Demountable Construction and Component Therefor

The present invention relates to a demountable frame building, and is particularly concerned with a connection member for connecting elongate frame members of the building.

The following discussion of the background art is intended merely to facilitate an understanding of the present invention; it should not be taken as an acknowledgement or admission that any of the material referred to is part of the common general knowledge.

Demountable frame buildings are known and comprise a plurality of elongate column members releasably connected to a plurality of elongate beam members. The frame buildings may also comprise roofing and flooring as well as cladding in a variety of forms that is applied to the frame to selectively close off the interior of the building.

In one arrangement one elongate column member and at least a first of the elongate beam members are connected together by a connection member.

One example of a demountable frame building according to this arrangement is described in Australian patent application AU2015201461 and its US equivalent U.S. Pat. No. 9,598,852. In this arrangement, a connector member of generally box shape has mating formations provided on two of the vertical faces of the box shape for sliding engagement with a hollow end of respective beam members. The mating formations are shaped to provide positive engagement between the connector member and beam members. Additionally, the mating formations may be secured in the hollow end portions by bolts. A horizontal face of the connector member has a male keying formation to engage a corresponding female keying formation formed on an end cap of the respective column member to prevent lateral and rotational movement of the end cap relative to the connector member. The end cap has a portion that extends exteriorly of the column member through which bolt holes are provided to secure the end cap to the connector member.

Other examples of connector members for demountable frame buildings are described in WO2011050492, U.S. Pat. Nos. 3,890,022, 3,921,360, 4,678,359, 6,338,226, 6,378,265, 6,390,719 and 63,516,955, all cited against U.S. Pat. No. 9,598,852.

Still other examples of connector members, and of connected frame members, are described in CN207296339U, WO96/00336 and U.S. Pat. No. 10,738,457 identified in an international-type search conducted by IP Australia.

Many of the structures described in the aforementioned prior art require frame members having complex profiles and/or connector members with complex manufacturing requirements.

Another known example of a connector member for a demountable frame building and having complex manufacturing requirements is illustrated inin assembled and exploded forms, respectively.illustrate a lower connector member. This connector memberhas been used by the applicant and is designed for rectangular cross-section frame members. It is fabricated from five main steel components that are welded together: a hollow attachment portionof rectangular cross-section and having two orthogonally disposed rectangular attachment facesand, first and second end platesand, a projecting L-profile receiving portionthat extends through the hollow attachment portionand a drainage tubethat extends through the hollow attachment portion, welded to and supported by the end platesand. A connector pipeis welded to the drainage tubeand projects from the lower end of the attachment portion.

similarly illustrate in assembled and exploded form respectively a corresponding upper connector member′ that has been used by the applicant. It is also fabricated from five main steel components that are welded together: a hollow attachment portion′ of rectangular cross-section and having two orthogonally disposed rectangular attachment faces′ and′, first and second end plates′ and′, a projecting L-profile receiving portion′ that extends through the hollow attachment portion′ and a drainage tube′ that extends through the hollow attachment portion′, welded to and supported by the end plates′ and′. A drainpipe connector′ has an upper flangethat is welded to the lower face of the bottom end plate′ so as to project below the attachment portion′ between the arms′ and′ of the L-profile receiving portion′. Furthermore, the drainage tube′ has a lateral opening′ to which is welded one end of an L-shaped rainwater collector pipe′. The collector pipe′ passes through a slot′ in the wall of the attachment portion′ and a corresponding opening′ in the arm′ of the receiving portion′.

An example of a demountable frame buildingof the type in which the connector membersand′ have been used is shown in.shows the frame buildingin assembled form with floor panels in place, whileshows an exploded view without the floor panels.

The demountable frame buildingcomprises a pre-assembled rectangular base structure, a pre-assembled rectangular roof structureand four identical corner column members. Each of the base structure, roof structureand column membersmay be assembled and otherwise prepared for use in a factory and then transported together in a flat knock-down state for assembly together on site. Alternatively, the overall assembly may also take place in a factory so that the assembled buildingis shipped to site.

The base structurecomprises two longitudinal beam membersand two lateral beam membersall of rectangular cross-section and attached to the attachment portionof a respective connector memberat each corner of the base structure. The rectangular cross-section of the beam membersandcorresponds approximately to the rectangular profile of the attachment facesandof the attachment portion. The end faces of each beam member butt up against and are welded to the respective attachment faceor. While welding is preferred, other attachment options may be considered including using fasteners.

The receiving portionof each lower connector memberprojects above the plane of the beam membersand, at right angles to the plane.

The base structurefurther comprises an array of cross-membersthat may be welded or otherwise secured at each end to the longitudinal beam members. The cross-membersmay additionally be supported at each end by an inwardly projecting flange (not shown) on each longitudinal beam member. A floor system comprising individual floor panels, for example of plywood or particle board, is supported by the cross-members between the beam membersand.

The roof structurecomprises two longitudinal beam membersand two lateral beam membersall of rectangular cross-section and attached to the attachment portion′ of a respective connector member′ at each corner of the roof structure. The rectangular cross-section of the beam membersandcorresponds approximately to the rectangular profile of the attachment faces′ and′ of the attachment portion′. The end faces of each beam member butt up against and are welded to the respective attachment face′ or′. While welding is preferred, other attachment options may be considered including using fasteners.

The receiving portion′ of each upper connector member′ projects below the plane of the beam membersand, at right angles to the plane.

The roof structure further comprises roof panelsthat together have a shallow gable profile that extends between the longitudinal beam membersfrom one lateral beam memberto the other. The roof panelsare supported on cross-members (not shown) similar to the cross-membersbut having a triangular shape to reflect the gable profile of the roof panels. The roof structure cross-members are stich welded to flanges (not shown) extending inwardly from the longitudinal beam members. The roof panelsare supported below the profile of the upper face of the beam membersand.

The support flanges conveniently have an inner lip so as to form gutters at the longitudinal outer edges of the roof panelsto collect rainwater coming off the roof panels. The gutters are connected by openings(one visible in) in the end portions of the inner wall of each longitudinal beamand connected to the rainwater collector pipe′ associated with each upper connector member′.

The column membershave a hollow rectangular cross-section and are each provided with a steel internal drainage pipe supported in the interior of the column member. The upper endof a drainage pipe is visible in two of the column membersin. When the frame building is assembled the drainage pipe extends between the drainage tubeof the respective lower connector memberand the drainpipe connector′ of the respective upper connector member′ to provide drainage of water from the roof panelsto the exterior at ground level.

To assemble the frame building, any necessary ground preparation is performed, including, if necessary, levelling and the installation of drainpipes to take water from the outlet ends of the drainage tubes. Drainpipes or other rainwater control at ground level may not be necessary when the frame building is used as a temporary structure. The pre-assembled base structureis then laid on the ground and any drainpipes are connected to the outlet end of the four drainage tubes. The four column membersare then mounted upright on the receiving portionof the respective lower connector members. As each column member is lowered on to the receiving portionthe pre-assembled drainage pipe within it is engaged with the respective drainage tube.

The armsandof the receiving portionare a close fit in the bottom end of the respective column membersand each column member is secured to the receiving portion by two pairs of boltspassing through openingsin the inner faces of the bottom ends of the column members and screw threadedly engaging corresponding openingsin the armsandof the receiving portion.

The roof structureis then lifted by crane or hoist and lowered onto the upper ends of the column members. As the roof structure is lowered, the arms′ and′ of the receiving portions′ slide into the upper ends of the column membersand the drainpipe connectors′ are engaged with the upper endsof the pre-assembled drainage pipes in the column members.

The arms′ and′ of the receiving portion′ are a close fit in the upper end of the respective column members and each column member is secured to the receiving portion by two pairs of boltspassing through corresponding openingsin the inner faces of the upper ends of the column members and screw threadedly engaging corresponding openingsin the arms′ and′ of the receiving portion.

The demountable frame buildingis modular, having dimensions of, for example, about 6 m in length, about 2.5 m in width and about 3 m in height. In one embodiment, the external length and width may be the same as a standard shipping container (6058 mm×2438 mm). The basic building components, that is the base structure, the roof structure and the four corner column members, are of substantial mass. For example, the masses of the basic components may be as follows: base structure about 850 kg or about 1,000 kg including a floor; roof structure about 1000 kg including the roof panels; and each column member about 70 kg. The column members may be about 2.7 m in length or, for example, up to about 3 m if a higher ceiling is desired. An advantage of such a heavy demountable frame building structure is that it may be considered to be self-ballasting so that no tethering to the ground is required.

Once the aforementioned components are assembled flooring and modular wall components, including any of solid wall modules, door modules and window modules, may be secured to the building, both internally and externally as desired. U-channels (not shown) are conveniently provided on the opposed faces of the beam members of the base structureand roof structureto receive and support external wall, door and window panels. Any such panel may be lifted over the respective base U-channel into the corresponding roof U-channel and then aligned with the base U-channel and lowered into it while still remaining engaged with the roof U-channel. Additional securing, such as with fasteners and/or narrow support panels on the column members, may also be used.

Any of the modular components may include pre-assembled electrical power and lighting outlets and/or plumbing. The basic frame building components described above may be formed in mild steel, stainless steel or a combination of mild steel and stainless steel components depending on the environment. The roof panelsare formed of mild steel but other material could be used, and solid wall modules may be formed of sandwich panels (for example, foam between skin metal sheeting), optionally also supported between steel studs.

In some situations, such as in windy or potentially windy environments, some bracing of the demountable frame building may be required, such as by cross-bracing and/or by the use of load-bearing or structural walls.

The demountable frame buildingmay be enlarged by bolting one or more other such frame buildings to it at ground level and/or by sitting another such frame building atop it and bolting the respective base and roof beam members together. In the latter arrangement, the drainage pipes of the aligned column members would be connected together through the respective connection members.

The stacking of the demountable frame buildings described above has been found to be restricted by potential strength limitations of the fabricated connector membersand′.

It would be desirable to provide an alternative connector member for demountable frame buildings formed of a small number of parts and offering the possibility of greater strength.

According to the present invention, there is provided a demountable frame building connection member for connecting two elongate frame members of the frame building, the connection member comprising an attachment portion for attachment to a first of the elongate frame members and a receiving portion extending from the attachment portion for sliding engagement with a hollow end portion of a second of the elongate frame members, the receiving portion having at least one screw-threaded passage therein for receiving a locking member to secure the receiving portion in the hollow end portion of the second elongate frame member, wherein the attachment portion and receiving portion are integrally formed from a single piece of material and have respective rectangular cross-sections, the cross section of the receiving portion being smaller than and offset relative to that of the attachment portion to define a shoulder around the receiving portion on the attachment portion that is of greater depth on at least one side of the receiving portion, and wherein the at least one passage opens for receipt of the locking member on an opposite side of the receiving portion to said at least one side.

Generally, in use of the connector member, the first of the elongate frame members will be a beam member of the demountable frame building and the second of the elongate frame members will be a column member of the demountable frame building, and for convenience only the invention will be further described with this use in mind.

Further according to the invention there is provided a demountable frame building comprising a plurality of elongate column members and a plurality of elongate beam members connected together, wherein a first of the elongate column members has a hollow end portion of rectangular cross-section and said first elongate column member and a first and second of the elongate beam members are connected together by a connection member, the connection member comprising an attachment portion attached to the first and second elongate beam members and a receiving portion extending from the attachment portion and slidably engaged within the hollow end portion of the first elongate column member, the receiving portion having at least one screw-threaded passage therein aligned with a cooperating opening through the hollow end portion of the first elongate column member and receiving a screw-threaded locking member to secure the receiving portion in the hollow end portion of the first elongate column member, and further wherein the attachment portion and receiving portion of the connection member are integrally formed from a single piece of material and have respective rectangular cross-sections, the cross section of the receiving portion being smaller than the internal cross-section of the hollow end portion of the first elongate column member and being smaller than and offset relative to the cross-section of the attachment portion to define a shoulder around the receiving portion on the attachment portion for abutment with the hollow end portion of the first elongate column member, the shoulder being of greater depth on at least one side of the receiving portion, and wherein the at least one passage opens for receipt of the locking member on an opposite side of the receiving portion to said at least one side whereby screwing the locking member through the opening and into the passage acts to secure the hollow end portion of the first elongate column member against said opposite side of the receiving portion.

In one embodiment, the building comprises a pre-assembled base structure comprising plural elongate beam members with two of the beam members attached at each corner of the base structure to a respective one of the connection members, a pre-assembled roof structure of corresponding shape to the base structure and comprising plural elongate beam members with two of the beam members attached at each corner of the roof structure to a respective one of the connection members, and a respective column member at each corner slidingly engaged at each end with two opposed connection members of the base structure and roof structure. The base and roof structures may each be of rectangular shape and for convenience only are hereinafter described in this form. However other shapes are possible, such as triangular or polygonal with 5 or more sides and a corresponding number of corners and column members. By the present invention, the connection member can have considerably greater strength than one fabricated in the same engineering material, such as mild steel, stainless steel or aluminium, from multiple components welded or otherwise connected together. In some embodiments, the increase in strength in use of the connection member can be up to 8 times. This can permit stacking of a greater number of demountable frame buildings according to the invention, for example 3 or more, but can also alleviate or even eliminate any need for additional bracing of the demountable frame building through cross-bracing or the use of structural walls or wall members. This can greatly simplify the assembly of the demountable frame building and its subsequent disassembly.

In one embodiment, the connection member is milled from a single billet or piece of plate of engineering material. In one embodiment the milling is computer numerically controlled (CNC). Alternatively, the connection member could be cast.

Furthermore, by forming the connection member of the invention with a shoulder on the attachment portion that is of greater depth on at least one side, and thereby forming the receiving portion with a smaller cross-section than the internal cross-section of the hollow end portion of the first elongate column member, the receiving portion may be more readily slidably engaged with the hollow end portion. This is important for ease of assembly of the first elongate column member to the connector member.

The connection member of the invention may be used in essentially the same way as described above for the applicant's fabricated connection member, and that description may be considered as applicable, mutatis mutandis, to the present invention. Additional features of embodiments of the connection member of the invention are described below.

In one embodiment, the longitudinal edges between adjacent sides of the receiving portion are chamfered. This may also enhance the sliding engagement of the receiving portion in the hollow end portion of the first elongate column member.

In one embodiment, the receiving portion has at least one further screw-threaded passage for receiving a corresponding locking member in a side thereof adjacent to said opposite side, and the hollow end portion of the first elongate column member has a further cooperating opening(s) for the corresponding locking member, to additionally secure the receiving portion in the hollow end portion of the column member.

In one embodiment, the shoulder around the receiving portion on the attachment portion is of greater depth on the one side of the receiving portion and on an adjacent side thereof. In one embodiment of this arrangement and where the receiving portion has at least one further screw-threaded passage for receiving a corresponding locking member in a side thereof adjacent to said opposite side as described above, the adjacent side of the receiving portion on which the shoulder has a greater depth is opposite to the side on which the at least one further screw-threaded passage opens.

In one embodiment, the shoulder portion that is of greater depth has a depth that is about 2 to 3 times the depth of the remainder of the shoulder. In one embodiment, the shoulder has a depth of 6 mm to 10 mm, for example about 8 mm, except on the side or sides of the receiving portion where it has a greater depth. In one embodiment, the depth of the shoulder on the side or sides where it has a greater depth is in the range of 15 mm to 25 mm, for example about 20 mm.

In one embodiment, there are two or more screw-threaded passages, for example 3, spaced along the receiving portion in said opposite side of the receiving portion or in each of said opposite side and adjacent side of the receiving portion, and a corresponding number of openings in the hollow end portion of the first elongate column member and locking members.

In one embodiment, the locking member or each of the locking members is a bolt, but other forms of screw-threaded fastener may be used, for example a grub screw. The locking member may be formed of stainless steel.

In one embodiment, the receiving portion of the connection member has a length that is at least about 1.5 times the length of the attachment portion, for example 1.5 to 2.5 times. In one embodiment, the receiving portion of the connection member has a length that is at least about 1.5 to about 1.75 times the length of the attachment portion.

In one embodiment, the receiving portion of the connection member when engaged with the hollow end portion of the column member extends a substantial way into the column member, for example by from 5% to 20% of the length of the column member. In one embodiment, the receiving portion of the connection member when engaged with the hollow end portion of the column member extends into the column member by at least 10% of the length of the column member. In one embodiment, the receiving portion has a length of about 180 mm to about 500 mm, for example about 270 mm to about 400 mm. In a particular embodiment the receiving portion has a length of about 330 mm. The column member may in some embodiments have a length in the range of 2.7 m to 3 m, or even 4 m if a higher ceiling is required.

In one embodiment, the connection member has a longitudinal passage for drainage purposes through the attachment and receiving portions from one end to the other. The or each screw-threaded passage for receiving a locking member may extend laterally towards the drainage passage, but in one embodiment is blind and does not open into the drainage passage. This may alleviate leakage of rainwater from the drainage passage. In one embodiment, the drainage passage extends along the central axis of the attachment portion.

In one embodiment, the drainage passage carries rainwater directly through the connection member. This is possible where the connection member is formed in a rainwater resistant material such as stainless steel. In another embodiment, a sleeve is provided in the drainage passage to carry the rainwater from one end of the drainage passage to the other. This arrangement is advantageous where the material of the connection member is subject to corrosion by the rainwater, for example when it is formed of mild steel, and/or where the drainage passage is interrupted by other openings such as the aforementioned at least one screw-threaded passage for receiving a locking member. The sleeve may be formed of any suitable material, including plastics or metal such as mild steel or stainless steel.

In one embodiment, each end of the drainage passage through the connector member, or one of them, is screw threaded to receive a connector pipe. In another embodiment, each end of the drainage passage through the connector member, or one of them, is enlarged to slidably receive the end portion of a drainage tube therein.

In one embodiment, a side port opens into the drainage passage from a side face of the attachment portion. In a connector member associated with the roof structure, the side port may be connected to a collector pipe to receive rainwater off the roof panels. In one embodiment, the side port is screw-threaded to threadedly receive a connector of the collector pipe.