GB2122242A - Scaffolding beams - Google Patents

Abstract

In a scaffolding system which comprises a plurality of elongate ledger beams of narrow ladder-like (2, 3) formation that are intended for horizontal disposition in the system, some such beams 1A carry return members 8 in the form of spaced metal straps 9 that are slidable lengthwise along upper and lower tubes 2 of each beam 1A, the straps 9 being rigidly interconnected by a metal bar 10 of L-shaped cross- section. The use of such a ledger beam 1A in the or each scaffolding level at, for example, the corner of a building enables a 90 DEG junction to be strongly and safely formed without the conventional necessity of providing additional upright legs or standards 4. <IMAGE>

Description

SPECIFICATION Scaffolding beams This invention relates to scaffolding beams and particularly to the way in which such beams are employed to form right-angled scaffolding structures, as seen in plan view, around the corners of buildings and the like.

A well-known, safe and efficient scaffolding system employing tubular metal beams comprises ledger beams, intended for horizontal use, in the form of pairs of parallel tubes, rigidly interconnected at intervals by plates or strips to give a narrow ladder-like appearance, the ends of the ledger beams carrying pairs of engagement hooks for co-operation with vertically spaced anchorages on single upright tubular legs or standards. Oblique tubular and other members can, of course, also be employed when required.

A feature of this known scaffolding system is that, at the corner of a building or the like, it is always necessary to employ an additional pair of legs or standards which are necessary from the point of view of strength and are needed to enable the ledger beams of the scaffolding to be reliably interengaged around the corner concerned.

It is, accordingly, an object of the invention to overcome, or at least very significantly to minimise, this disadvantage of the known system by providing an elongate ledger beam, intended for substantially horizontal positioning in a scaffolding system, which ledger beam carries a return member at a location between its opposite ends, the return member being furnished with anchorages arranged for hooking co-operation with engagement members located at the ends of other ledger beam in the use of the firstmentioned ledger beam.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a diagrammatic plan view of the way in which the known scaffolding system referred to above is employed in forming a rightangled junction or "return" around the corner of a building, Figure 2 corresponds to Figure 1 but illustrates the formation of the same junction or "return" by employing at least one ledger beam provided with a return member in accordance with the invention, and Figure 3 is a perspective view illustrating a ledger beam provided with a reutrn member in accordance with the invention and also shows a tubular leg or standard of the system of which said ledger beam forms a part.

Referring to the accompanying drawings, and particularly to Figure 1 thereof which shows a well-known arrangement, the junction or "return" which is illustrated in Figure 1 comprises a plurality of elongate ledger beams 1 that are provided in serveral different standard lengths.

Each ledger beam 1 comprises a pair of parallel metal tubes 2 (Figure 3) rigidly interconnected at intervals by plates or strips 3 that may be of different widths and/or thicknesses in different beams to make those beams either of "standard" strength or "reinforced" strength.

At the opposite ends of the ledger beam 1, there are vertically or substantially vertically disposed tubular legs or standards 4 and each leg or standard 4 carries, at vertically spaced apart locations, pairs of downwardly tapering sockets 5 of which only a few are chosen in Figure 3 of the drawings whereas, in practice, further pairs thereof will actually be furnished. The two tubes 2 of each ledger beam 1 are provided, at their opposite ends, with downwardly tapering engagement members 6 of trapezoidal shape and strong plate-like formation.The spacing between the two engagement members 6 of each pair is the same as that between the two sockets 5 of each pair and it will be apparent that, in known manner, the ends of the ledger beams 1 can be firmly engaged under the action of gravity with appropriate horizontal locations on the legs or standards 4 by hooking the engagement members 6 into the matchingly downwardly tapering sockets 5. Each ledger beam 1 is of narrow ladder-like appearance and is intended, in use, to extend horizontally or substantially horizontally with its general plane vertically or substantially vertically disposed in parallel relationship with the length of the legs or standards 4.

Returning now specifically to the known arrangement of Figure 1 of the drawings, it will be seen that the longer ledger beams 1 that are illustrated extend parallel to one another in a spaced relationship which is dictated by the length of a number of shorter ledger beams 1 which perpendicularly and horizontally interconnect them via the legs or standards 4. Boards, planks or other treads (not shown in the drawings), can thus reliably be supported on the upper tubes 2 (Figures 3) of the various ledger beams 1 to produce safe walkways at various horizontal levels approximately corresponding, where required, to the successive storeys of a building 7. In this connection, it is noted that, in effect, only one horizontal level is visible in Figures 1 and 2 of the drawings but that substantially the same arrangement will exist at each horizontal level where a walkway is required.

At the actual 900 junction between the two parts of the scaffolding structure which lie alongside corresponding upright walls of the building 7 as shown in Figure 1 of the drawings, it is necessary to provide two legs or standards 4 to co-operate with the otherwise free ends of the ledger beams 1 that extend in one direction and that perpendicularly meet intermediate locations on a single ledger beam 1 (at each horizontal level) extending in another direction. These additional legs or standards 4 are necessary from the point of view of strength and are needed to terminate the otherwise free ends that have just been mentioned and to establish fixed connections, by way of known clamps that are not illustrated in the drawings, with the intermediate locations on the single perpendicularly extending ledger beam 1 at a single level or at each horizontal level.

Figures 2 and 3 of the drawings illustrate the provision of a reinforced ledge beam 1 A with a return member 8 designed to eliminate the need for the additional legs or standards 4 at a 90" junction as described above with reference to Figure 1. The return member 8 comprises a pair of metal straps 9 formed from strong and broad metal strip that engage slidably around both the upper and lower tubes 2 of the ledger beam 1 A, the two straps 9 being rigidly connected to one another by a piece 10 that is preferably, as illustrated, in the form of a metal bar of L-shaped cross-section. The length of the connecting piece 10 is such that the spacing between the two metal straps 9 is the same as the effective length of each of the shorter ledger beams 1 that are shown diagrammatically in Figures 1 and 2 of the drawings.One upright side and, if required for any particular reason, both upright sides, of each strap 9 is/are provided with sockets 5A that have the same downwardly tapering formation and vertical spacing from one another as do the pairs of sockets 5 that are carried by each leg or standard 4. It will immediately be appreciated that the engagement members 6 carried by the ends of the tubes 2 of the ledger beams 1 can make engagement with the sockets 5A in the same manner as they do with the sockets 5.

As shown in Figure 2 of the drawings, one of the ledger beams 1 A is provided at the single horizontal level, or at each horizontal level, of that part of the scaffolding structure which projects significantly beyond the corner of the building 7 and the engagement members 6 at the ends of the relatively perpendicular ledger beams 1 which register with the single ledger beam 1 A or the ledger beam 1 A at each horizontal level are engaged in the pairs of sockets 5A carried by the return member 8 or corresponding return member 8, said return member or members 8 being slidable lengthwise along the tubes 2 of the or each ledger beam 1 A to an appropriate intermediate position or appropriate intermediate positions between the ends of the tubes 2 concerned, it being remembered that the spacing between the metal straps 9 which carry the sockets 5A matches the effective length of the shorter transversely interconnecting ledger beams that are illustrated diagrammatically in Figures 1 and 2.

There is no need to provide means for fixedly retaining the return members 8 in appropriate positions lengthwise along the ledger beams 1 A since, to a very large extent, the scaffolding system of which the described items form parts is maintained purely by gravity, any loading on the system immediately tending to reinforce the basic connections rather than weaken them. It is noted that only those parts of the system which are relevant to the present invention have been described and diagrammatically illustrated and that, when required on any particular site, other scaffolding items including clamps, oblique strengthening beams and so on can be included.

Figure 3 of the drawings shows only a single tubular leg or standard 4 and a single ledger beam 1 A despite the fact that, in practice, a doubled structure as diagrammatically shown in Figures 1 and 2 will almost always be employed.

Claims (Filed on 21/6/83) 1. An elongate ledger beam, intended for substantially horizontal positioning in a scaffolding system, which ledger beam carries a return member at a location between its opposite ends, the return member being furnished with anchorages arranged for hooking co-operation with engagement members located at the ends of other ledger beams in the use of first-mentioned ledger beam.

2. An elongate ledger beam as claimed in claim 1, wherein the return member is displaceably mounted thereon.

3. An elongate ledger beam as claimed in claim 2, wherein the return member is slidable lengthwise therealong.

4. An elongate ledger beam as claimed in claim 3, wherein the return member comprises spaced straps engaged slidably around elongate parallel elements of the elongate ledger beam, said spaced straps being rigidly interconnected.

5. An elongate ledger beam as claimed in claim 4, wherein the rigid interconnection is afforded by a bar of L-shaped cross-section.

6. An elongate ledger beam as claimed in claim 3 or 4, wherein the return member anchorages are carried by said spaced straps.

7. An elongate ledger beam as claimed in any preceding claim, wherein the return member anchorages are in the form of pairs of sockets.

8. An elongate ledger beam as claimed in claim 7, wherein each socket is of a downwardly tapering formation and is constructed and arranged for hooking co-operation with an engagement member of downwardly tapering trapezoidal shape and plate-like formation.

9. An elongate ledger beam when provided with a return member that is substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.

1 0. A scaffolding system comprising a plurality of elongate ledger beams as claimed in claim 6 or 9 or in claims 7 or 8 when read as appendant to claim 6, and also comprising relatively short ledger beams intended for substantially horizontal positioning in the system, wherein the effective length of each such short ledger beam equals the spacing between the straps of the return beams which carry said anchorages.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. mentioned and to establish fixed connections, by way of known clamps that are not illustrated in the drawings, with the intermediate locations on the single perpendicularly extending ledger beam 1 at a single level or at each horizontal level. Figures 2 and 3 of the drawings illustrate the provision of a reinforced ledge beam 1 A with a return member 8 designed to eliminate the need for the additional legs or standards 4 at a 90" junction as described above with reference to Figure 1. The return member 8 comprises a pair of metal straps 9 formed from strong and broad metal strip that engage slidably around both the upper and lower tubes 2 of the ledger beam 1 A, the two straps 9 being rigidly connected to one another by a piece 10 that is preferably, as illustrated, in the form of a metal bar of L-shaped cross-section. The length of the connecting piece 10 is such that the spacing between the two metal straps 9 is the same as the effective length of each of the shorter ledger beams 1 that are shown diagrammatically in Figures 1 and 2 of the drawings.One upright side and, if required for any particular reason, both upright sides, of each strap 9 is/are provided with sockets 5A that have the same downwardly tapering formation and vertical spacing from one another as do the pairs of sockets 5 that are carried by each leg or standard 4. It will immediately be appreciated that the engagement members 6 carried by the ends of the tubes 2 of the ledger beams 1 can make engagement with the sockets 5A in the same manner as they do with the sockets 5. As shown in Figure 2 of the drawings, one of the ledger beams 1 A is provided at the single horizontal level, or at each horizontal level, of that part of the scaffolding structure which projects significantly beyond the corner of the building 7 and the engagement members 6 at the ends of the relatively perpendicular ledger beams 1 which register with the single ledger beam 1 A or the ledger beam 1 A at each horizontal level are engaged in the pairs of sockets 5A carried by the return member 8 or corresponding return member 8, said return member or members 8 being slidable lengthwise along the tubes 2 of the or each ledger beam 1 A to an appropriate intermediate position or appropriate intermediate positions between the ends of the tubes 2 concerned, it being remembered that the spacing between the metal straps 9 which carry the sockets 5A matches the effective length of the shorter transversely interconnecting ledger beams that are illustrated diagrammatically in Figures 1 and 2. There is no need to provide means for fixedly retaining the return members 8 in appropriate positions lengthwise along the ledger beams 1 A since, to a very large extent, the scaffolding system of which the described items form parts is maintained purely by gravity, any loading on the system immediately tending to reinforce the basic connections rather than weaken them. It is noted that only those parts of the system which are relevant to the present invention have been described and diagrammatically illustrated and that, when required on any particular site, other scaffolding items including clamps, oblique strengthening beams and so on can be included. Figure 3 of the drawings shows only a single tubular leg or standard 4 and a single ledger beam 1 A despite the fact that, in practice, a doubled structure as diagrammatically shown in Figures 1 and 2 will almost always be employed. Claims (Filed on 21/6/83)

1. An elongate ledger beam, intended for substantially horizontal positioning in a scaffolding system, which ledger beam carries a return member at a location between its opposite ends, the return member being furnished with anchorages arranged for hooking co-operation with engagement members located at the ends of other ledger beams in the use of first-mentioned ledger beam.

2. An elongate ledger beam as claimed in claim 1, wherein the return member is displaceably mounted thereon.

3. An elongate ledger beam as claimed in claim 2, wherein the return member is slidable lengthwise therealong.

4. An elongate ledger beam as claimed in claim 3, wherein the return member comprises spaced straps engaged slidably around elongate parallel elements of the elongate ledger beam, said spaced straps being rigidly interconnected.

5. An elongate ledger beam as claimed in claim 4, wherein the rigid interconnection is afforded by a bar of L-shaped cross-section.

6. An elongate ledger beam as claimed in claim 3 or 4, wherein the return member anchorages are carried by said spaced straps.

7. An elongate ledger beam as claimed in any preceding claim, wherein the return member anchorages are in the form of pairs of sockets.

8. An elongate ledger beam as claimed in claim 7, wherein each socket is of a downwardly tapering formation and is constructed and arranged for hooking co-operation with an engagement member of downwardly tapering trapezoidal shape and plate-like formation.

9. An elongate ledger beam when provided with a return member that is substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.

1 0. A scaffolding system comprising a plurality of elongate ledger beams as claimed in claim 6 or 9 or in claims 7 or 8 when read as appendant to claim 6, and also comprising relatively short ledger beams intended for substantially horizontal positioning in the system, wherein the effective length of each such short ledger beam equals the spacing between the straps of the return beams which carry said anchorages.