AU2005201582B2 - A security screen frame - Google Patents

Abstract

A security screen frame includes a V-shaped channel in which a screen edge is inserted. The channel includes protrusions which act on an associated wedge to provide a compressive force to the screen and thus maintain it in position. 10 10\16 22 12 26 28 24 >-24 29 -24 1K 16 23 34 36>\38 Fig. 1

Description

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (Original) APPLICATION NO: LODGED: COMPLETE SPECIFICATION LODGED: ACCEPTED: PUBLISHED: RELATED ART: NAME OF APPLICANT: Norma Beatrice Carmen Bond ACTUAL INVENTOR(S): Brian Peter Bond ADDRESS FOR SERVICE: LORD AND COMPANY, Patent and Trade Mark Attorneys, of 4 Douro Place, West Perth, Western Australia, 6005, AUSTRALIA. INVENTION TITLE: A SECURITY SCREEN FRAME DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO'S: Australian Provisional Patent Application Number 2004901995 filed on 16 April 2004. The following Statement is a full description of this invention including the best method of performing it known to me/us: TITLE A SECURITY SCREEN FRAME FIELD OF THE INVENTION The present invention relates to a security screen frame, and a method of attaching a security screen thereto. BACKGROUND TO THE INVENTION It is known to require secure means of mounting security grilles and screens into frames, in order to form security screens for doors, windows and the like. Known methods of mounting screens within frames include the use of rivets, and the use of internal teeth within a frame. Such methods may be cumbersome in use, and frequently require dedicated machinery. The present invention attempts to overcome at least in part some of the aforementioned disadvantages of previous security screen frames. SUMMARY OF THE PRESENT INVENTION In accordance with one aspect of the present invention there is provided a security 0 screen frame including a channel in which an outer edge of a screen is received, the channel including at least one first bearing surface which is arranged to engage with a screen in an interference fit, and at least one second bearing surface adjacent to an outer edge of the screen frame, the screen frame being arranged to receive pressure 2 distributing means between the or each second bearing surface and the screen, the pressure distributing means being arranged to apply a compressive force over an area of the screen edge and thus maintain the screen within the frame, wherein the pressure distributing means comprises a pair of wedges, each wedge having a recess and the frame having a corresponding catching member such that, in use, the respective catching member locates within the recess of a wedge to maintain the wedge in position. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic cross sectional representation of a security screen frame in accordance with the present invention; and Figure 2 is a schematic cross sectional representation of the security screen frame of Figure 1 during assembly. DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the Figures, there is shown a cross section of a portion of a security screen frame 10. It will be understood that the security screen frame 10 is comprised 0 of four members, each of which is extruded with the cross section shown. The security screen frame is constructed of suitable strong, resilient material such as aluminium. The security screen frame 10 is substantially rectangular in cross section, with shorter outer and inner edges 12, 14 respectively and longer side faces 16. 3 A corner stake receiving aperture 18 extends through the security screen frame parallel to, and adjacent, the outer edge 12. A security screen receiving channel 20 extends inwardly of the inner edge 14. The receiving channel 20 is substantially V-shaped, having an apex 21 remote from the inner edge 14. The receiving channel 20 has a first side 22 and a second side 23. The receiving channel 20 is partially enclosed by catch members 24 located along the inner edge 14 of the security screen frame 10. The catch members 24 represent extensions of the inner edge 14 across the end of the channel 20. The receiving channel 20 includes a first bearing surface 26 located on the first side 22. The first bearing surface 26 is located approximately one third of the way between the apex 21 and the relevant catch member 24. In the embodiment of the drawings the first bearing surface 26 is a rounded protrusion which projects internally of the channel 20. It will be appreciated that the first bearing surface 26 may be of another shape, such as tooth-shaped. The first bearing surface 26 protrudes sufficiently into the channel 20 such that when an edge of a screen 30 is located within the channel 20 the first bearing surface 26 bears against the screen 30. The first side 22 further includes second bearing surfaces 28 which are spaced between the first bearing surface 26 and the relevant catch member 24. In the embodiment of the drawings these are shown as two rounded protrusions, however it 0 will be appreciated that any number of protrusions or other shaped surfaces may be employed. The second bearing surfaces 28 do not protrude sufficiently within the channel 20 so as to directly bear against the screen 30. The second side 23 of the receiving channel 20 includes a plurality of ridges 29 along its length. 4 The security screen frame 10 further includes pressure distributing means in the form of a first wedge 32 and a second wedge 34. The wedges 32, 34 are shaped so as to locate, in use, between the first and second sides 22, 23 respectively and the screen 30. The wedges 32, 34 each include a recess 36 arranged to engage with the catch members 24. Preferably, the wedges 32, 34 have an outer lip 38 which is arranged, in use, to lie along the inner edge 14 of the frame 10 and provide an insulating effect. The first wedge 32 is preferably constructed of a rigid plastic. The second wedge 34 is preferably constructed in two parts, with an rigid plastic outer portion arranged to lie adjacent the second side 23 and a flexible, preferably foamed plastic portion arranged to lie adjacent the screen 30. In use, the second wedge 34 is inserted into the channel 20 and located over the catch member 24. The ridges 29 provide a frictional engagement with the second wedge 34. The screen 30 is then positioned within the channel 20. It is maintained in position during assembly of the security screen by an interference fit between the first bearing surface 26 on one side and the second wedge 34 on the other. When the screen has been assembled into a desired configuration, the first wedges 32 is driven into the channel 20 adjacent the first side 22. This causes a slight outward 0 flexing of the side faces 16. When the first wedge is located in position with the catch member 24 engaged in the recess 34, the flexed side walls 16 provide a compressive force to the wedges 32, 34. This is applied on the first side via the second bearing surfaces 28, and distributed along an inner face of the first wedge 32 to the screen 30. 5 The compressive force acting on the second wedge 34 causes the foamed portion to engage within mesh of the screen 30. The compressive force thus applied maintains the screen 30 in position, and provides resistance to externally applied blows. Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. For instance, the present invention may be performed using the arrangement of the first side 22 on the second side 23, and two identical first wedges 32. 6

Claims (8)

1. A security screen frame including a channel in which an outer edge of a screen is received, the channel including at least one first bearing surface which is arranged to engage with a screen in an interference fit, and at least one second bearing surface adjacent to an outer edge of the screen frame, the screen frame being arranged to receive pressure distributing means between the or each second bearing surface and the screen, the pressure distributing means being arranged to apply a compressive force over an area of the screen edge and thus maintain the screen within the frame, wherein the pressure distributing means comprises a pair of wedges, each wedge having a recess and the frame having a corresponding catching member such that, in use, the respective catching member locates within the recess of a wedge to maintain the wedge in position.

2. A security screen frame as claimed in claim 1, wherein a first wedge is comprised of a rigid material and a second wedge has a first portion adjacent the frame comprised of a rigid material and a second portion adjacent the screen comprised of a flexible portion.

3. A security screen frame as claimed in claim 2 wherein the flexible portion is comprised of a foamed material.

4. A security screen frame as claimed in any one of the preceding claims, wherein the or each first bearing surface is a rounded protrusion.

5. A security screen frame as claimed in any one of the preceding claims, wherein the or each second bearing surface is a rounded protrusion.

6. A security screen frame as described herein above with reference to, and as shown in, the accompanying drawings. 7

7. A method of inserting a security screen within a frame, the method comprising the steps of inserting a second wedge into a channel within the frame, inserting the screen into the channel such that the screen is held in an interference fit between the second wedge and a first bearing surface, and inserting a first wedge opposed to the second wedge such that at least one second bearing surface acts against the first wedge in order to provide a compressive force on the security screen.

8. A method of inserting a security screen within a frame as described herein above with reference to, and as shown in, the accompanying drawings.