Description

There are many types of ladder and platform used for building, decoration, maintenance and repairs and many have multiple functions including features such as platforms, steps, variable height ladder extensions, variable height legs, hinged and pivoting elements. The Platform, Combination and the Folding Ladder are typical examples of these and can be found in many sizes and formats.

In many instance these ladders are configured to present a horizontal surface or working platform on which people can stand and work from. Few of these ladder platforms, combination ladders or steps have safety or handrails and as such many accidents occur as people inadvertently fall or step of the platform edge. The user is often at an elevated height above the ground, and on ladder assemblies designed for use on stairs and variable height locations the operator can be above stairwells and staircase. In the event the user looses their footing or balance and falls from the platform there is a risk of injury.

There are many other devices that utilise elevated platforms or surfaces where the user is subject to similar risks and injury. Rostrums, trampolines, play spaces and stages, being examples but not limited to such.

To reduce the possibility of injury and provide better safety and assurance when these types of ladder or device are in use it is beneficial to include safety barriers above and around the operating surface or platform. The simplest device is a safety or hand rail at waist height above the surface. A hand rail can prevent the user out stepping the platform edge and also provide a secure rail for the user to hold while accessing the ladder and then performing the tasks whilst on it so preventing serious injury. Safety barriers are particularly useful for users with less experience in the use of ladders and platforms, for the younger, for the more elderly or less able user.

The inclusion of handrails and safety barriers can already be identified in many temporary and dismountable scaffolding and staging devices but they typically are complex and time consuming to erect and install, more difficult to transport and store. In other instances the devices are permanently attached making the ladder or platform more bulky and difficult to install, use or transport.

It is beneficial in many devices to have safety rails, barriers and screens and that they are so constructed and incorporated as to still enable, simple and quick erection and installation, and are portable, providing safety and security during their use and efficient and easy stowage and removal once the task or event has been completed. It is for this purpose and more importantly reducing or eliminating risk of injury or death that this invention has been developed. Description of the invention

An elevated horizontal plane, surface or platform can be established in many ways but in one example of this invention there are collapsible trapezoid side frames that combined form the boundaries for a rigidly or flexibly attached elevated platform, surface or space, above which are located handrails or safety barriers. The surface can be of any type or made for any materials and can be rigid, flexible, or extensible.

The collapsible trapezoid frame, in this instance consists of two predominantly horizontal and parallel elements, one to support the platform or surface and the other above this to form a hand or safety rail. The horizontal elements are centrally pivoted and attached at either end to vertical or inclined members adjoined by pivotally fixed horizontal members.

Used as a platform, folding ladders can all be configured to create horizontal surfaces on which the user can stand or walk to gain access and complete tasks. These horizontal surfaces are often of a typical ladder construction, with rungs and stiles on to which is placed a flat secure platform suitable for standing on. Alternatively, a bespoke structural platform member is provided creating a secure unitary floor suspended between two or more supports.

It is advantageous that this horizontal platform is bounded on one or more sides with a safety or handrail typically but not exclusively at waist height such that the user cannot walk or inadvertently progress over any edge of the platform while performing any task or entering or exiting the same platform.

Embodied in this invention is a novel construction such that when the ladder and platform assembly is unfolded and configured in the preferred operating mode, any horizontal working area or platform is automatically bounded partially or entirely by a hand rail or safety rail. Through the same configuration flexible barriers or sheet may be suspended from the constructional elements to provide further security and safety.

One typical embodiment of this novel construction is for a foldable horizontal platform used by tradesman to assist in plastering, painting, decorating, and many other tasks. In this embodiment the secure platform ladder is constructed of several elements. Firstly a platform that is centrally hinged and has pivoting supports at either end. Also a matched pair of hand or safety rails that are centrally hinged and has pivoting supports at either end. Two ladder elements are located at either end of the platform and rails and so connected by the pivoting supports, and struts, as to create a trapezoid or rectilinear and stable structure when expanded. The stability of the structure is enhanced by the inherent weight of the device and any additional weight put on the structure.

In this stable and robust form it is possible to ascend the ladder rungs at either or one end and step on to the platform with the rails ether side to assist access and provide security while accessing and working on the platform. The hinges at the centre of the rails and the platform are preferably locked to provide correct alignment and strength for the entire structure. By unlocking the central hinges and pushing them downward or upward the structure can be folded into a flat compact configuration typically only the width and depth of the two ladder stile elements, so enabling easy stowage and transportation. The lockable and rotationally indexed hinges can be configured such that the central hinges collapse in a vertically downward or a vertically upward direction. The hinges are preferably locked in their flat and folded positions with use of an automatically engaging sprung latch or similar device. In some configurations it may be preferable to have hinges that are totally free to rotate and are restrained only at predefined points at the extremes of their rotation by mechanical stops. The mechanical stops can be embodied within the hinge or at some other location.

In this configuration of the secure platform ladder it is preferable to displace both sets of hinges at the same time and to improve this process and enable simpler and safer erection and dismounting parallel struts are can be attached on either end and on either side of the secure platform ladder assembly. The struts run parallel to and have the same centre distance as that between the pivots located on the stiles for the platform and rail connections being freely pivoted as a parallelogram. With these parallel struts fitted it is only necessary to fold unfold or lock and unlock one or one pair of hinges as the matching hinges on the platform or rails will be opened or shut simultaneously by the transfer or movement and force to the parallel elements by the struts.

The structure typically uses four struts but configurations with less or more struts enable a similar transfer of movement and forces. The number of locking elements is preferably two but one or more can also be embodied on this invention. The device can be configured with all pivoting means free and constrained by end stops.

In some applications the use of lockable hinges is not essential. The hinges or pivots can be so arranged that the weight of the structure applies a downward force to the end stops of the hinges on the platform, rails and ladder elements and or working against mechanical stops to align the completed structure in the working geometry.

One configuration of this invention has been described in which a folded extendable and collapsible structure can be opened to form a walk through elevated platform with access at either end. There are unlimited configurations of this invention which embody self erecting hand rails and safety rails.

In other configurations of this invention the number of ladder, platform and step functions can be increased for example access to the platform can be limited to one end and at the other end the number of ladder rungs increased to create a ladder for higher access making the unit more versatile and useful. The embodiment of an independently sliding ladder element at the one end of the platform ladder allows another configuration in which the separate sliding ladder element can be attached and extended vertically as is typical in a traditional two piece extending ladder. This

extending ladder element gives increased height access and is adjustable by increments typically but not exclusively matched to the rung pitch. With increase to higher working levels a stabiliser bar can be added at the base of one or both ends of the secure platform ladder assembly to ensure the ladder does not fall over when the user climbs to the uppermost working point.

So with the combination of ladder elements, and steps, platforms, handrails, safety rails, stabilisers, pivots, struts, indexed hinges, lockable hinges, any number of platform ladder devices can be configured embodying this inventive use of simultaneously erecting safety and hand rails around a working platform.

Construction of ladders, ladder stiles, rungs, steps, hinges, pivots, rails, struts and platforms exploiting this inventive concept are not limited to any particular form, size, material or construction.

In some instances the rung can be replaced by a step or other member.

Struts can be made for the same material and section as the ladder stiles but are not limited to such.

Any manner of hinge or pivot can be used.

The platform can be made as a separate unitary structure or it may be a loose or tied independent platform element of one or more parts which is placed on one or more structural members of the ladder assembly.

One or more stabilisers can be attached to the base or feet of the ladder elements to improve the stability of the platform ladder.

This description describes a structure which includes ladders, steps, platforms and handrails. The invention may be embodied in other products or structures such as but not limited to play pens, trampolines, rostrums, staging.

The invention is not limited to one handrail or set of handrails on a common plane. The mechanism or structure can have multiple or parallel elements, preferably but not exclusively parallel to the working surface so creating a more complete and secure handrail, screen, or panels around the working surface.

It also advantageous to make provision or include fixed, temporary or removable barriers or hand rails at the entry and exits to the platform. These may be a fixed and permanent part of the structure, a moveable or pivoting element or a removable part. The barrier or handrail means can be of rigid or flexible construction from any suitable material. This description of a platform and ladder device describes one example of how the invention can be configured to create a safe elevated surface or platform.

In this example there are two collapsible trapezoid frames forming parallel sides to a rectilinear platform. Additional parallel elements may be added adjacent to either frame so increasing the size of the platform.

It is a notable feature of this invention that the collapsible trapezoid or rectilinear frame can be joined as a polygon and configured to create a multiple sided safe platform or enclosure of any size or height.

In the example previously described the two frames are parallel and joined by

predominantly horizontal members.

In other embodiments of the invention three or any number of similar collapsible frames can be co-joined at their edges about a central vertical axis to create a secure elevated platform, surface or space for any manner of uses. An example is a play space or trampoline of four or more sides. With the increase and number of side frames the enclosed space increases enabling polygon or circular elements to be suspended from the frames.

So with all these axially arranged collapsible side frames the entire structure can be folded or collapsed to a compact arrangement around the central axis in one continuous process. In this form the structure takes up significantly less space and is transportable.

The features embodied in the description of this invention can be changed to increase the security and capability of each particular configuration.

The platform and horizontal structural supports can be constructed as two hinged unitary homogenous elements.

Horizontal members can be used to form steps up to the surface, platform or space

Extending legs may be attached to the frames to adjust the height of the surface or be adjusted to fit uneven ground.

Hinged, fixed or sliding elements can be attached to the legs that give greater stability to the structure

Fixed or adjustable inclined and extendable elements can be attached to the frames so forming a raised framework or enclosure around the elevated surface.

Fixed or adjustable inclined and extendable elements can be added to create suspension points for other foldable non rigid elements or structures Flexible and extendable barriers or netting that can be suspended as one unitary element from the surface or other parts of the structure

Flexible or extendable sheets or netting that can be attached to form the surface

Flexible or extendable sheets or netting arranged to fill part or all the voids it the framework to enhance security.

Examples of this invention are shown in Figures 1 to 19, where Figures 1 to 10 show the invention manifest as a series of platforms and access devices and Figures 11 to 19 demonstrate additional configurations where the device provides means for creating an elevated predominately horizontal and secure stable, platform, surface or space.

In particular, the figures show the following illustrative embodiments.

FIGURE 1 is a perspective side view of a first embodiment of the collapsible elevated platform according to the present invention;

FIGURE 2 is a perspective side view of a second embodiment of the collapsible elevated platform;

FIGURE 3 is a perspective side view of a third embodiment of the collapsible elevated platform;

FIGURE 4 is a fourth embodiment of the collapsible elevated platform of the present invention;

FIGURE 5 is an enlarged perspective side view of the hinge shown in Figures 1 to 4;

FIGURES 6a to 6d show perspective views of collapsible elevated platforms in their collapsed configuration;

FIGURE 6e shows a schematic side view of a fifth embodiment of the collapsible elevated platform with a triangulated configuration;

FIGURES 7a, 7b and 8 show alternative hinges that form a pivot and integrated rotational constraints;

FIGURE 9 shows a platform element of unitary construction;

FIGURE 10a shows a sixth embodiment of the present invention, in which the platform element comprises two independent self-supporting surfaces;

FIGURE 10b shows the hinge portion of the elevated platform shown in Figure 10a;

FIGURES 11 and 12 show perspective views of a triangulated collapsible structure; FIGURE 13 shows a perspective view of a collapsible structure with two trapezoid or rectilinear frames;

FIGURE 14 shows a perspective view of a collapsible structure with two rectilinear frames;

FIGURE 15 shows a perspective view of a collapsible structure with two pentagonal frames;

FIGURE 16 shows a perspective view of a trapezoid collapsible structure with two pentagonal frames;

FIGURE 17 shows a perspective view of the trapezoid collapsible structure of Figure 16 with an external cover;

FIGURE 18 shows a collapsible structure, similar to the structure of Figure 15, wherein one of the pentagonal frames forms a supporting surface for a rigid, flexible or extensible platform or surface;

FIGURE 19 shows the collapsible structure of Figure 18 with an extensible support.

Figure l,shows a horizontally biased platform, 13, supported by two ladder elements or vertically biased structural elements, 11, 12, and two handrails, 9, located above the platform, 13, and so fixed that the structure can be folded for easier transportation and stowage, as shown in Figures 6a, 6b, 6c, and 6d. The platform 13 itself is supported by horizontal supporting members 10, which are centrally joined by means of hinge 1. The opening and closure of the structure is further controlled by structural elements or struts, 15, which are freely pivoted and parallel to the ladder elements, 11, 12. Any number of members parallel to each handrail can be located between the opposing ladder stiles, 6, and the struts so providing further safety or functionality.

The extended and open structure can be further restrained by lockable hinges, 1, so the entire structure is constrained or locked in the closed or open format. It may be preferable in another version of this invention to have all pivots, 2, 3, 4, or hinges, 1, unlocked and freely pivoted such that the structure is self supporting in the open or closed positions. Figures 1 to 4, illustrate the structure in the open format. Figures 6a, 6b, 6c, 6d, show the structure in alternative closed formats.

The structure can be configured in different sizes and of different structural sections but another attribute of this invention is that the platform ladder can consist of a common set of parts so configured to offer a range of alternative solutions to suit different uses of the platform ladder device.

Figure 1 illustrates a typical configuration where at one end there is open access to the platform and at the other is a ladder. Figure 2 shows a simpler configuration where there is open access to the ladder platform at both ends. The configuration shown in Figure 2 can also be configured without the tie or strut elements, 15, and with lockable hinges, 1, to retain the platform ladder assembly in the preferred working format. A further example shown in Figure 3 is a platform ladder of similar construction but with an additional moveable ladder section, 16, that can be freely raised and lowered on the fixed ladder element at the one end of the platform structure. Hooks, 17, being provided to locate on any rung, 7. These are three examples but the structural principle can be used in many other devices including but not limited to working platforms, stages, rostrums, safe enclosures for functional, recreational, commercial and sports activities.

As shown in Figure, 4, other variations of this invention the platform ladder can have, handrail extensions, gates, or moveable constraints, at one or both ends of the handrail.

Figure 1 shows the platform ladder with the platform, 13, and handrails, 9, supported by two ladder sections, 11 and 12, and struts, 15, each pair being arranged parallel to the adjacent ladder section and arranged such that when with all the hinges, 1, unlocked raising one element of either the handrail, 9, or platform, 13, will raise the handrails, 9, and platform elements, 13, simultaneously to enable the platform ladder to be collapsed into a predominantly flat form as shown in Figures 6a, 6b, 6c, 6d.

This arrangement can also be used with a plurality of members parallel to the handrail, 9, each freely pivoted at both ends.

The hinges, 1, which may be locked in predetermined positions by inclusion of a sprung latch, 21, or freely rotating between two end stops, can be so arranged that as an alternative to the platform, 13, and handrails, 9, being raised as shown in Figure 6c, the elements can be lowered as shown in Figure 6a. At the point of lowering or raising the connected platform, 13, and handrail elements, 9, is such they are no longer axially aligned or parallel the entire structure can be closed or opened by pushing the two ladder sections , 11 and 12, together or apart, they being connected to together as to form a parallelogram. Figures 6b and 6d show alterative configurations where the horizontal elements are closed in opposing directions. To install or erect the platform ladder the reverse sequence is affected.

The ladder forming predominantly vertical structural elements, 11 and 12, as shown in Figure 1 supporting the platform, 13, are typically constructed of two vertical members or stiles, 6, held at a set distance from each other by rungs, 7, or similar structural members so as to form a robust unitary construction. The ladder stiles, 6, and rungs, 7, may be aluminium, steel, wood or glass reinforced plastic or combinations of such materials but not limited to such.

The rungs, 7, and stiles, 6, may be connected by any fixing means such as but not limited to screws, rivets, swaging and welding.

The ladder sections, 11 and 12, at either end of the platform ladder have matched pivot points, 2, being tubes or pins, 23, fixed through plates, 24, into the ladder stiles, 6, but is not limited to such and other methods of hinges can be configured to form pivots such as but not limited to using the rungs or similar structural elements as the hinge pivot. The pivot or hinge points are arranged so as to form two horizontally mirror imaged parallelogram structures hinged at the mid points of the handrails and platform. The centrally hinged platform element, 13, can be of unitary construction, as shown in Figure 9, or consisting of multiple parts or assemblies, as shown in Figures 10a and 10b. In the configuration, illustrated in Figure 9, the platform, 25, is a predominantly flat panel of unitary construction located on and above horizontal structural members of any configuration but in this instance that of a ladder section with stiles, 6, and rungs, 7, forming a rigid structure.

The platform, 25, can be fixed to, or lie on horizontal structural members, 10. Any form of platform can be used whether permanently attached to the structure in one or more parts.

In Figure, 9, is shown a single platform, 25, which extends across the centrally located hinge, 1, along the entire length of the horizontal structural member, 10. The platform, 25, is located on one part by straps, 26, which give constraint to linear movement of the platform. On the other end of the platform are hooks, 27, which locate under the cross members or rungs, 7, of the other hinge part of the horizontal structural member, 10. With the platform ladder assembly fully opened the platform, 13, can slide along the horizontal structural member, 10, such that the hooks, 27, locate over the cross members or rungs, 7, so locking the horizontal structural member, 10, in a predominantly linear plane across the centrally located hinges, 1, preventing their rotation.

The use of the platform assembly, 13, as a locking device across the hinged structural member, 10, can be configured in other ways. The platform, 25, or platform assembly, 13, can be in two or more parts interlocked to maintain the structural integrity of the platform. The interlocking can be by mating of the platform ends or by separate locking devices such as sliding bolt but not limited to such.

The platform, 25, can be made from one homogenous material or a combination of materials to form a rigid safe surface.

In another form of the device the platform, Figures, 10a, 10b, is made from two self- supporting structurally independent surfaces, 32a and 32b that are suspended from the horizontal rails, 10, without need for the horizontal supporting rungs.

The independent self-supporting surfaces 32a, 32b can be joined and hinged with the hinge pivoting axis 34 coincident with the rotational axis of the hinge pin 33 located at the centre of the horizontal supporting members, 10.

The hinge pin, 33, connecting the two parts of the platform can be extended to go through a hole in the centre of the supporting hinge, 1, or attached in this alignment providing greater structural support for the central part of the platform. Vertical flanges, 35, on the ends of the platform elements further increase the strength and rigidity of the platform.

The handrails, 9, typically form the uppermost element of the platform ladder structure as shown in Figures 1, 2, and 3. The handrails, 9, can be of any material or construction and provide structural support for the platform ladder. Sliding or interlocking parts on the handrails, 9, can provide similar locking of the platform ladder assembly as can the sliding interlocked platform.

The handrail, 9, can be of the same section as the ladder stiles, 6, but is not limited to such

Additional rails can be positioned parallel to and vertically above or below the handrail to increase functionality, structural integrity and safety.

The struts, 15, shown in Figure 1, ties or links complete the two mirror imaged parallelogram structures allowing easier opening and shutting of the platform ladder. The struts, 15, can of the same section as the ladder stiles, 6, but is not limited to such.

Figures 1 to 11 show alternative means of forming pivots for the platform ladder structure. Figure 6e shows a pin or tubular pivot, 50. Figure 7a, 7b and 8 shows alternative hinges that form a pivot 23 and integrated rotational constraints 24. Figure 6e shows a triangulated format, with two struts 51, 52 extending from the collapsible platform to the tubular pivot 50. The struts 51, 52 form two side edges of a triangle and meet at the tip of the triangle, which is aligned with the pin or tubular pivot. The platform 53 corms the base of the triangle between ends of the struts 51, 52.

The structure of the platform ladder and handrails is illustrated in Figures 1, 2and 3, which show three variations of the same platform ladder.

To these structure additional safety features can be added.

Figure 4 shows hand rail extensions, 28, a flexible barrier, 20, and an end gate, 19.

Figure 3 shows a stabiliser bar, 29.

Figure 1 shows an anti-slip foot, 5.

Additional features can be added to the platform ladder to increase the functionality.

The constructional and operational formats embodying this invention, described and shown in Figures, 1 to 10, can be further arranged to form other configurations of elevated platform, surface, space or free standing structure.

Figure, 11 to 19, show alternative configurations but these are not limited to such.

Figures, 11 and 12 shows a triangulated collapsible structure which closes about a central vertical axis.

In any of the structures describe here within the structure may embody adjustable, hinged or axially extending elements 32, to increase the size, to improve stability and to allow use of the structures on uneven surfaces. In more detail, the triangulated collapsible structure shown in Figures 11 and 12 comprises three extending elements 32, which are designed as telescopic cylinders and comprise a barrel 31 and at least one stage 30 that can be moved telescopically in a vertical direction as shown by the arrows in Figure 11. The three telescopic extending elements 32 are interconnected by two triangular frames 60 and 61. Each of the triangular frames 60, 61 comprises three hinged horizontal supporting members 63, each of which interconnects two of the stages 30 of the corresponding telescopic extending elements.

Figure 12 shows how the collapsible structure of Figure 11 can be collapsed towards a central axis 65, via hinges 64, which are provided in the centre of each horizontal supporting member 63.

Figure, 13, show a collapsible structure where two similar trapezoid or rectilinear frames are connected to the other using predominately horizontal members and which close toward a central vertical plane. Similar to the triangulated collapsible structure of Figures 11 and 12, the rectangular structure of Figure 13 comprises two rectilinear frames 70, 71,

interconnecting four telescopic extending elements 32. Each of the rectilinear frames 70 and 71 comprises two hinged horizontal supporting members 73, which are arranged in parallel and two non-hinged horizontal supporting members 74, which are arranged at a right angle to the hinged supporting members 73 and in parallel to each other. The structure of Figure 13 can be collapsed in a similar way as shown in Figures 6a to 6d.

Figure, 14 shows a rectilinear collapsible structure of multiple hinged horizontal supporting members 83, each forming elements which can be folded toward a central vertical axis. In contrast to the embodiment shown in Figure 13, this supporting frame comprising two square frames 81 and 82, which comprise four hinged horizontal supporting members 83. The supporting structure of Figure 14 can be collapsed in a similar fashion to the trapezoid supporting structure shown in Figures 11 and 12.

Figure 15 shows a pentagonal collapsible structure with two pentagonal frames, which interconnect five telescopic extending elements 32, the two supporting frames 91 and 92 comprise five hinged horizontal supporting members, each of which interconnects two of the telescopically extending elements 32.

Figure 16 shows yet another collapsible structure with two pentagonal supporting frames 101 and 102, the pentagonal frames each comprise five hinged horizontal supporting members and can be folded toward a central vertical axis. As can be derived from Figure 16, the upper frame 101 has shorter horizontal supporting members than the lower frame 102. Consequently, the collapsible structure shown in Figure 16 is arranged to taper inwardly from the bottom to top of the extending elements 32. Alternatively, the horizontal support members of the upper frame 101 may be formed larger than the horizontal supporting members of lower frame 102 and thus would form a collapsible structure that tapers outwardly in a vertical direction from the bottom to the top of the extending elements 32.

The collapsible structure shown in Figure 18 has two pentagonal frames 111 and 112, similar to the structure shown in Figure 15. In contrast to the structure shown in Figure 15, however, the lower frame 112 of this structure comprises horizontal supporting members, which project horizontally from the lower edge of the horizontal supporting members 120. The horizontal supporting surfaces 121 extend inwardly towards a vertical axis of the support structure from the lower edge of the horizontal supporting members 120. In order to increase stability of the supporting surfaces 121, the lower frame 112 may further comprise reinforcement struts 122 that extend between the inner edge of the supporting surfaces 121 and the upper edge of the horizontal supporting members.

Figure, 17, shows the structure of Figure 16 used to support an external cover 110 of any means.

Figure, 18 shows a structure formed of co-joined collapsible sections adapted to support a rigid, flexible or extensible horizontal platform or surface.

Figure, 19, shows a structure formed of co-joined collapsible sections used to support or suspend from a rigid, flexible or extensible enclosed space 130. The structure shown in Figure 19 comprises horizontal supporting surfaces similar to the supporting surfaces 121 shown in Figure 18. The horizontal supporting surfaces are used to carry the weight of the rigid, flexible or extensible enclosed space 130. In this particular embodiment, the extensible enclosed space 130 is attached to the upper end of the extending elements 32 by means of flexible struts 131.

The following clauses describe further preferred embodiments of the present invention. Clause 1

A collapsible elevated platform with integrated simultaneously erecting safety rails and handrails formed by two or more conjoined similar regular trapezoidal structures each comprising two supporting members uniformly inclined and equally distant from a common vertical axis and connected by pivoting means to a plurality of horizontal members each having additional pivoting means at the midpoint between the two supporting pivoting means and coincident with the central vertical axis of the regular trapezoid and on one or both sides of this central pivoting means is an additional member parallel to the inclined supporting member pivotally connected to all horizontal members so that when one horizontal member is displaced then all pivoting members move uniformly as a

parallelogram arrangement the platform can then be collapsed or extended by one inclusive operation with the handrails and safety rails collapsing and engaging by the same process and there being restricting means on the central pivoting means of the platform that when the collapsed closed structure is open the restricting means retains the platform as one continuous horizontal structural member.

Clause 2

An apparatus as in Clause 1 where there are no additional parallel inclined members and the lateral movement of the trapezoid structure is constrained by opposing stops on the pivoting means either end of the horizontal members.

Clause 3 An apparatus as in Clause 1 where pivoting means of the innermost end of two inclined parallel members equally distant are coincident with the central pivoting means of a horizontal member and the central axis of the trapezoid

Clause 4

An apparatus as in Clauses 1 and 2 where the central pivot on one or more of the horizontal members have means to restrict and dynamically restrain rotation.

Clause 5

An apparatus as in Clause 1 and 2 where the central pivoting means of the horizontal members are automatically locked and have an independent safety release device that must be disengaged before the member can be displaced and the trapezoid structure opened or closed.

Clause 6

An apparatus in Clause 1 and 2 where two regular trapezoid frames are conjoined by additional horizontal members so the central axes of the frames are aligned in a common plane perpendicular to frames

Clause 7

An apparatus as in Clauses 1 and 2 where three or more regular trapezoid frames where the inclined supporting members of the adjacent inclined frames are conjoined forming a polygon of three or more sides about a common central vertical axes.

Clause 8

An apparatus as in Clause 6 where adjacent trapezoid frames forming the polygon structure share a common inclined structural member.

Clause 9

Apparatus as in Clauses 1 and 2 where the central pivots have mechanical stops restraining the collapsible horizontal members so that the gravitational loads of the horizontal members and additional applied gravitational loads act to retain the structure in the open

configuration.

Clause 10

Apparatus as in Clauses 1 and 2 where one adjacent pair of collapsible horizontal members on the lower part of the structure are incrementally longer than their theoretical length as a correct geometric trapezoid so putting these extended horizontal members in compression which applies torsional loads onto the inclined members so eliminating movement in the pivots making the open structure more rigid Clause 11

Apparatus as in Clauses 1 and 2 where adjacent pairs of horizontal members as in Clause 8 and 9 have stops on the pivots arranged so the horizontal members stop incrementally past their linear alignment and over centre of the pivot and are retained in this position by the compressive over centre load applied either end of the horizontal members.

Clause 12

An apparatus as in Clause 1 and 2 where the inclined supporting members are extended upwards to provide supporting means for additional devices including safety nets, safety guards and safety barriers.

Clause 13

Apparatus in Clauses 1 and 2 where the legs of the inclined members of the trapezoid frames are adjustable in length

Clause 14

Apparatus in Clauses 1 and 2where the platform is rigid Clause 15

Apparatus in Clauses 1 and 2 where the platform is in two parts conjoined by a hinge or any configuration

Clause 16

Apparatus in Clauses 1 and 2 where the platform is semi-rigid, flexible or elastic material or fabric or combination of these and is suspended form the horizontal and inclined members

Clause 17

Apparatus in Clauses 1 and 2 where there are detachably attached barriers, rails and screens of any type

Clause 18

Apparatus in Clauses 1 and 2 where all internal angles of each trapezoid frame are 90 degrees

Clause 19

Apparatus in Clauses 1 and 2 where stabiliser members are attached to the base of the structure

Clause 20

Apparatus in Clauses 1 and 2 where the joining members of the two trapezoid frames form steps or ladder rungs. Clause 21

Apparatus in Clause 5 where there is an adjustable extending ladder incorporated at either end or the collapsible platform structure

Clause 22

Apparatus as in Clauses 1 and a where a rigid sliding element is displaced across the central pivotal means of the horizontal members or structure so locking them in the horizontal positon