"DEMOUNTABLE STRUCTURE" — BACKGROUND OF THE INVENTION — This invention relates to a demountable structure. This invention has particular but not exclusive application to a structure for use as a sun shade and for illustrative purposes reference will be made to such application. However, it is to be understood that this invention could be used in other applications such as for temporary accommodation. Various types of sun shades are available including umbrella shades which are particularly attractive as well as being easily collapsible and portable. Furthermore they can be aesthetically pleasing and thus are often used in home gardens and for covering commercial eating and relaxing outdoor areas.

Umbrella type shade structures are often used as semi¬ permanent structures having a significant span such as between four to six metres. The cloth or fabric that covers the frame of the shade structure deteriorates from the effects of rain, wind and sun and accordingly, such structures are capable of being folded to minimise exposure to the elements. The presently utilised folding mechanisms are often cumbersome and difficult to operate.

A further disadvantage of currently available umbrella shades results from the centrally located support shaft. This reduces the available usable area covered by the umbrella. Accordingly, tables, chairs, bodies etc must be arranged to about the central support shaft. Furthermore because the shaded area is constantly moving between sunrise and sunset, any articles protected beneath the umbrella must be shifted if continuous sun protection is required, or the position of the shade canopy must be adjusted. This is difficult to achieve in large structures.

— SUMMARY OF THE INVENTION — The present invention aims to alleviate at least one of the above disadvantages and to provide a sun shade which will

be reliable and efficient in use.

With the foregoing in view this invention in one aspect resides broadly in a sun shade assembly including:- shade means, and support means having a mounting base and an upstanding support structure supporting said shade means offset from said support structure, and transfer means for transferring the operative position of the shade means. The transfer means may allow for the transfer of the shade means from one position to another such as for example enabling the support structure to tilt about the mounting base or it may allow the support means to move laterally along a laterally adjustable mounting base assembly. Preferably however the transfer means permits the shade means to be moved substantially orbitally about said mounting base. For this purpose the support structure may extend upwardly beneath the shade structure but preferably it is offset to one side of and spaced from the shade means whereby it extend up and over the shade means so as to support it from above. The transfer means may include transfer locking means to lock the support structure in a selected position upon movement of the shade means to the selected position.

The shade means may be a permanent assembly, constructed as a rigid fibreglass structure for example, or it may be an umbrella type structure which may be selectively folded or erected. Alternatively it may be a blind type assembly having a fabric cover which may be extended from a stowed position, suitably adjacent the support structure to a shading position extending away from the support structure. The shade means may include a frame and a cover and the frame means may be rigid or demountable. The cover may be canvas, vinyl, or other fabric or flexible sheet material and suitably formed so as to at least partially inhibit the passage of rain and sun or UV rays therethrough.

The support structure may be a rigid structure or it may

be collapsible. For example it may be constructed of connectable segments which may include telescoping portions permitting ready break down into component parts. The support structure may further include erecting means for erecting and collapsing of the shade means. The erecting means may be a lever connected directly to the shade means so as to act in a manner wherein the shade means may be moved from a stowed position to an erected position.

Preferably the erecting means includes a winch including a winch handle or some other operative member, located either internally or externally of the support structure and suitably connected to the shade means by a winch line or a flexible drive associated with a folding mechanism operable to perform the required folding and unfolding of the shade means. Alternatively, the erecting means may include an electrically operated mechanism with a motor located at the supporting end of the support structure and connected to the folding mechanism. Preferably the folding mechanism is located above the shade means whereby it is not visible from below when in the erected attitude.

The sun shade assembly may further include secondary stabilising means connected between the shade means and the support means for providing further stability against the driving force of wind and rain and it may also include secondary stabilising means connected between the periphery of the shade means and the ground or some other structure to help protect the shade means in severe weather conditions. In another aspect this invention resides broadly in a sun shade assembly including:- shade means; a support structure extending above the shade means; support arms for supporting the shade means and connected pivotally at their inner ends to the support structure and adapted to be elevated from a folded attitude, depending from the support structure, to an operative outwardly extending attitude by cables passing from the

support arms upwardly into the support structure for retraction into said support structure. Preferably the cables are retracted by a winch assembly. It is also preferred that the support arms each include spreader means maintaining an operative divergence between the respective cables and the arms, and wherein the spreader means extend outwardly in the collapsed attitude and upwardly in the operative attitude and the connection of the cables to the spreader arms is adjacent the position the cables extend into the support structure when the spreader means are in their operative attitudes.

— BRIEF DESCRIPTION OF THE DRAWINGS — In order that this invention may be more readily understood and put into practical effect reference will now be made to the accompanying drawings which illustrate typical embodiments of the invention and wherein:

Fig. 1 is a side view of a sun shade assembly constructed in accordance with the present invention with the shade means in the erected position; Fig. 2 is an assembly view of a sun shade assembly constructed in accordance with the present invention; Fig. 3 is an exploded view of the erecting means of the sun shade assembly illustrated in figure 1; Fig. 4 is a pictorial representation of a clamping member for preventing rotation of the support means in accordance with the invention;

Fig. 5 is an exploded view of a section through the lower portion of the support means showing the clamping member clamping the support means to the spigot in accordance with the present invention;

Fig. 6 is an expanded view of the winch assembly, and Fig 7 illustrates a further embodiment of the invention.

—DESCRIPTION OF THE PREFERRED EMBODIMENT — The sun shade assembly 10 illustrated in the Fig. 1 to 5 of the drawings comprises shade means 11 supported from above by support means 12 which is displaced laterally from the

shade means 11 so as not to intrude upon the region directly below the shade means 11.

The shade means 11 is capable of movement between a stowed or folded position, illustrated in dashed outline, and an operative shading position, as illustrated in Fig. 1. The shade means includes a fabric cover 13 which is supported by a plurality of outwardly divergent support arms 14 which are pivotally connected at their inner ends to a central support 47 mounted to the upper end of the support means 12. The support means 12 includes a tubular post 15 comprising a mounting base 16, an upstanding intermediate member 17 rotatably mounted on the base 16, and an upper arm portion 18 which is connected to, and extends both upwardly and outwardly from, an end of the intermediate member 17. The arm portion 18 includes a downturned end portion 18a terminated by the support 47 to which the shade means is connected.

The mounting base 16 is adapted for secure attachment to a mounting surface and includes an upstanding spigot 19 which is located within the lower end portion of the member 17.

The member 17 has a circular cross-section so that the member 17 may rotate freely relative to the mounting base 16. This enables the shade means 11 to orbit about the mounting base 16 such that the area to be covered or shaded by the shade means may be selectively varied.

In order to prevent unwanted rotation of the shade means 11, the sun shade assembly 10 is provided with locking means 20, as illustrated in Figs. 2 and 3, which is selectively operable to clamp the member 17 to the spigot 19, which in this embodiment is a tubular member which nests neatly within the member 17. The locking means 20 includes an inverted "L" shaped clamping member 21 having a lower end portion 22 and a stepped end portion 23. The lower end portion 22 frictionally engages the internal wall of the spigot 19. Engagement and disengagement of the clamping member 21 with the spigot 19 is effected by tightening of a bolt 24 having a threaded stem 25

which extends through an aperture formed in the wall of the intermediate portion 17 to threadably engages with a threaded aperture formed in the clamping member 21.

Each support arm 14 is associated with a spreader bar 31 adjacent its inner end connected by a stay 44 to an outer portion of the respective arm 14. A further sub-stay 45 passes from each bar 31 passes through a stay exit box 46 for connection to a winch cable 30 located within the arm portion 18 and passing to the winch assembly 37. The spreaders maintain an minimum stay angle relative to the arms 14 and pivot upwardly to a position adjacent the exit box 46 such that maximum leverage is achieved as the cover 13 moves to its operative shading position and minimum leverage is provided at minimum load when the cover 13 is folded. The maximum outward pivoting of the arms 14 is determined by the circumference of the fabric cover 13 and is limited to the operative position illustrated in Fig. 1.

In order to maintain clearance between the stay 30 and the inner face of the post 15, the cable 30 passes over four roller assemblies 48. These are arranged along the neutral axis at opposite sides of the top bend 51t and at the centre o the lower bend 511. The forth roller is located adjacent the winch assembly 37 so as to provide a cable lead-on guide for the winch assembly 37. Each roller assembly 48 includes a roller member 52 tapering inwardly to a necked central portion which ensures that the cable 30 is biased to the middle of the roller member. The roller assembly further includes an axle 54 rotatably supported by end bushes 53 arranged at each end of the roller member 52 and adapted to be retained within apertures in the opposed walls of the post 15 by screws 55 extending into the axle 54.

The winch assembly 37 is mounted in opposed apertures 50 in the intermediate member 17 and comprises a hub assembly 32 mounted on a winch shaft 33 passing through apertures 60. The opposite end of the winch shaft 33 includes a hexagonal

drive nut 34 maintained in place by pin 35, so that the drive nut can rotate the shaft 33. The winch shaft 33 extends into the bore of the intermediate member 17 and the cable 30 is connected to the hub assembly 32 via a aperture 39 in the cylindrical face thereof and held in position by a grub screw 36.

The winch assembly 37 further includes a releasable anti-reverse mechanism to prevent unwinding of the winch shaft. The mechanism includes a ratchet wheel 40 slidably mounted to the shaft 33 between the nut 34 and the hub assembly 32 so as to be able to rotate the shaft through a pin 41 extending through the shaft and engaging in a slot 42 formed in the ratchet wheel 40. The anti reverse mechanism also includes a pawl 43 located on the shaft of the adjacent guide roller for operative engagement with the ratchet wheel to prevent reverse rotation of the shaft 33. The pawl may be released upon pressure being removed therefrom by being flipped over to present its opposite side to the ratchet wheel. The winch assembly also includes a drive handle 38 having a hexagonal drive socket 60 for easy slide-on attachment to the drive nut 34 for rotating the winch shaft 33. Suitably the cable 30 is so dimensioned that a single layer rolled around the shaft 33 provides sufficient length for movement of the cover 13 between the folded and unfolded positions. This coupled with the short cable lead from the adjacent roller 48 enables overrides and jamming to be substantially eliminated.

In use, the shade means 11 is erected by rotating winch handle 38 in an anti-clockwise direction so that cable 30 is wound onto winch shaft 33 and hub 32 thereby pulling the shade means 11 upwardly to the erected position. When fully erected the pawl 43 is moved so as to engage the ratchet wheel 40 thereby holding the cable tight and maintaining the shade means in the erected position.

The shade means 11 can be moved so as to shade a desired

8 region by rotating support means 12 about spigot 19. Upon rotation to a desired position support means 12 can be locked to spigot 19 by tightening bolt 24 so as to pull clamp 21 against an inner face of spigot 19 and a portion of the inner face of intermediate member 17 against the spigot. The hexagonal drive nut 34 is the same dimension as the bolt head 24 so that the handle 38 may be used for both operations.

The folded fabric cover 13 may be stowed in an out of the way location by pivoting the post about its mounting base. When shading is required the fabric cover may be winched upwardly into position and swung about the base mounting 16 to its operative position where it may locked if desired. Thereafter as the sun changes position, the covering may be moved to achieve a more effective shade, if possible.

In the embodiment illustrated in Fig 7, the post 70 has welded right angle joints and the sub-stays 71 extend directly from outwardly positioned blocks 72 to the support arms 73 providing the desired stay angle for initial lifting from the folded position. The sub-stays 71 connect to a single winch stay 74 for actuation thereby

It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as defined in the claims appended hereto.