GB2237596A - Door leaf incorporating flyscreen - Google Patents

Abstract

A door leaf 11 comprises a GRP resin shell 12, 13 encasing an expanded UPVC foamed plastics core 14 and incorporates a flyscreen 15, 16. In a preferred embodiment the flyscreen forms an integral part of the plastics shell. Alternatively the flyscreen periphery is encased by the shell and/or the core. The shell may be joined to the core by a composition comprising a mixture of polyester resin and glass microspheres. A door leaf embodying the invention is characterised by its capacity to fix to a door frame (as distinct from the standard flyscreen which fixes to the door leaf itself) using either moulded or two-part hinges. <IMAGE>

Description

DOOR LEAF INCORPORATING FLYSCREEN Field of the Invention The invention relates to the use of flyscreens in association with door leaves.

Review of Art Known to the Applicant Flyscreens, intended to fit onto and to be used in conjunction with conventional door leaves, are well known. The products of Flydor Limited, of Newton St Faiths, Norwich, Norfolk, United Kingdom are one example of this. They consist of lightweight metal frames supporting metal or plastics meshes and, whilst the screens are manufactured and sold to fit onto a conventional door leaf, actual metal door leaves incorporating the screens are also made by this Company.

Door leaves comprising relatively rigid plastics shells encasing an expanded foamed plastics core are also well known. One Company currently producing them within the United Kingdom is Residor Limited of Norfolk. But these door leaves are internal residential door leaves and are not intended for external use or for use with flyscreens.

Summary of the Invention In its broadest aspect, the invention is embodied in a door leaf comprising a relatively rigid plastics shell encasing an expanded foamed plastics core and characterised by the incorporation of a flyscreen into the door leaf.

This non-obvious combination of two individually known components gives several advantages over the conventional use of the separate or the integrally-constructed metal door flyscreen.

The advantages of ease of production, light weight, attractive self-coloured surface finish and moulding, and rapid replacement (to say nothing of good heat-insulating properties) of the plastics foam-cored door, are combined with the known desirable qualities of the flyscreen, in one single unit which can be fixed directly to the door frame - i.e. without having to be first screwed, like the separate flyscreen, to a supporting door leaf. Whilst the Flydor-produced integral-screen metal door leaf can also be screwed direct to its carrying frame, it simply does not have the advantages just listed for the plastics component.

Another advantage revealed by the invention is that the screen itself, which can be made of plastics instead of metal mesh, can be moulded into the plastics shell of the door leaf as an integral part of one or more faces of the shell. No equivalent integral-part construction is possible with a metal door leaf, irrespective of whether a plastics or a metal mesh is used with such a leaf.

In a further characterised feature of the invention, therefore, a door leaf embodying the invention is characterised by the feature that the flyscreen forms an integral part of the plastics shell.

In another advantageous feature of the invention, and again resulting directly from the specified use of a plastics foamcored door leaf, the flyscreen can be held in place by having its periphery encased by the shell and/or the core. For example, the screen could be let into the foam, as the foam sets, and then cleaned up and rebated as or after the door leaf cures.

It has been proposed, in the construction of plastics foamcored door leaves generally, to use a GRP resin shell encasing a core which is joined to the shell by the intermediary of glass microspheres. UK patent specification number 2 169 943 (Residor) describes and illustrates such door leaves.

They incorporate glass microspheres which, at the time the specification was drafted, were sold under the trade mark ARMOSPHERES in the United Kingdom by Armoform Marketing Limited of Beverley (North Yorkshire) and Dewsbury (West Yorkshire) and had previously been described in trade magazines.

In another particularly advantageous embodiment of the present invention, the door leaf comprises a GRP shell joined to the core by a composition comprising a mixture of polyester resin and glass microspheres. Specification 2 169 943 describes in detail how to make such a door leaf, and gives some of the advantages resulting from its use. The incorporation of a flyscreen into such a door leaf is advantageous again, over and above that original disclosure, and the traditional metalframed screen or screen-incorporating door leaf can have no such analogous enhanced properties by contrast.

Brief Description of the Drawings Figure 1 of the accompanying drawings shows, in partly "exploded" perspective, the construction of one door leaf embodying the invention; Figure 2 shows the door leaf of Figure 1, fully cured, in side section; Figure 3, again in perspective, shows a different door leaf embodying the invention.

Description of the Preferred Embodiment A rectangular door leaf 11 consists of a glass fibre reinforced plastics resin shell encasing an expanded foamed plastics core.

The shell is in two parts referenced respectively 12 and 13 and, as shown, the bottom "tray" part 13 is first moulded up, preformed and cured, before the foam 14 is injected into it and the similarly-preformed fllidr 12 secured to it.

The technical ways of laying up, foaming and bonding, and curing the completed door leaf are known in themselves and can be provided by the skilled addressee of this specification.

The features which characterise the door leaf of Figure 1 are the incorporation of flyscreen areas 15 and 16 into the lower half region of the door leaf.

In the Figure 1 embodiment, the flyscreen areas are formed by perforating appropriate regions of the door leaf faces as shown. A wooden frame 17 is fixed in position inside the tray 13, before foaming and before bonding the lid 12 into place. The foam 14 is injected only into that region of the door - the upper region, in use - between the wooden frame 17 and the top edge 18 of the door. The bottom half region of the door, containing the perforated faces 15 and 16, is left empty.

When the door has cured, and is hung ready for use via hinges (which can be chosen to suit) in a door frame (not shown in the drawings) with the top edge 18 of the door closing under the top rail of the door frame, then the bottom half region of the door incorporating the areas 15 and 16 acts effectively as a flyscreen. The flyscreen area, it will be appreciated, effectively forms an integral part of the door leaf.

Figure 2 shows the Figure 1 construction in sectioned side elevation.

Figure 3 shows an alternative construction. Here, the top half region 19 of the finished door is glazed, whilst the bottom half region incorporates two mesh panels 21, 22 respectively which are let into the door frame and are rebated to give the appearance of a conventional single-sheet-thickness panel.

The mesh panels 21 and 22, which could be plastics or alternatively could be metal meshes, act as flyscreen areas and again, although they are incorporated into the door leaf, they are this time encased by the shell and the core to hold them in place.

A door leaf embodying the invention can take many different shapes and configurations and individual panel patterns. Within the broadest aspect of the invention, it is not necessarily essential for the flyscreen either to form an integral part of the door leaf or to be held, as in the Figure 3 embodiment, by the door leaf shell and/or core; it could be screwed onto the frame. But the advantages of doing it in the ways illustrated are apparent.

Claims (5)

CLAIMS:

1. A door leaf comprising a relatively rigid plastics shell encasing an expanded foamed plastics core and characterised by the incorporation of a flyscreen into the door leaf.

2. A door leaf according to Claim 1 and characterised by the feature that the flyscreen periphery is encased by the shell and/or the core of the door leaf.

3. A door leaf according to Claim 1 or Claim 2 and charac terised by the feature that the flyscreen forms an integral part of the plastics shell of the door leaf.

4. A door leaf according to any of the preceding Claims and characterised by the feature that the plastics shell is a glass fibre reinforced plastics resin shell and is joined to the core by a composition comprising a mixture of polyester resin and glass microspheres.

5. A door leaf substantially as described herein with ref erence to and as illustrated in any appropriate combination of the accompanying drawings.