AU706856B3 - Construction platform - Google Patents

Description

2 CONSTRUCTION PLATFORM Field of the Invention The invention relates to construction platforms, that is to say temporary landings which in use extend away from an exterior face of a multi-storey building under construction.

Background of the Invention In the construction of multi-storey buildings it has been proposed to employ construction platforms to facilitate the removal and delivery of "'"materials to various floors under construction. One previously proposed .ooooi platform comprises a pair of generally parallel, co-extensive, transversely 15 spaced apart, horizontal beams which extend outwardly from a floor of a building under construction, a landing floor extending between the beams, and a safety rail extending about the outer free edges of the platform. The beams comprise supported portions that are fixedly secured on a floor of the building and cantilever portions that project from the building and carry 20 thelanding floor. Each beam may be so secured in position by at least two S•length adjustable struts which extend between a portion of the beam contacting one floor and an adjacent (usually the next above) floor of the building.

For descriptive convenience the terms "inboard" and "outboard" are used hereinafter with reference to a building, in the sense that items designated as inboard are disposed, when in use, within the perimeter of a relevant floor of the building, whereas items designated as outboard project from the building when in use and are disposed outside of that perimeter.

The terms are similarly used to designate the positions for the time being of F:\SPECS\30578.PET.DIV 12-February 1999 3 movable items that may be inboard at one time and outboard at another.

Further construction platforms having retractable decks which may be moved from an outboard to an inboard position and vice versa have also been previously proposed by the present inventor. Such prior known retractable deck platforms have comprised semi-permanent supporting beams of the kind used for conventional fixed floor platforms and a horizontally movable landing deck riding upon and carried by those beams.

However, such prior known movable deck constructions have been widely 10 regarded as unstable and therefore unsafe, and hitherto have not been widely adopted in practice. That perception has arisen because of the possibility of heavy loads, particularly impact loads, applied to the deck may cause the supporting beams to move apart, particularly at their free ends, to an extent where the deck is in danger of falling between them.

Objects and Summary of the Invention It is an object of the invention to provide a construction platform which substantially overcomes or at least alleviates the above mentioned 20 deficiency of prior proposed platforms, by very simple means.

The invention attains that objective by providing, in construction platforms of the kind having a retractable deck and releasable immobilising means for retaining the movable deck in a selected outboard operating position, of formations on the beam ends and the outermost edge of the deck which mutually engage as the deck moves into said position, whereby spreading apart of the beams is constrained by the deck.

Therefore the invention consists in a construction platform comprising a stationary support structure comprising two, spaced apart, F:\SPECS\30578.PET.DIV 12-February 1999 4 substantially parallel cantilever beams adapted to be fixedly secured to a floor of a building under construction, a movable landing deck having an outermost edge, which deck is carried by said beams and is able to ride to and fro thereon between an inboard and an outboard position relative to the building, immobilising means to releasably lock the deck in said outboard position, safety barrier means movable with the deck and extending along its said outermost edge and bracing means comprising mutually engagable formations on the cantilever beams and the deck which become engaged as the deck moves into said outboard position to thereby resist spreading apart of the beam's outboard ends.

The safety barrier means may comprise fixed safety railings or walls extending along the cantilever beams and swing mounted, lockable gates extending (when closed) along the outermost edge of the deck and moving 15 therewith.

Brief Description of the Drawings Figure 1 is a perspective view of three construction platforms 20 according to the invention having retractable landing decks supported by a partly outboard support structure comprising semi-permanently erected cantilever beams.

Figure 2 is a perspective view of the platforms of Figure 1 shown as used to load and unload a truck.

Figure 3 is a perspective view of portion of a cantilever beam and deck immobilising means, being components of a platform of the kind depicted in figure 1.

F:\SPECS\30578.PET.DIV 12-February 1999 Figure 4 is a cross section taken on line 4-4 of Figure 3, illustrating the immobilising means in the locked position.

Figure 5 is a view similar to figure 4 illustrating the immobilising means in the unlocked position.

Figure 6 is a perspective layout of a platform of the kind depicted in figure 1 with an electrically powered deck drive means.

Figure 7 is a detail view from one side of the portion of figure 6 .••included within the enclosure marked 7 in that figure.

Figure 8 is a view similar to figure 7 showing a drive means, being a S"component of the platforms of figure 1.

Figure 9 is a detail front elevation of guide and support means for a retractable deck, being components of a platform of the kind depicted in figure 1.

20 Figure 10 is a perspective view of an electrically powered friction drive means, being components of a platform of the kind depicted in figure 1.

Figure 11 is a view similar to figure 10 of an alternative drive means incorporating a rack and pinion mechanism which is electrically, mechanically or hydraulically powered.

Figure 12 is a perspective view of an end portion of a platform of the kind illustrated in figure 1 with its deck fully extended and braced for use, but with its end safety barrier omitted.

F:\SPECS\30578.PET.DIV 12-February 1999 Figures 13 and 14 illustrate details of bracing means, being components of the platform illustrated in Figure 12.

Figure 15 is a perspective view of an end portion of another embodiment of a platform according to the invention of the kind shown in figure 1.

Figure 16 is a perspective view of a brace element and a pair of length adjustable struts being components of a platform in accordance with the invention.

9. 99 9 9o Figure 17 is an exploded perspective view of the brace element and the pair of struts illustrated in Figure 16.

Best Mode and Other Embodiments of the Present Invention As shown in Figure 1, movement of materials into and out of a building under construction is facilitated by the use of one or more S 20 retractable deck, construction platforms 100 in accordance with the *o9invention and an overhead gantry or monorail crane 101. Each platform 100 comprises a semi-permanently erected stationary support structure comprising side rails or beams 102 and a movable landing deck 103 which is supported by and travels upon the beams 102 on rollers or bearings as described in more detail hereinafter. The deck 103 may be shifted between an inboard position (as shown in the two uppermost platforms of the figure) and an outboard position (as shown in the bottom platform of the figure), so that a load can be lifted straight through to the overhead rail 101. Similarly, a load may be deposited on any deck 103 when in its outboard position. Each platform 100 further comprises safety F:\SPECS\30578.PET.DIV 12-February 1999 barrier means comprising side walls 104 extending along at least the outboard portions of the beams 102 and folding or swinging doors 105 mounted on the deck 103. An end gantry 105 may be required to support the far end of the rail 101.

Figure 2 shows this type of construction platform permitting a load to be picked up from, or delivered to, a truck 106. Note that each platform is secured in place by telescopic struts 107 which may be located in pairs on either side of the platform and which may be manually or otherwise extended to secure the inboard portions of the beams 102 between floors of the building.

Figures 3 to 17 inclusive illustrate in greater detail the embodiment of the invention appearing in figure 1.

•C As shown in Figures 6, 7 and 8, the rear portion 7 of one of the support structure beams 102 may partially house electrical components depicted in Figures7 and 8, being a drive motor 108, operating switches 109 and a rear limit switch 110 for shutting off the motor 108 of o the drive means which advances and retracts the movable deck 103. The S" platform may also include a front limit switch 111 and various locking pins 112 for immobilising the deck in predetermined positions of use. A rear security gate or chain 113 may also be provided.

As shown in Figure 9 the deck 113 may comprise substantial Rectangular Hollow Section side members 114 with longitudinally extending flange plates 115 affixed to a rigidified floor panel 116 and running as movable rails upon supporting guide rollers 117 mounted on the respective I-beams 102.

F:\SPECS\30578.PET.DIV 12-February 1999 Figure 10 illustrates the drive means of the embodiment now being described. Those means comprise the electric 108 or other motor driving a driving wheel 118 through a right angled gearbox 119 mounted on a beam 102. The wheel 118 has a high friction surface to minimise slip between it and the floor panel 116. This friction drive mechanism further includes an adjusting or tensioning screw 120 which is used to increase or decrease the amount of pressure exerted by the wheel 118 on the deck floor 116. The friction roller 118 is held on a pivoting bracket 121 which is raised or lowered by adjustment of the tension screw 120.

*99* Figure 11 illustrates an alternative drive means for shifting the deck 103. In this instance the drive motor and gear box mounted on the :o beam 102 turns a pinion of a rack and pinion pair 122. The pinion is mounted for rotation about a fixed vertical axis and engages a longitudinally extending rack on the rail 114 through a slot in the web of the beam 102.

Rotation of the pinion gear causes the deck 103 to advance and retract.

Guide rollers 123 and 124 prevent the rack and pinion from becoming disengaged, and wheel 125 supports the weight of the deck and provides oo99 for its free movement.

S" Figures 3, 4 and 5 illustrate in greater detail a preferred embodiment of a locking mechanism, being. an immobilising means of the embodiment of the invention now being described. The illustrated mechanism comprises a latch bolt 126, a bolt guide 127 and a clip 128 to hold the bolt 126 in a retracted inoperative position.

Figure 4 illustrates the locking mechanism in an operative position with bolt 126 extending through openings in the top and bottom flanges of support beam 102, and through a hole in the edge margin of the movable deck 103 when the hole and openings are brought into register thereby F:\SPECS\30578.PET.DIV 12-February 1999 preventing relative sliding movement between the deck 103 and the beam 102. Whereas Figure 5 illustrates the locking mechanism in an inoperative position with bolt 126 (in ghost outline) in a retracted position in engagement with the clip 157, thereby permitting relative sliding movement between the deck 128 and the beam 102.

Figures 12, 13 and 14 illustrate details of the outer edge of the embodiment now being described, with the deck 103 in its outboard position of use. In particular, they illustrate bracing means for the platform comprising a pair of elongate stay elements 129, each having an end hinged by means of hinge joint 130 or otherwise pivotally mounted to a top S. Sedge of the exposed end of the retractable deck 103. The other end of 0l each of the stay elements 129 is releasably fastened or secured to a respective safety wall 104. The latter securement may be effected by the releasable fastening means shown in more detail by Figures 13 and 14 s comprising a tongue 131 having one end welded or otherwise attached to the stay element 129 thereby to extend substantially perpendicular to the S.i longitudinal axis of the stay element 129. The tongue 131 has an opening 132 piercing it near its other end. To fasten the stay element 129 to the safety wall 104 the tongue 131 is positioned to extend through an aperture S* 133 in an upright member 134 to enable a latch pin 135 having a hooked end 136 is then driven into said opening 132 thereby releasably securing the stay element 129 to the safety barrier wall 104. The latch pin 135 also extends through a clearance hole in a substantially horizontal member 137 of the wall 104 with the hooked end 136 hooked thereover.

The illustrated embodiments of the invention further comprise bracing means comprising, for example, locating holes 138 in end plates 139 applied to the beams 102 and pins 140 protruding from the front edge of the deck 103 adapted to penetrate the respective holes 138 to F:\SPECS\30578.PET.DIV 12-February 1999 thereby resist any tendency of the beams to spread apart. Those pins 140 thus constitute the third points of triangular constructions positively bracing the deck 103 and the beams 102 into a rigid entity.

Figure 15 shows an alternative bracing structure wherein the simple pins 140 are replaced by tongues 141 adapted to pierce slots in the end plates. This is a preferred form in that it better resists spreading of the lower flanges of the beams due to torsional strain therein. Moreover the tongues 141 may accept cotter pins 142 to lock the deck in place and provide further immobilising means.

:The end edge of the deck 103 is able to be closed by means of doors 114, detachably hinged to the walls 104. In this regard it is mentioned that the gates and/or chain 113 at the inboard end of the deck is/are primarily relied upon as a safety measure.

Figures 16 and 17 illustrate a pair of struts 143, such as struts 107, together with a releasably secured strut brace 144 to impart rigidity and stability to the strut structure. Each strut 143 comprises a Rectangular Hollow Section (RHS) member 145, a manually adjustable jack screw 146 with one end extending into the hollow core of tubular member 145, wing IglOO nut 147, floor or beam abutment means 148 at the other end of screw 146 and a bracket member 149. Said bracket member 149 comprises a tubular abutment member 150 of substantially the same cross section and dimensions as member 145, disposed within a sleeve 151 of substantially the same cross sectional shape but of larger dimensions, formed so that the bracket member 149 fits neatly over and sits on the end of the tubular member 145. A flange 152 projects from the sleeve 151. The flange 152 provides a mounting for the ends of brace element 144. The brace element 144 is in the form of an elongate C-section structural member. The brace F:\SPECS\30578.PET.DIV 2-February 1999

II

element 144 is mounted to the bracket member 149 by fastening means, for example the nut and bolt illustrated in Figure 17.

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1. A construction platform comprising a stationary support structure comprising two, spaced apart, substantially parallel cantilever beams s adapted to be fixedly secured to a floor of a building under construction, a movable landing deck having an outermost edge, which deck is carried by said beams and is able to ride to and fro thereon between an inboard and an outboard position relative to the building, immobilising means to releasably lock the deck in said outboard position, safety barrier means movable with the deck and extending along its said outermost edge and bracing means comprising mutually engagable formations on the cantilever beams and the deck which become engaged as the deck moves into said o outboard position to thereby resist spreading apart of the beam's outboard i. ends.

2. A construction platform according to claim 1 wherein said bracing means comprise end plates on the beams and pins on the deck which extend through respective clearance holes in said end plates when the deck is in the outboard position.

3. A construction platform according to claim 1 wherein said bracing means comprise end plates on-the beams and tongues on the deck which extend through respective clearance slots in said end plates when the deck is in the outboard position.

DATED: 15 February 1999 CARTER SMITH

BEADLE

Patent Attorneys for the Applicant: JOHN CLEMENT PRESTON F:\SPECS\30578.PET.DIV 12-February 1999

Claims (1)

12-February 1999