Background to the Invention A roof vent consists of a frame and a sash for holding a glazing element, such as a double-glazing unit. To fit the roof vent into a glazed structure such as a conservatory the vent frame has to be secured in between two glazing bars and also between two glazing elements.

The glazing elements can be of a variety of thicknesses, for instance 16mm, 25mm or 35mm. A given glazing bar is normally intended to receive a given glazing element on either side thereof, for instance a 25mm glazing.

However, in a roof vent application the glazing bar on one side needs to receive a glazing element and on the other the frame of a roof vent. Since the frame of the roof vent is also intended to receive a 25mm glazing element (in this example) in the current practice the glazing bar tends to be trimmed to fit which can add to the complexity of assembly and lead to leakage.

Further, given the different glazing element thicknesses available it is undesirable to have to produce entirely new extrusions for the frame for each size.

It is an aim of preferred embodiments of the present invention to obviate or overcome a disadvantage encountered in relation to the prior art, whether referred to herein or otherwise.

Summary of the Invention According to the present invention in a first aspect, there is provided a roof vent comprising a frame and a sash, means for connecting the frame to the sash, the frame comprising a glazing element receiving portion and a glazing bar seating portion, the glazing bar seating portion being of a reduced external width in cross-section as compared to the external width of the glazing element receiving portion.

Suitably, the glazing bar seating portion is of a reduced width by the additional thickness of the glazing element receiving portion. Suitably, the external width of the glazing bar seating portion corresponds to the internal width of the glazing element receiving portion.

Suitably, the glazing bar seating portion comprises a first limb and a second limb, the first limb being intended to lie over part of a first surface of a glazing element and the second limb being intended to lie over a part of the second surface of the glazing element, the glazing bar seating portion forming a generally U-shaped receiving portion behind the base (of the U) of which is the reduced width portion.

Suitably, the glazing bar seating portion is configured to seat a glazing bar top cap and a glazing bar bottom cap on either side thereof.

Suitably, the means for connecting the frame to the sash comprises means for opening the roof vent, normally pivotally.

According to the present invention in a second aspect, there is provided a conservatory structure comprising a roof vent according to the first aspect of the present invention, a glazing bar and a glazing element, in which the glazing bar engages on one side with the frame of the roof vent and on the other side engages with a glazing element.

According to the present invention in a third aspect, there is provided a method of assembly of a conservatory structure, which method comprises the steps of engaging a glazing bar with a roof vent frame according to a first aspect of the present invention.

According to the present invention in a fourth aspect, there is provided a method of assembly of a roof vent, which method comprises the steps of providing a roof vent frame or sash element, selecting a glazing bead of a desired size from a plurality of available sizes and attaching the glazing bead to the frame or sash element.

Suitably, the vent is according to the first aspect of the present invention.

Suitably, glazing beads are provided to provide a glazing element receiving portion for receiving glazing elements of widths selected from 16mm, 25mm and 35mm.

According to the present invention in a fifth aspect, there is provided a method of assembly of a conservatory structure, which method comprises the step of providing a roof vent in the conservatory structure according to the fourth aspect of the present invention.

According to the present invention in a sixth aspect, there is provided a kit for a roof vent, which kit comprises a sash and a frame, which frame comprises a glazing element receiving portion comprising a first limb for contacting a part of a first side of a glazing element and means for receiving and engaging a second limb for contacting a part of a second side of a glazing element, in which a plurality of second limb beads are provided whereby the width of the glazing element receiving portion can be adjusted.

Suitably, the engaging means comprises a fir-tree formation to enable the push fitting the second limb bead into the frame.

Suitably the glazing beads include a tail portion extending the limb, which tail portion is configured as a screw cover.

Suitably, the frame comprises at least one drill guide for the formation of a drainage channel therethrough.

Brief Description of the Drawings Embodiments of the present invention will now be described, by way of example only, with reference to the drawings that follow; in which: Figure 1 is a cross-sectional elevation of a roof vent according to an embodiment of the present invention, with the vent shown in an open and a closed configuration.

Figure 2 is an enlarged cross-sectional elevation of the frame, sash and glazing bar shown in Figure 1.

Figure 3 is a view corresponding to Figure 1 with a larger glazing element.

Figures 4A-4C are cross-sectional elevations of a roof vent engaged with a glazing bar of, respectively, different widths.

Figures 5A-5C are cross-section elevations of a roof vent according to the present invention engaged with a glazing element of different widths.

Figures 6A-6C are cross-sectional elevations of the frame and sash arrangements of Figures 5A-5C without the glazing elements and glazing bar for clarity.

Like reference numerals are used for like parts in the figures.

Description of the Preferred Embodiments Referring to Figures 1 and 2 of the drawings that follow there is shown a roof vent 2 comprising a frame 4 and a sash 6, means 8 for connecting the frame 4 to the sash 6, the frame 4 comprising a glazing element receiving portion 10 and a glazing bar seating portion 12, the glazing bar seating portion 12 being of a reduced external width in cross-section as compared to the corresponding external width of the glazing element receiving portion 10.

A roof vent glazing element 14 is provided in the sash 6.

The frame 4 is engaged in a glazing bar 16 on one side thereof. On the other side of glazing bar 16 a glazing element 18 is engaged.

Sash 6 comprises a plastics extrusion 20 of substantially constant cross-section with an aluminium structural reinforcement extrusion 22 in a channel thereof. The plastics extrusion 20 of sash 6 includes a limb 24 for contacting a part of a first surface of glazing element 14, which limb 24 includes a co-extruded gasket 26. The sash further includes a screw port for receiving screw 28 for attaching the first part 30 of connection means 8 to the sash 6. A second limb 32 for contacting the other surface of glazing element 14 is provided by glazing element receiving glazing bead 34. The second limb is provided with a coextruded gasket 36 at the distal (glazing element contacting) end thereof. The bead 34 includes an upstanding portion 38 perpendicular to limb 32, which upstanding portion comprises a fir-tree formation for engaging in a corresponding slot 40 with

serrations or the like for receiving the fir-tree formation and enabling it to engage in the slot 40. Thus the slot 40 acts as a means for receiving and engaging the bead 34. The bead 34 further comprises a tail 42 extending perpendicular to the upstanding portion 38 and is generally an extension of the limb 32. The tail 42 is used as a screw cover to improve the aesthetics of the roof vent and minimise the risk of a screw falling.

The frame 4 (also a plastics extrusion) additionally comprises a sash support 44 and a body portion 46. Sash support 44 is generally perpendicular to body portion 46 and includes a screw port for receiving a screw 48, which secures a second part 50 of the sash and frame connection means 8 thereto. The sash and frame connection means 8 enables pivotal movement of the sash 6 relative to the frame 4 and thereby opening of the roof vent 2. The sash support 44 includes two gaskets 52 for softly seating the sash 6 thereon. A drill guide 54 is provided to assist in the drilling of a drainage channel (horizontally in Figure 2) through the sash support 44.

Body portion 46 includes a channel 56 for receiving an aluminium structural reinforcement extrusion 58 secured in place by screw 59.

Extending from body portion 46 is a first limb 60 for contacting a first surface of a glazing element (which it will need to do on another side of the vent), which includes a coextruded gasket 62. A second limb 64 for contacting the opposite side of a glazing element is provided with a coextruded gasket 66. The second limb 64 is provided by a glazing element receiving glazing bead 68

that is substantially similar to the bead 34 used with the sash 6 and incorporates substantially similar parts and features, including an upstanding portion 70 and a tail 72.

Glazing bar 16 comprises an inverted-T 82 forming a central aluminium extrusion, a top cap 84 and a bottom cap 86. Top cap 84 includes depending arms 88,90, at the end of each of which is a respective co-extruded gasket 92, 94.

It is noted that the glazing bar seating portion 12 (more easily seen in Figures 6A-6C in which the glazing bar is not present) is of a reduced width when compared with the corresponding external width of the glazing element receiving portion 10. This can be seen clearly, by way of example with reference to Figure 6A in which the internal width for receiving a glazing element is 16 mm and the external width for the glazing bar receiving portion 12 is also 16 mm because of the sloped section 74 which reduces the external cross sectional width to that of the internal cross sectional width. However the external width of the glazing element receiving portion is 22 mm because of the additional width (2mm each) of the limbs 60 and 64. Thus the glazing bar 16 can be fitted over the external width of the glazing element receiving portion to seat in the reduced width portion without straining the glazing bar when in place and without the need for trimming.

Referring now to Figure 3 of the drawings that follow there is shown a view similar to that of Figure 2 in which a wider glazing element is used (and hence a larger glazing bar 16). It is noted that the bead 34 provides

for the wider glazing element 14 and the corresponding bead for engaging with the glazing bar 16 is also wider.

Thus a plurality of glazing element widths can be accommodated using a plurality of corresponding glazing beads in a kit.

Referring to Figures 4A-4C and 5A-5C of the drawings that follow, there are additional views of frames 4 engaging with glazing bars (Figures 4A-4C) and with glazing elements 80 (Figures 5A-5C), accommodating different widths.

The vent described can be incorporated as part of a conservatory structure. A method of assembly of a vent as part of such a structure will now be described.

During the design phase a glazing element width will be selected, let us say 24 mm, for use in a conservatory and in particular for a rafter. Accordingly, glazing beads 34, 68 are selected of an appropriate size and a are push fit into and engaged with the frame 4 and sash 6 to be used. The fir-tree structure of the beads provides a secure fit, enabling the bead and frame/sash to interengage. As appropriate glazing bars 16 and glazing elements 80 are fitted to the frame 4. Glazing bars 16 are fitted so that one of the ends of depending arms 90 rests in the glazing bar seating portion 12 and/or the coextruded gasket 94 thereof. The reduced width enables the glazing bar to sit in the glazing bar seating portion without undue stress. and without the need for trimming.

The glazing element 80 is inserted in a glazing element receiving portion 10 with the external major surfaces of the glazing element in contact with the respective limbs

of the glazing element receiving portion. The glazing element lies between the two limbs and will normally be a good fit between them.

Further a conservatory structure can be assembled incorporating a vent in the manner described above.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.