Scaffold ledger

Abstract

There is disclosed a scaffold ledger for use in a scaffolding system, whereby pairs of the scaffold ledger are arranged to support scaffolding boards for assembling a continuous working platform. The scaffold ledger has a tube with opposed ends, the tube carrying opposed connecting heads provided at each of the opposed ends. The connecting heads are laterally offset from a longitudinal axis of the tube so that the opposed ends of the tube extend outwardly beyond their respective connecting heads. The opposed ends of the tube are at least partially cut-away along a plane parallel to the longitudinal axis of the tube to form opposed access spaces located operatively above the connecting heads, thereby to permit access for the installation or removal of locking wedges to / from the respective connecting heads.

Description

[0001] Scaffold ledger

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a scaffold ledger.

[0004] More particularly, the present disclosure relates to a scaffold ledger for use in a scaffolding system for enabling a continuous work platform to be erected above an intermediate support post of the scaffolding system.

[0005] BACKGROUND ART

[0006] Ringlock scaffold systems include upright support posts with a series of connection points located at selected points along the length of the support posts. The support posts are also commonly referred to as standards. The connection points are rosettes that are used to releasably engage ledgers, transoms, and bracing members to provide a stable frame structure for supporting scaffolding boards to form a raised working platform. The ledgers are joined to and extend horizontally between two neighbouring support posts, while the scaffolding boards are supported between two parallel ledgers. The scaffolding boards used to be wooden planks but in ore modern times are more commonly manufactured as a metal body.

[0007] Often a project will require multi-level work platforms to provide a flat work surface over uneven terrain. This is typically the case in large construction or renovation projects that require multiple subcontractors, such as electricians, plumbers, plasterers, and painters, to be working simultaneously at the same jobsite.

[0008] In conventional scaffolding systems, the upper parts of the support posts that are located within the perimeter of the raised working platform protrude above the scaffold boards and these create a trip hazard for workers moving around on the working platform. This problem is illustrated in Figures 1a and 1b, wherein the upper parts of the scaffolding support post, and the fixing pins of a ledger joined thereto, are shown protruding above the working platform (indicated by arrow “A”).

[0009] One method currently used to overcome the above problem is to build a support grid (indicated by arrow “B”) on top of the scaffolding support posts and then cover this support grid with wooden sheets (indicated by arrow “C”), e.g. plywood sheets, to provide a continuous working platform (see the photos in Figures 1c and 1d). This arrangement causes difficulties when the working platform needs to be raised to a different height, because the support grid and all the wooden sheets would need to be dismantled to permit the support posts to be extended to the new height, whereafter the support grid and wooden sheets would need to be replaced. This is a very timeconsuming process.

[0010] There is thus a need for a scaffolding system that permits the height of a large working platform to be changed more easily and quickly.

[0011] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

[0012] SUMMARY OF THE DISCLOSURE

[0013] According to a first aspect of the disclosure, there is provided a scaffold ledger for use in a scaffolding system, whereby pairs of the scaffold ledger are arranged to support scaffolding boards for assembling a continuous working platform, wherein the scaffold ledger comprises a tube having opposed ends, wherein the tube has a longitudinal axis; opposed connecting heads being joined to the opposed ends of the tube, whereby the connecting heads are laterally offset from the longitudinal axis of the tube, and wherein the opposed ends of the tube extend outwardly beyond their respective connecting heads; wherein the opposed ends of the tube are at least partially cut-away along a plane parallel to the longitudinal axis of the tube to form opposed access spaces located operatively above the connecting heads, thereby to permit access for the installation or removal of locking wedges to / from the respective connecting heads.

[0014] According to a second aspect of the disclosure, there is provided scaffold ledger for use in a scaffolding system, whereby pairs of the scaffold ledger are arranged to support scaffolding boards for assembling a continuous working platform, wherein the scaffold ledger comprises a first tube having opposed ends, wherein each of the opposed ends is provided with a connecting head; a second tube having opposed ends, wherein the second tube is located in a spaced lateral relationship parallel to the first tube, and wherein the opposed ends of the second tube extend outwardly beyond the opposed ends of the first tube, wherein the second tube is arranged to support the scaffolding boards; one or more bridging members rigidly joining the first tube to the second tube; wherein the opposed ends of the second tube are at least partially cut-away along a plane parallel to and offset to a plane extending through the longitudinal axes of the first tube and the second tube, thereby to form opposed access spaces located operatively above the connecting heads and permit access for the installation or removal of locking wedges to / from the respective connecting heads.

[0015] The opposed ends of the tube of the first aspect, or the opposed ends of the second tube of the second aspect, may be cut-away for more than 50% of its cross-section.

[0016] The opposed ends of the tube of the first aspect, or the opposed ends of the second tube of the second aspect, may have stiffener plates extending along the cut-away plane between its free circumferential edges, whereby the stiffener plates are arranged to increase the carrying strength of the segment ends.

[0017] The connecting heads may be laterally offset from the tube, or second tube, to an extent that is, in use, sufficient to cause the tube, or second tube, to support the scaffolding boards at a level where a top surface of the scaffolding boards lies substantially co-planar with or above a top end of any support posts to which the connecting heads are connected.

[0018] BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other features will become more apparent from the following description with reference to the accompanying schematic drawings given as an example. The drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

[0020] Figures 1a, 1b, 1c, and 1d show various prior art scaffolding systems;

[0021] Figure 2 is a perspective view of a first embodiment of a scaffold ledger according to the present disclosure; and

[0022] Figure 3 is a perspective view of a scaffolding system showing a raised working platform supported by the scaffold ledgers of Figure 2;

[0023] Figures 4 is an enlarged perspective view of a central part of the working platform of Figure 3 that shows an intermediate support post located within the confines of the working platform;

[0024] Figure 5 is a side view of the working platform shown in Figure 4;

[0025] Figures 6a to 6d show respective operational steps in connecting one end of the scaffold ledger of Figure 2 to a rosette on a support post;

[0026] Figure 7 is a perspective view equivalent to that of Figure 4, wherein the intermediate support post is covered by an infill panel; and

[0027] Figure 8 is a perspective view of a second embodiment of a scaffold ledger according to the disclosure.

[0028] DETAILED DESCRIPTION OF THE DRAWINGS

[0029] Referring to Figure 2, there is shown a scaffold ledger 10 according to the present disclosure for use in a scaffolding system 100 as shown in Figure 3. The ledger 10 is arranged to enable the formation of a continuous raised working platform 102 above any intermediate scaffold support posts of the scaffolding system 100.

[0030] As shown in Figures 3 to 5, the scaffolding system 100 includes a series of support posts 104 that are normally arranged in a rectangular matrix. The example shown is a three-by-three square matrix wherein there are four corner support posts 104a, four lateral support posts 104b, and a single central or intermediate support post 104c that is located at the center of the working platform 102 but that is largely hidden from view beneath the working platform 102. The scaffolding system 100 can be enlarged to any larger n-by-n matrix having a larger number of lateral support posts 104b and multiple intermediate support posts 104c. The scaffolding system 100 can also be constructed into other non-rectangular polygonal shapes.

[0031] The support posts 104 have feet 106, referred to as screwjacks or base plates, and are further provided with a number of connection points that are positioned at spaced locations along the length of the support posts 104 - in the exemplary embodiment these are provided as rosettes 108 that are mounted onto or welded to the support posts 104. The feet 106 typically have a screw adjustment for making small height adjustments to the level of the working platform 102 so that it can be made horizontally level. The longitudinal length (i.e. operative height) of the support posts 104 can be increased by joining multiple supports posts end-on-end by inserting interconnecting spigots into the open ends of the support posts 104. The rosettes 108 define a number of through-hole ports 110 spaced around the support posts 104 that are arranged to receive a locking wedge as will be described below.

[0032] The support posts 104 are interconnected by conventional ledgers 112 that are joined to the rosettes 108, and arranged to extend horizontally between neighbouring support posts 104 so that the conventional ledgers 112 form one or more rectangular grids having opposed parallel sides. The support posts 104 are also often interconnected by angled braces (not shown), which cooperate to increase the structural rigidity of the scaffolding system 100.

[0033] The conventional ledgers 112 are single tube ledgers comprising a single elongated tube - these types of ledgers are shown in Figure 3 in a lower part of the structure and also as guardrails surrounding the working platform 102.

[0034] The ledgers 10 of the present disclosure are used to support the working platform 102. The ledgers 10 are also joined to the rosettes 108 so that they extend horizontally between neighbouring support posts 104.

[0035] The working platform 102 comprises a number of scaffolding boards 114 that are arranged side-by-side and end-on-end to form the working platform 102. The scaffolding boards 114 have hooks 116 on their opposed ends for hooking over the ledgers 10. The hooks 116 are arranged in an offset manner so that they are able to interlocate between the hooks of a neighbouring scaffolding board when these are placed end-to-end on a common ledger 10 - this interlocation is illustrated more clearly in Figure 4.

[0036] As shown in Figure 2, the ledger 10 includes parallel first and second tubes 12, 14 that are joined together by a number of spaced bridging members 16. The first tube 12 is effectively a connecting tube and is arranged to be joined to the rosettes 108; whereas the second tube 14 is effectively a carrying tube and is arranged to support the scaffolding boards 114. The carrying tube 14 is arranged to be located operatively above the connecting tube 12 when the ledger 10 is joined to the support posts 104 in use. The opposed ends of the connecting tube 12 are each joined to a connector head 18, with the connector heads 18 being laterally offset from the longitudinal axis of the carrying tube 14. The connector head 18 defines a slot 20 formed between an upper flange 22 and a lower flange 24. The connector head 18 is arranged to be joined to the rosette 108 whereby the peripheral rim of the rosette 108 is received within the slot 20 so that the upper flange 22 and the lower flange 24 are positioned either side of a port 110 through the rosette 108. A removable locking wedge 26 is insertable through orifices in the flanges 22, 24 and through the port 110 to secure the connector head 18 to the rosette 108 and thereby join the connecting tube 12 to the support post 104.

[0037] The carrying tube 14 is longer than the connecting tube 12 so that the opposed ends of the carrying tube 14 extend outwardly and overlap the connector head 18 of the connecting tube 12. The opposed ends of the carrying tube 14 extend up to, or outwardly beyond, the outer edges of their respective connecting heads 18. The opposed ends of the carrying tube 14 are cut-away to form a segment end 28 and provide an access space 30 for the locking wedge 26 to be inserted or removed from the connector head 18. The opposed ends of the carrying tube 14 are cut-away along a chord that is parallel and offset to a plane extending through the longitudinal axes of the connecting tube 12 and the carrying tube 14, i.e. the opposed ends of the carrying tube 14 are cut-away along a chord that will be aligned parallel with a longitudinal axis of the support post 104. In the exemplary embodiment the cut-away part of the opposed ends extends beyond the longitudinal axis of the carrying tube 14, i.e. is more than 50% of its cross-section, thereby permitting the locking wedge 26 to be positioned along the longitudinal axis of the carrying tube 14.

[0038] The opposed segment ends 28 of the carrying tube 14 have stiffener plates 32 extending along the cut-away plane between the free circumferential edges 34 of the carrying tube 14. The stiffener plates 32 increase the carrying strength of the segment ends 28 thereby preventing deformation of the segment ends 28 when carrying the weight of the scaffolding boards 114 or any loads placed thereon. The stiffener plates 32 also prevent damage and distortion to the segment ends 28 during the assembly of the ledger 10 in the scaffolding system 100, for example if the segment ends 28 is accidentally struck when the locking wedge 26 is being hammered into the rosette 108. The stiffener plates 32 can also close off any openings into the carrying tube 14 to prevent ingress of dirt into the carrying tube 14. The specific dimensions of the connecting and carrying tubes 12, 14 (e.g. their lengths and outer diameters) and the sizes of the bridging members 16 can be selected based on the specific industrial standards applicable to the scaffolding system so that the desired operative height of the ledger 10 is obtained, i.e. for use in a metric scaffolding system, or an imperial scaffolding system, or a Euro scaffolding system. The height of the ledger 10 is selected and arranged so that when the scaffolding boards 114 are supported on the carrying tube 14, the top surface of the scaffolding boards 114 lie substantially co-planar with or above the top end 118 of any of the intermediate support posts 104c to which the ledgers 10 are connected - this is more clearly shown in Figure 5 - so that the intermediate support posts 104c, and any associated locking wedges 26, are concealed within or beneath the working platform 102.

[0039] Referring to Figures 6a - 6d, there is shown the respective operational steps in connecting one end of the ledger 10 to the rosette 108 of the support post 104. In Figure 6a the connector head 18 is aligned with the rosette 108 - at this stage the locking wedge 26 can be either fully removed I omitted, or loosely inserted into only the upper flange 22 as shown. In Figures 6b and 6c the connector head 18 is moved over the rosette 108 so that the rosette 108 is received within the slot 20 - the access space 30 provided by the cut-away ends of the carrying tube 14 allow the locking wedge 26 to be inserted into the orifice of the upper flange 22. Finally, in Figure 6d the locking wedge 26 is shown hammered down through the port 110 and the lower flange 24 to secure the connector head 18 to the rosette 108 and thereby join the connecting tube 12 to the support post 104.

[0040] It will be appreciated that the provision of the access space 30 permits a user to insert the locking wedge 26 in a conventional manner as is normally done with the conventional ledgers 112. The access space 30 provides unhindered and unrestricted vertical access to the locking wedge 26 for the striking thereof by a hammer in a downwards direction. It will further be appreciated that during subsequent disconnection of the ledger 10 from the support post 104, the locking wedge 26 can be hammered upwards out of the connector head 18 and that the access space 30 provides a clearance space for the locking wedge 26 to eject into and for a user to grab and remove the locking wedge 26 from the connector head 18.

[0041] Referring now to Figure 7, in some embodiments the scaffolding system 100 includes an infill panel 120, which includes a flat plate mounted onto a spigot. The raised working platform 102 formed by the ledgers 10 permits the spigot to be slidingly inserted into the open top end 118 of the intermediate support post 104c so that the flat plate can lie flush against the scaffolding boards 114.

[0042] During use, the ledgers 10 permit the scaffolding boards 114 to provide full horizontal coverage across the working platform 102 to effectively define an uninterrupted horizontal surface without trip hazards.

[0043] It is appreciated that raising the working platform 102 slightly above its normal industrial position per the current disclosure will have further knock-on effects on the safety regulations when using other standard scaffolding equipment, e.g. effectively reducing the clearance height of any standard guard rails that are assembled from conventional ledgers 112. In most cases the height by which the working platform 102 is raised is relatively minor and thus the use of the conventional ledgers 112 as handrails still exhibit the requisite clearance height to meet the safety regulations. However, even if the safety regulations require a greater clearance height, it will be possible to also use the ledgers 10 to assemble the guard rails, which will then automatically raise the height of the guard rail by the same extent that the working platform 102 is raised.

[0044] The ledger 10 can be used with conventional prior art scaffolding components, such as support posts, braces, locking wedges, or guardrails, without the need for any additional or customised componentry. Specifically, the ledger 10 permits the use of conventional locking wedges 26 that can be accessed in an unhindered and unrestricted manner for the striking thereof by a hammer.

[0045] Subsequently, as shown in Figure 8, in order to raise the level of the working platform 102 or assemble a second working platform 102b, it will simply be necessary to remove any infill panels 120 and insert connector spigots into the intermediate support posts 104c whereafter all the support posts 104 can be lengthened to continue building the scaffolding upward to the next level requirement. At the desired new level, further ledgers 10 can be installed to support further scaffolding boards 114. There is no need, as is the case in the prior art arrangements, to first dismantle the original working platform 102 to the point where the specialised components (shown in Figure 1c and 1d) have been removed in order to enable the support posts to be extended. It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the scaffold ledger as shown in the specific embodiments without departing from the spirit or scope of the disclosure as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

[0046] For example, in Figure 9 there is shown a second embodiment of a scaffold ledger 10b, which is substantially identical to the scaffold ledger 10 and in which like parts have been indicated by the same reference numerals. The main difference of the scaffold ledger 10b is that it is not a double tube ledger, i.e. does not include the first tube 12. Rather, in this embodiment the connector heads 18 are mounted to angled brackets 36 extending from the carrying tube 14, thereby to join the connecting heads 18 to the opposed ends of the carrying tube 14. The connecting heads 18 are laterally offset from the longitudinal axis of the carrying tube 14 and located so that the opposed ends of the carrying tube 14 extend up to, or outwardly beyond, their respective connecting heads 18.

[0047] In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments.

[0048] Reference numerals

[0049] 10 ledger

[0050] 12 first tube I connecting tube

[0051] 14 second tube / carrying tube

[0052] 16 bridging members

[0053] 18 connector head

[0054] 20 slot

[0055] 22 upper flange

[0056] 24 lower flange

[0057] 26 locking wedge

[0058] 28 segment end

[0059] 30 access space

[0060] 32 stiffener plate

[0061] 34 circumferential edges

[0062] 36 brackets

[0063] 100 scaffolding system

[0064] 102, 102b working platform

[0065] 104 support posts

[0066] 104a corner support posts

[0067] 104b lateral support posts

[0068] 104c intermediate support posts

[0069] 106 feet

[0070] 108 rosettes

[0071] 110 through-hole ports

[0072] 112 conventional ledgers

[0073] 114 scaffolding boards

[0074] 116 hooks

[0075] 118 top end (of support posts)

[0076] 120 infill panel

Claims

CLAIMS1 . A scaffold ledger for use in a scaffolding system, whereby pairs of the scaffold ledger are arranged to support scaffolding boards for assembling a continuous working platform, wherein the scaffold ledger comprises a tube having opposed ends, wherein the tube has a longitudinal axis; opposed connecting heads being joined to the opposed ends of the tube, whereby the connecting heads are laterally offset from the longitudinal axis of the tube, and wherein the opposed ends of the tube extend outwardly beyond their respective connecting heads; wherein the opposed ends of the tube are at least partially cut-away along a plane parallel to the longitudinal axis of the tube to form opposed access spaces located operatively above the connecting heads, thereby to permit access for the installation or removal of locking wedges to / from the respective connecting heads.

2. A scaffold ledger as claimed in claim 1 , wherein the opposed ends of the tube are cut-away for more than 50% of the cross-section of the tube.

3. A scaffold ledger as claimed in claim 1 or 2, wherein the opposed ends of the tube have stiffener plates extending along the cut-away plane between its free circumferential edges, whereby the stiffener plates are arranged to increase the carrying strength of the segment ends of the tube.

4. A scaffold ledger as claimed in any one of claims 1 to 3, wherein the connecting heads are laterally offset from the tube to an extent that is, in use, sufficient to cause the tube to support the scaffolding boards at a level where a top surface of the scaffolding boards lies substantially co-planar with or above a top end of any support posts to which the connecting heads are connected.

5. A scaffold ledger for use in a scaffolding system, whereby pairs of the scaffold ledger are arranged to support scaffolding boards for assembling a continuous working platform, wherein the scaffold ledger comprises a first tube having opposed ends, wherein each of the opposed ends is provided with a connecting head; a second tube having opposed ends, wherein the second tube is located ina spaced lateral relationship parallel to the first tube, and wherein the opposed ends of the second tube extend outwardly beyond the opposed ends of the first tube, wherein the second tube is arranged to support the scaffolding boards; one or more bridging members rigidly joining the first tube to the second tube; wherein the opposed ends of the second tube are at least partially cut-away along a plane parallel to and offset to a plane extending through the longitudinal axes of the first tube and the second tube, thereby to form opposed access spaces located operatively above the connecting heads and permit access for the installation or removal of locking wedges to / from the respective connecting heads.

6. A scaffold ledger as claimed in claim 5, wherein the opposed ends of the second tube are cut-away for more than 50% of the cross-section of the second tube.

7. A scaffold ledger as claimed in claim 5 or 6, wherein the opposed ends of the second tube have stiffener plates extending along the cut-away plane between its free circumferential edges, whereby the stiffener plates are arranged to increase the carrying strength of the segment ends of the second tube.

8. A scaffold ledger as claimed in any one of claims 5 to 7, wherein the connecting heads are laterally offset from the tube to an extent that is, in use, sufficient to cause the tube to support the scaffolding boards at a level where a top surface of the scaffolding boards lies substantially co-planar with or above a top end of any support posts to which the connecting heads are connected.

Images