GB2519696A

GB2519696A - A modular building assembly

Info

Publication number: GB2519696A
Application number: GB1501267.7A
Authority: GB
Inventors: Douglas Rose; David Thomson
Original assignee: Portakabin Ltd
Current assignee: Portakabin Ltd
Priority date: 2013-10-22
Filing date: 2013-10-22
Publication date: 2015-04-29
Anticipated expiration: 2033-10-22
Also published as: GB2513935A; GB201501267D0; GB2513935B; GB2519696B; GB201318689D0

Abstract

A modular building assembly comprises a modular building unit having at least two lifting interface members provided in predetermined locations with a fixed spacing therebetween and proximate a roof of the building unit. A lifting structure for the assembly has at least two couplings having a corresponding fixed spacing therebetween. The lifting structure has a connection arrangement for connection to a crane or the like. The couplings are arranged with respect to the interface members such that a movement of the lifting structure with a horizontal component with respect to the interface members results in engagement therebetween to enable lifting of the building unit.

Description

A modular building assembly

FIELD OF THE INVENTION

The present invention relates to modular building assemblies, particularly but not exclusively those used in temporary building constructions

BACKGROUND OF THE INVENTION

Modular building units are prefabricated in a factory and transported on lorries to the installation site where one or more modular building units are assembled into buildings. The buildings can he sin&e stirey or multi-storey. Multi-storey buildings include two or more building units stacked vertically. The buildings may he temporary (e.g. a site office on a building site) or substantially permanent (e.g. offices, classrooms, hospital buildings and the like).

A crane is typically used to lift building units from the lorry to a desired position, be it on the ground or on top of another unit to form a multi-storey structure. A crane will also he used when removing the buildings from a site. The crane is usually attached to four chains which have crane hooks or the like at their lower ends. Typically, four connection points are provided on the roof of the building unit, one in each corner.

Each connection point is arranged to rcceive one of the crane hooks. A problem with this arrangement is that installation personnel require ladders or lifting platforms to reach the attachment points and engage the hooks. Ladders are generally considered undesirable under current safety regulations, and provision of lifting platforms acids to the cost of installation.

In GB2408494B, the present applicant proposed a lifting arrangement which enabled the hooks to be engaged with the building at the bottom thereof. Whilst this is of assistance when erecting single and two storey buildings, it cannot assist with higher buildings as adders/lifting platlorms are needed, or those where units are p'aced adjacent each other due to lack of access.

The present invention seeks to overcome or at least mitigate the problems ol the prior art.

SUMMARY OF THE NVENTION

A first aspect of the invention provides a modular building assembly, comprising: a modular building unit having at least two lifting interface members provided in predetermined locations with a fixed spacing therebetween and proximate a roof of the building unit; a lifting structure having at least two couplings having a corresponding fixed spacing therebetween, the lifting structure having a connection arrangement for connection to a crane or the like; and wherein the couplings are arranged with respect to the interface members such that a movement of the lifting structure with a horizontal component with respect to the interface members results in engagement therehetween to enable lifting of the building unit.

Advantageously this enables structure to be lifted without use of ladders/lifting platforms. Horizontal guidance enables existing features of unit to act as part of the guide arrangement.

Preferably thc coupling comprises a male engagement member and the interface member comprises a female engagement member which may be advantageous as female members tess likdy to be an obstruction on die unit.

More preferably the male engagement member comprise a lug.

Still more preferably the lug of at least one of the couplings is substantially hook shaped.

In one embodiment the lug of at kast one of the couplings is substantially bulb shaped.

Optionally the female engagement member comprises an upstanding plate with an aperture therein. This is a simple form of female member that can be easily secured to unit.

Each eouphng may comprise a shackle arranged to couple to a crane hook wherein the shackles form the connection arrangement.

Preferably, the at least one coupling may be associated with a guide arranged to engage the building unit when moving the lifting structure substantially horizontally with respect to the interlace members to assist in alignment of the coupling with (lie interface member. This means it is easier to cause engagement from ground level.

The guide preferably comprises a relatively low friction surface to reduce damage to unit.

Advantageously the low friction surface may comprise a plastics material or wood.

Advantageously each coupling may comprise an indicator having a first state when the coupling is not in engagement with the corresponding interface member and a second state when the coupling is in engagement with the corresponding interface member.

This ensures operatives know when the lifting structure has properly engaged.

Preferably, the first state may be a position and the second state is a position.

More preferably, the indicator may comprise an indicator arm which is pivotable between respective first and second positions. This provides a convenient, low cost form of indication.

Yet more preferably. the indicator arm may have a base portion arranged to engage the interface member to pivot the arm.

Optionally, the hfting structure may comprise a frame. This is a convenient way of setting the spacings between the couplings.

Preferably, the frame may comprise a plurality of sections having interface foimations releasably securable together to assemble the frame. This enables easier transportation.

More preferably. one or more of the sections may comprise a tube.

Even more preferably. the interface formations may comprise a spigot or a socket which provides a convenient means of assembly.

The frame may advantageously further comprise one or more securing members to secure the sections together.

In one embodiment, the modular building unit may be selected from one of at least two standard dimensions and additional sections corresponding to the differences in the at least two dimensions may be assembled to enable the lifting structure to lift a larger dimension of building unit. This provides a convenient way of being able to lift units of different sizes.

Optionally, one or more of the couplings may be relcasably securable to the frame.

The assembly may preferably have four interface members and four couplings to improve stability.

In one embodiment, the building unit may be substantially rectangular in plan and the predetermined locations may be in the vicinity of the corners of the roof of the building module to improve stability.

A method of assembling a modular building comprises the steps of; providing a modular building assembly of any preceding claim; coupling the crane or the like to the connection arrangement of the lifting structure; moving the crane preferably substantially horizontally to engage one of the couplings to one of the connection points; and raising the building module using the crane. Advantageously this enables structure to be lifted without use of ladders/lifting platforms. Horizontal guidance enables existing features of unit to act as part of the guide arrangement.

Advantageously, the step of coupling the crane or the like to the connection arrangement may take place in the vicinity of ground level and the method further comprise raising the lifting member prior to moving the lifting member horizontally and engaging the couplings and the connection points.

A second aspect of the present invention provides a lifting structure comprising a connection arrangement for connection to a crane or the like and at least two couplings having a fixed spacing therebetween, the fixed spacing corresponding to a fixed spacing between at least two interface members of a modular building unit, wherein substantially horizontal movement of the lifting structure with respect to the interface members results in engagement therebetween to enable lifting of the building unit. Advantageously this enables structure to be lifted without usc of ladders/lifting platforms. Horizontal guidance enables existing features of unit to act as part of the guide arrangement.

Preferably, the coupling may comprise a male engagement member arranged to engage a female engagement member of the interface member.

More preferably, the male engagement member may comprise a lug.

Yet more preferably, the lug of at least one of the couplings may he substantially hook shaped.

Further or alternatively, the lug of at least one of the couplings may be substantially bulb shaped.

Preferably, each coupling may comprise a shackle arranged to couple to a crane hook wherein the shackles form the connection arrangement.

Optionally, at least one coupling may be associated with a guide arranged to engage the building unit when moving the lifting structure substantially horizontally with respect to the interface members to assist in alignment of the coupling with the interface member. This may make it. easier to cause engagement from ground level.

The guide may comprise a relatively low friction surface such as a plastics material or Optionally, each coupling may comprise an indicator having a first state when the coupling is not in engagement with the corresponding interface member and a second state when the coupling is in engagement with the colTesponding interface member.

This ensures operatives know when the lifting structure has properly engaged.

The first state may preferably be a posilion and the second state may be a position.

The indicator may comprise an indicator arm which is pivotable between respective first and second positions which provides a convenient, low cost form of indication.

The indicator arm may have a hasc portion arranged to cngagc the interface member to pivot the arm.

Advantageously, the lifting structure may comprise a frame.

The frame preferably may comprise a plurality of sections having interface foimations releasably securable together to assemble the frame.

One or more of the sections may comprise a tube.

The interface formations preferably compnse a spigot or a socket and the frame may further comprise one or more securing members to secure the sections together.

Optionally, one or more of the couplings may comprise an intcrfacc formation releasably securable to the frame.

Preferably the structure has four couplings.

A modular building unit comprises at least two hfting interface members provided in predetermined locations with a fixed spacing therebetween and proximate a roof of the building unit, the lifting interface members corresponding to at least two couplings of a lifting structure having a corresponding fixed spacing therebetween. and wherein the interface members are arranged to engage the couplings in response to a substantially horizontal movement of the lifting structure with respect to the interface members, thus enabling lifting of the building unit when the interface members and couplings are engaged.

The interface member may comprisc a female engagement member arranged to engage a male engagement member of the coupling.

Advantageously, in embodiments where the building unit has vertical columns which transfer (he load from upper an upper unit to one below, the interface members may be offset from the columns. This makes it possible for the building unit to be stacked on top of another unit, and be abutted against a further adjacent unit in a motion that is substantially horizontal or has a horizontal component. This may be particularly advantageous when a seal is provided between adjacent units which is compressed in a horizontal direction.

Preferably the female engagement member may comprise an upstanding plate with an aperture therein.

A portion of the plate may be inclined to the vertical, preferably at around 300 to the vertical.

The modular building unit preferably has four interface members.

The modular building unit may be substantially rectangular in plan and the predetermined locations may be in the vicinity of the corners of the roof of the building module.

The interface members may be usable as securing members for securing adjacent vertically stacked building module units.

A modular building assembly comprises; a modular building unit having at least two lifting interface members provided in predetermined locations with a fixed spacing therehetween and proximate a roof of the building unit; a lifting structure having at least two couplings having a conesponding fixed spacing therebetween; the lifting structure having a connection arrangement for connection to a crane or the like; and wherein the couplings are ananged with respect to the interface members such that a predetermined movement of the lifting structure with respect to the interface members results in engagement therebetween to enable lifting of the building unit.

Optionally the interface members are angled away from the vertical at suhstantially the same angle as lifting chains or straps mounted to the lifting structure.

Optionally an indicator is provided to show when engagement has been achieved.

Optionally, the lifting structure may be formed from a plurality of sections.

Optionally in embodiments where the building unit has vertical columns which transfer the load from upper an upper unit to one below, the interface members may be offset from the columns. This makes it possible for the building unit to be stacked on top of another unit, and be abutted against a further unit in a motion that is substantially horizontal or has a horizontal component. This may be particularly advantageous when a seal is provided between adjacent units which is compressed in a horizontal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be descr bed with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a modular building unit according to an embodiment of the present invention; Figure 2 is a perspective view of a building formed from four modular building units of Figure 1; Figures 3 and 4 are exploded and assembled isometric views of a lifting structure according to an embodiment of the present invention; Figures 5 and 6 are enlarged isometric views of coupling structures incorporated into the lifting structure of Figure 4; Figure 7 is an isometric view of a modular building assembly according to an embodiment of the present invention incorporating a building unit of Figure 1 and a lifting structure of Figure 4; Figure 7A is a detail isometric view of a column of the modular building unit of Figure 1 having an interface member attached; Figures 8 and 9 are isometric views showing the motion of one coupling to cause it to engage an interface member; Figure 10 is a side view of the coupling and lifting structure of Figures 8 and 9 in a fully engaged state: Figures 11 and 12 are isometric views showing the motion of another coupling to cause it to engage an interface member; Figure 13 is a side view of the coupling and lifting structure of Figures 11 arid 12 in a fully engaged state; and Figure 14 is an isometric view of a portion of an assembly according to another embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Figure 1 illustrates a modular building unit 100 comprising a roof 102, a floor 108, and two side walls 104 and 106. The modular building unit 100 has a rear wall 110.

hut no front wall, so that the modular building unit 100 is open from the front. In other embodiments, various other wall formats may he used, dependent upon whether the unit 100 is designed to be self-contained or part of a larger building.

The structure of the unit 100 is formed from four steel box section corner columns 113. joined by four C-section floor beams 111 and four C-section roof beams 114.

The roof 102 of the modular building unit 100 is supported by (lie roof beams 114. In certain embodiments, the building unit may have seals 125 on the roof beam 111 floor beams 114 and/or colunms 113, or in other similar locations around the periphery of one face of the unit, but this is not necessarily the case. Those seals 125 may be compressible in a substantially horizontal direction.

Figure 2 shows how four modular building units 100, shown in Figure 1 are combined to form a building 350 on two storeys with two units having their open fronts facing each other on each storey to form a large open-plan interior space.

As can be seen most clearly in Figure 7A, lifting interface members in the foim of lifting eyes 120 are secured to the top of the building unit 100 proximate each corner.

Each lifting eye 120 is formed from stcd plate and is welded to its adjacent corner column 113 via a bracket 121. The bracket 121 is an angle section with stiffening plates 123 in this embodiment.. In other embodiments bolted or riveted connections may be employed, and other suitable forms of bracket may be used. The lifting eye has an upper portion 122 which projects above the top of (lie roof beam 114 is cranked to approx 30° to the vertical and includes a through hole 124 to enable it to be used for lifting. The upper portion is cranked towards a middle of the modular building unit in a longitudinal direction.

Turning to Figures 3 and 4 a lifting structure 160 in the form of a disassemblable tubular frame is shown in exploded and assembled states.

The lifting structure 160 comprises two fabricated end frames 162 alTanged to space first and second coupling structures 172 laterally. Extension tubes 164 arc provided to space the end frames longitudinally and interlock with a spigot 166 and socket 168 type connection. Each coupling structure 172 is also secured to the end frames 162 with a spigot 166 and socket 168 connection. Cross pins 170 hold the tubes together.

The present applicant's building units come in two lengths. The dilTerence between these two lengths is 2.4 metres. Accordingly the extension tuhes 164 are made in 2.4m lengths so that an extra extension tube can be used on each side of the frame when using the beam with the larger modules. Other modular building manufacturers may utilise different standard lengths. so these dimensions maybe altered as appropriate.

In the present embodiment the liliing structure 160 is labricated from square box-section steel tubes convenient sizes, hut round, rectangular and other sections could he used equally well. The lifting structure 160 could, of course, be formed of fewer pieces, or indeed just a rigid one-piece structure. However, its sectional design allows it to be transported more easily between installation sites in a van or similar and individual parts to he lifted manually.

Each coupling structure 172 is handed. In this embodiment a first pair of structures 172a can additionally be considered to be leading structures, and a second pair 172b are different, and can be considered trailing for reasons discussed below.

Considering the leading structures 172a illustrated in Figure 5, these incorporate a shackle 174a for attaching to hfting chains, a main plate 176a mounting the shackle and having an abutment surface l77a inclined at approximately 300 to the vertical, a lifting lug 178a secured to the main plate, an indicator 180a, and a guide 181a to help align the leading end of the lifting structure with the building lifting eyes 120. The lilting lug 178a is in the form of a huth shape 184a inclined upwardly at approximately 60° to the vertical.

The trailing structures shown in Figure 6 172b incorporate a shackle 174b, a main plate 176b having an abutment surface 177b inclined downwardly at approximately 30° to the verticaL a lifting lug 178h secured to the main plate. an indicator 180h, and a guide l8lb to help align the trailing cnd of the lifting structure 160 with the relevant lifting eyes 120. The lifting lug 178b is in the form of a hook shape extending downwardly from the abutment surface 177b at approximately 1200 to the vertical and then having a head 186 ending generally upwardly at a similar angle.

The lifting structure is intended to be lifted by a crane 150 or other suitable lifting device having a hook 152, and is attached to the crane using a set ol four equal ength chains or lifting straps 153 attached to the shackles 174, as shown in Figure 7.

It generally considered best practise' to have the chains inclined at 30° to the vertical, and inclining the main plates 176a and l76b at this angle with respect to a longitudinal direction ol the unit 100 means the minimum of bending and shear forces pass into the rest ol the lilting structure. Furthermore the main plates 176a and 176h are also shaped to perform a similar function transverse to the longitudinal direction. Thus, as nearly as possible, the line of force of the lifting chain passes in a straight line through the main plate to the lifting lug. This enables the weight of the lifting structure to be minimised.

Refening to Figure 5. the guides 181a on the leading coupling structures 172a are mounted adjacent to the main plate 176 on the socket 168. The coupling comprises a first substantially horizontal guide surface l88a located underneath the socket 168 and extending forward thereof so as to be arranged to rest on an upper surface of the roof beam 114 to which the hfting eye 120 is secured and set the correct height for the lifting lug 178a relative to the lifting eye 120. In this embodiment, the guide surface 188 is formed from a low friction pad manufactured from nylon or another suitable plastics material such as PTFE. Other embodiments, wooden pads or other suitable materials may he used.

Each guide ISla lurther comprises a vertical guide surlace 190a which extends laterally in the form of a ramp so that the lifting lug 178a may be aligned with the lilting eye 120 in a horizontal direction (i.e. transverse to the longitudinal axis of the unit as the lilting structure 160 as a whole is moved in the longitudinal direction.

Simfiar guides 181h are provided on the trailing coupling structures 172h shown in Figure 6.

The coupling structures 172 further comprise an indicator in the form of a pivoting flag or finger 180a that is mounted to the main plate l76a by a suitable fastener 192a and is provided with a nose 194a arranged to project beyond the abutment surface 177a when in a rest position (as illustrated in Figure 5). However, when the lifting eye 120 is brought into contact with the abutment surface 177a. this causes the indicator I SOa to pivot about the fastener 192a into a more upright position (as shown in Figure 9) in order to show that the lifting lug 178a has correctly engaged with the lifting eye 120. The flag may be different colour to the remainder of lifting structure to enhance its visibility.

Again, a similar arrangement is provided on the trailing coupling structures 172h.

With relerence to Figures 7 to 12, use of the lilting structure 160 with a modular building unit 100 is discussed in more detail.

Initially, the lifting structure 160 is assembled, typically at ground level by assembling the required number of extension tubes 164 using the spigot 166 and socket anangement 168, and securing them in place with the cross pin 170. In addition, the coupling structures l72a and l72b are secured to each lateral end of the end frames 162. In addition, the lifting chains or straps 182 are secured to the shackles l74a and 174b, and at the opposite end to a crane 150, whose jib 152 is suitably lowered.

Finally, one or more "tag lines" 154 may be attached at suitable locations on the lifting structure 160 to enable operatives located on the ground to control the position of the lifting structure 160 when it is elevated, as illustrated in Figure 7.

In order to engage the lifting structure 160 with the lifting eyes 120, the lifting structure 160 is preferably lifted to a level slightly above the top of the modular building unit 100 and moved in a longitudinal direction X' until the horizontal guide surfaces 188 are above the roof beams proximate their leading edges. Additionally, the lifting structure should be aligned so that the vertical guide surfaces on each end frame 162 are within the lifting eyes 120 at the respective longitudinal end of the building unit 100.

The lifting frame 160 may then he lowered so that the horizontal guide surfaces 188a and 188b rest on the upper surface of the beams 114. The crane then slowly slides the lifting structure 160 further in direction X' with the horizontal guide surfaces continuing to rest on the roof beams, with the roof beams taking at least some of the load of the lifting frame. As the frame is moved in the direction X' any transverse or lateral misalignment between the lifting lugs 178a and 178b and the lifting eyes 120 is corrected by the ramp surfaces of the vertical guide surfaces. This motion continues until the leading lifting lugs 178a protmde through the leading lifting eyes 120 as can he seen in Figures 9 and 10, and substantially simultaneously the trailing lifting lugs 178b engage with the corresponding lifting eyes 120 as can be seen most clearly in Figures 12 and 13.

It will he appreciated that the geometry of the leading coupling structures 172a relative to the respective lifting eyes 120 is such that the lifting eyes will offly abut the colTesponding abutment surfaces 177a once it has been slightly lifted, and it is only at this point that the leading indicators 1 80a will be pivoted to the upright position.

In these positions. the lifting eyes 120 are abutting the corresponding abutment surfaces 177a and 177b of the main plate 176a and 176b. having caused the indicators I 80a and I SOb to pivot into the upright position as shown in Figures 9, 10, 12 and 13.

Therefore, operatives standing on the ground adjacent the building unit 100 are able to confirm visually that the Ufting structnre 160 has correctly engaged with the Ufting eyes. At this point, the crane is able to lift and move the modular building unit 100 into a desired position, either from the ground or on top of a second modular building unit as illustrated in Figure 2.

The arrangement of the main plates 176a and 176b and the lifting eyes at the same 30° to the vertical angle as the Ii Ring chains together with careful control of (lie dimensions of the lilting structure and angles of the lugs minimises bending load on structures and means the lifting structure may be fabricated to be somewhat lighter than may otherwise be the case as the majority of any compressive stresses are directed through the roof beams and not the lifting structure.

Once the moving operation is complete. the lifting structure 160 can be disengaged from the modular building unit 100 in a reverse of the engaging process.

Figure 14 illustrates an alternative embodiment of the present invention in which like parts are labelled by like numerals, but 100 higher. In this embodiment, the lifting eyes 220 are in the form of hoops protruding from the top of the corner columns 113.

Since all the lifting eyes are identical, the leading and trailing coupling structures, whilst handed, are identical front to rear. It will be appreciated that these lifting eyes have a secondary function of assisting with the alignment of an upper modular building unit as it is brought onto a lower building unit onto which it is to he stacked.

Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims. For example, the lifting eyes may be placed in a different location on the modular building unit 100, for example on the outside of the roof beams.

Additionally, the shape of the lifting eyes may be changed. Numerous different foirns of indicator arrangement may be provided. For example, electronic indicators that utilise switches or load transducers may he used instead of the mechanical arrangements disclosed above. The arrangement of lug and lifting eye may he reversed so that the lugs arc provided on the modular building unit 100 and the eyes on the lifting structure 160.

Claims

Claims I. A modular building assembly. comprising; a modular building unit having at least two lifting interfacc members providcd in predetermined locations with a fixed spacing therebetween and proximate a roof of the building unit: a lifting structure having at least two couplings having a corresponding fixed spacing therebetween, the lifting structure having a connection arrangement br connection to a crane or the like; and whcrcin the couplings are arranged with respect to the interface members such that a movement of the lifting structure with a horizontal component with respect to the interface members results in engagement therebetween to enable lifting of the building unit.
2. The assembly of claim 1 wherein the coupling comprises a male engagement member and the interface member comprises a female engagement member.
3. The assembly of claim 2 wherein the male engagement member comprises a lug.
4. The assembly of claim 3 wherein the lug of at least one of the couplings is substantially hook shaped.
5. The assembly of claim 3 of claim 4 wherein the lug of at least one of the couplings is substantially bulb shaped.
6. The assembly of any of claims 2 to 5 wherein the female engagement member comprises an upstanding plate with an aperture therein.
7. The assembly of any preceding claim wherein each coupling comprises a shackle arranged to couple to a crane hook wherein the shackles form the connection arrangement.
8. The assembly of any preceding claim wherein at least one coupling is associated with a guide alTanged to engage the building unit when moving the lifting structure substantially horizontally with respect to the interface members to assist in alignment of the coupling with the interface member.
9. The assembly of claim 8 wherein the guide comprises a relatively low friction surface.
10. The assembly of claim 9 wherein the low friction surface comprises a plastics material.
11. The assembly of any preceding claim wherein each coupling comprises an indicator having a first state when the coupling is not in engagement with the corresponding interface member and a second state when the coupling is in engagement with the corresponding interface member.
12. The assembly of claim 11 wherein the first state is a position and the second state is a position.
13. The assembly of claim 12 wherein the indicator comprises an indicator arm which is pivotable between respective first and second positions.
14. The assembly of claim 13 wherein the indicator arm has a base portion arranged to engage the interface member to pivot the arm.
15. The assembly of any preceding claim wherein the lifting structure comprises a frame.
16. The assembly of claim 15 wherein frame comprises a plurality of sections having interface formations releasably securable together to assemble the frame.
17. The assembly of claim 16 wherein one or more of the sections comprises a S tube.
18. The assembly of claim 17 wherein the interface formations comprises a spigot or a socket.
19. The assembly of any of claims 16 to 18 wherein the frame further comprises one or more securing members to secure the sections together.
20. The assembly of any one of claims 16 to 19 wherein the modular building unit is selected from one of at least two standard dimensions and additional sections corresponding to the dillerences in the at least two dimensions may he assembled to enable the lifting structure to lift a larger dimension of building unit.
21. The assembly of any of claims 16 to 20 wherein one or more of the couplings are releasably securable to the frame.
22. The assembly of any preceding claim having four interface members and four couplings.
23. The assembly of any preceding claim wherein the building unit is substantially rectangular in plan and wherein the predetermined locations are in the vicinity of the corners of the roof of the building module.
24. A lifting structure comprising a connection arrangement for connection to a crane or the like and at least two couplings having a fixed spacing therebetween. the fixed spacing corresponding to a fixed spacing between at least two interface members of a modular building unit, wherein substantially horizontal movement of the lifting structure with respect to the interface members results in engagement therehetween to enable lifting of the building unit.
25. The structure of claim 24 wherein the coupling comprises a male engagement member arranged to engage a female engagement member of the interface member.
26. The structure of claim 25 wherein the male engagement member comprises a lug.
27. The structurc of claim 26 whcrein thc ug of at Icast one of the couplings is substantially hook shaped.
28. The structure of claim 26 or claim 27 wherein the lug of at least. one of the couplings is substantially bulb shaped.
29. The structure of any of claims 24 to 28 wherein each coupling comprises a shackle arranged to couple to a crane hook wherein the shackles form the connection arrangement.
30. The structure of any of claims 24 to 29 wherein at least one coupling is associated with a guide arranged to engage the building unit when moving the lifting structure substantially horizontally with rcspcct to the interface mcnibcrs to assist in alignment of the coupling with the interface member.
31. The structure of claim 30 wherein the guide comprises a relatively low friction surface.
32. The structure of claim 31 wherein the low friction surface comprises a plastics material.
33. The structure of any of claims 24 to 32 wherein each coupling comprises an indicator having a first state when the coupling is not in engagement with the corresponding interface member and a second state when the coupling is in engagement with the corrcsponding interface member.
34. The structure of claim 33 wherein the first state is a position and the second state is a position.
35. The structure of claim 34 wherein the indicator comprises an indicator arm which is pivotahie between respective first and second positions.
36. The structure of claim 35 wherein the indicator arm has a base portion arranged to engage the interface member to pivot the arm.
37. The structure of any of claims 24 to 36 wherein the lifting structure comprises a frame.
38. The structure of claim 37 wherein frame comprises a plurality of sections having interface formations releasably securable together to assemble the frame.
39. The structure of claim 38 wherein one or more of the sections comprises a tube.
40. The structure of claim 39 wherein the interface formations comprises a spigot or a socket.
41. The structure of any of claims 38 to 40 wherein the frame further comprises one or more securing members to secure the sections together.
42. The structure of any of claims 38 to 41 wherein one or more of the couplings comprise an interface formation releasably securable to the frame.
43. The structure of any of claims 24 to 42 of any preceding claim having four couplings.