AU718163B3 - Security grill - Google Patents

Description

AUSTRALIA

Patents Act 1990

COMPLETE

FOR A Name of Applicant: Actual Inventor: Address for Service:

SPECIFICATION

PETTY PATENT GEOFFREY COLCLOUGH GEOFFREY COLCLOUGH CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

Invention Title: SECURITY GRILL The following statement is a full description of this invention including the best method of performing it known to me: FIELD OF THE INVENTION This invention relates to security grills for windows of buildings which can only be demounted from the inside of the buildings.

BACKGROUND OF THE INVENTION The first requirement of window security grills is that they be totally secure against forced entry. The second requirement is that they can be readily removed or pivoted open for emergency purposes or for cleaning the window. While these two requirements may seem to be at odds, products have been developed which address these requirements. Unfortunately however, such products suffer from a number of faults which make them less than 100% satisfactory. In today's security conscious climate, anything that is less than 100% satisfactory is not good enough.

Typically, a window security grill comprises a rectangular metal frame which supports a metal grill of desired pattern and which is fitted to the inside of a window frame so that it can pivot arcutaley inwardly when access to the window or window opening is required.

Pivoting invariably occurs about the top horizontal member of the frame and a locking mechanism is usually associated with the bottom horizontal member of the frame and the jambs of the window.

The majority of faults are found in the pivoting mechanism. This mechanism is practically always formed contiguous integral with the upper support arrangement for the grill. Faults in known products include complicated and awkward arrangements for removing the grill making such products unsatisfactory in emergency situations such as fires; arrangements in which the grill must be pivoted to an essentially horizontal position before it can be removed making such products difficult for short people to demount; and pivoting arrangements which enable the grills to be readily levered off their hinge supports and removed by intruders on the outside of the building. This latter fault is found in a product which is currently widely used in the Australian market and is the subject of Australian Patent No. 689434. In that product, it is possible to insert a lever under the bottom horizontal grill member (see Fig.

4 of that patent) and raise the entire frame a sufficient height to permit the upper horizontal grill member (12) to rise over the pivot pin 15 and be removed.

OBJECT OF THE INVENTION It is therefore an object of the present invention to provide a security grill arrangement which fully addresses the above-mentioned faults in known products and/or provides the public with a useful alternative.

SUMMARY OF THE INVENTION According to the invention there is provided a security grill arrangement for a window opening, said arrangement including: two metal plates for fixing to the respective left and right upper corners of a jamb of the window opening, each said plate having an upwardly open channel member projecting perpendicular thereto and a tongue located below the channel member; (ii) grill suspenders located on the respective left and right upper corners of a security grill, each said grill suspender including a hanger which pivotally fits into one of said channel members for supporting the grill, and a projection which, when the grill is fitted in situ, extends below the tongue; and (iii) a locking mechanism which locks the grill to the window jambs and/or sill; the construction and arrangement being such that when the security grill is fitted in situ, upward movement of the gill is prevented by contact between the tongue and the projection but when the grill is pivoted through an arc of between about 100 and 400, the grill can be raised sufficiently to enable removal.

DESCRIPTION OF THE INVENTION Preferably the metal plates which are fitted to the window jambs are angle plates which are designed so that one portion of each plate can be screwed or otherwise affixed to an upper end of the window jamb and the other portion of each plate extends out perpendicular to the jamb and covers the opening between the jamb and the security grill, as viewed from the exterior of the building. This is an additional security feature which prevents access to the grill support mechanism from outside. It is also an aesthetic feature in that in hiding the pivoting arrangement, a pleasant finish is provided to the product.

The channel member projecting from each metal plate preferably comprises a tube section which has been sliced longitudinally about is diameter. This can be formed integrally with the metal plate, or it can be welded or threaded thereto.

The tongue which is located below the channel member can be any form of protuberance which prevents the upward movement of the grill when in situ. Suitably it is a metal block which projects perpendicularly from the plate and, like the channel member, can be formed integrally with the plate, or it can be welded or threaded thereto. When the plate has an angular formation, as in the aforementioned preferred form, the tongue can be formed on both or either portion of the plate.

The tongue can be located spaced from the channel member or it can, most preferably be located adjacent to the channel member and be connected thereto.

In this latter arrangement the tongue can be designed to give added support to the channel member.

Preferably, the grill suspenders located on the respective left and right upper corners of the security grill, each consist of an inverted channel shaped hanger, one side of which projects downwardly to meet the top vertical end member of the security grill.

The locking mechanism can be any mechanism which is conventionally used on similar types of security grills. That is, it can comprise one or more bolts which are adapted to extend through an appropriate lock housing formed on or within the rectangular metal frame of the grill, into the sill and/or jamb of the window opening.

The fact that a sill lock can be used with this security grill arrangement is another improvement over the aforementioned product of patent 689434 which requires a jamb lock system to be effective.

The security grill arrangement is simple to remove. It merely requires the locking mechanism to be released thereby enabling the grill to be pivoted inwardly by a few degrees at the bottom, generally about 200, to by-pass the stop-tongue, thereby permitting the grill it to be lifted off the channel support and removed from the window opening.

In use, any attempt to lever the security grill upwardly and off its pivotal support, is met by resistance due to the tongue arrangement, thereby preventing removal of the grill. Furthermore access to the pivot supports is prevented and completely hidden from the exterior by virtue of the cover plates.

The security grill arrangement overcomes the problems found in existing security grills and provides the public with a useful alternative.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a metal plate comprising one element of the security grill arrangement; Figure 2 is a perspective view of a grill suspender comprising another element of the security grill arrangement; Figure 3 is an end elevational view of the two elements of the opposed side to that depicted in Figures 1 and 2, in situ; Figure 4 is an elevational view of the two elements of the opposed side to that depicted in Figures 1 and 2 in a relatively removable configuration; Figure 5 is an end on view of a security grill fitted to a window opening; Figure 6 is an elevational view of the security grill of Figure 5, viewed from inside the building; and Figure 7 is an elevational view of the security grill of Figures 5 and 6, view from outside the building.

DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the accompanying drawings, in all of which like reference numerals refer to like parts.

Referring firstly to Figure 1, the metal plate is formed from case hardened angular steel section.

Openings 11 are formed to enable it to be screwed to the upper jamb of a window opening as shown in Figure 6. A semi-circular cross-section channel member 12 extends perpendicularly from a face of the plate. This channel member is also formed of case hardened steel and is of sufficient strength to support the weight of the security grill in combination with a minor image metal plate which is fitted to the other side of the window opening.

A tongue 13 in the form of a case hardened panel extends below the channel member, perpendicularly from the plate Figure 2, to which reference is now made, shows a grill suspender 14 located in the corner of a security grill. It comprises a case hardened metal profiled spigot having a hanger 15 which is adapted to co-act with the channel 12 of the plate (as shown in Figure The hanger includes an arm 16 and a base 17 which are connected either directly to the upper end of a vertical frame member 18 of the security grill, or formed integrally therewith, and the end of an upper horizontal frame member 19 of the security grill.

Figures 3 and 5 show the combination of the plate 10 and grill suspender 14 when in a secured position. In this position it will be noted that upward movement of the grill is prevented by the tongue 13 coming into contact with the base 17 of the grill suspender. This prevents leverage upwardly of the grill as can occur in the aforementioned commonly used security grill.

Figure 4 shows the position to which the security grill suspender need be arcuately pivoted in order to enable the grill to be fractionally raised and removed from the fixing plate 10. In this instance, the arc which enables the base 17 to clear the tongue 13 is about 200.

A twin lever locking mechanism is provided in this example for securing the grill in position to the window surround. The mechanism comprises a keyed lock housing 20 in the bottom frame member 23 (see Figures and 6) and two reciprocally movable pins 21, 22 which project from each end of the bottom frame member into appropriately recesses in the jambs 24, 25 of the window opening. The pins are drawn into and out of their recesses by a lever arrangement within the bottom frame member by known means.

Figure 7 illustrates the exterior view of the security grill and it will be noted that the metal plates 30 which comprise the security arrangement, completely cover the pivotal support region of the grill.

Similar plates 31, 32 cover the region where the locking pins extend into the window jambs.

In this manner a total secure, but readily removable security grill is provided which does not have the faults found in known security grills.

Claims (2)

1. A security grill arrangement for a window opening, said arrangement including: (iv) two metal plates for fixing to the respective left and right upper corners of a jamb of the window opening, each said plate having an upwardly open channel member projecting perpendicular thereto and a tongue located below the channel member; grill suspenders located on the respective left and right upper corners of a security grill, each said grill suspender including a hanger which pivotally fits into one of said channel members for supporting the grill, and a projection which, when the grill is fitted in situ, extends below the tongue; and (vi) a locking mechanism which locks the grill to the window jambs and/or sill; the construction and arrangement being such that when the security grill is fitted in situ, upward movement of the gill is prevented by contact between the tongue and the projection but when the grill is pivoted through an arc of between about 100 and 400, the grill can be raised sufficiently to enable removal-.

2. A security grill as claimed in claim 1, wherein the metal plates are angle plates which are designed so that one portion of each plate can be screwed or otherwise affixed to an upper window jamb and another portion of each plate extends out perpendicular to the jamb so as to cover an opening between the jamb and the security grill, as view from the exterior side of the window opening. A security grill as claimed in claim 1 and 9 substantially as herein described with reference to the accompanying drawings. DATED this 3 rd day of February 2000 GEOFFREY COLCLOUGH By his Patent Attorneys CULLEN CO.