GB2334508A

GB2334508A - Mobile platform assembly

Info

Publication number: GB2334508A
Application number: GB9803910A
Authority: GB
Inventors: Peter Arnall
Original assignee: Lin Pac Mouldings Ltd
Current assignee: Linpac Mouldings Ltd
Priority date: 1998-02-24
Filing date: 1998-02-24
Publication date: 1999-08-25
Anticipated expiration: 2018-02-24
Also published as: GB2334508B; GB9803910D0

Abstract

A mobile platform assembly has a superstructure 2 on a deck 4. The superstructure 2 has side walls 40 and 41 hingedly connected to a rear wall 42. The side walls 40 and 41 are interconnected by a strut 30 which is hinged to be length variable. The rear wall 42 has legs 45 carrying feet 47. The front ends of the side walls have legs 49 carrying feet 50. To assemble the superstructure 2 with the platform 3, the feet 47 are located in seatings on the rear face 51 and with the strut 30 of reduced length the feet 50 and legs 49 are located in seatings 60 in the deck 4. The seatings 60 have cam surfaces (70,Figs 20-23) arranged so that when the strut 30 is straightened, the legs 49 slide over the cam surfaces (70) and displace the superstructure longitudinally relative to the deck 4 to urge the feet 47 into the seatings in the rear face of the platform 3. As the legs 49 slide along the seatings 60 their feet 50 move to underlie the underside face 5 of the platform 3 to firmly retain the superstructure 2 on the platform 3. The strut 30 may be a spring loaded telescopic member which biases the strut to its extended length condition. The superstructure 2 may be a framework which is of triangular shape (Figs 1-13) with the deck 4 and has a crossbar for suspending articles therefrom. The superstructure 2 may be collapsible into a compact condition for storage or transportation. The seatings may be key-hole shaped (22, Figs 1 and 8).

Description

TITLE "A mobile platform assembly" TECHNICAL FIELD & BACKGROUND ART The present invention relates to a mobile platform assembly of the kind having a mobile platform which carries a superstructure such as wall members, a collar or a framework which may provide a container or enclosure on the mobile platform or more simply a structure from which articles may be suspended for carriage on the platform.

It is well known to provide a superstructure on a mobile platform (sometimes known as a dolly) as aforementioned, usually for providing upstanding side walls or a collar which serves as a container or enclosure for retaining goods for storage or transport on the platform.

It is most desirable that the superstructure when in use is firmly retained on the mobile platform and yet may be removed from the platform when not in use for convenience of storage or transportation. It is an object of the present invention to provide a mobile platform assembly in which a superstructure thereof may simply and conveniently be firmly secured to the platform and which assembly lends itself to providing a quick, convenient and inexpensive means for removing the superstructure from the platform.

STATEMENT OF INVENTION & ADVANTAGES According to the present invention there is provided a mobile platform assembly comprising a superstructure removably mounted on a mobile platform, said superstructure having lower parts which feet thereon cooperating with the platform, and wherein displacement means is provided on the superstructure for displacing the lower parts relative to each other to thereby displace the feet relative to the platform and into an engaged condition in which the feet firmly retain the superstructure on the platform.

Usually the superstructure will have two lower parts which extend longitudinally and are laterally opposed and spaced and the displacement means acts to displace the two lower parts laterally relative to each other to cause the feet on the lower parts to be displaced into their engaged conditions. By the present invention it is envisaged that the superstructure will be fitted to the mobile platform initially with the feet on the lower parts of the superstructure cooperating with seatings or regions in the platform and thereafter actuating or adjusting the displacement means to cause the feet to be displaced relative to the platform and the respective seatings or regions until the feet attain respective engaged conditions in which the superstructure is securely retained on the platform.

The displacement means will usually act on the lower parts of the superstructure to displace those lower parts in a direction away from each other to cause the feet to move into their engaged conditions on the platform.

However it will be appreciated that structures are envisaged in which the displacement means on the superstructure acts to displace the lower parts of the superstructure relatively towards each other to cause the feet to move into their engaged conditions on the mobile platform.

Typically the two laterally opposed and spaced lower parts of the superstructure as aforementioned will be parallel with each other and arranged so that they can be fitted to a conventional rectangular deck of a mobile platform with the lower parts extending along opposed side edges of the rectangular deck.

In a preferred embodiment of the platform assembly where the lower parts of the superstructure extend longitudinally and are laterally opposed, those lower parts may have first feet and second feet which cooperate with respective seatings or regions in the platform and during lateral displacement of the lower parts relative to each other, the first feet are displaced laterally in their respective seatings or regions and over cam surfaces on the platform to their respective engaged condition and displacement of the first feet over the cam surfaces causes the lower parts to be displaced longitudinally relative to the platform and this longitudinal. displacement causes the second feet to move into firm engagement with their respective seatings or regions for those second feet to additionally securely retain the superstructure on the platform. Usually some, if not all, of the seatings or regions will be located in the or a deck of the mobile platform. Also some, if not all, of the seatings may be located in a side face of the mobile platform. With a conventional mobile platform the platform will have a substantial thickness to provide a load bearing upper surface or deck to the underside of which platform castored and/or non-castored wheels (or other forms of rollers) may be fitted to provide the required mobility; consequently the side face of the platform may have adequate depth in which to locate seatings or regions for receiving the feet.

Usually however, some if not all of the seatings or regions will be located in the deck. The regions or seatings may be in the form of recesses in the deck or in a side face of the platform within which the feet are received but usually the seatings or regions will be in the form of apertures in the deck or in a side face of the platform within which the feet are received, in each case so that the feet can be displaced into their engaged conditions where they underlie a part of the platform and are thereby prevented from being withdrawn from the apertures or recesses. With the feet engaging with apertures or recesses in the platform as aforementioned, side edges of the apertures or recesses may be shaped or angled to provide the previously mentioned cam surfaces over which the feet (or legs on which the feet may be carried by the superstructure) can slide as the displacement means moves the feet into their engaged conditions so that the sliding movement of the feet/legs over the cam surfaces displaces the superstructure longitudinally relative to the platform as the lower parts of the superstructure are displaced by the displacement means laterally relative to each other. Conveniently a rigid leg on the superstructure with a foot thereon is of generally L-shape with the leg of that shape upstanding whilst an aperture or recess for that foot in the or a deck of the platform is of generally L-shape so that the foot can pass initially through a first limb of the L-shaped aperture or recess and thereafter the leg may be displaced by the displacement means along the second limb of the Lshaped aperture to the engaged condition in which the foot underlies part of the platform. The aforementioned second limb of the aperture is conveniently profiled and angled in the platform deck to provide a previously described cam surface for displacing the superstructure longitudinally relative to the platform. In a further embodiment a foot is carried on a rigid leg of the superstructure to present a generally inverted mushroom shape. The aperture or recess which receives this latter leg and foot may be of generally keyhole shape to provide a broad aperture section and a narrow aperture section (which extends from the broad section) so that the foot may pass initially through the broad aperture section and the leg may thereafter be displaced along the narrow aperture section to its engaged condition in which the foot underlies a part of the deck. The narrow aperture section of the keyhole shaped aperture or recess in the deck of the platform may be profiled and angled in that deck to present the aforementioned cam surface which causes the superstructure to be displaced longitudinally relative to the platform as the leg which extends into that aperture or recess is displaced laterally by the displacement means.

Preferably the superstructure has opposed side walls having the lower parts with the feet thereon and a rear wall interconnecting the side walls to present with the deck of the platform an upstanding container or enclosure.

The rear wall may be hingedly connected to the side walls at upstanding corners of the enclosure or container to permit the superstructure, when removed from the mobile platform, to be collapsed into a generally flat pack for convenience of transport or storage.

The superstructure when fitted to a mobile platform having a rectangular deck will usually provide a generally parallelopipedon shaped container or enclosure. In another embodiment the superstructure may have two opposed upstanding side walls or subframes having the lower parts with feet thereon and which side walls or subframes are hingedly connected at upper parts thereof for pivotal displacement relative to each other about a substantially horizontal axis. This superstructure may include a rail which extends along the aforementioned horizontal axis and which rail may be convenient for suspending articles such as clothes hangers from the superstructure. The two opposed upstanding side walls or subframes are not necessarily hinged together at their upper parts.

Preferably the two opposed upstanding side walls or subframes are hingedly connected together at their upper parts along the horizontal axis for the superstructure to form with the platform a shape of generally triangular section.

The superstructure, particularly when providing an enclosure or container, may have upstanding side walls which are of an open framework, a mesh or a closed panellike structure.

The displacement means is preferably in the form of a length variable strut (length variable in the sense of variations in the rectilinear distance between opposite ends of the strut). In one arrangement the strut is spring loaded, for example as a telescopic structure, to be biased to an extended or a contracted length condition for biasing the feet of the superstructure into the engaged condition with the mobile platform (depending upon whether that engaged condition is achieved by displacing the lower parts of the platform relatively away from each other or relatively towards each other respectively). In a further arrangement the length variable strut has strut parts or links which are hingedly connected together and is length variable by pivotting the strut parts or links relatively to each other about their hinged connections to straighten the strut and displace the opposite ends thereof relatively away from each other, thereby causing displacement of the lower parts of the superstructure away from each other as the feet are displaced into their engaged condition.

DRAWINGS Embodiments of mobile platform assemblies constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 is a perspective view of a first embodiment of the assembly in which the superstructure and mobile platform present a shape of triangular section; Figure 2 is a side view of the assembly in Figure 1; Figure 3 is an end view of the assembly in Figure 1; Figure 4 is an end view of the superstructure of Figure 1 removed from the platform assembly and in a collapsed condition; Figure 5 is a perspective view of part of the superstructure in Figure 4 which part includes a leg with a foot thereon; Figure 6 is a section taken on the line VI - VI of Figure 5; Figure 7 is a plan view of the part shown in Figure 5; Figure 8 is a plan view of a seating in the deck of the mobile platform in the embodiment of Figure 1; Figure 9 is a section of the seating taken on the line IX - IX of Figure 8; Figure 10 is an end elevation of the superstructure shown in Figure 4 illustrating that superstructure being fitted to the mobile platform; Figure 11 is a similar view to that shown in Figure 10 and illustrates the displacement means on the superstructure being adjusted to displace the feet of the superstructure into their engaged condition; Figure 12 is a similar view to that shown in Figure 11 and illustrates the displacement means fitted to its operative position in which it biases the feet into their engaged condition; Figure 13 shows a lower part of the superstructure and displacement means with the displacement means being in section to show a spring biasing arrangement thereof; Figure 14 shows a modification to the embodiment of Figure 1 where the displacement means is in the form of a hinged strut rather than a spring biased strut; Figure 15 is a perspective view of a second embodiment of the platform assembly in which the superstructure provides a generally parallelopipedon enclosure; Figure 16 is a plan view of the assembly shown in Figure 15; Figure 17 is a perspective view of the superstructure of the assembly shown in Figure 15 and which superstructure is partly collapsed for convenience of storage or transport; Figure 18 is a perspective view of the assembly in Figure 15 showing the superstructure positioned for fitting to the mobile platform; Figure 18A shows a detail of the mobile platform in Figure 18, in particular a seating in a side wall of that platform; Figure 18B shows a detail of the mobile platform shown in Figure 18, in particular a seating in the deck of the platform; Figure 19 is a side view of the embodiment shown in Figure 15 and illustrates initial engagement between the superstructure and mobile platform as that superstructure is fitted to the platform; Figure 20 is a plan view of part of the assembly in Figure 18 and illustrates a foot of the superstructure positioned for fitting to its seating in the deck of the mobile platform; Figure 21 is a plan view of the underside of the platform in Figure 20 and shows the foot engaging with its seating; Figure 22 is a perspective view of the assembly in the embodiment of Figure 15 and shows the feet of the superstructure engaging with their respective seatings and the displacement means set for being adjusted to displace the feet into their engaged conditions; Figure 23 is a similar view to that shown in Figure 21 and illustrates the foot having been displaced into its engaged condition, and Figure 24 is a plan view of the assembly shown in Figure 22 and illustrates the manner in which the superstructure is displaced relative to the mobile platform as the displacement means displaces the feet of the superstructure into their engaged conditions.

DETAILED DESCRIPTION OF DRAWINGS The mobile platform assembly shown in Figure 1 has a mobile platform 1 on a platform 3 of which is carried a superstructure framework 2. The platform 3 has a flat rectangular upper face or deck 4 on which the superstructure 2 is mounted. Secured to the underside face 5 of the platform 3 adjacent to each corner thereof are a pair of ground engaging castored wheels 6 and a pair of ground engaging non-castored wheels 7 as are conventional for dollies. A front side face 8 of the deck is provided with sockets 9 to which may be fitted a handle (not shown) for manoeuvring the assembly.

The frame of the superstructure 2 comprises two substantially identical generally U-shaped side or subframes 11 and IlA which have lower rods or bars 13 and 13A respectively and parallel upstanding rods or bars 14 and 15, and 14A and 15A respectively. The lower rods 13 and 13A are parallel. The upper ends of the rods 14A and 15 and the upper ends of the rods 14 and 15A respectively are hingedly connected for pivotal movement about an axis 17 which is horizontal when the deck 4 of the platform is horizontal. Extending along the horizontal axis 17 between the upper ends of the "A" frames formed by the rods 14A and 15 and the rods 14 and 15A respectively is a horizontal crossbow or rod 18 which permits the U-frames 11 and llA to pivot relative to each other. The crossbar 18 conveniently provides a support from which articles such as clothes hangers may be suspended for display or transportation.

Extending downwardly on each of the lower rods 13 and 13A and rigid therewith are a pair of rigid legs 20 and 20A respectively at the lower ends of which are circular profiled feet 21 so that each leg 20 or 20A with its foot 21 resembles an inverted mushroom shape as shown in Figures 5 to 7. Located in the upper surface 4 of the platform 3 are four keyhole shaped apertures 22 positioned one pair adjacent to each of two parallel side edges of the surface 4. Each keyhole shaped aperture has a large diameter part circular section 22A from which extends a narrow section 22B. The apertures 22 extend throughout the thickness of the platform 3 (as indicated in Figure 9) and each aperture 22 is positioned adjacent to its adjacent side edge of the deck 4 so that its narrow section 22B extends generally perpendicularly relative to that side edge of the deck 4 and is disposed between that adjacent side edge and the large diameter part circular section 22A.

Pivotally mounted at 24 at an end of the lower bar 13 adjacent to the bottom end of the bar 15 is one end of a length variable strut 25. The strut 25 comprises two telescopic members 26 and 27 (see Figure 13) which are spring loaded relative to each other by a coil spring 28 so that the members 26 and 27 are biased to an extended length condition of the strut 25. Positioned adjacent to the junction between the bars 14A and 13A is a cup 88 which is intended to receive the end of the strut 25 remote from its pivotal mounting 24. A similar length variable strut 25A formed with spring loaded sections 26 and 27 is pivotally mounted at 24A adjacent to the junction between the lower bar 13A and bar 15A of the frame section llA whilst a cup 88A is provided adjacent to the junction between the lower bar 13 and bar 14 of the subframe 11. The cup 88A is to receive the end of the strut 25A remote from its pivotal mounting 24A.

When not in use the superstructure 2 will usually be stored in a collapsed condition as a relatively flat pack where the struts 25 and 25A are pivotted to an upstanding condition in which they lie alongside the respective upstanding bars 15 and 15A of the frames on which they are mounted (for convenience, only a single strut 25 has been shown in Figures 4 and 10 to 12) and the subframes 11 and llA are pivotted about the axis 17 to closely overlie each other as shown in Figure 4. When the superstructure 2 is to be fitted to the mobile platform 1, the subframes 11 and llA are pivotted relative to each other about the axis 17 to a splayed condition (as shown in Figure 10) where the feet 21 on the respective legs 20 and 20A overlie and coincide one with each of the part circular sections 22A of the four keyhole apertures 22 in the deck 4. In this latter condition the circular feet 21 are concentric with the respective part circular section 22A of the aperture 22 and have a diameter slightly less than that part circular section. The superstructure 2 is now lowered towards the mobile platform 1 so that the feet 21 enter the part circular sections 22A of the keyhole apertures 22 and each foot 21 together with the leg 20 or 20A on which the foot is carried extends through the thickness of the platform 3 as indicated by the broken lines 20 (20A) in Figure 9.

With the legs 20 and 20A with their feet 21 accommodated in seatings provided by the aperture sections 22A, the struts 25 and 25A are lowered by rotation about their pivots 24 and 24A respectively whilst the telescopic members 26 and 27 are displaced manually relative to each other against the biasing of spring 28 to temporarily shorten or contract the respective strut 25 and 25A (see Figure 11). Whilst the respective strut is contracted, the end of that strut remote from its pivot 24 or 24A is located within the respective cup 88 or 88A as appropriate (as shown in Figure 12). Thereafter the strut is permitted to increase its length under the biasing of spring 28 to urge the lower rods 13 and 13A laterally away from each other by pivotal movement of the U-shaped frames 11 and llA about the axis 17. This pivotal movement of the subframes 11 and llA under the biasing of spring 28 in each of the struts causes the legs 20 and 20A to be displaced from the large diameter part circular sections of the keyhole apertures into and along the narrow sections 22B of the keyhole apertures and into an engaged condition as shown at 20'(20A') in Figure 9. In this engaged condition each foot 21' is displaced to a position in which at least a part of the foot underlies a downwardly directed face of the platform 3; in Figure 9 it will be seen that in the engaged condition part of the foot 21' underlies the underside face 5 of the platform 3. The feet 21 in the engaged condition thus prevent the superstructure 2 from being lifted off the deck 4 of the platform 3 so that the feet firmly retain the superstructure on the platform. It will be appreciated that this latter retention is maintained by the biasing springs 28 in the respective struts 25 and 25A.

To disengage the superstructure 2 from the mobile platform 1 it is simply necessary to reduce the length of the struts by compressing the telescopic sections 27 against the respective biasing strings until the ends of the struts clear the cups 88, 88A to pivot the struts upwardly clear of the cups 88, 88A and thereafter to pivot the U-shaped frames 11 and llA about the axis 17 so that the legs 13, 13A move into the part circular sections 22A of the respective keyhole apertures 22 following which the superstructure as a whole may be lifted from the platform 5 to withdraw the legs 20 and 20A with their respective feet 21 from the keyhole apertures 22 and clear of the deck.

In the modification shown in Figure 14 the spring loaded struts 25 and 25A are replaced by a single hinged strut or linkage 30 comprising two rigid links 31 and 32 which are hingedly connected together at 33. The end of the link 31 remote from the hinge 33 is hingedly connected at 34 to the lower bar 13 whilst the end of the link 32 remote from the hinge 33 is hingedly connected at 35 to the lower bar 13A. When the superstructure 2 is removed from the mobile platform 1, the strut 30 may be adjusted to decrease its length or the spacing between the hinges 34 and 35 by folding the links 31 and 32 about the hinge 33 as the hinge 33 approaches the cross bar 18. In a fully folded or collapsed condition of the superstructure, the links 31 and 32 may closely overlie and oppose each other so that the U-shaped frames 11 and llA pivot to a compact or collapsed condition in which they closely overlie each other for storage or transport purposes. To fit the superstructure to the mobile platform it is merely necessary to pivot the links 31 and 32 by displacement of the hinge 33 away from the crossbar 18 until the U-shaped frames are sufficiently splayed to locate the respective feet 21 over the part circular sections 22A of the keyhole apertures 22 for the feet and legs to be lowered through the keyhole apertures as previously described. With the feet and legs in the position shown at 20 and 20A of Figure 9, the strut 30 is extended to a straight condition by displacing the hinge 33 fully away from the crossbar 18 so that the strut 30 bears against the deck 4 of the platform 3. This latter displacement causes the legs and feet to be displaced along their respective keyhole apertures to the engaged condition (shown at 20' 20A' and 21' in Figure 9).

The links 31 and 32 may be pivotted about the hinge 33 through a dead centre condition which alleviates the likelihood of the strut being inadvertently decreased in length by accidentally displacing the hinge 33 towards the crossbar 18 (as will be required for intentionally disengaging the feet from their engaged conditions). The strut 30 is conveniently adjusted to its maximum length condition consistent with the feet being displaced into their engaged condition by an operative applying pressure by foot onto the strut 30. It will be noted that in the condition in which the strut 30 retains the feet in their engaged conditions, it is located adjacent to the upper surface 4 generally unobtrusively. It will be appreciated that the modification shown in Figure 14 may have two or more of the struts 30 longitudinally spaced to extend between the lower bars 13 and 13A whilst the embodiment shown in Figure 1 may have a single centrally disposed strut 25 engaging between the lower bars 13 and 13A.

In the embodiment of Figures 15 to 24 the superstructure 2 of the pallet assembly forms with the deck 4 of the platform 3 an open fronted, open topped enclosure or container of generally parallelopipedon shape having laterally spaced, longitudinally extending and parallel rectangular side walls 40 and 41 extending upwardly at right angles to the deck 4 and a laterally extending rectangular rear wall 42 also extending perpendicularly from the deck 4 and interconnecting the rear of side walls 40 and 41. The rear wall 42 is formed by rectangular wall parts 42A and 42B which are interconnected by hinges 43 (see Figure 22) for those wall parts to exhibit pivotal movement relative to each other about an upstanding axis.

Also the rear wall part 42A is connected by hinges 44 to the rear end of the side wall 41 so that side wall is capable of pivotting about an upstanding axis relative to the rear wall part 42A. Similarly the rear wall part 42B is connected by hinges 45 to the rear end of the side wall 40 so that that side wall can pivot about an upstanding axis relative to the rear wall part 42B. In the drawings, the side walls 40 and 41 and end wall 42 are shown as open framework structures formed by rectangular frames closed by a mesh so that the superstructure 2 is in the form of a cage. It will be realised however that the side walls and end wall parts can have other structures such as a solid or fully closed appearance as presented by panels.

The side walls 40 and 41 have lower parts adjacent to the deck 4 in the form of longitudinally extending bars 40A and 41A respectively which are interconnected at a front end of the superstructure by a variable length strut 30 which is similar to that previously described with reference to Figure 14 and has the links 31 and 32 connected together by a hinge 33 and hinge 34 which connects link 31 to the bar 41A and hinge 35 which connects the link 32 to the bar 40A.

With the superstructure 2 of Figure 15 removed from the mobile platform 1, it can be collapsed into a substantially flat pack convenient for transport or storage by folding the rear wall parts 42A and 42B inwardly of the opposed side walls by pivotal movement about the hinges 43, 44 and 45 and reducing the effective length of the strut 30 by folding that strut about its hinges 33, 34 and 35 inwardly of the opposed side walls 40 and 41 as shown in Figure 17. The folding of the rear wall 42 and strut 30 as aforementioned has the effect of displacing the side walls 40 and 41 towards each other into the compact condition where the spacing between the side walls is approximately that of the thickness presented by the overlying rear wall parts 42A and 42B.

Extending downwardly and rigidly from a lower part of the rear wall 42 are a pair of rigid legs 45 located one each on a bottom bar 46 on each of the rear wall parts 42A and 42B (see Figure 18). The bottom ends of the legs 45 are provided with forwardly directed blocks or feet 47 so that each leg 45 with its foot 47 presents a generally Lshape. Provided one on each of the front ends of the lower bars 40A and 41A of the opposed side walls and extending downwardly therefrom are a pair of rigid legs 49 at the bottom ends of which are provided plate-like feet 50 so that each leg 49 and its foot 50 presents a generally Lshape.

The platform 3 has a rear side face 51 located in which are a pair of laterally spaced seatings 53 (see Figures 18A and 22). Each seating 53 has a shallow upper part 54 and a deeper lower part 55, the shape of which parts correspond to that of the leg 45 and the foot 47 respectively. When the rear wall 42 is straight, the lateral spacing between the pair of legs 45/feet 47 corresponds to that between the pair of seatings 53 on the rear face 51 of the platform 3.

Located in the deck 4 of the platform 3, one adjacent to each of front corners of the deck 4 are a pair of apertures 60 which extend through the thickness of the platform 3. Each aperture 60 is of generally L-shape, one limb of which shape presents a relatively broad section 61 located inwardly of the deck 4 and the other limb of which provides a relatively narrow outer section 62 which extends at an acute angle, typically 45 , relative to the side edges of the deck 4 (see Figures 18B and 20 to 23). Typically the narrow section 62 of each aperture 60 will extend towards the front corner of the deck surface 4 to which that aperture is adjacent.

The apertures 60 provide seatings which are to receive, one each, a leg 49 with its foot 50.

The superstructure 2 is fitted to the mobile platform 1 from the condition of the superstructure shown in Figure 18 (that is with the rear wall 42 straight and the variable length strut 30 cranked to a reduced length) and lowering the rear of the superstructure so that the legs 45 and the feet 47 which they carry are received one each in the two seatings 53 on the rear side face 51 of the platform 3 (as shown in Figure 19). The front end of the superstructure 2 is now lowered so that the two feet 50 at that front end are accommodated one in each of the broader sections 61 of the seatings 60 (see Figures 20, 21 and 22). It will be noted from Figures 20 and 21 that each foot 50 is angled to correspond with angling of the broad section 61 of the aperture 60. It will be appreciated that whilst Figures 20, 21 and 23 show the arrangement for a foot 50 and ape accommodated in the broader sections 61 of the apertures 60, the side walls 40 and 41 bear on the deck 4 whilst the legs 49 extends through the apertures 60 so that the feet 50 are located in a plane below that of the underside face 5 of the platform 3. Furthermore, the strut 30 remains cranked as shown in Figure 22 to a reduced length condition consistent with the location of the feet 50 within the broad section parts 61 of the apertures 60. The strut 30 is now straightened to increase its effective length as shown in Figure 15 (conveniently by an operative standing on the hinge 33). The effect of straightening the strut 30 displaces the legs 49 laterally away from each other in the direction of arrow 69 (see Figure 20) so that the legs 49 move into sliding engagement with a cam surface 70 presented by an outer side edge of the aperture 60 within which the respective leg 49 is received. As the strut 30 is progressively straightened the legs 49 are driven along the narrow sections 62 of the respective apertures 60 and over the cam surface 70 for those legs to move diagonally (typically at 45 ) relative to the edges of the deck 4 as indicated by the arrow 71 in Figures 20 and 21. During this latter displacement of the legs 49 their feet 50 slide beneath the underside face 5 of the platform 3 as shown in Figure 23 so that abutment between the feet 50 and the underside face 5 prevents the legs and feet from being lifted from the respective seatings 60 in which they are received. Furthermore, as the strut 30 is straightened as aforementioned to displace the feet 50 into an engaged condition as shown in Figure 23, the sliding movement of the legs 49 over the respective cam surfaces 70 causes the superstructure 2 to be subjected to a longitudinally directed force in the direction of arrow 72 in Figure 20 so that the superstructure is displaced longitudinally relative to the deck 4. This latter displacement of the superstructure drives the rear legs 45 and the feet 51 into firm engagement with their respective seatings 53 in the rear face 51 of the deck 3. More particularly, when the front feet 50 are fully engaged with their respective seating 60 as shown in Figure 23, the rear legs 45 are firmly accommodated in the shallow recess section 54 of the respective seatings 53 whilst the rear feet 47 are firmly accommodated within the deeper recesses 55 of those respective seatings 53 so that the superstructure is firmly retained on the platform deck 4. Preferably the strut 30 in its extended condition is located unobtrusively adjacent to the deck 4 but also so that as the strut is straightened to its maximum length extent, its hinges 33, 34 and 35 permit the links 31 and 32 to be pivotted slightly through a central condition (where the hinge 33 to lie below the level of the hinges 34 and 35) so that the strut is locked to alleviate the likelihood of the hinge 33 being accidentally raised (thereby permitting the legs 49 to move from the narrow sections of the apertures 16 and into the broad sections 61 of those apertures where the legs and feet can be lifted out of the seatings 60 and the superstructure 2 removed from the mobile platform 1).

It will be appreciated that the strut 30 may be replaced by a spring loaded strut similar to that shown and described with reference to Figure 13. Also the legs 49, feet 50 and seatings 60 in the embodiment of Figure 15 can be replaced by the legs 20, feet 21 and seating 22 in the embodiment of Figure 1 (with the narrow section 22 corresponding in angle to the limb 62).

Conveniently the deck 4 of the platform 3 is provided with four recessed regions 80 which are located one to overlie each of the wheels 6 and 7. These recessed regions 80 are arranged so that several mobile platforms 1 (with their superstructures 2 removed) can be stacked vertically one above another with the wheels 6 and 7 of an upper platform in the stack being received, one each, in the recessed regions 80 of the immediately underlying mobile platform in the stack. The engagement of the wheels in the respective recessed regions 80 alleviates the wheels from running over the immediately underlying deck 4 to provide a stable stack.

The embodiment of Figure 15 may have a front wall hinged to the side wall 40 and connectable to the side wall 41 to provide an open topped enclosure.

Claims

CLAIMS 1. A mobile platform assembly comprising a superstructure removably mounted on a mobile platform, said superstructure having lower parts with feet thereon cooperating with the platform, and wherein displacement means is provided on the superstructure for displacing the lower parts relative to each other to thereby displace the feet relative to the platform and into an engaged condition in which the feet firmly retain the superstructure on the platform.
2. An assembly as claimed in claim 1 and comprising two said lower parts which extend longitudinally and are substantially laterally opposed and said displacement means displaces the lower parts laterally relative to each other for the feet to move into the engaged condition.
3. An assembly as claimed in claim 2 in which the displacement means displaces the lower parts laterally away from each other for the feet to move into said engaged condition.
4. An assembly as claimed in either claim 2 or claim 3 in which said two lower parts are substantially parallel.
5. An assembly as claimed in any one of claims 2 to 4 in which the feet on the lower parts of the superstructure comprise first feet and said superstructure has second feet which cooperate with respective seatings in the platform and wherein during lateral displacement of the lower parts relative to each other, said first feet are displaced laterally over cam surfaces on the platform to said engaged condition and said displacement of the first feet over the cam surfaces displaces the superstructure longitudinally relative to the platform to displace the second feet into firm engagement with their respective seatings.
6. An assembly as claimed in any one of the preceding claims in which the feet are located in seatings in a deck or upper face of the platform and are displaced in those seatings to the engaged condition.
7. An assembly as claimed in any one of the preceding claims in which the feet are located in seatings in a side wall or face of the platform and are displaced in those seatings to an engaged condition.
8. An assembly as claimed in any one of the preceding claims in which the feet are carried on legs of the superstructure.
9. An assembly as claimed in claim 8 when appendant to claim 6 in which the seatings comprise apertures or recesses in the deck into which the legs extend for the feet to be displaced into the engaged condition where they underlie a part of the platform.
10. An assembly as claimed in claim 9 in which a leg with a foot thereon is of substantially L-shape and the aperture or recess which receives that leg and foot is of substantially L-shape for the foot to pass initially through a first limb of said L-shape and thereafter the leg can be displaced along the second limb of said L-shape to said engaged condition.
11. An assembly as claimed in claim 10 when appendant to claim 5 in which the said second limb of the L-shaped aperture comprises a said cam surface.
12. An assembly as claimed in any one of claims 9 to 11 in which a leg with a foot thereon is of substantially an inverted mushroom shape and the aperture which receives that leg and foot is of substantially keyhole shape to provide a broad aperture section and a narrow aperture section extending from said broad section whereby the foot can pass initially through the broad aperture section and thereafter the leg can be displaced along the narrow aperture section to said engaged condition.
13. An assembly as claimed in claim 12 when appendant to claim 5 in which said narrow aperture section comprises said cam surface.
14. An assembly as claimed in any one of the preceding claims in which the superstructure comprises opposed side walls having said lower parts and a rear wall interconnecting said side walls to provide with the or a deck of the platform an upstanding container or enclosure.
15. An assembly as claimed in claim 14 in which the rear wall is hingedly connected to the side walls at upstanding corners of the container.
16. An assembly as claimed in claim 15 in which the rear wall comprises at least two rear wall parts which are hingedly connected together to each other along upstanding hinge lines substantially parallel with said upstanding corners to permit the superstructure to be collapsed into a compact condition when that superstructure is removed from the platform.
17. An assembly as claimed in any one of claims 14 to 16 in which the superstructure comprises a hinged front wall interconnecting the side walls to provide an open topped enclosure on the deck.
18. An assembly as claimed in any one of claims 14 to 17 in which the walls of the superstructure when removed from the mobile platform are adjustable by pivotal movement along respective hinged connections to a substantially compact condition for convenience of storage or transportation.
19. An assembly as claimed in any one of claims 14 to 18 in which the superstructure and the or a deck of the platform provide a substantially parallelopipedon shaped container or enclosure.
20. An assembly as claimed in any one of claims 1 to 13 in which the superstructure comprises two opposed upstanding side walls or subframes having said lower parts and which side walls are hinged at upper parts thereof for pivotal displacement relative to each other about a substantially horizontal axis.
21. An assembly as claimed in claim 20 in which the superstructure includes a crossbar along said substantially horizontal axis.
22. An assembly as claimed in either claim 20 or claim 21 in which the opposed side walls are hinged connected together along said horizontal axis for the superstructure to form with the platform a substantially triangular section shape.
23. An assembly as claimed in any one of claims 14 to 22 in which the walls are of substantially an open framework a mesh or a closed panel-like structure.
24. An assembly as claimed in any one of the preceding claims in which the displacement means comprises a length variable strut.
25. An assembly as claimed in claim 24 in which the strut is spring loaded to be biased to a condition in which the feet are biased into said engaged condition.
26. An assembly as claimed in claim 25 in which the strut comprises telescopic members spring biased relative to each other to be biased to an extended length condition.
27. An assembly as claimed in claim 24 in which the strut comprises parts or links hingedly connected together and is length variable by pivotting the links relative to each other.
28. An assembly as claimed in any one of claims 24 to 27 when appendant to claim 14 in which the strut is pivotally mounted at one end thereof to one said side wall having a said lower part and is pivotally mounted or removably connected at its opposite end to another side wall having a further said lower part so that displacement of the lower parts to displace the feet thereon into the engaged condition causes said side walls to be displaced relative to each other.
29. A mobile platform assembly substantially as herein described with reference to the accompanying illustrative drawings.