AU2010241512B2 - An extrusion having a security feature - Google Patents

Abstract

An extrusion for use in a frame for a security door or window, the extrusion including: a body (6); first and second limbs (7,4) extending from the body and defining a channel (2) therebetween for receiving an edge of a mesh screen; and a jamming means (15) for jamming the mesh screen edge within the channel if an impact or other high force is applied to the mesh screen. cf)n

Description

1 AN EXTRUSION HAVING A SECURITY FEATURE The present invention relates to an extrusion and, in particular, to an extrusion having a security feature for a door or window frame. This invention is applicable for use as a frame for a security door or window. 5 BACKGROUND TO THE INVENTION Security doors and windows are routinely installed in houses and the like to prevent access by unwanted or unwelcome persons. The main role of a security door is to provide a mesh which does not permit the arms or the legs of a would-be intruder from reaching through the doorway or window. The mesh is 10 typically supported within a frame. Security doors and windows often include two forms of mesh screen. A finer mesh which prevents people from reaching into the doorway, and a larger mesh in the form of a grille, is often used. However, finer mesh is able to be deformed easily, and the grille allows implements into the house, therefore the 15 combination of the large and fine mesh provides security for the occupants of the home. The grille can however be unsightly and can impede the view through the door or window. More recent security door and window designs have therefore used a single sheet of the finer mesh which is made from high strength material such as stainless steel, without the need for any larger mesh screen. 20 These designs are only capable of being used to support the finer mesh and cannot be used to support the larger mesh. The finer mesh is fixed to the frame by screws or rivets which, to maintain the finer mesh within the frame, requires apertures to be provided in both the mesh and the frame attached at the edge. 25 However, in the event that extreme force is applied to the mesh, such as a kick or hitting the mesh with a heavy instrument the mechanical fasteners have a tendency to shear and thereby fail to secure the mesh within the frame. Another fault which may occur is that the apertures can become larger and tear when a sufficiently high force is placed on the mesh, releasing the mesh from the frame 30 and thereby allowing a person to reach into the house, or force an implement such as a knife into the house. The Applicant has developed an extrusion that overcomes one or more of the disadvantages of the above described prior art. This extrusion is described in 2 the Applicant's Australian Patent application No: 2006202825, details of which are incorporated herein by reference. It would however be desirable to provide an extrusion that provides an improved security feature for security doors and windows that also overcomes one or more of the disadvantages of the above 5 described prior art. SUMMARY OF THE INVENTION With this in mind, the present invention provides an extrusion for use in a frame for a security door or window, the extrusion including: a body; 10 first and second limbs extending from the body and defining a channel therebetween for receiving an edge of a mesh screen; and a jamming means for jamming the mesh screen edge within the channel if an impact or other high force is applied to the mesh screen, the jamming means including a leg member having a fixed end connected to one said limb and an 15 opposing free end for engaging the mesh screen edge, the leg member being displaceable about its fixed end such that the free end is displaceable towards the opposing said limb when said impact or other high force is applied to the mesh screen. The leg member may be integrally formed as part of the extrusion, and 20 may include a bendable portion at the fixed end thereof. The bendable portion of the leg member may be narrower in thickness than the rest of the leg member. The present invention also provides a door assembly including a mesh screen, a frame formed from an extrusion as described above, and a retaining member located between the limbs to retain the mesh screen edge within the 25 channel. The free end of the leg member may engage the mesh screen edge when the retaining member is inserted into the channel urging the edge against the leg member. When an impact or other high force is applied to the mesh screen, this acts to induce a tension force along the mesh screen edge acting to pull the edge 30 out of the channel. As the free end of the leg member may be engaged with the edge, this results in the mesh being forced down onto the leg member thereby applying a force on the free end thereof. The leg member may therefore be 2a jammed against the mesh. The leg member may have a bendable portion about its fixed end, and may therefore be displaced about its fixed end when a sufficient force is applied to its free end. The leg member may therefore pivot about its free end towards the opposing limb thereby also jamming the mesh screen edge 3 between the opposing limb and the leg member. As further force is applied to the mesh screen, the leg member may be displaced closer to the opposing limb further increasing the degree of jamming within the channel of the frame thereby making it more difficult to extract the mesh screen edge out of the channel. 5 The extrusion according to the present invention therefore provides an improved security feature by making it more and more difficult to extract a mesh screen from a frame made from the extrusion when multiple impacts or other high force is applied to the mesh screen. BRIEF DESCRIPTION OF THE DRAWINGS 10 A preferred embodiment of the present invention will now be described by way of example only with reference to the drawings in which: Figure 1 is a perspective view of a prior art extrusion; Figure 2 is a side cross-sectional elevation of the extrusion of Figure 1; Figures 3 and 4 respectively illustrate an edge of a mesh screen and a 15 retaining member being inserted into the extrusion of Figure 1; and Figure 5 is a side cross-sectional view of an extrusion according to the present invention. DETAILED DESCRIPTION OF THE DRAWINGS Referring now to Figure 1, there is shown a prior art extrusion 1 as 20 described in the Applicant's Australian Patent application No. 2006202825. The extrusion 1 includes a body 6 which may include a void 6a to reduce the weight of the extrusion 1, a first limb 3 and a second limb 4 extending from the body 6 to define a channel 2 therebetween. The channel 2 includes an outer section 2a located adjacent the opening of the channel 2, and an inner section 2b. Surface 25 formations 7a in the form of a series of parallel ribs are provided on an innermost wall of the channel inner section 2b. The limbs 3 and 4 include formations 5a and 5b extending into the channel. As shown in Figures 3 and 4, the formations 5a and 5b are offset such that when the limbs cooperate with a retaining member 10 to urge a mesh 8 against the formations 5a and 5b. The formations 5a and 5b 30 cause the bending of the mesh to retain the mesh within the channel 2. Figure 2 shows a side view of the frame shown in Figure 1 in which the formations 5a and 5b may be seen more clearly. Formation 5a includes a lug or rib or shoulder arrangement to engage and grip the mesh when inserted.

4 Formation 5b is a shoulder arrangement which can also act to engage the mesh which inserted. The limb 4 includes surface formations 7 in the form of a series of parallel ribs to assist in holding in place a retaining member 10, as shown in Figure 4. 5 Referring specifically now to Figure 3, and 4, there is shown an edge of a mesh screen 8 inserted into the channel 2 of the extrusion 1 before the mesh 8 is bent. The mesh 8 also includes a plastic insulator 9 to protect the edge of the mesh. The mesh 8 is inserted into the channel 2 at an angle as shown in Figure 3 such that it enters the inner section 2b of the channel 2. Referring now to 10 Figure 4, the mesh 8 is retained by moving the mesh 8 towards the limb 3 and inserting a retaining member 10. Moving the mesh 8 towards the limb 3 causes the mesh 8 to bend about the formation 5b in a first direction and subsequently bend about the formation 5a in a second direction, to engage the frame 1 at two points thus securing the mesh 8 to the frame 1. The edge of the mesh 8 engages 15 the surface formations 7a within the channel inner section 2b as the mesh 8 is moved towards limb 3 so that the mesh 8 is prevented from moving away from the formation 5a on the second limb 4. This thereby forces the mesh 8 to also bend around formation 5a. Referring now to Figure 4 the retaining member 10 is shown within the 20 channel 2. The retaining member 10 is forced into the channel, to engage with both the mesh 8 and the surface formations 7 of limb 4, with a mallet or other such implement. Forcing the retaining member 10 into the channel 2 causes the mesh 8 to be bent at the formations 5a and 5b such that the mesh is difficult to dislodge, even when an external force is applied to the mesh 8. 25 The extrusion 1 can alternatively support a larger grille (not shown) having a greater thickness than the mesh within the outer section 2a of the channel 2. This thereby allows the extrusion 1 to accommodate both fine mesh and larger grilles. Figure 5 shows an extrusion 11 according to the present invention and the 30 same reference numerals for corresponding features of the prior art extrusion are used for clarity reasons. The extrusion 11 similarly includes a body 6 having a first limb 3 and a second limb 4 defining a channel 2 therebetween. A retaining member (not shown) is used to urge the edge of the mesh screen against the first 5 limb 3 in the same manner as previously described, with surface formations 7 on the second limb 4 helping to retain the retaining member in position within the channel 2. A leg member 15 is also provided extending generally laterally from the 5 second limb 4 into the channel 2. This leg member 15 has a fixed end 17 connected to the second limb 4 and an opposing free end 19. The leg member 15 is integrally formed as part of the extrusion 10, and the fixed end 17 is narrower in thickness than the rest of the leg member 15. This narrow portion allows displacement of the leg member 15 about its fixed end 17 as bending at 10 this narrow portion is possible if any significant force is applied to the leg member 15. When the edge of the mesh is inserted into the channel 2 and a retaining member forced into the channel in the same manner as shown in Figure 4, the edge of the mesh is urged against the leg member free end 19. If any impact or 15 other force is applied to the mesh, the mesh edge is forced onto and jams against the leg member free end 19. This is because the impact or other high force applied to the mesh results in a tensional force being applied to the mesh edge in a direction away from the extrusion 11. As the leg member free end 19 abuts the mesh edge, this tensional force is transferred to the leg member 15 resulting in 20 the leg member 15 being jammed against the mesh. The transferred force may result in bending of the leg member 15 about its fixed end 17. Depending on the degree of the force, or the number of times a force is applied, the leg member 15 will pivot closer and closer towards the first limb 3 within the channel 2. The mesh edge will therefore be more tightly jammed between the leg member 15 and 25 the first limb 3 making it more difficult to extract the mesh from the channel 2. Those skilled in the art will appreciate that the invention described above is susceptible to variations and modifications are even more specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the features and products 30 referred to or indicated in the specification, individually or collectively in any or all combinations of two or more of the features.

Claims (5)

1. An extrusion for use in a frame for a security door or window, the extrusion including: a body; first and second limbs extending from the body and defining a channel therebetween for receiving an edge of a mesh screen; and a jamming means for jamming the mesh screen edge within the channel if an impact or other high force is applied to the mesh screen, the jamming means including a leg member having a fixed end connected to one said limb and an opposing free end for engaging the mesh screen edge, the leg member being displaceable about its fixed end such that the free end is displaceable towards the opposing said limb when said impact or other high force is applied to the mesh screen.

2. An extrusion according to claim 1, wherein the leg member is integrally formed as part of the extrusion, and includes a bendable portion at the fixed end thereof.

3. An extrusion according to claim 2 wherein the bendable portion of the leg member is narrower in thickness than the rest of the leg member.

4. An extrusion for use in a frame for a security door or window substantially as hereinbefore described with respect to what is shown in Figure 5.

5. A door assembly including: a mesh screen; a frame formed from an extrusion as claimed in any one of the preceding claims; and 7 a retaining member located between the limbs to retain the mesh screen edge within the channel. EDWARD DONALD ALLEN WATERMARK PATENT AND TRADE MARKS ATTORNEYS P31701AUOO