AU634878B2

AU634878B2 - Corner stakes for use in frames

Info

Publication number: AU634878B2
Application number: AU75062/91A
Authority: AU
Inventors: Derek Boden
Original assignee: G JAMES Pty Ltd
Current assignee: G JAMES Pty Ltd
Priority date: 1990-06-28
Filing date: 1991-04-17
Publication date: 1993-03-04
Anticipated expiration: 2011-04-17
Also published as: AU7506291A

Description

S6348 78 COMMONWEALTH OF AUSTRALIA The Patents Act 1952-1969 Name of Applicant(s): Address of Applicant(s): G JAMES PTY LTD 800 Kingsford Smith Drive EAGLE FARM QLD 4007

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Address for Service: CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: CORNER STAKES FOR USE IN FRAMES The following statement is a full description of the invention including the best method of performing it known to us: This invention relates to corner stakes for use in frames and in particular mesh frames for use as fly screens and window screens.

Hitherto a fly screen for domestic use included four aluminium frame members which were retained in a rectangular orientation by four corner stakes located at each corner of the rectangular frame. Each of the rectangular frame members could be formed by extrusion or as a rolled section and included a hollow part which was adapted to receive a corner stake in slidable relationship at each end as well as an elongate recess extending the length of the frame member for receiving a plastics spline which was adapted to receive an e: associated edge of a mesh typically formed from fibreglass.

In order to produce a fly screen which is satisfactory both in a functional sense and in an aesthetic sense, it is necessary to stretch the fibreglass mesh sheet tightly across the rectangular frame. When this stretching procedure is carried out this will. cause a bending load on each of the aluminium frame members. In the interests of minimising weight and the cost of production of the frame the frame members are normally very light. Thus, when the mesh is stretched tightly across the frame this will cause a visible bend or bow in the fly screen once it is assembled. The extent of the bend or bow is a function of dimensions of the frame and the tension which is applied to the mesh sheet during assembly of the frame.

A conventional procedure which is currently in use to counteract this bend or bow is to roll into each of the frame members prior to assembly of the fly screen a deflection which is equal and opposite to the deflection that is produced by tensioning of the mesh sheet.

When this conventional procedure is followed the rectangular frame will be wider across a middle portion thereof in two directions that are each substantially parallel to an associated pair of frame members than at the corners.

This is caused by the fact that conventional corner stakes are rigid members with an included angle of ninety degrees and this will ensure that each corner of the fly screen is rigid

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prior to assembly and subsequent to assembly.

ca ~Although the extent of the deflection that must be 5055

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S. compensated for varies with frame dimensions, a single radius S of curvature is rolled into each frame member to cover all screen sizes and so far this procedure has been found to be generally satisfactory when due care is taken during assembly.

However, this practice prior to cutting and assembly of the 0 frame is time consuming and expensive and it also causes 5.

difficulties in package and storage of the frames.

A further difficulty that is relevant is that in some situations the single radius of curvature may be insufficient to compensate for the deflection imparted to each S frame member upon stretching of the fibreglass mesh sheet or alternatively the single radius of curvature may in some cases have been in excess of what was required to produce a rectangular orientation of the frame after stretching. This also caused problems in packing or storage of the fly screens.

Another procedure which was followed in regard to 4 prior art screens and especially those of a relatively large size, i.e. those of around 1200 m 1500 m in height was to include a spreader bar to compensate for the deflection in the frame members. However, this procedure was found to be time consuming and expensive and was undesirable because of its lack of aesthetic appearance.

Corner stakes or corner connecting members for attaching adjacent elongate frame members to form a generally rectangular framework have also been proposed in Australian Specification 32244/89 and foreign specifications DE 3615486, DE 3610908, DE 2810392, DE 2351766 and NL 7610404. However this prior art has been reviewed and is considered not ego• relevant to the present invention.

It therefore is an object of the invention to provide a corner stake for use in frames which may alleviate S at least some of the problems of the prior art discussed above.

The invention therefore provides a corner stake for S: use in connection of adjacent frame members to form a mesh 2'.i surround frame, said corner stake being strictly L shaped and having a pair of body portions with an included angle of 90 or greater which body portions are resiliently deformable in such a manner that when a mesh -creen is attached to the mesh surround frame each body portion deforms resiliently to substantially inhibit outward bowing or deflection of said frame members.

S d f-i el- -F In a preferred form of the invention the pair of elongate body portions are oriented at an angle of greater than 900 and more suitably this included angle may be between 900 and 950 and most preferably 93.50.

Each body portion may also include one or a plurality of bearing projections which preferably are tapered in a direction away from a free end part of the respective body portions and suitably at an acute angle thereto. For best results each bearing projection may be located on a 0 common surface such as an outer surface of the body portion but this is not absolutely necessary and thus it is possible for the bearing projections to be located on different surfaces of the body portion such as an inner surface and the outer surface.

Preferably each bearing projection may also include a free end which has a sharper degree of taper or in some cases may extend substantially parallel to its associated body portion.

The purpose of the abovementioned bearing projections is to facilitate the use of the corner stake of the invention with tubular frame members of varying lateral dimensions or widths. The use of the bearing projections may also enhance the retention of the corner stake in its associated frame members as the direction of taper of the bearing projections may resist extraction of each body portion of the corner stake from their associated frame members.

Reference may also be made to a preferred embodiment of the invention which is illustrated in the attached drawings wherein FIGS l(a) and l(b) illustrate conventional fly screen frame members which may be used in conjunction with the corner stake of the invention; FIG 2 shows a fly screen frame showing the various components of the frame including four corner stakes and four frame members in exploded relationship; FIG 3 shows the degree of deformation of conventional frame members when used in relation to a prior art fly screen frame as described above; FIG 4 illustrates the results obtained by the use of corner stakes in regard to this invention wherein little or no deformation or deflection of the respective frame members of the fly screen frame are obtained; FIG 0* 0.o illustrates an extruded continuous form of the corner stake of the invention in perspective view and FIG 6 illustrates a perspective view of the corner stake of the invention.

In FIG l(a) there is shown an extruded section 10 of a frame member for use with the corner stake of the invention.

This frame member includes a rectangular, tubular portion 11 for accommodating the corner stake as well as a channel portion 12 for receiving the aforementioned plastics spline.

This channel portion 12 is also provided with projections 13.

The tubular portion 11 is also provided with elongate ribs 14.

In FIG l(b) there is shown a rolled section 15 of a frame member having a tubular portion 16 for accommodating a corner stake of the invention in slidable inter-relationship and a channel portion 17 for accommodation of the aforementioned plastics spline. The rolled section 15 also includes respective abutting parts 18 and 19 as shown.

In relation tc FIG 2 there is shown four corner stakes 20 constructed in accordance with the invention as well as associated frame members 21. Each of the frame members 21 are broken away for convenience. It will also be noted that each of the frame members 21 have mitred ends 22.

In FIG 3 there is shown a fly screen frame 24 constructed in accordance with the invention using the components shown in FIG 2. It will be noted that each frame member 21 is bent or deflected laterally outwardly at both 26 and 27 as illustrated by reference line 28 shown in phantom.

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The bending of the frame members 21 is caused by the presence of corner stakes In FIG 4 there is shown the fly screen frame of FIG 3 and it will be noted that each of the frame members 21 are relatively straight and do not have the deflection illustrated in FIG 3 as shown by reference line 30 shown in phantom. This has been caused by tlhe attachment of mesh screen 31 which has

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tensioned each of the frame members 21 so that no deflection is now present.

In FIG 5 there is shown an extrusion which is the precursor of the corner stake of the invention. This precursor 32 includes body portions 33 and 34 together with a

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S" central groove 35 which is present to facilitate manufacture of extrusion 32. It is emphasised that the groove 35 is not essential to the corner stake of the invention and thus may be omitted, if required, so that the inner surfaces 36 and 37 of body portions 33 and 34 may meet at right angles if such is considered appropriate. Also shown are bearing projections 38 and 39 of each body portion 33 and 34 respectively. There is also illustrated an enlarged central portion In FIG 6 the corner stake 41 of the invention is shown in perspective view including the aforementioned body portions 33 and 34 as well as central groove 35 and bounding arcuate surfaces 42 and 43. Each body portion 33 and 34 include a pair of parallel, broad surfaces defined by inner surfaces 44 and 45 and outer surfaces 46 and 47. Also, each body portion 33 and 34 has free ends 48 and 49 each having bevelled edges 50 to facilitate entry of body portions 33 and 34 into the tubular portions 11 and 16 of the frame members as illustrated in FIGS l(a) and The corner stake 41 also 0* includes bearing projections 38 and 39 each having an intermediate part 51 which is tapere4 away from a respective free end 48 or 49 and also including free end portion 52 of a sharper degree of taper. Each bearing projection 38 and 39 may also include outer planar or flat surfaces 53 which may abut with an associated internal surface of the tubular portions 11 and 16 of the frame members shown in FIGS l(a) and Enlarged central portion 40 may also include planar or flat surfaces 54 which are substantially parallel or co-planar with flat surfaces 53 of bearing projections 38 and 39.

Surface 54 may constitute an impact surface for a hammer to facilitate entry of body portions 33 and 34 into tubular portions 11 and 16. There is also illustrated bevelled surface From the foregoing it therefore will be appreciated that the corner stake of the invention represents a marked improvement over conventional corner stakes in having an included angle of 90° or greater and also being conveniently flexible and more preferably at least resiliently deformable to a degree that the respective body portions of the corner stake may be firmly retained within the associated frame members.

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Claims

1. A corner stake for use in connection of adjacent frame members to form a mesh surround frame, said corner stake being strictly L shaped and having a pair of body portions with an included angle of 90° or greater which body portions are resiliently deformable in such a manner that when a mesh screen is attached to the mesh surround frame each body portion deforms resiliently to substantially inhibit outward bowing or deflection of said frame members.

2. A corner stake as claimed in claim 1, wvlierein the included angle is greater than

3. A corner stake as claimed in claim 2, wherein the included angle is between 90° and

4. A corner stake as claimed in claim 3, wherein the included angle is 93.5°. A corner stake as claimed in any preceding claim, wherein each body portion includes one or more bearing projections.

6. A corner stake as claimed in claim 5 wherein each bearing projection is tapered n a direction away from an adjacent free pnd of its respective body portion and at an acute angle thereto.

7. A corner stake as claimed in claim 6, wherein each bearing projection has a free end having a sharper degree c taper than the remainder thereof.

8. A corner stake as claimed in claim 5 or 6, wherein the or each bearing projection is located on an outer surface of its respective body portions. T 9. A corner stake as claimed in any one of claims 6-8 11 wherein there is provided an enlarged central portion at the junction of earh body portion which has substantially the same width as each .earing projection. A corner stake as claimed in claim 9, wherein the enlarged central portion is provided with outer planar surfaces wherein each planr.. surface is substantially coplanar with corresponding planar surfaces provided on each bearing projection of an adjacent body portion.

11. A corner stake substantially as herein described with reference to the accompany drawings.

12. A mesh surround frame assembly including a plurality of tubular flexible frame members each having an internal bore wherein each flexible frame member has mitred ends and a plurality of corner stakes wherein each corner stake is as defined in any preceding claim and wherein each corner stake is retained in an associated corner of the mesh surround frame assembly in respective internal bores of adjacent frame 0 members. DATED this twenty-first day of December 1992. G JAMES PTY LTD By their patent attorneys CULLEN CO. ~p LIAlt, 0l