Void platforms are erected in voids in multistorey dwellings during the construction phases to provide safe access for tradespeople, to prevent falls and to facilitate work which needs to be completed within the void area.

Platform systems are preferable to other forms of access systems such as scaffolds, ladders and the like.

One well known platform system in use throughout Australia is the system known as FlexiSafeT" by Oldfields Access.

Whilst the FlexiSafeT" system is capable of providing a safer working environment in void spaces, the system is based on the use of brackets which are secured to horizontal surfaces and as such in many instances an erected platform is an obstacle to vertical work surfaces particularly affecting plasterboard installers who are required to create expansion joints between sheets of plasterboard adjacent to floor height.

Another issue in relation to platform systems is erection times.

It is desirable that a void platform system should be easily installed and dismantled.- An object of the present invention is to provide a platform system and methodology for void areas in dwellings the system which is efficiently erected and dismantled and which allows ready access to areas adjacent to the void.

Further objects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

Disclosure of Invention According to the present invention, there is provided a void platform comprising a work platform, at least one support rail and a pair of elongate extendable members wherein the working platform comprises a tread having attachment means at opposed ends for engagement with the elongate members, said elongate extendable members having an end for resting on the support rail and wherein the support rail includes an attachment flange for fixture in a substantially horizontal plane and a land for supporting the attachments of the elongate extendable members.

The work platform of the present invention may be supported between a pair of opposed walls or, in an alternative embodiment may be supported on one wall with leg supports extending upwards from a floor or other horizontal base. In a stairwell, for example, the end of the working platform that extends over the void may be supported by an elongate tube that extends between support rails mounted on opposed walls whilst the other end of the tread may be supported on an elongate member that is mounted on legs that extend upwards from a landing or tread of the stairs.

In other environments, it may not be possible to utilise a pair of opposed walls to affix opposed support rails to and that a single support rail may be attached to a wall, having an elongate extendable member supported therefrom. The remote end of the elongate member may be supported on a leg-that extends-from a stable base.

The working platform comprises a tread having attachment means at opposed ends for engagement with the elongate members. The tread may be of any convenient form and made from any suitable material.

For example, the tread may be formed from plastics, metal or timber.

Suitable tread may be formed from a checker plate metal product, a reinforced plastics material or a timber product such as a particle board or other suitable weight bearing sheet material. At opposed ends of the tread, attachment means are provided for engagement with the elongate members.

Generally the elongate members are in the form of tubes, rods of round, square, triangular or other regular cross-section and the attachment means

are in the form of a hook which can engage the elongate members. The weight of the working platform may be sufficient to retain the working platform securely on the elongate members simply using an open hook, alternatively it may be desirable to have a fastening device that prevents the working platform being inadvertently raised from the elongate members such an attachment means may include a loop fastener that can be tightened around the elongate member.

The support rail includes an attachment flange for fixing to a substantially horizontal wall. The attachment flange preferably includes a series of spaced apart apertures that will allow the flange to be affixed to regularly spaced structural members of the wall such as wall studs that may be spaced apart at say 600mm or 900mm. By having a series of apertures in the attachment flange it is possible to affix the attachment flange securely to the wall whilst providing a land at the desired position for supporting the support rail. For example, where the wall studs are inconveniently positioned, it is possible to attach the attachment flange to the wall securely and with the land extending along the length of the attachment flange, the support rail may be positioned such that the tread of the work platform is in the desired location.

The support rail includes a land for supporting the elongate extendable members. The land may be of any convenient form, but preferably extends along the length of the support-rail so that the--elongate extendable members can be positioned at any desired location therealong. In one form, the land may be in the form of a horizontal flange extending from the attachment flange. It is preferred that such a horizontal flange include a longitudinal detent for preventing the elongate extendable member from being displaced from the land during set up. In an alternate embodiment, the land may be in the form of a flange extending parallel to the attachment flange and joined thereto by a common web. The use of a land that is disposed parallel to the attachment flange provides an increased level of security in that it is less likely that the elongate extendable members will be displaced from the land during setup.

The elongate extendable members have an end for resting on the land of the support rail. It is preferred that the elongate extendable members have opposed identical ends such that the ends may be mounted either on the land of the support rail or affixed to a suitable leg that may extend from the floor or other suitable stable base. In a preferred form of the invention, the elongate members are tubular members so that the weight of the members is reduced for convenience in assembly, transport and manufacture. It will be apparent to those skilled in the art that it is not essential that the elongate members be tubular but that they may include solid sections. The elongate extendable members may include an extendable segment disposed anywhere along the length of the member, for example such as by a telescoping arrangement centrally disposed along the member.

A suitable telescoping arrangement may include a threaded section which permits each end of the member to be counter rotated so as to lengthen or shorten the member. In an alternate form, each end of a tubular member may include a threaded section into which a threaded male member may be screwed. The threaded male member may include an end for engagement with the land of the support rail or may include a suitable end for engagement with a leg or other support for the work platform.

In another form the tubular member may not require a threaded portion but may merely be sized so as to closely receive a threaded shank of the-extendable end of-the elongate-member. The extendable end of the-- elongate member may include a nut having a cross-section of sufficient diameter to urge the tubular member upon rotation of the nut on the male member. The use of an adjustment nut allows for axial adjustment of the end with respect to the tube.

Suitable ends may include an end having a flange for engagement with the support rail. In one form, the flange may be affixed to the end of the elongate member extending laterally therefrom so as to engage the support rail at 90°. In certain applications the wall may not be oriented at 90° to the desired orientation of the working platform and in one embodiment the flange may be rotatably mounted on the end of the elongate

member. In another form, the end of the elongate member may include a hook or other fastener for engagement with a separate type of support provided that at least one of the supports for the working platform is in the form of a support rail as herein described.

In the assembly of a large void platform it may be desirable to intersperse support legs between the end supports of the elongate member.

In one embodiment a T piece may be inserted at an intermediate position along the elongate member where the arms of the T piece are inserted into respective tubular members and the base of the T piece extends downwards and engages a leg or other suitable support.

The support of a remote end of the elongate member where it is not possible to engage a wall or other fixture, may be by an L-shaped end piece that is inserted in the end of the elongate tube and extends downwards to a suitable support such as a leg. Optionally a lateral member may also extend from the L-shaped member to provide the connection to an additional extendable member such that a void platform of complex construction may be formed.

We have found that the engagement of the end of the elongate extendable member with the support rail is facilitated by including a rubberised base on a flange mounted on the end of the elongate member such that the frictional engagement reduces the likelihood of lateral displacement of the end of the elongate member-during assembly, once-the elongate member is extended and the void platform assembled, the stressed extendable members are rigidly affixed to the support rail and other supporting members.

In another preferred configuration the ends of the support rails preferably include stops so as to prevent the ends of the elongate members from sliding out of the ends of the support rails during assembly.

Legs for providing end or intermediate support of the working platform may be provided with a floor mounting upright adapted to support at least one end of the extendable elongate member. The floor mounting upright may comprise a base plate and a tube or male member extending

perpendicularly (vertically) from the base plate. Where the floor mounting upright is adapted to have an extendable elongate member mounted directly thereupon the upright may include a tube having a slot in one wall thereof adapted to receive and secure one end of the extendable elongate member.

The adjustable attachment can include a shank for insertion in the ends of the tubes and a footing at one end of the shank.

The shank of the attachment can be threaded and has an adjustment nut which provides for axial adjustment of the footing with respect to the tubes.

According to a further aspect of the present invention there is provided a method of erecting a void platform, the method comprising: (a) fixing at least one support rail on a horizontal plane with respect to wall or wall framing members in a void area of a dwelling, (b) fixing a second rail with respect to an opposed wall frame in the void area, (c) erecting at least two elongate tubes in a parallel spaced relationship with respect to the tubes, (d) placing and securing elements of a working platform on the tubes.

The elongate tubes can be extended and tensioned prior to the placement of the working platform elements.

According to a still further aspect of the present invention, there is provided a method of erecting a void platform, the--method-comprising :--- (a) fixing at least one support rail on a horizontal plane with respect to wall framing members in the void area of a dwelling, (b) fixing upstands at the floor line adjacent the void, (c) erecting at least two elongate tubes in a parallel spaced relationship with respect to the support rail and the footing, (d) placing and securing elements of a working platform on the rails.

Brief Description of the Drawings Figures 1 to 4 are perspective drawings showing platform

systems according to the present invention in different situations and perspectives, and Figures 5 to 11 are illustrations of components of the platform system.

With respect firstly to figure 1 of the drawings, in one aspect of the present invention provides a void platform including a working platform generally indicated by arrow 1 including a tread 2 and attachment means generally indicated by arrow 3 extending from opposed ends of the platform.

Support rails generally indicated by arrow 4 are secured to vertical wall surfaces 5 within a void area the support rails being adapted to receive elongate hollow tubes generally indicated by arrow 6 which support the platform 1.

In the situation illustrated by figure 2, one end of the platform 1 is supported similarly to that shown in figure 1 and another end of the platform is supported by a tube 6 secured to upstands generally indicated by arrow 7 secured to a stair tread 8 via footings 9.

Figure 3 is a close-up perspective view of a rail 4 and a tube 6.

Figure 4 of the drawings is an underside perspective view of the manner in which elements of the system can be set up to support a platform (not shown) in two directions.

The support rail 4 provides an attachment flange 10 and a -support flange 11 joined by a common web 12.--- The flange 10 is provided with clusters of apertures 13 which enable it to be fixed in a horizontal plane to a wall or framing members by screws, bolts or other types of fasteners (not shown).

The attachment flange 10 is deeper than the support flange 11 and in combination with the web 12 a shallow channel 14 is provided.

The ends of the tubes 6 receive an adjustable attachment generally indicated by arrow 15 which can be in a number of forms best exemplified by figures 8,9 and 10.

In one form (figure 8), the adjustable attachment 15 comprises a footing 18, a threaded shank 19 and an adjustment nut 20.

In another form (figure 9) the adjustable attachment 15 comprises a footing 16 and a shank 17.

In yet another form (figure 10), the adjustable attachment 15 comprises a shank 21 and a bifurcated member 22 and a security bolt 22a.

Individual elements of the system are illustrated by figures 5 to 10 and elements of the system are used in the various system applications illustrated.

With respect to figure 11 of the drawings, the platform 1 and tread 2 can be reinforced by rails 22 to which the attachment means 3 in the form of tube hooks are secured.

The system and methodologies illustrated provide an unobtrusive void platform which can be speedily dismantled and erected in accordance with the objectives of the invention.

Erection of the platform which may be carried out by specialist installers or tradespeople on site involves erecting and securing the support rails 4 and/or upstands 7. The attachments 15 are then inserted in the ends of the tubes 6 and the tubes located on the support rails 4 or upstands 7 in the manner indicated. The nuts 20 of the figure 8 type attachment are wound on the threads 19 towards the tubes 6 so that the combination of the attachments 15 and tubes 6 is rigid. Where the platform is laid in two directions (figure 4), the attachment 15 illustrated by figure 10 can be used to secure one end of a tube in the manner illustrated.

The platforms can then be laid on the tubes 6 to provide a secure and safe horizontal working and support surface.

Dismantling of the platform is merely a reverse of the erection procedure.

Aspects of the present invention have been described by way of example only and modifications and additions thereto may be made without departing from the spirit or scope thereof.