This invention relates generally to play structures and is concerned with a new playground concept which may be applied to both outdoor and indoor playgrounds. In Australia, the dominant style of outdoor playground over the past decade or so has comprised multiple large upright tubes, often arranged in an orderly rectangular array. Rails and platforms have been connected between these posts by means of annular clamps. While the style of playground has been an improvement in several respects over the earlier welded pipe and pine log playgrounds, the core spatial concept has remained the same: a lattice of posts and rails providing a framework over which children may clamber and from which a wide range of accessories can be supported. Even variations from these basic concepts, such as mixed metal and timber structures, square post configurations and modular systems involving pre-drilled fastening apertures, have maintained the basic concept, and innovations in accessories have assumed adaptation to a rectangular lattice array.

An issue with traditional outdoor playgrounds has been the problem of injuries created by falls from the structures. In consequence, the preparation of the undersurf ace, to reduce the risk of injury, has become a major element of the cost of outdoor playgrounds. The subject has also become somewhat of a consumer issue and there would therefore be benefits to manufacturers if they could reduce the possibilities for injuries arising from falls from playground structures.

The depth of the prepared undersurface is determined by the "critical fall height", the greatest height of an item of play equipment from which a child could fall head first. This is usually held to be height of the highest deck or platform but only some playgrounds guard against easy child access to higher still roofs and rails. Where such access is not restricted, or at least positively discouraged, by the manner of construction, the real critical fall height may be much greater than that provided for by the undersurface.

More recently, the present applicant has developed a new style of playground which was particularly suited to indoor applications in confined spaces. This playground involves a series of levels within an external mesh wall. Access openings between the levels are of varying types and carefully offset to limit the maximum

possible descent, and children can be seen at all times within the structure by virtue of the open mesh walls. This playground has had the advantage that there is no particular risk posed by the undersurface but it has limitations in its applications to outdoor use. This invention essentially entails quite novel concepts in the configuration of play structures. The concepts are suitable both for indoor and outdoor structures and incur a further preferred benefit in that it is possible to reduce the opportunities for injury by falls from within the play zone of the structure.

The invention accordingly provides, in a first aspect, a play structure comprising: a column; a plurality of enclosures supported from the column and disposed above a ground or floor surface; means for children to access at least one of the enclosures from the ground or floor surface; and means for children to move between the enclosures.

In a second aspect, the invention provides a play structure comprising: a column; an enclosure, preferably spherical or ellipsoidal, suspended or supported laterally of the column and disposed above a ground or floor surface; means for children to access the enclosure from the ground or floor surface.

In a third aspect, the invention provides a play structure comprising: a plurality of discrete spaced enclosures supported above a ground or floor surface; means for children to access at least one of the enclosures from the ground or floor surface; and enclosed transfer passages interconnecting each of said enclosures to at least one other of said enclosures; whereby said enclosures and enclosed transfer passages define a substantially enclosed play zone.

The invention still further provides, in a fourth aspect, a play structure comprising:

an array of spaced spherical or ellipsoidal enclosures; means to support the enclosures above a ground or floor surface; means for children to access at least one of the enclosures from the ground or floor surface; and means for children to move between the enclosures.

A preferred play structure preferably embodies all four of the above aspects of the invention. The invention still further provides a kit or disassembled set of components comprising one or more of the four groups of integers defined above as comprising the respective aspects of the invention, which components are adapted for assembly to form the respective defined play structure.

In the first, second and third aspects of the invention, the enclosures may be ellipsoidal, spherical, oblong or cuboid, but spherical or ellipsoidal shells are preferred because this shape reduces the opportunity for children to climb onto or stand on the exterior of the enclosures. The support for a given play structure of interconnected enclosures preferably comprises a single column. The column is preferably metal and may advantageously be tapered. It may typically be hollow and may, for example, be of hexagonal or octagonal cross-section. Such exemplary column may conveniently be formed by butt welding two or more part octagonal segments along their longitudinal edges. The enclosures are preferably supported from the column by a combination of one or more rods or cables and one or more rigid links. The enclosures are preferably disposed at different levels so that passage between the enclosures involves a climbing or descending action.

Each of the enclosures preferably includes at least a wall portion, eg a curved panel, window or slotted wall segment which allows a supervisor external to the play structure to see the children in the respective enclosure. This wall portion, which may be a substantial portion or even substantially the whole of the enclosing wall of the enclosure, may for example be formed in a suitable metal or reinforced plastics mesh. There are preferably at least two different points of access between the play structure and the ground or floor surface. One may be essentially an exit, for example a slide, but they are preferably associated with two different enclosures.

The means for children to move between the enclosures in the first and fourth aspects of the invention are preferably enclosed transfer passages, as in the second aspect. These enclosed transfer passages are preferably tubes of curved cross- section, to discourage children from climbing on or remaining on their exterior, and may have internal steps and/or floor segments..

The enclosures are preferably defined by frames of coupled metal, eg, steel or aluminium, bands which support intervening wall segments. These frames are preferably to the exterior and, in the spherical case, may define three mutually orthogonal equators. The invention still further provides q play enclosure of general spherical or ellipsoidal shape, wherein the interior of the enclosure includes a pillar and a plurality of deck means, and respective means to access or exit the enclosure at the respective deck means.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 depicts a play structure comprising a first embodiment of all four aspects of the invention;

Figures 2 and 3 are respectively a diagrammatic side elevation and a diagrammatic plan view of the structure, but depicting only the relative arrangements of the column and enclosures, the fastenings by which the enclosures are supported from the column, and some exemplary configurational dimensions;

Figures 4 and 5 are respective diagrams depicting the arrangement of the frame bands in each enclosure;

Figure 6 is a representative cross-section showing an enclosure frame band and an adjacent wall panel.

Figures 7 and 8 are elevations of the cover and body components of a representative clamp coupling by which the frame bands are interconnected;

Figures 9 and 10 are respective cross-sections showing how the cover and body components co-operate; Figures 11 and 12 are plan and cross-sectional views depicting the assembly of a clamp coupling with frame bands;

Figure 13 depicts one of the lower viewing grilles;

Figure 14 is a plan view of the set of cap plates by which the rods are attached to the top of the column;

Figures 15 and 16 are cross-sections on the lines 15-15 and view 16-16 in Figure 14; Figure 17 is a diagrammatic exploded view showing one of the rod mountings at the sides of the enclosures;

Figure 18 is a partly exploded and sectioned side elevation of a representative brace by which the enclosures are laterally supported from the column;

Figures 19 and 20 are a plan view and a cross-section of the brace; Figure 21 is a cross-section of the column on the line 21-21 in Figure 2.

Figure 22 is an axial cross-section of a transfer tube;

Figures 23 and 24 are plan diagrams of typical lower and upper deck layouts in the enclosures; and

Figures 25 and 26 are elevations views of a second embodiment of the second aspect of the invention.

The illustrated play structure 10 includes a primary support in the form of a tapered column 12, four discrete spaced enclosures 14a-14d of generally spherical configuration, respective means 16,18 for accessing and exiting the structure, and respective means 20 in the form of closed transfer passages for allowing children to move between enclosures 14. Enclosures 14 are of similar dimensions sufficient to accommodate several children, and are preferably at different heights above ground surface 8.

Column 12 is a hollow tapered structure of upwardly diminishing octagonal cross-section formed by abutting two half octagonal segments 22 and welding along the resultant longitudinal seams 23. The column may be formed in two or more vertical sections, one above another. The column must of course be of sufficient strength and be sufficiently anchored in the ground 8, by means of a base plate 12a fixed to a footing 13, to stably support the weight of the enclosures 14 and children within them. One geometrical arrangement of the enclosures about the column is evident from Figures 2 and 3. The enclosures are at successively equally incremented greater heights, and, viewed in plan, their centres lie on respective pairs of

orthogonal diameters with respect to the axis of column 12. They are substantially equidistant from the axis and accordingly lie at the corners of a square. Satisfactory heights and other dimensions are indicated in Figures 2 and 3.

Each enclosure 14 is defined by an external frame of six curved metal, eg aluminium, semi-circular bands 24 interconnected by couplings 26 along three mutually orthogonal equators in the configuration depicted in Figures 4 and 5. Bands 24 are of generally isosceles triangular hollow cross-section, with an integral reinforcing web 24a, as depicted in Figure 6. The widest face 25a faces out and is slightly outwardly convex. Each coupling 26 (Figures 7 to 12) includes an underlying body 70 and a cap

72 which co-operate to clamp the bands at each strap intersection: in each case (Figure 4), one band passes through the coupling at its mid point, while the other bands terminate at the coupling. The bottom and top couplings have central apertures 74, 75 in the body 70 and cap 72 to receive and secure a vertical centre pillar or handrail 58 (Figure 1) for the enclosure. This pillar 58 assists in stabilising and distributing weight in the enclosure.

Body 70 defines crossed channels 78 of triangular cross-section for seating the bands 24. Each end of each channel has a depending stud 79 for engaging a complementary hole in the respective band. In the four corners of body 70, segmental flats 80 have counterbored apertures 82 for receiving nuts 84a for bolts 84 (Figures 11, 12) by which cap 72 is fastened to body 70 to clamp the frame bands 24 in position.

For reasons which will become apparent, one frame band equator is in a vertical plane, symmetrically bisecting pole 12 (Figure 3), another is in a horizontal plane, and the third is orthogonal to these two. The eight spaces between the strap segments are closed by respective wall portions in the form of curved octant panels 30 each shaped to define substantially a one-eighth portion of a spherical shell. Octant wall panels 30 are fastened to the respective bordering frame bands 24. Each panel 30 has an inturned marginal lip 31 at the respective edge (Figure 6). This lip 31 seats flush against one of the inwardly facing narrower faces 25b of the triangular- section frame band 24, to which the lip is fastened, eg by bolts 29. Strip faces 25b include interior ribs 27 to provide sufficient depth to form threads for bolts 29. Ribs

27 are also useful in reinforcing bands 24. The panels 30 are depicted in the drawings as single skinned but they may of course be double skinned hollow structures if desired.

With each enclosure 14, at least some of the curved wall panels 30, generally some or all of those in the lower half of the sphere, are formed so that a person standing on the ground can see children within the enclosure. In one arrangement, a generally circular curved spy "window" 85 is provided. This window may be a metal mesh with multiple see-through slots 87 (Figure 13), for example expanded or cast aluminium mesh, but a material such as a transparent or mesh reinforced plastics may be employed. Each enclosure will usually have at least one spy window 85 in its lower half and should usually be weight-supporting.

Each enclosure is supported from column 12 by three generally upwardly extending mild steel rods 32 and by a cantilever stay or brace 34. Cables may be employed in place of rods 32 but rods are preferred for their greater rigidity and for the additional stability imparted to the overall structure. The rods extend from a head or cap structure 36 of pole 12. In each case, one rod is fastened to a mounting 38 on one of the couplings 26a at the centre top of the enclosure. The other two rods are attached to mountings 39 (Figure 17) approximately half-way along strap segments 24 extending laterally away from coupling 26a. Cantilever brace or stay 34 projects horizontally from column 12 and has an end bracket 72' which forms a component of another of couplings 26b disposed at the point on the enclosure nearest the pole. To discourage children from clambering onto braces 34, each is of an isosceles triangular cross-sectional shape and is topped with an upstanding shaped fin 35 which is flat in the vertical plane. By virtue of the manner of support of the enclosures from the pole, it may be said that the enclosures are suspended from the pole.

Cap structure 36 includes a concave cap 90 and an underlying cap plate assembly 92. The latter is made of four complementary segments 93 (Figure 14) each having a base plate 94, a centre reinforcing stud 95, an outer arcuate upstanding flange 96, and radial reinforcing ribs 97. Base plate 94 is fixed to an underlying head plate (not shown) of column 12, while flange 96 carries three outstanding bracket tabs 98 to which the rods 32 are respectively pinned. Each

flange 96 also has a vertical tab 99 for fixing cap 90.

Each rod 32 is threaded at its ends to receive respective ferrules 100 (Figure

2) by which it is rotatably attached to the cap plate tabs 98 and to similar attachment points on the enclosures. Flats on the rods adjacent the threaded ends allow the rods to be rotated with a tool after installation, for tightening or adjusting the tension in the rods.

Each brace or stay 34 is detailed in Figures 18-20. The respective ends carry integral brackets 105, 72' by which the stay is fixed to column 12 and to the enclosure; it will be understood that bracket 72' is configured to substitute for one of the caps 72 at the coupling 26 nearest the column (Figure 18). Bracket 105 is angled (Figure 20) to embrace a corner edge of column 12, which is reinforced at that level on the inside of the column by a horizontally extending gusset plate 106 (Figure 21).

It will be appreciated from an inspection of the drawings that several of the enclosure wall octant panels 30 are adapted to have openings formed in them for various purposes. One has already been mentioned - i.e. to receive spy window 85. Another such purpose is to form a generally square opening 40a in the lowermost enclosure to cooperate with access means 16 (Figure 1). This access means comprises a simple step structure 42 fixed to both the enclosure and to the ground and includes hand-rails 44. A second opening at 40b of a different enclosure receives an inclined tube 46 serving as an exit slide from the play structure. Slide tube 46 curves into a horizontally directed lower portion 47 fastened to the ground by a small pedestal 48 and providing an exit opening 50 from which children emerge. Other openings 40c in the upper halves of all of the enclosures are associated with transfer tubes 20 which are fastened to the rims of the openings 40c. Figure 1 depicts three transfer tubes, allowing movement from each enclosure to at least one other enclosure, and in two cases to two other enclosures. A typical transfer tube 20 is shown in cross-section in Figure 22. It includes steps 52 in its bottom surface to facilitate upward travel along the tube. Two of the enclosures 14 as illustrated have potential openings 40d which are closed by wall panels 54 which may be either part-spherical segments or flat discs. The provision of these removable wall panels 54 allows for flexibility during

installation and permits the structure to be expanded in the future by the addition of further enclosures 14 or additional accessories such as slides. Wall panels 54 may be transparent, e.g. in polycarbonate, to serve as windows.

The interiors of enclosures 14 may be fitted out in any chosen manner to enhance the play possibilities of the enclosures. For example, and with reference to the partial sectioning of the left-most enclosure in the drawing, there may be, in addition to centre pillar 58, platform, table or decking surfaces 60, and steps 62. In general, there will be a lower deck 60a, and a partial upper deck 60b to facilitate access to the transfer tubes 20. A typical lower deck configuration is shown in Figure 23: The lower deck is an assembly of four quadrants, but a quadrant is omitted opposite a spy window 85 and flattened off adjacent an access 16. Alternatively, instead of wholly omitting a deck component opposite window 85, the deck component at this location may be cut back to a concave edge. A typical upper deck configuration is depicted in Figure 24: Any edge not open for the purpose of steps 62 is protected by a vertical open construction safety barrier comprising posts and/or rails.

It will be seen that the play structure illustrated in Figures 1-24 provides a playground which departs substantially from the classic post and rail lattice of the last several decades. The interiors of the enclosures 14, enclosed transfer passages 20 and exit tube 18 together define a play zone which is substantially wholly enclosed, thus mitigating the danger of injury from falls. On the other hand, children playing within the zone may be generally supervised by virtue of the spy windows 85 in the enclosure walls. Access to and exit from the play zone is a simple matter by virtue of steps 42 and tube 18 and the overall configuration provides a stimulating and adventurous play environment. A larger playground may be readily constructed by adding further column and enclosure sets and may be interconnected to an existing structure by additional transfer tubes 20. It may be desirable to adopt a design principle that every enclosure of the playground has an entry and an exit, the latter being preferably to the ground. The entry may be from the ground or from another enclosure.

The visual external effect is quite revolutionary in its departure from the appearance of traditional playgrounds. By employing spherical or ellipsoidal

enclosures, and generally curved transfer tubes, and a smooth surface tapered central pole, and by supporting the enclosures with rods or cables and protected stays or braces, there is positive discouragement of children attempting to clamber onto and maintain any kind of grip on the externals of the structure. The risks of falls from above the enclosures or from the general support structure are therefore minimised and the opportunities for vandalism are reduced.

An important further advantage of this novel style of playground is that peripheral fencing of the playground may not be necessary: this is a requirement of some authorities with existing playground structures. Figures 25 and 26 depict a simple second embodiment. A single spherical enclosure 14', of generally similar construction and fit-out to enclosure 14, is suspended from a column 12'. Column 12' has a straight lower section 110 of wider diameter and a curved upper section 112 mounted atop section 110 by clamp assembly 114. The outer end of section 112 extends horizontally and suspends the enclosure 14' by three short steel rods 32' attached as in the first embodiment. The enclosure is also fixed to clamp assembly 114 by a brace 34' similar to brace 34 and similarly topped by a fin 35'. Enclosure 14' is provided with access/exit means (not shown) such as a step set or slide in a manner similar to the first embodiment.