AU722781B2 - Partly retractable construction platform - Google Patents

Description

-1- P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

S. S a.

Name of Applicant: Actual Inventor: Address for service in Australia: Invention Title: John Clement Preston John Clement Preston CARTER SMITH BEADLE Level 10, 189 Kent St Sydney NSW 2000 Australia Partly Retractable Construction Platform The following statement is a full description of this invention, including the best method of performing it known to us 2 PARTLY RETRACTABLE CONSTRUCTION PLATFORM This invention is an improvement in, or modification of, the invention described and claimed in the complete specification belonging to Australian Patent No. 708796, referred to as the "main invention" and the "main patent" respectively hereinafter.

The main invention relates to construction platforms of the kind that may be temporarily affixed to a floor of a multi-storey building under construction, so as to 10 project from floor outboard of the building. Such platforms are commonly used for the transfer of materials to or from the floor, by means of a crane able to deposit loads on the platform or uplift loads from the platform.

ooooo More particularly, the main invention relates to such platforms, known as retractable deck platforms, which comprise a stationary inboard portion, that may be affixed to the floor, and a movable deck, that is supported by the fixed portion and may ride to and fro thereon between an outboard position, in which the deck projects as a cantilever beyond an edge of the building floor, and an inboard 2 position, in which the deck is retracted into substantial registration with the inboard stationary portion. Such retractable deck platforms were developed to overcome a deficiency in earlier known fixed deck platforms, namely the need to stagger the positions of the platforms over the face of the building to ensure that platforms on higher floors did not impede crane load access to platforms on lower floors.

Retractable deck platforms are individually more complex and expensive than fixed deck platforms. Nevertheless they have found wide spread acceptance in the construction industry because they may be disposed in a single vertical file, one above the other, and this permits all the platforms to be serviced by a small, fixed and relatively inexpensive crane positioned above the file of platforms.

DOB:GUE:#33468.POA 25 January 2000 The main invention consists in a partly retractable platform in which the stationary portion may extend as a cantilever to a designed extent beyond the edge of the building floor to reduce the unsupported cantilever overhang of the movable deck when in its extended position. This enables a lighter and cheaper movable deck to be used. The limited projection of the fixed portion is chosen so that it does not unduly limit the volumetric size of crane loads that may be deposited upon or uplifted from a lower platform when the decks of higher platforms are retracted at least until the free or outboard ends of the movable decks substantially coincide with the free or outboard ends of the respective stationary portions.

99** V*9 o For safety's sake it is essential that the stationary portion of each platform in a vertical file of platforms projects beyond the edge of the floor to the correct or intended extent. If any stationary portion were to project too far, that portion would be subjected to greater than designed bending stresses at full load on its extended oooo deck. If one were to project too little the crane driver may cause the crane cable to foul others in the file on attempting to position a load on or near the centre of an extended deck supported by the offending stationary portion.

9 The main invention addresses that requirement by providing abutment means projecting from the underside of the stationary portion at one end thereof adapted to contact the edge of the building floor when the stationary portion is projecting to the designed extent.

As described in the specification of the main patent those abutment means are integral with, or also serve as, a rigidifying frame for the stationary part as a whole at one end thereof, being the free end as discussed above.

The modification or improvement of the present invention is to reposition the abutment means of the main invention either by positioning the rigidifying frame somewhat inboard of the free end of the stationary portion if and when such a frame is present and also serves as the abutment means, or to separate and space the 3IOI1:(:GUE:#3348POAna 25 January 2000 4 abutment means from the rigidifying frame if and when the latter remains at the free end of the stationary portion.

Therefore the present invention consists in a construction platform comprising a stationary support structure adapted to be fixedly secured to a floor of a building under construction so as to project as cantilever beyond an edge of the floor to a free end spaced from the edge of the floor to a predetermined maximum extent, and a movable deck mounted on the stationary support structure, which deck may be moved to and fro between an extended position wherein it projects as a 10 cantilever having an end spaced beyond the free end of the support structure and a o* retracted position wherein the said end of the deck substantially coincides with or lies inboard of the free end of the support structure, characterised in that abutment means projects from the underside of said support structure intermediate the ends thereof and in that, in use, said abutment means contacts said edge of the floor to ensure that said stationary support structure then projects beyond the edge of the floor so that its free end is spaced from the edge of the floor to said predetermined maximum extent.

In one class of embodiments the abutment means may be in the form of a 20 frame adapted to rigidify the stationary support structure. In that event, in accordance with the present modification of the main invention, that frame would be spaced inboard of the free end of the stationary support structure to an appropriate extent.

In a second class of embodiments such a rigidifying frame may be provided at the free end of the support structure, in which event, again in accordance with the present modification of the main invention, the abutment means would be independent of the frame and spaced inboard thereof. In preferred versions of this second class of embodiments, the abutment means may be detachably secured to the stationary support structure by means permitting positional adjustment of the abutment means to provide for variation of the extent to which the stationary 110OB:( UE:#3 3408. POA 25 January 2000 support structure projects beyond the edge of the floor. Such variation allows end users to opt for the convenience of greater platform projection at the cost of lower weight carrying capacity or vice versa, as they deem more appropriate to suit a particular crane at a particular building site.

By way of example, several embodiments of the subject invention are described in more detail hereinafter with reference to the accompanying drawings.

Figure 1 is a diagrammatic side elevation of a construction platform 10 according to the invention.

Figure 2 is a view from below of an outboard part of the platform of figure 1 drawn to a larger scale.

Figure 3 is a view similar to figure 2 of a second embodiment of the invention.

eeoe# Figure 4 is a view similar to figure 2 of a third embodiment of the invention.

20 Figure 5 is a side elevation of an outboard portion of the stationary support structure of the platform appearing in figure 2 drawn to a larger scale.

Figures 6 and 7 are views similar to figure 5 of further embodiments of the invention.

Figure 8 is a view similar to figure 5 of another embodiment of the invention drawn to a still larger scale.

Figure 9 is a view similar to figure 1 showing another embodiment of the invention II01:GUE:33468.I'OA 25 January 2000 The various illustrated embodiments have much in common and corresponding components in the several embodiments bear corresponding reference numerals in the drawings. Furthermore they have much in common with the embodiments of the main invention described with reference to the drawings in the specification of the main patent, which specification is incorporated herein by reference. Thus, for the sake of clarity, many of those components that have not been modified by the present invention do not appear in the drawings and are not described in detail hereinafter.

10 The construction platform illustrated by figures 1, 2 and 5 comprises a stationary support structure 10 and a movable deck 11.

a.

The stationary support structure 10 comprises two side beams 12 and four adjustable length props 13, of which two are associated with each side beam 12, 15 abutment means 14 projecting downwardly from the side beams 12, a cross member (not shown) extending from beam to beam at or near the inboard ends of the beams and a rigidifying frame 15 extending from beam to beam at their free ends.

o*o.

The various components of the stationary support structure 10 are welded or 20 otherwise fixed together, so that the structure is a rigid, unitary structure. The stationary support structure 10 may rest upon a floor 16 of a building under construction, with the props 13 extending to, and compressed against, the floor above, so as to clamp the platform in place. In other instances the stationary support structure may be temporarily fixed to the floor by other suitable means.

The abutment means 14 comprise a beam 17 extending from one side beam 12 to the other. Beam 17 may be a length of solid bar, square section tube or other hollow rectangular section, angle, channel or other conventional structural member, preferably presenting a flat face for contact with the edge of the floor 16.

The beam 17 is positioned such that when it contacts the floor 16 then the stationary BO13:GUE:#33468.POA 25 January 2000 support structure is projecting beyond the edge of the floor to the predetermined designed extent.

The side beams 12 may be I-beams or channels providing upper and lower spaced apart flanges. The movable deck 11 comprises deck beams 18, joists (not shown) extending between beams 18, a floor sheet 19 supported by those joists, and safety fences 20, including gates (not shown) at the ends of the floor sheet, extending about the periphery of the floor sheet. The deck beams 1 8 fit between the flanges of the corresponding side beams 16, and rollers or wheels are carried by one or other or both beams of each pair to allow the deck to ride to and fro upon the Sstationary portion, all as described more fully in the specification of the main patent.

The rigidifying frame 15 is disposed below the side beams 12 so as not to interfere with the movement of the deck. In the embodiment now being described the frame 15 is a triangulated frame comprising cross members 21 and braces 22.

The embodiment of the invention illustrated by figure 3 is the same as that of figures 1, 2 and 5 except that the beam 17 of the latter has been replaced by two individual abutments 23 welded to the respective side beams 12. Each of the 20 localised abutments may be a short length of the stock material of the beam 17.

The embodiment of the invention illustrated by figure 4 is the same as that of figures 1, 2 and 3 except that the triangulated frame 15 of the latter has been replaced by a ladder frame 24 comprising stiles 25 and rungs 26.

The embodiment of the invention illustrated by figure 6 is the same as that of figure 3 except that each localised abutment 23 of the latter has been replaced by a fabricated localised abutment 27 comprising, for example, a face plate supported by one or more preferably triangular gussets.

1O1:(ilJl:#33408. IOA2 25 January 2000 8 The embodiment of the invention illustrated by figure 7 is the same as that of figure 3 except that each localised abutment 23 of the latter has been replaced by a replaceable localised abutment 28 comprising, for example, a short length of rolled steel angle bolted to a flange of the corresponding side beam 12 The embodiment of the invention illustrated by figure 8 is the same as that of figure 7 except that a plurality of pre-drilled bolt holes are provided through a flange of each side beam 12, as indicated by hole centre lines in figure 8, to enable the position of each replaceable abutment 23 to be selected from a plurality of available positions.

The embodiment of the invention illustrated by figure 9 is the same as that of figures 1,2 and 5 except that the abutment beam 17 has been omitted and the frame 15 repositioned somewhat inboard of the free ends of the side beams to enable it to perform the dual functions of rigidifying the stationary support structure and serving as an abutment means, intermediate the inboard and outboard ends of the stationary support structure.

Il1A:(; UI :#33468.1IOA 25 January 2000

Claims (7)

1. A partly retractable construction platform comprising a stationary support structure adapted to be fixedly secured to a floor of a building under construction so as to project as cantilever beyond an edge of the floor to a free end spaced from the edge of the floor to a predetermined maximum extent, and a movable deck mounted on the stationary support structure, which deck may be moved to and fro between an extended position wherein it projects as a cantilever having an end spaced beyond the free end of the support structure and a retracted position wherein the said end of 10 the deck substantially coincides with or lies inboard of the free end of the support structure, characterised in that abutment means projects from the underside of said support structure intermediate the ends thereof and in that, in use, said abutment means contacts said edge of the floor to ensure that said stationary support structure then projects beyond the edge of the floor so that its free end is spaced from the 15 edge of the floor to said predetermined maximum extent.

2 A landing platform according to claim 1 wherein said stationary support structure at least partly comprises two substantially parallel, spaced apart side beams extending substantially from end to end of the support structure and a 20 rigidifying frame underlying and uniting said beams, and wherein said frame constitutes said abutment means and is spaced from the free end of the structure.

3. A landing platform according to claim 1 wherein said stationary support structure at least partly comprises two substantially parallel, spaced apart side beams extending substantially from end to end of the support structure and a rigidifying frame underlying and uniting said beams at the free end of the structure, and wherein the abutment means is independent of the frame and is spaced inboard thereof.

4. A landing platform according to claim I wherein said abutment means are fixed to the support structure by means permitting positional adjustment of the 111( i :G I:#33408. 11A 25 Januury 2000 abutment means to provide for adjustment of the extent to which the support structure projects beyond the edge of the floor.

A landing platform according to claim 3 wherein said abutment means comprises a beam extending from one said beam to the other.

6. A landing platform according to claim 3 wherein said abutment means comprises two individual abutments respectively fixed to said beams. 10

7. A landing platform substantially as described herein with reference to figures 1, 2 and 5, 3, 4, 6, 7, 8 or 9 of the accompanying drawings. DATED: 18 January 2000 CARTER SMITH BEADLE Patent Attorneys for the Applicant: JOHN CLEMENT PRESTON ()1OU:G UI.E:#3346(8.POA 25 January 2000