AU2021221766A1

AU2021221766A1 - Cold-formed portal framed structures and components for such structures

Info

Publication number: AU2021221766A1
Application number: AU2021221766A
Authority: AU
Inventors: George Campbell; Garry Grace; Alasdair Wright
Original assignee: Spanlift Australia Pty Ltd
Current assignee: Spanlift Australia Pty Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2023-03-16

Abstract

A bracket 68 for receipt of an end of a column or rafter 52, 54, of a portal frame 50, in which the column or rafter 52, 54 is formed from a pair of C-sections 30 that each have a base 31 and spaced apart side walls 32. The C-sections 30 being in facing 5 relationship with free ends of the side walls 32 being in facing engagement. The bracket 68 having an outer housing 76, 78 and an inner sleeve 80, 82. The outer housing 76, 78 has an opening 84, 86 for receiving the end of a column or rafter 52, 54. The outer housing 76, 78 has an internal surface that is a close fit about facing outer surfaces of the opposite bases 31 and side walls 32 of the column or rafter 52, 10 54. The inner sleeve 80, 82 of the bracket 68 is being positioned to extend into a column or rafter 52, 54 that has been inserted into the outer housing 76, 78, in close facing relationship with facing inner surfaces of the opposite bases 31 of the column or rafter 52, 54. Fasteners 106 are employed to extend through the outer housing 76, 78, the opposite bases 31 of the column or rafter 52, 54 and the inner sleeve 80, 82 to 15 fasten the end of the column or rafter 52, 54 within the bracket 68. Fig 7 4/13 Fig7 1-15 C) 1oqt 372 3C fog SW

Description

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SW COLD-FORMED PORTAL FRAMED STRUCTURES AND COMPONENTS FOR SUCHSTRUCTURES

Technical Field

[0001] The present invention relates to building structures that incorporate "portal frames" and which are known more broadly as "cold-formed steel structures", or "cold formed portal frame buildings" or variations of these names. For simplicity, throughout this specification, the building structures according to the invention will generally be referred to as "cold-formed structures".

[0002] The present invention has been developed in particular to what can be domestic, commercial, agricultural or industrial types of cold-formed structures and development of the invention has also led to the development of component parts for cold-formed structures.

Background of the Invention

[0003] The discussion of the background to the invention that follows is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application.

[0004] Agricultural, industrial and domestic buildings or sheds are constructed in various shapes and sizes, depending on the use to which the building or shed is to the put. Garden sheds are usually quite small structures and their small size means that they need little or no internal framing and support. Rather, garden sheds normally just include upstanding posts that support wall and roof panels, that are connected together by fasteners and the connected panels gives the shed its strength. Door and window frames can be installed to support doors and windows, but those frames do not otherwise provide significant strength. There is little or no engineering standards for garden sheds given their usually very small size.

[0005] Cold-formed structures are larger structures that have a much larger height and span (width) than garden sheds. These structures connect columns to rafters, with the columns and rafters being formed from cold-formed steel sections to support wall and roof panelling. The frame of such a structure includes the columns and rafters that are connected directly together, either by brackets or with nuts, bolts or tek screws, or a combination of both. The frame consists of multiple portal frames, which are units comprising two columns and two rafters and these units are connected or held together with roof purlins and wall girts. The cold-formed steel sections are usually formed as C-sections or purlins (or Cee-sections or purlins) that have a wall thickness in the order of 0.9mm to 4mm. Alternative sections are Zed sections or pulins. Cold formed structures or buildings are usually constructed by the frame being erected first and then the wall and roof sheeting is connected to the frame by wall girts and roof purlins.

[0006] A frame structure manufactured from structural steel can be a larger structure again by employing hot rolled steel beams of significantly greater structural strength than the C- sections employed in cold-formed steel structures. The steel beams will typically be universal beams, although rectangular or square hollow sections, or fabricated members can also be employed. The use of hot rolled steel beams in frames allows the frames to have much greater wall or eave height and roof span. These frames can also employ fabricated trusses or open web joists rather than rafters, thus providing greater roof strength for greater roof span. Frames employing hot rolled steel beams have historically been built for roof spans of 9-70m and bay sizes (the distance between adjacent columns on the same wall, or the distance between adjacent portal frames) of 6-11m.

[0007] The size of the frame is a principal consideration when choosing between cold-formed or hot rolled steel structures. Environmental factors, principally wind loading, are also important. Wall or eave height and roof span can dictate when transition from cold-formed frame structures to hot rolled frame structures is required, while transition from cold-formed structures to hot rolled structures will occur earlier in high wind load environments. Cold-formed frames have historically been limited to roof spans of between 6-30m, however 50m roof spans have been built with special design. The bay sizes for cold-formed frames are however typically limited to 3-4m and so are significantly smaller than what is available in a hot rolled frame. Nevertheless, cold-formed frames are usually significantly cheaper than hot rolled frames given the use of the cold formed (or roll formed) steel sections, which have a much lower steel content and given that they can often employ simple bracket connection between columns and rafters, rather than requiring plates to be welded to the ends of the steel sections for bolt connections between sections as is often employed in hot rolled frames. Cold-formed frames are thus preferred over hot rolled frames where the size and performance allow them. There is of course overlap in the structure sizes available in cold-formed and hot rolled frames, and so customer preference also plays a part in deciding which form of structure is selected.

[0008] In structures of the kinds discussed above that mainly use cold formed C sections, the C- sections are relatively thin walled, particularly compared to the hot rolled beams used in structural steel frames and structures, and this limits the strength of the frame of the structure. To improve the strength, in some prior art arrangements a pair of C-sections are connected together back-to-back by bolting or screwing through the main wall of the sections, or by welding. That is, the bases of the C-sections are in facing engagement and the side walls of the beams extend away from each other. However, this is an expensive additional cost to the production cost of the columns and rafters. Moreover, the strength gain through back-to-back connection is less than if the C-sections are connected by free ends of the side walls (so-called "toe-to-toe" connection) so that in the connected condition, the pair of C-sections form a box shape. However, welding the C-sections in this manner has disadvantages in that not only does it add cost, but when a cold-formed section is welded it actually reduces the strength of the section and also creates a corrosion issue, as the cold-formed sections are roll-formed from pre-galvanised steel and welding damages the galvanised coating and when the sections are welded together in toe-to-toe configuration, access to inside faces of the sections for re coating is prevented.

[0009] Cold-formed frames are therefore generally formed from single C-sections with the reduced strength compensated by greater numbers of portal frames and bracing arrangements.

[0010] The bracket connection made between columns and rafters of portal frames is another area of recognised weakness in portal frame structures. There are many different arrangements available for connecting columns and rafters and in portal frames, usually some form of bracket is bolted to the meeting ends of a column and rafter pair, however, there is evidence to indicate that these brackets are the weakest link in the portal frame. This is because most brackets are single plane metal sheet brackets that lack strength laterally to the plane of the metal sheet. The metal sheet brackets may employ stiffening and strengthening ribs to improve bracket strength, but this makes only relatively small improvements in overall bracket strength. In addition, often a significant number of bolts or screws is required to secure the brackets to the column and rafter ends and installation of these bolts and screws is time consuming as well as being performed at height for haunch and apex brackets, which often requires the use of scissor lifts for safety. This requires the scissor lifts to be transported to the installation site and means the number of brackets that can be installed at the same time is limited to the number of scissor lifts being employed.

[0011] Given that consumers will usually prefer to purchase a cold-formed structure where possible given the cost savings, manufacturers will often try to design a cold-formed structure to meet the structural requirements even when they are close to the transition point at which a hot rolled structure might be better suited than a cold formed structure. The strength of cold-formed structures can be improved by structural bracing applied across the apex of the shed roof and by "knee" bracing applied at the haunch bracket connection between columns and rafters, but bracing of this kind often detracts from the aesthetic appeal of the structure, and because the bracing projects into the interior of the structure, it can reduce the stacking height for goods within the structure or interfere with movement of equipment within the structure. Despite this, consumers will accept these drawbacks if the cost savings are sufficient.

[0012] In one form of construction, the frame structure (the columns and rafters of the structure) can be constructed lying on the ground, but with the columns connected to the rafters at 90° by pin or hinge connection. In this form of construction, once the frame structure is completed, it is lifted by crane and the columns progressively rotate into their final vertical orientation when the rafters reach their operational height. While this form of construction is advantageous in that most of the construction of the structure, including the addition of roof sheeting, takes place at ground level and so construction personnel are not working at height, it has not been applicable to construction of cold-formed structures given the lack of strength in the frame structure (including the brackets) that precludes it being lifted.

[0013] The present invention has been developed with the intention to increase the structural capacity of cold-formed steel structures so that the transition point at which a hot rolled steel structure is required rather than a cold-formed structure can be shifted, so that cold-formed structures can be built in circumstances where previously a hot rolled structure was required. An alternative intention is to provide a cold-formed construction which provides improvements in the ease of construction.

Summary of the Invention

[0014] The present invention provides a unique form of bracket that allows portal frames to be constructed with columns and rafters formed from C-sections in "toe-to toe" connection, so that the strength advantage obtained from this orientation or layout of C-sections can be employed. The brackets of the present invention are thus intended for use with columns or rafters that are formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, with the C sections being in facing relationship with free ends of the side walls remote from the bases being in facing or bearing engagement. References hereinafter to columns and rafters will be references to columns and rafters formed with this construction. The free ends of the side walls will usually have inwardly extending lips with the engagement between the C-sections being made between facing lips. The unique form of bracket according to the invention secures the ends of the C-sections in "toe to-toe" connection. Different forms of the bracket according to the invention are suitable for connecting columns to rafters, or columns to footings, or rafters to rafters.

[0015] In a broad form of the invention, the bracket is configured for connection with the ends of columns or rafters that are formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, with the C sections being in facing relationship with free ends of the side walls remote from the bases being in facing relationship (the so-called "toe-to-toe" relationship). The bracket has an outer housing which has an opening for receiving the end of a column or rafter and the outer housing has an internal surface that is a close fit about facing outer surfaces of the opposite bases and side walls of the column or rafter. The opening can also be a close fit about the outside of the column or rafter. The opening can be a square or rectangular opening of the same shape as the outside shape of the end of the column or rafter that is to be inserted through the opening. Inboard of the opening, the outer housing has an internal surface that is a close fit about facing outer surfaces of the opposite bases and side walls of the column or rafter. The shape of the outer housing inboard of the opening can be square or rectangular. In use, with a column or rafter end inserted into the bracket, a first set of fasteners extends through a first of the C-sections and through the outer housing to connect the C-section to the internal surface of the outer housing and a second set of fasteners extends through a second of the C-sections and through the outer housing to connect the C-section to the internal surface of the outer housing.

[0016] It is expected that the fasteners will extend through the bases of the C sections rather than the side walls, however in some forms of the invention, it may be more convenient for the fasteners to extend through the side walls and so the invention is not limited to the fasteners extending just through the bases.

[0017] The fasteners can be rivets, but the preference at the time of filing this application is that the fasteners are bolts. Regardless, the fasteners will engage the inside surface of the column or rafter end and the outside surface of the outer housing to connect the column or rafter end internally of the outer housing. The connection can be a sandwich connection. The connection can be a direct connection, or it can be indirect if an intermediate plate or member, for example a metal stiffening member. is employed.

[0018] Where bolts are employed, the nuts can be positioned internally of the column or rafter end so that the nut bears against the inside surface of the column or rafter end, and the bolt head bears against the outside surface of the outer housing. The nuts can be fixed to the inside surface of the column or rafter end, such as by manually reaching inside the column or rafter end to hold them in place, or by using a fixing such as a hollow bolt(see "hollo bolt" by Lindapter International or other fasteners sold under the trade marks "Nutsert" or "Rivnut") or simply by using solder or braze, about pre-punched holes or openings, so that the bolts can be inserted through the pre- punched holes or openings to engage the nuts without having to access and handle the nuts internally of the column or rafter end. The pre- punched holes or openings and the attachment of the nuts can all be made when the C sections for the columns and rafters are manufactured. Likewise, pre- punched holes or openings can be formed in the outer housing of the brackets so that upon insertion of the column or rafter end into the outer housing, the pre- punched holes or openings in both the column or rafter end and the outer housing align for insertion of the bolts.

[0019] Brackets of the above kind can be provided for receipt of a single end of a column or rafter end, usually a column end as a footing connection for the bottom end of a column. Brackets of the above kind can also be provided as haunch brackets for receipt of a pair of ends of a column and a rafter, or as apex brackets for connecting a pair of ends of a pair of rafters.

[0020] A bracket according to the invention can also have an inner sleeve within the outer housing. The inner sleeve of the bracket extends into a column or rafter that has been inserted into the outer housing, in close facing relationship with facing inner surfaces of the opposite bases, or opposite side walls of the column or rafter. Thus, the inner sleeve can be spaced from the internal surface of the outer housing slightly more than the wall thickness of the opposite bases or the opposite side walls of the column or rafter so that the opposite bases or the opposite side walls can be inserted into the spaces between the outer housing and the inner sleeve.

[0021] With the end of the column or rafter inserted into the bracket, fasteners can be employed to extend through the outer housing, the opposite bases or the opposite side walls of the column or rafter and the inner sleeve to fasten the end of the column or rafter within the bracket. The preference is that the fasteners extend through the opposite bases of the column or rafter and so further discussion will be made in relation to that arrangement.

[0022] The inner sleeve can be a separate part to the outer housing and can be inserted into the outer housing prior to the end of the column or rafter being inserted into the outer housing, or the inner sleeve can be connected to the outer housing, such as by bolt or rivet connection. The inner sleeve could alternatively be connected to the outer housing by welding or similar. The connection between the inner sleeve and the outer housing can be a relatively low strength connection, as the introduction of fasteners to fasten the end of the column or rafter within the bracket fully secures the inner sleeve connected to the outer housing. The inner sleeve can be connected to the outer housing remote from the opening of the outer housing.

[0023] The inner sleeve can be a single sleeve formed in a U-shape having an end plate and a pair of opposite side plates extending from the end plate. When the inner sleeve is inserted into the outer housing, the end plate can be inboard of the opening of the outer housing, or it can be at or adjacent to the opening of the outer housing. Where it is adjacent to the opening of the outer housing, the end plate can act as a guide surface to guide entry of a column or rafter, or a C-section beam of a column or rafter, into the bracket. Thus, when a column or rafter, or a C-section of a column or rafter is being inserted into a bracket, if the column or rafter or the C section is not properly aligned for insertion, the column or rafter or the C-section can slide in contact with the end plate to the position at which it is properly aligned with the bracket for entry into the bracket. The inner sleeve can transition between the end plate and the side plates with inclined surfaces that also assist to insert a column or rafter or a C-section into the bracket.

[0024] Alternatively, the inner sleeve can be formed of a pair of separate sleeve sections or legs that are attached to opposite sides of the outer housing and that extend to at or adjacent the opening of the housing. The portions of the sleeve legs that extend to the opening of the housing can be inclined inwardly to act as a guide surface to guide entry of a column or rafter, or a C-section of a column or rafter, into the bracket.

[0025] It is to be noted that an end of a column or rafter can be inserted into a bracket of the invention by forming a column or rafter from a pair of C-sections before insertion into the bracket, so that the pair of C-sections is inserted into the bracket as a pair. Alternatively, the C-sections of a column or rafter can be separately inserted into a bracket one after the other. This latter approach is considered to be more appropriate given that the C-sections will not be connected to each other and so handling them separately is likely to be easier than handling them together.

[0026] It is also to be noted that while it has been stated that one benefit of the present invention is that the C-sections do not need to be connected together, such as by welding, as in the prior art to form the columns or rafters, it is permissible for the

C-sections to be connected together if that assists operation of the invention. The columns or rafters could in fact be welded together, or they could be strapped together. Strapping could assist handling without the expense and effort associated with welding.

[0027] The fasteners that are employed to extend through the outer housing, the opposite sides of the ends of the column or rafter (formed by the bases of the facing or toe-to-toe C- sections) and the inner sleeve to fasten the end of the column or rafter within the bracket can be of any suitable kind. While rivets can be employed, threaded bolts are expected to be preferred. In some forms of the invention, the outer housing and the inner sleeve have pre- punched holes or openings that are aligned for receipt of a fastener such as a bolt or rivet. In this form of the invention, threaded nuts can be fixed to an internal surface of the inner sleeve which is opposite the inner sleeve surface that faces the internal surface of the outer housing, about the openings formed in the inner sleeve, so that a bolt that is inserted through an opening in the inner sleeve can threadably engage the nut on the opposite side of the opening. Female threads can be fastened to the inner housing by a Rivnut or a Nutsert, or the nuts can be fixed by spot welding or by solder or brazing and can be fixed to the inner sleeve during manufacture of the inner sleeve. By fixing the nuts to the inner sleeve, access to the inside of the inner sleeve is not required when a bolt is being inserted through an opening in the inner sleeve.

[0028] In the above form of the invention, openings can be pre- punched in the end of the column or rafter that is to be secured within the bracket which align with the openings in the outer housing and the inner sleeve when the end of the column or rafter has been inserted into the bracket. Advantageously, all of these openings can be formed during manufacture of the outer housing and inner sleeve, and the C sections that eventually form the columns or rafters so that no on-site drilling to secure the ends of the column or rafter within a bracket is required during construction of the portal frame. Moreover, the openings in the outer housing and the inner sleeve can be provided in positions to align with the pre-punched holes that have a standard gauge line (spacing) that are made in standard cold-formed purlins, so that customised cold-formed purlins are not required. Rather, "off the shelf' cold formed purlins can be used with the present invention, meaning the cold-formed purlins can be sourced generally from any supplier around the country.

[0029] In alternative forms of the invention, holes or openings can be formed or provided on site, such as being drilled, through the outer housing, the end of the column or rafter and the inner sleeve once the end of the column or rafter has been inserted into the bracket, or openings can formed in the outer housing and the inner sleeve and once the end of the column or rafter has been inserted into the bracket, openings can be drilled through the end of the column or rafter, using the openings in the outer housing as a guide to the position of drilling.

[0030] Once the rivet or bolt connections are made through the outer housing, the end of the column or rafter and the inner sleeve, the end of the column or rafter is firmly secured within the outer housing. Tightening of the rivet or bolt connectors sandwiches the bases of the C-sections between the outer housing and the inner sleeve and prevents movement of the column or rafter out of the outer housing, while the close fit of the end of the column or rafter within the outer housing resists torsional rotation of the column or rafter. It will be understood that the tightening of the rivet or bolt connectors draws the bases of the C-sections into firm connection with the facing inside surface of the outer housing and so tightening of the connectors tends to slightly separate the C-sections of the column or rafter ends within the bracket.

[0031] Any number of fasteners can be employed to secure the ends of the columns or rafters within the outer housing of the brackets. In some forms of the invention, two sets of four fasteners are employed on each side of the outer housing. The respective sets of fasteners are spaced apart. However, any number and pattern of fasteners can be employed.

[0032] The fasteners each operate on one side of the outer housing only. Accordingly, there are fasteners on one side of the outer housing that extend through the inner sleeve and C-section base on that side of the housing and there are fasteners on the other side of the outer housing that extend through the inner sleeve and C-section base on that side of the housing.

[0033] The outer housing can have any suitable configuration. While the opening of the outer housing can be square or rectangular and dimensioned to be a close fit about the end of the column or rafter that is to be inserted into it, the opening can be larger than this, for example to assist insertion of the end of the column or rafter, or the separate C-sections that make up the column or rafter. Inboard of the opening, the outer housing forms a close fit about the outside surface of the end of the column or rafter to securely locate the end.

[0034] The outer housing can be fabricated from plate steel to form front and rear walls and opposing side plates. The walls and plates can be bolted or welded together for example.

[0035] A bracket that is formed as a footing bracket can include flanges extending from a bottom end of the outer housing so that the bracket can be secured to a concrete floor. The flanges can extend from just the front and rear walls or just from each of the side plates, or from all of the front and rear walls and the side plates. The flanges can include openings for receipt of fasteners for fastening into the concrete floor. The flanges can be formed by folding an end of the front and rear walls and/or the side plates, or they can be edges of a plate that forms the bottom end of the bracket, for example that is attached to the bottom end or edge of the outer housing. The flanges or plate can include alignment notches for assisting alignment of the footing bracket with string lines of a purlin shed construction.

[0036] A bracket that is formed as an apex bracket can be formed of two bracket parts, each having the form of a bracket as described above and so each having an outer housing, or an outer housing and an inner sleeve and each having an opening in the outer housing for receipt of an end of a rafter. The two bracket parts can be formed integrally or can be formed separately and include can include base connectors that facilitate connection of the parts together. The base connectors can be flanges for example through which bolt connections can be made. The base connectors can be provided on opposite sides of the side plates of the outer housings, or on the front and rear walls of the outer housing, or on both. The two bracket parts can be connected so that the interior into which the end of the rafters is closely received is angled at the required rafter angle, so that no further adjustment of the angles of the rafters is required once the ends of the rafters are inserted into the respective outer housings of the two bracket parts. The angle of the two bracket parts can be set for manufacture of the apex bracket, so that when apex brackets are ordered, they are manufactured to a specified roof pitch or rafter angle.

[0037] In some forms of the invention, the connection between the two bracket parts of an apex bracket includes at least first and second connections in which the first connection is a hinged connection, so that when only the first connection is made, the two bracket parts can pivot or rotate relative to each other. For example, the two bracket parts can be connected by a first hinge connection at the top of the apex bracket so that in absence of the bracket parts being connected elsewhere by the second connection, the two bracket parts can hinge about the top of the apex bracket. The two bracket parts can be connectable opposite the hinge connection by the second connection, such as at the bottom of the apex bracket, so that when the second and bottom connection is made, hinged movement between the two bracket parts is prevented. Intermediate connections can also be made. The hinged connection will advantageously allow two rafters to be laid generally flat or straight on a ground or floor surface rather than at the specified rafter angle, so that work on the rafters (such as installing roofing iron) may be more easily completed. In this respect, as will become apparent from later discussion herein, portal frames can be constructed on-site at ground or floor level, with the rafters and columns laid generally flat. The columns can be connected to rafters while still lying of the ground or floor surface and when ready, the rafters can be lifted by crane with the columns transitioning from generally horizontal to vertical as the rafters are lifted. This method of construction allows the entire building frame or frame structure to be constructed so that multiple sets of columns and rafters can be connected by wall girts and roof purlins, as well as other fittings - electrical and plumbing for example, all at ground level rather than at height, thus improving the safety for construction workers. The first hinged connection can be made between all of the pairs of rafters and when the rafters are being lifted, they will rotate about the hinge to the point at which the second connection can be made and once made, hinging about the first hinged connection can no longer occur and the rafters are fixed at the specified roof pitch.

[0038] In the above arrangement in which a first connection between two bracket parts is a hinged connection, the two bracket parts may be formed to engage in the position in which the second connection is made. For example, the outer housing of each of the two bracket parts can be formed with abutments that meet when the rafters have reached the specified rafter angle. The abutments may be bottom parts of the outer housings of the two bracket parts, such as bottom edges of the side plates and/or the front and rear walls of the outer housings, that rotate towards each other about the first hinge connection and eventually meet in the position in which the second connection is made.

[0039] A bracket that is formed as a haunch bracket can also be formed of two bracket parts, each having the form of a bracket as described above and so each having an outer housing and an inner sleeve and each having an opening in the outer housing one for receipt of an end of a column and the other for receipt of an end of a rafter. The two bracket parts can be formed integrally or can be formed separately and include cooperating engagement parts that connect them together at a specified angle depending on the required roof pitch or rafter angle relative to the generally vertical column.

[0040] In some forms of the invention, the connection between the two bracket parts of a haunch bracket includes a first and second connections in which the first connection is a hinged connection, so that when only the first connection is made, the two bracket parts can pivot or rotate relative to each other. For example, the two bracket parts can be connected by a first hinge connection that in absence of the bracket parts being connected elsewhere by the second connection, the two bracket parts can hinge so that the column connected to one of the two bracket parts can rotate to a position to underlie the rafter that is connected to the other of the two bracket parts. The opposite arrangement could alternatively be applied in which column connected to one of the two bracket parts can rotate to a position to overlie the rafter that is connected to the other of the two bracket parts. The two bracket parts can be connectable opposite the hinge connection by the second connection, so that when the second connection is made, hinged movement between the two bracket parts is prevented. This hinged connection will advantageously allow the column and the rafter to be laid generally flat or straight on a ground or floor surface so that the rafter can also be located close to the ground or floor surface. Intermediate connections can also be made.

[0041] In the above arrangement in which a first connection between two bracket parts is a hinged connection, the two bracket parts may be formed to engage in the position in which the second connection is made. For example, the outer housing of each of the two bracket parts can be formed with abutments that meet when the column and rafter have reached the specified angle between them. The abutments may take any suitable form. The two bracket parts may also nest together in the position where the second connection can be made. This can be useful in some construction techniques in which the respective bracket parts of the haunch bracket are attached to ends of a column and a rafter before they are connected together. To assist connecting the bracket parts of the haunch bracket together when they are already connected to a column and a rafter, one of the two bracket parts can for example, include inclined guiding surfaces that cooperating parts of the second bracket part can engage as connection between the bracket parts is occurring. The cooperating parts of one of the brackets can be leading edges of side plates of the outer housing of one bracket part and the inclined guiding surfaces of the other bracket part can be leading edges of side plates of the outer housing of that bracket part. The interface between the two bracket parts can be what sets the angle between the column and the rafter.

[0042] The hinged connection in the haunch bracket also advantageously facilitates repair of damaged columns. A column may be damaged for example after being struck by a forklift in a warehouse. The damaged column can be replaced by releasing the footing of the column from the concrete floor or concrete footing and releasing one of the connections between the bracket parts to allow the column to be swung upwardly about the remaining hinge connection. The damaged column can then be removed and replaced with the removal and replacement being facilitated by the hinging capability of the haunch bracket.

[0043] The foregoing discussion has been made principally in relation to brackets for use in cold-formed steel structures such as portal frames. However, the invention also provides frame structures for a building. Thus, according to the present invention there is provided a frame structure which comprises:

first supporting columns extending along one side of the frame, and second supporting columns extending along an opposite side of the frame, the columns of the first and second supporting columns being aligned opposite each other and rafters connecting to upper ends of aligned supporting columns and connecting between them to form a plurality of generally parallel rafters, the first and second supporting columns and the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the connection between the rafters and the columns of the first and second supporting columns being made with a haunch bracket. In a first form of the invention the haunch bracket comprises an outer housing, a. the outer housing having a column end entry and a rafter end entry for receiving an end of a column and a rafter at an angle, b. inside surfaces of the outer housing being a close fit to outside surfaces of the bases and side walls of the column and rafter ends, fasteners extending though the column and rafter end entries of the outer housing and the column and rafter ends to sandwich the column and rafter ends against the inside surfaces of the outer housing.

[0044] In a second form of the invention the haunch bracket comprises an outer housing and an inner sleeve,

a. the outer housing having a column end entry and a rafter end entry for receiving an end of a column and a rafter at an angle, b. the inner sleeve including a column end entry portion disposed within the column end entry of the housing and a rafter end entry portion disposed within the rafter end entry of the housing, c. outside surfaces of the column end entry portion and the rafter end entry portion being spaced apart from facing inside surfaces of the column end entry and the rafter end entry slightly more than the wall thickness of the pair of C-sections so that the column and rafter ends received in the haunch bracket are a close fit between the column and rafter end entries of the outer housing and the column and rafter end entry portions of the inner sleeve, d. fasteners extending though the column and rafter end entries of the outer housing, the column and rafter ends and the column and rafter end entry portions of the inner sleeve to sandwich the column and rafter ends between the column and rafter end entries and the column and rafter end entry portions.

[0045] The invention employs a unique haunch bracket of the kind described above, that comprises an outer housing, or an outer housing and an inner sleeve that receives the column and rafter ends and secures them by fasteners, such as bolt connections. The column and rafter ends are firmly secured relative to each other but in addition, the column and rafter ends are easy to insert into the haunch bracket and to secure within the haunch bracket.

[0046] In addition, the haunch brackets accept a pair of facing C-sections so that the columns and rafters can be formed from a pair of C-sections formed in a box shape rather than a single C-section, thus significantly increasing the strength of the columns and rafters. The haunch bracket secures the facing C-sections together so that the C-sections do not otherwise have to be fixed together, so that welding of the C-sections together is not required.

[0047] A portal frame according to the invention can employ the footing brackets and/or the apex brackets described above also.

[0048] According to the present invention there is provided a building structure that employs the brackets and/or portal frame described above. Benefits of the building structure according to the invention include that bay sizes (distance between portal frames) of up to 9m will be achievable, while spans of up to 50m are expected to be achieved.

[0049] Construction of "purlin sheds" of the prior art have to be temporarily braced and the construction sequence carefully followed due to the lack of structural integrity within the portal frames of the sheds. By employing the aspects of the present invention, the portal frame can be greatly strengthened enabling the use of erection methodology typically only currently available in the erection of structural steel structures. When this is combined with roof lift systems, should see safer construction on site and erection times reduced by up to 40%.

[0050] The present invention also provides in removing or reducing welding requirements and providing a rust advantage as a result. Being able to supply just brackets and then source pre-punched Cee purlins from a roll forming company close to site also reduces transport and manufacturing costs.

[0051] The present invention also provides a connector or "cleat" (hereinafter "cleat") that enables the connection of columns and/or rafters with lateral members known as "wall girts" and "roof purlins". Individual portal frame units comprising a pair of rafters connected at opposite ends to a pair of columns are connected to adjacent portal frame units by such wall girts and roof purlins. The wall girts and roof purlins support wall and roof sheeting or cladding and other building components, such as lights, electrical wiring, insulation etc.

[0052] A cleat according to the invention includes a pair of arms that connect to opposite side walls of a column or rafter and that extend upwardly to connect to a roof purlin, or sideways to extend to a wall girt. The cleat can be U-shaped and thus include a base from which the pair of arms extend. The base and arms can be a close fit about three sides of the column or rafter. In this arrangement, in use, the cleat can be fixed to a column or rafter and can connect a wall girt or roof purlin to the column or rafter so that the wall girt or roof purlin extends close to or in engagement with the remaining surface of the column or rafter, so that the cleat and the wall girt or roof purlin enclose the column or rafter. By this arrangement, the pair of C-sections that form the column or rafter are tightly held together as a boxed section beam without the requirement for welding the two C-sections together.

[0053] Moreover, the cleat can transfer load from the wall girts and roof purlins down to the two faces of the column or rafter to which the cleat is connected, which is usually the long sides of the column or rafter, which is usually the bases of the facing C-sections. This allows the forces that the wall girts and roof purlins are subject to, to be transferred to the long sides of the column or rafter where load absorption is greatest.

[0054] The C-sections of the columns and rafters can also be predrilled with holes or openings for accepting bolts that are used to secure the cleats to the columns or rafters so that the position and spacing of the cleats is preset during manufacture of the C-sections. This removes the need for the position of the wall girts and roof purlins to be measured on site and so ensures that the wall girts and roof purlins can be installed in exactly the position they are required.

[0055] The present invention also provides methods of constructing a portal frame as will be apparent from the discussion herein.

[0056] Brackets according to the present invention have been described in relation to those that include an inner sleeve and those that do not. It is to be appreciated that unless an arrangement of the invention specifies the requirement for a bracket having an inner sleeve, that either form of bracket can be employed, ie with or without an inner sleeve. For example, portal frames can be constructed with a haunch bracket and an apex frame that each includes an inner sleeve, but with a footing bracket that does not include an inner sleeve.

Brief Description of the Drawings

[0057] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0058] Figure 1 is an end view of a prior art portal frame.

[0059] Figure 2 is a portion of a C-section for use in the present invention.

[0060] Figures 3 to 5 illustrates a pair of C-sections respectively in back-to-back, box and nested relationship.

[0061] Figure 6 illustrates a portal frame according to one embodiment of the invention.

[0062] Figure 7 illustrates a haunch bracket according to one embodiment of the invention in exploded view

[0063] Figure 8 illustrates one bracket part of the haunch bracket of Figure 7.

[0064] Figure 9 illustrates the haunch bracket of Figure 7 fully assembled.

[0065] Figure 10 illustrates the bracket parts of the haunch bracket of Figure 7 connected respectively to the ends of a column and a rafter and ready for connection together to the assembled form of Figure 9.

[0066] Figures 11 and 12 illustrates an assembled and exploded view of the bracket part of Figure 8 respectively.

[0067] Figures 13 and 14 illustrate an apex bracket according to one embodiment of the invention.

[0068] Figures 15 to 17 illustrate a footing bracket according to one embodiment of the invention.

[0069] Figure 18 illustrates a portal frame with the columns collapsed.

[0070] Figure 18a is a detailed view of one of the haunch brackets illustrated in Figure 18.

[0071] Figure 19 is an end view of a frame unit according to one embodiment of the invention.

[0072] Figure 20 illustrates a cleat arrangement according to one embodiment of the invention.

[0073] Figures 21 to 24 illustrate a method of construction of a portal frame according to one embodiment of the invention.

[0074] Figure 25 illustrates a portion of a purlin shed with one column shown in position for removal.

Detailed Description

[0075] Figure 1 shows a form of cold-formed steel portal frame 10 for a shed or warehouse structure for example, in which a plurality of columns 12 support a plurality of rafters 14. The columns 12 and the rafters 14 form individual frame units (portal frame units for example) comprising a pair of opposite columns 12 and a pair of connecting rafters 14. Bottom ends 16 of the columns 12 are fixed in footers 18, while upper ends 20 of the columns 12 are connected to adjacent ends of the rafters 14 by haunch brackets 22. The opposite ends of the rafters 14 meet at an apex and are connected by apex brackets 26. The rafters 14 extend to the apex centrally between pairs of columns 12, and the frame of the frame 10 comprises a plurality of the individual frame units being connected together in spaced apart relationship by laterally extending elongate purlins 24.

[0076] The frame 10 further includes "knee" and apex bracing members 28 and 29 at the haunch and apex brackets 22 and 26 (although not all the bracing members are shown - usually if bracing members are required they are provided at each haunch and apex bracket 22 and 26). The bracing members 28, 29 stiffen and strengthen the connections between the columns 12 and the rafters 14, and between the rafters 14 at the apex 24. The addition of bracing members is not always allowable, as the bracing members extend into the interior of the portal frame and thus can reduce the effective working area within the portal frame 10.

[0077] The columns 12 and the rafters 14 are formed from C-sections or "Cee purlins" (hereinafter C-sections), one form of which is illustrated in Figure 2. The C section 30 is a cold rolled section and comprises a base 31 and upstanding sidewalls 32. Inwardly extending lips 34 extend from the free edges of the sidewalls 32, remote from the base 30. The C- sections have a wall thickness usually in the order of 1.2mm to 3mm. The brackets 22 and 26 can also be formed from the same C-sections as shown in Figure 2. While the portal frame 10 of Figure 1 can be formed using the C section 30 illustrated in Figure 2, increased strength can be achieved by placing a pair of C-sections back-to-back as shown in Figure 3. Thus, in Figure 3, the respective bases 31 of the two C-sections 30 are in facing engagement (Figure 3 shows the bases 31 slightly spaced apart for illustrative purposes only) and the C-sections 30 can be connected together, such as by welding at each of the circled sections in Figure 3.

[0078] In alterative arrangements, two C-sections 30 can be connected together as shown in Figure 4, in which the lips 34 of the respective sections 30 are connected together. Again, the lips 34 of the respective sections 30 are shown slightly spaced apart, but the lips can be welded together again, in the circled regions, or bolted together, and the benefit of the Figure 4 arrangement, is that a box section beam is formed which has greater strength than a C-section in isolation, or in the back-to-back configuration of a pair of C-sections as shown in Figure 3. The toe-to-toe configuration also has the advantage of forming a closed box shape and is beneficial by keeping bird nesting out.

[0079] In either of the arrangements of Figures 3 and 4, connection, usually by welding or bolting of the C-sections 30 together, is required. This obviously adds expense to the beam production process and adds workshop labour given the need to freight the C- sections to the workshop, weld them then freight to site. It also introduces the disadvantages as discussed earlier herein relating to corrosion or rust issues.

[0080] A still further form of beam is a boxed column or rafter as illustrated in Figure 5 in which two C- sections 36 and 38 nest together. The sections 36 and 38 are connected together by nesting in the manner shown in Figure 5, while welding, usually spot welding, takes place along the external lips 43 and 44.

[0081] Figures 3 to 5 illustrate the current arrangements for improving the strength of columns and rafters used in cold-formed steel portal frames. Given that all of the examples of Figures 3 to 5 require bolting or welding, they are used only where strength requirements demand it.

[0082] A cold-formed building frame 50 according to one embodiment of the invention is illustrated in Figure 6. Like the frame 10 illustrated earlier, the building frame 50 includes columns 52 and rafters 54. The rafters and columns form portal frames 56 that each comprise a pair of columns 52 on either side of the building frame 50 and a pair of rafters 54 that extend between the columns 52. The rafters 54 meet at an apex 58. Wall purlins or "girts" 60 extend horizontally between the columns 52 on one side of the building frame 50, while roof purlins 62 extend across the entire roof between adjacent rafters. There are three wall girts 60 illustrated on one side of the frame 50 (are typically installed at approximately 1200mm centres) and none on the other side. The other side includes a fascia purlin 64 but the absence of wall girts 60 on that side allows for that side to remain open for entry and exit to within the frame 50, or for closable doors to be installed. Each of the girts 60 and roof purlins 62 can be formed from cold rolled steel section that can be of smaller size and lighter gauge than is used for the columns and rafters. The girts and purlins will often be formed as C or Z-section or "top hat" section and these allow for wall and roof sheeting to be secured to the girts 60 and purlins 62 as well as for securing other fittings, such as electrical and plumbing fittings.

[0083] As will become evident from the description that follows, the columns 52 and the rafters 54 are each formed from pairs of C-sections which are formed in the box style shown in Figure 4. However, advantageously according to the invention, the C- sections are not required to be welded or bolted together. This requirement is unnecessary in cold-formed structures of the present invention, given the use of the particular form of bracket connecters that connect the columns 52 and the rafters 54 together.

[0084] In the frame 50, bracket connecters are made at the feet of each of the columns 52, at the connection between the upper ends of the columns 52 and the rafters 54 (this bracket connection is "haunch" bracket connection) and at the apex between facing rafters 54. Thus, Figure 6 shows footing brackets 66, haunch brackets 68 and apex brackets 70. An example form of a haunch bracket 68 will now be described.

[0085] Figure 7 shows a haunch bracket 68 in two parts and shows the ends of a column 52 and a rafter 54 ready for insertion into the haunch bracket 68. The haunch bracket 68 has two parts 72 and 74 that are shown apart in Figure 7 but which are connected together to form the haunch bracket, with the connection allowing pivoting or rotating movement of the two parts 72 and 74 relative to each other. The advantages of that pivoting or rotating connection will be discussed later herein.

[0086] Each of the parts 72 and 74 of the haunch bracket 68 includes an outer housing 76, 78 and an inner sleeve 80, 82. The inner sleeves are generally obscured by the outer housings.

[0087] It will be appreciated from the preceding discussion, that brackets according to the invention can be provided with or without an inner sleeve. In the drawings, all of the brackets are illustrated with inner sleeves, however, it will be appreciated that the inner sleeves of the brackets can be omitted, and the brackets can still function. There are advantages to providing the inner sleeves, but it will be evident from the drawings that the inner sleeves could be omitted and connections between brackets and columns and rafters can still be made.

[0088] The outer housings 76 and 78 have respective column end and rafter end entries 84, 86. These entries are for receipt of the ends of the columns 52 and the rafters 54 as illustrated in Figure 7. The arrows show the direction of entry. The outer housings 76 and 78 thus have side plates 88 spaced apart slightly more than the spacing S1 between the bases 90 of the C-sections that form the columns 52 and the rafters 54. In this respect, the columns 52 and the rafters 54 are formed from C sections of the same dimensions and so the dimensions of the actual columns 52 and the rafters 54 are the same except in relation to their overall length.

[0089] Likewise, the outer housings 76 and 78 have front and rear walls 92 that are spaced apart slightly greater than the spacing S2. The side plates 88 and the front and rear walls 92 thus form a square opening which is a close fit about the perimeter of the ends of the columns 52 and the rafters 54 so that those ends are a snug fit respectively within the column end entry 84 and the rafter end entry 86.

[0090] The inner sleeves 80 and 82 are U-shaped so they include a base and side walls upstanding from the base. The inner sleeves 80 and 82 are connected within the outer housings, such as by bolt fasteners, in order to form a gap between facing surfaces of the outer housings and the inner sleeves, specifically between inside surfaces of the side plates 88 of the outer housings 76 and 78 and facing surfaces of the inner sleeves 80 and 82. The gap created is slightly greater than the wall thickness of the bases of the C-sections that form the columns 52 and the rafters 54. This means that when the ends of the columns 52 and the rafters 54 are inserted into the outer housings, the inner sleeves enter the interior of the columns 52 and the rafters 54 in close facing relationship with the inside surfaces of the bases of the C sections that form the columns 52 and the rafters 54. In other words, the inside of the outer housings 76 and 78 and the outside surface of the inner sleeves 80 and 82 are spaced apart slightly more than the wall thickness of the bases of the C-sections so that the spacing forms a slot into which the bases of the C-sections slide into in close fitting relationship.

[0091] The side walls 32 and lips 34 of the C-sections 30 fit closely through the respective column end and rafter end entries 84, 86 and they fit closely to the front and rear walls 92 of the outer housings 76 and 78, but the inner sleeves 80 and 82 are open in proximity to side walls 32 and lips 34.

[0092] The very close fit of the columns 52 and the rafters 54 within the outer housings 76 and 78 and particularly the capture of the bases 31 of the C-sections 30 that form the columns 52 and the rafters 54 within the slot or gap created between the inside of the outer housings 76 and 78 and the outside surface of the inner sleeves 80 and 82, secures the pair of C-sections 30 of the columns 52 and the rafters 54 in place relative to one another, so that welding or bolting of the C-sections together is not required. This is a particularly beneficial outcome of the invention. As will become apparent from the discussion that follows, in the embodiment of the invention illustrated in Figure 7, the pair of C-sections 30 of the columns 52 and the rafters 54 can also be secured at their opposite ends in footing or apex brackets 66, 70 that use the same principle of connection and so the beams 30 of the columns 52 and the rafters 54 are securely held in place relative to one another at each end. The arrangement of the invention illustrated in Figure 7 thus advantageously means that column and rafter strength is greatly improved by the use of a box formation between a pair of C-sections, while welding of the C-sections together is not required, so that the box section approach can be adopted without the expense or disadvantages (as previously discussed) of welding.

[0093] With the ends of the columns 52 and rafters 54 inserted into the outer housings 76, 78, and thus with the inner sleeves 80 and 82 inserted into the interior of the ends of the column 52 and the rafter 54, the column and rafter ends can be secured within the respective haunch bracket parts 72 and 74 by bolt connection. Beneficially, a column 50 can be inserted into an outer housing 76, while a rafter can be separately inserted into an outer housings 78, and thereafter, the outer housings 76, 78 can be connected together to form the haunch bracket and to secure the column relative to the rafter. This can assist installation whereby on site, all that is required is for the outer housings 76, 78 to be connected together.

[0094] Figure 8 shows the haunch bracket part 72 in exploded view with the inner sleeve 80 separated from the outer housing 76 and from this, it can be seen that the inner sleeve 80 includes nuts 94 fixed to an inside surface 96 of the sleeve 80 and the openings of those nuts align with openings provided through the inside surface of the plate 96. The opposing plate 98 of the inner sleeve 80 includes openings 100 and nuts are aligned with those openings 100 on the inside surface of the plate 98, although those nuts are obscured in Figure 8. When the inner sleeve 80 is inserted into the outer housing 96, the openings 100 and thus the nuts 94 of the inner sleeve 80 align with openings 102 in the outer housing 76. It follows, that bolts can be inserted through the openings 102 of the outer housing 76 and through the openings 100 of the inner sleeve 80 for threaded connection with the nuts 94.

[0095] Returning to Figure 7, the ends of the column 52 and the rafter 54 shown in Figure 7 each include two sets of four openings 104. When the column and rafter ends are inserted into the respective outer housings 76 and 78, the openings 104 align with the openings 100 and 102 of the inner sleeve 80 and the outer housing 76. Thus, insertion of the bolts 106 shown in Figure 7 through the openings in the outer housing 76 and the inner sleeve 80 to engage the nuts 94, also results in those bolts extending through the openings 104 in the ends of the column 52 and the rafter 54. Tightening of the bolts 106 to the nuts 94 allows the ends of the columns and rafters 52 and 54 to be firmly secured within the outer housings 76 and 78 and firmly sandwiched between the outer housings 76 and 78 and the inner sleeves 80, 82. This bolted connection occurs on both sides of the column 52 and the rafter 54 as the openings and bolting arrangements discussed above are provided on each of the opposite sides of the outer housings 76 and 78 of the inner sleeves 80 and 82.

[0096] Each of the column 52 and the rafter 54 has two sets of four openings or holes 104 as shown with respect to the end of the rafter 54 in Figure 7. These openings can be punched through the bases of the columns and rafters when they are formed and can be positioned according to client requirements. Only one set of four openings 104 is visible with respect to the end of the column 52, but the end of the column 52 does in fact have two sets of four openings 104. The ends of the ends of the column 52 and the rafter 54 shown in Figure 7 are thus secured on each opposite side by 8 bolts and so a total number of 16 bolts secures each end in the haunch bracket 68. Also, the application and tightening of the bolts 106 is simple given that the nuts are secured in place on the inside of the inner sleeves 80 and 82 and so all that is required is to insert the bolts through the openings in all of the outer housings 76 and 78, the column and rafters ends and the inner sleeves 80 and 82, whereafter the bolts will engage with the nuts.

[0097] Conveniently, the haunch bracket 68 illustrated in Figure 7 can be fabricated off site and delivered with the inner sleeves 80 and 82 already disposed within and fixed to the outer housings 76 and 78. Accordingly, on site, all that is necessary is for the respective parts 72 and 74 of the haunch bracket 68 to be fitted on to the ends of the column 52 and the rafter 54 and the bolts 106 can thereafter be secured in place thus anchoring the ends of the column 52 and the rafter 54 within the haunch bracket 68. Even more conveniently, the haunch bracket parts 72 and 74 can be connected to columns and rafters prior to delivery, so that connection on site is not required. It is still possible for the haunch bracket 68 to be fixed together when the bracket 68 is manufactured, so that connection of those two parts is not required on site, but that is not expected to be preferred.

[0098] A completed haunch bracket 68 is illustrated in Figure 9. In that figure, the ends of a column 52 and a rafter 54 have been secured within the haunch bracket 68 (comprising parts 72 and 74) and the various bolts have been fitted within the respective openings to sandwich the column and rafter ends between the outer housings 76 and 78 and the inner sleeves 80 and 82. It can be seen from Figure 9, at least with respect to the column 52, that the two C-sections that form the column 52, are firmly held together in facing relationship.

[0099] Returning to Figure 7, the two parts 72 and 74 of the haunch bracket 68 are secured together by bolt connections 108 at the top and bottom corners of the side plates 88. Further bolts can be added as required, such as between the top and bottom corners. For example, four bolts might be employed along each side of the haunch bracket 68. As will be described later herein, by initially only making a bolted connection at only one of the upper or lower corners of the side plates 88, the parts 72 and 74 can pivot or rotate relative to each other and this is relevant to construction of the portal frame 50.

[0100] As indicated above, the preference is to provide the parts 72 and 74 of the haunch bracket 68 separated so that they can be fitted to ends of respective columns and rafters, prior to being connected together. Figure 10 shows this arrangement, whereby the last part of the connection process is to connect the parts 72 and 74 together after those parts have been fully connected or secured to the ends of the column 52 and the rafter 54.

[0101] Figures 11 and 12 show the haunch bracket part 72 from a different angle and in exploded view respectively. The exploded view of Figure 12 clearly shows the side plates 88 and the front and rear walls 92 and shows the U-shaped inner sleeve

80. Figure 12 also shows trapezoidal inserts 107 that fit between the inside surface of the side plates 88 and the ends 110 of the inner sleeve 80, in order to space the inner sleeve 80 slightly away from the facing surface of the side plates 88. The inserts 107 have a wall thickness which can be less than the wall thickness of the bases of the C sections of the columns and rafters that are inserted into the haunch brackets 68.

. The inserts 107 can have a wall thickness of between 0.9-2mm, for example, whereas the columns or rafters can have a wall thickness of up to about 3mm.The inserts 107 can be formed from similar plate metal that the C-sections are formed from. The inserts 107 create the spacing between the outer housing 76 and the inner sleeve 80 in order to facilitate insertion of a column end into the column entry end 84 of the part 72. The same arrangement is employed in the haunch bracket part 74.

[0102] The inserts 107 additionally form an abutment to terminate insertion of the end of the column 52 into the part 72 of the haunch bracket 68 when the column end has been fully inserted. When the end edge of the column 52 abuts a facing edge of the inserts 107, further insertion of the column end is prevented or terminated and at the same time, there is alignment or registration of the openings 104 of the column 52 with the openings 100 of the inner sleeve 80 and with the openings 102 of the outer housing 76, so that the bolts 106 can be passed through the various openings and threadably engage the nuts 94. It can be seen from the exploded view of Figure 12, that the side plates 88 and front and rear walls 92 can all be bolted together.

[0103] The inserts 107 include three openings through which bolts 110 extend for threaded engagement in openings 109 formed in the inner sleeve 80. The bolts 110 thus connect the inner sleeve 80 to the outer housing 76, sandwiching the insert 107 therebetween and that connection is the only connection made between the inner sleeve 80 and the outer housing 76 prior to insertion of the column end into the part 72. The bolts 110 do not inhibit insertion of the end of a column 52 sliding into the part 72 because the leading edge 111 of the inserts 107 is where the end of the column 52 terminates and the openings through the inserts 107 are therefore behind that termination edge in the direction of insertion into the part 72. This initial connection between the inner sleeve 80 and the outer housing 76 is relatively simple, which is acceptable, because the major strength within the haunch bracket 68 is when the column and rafter ends have been inserted and the bolts 106 have been threadably engaged with the nuts 104.

[0104] The concept adopted in the haunch bracket according to the invention, can also be adopted in footing brackets and apex brackets. An apex bracket according to the invention is illustrated in assembled form in Figure 13 and in partial exploded form in Figure 14 In Figure 13, the apex bracket 70 (see also Figure 6), includes a pair of connected outer housings 114 and inner sleeves 116 (that are obscured in Figure 13 and so only one of which is shown in Figure 14). Figure 14 shows one of the outer housings 114 in exploded view. The inner sleeve 116 is U-shaped and comprises a pair of sleeve legs 119 and a connecting end plate 120. The sleeve legs 119 and the end plate 120 are riveted together. The inner sleeve 116 connects within the outer housing 114 via rivet connections made through and openings 118 and 119 in the inner sleeve 116 and the outer housing 114. The outer housings 114 are two-part housings having a major part 121 and a front plate 120 that bolt together. The two outer housings 114 also bolt together to orient the inner sleeves 116 at an angle to each other. Fixed to opposite inside surfaces 123 of the inner sleeve 116 are nuts 124. The nuts 124 are threadably engaged by bolts 125 (see also Figure 13) that extend through the outer housings 114, the rafter ends and the inner sleeves 116 to secure the rafter ends within the apex bracket 70.

[0105] Figures 15 to 17 illustrate the footing brackets 66 with Figure 15 showing the bracket 66 in part transparent view with half of a column end inserted into it, while Figure 16 is a solid view showing a full column inserted into the bracket 66 and Figure 17 shows the bracket 66 without a column inserted.

[0106] The footing brackets 66 are constructed with the same general principle as the haunch bracket 68 and the apex brackets 70. Figures 15 - 17 show one form of footing bracket according to the invention. The footing bracket 66 comprises an outer housing 130 and an inner sleeve 132. The outer housing 130 has opposite side plates 134 and front and rear walls 136. The Figure 15 and 16 arrangements are slightly different to the arrangement of Figure 17, in that in Figure 15, the inner sleeve 132 includes sleeve legs 138 that attach to the inside of the facing side plates 134 of the outer housing 130 and to an end plate 140, whereas the inner sleeve of Figure 17 omits the end plate 140.

[0107] Figure 15 illustrates a single C-section 30 that has been inserted in between one of the side plates 134 and the facing sleeve leg 138. In accordance with previous discussion, the sleeve legs 138 are in close facing relationship with the facing surface of the side plates 134 and the gap between the sleeve legs 138 and the side plates 134 is slightly greater than the wall thickness of the base 31 of the C section 30 being inserted into the footing bracket 66. Figure 15 highlights that one way of inserting columns or rafters into any one of the footing, haunch or apex brackets described herein, is to insert one of the C-sections into the bracket first and to follow-up with the second of the beams second. In Figure 15, one of the C sections 30 has been inserted ready for the second C-section to be inserted, and in Figure 16, the second C-section has been inserted. This sequence of insertion can be convenient, given that the pair of C-sections 30 are not connected or fixed to each other prior to insertion into the bracket, but rather, are loose or disconnected. However, once both C-sections 30 have been inserted into the footing bracket 66, they will be secured together at the insertion end.

[0108] Accordingly, it can be seen from Figure 15, that the C-section 30 has been inserted into one side of the footing bracket 66, so that the base 31 of the beam 30 is interposed between a side plate 134 of the outer housing 130 and a facing sleeve leg 138, and the walls 32 of the beam 30 are in close facing relationship with the inside surfaces of the front and rear walls 136. The C-section 30 is thus a close and snug fit within the outer housing 130 and is largely restricted or restrained against movement.

[0109] In the position shown in Figure 15, the C-section 30 can be bolted into the footing bracket 66 prior to the second C-section 30 being inserted. Alternatively, both C-sections 30 can be inserted as shown in Figure 16 before bolting connection takes place.

[0110] The side plate 134 and the front and rear walls 136 of the bracket 66 can be bolted together by flange connections such as at the flanges 142. Further flanges 144 are provided for bolting the footing bracket 66 to a floor of the shed, such as a concrete floor. The inner sleeve 132 can be bolted or rivetted to the outer housing 130 such as at the lower or bottom edges 146.

[0111] With the single column C-section 30 inserted as shown in Figure 15, or with both C-sections 30 inserted as shown in Figure 16, bolts can be inserted through openings 148 (which are preferably pre-punched holes) in the outer housing 130 and into openings 150 in the sleeve legs 138 which will take those bolts through the C sections 30 inserted into the bracket 66 and the bolts can threadably engage nuts 151 (see Figure 17) which are fixed to the inside surfaces of the sleeve legs 138 aligned with the openings through which the bolts extend.

[0112] The difference noted above between the 132 of Figures 15 and 17 is by the absence of the end plate 140 in the inner sleeve 132 of Figure 17. The end plate 140 in Figure 15 assists to insert the C-sections 30 into the bracket 66, by providing a guiding surface for directing the leading end of the C-sections 30 into the space between the inside surfaces of the side plates 134 and the facing surfaces of the sleeve legs 138. Side edges of the end plate 140 that join with the sleeve legs 138 are angled or inclined to assist that insertion. Thus, the C-section 30 may engage the end plate 140 directly as insertion of the C-section 30 into the bracket 66 takes place, and if that occurs, the installation personnel will know to move the C-section 30 laterally towards the side plate 134. When the C-section 30 reaches the angled or inclined side edges of the end plate 140, the C-section will naturally move towards the space between the inside surfaces of the side plates 134 and the facing surfaces of the sleeve legs 138, whereafter the C-section can be pushed into that space.

[0113] In contrast, the inner sleeve 132 of Figure 17 does not include an end plate, but rather, include the sleeve legs 138 have an angled top edge 152 at the leading or insertion end of the sleeve legs 138. The angled top edges 152 will guide the C-sections naturally towards the space between the inside surfaces of the side plates 134 and the facing surfaces of the sleeve legs 138, whereafter the C-section can be pushed into that space.

[0114] Figure 18 shows the portal frame 50 in a partly constructed state. In Figure 18, the columns 52 have all been connected to the rafters 54 and all of the wall girts 60 and the roof purlins 62 have been connected. The connection of the girts and roof purlins to the columns and rafters is by unique cleats that will be discussed later herein.

[0115] Figure 18 shows that the rafters 54 are connected at apex brackets 70 at an angle to each other, while opposite ends of the rafters 54 are connected by haunch brackets 68 to the columns 52. However, the haunch brackets 68 are not yet fully connected, so that the separate parts 72 and 74 of the haunch brackets 68 can rotate relative to each other. This allows the columns 52 to be rotated to a position underlying the rafters 54 as shown. In the preferred construction method, the separate parts 72 and 74 of the haunch brackets 68 are first separately applied to the ends of the columns and rafters before they are connected together. It will be appreciated, that in the condition shown in Figure 18, the roof purlins 62 can be installed and other fittings, such as roof cladding and gutters can be installed. This installation thus takes place at or close to ground level, importantly providing greater safety to installation personnel and making installation less difficult than installing at height when the columns 52 are vertical.

[0116] Once the frame 50 has been assembled to the extent required, a crane can be used to lift the frame 50, either by engaging the apex brackets and/or the rafters 54, and as the frame 50 is lifted, the columns slowly rotate to a vertical orientation in which the footing brackets 66 at the base of the columns 52 can be fixed to a concrete floor or to concrete footings. An end view of the frame 50 once fully lifted is shown in Figure 19.

[0117] As indicated above, cleats can be fixed to the columns 52 and the rafters 54 to fix the girts and roof purlins to the columns and rafters. Figure 20 illustrates a cleat 152 suitable for use in the present invention, and this is formed as a U bracket, that has a lower portion 154 for connecting to a column or rafter and an upper portion 156 for connecting to a girt or purlin. The lower portion 154 extends underneath the rafter 54 as shown in Figure 20 (see also Figure 9) and a flange 158 includes openings through which bolt connections can be made to the column 52. Two bolts 160 secure the flange 158 two each side of the rafter 54. The bolts 160 extend completely through the pair of C-sections that form the rafter 160.

[0118] The upper portion 156 of the cleat 152 extends to a position to engage with and be secured to the web 162 of a Z or C-shaped roof purlin 164. Bolts 166 extend through the upper portion 156 of the cleat 52 for engagement with the web 162 of the roof purlin 164.

[0119] The use of the cleats 152 provides a unique advantage, in that the C sections30 that form the columns 52 and rafters 54 can be pre-punched with openings for accepting the bolts 160 and the bolts 166, so that the cleats 152 can be fixed to the rafters and columns wherever the bolt holes are provided and so that spacing between adjacent cleats 152 can be preset during manufacture of the beams for the columns and rafters. This is shown in Figure 19, where the cleats 152 have a general spacing of 1200mm between them (other than at the opposite ends of the rafters), and openings in the columns and rafters facilitate placement of the cleats. With the cleats 152 in place, the wall girts and roof purlins can be installed in exactly the position they are required. This differs from prior art arrangements, whereby the wall girts and roof purlins are connected directly to columns and rafters and the position of the girls and purlins must be measured onsite during construction of the portal frame 50. Accordingly, the use of cleats according to the invention along with predrilled openings in the columns and rafters is expected to significantly speed up the process of shed construction by eliminating the need for construction personnel to mark out the positions at which the wall girts and roof purlins are to be attached to the columns and rafters.

[0120] Moreover, the cleats 152 have a structural function in that it is designed to hold the two C-sections in the box shape of the columns and rafters and to transfer load from the roof purlins in a particular and favourable manner. The illustrated form of the cleat 152 operates to transfer load from the roof purlins 164 down to the two outside faces of the rafters 54. This distinguishes the cleat 152 from prior art arrangements in which a cleat is simply screwed to the top of the rafter, or the roof purlins are screwed directly to the top of the rafter, so that in either case, the forces from the roof purlins are transferred to the top of the rafter. The top of the rafter has less load absorption capacity compared to the sides of the rafter and so by use of the cleat 152, greater load absorption is provided.

[0121] The cleat 152 is formed in a U-shape so that once connected to a roof purlin, the roof purlin forms a top member so that by the cleat and the roof purlin, the rafter is encapsulated. This permits the rafter to perform as a boxed section beam without the requirement for welding the two C-sections together.

[0122] The cleat 152 is also designed with sufficient stiffness to eliminate the requirement of "fly bracing" that is often required in prior art portal frames. The purpose of "fly bracing" is to strengthen the rafter or column member from twisting as load is applied.

[0123] Figures 21 to 24 show a basic sequence that can be used to erect the frame 50. In Figure 21, a pair of rafters 54 are connected together by an apex bracket 70 and part 72 of a haunch bracket 68 has been connected to a column 52. For the frame 50, three pairs of rafters 54 and five columns 52, or three portal frames and one column removal can initially be erected according to Figure 21.

[0124] In Figure 22, cleats 152 have been attached to the rafters 54 and to the column 52, while the parts 74 of the haunch brackets 68 have been attached to the free ends of the rafters 54. A footing bracket 66 has also been applied to the foot end of the column 52

[0125] Figure 23 shows the column 52 of Figure 22 reproduced three times and spaced apart by the wall girts 60. The wall girts 60 are connected to the cleats 152 that have been attached to the columns 52. Figure 23 shows two further columns 52 with no wall girts connected between them, but rather, a carry beam 165 connects those columns 52. It is to be noted, that the centre of the carry beam 165 includes one part of a haunch bracket that has connections similar to the haunch bracket part 72, but which is configured for attachment to the fascia purlin 64. Figure 23A shows the haunch bracket part 167 in more detail.

[0126] In Figure 23A, the haunch bracket part 167 attaches to the carry beam 165 by bolts 168 on either side of the carry beam 165, to sandwich the beam 165. The haunch bracket part 167 is otherwise formed very similar to part 72 of the haunch bracket 68 of the earlier figures, so as to connect with a haunch bracket part 74 connected to a rafter as shown in Figure 24 with respect to the rafter 54.

[0127] Figure 24 adds to the layout of Figure 23, the rafters 54 that are connected by apex brackets 70 in the manner shown in Figure 22. In Figure 24, the haunch bracket parts 72 and 74 are connected, but only at one of two connection points. Returning to Figure 10, the connection points with respect to the bracket part 72 are circled and are marked A and B. Connections A and B are also marked with respect to part 74 and for the frame position of Figure 24 to be assumed, connection between the bracket parts 72 and 74 is made only at connection B in Figure 10 which allows the columns 54 of Figure 24 to underlie the rafters 52.

[0128] With the frame constructed as shown in Figure 24, the wall girts and roof purlins can be added to bring the frame to the condition shown in Figure 18 and then the rafters can be lifted to bring the frame into the condition shown in Figure 6. At that Figure 6 position, connection between the haunch bracket parts 72 and 74 can be made at position B of Figure 10, thus securing the parts 72 and 74 firmly together in the manner shown in Figure 9.

[0129] A further feature of the invention includes that the haunch bracket part 74 includes an eave purlin bracket connection 174 as shown in Figures 7 and 19 for connecting eave purlins 176 (see Figure 6). The bracket connection 174 enables the building frame to be lifted with roof sheeting/cladding already installed. There are very few buildings where the design enables the fascia purlin to be installed as part of the rafter. The fascia is normally mounted on a column or on a single piece haunch bracket, however, the fascia is better connected to the rafters so that guttering can be installed before the roof sheeting, as the roof sheeting screws into the fascia, Moreover, connecting the fascia to the rafters is important to enable a roof lift including the roof sheeting.

[0130] A further benefit of the present invention is that columns that are damaged, such as being struck by a forklift for example, can be replaced by releasing the footing of the column from the concrete floor or concrete footing, and releasing the connection between the haunch bracket parts 72 and 74 at the connection A (see Figure 10) so that the column can be swung about the connection B to remove the column from the haunch bracket part 72 for replacement. Of course, the wall girts that are connected to the column must also be released. An image of that movement is shown in Figure 25. Column removal in this manner also facilitates creation of a larger entry or bay size which might be temporary for particular large objects that need to be housed within or removed from a building in accordance with the invention, or may be permanent with further structural strengthening of the portal frame to compensate for the removed column. It is envisaged that that many clients will order buildings with extra large bays which the present invention can facilitate by column removals and installing carry beams.

[0131] The present invention can significantly improve the structural strength and stiffness of cold-formed portal frame. The haunch brackets 68 provide particular improvements to strengthen stiffness, but by adopting apex and footing brackets that use the same structural approach as the haunch brackets to effectively sandwich a box column formed of two facing C-sections firmly, assists to provide even more structural stiffness and strength. The haunch bracket, apex bracket and footing brackets and the cleat brackets are also anticipated to simplify the onsite construction of cold-formed structures, or at least not to increase the complexity of construction. The columns and rafters that are employed in portal frames according to the invention are simply fed into the respective brackets at the feet, haunch and apex of the portal frame and are subsequently bolted in place by the application of bolts through aligned openings. While the present invention will retain significant bolting, it is not expected that the bolting requirements exceed what is already required in prior art cold-formed structures such as purlin sheds. Moreover, because the present invention employs preformed or pre-punched and aligned holes, the skill required in positioning the columns, rafters and brackets is considered to be no more complex than arrangements already employed, and may well be less complex.

[0132] Importantly, the present invention facilitates the use of facing C-sections to be employed without requiring the C-sections to be preconnected, such as by welding. This maximises the strength of the columns and rafters, while the bracket connections between them enhance the strength and stiffness of the shed as well.

[0133] It will be clear from the foregoing discussion, that the brackets according to the invention allow ends of a column and a rafter to be inserted into the bracket by sliding and thereafter to be secured by bolts that extend through the outer housing of the bracket, the ends of the column and rafter and through the inner sleeve before, threadably engaging nuts attached to the inner sleeve. The brackets secure the two C-sections used to form the column and rafter together in facing relationship and insertion of the column and beam into the bracket is terminated at a suitable position where the various openings for receipt of bolt connecters are aligned or in registration. It will thus be evident that use of the bracket of the invention to secure ends of a column and/or rafter together, or a column to a concrete floor or footer is relatively simple and requires no welding. Moreover, the brackets can be constructed to provide significant strength at the joint between the column and rafter for example, which is significantly greater than the strength provided by prior art sheet metal brackets. This additional strength is provided without increasing the difficulty with which a column is connected to a rafter. Indeed, it is expected that use of the brackets according to the invention will simplify that connection process.

[0134] Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

[0135] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

[0136] Future patent applications may be filed in Australia or overseas on the basis of or claiming priority from the present application. It is to be understood that the following provisional claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in any such future application. Features may be added to or omitted from the provisional claims at a later date so as to further define or re-define the invention or inventions.

Claims

The claims defining the invention are as follows

1. A bracket for receipt of an end of a column or rafter of a of a portal frame in which the column or rafter is formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, with the C-sections being in facing relationship with free ends of the side walls remote from the bases being in facing relationship,

bracket having an outer housing which has an opening for receiving the end of a column or rafter and the outer housing has an internal surface that is a close fit about facing outer surfaces of the opposite bases and side walls of the column or rafter,

use, with a column or rafter end inserted into the bracket, a first set of fasteners extends through a first of the C-sections and through the outer housing to connect the C-section to the internal surface of the outer housing and a second set of fasteners extends through a second of the C-sections and through the outer housing to connect the C-section to the internal surface of the outer housing.

2. A bracket for receipt of an end of a column or rafter of a portal frame in which the column or rafter is formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, with the C-sections being in facing relationship with free ends of the side walls remote from the bases being in facing relationship,

the bracket having an outer housing and an inner sleeve, the outer housing having an opening for receiving the end of a column or rafter, the outer housing having an internal surface that is a close fit about facing outer surfaces of the opposite bases and side walls of the column or rafter,

the inner sleeve of the bracket being positioned to extend into a column or rafter that has been inserted into the outer housing, in close facing relationship with facing inner surfaces of the opposite bases of the column or rafter, in use, with a column or rafter inserted into the bracket and the inner sleeve of the bracket extending into the column or rafter, fasteners are employed to extend through the outer housing, the opposite bases of the column or rafter and the inner sleeve to fasten the end of the column or rafter within the bracket.

3. A bracket according to claim 2, the inner sleeve being spaced from the internal surface of the outer housing slightly more than the wall thickness of the opposite bases of the column or rafter that is to be inserted into the bracket so that the opposite bases can be inserted into the spaces between the outer housing and the inner sleeve.

4. A bracket according to claim 2 or 3, the outer housing and the inner sleeve having openings that are aligned for receipt of a bolt or rivet.

5. A bracket according to claim 4, the inner sleeve including threaded nuts fixed to an internal surface of the inner sleeve which is opposite the inner sleeve surface that faces the internal surface of the outer housing, the threaded nuts being fixed about the openings formed in the inner sleeve and being threadably engageable by bolts that are inserted through the openings.

6. A bracket according to any one of claims 2 to 5, the opening of the outer housing being a square or rectangular opening of the same shape as the outside shape of the end of the column or rafter that is to be inserted through the opening.

7. A bracket according to claim 6, the opening being a close fit about the outside of the column or rafter that is to be inserted through the opening.

8. A bracket according to any one of claims 2 to 76, the inner sleeve being connected to the outer housing.

9. A bracket according to claim 8, the inner sleeve being connected to the outer housing by bolt or rivet connection.

10. A bracket according to claim 8 or 9, the inner sleeve being connected to the outer housing remote from the opening of the outer housing.

11. A bracket according to any one of claims 2 to 10, the inner sleeve being formed in a U-shape having an end plate and a pair of opposite side plates depending from the end plate.

12. A bracket according to claim 11, the end plate being at or adjacent to the opening of the outer housing.

13. A bracket according to claim 11, the inner sleeve transitioning between the end plate and the side plates with inclined surfaces that form guide surfaces to guide entry of a column or rafter, or a C-section of a column or rafter, into the bracket.

14. A bracket according to any one of claims 2 to 10, the inner sleeve being formed of a pair of separate sleeve sections that are attached to opposite sides of the outer housing and that extend to at or adjacent the opening of the housing.

15. A bracket according to claim 14, the portions of the sleeve sections that extend to the opening of the housing being inclined inwardly as guide surfaces to guide entry of a column or rafter, or a C-section of a column or rafter, into the bracket.

16. A bracket according to any one of claims 2 to 15, in use, with a column or rafter inserted into the bracket, opposite bases of the column or rafter being positioned between opposite sides of the outer housing and the respective inner sleeves proximal the opposite sides of the outer housing and a first set of fasteners extends through one of the opposite sides of the outer housing, the base of a first of the pair of C-sections of the column or rafter and the inner sleeve on one side of the bracket to sandwich the base between the outer housing and the inner sleeve and a second set of fasteners extends through the other of the opposite sides of the outer housing, the base of the second of the pair of C-sections of the column or rafter and the inner sleeve on the opposite side of the bracket to sandwich the base between the outer housing and the inner sleeve.

17. A bracket according to claim 16, the first and second sets of fasteners comprising two sets of four fasteners with the first set of four fasteners being spaced from the second set of four fasteners.

18. A bracket according to any one of claims 2 to 17, the outer housing being fabricated from plate steel to form front and rear walls and opposing side plates.

19. A bracket according to any one of claims 2 to 18, the bracket being a footing bracket for receiving the bottom end of a column and including a base flange for securing the bracket to a concrete floor or concrete footing.

20. A bracket according to claim 19, the base flange including alignment notches for assisting alignment of the footing bracket with string lines of a purlin shed construction.

21. A haunch bracket for connecting a column and rafter of a portal frame, the column and rafter being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the haunch bracket being formed of two bracket parts each being formed as a bracket according to any one of claims 1 to 18, the two bracket parts including cooperating engagement parts that connect them together at a specified angle depending on the required rafter angle relative to the generally vertical column.

22. A haunch bracket according to claim 21, the connection between the two bracket parts of a haunch bracket includes a first and second connections in which the first connection is a hinged connection, so that when only the first connection is made, the two bracket parts can pivot or rotate relative to each other.

23. A haunch bracket for connecting a column and rafter of a portal frame, the column and rafter being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the haunch bracket comprising an outer housing and an inner sleeve, a. the outer housing having a column end entry and a rafter end entry for receiving an end of a column and a rafter at an angle, b. the inner sleeve including a column end entry portion disposed within the column end entry of the housing and a rafter end entry portion disposed within the rafter end entry of the housing, c. outside surfaces of the column end entry portion and the rafter end entry portion being spaced apart from facing inside surfaces of the column end entry and the rafter end entry slightly more than the wall thickness of the bases of the pair of C-sections of the column and rafter intended for connection with the haunch bracket so that the column and rafter ends received in the haunch bracket are a close fit between the column and rafter end entries of the outer housing and the column and rafter end entry portions of the inner sleeve.

24. A connection between a column and rafter of a portal frame, the column and rafter being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C sections in facing relationship, the connection between a column and rafter being made by a haunch bracket comprising an outer housing and an inner sleeve,

a. the outer housing having a column end entry and a rafter end entry for receiving an end of a column and a rafter at an angle, b. the inner sleeve including a column end entry portion disposed within the column end entry of the housing and a rafter end entry portion disposed within the rafter end entry of the housing, c. outside surfaces of the column end entry portion and the rafter end entry portion being spaced apart from facing inside surfaces of the column end entry and the rafter end entry slightly more than the wall thickness of the bases of the pair of C-sections of the column and rafter intended for connection with the haunch bracket so that the column and rafter ends received in the haunch bracket are a close fit between the column and rafter end entries of the outer housing and the column and rafter end entry portions of the inner sleeve. d. fasteners extending though the column and rafter end entries of the outer housing, the column and rafter ends and the column and rafter end entry portions of the inner sleeve to sandwich the column and rafter ends between the column and rafter end entries and the column and rafter end entry portions.

25. The connection according to claim 24, the fasteners being bolt fasteners.

26. The connection according to claim 24 or 25, the fasteners including first and second sets of fasteners to at each of the column and rafter end entries of the outer housing, a first set of fasteners extending through one of the opposite sides of the outer housing, the base of a first of the pair of C-sections of the column and the rafter and the inner sleeve on one side of the bracket to sandwich the base between the outer housing and the inner sleeve and a second set of fasteners extending through the other of the opposite sides of the outer housing, the base of the second of the pair of C-sections of the column and the rafter and the inner sleeve on the opposite side of the bracket to sandwich the bases between the outer housing and the inner sleeves.

27. The connection according to any one of claims 24 to 26, the outer housing, the bases of the pair of C-sections of the column and the rafter and the inner sleeve including aligned openings through which bolts extend.

28. The connection according to claim 27, threaded nuts being fixed to an internal surface of the inner sleeve about the openings formed in the inner sleeve and being threadably engageable by bolts that are extend through the aligned openings.

29. An apex bracket for connecting a pair of rafters of a portal frame, the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the apex bracket being formed of two bracket parts each being formed as a bracket according to any one of claims 1 to 18, the two bracket parts including cooperating engagement parts that connect them together at a specified angle depending on the required rafter angle between the rafters.

30. An apex bracket for connecting a pair of rafters of a portal frame, the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the apex bracket comprising an outer housing and an inner sleeve,

a. the outer housing having a pair of rafter end entries for receiving ends of a pair of rafters at an angle, b. the inner sleeve including a pair of rafter end entry portions disposed within the rafter end entry of the housing, c. outside surfaces of the rafter end entry portions being spaced apart from facing inside surfaces of the rafter end entries slightly more than the wall thickness of the bases of the pair of C-sections of the rafters intended for connection with the apex bracket so that the rafter ends received in the apex bracket are a close fit between the rafter end entries of the outer housing and the rafter end entry portions of the inner sleeve.

31. A connection between a pair of rafters of a portal frame, the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the connection between the pair of rafters being made by an apex bracket comprising an outer housing and an inner sleeve,

a. the outer housing having a pair of rafter end entries for receiving ends of a pair of rafters at an angle, b. the inner sleeve including a pair of rafter end entry portions disposed within the rafter end entry of the housing, c. outside surfaces of the rafter end entry portions being spaced apart from facing inside surfaces of the rafter end entries slightly more than the wall thickness of the bases of the pair of C-sections of the rafters intended for connection with the apex bracket so that the rafter ends received in the apex bracket are a close fit between the rafter end entries of the outer housing and the rafter end entry portions of the inner sleeve, d. fasteners extending though the rafter end entries of the outer housing, the rafter ends and the rafter end entry portions of the inner sleeve to sandwich the rafter ends between the rafter end entries and the rafter end entry portions.

32. The connection according to claim 31, the fasteners being bolt fasteners.

33. The connection according to claim 31 or 32, the fasteners including first and second sets of fasteners to at each of the rafter end entries of the outer housing, a first set of fasteners extending through one of the opposite sides of the outer housing, the base of a first of the pair of C-sections of the rafters and the inner sleeve on one side of the bracket to sandwich the base between the outer housing and the inner sleeve and a second set of fasteners extending through the other of the opposite sides of the outer housing, the base of the second of the pair of C-sections of the rafters and the inner sleeve on the opposite side of the bracket to sandwich the bases between the outer housing and the inner sleeves.

34. The connection according to any one of claims 31 to 33, the outer housing, the bases of the pair of C-sections of the rafters and the inner sleeve including aligned openings through which bolts extend.

35. The connection according to claim 34, threaded nuts being fixed to an internal surface of the inner sleeve about the openings formed in the inner sleeve and being threadably engageable by bolts that are extend through the aligned openings.

36. A portal frame including first supporting columns extending along one side of the frame, and second supporting columns extending along an opposite side of the frame, the columns of the first and second supporting columns being aligned opposite each other and rafters connecting to upper ends of aligned supporting columns and connecting between them to form a plurality of generally parallel rafters, the first and second supporting columns and the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship, the connection between the rafters and the columns of the first and second supporting columns being made with a haunch bracket according to any one of claims 21 to 23.

37. A portal frame according to claim 36, the connection between the rafters being made with an apex bracket according to claim 29 or 30.

38. A portal frame including first supporting columns extending along one side of the frame, and second supporting columns extending along an opposite side of the frame,

the columns of the first and second supporting columns being aligned opposite each other and rafters connecting to upper ends of aligned supporting columns and connecting between them to form a plurality of generally parallel rafters,

the first and second supporting columns and the rafters being formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, the pair of C-sections being in facing relationship with free ends of the side walls of the respective C-sections in facing relationship,

the connection between the rafters of the first and second supporting columns being made with an apex bracket according to claim 29 or 30.

39. A portal frame according to any one of claims 36 to 38, the connection between the columns of the first and second supporting columns and a floor or footing of a purlin shed being made with a footing bracket according to claim 18 or 19.

40. A portal frame comprising

first supporting columns extending along one side of the frame, and second supporting columns extending along an opposite side of the frame,

the connection between the rafters and the columns of the first and second supporting columns being made with a haunch bracket, the haunch bracket comprising an outer housing and an inner sleeve,

41. A cold-formed portal framed structure that includes the portal frame according to any one of claims 36 to 40.

42. A bracket for receipt of an end of a column or rafter of a portal frame in which the column or rafter is formed from a pair of C-sections that each have a base and spaced apart side walls extending from the base, with the C-sections being in facing relationship with free ends of the side walls remote from the bases being in facing relationship,

the bracket having an outer housing, the outer housing having an opening for receiving the end of a column or rafter, the outer housing having an internal surface that is a close fit about facing outer surfaces of the opposite bases and side walls of the column or rafter,

in use, with a column or rafter inserted into the bracket, fasteners are employed to extend through the outer housing and the opposite bases of the column or rafter to fasten the end of the column or rafter within the bracket.

43.A cleat for a portal frame, the cleat including a pair of arms that connect to opposite side walls of a column or rafter and that extend upwardly to connect to a roof purlin, or sideways to extend to a wall girt.

44. A cleat according to claim 43, the cleat being U-shaped and including a base from which the pair of arms extend, the base and arms being a close fit about three sides of the column or rafter.

Fig 1

Fig 2 1/13

Fig 3

Fig 4 2/13

Fig 5 3/13

Fig 7 4/13

Fig 9 Fig 8 5/13

Fig 10

Fig 11 6/13

Fig 12

Fig 25 7/13

Fig 14 Fig 13 8/13