AU2002300387B2 - Improved bridging member - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Stramit Corporation Limited Actual Inventor(s): Christopher Lee Healy Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: IMPROVED BRIDGING MEMBER Our Ref: 674949 POF Code: 237473/169406 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 2 IMPROVED BRIDGING MEMBER This application is a divisional application of AU 20787/00, which, in turn is a divisional of AU 31570/97, and the contents of these applications are herein incorporated by cross reference. This invention related to an improved bridging member, and to components for such bridging member, for use as spacers or bridging between successive structural members such as purlins, girts or the like of a building structure.

A number of forms of bridging members are known. These include those of Australian patent specification AU-B-21347/70, AU-B-16953/88 and AU-B- 10356/92, and British patent specification GB-1507136. A further known arrangement is that of our Australian patent specification AU-A-5327994.

In general terms, these known forms of bridging members, like those of the present invention, have an elongate body, which to enhance structural strength, is of C-section channel form. At each end of the body, there is a respective engagement portion by which each of successive bridging members is adapted to be secured between a successive pair of structural members, with the bridging member directly, or indirectly, inter-connected in end-to-end relationship. Each engagement portion may comprise a tongue, or its equivalent, as in AU-B-21347/70 and AU-B-10356/92, with first tongue of one bridging member projecting through a slot in one structural member of its pair and engaging with a second tongue of a further bridging member for the next pair of structural members. Alternatively, the respective engagement portions may comprise hooks and lugs as in AU-B-16953/88. In a still further alternative, the respective engagement portions may comprise various forms of interengaging male and female members as in our invention of AU-A-63279/94.

In general, the bridging member of the present invention is concerned with an improved, or alternative, form of our invention of application AU-A- 63279/94.

In the bridging member of AU-A-63279/94, the male engagement portions are in the form of a laterally spaced pair of projections which are inserted through holes in the web of the first structural member of its pair. In the supply of such members, as with other bridging members, it is usual for a plurality of them to be bundled together for ease of transport and handling on site and the bundles can be of a substantial weight. In the event of a bundle N:Madivof20787-OO.doc 3 being dropped, the projections can be damaged by being bent, and it then can be difficult to straighten them sufficiently to enable use of a damaged bridging member. In the applicant's earlier patent 713646 and co-pending application 20787/00, to which this application is a divisional, a bridging member is disclosed which is concerned with providing a solution to this problem, both for bridging members according to AU-A-63279/94, and other forms of bridging members for which this solution is applicable, including other forms of the present invention.

In the invention defined in 31570/97, there is provided a first engagement portion for a bridging member, or a bridging member having such first portion at a first of opposite ends thereof, which is co-operable with a second engagement portion at the other end of a similar bridging member. The first engagement portion includes a body which has first and second opposite ends. The body is connectable or is connected at the first end, directly or indirectly with a second engagement portion. At the second end, the first engagement portion has at least one projection which extends away from the first end. The or each projection is adapted for insertion through an opening or respective opening, such as a slot or hole in a web of a first structural member, and it has a leading end region is adapted to preferentially deform, under the action of substantial impact forces applied thereto, whereby the projection otherwise is substantially protected from bending and is able to remain in a form still enabling its insertion through the opening substantially without being impeded by the preferentially deformed end region.

The risk of damage to the male or first engagement portions also exists with female or second engagement portions where these comprise projections from a body as, for example, in AU-A-63279/94. The present invention is concerned with providing a solution to this problem, both for bridging members according to AU-A-63279/94, and for other forms of bridging members for which this solution is applicable, including other forms of the present invention.

In accordance with the present invention, there is provided a second engagement portion for a bridging member, or a bridging member having such engagement portion at a second of opposite ends thereof, which is co-operable with a first engagement portion at the other, first end of a similar bridging member. The second engagement portion includes a body having first and N:,Warkd of2O787-OO.doc IC connected, directly or indirectly with a first engagement portion. At the second Send, the second engagement portion has at least one means co-operable with 3 the first portion of a similar bridging member with the or each co-operable T means defined by the body inboard with respect to the second end whereby the co-operable means is substantially protected against impact loading applied to the second end. The second engagement portion includes a body and the cooperable means includes at least one locating tab which projects from the body oo Mc, and is receivable in a slot defined by the first engagement portion of a similar bridging member.

t'q The said co-operable means may comprise or include at least one tab Swhich is cut or stamped from the body of the second engagement portion and is turned so as to project from the body, within a margin of the body adjacent to the second end. Where there is more than one co-operable means, the tabs are spaced laterally on the body. The or each tab is co-operable with a respective part of a first engagement portion of a similar bridging member, such as with the or a respective projection of the first portion of that similar member.

The body of the engagement portion, in a preferred form of the invention may have a web, whether this is in the form of a flat or laterally curved plate, or a web of the C- or Z section channel. In such case, the or each tab is turned so as to project from the web in the direction in which the web is to approach the first engagement portion of a similar bridging member. The or each tab preferably is substantially perpendicular to the web.

The engagement portion of a preferred form of the invention most preferably provides for locking engagement with the first engagement portion of a similar bridging member. This can, for example, be achieved by folding over the or each tab when it is engaged with the first engagement portion, such as after it has been received through an opening of a projection of the latter.

However, the locking engagement preferably results from a releasable snap in engagement between first and second engagement portions, to facilitate unlocking.

To provide a releasable snap engagement between first and second engagement portions, the or at least one tab of the latter portion may have detent means which interacts with the first engagement portion. The detent of a tab means may comprise a suitably positioned dimple on the tab which, as the W:%Sandra1RNC WORKkRNC WORIORNC NO DELETE2002300387 Claims.doc 4a 0 tab is inserted through an opening, is force fit through the opening, requiring 0 application of a suitable force to withdraw the tab. Alternatively, the tab may 3 have a resiliently flexible tang which projects rearwardly with respect to a 00 oo oo mq 0q W:\Sanrra\RNC WORK\RNC WORK\RNC NO DELETE\2002300387 Claims.doc leading edge of the tab, such that the tang is required to flex to enable it to pass through the opening and then is able to recover so as to engage the first portion. In that alternative, the tang may be able to be flexed, by application of a force, to enable the tab to be withdrawn. However, still further arrangements are possible in which detent means are not provided on the tab itself, but on an adjacent part of the second engagement portion. In one form, the tang includes a distal outer end, which is engageable with the first engagement portion, is arcuate in cross-section. This increases the effective thickness of the distal end and reduces the problems of tolerance. It also assists in increasing the stiffness of the tang.

In one arrangement, suitable for use where the first engagement portion has projections, the tab may be receivable in an opening of a projection of the first portion of a similar bridging member. In such case, there may be an upstanding part, such as a further tab or a flange, with that part laterally adjacent and substantially parallel to the tab. The arrangement may be such that, with the tab received in an opening of a projection of a first engagement portion, the upstanding part is adjacent to a side edge of the projection, with the part having detent means such as described in the last preceding paragraph herein for engaging with that side edge.

In one preferred form, the or at least one tab of the second engagement portion may be adjacent to a side flange of the body of its portion, with the side flange having the detent means. In such case, the detent means may be provided by a tang or tongue formed in the side flange, by providing a U-shaped slot in the flange, with the tang or tongue extending towards the web of the body, but bent slightly towards the tab so as to be engageable with the side edge of a projection of the first engagement portion of a similar bridging member. Where the second engagement portion is a C-section channel, each side flange may have a similar detent adjacent to each of respective laterally spaced tabs. Where the second portion is a Z-section channel, one side flange may have such detent means for one of two laterally spaced tabs, with a similar detent means for the other tab being provided by an upstanding part cut or stamped, and then bent from the web, so as to be laterally adjacent to the other tab.

N:Markddivof20787-00.doc 6 In order that the invention may be more readily understood, description now is directed to the accompanying drawings, in which: Figure 1 is a side elevation showing a bridging member according to an embodiment of the invention; Figure 2 is a top plan view of the member of Figure 1; Figure 3 is an elevational view of the member of Figure 1, from the trailing end; Figure 4 is a partial side elevation, showing initial insertion of the leading end of the member of Figure 1, through the web of a first structural member; Figure 5 is a view from the right hand side of Figure 4, after the member has been swung to its in use position; Figure 6 is a partial perspective view showing inter-engagement of the trailing end of the member of Figure 1, when in its use position, with the leading end of a similar member inserted through the web of a second structural member; Figure 7 is a partial longitudinal sectional view through the members of Figure 6; Figure 8 is a perspective view of the member of Figure 1; and Figure 9 is a partial side elevation showing a leading end of a bridging member according to a second embodiment of the invention; Figure 10 is a top plan view of the member of Figure 9; Figure 11 is a partial side view showing a leading end of a bridging member according the third embodiment of the invention; and Figure 12 is a top plan view of the member of Figure 11.

As shown in the drawings, the bridging member 11 is of elongate form. It is suitable for bridging between a successive pair of a plurality of laterally spaced structural members such as purlins, girts or the like. Such bridging is provided by an end to end series of bridging membersl 1, each engaging with a web of each of a successive pair of structural members. The bridging member 1 has a length slightly greater than the uniform spacing between the webs of successive structural members.

The member 11, of channel shape in transverse section, has an elongate central portion 12, a forward fastening portion 13 and a rear fastening portion 14. Portion 12 is longer than illustrated, with a mid-region of it shown as broken away. Each portion 13 and 14 is of slightly larger section than portion 12, such that a respective end of portion 12 can be neatly received in partial overlapping N:Mardivof20787-OO.doc relationship in each of portions 13 and 14. Also, portion 12 is secured to each of portions 13 andl4, at the respective overlapping webs, such as by punched clinches 15. Also, a fastener (not shown) can be provided through aligned holes 16 of the overlapping web. However, if required, each of the portions 13 and 14 can be formed integrally with portion 12.

The forward portion 13 has a channel shaped body 17 having a side flange 17a upstanding from each side of its web 17b. The leading edge 18 of each flange 17a is in a common plane with a mid-part of the stepped, leading edge 19 of the web 17b. Projecting beyond edge 19, portion 13 has a laterally spaced pair of projections or spears Each spear 20 has a channel shape provided by a first, outer side flange which is a continuation of a respective flange 17a, a web20b which is a continuation of web 17b and a second, inner flange 20c. In accordance with the first form of the invention, web 20b has a tab 21 by which it projects beyond its flanges 20a and 20c and, intermediate its ends, web 20b defines a longitudinal slot 23.

The flanges 20a and 20c of each spear 20 are of lesser width than the flanges 17a. Also, a rear part of the edge of flange 20a increases in width to define an arcuate ramp 26 by which it merges towards its flange 17a, but with an undercut 27 being provided in flange 17a at the trailing end of ramp 26.

The tab 21, by which the web 20b of each spear 20 projects beyond flanges 20a and 20c is shaped to preferentially deform under the action of substantial impact forces applied to the leading end region of the spears 20. As shown in the embodiment of Figures 1 to 8, the tab 21 is folded upwardly from the general plane of web 20b, in the direction in which flanges 20a and extend. The fold is provided by bending web 20b on a transverse fold line 22 adjacent to the leading ends of flanges 20a and 20c, but with tab 21 itself being bent in the reverse direction on second transverse fold line 22a. The tab 21 thus is of somewhat arcuate form as viewed in side elevation. The form of the tab 21 is such that an end impact force applied to member 11 at one or each tab 21, such as by member 11 being dropped on its leading end, will result in preferential bending of tab 21 on line 22 and/or line 22a, rather than bending of spear 20 other than at tab 21. This is facilitated by tab 21 projecting beyond the N:%Markdivof20787-OO.doc 8 leading end of each flange20a and 20c, and also by tab 21 decreasing in width, as shown, in a direction away from those flanges.

An alternative form of the forward portion 13 is disclosed in Figures 9 and The embodiment of Figures 9 and 10 includes many of the features of the embodiments of Figures 1 to 8 and accordingly like reference numerals have been given to like features. The main difference with the embodiment of Figures 9 and 10 is in the construction of the tab 21. Again this tab is adapted to preferentially deform but in this embodiment rather than being folded, the tab 21 includes an opening 50 within opposite sides 51 and 52 of the tab 21. With this arrangement, marginal regions 53 and 54 of the tab which are located intermediate the opening 50 and respective ones of the opposite sides 51 and 52 are adapted to collapse under the action of substantial impact force applied to the tab 21 to provide the preferential deforming of the tab 21.

Yet another form of the forward portion 13 is disclosed in Figures 11 andl2. Again, the embodiment of Figures 11 and 12 include many of the features of the embodiments of Figures 1 to 8 and accordingly like reference numerals have been given to like features.

In the embodiment of Figures 11 and 12, the tab 21 includes a pair of recesses 55, 56 along its opposite side. These recesses extend towards a central region of the tab 21 to form a central waisted region 57of the tab. This waisted region is adapted to preferentially deform under impact loading due to its reduced width as compared to the remaining part of the tab 21. To further increase the propensity of the tab 21 to preferentially deform, a crease 58 is formed across the waisted region 57. The crease58 is in the form of an indent to form a line of reduced thickness across the waisted region 57.

While the outer flange 20a of each spear 20 is similar in overall form to the corresponding flange of the bridging member of the drawings of specification AU-A-63279/94, this is not the case with the inner flange While the inner flange 20c may extend in the opposite direction to that shown, its principal characteristic is the provision of a tab 24 in accordance with the second form of the invention, formed by a longitudinal slot 25 (see Figure 6) extending forwardly from the trailing edge of flange 20c. In the form shown, tab 24 diverges inwardly, away from flange 20a, while the same applies if flange extends in the opposite direction.

N:~Mark\divof20787-OO.doc The arrangement of fastening portion 13 is such that, with bridging member 11 suitably disposed between, and at an acute angle to, a pair of structural members, member 11 can be advanced longitudinally to insert each spear 20 in a respective hole 36 defined in the web 37 of a first one of the structural members. These holes 36 preferably are of industry standard dimensions, known as ASIC holes, as specified by the Australian Institute of Steel Construction. Thus, as shown, the holes 36 may be elliptical in form, about 18 mm by 22 mm across, and at a standard spacing between centres depending on the size of the structural members. Also, the width between flanges 17a and the width of spears 20 generally accord with such standard holes.

The spacing between the flanges 20a and 20c at a leading part of each spear 20 is such that the leading end of each spear 20 is able to be inserted into a respective hole 36 of the web 37 of the structural first member. However, that spacing increases towards the trailing part of each spear 20 due to the divergence of its tab 24. The arrangement is such that, for each spear 20 to be fully inserted through the respective hole 36, its tab 24 is resiliently flexedso as to straighten, that is, towards the respective flange 20a. Also, the length of the tab 24 is such that, with its spear 20 fully inserted through the respective hole 36, the trailing end of the tab 24 is slightly clear of the hole 36 and thus is able to resiliently return substantially towards its divergent position. In the returned position, the trailing end of the tab 24 is opposed to the web 37 of the first structural member, and thus prevents withdrawal of its spear 20. However, if such withdrawal is required, the tab can be flexed, such as manually, so as to permit this.

With each spear 20 fully inserted through its respective hole36 of the first structural member, the bridging member 11 then is able to be swung to a position in which it is perpendicular to the web of each of the first and second structural members between which it is to provide bridging. The direction in which member 11 is swung is clock-wise relative to the view of Figure 1 and, in that movement, member 11 is guided by each ramp 26 riding across the periphery of the respective hole 36. When member 11 is in that perpendicular position, its rear portion 14 then is adjacent to the web of the second structural member of that pair. In being swung to that position, the portion 14 is able to N:Warkldivof20787-00.doc engage with the spears of a similar bridging member 111 which have been inserted through the holes of the second structural member from a side of the latter remote from the first structural member. The similar member has previously been installed between a next adjacent pair of structural members comprising the second structural member and the next one beyond this in a direction away from the first structural member.

The rear portion 14 of bridging member 11 has a channel shaped body 29, having a side flange 29a, upstanding from each side of its web 29b.

Adjacent to the trailing edge 30 of body 29 and each flange 29a, a respective tab 31 is punched from web 29b. Each tab 32 is punched and bent so that it is substantially parallel to the adjacent flange 29a, leaving a respective opening 31a in web 29b. Also, adjacent to its tab 31, each flange has a U-shaped cut-out 32 so as to define a depending detent tab 34 which is slightly bent inwardly towards the respective tab 31.

The arrangement of rear portion 13 is such that, as its member 11 is swung to the abovementioned perpendicular position, portion 14 is able to receive and releasably engage the spears 120 of the installed member 111.

For this, the spacing between its flanges 29a slightly exceeds the spacing between flanges 17a and, hence, between flanges 20a. Thus, as the member 11 is swung to that position, its web 29b is moved towards the underside of the web 120b of the projections 120 of the installed member 111. The spacing of each tab 31 from its adjacent flange 29a is such that the tab 31 is received through the slot 123 of a respective projection 120 of the installed bridging member 111. Each tab 31 may include an undercut region at the base of its forward facing surface. With this arrangement, the leading end of the spears 120 are captured in the undercut which prevents them from coming out of engagement. It also limits the eccentricity of the loading applied on the tabs when in tension. Also each tab 34 is engaged by the flange 120a of a respective projection 120 of the installed member 111, causing the tab 34 to flex outwardly. When the member 11 achieves its perpendicular position, the engaged projections 120 of the installed member 111 contact its web 29b.

Also, when that contact is achieved, the lower end of each tab 34 is slightly above the upper leading edge of the flange 120 of the installed member 111, such that the tabs 34 are able to resiliently recover to their inward bent N:AWarlkdivof20787-OO.doc positions. In those positions, the tabs 34 releasably lock the portion 14 in relation to spears 120 and thus hold member 11 in its perpendicular position.

However, tabs 34 can be manually flexed for unlocking, if required. Further, whilst not shown, the lower end of each tab may be arcuate in cross-section.

This increases the stiffness of the tabs 34 and increases their effective thickness to provide a better contracting surface which reduces the problems of tolerance error.

The arrangement of rear portion 14 is such that tabs 31 and 34 are substantially protected against damage, in the even of an end applied impact load. Thus, at least relative to the arrangement of AU-A-63279/94, damage is less likely if, for example, a bundle of members 11 is dropped.

An upper margin of each flange 29a of rear portion 14, along a trailing portion thereof, is turned outwardly to define a lip 40. This serves two functions.

The first function of each lip 40 is to strengthen its flange 29a, and thereby increase its resistance to damage by end applied impact forces. The second function of lips 40 is to serve as a guide providing for correct alignment of member 11, as it is swung to perpendicular position, for receiving therein the spears 120 of the installed member 111.

A bridging member according to the invention is able to be readily fabricated from sheet metal of a suitable gauge. As installed to provide bridging between successive structural members, such as purlins and girts, and end-toend series of the bridging members acts to restrain sagging and/or twisting of the structural members and maintenance of a parallel relationship therebetween.

The present invention, according to its preferred embodiments, allows the bridging member to be installed simply by inserting the spears through the first structural member at an angle and swinging the bridging member to the perpendicular to engage with the spears of an installed bridging member, adjacent to the second structural member. In that perpendicular position, the bridging members hold the structural members, improving safety conditions as the person installing the bridging members moves forward to install successive bridging members.

In the case of at least the preferred forms of bridging member disclosed in AU-A-63279/94, the bridging member necessitates it being positioned at an N:Varktdivof2O787-O.doc 12 acute angle to the web of each structural member between which it is to provide bridging. Such angle is necessary in order to enable the projections at the leading end to be inserted through the holes of the web of the first structural member, prior to the member being swung to its perpendicular position. In general, with at least preferred forms of the bridging member of the present invention, such acute angle positioning is not necessary for the purpose of enabling such insertion of the projections at the leading end, although such positioning can be necessitated by the spacing between successive structural members. Thus, for example, if a bridging member were to have its projections inserted through the openings of the web of a first structural member, before installation of a second structural member, the bridging member need not initially be presented at an acute angle to the web of the first structural member.

That is, the bridging member could simply be initially positioned perpendicular to that web, and then removed longitudinally to insert its projections through the holes of the web. If required, the bridging member then could be used to ensure correct installation of a second structural member adjacent to its trailing end.

The preferred bridging member is compatible with any purlin with industry standard, AISC holes. The installation requires no tools, and maybe done by one person. Furthermore, if it is necessary to remove an individual bridging member, for example to install a roof ventilator or air conditioner, the bridging member can be simply removed without needing to remove the other bridging members, by pushing back first the tabs 34 and then the tabs 24. The fastening portions are designed to provide ease of location and a positive snap connection between the bridging members, while holding the structural members against rotation.

While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered as illustrative and not restrictive, and all changes which come within the meaning and range of equivalency of this disclosure are therefore intended to be embraced therein.

N:kMrk divof20787-O0dOC

Claims (25)

1. A bridging member for providing bridging between first and second Ssuccessive structural member, such as purlins, girts or the like, of a plurality of a, 4 laterally spaced said structural members; wherein the bridging member is of oo 5 elongate form and has at respective first and second ends thereof, a first engagement portion and a second engagement portion; wherein the second engagement portion has at least one means co-operable with the first oo rn, engagement portion of a similar bridging member, with the or each co-operable 0 means being located inboard with respect to the second end of the bridging member whereby the co-operable means is substantially protected against Simpact loading applied to the second end; and wherein the second engagement portion includes a body and wherein the co-operable means includes at least one locating tab which projects from the body and is receivable in a slot defined by the first engagement portion of a similar bridging member.

2. A bridging member according to claim 1, wherein the at least one locating tab is cut or stamped from the body and is turned so as to project from the body, within a margin of the body adjacent to the second end.

3. A bridging member according to claim 1 or claim 2, wherein the body of the second engagement portion includes a web and wherein the or each locating tab is turned so as to project from the web in the direction in which the web is to approach the first engagement portion of a similar engaging member.

4. A bridging member according to claim 3, wherein the or each locating tab is receivable in an opening formed in the projection, or a respective one of the projection, of the first engagement portion of a like bridging member.

5. A bridging member according to claim 4, wherein the or each locating tab includes an undercut region on its edge surface which faces towards the first end, a portion of said projection adjacent said opening is operative to locate in said undercut region to maintain the first engagement portion of a similar bridging member in engagement with said second engagement portion.

6. A bridging member according to claim 4, wherein the second engagement portion includes detent means to provide for locking engagement thereof with the first engagement portion of a similar bridging member.

7. A bridging member according to claim 6, wherein said detent means are formed on the or each locating tab.

WASandra\RNC WORK\RNC WORK'RNC NO DELETE002300387 Claims.doc 14 C8. A bridging member according to claim 6, wherein the body of the second Sengagement portion includes at least one flange which extends from the web in 3 a direction which is substantially parallel to the or each locating tab, and T wherein the or each flange includes said detent means such that with the 00 5 locating tab received in an opening of a projection of the first engagement portion, the flange is adjacent to a side edge of the projection with the detent means adapted for engagement with that side edge. oo 00 Mc

9. A bridging member according to claim 8, wherein the detent means is in Sthe form of a resilient tang located on the or each flange, the or each tang projecting towards the locating tab, or a respective one of the locating tabs.

A bridging member according to claim 9, wherein the or each tang is formed by providing a U-shaped slot in its flange.

11. A bridging member according to either claim 9 or 10, wherein a distal end of said tang is arcuate in cross-section.

12. A bridging member according to any one of claims 8 to 10, wherein the flange, or at least one of the flanges, including said detent means forms a continuation of the flange, or a respective one of the flanges, of the bridging member.

13. A bridging member according to any one of claims 8 to 12, wherein the flange, or at least one of the flanges, including said detent means, is cut or stamped from the second engagement portion web and is turned so as to project from the web in a direction substantially parallel to the locating tab or a respective one of the locating tabs.

14. A bridging member according to any one of claims 8 to 13, wherein the or at least one of the flanges includes an upper margin which extends at an angle to said web of said second engagement portion to form an outer lip.

An engagement portion for a bridging member for providing bridging between first and second structural members, such as purlins, girts or the like, of a plurality of laterally spaced said structural members, said engagement portion including a body which has first and second opposite ends, and including at least one means co-operable with a complementary engagement portion of a similar bridging member with the or each co-operable means being located inboard with respect to one of said ends of the bridging member W:\Sandra\RNC WORKXRNC WORK\RNC NO DELETE\2002300387 Claims.doc ICwhereby the co-operable means is substantially protected against impact Sloading applied to said one end. 3

16. An engagement portion according to claim 15, wherein the co-operable T means includes at least one locating tab which is cut or stamped on the body 00 5 and is turned so as to project from the body, within a margin of the body adjacent to the second end.

17. An engagement portion according to claim 16, wherein the body of the oo 00 Mc, engagement portion includes a web and wherein the or each locating tab is turned so as to project from the web in the direction in which the web is to t'q approach the first engagement portion of a similar engagement member.

18. An engagement portion according to claim 16, wherein the or each locating tab includes an undercut region on its edge surface which faces towards the first end.

19. An engagement portion according to claim 17, further including detent means to provide for locking engagement thereof with the complementary engagement portion of a similar bridging member.

An engagement portion according to claim 19, wherein the body of the engagement portion includes at least one flange which extends from the web in a direction which is substantially parallel to the or each locating tab, and wherein the or each flange includes a resilient tang which projects towards the locating tab, or a respective one of the locating tabs.

21. An engagement portion according to claim 20, wherein the tang is formed by providing a U-shaped slot in the flange.

22. An engagement portion according to either claim 20 or 21 wherein a distal end of said tang is arcuate in cross-section.

23. An engagement portion according to any one of claims 19 to 22, wherein the or at least one of the flanges includes an upper margin which extends at an angle to said web to form an outer lip.

24. An engagement portion according to any one of claims 15 to 23, wherein the other end of the body is connectable to a central portion of the bridging member. W:Sandra\RNC WORK\RNC WORKRNC NO DELETEQ2002300387 Claims.doc 0

25. A second engagement portion substantially as herein described with 0 reference to the accompanying drawings. N F4 DATED: 8 February 2006 0 By: PHILLIPS ORMONDE FITZPATRICK Attorneys for: STRAMIT CORPORATION LIMITED r- (O 0c 0c L W:Sanda'RNC WORKXRNC WORK\RNC NO DELETE\2002300387 Claimsdoc