That is to facilitate extrusion of that type of glazing bar, say from aluminium or aluminium alloy, it being easier to extrude smaller rather than larger enclosed sections. A preferred shape for the duct has a flat top and convergent sides from the flat top to a curved base. The ducts of glazing bars according to this aspect of the invention, as well as giving torsional stability to the glazing bars, may also be used to carry service cabling or piping and to provide locations for connecting members, such as fixing cleats or brackets of a tenon type. Furthermore, hollow duct glazing bar have improved "U" values compared to single stem glazing bars. Glazing bars of the invention may be secured to other components of a roof system by means of screws, bolts or the like through the cross bars thereof. However, for some situations end fixing of glazing bars may be desirable. For that purpose the upstanding limb of a glazing bar may be formed with a screw or bolt port to receive same in a longitudinal direction of the glazing bar. As the glazing bars of the invention will normally be formed as extrusions, the port will run the length of a glazing bar section and be available, therefore, at opposite ends of the glazing bar to receive a screw, bolt or other suitable fixing. The screw port may be formed as part of the upstanding limb duct preferably either at or just above the base thereof. Alternatively, the screw port may be formed in a single web upstand between the cross bar and a double web duct. The invention further provides a roof beam comprising a glazing bar of the invention with upper and lower cappings fitted thereto. A preferred lower capping is of extruded plastics material, such as PVC, and is preferably formed as a channel section with either a flat base or with a base having a pair of angled longitudinal facets. The gasket material is preferably co-extruded onto the capping and is preferably of rubber or a synthetic elastomeric material. The gaskets preferably extend inwards from opposite sides of the channel and may have deformable resilient ribs or the like, especially at edges and also possibly centrally thereof to provide a good seal when compressed. Preferred gaskets are generally arcuate in section, so that they are concave on their underside. This feature may be of advantage in fitting the cappings to glazing bars by allowing more room for the gaskets to be slipped over edges of the glazing bar cross bar. Internally of the lower cappings are preferably one or more spaced projections or ribs to ensure correct alignment of the glazing bar and capping when fitted together. The lower cappings may have their bases formed with a relatively flexible mid-section, which may facilitate fitting thereof to glazing bars. In one preferred form the lower capping base is formed with a co-extruded rubber or elastomeric strip centrally thereof along its length. The upper capping may be of any desired cross-section provided that it has at least one depending edge on which a gasket is formed. The preferred upper capping is formed by extrusion of plastics material, such as PVC, and has gaskets co-extruded onto its depending edge or edges, again preferably of rubber or of synthetic elastomeric material. Internally of the upper capping there is preferably a means for coupling the capping to the glazing bar. Preferably resilient formations depend from the inside of the capping, which formations have outward projections thereon and these formations locate in any upwardly open channel of the glazing bar which has a series of internal recesses or notches for receiving the projections allows the resilient depending formations of the cappings to be pressed down into the glazing bar any desired distance depending on the thickness of the roofing panel or panels which is or are being secured in place by the capping and make a snap fit. The upwardly open channel preferably has converging sides leading to first notches. The converging sides may be planar or curved. The channel is preferably sufficiently deep with sufficient notches or recesses to receive a single size capping irrespective of the depth of the glazing panels being accommodated. A series of two notches or recesses on each side of the channel, may be sufficient for most purposes provided the channel is deep enough. A roof beam according to the invention may be formed for locating the roofing panel on one side thereof, such as when the other side of the beam is to be secured to a wall or may be formed for locating roofing panels on opposite edges thereof for use intermediate edges of the roof structure. This invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a first roof beam arrangement not according to the invention; Figure 2 shows a second roof beam arrangement not according to the invention; Figure 3 shows a schematic plan view of a typical Victorian style conservatory; Figures 4 to 21 show various forms of glazing bar according to the invention and lower cappings therefor; and Figures 22 and 23 show variations on lower cappings for glazing bars according to the invention. Referring to Figures 1 and 2 of the accompanying drawings, which are included herein by way of explanation, a roof beam arrangement for forming conservatory or like roofs comprises a glazing bar 10, an upper capping 12 and a lower capping 14. In use roofing panels, such as of translucent plastics material, for example polycarbonate, will have their edges sandwiched between the upper capping 12 and the lower capping 14 on opposite sides of the roof beam arrangement. The glazing bar 10 is extruded from aluminium and is generally of T-section but inverted in use. Thus, the glazing bar 10 has a pair of flanges 16, which are turned back on themselves at their remote ends, and an upstanding limb 18 which is bifurcated to form an upwardly open channel 20 having generally parallel sides 22. On the inside of each side 22 is a series of notches 24 forming downwardly open recesses. Each flange 16 has a first part 25 generally perpendicular to the upstanding limb 18 and a second part which forms a trough 26 remote from the upstanding limb 18. The upper capping 12 is extruded from PVC and is generally of inverted V-section but comprises a flat top 28 and depending sides 30. The remote edges of the sides 30 have gaskets 32 formed thereon by co-extrusion of rubber or synthetic elastomeric material. Internally of the capping 12 and depending from its flat top 28 are a pair of resilient divergent flaps 34 having outwardly projecting lips 36 at their ends. The lower capping 14 is also extruded from plastics material, such as PVC, and is generally formed as a channel section having a flat base 38 and upstanding side walls 40. Internally of the channel on the base 38 and on the side walls 40 are spacing projections 42. The free edges of the side walls 40 have co-extruded thereon, from rubber or synthetic elastomeric material, gaskets 44 which extend inwardly and are inclined slightly upwardly. The gaskets 44 include resilient deformable projections 46 and 48 on their upper surface along their outermost edge and centrally thereof respectively. Figure 1 illustrates a typical transom roof beam but the same glazing bar and upper capping can be used with a different lower capping to form a Victorian style roof beam, in which the lower capping 50 has its base formed from a pair of longitudinal facets 52 angled relative to each other to form a concave surface when viewed from below. The capping has side walls 53 each perpendicular to its adjoining facet 52. Atop each side wall is a co-extruded gasket 55 extending inwardly and upwardly. As can be seen by comparison of Figures 1 and 2, both the flat base lower capping 14 and the faceted lower capping 50 can be accommodated on the same glazing bar 10. That is because for both lower cappings the distance between the co-extruded gasket and the base is the same, whilst the longitudinal central recess formed underneath the cross bar of the glazing bar lower capping accommodates the angled facets 52 of the base of the Victorian style lower capping 50. Figure 3 of the accompanying drawings shows where the different types of roof beam illustrated in Figures 1 and 2 may be used in forming a Victorian style conservatory 70. Typically a Victorian style conservatory 70 has a first part 72 having a central 74 ridge with rectangular roofing panels 76 sloping down from the ridge and supported between roof beams of the type of Figure 1 of the accompanying drawings, which have the lower cappings 14 with flat bases. One end of the ridge 74 will usually be abutted against another building and at the opposite end of the ridge is a bow end 78 having its roof formed of triangular section roofing panels 80 sloping down to the eaves. In this section of the conservatory the roof beams will be of the type shown in Figures 2 of the accompanying drawings which are generally known as Victorian style roof beams. Figures 4 to 21 show variations of glazing bar and lower capping combinations that may be in place of the glazing bars of Figures 1 and 2 in, for example, forming a roof of the type shown in Figure 3. In Figures 4 to 21 the glazing bar has a cross bar 800 that is flat but at each end are flanges extending upwardly and downwardly. Upper flanges 802 have inward returns 806 that are ribbed on their top surface for providing grip with the underside of the co-extruded gaskets of the lower cappings. Lower flanges 804 in the embodiments of Figures 4, 5 and 10 to 13 are returned inwards to provide hook like formations 807 that engage complementary formations 808 internally of the lower capping. Lower flanges 810 of the embodiments of Figures 6, 7 and 14 to 17 have outwardly projecting lips 812 engaged below complementary ribs 814 internally of the lower capping. Lower flanges 816 of the embodiments of Figures 8, 9 and 18 to 20 end with a bead 818 that is a snap-fit into complementary slots 820 in corners of the lower capping. In Figures 4, 7, 8 and 9 the glazing bars have a ducted stem 862 with a screw port 864 between the duct and the cross bar. The duct is generally an inverted isosceles triangle in section. In Figures 10, 11, 14 and 15 the glazing bars have ducted stems 870 but tapering upwardly. A screw port 872 is provided between the duct and the cross bar. In Figures 12, 13, 16, 17, 20 and 21 the glazing bars have stems 880 having two ducted sections 882 connected by a single web 884. A screw port 886 is provided between the lowermost duct and the cross bar. Finally in Figures 22 to 24, variations of the lower capping are shown. The main difference between these cappings and the previously described cappings is that each capping has a base 900 that is formed in three co-extruded parts i.e. between outer parts 902 of the cappings is a co-extruded strip of flexible material 904, such as of rubber or of other elastomeric material, whereby the cappings can be opened out to facilitate fitting thereof to glazing bars. The roof beam arrangements of Figures 4 to 21 are used in the following manner. The glazing bar is fixed between lateral beams of a roof under construction, such as between the ridge and the eaves, and the lower capping fixed onto the glazing bar. The roofing panels are laid on opposite sides of the reinforcing bar on top of the gaskets of the lower capping. Then the upper capping is pressed into place onto the reinforcing bar to hold the roofing panels in place, the gaskets of the upper and lower cappings providing good seals above and below the roofing panels. By providing sealing gaskets on the capping and the lower cappings instead of separately therefrom, the number of procedural steps for constructing a roof are reduced, so that the construction can be simpler and quicker than hitherto. Furthermore, as the same type of glazing bar can be used in different situations in the same conservatory, i.e. without the need for two different styles of glazing bar, cost may be reduced and erection of the conservatory may be simplified. Attention is directed to our co-pending British Patent Application No. GB2315800A concerning roof beam glazing bars and from which the present application has been divided.

Claims: A glazing bar for use in forming a conservatory roof beam, the glazing bar being of generally inverted T-section providing a cross bar (800) and an upstanding limb, the latter being in the form of a hollow section duct (862), wherein the cross bar has a central section and side walls that extend below the central section to form a recess in the underside of the glazing bar between the side walls (804). A glazing bar as claimed in claim 1, wherein side walls (804) of the cross bar also extend above the cross bar. A glazing bar as claimed in claim 2, wherein tops of the side walls (804) have inward returns (806). A glazing bar as claimed in claim 1, 2 or 3, wherein the side walls (804) are parallel to the plane of the upstanding limb (862). A glazing bar as claimed in any one of claims 1 to 4, wherein the inward returns (806) of the side walls (804) have arcuate top surfaces. A glazing bar as claimed in any one of claims 1 to 5, wherein the inward returns top surfaces are profile or roughened. A glazing bar as claimed in any one of claims 1 to 6, wherein the duct is of rectangular section. A glazing bar as claimed in any one of claims 1 to 6, wherein the duct (862) is of triangular section. A glazing bar as claimed in any one of claims 1 to 6, wherein the duct (862) has a flat top a curved base and convergent sides from the top to the base. A glazing bar as claimed in any one of claims 1 to 6, wherein the upstanding limb (880) comprise a pair of ducts (882) one above the other. A glazing bar as claimed in any one of claims 1 to 10, wherein the upstanding limb includes a port (886) for receiving a fixing screw or bolt. A glazing bar as claimed in any one of claims 1 to 11 including means (812) for positive engagement with a lower capping for the glazing bar. A roof beam comprising a glazing bar as claimed in any one of claims 1 to 12 and upper and lower cappings fitted thereto. A roof beam as claimed in claim 13, wherein the lower capping (900) has lengthwise a flexible central strip (904).

Inventors: RICHARDSON CHRISTOPHER, RICHARDSON, CHRISTOPHER
Applicants: ULTRAFRAME UK LTD, ULTRAFRAME (UK) LIMITED
Application year: 1997
Main classification: E04D3
IPC codes: E04D3, E04B7