"SHELTER STRUCTURE HAVING OPEN ENDS" This invention relates to a shelter structure having open ends which may be used as a mobile shelter having wheels or in a fixed installation such as shopping malls or covered walkways. Reference may be made to WO 02/01012 as relevant prior art which refers to a mobile shelter structure having a pair of end frames and a canopy frame interconnecting the end frames. There was also provided a plurality of adjustable bracing members interconnecting frame members of the canopy frame. The adjustable bracing members may be tensioned during installation of the shelter structure to stabilise the canopy frame against lateral or transverse forces.

A feature of the above described conventional shelter structure was the provision of end frames which had a base frame which was supported by ground engaging wheels at each end thereof. The base frame also incorporated an undercarriage having ballast tanks which occupied an intermediate part of the base frame between the wheels. Each end frame also included above the base frame opposed pairs of diagonal frame members which extended vertically from the base frame to the canopy frame. Each opposed pair of diagonal members were interconnected by horizontal bracing and angled bracing which strengthened the overall structure of each end frame. However the shelter structure of WO 02/01012 was found to by unduly complicated in structure which made each end frame relatively expensive and time consuming to manufacture.

Reference may also be made to US Patent 5,967,162 which refers to

a mobile shelter having a canopy mounted on a canopy frame which comprises a series of curved rib units that are each connected to a triangular support system which is attached at each end to a truncated A frame support on wheels. While this reference discloses open ends formed by each A frame support it is considered that this mobile shelter would be unstable in strong cross winds and thus would not have the durability or stability of the mobile shelter structure of WO 02/01012.

It has now been found unexpectedly that each end frame of the shelter structure of WO 02/01012 may be modified in a manner wherein at least a substantial part of the stability and durability of the original end frame may be retained but which provides a fundamental advantage of providing an essentially open structure which permits passage or access through each end frame.

The invention therefore provides a shelter structure having: (i) a pair of end frames each bounding an open accessway, and

(ii) a canopy frame interconnecting each of the end frames characterised in that each end frame is provided with a pair of vertical frameworks each comprising a plurality of upright frame members interconnected by one or more bracing members whereby each vertical framework has mounted thereto a ballast tank or is adapted to be embedded in concrete.

There also may be provided opposed pairs of angled support members which interconnect a respective inner upright of each of the vertical

support frameworks and the canopy frame.

More preferably each vertical support framework may comprise four upright frame members so as to provide a cross sectional shape which approximates a square or rectangle. However it will be appreciated that each vertical support framework may have a cross sectional shape approximating a triangle or polygon such as a pentagon, hexagon or octagon.

The bracing members may interconnect each of the upright frame members in the same plane so that for example rectangular bracing may be provided at spaced intervals along the length of the vertical support frameworks when it has four upright frame members. In similar fashion triangular or pentagonal bracing may be provided when each vertical support framework has three or five upright frame members.

Reference may now be made to a referred embodiment of the invention as shown in the attached drawings wherein: FIG 1 is a perspective view of a shelter structure constructed in accordance with the invention which is mobile having ground engaging wheels;

FIG 2 is a similar view to FIG 1 showing a shelter structure which is fixed in the ground; and FIG 3 is a side view of an end frame of the shelter structure shown in

FIG 1.

In the drawings as best shown in FIGS 1 to 2 there is provided a shelter structure 10 having a pair of end frames 11 and a canopy frame 12. Each end frame 11 is provided with an open accessway or archway 13

bounded by a pair of vertical support frameworks 14. In the FIG 1 embodiment each framework 14 is supported by ground engaging wheels 15 each having an associated wheel support 16 attached to an adjacent wheel 16 by axle 16A. Each framework 14 has a pair of opposed upright frame members

17A and a pair of opposed upright frame members 17B which are interconnected by bracing frames 18. There is also provided a hollow box or housing 19 shown in FIG 1 which functions as a ballast tank and which is adapted to be filled with mineral sand or other suitable particulate material which functions as a suitable ballast.

As shown in FIGS 1 to 2 and as best shown in FIG 3 there is also provided a pair of opposed bracing members 20 and 21 located adjacent each top framework 22 of each end frame 11. Each bracing member 20 and 21 is attached to an associated vertical support framework 14 at 23 and to horizontal frame member 28 of each top framework 22 by an angle bracket 26. There is also provided angle support brackets 25 attaching each upright 17B to horizontal frame member 28.

In the FIG 2 embodiment each vertical support framework 14 has a base frame 29 embedded in a concrete block 30 below the ground and thus there is no requirement for ballast tanks 19.

Each base frame 29 may comprise a continuation or extension of upright frame members 17A and 17B interconnected by bracing frames 18 or alternatively each base frame 29 may be of reduced transverse dimensions as shown in FIG 2.

Each top framework 22 includes horizontal frame member 28, vertical frame member 31 and hoop 32. There is also provided corner brackets 33 interconnecting hoops 32 and horizontal frame member 28. There is also shown oblique bracing members 33 and 34 which have been omitted from FIGS 1 to 2 for the sake of clarity and convenience. Also shown are brackets 34A interconnecting hoops 32 and top horizontal rail 40. Also each framework 14 has a substantially vertical upright 17B and a slightly angled vertical upright 17A for the purpose of strength and stability.

Canopy frame 12 as shown in FIGS 1 to 2 includes horizontal rails 35 and hoop assemblies 36 which each include a transverse rail 37, hoop 38 and post 39. There is also provided top horizontal rail 40 and diagonal or oblique bracing struts 41 which interconnect connection points 42 and 44. Connection points or assemblies 42 are located closely adjacent to and below connection point 43 of hoop 38 and horizontal rail 40 and such connection assemblies 42 interconnect post 39, horizontal rail 40 and struts 41. There is also provided connection points 44 of hoop 38, horizontal rail 35 and transverse rail 37. There is also provided horizontal bracing struts 44A which interconnect each alternative connection point 44 as shown. Each bracing strut 44A is located in a horizontal plane as shown and are also attached to connection points 45 between posts 39 and transverse rails 37.

Each end frame 11 also includes top frameworks 22 previously described which may comprise a pair of adjacent hoops 32 and 32A supported by horizontal frame members 28 and 28A interconnected by cross members 46.

It will be appreciated that the structure of the canopy frame 12 is the

same as that described in WO 02/01012 which is therefore incorporated herein by reference. Full detail of connection points 42, 43, 44 and 45 are provided in this reference.

In relevance to the preferred embodiment as described above, it will be appreciated that the shelter structure 10 of the invention has advantages over the prior art described above in that all of the weight of each end frame may be carried by each vertical support framework 14 reinforced by ballast tanks 19 in the case of the FIG 1 embodiment or being embedded in concrete in the case of the FIG 2 embodiment. This is a fundamental advantage over US patent 5,967,162 previously described which was unstable in heavy cross winds because of its lack of ballast and its relatively light structure.

Also canopy frame 12 by virtue of having bracing members 41 and 44 capable of being tensioned to a desired tension also contribute to the overall stability of shelter structure 10 as do frameworks 14 to provide a very stable structure suitable not only for shopping malls and airports but also for golf practice shelters having access passageways 13.