GB2263927A

GB2263927A - Insect screen

Info

Publication number: GB2263927A
Application number: GB9212188A
Authority: GB
Inventors: Perry Day
Original assignee: Bernadette Etheldreda Harris
Current assignee: Bernadette Etheldreda Harris
Priority date: 1992-02-07
Filing date: 1992-06-09
Publication date: 1993-08-11
Anticipated expiration: 2012-06-09
Also published as: GB9202591D0; GB9212188D0; GB2263927B

Abstract

A frame, covered by a mesh 2, is formed of extruded sections having a rectangular rear part 10 having an inner fixing channel 12 with a mouth 13 extending through a second channel 15. The sections are joined by connecting plates 20, with screws 21 inserted through the mouth 13 into nuts 23 slid into the fixing channel. Between the connecting plates, sealing brushes are slid into the outer channels 15 to project from the mouths 13. The sections can have a D-shaped front part 11 which includes a channel 16, preferably with teeth, in which the mesh is entrapped by beading 35. The brushes could also be inserted into the fixing channels 12, and the connecting plates could be slid into the fixing channels and secured by grub screws. <IMAGE>

Description

INSECT SCREENS TECHNICAL FIELD OF THE INVENTION This invention relates to insect screens of the kind which include a mesh supported by a frame. The screen may, for example, be fitted over a window or door opening.

BACKGROUND In existing forms of insect screen the frame is formed of standard extruded hollow sections which are cut to length and joined by special connecting pieces having spigots which are push-fitted into the ends of the sections. The frame sections also have a lateral channel portion which runs around the inside of the frame in which the mesh is entrapped by a semi-rigid bead. In the case of door screens the lower part of the screen may be protected by a kick plate which is attached to the frame by self-tapping screws.

Such existing screens suffer from several problems which may be summarised as follows: - The finished frame is not very rigid in the region of the connecting pieces.

- The lengths of the frame sections must be carefully calculated, subtracting the space taken up by the connecting pieces.

- The addition of fittings such as hinges, catches and kick plates also requires skill and accurate workmanship.

- The size of the frame sections is quite substantial, making them obtrusive and expensive to produce.

- Since the channel portions for attachment of the mesh must run around the inside of the frame the frame sections must be carefully handed, which further complicates construction.

- The presence of mesh attachment channels on the inside further complicates the design of the frame in the joint regions.

The present invention addresses these problems among others.

SUMMARY OF THE INVENTION The present invention proposes an insect screen which includes a mesh supported by a frame, in which the frame is formed of a number of sections joined by connecting pieces and each frame section includes a longitudinal fixing channel for securing the connecting pieces, and in which the said channels have mouths extending longitudinally of the frame sections which are narrower then the said channels and which receive fixing screws for securing the connecting pieces to the frame sections.

With such an arrangement the frame sections can be abutted with simple mitre or butt joints, yet the finished frame is relatively rigid.

In one preferred arrangement nut elements are captive in the fixing channels and the fixing screws are inserted through the connecting pieces and the mouths of the channels into the nut elements. After preassembly of the nut elements, fixing screws and connecting pieces, the nut elements can simply be slid into the channels before tightening the screws. Other fittings such as hinges can be similarly secured to the frame using screws and nut elements slid into the channels.

In another preferred arrangement the connecting pieces are inserted into the channels and the fixing screws are received in screw-threaded apertures in the connecting pieces. The fixing screws may be grub screws which are tightened to bear against the rear faces of the channels. Thus, neither the fixing screws or the connecting pieces need project from the frame sections so that the frame sections can butt close up against a window frame or the like. Again, the assembled connecting pieces and fixing screws can be pre-assembled and slid into the ends of the frame sections before tightening the screws.

The frame sections may include additional beading channels for securing the mesh. With the object of reducing the size of the frame sections and increasing ease of construction, the beading channels preferably open at a front face of the section which is opposite to the face through which the mouths of the fixing channels open.

The opposed inner side faces of the beading channels are preferably provided with a plurality of opposed longitudinally extending teeth.

The beading channels are preferably contained within substantially D-section front portions of the frame members.

The sections are preferably symmetrical about a frontrear axis so that they do not require to be handed during manufacture.

The frame sections may include longitudinally extending closed cavities in addition to the fixing channels, to increase the torsional rigidity of the sections.

The screen preferably comprises a plate provided with fixing channels which open through mouths which are narrower than the fixing channels, for use in securing the plate to the frame. The plate may be secured to the frame sections by means of connecting pieces. The plate preferably includes integral beading channels for securing the mesh.

The invention also proposes an insect screen which includes a mesh supported by a frame, in which the frame is formed of a number of sections joined by connecting pieces, and in which the frame sections include sealing elements which project from the rear of the frame.

The sealing elements (e.g. brushes) are preferably inserted into channels in the frame sections. The sealing elements preferably have a base portion which is retained in the channels and a sealing portion which projects from mouths which are narrower than the channels.

Where the frame sections include the fixing channels referred to above, in order to reduce the size of the frame section to a minimum the sealing elements may be inserted into the fixing channels in the regions between the connecting pieces. Alternatively, additional channels may be provided for the sealing elements with the additional channels sharing a common mouth with the fixing channels.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is exemplified in the accompanying drawings, in which: Figure 1 is a front view of an insect screen of the invention, Figure 2 is a transverse section II-II through the frame of the screen shown in Fig.

1, Figures 3 and 4 are perspective views of connecting pieces for the frame, Figure 5 is a further transverse section V-V of Fig. 1 taken through the frame, Figures 6 and 7 are transverse sections through alternative forms of the extruded frame member, Figure 8 is a transverse section through a frame member for use in making larger screens, Figure 9 is an end view of a kick plate for use with such larger screens, and Figure 10 is a transverse section through the frame member of Fig. 2 showing an alternative means of connection.

DETAILED DESCRIPTION OF THE DRAWINGS Referring firstly to Fig. 1, the insect screen which is shown by way of illustrative example is intended to be placed over a window opening and includes a frame 1 covered by a mesh 2, only part of which is shown for convenience of illustration. The frame includes parallel top, bottom and middle sections 3, 4 and 5 respectively, and parallel side sections 6 and 7, all of which are cut from a length of extruded aluminium.

It will be appreciated however that the frame sections could also be of other metals or plastics such as upvc, preferably with a longitudinal metal reinforcing bar.

As shown in Fig. 2, the frame sections are symmetrical and include a rectangular rear portion 10 formed on the flat of a D-shaped front portion 11. The rear portion 10 includes a rectangular inner channel 12 adjacent to the front portion 11 having a narrower mouth portion 13 which opens through the rear face 14 of the section opposite to the front portion 11. The mouth portion 13 extends through an outer channel 15 located between the inner channel 12 and the rear face 14. The D-shaped front portion 11 includes a D-shaped channel 16 having a narrow mouth 17 which opens through the curved front face of the section directly opposite the rear face 14.

Referring back to Fig. 1, the sections are mitred at the corners of the frame so that they abut each other.

Thus, the lengths of the sections are easily determined during construction. The sections are joined by Lshaped steel connecting plates 20, one of which is shown in Fig. 3, abutted to the rear face 14 of the frame sections. Countersunk-head screws 21 (Fig. 2) are inserted through countersunk apertures 22 in the connecting plates 20 and pass through the mouths 13 into screw-threaded nut elements 23 which are nonrotatably located in the inner channels 12 of the two frame sections. The nut elements 23 are pre-assembled on the screws 21 and slid into the mitred ends of the frame sections, following which the screws are tightened to draw the nut elements 23 towards the connecting plates 20. The frame sections are thus firmly clamped to the connecting plates.

The transverse middle section 5 is butt-jointed to the sides of the side members 6 and 7 and connected thereto by T-shaped connecting plates 26 (Fig. 4) in a similar manner to the corner plates 20. Other fittings such as hinges or catches can be similarly secured to the frame sections using further screws 21 and nuts 23. In addition, as shown in Fig. 5, sealing brushes 30 are inserted into the rear faces of the frame sections in the regions between the connecting plates and any other fittings. The brushes include strips 31 which are slid into the outer channels 15 so that brush portions 32 project from the rear face 14 of the sections. Thus, when the screen is mounted with the rear face 14 against a window frame for example, the brushes make sealing contact with the window frame.

If desired, magnetic strips can be adhesively secured to the window frame to attract the steel connecting pieces 20 and 26, thereby providing an alternative and simple means of removably affixing the screen.

In order to secure the mesh 2 to the frame 1 lengths of bead 35 are urged into the forwardly facing channels 16, as shown in Fig. 2, so as to entrap the mesh between the bead and the channel walls. The bead may be of spongy natural or synthetic rubber, e.g. expanded neoprene, but for better retention the preferred form of bead is externally ribbed pvc tube or solid natural or synthetic rubber section (e.g. neoprene). Since the mesh-fixing channels 16 open at the front face of the frame a continuous length of mesh can be used to cover the frame shown in Fig. 1 without having to join the mesh at the centre bar 5. The mesh is simply continued over the centre bar and pressed into its channel 16 by a suitable length of beading.

The cross sectional area of the extruded frame section is about one third of that of prior frame sections making the screen aesthetically attractive and unobtrusive.

A modified form of the frame section is shown in Fig.

6. This section differs from that of Fig.s 2 and 5 in that the front portion 11 is non-symmetrical. A flat platform 18 is formed externally to one side of the bead-receiving mouth 17 to provide positive support for the mesh 2. The platform meets the extended side face 19 of the section perpendicularly. It will also be noted that the opposide side of the mouth 17 projects a short distance above the platform 18 in order to protect the edge portion of the mesh against abrasion damage. Fig. 6 also shows another possible modification to the section in which the bead-receiving channel 16 is provided with a series of inwardly directed longitudinally extending teeth 16a which project from opposite sides of the channel in order to provide a better grip on the mesh-securing bead 35 (not shown).In fact, the channel 16 could be substantially square or rectangular when such teeth are provided, but the general D-shape is retained simply in order to minimise the amount of metal in the front portion 11.

Since this section is non-symmetrical the opposite members of the frame will need to be handed during construction.

A further modified form of the frame section is shown in Fig. 7. This version is symmetrical and has a rectangular rear portion 10 formed on the back of a Dshaped front portion 11. The rear portion 10 includes a closed rectangular internal cavity 40 adjacent to the front prtion 11 and a single inner channel 12 having a narrower mouth portion 13 which opens through the rear face 14 of the section. The front portion 11 includes a D-shaped channel 16 having a bead-receiving mouth 17 which opens through the front face of the section directly opposite the rear face 14. The section is used in the same way as that of Fig.s 2 and 5 except that the brush strips 31 are poked into the channel 12 through the mouth 13 between the connecting plates and fittings after assembly of the frame. The closed cavity 40 increases the torsional rigidity of the frame sections.

To make a larger screen, e.g. for covering a doorway, the larger section shown in Fig. 8 can be used. The frame sections are symmetrical and include a rectangular rear portion 10 formed on the flat of a Dshaped front portion 11. The rear portion 10 again includes inner and outer channels 12 and 15 and a common mouth portion 13 which opens through the rear face of the section. This rear face may be flat as in the sections of Fig.s 2 and 5, but in the case of the sections shown in Fig. 8 there are two further channels 36 and 37 located either side of the mouth portion 13.

These additional channels can receive the sides of a channel-shaped connecting piece 20' which, being nonflat, is of increased strength. The connecting pieces are secured to the frame sections as described above using screws and nut elements slid into the inner channels 12. Brushes can again be mounted in the outer channels 15, or the outer channels can be omitted and the brushes inserted in the same channel as the nut elements 23. The front portion 11 includes a D-shaped channel 16 for mesh attachment, but now further includes an internal cavity 40.

The door can be provided with an extruded kick plate shown in Fig. 9 which includes a plate portion 42 having rearwardly directed channel portions 43 extending along its top and bottom edges. These channel portions 43 are of similar shape to the rear portions 10 of the frame sections shown in Fig.s 2 and 5 so that they can be connected with the frame members of Fig. 8 in the manner described. For attachment of the mesh a length of frame section is secured to the side sections immediately above the kick plate. The plate of Fig. 9 can also be used as a transverse centre panel in a door with transverse frame sections immediately above and below for securing separate pieces of mesh. As an alternative to using additional frame sections adjacent to the plate, bead-receiving channels (not shown) can be incorporated into the side edges of the plate opposite to the channel portions 43.

Various alternative means of joining the frame sections are envisaged. Instead of using the nuts 23 the bolts 21 could have enlarged heads which are non-rotatably slid into the channels 12. The connecting plates 20 and 26 are then placed over the protruding shanks of the bolts followed by co-operatively threaded nuts.

The nuts are then tightened on the bolts to clamp the connecting plates to the sections.

Another alternative means of connecting the frame sections is to insert the connecting plates 20, 26 into the channels 12, as shown in Fig. 10. The connecting plates, which are exemplified by plate 20', have screwthreaded apertures 22' and are secured by grub screws 21' inserted through the mouths 13 into apertures 22' and tightened against the rear face of the channels 12 to urge the plates 20' against the opposite face of the channels 12. The grub screws 21' may have flat tips or they may have a shallow point at their tips to bite into the wall of the frame sections, as shown. Largeheaded bolts, or bolts and washers, could be used instead of the grub screws 21', with the heads of the bolts being tightened against the rear faces 14 of the frame sections.

Claims

1. An insect screen which includes a mesh supported by a frame, in which the frame is formed of sections joined by connecting pieces, and each frame section includes a longitudinal fixing channel for securing the connecting pieces, and the said channels have mouths extending longitudinally of the frame sections which are narrower then the said channels, and which receive fixing screws for securing the connecting pieces to the frame sections.

2. An insect screen according to Claim 1, in which nut elements are captive in the fixing channels and the fixing screws are inserted through the connecting pieces and the mouths of the channels into the nut elements.

3. An insect screen according to Claim 1, in which the connecting pieces are inserted into the fixing channels and the fixing screws are received in screwthreaded apertures in the connecting pieces.

4. An insect screen according to Claim 3, in which the fixing screws are grub screws which are tightened to bear against the bottom faces of the channels.

5. An insect screen according to any preceding claim, in which the frame sections include beading channels for securing the mesh.

6. An insect screen according to Claim 5, in which the beading channels open at a front face of the section which is opposite to the face through which the mouths of the fixing channels open.

7. An insect screen according to Claim 5 or 6, in which the opposed inner side faces of the beading channels are each provided with a plurality of longitudinally extending teeth.

8. An insect screen according to any preceding claim, in which a front portion of each frame member, which is opposite to the fixing channel, is substantially D-shaped.

9. An insect screen according to any preceding claim, in which the frame sections are symmetrical about a front-rear axis.

10. An insect screen according to any preceding claim, in which the frame sections include longitudinally extending closed cavities which are separate from the fixing channels.

11. An insect screen according to any preceding claim, in which the corners of the frame are mitred.

12. An insect screen according to any preceding claim, in which the frame sections include sealing elements which project from the rear of the frame.

13. An insect screen according to Claim 12, in which the sealing elements are inserted into channels in the frame sections.

14. An insect screen according to Claim 13, in which each sealing element has a base portion which is retained in the respective channel and a sealing portion which projects from a mouth which is narrower than said channel.

15. An insect screen according to Claim 13 or 14, in which the sealing elements are inserted into the aforesaid fixing channels in the regions between the connecting pieces.

16. An insect screen according to Claim 13 or 14, in which the sealing elements are inserted into additional channels in the frame section.

17. An insect screen according to Claim 16, in which said additional channels share a common mouth with the aforesaid fixing channels.

18. An insect screen according to any preceding claim, in which the screen comprises a plate provided with fixing channels opening through narrower mouths for securing the plate to the frame.

19. An insect screen according to Claim 18, in which the plate includes integral beading channels.

20. An insect screen according to any preceding claim, in which the frame sections each include a closed internal cavity.

21. An insect screen substantially as described with reference to the drawings.