[0001] THIS INVENTION relates io improvements in or in relation 1o security screens and in particular cut not limited to a method by which stainless steel mesh is secured in a surrounding frame.

BACKGROUND

[0002] There have been a m ultitude of arrangements for securing a screen in a frame. The art may be described as "crowded" or a "developed" art. Problems encountered by other patent owners include the overall requirement for security as reflected by satisfying the prevailing "Official Standards", thus to make sure th e screen and frame can withstand the actions of an intruder and as well as this there is the desire for efficient and economic fitting. Some patents utilise fasteners at specific intervals while others are fastenerless utilising a toothed channel in the frame and a corresponding toothed insert holding the marginal edge of the mesh. The fastener arrangement is said to be more secure but it suffers from galvanic corrosion at the fastener due to galvanic current between the aluminium and the stainless steel. Examples of different types of s creen assemblies include those shown in the following Australian patent specifications: 2006202856; 2007101213;

2007216631 ; 2007272305; 2008202835; 200926641 2; 2010241512; 20111 01076; 2011200501 ;

201 1218770; 2005252260.

[0003] In order to alleviate th e problem of corrosion there have been a host of frame profiles, insulating strips and tapes used to prevent galvanic current but this means there can be extra components and sometimes rather complex assembly processes with preformed mesh, wedges and special tools all adding the wide variety of solutions.

[0004] tn some cases the screens may be fabricated on-site in others they are made to meas ure in a factory.

[0005] In recent times in Patent Application AU2011 200501 the re has been an effort to have the benefits of a secure fastener with an insulator in the form of a toothed plastic strip fitted in a corre spondingly toothed channel. The screen and frame are first fitted and assembled with the toothed insulating strip around the screen and this is push fitted into the channel in the frame.

[0006] This type of arrangement was used previously without fasteners before but hi this latest patent appl ication it is strengthened using spaced discrete fasteners. It tries to have the best of both worl ds. The frame, stri p and screen are drilled at spaced intervals and then an insulating plug is inserted into each of the drill holes and then a screw fastener is inserted inside the plug. It seems that this has been needed since through various marketing and advertising campaigns

homeowners in Australia have to a degree been convinced that security is only available through the use of discrete fasteners. Therefore with products like that described in AU2011200501 there seems to be a trend back to the simple spaced fasteners of the earliest screen s. Once fasteners are e mployed it really make s the toothed strip superfluous other than to provide an insulating function.

[0007] Even though the fastener version was developed before all the l ater fasteneriess versions and the art has become crowded, the later offerings have not been widely accepted. Consequently, there is a requirement for a fresh look at the general problems and to look "outside the box" through new eyes in an effort to provide an attemative to the efforts made over the last twenty years. It would be desirable to have something that is simple and easy to assemble yet effective.

[0008] All the above security screens work and are generally made to the prevailing standards so in this sense there is nothing wrong with them and they do not in any way lead to the conclusion that there is a specific obvious problem in n eed of solution.

[0009] This means that the present invention dees not arise through any deterministic relationship to the prior art but rather is the inventor's own inspiration in an individual istic way applying bis m ind to the general problem of fastening a screen in a frame , this being as an alternative to what is currently available, rather than an effort to deal with any specific recognised extant problem of the prior art. · SUMMARY OF INVENTION

[0010] With the above in mind the present invention resides in one broad aspect in a method of assembly of a security screen assembly of the type employ ing an outer extruded frame and a screen, preferably of woven stainless steel , the method comprising the steps of (in no particular order): - 1. providing an extruded frame with an inside having a screen receiving portion, preferably an inside facing channel;

2. inserting a marginal edge portion of the screen into the frame;

3. insulating at least part of the marginal edge portion of the screen;

4. subsequent to steps 1-3, applying compression to deform at least part of the assembly and preferably by deforming at least a part of the screen in the region of the marginal edge portion of the screen in order to secure the s creen to the frame.

[0011] In one embodiment the frame is compressed to damp the screen and an insert located around a marginal edge of the screen. In another embodiment the screen is deformed. In an other embodiment the screen and frame are deformed. Ά punch, press or combined punch and press may be employed. Preferably, the screen is a woven stainless steel screen and the screen receiving portion is a channel and in the compression step a hole is punched through a wall of the channel and also through the screen so that the screen is deformed into a cavity in the frame. In another form of the compression step at each of spaced apart locations the assembly is deformed or punched simultaneously in two adjacent spots at each location. Preferably, the deformation of the screen i s at fixed spaced intervals aroun d the frame. Typically, this is by use of punch. White the screen only need be deformed there may be deformed sections of screen , insulator frame sections that are simultaneously deformed. In a preferred form the frame i ncludes a space, cavity or chamber downstream of the punch travel to serve as a region for the deformed sections of screen , insulator or frame section to occupy. [0012] In one embodiment a hole is punched through a wall of the channel and also through the screen so that the screen is deformed into a collar projecting transversely into a cavity in the frame. In another embodiment a hole is not punched but rather the frame and/or screen are deformed to provide a shoulder to prevent sideways movement of the mesh in the frame. [0013] Preferably, the frame has one of more weakene d zones or re gions at and/or in the vicinity of the area of application of the applied pressure from a punch or press or combined punch or press, these weakened Tones being for the purpose of stress relief upon application of t he compression arising for the method. This means that the applied force is essentially isolated from the rest of the frame in order to minimise any frame distortion that might otherwise arise from the method. The weakened zones may comprise grooves, back to back grooves, cru mple zones or other sacrificial means used to distribute localised stresses in the frame arising from the method.

[0014] Preferably, the edge is insulated using an insulating strip so sized and arranged so that it deforms or is punched with the s creen but d oes not break the irrsulative effectiveness of the insulator.

[0015] As the above method gives rise to a new s creen asse mbly, in anothe r aspect there is provided a screen assembly, preferably a security screen assembly comprising ^~ a frame, a screen fitted to 1he frame, ihe screen be ing deformed at spaced intervals about t he frame and said deformations serving to retain the screen in the frame. Typically and insulating strip is used between the screen and frame.The screen may be deformed by being laterally displaced out of the plane of the frame or by having a hole punched through the screen or a combination of both. [0016] In another aspect, there comprises a screen assembly, preferably a security screen assembly, comprising a frame holding a screen, the frame includes compression points or regions around "the frame applied to the frame subsequent to t he screen being inserted into t he frame t o hold the "screen in the frame. Typically, a marginal edge portton of the screen is held in the frame and an insulating strip is used between the s creen and frame. As compression is applied to the frame at selected locations, this gives rise to a strH further a spect where localised stress in the frame is preferably distributed by zones t hat break or deform along predetermined stress relieving areas for the purpose of preventing stress being carried into the frame proper and to thereby prevent distortion of the frame.

[0017] In a further preferred form there is provided in a security screen assembly an extrusion having a hollow body portion, a front face, a rear face, an outside wall and an inner panel or screen receiver section, the receiver section having a first channel and second and third channels extending along an inside wall of the first channel, the first and second chan nels being separated by an upstand located generally in the line of travel of a punch , the punch being adapted to punch a pair of n otes through the first chan nel drive and into the second and third channels straddling the upstan d. In a further aspect of this embodiment there is provided a security screen assembly having a screen held in place by pairs of holes punched at spaced intervals, the holes being punched simultaneously through a channel of a surrounding frame, a screen spacer and the screen, each pair of holes having an upstand opposite the holes on the other side of the screen and being positioned to resist the punch force.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order that t he present improvements may be more readily understood an d put into practical effect referen ce will now be made to the accompanying drawings which illustrate preferred embodiments of t he invention and wherein :- Figure 1 is a p art perspective view of a security screen assembly illustrating application of the method of the present invention ;

Figure 2 is a section through a typical frame showing a punch being extracted after punching a hole through the frame and screen;

Figures 3-5 illustrate a further embodiment where two frangible sections of the frame break while the screen and insulator are deformed without breaking;

Figures 6 and 7 are sections illustrating another embodiment where the frame is not deformed but the screen is formed into the frame;

Figure 8 is a section where the frame and screen are deformed;

Figures 9-11 illustrate an embodiment where there is minimal compression applied;

Figures 12 and 13 illustrate the use of a combined punch and press;

Figures 14 and 15 are respective sections t hrough extruded frames suitable for use. hi another embodiment, Figure 14 being at scale 1 :1 for a window frame and Figure 15 being for a larger frame as in for example a door;

Figures 16, 17 and 18 are sections illustrating set up of the screen and frame section using an extrusion similar to that of Figures 14 and 15 and application of a punch;

Figure 19 is a drawing illustrating part of the frame similar to that of Figures 16-18 showing two sets of punches holes; and Figure 20 is an en larged view of one set of holes showing frame distortion adjacent the holes.

[0018] Referring to the drawings and initially to Figure 1 there is illustrated a comer 10 of a frame assembly for a door or window where frame members 11 and 12 are mitred in the usual way with a stainless steel screen 13 having its peripheral marginal edge 14 inserted into the frame members. An insulating strip 15 is wrapped around the marginal edge 14. The whole door or window frame may be assembled or each side in turn. Afterwards various punch options shown at 16 and 17 are used to punch holes 18 and 19 or deform the frame and screen so that the deformed screen acts as an effective fastener. A cover strip is used to cover up the deformed sections.

[0019] This punching takes place at spaced intervals with typtcafly a 20 torme punch being used.

[0020] The other drawing figures illustrate various frame and punch options that are exemplary and non-limiting examples of the present invention.

[0021 ] Referring to Figure 2 there is illustrated a doorframe extrusion 20 having an i nside screen receiving channel 21 wh ere a conical punch 22 has been used to punch a hole 23 through walls 24 and 25 of the channel 21. The marginal edge 14 of the screen 13 has an insulating strip 15 and the hole 23 passes th rough the strip 15 and the screen and this is depicted schematically in Figure 2 so that the circular hole 23 formed by the punching of the pre-assembled el ements locks the screen into the frame channel section 26. In the illustrated embodiment the section 26 includes a chamber or cavity 27 serving as a space so that the deformed section of the screen and frame have a space to occupy.

[0022] Referring now to Figures 3-5 there is i llustrated another embodiment of the me#»od where in Figure 3, the frame is set up prior to punching with an extruded frame m ember 26 having an inside channel 29 defined by walls 30 and 31 holding an insulating strip 15 an d a marginal edge 14 of a screen 13. The walls 30 and 31 have fou r parallel lines of weakness 32, 33, 34, 35, 36, 37, 38 and 39. The frame section 28 h as cavities 40 and 41 to receive wall sections 42 and 43 when they a deformed. [0023] A punch 44 as shown in Figure 4 is aligned with the lines of weakness so that the walls 30 and 31 breakaway in the region of the applied punch and this drives the lower wall sections 42 and 43 down into the cavities 40 and 41 white deforming the screen and insulating strip as shown in Figure 4. This locks the screen in the frame this is repeated progressively around the frame.

[0024] The punch 44 has an annular wall 45 and an annular cutting edge 46.

[0025] The punch 44 is applied at spaced intervals around a frame and afterward a cover strip 46 is clipped into place as shown in Figure 5.

[0026] It will be appreciated that the channel 21 need only serve to tocate, an d the present invention can be u sed without deformation of the channel walls, it on ly requires the deformation of the screen with p art of the frame o perating as a die and the provision of an effective shoulder to lock the screen in place. An example of this is given in Figures 6 and 7 where there is an extruded frame member 47 where a punch 48 is shown being retracted after deforming the marginal edge at 49 as shown in Figure 6. The frame member 47 has a shallow channel 50, cavities 51 and 52 and gaps 53 and 54 between sections 55, 56 and 57. Prior to deformation, the insulating strip 15 and screen section 14 are located with end 58 in the channel 50. The punch has a ring section 59 so it punches a ring into the cavities 51 and 52 through the gaps 53 and 54. A cover strip 60 is used to finish the assembly.

[0027] Figure 8 illustrates another embodiment whereby a frame 61 has a channel 62 shown in its deformed configuration in Figure 8. The frame section 61 includes a cavity 63 that takes the bulge 64.

[0028] The previous e mbodiments show quite a large deformation of the scre en but it wiH be appreciated that depen ding upon the application of the present invention and the number of times and spacing of the applied punch the amount of deformation may be quite minimal using a slight compression and minor fracture.

[0029] This is shown in Figures 9-11 where a frame 65 similar to Figure 3 embodiment has a channel 66 having internal beading 67 so that a matching insulating strip 68 may slide axially into the channel. In the previous embodiments the strip can be inserted sideways. After the strip is inserted the marginal edge 14 of the screen is inserted and then punch 69 is applied to compress the channel 68. The compress ion of the walls 70 an d 71 is facilitated by providing various parallel 1mes of weakness 72, 73, 74, 75, 76, 77, 78 and 79. The assembly is then completed using «oover strip [0030] lt wilt be appreciated in the preceding figures that a full pu nch through approach may be taken or simply by applying a press without punching a hole of any kind. In another embodiment a combined press and punch may be used and this is given by way of example in Figures 12 and 13 where a combined punch and press 81 engages a frame 82 having a channel 83 , a cavity 84 and lines of weakness, in this case, back-to-back pairs of grooves 85, 86 and 87. prior to application of the pun ch press 81 the channel 83 is fitted with a PVC insulator 88 around the marginal edge portion 89 of screen 90 as shown in Figure 12. The press punch 81 has a punch section aligned with the grooves 86 and the edge 92 of the press is aligned with the grooves 85. upon application of the press a section of the watt 93 is displaced tateratty out of the plane of the watt 93 and the screen and insulator is punched as shown at 94 in Figure 13. The frame 82 has a ribbed channel 95 and this receives a push fit cover strip 96 as finish ing shown in Figure 13.

[0031] Referring to Figures 14 and 15 there is illustrated in two sizes (like numerals illustrate like features) extrusions 97 and 98. Extrusion 97 is suited to a window whereas extrusion 98 might be used for a door. The extrusions include a hollow body portion 99 having a front face 100, a rear face 101 , an outside wait 102 and an inner panel or screen receiver section 103. The receiver section 103 have a first chann el 104 an d secon d an d third channels 105 and 106 exten ding along the inside wall of the first channel. The channels 105 and 106 are separated by an upstand or tib 107. The fib 107 has a trapezoidal section. Th e fib 107 has a narrow top edge or s urface 108 and a relatively wide base 109. The top edge 108 is positioned about halfway between watts 110 an d 111 and directly below the medial raised section 112 of upper wall 113. The medial raise d section 112 has grooves or shoul ders 114 and 1 15 which are generally centred on the middle of Channels 105 and 106 respectively. Grooves 114 and 115 are set for alignment with a punch adapted to punch a pair of holes through the wall 113 and drive the punch down into channels 106 and 107. In this embodiment the arrangement is to minimise the distortion of wall 113 and cut clean holes and also maintain the cross-section of the balance of the extrusion. There are other variables which come into play which aida clean cut and depending upon the fill material in the channel 104 and t he reactive force upward in response to the punch, the l evel of deformation around the holes may be minimised so that it is not noticeable in t he finished frame.

[0032] Referring now to Figures 16, 17 and 18 (some section lines have been omitted for clarity), these drawings illu strate the process for pun ching out the holes in a similar extrusion 116. In this case the channels 117 and 1 18 are wider than in Figure 14 and the dimensions are clearly slightly different The pu nch 119 is U-shaped having a first hole pu nch 120 and a second hole punch 121 which together punch a pair of holes 122 and 123 as shown in Figure 20 on either side of rib 106. The hole punches have their entry edges 124 and 125 aligned with grooves 126 and 127 and the rib 126 is centred between the hole punch sections 120 and 121. The rib is shown in phantom in Figures 19 and 20.

[0033] In Figures 16-18 a U-shaped PVC insert 130 is positioned about the marginal edge 131 region of a screen 132. In Figure 18 the deformed sections of the wall 133, the insert 130 and screen 132 is shown generally at 134. As shown in Figure 20 a rounded region of deformation is generally formed as a margin al pressed area 134 around th e two holes but confined a smalt area of the wait section 133.

[0034} As illustrated in Figures 14 and 16 there is some variability in the dimensions of the various parts when compared to Figures 19-10. Another variable is the type of PVC insert 130 and if it is made harder or softer, the channels 117 or 118 made wider, or the rib 126 varied, the formation of the holes 122 and 123 can be optimised and deformation minimised by appropriate selection of these.

[0035] Whilst the above has been given by way of illustrative example of the invention many variations and modifications will be apparent to those skilled in the art with out departing from the broad ambit and scope of the invention as herein set forth. In addition where expressions including, comprises, comprising and the like are used herein these should be taken as non-exhaustive and non-limiting meaning that extra features may be added to the combination referred to by these terms and still fall within the broad ambit and scope of the invention.