This invention concerns improvements in and relating to window screens or blinds, especially but not exclusively, to window screens or blinds suitable for installation in conservatories.

Window blinds are commonly installed in conservatory roofs to provide a heat and light barrier. Such blinds are usually of pleated fabric that slide along cords fixed usually between top and bottom frame members of the roof. Fitting of window blinds to a conservatory roof can be difficult, firstly because of having to retrofit attachment means for ends of the cords, and secondly because many conservatory roofs have triangular panel sections where upper attachment of the cords has to be to side frame members.

Window blinds are, of course, also fitted to conventional windows. Different types of blinds are available, such as roller blinds and "Venetian blinds". A common problem with window and conservatory roof blinds is that gaps may be present between the edges of the blinds and the window frames between which they are mounted allowing light to penetrate, which can be irritating to persons close to the windows who may be dazzled by the light. Furthermore, penetration of light may cause damage, such as discolouration, over a period of weeks, months or years to soft furnishings.

An object of this invention is to provide an improved window blind or screen system suitable for use with windows and conservatory roofs.

According to a first aspect of the invention there is provided a blind or screen system for a window, especially of conservatory roof, wherein a blind or screen is supported between sides of the window in a manner that edges of the blind or screen are concealed by parts of, or attached to, the sides of the window. According to a second aspect of the invention there is provided a blind or a screen system for a window, especially of a conservatory roof, wherein a blind or screen is of flexible material and supported between sides of window in a manner that edges of the blind or screen are concealed by parts of, or attached to, the sides of the window.

According to a third aspect of the invention there is provided a blind or screen system for a window, especially a conservatory roof, wherein a blind or screen is of flexible material and supported with its side edges in channels of, or associated with, sides of the window.

According to a fourth aspect of the invention there is provided a blind or screen system for a window, especially of a conservatory roof, wherein a blind or screen is of flexible material provided with support means to retain the screen or blind in channels of, or associated with, sides of the window.

According to a fifth aspect of the invention there is provided a blind or screen for a window, especially of a conservatory roof, comprising a pair of spaced apart slidable bars, a screen material secured to the spaced bars and means for tensioning the screen material.

According to a sixth aspect of the invention there is provided a blind or screen for a window, especially of a conservatory roof, comprising a pair of spaced apart slidable bars, a screen material secured to the spaced bars and the screen being deformable for fitting to retaining channels.

According to a seventh aspect of the invention there is provided a window assembly, especially of a conservatory roof, comprising a pair of window side frame members supporting glazing panels therebetween, wherein each side frame member has a facing longitudinal slot for receiving one side of a slidable screen, the screen comprising a pair of spaced apart side members having screen material secured therebetween and means for tensioning the screen material.

The screen or blind used in the invention will generally require tensioning means. The tensioning means may be provided as a component of the screen or blind or may be provided by means of attachment of the blind or screen to the window.

The means for tensioning the screen material is preferably at least one substantially rigid but resiliency deformable member. The use of tensioning means is primarily intended to allow the screen to be easily fitted and removed from a window assembly by drawing the side frame members towards each other. Also the tensioning means will help to retain a generally flat shape for a screen.

Alternatively, the screen or blind and the sides of the window may be provided with mutually cooperative attachment or engagement means to tension the screen or blind material. Such means may include clips on one of the screen or window that engage in slots provided on the other. Other attachment means, such as Velcro magnetic means, press studs or the like, may be used.

The screen may be fitted internally or externally of a window or conservatory roof glazed panel.

Preferably a window or conservatory roof glazed panel will have at least two screens according to the invention, whereby additional light may be admitted by sliding one or other of the screens to overlap them. Screens supported by side members may have solid or hollow side members. Preferably such screen side members are of hollow rectangular section.

Substantially rigid but resiliently deformable members suitable for screens or blinds used in the invention are preferably provided in pairs, one at each end of a screen. The preferred members are rods of fibre glass. Alternatively spring-loaded telescopic rods may be used.

Screens or blinds may be stretched across windows to tension them. In one preferred embodiment a screen or blind is in the form of a spring-loaded roller blind mounted in a channel of or associated with one glazing bar and has a hook or the like for engaging a latch of or associated with an adjacent glazing bar.

The screen material is preferably of fabric, although other materials may be used, such as a slatted material, e.g. wooden slats. Pinoleum (wooden slats woven together to form a screen) is a possibility for the screen material.

Fabric screen materials and the like may be provided as a single layer with its ends wrapped around the side members and secured to itself or fixed or adhered to the side member in any other suitable way depending on the nature of the fabric. Alternatively, the screen fabric may be formed into a loop and stretched around two side members. This provides a two layer screen having a spaced therein that may be used to receive insulation material, such as, for example, multi-layer metal foil insulation or foamed, expanded or fibrous insulation material.

The screen material may be affixed to itself or to a side member by stitching, lacing, fastening material, such as Velcro (Trade Mark), magnetic means, press studs and the like, zips for engaging or cooperating means for any other suitable means. The preferred window assembly according to the invention comprises window side frame members in the form of glazing bars that support glazing panels between them and that have slot forming members mounted thereon. The slot forming members may be mounted internally or externally of a window, which may be a conservatory roof panel. The provision of slots or channels for edges of the window screens has the advantage of reducing light admission around edges of the screens.

For an internal screen the glazing bar preferably has or is provided with attachment means for a slot forming member. For example, the glazing bar or cladding thereon may have a channel for receiving slidingly a slot forming member.

The slot forming member is preferably of T section and the free end of the stem thereof is preferably slidably retainable in a channel on the underside of the glazing bar or cladding therefor.

The slot for receiving one side of a screen may thereby be provided between the glazing bar cross bar or its cladding and the cross bar of the T-section slot forming member.

Alternatively, for an external screen the head of a glazing bar or a cap therefor preferably has attachment means for a slot forming member. The attachment means may be a channel for slidingly receiving a free end of the stem of a T-section slot forming member.

The slot for receiving one side of a screen may thereby be provided between the glazing bar head or capping and the cross bar of the T-section slot forming member. The screens of the invention may be used other than for windows and conservatory roofs, such as in situations where a readily demountable screen or barrier is needed, such as to provide cladding for a wall or replaceable advertising boards.

The invention will now be further described by way of example only, with reference to the accompanying drawings, in which:

Figures 1 and 2 show a screen according to the invention and its means of fitting to a conservatory roof;

Figure 3 is a close up of a fitted screen of Figure 1 ; Figure 4 shows provision for internal fitting of a screen of Figures 1 to 3;

Figures 5, 6 and 7 show a pair of screen fitted to a conservatory roof and their operation;

Figures 8 and 9 show a conservatory roof fitted with screens according to Figures 5 and 7; Figure 10 shows external fitment of a screen according to the invention;

Figure 11 shows an alternative form of screen according to the invention;

Figure 12 shows a stretched blind or screen arrangement;

Figures 13 to 15 show a roller blind arrangement according to the invention;

Figures 16 and 17 show other arrangements for attaching a blind or screen to a window;

Figure 18 shows an alternative tensioning means for a blind or screen according to the invention; and

Figure 19 shows another alternative blind or screen according to the invention.

Referring to Figures 1 to 3 of the accompanying drawings, a screen or blind 10 for a window, such as in a roof of a conservatory, has side members, in the form of a pair of hollow rectangular runners 12, spaced apart by tensioning means, in the form of a pair of glass fibre rods 14, at opposite ends of the runners 12. The glass fibre rods 14 are each secured in a hole 16 of a runner 12. A fabric screen 18 is attached to the runners 12. The fabric layer 18 is wrapped around a runner 12 and adhered or attached to itself, so as to loop around the runner 12.

The glass fibre rods 14 allow some flexing of the screen for fitting purposes, whilst, when the screen is fitted, the rods tension the screen, i.e. rods 14 are resiliently deformable.

In order to fit a screen 10 to a conservatory roof or indeed any other window, channels 20 are provided on opposite sides of a glazing panel 22. Said channels 20 may be internal of, or external to, a window. As shown in Figure 4 of the accompanying drawings, glazing panels 22 are mounted between glazing bars 24. The glazing bars

24 are generally of T-section having a cross bar 26 and a stem 28. The glazing bar will usually be of aluminium with a uPVC cover 30 on the cross bar and a uPVC cap 32 on the stem.

The cover 30 has top edges 34 that overlie top edges of the cross bar and that carry sealing material 36 on which one side of the glazing panels sit. The cap 32 has sides 38 with sealing material 40 on their free edges. The cap is pressed onto the top of the stem of the glazing bar 24, so that the sealing material 40 seals against the other side of the glazing panels 22.

The cover 30 has a base 50 with a longitudinal slot 52 therein with recessed sides 54 to receive a channel forming member 56. The channel forming member 56 is a T- section uPVC extrusion and has a stem 58 and a cross bar 60. The free end of the stem has resiliently deformable sides 62 with notches 64, whereby the end of the stem can locate in the slot 52 of the cover 30. Then between the underside of the cover 30 and the cross bar 60 of member 56 on opposite sides of the stem of the member 56 are channels 70 for receiving the runners of screen 10 on either side of a glazing bar.

A screen 10 is fitted to a pair of facing channels 70 by bending the fibre glass rods 14to reduce the width of the screen for it to fit between the channels (see Figures 1 and 2). Releasing the rods 14to return to their normal shape tensions the screen and locates the runners 12 in the channels 70. The size of the channels 70 and runners 12 are chosen so that the screens can slide along the channels 70.

Figure 5 to 7 of the accompanying drawings show how a pair of screens may be accommodated by having wider channels 70, so that a pair of screens 10 can slide over each other to open and close the screen cover.

Figures 8 and 9 show a conservatory roof 200 having screens 10 fitted according to the embodiment of Figures 5 to 7. Here the screens can be slid to overlap to let in light (Figure 8) or slid to their opposite limit to inhibit light admission. The glazing panels have been omitted from roof for simplicity.

Figure 10 of the accompanying drawings shows a conservatory roof having provision for external screens. As in the embodiment of Figure 1 the construction of the conservatory roof is the same except that the channel forming member 56 is attached to the glazing bar capping 100.

The capping 100 has a top 102 and divergent sides 104. The capping is twin-walled with webs connecting the walls. At the free ends of the side walls sealing strips of rubber or synthetic elastomeric material are provided to seal against the top surface of glazing panels. The top 102 of the capping has a slot 106 with recessed sides 108 to receive the free end of the stem of the member 56. Thus, channels 110 for screens 10 are provided externally of the conservatory roof between the tops of a capping and the cross bar of the members 56 either side of its stem.

Figure 11 of the accompanying drawings shows a screen 10' according to the invention, which has its fabric formed as a loop 300 around the runners 12. Within the loop 300 is a layer of insulation material 302.

Referring to Figure 12 of the accompanying drawings, using a glazing bar system of the type shown in Figure 4 a blind or screen of fabric 400 has at its corners hooks 402 and the channels 70 have slotted components 404 to receive the hooks 402.

Thus, the blind can be tensioned by its attachment to the glazing bar system but with its edges concealed in the channels 70.

Figures 13 to 15 show an arrangement in which a conventional roller blind 500 may be adapted to provide a screen system according to the invention. Using the glazing bar system of Figure 4 a roller blind 500 is mounted in a channel 70 on one side of a window. Not shown are end supports for receiving spigots 506 at opposed ends of the blind. The roller blind 500 has on its free edge a hook 502. The opposite channel 70 has a latch 504 which is engageable by the hook when the roller blind is stretched across the window.

Usually roller blinds have a cylindrical cardboard core with spring loaded support ends pushed into the ends of the core. These can be removed, so that the core can be cut to a desired length before re-insertion. Figure 15 shows how a roller blind 500 ¹ may be used not only in rectangular windows but also in triangular windows, such as in a Victorian style conservatory roof.

The arrangement of Figures 13 to 15 maintains tension in the screen by virtue of the spring-loaded nature of a typical roller blind.

As shown in Figures 16 and 17 it is possible using the channel forming member 56 (see Figure 4) to attach blinds directly to the member 56. The walls of the stem 58 have a series of holes 600 at regularly spaced intervals along its length. In Figure 16 double-ended hooks 602 have one end 604 attached to the stem 58 using the holes and eyelets 606 of a blind 608 are attached to their other ends 610.

In Figure 17 the holes 600 are used to lace a blind or screen 608 to the channel forming member 56 by means of a lace 622 through the holes and the eyelets 606 of the blind or screen 608.

Figure 18 shows a telescopic spring-loaded rod 700 that may be used in place of the fibre glass rods used in the screens of Figures 1 to 3. A wider tube 702 has internally a spring 704 at each end of which is a plug 706 retained on the spring. Each plug 706 has a narrower tube 708 attached thereto and extending from the wide tube 702.

In a screen, the tubes 708 can be pushed inwards to reduce the overall width of the screen for fitting to a conservatory roof window and then released to hold the screen in place.

Finally, in Figure 19, a screen 800 has two part side members 802. First parts 804 and the parts 804 are joined by fibre glass rods 806 or possibly rods 700 of Figure 18. Each first part 804 has a slot 810 for receiving a second part 812 in snap-fit manner, whereby a fabric screen 814 can be trapped between the two parts 804, 812 and either side.