AU2011265552A1

AU2011265552A1 - Mobile gantry crane

Info

Publication number: AU2011265552A1
Application number: AU2011265552A
Authority: AU
Inventors: Tate Mcfarlane
Original assignee: BOMAC ENGINEERING Pty Ltd
Current assignee: BOMAC ENGINEERING PTY Ltd
Priority date: 2011-12-23
Filing date: 2011-12-23
Publication date: 2013-07-11
Anticipated expiration: 2031-12-23
Also published as: AU2011265552B2

Abstract

Disclosed is a mobile lifting apparatus, which may be embodied in a gantry crane, wherein an operating span and/or operating height is adjustable, and/or which comprises sections 5 which are configured with cavities and slots through which the cavities are accessible, and fasteners extending through the slots and into the cavities to be retained by the cavities, thereby effecting clamping of portions of the sections such that the sections are held together, the fasteners being releasable to permit disassembly of the lifting apparatus. Also disclosed is a kit for assembly of the apparatus. m Cr) I - -- - - - -------) -f -------- - A - - - - - - - - - -~ ylN-a

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title "Lifting Apparatus" The following statement is a full description of this invention, including the best method of performing it known to us: C \NRPortbI\DCC\A 2MVI070316_ .DC - 23/1/11 -1 LIFTING APPARATUS The present invention relates to a lifting apparatus, and more particularly to a gantry crane. 5 A mobile gantry crane typically comprises a pair of spaced apart uprights, a beam carried by, and extending between upper ends of, the uprights, a trolley moveable along the beam, and a hoist supported from the trolley to engage a load between the uprights whereby the load can be suspended from the beam via the trolley and hoist. Mobile gantry cranes are used in factories, workshops or production areas, where it may be necessary to suspend a 10 load, e.g. for the purposes of loading it onto or unloading it from a vehicle at a given location, and/or to move it to another location, The present invention provides improvements in such gantry cranes. According to a first aspect of the present invention, there is provided a mobile lifting 15 apparatus comprising a pair of spaced apart supports, a beam member extending between the supports and held thereby to be supported above a floor surface, the beam member being configured with a track engageable by a trolley such that the trolley can move along the beam member and suspend a load over the floor surface, wherein either or each of the supports is moveably coupled to the beam member such that the span of the apparatus can 20 be adjusted throughout a continuum. Preferably, the apparatus can be disassembled for stowage and/or transportation. Preferably, the supports, to this end, comprise sections which can be decoupled from the beam member. 25 Preferably, the or each support which is moveably coupled to the beam member ("moveable support") comprises a main section and a fitting carried by the main section, the fitting being moveably engaged with the beam member for adjustment of the span and able to be detached from the main section whereby the span can be set when the main 30 section is so detached. Preferably, the beam member extends through the or each fitting.

-2 Preferably, the fitting and main section are configured with at least one pair of aligned cavities, and an elongate joiner is fixedly received by the cavities of the or each pair to hold the fitting and main section together, the or each joiner being releasable to permit separation of the fitting from the main section. Preferably, the or each joiner comprises a 5 bar retained in the cavities of the respective pair. Preferably, each joiner is provided with releasable fasteners which extend through external slots in the fitting and main section whereby portions of the fitting and main section are clamped between the joiners and parts of the fasteners. The fasteners may comprise bolts, so that said parts comprise heads of the bolts. Each fastener instead may comprise, for example, a threaded shank, which may be 10 integrally formed with the joiner or screwed thereinto, and a nut, the nuts then comprising said parts. Preferably, the or each moveable support is slidably coupled to the beam member. Preferably, the beam member is configured with at least one slot through which at least 15 one releasable fastener extends to effect clamping between the or each movable support and a portion of the beam member. Preferably, the beam member is configured with at least one axial cavity within which is retained at least one first fastening element of a said fastener, the or each first fastening element being engaged with a respective second fastening element of that fastener which extends through a said slot in the beam men-iber 20 such that portions of the beam member are clamped by the first and second fastening elements. Preferably, the or each axial cavity is arranged above the track. Preferably, the or each slot in the beam member is upwardly opening. 25 According to a second aspect of the present invention, there is provided a mobile lifting apparatus comprising a pair of spaced apart supports and a beam member extending between the supports and carried thereby to be supported above a floor surface, the beam member being configured with a track engageable by a trolley such that the trolley can 30 move along the beam member and suspend a load over the floor surface, wherein each support comprises a first section from which the beam member is supported and a second -3 section from which the first section is supported and with which the first section is interengaged via a mechanism for adjusting spacing between the beam member and the floor surface, the mechanism being configured to be coupled to a rotary power tool such that operation of the power tool in opposite rotational directions effects the upward 5 displacement and downward displacement, respectively, of the first section. Preferably, the apparatus accords with the first aspect of the invention. In a preferred embodiment of the invention, each support is provided with a respective said mechanism. Alternatively, the apparatus may comprise only one said mechanism operable 10 to effect displacement of the supports. In a preferred embodiment, the or each mechanism includes an input fitting which is complementary to a fitting attached to said power tool whereby it is coupleable to the power tool. Preferably, the input fitting comprises a hexagonal portion receivable by a 15 socket fitting of said power tool. In a preferred embodiment of the invention, the or each mechanism comprises members formed with interengaging threads whereby said operation of the power tool effects relative rotation between the members and thereby said displacement. Preferably, the 20 members comprise a threaded rod supported from one section and a threaded sleeve supported from the other, Preferably, the rod is rotatably supported from said one section but axially fixed with respect to that section and sleeve is fixed with respect to said other section. Preferably, said rod is rotatably mounted to said one section via bearings at upper and lower ends thereof, Preferably, said one section is said first section. In one 25 embodiment of the invention, a respective said input is provided on the rod at each of the upper and lower ends. Said power tool may be a drill. 30 According to a third aspect of the present invention, there is provided a mobile lifting apparatus comprising a pair of spaced apart supports, a beam member extending between -4 the supports and held thereby to be supported above a floor surface, the beam member being configured with a track engageable by a trolley such that the trolley can move along the beam member and suspend a load over the floor surface, the apparatus comprising sections which are configured with cavities and slots through which the cavities are 5 accessible, and fasteners extending through the slots and into the cavities to be retained by the cavities, thereby effecting clamping of portions of the sections such that the sections are held together, the fasteners being releasable to permit disassembly of the lifting apparatus. Preferably, the apparatus accords with the first and/or second aspect of the invention. 10 Preferably, the sections comprise sections of which the supports are comprised ("support sections"). Preferably, the sections comprise a section of which the beam member is comprised 15 ("beam section"). Preferably, the support sections comprise respective upright sections attached to the beam section via ones of the fasteners and sections which hold the upright sections clear of the floor surface. In one embodiment of the invention, the sections which hold the upright 20 sections clear of the floor surface comprise base sections each extending transverse to and underlying a respective upright section, whereby the supports have inverted T-shaped configurations in planes perpendicular to the beam section. Preferably, ground-engaging wheels are attached to opposite ends of the base sections. In another embodiment of the invention, the sections which hold the upright sections clear of the floor surface define 25 pairs of legs, each pair having an inverted V-shaped configuration in a respective plane perpendicular to the beam section. Preferably, ground-engaging wheels are mounted at lower ends of the legs. Preferably, the sections defining the pairs of legs are pivotable with respect to respective upright sections whereby they can assume a retracted condition in which they extend in general alignment with the upright sections. 30 Preferably the beam section and support sections comprise lengths of extruded section.

-5 Preferably the support sections have identical cross-sectional configurations. Preferably, the slots and cavities of the support members are arranged on opposite sides of 5 the support members. Preferably, ones of said slots and cavities of the support members are arranged adjacent opposite edges of the support members. 10 Preferably, said fasteners comprise elongate joiners fixedly received by ones of the cavities. Preferably, the or each joiner comprises a bar. Preferably, each joiner is provided with releasable fasteners which extend through ones of said slots. The fasteners may comprise bolts, so that said parts comprise heads of the bolts. Each fastener instead may comprise, for example, a threaded shank, which may be integrally formed with the joiner 15 or screwed thereinto, and a nut, the nuts then comprising said parts. Preferably, the apparatus includes brackets via which ones of said fasteners connect ones of said sections. Preferably, the brackets are removable from said sections releasing said fasteners, 20 According to a fourth aspect of the present invention, there is provided a kit from which a mobile lifting apparatus as defined above can be formed, the kit comprising said sections and said fasteners. Preferably, the kit further comprises said brackets. Preferably, the kit is configured such that the apparatus able to be formed therefrom accords with any one or 25 more of the first, second and third aspects of the invention. Ordinarily, the apparatus will include ground-engaging wheels, preferably castors, provided at lower ends of the supports, conferring its mobility. 30 Preferably, the apparatus includes said trolley engaged with the track to be movable along the beam member, --------- 6 --- -6 Generally, the load will be suspended by the trolley via a hoist attached to the trolley, Preferably, the supports are provided with ground-engaging wheels which confer mobility 5 to the apparatus. Preferably, at least one of the wheels is provided with a respective brake, which is preferably foot-operable. In the preferred embodiments of the invention, the apparatus is a gantry crane. 10 The present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Figure 1 is a cutaway cross-sectional perspective view showing a section from which support members of gantry cranes according to preferred embodiments of 15 the present invention are formed; Figure 2 is a cutaway cross-sectional perspective view of a section from which a beam member of each of the gantry crane units is formed; 20 Figures 3A and 3B show details of joiner bars and associated bolts used to interconnect various parts of the gantry cranes; Figure 4 shows a square nut and associate bolt for interconnecting particular parts of the gantry cranes; 25 Figure 5 is a perspective view of an assembled gantry crane according to a first preferred embodiment of the present invention; Figure 6 is an exploded perspective view showing components of a support stand of 30 the gantry crane of the first embodiment and brace assemblies via which it is secured, and provides bracing, to a beam member of the gantry crane; -7 Figure 7 shows detail A marked in Figure 5; Figure 8 shows detail B marked in Figure 5; 5 Figure 9 is shows detail C marked in Figure 5; Figure 10 shows detail D marked in Figure 5; 10 Figures 1 to 13 show the gantry crane according to the first embodiment in use; Figure 14 is a perspective view of a gantry crane unit according to a second preferred embodiment of the present invention; 15 Figure 15 is a further perspective view of the gantry crane of the second embodiment; Figure 16 is an exploded perspective view showing details of an arrangement via which a support stand of the gantry crane of the second embodiment attaches to a 20 beam member of that crane; Figure 17 indicates how the operating span of the gantry crane of the second embodiment can be adjusted; 25 Figure 18 shows detail E marked in Figure 15; Figures 19 to 21 show how the height of the beam member of the gantry crane of the second embodiment can be adjusted; 30 Figure 22 shows sluing of legs of a support stand of the gantry crane of the second embodiment between a stowed condition and an operational position; and Figures 23 to 25 show the gantry crane of the second embodiment in use. A gantry crane unit I according to a first preferred embodiment of the present invention is 5 shown in Figure 5. The gantry crane 1 comprises a pair of spaced apart support stands 3 and a beam member 5 extending between, and fixed to upper ends of, the stands 3. The crane I further comprises a trolley 7 which engages beam member 5 and is moveable therealong, and a hoist 9 depending from the trolley to be engageable with a load. The crane 1 additionally comprises castors 11 provided at lower ends of the stands 3 such that 10 the unit 1 can be pushed or pulled over a floor surface - for example, to be positioned so as to engage a load or to carry a load with which it is already engaged to another location. The gantry crane I may be used, in a factory, workshop, or production area or the like, eg. to transfer a load 100 from a floor to a vehicle 110, as shown in Figures 11 to 13. 15 Each stand 3 comprises an elongate base member 30 which extends horizontally along an axis which is perpendicular to that of the beam member 5, and an elongate upright member 31 which is supported on the base member 30 at a central position therealong and extends upwardly therefrom. Each of the base and upright members 30, 31 comprises a 20 length of extruded section, as shown in Figure 1. The section comprises main walls 2, defining a box hollow section configuration, and, arranged at respective corners of the section, channel portions 4, each of which itself takes the form of a box hollow section and is configured with a central slot 6 formed through a laterally outer wall thereof, thereby defining retaining lips 8 which retain and frictionally engage fastener elements received in 25 the longitudinal cavity 12 defined in the channel portion, as will be described in further detail later. The section may be extruded from any suitable metal, such' as steel or aluminium, or formed from such metal by a drawing and extrusion process. 30 Referring to Figure 9 in particular, each stand 3 includes a pair of gussets 32 via which the -9 upright 31 is secured to the base member 30. With reference also to Figure 6, the base member 30 and upright member 31 are orientated such that the slots 6 in each of them face in opposite directions which are parallel to the axis of the beam member 5, and the associated cavities 12 receive elongate fastener elements 14, as shown in Figure 3A, each 5 of which is in the form of a bar configured with spaced apart threaded through holes 16 therealong, which are introduced into the respective cavities 12 at ends of the members 30, 31 (where the cavities 12 open) and retained therein by the respective pairs of lips 8. The elements 14 are shaped and proportioned so as to fit substantially size-for-size in the cavities 12, though with sufficient clearances to be slideable within the channel 10 portions 6. The holes 16 are arranged so as to be accessible through the slots 6 when the fastener elements 14 are received in the channel portions 6. Each gusset is configured in the form of a plate having lines of fastener holes 33 therethrough, each line of holes being positioned to overlie a respective slot 6 when the 15 gusset 32 is received against the members 30, 31, and comprising hole spacing such that the holes align with the holes in the fastener element 14 when appropriately positioned in the respective cavity 12. Referring to Figure 3, threaded fasteners, typically bolts 17 (which may be provided with washers), are received through the aligned holes 33 and 16, such that the respective pairs of retaining lips 8 of the sections are tightly clamped between 20 the thus-fastened fastener elements 14 and gussets 32, whereby the members 30, 31 of each leg 3 are securely fixed together. Each castor 11 is fixed to a respective base member end via a pair of brackets 20 each of which comprises a base portion 21 and a flange 22 projecting upwardly from the base 25 portion 21 to be received against a respective one of opposed lateral sides of the base member 30. Each flange 22 is configured with spaced apart lines of holes 23 which align with the slots 6 at the side of the member 30 against which the flange 22 is received, so as to align, in turn, with the holes 16 of (additional) fastener elements 14 received in the respective cavities 12 (via insertion through the open ends thereof as previously described). 30 Fasteners 17 received through the aligned holes effect clamping of the pairs of lips 8 between the flanges 22 and fastener elements 14 whereby the castors are securely fixed to -10 the base members 30. With reference to Figures 6 and 10, one of the castors I1 on each of the support stands is provided with a brake 13, which a person can engage and disengage by foot, whereby 5 movement of the crane 1 over the floor surface can be prevented. A brake could, alternatively, be provided at each end of each base member Referring to Figures 6 and 7, the beam member 5 is secured to the upper ends of the upright members 31 via bracket assemblies 40, each of which comprises a first bracket 41 10 and a second bracket 47. Bracket 41 comprises a side plate section 42, a top plate section 43 and a pair of gussets 44 extending between the sections 42, 43. The side plate section 42 is configured with a pair of spaced apart upright lines of holes 45 therethrough. The holes 45 in each line align with holes 16 of elongate fastener elements 14 received in the cavities 12 of the inner channel sections 4 of the respective upright member 3 1. 15 Fastener elements 17 received through the aligned holes effect clamping of the pairs of lips 8 of those channel sections between the thus engaged fastener elements 14 and side plate section 42. The top plate section 43 is configured with spaced apart lines of holes 46 therethrough, through which mounting of the beam member 5 to the bracket 41 is effected, as will now be described. 20 Referring in particular to Figure 2, the beam member 5 comprises a length of extruded section 50 which is formed with a tubular rail 51, in the form of a circular cross-section pipe portion, an upright web portion 52, from which the rail 51 depends, and a flange section 53, from which the web portion 52 depends, via which the beam member 5 is 25 affixed to each bracket assembly 40. The flange section 53, consistent with the flanges of an I-beam in a conventional gantry crane unit, resists much of the bending moment to which the beam member 5 is subjected when a load is suspended therefrom, though is not configured in the form of a plate. Rather, the flange section 53 comprises a plate portion 54 which is arranged perpendicular to the web portion 52 and from which that web 30 portion projects, spaced apart web portions 55 which project upwardly from the plate portion 54, and lips 56 projecting laterally inwardly from the upper most ends of laterally -11 outermost ones of the portions 55 and projecting both laterally inwardly and laterally outwardly from uppermost ends of the remaining, laterally inner, portions 55. The portions 54, 55 and 56 define, consistent with the channel sections 4, cavities 12 and slots 6 through which the respective cavities 12 can be accessed. 5 The second bracket 47 is in the form of a plate which is configured with lines of holes 48 therethrough, these holes being positioned and spaced so as to align with the holes 46 of the bracket 41 when the bracket 47 is appropriately positioned. Fastener elements, in the form of three-hole joiner bars 14 (see Figure 3A), are received into the cavities 12 (by 10 being introduced through the open ends thereof) to receive bolts 17 which are received through the aligned holes 46, 48, whereby the lips 56 are clamped between the top plate portion 45 and the elements 15 and the beam member 5 is thus securely fixed to each bracket assembly 40. A portion of each second bracket 47 projects beyond the respective end of the beam member 5 so as to engage overlappingly the upper end of the respective 15 upright member 31, thereby transferring, in shear, downward loads from the beam member 5 into the supports 3. The crane 1 further comprises diagonal braces 60 which provide bracing between the beam member 5 and the upright members 31 interconnected therewith. Each brace 60 comprises 20 a first mount 61 which is secured to the beam member 5 via fastener elements 15, which are received in the beam member cavities 12, and fastener elements 17 interengaged therewith. Each brace 60 further comprises a second mount 62 which is mounted to the respective upright member 31 via fastener elements 15, received in the laterally inner cavities 12 thereof, and fastener elements 17 engaged therewith. The braces 60 further 25 include bar members 63 which extend between and are fixed, via threaded fasteners, to the mountings 61, 62, which mountings are identical to each other. Referring to Figures 6 and 8, the trolley 7 comprises a body 18, pairs of spaced apart wheels 19A, which are carried by the body 18 and engage the rail 51 on opposed sides 30 thereof, and may also comprise a pair of wheels 19B which are also carried by the body 18 and which engage the flange portion 52 on opposed sides thereof to stabilise the trolley, - 12 The construction of the trolley is generally in accordance with that of the trolley disclosed in Australian patent application no. 199876190, the content of which is incorporated herein by reference in its entirety. 5 A mobile gantry crane I' according to a second preferred embodiment of the present invention will now be described with reference to Figures 14 to 25. In the description of this embodiment, the same reference numerals as have been used in respect of the first embodiment are used to denote and refer to corresponding features. 10 The gantry crane ' like the crane 1, may be used, for example, in a factory, workshop or production area, e.g. to transfer a load 100 from a floor to a vehicle 110, as shown in Figures 23 to 25. The gantry crane ' is similar in construction in many respects to the gantry crane 1, though 15 is configured such that the operating height and span of the beam member 5 are adjustable. The differences between crane ' and the crane I reside in particular in the construction of the supports 3' and the manner in which those supports are fixed to the beam member 5. Each support stand 3', instead of comprising a generally horizontal base member, comprises a pair of legs 70 which are downwardly divergent and attached to an upright 20 member 31' of the respective support 3', via gussets 32% which are attached to each of the upright members 31' via joiner bars 14 and fastener elements 17, consistent with the first embodiment. Each leg 70 is formed from a length of the section illustrated in Figure 1 and, consistent with the base members 31, orientated to receive joiner bars 14', as shown in Figure 3B, which are the same as the joiner bars 14 but may be longer and are configured 25 with four holes instead of three, and which receive bolts 17 inserted through holes in the gusset 32' so as to be fixed to the gusset 32'. Each gusset 32', in turn, is fixed to the respective upright 31' via joiner bars 14 received in the cavities 12 of the upright member 31' and bolts 17 received through the gusset 32' to engage the joiner bars 14. Each gusset 32', however, is configured with two pairs of opposed arcuate elongated holes or 30 slots 34, each slot 34 in each of the pairs receiving one of the fastener elements 17 received in a respective joiner bar 14' in a respective leg 70, whereby, when the fastener elements -13 17 received in the slots are slack and the others are removed, each of the legs 70 may pivot, about a bolt or pin 35 which is received through the gussets 32' and the log 70 (to keep them together), such that, referring to Figure 22, each leg 70 can be pivotally moved between a retracted, or stowed, position and an expanded, or operating, position. 5 Additionally provided are slew stops 37 which attach to each of the legs, on both sides thereof, via bolts received by lowermost holes in the respective joiner bars 14', to bare against respective lower edge portions of the gussets 32' once the stands 3' are in their expanded/operating conditions, providing rotational restraint between the upright 31' and legs 70 in each support stand 3'. 10 The crane 1' can be (partially) disassembled rapidly so as to be readily stowable for the purposes of storage or transportation, and later quickly and easily re-assembled. In particular, with the legs 70 in their retracted conditions and the head units 31 B separated from the main sections 31A (though still attached to the beam member 5), the crane ' 15 assumes a disassembled condition particularly suited for stowage. The crane 1' comprises castors 11' which are attached to the lower ends of the legs 70 via brackets 20, square nuts 15 and fasteners 17. Each support 3' further comprises a tie member 36, in the form of a rod, which, once the legs 70 assume their expanded positions, 20 is fixed at its ends 2, and extends between, the brackets 20 provided at the lower ends of the legs 70 of the support 3'. The tie member 36 supports the legs 70 in tension. Each support 3' additionally comprises a raising and lowering mechanism 80 via which the upright member 31' and legs 70 are interengaged whereby the former is moveable along an 25 upright axis relative to the latter. Referring in particular to Figure 18, the mechanism 80 comprises upper 81 and lower 82 brackets which are fixed at upper and lower positions respectively to the upright member 31' via fasteners 17 and fastener elements 15 received in the cavities 12 on the outer lateral side of the upright member 31'. Each mechanism further comprises respective bearings 83 which are rotatably mounted to the 30 brackets 81, 82, and a threaded rod 84 rotatably supported from the brackets 81, 82 via the bearings 83, so as to be axially fixed with respect to those brackets. The mechanism 80 -14 further comprises a threaded sleeve 85 which forms part of a bracket 86 fixed to the laterally outermost gusset 32', which sleeve receives the rod 84 therethrough. The mechanism 80 further comprises respective fittings, in the form of hexagonal 5 blocks 87, which are fixed to the upper and lower ends of the rod 84 to be engageable with a socket fitting, configured with a complementary hexagonal recess, mounted to a power drill, as will be described in further detail later. Referring in particular to Figure 16, each upright member 31' comprises a main 10 section 31 A, which makes up most of the height of the upright member 31', and a head unit 31B, removably attached to the main section 3 1A, through which the respective end section of the beam member 5 is received. Each head unit 31B, like the main section 31A atop which it is received, is formed from a length of the section illustrated in Figure 1, and is fixed to that main section 31A via joiner bars 14' received in aligned cavities 12 of the 15 head unit 31 B and main section 31 A, and bolts 17 engaging the joiner bars 14'. Referring still to Figure 16, each head unit 31B is configured with openings 90, provided through opposed walls 2 of the extruded section, into which a respective end portion of the beam member 5 is received, The openings 90 are shaped for close-fitting slideable 20 engagement between the head unit 31B and beam member 5. Each head unit 31B is provided with a pair of brackets 91, for securing it to the beam member 5, which attach, via square nuts 15, received into respective cavities 12 of the head unit 31B, and bolts 17, to opposite sides of the head unit 31 B and which attach also, via square nuts 15, received in cavities 12 of the beam member 5, and bolts 17, to the beam member 5. 25 Owing to the separability of the head units 31 B from the main sections 31 A, the operating span of the beam member 5 can, advantageously, be set, particularly during assembly of the crane 1', before the supports 31' are assembled. More particularly, the head units 3 1B, with the bolts 17 that secure the brackets 91 to the beam member 5 sufficiently slackened 30 (and the braces 60 duly disengaged), can be slid along the beam member 5 to appropriate positions and the said bolts then tightened, whereby the span is set, before they are -15 mounted to the main sections 31A, which sections, due to their size and weight, would hinder the span adjustment if in situ during the adjustment. Referring to Figures 20 and 21, the operating height of the beam member 5 is adjustable as 5 follows. Firstly, the bolts 17 which are received through the gussets 32' to engage with the joiner bars 14 in the cavities 12 of the main sections 31 A are slackened, whereby the load transfer from the upright members 31' to the legs 70 is through the mechanisms 80 and gussets 32'. The mechanisms 80 are then operated to raise or lower the upright members 31, and thus the beam member 5. Operation of each mechanism 80 involves 10 engagement of the hexagonal fitting 87 at either end of the rod 84 with a socket fitting attached to a drill (which is preferably cordless) and operation of the drill to effect rotation of the rod 84 to displace it, and thus the upright member 31 A to which it is mounted, upwardly or downwardly with respect to the sleeve 85/bracket 86 of the mechanism 80. The raising/lowering can be carried out by either operating one mechanism at a time (there 15 being enough "give" in the assembly to permit the height of one support to be adjusted to an extent while the height of the other remains fixed) or by operating both mechanisms 80 simultaneously using respective drills which are operated by two people. Which of the two hexagonal fittings 87 at the ends of a given rod is engaged by the drill may depend upon the height setting of the respective support 3' when the adjustment is being made; for 20 example, if the upright member 31' is at a low position setting relative to the legs 70, as shown in Figure 20, the upper hexagonal fitting may be suitably positioned for engagement with the drill whereas, if the upright member 31' is at a relatively high position setting, as shown in Figure 21, it may be the lower hexagonal fitting 87 which is so positioned. 25 Once the positions of the upright members 31' have been thus adjusted, the slackened bolts 17 through the gussets 32' are tightened to fix the gussets 32' to the main sections 31A. The crane ' may incorporate plastic anti-wear strips 37 (see Figure 22) which are 30 configured with holes and received between the gussets 32' and legs 70 and also between the gussets 32' and uprights 31, the holes of the anti-wear strips receiving therethrough the -16 bolts 17 in the bolt/joiner bar interconnections between the gusset and legs and between the gusset and upright. In an alternative embodiment, the crane may instead comprise a single mechanism 5 engageable with a drill at an input thereof to raise and lower both upright members 31'/beam member ends simultaneously, or respective mechanisms - one for each support - which are intercoupled such that operation of one mechanism drives the operation of the other. 10 Advantageously, the mechanisms 80 provide a simple, reliable and rapid means of height adjustment through the use of a rotary power tool, as will generally be on-hand in work area environments to which the gantry crane is suited. It will be appreciated that, in either of the illustrated embodiments, lines of adjacent 15 fastener elements 15, where they are employed, can be replaced with joiner bars 14 (configured with the appropriate number of holes), and vice versa. Advantageously, and owing in particular to the slots 6 and cavities 12 in the structural members of the cranes I and 1', those cranes can be assembled and disassembled, and the 20 working height and span of later adjusted easily and quickly. In the illustrated embodiments, the trolley is unpowered, though in other embodiments it may be powered. 25 While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus; the present invention should not be limited by any of the above described 30 exemplary embodiments.

-17 Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 5 The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of 10 endeavour to which this specification relates.

Claims

1. A mobile lifting apparatus comprising a pair of spaced apart supports, a beam member extending between the supports and held thereby to be supported above a floor 5 surface, the beam member being configured with a track engageable by a trolley such that the trolley can move along the beam member and suspend a load over the floor surface, wherein either or each of the supports is moveably coupled to the beam member such that the span of the apparatus can be adjusted throughout a continuum. 10 2. An apparatus according to claim 1, being able to be disassembled.

3. An apparatus according to claim 1 or claim 2, wherein the or each support which is moveably coupled to the beam member ("moveable support") comprises a main section and a fitting carried by the main section, the fitting being moveably engaged with the beam 15 member for adjustment of the span and able to be detached from the main section whereby the span can be set when the main section is so detached.

4. An apparatus according to claim 3, wherein the beam member extends through the or each fitting. 20

5. An apparatus according to claim 3 or 4, wherein the fitting and main section are configured with at least one pair of aligned cavities, and an elongate joiner is fixedly received by the cavities of the or each pair to hold the fitting and main section together, the or each joiner being releasable to permit separation of the fitting from the main section. 25

6. An apparatus according to claim 5, wherein the or each joiner comprises a bar retained in the cavities of the respective pair. 7, An apparatus according to claim 5 or 6, wherein each joiner is provided with 30 releasable fasteners which extend through external slots in the fitting and main section whereby portions of the fitting and main section are clamped between the joiners and parts -19 of the fasteners. 8, An apparatus according to any one of claims 3 to 7, wherein the or each moveable support is slidably coupled to the beam member. 5

9. An apparatus according to any one of claims 3 to 8, wherein the beam member is configured with at least one slot through which at least one releasable fastener extends to effect clamping between the or each movable support and a portion of the beam member. 10 10. An apparatus according to claim 9, wherein the beam member is configured with at least one axial cavity within which is retained at least one first fastening element of a said fastener, the or each first fastening element being engaged with a respective second fastening element of that fastener which extends through a said slot in the beam member such that portions of the beam member are clamped by the first and second fastening 15 elements.

11. An apparatus according to claim 10, wherein the or each axial cavity is arranged above the track. 20 12. A mobile lifting apparatus comprising a pair of spaced apart supports and a beam member extending between the supports and carried thereby to be supported above a floor surface, the beam member being configured with a track engageable by a trolley such that the trolley can move along the beam member and suspend a load over the floor surface, wherein each support comprises a first section from which the beam member is supported 25 and a second section from which the first section is supported and with which the first section is interengaged via a mechanism for adjusting spacing between the beam member and the floor surface, the mechanism being configured to be coupled to a rotary power tool such that operation of the power tool in opposite rotational directions effects the upward displacement and downward displacement, respectively, of the first section. 30

13. An apparatus according to claim 12, wherein each support is provided with a - 20 respective said mechanism.

14. An apparatus according to claim 12 or claim 13, wherein the or each mechanism includes an input fitting which is complementary to a fitting attached to said power tool 5 whereby it is coupleable to the power tool.

15. An apparatus according to claim 14, wherein the input fitting comprises a hexagonal portion receivable by a socket fitting of said power tool. 10 17. An apparatus according to any one of claims 12 tol4, wherein the or each mechanism comprises members formed with interengaging threads whereby said operation of the power tool effects relative rotation between the members and thereby said displacement, 15 18. An apparatus according to claim 17, wherein the members comprise a threaded rod supported from one section and a threaded sleeve supported from the other.

19. An apparatus according to claim 18, wherein the rod is rotatably supported from said one section but axially fixed with respect to that section and sleeve is fixed with 20 respect to said other section.

20. An apparatus according to claim 19, wherein said rod is rotatably mounted to said one section via bearings at upper and lower ends thereof 25 21. An apparatus according to any one of claims 18 to 20, wherein said one section is said first section.

22. An apparatus according to any one of claims 19 to 21 as appended to claim 14, wherein a said input is provided on the rod at either or each of upper and lower ends of the 30 rod. -21

23. A mobile lifting apparatus comprising a pair of spaced apart supports, a beam member extending between the supports and held thereby to be supported above a floor surface, the beam member being configured with a track engageable by a trolley such that the trolley can move along the beam member and suspend a load over the floor surface, the 5 apparatus comprising sections which are configured with cavities and slots through which the cavities are accessible, and fasteners extending through the slots and into the cavities to be retained by the cavities, thereby effecting clamping of portions of the sections such that the sections are held together, the fasteners being releasable to permit disassembly of the lifting apparatus, 10

24. An apparatus according to claim 23, wherein the sections comprise sections of which the supports are comprised ("support sections").

25. An apparatus according to claim 24, wherein the support sections comprise 15 respective upright sections attached to the beam section via ones of the fasteners and sections which hold the upright sections clear of the floor surface.

26. An apparatus according to claim 25, wherein the sections which hold the upright sections clear of the floor surface comprise base sections each extending transverse to and 20 underlying a respective upright section, whereby the supports have inverted T-shaped configurations in planes perpendicular to the beam section.

27. An apparatus according to claim 26, wherein ground-engaging wheels are attached to opposite ends of the base sections, 25

28. An apparatus according to claim 25, wherein the sections which hold the upright sections clear of the floor surface define pairs of legs, each pair having an inverted V-shaped configuration in a respective plane perpendicular to the beam section. 30 29. An apparatus according to claim 28, wherein ground-engaging wheels are mounted at lower ends of the legs. - 22 30, An apparatus according to claim 28 or 29, wherein the sections defining the pairs of legs are pivotable with respect to respective said upright sections whereby they can assume a retracted condition in which they extend in general alignment with the upright sections. 5 31. An apparatus according to any one of claims 24 to 30, wherein the support sections have identical cross-sectional configurations.

32. An apparatus according to any one of claims 24 to 31, wherein the slots and cavities of the support members are arranged on opposite sides of the support members. 10

33. An apparatus according to any one of claims 24 to 32, wherein ones of said slots and cavities of the support members are arranged adjacent opposite edges of the support members. 15 34. An apparatus according to any one of claims 23 to 33, wherein the sections comprise a section of which the beam member is comprised ("beam section").

35. An apparatus according to any one of claims 23 to 34, wherein the sections comprise lengths of extruded section. 20

36. An apparatus according to any one claims 23 to 35, wherein said fasteners comprise elongate joiners fixedly received by ones of the cavities.

37. An apparatus according to claim 35, wherein the or each joiner comprises a bar. 25

38. An apparatus according to claim 36 or 37, wherein each joiner is provided with releasable fasteners which extend through ones of said slots.

39. An apparatus according to any one of claims 23 to 38, including brackets via which 30 ones of said fasteners connect ones of said sections. -23

40. A kit from which a mobile lifting apparatus according to any one of claims 23 to 38 can be formed, the kit comprising said sections and said fasteners.

41. A kit from which a mobile lifting apparatus according to claim 39 can be formed, 5 the kit comprising said sections, said fasteners and said brackets.

42. An apparatus according to any one of claims I to 39, wherein castors are provided at lower ends of the supports, conferring mobility to the apparatus. 10 43. An apparatus according to any one of claims 1 to 39 and 42, the apparatus including said trolley engaged with the track to be movable along the beam member.

44. An apparatus according to any one of claims I to 39, 42 and 43, being a gantry crane. 15

45. An mobile lifting apparatus substantially as hereinbefore described with reference to the accompanying drawings.