WO2001034923A1

WO2001034923A1 - Scaffolding system

Info

Publication number: WO2001034923A1
Application number: PCT/AU2000/001385
Authority: WO
Inventors: Paul Rodney Hodges
Original assignee: Auscaf Pty Ltd; Auscaf Holdings Pty Ltd
Priority date: 1999-11-10
Filing date: 2000-11-10
Publication date: 2001-05-17

Abstract

According to the first aspect of the present invention there is provided apparatus for positioning a ledger (14) on scaffolding or the like, including a plurality of linearly-spaced depressions extending along an external surface of the scaffolding, comprising a ledger coupling (18) through which the ledger (14) is coupled to the scaffolding and a bidentate element pivotally mounted to the ledger coupling and arranged in use for engaging a selected one of the depressions to prevent movement of the ledger along the scaffolding. Other aspects of the invention include a base support (50) for supporting scaffolding, and a load-bearing member for bearing the load of a suspended scaffolding system.

Description

SCAFFOLDING SYSTEM

Field of the Invention

The present invention relates to scaffolding arrangements or similar framework.

Background to the Invention

Scaffolding arrangements typically comprise a plurality of bracketed vertical poles with a ledger secured to each pole. The term ledger typically refers to a horizontal pole or member that is lashed or otherwise fastened across the standards in a scaffold. In the present specification the term "ledger" will be used to refer to any generally horizontal member that is used in framework to provide a support (ledge-like) function. Typically, a ledger provides support for one end of a ledger board, with an opposing ledger providing support for the opposite end of the board. Ledger boards enable builders and tradesmen to walk around the external (or internal) faces of a building, particularly at elevated heights . Suspended scaffolding is scaffolding that is hung or suspended off the side of a building (i.e. it is not constructed from the ground up) . For example, suspended scaffolding is often mounted to rafters and trusses in building structures. When such scaffolding is used at life threatening heights, it is important that it be easy and safe to construct and use.

In many types of scaffolding, ledgers must be moved from time to time to adjust the height of the ledger board (e.g. for working on different levels, or where the building height is increased etc). Thus, systems have

Substitute Sheet (Rule 26) RO/AU been developed which enable the ledger to be moved up and down a scaffolding pole and be fastened at different points therealong. In the case of suspended scaffolding, operators cannot step down to a lower support scaffolding when moving the ledger and hence it would be desirable for the ledger to be capable of both easy movement and easy fastening.

Summary of the Invention

According to a first aspect of the present invention there is provided apparatus for positioning a ledger on scaffolding or the like, including a plurality of linearly-spaced depressions extending along an external surface of the scaffolding, comprising a ledger coupling through which the ledger is coupled to the scaffolding and a bidentate element pivotally mounted to the ledger coupling and arranged in use for engaging a selected one of the depressions to prevent movement of the ledger along the scaffolding.

The employment of apparatus configured in this manner can allow for easy fastening of the ledger at a given position but can still enable the ledger to be readily released for movement up and down the scaffolding (or similar) .

Preferably the bidentate element faces the depressions when the ledger is mounted on the scaffolding, wherein in use the bidentate element engages a selected one of the depressions in a first tilted position of the ledger to prevent movement of the ledger along the scaffolding, and is released from engagement by tilting the ledger to a second position. In this regard, the bidentate element and a selected one of the depressions can be brought into interfering engagement to restrict the movement, and can be moved out of such engagement whilst still maintaining the mounting of the ledger on the scaffolding, thus enabling the ledger to be moved along the scaffolding (e.g. up or down) .

Preferably the plurality of linearly-spaced depressions are in the form of a corrugated section fixable to or incorporated within one side of a post of the scaffolding (or similar) . The bidentate element may comprise a bifurcated pin insertable through the ledger and locatable in a given depression to fasten the ledger at a given position on the scaffolding.

The bidendate element preferably includes two teeth, and either of the two teeth may engage the selected depression, depending upon the relative orientation of the two teeth. In particular, where a telescopically- extendable scaffolding is used, those sections of scaffold which extend out from base sections have a lesser cross- section than the base sections and so the depressions on the extended sections of scaffolding will be further from the bidendate element than depressions on the base sections. Thus a first tooth of the bidentate element will engage these depressions while a second, relatively shorter tooth of the bidentate element will engage the depressions on the base sections. In a particular embodiment, the first and second teeth differ in length by about 3mm.

Preferably the ledger coupling includes oppositely- facing flange plates and the bidentate element is mounted to one of these. In use, each depression is preferably formed on one side of a scaffolding post (also referred to as a strut) , and the post is preferably positioned between the flange plates such that one of the teeth of the bidentate element is locatable in a depression. Preferably the ledger coupling is arranged such that it can be tilted with respect to the post about a horizontal axis, such tilting enabling the bidentate element to be moved out of one depression and, after movement of the ledger coupling along the post, into another depression. Preferably the apparatus is designed such that the ledger is fasteningly engaged to the post by default unless the ledger coupling is tilted to bring it out of engagement.

Preferably the ledger coupling is connected (e.g. welded) to the ledger through a brace plate, which in turn connects the flange plates at a side of the post opposite to said one side of the post, wherein the weight of the ledger is distributed so as to urge one of the teeth of the bidentate element into a depression in use. In other words, the weight of the ledger is distributed to bias the bidendate element into engagement with one of the depressions, unless the weight is counteracted, such as by lifting the ledger board.

Preferably the ledger is pivotally mounted to the ledger coupling. The ledger may be connected to form a bracing structure for bracing a scaffold against movement relative to a building. The ledger coupling may further comprise a stop member against which a base of the ledger rests when in an operational configuration and which stops further rotation of the ledger.

Typically the ledger supports a scaffolding board or similar (e.g. a ledger board, ribbon, strip, gird strip, horizontal timber, shelving etc) when in the operational configuration, typically when disposed horizontally. According to a second aspect of the present invention there is provided a scaffold comprising at least one upright post, each with a plurality of linearly-spaced depressions extending along an external surface thereof, a ledger mounted to each post of the scaffold through a ledger coupling, and a bidentate element pivotally mounted to each ledger coupling and arranged in use to engage a selected one of the depressions to prevent movement of the ledger along a respective post. The scaffold may be either a suspended scaffold or constructed from the ground up.

The ledger may comprise a post support means for providing laterally bracing a scaffold post, and may comprise an extendable arm. The arm may be telescopically adjustable in length so as to allow the scaffold to be spaced a suitable distance from the building. The post support means may include a stud engagement means at an end distal to the ledger coupling, for engaging a stud forming a part of a building. The position of the post support means on the scaffolding may be adjusted in the same manner as the ledger described above. Any suitable stud engagement means may be employed, such as a bracket which extends around a stud.

The scaffolding may also include a hand rail system. Advantageously the hand rail system is separate to the scaffold and may be connected thereto during construction, but may also contribute to bracing the structure.

In a particularly preferred embodiment, the hand rail is reversibly secured by clamp means associated with clamp coupling means which couple the clamp means to the scaffolding. In particular, these may comprise a bracket adapted for a loose fit about the hand rail post, which may be wedged in the desired position.

According to a third aspect of the present invention there is provided a base support for supporting scaffolding, comprising a base plate for resting upon the ground on an underside and having socket on an upper side arranged to form a ball-and-socket joint with a ball formed on a piece of scaffolding.

The ball may be formed at an end of a vertical scaffolding post, which may be extendable. A scaffolding post may be supported by the base support as well as a post support means as described above. Accordingly, once a plurality of post support means are secured to a building, the respective posts can be bracketed together and extended upwards. The scaffolding may be fixed to a building at various points in the manner described above for the post support means . The posts may be telescopically extendable and additional posts may be joined on top, where necessary. In one embodiment of the invention a pin adapted to fit the depressions formed in the scaffold may be used to secure the extension in the extended position.

According to a fourth aspect of the invention there is provided a load-bearing member for bearing the load of a suspended scaffolding system, comprising: - a cantilever member on which a plurality of linearly-spaced depressions are formed, the cantilever being arranged to pivot at a pivot point along its length; a bracket being moveable along the cantilever and being arranged to hold the cantilever at a selected position along its length by engaging a selected one of the depressions; and a pitch control means connected to the bracket for tilting the cantilever around its pivot point and holding the cantilever at a selected pitch.

In one embodiment the bracket member is associated with the cantilever member at an end distal to an end joined to the scaffold, said cantilever member being pivotally mounted to the building. The pitch control member is joined to said bracket member and movement of said bracket member in the manner described above in connection with the ledger allows for adjustment of the pitch of the cantilever member.

According to a fifth aspect of the present invention there is provided scaffolding apparatus allowing for a positional adjustment of a cantilever member, including a first element located on or incorporated at an external surface of the cantilever member and a second element associated with the cantilever member and arranged in use for engaging the first element to prevent movement of the cantilever member once the positional adjustment has been made . The scaffolding may also include a hand rail system. Advantageously the hand rail system is separate to the scaffold and may be connected thereto during construction, but may also contribute to bracing the structure.

In a particularly preferred embodiment, the hand rail is reversibly secured by clamp means associated with clamp coupling means which couple the clamp means to the scaffolding. In particular, these may comprise a bracket adapted for a loose fit about the hand rail post, which may be wedged in the desired position. Throughout this specification and the claims, the words "comprise", "comprises" and "comprising" are used in a non-exclusive sense, except where the context requires otherwise .

Brief Description of the Drawings

Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 shows a side elevation of a tilt-up ledger in accordance with the present invention;

Fig. 2 shows a typical scaffolding arrangement in accordance with the present invention;

Fig. 2A shows a side elevation of base support means in accordance with the present invention, including detail of the extendable arm and stud connection means;

Fig. 3 shows the detail of the stud connection means and ball top plate connection means;

Fig. 4 shows an arrangement for connection suitable for use at a corner;

Fig. 5 shows a unidirectional base plate in accordance with the present invention; Fig. 6 shows means for extending the vertical poles in a scaffold in accordance with the present invention;

Fig. 7A shows a preferred means of adjusting the pitch of a cantilever member in a suspended scaffold in accordance with the present invention; Fig. 7B shows another means of adjusting the pitch of the cantilever member,-

Fig. 7C shows various other arrangements for suspending scaffolding;

Fig. 8 shows the application of a bracing system to the scaffolding;

Fig. 9 shows a guard rail arrangement in accordance with the present invention;

Fig. 10 shows a guard rail to post connection in accordance with the present invention; and

Fig. 11 shows a hand rail joiner and corner swivel.

Detailed Description of the Drawings

Referring firstly to Figs 1 to 3, apparatus for positioning a ledger on scaffolding will now be described. It should be remembered that the apparatus can be used on any framework and is not limited to scaffolding applications (e.g. it can be used on ladders, shelves etc) .

The apparatus includes a first element in the form of corrugated plate 10 mounted (such as by welding, bolting, riveting etc) to a vertical strut 12, being part of a scaffolding system (e.g. a suspended scaffolding system) . Mounted on vertical strut 12 for sliding movement therealong is a ledger 14, which comprises a generally horizontally extending ledger member 16 attached to and extending outwardly from a ledger coupling 18. The ledger member typically supports timber (or other) planking thereon to provide a walkway for users of the scaffolding system.

The ledger coupling 18 includes a front brace plate 20 (to which the ledger member 16 is mounted - e.g. welded) and a pair of opposing flange plates 22 extending away from the brace plate in a direction opposite to the member 16. One or both flange plates has a bidendate element in the form of a bifurcated pin 24 including teeth 25, 26 pivotally mounted thereto via pivot 27. It will be appreciated that either of the teeth 25, 26 may engage one of the depressions in corrugated plate 10, depending upon the relative orientations of the two. In this respect corrugated plate 10A is shown in phantom, this plate representing, for example, the corrugated plate on a base piece of a telescopic strut, which will be closer to the pivot 27 than the corrugated plate 10 on the extension since the extension if of lesser cross-section. In the operative configuration, with the tilt-up ledger 16 shown in the horizontal position (referred to by reference numeral 16A) , it can be seen that the apparatus will have a certain amount of play or tilt with respect to post (or strut) 12. The weight of the ledger in this position will tend to cause the ledger coupling 18 to pivot so that its rear (adjacent where the bifurcated pin 24 is attached) will be raised and its front lowered. The bifurcated pin 24 is shown is nestled within a depression on corrugated plate 10 and in such a position the ledger is effectively locked against movement along post 12.

It will also be appreciated that the ledger 16 is able to tilt from a horizontal, operative position (designated as 16 in the drawing) to an inoperative position (designated as 16A) in which it is tilted upwards. The ledger 16 pivots about pivot 17, but can only pivot so far that its end adjacent the ledger coupling 18 abuts stop member 19. In this position no matter what amount of weight is positioned on the ledger it cannot rotate beyond stop member 19 and so cannot go beyond the horizontal.

By releasing weight from the ledger coupling 18, the bifurcated pin 24 is freed for sliding movement up and down strut 12. Once the ledger has been moved to a new desired height, the ledger member is allowed to tilt back downwardly until it resumes the original position, and the bifurcated pin 26 is then located within a new depression.

Typically the depressions are spaced to provide a wide selection of height levels for a user of the system.

The diameter of the bifurcated pin 24 and internal diameter of each depression can be set so that small increments of movement of the ledger up and down the post can be achieved, thus providing a user with a full range of height levels along the vertical post. This contrasts favourably with prior art arrangements . Fig. 2 shows an embodiment of an apparatus in accordance with the present invention in use. As can be seen, the ledger 16 supports a plank 36 to enable the user

(e.g. a tradesman) to access the wall 38 or roof 40 of a building 42. As can be seen the scaffolding may be suspended from the roof 40 of the building and a lower end of the post 12 is fitted with a post support means in the form of an arm 46, which spaces a lower end of the post 12 from the dwelling and can be secured thereto. Fig. 2A shows an alternative embodiment of a scaffold in which the ledger is in the form of a telescopically-extendable ledger 47 comprising a first section 47A attached to the ledger coupling and a second section 47B which is received within the first section 47A. A hand-tightened bolt 47 As used to lock the second section 47B relative to the first section 47A and prevent relative sliding. A stud engaging means 47C is provided at an end 47D of the extendable arm 47 distal to the ledger coupling 20. The bracket 47C is connected to the arm 47 via a shaft 48 which permits the bracket to be rotated 360°. A further embodiment is shown in Fig 4 in which the arm 47 is articulated at four pivot points 49. This embodiment is particularly useful for connecting to two studs 49B which join at an angle, such as at an eve of a roof.

Fig. 5 shows an embodiment of a base support 50 for supporting scaffolding. The base support comprises a base plate 52, having an underside for contacting the ground, and a ball and socket joint 54 mounted to its upper surface. The joint 54 receives ball 56 attached to the base of strut 12. The base plate illustrated in Fig. 5 ensures that scaffolding can extend vertically from a base plate which is orientated to lie squarely on sloping ground, thereby ensuring that there is a solid base for the scaffolding.

Fig. 6 shows a height adjustment mechanism for vertical post 12 in a scaffolding system. In this case a pin 60 and another pin 62 engage the corrugated plate 10 on the vertical strut 12 in the region of overlap of two sections of the telescopically extendable strut in order to secure the two portions of the strut in the disposition shown .

Fig. 7 shows an arrangement for suspending a scaffolding system in which a cantilever member 60 has linearly-spaced depressions in the form of a corrugated top surface 62, and a bracket 64 formed therearound at the end distal to the cantilever member. A pitch control member such as rod 66 is connected to the bracket 64 in the manner of a ledger to a ledger coupling, and is held in the position shown using the bidendate element described above in relation to that system. Movement of the bracket 64 along the cantilever member 60 results in a change in pitch in the cantilever member, which allows for non-standard eaves to be accommodated in building a suspended scaffold. In the embodiment shown in Fig 7, the cantilever member 60 is fastened with a pin 67 to an inverted U-shaped extension 68 of scaffold post 12 since a gutter 69A and fascia 69B prevent a direct connection between the cantilever member and scaffold post. Although not essential, the rod 66 in this embodiment is in the form of a length-adjustable threaded rod for enabling very small pitch adjustments.

Fig. 8 shows a bracing system in which a brace 70 is secured to a strut 12 through engagement with corrugated plate 10. In this case bracing coupling 72 is secured to the bracing 70 and attaches to the corrugated plate 10 in the manner described above for a ledger. The bracing system extends between a plurality of vertical struts 12 in order to brace the scaffolding.

An embodiment of a guard rail system is illustrated in Figs. 9 to 11. The guard rail system comprises a guard rail post 80 secured through an extendable safety rail bracket 82 to the top plate of a stud 83. Each guard rail post 80 has a groove 86 machined near its base and a pin may be inserted into a collar 88 in which the base of the post 80 rests, to secure the post therein. It will also be noted that the safety rail bracket is adjustable in length to adjust for the eave width. Once the guard rail posts are in place, each post 80 is connected (see Fig 10) at an upper end to a transverse guard rail 84 using a clamping arrangement 90. The clamping arrangement 90 comprises clamp members 92, 94 pivotally connected by member 96. The arrangement also includes a bolt 98 which acts on member 96 so that the clamp members 92,94 may be locked in clamped disposition, as shown in Fig. 10. The clamping arrangement 90 includes a bracket 100 sized to slide over guard rail post 80 but to be a loose fit, whereby forcing wedge 102 into the position shown secures the clamping arrangement 90 at a particular height. It will be noted that wedge 102 is connected to the bracket 100 by chain 104 to ensure it is not lost. Detail of the arrangement of the hand rail at a corner is shown in Fig. 11.

Whilst the invention has been described with reference to a number of preferred embodiments, it should be appreciated that the invention can be embodied in many other forms .

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. Apparatus for positioning a ledger on scaffolding or the like, including a plurality of linearly-spaced depressions extending along an external surface of the scaffolding, comprising a ledger coupling through which the ledger is coupled to the scaffolding and a bidentate element pivotally mounted to the ledger coupling and arranged in use for engaging a selected one of the depressions to prevent movement of the ledger along the scaffolding.

2. The apparatus according to claim 1 wherein the plurality of linearly-spaced depressions are in the form of a corrugated section fixable to or incorporated within one side of a post of the scaffolding.

3. The apparatus according to either claim 1 or claim 2 wherein in use the bidentate element engages a selected one of the depressions in a first tilted position of the ledger to prevent movement of the ledger along the scaffolding, and is released from engagement by tilting the ledger to a second position.

4. The apparatus according to any one of the preceding claims wherein the bidentate element comprises a bifurcated pin locatable in a selected depression.

5. The apparatus according to any one of the preceding claims wherein the bidentate element comprises a first tooth and a second tooth, the first and second teeth having different lengths.

6. The apparatus according to any one of the preceding claims wherein the weight of the ledger is distributed such that in use the bidentate element is urged to engage one of the linearly-spaced depressions .

7. The apparatus according to any one of the preceding claims wherein the ledger coupling further comprises a stop member against which a base of the ledger rests when in an operational configuration and which stops further rotation of the ledger.

8. A scaffold comprising at least one upright post, each with a plurality of linearly-spaced depressions extending along an external surface thereof, a ledger mounted to each post of the scaffold through a ledger coupling, and a bidentate element pivotally mounted to each ledger coupling and arranged in use to engage a selected one of the depressions to prevent movement of the ledger along a respective post.

9. The scaffold according to claim 8 wherein the ledger comprises a post support means for laterally bracing a post.

10. The scaffold according to claim 9 wherein the post support means comprises an extendable arm.

11. The scaffold according to either claim 9 or claim 10 wherein the post support means includes a stud engagement means at an end of the arm distal to the ledger coupling, the stud engagement means being arranged to engage a stud forming part of a building.

12. A base support for supporting scaffolding, comprising a base plate for resting upon the ground on an underside and having a socket on an upper side arranged to form a ball-and-socket joint with a ball formed on a piece of scaffolding.

13. The base support according to claim 12 wherein the ball is formed at an end of a vertical scaffolding post .

14. A load-bearing member for bearing the load of a suspended scaffolding system, comprising: a cantilever member on which a plurality of linearly-spaced depressions are formed, the cantilever being arranged to pivot at a pivot point along its length; a bracket being moveable along the cantilever and being arranged to hold the cantilever at a selected position along its length by engaging a selected one of the depressions; and a pitch control means connected to the bracket for tilting the cantilever around its pivot point and holding the cantilever at a selected pitch.

15. The load-bearing member of claim 14 wherein the bracket member is associated with the cantilever member at an end distal to an end joined to the scaffold, said cantilever member being pivotally mounted to the building.

16. Scaffolding apparatus allowing for a positional adjustment of a cantilever member, including a first element located on or incorporated at an external surface of the cantilever member and a second element associated with the cantilever member and arranged in use for engaging the first element to prevent movement of the cantilever member once the positional adjustment has been made.

17. An apparatus for positioning a ledger on scaffolding or the like substantially as herein described with reference to the accompanying drawings.

18. A scaffold substantially as herein described with reference to the accompanying drawings . - 1 <

19. A base support substantially as herein described with reference to the accompanying drawings .

20. A load-bearing member for bearing the load of a suspended scaffolding system, substantially as herein described with reference to the accompanying drawings .

21. Scaffolding apparatus allowing for a positional adjustment of a cantilever member, substantially as herein described with reference to the accompanying drawings.