AU630127B2 - Adjustable space frames and trusses - Google Patents

Description

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XRECED

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Corrections: under INID Number (81) Designated States*, insert: GB (European patent) WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau k lvx Y4 t 9J7 INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 90/05220 E04B 1/19, 1/344 Al (43) International Publication Date: 17 May 1990 (17.05.90) (21) International Application Number: PCT/AU89/00474 Published With international search report.

(22) International Filing Date: 3 November 1989 (03.11.89) With amended clair.

Priority data: PJ 1277 3 November 1988 (03.11.88) AU (71X72) Applicant and Inventor: HART, Garry, Randall [AU/ S U~b 1 ld-,.uL. Tile irane, QLP'r(7)., r St-.'t fAi a-o 4-ogl (74)Agent: GRANT ADAMS COMPANY; 144 dward Street, G.P.O. Box 1413, Brisbane, QLD 4000 l O (81) Designated States: AT (European patent), AU, BE (Euro- ca\ pean patent), BR, CH (European patent), DE (European patent), DK, FI, FR (European patent), GB, GB (Euro- "0 P pean patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), NO, SE (European patent), SU, US.

(54)Title: ADJUSTABLE SPACE FRAMES AND TRUSSES 13 (57) Abstract An adjustable space frame or truss (10) has chords (12) and posts (15) hingedly interconnected at nodes (201) and adjustable length tension braces and/or compression s.ruts irt Irconnect respective nodes between adjacent chords to enable angular movement of the chords and posts in the plane of the posts and chords.

(Referred to in PCT Gazette No. 16/1990, Section II).

C- I IWO 90/0522.0 PCT/AU89/00474 1 Title: "ADJUSTABLE SPACE FRAMES AND TRUSSES" BACKGROUND OF THE INVENTION Field of the Invention THIS INVENTION relates to improvements in adjustable space frames and trusses. The term "space frame" shall be used in respect of three-dimensional structures and the term "truss" shall be used in respect of two dimensional structures, where a space frame may incorporate a plurality of parallel or intersecting trusses connected together.

Prior Art Existing space frames are generally complex, expensive and difficult to manufacture and assemble.

Their joint behaviour under load is difficult to analyse and compute and they suffer from a lack of ductility the ability to bend without permanent damage).

In an effort to overcome these problems, my International Application No. PCT/AU86/00239 (International Publication No. WO87/01150) disclosed an adjustable space frame where the lengths of the compression braces or tension struts were adjustable to apply a curvature to the space frame and/or vary its rigidity.

While this space frame was an advance on the prior art, it suffered from a number of deficiencies, In FIG. 6 in my International Application No. PCT/AU86/00239 (International Publication No.

WO87/01150), the tensile or compression load is first transferred via shear on a connecting pin to the first stub and then into the wall of the post. This force is then transferred through the walls of the post by complicated load paths (requiring sophisticated computer analysis) to the stub on the opposing side, where again it is transferred via shear action on a second i WO 90/05220 PCT/AU89/00474.

2 connecting pin to the opposing chord. This three stage method of transferring chord loads through the node can set up rotational instabilities; the amount of angular adjustment between the chord and post or stub is limited by the tolerences available between the internal dimensions of the chord and the external dimensions of the stub i.e. the point at which the inside wall of the chord bears on the outside wall of the stub fixes the amount of angular adjustment available; the use of a single pin to transfer shear loads from chords to stubs does not provide lateral restraint against end bearing ormation in either the chord or stub wall; load transfer methods sometime rely on welded connection e.g. FIG. 6 of my International Application No. PCT/AU86/00239. This can add significantly to the total cost, particularly in remote areas or developing countries.

FIGS. 8 and 9 of my International Application No. PCT/AU86/00239 go only part way in solving some of the above deficiencies e.g. FIG. 8 eliminating load transfer through the post walls, however, the rotational suitability problem remains. Also FTC, 9 provides a means of transferring chord loads through a single pin, however, this is done at the expense of angular adjustment.

SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide space frames or trusses with ductility to enable them to be assembled on the ground and raised in one piece.

It is one preferred object to provide such frames or trusses which do not require stringent tolerances and which can accommodate members of a ~nar.as WO 90/05220 PCT/AU89/00474 3 different lengths.

It is a second preferred object to provide such frames or trusses where the behaviour can be easily analysed.

It is a third preferred object of the present invention to provide a simple, more direct transfer of load between the chords and the posts.

It is a fourth preferred object of the present invention to provide a greater degree of angularity between the chords and the posts.

It is a fifth preferred object to provide a non-welded connection between the chords and the posts.

It is a sixth preferred object to provide trusses which can be assembled on space-frame type principles of construction.

It is a seventh preferred object of the present invention which can employ the tension braces of my International Application No. PCT/AU86/00239.

It is an eighth preferred object to provide frames or trusses where continuous cable braces may be provided to prestress or change the profile of the frames or trusses, and where stops on the cable braces can co-operate with the chords and/or posts to define the final configuration of the frames or trusses.

Other preferred objects of the present invention will become apparent from the following decription.

In one aspect the present invention resides in an adjustable space frame or truss comprising a plurality of chords interconnected by posts at respective nodes wherein: the chords and/or posts are hingedly connected at the nodes; and adjustable length tension braces and/or compression struts interconnect respective nodes between b

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7 i ii 1: 0V 90/05220 PCT/AU89/00474' adjacent chords to enable angular movement of the chords and/or posts in the plane of the chords and posts.

Preferably the lengths of the chords and the lengths of the posts between respective nodes are fixed so that adjustment of the length of the braces and/or struts enable the configuration of the frame or truss to be changed and/or introduce prestressing forces to the frame or truss.

The chords may be continuous at the nodes, or comprise respective chord sections hingedly connected together at the nodes.

Preferably, at each node, the chords (or chord sections) and the poLt are interconnected by at least one bolt or pin defining the axis about which the angular movement of the chords and post is effected.

Preferably, each end of the braces or struts are connected to the chords or posts by means which enable the angular relationship of the braces or struts to' the chords or posts to be varied as the braces or 20 struts are varied in length.

Preferably, at least one end of the braces or struts are connected to the bolts or pins to enable the angular relationship of the braces or struts to the chords or posts to be varied as the braces or struts are varied in length.

Preferably, the chords are formed of cold rolled steel sections having at least one channel portion in which the posts are hingedly connected at the nodes, and having at least one inclined side flange to receive a brace or strut from an adjacent frame or truss.

In a second aspect, the present invention resides in an adjustable space frame or truss comprising a plurality of chords interconnected by posts at nodes, wherein: i LLL_-II.

WO 90/05220 PCY/AU89/00474 WO 90/05220 the chords and/or posts are hingedly connected at the nodes; at least one wheel or pulley is provided at at least one of the nodes; and flexible tension means are anchored at one end and pass around the wheel or wheels, a load being applied to the flexible tension means to cause angular movement of the chords and/or posts in the plane of the chords and posts to vary the configuration of the frame or truss.

Preferably, the load is applied by a weight or mechanical tensioning means attached to the other end of the flexible tension means. The mechanical tensioning means may comprise a winch mechanical or electrichyrdaulic), a jack or a hydraulic ram.

In a third aspect, the present invention resides in an adjustable space frame or truss comprising a plurality of chords interconnected by posts at nodes, wherein: the chords and/or posts are hingedly connected at the nodes; a respective wheel or pulley is provided at a plurality of the nodes; and continuous flexible tension means pass around the wheels, the tension means being tensioned to cause angular movement of the chords and/or the posts in the plane of the chords or posts to vary the configuration of the frame or truss.

Preferably, the chords are continuous or discontinuous at the nodes.

Preferably, the lengths of the chords and the lengths of the posts between respective nodes may be fixed.

Preferably, the lengths of the tension means between respective nodes are adjustable between initial untensioned 1 tensioned leni frames or truz Pref 5 tension means tension means The on the tens: respective no 10 tension means respective nod to define the Pref provides a pi 15 and/or causes configuration erected config Prf, and wheels are 20 the tension me, Preft at least one direction to c; the horizontal 25 In resides in a more of the described.

BRIEI

understood, a be described drawings, in wh

FIG.

35 employing space

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WO 90/05220 WNo 00/05220 PCT/AU89/00474 WO 90/05220 PCT/AU89/00474, 6 untensioned lengths and final tensioned lengths, the tensioned lengths determining the configuration of the frames or trusses.

Preferably, limit means are provided on the tension means to determine the tensioned lengths of the tension means between respective nodes.

The limit means may include adjustable stops on the tension means which engage the wheels at respective nodes or tubular members surrounding the tension means to define the minimum length between respective nodes; or rods adjacent to the tension means to define the maximum length between the nodes.

Preferably, tensioning of the tension means provides a prestressing load on the frame or truss and/or causes the frame or truss to change its configuration from an assembled configuration to an erected configuration.

Preferably, the bottom chord may be eliminated and wheels are provided at the lower ends of the posts, the tension means passing around the wheels.

Preferably, as the tension means is tensioned, at least one of the posts is anchored in the vertical direction to cause the adjacent chords to be inclined to the horizontal at the node.

In a fourth aspect, the present invention resides in a building structure incorporating one or more of the space frames or truss as hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a number of preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 is an isometric view of a building employing space frames and trusses in accordance with i: i ,WO 90/05220 PCT/AU89/00474 7 the present invention; FIG. 2 is an isometric view of a node at A on FIG. 1; FIGS. 2A and 2B are modifications of the node of FIG 2; FIG. 3 is an isometric view of the node at B on FIG. 1; FIG. 4 is an isometric view of the node at C on FIG. 1; FIGS. 5 and 5A are respective isometric and plan views of a fourth node; FIGS. 6 and 6A are similar views of a fifth node; FIGS. 7 and 7A are similar views of a sixth node; FIG. 8 is an isometric view of seventh, eighth, ninth and tenth nodes; FIG. 9 is an isometric view of a truss showing further alternative 'nodes and compression strut and tension brace details; FIG. 10 shows the anchoring of the tensj,on braces in FIG. 9 in more detail; FIGS. 11 to 13 show alternative tension brace arrangements; FIGS. 14 and 14A are respective isometric and side views of a further tension brace arrangement; FIGS. 15 and 15A are similar views of a still further tension brace arrangement; FIGS. 16 to 18 show truss and frame assemblies incorporating cold rolled chord sections; FIGS. 19 to 20 are front views of alternative trusses or support frames incorporating cables as additional tension braces; FIGS. 21 and 21A are respective isometric and plan views of a node in the space frame or truss of FIG.

r WO 90/05220 PCT/AU89/00474 FIGS. 22 and 23 are front views of a truss before and after erection; FIGS. 24 and 25 are front views of alternative erect truss configuration; FIG. 26 is a front view of a further truss configuration; FIGS. 27 and 28 are similar views of fur'Cher truss configurations; FIGS. 29 and 30 are front views of a further truss or frame before and after erection; FIGS. 31 and 32 show similar views of a further truss; FIG. 31A is an isometric view of a stop for one of the cables; FIGS. 33 and 34 are front views of alternative trusses with continuous chords; FIGS. 35 and 35A are isometric views of the continuous tension cables of FIGS. 22 and 29; FIG. 36 is a front elevation view of a space frame or truss in an elevated position; FIGS. 37 and 37A are respective isometric and sectional views of a washer assembly to increase the bearing area between the pin and the chords at a node; FIGS. 38 and 39 show the steps in erecting a tower in accordance with the invention; FIGS. 40 and 40A show the erection of prefabricated units using the present invention; FIG. 41 is an isometric view of a building constructed in accordance with the present invention; and FIGS. 42 to 46 show examples of alternative building configurations available using the present invention.

DETAILED DESCRIPTION OF THE PREFERRED r YWVO 90/05220 PCT/AU89/00474 9

EMBODIMENTS

FIG. 1 is an isometric view of a building space frame 10 assembled using the invention. Gable trusses 11 and parallel chord trusses 12 intersect to form a framework supported on column legs 13.

Each truss 11 or 12 is made up of upper and lower cnords 14, vertical posts 15, tension braces 16 and pivotal pins or bolts 17 interconnected at nodes (see FIGS. 2 to 4).

The building structure further includes purlins 18, roo sheeting 19, tension fly braces compression fly braces or struts 21, wind bracing 22, tension truss braces 23 and compression truss braces 24.

FIG. 1 illustrates two types of structural designs using the invention.

In the upper left hand section of the drawing, gable trusses 11 running in the lateral, direction (and also called lateral trusses) are intersected by parallel chord trusses 12 running in the longitudinal direction (and also called longitudinal trusses). The length of individual chords 14 is determined by the length between intersecting trusses and the chords are terminated at node points as illustrated in FIGS. 2 and 4. Also shown, although not essential, are secondary posts 27 jointed to the continuous chord as shown in FIG. 3.

Posts occurring at the intersection of trusses are referred to as primary posts. The design of the chords 14 when secondary posts 27 are used, is calculated from a buckling length between intersecting trusses in a horizontal direction and a buckling length from secondary to primary posts in a vertical direction. It can be seen then that it can be economically advantageous to fabricate or use chords which are structurally stronger in the horizontal direction than the vertical direction. Some variations of fabricated IL 1 WO 90/05220 PCT/AU89/00474, chords achieving this are shown in FIGS. 8, 9 and 16.

The bay of the building in the upper left hand part of the space frame 10 contained by the two gable trusses 11 and the two perimeter longitudinal trusses 12 is thus structurally stable in three dimensions if wind tension bracing 22 is installed between all truss intersection points at either the top or bottom chord level. It should be noted that in the upper left hand half of the frame, the purlins 18 (only two shown for clarity) have not been used as part of the structural integrity of the frame.

In contrast to the upper left hand section of the space frame, the lower right hand bay contained by two gable trusses 11 and two perimeter longitudinal trusses 12 has no intermediate lateral trusses 12 between the perimeter longitudinal trusses 12. This obviously leads to a horizontal stability problem in the long upper and lower chords of the lateral trusses.

Horiztonal stability of these chords over the width of the structure can be obtained using some or all of the purlins 18, rcof sheeting 19, tension fly braces compression fly braces 21, wind braces 22, tension truss braces 23, and compression truss braces 24.

In the lower right hand bay of the space frame, the tension and compression fly braces 20 and 21 are fixed to the lower chords of the lateral trusses 11 and the purlins 18. Note that in perimeter trusses, a compression fly brace must be used to prevent the lower chord of the lateral truss from buckling inwards under wall loads. With the addition of wind braces 22, preferably at the upper chord level between all chord intersection points (eight required, only two illustrated) the lower right hand bay is structurally stable in three dimensions, assuming the purlins have been designed to take the additional longitudinal WO 90/05220 PCI/A U89/00474 11 tension or compression loads as well as their normal distributed load from the roof sheeting. The diaphragn action gained by fixing of the roof sheeting to the purlins also aids in structural rigidity of the frame.

As an alternative to tension and compression fly braces in the lower right hand bay, coairS-sion truss braces 24 may be used to join nodes at chord ends as shown, and with diagonal wind braces 22 at the upper and lower chord levels the end bay becomes structurally stable in three dimensions. Tension truss braces 23 can assist in the horizontal chord sizing. of lateral trusses not on the perimeter provided the perimeter truss chord has been designed to take this accumulated anti-buckling load. One way of achieving this is by use of a chord truss brace It can be seen that either method of stabilizing the end bay of a structure could be used at boti' end bays of any length structure, incorporating any number of intermediate lateral trusses, allowing the top and bottom chords of all intermediate lateral trusses to be stabilized by only the purlins at the upper chord level and either tension fly braces 20 or tension truss braces 23 at the lower level- Of course in FI'. 1 the short longitudinal trusses 12 in the upper left hand bay could be extended for the full length of the building giving a space frame of: any number of parallel lateral trusses and any number of parallel longitudinal trusses. This is one advantage in space frames with aspect ratios up to 2:1, the length is no more than twice the width, as the member sizes can be reduced by virtue of frame loads having more than one load path back to the support points.

In FIG. 2 the node 201 is defined by the joining of two chords 202. The chords 202 in this case are square hollow sections with parts of the top and

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WO 90/05220 PCT/AU89/00474 12 bottom walls removed and each remaining side wall has a hole 203 to accept a pin, or bolt 17. The post 204 has hole 205 also able to accept the pin or bolt 17 such that the node may also be formed by two chords 202 and a post 204. An alternative post 204a with parts of two walls removed is also shown. Chords 202 and posts 204 with extended side walls, caused by the removal of parts of the top and bottom walls are referred to as "bayonet ends". It can be readily seen that the joining of the two chords 202 with one pin or bolt 17 allows a large amount of planar angular movement between the two chords 202. Also the inclusion of the post 204 in the node joint still allows a large amount of planar angular movement between the two chords 202 and also between either chord 202 and the post 204. Tension braces 206 are provided with holes 207 which may also be connected to the node joint using the same pin 17 that connects the chords 202 and post 204. Various components and the method of operation, of the tension brace will be.

explained in detail with reference to FIG. 9. A tube spacer 10 is also shown which fits neatly between the inside walls of the post 204 or between the inside faces of the extended walls of the chords 202 in the assembled node 201. The purpose of the spacer is to provide a fully laterally restrained joint to be constructed such that the use of one pin 17 in the assembly restrains the walls of the chords 202, posts 204 and tension braces 206 from lateral buckling, and thus allows a greater design load to be transferred between the members. Of course two bolts 17 would achieve the same purpose, one bolt for each half of thejoint, without the use of the spacer (see FIG. 2A). By way of illustration of the use of various chord sizes FIG. 2A is a plan view of a node 220 using equal sized chords 221 with bayonet ends and two bolts 222 to restrain the chord side walls. FIG. 2B I WO 90/05220 PCT/AU89/00474 13 is a plan view of chords 241, 242 of a sleeving size forming a node 240 with spacer 243 and bolt 244.

FIG. 3 shows a node 301 formed from a continuous chord 302, a bayonet ended, post 303, tension braces 304 where separate holes 305 are used for the connection of each mimber end.

FIG. 4 shows an exploded view of a two directional joint 401 from the space frame illustrated in FIG. 1. It can be seen here that the two opposite chords 402 in the one direction and the two tension braces 403 in that same plane join at the node as in FIG. 2. However, a third chord 404 and a third tension brace 405 connect to the node at 900, in plan view to a separate hole 406 in the post 407 at a different level to the chords 402 and tension braces 403. In effect this is similar to the continous chord 302 in FIG. 3 except the post 407 is continous through the node and it is readily seen any number of pairs or single chords could be attached at any level to a post of any length and that the tension braces 403 and 405 could be connected via separate holes in either the chord or post.

FIG. 5 shows the use of strengthening cleat plates at the node connection 501. Separate chords 502 are joined at the node with a primary post 503. The use of cleat plates 504, which are thicker than the walls of the zTha.rds, allows a greater load carrying capacity across the node because of the increased area bearing against the bolt or pin 505. Cleat plates 506, shown here attached to post 507 may also be used to increase the load carrying capacity between chords and posts. It can also be seen from FIG. 5 and plan view FIG. 5A that packing cleats 508 can be used to give a neat fit to the node when equal sized chords and posts are used. Also a secondary post 510 can be fixed to a continous chord ~111

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PCT/AU89/0474, WO 90/05220 14 joint using cleat plats 509 fixed to the chord 502. The cleat plates may be welded or bolted or fixed to the chords and posts by any other suitable means. It is important to note the cleat plates do not impair the planar angular movement available between chords and posts.

FIG. 6 shows an alternative cleat arrangement at node 601 where two cleats 602 are fixed to the inside of chord 603 and two cleats 604 are fitted to the outside of chord 605. A neat fit joint is then available by using a bayonet ended post 606 using the walls of a post of equal size to both chords. Plan view FIG. 6A shows the neat fit of the joint using a spacer 609 between cleats 602 suitable for a laterally r:strained joint using one bolt 610. Cleat plates 607 can be used with secondary post 608 with attached cleats 611. The three upper holes in cleat 607 are for the attachment of one post and two tension braces.

FIG. 7 and plan view FIG. 7A show a node joint 701 using three different sized members. The smaller chord 702 sleeves inside a larger chord 703. The post 704 is tha largest member and has a bayonet eid. This node is suitable where a relatively small amount of angular movement between chords is required.

FIG. 8 shows different node joints 801, 802, 803 and 804 using hot rolled universal beam chord 805 or hot rolled channel chord 806. Cleat plates 807 are fixed to chord 805 to engage the post 80a which may or may not have cleat plates itself. Cleat plates 809 attached to chord 806 also engage post 808. Cleat plates 810 are typical for nodes 802 and 804 at a secondary post attachment al:t a continuous chord node.

Of course any of the cleat plates may have additional holes for separate tension brace attachment.

FIG. 9 shows alternative node construction, it is transferred via shear action on a second WO 90/05220 PCT/AU89/00474 tension brace and compression strut details. Post 901 has cleat plates 902, attached to it at four different levels, the two upper levels forming a first node and the two lower levels forming a second node. The four cleats at each of the upper and lower locations are referred to as "flyover cleats" or "flyover stubs".

Whilst the vertical separation of the flyover cleats or stubs sets up an eccentric bending movement in the post, it has been found in practice that the size of the stress is relatively small and has no influence in the sizing of the post, which is nearly always sized by the geometric requirements for cleat and chord connections and therefore normally has a reserve capacity. The post 903 in FIG. 9 has cleats 904 attached to it packed out with packing clE.,ts 905 to allow the correct alignment for cleats 906 attached to the chord 908, assuming the chord 908 and post 903 are the same size. Cleats 907 attached to the lower end of post 903 are fabricated to allow four chords to connect to the post at the same level. The lower chord 909 in FIG. 9 is fabricated from two squre or rectangular hollow sections in a side-byside relationship which gives a greater lateral horizontal stiffness. This double or twin chord is joined at the node to the post by a short length of single chord 910 between the double chords. Additional strength can be given to the fabricated double chord by attachment of cleat plates 911 to both chords by the formation of a horizontal battened strut. Secondary posts 912 are attached to the single chord at the upper level through cleat plates 913, and through holes in the post 912 and double chord 909, when the post 912 is inserted between the double chords. The battened strut 909 can also be formed from any hot rolled or cold rolled sections e.g. angles, parallel flanged channels and universal beams or columns. FIG. 9 also shows two C1 i~L WO 90/05220 PCT/AU89/00474 16 tension braces 912 and one compression strut 913 which are used to adjust both the riqidity and/or geometry of the individual bays of the trusses making up the space frame. Each individual tension brace is made up of a Ushaped cradle 914, semi-circular washer 915, tension rod or cable 916 and nuts 917. The tension rod or cable can be fabricated with one left hand and one right hand thread and it can be seen from FIG. 9 that the assembled tension brace can be so shortened to apply tension by rotating the rod 916. An alternative to the U-shaped ciadle 914 and semi-circular washer 915 can be seen in FIG. 9 and elevation FIG. 10 in which a cleat plate 918 with one hole is welded between the twin chords 909 and a circular faced washer 919 allows transfer of an even load distribution from the rod 916 through the washer 919 to the nut 917 whilst maintaining an angular movement capability. The compression strut 913 is made up of two U-shaped brackets 920 each fixed to a rigid tube 921 eacb of which has an. internal thread at the opposite end to the U-bracket. By using one left hand and one right hand thread in the tubes 921 and engaging a respective left and right hand thread on an internal drive rod 922, rotation of the drive rod will cause the total length of the compression strut between holes in the brackets to shorten or lengthen depending on the direction of rotation.

FIGS. 11, 12 and 13 show two alternative tension brace arrangements.

In FIG. 1.1 a post 1101 is shown as part of an exploded view node. Four bayonet ended chords 1102 are to connect to the post 1101 at two different levels. In this node the chords are fabricated from circular tube or pipe. In FIGS. 11 and 12 an L-shaped bracket 1103 is fixed to the chord 1102 by a bolt 1106 through a hole in the bracket and one in the chord. The tension rod 1104 WO 90/05220 PCT/AU89/00474 17 is assembled through another hole in the bracket 1103 and tension applied by the nut 1105. In FIG. 11 and sectional elevation FIG. 13 another method of connecting a tension rod o- rods 1107 is shown by simply passing the rod through elongated holes 1109 in the chords 1102.

These elongated holes allow angular adjustment between the tension rod and chords whilst the nuts 1108 allow tensioning of the rod 1107. In this case the rod 1107 not being directly in the line of force in the truss bay it is tensioning, it sets up bending moments in the chord 1102 thorugh which it passes, however, these eccentric forces are minimized if the holes 1109 are kept as close as possible to the plan centre of the post 1101.

In FIGS. 14 and 14A, at node 1401, the chords 1402 and post 1403 are provided with elongate slots 1404 which receive tension braces 1405 which are secured by hemispherical washers 1406 and nuts 1407 which allow the angularity between the chords and the post to be varied.

In FIGS. 15 and 15A, at node 1501, the chords 1502 and post 1503 are connected by a pin 1504 which has slots 1505 to receive tension braces 1506, secured by nuts 1507.

FIGS. 16, 17 and 18 show methods of using cold rolled chord sections. In FIG. 16 the post 1601 has "flyover cleats" 1602 attached to it. The top chord 1603 in FIG. 14 is a cold rolled steel C-section which is used, such that its main axis of strength is in the horizontal direction. The connection means of the Csection to the post is via a small length of square hollow sections with part of the top and bottom walls removed. This connector 1604 is bolted to the C-section and a pin or bolt secures it to the post 1601. A secondary post 1605 may be secured to the chord 1603 by means of a connector 1606 fabricated from a U-shaped i I WO 90/05220 PCr/AU89/00474' 18 section of material thicker than the chord and rigidly fixed to the chord by bolts or other fasteners. One pin or bolt fixes the post to the connector allowing planar angular mrvement. The lower chord 1607 is a cold rolled section designed with a shape to perform specific functions. The cross sectional shape is shown in FIG.

16 and also in elevation FIG. 17 as part 1702. In FIG.

16 it can be seen that the roll formed chord has three sides of a square hollow section shape, two horizontal flanges and two sectional lips. The shape, particularly the two flanges and two lips gives the chord section substantial horizontal strength thus allowing greater spanning capacity in the horizontal direction as compared to the vertical direction. The inclined lips provide a suitable connection means for tension fly braces as will be described in FIG. 17 and the shape of the section also allows stacking for transport and lap joining as will be described in FIG. 18. The chord 1607 can be joined to the node using cleat plates 1608 which are rigidly bolted to the chord 1607 and pin fixed to the fly over cleats 1602. Secondary posts 1605 can be attached to the chord by means of cleat plates 1609 which are rigidly fixed to the chord by bolts and pin fixed to the post 1605. FIG. 17 is an elevation showing connection means between posts 1701, roll formed chords 1702, separate rafters or purlins 1703, tension fly brace 1704 and/or compression fly brace 1705.

Referring to FIGS. 1 and 17, the use of purlin or rafters 18, tension fly bracing 20 and compression fly braces or struts 21 to achieve three dimensional stability for trusses is described in relation to FIG.

1. FIG. 17 can be regarded as an elevation of part of the space frame in FIG. 1 where the posts 1701 and chords 1702 are part of two separate lateral trusses in FIG. 1 with the chords 1702 being roll formed sections ~nL_ l;li C_ ,WO 90/05220 PCT/A U89/00474 19 as shown. In FIG. 17 the tension fly braces 1704 are fixed to the chords 1702 through a hole in the lip of the chord. The fly brace 1704 consists simply of a length of rod with a thread at each end Fixing of the tension fly brace 1704 to the flange of a standard Zpurlin 1703 is achieved via a hole in the flange of the Z-purlin and a shaped washer 1705 which allows adequate load transference from the tension rod 1704 to the Zpurlin flange at the same as allowing planar angular movement between the rod and flange. A compression fly brace or strut 1705 can be formed from a tension fly brace 1704 by sleeving a tube over the rod where the tube is capable of resisting the designed compression load, the ends of the tube bearing against the lip of the chord 1702 and flange of the Z-purlin 1703.

Connection means for the compression fly brace 1705 are as for the tension fly brace 1704. The compression fly brace 1705 can be made adjustable in length as described under FIG. 9. .Connection of the post 1701 to the chords 1702 is detailed in FIG. 18.

In FIG. 18 two methods of connection of the roll formed section 1801 to a post are shown. Post 1802 has two holes, one for each of two chords entering at the same level and maintaining angular adjustment between the post and chord. The two chords 1801 are lap joined at post 1803 using four bolts, two on each parallel face of the box of -he roll formed section and an aligned hole between the fixing bolts joins the post 1803 to the chord 1801 via a single pivotal pin or bolt.

The holes and bolts used to fix the two chords together may also be used to secure the tension brace 1804. An alternative tension brace 1805 is shown consisting of a rod 1806 and a nut 1807 and a pin 1808. The pin 1808 has a hole in it which accepts the rod 1806 and the nut 1807 applies tension to the brace. The pin 1808 rotates WO 90/05220 PCT/AU89/00474.

in holes in the box side walls of the chord section 1801.

FIG. 19 shows how cables may be used in space frames or trusses to provide additional support points or partial support points. In FIG. 19 the space frame or truss 1901 as previously described is supported on columns 1902. The space frame or truss 1901 can be fixed to the columns by any suitable means. Tension cable 1903 fixed to the column 1902 and to the mid point of the frame acts against downwards live and dead loads.

Tension cable 1904 fixed to an extension of the column and to the top of the frame will also resist downwards live or dead loads. Tension cables 1905 fixed to the columns and upper mid point of the frame act against upward applied loads while tension cables 1906 fixed to the columns and to an extended post 1907 on the frame also act against upward applied loads. One problem with cables is that they relax under load over a period of time and then do not funct.on to the capacity as originally designed. In order tn allow tension cables to function against upwards and downwards .oads without the problems of relaxation of the cable a block and J tackle system in conjuction with a gravity acting weight :i can be employed as shown in FIG. 19. The block and tackle system 1908 consists of a mobile pulley block 1909 attached to the lower mid point of the frame and a fixed pulley block 1910 attached to the column. A continuous cable 1911 is fixed to the fixed pulley block and then wound around wheels in a number of loops successively from mobile pulley block 1909 to fixed pulley block 1910 and finally attached to a free acting weight 1912. The weight 1912 moves downwards to take up any relaxation in the cable and to apply a constant tension to the cable, this in turn provides an uplifting force or partial support at the point of attachment of i WO 90/05220 PCT/AU89/00474 21 the mobile pulley block 1909 to the frame 1901. Of course this block and tackle arrangement can be located to act against uplift forces.

In FIG. 20 the space frame or truss 2001 is supported on columns 2002 fixed by any suitable means.

By way of example only the left hand half of the illustrated frame uses tension braces 2003 and the right hand half compression struts 2004. Wheels 2005, free to rotate, are attached at the node point. The method of attaching wheels will be described with reference to FIG. 21. A continuous cable 2006 is wound around the wheels 2005 in any desired pattern such that when it is tensioned a beneficial prestressing force is held in members of the frame, such stored energy designed to act against imposed loads on the frame. The tension in the cable may be applied by any suitable means a hydraulic ram or a winch) and the problem of relaxation of the cable may be solved by using a free weight as shown in FIG. 19.

FIGS. 21 and 21A show one method of incorporating a wheel at the node points. The node connection 2101 is made up of two bayonet end chords 2102 and a bayonet end post 2103 as shown under FIG. 2.

A pin or bolt 2104 used to fix the chords to the post may also function as an axle for a wheel 2105. The bayonet end of the chords and the posts allow the cable to be wound in a pattern as shown in FIG. 20 with the cable acting in the central plane of the truss. Two wheels 2105 could be suppotred by the axle 2104 one on either outside face of the chords 2102.

FIG. 22 shows a space frame or truss assembled as previously described consisting of chords 2201, posts 2202 and wheels 2203 at node points and depicted in FIG.

21. A continuous tension brace cable 2204 is wound around the wheels in the pattern shown and anchored st r: PC/A U89/00474, WO 90/05220 22 one end. The other end of the cable is fixed to or passes through a tensioning device allowing an even tension and cable shortening to be applied to the continous cable. Compression struts 2206 consisting of tubes are positioned over the cables as shown. These compression tubes 2206 also act as a length restraint of the cable between nodes, such that when the cable is tensioned the frame will self erect into the shape shown in FIG. 23. It is preferable if one end of the frame is fixed and one end allowed to silide in' horizontally.

Obviously a substantial degree planar angular movement between chords, posts and the continuous tension brace cable is necessary as allowed by the node construction previously explained. It should be noted that the length of the compression struts positioned over the continuous tension brace cable will determine the final shape of the space frame or truss.

FIG. 24 shows an arch shape obtained by varying the 'length of the compression tubes 2206 and FIG. 25 shows two connected inverted arches. In FIG. 23 it can be readily seen that where the tension cable has been tensioned so that all compression struts are bearing at each end and the structures' geometry has been determined, and if desired a further stressing of the cable is applied, locking off of the tension cable will provide a stable structure in which the tension cable provides the bracing restraint under downwards load and the compression struts provide the bracing restraint against an upwards load. Of course this principle of a continous tension cable brace can be used in any number of trusses in a space frame or truss and if used in multi-directional intersecting trusses any three dimensional space frame geometry can be achieved.

Also a constant tension can be retained in the cable by using a free weight as in FIG. 19 or by any other means ,WO 0/05220 PCT/AU89/00474 23 or the cable may be grouted within the compression strut to retain a prestressing force in the cable.

FIG. 26 shows an extension of the principles described in FIGS. 22 to 25 where an exaggerated change of geometry in the two outside bays of the truss form legs or columns for the space frame or truss.

FIG. 27 shows that a space frame or truss 2701 can be erected using adjustment of standard tension braces 2702 or compression struts 2703, also shown as 1 adjustable tension braces 912. and adjustable compression struts 913 in FIG. 9. This adjustment using individual tension braces and compression struts is often used to build a slight upwards precamber into a flat frame such that on lifting the dead weight, of the frame itself allows a settling back to a level or straight frame.

FIG. 28 shows a space frame or truss 2801 in which the bottom chords have been eliminated. The structure is formed from chords 2802, posts 2803, tension braces, 2804 and/or compression struts 2805.

Stabiilty of the structure can be achieved using various combinations of tension brace 2804 and compression strut 2805. Also a continuous tension brace cable could be used as described under FIGS. 22 to 26. Without bottom chords this frame can now include posts which are not vertical.

FIG. 29 shows a frame 2901 similar to that in FIG 22 with a continuous tension brace cable 2902 except that in FIG. 29 when a tension is applied to the continuous cable the erected shape is controlled or defined by tension restraint cables or rods 2903 such that the erected shape may be as in FIGS. 30, 24, 25 or 26. Details of how the compression struts 2206 in FIG.

22 and the tension restraints 2903 in FIG. 29 work will be described with reference to FIGS. 35 and FIG. 31 shows yet another means of using a

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WO 90/05220 PCT/AU89/00474 24 continuous tension brace cable, controlling the erected shape by stops 3101 (see FIG. 31A) fixed at various locations on the continuous cables. Positioning of the cable stops 3101 as shown in FIG. 31 will result in an erected shape as in FIG. 32 with the stops bearing against the wheels at the nodes. Of course locating the stops at other locations on the continuous cables will give other shapes. Also additional cable stops may be fixed after the space frame or truss is erected to allow individual sections of the brace to work under downwards loads. If all of the sections of tension cable brace are isolated by using stops the cable may partially function as individual separate sections developing loads in them as if they were individual braces.

FIGS. 33 and 34 demonstrate the use of continuous chords in the space frame or truss. In FIG.

33, continuous top and bottom chords 3301 are used, where the top and bottom chords 3301 are one piece for the full width of the frame, or are joined with fixed joints to behave as one continuous chord. Erection of the frame using individual tension braces or a continuous tension brace cable or extendable compression struts puts bending into the top and bottom chords.

Note the nodes must allow planar angular movement between the posts and chords and that in this case the posts remain vertical. FIG. 34 is another form using the continuous chord principle in which the bottom chord is eliminated which allows the tension braces or compression struts to pull the posts away from the vertical position such the top chord could form a semicircle with the outer posts being horizontal or in the extreme case the top chord could be pulled into a complete circle. As in FIG. 33 the top chord behaves as one piece, however, in FIG. 34, the join of the posts to the chords may or may not allow angular movement between WO 00/05220 PCT/AU89/00474 the chords and post.

FIG. 35 shows how the compression struts 2206 in FIG. 22 and the tension restraint cables or rods 2903 in FIG. 29 function. In FIG. 35 two chords 3501 are joined at the node with a single pin or bolt 3502 with a wheel 3503 between the bayonet ends of the chords. A Ushaped bracket 3503 with two side walls and a base can be used to transfer compression strut loads or tension rod restraint loads. In the case of the compression struts the base 3504 has one hole in it and a length of sleeving tube 3503 rigidly attached to it. The holes in the side walls of the U-bracket 3505 are used to join the bracket to the node using the same pin or bolt used to secure the chords and post. When the length of the compression strut is reduced by tensioning the cable which passes through the inner sleeve 3505 and the outer sleeve 3506 the outer sleeve will bear on the base of the U-bracket at both ends of the outer sleeve at the length of the outer sleeve. In the case of the tension rod restraint the U-bracket 3503 has three holes in the base, the central one for the cable 3509 and the two outer ones have tension rods 3507 passing through them.

The length of the tension restraint rods 3507 can be set by screwing the nut 3508 on either end of them to the required distance. Tensioning of the cable 3509 causes the nuts to bear on the inside face of the base of the U-bracket.

FIG. 36 is an elevation showing a space frame or truss 3601 in an erected elevated position. A roll formed or pressed inverted U- or charnel section 3602 is fixed to the underside of the frame or truss.

Prefabricated wall sections or panels 3603 can now be inserted into the inverted channels and fixed to or held laterally at floor level. In one view of the wall panels the lower end is fixed rigidly to the floor. In 0 WO 90/05220 PCT/AU89/00474 26 another view the lower end of the panel sits ina Uchannel which is fixed to the floor. This U-channel can also act as a bottom skirting borad in house construction carrying service cables and pipes. The height of the wall panel 3'03 and depth of the U-channel 3602 and 3604 is such that the frame 3601 can move up and down over the wall panel whilst the panel gains lateral restraint from the U-channels.

FIGS. 37 and 3.A show a washer 3701 which has three separate diameters and two separate thicknesses.

The washer is known as a shouldered washer and is used to increase the shear carrying capacity of a pin or bolt 3702 through the wall of a chord 3703 or other member of the space frame. By way of example the three diameters of the washer are shown as d, 2d nd 3d and the two thicknesses t and 2t. The thickness of the wall of the chord is t and the normal shear carrying capacity for a bolt of diameter d is a direct function of d multiplied by t. When the washer is used the bolt bears on thickness 2t in the washer at d diameter and the washer bears on the chord wall at diameter 2d at t thickness so that at both bearing faces the shear capacity is a direc function of 2dti These thicknesses and diameters are used by way of illustration only and may be varied to suit the bolt diameter, wall thickness and load to be transferred.

FIGS. 38 and 39 show a method of constructing high rise towers using the invention in which a temporary support structure 3801 is located on the ground adjacent to a number of bored holes 3802 in the ground. A set of telescoping posts 3803 is placed in each hole and the smallest sized post elevated from each set by any suitable means from the temporary support structure 3801. With each of the smallest posts held in a temporary vertical position chords 3804 and tension U ,WO 90/05220 PCT/AU89/00474 27 braces or compression struts 3805 are fixed to the post by any means previously described. This operation of raising the next smallest post size and attaching chords and posts is repeated until the largest post is elevated. At this stage a footing in the largest post is secured in palce by filling the hole remaining in the ground with concrete. The connection means between posts 3803 is preferably of a type to give a rigid connection such that the post behaves as if it were continuous.

FIGS. 40 and 40A show a method of using the invention as prefabricated v,nits for high rise building construction, the members of the units being either permanent framing members or temporary formwork members or a combination of both. By way of illustration only and not limiting the type of framing member, FIG. shows the use of angles as posts 4001 and chords 4002.

A single pin is used to join each chord end to a post to form a box-,like construction.

This allows angular movement between posts 4001 and chords 4002 in the four vertical planes of the box. Preferably all six planes of the box are braced using pairs of tension braces 4003, however, the lower and/or upper planes may be braced by means of casting a concrete floor in that plane or by metal formwork sheeting 4004 suitable for concrete casting after erection. The boxes can be of a size suitable for easy transportation after factory fabrication rather than onsite fabrication. The prefabricated boxes can now be assembled in any side-by-side oz vertical stacking arrangement to produce the typical columns (posts 4001) and floors 4004 cf a high rise structure. Assembly of the boxes is prferably carried out by tower crane. of course the tension braces in most cases will not be acceptable either aesthetically or practially and they i WO 90/05220 PCT/AU8 '"O474 28 may be removed by rigidizing the nodes after erection.

One method of rigidizing the nodes is shown using a brace 4005 fixed to the post and chord to provide stable triangulation. Having braced or rigidized sufficient nodes in the whole structure consisting of any number of prefabricated boxes the column and floor system for a high rise building is complete provided the posts, chords and floors are of sufficient size for full design loads. Alternatively any or all of the chords 4002, posts 4001 and tension braces 4003 may be considered as temporary, or may need to be strengthened after erection, i.e. the members or boxes can be used as temporary formwork. In this case steel columns 4006 of a larger size could be dropped through a number of holes in the floors, fixed to the floors and then the posts 4001 of the box removed. This is shown in FIG. Similarly, and not shown, larger horizontal beams could be fixed to these columns and the chords 4002 of the boxes removed or become redundant lost members in the finished structure. Connection of the boxes to each other can be achieved by bolting through adjacent flanges of adjacent boxes a shown in FIG. FIG. 41 shows a particular type of building construction using the invention. Two U-shaped frames 4101 are assembled on the ground and fixed to the ground or a footing in the ground by a substantial pin 4102 at each end of each frame. The frames 4101 are constructed from posts, chords, tension braces and/or compression struts as previously described. The frames are now erected by rotating them about the pin, and tension cable purlins 4103 and tension cable columns 4104 attached at suitable locations. Tensioning of the tension cable columns will, in conjunction with the weight of the U-frames 4101, provide a tension in the tension cable purlins 4103 such that roof sheeting 4105 MM MNEW;';-' ,wo 90/05220 PC/A U89/00474 29 can be attached directly to them by any suitable means.

By combining the various trus.v 2s and space frame configurations hereinbefore described, it is possible to produce gable roofs with flat or pitched ceilings (FIGS. 42, 43; barrel vaults (FIG. 44); arched frames (FIG. 45) and double curved frames (FIG. 46).

This makes it clear to the skilled addressee that the present invention has an extremely high degree of flexibility open to the architect or designer, which provides strong, efficient structures.

Various changes and modifications may be made to the embodiments described without departing from the scope of the present invention as defined in the appended claims.

Claims (16)

1. An adjustable space frame or truss comprising a plurality of chords interconnected by posts at respective nodes wherein: the chords and/or posts are hingedly connected at the nodes; and adjustable length tension braces and/or compression struts interconnect respective nodes between adjacent chords to enable angular movement of the chords and/or posts in the plane of the chords and posts.

2. A frame or truss as claimed in Claim 1 wherein: the lengths of the chords and the lengths of the posts between respective nodes are fixed so that adjustment of the length of the braces and/or struts enable the configuration of the frame or truss to be changed and/or introduce prestressing forces to the frame or truss.

3. (Amended) A frame or truss according to Claim 1 or Claim 2 wherein: the chords are continuous at the nodes.

4. (New) A frame or truss according to Claim 1 or Claim 2 wherein: the chords comprise respective chord sectijis hingedly connected together at the nodes, to enable, at the nodes, the angular relationship between the respective chord sections to be varied. (Amended) A frame or truss according to any one of Claims I to 4 wherein: at each node, the chords (or chord sections) and the post are interconnected by at least one bolt or pin defining the axis about which the angular movement of the chords and post is effected.

6. (Amended) A frame or truss according to any one of Claims 1 to 5 wherein: each end of the braces or struts are ,0 i U. AY I kI Lf 0 PIZ 31 rCU'E APR IWJ connected to the chords or posts 6by means which enable the angular relationship of the braces or struts to the chords or posts to be varied as the braces or struts are varied in length.

7. (Amended) A frame or truss according to Claim wherein: at least one end of the braces or struts are connected to the bolts or pins to enable the angular relationship of the braces or struts to the chords or posts to be varied as the braces or struts are varied in length.

8. (Amended) A frame or truss according to any one of Claims 1 to 7 wherein: the chords are formed of cold rolled steel sections having at least one channel portion in which the posts are hingedly connected at the nodes, and having at least one inclined side flange to receive a brace or strut from an adjacent frame or truss.

9. (Amended) A frame or truss according to any one of Claims 1 to 8 wherein: chord sections or cleats are rigidly fixed to at least one end of the posts; and the chord sections or cleats are hingedly connected to adjacent sections of the chords to provide the hinged connection between the chords and the posts. (Amended) An adjustable space frame or truss comprising a plurality of chords interconnected by posts at nodes, wherein: the chords and/or posts are hingedly connected at the nodes; at least one wheel or pulley is provided at at least one of the nodes; and flexible tension means are anchored at one end and pass around the wheel or wheels, a load being applied to the flexible tension means to cause angular -4 movement of the chords and/or posts in the plane of the Sli a nin 2j V 1 5 tj L, P CT/T AU 0 4 7 /4 ,K 1 ,CL~iv Li $1990 chords and posts to vary the configuration of the frame or truss.

11. (Amended) A frame or truss according to Claim wherein: the load is applied by a weight or mechanical and tensioning means attached to the other end of the flexible tension means.

12. (Amended) An adjustable space frame or truss comprising a plurality of chords interconnected by posts at nodes, wherein: the chords and/or posts are hingedly connected at the nodes; a respective wheel or pulley is provided at a plurality of the nodes; and continuous flexible tension means pass around the wheels, the tension means being tensioned to cause ang-ular movement of the chords and/or the posts in the plane of the chords or posts to vary the configuration of the frame or truss.

13. (Amended) A frame or truss according to any one of Claims 10 to 12 wherein: the chords are continuous or discontinuous at the nodes; the lengths of thb:! hords and the lengths of the pQ6.%t4 between respective nodes may be fixed; and the lengths of the tension means between respective nodes are adjustable between initial untensioned lengths and final tensioned lengths, the tensioned lengths determining the configuration of the frames or trusses.

14. (Amended) A frame or truss according to Claim 13 wherein: limit means are provided on the tension means to determine the tensioned lengths of the tension means between respective nodes. (Amended) A frame or truss according to Claim 1 i O1t 0 A t, 9 i 0 PCT/AU 8 9 0 4 7 4 33 RECEIVED 0 9 APR 1990 14 wherein: the limit means may include adjustable stops on the tension means which engage the wheels at respective nodes or tubular members surrounding the ten:ion means to define the minimum length between respective nodes; or rod adjacent to the tension means to define the maximum length between the nodes.

16. (Amended) A frame or truss according to any one of Claims 10 to 15 wherein: tensioning of the tension means provides a prestressing load on the frame or truss and/or causes the frame or truss to change its configuration from an assembled configuration to an erected configuration.

17. (Amended) A frame or truss according to any one of Claims 10 to 16 wherein: the bottom chord may be eliminated and wheels are provided at the lower ends of the posts, the tension means passing around the wheels.

18. (Amended) A frame or truss according to any one of Claims 10 to 17 wherein: as the tension means is tensioned, at least one of the posts is anchored in the vertical direction to cause the adjacent chords to be inclined to the horizontal at the node.

19. (Amended) A building structure incorporating one or more of the space frames or truss according to any one of Claims 1 to 18. -SUSSTITUT SIHET 6L