GB2118602A

GB2118602A - Security screens

Info

Publication number: GB2118602A
Application number: GB08307464A
Authority: GB
Inventors: Gerald Clifford Burlingham
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-24
Filing date: 1983-03-17
Publication date: 1983-11-02
Also published as: GB8307464D0

Abstract

A security screen comprises a rectangular frame supporting within it a grid consisting of a plurality of upright members interconnected by pivotal linkages. The grid is movable between an inoperative stowed position at one side of the frame and an operative extended position in which the grid extends across the width of the frame which in use in intended to overlap a window opening.

Description

SPECIFICATION Security screens Field of the Invention This invention relates to security screens for fitting to window or door openings, the screens being capable of being drawn across the openings for security purposes.

Background to the Invention Many burglaries, particularly of domestic properties, result from intruders gaining access to the property by breaking or forcing a window or door. Whilst complicated electrical alarm systems may be appropriate for some circumstances, in many cases a simple mechanical device would be sufficient to deter or prevent the would-be intruder from gaining access. The invention aims to provide a primarily mechanical security device which is particularly suitable to be fitted to domestic premises, for example by householders themselves as a simple do-it-yourself installation.

Summary of the Invention According to the invention, a security screen for a door or window opening comprises a frame and a grid supported within the frame, the grid being movable between an inoperative stowed position at one side of the frame and an operative extended position in which the grid extends partially or completely across the frame so as in use to protect the door or window opening.

A frame containing a single grid is likely to be sufficient for openings of most widths, but for openings of larger width the frame may support two grids which are then extended towards one another and attached together in the middle of the opening to provide security protection across the whole width of the opening.

The grid preferably comprises a plurality of upright members interconnected by pivotal linkages which pivot to enable the horizontal spacing between adjacent upright members to be varied, to enable the grid to be moved between the stowed and extended conditions.

The upright members may abut in the stowed position, the upright members being recessed to accommodate the linkages in the stowed or collapsed position.

The upright members may be H-shaped in cross-section, the linkages being pivotally mounted to the upright members in the recesses provided by the H shape. In the preferred embodiment to be described each linkage comprises three individual links consisting of two spaced parallel links which at one end are pivotally attached to the corresponding upright member and which at the other end pivotally receive between them one end of the third link, the other end of which is pivotally received in the adjacent upright member.

The upright members are preferably interconnected by the linkages at points which form horizontal rows, each row being spaced vertically from the adjacent row.

Certain or all of the upright members are conveniently guided at their upper and lower ends by upper and lower horizontal members of the frame. Preferably, the upper ends of the upright members carry rollers which roll within and are guided by the upper horizontal frame member which therefore forms a guide track. The lower ends of the upright members may have horizontally projecting flanges which are guided within the lower horizontal member of the frame.

The frame is preferably made considerably wider than the door or window opening for which it is intended, so that in the stowed condition the grid is folded up at one side of the frame and does not obstruct the opening.

When moved to the expanded condition the grid preferably covers the whole of the door or window opening, and may either extend across the whole width of the frame or may extend merely across the width of the frame overlapping the window or door opening. In the latter case the frame is provided with stop means which, when the grid is moved to the extended position, limit movement of the trailing upright member.

A security screen according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an elevation of the screen showing the grid in the operative extended position, Figure 2 is a composite elevation showing in the upper part thereof the grid partially extended and in the lower part thereof the grid fully retracted or stowed, Figure 3 is a sectional view, on an enlarged scale, on the line Ill-Ill of Fig. 1, and Figure 4 is a sectional view, on an enlarged scale, on the line IV-IV of Fig. 1.

Detailed Description of the Drawings The security screen comprises a rectangular frame 10 having vertical members 12 and 14 interconnected by an upper frame member 16 and a lower frame member 18. Within the frame 10 is supported a grid made up of a plurality of upright members 20 interconnected by linkages 22.

Each upright member 20 is H-shaped in cross-section, as best shown in Fig. 4, and in the collapsed or stowed position of the grid the upright member 20 abut as shown in the lower half of Fig.. 2.

The linkages 22 are arranged in rows which extend horizontally across the screen and which are vertically spaced. Each linkage 22 consists of three individual links, namely a pair of parallel links 22a and a single link 22b. At one end the parallel links 22a are pivotally mounted on a pin 24 spanning the side flanges of the corresponding upright member 20. At the other end, the parallel links 22a pivotally receive between them one end of the link 22b the other end of which is pivotally mounted on a pin 26 spanning the side flanges of the adjacent upright member 20. In the fully collapsed or stowed position of the grid the links 22a and 22b are received within the recesses of the H-shaped upright members 20.

The upper end of each upright member 20 is fitted with nylon wheels 28 which run in guide tracks formed by the upper frame member 16. The lower end of each upright member 20 has a projecting flange 30 which is guided within the lower frame member 18.

In its fully stowed or collapsed position, the grid occupies the width A at the left hand end of the frame 10 as illustrated in the lower half of Fig. 2. In the fully operative or extended position, the grid extends across the width B of the frame, the width B being the width of the window opening for which the screen is intended.

As can be seen from Fig. 1, the links 22a and 22b of each linkage are horizontally aligned in the fully extended position of the grid. The upper and lower frame members 16 and 18 are provided with stops 32 and 34, and the upright member 20 at the extreme left hand side of the grid has upper and lower projections 36, 38 which respectively engage the stops 32 and 34 to limit movement of this upright member 20 towards the right when the grid is expanded.

The frame 10, the upright members 20 and the linkages 22 are preferably made of metal to provide a strong screen which cannot readily be broken by a would-be intruder. When stowed, the grid is positioned neatly to one side of the window opening and does not obstruct the transmission of light or hinder opening of the window. It is envisaged that the screen would be produced in a number of sizes to suit window (or door) openings of different widths, the frames being suitable to be fixed to openings on a do-it-yourself basis.

Claims

1. A security screen for a door or window opening, the screen comprising a frame and a grid supported within the frame, the grid being movable between an inoperative stowed position at one side of the frame and an operative extended position in which the grid extends partially or completely across the frame so as in use to protect the door or window opening.

2. A security screen according to claim 1, wherein the grid comprises a plurality of upright members interconnected by linkages which pivot to enable the horizontal spacing between adjacent upright members to be varied, to enable the grid to be moved between the stowed and extended postions.

3. A security screen according to claim 2, wherein the upright members abut in the stowed position of the grid, the upright members being recessed to accommodate the linkages in the collapsed position of the grid.

4. A security screen according to claim 3, wherein the upright members are H-shaped in cross-section, the linkages being pivotally mounted to the upright members in the recesses provided by the H-shape.

5. A security screen according to any claims 2 to 4, wherein each linkage comprises three individual links consisting of two spaced parallel links which at one end are pivotally attached to the corresponding upright member and which at the other end pivotally receive between them one end of the third link the other end of which is pivotally received in the adjacent upright member.

6. A security screen according to any of the preceding claims, wherein the upright members are pivotally interconnected by the linkages at points which form horizontal rows, each row being spaced vertically from the adjacent row.

7. A security screen according to any of the preceding claims, wherein certain or all of the upright members are guided at their upper and lower ends by upper and lower horizontal members of the frame.

8. A security screen according to claim 7, wherein the upper ends of the upright members carry rollers which roll within the are guided by a guide track forming the upper horzontial member of the frame.

9. A security screen according to cla#im 8, wherein the lower ends of the upright members have a horizontally projection flange which is guided within a guide forming the lower horizontal member of the frame.

10. A security screen according to any of the preceding claims, wherein in the extended position the grid extends across a portion only of the frame, this portion being intended to overlap the window or door opening.

11. A security screen constructed and arranged substantially as herein particularly described with reference to the accompanying drawings.