GB2259934A

GB2259934A - Reinforced uPVC component

Info

Publication number: GB2259934A
Application number: GB9117915A
Authority: GB
Inventors: Ernest Malcolm Heywood Scholes
Original assignee: Scholes Ernest M H
Current assignee: Scholes Ernest M H
Priority date: 1991-08-20
Filing date: 1991-08-20
Publication date: 1993-03-31
Anticipated expiration: 2011-08-20
Also published as: GB2259934B; GB9117915D0; IE922596A1

Abstract

This invention provides an extruded hollow uPVC component for use in a window or door unit, the component having one or more internal longitudinal cavities and a reinforcing member located inside one of the cavities. The reinforcing member 25, 27 is so located in the cavity as to leave substantially free from obstruction at least one region of the cavity wall into which fixing elements can be driven, without penetrating the reinforcing member, in order to secure the component to other items in the window or door unit or to external fixtures or fittings. The invention allows the thickness of the reinforcing member, and therefore the strength of the PVCu component, to be increased relative to conventional designs. The invention also provides an assembled window or door unit incorporating the component, and a reinforcing member adapted to be located inside such a component. <IMAGE>

Description

REINFORCED PVCu COMPONENT Field of the Invention This invention relates to an extruded hollow PVCu component of the type used in window or door units; to a window or door unit incorporating one or more such components; and to a reinforcing member for use with such a component.

Background to the Invention Known PVCu components for use in door and window units, such as frames, sashes, transoms and mullions etc., typically take the form of extruded PVCu sections having one or more internal longitudinal cavities. It is known to reinforce these components, to increase their rigidity and to prevent unwanted distortion (especially expansion) of the components, using internally located steel and/or aluminium reinforcing members. These are profiled so as to fit inside the cavity or cavities of the component, abutting the cavity walls. They are typically centrally placed within the component, for instance occupying the central cavity of a three-cavity component, and as such have always in the past been positioned in those regions of the component into which screws and other fixing elements are driven to attach external parts and fittings to the component.

The presence of a reinforcing member makes it difficult to secure the component to fixings such as friction stays, riser blocks and keeps for locking, or to connect two or more similar components (e.g. frames, sashes, meeting stiles, transoms, mullions, etc.) together. A single thickness of PVCu is insufficient to provide a secure fastening for components or fixings, and screws and rivets used for attachment should preferably therefore be fastened through the external wall of the PVCu component and into the reinforcing member within.

The structural strength of steel makes this a difficult and time-consuming operation in the case of steel reinforcing members, and increases wear on drilling tools.

Some PVCu components are not reinforced at all because of the difficulties associated with fixing into or through the reinforcement. This leads to a problem in that the builder installing, or the factory assembler assembling, a door or window unit often does not know, until he commences drilling, whether the PVCu components which he is using are steel-reinforced.

Builders fixing components of a window or door unit require a steel drill to drill the necessary clearance hole through reinforced components. It is not normal practice for suppliers of PVCu components to indicate whether or not they are reinforced. It is also necessary to change to a conventional masonry drill to drill into masony as opposed to reinforced PVCu. This causes great inconvenience, as PVCu components are not usually predrilled in the factory and must be drilled on site. Even where a component is drilled in the factory, two separate drilling operations are still needed overall, one at the factory and one at the site of installation.

Aluminium reinforcing members are occasionally used instead of steel, since aluminium is a softer metal and easier to penetrate with screws or rivets. However, aluminium is in general a structurally weaker, more expensive material than steel and is less resistant to thermal expansion, making aluminium on the whole an undesirable alternative to steel.

There is therefore a need for PVCu components which are sufficiently reinforced to have the desired rigidity and resistance to distortion, but which are easy to assemble at the site of installation of a window or door unit.

Statement of the Invention According to the present invention there is provided an extruded hollow PVCu component for use in a window or door unit, having one or more internal longitudinal cavities and having a reinforcing member located inside one of the cavities, wherein the reinforcing member is so located as to leave substantially free from obstruction at least one region of the cavity wall into which fixing elements can be driven, without penetrating the reinforcing member, in order to secure the component to other items in the window or door unit or to external fixtures or fittings.

The component may be, for instance, a window or door outer frame or sash, a window or door meeting stile or a a transom or mullion.

The invention is based on the unexpected discovery that a reinforcing member need only occupy part of the internal cavity of a PVCu component and yet still provide an acceptable level of reinforcement. For example, the reinforcing member need occupy only one half of the central cavity of a three-cavity component, thus leaving the other half of the cavity free to receive screws, rivets, etc for attaching other items. The reinforcing member could equally be displaced to one side of any region adapted to receive fixing elements, leaving the reinforcing member out of the line of the drilling which would be needed to install such fixing elements. For instance, since most drilling will occur along a line passing approximately through the centre of the PVCu component, the reinforcing member is ideally located to one side of this central line.

Thus, components in accordance with the present invention can easily be assembled into a door or window unit by the factory assembler, without the need to drill through a steel reinforcing member, leading to considerable savings in time, drill costs and labour costs. At the same time, the assembled unit has comparable strength and rigidity to a fully reinforced or selectively reinforced unit such as would previously have been available.

Moreover, the invention allows the thickness of the reinforcing member (and therefore the strength of the PVCu component) can be substantially increased. The only fixing required through the reinforcing member is its own fixing to the component, which can be done using conventional, automated machines at the factory. All other fixings can subsequently be hand-drilled into the component. In known systems, the reinforcing member is usually of a reduced thickness in regions into which drilling is likely to occur, to ease the drilling operation, which leads to less of structural strength of the component in those regions. In contrast, a component in accordance with the invention need have no such regions of reduced strength.

The reinforcing member is preferably formed from steel or aluminium, more preferably steel which, relative to aluminium, is cheaper, stronger and more resistant to thermal expansion.

The reinforcing member is preferably profiled so as to fit snugly inside that region of the cavity of the component which it occupies, abutting the cavity walls.

It will typically be secured inside the component using flat headed screws or other conventional attachment means.

The component will conveniently also comprise one or more regions of increased thickness PVCu, into which fixing elements for ancillary fittings such as friction stays, lock keeps, etc can be driven. These regions, which will typically be formed from a double thickness layer of PVCu, are also unobstructed by the reinforcing member inside the component.

The invention also provides an assembled window or door unit incorporating one or more PVCu components such as are described above as being in accordance with the invention.

Further, the invention provides a reinforcing member adapted to be fitted inside an internal longitudinal cavity of an extruded hollow PVCu component for use in a window or door unit, so as to leave free from obstruction at least one region of the cavity wall into which fixing elements can be driven, without penetrating the reinforcing member, in order to secure the component to other items in the window or door unit or to external fixtures or fittings.

The reinforcing member may be made from, for instance, aluminium or steel, more preferably steel. The member is conveniently of such a size and shape as to occupy only a portion of the width of the cavity, preferably so as to sit inside the cavity displaced to one side of that region most likely to receive fixing elements.

The present invention will now be described, by way of example only and with reference to the accompanying illustrative drawings, of which: - Figure 1 shows in section two conventionally reinforced PVCu components in a window or door unit; - Figure 2 shows in section two PVCu components in accordance with the present invention; - Figure 3 shows a PVCu window or door frame in accordance with the invention, and illustrates its connection to a transom or mullion; - Figure 4 shows a PVCu door sash in accordance with the invention; - Figure 5 shows an alternative PVCu door sash in accordance with the invention, and illustrates schematically its connection to an outer door frame; and - Figures 6-9 show respectively a door or window meeting stile and three alternative door or window outer frames in accordance with the present invention.

Detailed Description of the Drawings Referring firstly to Figure 1, there is shown in section part of a conventionally reinforced window or door unit comprising an outer frame 1 and a window or door sash 3.

Sash 3 supports a double glazed window or door panel, comprising glass panes 6, and glazing bead 8.

Components 1 and 3 are both formed from extruded PVCu and have central internal longitudinal cavities, 2 and 4 respectively. These cavities contain steel reinforcing members 5 and 7, which in conventional manner circumvent the entire internal wall surface of the cavities.

Reinforcing members 5 and 7 are conventionally secured within the PVCu components 1 and 3 by means of flat headed screws (not shown).

In order to secure ancilliary fittings, such as friction stay fittings, to the components 1 and 3, the screws or rivets used must penetrate both the PVCu walls of the components and also the reinforcing steel members 5 and 7.

In accordance with the present invention, the components shown in Figure 1 would be reinforced as illustrated in Figure 2, which shows in section that part of a window or door unit comprising an outer frame component 21 and a door or window sash 23. Glass panes, glazing beads and other fittings forming part of the unit have been omitted from the Figure for clarity.

The extruded PVCu components 21 and 23 have central internal cavities 22 and 24, in which are located steel reinforcing members 25 and 27. The reinforcing members are secured within the cavities 22 and 24 by means of flat-headed screws 29 and 31.

The reinforcing members 25 and 27 occupy only a part of the internal cavities 22 and 24 respectively, leaving unobstructed those regions of the internal cavity walls, 41 and 43, adapted to receive fixing members for securing the components 21 and 23 to other parts of the window or door unit. Despite this selective positioning of the reinforcing members, components 21 and 23 are rendered acceptably strong and rigid by the use of the reinforcement.

The members 25 and 27 can also be made from a relatively high thickness steel, without the need for regions of reduced thickness as would be present in conventionally reinforced components.

Regions 41 and 43 of the PVCu component walls are in fact of double thickness PVCu, as shown in Figure 2, and can therefore receive the two shallow pan headed friction screws with piercing points, 37 and 39. These can be used to secure friction stay fittings 33 and 35 to components 21 and 23 respectively, without the need for the screws to penetrate reinforcing members 25 and 27.

Figure 3 illustrates the connection between a transom or mullion, 47, and a door or window outer frame 45, both constructed in accordance with the present invention. Component 45 has within its central internal cavity 46 a steel reinforcing member 49, secured in position by means of flat headed screw 51. Member 49 occupies less than half of the full width of component 45, and its shape and position inside cavity 46 mean that a large portion of the walls of the cavity remains unobstructed by the reinforcing member. Screw 53, used to connect the frame 45 to the transom or mullion 47, thus need not penetrate the reinforcing member 49 but instead passes relatively easily through the two PVCu walls of the component 45. Screw ports 55 in the transom/mullion 47 are adapted to receive connecting screws such as 53.

Assembly of the window/door unit of Figure 3 on site, and attachment of transoms and/or mullions as desired, is therefore a relatively simple job and much less time- and labour-consuming than it would have been in the past.

There is often a need to reinforce transoms and mullions such as are shown in Figure 3, and hence component 47 contains a steel reinforcing member 50 occupying the lower part of internal cavity 48. Screw ports 55 are still left clear of obstruction, and thus the transom or mullion can be connected to the outer frame 45 without the need for screw 53 to penetrate steel. Nevertheless, the strength of component 47 is still preserved to a high level in all directions in the plane of Figure 3.

PVCu component 65, shown in section in Figure 4, is a door sash, and is reinforced by means of internal steel member 67, secured with flat headed screw 68. Connecting screw 69, shown in this case securing the door sash 65 to a door midrail 66, passes unobstructed through two walls of component 65, avoiding the steel reinforcing member 67. Nevertheless, the presence of member 67 reinforces component 65 to an adequate degree for the purposes of most window or door units.

The dimensions of reinforcing member 67 are shown in more detail on the left hand side of Figure 4.

In Figure 5, PVCu door sash 71 is internally reinforced by means of steel component 73. Again, component 73 occupies only a small portion of the internal walls of the central cavity of component 71, leaving a large area of cavity wall free to accommodate components such as the door lock 75. This cooperates with latch plate 79 in outer frame 81 (not shown in detail) to which door sash 71 is connected. Dashed lines 77 indicate the position of the door handle for the door unit of which components 71 and 81 form a part.

The door or window meeting stile shown in Figure 6 also comprises a hollow extruded PVCu component 83, reinforced by means of steel member 85 (dimensions shown at the left hand side of the Figure). In accordance with the invention, member 85 is so positioned inside component 83 as to leave a large region of the walls of the internal cavity 84 unobstructed and therefore able to receive fixing members such as screws or rivets to attach the style to a door or window sash or other item.

Three alternative outer frame components, 87, 95 and 103, are illustrated in Figures 7-9 respectively. The components contain steel reinforcing members 89, 97 and 105 respectively, secured in place by means of flat headed screws 91, 99 and 107. In each case, a connecting screw (93, 101, 109), used to connect the outer frame to a transom or mullion or other window or door component, can pass through the PVCu outer frame unobstructed by the relevant reinforcing member.

It will be seen from the above that in most of the PVCu components in accordance with the present invention, the internal reinforcing member is offset from the centre line of the component. Thus, the user can drive a screw or rivet along this centre line in the certain knowledge that its passage will not be obstructed by the presence of a difficult to penetrate reinforcing member. Assembly of the components is therefore a quicker and simpler task than has been possible in the past.

Regions labelled 113 on Figures 7-9, being regions of double thickness PVCu, further allow for the attachment of ancillary fittings such as friction stays, locks, etc to the components shown.

Claims

1. An extruded hollow PVCu component for use in a window or door unit, the component having one or more internal longitudinal cavities and having a reinforcing member located inside one of the cavities, wherein the reinforcing member is so located in that cavity as to leave substantially free from obstruction at least one region of the cavity wall into which fixing elements can be driven, without penetrating the reinforcing member, in order to secure the component to other items in the window or door unit or to external fixtures or fittings.

2. A component according to Claim 1, wherein the reinforcing member occupies only approximately one half of the cavity in which it is located, thus leaving the other half of the cavity free to receive fixing elements.

3. A component according to Claim 1 or Claim 2, wherein the reinforcing member is displaced to one side of a region of the cavity wall which is adapted to receive fixing elements, such that the reinforcing member is out of the line of the drilling which would be needed to install such fixing elements.

4. A component according to any one of the preceding claims, wherein the reinforcing member is of substantially uniform thickness and in particular has no regions of significantly reduced thickness.

5. A component according to any one of the preceding claims, wherein the reinforcing member is formed from steel.

6. A component according to any one of the preceding claims, wherein the reinforcing member is profiled so as to fit snugly inside that region of the cavity of the component which it occupies, abutting the cavity walls.

7. A component according to any one of the preceding claims, wherein the reinforcing member is secured inside the component using flat headed screws or other conventional attachment means.

8. A component according to any one of the preceding claims, additionally comprising one or more regions of increased thickness PVCu, into which fixing elements for ancillary fittings may be driven.

9. A component according to Claim 8, wherein the regions of increases thickness PVCu are also unobstructed by the reinforcing member located inside the component.

10. An extruded hollow PVCu component for use in a window or door unit, substantially as herein described with reference to the accompanying illustrative drawings.

11. An assembled window or door unit incorporating a PVCu component according to any one of the preceding claims.

12. An assembled window or door unit substantially as herein described with reference to the accompanying illustrative drawings.

13. A reinforcing member adapted to be fitted inside an internal longitudinal cavity of an extruded hollow PVCu component for use in a window or door unit, so as to leave substantially free from obstruction at least one region of the cavity wall into which fixing elements can be driven, without penetrating the reinforcing member, in order to secure the component to other items in the window or door unit or to external fixtures or fittings.

14. A reinforcing member according to Claim 13, made from steel.

15. A reinforcing member according to Claim 13 or Claim 14, of such a size and shape as to occupy only a portion of the width of a cavity inside which it is to be fitted.

16. A reinforcing member according to any one of Claims 13 15, adapted so as to sit inside the cavity displaced to one side of that region of the cavity wall most likely to receive fixing elements.

17. A reinforcing member for use in an extruded hollow PVCu component, the reinforcing member being substantially as herein described with reference to the accompanying illustrative drawings.