GB2037928A

GB2037928A - Cross-member for Scaffolding

Info

Publication number: GB2037928A
Application number: GB7942122A
Authority: GB
Original assignee: Form Scaff Pty Ltd
Current assignee: Form Scaff Pty Ltd
Priority date: 1978-12-07
Filing date: 1979-12-06
Publication date: 1980-07-16
Also published as: IT1126567B; ZA786869B; FR2443545A1; MW3579A1; AU5352079A; IT7927997A0; DE2949403A1

Abstract

A scaffolding comprises standards 14, on which are formed clusters 26 of channel-shaped members 28, and ledgers or cross-members 18. The ends of the ledgers 18 are flattened into substantially rectangular form and a spigot 30 formed of round bar is welded directly to the rectangular form end 40. A wedge 32 is slidably carried in slots 44 and 46 (not shown) in each rectangular form end 40 inboard of the spigot 30 and in use each channel-shaped member 28 is clamped between a spigot 30 and a wedge 32. Formed on the wedge 32 is a dimple which can pass through the lower slot 46 but not the upper slot 44 thereby retaining the wedge 32 in the end of the ledger 18. <IMAGE>

Description

SPECIFICATION Cross-member for Scaffolding This invention relates to scaffolding.

This invention is concerned with scaffolding of the kind comprising vertical tubular members (hereinafter called "standards"), horizontal members (hereinafter called "cross-members") extending between the standards, substantially channel shaped members provided on the standards and each channel shaped member having arms by which it is secured to the standard, a spigot at each end of each crossmember engaging in a channel shaped member, a movable wedge carried by each cross-member in board of the spigot, bearing against the outside of the channel shaped member and clamping the channel shaped member against the spigot. Such scaffolding is hereinafter referred to as "scaffolding of the kind set forth".

Scaffolding of the kind set forth has the advantage that a scaffolding structure can be formed using standards of different wall thicknesses or diameters provided only that the bases of the channel shaped members are all the same distance from the centres of the standards.

According to one aspect of the invention there is provided a cross-member for use in scaffolding of the kind set forth, the cross-member comprising a tubular member having ends of substantially rectangular form, the side portions of the rectangular form ends being connected directly to the spigot preferably by means of welds running the length of the side portions of the cross-member.

Each wedge is preferably received in a pair of slots formed, preferably by being punched, into the end of the cross member. The end of the lower of the slots is preferably reinforced at its inner end, which is remote from the spigot, preferably by a bar, preferably of substantially square section, welded to the cross member at that end of the lower slot.

The wedge preferably has a portion of greater width than the remainder thereof and the width of the lower slot is greater than this portion of the wedge, the width of the upper slot being less than such width so that the aforementioned portion of the wedge can pass through the lower slot and not through the upper slot. Such an arrangement will permit the wedge to be lifted up above the lower edge of the cross member and to be held there until the wedge is manipulated so that the enlargement can pass through the slot. This would have the effect that the wedge would not engage a channel member until is it so desired i.e.

until after it has been engaged by the dependant member. To increase the possibility of the wedge not falling below this lower edge of the crossmember until so desired, only a portion of the slot may be of this enlarged width but preferably the slot is of the enlarged width over its entire length.

A spacer is preferably wedged to the upper end of the spigot which spacer is preferably welded to the upper end of the spigot. The space is preferably of the same width as the space thickness of the channel shaped member.

According to another aspect of the invention there is provided a scaffolding construction of the kind set forth comprising a plurality of standards joined together by a plurality of cross-members as set out above. Each standard preferably comprises a plurality of clusters of four channel shaped members welded thereto and these channel shaped members are preferably in aligned disposition on the standard.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

In the drawings: Figure 1 is a perspective view of a scaffolding structure embodying the invention, Figure 2 is an enlarged detail showing a ledger between a pair of standards, Figure 3 is an enlarged detail showing the connection between the ledger and the standards, Figure 4 is a section along line 4-4 of Figure 3 with the wedge being omitted for clarity, Figure 5 is a section along line 5-5 of Figure 3, and Figure 6 is a section along line 6-6 of Figure 4 with the wedge approaching the operative position.

Referring now to Figure 1 there is shown a scaffolding structure 10 erected beside a wall 12 of a building being constructed. The scaffolding structure 10 comprises vertical members or standards 14 mounted on jacks 16 in the usual way and being connected by cross-members or ledgers 18 to form rectangular units. Diagonal braces 20 are also provided. The scaffolding 10 supports a platform 22 formed of hook-on type steel scaffolding boards, the hooks 24 of which engage over the shorter ledgers 1 8b.

Each standard 14 is provided with a number of clusters 26 of channel shaped members 28 formed as pressings. Each ledger 18 is provided with a spigot 30 at its ends which fits into a channel member 28. A wedge 32 is also provided at each end of the ledger 18 and the base of the channel member 28 is clamped between the wedge 32 and the spigot 30.

The channel members 28 are. best shown in Figure 4. Each member 28 has a semi-circular base 34 and arms 36 which are welded at 38 to the standard 14.

Each ledger 18 comprises a tubular member (best seen in Figure 2), the ends 40 of which are flattened into a substantially rectangular shape as shown in Figure 5. The spigot butts up against the end edges of the rectangular form end 40 of the ledger 18 and is there welded to this end 40 by elongated welds 42 running the entire height of the flattened end 40. The spigot is comprised by a circular section bar.

Inboard of the spigot 30, the end 40 is provided with a pair of slots 44 and 46 respectively in the upper and lower portions of the rectangular form end 40. The lower slot 46 is wider than the upper slot 44 for the purpose which will be described below. At the inner end of the lower slot 46 a rectangular section bar 48 is welded to the end 40. This provides reinforcement for the end of the slot 46.

A spacer piece 50 is welded to the spigot 30 at its upper end and within the body of the end 40.

The width of the spacer 50 is approximately the same as that of the members 28.

Slidably received within the slots 44 and 46 is the wedge 32 which tapers from its upper end to its lower end. At its upper end the wedge 32 is wider than the length of the slot 44. A dimple 54 is provided at the lower end of the wedge. This dimple 54 forms a portion of enlarged effective thickness. The thickness of this portion is greater than the width of the slot 44 but less than that of the slot 46. Thus the wedge 32 can be moved from its downward operative position to an upward retention position as shown in chain lines in Figure 3 where its lower end is wholly within the flattened end 40 of the ledger 1 8 but is restrained from escaping through the slot 44 by the enlarged portion constituted by the dimple 54.

Each ledger 1 8 is engaged in a channel shaped member 28 as follows. First the wedges 32 are moved to their inoperative retention positions (as shown in chain lines). The spigots 30 are then inserted into the channel members 28. Because the wedges 32 are in their inoperative retention positions the manipulation of the ledger to effect this engagement is considerably simplified.

Each wedge is now moved to the operative positions and inserted down through the lower slot 46 to lie beside the semi-circular base 34 of the channel member 28. The wedge 32 is now struck by a hammer or mallet so that it bears against three points viz the spacer 50, the reinforcing bar 48 and the base 34 of the channel member 28. In so doing the channel member 28 is clamped between the spigot 30 and the wedge 32. Thus the ledger 1 8 will be firmly secured to the standard 14. In this way a rigid structure 10 can be formed.

Because the spigot 30 comprises round bar the width of the channel member 28 can be reduced.

This has the effect of permitting there to be sufficient space between the arms 36 of the four channel members 28 for these arms to be welded to the standard 1 4 in spaced relationship. This in turn permits the four channel members 28 forming a cluster to be located in aligned relationship. Thus four ledgers 1 8 can be connected to any one cluster and all these ledgers will be at the same level.

It will be seen that the scaffolding of the invention may be used with standards 1 8 of various diameters provided only that the distance between the central axis of the standard 14 and the semi-circular base 34 of the channel member 28 is constant. This can be achieved by bearing the length of the arms 36 of the channel member 28 independant upon the outside diameter of the standard 14.

It will be appreciated that the re-inforcing bar 48 will accept the substantial forces exerted by the wedge on the inner end of the slot 46.

The invention is not limited to the precise constructional details hereinbefore described and illustrated in the drawings.

For example it will be noted that the ledgers are shown in the structure 10 to lie at right angles to one another. (i.e. with the axes of the ledgers being aligned with the axes of two adjacent channel members 28 to which they are connected). However the angles at which the ledgers 1 8 are inclined can be varied within fairly wide limits because of the circular section of the spigot 30 and the base 34 of the channel members 28 so that the ledgers can lie along the sides of a non-rectangular paralleiogram, a triangle or any other polygon as designed.

In this way a scaffolding structure can be designed which has increased bearing strength at any desired position or which can be arranged to follow a non-rectilinear path such as an arcuate path.

than the thickness of the enlarged portion 54 over a great portion of the length of the slot 46 leaving only a small enlarged portion through which the dimple 54 can pass. This will prevent the wedge 32 moving from its inoperative position inadvertently, thereby providing an additional safeguard to the system as described above.

The width of the upper end of the wedge 32 may be less than the length of the upper slot 44.

In such a case this width must be greater than the length of the lower slot 46 to prevent the wedge escaping from the slots or alternatively some other means to carry out this purpose should be provided.

The scaffolding structure can take any desired form and of greater heights as may be approved by those skilled in the art.

We have found that the ledgers or crossmembers as described above have a number of significant advantages. First, due to the fact that the spigots are welded directly to the ledgers, the costs of manufacture of the ledgers is considerably reduced as compared to such ledgers having the spigots formed as separate castings with ends inserted into the ends of the ledgers. Furthermore by having the ends of the ledgers flattened elongated welds may be provided holding the spigots to the ledger. This provides for a particularly strong connection between the ledgers and the spigots. The fact that the spigots are formed of circular section bar also improves the economy of manufacture of the ledger. We have found a further advantage in that the ledgers can swing relative to the channel shaped members which enables the scaffolding to be used for forming structures other than rectangular structures i.e. arcuate, hexagonal or other polygonal structures.

Claims

1. A cross-member for use in scaffolding of the kind set forth, the cross-member comprising a tubular member having ends of substantially rectangular form, the side portions of the rectangular form ends being connected directly to the spigot.

2. A cross-member as claimed in claim 1 wherein the wedge is movably mounted in a pair of substantially registering slots formed in the tubular member.

3. A cross-member as claimed in claim 2 wherein the slots are formed in the upper and lower sides of the rectangular formed ends of the tubular member.

4. A cross-member as claimed in claim 2 or claim 3 wherein a re-inforcing part is provided at the end of the lower slot which is remote from the spigot.

5. A cross-member as claimed in claim 4 wherein the re-inforcing part is a bar welded to the cross-member at the aforesaid end of the lower slot.

6. A cross-member as claimed in claim 5 wherein the bar is of substantially rectangular section.

7. A cross-member as claimed in any one of claims 2 to 6 wherein the wedge has a portion of greater thickness than the remainder thereof, wherein the width of at least a portion of the lower slot is greater than the thickness of the aforesaid portion of the wedge and wherein the width of the upper slot is less than the thickness of the aforesaid portion of the wedge so that the aforesaid portion can pass through the lower slot but not through the upper slot.

8. A cross-member as claimed in claim 7 wherein the entire width of the lower slot is greater than the thickness of the aforesaid portion of the wedge.

9. A cross-member as claimed in any one of the preceding claims wherein each spigot is welded to the rectangular form end of the crossmember by elongated welds running the length of the side portions thereof.

10. A cross-member as claimed in any one of the preceding claims further comprising a spacer secured to the spigot near the upper slot and arranged in use to engage one edge of the wedge.

11. A cross-member as claimed in claim 10 wherein the thickness of the spacer is approximately the same as the thickness of the channel shaped member.

12. A cross-member as claimed in any one of the preceding claims wherein the spigot comprises a circular section member.

13. A cross-member as claimed in claim 12 wherein the spigot comprises a round bar.

14. A cross-member for use in scaffolding of the kind set forth, the cross-member having parts constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 5. Scaffolding comprising standards, cross members extending between the standards, substantially channel shaped members provided on the standards and each channel shaped member having arms by which it is secured to the standard, a spigot at each end of each cross member engaging in a channel shaped member, a movable wedge carried by each cross-member inboard of the spigot and clamping the channel shaped member against the spigot, characterised in that the ends of the cross-members are of substantially rectangular form with the side portions of the ends being connected directly to the spigot.

16. Scaffolding as claimed in claim 1 5 wherein the spigot comprises round bar.

17. Scaffolding as claimed in claim 15 or 16 comprising a cluster of four channel shaped members on the standard having the arms of the members welded to the standard and wherein the channel shaped members are in aligned disposition from the standard.

1 8. Scaffolding as claimed in claim 1 7 wherein each standard carries a plurality of clusters of four channel shaped members at spaced locations along its length.

1 9. Scaffolding of the kind set forth comprising a plurality of standards joined together by a plurality of cross members as claimed in any one of claims 1 to 13 each having its spigots engaging in channel shaped members on the standards and the said channel shaped members being clamped between the spigot and wedge of each end of the cross member.

20. Scaffolding substantially as hereinbefore described with reference to and as illustrated in -the drawings.