GB2299362A - Bar for use in a security grille - Google Patents

Abstract

A bar 10 for use within a security grill of the type comprising one or more bars releasably securable across an aperture in a building, for example a window, has both end portions adapted for securable engagement with its respective housing. One end portion (not shown) has a formation by which it can be securably engaged in housing in a manner known in the art. The other end portion 5 also has at least one formation extending around at least a part of the end portion such that attempted removal of the bar when securably engaged causes interference between the formation and the housing 11. The formation is preferably a recess 16 such as a groove, such that attempted removal causes a flange 17 corresponding to a part of the recess to catch on part 30 of the housing.

Description

Title: Window Bars Description of Invention This invention relates to a bar for use in a security grille of the type comprising one or more bars releasably securable across an aperture in a building, for example a window.

A security grille of the type with which the bar is associated, henceforth referred to as a security grille of the type described, comprises one or more security bars which are releasably securable between housings mounted on opposed edges of an aperture in a building, for example a window. Such a security grille is releasably securable by virtue of at least one of the bars having an end adapted for securable engagement with one of the housings.

An example of such a security grille is described in GB 2274303A, which discloses, amongst variants, spaced parallel bars which are releasably securable between generally parallel elongate housings mounted adjacent top and bottom horizontal edges of a window or like aperture.

In GB 2274303A the lower end of each bar is shaped so as to be lockable within slots in a lower housing by a locking means, and the upper, generally cylindrical end of each bar is located within holes in an upper housing, such that when the locking means is engaged, the bars cannot easily be removed from the housing.

It is an object of the present invention to provide a new and improved bar for use in a security grille as described above.

According to the invention, there is provided a bar for use within a security grille of the type described, the bar comprising a body of length defined by first and second end portions, the second end portion being adapted for securable engagement with a second housing, the first end portion being adapted for engagement with a first housing, the first end portion comprising at least one formation extending around at least a part of the first end portion such that attempted removal of the bar when securably engaged causes interference between the formation and the first housing.

Preferably the formation comprises a recess.

Preferably the recess comprises a groove or channel within the first end portion.

Preferably the recess extends completely around the circumference of the first end portion, such that the recess is continuous.

Preferably, in the case where the recess extends completely around the circumference of the first end portion, a plane defined by the recess lies substantially perpendicular to the axis of the bar.

The first end portion may comprise a solid first part of the body of the bar, such that the recess is cut therein. Alternatively, the first part of the body may be hollow such that the first end portion is initially separate therefrom.

Conveniently, the separate first end portion comprises at one end a plug like protrusion adapted for connection with the hollow first part of the body.

Conveniently, such interconnection is by virtue of an interference fit therebetween.

Preferably the separate first end portion further comprises at the other end a spigot, the spigot having an identical or nearly identical width to that of the body, the spigot further comprising a recess therein.

A bar as above in a security grille of the type described provides advantages over those previously known in that when subjected to a transverse force, i.e. a force in a direction substantially perpendicular to the axis of the bar, a flange corresponding to an upper part of the recess, engages with an adjacent part of the first housing, such that the bar "catches" on the housing. It has been found that such a catching engagement results in up to a 50% increase in transverse force required to disengage a bar of this type from the first housing.

Accordingly, a security grille equipped with such bars provides greater security than those previously known by rendering forced entry therethrough considerably more difficult.

Reference will now be made by way of example only to the accompanying drawings wherein: FIGURE 1 is a transverse cross-sectional view showing a first end portion of the bar situated in a simplified first housing, the bar being in a normal, unstressed state, and wherein FIGURE 2 is a similar view, showing the bar in a displaced, stressed state and the resulting catching engagement of the bar and first housing.

For the sake of convenience herein the first and second end portions shall henceforth be referred to as "upper" and "lower" end portions since the preferred orientation of the bars may be vertical. Similar considerations apply to "upper" and "lower" housings.

Referring to the drawings, an upper end portion 5 of a hollow bar 10 is shown, which part is adapted for engagement with an upper housing 11 of a security grille arrangement of generally known type. The upper housing 11 comprises an elongate channel conveniently formed as an aluminium extrusion, within a lower horizontal face 12 of which are situated a plurality of spaced apart holes 13. The diameter of holes 13 is just greater than the diameter of the upper end portion 5, but less than the diameter of collar 15. The bar 10 comprises a recess 16, which in the drawings extends completely around the bar 10, although it will be appreciated that such extension is not necessary for the functioning of the invention. By virtue of the recess 16, two opposing flanges 17 and 18 are presented.

In the drawings, the upper end portions 5 are shown are being separable from the rest of the bar 10 by virtue of a plug 20, such that they comprise a spigot 19 protruding from the upper end of the bar. It will be appreciated, however, that if the bar were made of solid, and not hollow, material then the recess could be formed by a simple cutting or grinding operation on the bar itself.

The collar 15 serves to limit the insertion of upper end portion 5 into the hollow bar 10. The insertion is preferably sufficiently tight, for example by virtue of an interference fit, so that additional securing means are not required.

Figure 2 shows the same embodiment as Figure 1, but where the bar 10 is subjected to a transverse force in the direction of arrow A. Similar considerations would of course apply if the force were applied in any other direction transverse to the bar.

By virtue of this force the bar 10 is bent, or flexed, in the direction of arrow A. Such bending causes the upper end portion 5 to move from an upright position as seen in Figure 1, to the displaced position seen in Figure 2. Part of the upper flange 17 engages in a catch like manner with upper part 30 of the horizontal face 12, which prevents further movement of the bar 10 through the hole 13, and thus keeps the bar located within upper housing 11.

In a typical embodiment, each bar may have an outside diameter of approximately 19mm, and the inside diameter of the recessed part 21 may be approximately 13mm, such that the flanges 17 and 18 are of widths of approximately 3mm in a radial direction.

The height of the recess 16, in a direction parallel to the bar may be approximately 3.5mm, and the distance from the top of collar 15 to the top of upper end portion 5 may be approximately 24.5mm. In order for the upper flange 17 to be able to engage in a catch like manner with the upper part 30 of the horizontal face 12, it will be appreciated that the depth of horizontal face 12 is less than the height of recess 16.

It has been shown that the recess arrangement, by allowing the catching engagement, provides up to 50% more strength in a transverse direction when a transverse force is applied.

Bars of this type thus greatly increase the protection offered by security grilles against intruders.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (15)

1. A bar for use within a security grill of the type described, the bar comprising a body of length defined by first and second end portions, the second end portion being adapted for securable engagement with a second housing, the first end portion being adapted for engagement with a first housing, the first end portion comprising at least one formation extending around at least a part of the first end portion such that attempted removal of the bar when securably engaged causes interference between the formation and the first housing.

2. A bar according to Claim 1 wherein the formation comprises a recess.

3. A bar according to Claim 2 wherein the recess comprises a groove or channel within the first end portion.

4. A bar according to Claim 2 or Claim 3 wherein the recess extends completely around the circumference of the first end portion, such that the recess is continuous.

5. A bar according to Claim 4 wherein a plane defined by the recess lies substantially perpendicular to the axis of the bar.

6. A bar according to any one of Claims 2 to 5 wherein the first end portion comprises a solid first part of the body of the bar, such that the recess is cut therein.

7. A bar according to Claim 6 wherein the first part of the body is hollow such that the first end portion is initially separate therefrom.

8. A bar according to Claim 7 wherein the separate first end portion comprises at one end a plug like protrusion adapted for connection with the hollow first part of the body.

9. A bar according to Claim 8 wherein such inter-connection is by virtue of an interference fit between the plug like protrusion and the hollow first part.

10. A bar according to Claim 8 or Claim 9 wherein the separate first end portion further comprises at the other end a spigot, the spigot having an identical or nearly identical width to that of the body, the spigot further comprising a recess therein.

11. A bar according to any one of Claims 2 to 10 wherein when subjected to a transverse force, i.e., a force in a direction substantially perpendicular to the axis of the bar, a flange corresponding to an upper part of the recess engages with an adjacent part of the first housing, such that the bar "catches" on the housing.

12. A bar substantially as hereinbefore described.

13. A bar substantially as shown in the accompanying drawings.

14. A security grill of the type comprising one or more bars releasably securable across an aperture in a building, wherein at least one of the bars is in accordance with any one of the preceding claims.

15. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.