AU2006202853A1 - Screen Insert - Google Patents

Description

P/00/009 28/5/91 Regulation 3.2

ORIGINAL

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION Invention title: "SCREEN INSERT" Applicant: ANTONY WILLIAM UPFIELD and CLIVE JAMES SINCLAIR Associated Provisional Application Nos.: 2005903657 and 2005906253 The following statement is a full description of this invention, including the best method of performing it known to me: 2 8 "SCREEN INSERT" Field of the Invention The present invention relates to a screen insert for a security screen of the kind typically used on windows and doors to permit air to pass through but to exclude insects and intruders.

OO Background to the Invention

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In the past flyscreen doors were common on external doors of most IN Australian houses and were primarily designed to prevent flies and other insects from entering the house while permitting a cool breeze to flow through the house. These flyscreen doors were often self-closing with a simple latch arrangement. They were not designed to exclude intruders as it was generally considered safe to leave the house unlocked. However in more recent years a number of factors have led to a different design of flyscreen door generally referred to as a security screen door, which is designed not only to exclude flies and insects but also intruders. Security screens are employed on windows and doors and are of much more robust design. They generally employ a rigid or semi-rigid screen mesh, typically made from stainless steel, which is secured to an aluminium alloy frame. Various prior art techniques have been developed for securing the mesh to the frame.

US Patent No. 2,255,581 (Ewing) employs a gripping member having a wedge-shaped exterior portion and an inwardly extending mouth portion for receiving an edge of the screen material. The wedge-shaped gripping member is preferably formed of rubber or other flexible material capable of gripping the edge of the screen. When the wedge-like retainer or gripping member is received in a hollow frame member with outwardly converging side wall portions, any tension applied to the screen tends to cause the wedge to engage the periphery of the screen with increased force in proportion to the tension. Hence, the gripping arrangement of Ewing is responsive to a pull on the screen to increase the gripping or retaining action. However a disadvantage of the Ewing system is the difficulty of inserting the wedge- Sshaped gripping member in the hollow frame member; because of its shape it 0 Ncannot be simply pushed in from the top.

Australian Patent No 748382 discloses a means of securing a screen mesh in a window or door frame which employs a folded back portion formed on an edge of the mesh at an acute angle. The folded back portion is received within a recess formed in the door or window frame having "means to OO interfere" with the exposed edge of the folded back portion to retain the folded

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Sback portion in the recess. The "means to interfere" is formed integrally with I the recess and the frame and takes the form of three parallel ribs formed on an internal wall of the recess. Parallel grooves are also formed on the opposing face of the recess to provide additional grip to minimise movement of the mesh relative to the frame. The distance between the exposed edge of the folded back portion of the mesh, and the main surface of the mesh, slightly exceeds the gap between the side walls of the recess so that when the mesh is inserted in the recess it is under compression. This helps to ensure that the folded back portion of the mesh is retained against one of the ribs to prevent withdrawal of the mesh from the recess.

One of the disadvantages of the system of AU 748382 is that the direct contact between dissimilar metals of the screen mesh and the frame can lead to corrosion problems due to galvanic action.

The present invention was developed with a view to providing a screen insert for securing a screen mesh in a frame that is less susceptible to the problems of the prior art.

References to prior art documents in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention According to one aspect of the present invention there is provided a screen insert for securing a rigid or semi-rigid screen mesh in a frame, the insert being adapted to enclose an edge of the screen mesh and having a cavity designed to receive a folded back portion of the edge of the screen mesh O therein wherein, in use, when the insert is received in the frame withdrawal of N the screen mesh is inhibited by the folded back portion being held captive in Zthe cavity.

According to another aspect of the present invention there is provided a security screen comprising: a screen mesh made from a rigid or semi-rigid material and having a folded

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00 back portion along an edge;

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N an outer frame in which the screen mesh is supported to form the security screen; and, a screen insert adapted to secure the screen mesh in the outer frame, the insert having a cavity designed to receive said folded back portion of the edge of the screen mesh therein wherein, in use, when the insert is received in the outer frame withdrawal of the screen mesh is inhibited by the folded back portion engaging the cavity.

Preferably the insert is made from a suitable plastics material to insulate the screen mesh from the frame.

In a preferred embodiment the insert comprises an elongate member having first and second side wall portions connected by a bridging portion, the side wall portions being shaped so that when they are brought into facing relation said cavity is formed in the insert.

Preferably the insert is of substantially symmetrical configuration about a central axis. Alternatively the insert is of asymmetrical configuration, with a cavity which is only capable of receiving a folded back portion of the screen mesh extending in one direction. Typically, in an asymmetrical insert the second side wall portion is shaped so that when it is brought into facing relation with the first side wall portion the cavity is formed within the insert. An asymmetrical insert may further comprise a compression member, which is inserted into the frame recess in a subsequent step, and is adapted to press the edge of the screen mesh against the first side wall portion of the insert, to lock it into the frame recess by a friction fit. The compression member is O preferably separate from the second wall portion but of a similar width N dimension.

Advantageously the insert is formed with a multi-chamber cavity, one or more of said chambers being capable of receiving a folded back portion of the screen mesh therein.

Preferably the side wall portions are formed with one or more grooves or ribs

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0on outer surfaces thereof, which are designed to engage with corresponding

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ribs or grooves provided on inner surfaces of a frame recess to help retain the Iinsert within the frame recess. Similarly, one or more ribs or protrusions may be provided on inner surfaces of the side wall portions to help grip the edge of the screen mesh. Advantageously each side wall portion may also be provided with a rebate extending along an upper edge thereof, the rebate being adapted to receive a lip formed on an edge of the frame recess to further help retain the insert in the frame recess.

The insert may be manufactured in any suitable length for door frames and window frames, and typically has a depth dimension of between 15mm to and a width dimension of between 6mm to The screen mesh is typically manufactured from a metallic material such as stainless steel. The screen mesh may be manufactured from either a woven or perforated material, and is typically between 0.5mm to 1.6mm in thickness.

The folded back portion is typically between 3mm to 15mm in length, more typically between about 5mm to 10mm in length. It may extend along the full length of the edge of the screen mesh. Alternatively, short lengths formed between cuts, made at spaced intervals along the edge of the screen mesh, may be folded back to form folded back flaps. The flaps may all be folded back in the same direction, or alternate flaps may be folded back in opposite directions. The folded back portion is typically bent back so as to form an angle of between 900 and 200 with the edge of the screen mesh. Preferably the folded back portion is bent back so as to form an acute angle with the edge of the screen mesh. The folded back portion along adjacent perpendicular edges of the screen mesh may be bent back in opposite directions.

Throughout the specification, unless the context requires otherwise, the word C1"comprise" or variations such as "comprises" or "comprising", will be Zunderstood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the r working of the invention.

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SBrief Description of the Drawings NThe nature of the invention will be better understood from the following detailed description of several specific embodiments of the screen insert, given by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a section view of a first embodiment of the screen insert according to the present invention; Figure 2 is a section view of a second embodiment of the screen insert according to the present invention; Figure 3 is a section view of a third embodiment of the screen insert according to the present invention; Figure 4 is a section view of a fourth embodiment of the screen insert according to the present invention; Figure 5 illustrates the screen insert of Figure 3 inserted into a frame; Figure 6 is a section view of a fifth embodiment of the screen insert according to the present invention; Figure 7 is a section view of a sixth embodiment of the screen insert according to the present invention; Figure 8 is a section view of a seventh embodiment of the screen insert according to the present invention; Figure 9 illustrates the screen insert of Figure 8 being inserted into a frame recess; O Figure 10 is a section view of an eighth embodiment of the screen N insert according to the present invention; Figure 11 is a section view of a ninth embodiment of the screen insert according to the present invention; Figure 12 is a section view of a tenth embodiment of the screen insert according to the present invention; 00

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Figure 13 illustrates one embodiment of a screen mesh that may be employed with a screen insert according to the present invention;

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Figure 14 illustrates another embodiment of a screen mesh that may be employed with a screen insert according to the present invention; Figure 15 is a section view of an eleventh embodiment of the screen insert according to the present invention; Figure 16 illustrates the screen insert of Figure 15 attached to an edge of a screen mesh; Figure 17 illustrates the screen insert of Figure 15 attached to an edge of a different screen mesh; and, Figure 18 illustrates the screen insert of Figure 15 attached to an edge of a screen mesh with a block member fitted in the second cavity.

Detailed Description of Preferred Embodiments A first embodiment of a screen insert 10 according to the invention, for securing a rigid or semi-rigid screen mesh 12 in a frame (not shown), is illustrated in Figure 1. The insert 10 is adapted to enclose an edge 14 of the screen mesh 12 and has a cavity 16 designed to receive a folded back portion 18 of the edge of the screen mesh 12 therein. When the insert 10 is received in the frame, withdrawal of the screen mesh 12 is inhibited by the folded back portion 18 engaging the cavity 16. Figure 2 illustrates a second embodiment of the screen insert 10, which is similar to the insert of Figure 1 and therefore the same reference numerals are employed for the similar parts.

O In both embodiments, the insert 10 comprises an elongate member shown in N section view, having first and second side wall portions 20 connected by a bridging portion 22. The side wall portions 20 are shaped so that when they are brought into facing relation to each other the cavity 16 is formed within the insert. The insert 10 is preferably manufactured from a suitable plastics material to insulate the screen mesh 12 from the frame. One possible suitable r plastics material is nylon. The insert 10 is preferably manufactured using a 00

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Nplastics injection moulding process. The bridging portion 22 is relatively thin, Sand therefore can be easily bent to allow the two side wall portions 20 to move apart so as to receive the edge 14 of the screen mesh 12 there Sbetween prior to insertion in a frame recess. The insert 10 may be manufactured in any suitable length for door frames and window frames, and typically has a depth dimension of between 15mm to 30mm and a width dimension of between 6mm to 25mm. Because the edge of the screen mesh 12 is completely enclosed within the screen insert 10, it is effectively insulated from the material of the frame in use, and there is therefore no possibility of galvanic corrosion.

The screen mesh 12 is preferably manufactured from a rigid or semi-rigid metallic material, and is typically manufactured from a stainless steel material.

The screen mesh 12 may be manufactured from either a woven or perforated material, and is typically between 0.5mm to 1.6mm in thickness. The folded back portion 18 is typically between 3mm to 15mm in length, more typically between about 5mm to 10mm in length. It may extend along the full length of the edge 14 of the screen mesh 12 as shown in Figure 13. Alternatively short lengths, formed between cuts made at spaced intervals along the edge 14 of the screen mesh 12, may be folded back to form flaps 24 as shown in Figure 14. The flaps 24 may all be folded back in the same direction, or alternate flaps 24 may be folded back in opposite directions as shown in Figure 14. The folded back portion 18 is typically bent back so as to form an angle of between 900 and 200 with the edge 14 of the screen mesh 12. Preferably the folded back portion 18 is bent back so as to form an acute angle with the edge 14 of the screen mesh 12. The folded back portion 18 along adjacent perpendicular edges of the screen mesh 12 may be bent back in opposite directions. This has the advantage of increasing the rigidity of the screen N mesh 12 and improving its resistance to warping.

Whatever form the folded back portion 18 may take, it serves the function of effectively locking the edge 14 of the screen mesh in the insert 10. The folded back portion is accommodated and held captive in the cavity 16 of the insert, and because of the strength and rigidity of the screen mesh material it cannot OO be easily withdrawn from the insert. To withdraw the edge 14 of the screen

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mesh 12 from the insert would require the material of the screen mesh to be IN returned to its flattened or pre-folded condition; this can only be achieved with the application of considerable force.

A third embodiment of an insert 30 according to the present invention is illustrated in Figure 3. The insert 30 is adapted to enclose an edge 34 of a rigid or semi-rigid screen mesh 32, and has a cavity 36 designed to receive a folded back portion 38 of the edge of the screen mesh 32 therein. When the insert 30 is received in a frame recess, withdrawal of the screen mesh 32 is inhibited by the folded back portion 38 engaging the cavity 36. In this embodiment, the folded back portion 38 is in the form of a plurality of flaps formed in the edge 34 of the screen mesh.

Figure 4 illustrates a fourth embodiment of the screen insert 30, which is similar to the insert of Figure 3 and therefore the same reference numerals are employed for the similar parts. The main difference between the embodiment of Figure 4 and that of Figure 3 is in the shape of the cavity 36; in the former an internal surface of the cavity 36 is sloped at an angle similar to the angle at which the folded back portion 38 is bent.

In both embodiments first and second side wall portions 40 are connected by a bridging portion 42. The side wall portions 40 are shaped so that when they are brought into facing relation to each other the cavity 36 is formed within the insert. Preferably the side wall portions 40 are formed with one or more grooves 44 or ribs 46 on outer surfaces thereof, which are designed to engage with corresponding ribs or grooves provided on inner surfaces of the frame recess to help retain the insert 30 within the frame recess. Similarly, one or more ribs or protrusions 48 may be provided on inner surfaces of the O side wall portions 40 to help grip the edge 34 of the screen mesh 32.

NAdvantageously each side wall portion 40 may also be provided with a rebate extending along an upper edge thereof. The rebate 50 is adapted to receive a lip formed on the edge of the frame recess to further help retain the insert in the frame recess.

Figure 5 is a slightly enlarged section view of the insert 30 of Figure 3 00 inserted in a frame recess 52. As illustrated in Figure 5, the side wall portions of the insert 30 have been squeezed together to grip the edge 34 of the screen mesh therebetween. The folded back portion 38 of the screen mesh is held captive within the cavity 36. Ribs 54 provided on the inner surfaces of the frame recess 52 engage with the matching grooves 44 on the outer surfaces of the side wall portions 40 of the insert 30. A lip 56 formed on each edge of the frame recess 52 is folded over to engage with the rebates 50 on the insert 30 and help to lock the insert into the frame recess 52.

A significant advantage of the preferred embodiments of the screen insert is that no screws or other fasteners are required to secure the screen mesh or the insert in the frame. The folded back portion of the screen mesh is held captive in the cavity without the need for any fasteners or other means of securing the mesh. Furthermore, by careful choice of the dimensions of the insert and the provision of ribs and/or grooves and/or a rebate, the insert is securely held in the frame recess without the use of fasteners. This eliminates a possible site for galvanic corrosion and significantly simplifies the installation procedure.

Figures 6 and 7 illustrate a fifth and a sixth embodiment of a screen insert according to the present invention. These two embodiments are also quite similar and therefore the same reference numerals have been used to refer to the similar parts. Both inserts 60 are adapted to enclose an edge 64 of a screen mesh 62 and have a double chamber cavity 66 designed to receive a folded back portion 68 of the edge of the screen mesh 62 therein. When the inserts 60 are received in a frame, withdrawal of the screen mesh 62 is inhibited by the folded back portion 68 which is held captive within a chamber of the double cavity 66.

In Figure 6 the screen insert 60 is shown with the edge 64 of the screen mesh ri having a folded back portion 68 extending along its full length; whereas in Figure 7 a series of flaps 70 are formed along the edge of the screen mesh, similar to that shown in Figure 14, with alternate flaps facing in opposite directions. In the insert 60 of Figure 7 the flaps 70 of the folded back portion are conveniently held captive in the upper chamber of the double chamber rcavity 66; whereas in the insert 60 of Figure 6 the folded back portion 68 is 00 N held captive in the lower chamber of the double chamber cavity 66. The main difference between the inserts of Figures 6 and 7 is that insert of Figure 6 is also provided with a series of barb-shaped ribs 72 extending along the outer surfaces of the side wall portions of the insert. These barb-shaped ribs 72 are designed to engage with the inner surfaces of the frame recess and help to retain the insert 60 in the frame recess in use.

Figure 8 illustrates a seventh embodiment of a screen insert 80 according to the present invention. The insert 80 is adapted to enclose an edge 84 of the screen mesh 82 and has a multi-chamber cavity 86 designed to receive a folded back portion 88 of the edge of the screen mesh 82 therein. When the insert 80 is received in a frame, withdrawal of the screen mesh 82 is inhibited by the folded back portion 88 held captive in one of the chambers of the multichamber cavity 86. In this example the folded back portion 88 is received in the lowermost chamber of the cavity, however it could be held in any one or more of the chambers of the multi-chamber cavity 86.

The insert 80 of this embodiment is also formed with a series of barb-shaped elongate protrusions 90 on the outer surfaces of the side wall portions of the insert. These barb-shaped protrusions 90 are adapted to engage with matching elongate protrusions 92 provided on the inner surfaces of a frame recess 94 as shown in Figure 9. When the insert 80 is pushed downwards into the frame recess 94, the side wall portions of the insert are compressed together against the edge of the screen mesh 82. At the same time the barbshaped protrusions 90 engage with the matching protrusions 92 in the frame recess 94 to lock the insert into the frame recess.

O An eighth embodiment of a screen insert 100 is illustrated in Figure 10. All of Nthe previous embodiments of the screen insert have been of symmetrical configuration about a central axis, with a cavity capable of receiving a folded back portion of the edge of the screen mesh protruding in either direction.

However this and the remaining embodiments are of asymmetrical configuration, with a cavity which is only capable of receiving a folded back tportion of the screen mesh extending in one direction. The insert 100 is 00

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Sadapted to enclose an edge 104 of a rigid or semi-rigid screen mesh 102, and has a rectangular cavity 106 designed to receive a folded back portion 108 of the edge of the screen mesh 102 therein. When the insert 100 is received in a frame recess (shown in broken outline), withdrawal of the screen mesh 102 is inhibited by the folded back portion 108 being held captive in the cavity 106.

As with the previous embodiments, the insert 100 is in the form of an elongate member, shown here in section view, having first and second side wall portions 110 and 112 connected by a bridging portion 114. The second side wall portion 112 is shaped so that when it is brought into facing relation with the first side wall portion 110 the cavity 106 is formed within the insert. The insert 100 preferably further comprises a rectangular compression member 116, which is preferably separate from the second wall portion 112 but of a similar width dimension. The compression member 116 is inserted into the frame recess in a subsequent step, and is adapted to press the edge 104 of the screen mesh 102 against the first side wall portion 110 of the insert 100, to lock it into the frame recess by a friction fit.

Figure 11 illustrates a ninth embodiment of a screen insert 120 according to the present invention. The asymmetrical insert 120 is adapted to enclose an edge 124 of a rigid or semi-rigid screen mesh 122, and has a cavity 126 designed to receive a folded back portion 128 of the edge of the screen mesh 122 therein. When the insert 120 is received in a frame recess (not shown), withdrawal of the screen mesh 122 is inhibited by the folded back portion 128 being held captive in the cavity 126. In this embodiment the folded back portion extends into the cavity at substantially 90* from the edge 124 of the screen mesh 122.

O The insert 120 comprises first and second side wall portions 130 and 132 N connected by a bridging portion 134. The second side wall portion 132 is shaped so that when it is brought into facing relation with the first side wall portion 130 the cavity 126 is formed within the insert. In this embodiment, the second side wall portion 132 is formed with an enlarged body 136 which presses the edge 124 of the screen mesh against the first side wall portion r130. If necessary, the body 136 of the second side wall portion 132 may also 00

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Naccept a pop rivet or other fastening means to secure the insert in the frame Srecess. A series of ribs or tooth-shaped elongate protrusions 138 are provided on the facing surfaces of the first and second side wall portions to Simprove the grip on the edge 124 of the screen mesh 122. An outer surface of the second side wall portion 132 is similarly formed with corrugations 140, to improve the grip of the side wall portion against an inner wall of the frame recess.

Figure 12 illustrates a tenth embodiment of a screen insert 100, which is similar to the insert of Figure 10 and therefore the same reference numerals are employed for the similar parts. The means of retaining the folded back portion 108 of the screen mesh 102 in the cavity 106 is the same for both Figures 10 and 12. The main difference between the insert of Figure 12 and that of Figure 10 is that in the case of Figure 12 the compression member 116 is of solid configuration, rather than of hollow configuration. Otherwise the screen insert 100 of the embodiment of Figure 12 is structurally and functionally substantially the same as that of Figure 10 and will not be described again.

Figures 15 to 18 illustrate an eleventh embodiment of a screen insert 150 according to the present invention. The insert 150 is adapted to enclose an edge 154 of a screen mesh 152, as shown in Figures 16 and 17, and has a double chamber cavity 156 designed to receive a folded back portion 158 of the edge of the screen mesh 152 therein. When the insert 150 is received in a frame, withdrawal of the screen mesh 152 is inhibited by the folded back portion 158 which is held captive within a chamber of the double cavity 156.

O The insert 150 is in the form of an elongate member, shown here in section N view, having first and second side wall portions 160 and 162 connected by a bridging portion 164. The second side wall portion 162 is provided with two parallel transverse portions 166, extending perpendicularly inwards from side wall portion 162 so that when it is brought into facing relation with the first side wall portion 160, the double chamber cavity 156 is formed within the n insert. The transverse portions 166 press against the screen mesh 152, when 00 N the insert 150 is inserted into a frame recess (not shown), helping to secure it Nin the frame recess in a tight friction-fit. The bridging portion 164 is arranged so as to form a bull-nose when the two side wall portions 160 and 162 are N brought into facing relation, as shown in the drawings, to facilitate easy insertion into the frame recess. The insert 150 is also provided with a series of barb-shaped ribs 168 extending along the outer surfaces of the side wall portions of the insert. These barb-shaped ribs 168 are designed to engage with the inner surfaces of the frame recess and help to retain the insert 150 in the frame recess in use.

In Figure 16 the screen insert 150 is shown with the edge 154 of the screen mesh 152 having a folded back portion 158 extending along its full length; whereas in Figure 17 a series of flaps 170 are formed along the edge of the screen mesh, similar to that shown in Figure 14, except that is this case all the flaps 170 face in the same direction. In the insert 150 of Figure 17 the flaps 170 of the folded back portion are conveniently held captive in the outermost chamber of the double chamber cavity 156; whereas in the insert 150 of Figures 16 and 18 the folded back portion 158 is held captive in the innermost chamber of the double chamber cavity 156.

The insert 150 of Figure 18 also has a block member 172 provided in the outermost cavity. Block member 172 is formed by a strip of semirigid plastics material which is inserted into the outermost cavity prior to folding of the side wall portions 160 and 162 about the end 154 of the screen mesh 152. It is intended to provide additional support for the innermost transverse portion 166, in use, so that the folded back portion 158 of the screen mesh 152 is securely held captive within the innermost chamber of the double cavity 156.

O Now that several preferred embodiments of the screen insert have been N described in detail, it will be apparent that it provides a number of advantages Z over the prior art, including the following: The insert is of simple one-piece or two-piece construction and can be easily and quickly attached to the edge of the screen mesh.

(ii) It provides improved retention of the screen mesh in the supporting frame

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0of a security screen under extreme impact and stress loading.

(iii) It overcomes the problem of galvanic corrosion caused by the contact of dissimilar metals and the presence of moisture.

(iv) The insert secures the screen mesh without the need for the use of screws or other fasteners.

It is inexpensive to manufacture and its design readily lends itself to massproduction.

(vi) It can be employed with a variety of different types of screen mesh material and designs of the supporting frame.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, in each of the illustrated embodiments the cavity provided in the insert is of generally rectangular configuration in cross-section. However it will be understood that the cavity may be of any cross-sectional shape capable of accommodating a folded back portion of the edge of the screen mesh therein. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described and is to be determined from the appended claims.

Claims (29)

1. A screen insert for securing a rigid or semi-rigid screen mesh in a frame, the insert being adapted to enclose an edge of the screen mesh and having a cavity designed to receive a folded back portion of the edge of the screen mesh therein wherein, in use, when the insert is received in the frame withdrawal of the screen mesh is inhibited by the folded back portion being held captive in the cavity. (N

2. A screen insert as claimed in claim 1, wherein the insert comprises an elongate member having first and second side wall portions connected by a bridging portion, the side wall portions being shaped so that when they are brought into facing relation said cavity is formed in the insert.

3. A screen insert as claimed in claim 1 or claim 2, wherein the insert is of substantially symmetrical configuration about a central axis.

4. A screen insert as claimed in claim 2, wherein the insert is of asymmetrical configuration, with a cavity which is only capable of receiving a folded back portion of the screen mesh extending in one direction.

A screen insert as claimed in claim 4, wherein in an asymmetrical insert the second side wall portion is shaped so that when it is brought into facing relation with the first side wall portion the cavity is formed within the insert.

6. A screen insert as claimed in claim 4 or claim 5, further comprising a compression member, which is inserted into the frame recess in a subsequent step, and is adapted to press the edge of the screen mesh against the first side wall portion of the insert, to lock it into the frame recess by a friction fit.

7. A screen insert as claimed in claim 6, wherein the compression member is separate from the second wall portion but of a similar width dimension.

8. A screen insert as claimed in any one of claims 2 to 7, wherein the insert is formed with a multi-chamber cavity, one or more of said chambers being capable of receiving a folded back portion of the screen mesh N therein.

9. A screen insert as claimed in any one of claims 2 to 8, wherein the side wall portions are formed with one or more grooves or ribs on outer surfaces thereof, which are designed to engage with corresponding ribs or grooves provided on inner surfaces of a frame recess to help retain OO the insert within the frame recess.

N A screen insert as claimed in any one of claims 2 to 9, wherein one or Imore ribs or protrusions may be provided on inner surfaces of the side wall portions to help grip the edge of the screen mesh.

11. A screen insert as claimed in any one of claims 2 to 10, wherein each side wall portion is provided with a rebate extending along an upper edge thereof, the rebate being adapted to receive a lip formed on an edge of the frame recess to further help retain the insert in the frame recess.

12. A screen insert as claimed in any one of claims 2 to 11, wherein the insert is manufactured in any suitable length for door frames and window frames, and has a depth dimension of between 15mm to 30mm and a width dimension of between 6mm to

13. A screen insert as claimed in any one of claims 1 to 12, wherein the insert is made from a suitable plastics material to insulate the screen mesh from the frame.

14. A screen insert as claimed in any one of claims 4 to 13, wherein the insert is formed with a double chamber cavity, one of said chambers having a block member housed therein.

A security screen comprising: a screen mesh made from a rigid or semi-rigid material and having a folded back portion along an edge; O an outer frame in which the screen mesh is supported to form the r security screen; and, Sa screen insert adapted to secure the screen mesh in the outer frame, the insert having a cavity designed to receive said folded back portion of the edge of the screen mesh therein wherein, in use, when the insert is t' received in the outer frame withdrawal of the screen mesh is inhibited by oO the folded back portion engaging the cavity. (N

16. A security screen as defined in claim 15, wherein the screen insert is as Idefined in anyone of claims 2 to 14. S 10

17. A security screen as defined in claim 15 or claim 16, wherein the screen mesh is manufactured from a metallic material such as stainless steel.

18. A security screen as defined in claim 17, wherein the screen mesh is manufactured from either a woven or perforated material, and is typically between 0.5mm to 1.6mm in thickness.

19. A security screen as defined in claim 18, wherein the folded back portion is between 3mm to 15mm in length.

A security screen as defined in claim 19, wherein the folded back portion is between about 5mm to 10mm in length.

21. A security screen as defined in any one of claims 15 to 20, wherein the folded back portion extends along the full length of the edge of the screen mesh.

22. A security screen as defined in any one of claims 15 to 20, wherein short lengths formed between cuts, made at spaced intervals along the edge of the screen mesh, are folded back to form folded back flaps.

23. A security screen as defined in claim 22, wherein the flaps are all folded back in the same direction.

24. A security screen as defined in claim 22, wherein alternate flaps are folded back in opposite directions. O

25. A security screen as defined in any one of claims 15 to 20, wherein the Sfolded back portion is bent back so as to form an angle of between 900 and 20' with the edge of the screen mesh.

26. A security screen as defined in claim 25, wherein the folded back portion is bent back so as to form an acute angle with the edge of the screen Smesh. oO

0027. A security screen as defined in any one of claims 15 to 26, wherein the (N Sfolded back portion along adjacent perpendicular edges of the screen Nmesh is bent back in opposite directions.

28. A screen insert, for securing a rigid or semi-rigid screen mesh in a frame, substantially as herein described with reference to as illustrated in any one or more of the accompanying drawings.

29. A security screen substantially as herein described with reference to as illustrated in any one or more of the accompanying drawings. Dated this 4th day of July 2006 Antony William Upfield Clive James Sinclair by their Patent Attorneys Janet Stead Associates